JP2002172464A - Motor driving method and driving device for consumable electrode type welding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving device for a motor of a wire feeding part which detects an abnormal behavior of a rotary encorder part and breakage of each control line, and stops the rotation of the motor after detection of the abnormality. SOLUTION: In a motor driving device of the wire feeding part, a rotary encoder RE which generates an encoder pulse signal Re with a frequency corresponding to the number of revolution of a motor M, a frequency and voltage converting circuit F/V which converts the frequency of the encoder pulse signal Re into the voltage and the value of the frequency and voltage converting signal Fv are compared and computed with a previously fixed encoder abnormality detection standard value Era, and in the case of Fv<Era, an encoder abnormality detection circuit ER determines the abnormality of the encorder and outputs an encoder abnormality detection signal Er, a breakage detection circuit MC detects the breakage of each signal line, and a motor driving device of a consumable electrode type welding machine stops the rotation of the motor when each of the abnormality occurs.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor driving device for a wire feeder used in a consumable electrode type welding machine.

[0002]

2. Description of the Related Art FIG. 2 is a connection diagram of a motor driving device of a motor of a conventional consumable electrode type welding machine. FIG.
, The motor control comparison operation circuit EA outputs the start signal S
When 1 is input, it operates, compares and calculates the feed speed command signal Iset and the frequency / voltage conversion signal Fv, and outputs a motor control comparison calculation signal Ea. The motor drive circuit DR converts the motor control comparison operation signal Ea into a motor drive signal Dr having a signal level at which the motor M can be driven.

A rotary encoder RE is shown in FIG.
And a rotating disk having a slit attached to the shaft of the motor of the motor M, and a light emitting diode LED and a phototransistor FTR which are opposed to each other and have a frequency corresponding to the rotation speed of the motor M. A pulse signal Re is generated. The waveform shaping circuit WSC shapes the encoder pulse signal Re into a signal corresponding to the input signal of the frequency / voltage conversion circuit F / V. The frequency / voltage conversion circuit F / V converts the voltage into a voltage corresponding to the value of the frequency of the encoder pulse signal Re to convert the frequency / voltage conversion signal F / V.
Output v.

FIG. 3 is a connection diagram showing an embodiment of the waveform shaping circuit WSC and the rotary encoder RE in the motor drive device connection diagram shown in FIG. In FIG. 3, the waveform shaping circuit WSC is formed by an amplifier circuit OP, a waveform shaping comparison circuit CP, a waveform shaping reference value setting circuit IE, a control power supply circuit DS, and a resistor R3, and the rotary encoder RE includes a resistor R1, It is formed by a resistor R2, an emitting diode LED, a photodiode FTR, and a rotating disk having a slit (not shown).

FIG. 4 is a timing chart for explaining the operation of the motor driving device of the conventional consumable electrode type welding machine shown in FIG. 2, and the operation of the motor driving device shown in FIG. This will be described with reference to a timing chart. FIG.
(A) shows the activation signal S1 and has an activation period T1. FIG. 4B shows a feed speed command signal Iset,
FIG. 4C shows an encoder pulse signal Re output from the rotary encoder RE. 4D shows the amplified signal Op, FIG. 4E shows the waveform shaping signal Ws output from the waveform shaping circuit WSC, and FIG. 4F shows the waveform shaping signal Ws from the frequency / voltage converting circuit F / V. This shows the output frequency / voltage conversion signal Fv.

When a start signal S1 shown in FIG. 4A is output from the start switch, the motor control comparison operation circuit EA starts operation at time t = t1, and the feed speed command signal I
The set and the frequency / voltage conversion signal Fv are compared and calculated, and a motor control comparison calculation signal Ea shown in FIG. 2 is output.

The motor drive circuit DR shown in FIG. 2 converts the motor control comparison operation signal Ea into a motor drive signal Dr of a signal level for driving the motor, and the motor M changes the number of revolutions according to the value of the motor drive signal Dr. Control.

The rotary encoder RE shown in FIG. 3 outputs an encoder pulse signal Re shown in FIG. 4C according to the rotation speed of the motor M. The amplifier circuit OP receives the input signal R
e is amplified to a predetermined gain. Waveform shaping comparison circuit C
P compares a predetermined waveform shaping reference value Ie set by the waveform shaping reference value setting circuit IE with the amplified signal Op, and shapes the waveform into a signal corresponding to the input signal of the frequency / voltage conversion circuit F / V. Then, the waveform shaping signal Ws shown in FIG.

The frequency / voltage conversion circuit F / V converts the voltage into the voltage shown in FIG. 4F according to the frequency value of the waveform shaping signal Ws, and outputs a frequency / voltage conversion signal Fv.

At time t = t2 shown in FIG.
If one or both of the control power supply line VC and the pulse signal line RL shown in FIG. 3 are disconnected, the encoder pulse signal Re input to the amplifier circuit OP is not output, so that the amplified signal Op shown in FIG. The pulse frequency is 0
As shown in FIG. 4 (E), the pulse frequency of the waveform shaping signal Ws becomes 0 Hertz, similarly to the pulse frequency of the amplified signal Op. Further, when the ground line GD is broken, a DC voltage signal divided by the resistors R2 and R3 is output.

A frequency / voltage conversion circuit F / V shown in FIG.
When the waveform shaping signal Ws having a frequency of 0 Hertz shown in FIG.
It becomes 0V as shown in (F).

The motor control comparison operation circuit EA shown in FIG.
Compares and calculates the feed speed command signal Iset and the frequency / voltage conversion signal Fv, and when the value of the frequency / voltage conversion signal Fv shown above is 0 V, the motor control comparison calculation signal E
The value of “a” becomes maximum, and the rotation speed of the motor M also becomes maximum.

[0013]

When the motor driving device is started with the control power supply line, pulse signal line, or ground line of the rotary encoder disconnected, the motor rotates at the maximum speed simultaneously with the start. Furthermore, since the motor rotates at the maximum number of revolutions in a state where the no-load voltage is applied to the wire, there is a danger that an operator may touch the wire tip and receive an electric shock.

