JPH0570767U - Remote control arc welder - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention relates to an improvement of a remote control arc welding machine in which an output adjusting unit and an output control unit are provided at positions separated from each other. In a remote-controlled arc welding machine in which an output control section and an output adjustment section for supplying an output setting signal are provided at positions separated from each other, a constant current source and an input current signal are fed to the output control section. A current / voltage conversion circuit for converting into a voltage signal corresponding to a value, and the output adjustment unit is constituted by a variable resistor for shunting the output of the constant current source from the output control unit, An output terminal of the current source and an input terminal of the output adjustment unit, and an output terminal of the output adjustment unit and an input terminal of the current / voltage conversion circuit of the output control unit are connected by cables. Remote control arc welder.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a remote control arc welding machine in which an output adjusting unit and an output control unit are provided at positions separated from each other.

[0002]

[Prior Art]

 Some arc welders have an integrated output control unit such as a welding power supply unit or wire feed control unit, and an output adjustment unit such as a voltage setting unit or a current setting unit. Workability improves if they are separated. When the above parts are installed separately, it is necessary to connect these parts with a cable to send and receive control signals. For this control signal, for example, in a consumable electrode type arc welding machine that uses a constant voltage power source, an output voltage setting signal is output from the output adjustment unit to the welding power source unit, and a wire feed control unit is output from the output adjustment unit. Requires a wire feed speed setting value, that is, a welding current setting signal. Normally, voltage signals are used for these signals, but if the distance between the output control section and the output control section reaches several tens of meters, the signal voltage will be greatly attenuated, and irregularly fluctuating welding current and other equipment will be used. The external noise generated from is easily mixed, and malfunctions often occur.

As a solution to these drawbacks, a voltage / current conversion circuit that converts a voltage signal into a current signal is provided in the output adjustment unit, and a current / voltage conversion circuit that returns the current signal to a voltage signal is provided in the output control unit. The device provided is proposed. (For example, JP-A-61-56774)

FIG. 1 is a connection diagram showing an example of the conventional device. In the figure, 1 is an output control unit and 2 is an output adjustment unit. The output control unit 1 receives power from the AC power supply AC, converts the input power according to the command signal from the output adjustment unit 1, and outputs the input power to the welding unit W. The output control unit 1 includes a power conversion unit 101 including a rectifier circuit and a switching circuit, and a current / voltage conversion circuit 102 that converts a current signal from the output adjustment unit 2 into a voltage signal. The output adjustment unit 2 includes a variable resistor 201 for setting an output, a DC power source 202, and a voltage / current conversion circuit 203 that converts the output voltage of the variable resistor 201 into a current signal corresponding thereto. The output control unit 1 and the output adjustment unit 2 are connected to each other by cables 3a and 3b.

[0005]

[Problems to be solved by the device]

 However, in the above-mentioned conventional device, since the output adjustment signal is sent as a current signal, the signal level is less attenuated even if the signal transmission distance becomes long, and it is hardly affected by external noise. However, not only is it necessary to provide a voltage / current conversion circuit in the output adjustment section, but also the power supply circuit is required, so the output adjustment section becomes large, and the output adjustment section must be held by the operator. It was inconvenient to carry.

[0006]

[Means for solving problems]

 In the present invention, in order to solve the above-mentioned problems of the conventional device, a constant current source is provided in the output control circuit, the output current of this constant current source is guided to the output adjustment unit, and the output current is divided by the variable resistor. A current signal corresponding to the set value is transmitted, this current signal is transmitted to the output control unit, and the current / voltage conversion circuit uses it as a voltage signal for the output control command.

[0007]

【Example】

 FIG. 2 shows an embodiment of the present invention. In the figure, the output controller 1 is provided with a constant current source 103. This constant current source can be easily obtained, for example, by extracting it from a DC power source through a transistor connected to an emitter follower. The output adjusting unit 2 is provided with only the variable resistor 201, and the slider 201a of the variable resistor 201 is connected to the output of the constant current source 103. Further, one terminal 201b of the variable resistor 201 is connected to the input terminal of the current / voltage conversion circuit 102 of the output control unit 1, and the other terminal forms a circuit which returns to the constant current source 103 via the ground terminal. In the figure, when the output current of the constant current source 103 is Ic, the resistance value between the terminals 201a and 201b of the variable resistor 201 is ra, and the resistance value between the terminals 201a and 201c is rb, the terminal 201a The current Ia supplied to the shunt is shunted by the variable resistor 201, and the current of Ic · rb / (ra + rb) is input to the current / voltage conversion circuit 102 from the terminal 201b. Therefore, by adjusting the variable resistor 201, an arbitrary output adjustment signal can be supplied to the output control unit 1.

