JP6773281B2 - Communication system and welding system - Google Patents

Description

The present invention relates to communication systems and welding systems.

Consumable electrode type welding systems are usually separated into a welding power supply that is not moved due to its weight and a wire feeder that is carried by the welder as the weld location changes. When the welding power supply is installed in a place away from the welding work position, it is efficient for the operator to go to the welding power supply installation location in order to set welding conditions such as welding voltage. bad. To solve this problem, a welding system has been developed that communicates between the welding power supply device and the wire feeding device. For example, Patent Document 1 describes a welding system that performs wireless communication between a welding power supply device and a wire feeding device. Further, Patent Document 2 describes a welding system that performs communication by superimposing a communication signal on a power cable.

Since there are multiple welding systems at the site where the welding work is performed, interference will occur unless the communication partner is specified and communication is performed. Even when communication is performed by superimposing communication signals on the power cables, the power cables of each welding system may be arranged in a bundle. In this case, due to magnetic coupling, signals transmitted and received by other welding systems may be superimposed to cause interference. In order to identify the communication partner, a pairing process for setting common identification information between the communication partners is performed. Patent Document 3 describes that the welding power supply device and the wire feeding device set the same identification information and perform communication.

Japanese Unexamined Patent Publication No. 10-30536 Japanese Unexamined Patent Publication No. 2013-184184 Utility Model Registration No. 3200612

If the pairing process is performed manually, incorrect identification information may be set. If incorrect identification information is set, the wire feeding device and the welding power supply device not connected to the wire feeding device may be paired. Therefore, it is desirable that the pairing process is set by automatically transmitting the identification information by communication instead of manually inputting.

However, since pairing has not been established at the stage of performing the pairing process, interference occurs when the identification information is transmitted by communication. Therefore, there is a high possibility that the pairing process will fail. This problem is not only a problem that occurs only in welding systems, but also a problem that occurs in various communication systems.

The present invention has been conceived under the above circumstances, and an object of the present invention is to provide a communication system and a welding system capable of transmitting information even before the establishment of pairing.

In order to solve the above problems, the following technical measures are taken in the present invention.

The communication system provided by the first aspect of the present invention is the communication system from the first communication device, the second communication device that communicates with the first communication device, and the first communication device. A communication system including a power transmission line for supplying electric power to a second communication device, wherein the first communication device is for power transmission for supplying electric power to the second communication device. The power supply unit, a switching unit that switches between a state in which a first level voltage is applied to the power transmission line and a state in which a second level voltage lower than the first level is applied, and the information obtained by acquiring information. The second communication device is provided with a transmission control unit that transmits the information by controlling switching by the switching unit based on the above, and the second communication device is supplied with electric power from the power transmission power supply unit. A power receiving power supply unit, an identification unit that identifies the voltage applied to the power receiving power supply unit via the power transmission line, and a reception control unit that restores the information based on the identification result by the identification unit. The transmission control unit is capable of adjusting the second level application period, which is the period in which the second level voltage is applied. According to this configuration, the switching unit switches between a state in which a first level voltage is applied to the power transmission line and a state in which a second level voltage is applied, and the identification unit is applied to the power receiving power supply unit. Identify the voltage. As a result, the second communication device can recognize the switching by the switching unit of the first communication device based on the identification result by the identification unit. Therefore, even if the pairing between the first communication device and the second communication device is not established, the information can be transmitted from the first communication device to the second communication device. Further, a capacitor for stabilizing the voltage is generally provided between the power transmission power supply unit and the power reception power supply unit. Due to this capacitor, the voltage applied to the power transmission line gradually changes (decreases) from the first level to the second level during the second level application period. However, when the capacitor deteriorates and the capacitance decreases, the voltage drops sharply and may fall below the voltage at which the reception control unit operates normally during the second level application period. According to this configuration, the transmission control unit can adjust the second level application period. Therefore, the second level application period can be shortened so that the voltage does not drop too much. As a result, the voltage supplied to the reception control unit can be prevented from falling below the voltage at which normal operation can be performed.

In a preferred embodiment of the present invention, the transmission control unit adjusts the second level application period based on the power supply status from the power transmission power supply unit to the power reception power supply unit. According to this configuration, the second level application period can be adjusted according to the power supply status.

In a preferred embodiment of the present invention, the first communication device further includes a detection unit that detects an output voltage applied to the power receiving power supply unit, and the transmission control unit has the output voltage from a threshold value. When the voltage drops, the second level application period is adjusted by switching from the state in which the second level voltage is applied to the state in which the first level voltage is applied. According to this configuration, the length of the second level application period can be adjusted based on the output voltage applied by the power transmission power supply unit to the power reception power supply unit as an index of the power supply status.

In a preferred embodiment of the present invention, the first communication device further includes a detection unit that detects the cumulative time of time when power is supplied from the power transmission power supply unit to the power reception power supply unit, and the transmission The control unit adjusts the second level application period based on the cumulative time. The deterioration of the capacitor depends on the usage time of the capacitor, and the longer the usage time of the capacitor, the more the deterioration of the capacitor and the greater the influence thereof. In addition, the cumulative time can be regarded as the usage time of the capacitor. According to this configuration, the cumulative time during which power is supplied from the power transmission power supply unit to the power reception power supply unit is used as an index of the power supply status, and the length of the second level application period is adjusted based on the cumulative time. be able to.

In a preferred embodiment of the present invention, the transmission control unit changes the first level application period, which is a period in which the first level voltage is applied based on the information, and the reception control unit determines. The information is restored according to the length of the period identified as the state in which the first level voltage is applied. According to this configuration, the transmission control unit changes the first level application period based on the information. Depending on the change in the first level application period, the length of the period identified as the state in which the first level voltage is applied also changes. As a result, the reception control unit can restore the information according to the length of the period identified as the state in which the first level voltage is applied.

In a preferred embodiment of the invention, the information is identification information for pairing. According to this configuration, identification information for pairing can be transmitted from the first communication device to the second communication device.

In a preferred embodiment of the present invention, the identification unit includes a voltage sensor that detects the voltage of the power receiving power supply unit and a voltage comparison unit that compares the detected voltage detected by the voltage sensor with a predetermined value. Whether the second level voltage is applied or the first level voltage is applied by the switching unit based on whether or not the detected voltage is equal to or lower than the predetermined value. Identifies which state of the above is switched to. According to this configuration, identification can be performed based on the voltage of the power receiving power supply unit.

In a preferred embodiment of the present invention, the identification unit includes a current sensor that detects a current flowing through the power transmission line and a current comparison unit that compares the detected current detected by the current sensor with a predetermined value. Whether the second level voltage is applied or the first level voltage is applied by the switching unit based on whether or not the detected current is equal to or less than the predetermined value. Identifies which state of the above is switched to. According to this configuration, identification can be performed based on the current flowing through the power transmission line.

In a preferred embodiment of the present invention, the second level voltage is 0V, the switching unit switches between a state in which a voltage is applied and a state in which no voltage is applied, and the identification unit uses the voltage. The state in which the voltage is applied and the state in which the voltage is not applied are distinguished. According to this configuration, since the state in which the voltage is applied and the state in which the voltage is not applied are switched, it is possible to easily identify the identification state.

In a preferred embodiment of the present invention, the switching unit is a switch that switches between a conduction state and a cutoff state of the power transmission line. According to this configuration, it is possible to clearly switch between the state in which the power transmission power supply unit applies the voltage and the state in which the voltage is not applied.

The welding system provided by the second aspect of the present invention is a welding system including the communication system provided by the first aspect of the present invention, and is a welding power supply device having the first communication device. , A welding peripheral device having the second communication device, and the like. According to this configuration, in the welding system, information can be transmitted from the welding power supply device to the welding peripheral device even if pairing is not established between the welding power supply device and the welding peripheral device.

According to the present invention, the switching unit switches between a state in which a first level voltage is applied to the power transmission line and a state in which a second level voltage is applied, and the identification unit is applied to the power receiving power supply unit. Identify the voltage. As a result, the second communication device can recognize the switching by the switching unit of the first communication device based on the identification result by the identification unit. Therefore, even if the pairing between the first communication device and the second communication device is not established, the information can be transmitted from the first communication device to the second communication device.

Other features and advantages of the present invention will become more apparent with the detailed description given below with reference to the accompanying drawings.

It is a figure which shows the whole structure of the welding system which concerns on 1st Embodiment. It is sectional drawing for demonstrating the gas pipe. It is a figure which shows an example of the internal structure of the power source part for welding and the power source part for power transmission. It is a time chart showing the waveform of each signal when the welding power supply device transmits information to the wire feeding device by switching a switch, assuming that the capacitor is not deteriorated. It is a time chart showing the waveform of each signal when the welding power supply device transmits information to the wire feeding device by switching a switch, assuming that the capacitor is deteriorated. It is a time chart showing the waveform of each signal when the welding power supply device transmits the identification information for pairing to the wire feeding device, assuming that the capacitor is not deteriorated. It is a time chart which shows the waveform of each signal when the welding power supply device transmits the identification information for pairing to the wire feeding device, assuming the state where the capacitor is deteriorated. It is a flowchart which shows the identification information transmission processing performed by the welding power-source device of 1st Embodiment. It is a flowchart which shows the identification information reception process performed by the wire feeding apparatus of 1st Embodiment. It is a flowchart which shows the identification information transmission process performed by the welding power source device of 2nd Embodiment. 6 is a time chart showing various transmission signals generated by performing the identification information transmission processing shown in FIG. 10. It is a figure which shows the structure of the wire feeding device of the welding system which concerns on 3rd Embodiment. It is a figure which shows the structure of the welding power-source device of the welding system which concerns on 4th Embodiment. It is a figure which shows the whole structure of the welding system which concerns on 5th Embodiment.

Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings.

1 to 3 are diagrams for explaining the welding system A1 according to the first embodiment. FIG. 1 shows the overall configuration of the welding system A1. FIG. 2 is a cross-sectional view for explaining a gas pipe. FIG. 3 shows an example of the internal configuration of the welding power supply unit and the power transmission power supply unit.

As shown in FIG. 1, the welding system A1 includes a welding power supply device 1, a wire feeding device 2, a welding torch 3, power cables 41, 42, power transmission lines 51, 52, a gas cylinder 6, and a gas pipe 7. ing. The welding system A1 actually includes a wire reel or the like around which a wire electrode is wound, but the description and description in the drawings are omitted.

One output terminal a for welding power of the welding power supply device 1 is connected to the wire feeding device 2 via a power cable 41. The wire feeding device 2 sends the wire electrode to the welding torch 3 so that the tip of the wire electrode protrudes from the tip of the welding torch 3. In the contact tip arranged at the tip of the welding torch 3, the power cable 41 and the wire electrode are electrically connected. The other output terminal b for welding power of the welding power supply device 1 is connected to the workpiece W via the power cable 42. The welding power supply device 1 generates an arc between the tip of the wire electrode protruding from the tip of the welding torch 3 and the workpiece W, and supplies electric power to the arc. The welding system A1 welds the workpiece W with the heat of the arc.

