JP3104495B2 - Control device for arc welding robot - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a welding robot for performing arc welding.

[0002]

2. Description of the Related Art Conventionally, when a welding tip is replaced, a welding wire passage in the tip is clogged with a wire (surface treating agent) scum, and the feeding of the welding wire becomes defective, thereby cleaning the tip or feeding the welding wire. As the hole (welding wire passage) of the tip gradually slipped, the welding wire passage in the tip became larger and the aim of welding seemed to be wrong, so the robot or the welding line was stopped and people changed the tip. .

[0003]

In the method of exchanging the tips due to the above-mentioned defective feeding of the welding wire or the misalignment of the welding purpose, a large number of defective workpieces for arc welding begin to occur and the welding tip exchanging operation is started. For this reason, a large number of arc welding defective workpieces are generated, and in a welding line composed of a plurality of robots, each robot has to be dealt with each time, which is troublesome. There has been a problem that the operation rate of the robot is reduced due to these matters.

[0004] The present invention solves the above-mentioned problem, and determines the integrated value of each of the arc ON time, the number of arc starts, and the welding wire feed weight, which are the consumable factors of the arc welding tip. The target value of chip exchange required and the previous integrated value are compared each time welding is completed.If any integrated value exceeds the target value, that is, if it becomes necessary to replace the welding tip, It is an object of the present invention to provide a welding robot control device capable of notifying and outputting an output warning that a welding tip needs to be replaced and stopping the robot at the final point of a welding cycle.

[0005]

In order to achieve the above object, a welding robot controller according to the present invention performs arc welding.
Tees that can be used for data entry in arc welding robots
Equipped with a chip pendant.
Arc ON time, number of arc starts, welding wire feeding weight
Obtain each integrated value of the quantity, and calculate each said integrated value.
Maintain in the memory that is backed up even after the primary power shut down
The wear factor input from the teach pendant.
Use the target value for each welding tip that needs to be replaced as a guideline.
Rewritable from the teach pendant, and
Of the integrated value to the corresponding target value
Can be displayed on the teach pendant.
Either integration while comparing the value with the target value each time welding is completed
When the value exceeds the corresponding target value,
A warning is issued to the outside as a replacement timing output.

[0006]

As described above, according to the present invention, the welding
Ear specific gravity, wire diameter and feeder of wire feeder
LA diameter, arc ON time, arc start frequency,
Set the welding tip replacement target value for each welding wire feed weight.
Equipped with a monitor that can input,
The rotation speed is received from the welding power source
Information of welding wire usage (feeding amount)
Arc ON time is when the robot moves in the welding section during actual welding
Time based on the actual welding current value based on the
The number of start times is the number of times the welding starts (starts) during actual welding.
You. These data are stored in the memory and after the primary power is turned off.
Is also backed up by batteries. Arc ON time
Considering the actual welding current value,
Can be provided to the outside through the monitor screen.
The data of these integrated values are
When it exceeds the standard value, output to the outside and weld
At the end of the cycle, the robot stops. Use this output
Robot automatically using a welding tip automatic exchange jig
With this configuration, the welding tip is replaced, and when the predetermined welding tip replacement target value is reached, the robot is stopped at the final point of the welding cycle and the welding tip is automatically replaced. I do. When the replacement is completed, the welding tip replacement completion signal is input to the robot, and the data accumulated by the robot (the arc ON time, the number of arc starts, the welding wire feed weight) is reset to the initial value 0. . Therefore, no human intervention is required, and no arc welding defective work is generated, so that the operation rate of the robot and thus the robot built-in welding line can be increased as compared with the related art.

[0007]

An embodiment of the present invention will be described below with reference to the drawings.

