JPS62142079A - Work face detecting method in automatic welding equipment - Google Patents

Abstract

PURPOSE:To shorten the operation time in sensing and to improve the accuracy by detecting a work surface with the closing discharging between the work surface and the tip of a contact chip. CONSTITUTION:The state of a contact chip 4b only being projected from the tip of the jacket of a torch 4 is made by retreating an electrode 5 into the contact chip 4b by reversing an electrode feeding roller 6b prior to the sensing. A discharging is then performed with the top of the contact chip 4b approaching to the surface of the work W when the torch 4 is moved for the surface of the work W to be sensed. An electrifying state detecting means 7e transmits the electrifying signal to a control means 9 and the movement of the torch 4 is stopped and the positional information of the tip of the contact chip 4b is taken up as well, and the detection of the surface of the work W is completed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application: i!f) The present invention provides an automatic welding system that performs automatic welding while controlling the relative positions of a workpiece fixture and a torch using an appropriate control means.
This invention relates to a work surface detection method in an lf6 contact device.

(Prior Art and its Problems) The present applicant previously published an automatic melting m'A
i? presented. In this automatic bath bathing device, Ja'
In response to a welding command or a sensor command from the control means, a welding voltage and a sensor voltage are selectively applied to the torch electrode via the voltage marking IJ11 means, respectively, to maintain the energization state between the electrode and the workpiece during sensing. It detects the width and searches for the weld line on the workpiece.

However, when a consumable electrode is used as an electrode, the length of the electrode emitted from the torch depends on the degree of welding of the electrode during welding. ! The most important thing in every encounter is the sweat expert. Also, generally between the electrode supply reel and the torch! The electrode is inserted into the canal, but in the case of C, the protruding length of the electrode is not necessarily kept constant due to changes in the bending state of the canal due to the movement of the torch, and sensing cannot be done in this state. Even if you do 1. Naturally, good welding results cannot be expected in automatic welding performed based on such accurate sensing since the harmful 18 contact R is not detected.

Therefore, the next g of work in t84iJd memory
When sensing n2iIm, the temperature of the torch is determined in advance before the actual sensing. 1, it is necessary to regulate the pole protrusion length to a predetermined length.

Conventionally, this electrode protrusion length has been regulated by setting a reference position at the outer edge of the workpiece fixture, and at one time of sensing, with the torch electrode slightly retracted, the virtual bath 4 at the tip of the torch is set based on a command from the control means. The electrode point is set to meet the reference position iff, the electrode is sent out in this state, and the feeding of the electrode is stopped by obtaining an energization signal between the electrode and the workpiece fixture, or automatic valley contact is made at a location where the workpiece is located. Before finishing the process and moving on to the next sensing, select the destination that has been programmed in advance. Valley γ
At the late blooming point at the final point r (often close to the next sensing and post-bath point), the questions were followed in the same manner. But rxi
In the case of l#, the relative position of the workpiece attachment V↓ and the torch's recollection welding point must be controlled each time sensing is performed, so the time required for sensing will be very long, especially if the torch has a long four-stroke distance. In addition, in the case of a later number, the reference position 1a of the workpiece, which is predetermined for regulating the electrode protrusion quality, is not necessarily accurate for all workpieces. However, the positional misalignment appears as an acid layer with the protrusion length of IEtJjl!) In any case, it is not possible to always obtain an accurate electrode protrusion length: it was not long.

(Means for Solving Problems) The method of detecting a workpiece surface in automatic welding of the present invention is such that the contact tip through which the electrode is inserted and guided is made into a conductor, and the contact tip is installed inside the jacket with a suitable distance protruding from the tip of the jacket of the torch. During sensing, the electrode is drawn into the contact tip, and the voltage applying means applies a sensor voltage to the contact tip directly or through the electrode, and the workpiece fixture or torch is moved in the direction in which the workpiece surface approaches the torch. When the workpiece surface is detected by the proximity change between the workpiece recess and the tip of the contact tip (f!
be a sign.