The welding system A1 uses a shield gas during welding. The shield gas of the gas cylinder 6 is supplied to the tip of the welding torch 3 by a gas pipe 7 provided so as to pass through the welding power supply device 1 and the wire feeding device 2. The gas pipe 7 is a pipe that connects the gas cylinder 6 and the welding power supply device 1, a pipe that is arranged inside the welding power supply device 1, a pipe that connects the welding power supply device 1 and the wire feeding device 2, and a wire. It is provided inside the feeding device 2 and has a pipe connected to the tip of the welding torch 3. FIG. 2 shows the connection fitting 1a and the wire in which the pipe connecting the welding power supply device 1 and the wire feeding device 2 of the gas pipe 7 is connected to the pipe arranged inside the welding power supply device 1. It is sectional drawing of the part connected to the connection fitting 2a connected to the pipe arranged inside the feeding device 2. For example, the rubber gas pipe 7 is connected so as to be fitted into the connection fitting 1a (2a). The material of the gas pipe 7 is not limited and may be different depending on each section, but the portion connecting the welding power supply device 1 and the wire feeding device 2 is made of an insulator such as rubber.

The electric power for driving the feed motor 24 (described later) for feeding the wire electrodes is supplied from the welding power supply device 1 to the wire feed device 2 via the power transmission lines 51 and 52. One output terminal of a power source for driving power of the wire feeding device 2 (a power transmission power supply unit 12 described later) provided in the welding power supply device 1 is a power source of the wire feeding device 2 (a power source of the wire feeding device 2) via a power transmission line 51. It is connected to one input terminal of the power receiving power supply unit 21) described later.

The power transmission line 51 is arranged inside the gas pipe 7 between the welding power supply device 1 and the wire feeding device 2. As shown in FIG. 2, inside the welding power supply device 1, the power transmission line 51 is connected to the conductive connection fitting 1a, and inside the wire feeding device 2, the power transmission line 51 is connected electrically. It is connected to the metal fitting 2a. Then, the power transmission line 51 arranged inside the gas pipe 7 is sandwiched and fixed between the gas pipe 7 and the connection fitting 1a (2a), and is electrically connected to the connection fitting 1a (2a). There is. That is, the connection fitting 1a functions as a connector for connecting the power transmission line 51 inside the welding power supply device 1 and the power transmission line 51 arranged inside the gas pipe 7, and the connection fitting 2a feeds the wire. It functions as a connector for connecting the power transmission line 51 inside the device 2 and the power transmission line 51 arranged inside the gas pipe 7.

Further, the other output terminal of the power transmission unit 12 and the power cable 41 are connected by a power transmission line 52 inside the welded power supply device 1, and the other input terminal of the power reception unit 21 and the power cable are connected. 41 is connected to the inside of the wire feeding device 2 by a power transmission line 52. That is, the other output terminal of the power transmission power supply unit 12 and the other input terminal of the power reception power supply unit 21 are electrically connected by a power transmission line 52 in which a part of the section becomes a power cable 41. The electric power output from the power transmission power supply unit 12 is supplied to the power reception power supply unit 21 by the power transmission lines 51 and 52. Further, the welding power supply device 1 and the wire feeding device 2 communicate by superimposing signals between the power transmission lines 51 and 52.

The welding power supply device 1 supplies DC power for arc welding to the welding torch 3. The welding power supply device 1 includes a welding power supply unit 11, a power transmission power supply unit 12, a control unit 13, a communication unit 14, a switch 15, a switching unit 16, a capacitor 17, a voltage sensor 18, and a storage unit 19.

The welding power supply unit 11 converts the three-phase AC power input from the power system into DC power suitable for arc welding and outputs it. As shown in FIG. 3A, the three-phase AC power input to the welding power supply unit 11 is converted into DC power by the rectifier circuit 111 and converted into AC power by the inverter circuit 112. Then, it is stepped down (or stepped up) by the transformer 113, converted into DC power by the rectifier circuit 114, and output. The configuration of the welding power supply unit 11 is not limited to the above.

The power transmission power supply unit 12 outputs electric power for driving the feed motor 24 and the like of the wire feed device 2. The power transmission power supply unit 12 converts the single-phase AC power input from the power system into DC power suitable for use in the wire feeding device 2 and outputs it. The power transmission power supply unit 12 is a so-called switching regulator. As shown in FIG. 3A, the AC power input to the power transmission power supply unit 12 is converted into DC power by the rectifier circuit 121, stepped down (or boosted) by the DC / DC converter circuit 122, and output. .. The power transmission power supply unit 12 supplies DC power whose voltage is controlled to the first level (for example, 48V) to the wire feeding device 2 via the power transmission lines 51 and 52. The configuration of the power transmission power supply unit 12 is not limited to the above. For example, it may have the same configuration as the power supply unit 11 for welding, or the AC power input from the power system is stepped down (or boosted) by a transformer, and then converted into DC power by the rectifier circuit 121 and output. You may do so.

The welding power supply unit 11 applies a voltage so that the potential of the output terminal a is higher than that of the output terminal b and the potential of the power cable 41 is higher than the potential of the power cable 42. The power transmission power supply unit 12 applies a voltage so that the potential of the power transmission line 51 is lower than the potential of the power transmission line 52. Since the power transmission line 52 is connected to the power cable 41, the potential of the power transmission line 51 is lower than the potential of the power cable 41. That is, by lowering the potentials of both the power transmission line 51 and the power cable 42 to be lower than those of the power cable 41, the potential difference between the power transmission line 51 and the power cable 42 is prevented from becoming too large. For example, when the no-load voltage output by the welding power supply unit 11 is 90V and the voltage output by the power transmission power supply unit 12 is 48V, the potential difference between the power transmission line 51 and the power cable 42 is 42V. If the potential of the power transmission line 51 is made higher than the potential of the power transmission line 52, the potential difference between the power transmission line 51 and the power cable 42 becomes 132V. If the potential difference between the power transmission line 51 and the power cable 42 is not a concern, the voltage applied by the power transmission power supply unit 12 is set to the opposite polarity (the potential of the power transmission line 51 is higher than the potential of the power transmission line 52). , A voltage may be applied).

The control unit 13 controls the welding power supply device 1, and is realized by, for example, a microcomputer or the like. The control unit 13 controls the inverter circuit 112 of the welding power supply unit 11 so that the welding voltage and the welding current output from the welding power supply device 1 become the set voltage and the set current. Further, the DC / DC converter circuit 122 of the power transmission power supply unit 12 is controlled so that the voltage output from the power transmission power supply unit 12 becomes a predetermined voltage. The control unit 13 controls such as changing the welding conditions according to the operation of a setting button (not shown) and activating the welding power supply unit 11 according to the operation of the start button (not shown). Further, the control unit 13 displays the detected values of the welding voltage and the welding current detected by the sensor (not shown) on a display unit (not shown), or notifies the notification unit (not shown) when an abnormality occurs.

Further, the control unit 13 also changes the welding conditions and activates the welding power supply unit 11 based on the signal input from the communication unit 14, and detects the detected welding voltage or welding current, or an abnormality occurs. A signal indicating the above, a signal for a wire feeding command or a gas supply command for the wire feeding device 2, and the like are output to the communication unit 14.

Further, the control unit 13 performs a pairing process in order to specify the wire feeding device 2 which is the communication partner of the welding power supply device 1. In the present embodiment, as a pairing process, the control unit 13 transmits the identification information set in itself to the wire feeding device 2 by controlling the switching unit 16. The details of the method of transmitting the identification information will be described later. The control unit 13 corresponds to the "transmission control unit" of the present invention.

The communication unit 14 is for communicating with the wire feeding device 2 via the power transmission lines 51 and 52. The communication unit 14 demodulates the signal received from the wire feeding device 2 and outputs it to the control unit 13. The signal received from the wire feeding device 2 includes, for example, a signal for setting welding conditions, an activation signal for instructing the activation of the welding power supply unit 11, and the like. Further, the communication unit 14 modulates the signal input from the control unit 13 and transmits it as a communication signal to the wire feeding device 2. The signal transmitted to the wire feeding device 2 includes, for example, a detected value of the detected welding voltage or welding current, a signal indicating the occurrence of an abnormality, a signal for a wire feeding command, a gas supply command, and the like. The signal transmitted to and received from the wire feeding device 2 is not limited to the above.

The communication unit 14 communicates using a direct sequence spread spectrum (DSSS) communication method. In the direct spread spectrum communication method, the transmitting side performs an operation using a spreading code on the transmitted signal, spreads the spectrum of the original signal over a wider band, and transmits the signal. The receiving side returns the received signal to the original signal by despreading the received signal using a common spreading code. Even when noise is superimposed on the communication signal, the noise spectrum is diffused by despreading, so that the original communication signal can be extracted by filtering. Therefore, communication can be performed with high communication quality. Further, after the pairing process is performed, the same diffusion code is set for the paired welding power supply device 1 and the wire feeding device 2, and the diffusion code is set differently for each welding system A1. Even if the communication signal transmitted and received by the welding system A1 of the above is erroneously received, the communication signal is back-spread with a different spreading code and removed as noise. Therefore, interference can be suppressed. However, since it is not known which wire feeding device 2 the welding power supply device 1 is connected to, the same diffusion code is initially set for all of them. Therefore, interference may occur in the communication before pairing.

The communication unit 14 includes a coupling circuit. The coupling circuit includes a high-frequency transformer in which a coil connected to the input / output end of the communication unit 14 and a coil connected in parallel to the power transmission lines 51 and 52 are magnetically coupled, and the communication unit 14 outputs the output. The communication signal is superimposed on the power transmission lines 51 and 52, and the communication signal superimposed on the power transmission lines 51 and 52 is detected. The communication unit 14 modulates the carrier signal by BPSK (Binary Phase Shift Keying) according to the signal input from the control unit 13, spreads the spectrum of the modulated signal, converts it into an analog signal, and transmits the modulated signal. The modulation method is not limited to BPSK modulation, and ASK modulation or FSK modulation may be performed. Further, the spread spectrum is not limited to the direct diffusion method, and a frequency hopping method may be used. In the present embodiment, the spectrum diffusion is performed, but the present invention is not limited to this, and the spectrum diffusion may not be performed. Further, the communication unit 14 detects the communication signal superimposed on the power transmission lines 51 and 52, converts it into a digital signal, performs despreading and filtering, demodulates the signal, and outputs the signal to the control unit 13. The signal transmitted from the welding power supply device 1 to the wire feeding device 2 and the signal transmitted from the wire feeding device 2 to the welding power supply device 1 are transmitted and received with a time lag. Note that different frequency bands may be used.

