JP4006952B2 - Welding equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a welding apparatus for feeding a consumable electrode (hereinafter referred to as a wire).
[0002]
[Prior art]
The wire feed control unit of the conventional welding apparatus closes the switching element and then connects both ends of the motor coil via a short circuit or a resistor to quickly reduce the counter electromotive voltage generated in the motor unit and reduce the rotational energy of the motor unit. Decreasing and braking.
[0003]
This conventional configuration will be described with reference to FIG.
[0004]
FIG. 2 shows the configuration of a welding wire feeding unit of a conventional welding apparatus, wherein 101 is a motor driving power source, 102 is a switching unit, 103 is a wire feeding motor, 104 is a motor stopping switching unit, and 105 is a motor. A drive signal unit 106 is a first control unit, and 107 is a second control unit.
[0005]
The motor drive power supply 101 forms a circuit by connecting the motor drive power supply 101, the switching unit 102, and the wire feeding motor 103 in series.
[0006]
A motor stop switching unit 104 is connected to a connection point between the switching unit 102 and the wire feeding motor 103 and the other end of the wire feeding motor 103, that is, both ends of the wire feeding motor 103.
[0007]
The control signal of the second control unit 107 is connected to the input terminal of the switching control signal of the switching unit 102, and the input side of the second control unit 107 is connected to the output side of the motor drive signal unit 105. ing.
[0008]
The control signal of the first control unit 106 is connected to the input terminal of the opening / closing control signal of the motor stop switching unit 104 so that the input side of the first control unit 106 is connected to the output side of the motor drive signal unit 105. Connected to.
[0009]
In the operation, when the motor drive signal from the motor drive signal unit 105 is turned OFF, the second control unit 107 stops the output to the switching unit 102 and opens the switching unit 102.
[0010]
At this time, when the motor drive signal is turned off from the motor drive signal unit 105, the first control unit 106 outputs a signal for closing the motor stop switching unit 104, and generates a back electromotive voltage generated in the wire feeding motor 103. The speed was lowered quickly, the rotational energy of the wire feeding motor 103 was reduced, and braking was applied.
[0011]
When driving a motor having a large inertia, the difference in braking time between low and high rotations is about several tens to several hundreds ms.
[0012]
For this reason, since the wire is pushed out by the inertia of the motor at the end of welding, a burnback process is performed to burn up the excessive wire.
[0013]
[Problems to be solved by the invention]
However, there is a difference of about several tens to several hundreds of ms in the motor braking time at the time of low rotation and high rotation, and in the welding wire feeding portion of the conventional conventional welding apparatus, the burnback processing time at the end of welding It was necessary to adjust according to the rotation speed.
[0014]
At this time, if the burnback condition is not an appropriate value, the wire and the base material may be fused or the tip and the wire may be fused. In order to prevent this, fine adjustment is made depending on the welding conditions. Therefore, the adjustment is troublesome and difficult, which is a factor that complicates the work.
[0015]
The present invention solves the above problem, and even if the welding current setting condition is changed and the motor rotation speed is changed, the wire tip protrusion length at the end of welding can be made constant, and the next welding start It aims at providing the welding apparatus which can improve.
[0016]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a motor for feeding a wire serving as a consumable electrode to a welding location, a motor current detection unit for detecting the current of the motor, and a motor stop current setting unit for stopping the motor. a comparator for comparing a signal of the signal and motor stop current setter from the motor current detecting section, a motor stop switching unit to be opened or closed in response to the output of the comparison unit, to stop from the time of motor rotation command completion A controller for controlling the braking time to be substantially constant is provided.
[0017]
Further, in the above configuration, the motor stop current setting device sets the set current value according to the motor rotation speed.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0019]
FIG. 1 is a block diagram showing a configuration of a wire feeding unit of a consumable electrode arc welder in the present embodiment.
[0020]
1 is a motor drive power source, 2 is a switching unit, 3 is a wire feed motor, 4 is a motor stop switching unit, 5 is a motor drive signal unit, 6 is a first control unit, 7 is a second control unit, and 8 is The comparison unit, 9 is a motor stop current setting unit, and 10 is a motor current detection unit.
[0021]