[0014]

As shown in FIGS. 5 and 3, a method of driving a wire feeder used in a consumable electrode type welding machine comprises the steps of:
The encoder pulse signal Re having a frequency corresponding to the rotation speed of the motor M is converted into a frequency / voltage conversion signal Fv having a voltage corresponding to the frequency value, and the value of the frequency / voltage conversion signal Fv is sequentially compared with a predetermined value. Frequency-voltage conversion signal Fv
Output an encoder abnormality detection signal Er when the value of the signal becomes a predetermined abnormal value.
v and a predetermined feed speed reference value Ms are selectively switched in accordance with the encoder abnormality detection signal Er, and
A consumable electrode type that compares and calculates the voltage conversion signal Fv and a predetermined feed speed reference value Ms with a feed speed command signal Iset, and controls the difference between the feed speed command signal Iset and the feed speed command signal Iset to be minimized. This is a motor driving method of the welding machine.

[0015] The invention of the method of claim 2 at the time of filing is a method of detecting an encoder abnormality when the value of the frequency / voltage conversion signal Fv is an abnormal value by successively comparing with a predetermined value of the invention of the method of claim 1 at the time of filing. Instead of outputting the signal Er, the frequency / voltage conversion signal Fv is compared and calculated with a not-shown predetermined encoder abnormality detection reference value Era, and the frequency / voltage conversion signal Fv is set to a predetermined encoder abnormality detection reference value. Era
A motor drive method for determining that the encoder is abnormal and outputting an encoder abnormality detection signal Er when the encoder pulse signal Re has a frequency corresponding to the rotation speed of the motor M and a voltage corresponding to the frequency value. Is converted to a frequency / voltage conversion signal Fv, and the value of the frequency / voltage conversion signal Fv is compared and calculated with a predetermined encoder abnormality detection reference value Era. When Fv <Era, it is determined that the encoder is abnormal. An encoder abnormality detection signal Er is output, and the frequency / voltage conversion signal Fv and a predetermined feed speed reference value M are output.
s is selectively switched according to the encoder abnormality detection signal Er, and the frequency / voltage conversion signal Fv and a predetermined feed speed reference value Ms are compared and calculated with a feed speed command signal Iset, and This is a motor driving method for a consumable electrode type welding machine that controls so that a difference from a supply speed command signal Iset is minimized.

As shown in FIGS. 7 and 8, the method according to the third aspect of the present invention differs from the method according to the first aspect of the present invention in that the values of the encoder pulse amplified output signal Op2 and the phototransistor emitter signal Tre are different from each other. A motor driving method, further comprising: outputting a disconnection detection signal Mc when a predetermined abnormal value is reached, and adding a configuration for turning on or off an energizing circuit of a start signal S1 according to the disconnection detection signal Mc. When the value of the frequency / voltage conversion signal Fv is an abnormal value by successively comparing with a predetermined value, instead of outputting the encoder error detection signal Er, a frequency / voltage conversion signal Fv and a predetermined encoder error detection (not shown) are detected. The reference value Era is compared and calculated, and when the frequency / voltage conversion signal Fv is smaller than a predetermined encoder error detection reference value Era, it is determined that the encoder is abnormal and the error is detected. A motor driving method for outputting a coder abnormality detection signal Er, encoder pulse amplified output signal Op2 and the encoder pulse signal obtained by amplifying the encoder pulse signal Re of a frequency corresponding to the rotational speed of the motor M R
DC shaped input waveform shaping signal W obtained by shaping the waveform distortion of e
s2, and outputs the DC component removal input waveform shaping signal Ws2.
And outputs a frequency / voltage conversion signal Fv, and sequentially compares the value of the frequency / voltage conversion signal Fv with a predetermined encoder abnormality detection reference value Era to satisfy Fv <Era. At this time, an encoder abnormality is determined and an encoder abnormality detection signal Er is output, and a disconnection detection signal Mc is output when the values of the encoder pulse amplification output signal Op2 and the phototransistor emitter signal Tre become predetermined abnormal values. The frequency / voltage conversion signal Fv and the predetermined feed speed reference value Ms are selectively switched in accordance with the encoder abnormality detection signal Er, and the frequency / voltage conversion signal Fv and the predetermined feed speed reference Ms are switched. The value Ms is compared and calculated with the feed speed command signal Iset to control the difference from the feed speed command signal Iset to a minimum, Activated in response to the detection signal Mc signal S1
Motor driving method of a consumable electrode type welding machine for energizing or interrupting the energizing circuit of FIG.

The invention of the method according to claim 4 at the time of filing is shown in FIG.
The SC is changed to WSC2 in FIG. 7 and the WSC in FIG.
Is changed to WSC2 of FIG. 8 to output an encoder pulse amplified output signal Op2 obtained by amplifying the encoder pulse signal Re of the invention according to the method of the present invention at a predetermined amplification factor. Is removed to output a sag signal Sa, and the sag signal Sa is output.
And a predetermined DC component removal input waveform shaping reference value Ie2, and when Sa> Ie2, a configuration for outputting a DC component removal input waveform shaping signal Ws2 is added. An encoder pulse amplification output signal Op2 obtained by amplifying an encoder pulse signal Re having a frequency corresponding to the rotation speed at a predetermined amplification rate is output, and a DC component of the encoder pulse amplification output signal Op2 is removed to output a sag signal Sa. Comparing the sag signal Sa with a predetermined DC component removal input waveform shaping reference value Ie2,
In the case of Ie2, a DC component removal input waveform shaping signal Ws2 obtained by shaping the waveform distortion of the encoder pulse signal Re is output, and converted into a voltage corresponding to the frequency value of the DC component removal input waveform shaping signal Ws2 to obtain the frequency A voltage conversion signal Fv is output, and the value of the frequency / voltage conversion signal Fv is successively compared with a predetermined encoder abnormality detection reference value Era to obtain Fv
In the case of <Era, it is determined that the encoder is abnormal, an encoder abnormality detection signal Er is output, and the frequency / voltage conversion signal Fv and a predetermined feed speed reference value Ms are selectively selected according to the encoder abnormality detection signal Er. To the above-mentioned frequency / voltage conversion signal Fv and a predetermined feed speed reference value Ms.
Is compared with the feed speed command signal Iset, and the motor driving method of the consumable electrode type welding machine is controlled to minimize the difference from the feed speed command signal Iset.