The switch 15 is arranged on the power transmission line 52, and switches between a state in which the power transmission line 52 is conducted (on state) and a state in which the power transmission line 52 is cut off (off state). When the switch 15 is on, the voltage output by the power transmission power supply unit 12 is applied to the power reception power supply unit 21 of the wire feeding device 2. On the other hand, when the switch 15 is in the off state, the voltage output by the power transmission power supply unit 12 is not applied to the power reception power supply unit 21 of the wire feeding device 2. The switch 15 switches between an on state and an off state based on an instruction from the switching unit 16. Therefore, in the present embodiment, the output voltage output from the welding power supply device 1 to the wire feeding device 2 via the power transmission lines 51 and 52 is a voltage of 48V (first level) output by the power transmission power supply unit 12. It can be switched between voltage V _H ) and voltage 0 V (second level voltage _VL ). Further, in the present embodiment, as the switch 15, a semiconductor switch such as a transistor is used in order to speed up the switching. The switch 15 may be a mechanical switch as long as it can be switched between an on state and an off state. The switch 15 may be arranged on the power transmission line 51. The period in which the switch 15 is on corresponds to the "first level application period" of the present invention, and the period in which the switch 15 is in the off state corresponds to the "second level application period" of the present invention.

The switching unit 16 switches the state of the switch 15 based on an instruction from the control unit 13. Normally, the switching unit 16 keeps the switch 15 on. As a pairing process, the control unit 13 outputs a signal based on the identification information set in itself to the switching unit 16. In the present embodiment, the switch 15 and the switching unit 16 correspond to the "switching unit" of the present invention.

The capacitor 17 stabilizes the output of the power transmission power supply unit 12, is connected in parallel to the power transmission power supply unit 12, and is provided after the switching unit 16. The capacitor 17 is a so-called bypass capacitor. When the switch 15 is on, the output voltage of the power transmission power supply unit 12 is applied to the capacitor 17, and an electric charge is accumulated (charged). On the other hand, when the switch 15 is off, the capacitor 17 does not apply the output voltage of the power transmission power supply unit 12, and discharges the accumulated electric charge. Due to the discharge by the capacitor 17, the voltage applied from the welding power supply device 1 to the wire feeding device 2 gradually decreases during the period when the switch 15 is in the off state. At this time, the rate of decrease of the voltage applied to the wire feeding device 2 changes depending on the capacitance of the capacitor 17, and the rate of decrease is slow when the capacitance is large, and the rate of decrease when the capacitance is small. Will be faster. The capacitance of the capacitor 17 decreases due to deterioration of the capacitor 17.

The voltage sensor 18 detects the voltage output from the welding power supply device 1 to the wire feeding device 2. Specifically, the voltage sensor 18 detects the voltage between the terminals of the capacitor 17. The voltage sensor 18 outputs the detected voltage to the control unit 13. The voltage detected by the voltage sensor 18 is defined as the detection voltage V1. In the present embodiment, the voltage sensor 18 corresponds to the "detection unit" that detects the output voltage of the present invention.

The storage unit 19 stores various types of information. The storage unit 19 is composed of, for example, a flash memory or a hard disk. In the present embodiment, the storage unit 19 stores identification information unique to the welding power supply device 1. The identification information is binary data and is information for identifying the welding power supply device 1. Such identification information includes, for example, a part (for example, lower 16 bits) or all of the MAC address set in the welding power supply device 1, a number arbitrarily set by the user, a serial number of the welding power supply device 1, and the like. Examples include serial numbers. If the welding power supply device 1 can be specified, the present invention is not limited to these. The control unit 13 acquires identification information from the storage unit 19 during the pairing process. In the present embodiment, the power transmission power supply unit 12, the control unit 13, the communication unit 14, the switch 15, the switching unit 16, the capacitor 17, the voltage sensor 18, and the storage unit 19 are put together in the present invention. Corresponds to the "first communication device". It should be noted that the welding power supply device 1 can be considered to correspond to the "first communication device" of the present invention.

The wire feeding device 2 feeds the wire electrode to the welding torch 3. Further, the wire feeding device 2 supplies the shield gas of the gas cylinder 6 to the tip of the welding torch 3. The wire feeding device 2 includes a power receiving power supply unit 21, a control unit 22, a communication unit 23, a feeding motor 24, a gas solenoid valve 25, a voltage sensor 26, and a voltage comparing unit 27.

The power receiving power supply unit 21 supplies electric power to the control unit 22, the feeding motor 24, and the gas solenoid valve 25. The power receiving power supply unit 21 is supplied with electric power from the welding power supply device 1 via the power transmission lines 51 and 52, and converts the voltage into a voltage suitable for each of the control unit 22, the feed motor 24, and the gas solenoid valve 25. Output. The power receiving power supply unit 21 includes a capacitor for storing electric power supplied from the welding power supply device 1, a diode for preventing current from flowing back from the capacitor to the power transmission lines 51 and 52, a control unit 22, a feed motor 24, and a power supply motor 24. A DC / DC converter for adjusting the voltage output to the gas electromagnetic valve 25 is provided. The configuration of the power receiving power supply unit 21 is not limited to the above.

The control unit 22 controls the wire feeding device 2, and is realized by, for example, a microcomputer. The control unit 22 communicates an activation signal for activating the welding power supply unit 11 of the welding power supply device 1 in response to an operation signal for activation input from a torch switch (not shown) provided on the welding torch 3. Output to unit 23. Further, the welding conditions stored in the storage unit (not shown) are changed according to the operation signal for changing the welding conditions input from the operation unit (not shown). Further, the control unit 22 outputs and displays the detection value of the welding voltage or welding current input from the communication unit 23 to a display unit (not shown), or is based on a signal input from the communication unit 23 indicating the occurrence of an abnormality. Therefore, an abnormality notification (for example, notification by a warning sound or vibration by a speaker) is made to be notified to a notification unit (not shown). Further, when the wire feeding command is input from the communication unit 23, the control unit 22 causes the feeding motor 24 to feed the wire electrodes, and sends the wire electrodes to the welding torch 3. When a gas supply command is input from the communication unit 23, the gas solenoid valve 25 is opened to release the shield gas of the gas cylinder 6 from the tip of the welding torch 3.

Further, the control unit 22 performs a pairing process in order to identify the welding power supply device 1 which is the communication partner of the wire feeding device 2. In the present embodiment, the control unit 22 receives the identification information based on the voltage drop detection signal (described later) input from the voltage comparison unit 27 as the pairing process, and sets it in a storage unit (not shown). The details of the method of receiving the identification information will be described later. The control unit 22 corresponds to the "reception control unit" of the present invention.

The communication unit 23 is for communicating with the welding power supply device 1 via the power transmission lines 51 and 52. The communication unit 23 demodulates the signal received from the welding power supply device 1 and outputs it to the control unit 22. The signals received from the welding power supply device 1 include, for example, the detection value of the welding voltage or welding current detected by the sensor in the welding power supply device 1, the signal indicating the occurrence of an abnormality, the wire feeding command, the gas supply command, and the like. There is a signal of. Further, the communication unit 23 modulates the signal input from the control unit 22 and transmits it as a communication signal to the welding power supply device 1. The signal transmitted to the welding power supply device 1 includes, for example, a signal for setting welding conditions, an activation signal for instructing the activation of the welding power supply unit 11, and the like. The signal transmitted to and received from the welding power supply device 1 is not limited to the above. Similar to the communication unit 14, the communication unit 23 also communicates using the direct spectrum diffusion communication method.

The communication unit 23 includes a coupling circuit. The coupling circuit includes a high-frequency transformer in which a coil connected in parallel to the power transmission lines 51 and 52 and a coil connected to the input / output end of the communication unit 23 are magnetically coupled, and the communication output by the communication unit 23 is provided. The signal is superimposed on the power transmission lines 51 and 52, and the communication signal superimposed on the power transmission lines 51 and 52 is detected.

The feed motor 24 feeds the wire electrodes to the welding torch 3. The feed motor 24 rotates based on the wire feed command from the control unit 22, rotates the feed roller, and feeds the wire electrode to the welding torch 3.

The gas solenoid valve 25 is provided in a gas pipe 7 that connects the gas cylinder 6 and the welding torch 3, and is opened and closed based on a gas supply command from the control unit 22. While the gas supply command is input from the control unit 22, the gas electromagnetic valve 25 is opened and the shield gas is supplied to the welding torch 3. On the other hand, when the gas supply command is not input from the control unit 22, the gas solenoid valve 25 is closed and the supply of the shield gas to the welding torch 3 is stopped.

The voltage sensor 26 detects the voltage between the input terminals of the power receiving power supply unit 21. The voltage sensor 26 may detect the voltage between the terminals of the capacitor of the power receiving power supply unit 21. The voltage sensor 26 outputs the detected voltage (detection voltage V2) to the voltage comparison unit 27.

The voltage comparison unit 27 compares the detection voltage V2 input from the voltage sensor 26 with a predetermined threshold value V _0, and detects that the voltage of the power receiving power supply unit 21 has dropped. The threshold value V ₀ is a voltage value set for determining a voltage drop, and is a voltage value between the first level voltage V _H and the second level voltage V _L applied from the power transmission power supply unit 12. Is set. In the present embodiment, a voltage value between a voltage of 48 V as the first level voltage V _H and a voltage of 0 V as the second level voltage _VL is set. If a large value is set as the threshold value V ₀ , the voltage drop can be detected quickly, but the possibility of erroneous detection increases. On the other hand, if a small value is set as the threshold value V ₀ , the possibility of erroneously detecting a voltage drop is reduced, but the detection is delayed. In the present embodiment, a value of, for example, 30 to 40 V is set as the threshold value V ₀ . The voltage comparison unit 27 outputs the comparison result as a voltage drop detection signal to the control unit 22. When the detection voltage V2 is equal to or higher than the predetermined threshold value V ₀ , the voltage comparison unit 27 determines that the voltage has not dropped, and sets the voltage drop detection signal to a low level. Meanwhile, the detection voltage V2 when a predetermined threshold value less than V _0, it is determined that the voltage has dropped to a voltage drop detection signal to a high level. The control unit 22 receives the identification information transmitted from the welding power supply device 1 based on the voltage drop detection signal input from the voltage comparison unit 27, and sets it in the storage unit. In the present embodiment, the voltage sensor 26 and the voltage comparison unit 27 correspond to the “identification unit” of the present invention. Further, a combination of the power receiving power supply unit 21, the control unit 22, the communication unit 23, the voltage sensor 26, and the voltage comparison unit 27 corresponds to the "second communication device" of the present invention. The wire feeding device 2 can also be considered to correspond to the "second communication device" of the present invention. Further, the wire feeding device 2 corresponds to the "welding peripheral device" of the present invention.

Next, the pairing process will be described.

The pairing process is a process for identifying a communication partner, and sets common identification information for each. By adding the identification information to the signal transmitted by the transmitting side and transmitting the signal, and processing only the signal to which the identification information is added by the receiving side, it is possible to eliminate the signal transmitted from other than the communication partner and received by interference. it can. As described above, in the present embodiment, the welding power supply device 1 and the wire feeding device 2 are connected by power transmission lines 51 and 52, and signals are superimposed and communicated between the power transmission lines 51 and 52. I do. When a plurality of welding systems A1 exist at the site where the welding work is performed, and the gas pipe 7 in which the power transmission line 51 is arranged and the power cable 41 which is a part of the power transmission line 52 are arranged in a bundle. There is. In this case, due to magnetic coupling, signals transmitted and received by the other welding system A1 may interfere with each other and be superimposed. Therefore, pairing processing is required for accurate communication. Further, in the case of wireless communication, since communication is not performed on the connected connection line, communication cannot be established unless pairing processing is performed.