The motor drive power source 1 forms a circuit by connecting the motor drive power source 1, the switching unit 2, and the wire feeding motor 3 in series.
[0022]
Further, a motor current detection unit 10 is connected between the switching unit 2 and the wire feeding motor 3, and a connection point between the motor current detection unit 10 and the switching unit 2 and the wire feeding motor 3. The motor stop switching unit 4 is connected to the end.
[0023]
The control signal of the second control unit 7 is connected to the input terminal of the switching control signal of the switching unit 2, and the input side of the second control unit 7 is connected to the output side of the motor drive signal unit 5. ing.
[0024]
The control signal of the first control unit 6 is connected to the input terminal of the opening / closing control signal of the motor stop switching unit 4, and the input side of the first control unit 6 is connected to the output side of the comparison unit 8. is doing.
[0025]
A motor stop current setting unit 9 is connected to one input side of the comparison unit 8, and a signal of the motor current detection unit 10 is connected to the other input side.
[0026]
In the operation, when the motor drive signal is turned off from the motor drive signal unit 5, the second control unit 7 stops the output to the switching unit 2 and opens the switching unit 2.
[0027]
Therefore, the motor current detection unit 10 detects that the power to the wire feeding motor 3 has been interrupted, and outputs a signal to the comparison unit 8.
[0028]
The comparison unit 8 inputs a motor stop current value determined in accordance with a preset burnback processing time from the motor stop current setting unit 9 and compares these values to the first control unit 6. Output a signal.
[0029]
The first control unit 6 outputs a signal for closing the motor stop switching unit 4 when a motor stop instruction is output from the comparison unit 8, and quickly reduces the back electromotive voltage generated in the wire feeding motor 3. Thus, the rotational energy of the wire feeding motor 3 is reduced and braking is applied.
[0030]
At this time, the current flowing through the wire feeding motor 3 is detected by the motor current detection unit 10, and this signal is continuously input to the comparison unit 8.
[0031]
The comparison unit 8 inputs a motor stop current value determined in accordance with a preset burnback processing time from the motor stop current setting unit 9 and compares these values to the first control unit 6. By outputting the signal, the wire feeding motor 3 can be stopped in a preset time.
[0032]
In this case, there is a case in which the time until the stop is extended as compared with the case where the motor stop switching unit 4 is always closed. However, by always stopping the wire feeding motor 3 for a fixed time, Processing can be performed under conditions.
[0033]
Therefore, the wire tip shape at the end of welding can be easily stabilized, and the next welding start property can be stabilized and improved.
[0034]
In addition, the motor stop current setting unit 9 can arbitrarily set the motor stop current according to the motor rotation speed, so that the motor braking time can be adjusted to be constant even when the motor rotation speed is different. Processing can be handled under the same conditions.
[0035]
【The invention's effect】
As described above, since the protruding length of the wire at the end can be controlled, when the rotation speed of the wire feeding motor changes according to the welding conditions, the motor braking time can be set to an arbitrary time or a fixed time. it can.
[0036]
Therefore, the shape of the wire tip can be stabilized without changing the burnback condition each time it is used.
[0037]
As a result, the following good arc start can be realized.
[Brief description of the drawings]
FIG. 1 is a block diagram showing a circuit configuration of a wire feeding section of a welding apparatus according to an embodiment of the present invention. FIG. 2 is a block diagram showing a circuit configuration of a wire feeding section in a conventional welding apparatus.
DESCRIPTION OF SYMBOLS 1 Motor drive power supply 2 Switching part 3 Wire feed motor 4 Motor stop switching part 5 Motor drive signal part 6 Control part 1
7 Control unit 2
8 Comparison unit 9 Motor stop current setting unit 10 Motor current detection unit

Claims (2)

The wire becomes the consumable electrode and the feeding Kyusuru motor to the welding position, a motor current detector for detecting a current of the motor, the motor stop current setting unit stopping the motor, signals the motor from the motor current detecting section A comparison unit that compares the signal of the stop current setting device, a motor stop switching unit that opens and closes according to the output of the comparison unit, and a control unit that controls the braking time from the end of the motor rotation command to the stop substantially constant Welding device provided.   The welding apparatus according to claim 1, wherein the motor stop current setting unit sets a set current value in accordance with the motor rotation speed.

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