(Operation) Prior to sensing, the electrode feeding roller is reversed to draw the electrode into the contact tip, leaving only the contact tip protruding from the base end of the torch.

Then, when the torch is moved toward the workpiece to be sensed, the original VI contact tip is emitted close to the workpiece surface, and the torch movement is stopped by the "energization" signal from the energization state detection means. ! +t, the positional information of the tip of the contact tip is acquired, and the detection of the work surface is completed.

When moving to the 1'8 contacting operation, the electrode feed roller is rotated in the normal direction to feed a 9-point electrode approximately corresponding to which electrode retracting claw, and the electrode protrudes from the tip of the contact tip again. The protrusion length from this electrode contact tip is
Since sensing is not performed by itself, there is no need to accurately regulate it. In this way, since sensing is performed using a contact tip whose protrusion length from the tip of the torch jacket is always constant +1j, there is no need for the conventional complicated and time-consuming electrode protrusion length adjustment work.

(Actual Ia example) A detailed description will be given below based on an embodiment shown in one drawing.

Prior to a detailed explanation of the present invention, an automatic welding apparatus 1, which is the background of the present invention, will be explained.

The mouth 'JJ't8P & device 1 has three orthogonal axes (X, Y,
The position can be controlled in the vertical direction [Torch mount 3 shown at the end of the vertical @ Hiiragi control axis 2,
A torch 4 is attached to the torch fixture 3 so that its position can be controlled along two rotational axes α and ψ4QI, an electrode feeding device 6 that feeds an electrode 5 to the torch 4, and a power source that feeds power to the electrode 5. The device 7 and the workpiece W are removably fixed, for example, 21
It consists of a workpiece fixture 8 whose movement position can be controlled in (

The torch 4 is shown in detail in FIG.

A socket 4C is provided in which a contact chip 4b is inserted and fixed in which the jacket 4a is tapered and a through hole 4b+ for inserting an electrode 5 is formed along the center axis inside the jacket 4a.
, 5 contact tip 4b is made of a conductor and is formed on the tip of the contact tip 4b.
The protrusion depth to the base end is specified as a distance of 4A'l. A predetermined pressure 41. is applied from the tip of the contact tip 4b. center of 1
A virtual contact point po is defined on the llI line, and the tip of the electrode 5 protruding from the tip of the contact tip 4b almost coincides with this virtual welding point po, but due to the bending of the electric wire I45 and the welding during welding. The four electrode feeding devices/a6, which do not necessarily match due to the four fathoms, are connected to the electrode 5 around the loop 6a and the 6
A pair of electrode feeding rollers 6b that rolls and drives the electrode 5 led out from the reel 6a in a pinched state to feed the electrode 5 to the torch 4 or rewind it to the reel 6a; and the electrode feeding roller 6b. 10,000 rotation base/help [j111T! It consists of a motor 6C.

Said? [The power source device 7 has a power source 7a that requires a power source connected in parallel.
And the detection power source 7b and the wiring 7C7Si section that slid after the electrode 5 portion coming out from the electrode feeding roller 6b can be attached to the sub power source 7a and 7b so that it can be connected to the auxiliary power source 7a and 7b.
, 'Is the energization state read in parallel to the J seaweed switch 7d and the detection power supply 7b? ll consists of ten stages of detection 7e, and an auxiliary power supply 7a.
・Anti-changeover switch 7 of 7b and energization state detection means 7e
d+tll wiring 7f is connected to the workpiece W via the workpiece fixture 8. The two power supplies 7a and 7b and the changeover switch 7d constitute a voltage Ihn means.

The detection power supply 7bii has a voltage of about 100 to 2, for example.
Use a capacitor with a low current of 111 at 000V. Further, the energization state detection means 7e detects a change in current and/or voltage, and outputs an "energized" signal or a "non-energized" signal.
An IC is provided to send signals to the control means 9.