When pairing two devices, the identification information of one device is set in the other device. However, when the identification information is transmitted by communication, interference may occur because the two devices have not been paired yet. That is, even if the identification information is transmitted from the communication unit 14 to the communication unit 23 before the welding power supply device 1 and the wire feeding device 2 are paired, they may not be correctly transmitted due to interference. If another wire feeding device 2 mistakenly receives the identification information, the welding power supply device 1 will be paired with another wire feeding device 2. In order to prevent this, in the present embodiment, the identification information is transmitted by another communication method that does not cause interference. Specifically, the welding power supply device 1 transmits identification information to the wire feeding device 2 by utilizing the switching of the switch 15 by the switching unit 16. Then, the wire feeding device 2 receives the identification information based on the comparison result output from the voltage comparison unit 27. In this way, the welding power supply device 1 transmits the identification information and the wire feeding device 2 receives the identification information, so that the identification information is transmitted from the welding power supply device 1 to the wire feeding device 2 in the welding system A1. Weld.

First, it will be described that signals can be transmitted / received (transmitted) by switching the switch 15 by the switching unit 16 and comparing with the voltage comparing unit 27.

FIG. 4 is a time chart showing waveforms of each signal when the welding power supply device 1 transmits information to the wire feeding device 2 by switching the switch 15.

FIG. 4A shows an example of a transmission signal output by the control unit 13 to the switching unit 16. In FIG. 4A, a pulse signal having a high level at time t1 and a low level at time t3 is taken as an example.

FIG. 4B shows the state of the switch 15. As shown in FIG. 4B, the switch 15 is in the on state while the transmission signal is at the low level and is in the off state while the transmission signal is at the high level. That is, the switch 15 is switched to the off state at the time t1 and is switched to the on state at the time t3.

FIG. 4C shows the detection voltage V2 detected by the voltage sensor 26. FIG. 4D shows a voltage drop detection signal output by the voltage comparison unit 27.

Until time t1, since the switch 15 is on, the power transmission line 52 is in a conductive state. Therefore, the voltage output by the power transmission power supply unit 12 is applied to the power reception power supply unit 21, and the detection voltage V2 of the voltage sensor 26 becomes a predetermined voltage (for example, 48V). At this time, since the detection voltage V2 is a predetermined threshold or more V _0, the voltage drop detection signal is at low level.

At time t1, the switch 15 is switched to the off state. Therefore, the power transmission line 52 is cut off and no voltage is applied to the power receiving power supply unit 21, so that the detection voltage V2 of the voltage sensor 26 is lowered. At this time, the detection voltage V2 of the voltage sensor 26 gradually decreases due to the capacitor 17, as shown in FIG. 4C. Then, at time t2, the detection voltage V2 is smaller than the threshold value V _0, the voltage drop detection signal is at high level.

Although the detection voltage V2 decreases thereafter, it starts to increase because the switch 15 is switched to the ON state at time t3. The time during which the switch 15 is turned off, that is, the high level period of the transmission signal is set to a predetermined time (hereinafter, referred to as “reference high level time”) set in advance at normal times. The reference high level time is set so that the voltage (detection voltage V2) of the power receiving power supply unit 21 can maintain a level at which the control unit 22 can be driven. That is, the reference high level time is from when the voltage is not applied from the power transmission power supply unit 12 to the power reception power supply unit 21 until the voltage of the power reception power supply unit 21 becomes the minimum voltage that can drive the control unit 22. It is set shorter than the time. In this embodiment, 150 ms is used as the reference high level time.

Then, at time t4, the detection voltage V2 becomes equal to or higher than the threshold value V ₀ , so that the voltage drop detection signal is at a low level. The detection voltage V2 continues to rise to a predetermined voltage, and the voltage is maintained.

As described above, the waveform signal corresponding to the transmission signal output by the control unit 13 of the welding power supply device 1 to the switching unit 16 is input to the control unit 22 of the wire feeding device 2 as a voltage drop detection signal. The voltage drop detection signal has a pulse waveform in which the rising timing of switching from low level to high level is later than that of the transmission signal, and the falling timing of switching from high level to low level is substantially the same as that of the transmission signal. When the threshold value V ₀ is large, the voltage drop detection signal has the same waveform as the transmission signal. In this way, the transmission signal output by the control unit 13 of the welding power supply device 1 is detected by the control unit 22 of the wire feeding device 2 by the switching of the switch 15 by the switching unit 16 and the comparison by the voltage comparison unit 27. It can be transmitted as a signal.

By the way, in FIG. 4, from time t1 to time t3, that is, while the switch 15 is in the off state, the output voltage of the power transmission power supply unit 12 is not applied to the power reception power supply unit 21, so that the capacitor 17 Due to the discharge, the detection voltage V2 of the voltage sensor 26 is gradually lowered. The rate of decrease of the detected voltage V2 depends on the capacitance of the capacitor 17, and becomes slower when the capacitance is large (the slope becomes smaller in FIG. 4C) and becomes faster when the capacitance is small. (In FIG. 4C, the inclination becomes large). For example, in a normal state (not deteriorated) of the capacitor 17, as shown in FIG. 4C, the detection voltage V2 gradually decreases, but in a state where the capacitor 17 is deteriorated, FIG. The decrease in the detection voltage V2 becomes more severe than in 4 (c). As a result, the voltage of the power receiving power supply unit 21 (detection voltage V2) may be lower than the level at which the control unit 22 or the voltage comparison unit 27 becomes unstable or cannot be driven. In this case, the wire feeding device 2 cannot properly restore the transmission signal transmitted from the welding power supply device 1.

Therefore, in the present invention, the control unit 13 adjusts (shortens) the high level period of the transmission signal, that is, the period during which the switch 15 is off, in consideration of the influence of the deterioration of the capacitor 17, thereby receiving power. It is suppressed that the voltage (detection voltage V2) of the power supply unit 21 drops too much. In the present embodiment, the control unit 13 monitors the detection voltage V1 of the voltage sensor 18, when the detection voltage V1 is below the threshold value V _S which is set in advance, without waiting for the reference high level time Forcibly, the transmission signal is switched from high level to low level, and the switch 15 is switched on. That is, the high level period of the transmission signal is made shorter than the reference high level time. By switching the switch 15 to the ON state, the output voltage of the power transmission power supply unit 12 is applied to the power reception power supply unit 21, so that the voltage (detection voltage V2) of the power reception power supply unit 21 rises. As a result, it is possible to prevent the operation of the control unit 22 or the voltage comparison unit 27 from becoming unstable or stopping. Incidentally, the threshold V _S, the voltage of the power receiving power supply unit 21 (detection voltage V2) is set based on the stable level capable of driving the control unit 22 or the voltage comparator 27. The threshold V _S is less than the threshold V ₀ to determine a voltage drop is set, for example, 20V.

Next, as described above, even when the period during which the switch 15 is off is adjusted (shortened) in consideration of the influence of the deterioration of the capacitor 17, the switching unit 16 switches the switch 15 and the voltage comparison unit. It will be explained that information can be transmitted / received (transmitted) by the comparison in 27.

FIG. 5 shows a welding power supply device 1 by switching the switch 15 when the period in which the switch 15 is off is adjusted (shortened) assuming a state in which the capacitor 17 is deteriorated (capacitance is reduced). Is a time chart showing the waveform of each signal when information is transmitted to the wire feeding device 2. For convenience of understanding, in FIG. 5, the waveforms of the signals shown in FIG. 4 are superimposed by the alternate long and short dash line.

FIG. 5A shows an example of a transmission signal output by the control unit 13 to the switching unit 16. FIG. 5B shows the state of the switch 15. FIG. 5C shows the detection voltage V1 detected by the voltage sensor 18 of the welding power supply device 1 and the detection voltage V2 detected by the voltage sensor 26 of the wire feeding device 2. FIG. 5D shows a voltage drop detection signal output by the voltage comparison unit 27. In FIG. 5C, the detection voltage V1 and the detection voltage V2 are arranged on the power transmission lines 51 and 52 so as to be seen from the arrangement positions of the voltage sensor 18 and the voltage sensor 26 shown in FIG. Therefore, the detected voltage is the same and the waveform is the same.

In the waveform of the detection voltage V2 shown in FIG. 5C, the rate of decrease of the detection voltage V2 of the voltage sensor 26 is faster during the period when the switch 15 is in the off state than in FIG. 4C. Thus, at an early time t11 to time t2, the detection voltage V2 is smaller than the threshold value V _0. At this time, as shown in FIG. 5D, the voltage drop detection signal is at a high level.

Detection voltages V1, V2 can then be continued to drop, at time t12, the since the detection voltage V1 is equal to or less than the threshold value V _S, the transmission signal is switched from the high level to the low level, the on-state switch 15 from the OFF state Can be switched to. As a result, the high level period of the transmission signal is shorter than the high level period (reference high level time) of the transmission signal shown in FIG. 4A. Then, when the switch 15 is switched from the off state to the on state, the detection voltage V1 and the detection voltage V2 (voltage of the power receiving power supply unit 21) have started to rise, and the voltage level of the power receiving power supply unit 21 has changed. It is suppressed to lower than the threshold V _S. After that, at time t13, the detection voltage V2 becomes equal to or higher than the threshold value V ₀ , so that the voltage drop detection signal is at a low level. The detection voltage V2 continues to rise to a predetermined voltage, and the voltage is maintained.

As shown in FIG. 5, even when the period in which the switch 15 is off is adjusted (shortened), the control unit 13 of the welding power supply device 1 responds to the transmission signal output to the switching unit 16 as in FIG. The waveform signal is input to the control unit 22 of the wire feeding device 2 as a voltage drop detection signal.

6 and 7 are time charts showing waveforms of each signal when the welding power supply device 1 transmits identification information for pairing to the wire feeding device 2. FIG. 6 assumes a state in which the capacitor 17 has not deteriorated, and FIG. 7 assumes a state in which the capacitor 17 has deteriorated. For convenience of understanding, in FIG. 7, the waveforms of the signals shown in FIG. 6 are superimposed by a alternate long and short dash line.

First, FIG. 6 will be described.

FIG. 6A shows a transmission signal output by the control unit 13 to the switching unit 16. The transmission signal is generated based on bit data in which the identification information is binary data. In the present embodiment, the pulse signal whose length of the low level period is switched based on the identification information is used as the transmission signal. The control unit 13 shortens the low level period when the bit data of the identification information is "0" (for example, 200 ms), and lengthens the low level period when the bit data of the identification information is "1" (for example, 400 ms). ), Generate a transmission signal. The transmission signal shown in FIG. 6A indicates “001 ...”. The control unit 13 generates a transmission signal based on the identification information and inputs it to the switching unit 16.

FIG. 6B shows the state of the switch 15. As shown in FIG. 6B, the switch 15 is on while the transmission signal is at low level and off when the transmission signal is at high level. That is, when the bit data of the identification information is "0", the on state of the switch 15 is short, and when the bit data is "1", the on state of the switch 15 is long.