As shown in FIGS. 7 and 8, the method of the invention according to the fifth aspect of the present invention is based on the encoder pulse amplification in which the encoder pulse signal Re of the invention of the fourth aspect of the application is amplified at a predetermined amplification factor. An output signal Op2 is output, a DC component of the encoder pulse amplified output signal Op2 is removed, a sag signal Sa is output, and the sag signal Sa is compared with a predetermined DC component removal input waveform shaping reference value Ie2. , S
When a> Ie2, the DC component removal input waveform shaping signal Ws2
A motor driving method in which an encoder pulse amplification output signal Op2 obtained by amplifying an encoder pulse signal Re having a frequency corresponding to the rotation speed of the motor M at a predetermined amplification factor is output, and the encoder pulse is output. A sag signal Sa is output by removing the DC component of the amplified output signal Op2, and the sag signal Sa is compared with a predetermined DC component removal input waveform shaping reference value Ie2. When Sa> Ie2, the encoder pulse signal is output. Re shaped waveform distortion,
It outputs the DC component removal input waveform shaping signal Ws2, converts it into a voltage corresponding to the frequency value of the DC component removal input waveform shaping signal Ws2, outputs a frequency / voltage conversion signal Fv, and outputs the frequency / voltage conversion signal Fv Is sequentially compared with a predetermined encoder abnormality detection reference value Era, and when Fv <Era, it is determined that the encoder is abnormal and an encoder abnormality detection signal Er is output, and the encoder pulse amplification output signal Op2
When the value of the phototransistor emitter signal Tre becomes a predetermined abnormal value, a disconnection detection signal Mc is output, and the frequency / voltage conversion signal Fv and the predetermined feed speed reference value Ms are converted to an encoder abnormality detection signal. The frequency / voltage conversion signal Fv and a predetermined feed speed reference value Ms are selectively switched in accordance with Er to supply speed command signal Is.
A consumable electrode type that compares / calculates with a control signal et to control a difference between the feed speed command signal Iset and the control signal so as to minimize the difference, and energizes or interrupts an energizing circuit of a start signal S1 according to the disconnection detection signal Mc. This is a motor driving method of the welding machine.

As shown in FIG. 8, according to the invention of the method of the invention as claimed in the application, as shown in FIG. 8, the disconnection detection signal Mc of the invention of the method as claimed in the application of claim 3 is such that the encoder pulse amplified output signal Op2 and the predetermined disconnection reference value When Op2 <Me1, it is determined that the control power supply line VC and the pulse signal line RL are disconnected, and the encoder disconnection comparison signal Cp3 is changed to High.
Level, the phototransistor emitter signal Tre is compared with a predetermined phototransistor emitter signal line disconnection reference value Me2, and when Tre <Me2, it is determined that the phototransistor emitter signal line is disconnected and the phototransistor emitter disconnection comparison is performed. When the signal Cp4 is High
Level, and an OR logic of the encoder disconnection comparison signal Cp3 and the phototransistor emitter disconnection comparison signal Cp4 is taken, and the disconnection detection signal Mc is output at a high level. Is H
A disconnection detection signal Mc output when the signal becomes high level
The motor driving method for a consumable electrode type welding machine according to claim 3 or 5, wherein

According to a seventh aspect of the present invention, an encoder pulse signal Re having a frequency corresponding to the number of rotations of a motor M is generated in a motor driving device of a wire feeder used in a consumable electrode type welding machine. A rotary encoder RE,
A waveform shaping circuit WSC for shaping the waveform distortion of the encoder pulse signal Re; a frequency / voltage converting circuit F / V for converting a voltage corresponding to a frequency value of the waveform shaping signal Ws of the waveform shaping circuit WSC; .Voltage conversion circuit F
The value of the frequency / voltage conversion signal Fv is sequentially compared with a predetermined value, and when the value of the frequency / voltage conversion signal Fv becomes a predetermined abnormal value, the encoder abnormality detection signal Er
An encoder abnormality detection circuit ER that outputs a predetermined feed speed reference value Ms, a feed speed reference value setting circuit MS that outputs a predetermined feed speed reference value Ms, the frequency / voltage conversion signal Fv, and a predetermined feed speed reference value Ms. A feed speed changeover switch SW1 for selectively changing over according to an encoder abnormality detection signal Er;
A motor that compares and calculates the frequency / voltage conversion signal Fv and a predetermined feed speed reference value Ms with a feed speed command signal Iset, and controls the difference between the feed speed command signal Iset and the feed speed command signal Iset to be minimized. This is a motor driving device of a consumable electrode type welding machine provided with a control comparison operation circuit EA.

The invention of the device according to claim 8 at the time of filing is characterized in that an encoder abnormality is detected when the value of the frequency / voltage conversion signal Fv is an abnormal value by successively comparing the predetermined value with the predetermined value of the invention of the device according to claim 7 at the time of filing. Instead of outputting the signal Er, the frequency / voltage conversion signal Fv is compared and calculated with a not-shown predetermined encoder abnormality detection reference value Era, and the frequency / voltage conversion signal Fv is set to a predetermined encoder abnormality detection reference value. Era
A motor drive device that outputs an encoder abnormality detection signal Er by determining that the encoder is abnormal when the value is smaller than the frequency and voltage conversion signal Fv and a predetermined encoder abnormality detection reference. Value E
8. The motor drive device for a consumable electrode type welding machine according to claim 7, wherein the motor drive device compares and calculates the value of ra and, when Fv <Era, determines that the encoder is abnormal and outputs an encoder abnormality detection signal Er.

