JPS6281270A - Contact sensor control method - Google Patents

Abstract

PURPOSE:To obtain the correct aiming spot of a welding torch by providing the sense retrying function which can continue the operation without stopping a welding wire even if it comes in contact with the base metal at the sensing motion starting point. CONSTITUTION:The contact type sensor used for a welding robot performs the sensing motion from the teaching point TP1 one before the contact sensing start teaching point TP2 of a welding wire 3. A welding torch 1 performs the motion of retreating in the escaping direction from the base metal 2 automatically when the sensing motion is performed from the teaching point TP1 and the wire 3 comes in contact with the base metal 2 before reaching to the teaching point TP2. The wire 3 performs a new sensing motion by working the sense retry function from said retreating point. The correct aiming spot of the welding torch can thus be obtd. even when the welding wire comes in contact with the base metal at the contact start point.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention temporarily retracts the KSM welding torch when the welding wire is already in contact with the base metal at the starting point of the sensing operation;
Once again, the present invention relates to a contact sensor control method that performs a contact sensing operation.

[Background of the invention]

Contact sensors, along with weld line tracing control, are becoming an indispensable function for welding robots. However, in the contact type sensor, the length of the welding wire changes due to bending of the welding wire or moving in and out from the tip of the torch, making accurate positioning of the welding torch sometimes impossible. This gives a bad impression to the welding condition. Especially when the welding wire is in contact with the base metal from the beginning, there is a possibility that the bath welding wire may be bent, which poses a problem in usage.

[Purpose of the invention]

An object of the present invention is to control a contact type sensor with a sense retry function so that even if the welding wire is in contact with the base metal at the start of contact, the target point of the welding torch can be accurately set by 1. It is about providing law.

[Key points of invention]

In order to achieve the above object, in the present invention, a sense operation is performed from the teaching point one before the teaching point of the contact type sense, and the trap and welding wire come into contact with the base material at the teaching point 1 of the contact type sense. Then, the welding torch automatically retreats in the direction away from the base metal, and senses again from the retreat point.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be cut away using the drawings.

The contact sensor is a method of sensing using a bath contact wire, and FIG. 1 shows this configuration diagram.

In Fig. 1, the welding torch 1 is operated by a button so that the welding wire 3 is sent from the welding wire storage part 5 by the welding wire feeding device 4, and in the case of normal arc welding, information on welding voltage and current is provided. is sent from the robot control panel 9 to the welding power source 6 through the welding machine control circuit 7, and an arc is produced between the welding torch and the base metal 2 to perform welding work. When performing a contact sensing operation, a command is given from the contact sensor control circuit 8 to the high voltage circuit 11, and the welding power source 6. Passing through the welding machine control circuit 7, the bath welding wire feeding device 4
A high voltage is applied to the welding wire 3 and the base metal 2 to detect contact between the welding wire 3 and the base material 2 through a detection circuit 10, and detection information is sent to the robot control panel 9. At this time, the welding torch 1 is moved around at a constant speed.

Next, the contact sensing operation will be explained with reference to FIG. Figure 2 (A)
shows the contact sensing operation of the horizontal fillet, where the welding wire 3 contacts the ice plane of the base metal 2 at TP, the point TP where it contacts the vertical surface, and the final horizontal fillet corner point TP.
e is the goal, and this is what we aim for. The actual sensing operation is T P, MTP, −eT P,
-)T P, -eT P, -+TPe. FIG. 2(B) is for determining the joint portion of the base metal with the downward groove, and the final target point TPe of the welding wire is determined from the contact point TPl + TP 2r TP3 + TP4.

When contact sensing an actual workpiece, if the position of the base material 2 at the time of teaching shifts to the position 2' during playback as shown in FIG. 3(A), the bath welding wire 3 will be It may bend like this. (Touch sense start teaching point T
P is in the workpiece. ) Also, Figure 3 (
If the welding wire is longer than the teaching time and the welding torch is slightly protruding as in B), the welding wire will hit the base metal and be bent.

In this way, even if the workpiece rubs, do not bend the welding wire,
The present invention enables touch sensing operation.

FIG. 4 is a diagram illustrating the internal medicine of the present invention.

Teach point TP, and contact sense start teach point TP.
Normally, there is no contact sensing operation, but this time it has been postponed that the contact sensing operation will be performed during this time. If contact occurs during this time, the robot temporarily retreats at the contact point, activates the sense retry function, and performs a new contact sensing operation.