FIG. 6C shows the detection voltage V1 detected by the voltage sensor 18 and the detection voltage V2 detected by the voltage sensor 26. As described above, the detected voltage V1 and the detected voltage V2 have the same waveform. FIG. 6D shows a voltage drop detection signal output by the voltage comparison unit 27. As described with reference to FIG. 4, the detection voltage V2 decreases when the switch 15 is switched to the off state, and the detection voltage V2 increases when the switch 15 is switched to the on state. Then, the voltage comparator unit 27, the detection voltage V2 when a predetermined threshold value less than V _0, the voltage drop detection signal to a high level. When the on state of the switch 15 is short, the time during which the detection voltage V2 becomes the threshold value V ₀ or more is short, so that the low level period of the voltage drop detection signal is short. On the other hand, when the switch 15 is on for a long time, the detection voltage V2 becomes the threshold value V ₀ or more for a long time, so that the low level period of the voltage drop detection signal becomes long. That is, the voltage drop detection signal has the same waveform as the transmission signal.

Since the voltage drop detection signal has the same waveform as the transmission signal, the control unit 22 can restore the identification information based on the voltage drop detection signal input from the voltage comparison unit 27. Specifically, the control unit 22 restores the bit data of the identification information based on the length of the low level period of the input voltage drop detection signal. For example, the control unit 22 compares the length of the low level period of the voltage drop detection signal with a predetermined threshold value (for example, 250 to 350 ms, hereinafter referred to as “identification information determination threshold value”) for identification information. If it is equal to or more than the determination threshold value, it is determined to be "1", and if it is less than the identification information determination threshold value, it is determined to be "0".

Further, in FIG. 6, it is assumed that the capacitor 17 has not deteriorated, and as shown in FIG. 6C, the detection voltages V1 and V2 gradually decrease during the period when the switch 15 is in the off state. Therefore, the detection voltage V1 does not _fall below the threshold value VS during the high level period of the transmission signal, that is, the period when the switch 15 is in the off state. Therefore, in the state where the capacitor 17 is not deteriorated, the high level period of the transmission signal, that is, the period in which the switch 15 is off is the reference high level time (for example, 150 ms).

The wire feeding device 2 that has received the identification information in this way stores the identification information in the storage unit, and transmits a signal from the communication unit 23 to the communication unit 14 to the effect that the identification information has been received. At this time, since the communication unit 23 can add the identification information to the signal to be transmitted and transmit the signal, interference does not occur. The pairing process is completed when the welding power supply device 1 receives a signal indicating that the identification information has been received.

Next, FIG. 7 will be described.

FIG. 7A shows a transmission signal output by the control unit 13 to the switching unit 16. FIG. 7B shows the state of the switch 15. FIG. 7C shows the detection voltage V1 detected by the voltage sensor 18 and the detection voltage V2 detected by the voltage sensor 26. FIG. 7D shows a voltage drop detection signal output by the voltage comparison unit 27. That is, FIG. 7 corresponds to FIG.

As shown in FIG. 7C, in the state where the capacitor 17 is deteriorated (waveform shown by the solid line), the switch 15 is in the off state as compared with the state where the capacitor 17 is not deteriorated (waveform shown by the alternate long and short dash line). During this period, the detected voltages V1 and V2 are drastically reduced. Since the detection voltage V1 is equal to or less than a threshold value V _S, the control unit 13, when the detection voltage V1 is below the threshold V _S, switches the transmission signal from the high level to the low level. Therefore, as shown in FIG. 7A, the transmission signal is switched to the low level before the high level period of the transmission signal reaches the reference high level time. At this time, since the switching unit 16 switches the switch 15 from the off state to the on state, the output voltage of the power transmission power supply unit 12 is applied to the power reception power supply unit 21, and the detection voltage V2 rises. Therefore, it is possible to prevent the voltage of the power receiving power supply unit 21 from dropping below a level at which it cannot be driven. That is, in the state where the capacitor 17 is deteriorated, the voltage of the power receiving power supply unit 21 is suppressed from being excessively lowered by shortening the high level period of the transmission signal as compared with the state where the capacitor 17 is not deteriorated. are doing.

Then, after switching the transmission signal from the high level to the low level, the control unit 13 shortens the low level period (for example, 200 ms) in the case of “0” based on the bit data of the identification information, and “1”. In the case of, a transmission signal having a long low level period (for example, 400 ms) is generated.

Further, as shown in FIGS. 7 (a) and 7 (d), the voltage drop detection signal has the same waveform as the transmission signal even when the capacitor 17 is deteriorated. Therefore, the control unit 22 can restore the identification information based on the voltage drop detection signal input from the voltage comparison unit 27.

Next, in the welding system A1, the processing performed by the welding power supply device 1 and the wire feeding device 2 when transmitting the identification information will be described.

FIG. 8 is a flowchart showing an identification information transmission process for transmitting identification information to the wire feeding device 2 performed by the welding power supply device 1. The identification information transmission process shown in FIG. 8 is started when the welding power supply device 1 is activated. Further, it may be started when it is determined that the wire feeding device 2 is connected while the welding power supply device 1 is activated. Further, when the operator performs a pairing start operation using an operation unit (not shown) provided in the welding power supply device 1, an instruction signal based on the pairing start operation is input to the control unit 13 and is input to the control unit 13. Based on that, it may be started. The identification information transmission process is started in a state where the welding power supply device 1 is activated, and the switch 15 is in an on state.

First, the control unit 13 acquires the identification information stored in the storage unit 19 (S1). Then, when the control unit 13 acquires the identification information, the control unit 13 once switches the transmission signal output to the switching unit 16 to a high level. As a result, the switching unit 16 switches the switch 15 to the off state (S2).

Next, the control unit 13 determines whether or not all the bit data of the acquired identification information (binary data) has been notified (S3). Here, when it is determined that the notification has not been performed (S3: YES), it is then determined whether or not a preset reference high level time (for example, 150 ms) has elapsed since the transmission signal was switched to the high level. (S4). That is, the switch 15 is switched to the off state, and it is determined whether or not a predetermined time has elapsed in a state in which the output voltage of the power transmission power supply unit 12 is not applied to the power reception power supply unit 21. In step S4, if the reference high level time has not elapsed (S4: NO), then, the detection voltage V1 by the voltage sensor 18 is equal to or less than a predetermined threshold value V _S (S5) .. In step S5, when the detection voltage V1 is not less than the threshold value V _S (the threshold V _S exceeds) (S5: NO), the process returns to step S4, after switching a transmission signal to the high level at step S2, reference high or level time elapses, or until the detection voltage V1 by the voltage sensor 18 becomes equal to or less than the threshold V _S, repeatedly executes the processing in step S4, S5.

If elapsed reference high-level time in step S4 (S4: YES), or when the detection voltage V1 in step S5 is determined to be below the threshold V _S (S5: YES), the control unit 13, a transmission signal Switch to low level. As a result, the switching unit 16 switches the switch 15 to the on state (S6). Note that, in step S5, the control unit 13, when the detection voltage V1 is determined to be below the threshold V _S, even if no elapsed reference high-level time after switching a transmission signal to the high level, forcing The transmission signal is switched to the low level, and the switch 15 is switched to the on state.

Then, the control unit 13 keeps the transmission signal at a low level based on the bit data of the acquired identification information. As a result, the switching unit 16 keeps the switch 15 in the ON state based on the transmission signal (S7). Specifically, the control unit 13 shortens the low-level duration when the bit data of the identification information to be transmitted is "0" (for example, 200 ms), and the low-level continuation when the bit data is "1". Increase the time (eg 400 ms). In this way, a transmission signal whose length is switched during the low level period is generated based on the bit data of the identification information. The control unit 13 continues the transmission signal at the low level for a low level period based on the bit data of the identification information, and then returns to step S2 to switch the transmission signal to the high level.

After that, the control unit 13 repeatedly executes the processes of steps S2 to S7, generates a transmission signal based on the bit data of the identification information, and the switching unit 16 turns on the switch 15 based on the transmission signal. Toggle between and off state. Then, when the control unit 13 switches between the on state and the off state of the switch 15 for all the bit data of the identification information, it is determined in step S3 that the transmission of the identification information is completed (S3: YES), the transmission signal is switched to the low level, and the switching unit 16 switches the switch 15 to the on state (S8). As described above, the welding power supply device 1 transmits the identification information to the wire feeding device 2, and the identification information transmission process is performed.

FIG. 9 is a flowchart showing an identification information reception process for receiving identification information from the welding power supply device 1 performed by the wire feeding device 2.

The identification information receiving process shown in FIG. 9 is started when power is supplied to the power receiving power supply unit 21 and the wire feeding device 2 is activated.

First, the control unit 22 has a voltage drop of the power receiving power supply unit 21 detected (S21). Specifically, the control unit 22 repeatedly determines whether or not the voltage drop detection signal input from the voltage comparison unit 27 has reached a high level, and if the voltage drop has reached a high level, the voltage drop is detected (assuming that the voltage drop is detected ( S21: YES), the process proceeds to step S22.

Next, the control unit 22 waits for the voltage recovery of the power receiving power supply unit 21 to be detected (S22). Specifically, the control unit 22 repeatedly determines whether or not the voltage drop detection signal input from the voltage comparison unit 27 has reached the low level, and if the voltage drop detection signal has reached the low level, voltage recovery is detected (assuming that the voltage recovery is detected ( S22: YES), the process proceeds to step S23.

Next, when the voltage recovery is detected, the control unit 22 activates a count timer that measures the elapsed time from the timing when the voltage drop detection signal becomes low level, based on the clock signal from the built-in clock circuit. (S23).

Subsequently, the control unit 22 checks the count timer and determines whether or not the elapsed time has elapsed more than a preset predetermined time (hereinafter, referred to as “time-out time”) (S24). If it is determined in step S24 that the timeout time has not elapsed (S24: NO), the control unit 22 determines whether or not the voltage drop of the power receiving power supply unit 21 has been detected again (S25). Specifically, the control unit 22 determines whether or not the voltage drop detection signal input from the voltage comparison unit 27 has reached a high level. Here, when it is determined that the voltage drop is not detected, that is, when the voltage drop detection signal is not at the high level (S25: NO), the process returns to the process of step S24, and the control unit 22 returns to step S24 and The determination in step S25 is repeated. On the other hand, in step S25, assuming that voltage recovery is detected when the voltage drop detection signal reaches a high level (S25: YES), the process proceeds to step S26.

Next, the control unit 22 confirms the count timer and determines whether or not the elapsed time is equal to or greater than a preset identification information determination threshold value (for example, 250 ms to 350 ms) (S26). The elapsed time confirmed in step S26 corresponds to the low level period of the voltage drop detection signal.

When the control unit 22 determines in step S26 that the low level period of the voltage drop detection signal is equal to or greater than the identification information determination threshold value (S26: YES), the identification information (1 bit data) transmitted from the welding power supply device 1 ) Is determined to be "1" (S27). On the other hand, when the low level period of the voltage drop detection signal is less than the identification information determination threshold value (S26: NO), the identification information (1 bit data) transmitted from the welding power supply device 1 is "0". Judgment (S28). The control unit 22 stops and resets the count timer after determining either step S27 or step S28 (S29). Then, the process returns to step S22 and waits for the voltage recovery of the power receiving power supply unit 21 to be detected again.

