Additional Circuit for Process Supply Lines of a Welding or Cutting Torch and Hose Pack Having an Additional Circuit

Abstract

A supplementary circuit for process supply lines of a welding torch or cutting torch has at least one connection device to a welding current source arranged on it, wherein electrical energy and other media are conveyed to the welding torch or cutting torch via the connection device and via a process supply line that is preferably held in a hose pack of the welding torch or cutting torch. Electrical energy for operating a peripheral device, such as a sensor, a drive unit or a controller for the drive unit, is branched or tapped off from at least one electrical process supply line without significantly affecting the electric arc process. The supplementary circuit provided for branching or tapping off the electrical energy is coupled in parallel onto the welding current circuit. This coupling is based on direct ohmic contact or on a galvanic coupling.

Claims

1. A supplementary circuit (10) for supplying electric energy to a welding torch or cutting torch (21) as well as to a peripheral device (4), comprising: at least one connection device (1) to a welding current source (2); at least one process supply line (3) that is held in a hose pack (6) of the welding torch or cutting torch (21), wherein electric energy is conveyed to the welding torch or cutting torch via the connection device (1) and via the process supply line (3); wherein electric energy for operating the peripheral device (4) is branched off from the at least one electric process supply line (3); and wherein the supplementary circuit (10) provided for branching off electric energy is coupled electrically in parallel onto the welding current circuit.

2. The supplementary circuit (10) according to claim 1, further comprising a rectifier (7) to convert alternating voltage into direct voltage.

3. The supplementary circuit (10) according to claim 1, further comprising a reverse-polarity protector (23).

4. The supplementary circuit (10) according to claim 3, wherein the reverse-polarity protector (23) has at least one transistor (25), at least one Zener diode (26), and at least one electric resistor (27).

5. The supplementary circuit (10) according to claim 3, further comprising an optical display device (28) and/or an acoustic signal means for indicating incorrect reverse polarity.

6. The supplementary circuit (10) according to claim 1, further comprising a switching DC-to-DC converter (8) or a step-down converter, wherein output voltage of the converter (8) can deviate from the input voltage of the converter (8).

7. The supplementary circuit (10) according to claim 6, further comprising a rectifier (7) to convert alternating voltage into direct voltage, wherein the input voltage for the DC-to-DC converter (8) is the direct voltage that is output by the rectifier (7).

8. The supplementary circuit (10) according to claim 1, further comprising at least one overcurrent protector (11), (12) for cutting out electric current if a predetermined current strength has been exceeded over a prescribed time such as may be experienced in case of electric short circuits or overloads.

9. The supplementary circuit (10) according to claim 1, further comprising an inductor (9) for damping voltage peaks of the welding current source.

10. The supplementary circuit (10) according to claim 1, further comprising at least one electric energy storage means (13), (14), (15), (16) configured to store electric charge in an electric field or else in an accumulator or a battery so that electric energy can be fed to the DC-to-DC converter (8) and/or voltage of the supplementary circuit (10) can be stabilized.

11. The supplementary circuit (10) according to claim 6, further comprising a suppressor diode (17) configured to protect the supplementary circuit (10) or the DC-to-DC converter of the supplementary circuit (10) against undesired voltage peaks.

12. The supplementary circuit (10) according to claim 1, further comprising an additional energy buffer or a super capacitor (18) for buffering electric energy.

13. The supplementary circuit (10) according to claim 6, further comprising at least one overcurrent protector (11), (12) for cutting out the electric current if a predetermined current strength has been exceeded over a prescribed time such as may be experienced in case of electric short circuits or overloads, wherein the overcurrent protector (11), (12) and the inductor (9) are installed upstream from the DC-to-DC converter (8).

14. The supplementary circuit (10) according to claim 7, further comprising a suppressor diode (17) configured to protect the supplementary circuit (10) or the DC-to-DC converter (8) of the supplementary circuit (10) against undesired voltage peaks, and further comprising at least one electric energy storage means (13), (14), wherein the rectifier (7) as well as the at least one energy storage means (13), (14) and the suppressor diode (17) are installed upstream from the DC-to-DC converter (8).

15. The supplementary circuit (10) according to claim 10, further comprising a switching DC-to-DC converter (8), wherein the at least one energy storage means (15), (16) is installed downstream from the DC-to-DC converter (8).

16. The supplementary circuit (10) according to claim 1, further comprising a connector housing (22) into which the supplementary circuit (10) is integrated, wherein the connector housing (22) is coupled to the welding current source (2).

17. The supplementary circuit (10) according to claim 1, further comprising an adapter (20) that is connected to the at least one electric supply line (3).

18. A hose pack (6) having a supplementary circuit (10) according to claim 1.

19. A hose pack having a supplementary circuit (10) according to claim 16.

20. The supplementary circuit (10) according to claim 1, wherein the peripheral device (4) is selected from the group consisting of: a sensor (5), a drive unit (19) and a control for a drive unit (19).