As shown in FIGS. 7 and 8, the invention of the device of the ninth aspect of the present invention differs from the invention of the seventh aspect of the invention in that the values of the encoder pulse amplified output signal Op2 and the phototransistor emitter signal Tre are different from each other. A disconnection detection circuit MC that outputs a disconnection detection signal Mc when a predetermined value is reached;
A start / disconnection detection signal change-over switch S for conducting or interrupting an energization circuit of the activation signal S1 in response to the disconnection detection signal Mc.
A rotary encoder for generating an encoder pulse signal Re having a frequency corresponding to the number of rotations of the motor M in the motor drive device of the wire feeder used for the consumable electrode type welding machine. RE, an encoder pulse amplified output signal Op that amplifies the encoder pulse signal Re, and an encoder pulse output waveform shaping circuit W that shapes waveform distortion of the encoder pulse signal Re.
SC2 and the encoder pulse output waveform shaping circuit WS
A frequency / voltage conversion circuit F / V for converting into a voltage corresponding to the value of the frequency of the DC component removal input waveform shaping signal Ws2 of C2.
And the value of the frequency / voltage conversion signal Fv of the frequency / voltage conversion circuit F / V is sequentially compared with a predetermined encoder abnormality detection reference value Era. When Fv <Era, it is determined that the encoder is abnormal and the encoder is abnormal. An encoder abnormality detection circuit ER that outputs a detection signal Er; and a disconnection detection circuit MC that outputs a disconnection detection signal Mc when the values of the encoder pulse amplified output signal Op2 and the phototransistor emitter signal Tre become predetermined abnormal values. A feed speed reference value setting circuit MS for outputting a predetermined feed speed reference value Ms, and the frequency / voltage conversion signal Fv and the predetermined feed speed reference value Ms according to the encoder abnormality detection signal Er. A feed speed changeover switch SW1 for selectively changing the feed speed,
A motor control comparison operation for comparing and calculating the frequency / voltage conversion signal Fv and the feed speed reference value Ms with a feed speed command signal Iset so as to minimize a difference between the feed speed command signal Iset and the feed speed command signal Iset. The circuit EA and the disconnection detection signal M
This is a motor drive device for a consumable electrode type welding machine provided with a start / disconnection detection signal changeover switch SW2 for conducting or interrupting an energizing circuit of a start signal S1 in accordance with c.

In the apparatus according to the tenth aspect of the present invention, the encoder pulse output waveform shaping circuit WSC2 amplifies the encoder pulse signal Re at a predetermined amplification factor with the control power supply circuit DS for supplying the control power supply Vcc. An encoder pulse amplification output circuit signal OP2 for outputting an encoder pulse amplification output signal Op2, a sag circuit for removing a DC component of the encoder pulse amplification output signal Op2 to output a sag signal Sa, and a sag signal Sa of the sag circuit. A comparison is made with a predetermined DC component removal input waveform shaping reference value Ie2, and when Sa> Ie2, a DC component removal input waveform shaping comparison circuit CP2 that outputs the DC component removal input waveform shaping signal Ws2 to a high level and outputs the signal. A motor driving device for a consumable electrode-type welding machine according to claim 9 provided.

According to the invention of the apparatus of claim 11 at the time of filing, the disconnection detecting circuit MC includes an encoder pulse amplified output signal Op
2 is compared with a predetermined disconnection reference value Me1, and Op2
<Me1, control power supply line VC and pulse signal line RL
Is disconnected, and the encoder disconnection comparison signal Cp3
Disconnection comparison circuit CP3 for setting the level to High level
And a phototransistor emitter signal Tre and a predetermined phototransistor emitter signal line disconnection reference value Me2
When Tre <Me2, it is determined that the phototransistor emitter signal line is disconnected, and the phototransistor emitter disconnection comparison circuit CP4 sets the phototransistor emitter disconnection comparison signal Cp4 to a high level.
11. The consumable device according to claim 9, further comprising: an OR circuit that outputs an OR logic of the encoder disconnection comparison signal Cp3 and the phototransistor emitter disconnection comparison signal Cp4 to output a disconnection detection signal Mc at a high level. It is a motor drive device of an electrode type welding machine.

[0025]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a diagram that best illustrates the features of the invention according to the present application. Since this is the same as FIG. 7 described later, the description will be given later with reference to FIG.

The embodiment of the present invention is the invention of the device according to claim 9 at the time of filing, and as shown in FIGS. 7 and 8, the motor drive of the wire feeder used in the consumable electrode type welding machine. In the device, a rotary encoder RE for generating an encoder pulse signal Re having a frequency corresponding to the number of rotations of the motor M
And an encoder pulse output waveform shaping circuit WSC2 for shaping waveform distortion of the encoder pulse amplified output signal Op2 and the encoder pulse signal Re obtained by amplifying the encoder pulse signal Re; and a DC component removal input waveform of the encoder pulse output waveform shaping circuit WSC2. A frequency / voltage conversion circuit F / V that converts the voltage into a voltage corresponding to the value of the frequency of the shaping signal Ws2;
An encoder abnormality detection circuit ER that sequentially compares the value of the voltage conversion signal Fv with a predetermined encoder abnormality detection reference value Era and determines that the encoder is abnormal when Fv <Era, and outputs an encoder abnormality detection signal Er; A disconnection detection circuit MC that outputs a disconnection detection signal Mc when the values of the pulse amplified output signal Op2 and the phototransistor emitter signal Tre become a predetermined abnormal value, and outputs a predetermined feed speed reference value Ms. The feed speed reference value setting circuit MS, the frequency / voltage conversion signal Fv and a predetermined feed speed reference value Ms are used to generate an encoder abnormality detection signal E.
feed rate changeover switch SW that selectively switches according to the speed
1, a motor that compares and calculates the frequency / voltage conversion signal Fv and the feed speed reference value Ms with a feed speed command signal Iset, and controls the difference between the feed speed command signal Iset and the feed speed command signal Iset to be minimized. A motor drive device for a consumable electrode type welding machine provided with a control comparison operation circuit EA and a start / disconnection detection signal changeover switch SW2 for turning on / off an energization circuit of a start signal S1 according to the disconnection detection signal Mc. .

[0027]

FIG. 5 is a motor drive device connection diagram showing a first embodiment of a drive device for carrying out a motor driving method for a consumable electrode type welding machine according to the present invention. In FIG. 5, the components having the same reference numerals as those of the motor driving device of the consumable electrode type welding machine of the prior art shown in FIGS.

In FIG. 5, an encoder abnormality detection circuit E
R sequentially compares the values of the frequency / voltage conversion signal Fv,
When the value of the frequency / voltage conversion signal Fv is lower than a predetermined encoder abnormality detection reference value Era, it is determined that the rotary encoder RE, the control power supply line, the pulse signal line, or the ground line is abnormal, and the encoder abnormality is detected. Signal Er
Is output.

The feed speed reference value setting circuit MS sets a predetermined feed speed reference value Ms. The feed speed changeover switch SW1 switches to the side b when the encoder abnormality detection signal Er is at the high level, and switches to the side a when the encoder abnormality detection signal Er is at the low level.