After that, when the processes of steps S27 or S28 are repeated from step S22 and it is determined in step S24 that the timeout time or longer has elapsed (S24: YES), it is determined that all the identification information transmitted from the welding power supply device 1 has been received. Judgment (S30). At this time, the count timer is stopped and reset. As described above, the wire feeding device 2 receives the identification information from the welding power supply device 1 and performs the identification information receiving process.

In the welding system A1, the welding power supply device 1 executes the identification information transmission process (see FIG. 8), and the wire feeding device 2 executes the identification information reception process (see FIG. 9). Various signals of the waveform shown in No. 7 are generated, and the identification information is transmitted from the welding power supply device 1 to the wire feeding device 2. As a result, the welding power supply device 1 and the wire feeding device 2 can perform a pairing process for setting common identification information. The specific method of the pairing process is not limited, and a well-known method may be used.

Further, the welding power supply device 1 executes the above identification information transmission process to transmit a transmission signal (see FIG. 6A) in which the high level period becomes the reference high level time when the capacitor 17 is not deteriorated. On the other hand, when the capacitor 17 is deteriorated (the capacitance of the capacitor 17 is reduced), a transmission signal whose high level period is shorter than the reference high level time (see FIG. 7A) is generated. To do. As described above, the welding power supply device 1 (control unit 13) is based on the voltage V1 detected by the voltage sensor 18, and in consideration of the influence of the deterioration of the capacitor 17, the high level period of the transmission signal, that is, the switch 15 is turned off. The period of the state (the period when no voltage is applied) can be adjusted.

Next, the operation and effect of the welding system A1 according to the present embodiment will be described.

According to the present embodiment, the switching unit 16 turns on the switch 15 when the transmission signal input from the control unit 13 is low level, and turns off the switch 15 when the transmission signal is high level. Since the power transmission line 52 is in a conductive state in the ON state, a voltage is applied to the power receiving power supply unit 21 from the power transmission power supply unit 12. On the other hand, in the off state, the power transmission line 52 is cut off, so that no voltage is applied to the power receiving power supply unit 21. The voltage comparison unit 27 compares the detection voltage V detected by the voltage sensor 26 with the threshold value V _0, and generates a voltage drop detection signal that becomes a high level when the power receiving power supply unit 21 is in the voltage drop state. The voltage drop detection signal has a waveform corresponding to the transmission signal. Therefore, even before the pairing is established between the communication unit 14 of the welding power supply device 1 and the communication unit 23 of the wire feeding device 2, the welding power supply device 1 uses the transmission signal as a voltage drop detection signal to feed the wire. It can be transmitted to the feeding device 2. Further, since the welding power supply device 1 can transmit the identification information of the welding power supply device 1 to the wire feeding device 2 without using the communication by the communication unit 14 and the communication unit 23, the pairing process fails. Can be suppressed.

According to the present embodiment, the control unit 13 determines whether the detection voltage V1 of the voltage sensor 18 is below the threshold V _S, if it is determined that below the threshold V _S, and the transmission signal to the high level Therefore, before the preset reference high level time elapses, the level is forcibly switched to the low level (switch 15 is turned on). As a result, the period during which the switch 15 is in the off state, that is, the period during which the output voltage of the power transmission power supply unit 12 is not applied to the power reception power supply unit 21 is adjusted, and the voltage of the power reception power supply unit 21 drops too much. It is possible to suppress the operation instability and the operation stop of the wire feeding device 2 (control unit 22, voltage comparison unit 27, etc.) generated in the above. Therefore, based on the detection voltage V1 of the voltage sensor 18, the wire feeding device 2 can be appropriately adjusted by adjusting (shortening) the period during which the switch 15 is in the off state in consideration of the influence of the deterioration of the capacitor 17. Identification information can be received. Therefore, in the welding system A1, the identification information can be appropriately transmitted from the welding power supply device 1 to the wire feeding device 2.

In the case where the capacitor 17 is too degraded, switch the switch 15 in the OFF state, the time until the detection voltage V1 drops below the threshold V _S becomes too short, the period switch 15 is OFF Is significantly shortened. As a result, the identification information may not be properly transmitted. Therefore, when the period in which the switch 15 is off is shorter than a certain period of time, it is determined that the life of the capacitor 17 has expired, and a notification unit (not shown) is used to notify that the life of the capacitor 17 has expired. You should do it like this.

In the first embodiment, in the identification information transmission processing by the welding power supply apparatus 1, while generating a transmission signal, monitors the detection voltage V1, when the detected voltage V1 is below the threshold V _S, the transmission signal The case of switching from the high level to the low level, that is, switching the switch 15 from the off state to the on state has been described as an example, but the present invention is not limited to this. For example, prior to generating the transmission signal, a high level period of the transmission signal according to the degree of deterioration of the capacitor 17 may be specified, and the transmission signal may be generated using the specified high level period. Good. Specifically, before transmitting a transmission signal based on the identification information, once switches the switch 15 in the OFF state, the time from switching the switch 15 to the OFF state, until the detection voltage V1 is below the threshold V _S To measure. Incidentally, when the detected voltage V1 is below the threshold V _S, switches the switch 15 to the ON state. Then, the high level period of the transmission signal is set based on the measured time. At this time, the high level period of the transmission signal to be set, by shorter than the time measured in period switch 15 is turned off, suppressing the voltage of the power receiving power supply unit 21 drops below the threshold V _S can do. Then, a transmission signal is generated using the set high level period, and the transmission signal is input to the switching unit 16. The switch 15 is switched based on the transmission signal input by the switching unit 16, and the transmission signal is transmitted. (Identification information) is transmitted to the wire feeding device 2. Even in this case, the period during which the switch 15 is in the off state can be adjusted based on the detection voltage V1 detected by the voltage sensor 18 in consideration of the influence of the deterioration of the capacitor 17. The same effect as that of the first embodiment can be obtained.

In the first embodiment, the identification information transmitting process by the welding power supply apparatus 1, when the detected voltage V1 is below the threshold V _S, by switching the transmission signal from the high level to the low level, turns off the switch 15 The case of switching from the state to the on state has been described as an example, but the present invention is not limited to this. For example, the transmission signal may be left as it is, that is, the switch 15 may be switched from the off state to the on state without switching the transmission signal from the high level to the low level. For example, the control unit 13 may directly control the switch 15 to switch from the off state to the on state, or the control unit 13 may switch the switch 15 from the off state to the on state with respect to the switching unit 16. , An interrupt signal (a signal having a higher priority than the transmission signal) different from the transmission signal may be input. Then, the control unit 13 may return to the state in which the on state and the off state of the switch 15 are switched based on the transmission signal at the timing when the transmission signal is switched from the high level to the low level. Even in this case, the period during which the switch 15 is in the off state can be adjusted based on the detection voltage V1 detected by the voltage sensor 18 in consideration of the influence of the deterioration of the capacitor 17. The same effect as that of the first embodiment can be obtained.

In the first embodiment, in the identification information transmission process by the welding power supply device 1, the welding power supply device 1 (control unit 13) has been described as an example of generating a transmission signal from the identification information, but the present invention is not limited to this. , Information for performing error detection or error detection correction may be added to the identification information to generate a transmission signal. Information for such error detection / error detection correction includes parity data (parity bit), checksum data, CRC data, and the like. The information is not limited to these, and may be any information for performing well-known error detection / error detection correction. By adding the information for performing error detection or error detection correction to the identification information in this way, the control unit 22 restores the identification information based on the voltage drop detection signal input from the voltage comparison unit 27. Consistency can be confirmed by error detection data. As a result, it is possible to prevent erroneous information from being received due to the influence of welding noise and the like. Therefore, the reliability of transmission of identification information is improved.

In the first embodiment, the identification information is binary data, and "1" and "0" are represented by the length of the low level period of the transmission signal, but the present invention is not limited to this. For example, the identification information may be used as decimal data, and the length of the low-level period of the transmission signal may be switched in 10 steps.

In the first embodiment, the case where the identification information for pairing is transmitted has been described, but the present invention is not limited to this. Information other than the identification information for pairing may be transmitted. If the control unit 13 outputs a signal based on the information to the switching unit 16, the voltage drop detection signal output from the voltage comparison unit 27 changes according to the switching by the switching unit 16, so that the control unit 13 is the control unit. Any information can be transmitted to 22 without interference. Therefore, when only one-sided communication is performed from the welding power supply device 1 to the wire feeding device 2, the welding power supply device 1 and the wire feeding device 2 are prevented from having the communication unit 14 and the communication unit 23, respectively, and the switching unit. Information may be transmitted only by switching by 16 and comparing by the voltage comparison unit 27.

In the first embodiment, the case where a part of the power transmission line 52 is a power cable 41 has been described, but the present invention is not limited to this. A part of the section of the power transmission line 52 may be a power cable 42. Further, the power transmission line 52 may directly connect the power transmission power supply unit 12 and the power reception power supply unit 21. Further, the case where the power transmission line 51 is arranged inside the gas pipe 7 has been described, but the present invention is not limited to this. The power transmission line 51 may be exposed between the welding power supply device 1 and the wire feeding device 2. Further, in the present embodiment, the case where the welding power supply device 1 and the wire feeding device 2 perform communication by superimposing signals between the power transmission lines 51 and 52 has been described, but the present invention is not limited to this. Signals may be superimposed between the power cables 41 and 42 for communication, or wireless communication may be used for communication. When communicating by wireless communication, a wireless communication unit 14'is provided instead of the communication unit 14, and a wireless communication unit 23'is provided instead of the communication unit 23, and the wireless communication unit 14'and the wireless communication unit 23'are provided. Communication that conforms to a predetermined wireless communication standard may be performed.

In the first embodiment, the power receiving power supply unit of the wire feeding device 2 is based on the detection voltage V1 detected by the voltage sensor 18 provided in the welding power supply device 1 and in consideration of the influence of deterioration of the capacitor 17. The case where the voltage of 21 is not lowered too much has been described as an example, but the present invention is not limited to this. For example, the capacitor 17 deteriorates according to its usage time. The capacitor 17 is charged when a voltage is applied from the power transmission power supply unit 12, and is discharged when the voltage is no longer applied. When a voltage is applied to the capacitor 17, the switch 15 is in the ON state and power is being supplied from the power transmission power supply unit 12 to the wire feeding device 2, so that the power transmission power supply unit 12 supplies the wires. The cumulative time (hereinafter, referred to as “cumulative power supply time”) Tt for supplying power to the device 2 can be regarded as the usage time of the capacitor 17. From the above, the influence of deterioration of the capacitor 17 may be taken into consideration based on the cumulative power supply time Tt. This case will be described below as a second embodiment.

The welding system A2 according to the second embodiment of the present invention is configured in the same manner as the welding system A1 (see FIG. 1) according to the first embodiment. Since the welding system A2 has the same overall configuration as the welding system A1 according to the first embodiment, the illustration is omitted. In the welding system A2, the welding power supply device 1 measures the cumulative power supply time Tt and considers the influence of deterioration of the capacitor 17 based on the cumulative power supply time Tt. different. Specifically, the cumulative power supply time Tt is confirmed, and the period during which the switch 15 is off according to the cumulative power supply time Tt is set.