This flowchart will be explained with reference to FIG. In step 2, the teach point (TP in Figure 4) before the touch sensing operation is
, ), and if so, in step 3, the contact sense operation starting point (TP in Figure 4) is determined.
It is fine if the robot does not make any contact during this time, but if it does, turn off the contact sense signal with step 11, and in step 12, move the robot while performing the sense operation. If the bath welding wire is in contact at the evacuation completion point, an error is determined in step 14, and an instantaneous stop is made in step 15.

In step 5, it is determined whether there is contact at the contact sensing start point, and if there is contact, the robot performs a retreat operation (
Step 7) Start sensing operation again from the escape point (
Steps 8 and 9).

FIG. 6 is a diagram showing the 70-chart in FIG. 5. In FIG. 6(A), the operation is performed from TP to TP,
When it comes into contact with the base material 2' on the way in (B), it performs a retreat operation from the contact point TPs to TPt, and in (C), this TPt
The sensing operation starts again from this point. However, CD
), when the position of TP is already inside the workpiece, a retraction operation is performed, and when the bath welding wire is in contact with the base material, it is treated as an error and instantaneous stop processing is performed.

The robot retreat operation in step 7.12 in the flowchart of FIG. 5 will be explained with reference to the flowchart of FIG. 7 and the diagram of FIG. 8. Step 2 of the flowchart in Figure 7
Perform all wrist axis direction calculations.

This is the X-Y-Z axis coordinate thread in Fig. 8. Taking the center of movement of the welding torch as 0, and considering the direction vector of the welding wire tip TPl, calculate the wrist axis direction. In step 3, it is broken down into X-Y-Z axes and the direction of the wrist axis is determined. Next, in step 4, the amount of retraction on the X-Y-Z axes is calculated. This amount of retraction is set as a parameter so that the customer can decide on the amount. In step 5, add the retreat amount of each X-Y-Z axis to the robot's current position, output the movement amount to each axis in step 6, and move the robot in step 7 to perform robot retreat operation. It is something.

An example of the touch sense glue trial operation is shown in FIG. 9 through such an operation. In FIG. 9(A), the welding torch is retracted in the opposite direction, and the retraction amount changes depending on the setting parameters.

Further, (B) is for retracting the robot horizontally and vertically with respect to the welding surface, and (C) is for retracting the welding torch upward.

〔Effect of the invention〕

According to the present invention, it is possible to avoid the bending of the welding wire due to the shift of the workpiece during the contact sensing operation, and even if the welding wire is bent before the contact sensing start point. Even if the robot comes into contact with a material, the robot does not stop there, but retreats and then performs the sensing operation again, so the robot can be operated continuously.

[Brief explanation of drawings]

Figure 1 - Contact sense system configuration diagram, Figure 2...
Contact sense operation diagram, Figure 3...Touch sense failure diagram, Figure 4...Touch sense forehead 1 work explanation diagram, Figure 5...Touch sense operation flowchart diagram, Figure 6...Contact use Detailed cut-away diagram of sense operation, Fig. 7...Evacuation movement coordinate system clear diagram, Fig. 9...Detailed view of the direction of evaporation, 'i-aki...'・Bath welding torch, 2, 2'... Base material, 3.
... Welding wire, 4... Welding wire feeding device, 5...
・Welding wire storage section, 6... Bath contact power source, 7... Welding machine control (ro) path, 8°°゛ Contact sensor control circuit, 9...
・Robot control panel, 1000. Detection path 1, 11...F
j, H-circuit, TP,, TP,. TPB, TP4. TPe, TP,', TPs, TPt・
・Robot movement point, 4 ・Robot base salary, XP, ・
... Torch direction X-axis amount, YP, -)-f direction Yllllt,
zp. ...Torch direction Z-axis amount, 0...Torch horizontal movement angle, α...Torch vertical movement angle 2\((2) Fig. 2 Fig. 3 Fig. 4 Fig. 6 Fig. $6 Fig.しに、、、、−、7、2、。 7th $ 8 Figure $ q Figure

Claims (1)

[Claims] When the welding wire is already in contact with the base metal at the sensing start point of the contact sensor used in welding robots, we have developed a sensor that allows the welding wire to continue operating without stopping.
Contact sensor control method with retry function.