FIG. 6 is a timing chart for explaining the operation of the first embodiment of the motor driving device for the consumable electrode type welding machine shown in FIG. 5, and shows the operation of the motor driving device shown in FIG. This will be described with reference to the timing chart of FIG. FIG.
(A) shows the activation signal S1 and has an activation period T1. FIG. 6B shows the feed speed command signal Iset,
FIG. 6C shows an encoder pulse signal Re output from the rotary encoder RE. FIG. 6D shows the amplified signal Op, FIG. 6E shows the waveform shaping signal Ws output from the waveform shaping circuit WSC, and FIG. 6F shows the waveform shaping signal Ws from the frequency / voltage converting circuit F / V. This shows the output frequency / voltage conversion signal Fv. FIG. 6 (G) shows an encoder abnormality detection signal Er output from the encoder abnormality detection circuit ER, and FIG. 6 (H) shows a frequency / voltage conversion signal Fv selected by the feed speed switch SW1 and the feed speed. Either the reference value signal Ms.

At time t = t2 shown in FIG.
If one of the control power supply line VC and the pulse signal line RL is disconnected, the encoder pulse signal Re input to the amplifier circuit OP is not output, and the pulse frequency of the amplified signal Op shown in FIG. , Waveform shaping signal W
The pulse frequency of s becomes 0 Hertz as shown in FIG. 6 (E), similarly to the pulse frequency of the amplified signal Op. When the ground line GD is broken, the resistance R2 and the resistance R3
The DC voltage divided by the above is input to the amplifier circuit OP to output the amplified signal Op. However, since the values of the resistors R2 and R3 are set so that the value of the amplified signal Op is smaller than the predetermined waveform shaping reference value Ie, the pulse frequency of the waveform shaping signal Ws becomes 0 Hertz. .

FIG. 6 shows the frequency / voltage conversion circuit F / V
When the waveform shaping signal Ws having a frequency of 0 Hz shown in (E) is inputted, the output voltage of the frequency / voltage conversion signal Fv becomes 0 V as shown in FIG. 6 (F), and the frequency / voltage conversion signal Fv becomes It is input to the a side of the feed speed changeover switch SW1 and the encoder abnormality detection circuit ER.

The encoder abnormality detection circuit ER has a frequency
The voltage conversion signal Fv is compared with a predetermined encoder error detection reference value Era (not shown). When Fv> Era, the encoder error detection circuit ER is determined to be normal, and the encoder error detection signal Er is output. The level becomes low, and the feed speed changeover switch SW1 is set to the a side.

The relationship between the frequency / voltage conversion signal Fv and a predetermined encoder abnormality detection reference value Era is Fv <Er
In the case of a, the encoder abnormality detection circuit ER is determined to be abnormal, and the encoder abnormality detection signal Er shown in FIG.
At the h level, the feed speed switch SW1 is switched from the a side to the b side.

When the feed speed changeover switch SW1 is set to the side "b", a predetermined feed speed reference value Ms for stopping the rotation of the motor M is input from the feed speed reference value setting circuit MS to the motor control comparison operation circuit EA. You.

The motor control comparison operation circuit EA compares and calculates the feed speed command signal Iset with a predetermined feed speed reference value Ms shown in FIG. 6H, and stops the rotation of the motor M.

FIG. 7 is a motor drive unit connection diagram showing a second embodiment of a drive unit for carrying out the motor drive method for a consumable electrode type welding machine according to the present invention. In FIG. 7, the components having the same reference numerals as those of the conventional technology shown in FIG. 2 and the motor driving device of the consumable electrode type welding machine of the first embodiment shown in FIG. The configuration will be described.

In FIG. 7, the disconnection detecting circuit MC detects disconnection of each of the control power supply line VC, the pulse signal line RL, and the phototransistor emitter signal line TR, and displays an abnormality on the abnormality display circuit LD. The activation / disconnection detection signal switch SW2 controls the activation signal S1 according to the disconnection detection signal Mc.

FIG. 8 is a connection diagram showing an embodiment of the encoder pulse output waveform shaping circuit WSC2, rotary encoder RE, and disconnection detection circuit MC in the motor drive device connection diagram shown in FIG. 8, the encoder pulse output waveform shaping circuit WSC2 includes an encoder pulse amplification output circuit OP2, a DC component removal input waveform shaping comparison circuit CP2, a DC component removal input waveform shaping reference value setting circuit IE2, a control power supply circuit DS, a capacitor C1, The rotary encoder RE is formed by a resistor R4 and a resistor R5.
1, a resistor R2, an emitting diode LED, a photodiode FTR, and a rotating disk having a slit (not shown). The disconnection detection circuit MC includes an encoder disconnection comparison circuit CP3, a phototransistor emitter disconnection comparison circuit CP4, and a disconnection. A reference value setting circuit ME1, a phototransistor emitter signal line disconnection reference value setting circuit ME2, an OR circuit OR, a resistor R6, and a zener diode VZ are formed.

FIG. 9 is a timing chart for explaining the operation of the motor driving device of the consumable electrode type welding machine shown in FIG. 7 according to the second embodiment, and shows the operation of the motor driving device shown in FIG. This will be described with reference to the timing chart of FIG. FIG.
9A shows the start signal S1, FIG. 9B shows the feed speed command signal Iset, and FIG. 9C shows the encoder pulse signal Re output from the rotary encoder RE. FIG. 9D shows an encoder pulse amplification output circuit O
9E shows the sag signal Sa, and FIG. 9F shows the encoder pulse output waveform shaping signal Ws2 output from the encoder pulse output waveform shaping circuit WSC2. , FIG. 9
(G) shows the frequency / voltage conversion signal Fv output from the frequency / voltage conversion circuit F / V. FIG. 9H shows an encoder disconnection comparison signal Cp3 output from the encoder disconnection comparison circuit CP3, and FIG. 9I shows a phototransistor emitter disconnection comparison signal Cp4 output from the phototransistor emitter disconnection comparison circuit CP4. FIG.
(G) shows a disconnection detection signal Mc output from the disconnection detection circuit MC.

When a start signal S1 shown in FIG. 9A is output from the start switch, the motor control comparison operation circuit EA starts operation at time t = t1, and the feed speed command signal I
Set and the frequency / voltage conversion signal Fv are compared and calculated, and a motor control comparison calculation signal Ea is output.