As a method for measuring the cumulative power supply time Tt, the control unit 13 measures the time during which the detection voltage V1 is detected (the detection voltage V1 is other than 0V) based on the detection voltage V1 input from the voltage sensor 18. Then, the cumulative total of the measured times is stored in the storage unit 19 as the cumulative power supply time Tt. Alternatively, as described above, since the control unit 13 controls the DC / DC converter circuit 122 of the power transmission power supply unit 12 and outputs the voltage set from the DC / DC converter circuit 122, the DC / DC The control time of the converter circuit 122 may be measured, and the cumulative total of the measured times may be stored in the storage unit 19 as the cumulative power supply time Tt. Alternatively, the control unit 13 responds to the operation of the start button of the welding power supply device 1 (not shown), controls the activation of the welding power supply device 1, and while the welding power supply device 1 is in operation, the wire feeding device 2 is sent from the welding power supply device 1. Since the electric power is supplied to the welding power supply device 1, the operating time of the welding power supply device 1 may be measured and the accumulated operating time may be stored in the storage unit 19 as the accumulated electric power supply time Tt. The method is not limited to these as long as it can measure the usage time of the capacitor 17. In the present embodiment, the control unit 13 corresponds to the "detection unit" that detects the cumulative time of the present invention.

Further, in the second embodiment, the storage unit 19 of the welding power supply device 1 stores identification information unique to the welding power supply device 1 as in the first embodiment, and further, a control unit. The information on the cumulative power supply time Tt measured by 13 and the correlation between the cumulative power supply time Tt and the high level period of the transmission signal is stored. This correlation is associated with the cumulative power supply time Tt for a high level period of the transmission signal set when the transmission signal is generated, that is, a period during which the switch 15 is in the off state. Specifically, each time the cumulative power supply time Tt elapses, a predetermined length is shortened from the initial high level period (for example, the above-mentioned reference high level time).

For example, when the initial high level period is set to 150 ms and the high level period set in the transmission signal is shortened by 10 ms every time the cumulative power supply time Tt elapses 1000 hours, the correlation information is 0 to 1000. A high level period (initial high level period) of a transmission signal of 150 ms is associated with the cumulative power supply time Tt of time (0 ≦ Tt <1000), and power of 1000 to 2000 hours (1000 ≦ Tt <2000). A high level period of the transmission signal of 140 ms is associated with the cumulative supply time Tt, and ... (the same applies hereinafter), and is stored. Since the capacitor 17 has a life, if the cumulative power supply time Tt exceeds a certain time (for example, 5000 hours), it is determined that the capacitor 17 has a life, and a notification unit (not shown) is used. It is sufficient to notify that the life of the capacitor 17 has expired. The above numerical example is an example, and the present invention is not limited to this. The range of the cumulative power supply time Tt and the degree of shortening the high level period in the correlation may be appropriately set based on the life and performance of the capacitor 17.

Further, in the second embodiment, the control unit 13 acquires the cumulative power supply time Tt stored in the storage unit 19 and the above correlation information, and based on these, the high level period of the transmission signal, that is, the switch. Adjust the period during which 15 is off. Specifically, when the control unit 13 transmits the identification information to the wire feeding device 2, the control unit 13 acquires the information of the correlation with the cumulative power supply time Tt stored in the storage unit 19, and is based on the correlation. The high level period of the transmission signal corresponding to the cumulative power supply time Tt is specified. For example, using an example of the above correlation, when the cumulative power supply time Tt is 300 hours, the high level period of the transmission signal is specified as 150 ms, and the cumulative power supply time Tt is 1800 hours. In this case, the high level period of the transmitted signal is specified as 140 ms. In this way, the control unit 13 adjusts the high level period of the transmission signal, that is, the period during which the switch 15 is in the off state, according to the cumulative power supply time Tt. Then, the control unit 13 generates a transmission signal which is a pulse signal having a specified high level period and a low level period based on the identification information, and inputs the generated transmission signal to the switching unit 16.

FIG. 10 is a flowchart showing an identification information transmission process performed by the welding power supply device 1 according to the second embodiment.

The identification information transmission process shown in FIG. 10 is started when the welding power supply device 1 is activated, similarly to the identification information transmission process according to the first embodiment. Further, it may be started when it is determined that the wire feeding device 2 is connected while the welding power supply device 1 is activated. Further, when the operator performs a pairing start operation using an operation unit (not shown) provided in the welding power supply device 1, an instruction signal based on the pairing start operation is input to the control unit 13 and is input to the control unit 13. Based on that, it may be started.

When the identification information transmission process is started, the control unit 13 first acquires the cumulative power supply time Tt stored in the storage unit 19 (S41). Subsequently, the control unit 13 acquires the correlation between the cumulative power supply time Tt stored in the storage unit 19 and the high level period of the transmission signal. Then, the control unit 13 specifies the high level period of the transmission signal from the acquired cumulative power supply time Tt and the correlation (S43).

When the control unit 13 specifies the high level period of the transmission signal in step S43, the control unit 13 acquires identification information from the storage unit 19 (S44) and generates a transmission signal based on the acquired identification information (S45). At this time, the control unit 13 generates a transmission signal having a low-level period whose length has changed based on the bit data of the acquired identification information and a high-level period specified in step S43. The control unit 13 inputs the transmission signal generated in step S45 to the switching unit 16, and the switching unit 16 switches the switch 15 based on the input transmission signal (S46). As a result, the welding power supply device 1 transmits the identification information to the wire feeding device 2 by switching the switch 15, and the identification information transmission process is completed.

FIG. 11 is a time chart showing waveforms of various transmission signals generated by the welding power supply device 1 executing the identification information transmission process shown in FIG. Note that FIG. 11 shows a transmission signal generated based on an example of the above correlation. As shown in FIGS. 11A to 11E, the high level period of the generated transmission signal is shortened each time the cumulative power supply time Tt increases by a predetermined time (1000 hours in FIG. 11). I understand. Further, since the low level period of the transmission signal is set based on the identification information, the low level period is the same length in all the waveforms shown in FIGS. 11A to 11E.

The welding power supply device 1 generates the transmission signal shown in FIG. 11 by performing the identification information transmission process (see FIG. 10), and switches the switch 15 based on the generated transmission signal to cause the wire feeding device 2. Send the identification information of. Then, the wire feeding device 2 receives the identification information transmitted from the welding power supply device 1 by performing the identification information receiving process (see FIG. 9) according to the first embodiment, and stores the received identification information. By setting it in the unit, pairing processing is performed.

According to the present embodiment, as in the first embodiment, the switch 15 is switched even before the pairing is established between the communication unit 14 of the welding power supply device 1 and the communication unit 23 of the wire feeding device 2. Information can be transmitted from the welding power supply device 1 to the wire feeding device 2 by the comparison between the welding power supply device 1 and the voltage comparison unit 27. Further, since the welding power supply device 1 can transmit the identification information of the welding power supply device 1 to the wire feeding device 2 without using the communication by the communication unit 14 and the communication unit 23, the pairing process fails. Can be suppressed.

Further, according to the present embodiment, the control unit 13 measures the cumulative power supply time Tt and stores it in the storage unit 19, and the control unit 13 stores it in the storage unit 19 before transmitting the identification information. Acquires the calculated power supply cumulative time Tt and the correlation between the power supply cumulative time Tt and the high level period of the transmission signal stored in the storage unit 19, and corresponds to the power supply cumulative time Tt at that time. Changed to specify the high level period of the transmitted signal. Then, the control unit 13 is set to generate a transmission signal using the specified high level period. Thereby, the period in which the switch 15 is in the off state, that is, the period in which the output voltage of the power transmission power supply unit 12 is not applied to the power reception power supply unit 21 can be adjusted based on the cumulative power supply time Tt. Therefore, it is possible to prevent the voltage of the power receiving power supply unit 21 from dropping too much due to the deterioration of the capacitor 17, and the operation of the wire feeding device 2 (control unit 22, voltage comparison unit 27, etc.) becomes unstable or stops operating. Can be suppressed. From the above, the wire feeding device 2 is appropriate by adjusting (shortening) the period during which the switch 15 is in the off state in consideration of the influence of the deterioration of the capacitor 17 based on the cumulative power supply time Tt. Identification information can be received. Therefore, in the welding system A1, the identification information can be appropriately transmitted from the welding power supply device 1 to the wire feeding device 2.

In the second embodiment, the case where the switch 15 is in the off state stepwise, that is, the high level period of the transmission signal is shortened based on the cumulative power supply time Tt has been described, but the present invention is not limited to this. The cumulative power supply time Tt may be compared with a predetermined value, and switching between a short high level period and a long high level period may be made based on whether the cumulative power supply time Tt is larger or smaller than the predetermined value.

In the first embodiment and the second embodiment, in order to stabilize the output power of the power transmission power supply unit 12 of the welding power supply device 1, the output terminals of the power transmission power supply unit 12 are connected in parallel. The influence of deterioration of the capacitor 17 is taken into consideration, but the present invention is not limited to this. For example, it may be a capacitor built in the power transmission power supply unit 12. Further, it may be a capacitor built in the DC / DC converter circuit 122 of the power transmission power supply unit 12. In these cases, the switching unit 16 may be arranged in the power transmission power supply unit 12 or the DC / DC converter circuit 122. Further, it may be a capacitor provided in the wire feeding device 2. The capacitor in this case is provided to stabilize the input power to the power receiving power supply unit 21.

In the first embodiment and the second embodiment, the power supply status from the power transmission power supply unit 12 to the power reception power supply unit 21 (detection voltage V1 in the first embodiment, power supply in the second embodiment). Based on the cumulative time Tt), the case where the high level period of the transmission signal, that is, the period during which the switch 15 is off is adjusted in consideration of the influence of the deterioration of the capacitor 17, has been described as an example, but the present invention is not limited to this. .. It is known that the capacitance of the capacitor 17 changes not only with deterioration but also with the operating temperature. Therefore, the period during which the switch 15 is in the off state may be adjusted in consideration of not only the deterioration of the capacitor 17 but also the influence of the operating temperature of the capacitor 17. Specifically, a temperature sensor for measuring the ambient temperature of the condenser 17 or a temperature sensor for measuring the temperature of the condenser 17 itself is provided in the welding power supply device 1, and the detection temperature of the temperature sensor is input to the control unit 13. Based on the input detection temperature, the control unit 13 sets the period during which the switch 15 is off from the correlation between the detection temperature and the period during which the switch 15 is in the off state (high level period of the transmission signal). It should be. According to this configuration, the period during which the switch 15 is in the off state can be adjusted based on the operating temperature of the capacitor 17. As a result, it is possible to prevent the voltage of the power receiving power supply unit 21 from dropping below a level at which the control unit 22 and the voltage comparison unit 27 can be normally driven, and the wire feeding device 2 appropriately provides identification information. It can be restored.