Description

DESCRIPTION OF THE DRAWINGS

[0069] In this context, the following is shown, at times schematically:

[0070] FIG. 1 a supplementary circuit of a welding or cutting torch, for branching off electric energy, having a hose pack and a welding current source, in a first embodiment,

[0071] FIG. 2 the supplementary circuit as shown in FIG. 1, in a second embodiment,

[0072] FIG. 3 a welding torch with a sensor,

[0073] FIG. 4 a wiring diagram of the supplementary circuit,

[0074] FIG. 5 the wiring diagram as shown in FIG. 4, with a storage means for electric energy,

[0075] FIG. 6 a wiring diagram for another embodiment,

[0076] FIG. 7 a wiring diagram as shown in FIG. 6, with a storage means for electric energy,

[0077] FIG. 8 a wiring diagram for another embodiment of the supplementary circuit, with optical reverse-polarity display, and

[0078] FIG. 9 a wiring diagram as shown in FIG. 8, with a storage means for electric energy.

[0079] For the sake of clarity, identical components or those having the same effect are provided with the same reference numerals in the figures of the drawing shown below, making reference to an embodiment.

DETAILED DESCRIPTION

[0080] FIG. 1 shows a schematic view of a supplementary circuit 10 of a welding torch or cutting torch 21, having at least one connection device 1 to a welding current source 2 arranged on it. The connection device 1 can especially have two poles, i.e., plus and minus, whereby their polarity sign can change in case of an alternating voltage (AC). Electric energy and other media can be conveyed to the welding or cutting torch 21 via the connection device 1 and via process supply lines 3 in a hose pack 6.

[0081] The connection device 1 provided on the hose pack 6 serves to establish electrical and mechanical contact of the hose pack 6 with the welding current source 2.

[0082] The supply lines 3 that convey electric energy and other media such as shielding gas or welding wire to the welding or cutting torch 21 are arranged in the hose pack 6. After the hose pack 6 has been electrically connected to the welding current source 2, an electric current circuit—the welding current circuit—is closed. Electric energy to operate a peripheral device 4 is branched off from this current circuit.

[0083] Electric energy to operate the peripheral device 4 is branched off from at least one electric process supply line 3. For purposes of branching off the electric energy, the supplementary circuit 10 in the present embodiment is electrically coupled in parallel to the welding current source 2 or to the welding current circuit, as can be seen in FIGS. 1 and 2. The term welding current circuit refers to the current circuit that is formed between the welding torch with the arc, the hose pack and the ground line of the welding device.

[0084] In particular, this is an electric current circuit connected in parallel that can process a highly variable input signal in terms of polarity, voltage and dynamics. Current and/or voltage frequencies within the range of direct current (in both directions), pulse-controlled direct current up to 200 kHz of pulsed frequency, or else alternating current up to 200 Hz can all be processed.

[0085] On the one hand, the supplementary circuit 10 for branching off electric energy can be provided on the hose pack 6; in particular, the supplementary circuit 10 can be integrated into an expanded connector housing 22 on the side associated with the machine, that is to say, on the side associated with the welding current source. This is advantageous because this housing 22 is already necessary anyway for the delivery of media, and also because the energy is supplied via the peripheral device 4. FIG. 1 illustrates this embodiment. In this context, the supplementary circuit 10 is arranged at the end of the hose pack 6 that is situated across from the torch 21.

[0086] On the other hand, the supplementary circuit 10 can also be connected outside of the hose pack 6 via process supply lines, as shown in FIG. 2. In this context, the supplementary circuit 10 is integrated into an adapter 20. This is preferably implemented in the electric ground line since, in contrast to the hose pack line, only electric current flows in it, but no other media such as gas, wire or water. Unlike circuits from the state of the art, the supplementary circuit 10 according to the invention is not based on an inductive operating principle, but rather on direct ohmic contact or on galvanic coupling.

[0087] The peripheral devices 4 can be, for example, sensors 5, especially temperature sensors or gyro sensors, or else communication units such as Bluetooth transmitters or Bluetooth receivers, WLAN devices or a wire drive and the like. FIG. 3 shows a welding torch 21 with a sensor 5.

[0088] Moreover, it is also possible to supply fans, for instance, for fume extractors in welding applications.

[0089] However, it is likewise conceivable to also operate drive units 19 with this supply modality since the output of the autonomous energy supply is sufficient for this as well. FIGS. 1 and 2 depict such a drive 19.

[0090] Such peripheral devices 4 make high demands in terms of the speed of the circuit; in particular, a response time of less than 50 ms should be ensured. The supplementary circuit 10 according to the invention that serves to branch-off electric energy ensures this.

[0091] As a rule, the open-circuit voltage of the welding current source 2 is enough to provide a sufficiently high output for the peripheral device 4. The open-circuit voltage is usually 113 V or 141 V.