The motor drive circuit DR converts the motor control comparison operation signal Ea into a motor drive signal Dr having a signal level for driving the motor. The motor M controls the number of revolutions according to the value of the motor drive signal Dr.

The rotary encoder RE shown in FIG. 8 outputs an encoder pulse signal Re shown in FIG. 9C according to the number of rotations of the motor M. The encoder pulse amplification output circuit OP2 amplifies the input signal Re to a predetermined gain, and outputs the encoder pulse amplification output signal O shown in FIG.
Output p2. The sag circuit formed by the capacitor C1 and the resistor R5 outputs the sag signal Sa shown in FIG. 9E from which the DC component of the encoder pulse amplified output signal Op2 has been deleted. The DC component removal input waveform shaping comparison circuit CP2 includes a DC component removal input waveform shaping reference value setting circuit I.
A comparison is made between the predetermined DC component removal input waveform shaping reference value Ie2 set by E2 and the sag signal Sa, and the waveform is shaped into a signal corresponding to the input signal of the frequency / voltage conversion circuit F / V. 9 (F), and outputs the DC component removal input waveform shaping signal Ws2.

The frequency / voltage conversion circuit F / V operates according to the frequency of the DC component removal input waveform shaping signal Ws2 as shown in FIG.
(G) is converted into a frequency / voltage conversion signal Fv.

At time t = t3 shown in FIG.
When one of the control power supply line VC and the pulse signal line RL is disconnected, the encoder pulse Re input to the encoder pulse amplification output circuit OP2 is not output, and FIG.
The pulse frequency of the encoder pulse amplified output signal Op2 shown in FIG.
The pulse frequency of s2 also becomes 0 Hertz as shown in FIG. At time t = t4 shown in FIG. 9I, if only the phototransistor emitter signal line TR is disconnected, the phototransistor emitter signal T shown in FIG.
The value of re changes from the zener voltage Vz of the zener diode VZ to 0V.

When the encoder pulse amplification output signal Op2 and the phototransistor emitter signal Tre are input to the disconnection detection circuit MC shown in FIG. 8, the encoder disconnection comparison circuit CP3 outputs the encoder pulse amplification output signal Op.
2 is compared with a predetermined disconnection reference value Me1, and Op2
<Me1, when the control power supply line VC or the pulse signal line R
It is determined that one of L has been disconnected or at the same time,
The encoder disconnection comparison signal Cp3 is set to High level. Further, the phototransistor emitter disconnection comparison circuit C
P4 is a phototransistor emitter signal Tre and a predetermined phototransistor emitter signal line disconnection reference value M
When Tre <Me2, it is determined that the phototransistor emitter signal line is disconnected, and the phototransistor emitter disconnection comparison signal Cp4 is set to High level.

The OR circuit OR includes an encoder disconnection comparison signal Cp3 and a phototransistor emitter disconnection comparison signal Cp3.
Then, the OR logic of No. 4 is formed, and the disconnection detection signal Mc shown in FIG. Further, during the period when the disconnection detection signal Mc is at the High level, the abnormality display circuit LD displays an abnormality.

Start / disconnection detection signal switch SW2
During the abnormal period td in which the disconnection detection signal Mc shown in FIG. 9G is at the High level, the switch SW2 is opened to shut off the start signal S1, and the motor control comparison operation circuit EA is stopped.

[0049]

According to the first embodiment of the present invention, the encoder abnormality detecting circuit detects an abnormality when each of the control lines installed on the rotary encoder is disconnected during welding. Then, immediately stop the rotation of the motor. In the second embodiment of the present invention, in addition to the above, during welding standby, when a disconnection occurs in each control line installed in the rotary encoder, disconnection of each control line is detected by a disconnection detection circuit, Even if the start signal is input, the rotation of the motor is stopped and the stop of the motor driving device of the wire feeding unit is maintained until the disconnection state is eliminated, so that electric shock due to wire feeding at the start of welding can be prevented.

[Brief description of the drawings]

FIG. 1 is a diagram that best represents the features of the invention according to the present application.

FIG. 2 is a motor drive device connection diagram of a motor drive device of a conventional consumable electrode type welding machine.

FIG. 3 is a connection diagram showing an embodiment of a waveform shaping circuit WSC and a rotary encoder RE in the motor drive device connection diagram shown in FIG. 2;

FIG. 4 is a timing chart for explaining the operation of the motor drive device shown in FIG. 2;

FIG. 5 is a motor drive device connection diagram showing a first embodiment of a drive device for carrying out the motor drive method of the consumable electrode type welding machine of the present invention.

FIG. 6 is a timing chart for explaining the operation of the motor drive device according to the first embodiment shown in FIG. 5;

FIG. 7 is a motor drive device connection diagram showing a second embodiment of the drive device for performing the motor drive method of the consumable electrode type welding machine according to the present invention.

8 is a connection diagram showing an embodiment of an encoder pulse waveform shaping circuit WSC, a disconnection detection circuit MC, and a rotary encoder RE in the motor drive device connection diagram shown in FIG. 7;

FIG. 9 is a timing chart for explaining the operation of the motor driving device according to the second embodiment shown in FIG. 7;

[Explanation of symbols]

CP waveform shaping comparison circuit CP2 DC component removal input waveform shaping comparison circuit CP3 encoder disconnection comparison circuit CP4 phototransistor emitter disconnection comparison circuit C1 capacitor DR motor drive circuit DS control power supply circuit EA motor control comparison arithmetic circuit ER encoder abnormality detection circuit FTR phototransistor F / V frequency / voltage conversion circuit IE waveform shaping reference value setting circuit IE2 DC component removal input waveform shaping reference value setting circuit GD ground line LD error display circuit LED light emitting diode MC disconnection detection circuit ME1 disconnection reference value setting circuit ME2 phototransistor emitter Signal line disconnection reference value setting circuit M Motor MS Feed speed reference value setting circuit OP Amplifier circuit OR OR circuit OP2 Encoder pulse amplification output circuit RE Rotary encoder RL Pulse signal line R1 Resistance R2 resistor R3 resistor R4 resistor R5 resistor R6 resistor SW1 feed speed changeover switch SW2 start / disconnection detection signal changeover switch SW3 frequency / voltage conversion signal and armature voltage shaping signal changeover switch TR phototransistor emitter signal line VC Control power line VZ Zener diode WSC Waveform shaping circuit WSC2 Encoder pulse output waveform shaping circuit Cp3 Encoder disconnection comparison signal Cp4 Phototransistor emitter disconnection comparison signal Dr Motor drive signal Ea Motor control comparison operation signal Er Encoder abnormality detection signal Era Encoder abnormality detection reference value Fv Frequency / voltage conversion signal Ie Waveform shaping reference value Ie2 DC component removal input waveform shaping reference value Iset Feed speed command signal Mc Disconnection detection signal Me1 Disconnection reference value Me2 Phototransistor Reference signal line disconnection reference value Ms feeding speed reference value Op amplification signal Op2 encoder pulse amplification output signal Re encoder pulse signal Sa sag signal S1 start signal ta normal operation period tb abnormal operation period tc normal period td abnormal period Tre phototransistor emitter Signal Ws Waveform shaping signal Ws2 DC component removal input waveform shaping signal