First, the integration of the welding wire feed weight will be described. As will be described later, the welding wire feed weight is calculated using the constants of the welding wire and the wire feeding device in FIG.
The calculation formula is (weld wire feed weight) [g] = (wire feed length) [cm
/ Min] × (wire weight per unit length) [g / cm] × (welding time) [min] (wire feed length) [cm / min] = (diameter of feed roller) [cm] × π × (unit (Number of rotations of feed roller per time) [times / minute] (wire weight per unit length) [g / cm] = (wire radius) ² [cm ² ] × π × (specific gravity of welding wire) [g / cm ³ ] Therefore, (welding wire feed weight) = (wire radius) ² × (feed roller diameter) × π ² × (number of rotations of feed roller per unit time) × (specific gravity of welding wire) × (welding Time). Here, the feed roller is a roller that is provided in the welding wire feeding device and directly feeds out the welding wire. For example, mild steel φ1.2 [mm] Number of rotation of feed roller of feeder 100 [times / min] Actual welding time 5 [min] Diameter of feed roller of feeder 40 [mm] Specific gravity of mild steel 7.8 [ g / cm ³ ], (the welding wire feed weight) = 0.06 ² × 4.0 × π ² × 1
00 × 7.8 × 5 = 554.28 [g]. The welding wire feed weight is calculated and integrated at the end point of the arc welding section, the temporary stop state point of the section, or the emergency stop state point of the section. In the welding robot system of FIG. 1, when arc welding is started, a welding wire is fed from a wire feeding device in direct proportion to a welding current. In order to stably perform welding, the welding wire feeding speed is kept constant. The number of rotations of the feed roller, that is, the feed length of the welding wire is directly proportional to the welding current and can be easily obtained. The rotation speed is obtained by the robot controller from the welding power source controller by communication. The welding wire diameter can be selected on the screen of the teach pendant (monitor) in FIG. Here, FIGS. 3 to 6 show only the screen portion of the teach pendant (monitor) of FIG. The diameter of the feed roller and the specific gravity of the wire can be input on the screen of FIG. In the screen of FIG. 4, the target values of the exchange time output terminal No., the reset input terminal No. and the welding tip exchange factors of the arc ON time, the number of arc starts, and the welding wire feed amount relating to the welding tip exchange input / output are required. Can be set. The value displayed on the 1/2 screen of FIGS. 3 and 4 is the welding wire diameter φ.
This is a standard value at the time of 1.2. On the 2/2 screen in FIG. 4, it is possible to select whether or not to execute the cycle stop of the robot when the welding tip replacement output occurs. Here, each item on the screen in FIG. 4 will be described.・ Replacement time output terminal No. When the conditions that require replacement of the welding tip are satisfied, the internal assignment of the output terminal No. that notifies the replacement time to the outside is changed to 1 /
Set on two screens. Normally, the value ranges from 1 to 16 and can take a value from 1 to a maximum of 80 when an optional additional input / output unit is added.・ Reset input terminal No. Output terminal No. that informs the outside of welding tip replacement time is O
When the state is N, the input terminal number for resetting the ON state is set on the 1/2 screen of FIG. When a signal is input to the reset input terminal in the ON state, each integrated value of the arc ON time, the number of arc starts, and the welding wire feed weight is reset to the initial state value 0. Usually 1 to 16
If an additional I / O unit is added as an option with values up to, values from 1 to a maximum of 80 can be taken. -Standard value of the tip exchange factor The values shown in Fig. 7 are the standard values of the respective tip exchange factors, but this value is based on the arc welding current value of 300A and varies depending on the welding wire diameter. The tip replacement standard value in FIG. 7 is derived from an empirical rule. At the welding site, the usage rate of the welding power source is 4 when the welding current is 200 A or less.
In the case of 0 to 50%, the welding tip is replaced once a half day. If the welding current is high, if the welding wire (surface treatment agent) residue gets stuck in the welding tip, or if the welding tip shifts due to the welding tip hole (wire passage) shifting as the welding wire is fed The welding tip is replaced, but in this case, the welding tip is replaced about once every half a day.

The replacement target values of the arc ON time, the number of arc starts and the welding wire feed weight, which are the tip replacement time factors, can be rewritten as reference values on the 1/2 screen of FIG. Rewriting does not have any effect on the respective integrated values of the chip replacement time factors.・ Calculation of arc ON time The arc welding current value is considered to be 300 A as a reference, and the arc ON time handled here is (arc ON time) = (actual welding time) × (actual welding current value) / (300 A) [min. ] Is calculated and integrated. The actual welding time is determined by the time required for the robot to move during welding. The calculation and integration of the arc ON time are performed at the end point, the temporary stop state point, and the emergency stop state point of the arc welding section.・ Calculation of the number of arc starts The number of arc starts (start of welding start) is simply added up.・ Calculation of welding wire feed amount As described above, the wire feed weight is integrated based on the rotation speed of the feed roller during wire feed and the actual welding time.・ Robot cycle stop If the robot cycle stop is set to valid on the 2/2 screen in Fig. 4, and if the output terminal No that notifies the outside of the welding tip replacement time is ON, the welding cycle will be stopped. The robot can be stopped at the end of a series of welding cycles.