[0092] The depictions of the wiring diagrams of the electric circuit according to FIGS. 4 and 5 show that the supplementary circuit 10 has a rectifier 7, especially a bridge rectifier, to convert alternating voltage into direct voltage. Likewise provided is a switching DC-to-DC converter 8, especially a step-down converter, wherein the output voltage of the converter 8 is smaller than the value of the input voltage of the converter 8. The step-down converter is also referred to as a buck converter.

[0093] Thanks to this step-down converter, the voltage and current values common in welding devices can all be processed. These values are, for instance, 20 V/100 A to 30 V/300 A and 113 V or 141 V during no-load operation.

[0094] As an alternative, a DC-to-DC converter with a wide-range input and constant output voltage can also be employed.

[0095] In the present embodiment, the input voltage for the DC-to-DC converter 8 is the direct voltage that is output by the rectifier 7, so that the supplementary circuit 10 according to the invention allows direct (DC) as well as alternating (AC) voltage operation.

[0096] The supplementary circuit 10 has at least one overcurrent protector 11, 12 for cutting out the electric current if a stipulated current strength has been exceeded over a prescribed time. These overcurrent protectors 11, 12 respond especially to electric short circuits or overloads of the supplementary circuit 10.

[0097] As can likewise be seen in FIGS. 4 and 5, the supplementary circuit 10 has an inductor 9 for damping voltage peaks of the welding current source and at least one electric energy storage means 13, 14, 15, 16 is provided for feeding electric energy to the DC-to-DC converter 8 and/or for stabilizing the voltage of the supplementary circuit 10.

[0098] Moreover, the supplementary circuit 10 has a suppressor diode 17 to protect the DC-to-DC converter 8 against undesired voltage peaks.

[0099] As can likewise be seen in FIGS. 4 and 5, the overcurrent protectors 11, 12 and the inductor 9 are installed upstream from the DC-to-DC converter 8.

[0100] Moreover, the rectifier 7 as well as the at least one energy storage means 13, 14 and the suppressor diode 17 are installed upstream from the DC-to-DC converter 8.

[0101] At least one energy storage means 15, 16 is installed downstream from the DC-to-DC converter 8.

[0102] The embodiments shown in FIG. 4 and FIG. 5 differ in terms of an additional energy buffer 18 in the variant shown in FIG. 5. In particular, a super capacitor 18 can be provided for buffering electric energy.

[0103] The input signal is filtered as soon as the supplementary circuit 10 has been connected to the process supply lines 3. This takes place irrespectively of whether the input voltage into the supplementary circuit 10 is a direct voltage or an alternating voltage. Then, in any case, a direct voltage is present on the side associated with the output. Pulse-controlled input signals are smoothed and high voltages of up to 160 V can be processed.

[0104] FIGS. 6 and 7 depict an alternative embodiment of the supplementary circuit 10. In this alternative, a reverse-polarity protector 23 is provided instead of the rectifier 7 in the circuit 10. In the embodiment shown here, reverse-polarity protection is implemented by means of a transistor 25, a Zener diode 26, and an electric resistor 27. In this manner, with the right connection and thus a correct polarity, the circuit delivers the requisite electric energy. As a rule, the polarity on the side associated with the torch is positive. Accordingly, if the user nevertheless reverses the polarity, the wrong connection will have the effect that no electric energy is released to the poles. It can be provided for the user to be informed about a fault.

[0105] In the embodiment shown in FIGS. 8 and 9, such a reverse-polarity display is implemented by means of an optical display device 28. Here, a light element 30 comprising a resistor 29 and a diode 31 is integrated into the supplementary circuit 10. As an alternative or in addition within the scope of the invention, it is conceivable for erroneous reverse polarity to be indicated through the modality of an acoustic signal means.

[0106] The embodiments of the supplementary circuit 10 as shown in FIG. 7 and FIG. 9 differ from the circuit 10 as shown in FIG. 6 and FIG. 8 in that an energy buffer 18 is additionally provided for the variant shown in FIG. 7 and FIG. 9. As already elaborated upon, especially a super capacitor 18 can be provided for buffering electric energy.

LIST OF REFERENCE NUMERALS

[0107] 1 connection device [0108] 2 welding current source [0109] 3 process supply line [0110] 4 peripheral device [0111] 5 sensor [0112] 6 hose pack [0113] 7 rectifier [0114] 8 DC-to-DC converter [0115] 9 inductor [0116] 10 supplementary circuit [0117] 11 overcurrent protector [0118] 12 overcurrent protector [0119] 13 energy storage means [0120] 14 energy storage means [0121] 15 energy storage means [0122] 16 energy storage means [0123] 17 suppressor diode [0124] 18 super capacitor [0125] 19 drive unit [0126] 20 adapter [0127] 21 welding or cutting torch [0128] 22 connector housing [0129] 23 reverse-polarity protector [0130] 24 ground line [0131] 25 transistor [0132] 26 Zener diode [0133] 27 resistor [0134] 28 optical display device [0135] 29 resistor [0136] 30 light element [0137] 31 diode