Claims (11)

[Claims] 1. A motor driving method for a wire feeder used in a consumable electrode type welding machine, comprising the steps of: converting an encoder pulse signal having a frequency corresponding to the number of rotations of a motor into a frequency / voltage conversion signal of a voltage corresponding to a frequency value; And sequentially compares the value of the frequency / voltage conversion signal with a predetermined value.
An encoder abnormality detection signal is output when the value of the voltage conversion signal becomes a predetermined abnormal value, and the frequency / voltage conversion signal and a predetermined feed speed reference value are selected according to the encoder abnormality detection signal. , And compares / calculates the frequency / voltage conversion signal and a predetermined feed speed reference value with a feed speed command signal, and controls so that a difference between the feed speed command signal and the feed speed command signal is minimized. A motor driving method for a consumable electrode type welding machine. 2. A method for driving a wire feeder used in a consumable electrode type welding machine, comprising the steps of: converting an encoder pulse signal having a frequency corresponding to the number of rotations of a motor into a frequency / voltage conversion signal of a voltage corresponding to a frequency value; The value of the frequency-voltage conversion signal is compared and calculated with a predetermined encoder abnormality detection reference value, and when the value of the frequency-voltage conversion signal is smaller than the predetermined encoder abnormality detection reference value,
The encoder converts the frequency / voltage conversion signal and the predetermined feed speed reference value selectively according to the encoder abnormality detection signal, and outputs the frequency / voltage conversion signal. A motor driving method for a consumable electrode type welding machine, comprising comparing and calculating a feed speed command signal with a feed speed command signal and controlling the feed speed command signal so that a difference between the feed speed command signal and the feed speed command signal is minimized. 3. A waveform of an encoder pulse amplified output signal and an encoder pulse signal obtained by amplifying an encoder pulse signal having a frequency corresponding to the number of rotations of a motor in a motor driving method of a wire feeding unit used in a consumable electrode type welding machine. A DC component-removed input waveform shaping signal in which distortion has been shaped is output, and converted to a voltage corresponding to the frequency value of the DC component-removed input waveform shaping signal, and a frequency / voltage conversion signal is output. Is sequentially compared with a predetermined encoder abnormality detection reference value, and when the value of the frequency / voltage conversion signal is smaller than a predetermined encoder abnormality detection reference value, it is determined that the encoder is abnormal and the encoder abnormality detection signal is output. Output, the disconnection is detected when the encoder pulse amplification output signal and the phototransistor emitter signal value become a predetermined abnormal value. A signal is output, and the frequency / voltage conversion signal and a predetermined feed speed reference value are selectively switched according to an encoder abnormality detection signal, whereby the frequency / voltage conversion signal and a predetermined feed speed reference value are output. And the feed speed command signal, and controls so that the difference between the feed speed command signal and the feed speed command signal is minimized. Motor driving method for a neutral electrode type welding machine. 4. A motor driving method for a wire feeder used in a consumable electrode type welding machine, wherein an encoder pulse amplified output signal obtained by amplifying an encoder pulse signal having a frequency corresponding to the number of rotations of the motor at a predetermined amplification factor. And outputs a sag signal by removing a DC component of the encoder pulse amplification output signal, and compares the sag signal with a predetermined DC component removal input waveform shaping reference value, so that the sag signal is determined in advance. When the DC component removal input waveform shaping reference value is larger than the DC component removal input waveform shaping reference value, a DC component removal input waveform shaping signal obtained by shaping the waveform distortion of the encoder pulse signal is output, and the frequency is determined according to the frequency value of the DC component removal input waveform shaping signal. The frequency / voltage conversion signal is output by converting the voltage / voltage into a voltage, and the value of the frequency / voltage conversion signal is sequentially compared with a predetermined encoder abnormality detection reference value. When the value of the voltage conversion signal is smaller than a predetermined encoder abnormality detection reference value, it is determined that the encoder is abnormal and an encoder abnormality detection signal is output, and the frequency / voltage conversion signal and a predetermined feed speed reference value are compared. Selectively switch according to an encoder abnormality detection signal, compare and calculate the frequency / voltage conversion signal and a predetermined feed speed reference value with a feed speed command signal, and calculate a difference between the feed speed command signal and the difference. Motor driving method for a consumable electrode type welding machine that controls so as to minimize the pressure. 5. A motor driving method for a wire feeder used in a consumable electrode type welding machine, comprising: an encoder pulse amplified output signal obtained by amplifying an encoder pulse signal having a frequency corresponding to the number of rotations of a motor at a predetermined amplification factor. And outputs a sag signal by removing a DC component of the encoder pulse amplification output signal, and compares the sag signal with a predetermined DC component removal input waveform shaping reference value, so that the sag signal is determined in advance. When the DC component removal input waveform shaping reference value is larger than the DC component removal input waveform shaping reference value, a DC component removal input waveform shaping signal obtained by shaping the waveform distortion of the encoder pulse signal is output, and the frequency is determined according to the frequency value of the DC component removal input waveform shaping signal. The frequency / voltage conversion signal is output by converting the voltage / voltage into a voltage, and the value of the frequency / voltage conversion signal is sequentially compared with a predetermined encoder abnormality detection reference value. When the value of the voltage conversion signal is smaller than a predetermined encoder abnormality detection reference value, it is determined that the encoder is abnormal and an encoder abnormality detection signal is output, and the values of the encoder pulse amplification output signal and the phototransistor emitter signal are determined to be a predetermined abnormality. Output a disconnection detection signal when the value becomes a predetermined value, selectively switching the frequency / voltage conversion signal and a predetermined feed speed reference value according to an encoder abnormality detection signal, and the frequency / voltage conversion signal Comparing and calculating a predetermined feed speed reference value with a feed speed command signal, controlling the difference between the feed speed command signal and the feed speed command signal to be minimized, and setting a start signal in response to the disconnection detection signal. A motor driving method for a consumable electrode type welding machine for energizing or interrupting an energizing circuit. 6. The disconnection detection signal compares an encoder pulse amplification output signal with a predetermined disconnection reference value, and when the encoder pulse amplification output signal is smaller than a predetermined disconnection reference value, the control power supply line And the pulse signal line is disconnected, and the encoder disconnection comparison signal is set to High.