The description of FIG. 4 is completed. Welding tip replacement time factor arc ON time, arc start frequency,
Each integrated value of the wire feeding amount can be grasped at a glance on the management data screen of FIG. 5 in the expression of a percentage with respect to the set value of the tip replacement timing in FIG.

Here, the welding tip replacement time output is turned on.
Is set when any one of the integrated values of the arc ON time, the number of arc starts, and the wire feed weight, which are the chip replacement time factors, is greater than or equal to the respective chip replacement time target values. The condition for turning off the welding tip replacement time output is when the replacement time output terminal is in the ON state and when a signal is input to the reset input terminal. At the same time, the integrated values of the arc ON time, the number of arc starts, and the wire feed weight are reset to the initial state value 0.

If the robot cycle stop is enabled on the 2/2 screen of FIG. 4 and the welding tip replacement time output is turned on, the robot displays the screen of FIG. 6 at the end of a series of welding cycles. And enter the stop state. When the external sequencer receives the welding tip replacement output, the robot executes the welding tip automatic replacement work and causes the robot to automatically replace the welding tip by the tip changer shown in FIG. In the tip changer of FIG. 8, the torch main body in the welding torch is firmly fixed, and the screw is removed without giving an impact force to the robot main body. When this operation is completed, the external sequencer inputs a signal to the welding chip exchange reset input on the robot side, and then restarts the robot to perform a cycle operation.

[0013]

As described above, according to the present invention, the arc ON cumulative time, the arc start cumulative frequency, and the welding wire feed cumulative weight, which are the wear factors of the welding tip, are obtained.
By setting a welding tip replacement target value for each integrated value, a starting condition for automatically replacing the welding tip of the arc welding robot can be created.

When the welding tip is replaced, the robot can be stopped at the end of a series of welding cycles, so that the welding tip can be replaced unattended in addition to stopping the welding line in the middle of the welding section. After welding tip replacement, if a tip replacement reset input signal is input to the robot side, the above integrated values are reset to the initial state value 0, and if a restart input signal is input after this, the robot starts up and the welding line is reset. The previous welding tip replacement function also starts working again.

As described above, the operating rate of the robot or the welding line incorporating the robot can be increased.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a welding robot system according to an embodiment of the present invention.

FIG. 2 Teach pendant diagram that teaches robots movement, various settings, and sequence flow

FIG. 3 is a view showing a screen for setting parameters required for calculating a welding wire feed weight;

FIG. 4 is a diagram showing a screen for setting input / output terminal numbers relating to chip exchange output and setting a guide value for performing chip exchange for each of an arc ON time, the number of arc starts, and a welding wire supply amount. The screen shows the screen to select whether to stop the robot cycle when it is time to replace the chip

FIG. 5 is a diagram showing a screen in which the integrated values of the arc ON time, the number of arc starts, and the welding wire feed amount, which are the tip exchange factors, are displayed as percentages relative to the respective tip exchange execution reference values.

FIG. 6 is a diagram showing a screen when a condition requiring replacement of chips is satisfied and the robot stops.

FIG. 7 is a diagram showing a tip replacement required value for each of an arc ON time, an arc start frequency, and a welding wire feed weight, which are tip replacement factors.

FIG. 8 is an overall view of an apparatus for fixing a welding torch body and automatically replacing a welding tip.

[Explanation of symbols]

 1 Teach pendant (monitor) 2 Robot controller 3 Welding power supply 4 Tip changer

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B23K 9/12 B25J 13/00

Claims (2)

(57) [Claims] [Claim 1 further comprising a data input capable teach pendant in the arc welding robot to perform an arc welding, the arc ON time which is a consumable factor of the welding tip, determined arc start times, the respective integrated values of the welding wire feeder weight , Each integrated value is back
The teach pen
Teach pendant using the target value of the wear factor, which is preliminarily input from the dant, that requires replacement of the welding tip as a guide value.
Rewritable from the
And as a percentage of the corresponding target value
Ndanto can be displayed, these integrated value and at the target value and the one of the integrated value by comparing each welding ends is equal to or higher than the corresponding target value, the outer <br/> section as welding tip essential replacement timing output Controller of the arc welding robot that issues a warning . 2. Output to the outside as welding tip required replacement time
2. An input which can stop the robot at the final point of the arc welding cycle when a warning is issued, turn off the external alarm output in this state, and reset the respective integrated values to initial values. A control device for the arc welding robot according to the above.