In the apparatus of FIG. 2, a fixed offset value can be given to the adjustment signal Ib by inserting a fixed resistor in series with the circuit on the terminal 201c side. In this case, it suffices to set the offset amount to be canceled inside the output control unit 1, and the noise removal effect can be further enhanced by providing the signal with an offset of a constant value.

FIG. 3 is a connection diagram showing another embodiment of the present invention. A variable resistor 201 and a fixed resistor 204 are provided in the output adjusting unit 2, and the variable resistor 201 is provided with a slider and a slider. The output current of the constant current source 103 is shunted by the resistance value of the variable resistor 201 and the resistance value of the fixed resistor 204. It should be noted that, in FIG. 3, even if the connection positions of the variable resistor 201 and the fixed resistor 204 are reversed, the same function is obtained only by reversing the relationship between the adjusting direction of the variable resistor and the changing direction of the output current. .

FIG. 4 shows the fixed resistor 204 in the embodiment of FIG. 3 which is moved to the inside of the output control unit 1. In this case, the cable connecting the output control unit 1 and the output adjustment unit 2 is connected. -It is possible to reduce the number of bull cores.

In each of the embodiments shown in FIGS. 2 to 4, the current / voltage conversion circuit 102 provided in the output control unit 1 has the resistance values of the variable resistor 201 and the fixed resistor 204 included in the output adjustment circuit. It is advantageous to use the one whose input resistance is sufficiently smaller than the above. For example, when an input signal is directly connected to the operational amplifier, an input resistance value of substantially zero can be realized by the virtual ground input of the operational amplifier. FIG. 5 is a connection diagram showing an example of a current / voltage conversion circuit using an operational amplifier, in which R is a resistor and OP1 is an operational amplifier. In the figure, assuming that the current supplied to the input terminal is Ia and the resistance value of the feedback resistor R of the operational amplifier OP1 is r, the output voltage Vo becomes Vo = −r · Ia.

[0012]

[Effect of the device]

 As described above, in the present invention, the constant current from the constant current source is shunted by the variable resistor provided in the output adjustment section, the shunted current signal is transmitted to the output control section, and the voltage is converted by the current / voltage conversion circuit. Since it is a signal, it is less susceptible to noise during signal transmission, and the output adjustment unit can be configured with only a variable resistor or a variable resistor and a fixed resistor. It is small and lightweight, and it is not bulky when placed in the hands of workers and is convenient to carry.

[Brief description of drawings]

FIG. 1 is a connection diagram showing an example of a conventional device.

FIG. 2 is a connection diagram showing an embodiment of the present invention.

FIG. 3 is a connection diagram showing another embodiment of the present invention.

FIG. 4 is a connection diagram showing still another embodiment of the present invention.

FIG. 5 is a connection diagram showing an example of a current / voltage conversion circuit used in the device of the present invention.

[Explanation of symbols]

 1 Output Control Unit 2 Output Adjustment Unit 101 Power Conversion Unit 102 Current / Voltage Conversion Circuit 103 Constant Current Source 104 Fixed Resistor 201 Variable Resistor 204 Fixed Resistor W Welding Load OP1 Operational Amplifier R Resistor

Claims (2)

[Scope of utility model registration request] 1. A remote control arc welding machine in which an output control section and an output adjustment section for supplying an output setting signal are provided at positions separated from each other, wherein a constant current source and an input current signal are provided in the output control section. Current to convert voltage to voltage signal corresponding to current value /
A voltage conversion circuit is provided, and the output adjustment unit is configured by a variable resistor that divides the output of the constant current source from the output control unit, and the output terminal of the constant current source of the output control unit and the output adjustment unit. A remote control type cable having a cable connected to the input terminal and a cable connected between the output terminal of the output adjustment section and the input terminal of the current / voltage conversion circuit of the output control section.
Qu welder. 2. A remote control arc welding machine in which an output control section and an output adjustment section for supplying an output setting signal are provided at positions separated from each other, wherein a constant current source and a constant current are provided in the output control section. A shunt resistor connected in parallel to the output terminal of the power source and a current / voltage conversion circuit for converting an input current signal into a voltage signal corresponding to a current value are provided, and the output adjustment unit is configured by a variable resistor, and Cables are provided between the output terminal of the constant current source of the output control unit and the variable resistor of the output adjustment unit, and between the variable resistor and the input terminal of the current / voltage conversion circuit of the output control unit. Remotely controlled arc welding machine connected by.