Level, comparing the phototransistor emitter signal with a predetermined phototransistor emitter signal line disconnection reference value, and when the phototransistor emitter signal is smaller than the predetermined phototransistor emitter signal line disconnection reference value, It is determined that the signal line is disconnected, the phototransistor emitter disconnection comparison signal is set to the high level, the OR logic of the encoder disconnection comparison signal and the phototransistor emitter disconnection comparison signal is taken, and the disconnection detection signal is set to the high level and output. 6. The motor driving method for a consumable electrode type welding machine according to claim 3, wherein at least one of the comparison signal and the phototransistor emitter disconnection comparison signal is a disconnection detection signal that is output when the signal has a High level. 7. A motor driving device for a wire feeder used in a consumable electrode welding machine, comprising: a rotary encoder for generating an encoder pulse signal having a frequency corresponding to the number of rotations of the motor; and a waveform distortion of the encoder pulse signal. A waveform shaping circuit for shaping the waveform, a frequency / voltage converting circuit for converting a voltage according to the value of the frequency of the waveform shaping signal of the waveform shaping circuit, and a value of the frequency / voltage converting signal of the frequency / voltage converting circuit in advance. An encoder abnormality detection circuit that outputs an encoder abnormality detection signal when the value of the frequency / voltage conversion signal becomes a predetermined abnormal value by successively comparing with a predetermined value, and outputs a predetermined feed speed reference value. A feed speed reference value setting circuit, and a feed speed for selectively switching the frequency / voltage conversion signal and a predetermined feed speed reference value in accordance with an encoder abnormality detection signal. A speed changeover switch,
A motor control comparison / calculation circuit for comparing and calculating the voltage conversion signal and a predetermined feed speed reference value with the feed speed command signal and controlling the difference between the feed speed command signal and the feed speed command signal to be minimized; Motor drive of consumable electrode type welding machine. 8. The encoder abnormality detection circuit compares and calculates a frequency / voltage conversion signal and a predetermined encoder abnormality detection reference value, and the frequency / voltage conversion signal is smaller than a predetermined encoder abnormality detection reference value. 8. The motor drive device for a consumable electrode type welding machine according to claim 7, wherein an encoder abnormality is detected when the encoder is determined to be abnormal. 9. A motor driving device for a wire feeder used in a consumable electrode type welding machine, comprising: a rotary encoder for generating an encoder pulse signal having a frequency corresponding to the number of rotations of a motor; and amplifying the encoder pulse signal. An encoder pulse output waveform shaping circuit for shaping the waveform distortion of the encoder pulse amplified output signal and the encoder pulse signal; and a frequency for converting into a voltage corresponding to a frequency value of a DC component removal input waveform shaping signal of the encoder pulse output waveform shaping circuit. A voltage conversion circuit, and sequentially comparing the value of the frequency / voltage conversion signal of the frequency / voltage conversion circuit with a predetermined encoder abnormality detection reference value, and the value of the frequency / voltage conversion signal of the frequency / voltage conversion circuit is If the value is smaller than the predetermined encoder error detection reference value, it is determined that the encoder is An encoder abnormality detection circuit that outputs a disconnection detection signal, a disconnection detection circuit that outputs a disconnection detection signal when the values of the encoder pulse amplification output signal and the phototransistor emitter signal become a predetermined abnormal value, A feed speed reference value setting circuit for outputting a feed speed reference value, and a feed speed switch for selectively switching the frequency / voltage conversion signal and a predetermined feed speed reference value according to an encoder abnormality detection signal. A switch, a motor control comparison / calculation circuit for comparing / calculating the frequency / voltage conversion signal and the feed speed reference value with a feed speed command signal and controlling the difference between the feed speed command signal and the feed speed command signal to be minimized. A motor drive device for a consumable electrode-type welding machine, comprising: a start / disconnection detection signal changeover switch for turning on / off an energization circuit of a start signal in accordance with the disconnection detection signal. 10. An encoder pulse output waveform shaping circuit, comprising: a control power supply circuit for supplying control power; and an encoder pulse amplification output circuit for amplifying an encoder pulse signal with a predetermined amplification factor and outputting an encoder pulse amplified output signal. Signal, a sag circuit for removing a DC component of the encoder pulse amplification output signal and outputting a sag signal, and comparing a sag signal of the sag circuit with a predetermined DC component removal input waveform shaping reference value, 10. A DC-removed input waveform shaping / comparing circuit for setting a DC-removed input waveform shaping signal to a high level and outputting the signal when a sag signal is greater than a predetermined DC-removed input waveform shaping reference value. Motor drive of consumable electrode type welding machine. 11. The disconnection detection circuit compares an encoder pulse amplified output signal with a predetermined disconnection reference value,
An encoder disconnection comparison circuit that determines that the control power supply line and the pulse signal line are disconnected when the encoder pulse amplification output signal is smaller than a predetermined disconnection reference value, and sets an encoder disconnection comparison signal to a high level; The signal is compared with a predetermined phototransistor emitter signal line disconnection reference value, and when the phototransistor emitter signal is smaller than the predetermined phototransistor emitter signal line disconnection reference value, it is determined that the phototransistor emitter signal line is disconnected. A phototransistor emitter disconnection comparison circuit that sets the phototransistor emitter disconnection comparison signal to a high level, and an OR logic of the encoder disconnection comparison signal and the phototransistor emitter disconnection comparison signal to output a disconnection detection signal at a high level Consumable electrode type welding machine motor driving apparatus according to claim 9 or claim 10, wherein is provided a A circuit.