JPH0549387B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an automatic welding device with a sensor.

Conventional technology When performing multi-layer welding on a grooved workpiece, a conventional automatic welding device with a sensor uses a sensor that detects the groove position and groove cross-sectional area before welding the first layer, and uses the sensing data of the sensor to It was stored in memory in correspondence with the welding line position on the workpiece, and the torch tracing and welding conditions were controlled not only for the first layer but also for all layers.

A contact type sensor as shown in FIG. 2 was often used as a sensor. That is, the position of the groove 11 of the groove workpiece 10 is determined by the position detector 15 as a position in a direction (Y direction) that almost perpendicularly traverses the welding line at the midpoint of the width of the roller of the roller type contact sensor 14 (point P). More can be obtained. The groove cross-sectional area S is the groove angle θ
is constant, the distance difference between the roller width W of the contact sensor 14, the position detector 15 of the contact sensor 14, and the position detector 17 of the contact sensor 16 in the plate thickness direction (Z direction), that is, the distance of the contact from the base material surface. From the distance d to the bottom end, S=cotθ/2・(1/2W+dtanθ
/2) It can be found by calculating ² .

Based on the groove position obtained in this way, for the second and subsequent layers, the torch tracing is controlled so as to have some offset in the Y direction, and the cross-sectional area S
The welding conditions (welding current, welding voltage, welding speed) of each layer were controlled so that the amount of excess welding was deposited.

Problems to be Solved by the Invention Since the welding conditions for all layers were controlled by the groove cross-sectional area before welding the first layer, the following problems occurred.

(1) Since sensing is performed only once, if the amount of welding that was intended to be controlled differs from the actual amount of welding due to variations in the material of the workpiece, there will be a large difference after the final layer is welded.

(2) The effect of thermal strain on the workpiece before and after welding the first layer is much greater than before and after welding the second and subsequent layers, and welding conditions based on the cross-sectional area before welding the first layer are not suitable. I couldn't do proper welding.

(3) Contact sensors were susceptible to the effects of spatter and dirt, and had poor cross-sectional area detection accuracy. Furthermore, it was not possible to detect the cross-sectional area of the first layer after welding.

(4) When welding the first layer, emphasis must be placed on controlling the Uranami (bead shape on the back side), but the relationship between the detected cross-sectional area and the amount of welding is not necessarily constant, and the welding conditions for the second and subsequent layers must be controlled. Difficult to control.

Means to solve the problem In an automatic welding device with a sensor that controls welding conditions based on sensing data from a sensor,
A non-contact optical distance sensor is used that sequentially obtains distance information to the object surface and detects the cross-sectional area while crossing the welding line in a direction approximately perpendicular to the weld line. The control device of the sensor-equipped automatic welding device is provided with a ROM programmed so that the CPU detects the cross-sectional area and controls the welding conditions based on the sensing data.

Function During multi-layer welding, the cross-sectional area of at least one of the second and subsequent layers before welding is detected, and welding conditions are controlled based on the cross-sectional area.

The final layer is included as a layer whose cross-sectional area is detected before welding the second and subsequent layers, and the welding conditions are controlled so that the final layer has a welding amount equal to the sum of the detected cross-sectional area and the excess amount.

Embodiment A case will be described in which the automatic welding device with a sensor of the present invention is applied to submerged two-layer welding using one electrode (torch).

In FIG. 1, the non-contact sensor 2 provided in front of the torch 3 detects the groove 11 of the groove workpiece 10 up to the front layer, that is, the first layer, as shown in FIG.
Detect the cross-sectional area 18 of the layer weld bead 12, and when the torch 3 comes to the sensing point,
The control device 1 consisting of CPU, ROM, RAM, etc. sets the welding conditions (welding current, welding voltage, welding speed)
control.