Next, in the variable contact device 1 having the above configuration, the contact tip 4b of the torch 4 is used as a sensor, and the horizontal member W1 and the vertical member W2, which extend in the Y-axis and X-axis directions perpendicular to each other, are brought into contact with each other. Workpiece W composed of
Regarding sensing the corner fixed weld line WL extending in the X-axis direction, firstly, with reference to the flowchart in FIG. Misao
``Manually operate the +Mff switch on panel 9a,
X-axis, Y-axis, and Z-axis position information x to place the tip of the contact tip 4b at the sensing start position P1 surrounded by two parts FfW1 and W2 using the official seal playback method.
, , y, , z are input together with the sensor command as one step of the user program, and a series of user programs are also input.

1i The computer is activated in auto mode, and the above-mentioned user program is output step by step as command information.Hereinafter, the IF based on the F sensing steps will be explained one by one.

(1) First, it is determined whether the program includes the sensor command flu (Sl).

(2) If it is included, turn it off (switch the switch 7d to the detection power supply 7b side (S2).

(3) The electrode feeding roller 6b is linked to pull the electrode 5 into the contact chip 4b (S3).

(4) Position the tip of the contact tip 4b to the start position P1 (S4).

+51 star) Position P! digit +c'ti'i'-/
II X 1r Yr + Z r is taken in (S5).

(6) Lower the torch 4 from the position P in the X-axis direction around the horizontal member W1 (S6).

(7) When the contact tip 4b is lowered, the tip of the contact tip 4b
iTI When approaching the upward direction f1 of the horizontal member W1, via the electrode 5 which is in constant contact with the contact chip 4b,
A discharge occurs between the contact tip 4b and the horizontal member W1,
The energization state detection means 7e transmits an "energization" signal to the control means 9 (S7).

(8) Location information of the sensing position rIiPt,
Y.

, Z2 (S8).

(9) Stop the descending of the torch 4 (S9), and then raise it slightly (several pg) in the Z-11 direction (S10)
).

QG Is that so? From the figure 6 of the torch 4 at t p, the sensing direction (X, Y・咄) and direction (+, −) are determined at t41 (Sll).

The torch 4 is moved in the determined direction, that is, in the Y-axis direction toward the member W2 (S12).

(2) When the diary is moved, the contact tip 4b comes close to the vertical direction f of the member W2, and a discharge occurs between the two;
The energization state detection means 7C transmits an "energization" signal to the control means 9 (S13).

Q3 The sensing position iii P 4 position information 't'1
lXt, Ys+Z) (S14).

Stop the movement of the α-ka torch (S15), then iTQ
Move back to the starting position WL P E via the position IIF P 3. (S16).

Determine the completion of αQ sensing and switch the changeover switch 7d to the welding power source 7a (S17)n+:u)+i
j Sensing position i+'LP!・P 40) Position 1a information ffl yoll) Calculate and find the position information Xl + 4 + Zl of the intersection position iit p s (S18)
.

(b) From the posture of the torch 4, the base end position Pc (Xc, Yc, Zc) of the contact tip 4b and the contact point P
.

Each axis position if! Find the differences △X, △Y, △Z (S19)
.

(to) l position information of the intersection point position P, Xs, Y4, Z
Calculate the position information X1 - △X, Y, -△Y, Z, -△Z by subtracting △X, △Y, △Z from 1: 1° from 1.520), this is is output as each axis position information of the welding line position pw (S21).

This completes all sensing work. After that, when moving on to the welding work, the electrode feeding roller 6b is rotated in the forward direction only when it is reversely rotated in step S3 (31).

The electrode 5 protrudes from the tip of the contact tip 4b as before. Therefore, as shown in FIG. 5, the torch 4 is moved to the welding line position PW (X, -ΔX, Y, -ΔY.

Fillet welding is performed along the welding line WL including ΔZ).

In addition to the embodiments described above, the present invention can also be modified as described below.

([) The automatic post-bath device may have a mechanical configuration other than the 1α angle coordinate system, for example, an articulated type.