12-14 show other embodiments of the present invention. In these figures, the same or similar elements as those in the first embodiment are designated by the same reference numerals, and the description thereof will be omitted.

FIG. 12 is a diagram showing a configuration of a welding system A3 according to a third embodiment of the present invention. In FIG. 12, the description of the welding power supply device 1 is omitted.

The welding system A2 shown in FIG. 6 includes a current sensor 26'and a current comparison unit 27'instead of the voltage sensor 26 and the voltage comparison unit 27, and welds according to the first embodiment and the second embodiment. Different from systems A1 and A2.

The current sensor 26'detects the current flowing through the power transmission line 51 or the power transmission line 52. The current sensor 26'outputs the detected current to the current comparison unit 27'. The current comparison unit 27'compares the detection current I input from the current sensor 26' with a predetermined threshold value I _0, and detects whether or not the current flowing through the power transmission lines 51 and 52 is reduced. is there. The threshold value I ₀ is a current value set for determining whether or not the current is decreasing. When the switch 15 is on, the power transmission line 52 is in a conductive state, and a current flows through the power transmission lines 51 and 52. On the other hand, when the switch 15 is in the off state, the current flowing through the power transmission lines 51 and 52 gradually decreases due to the action (discharge) of the capacitor 17 as in the voltage of the first embodiment. The current comparison unit 27'outputs the comparison result to the control unit 22 as a current drop detection signal. When the detected current I is less than the threshold value I ₀ , the current comparison unit 27'determines that the current has decreased, and sets the current decrease detection signal to a high level. On the other hand, when the detection current I is equal to or higher than the threshold value I ₀ , it is determined that the current has not decreased, and the current decrease detection signal is set to a low level. The current drop detection signal has a waveform (similar waveform) corresponding to the transmission signal output by the control unit 13 to the switching unit 16. The current sensor 26'and the current comparison unit 27'correspond to the "identification unit" of the present invention.

According to the third embodiment, the welding power supply device 1 detects a current drop in the transmission signal even before the pairing is established between the communication unit 14 of the welding power supply device 1 and the communication unit 23 of the wire feeding device 2. As a signal, it can be transmitted to the wire feeding device 2. Therefore, the same effect as that of the first embodiment and the second embodiment can be obtained in the third embodiment.

The wire feeding device 2 may be able to identify whether or not a voltage is applied to the power receiving power supply unit 21. Therefore, the wire feeding device 2 includes, for example, a power sensor instead of the voltage sensor 26 (current sensor 26'), and identifies whether or not the power supplied to the power receiving power supply unit 21 is reduced. You may do so.

FIG. 13 is a diagram showing the configuration of the welding system A4 according to the fourth embodiment. In FIG. 13, the description of the wire feeding device 2 is omitted.

The welding system A4 shown in FIG. 13 does not include the switch 15 and the switching unit 16, and the control unit 13 switches the output voltage of the power transmission power supply unit 12, and the welding systems A1 to the first to third embodiments. Different from A3.

The control unit 13 switches the output of the DC / DC converter circuit 122 of the power transmission power supply unit 12 according to the transmission signal. Specifically, the control unit 13 controls so that the output of the DC / DC converter circuit 122 becomes the first level voltage V _H while the transmission signal is at the low level, and while the transmission signal is at the high level. , The output of the DC / DC converter circuit 122 is controlled to have a voltage _VL of the second level lower than that of the first level. That is, in the welding power supply device 1 according to the fourth embodiment, instead of shutting off the power transmission line 52 by the switch 15, the output voltage of the power transmission power supply unit 12 is set to the first level voltage V _H and the second level. It is switched by the voltage _VL . At this time, by setting the first level voltage V _H to a predetermined voltage value (for example, 48 V) and setting the second level voltage V _L to 0 V, the switch 15 functions in the same manner as the switch 15 shown in the first embodiment. , The state in which the voltage is applied from the power transmission power supply unit 12 to the power reception power supply unit 21 is switched between the state in which the voltage is not applied. In the present embodiment, the DC / DC converter circuit 122 corresponds to the "switching unit" of the present invention.

Also in the fourth embodiment, the same effect as that of the first embodiment can be obtained. Further, the welding power supply device 1 according to the fourth embodiment does not include the switch 15 and the switching unit 16. Therefore, it can be used as the welding power supply device 1 according to the fourth embodiment only by changing the software without changing the hardware of the conventional welding power supply device.

In the first to fourth embodiments, the case where the welding power supply device 1 communicates with the wire feeding device 2 has been described, but the present invention is not limited to this. The present invention can also be applied when the welding power supply device 1 communicates with other peripheral devices. In the following, a case where the remote controller 9 for remotely controlling the welding power supply device 1 and the welding power supply device 1 communicate with each other will be described below as a fifth embodiment.

FIG. 14 is a diagram showing the overall configuration of the welding system A5 according to the fifth embodiment. In FIG. 14, the description of the wire feeding device 2, the gas cylinder 6, and the gas pipe 7 is omitted.

The welding system A5 shown in FIG. 14 includes a remote controller 9. The remote controller 9 remotely controls the welding power supply device 1, and includes a power receiving power supply unit 21, a control unit 22, a communication unit 23, a voltage sensor 26, and a voltage comparison unit 27. The remote controller 9 is supplied with electric power for driving from the welding power supply device 1. The power receiving power supply unit 21 of the remote controller 9 and the power transmission power supply unit 12 of the welding power supply device 1 are connected by power transmission lines 51 and 52. The electric power output from the power transmission power supply unit 12 is supplied to the power reception power supply unit 21 by the power transmission lines 51 and 52. Further, the welding power supply device 1 and the remote controller 9 communicate by superimposing signals between the power transmission lines 51 and 52. The power receiving power supply unit 21, the control unit 22, the communication unit 23, the voltage sensor 26, and the voltage comparing unit 27 are the power receiving power supply unit 21, the control unit 22, and the power receiving unit 22 of the wire feeding device 2 according to the first embodiment, respectively. It is the same as the communication unit 23, the voltage sensor 26, and the voltage comparison unit 27. The remote controller 9 actually includes an operation unit and the like, but the description is omitted in FIG. The remote controller 9 corresponds to the "second communication device" of the present invention.

Also in the fifth embodiment, the same effect as that of the first embodiment can be obtained. It should be noted that peripheral devices other than the remote control 9 (for example, a welding torch 3, a cooling water circulation device that controls the cooling water circulated in the welding torch 3, a device that controls the gas supply of the gas cylinder 6, etc.) communicate with the welding power supply device 1. Similarly, the present invention can be applied to the case. In these cases, each peripheral device corresponds to the "second communication device" of the present invention.

In the first to fifth embodiments and various modifications, the case where the present invention is applied to a welding system has been described, but the present invention is not limited thereto. The present invention can also be applied to other communication systems.

The communication system and welding system according to the present invention are not limited to the above-described embodiments. The specific configuration of each part of the communication system and the welding system according to the present invention can be freely redesigned.

A1 to A5 welding system (communication system)
1 Welding power supply device (first communication device)
11 Power supply unit for welding 111 Rectifier circuit 112 Inverter circuit 113 Transformer 114 Rectifier circuit 12 Power supply unit for power transmission 121 Rectifier circuit 122 DC / DC converter circuit (switching unit)
13 Control unit (transmission control unit, detection unit)
14 Communication unit 15 Switch (switching unit)
16 Switching unit 17 Capacitor 18 Voltage sensor (detection unit)
19 Storage unit 1a Connection bracket 2 Wire feeder (second communication device, welding peripheral device)
21 Power supply unit for power reception 22 Control unit (reception control unit)
23 Communication unit 24 Feed motor 25 Gas solenoid valve 26 Voltage sensor (identification unit)
26'Current sensor (identification unit)
27 Voltage comparison unit (identification unit)
27'Current comparison unit (identification unit)
2a Connection bracket 3 Welding torch (second communication device, welding peripheral device)
31 Torch switch 41,42 Power cable 51,52 Power transmission line 6 Gas cylinder 7 Gas piping 9 Remote control (second communication device, welding peripheral device)
W Work piece

Claims (10)

A second communication device that communicates between the first communication device and the first communication device, and a power transmission line for supplying power from the first communication device to the second communication device. It is a communication system equipped with
The first communication device is
A power transmission power supply unit for supplying electric power to the second communication device,
A switching unit that switches between a state in which a first level voltage is applied to the power transmission line and a state in which a second level voltage lower than the first level is applied.
A transmission control unit that transmits the information by acquiring the information and controlling switching by the switching unit based on the acquired information.
Is equipped with
The second communication device is
The power receiving power supply unit to which power is supplied from the power transmission power supply unit,
An identification unit that identifies the voltage applied to the power receiving power supply unit via the power transmission line, and
A reception control unit that restores the information based on the identification result by the identification unit,
Is equipped with
The transmission control unit, the Ri may der to adjust the second level voltage second level application period is a period of the state that applies the from the power transmission source of power to the power receiving power supply unit The second level application period is adjusted based on the supply status.
A communication system characterized by that. The first communication device is
A detection unit for detecting the output voltage applied to the power receiving power supply unit is further provided.
When the output voltage drops below the threshold value, the transmission control unit switches from the state of applying the second level voltage to the state of applying the first level voltage, whereby the second level application period. To adjust,
The communication system according to claim 1 . The first communication device is
Further, a detection unit for detecting the cumulative time of the time when power is supplied from the power transmission power supply unit to the power reception power supply unit is provided.
The transmission control unit adjusts the second level application period based on the cumulative time.
The communication system according to claim 1 . Based on the information, the transmission control unit changes the first level application period, which is the period in which the first level voltage is applied.
The reception control unit restores the information according to the length of the period identified as the state in which the first level voltage is applied.
The communication system according to any one of claims 1 to 3 . The information is identification information for pairing,
The communication system according to claim 4 . The identification unit
A voltage sensor that detects the voltage applied to the power receiving power supply unit and
A voltage comparison unit that compares the detected voltage detected by the voltage sensor with a predetermined value,
Is equipped with
Based on whether or not the detected voltage is equal to or lower than the predetermined value, either the state in which the second level voltage is applied or the state in which the first level voltage is applied by the switching unit. Identifies whether the state has been switched to,
The communication system according to any one of claims 1 to 5 . The identification unit
A current sensor that detects the current flowing through the power transmission line and
A current comparison unit that compares the detected current detected by the current sensor with a predetermined value,
Is equipped with
Based on whether or not the detected current is equal to or less than the predetermined value, either the state in which the second level voltage is applied or the state in which the first level voltage is applied by the switching unit. Identifies whether the state has been switched to,
The communication system according to any one of claims 1 to 5 . The second level voltage is 0V.
The switching unit switches between a state in which a voltage is applied and a state in which no voltage is applied.
The identification unit distinguishes between a state in which the voltage is applied and a state in which the voltage is not applied.
The communication system according to any one of claims 1 to 7 . The switching unit is a switch that switches between a conduction state and a cutoff state of the power transmission line .
The communication system according to claim 8 . A welding system including the communication system according to any one of claims 1 to 9 .
A welding power supply device having the first communication device and
A welding peripheral device having the second communication device and
Is equipped with
Welding system characterized by that.