The non-contact type sensor 2 is attached to a sensor support column 2b by a sensor mounting base 2a, and the sensor and torch mechanism 5 is used to move the groove direction, which is a weld line, in a substantially perpendicular direction along with a torch 3 attached to a torch support column 3a. can operate. Flux 6 is supplied from a flux container 6a through a hose 6b. The wire 8 is supplied to the torch 3 from a wire reel 8a. 13 is a weld bead covered with flux.

The entire welding device is mounted on a rail 9 by wheels 7 of a trolley 4.
move along the top in the direction of the weld line.

As a non-contact sensor 2, an optical distance sensor that emits a spot light onto the object to be measured and captures the optical image on the object with a PSD (position sensitive device) to detect the position using the principle of triangulation can be used to detect welding. Since distance information to the surface of the object can be obtained by crossing the welding line almost perpendicularly, the cross-sectional area can be easily obtained by sequentially obtaining distance information by crossing the welding line almost perpendicularly.

Of course, when welding the first layer, the non-contact sensor 2 controls the tracing of the torch 3 and the welding conditions. The tracing control is also performed for the second and subsequent layers based on the groove position data of the first layer.

The amount of welding should be such that the first layer has an optimal Uranami (bead shape on the back side), and the final layer should be the sum of the cross-sectional area of the groove and the amount of excess welding.

When welding three or more layers, the amount of welding between the first layer and the final layer is determined by determining the standard cross-sectional area of the remaining groove for each layer and calculating the amount of detected cross-sectional area - standard cross-sectional area, or by determining the detected cross-sectional area. is divided by the remaining number of welds.

It is also possible to perform only the sensing of the cross-sectional area before welding a layer and then weld that layer afterwards, and it goes without saying that this can be done in the same way in the case of multiple electrodes (torches).

In addition to submerged welding, it can be applied to CO ₂ and MAG welding, and it can also be applied to welding workpieces with joints such as fillets.

The layer that performs sensing is configured in advance in the control device 1.
Save it as a program to control the CPU.

Advantages of the invention (1) Since sensing is performed many times, even if the amount of welding that is intended to be controlled differs from the actual amount of welding, a correction effect works for each sensing, so the deviation in the amount of welding after welding the final layer is small. .

(2) Can cope with changes in groove cross-sectional area due to thermal strain. In particular, the effect of thermal strain before and after welding the second and subsequent layers is small, but the effect of thermal strain before and after welding the first layer is large, so welding conditions are controlled based on the cross-sectional area detected for the second and subsequent layers. Accurate control of welding amount is possible. Particularly when the method is based on detecting the cross-sectional area of the final layer before welding, the amount of welding can be accurately controlled.

(3) Non-contact sensors are less affected by spatter and dirt.

(4) Except for the first and final layers, the amount of welding can be determined directly from the detected cross-sectional area, making it easy to control welding conditions.

(5) Appropriate welding can be performed automatically and without human intervention up to the final layer.

(6) Detection of groove cross-sectional area and welding can be performed simultaneously, improving efficiency.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of an automatic welding device with a sensor according to an embodiment of the present invention, FIG. 2 is an explanatory view showing a conventional contact type sensor, and FIG. 3 is an explanatory view showing the amount of welding on a groove. 1...Control device, 2...Non-contact sensor, 3...
... Torch (electrode), 4 ... Cart, 5 ... Sensor and torch mechanism, 10 ... Groove work, 11 ... Groove, 12 ... Weld bead up to the previous layer, 18 ... Detection cross-sectional area, 19... Surplus amount.

Claims (1)

[Claims] 1. An automatic welding device with a sensor that is equipped with a sensor that detects information on a welding line, a dolly or robot hand as a means for moving a welding torch, and a control device, and that controls welding conditions based on sensing data from the sensor. In the case of multi-layer welding, the sensor uses a non-contact optical distance sensor that sequentially obtains distance information to the object surface and detects the cross-sectional area so as to cross the weld line almost perpendicularly. An automatic welding device with a sensor that detects the cross-sectional area of at least one layer before welding, and the control device is capable of setting welding conditions based on the cross-sectional area, and the control device controls the welding torch. .