(1) During sensing, the contact tip 4b is the electrode 5,
The detection voltage 71 is connected via the distribution 87C1 changeover switch 7d.
b, but as shown by two points and four glands in Figure 1, branch r mark ta 7 c and connect it to contact tip 4.
1).

(Ill) If it is predicted that at the end of welding, spatter is attached to the base end of the electrode 5 and the sensing 1q and 1λ5 cannot be drawn into the contact tip 4b,
The tip of the electrode 5 may be slightly cut at each end of the receptacle.

(+V) After sensing, if the method shown in FIG. 6 is used to return the electrode 5 to its original position and protrude from the contact tip 4b'IIa4, the order of the work piece, α
The protruding length of the electrode 5 can be accurately regulated according to the welding conditions. That is, the torch 4 is positioned such that, for example, only the center axis is perpendicular to the horizontal direction f of the workpiece W by 7 dimensions. Then, the torch 4 is lowered and the contact tip 4b/self 8. f8 is near-discharged in the horizontal direction f and stops (Fig. 6(a)). Next, the torch 4 protrudes by a desired amount t1 and e
, ・Only the target chick will rise. (Figure 6(b))
. While the torch 4 is stopped at that position, only the electrode 5 is fed, and the contact tip 4 protrudes downward 1-6 from the contact tip 4 o/, e d, V, and when the tip of the electrode 5 discharges near the horizontal 1 river f, the electrode 5 is fed. When the supply is stopped, the protrusion length of the electrode 5 from the tip of the contact tip 4b is precisely regulated to the length e. (V) Although the contact tip 4b has been described as being fixed, there is 4b is attached so as to be movable in the axial direction, and the contact tip 4b is connected to the dt concubine 1 temple and sensing 1 temple 2 (ffi directly position: dot
You can also make it your husband's wife. That is, -gl' si5 moves the contact tip 4b in the distal direction while keeping it fixed, the electrode 5 is completely accommodated in the contact tip 4b, and the mantle 4bffi
2 to the tip of the contact tip 4b is kept constant. In this case, the inner surface of the contact tip 4b and the electrode 5
The additional effect of scraping off spatter attached to the outer periphery by sliding with the outer periphery of the base end is also produced.

(Effects of the Invention) As explained above, according to the workpiece detection method according to the present invention, the contact tip, which is always held at one distance from the tip of the torch, is used as a sensor.
During sensing, a very simple method of replacing the conventional electrode with a contact tip protruding from the torch mantle, which guarantees high sensitivity, has a great effect on shortening the sensing work time and increasing the sensing work time.

[Brief explanation of drawings]

Fig. 1 is an overall schematic diagram of an automatic welding device based on the invention, Fig. 2 is a detailed vertical sectional view of the torch, Fig. 3 is an explanatory diagram of the sensing operation, Fig. 4 is a flowchart, and Fig. 5 is a detailed longitudinal sectional view of the torch. FIG. 6 is an explanatory diagram of the operation after I@, and is an explanatory diagram of the operation showing a method for calculating the protrusion length of the electrode. In the diagram, 1 is self! 11! l bath contact device, 4 is a torch, 4b is a contact tip, 5 is (16 is? d pole feeding device (a, 7
is a power supply device s7'', a welding power source %7b is a detection power source, 9 is a control means, and W is a workpiece.

Claims (1)

[Claims] (1) a workpiece fixture and a torch whose relative positions are controlled by appropriate control means; means for selectively applying welding and sensor voltages to the electrodes of the torch according to commands from the control means; and a means for detecting the energization state of the electrode, wherein a contact tip for guiding the electrode through the torch is made of a conductor and is mounted inside the jacket of the torch so as to protrude an appropriate distance from the tip of the jacket, and at the time of sensing, drawing an electrode into the contact chip, applying a sensor voltage to the contact chip directly or via the electrode by the voltage applying means;
A method for detecting a workpiece surface in an automatic welding device, characterized in that the workpiece fixture or the torch is moved in a direction in which the workpiece surface and the torch approach each other, and the workpiece surface is detected by proximity discharge between the workpiece surface and the tip of a contact tip. .