JPH1085938A - Method and equipment for multi-layer building-up welding for thick plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To automatically perform a multi-layered building-up welding for a thick plate continuously for each layer with a groove cross section immediately before reflected. SOLUTION: This equipment is provided with a welding torch 16 actuated by a means for setting welding conditions, and with a laser sensor 26 which precedes and moves in front of the welding torch 16 and which detects a groove cross section. This equipment is further provided with a memory for seeking and storing the groove cross section along a torch moving route through a detection signal from the laser sensor 26, a controller which, in welding each layer by the torch 16, obtains groove shape data from the memory and which operates the torch 16 through the means for setting welding conditions so as to meet the welding conditions corresponding to the groove shape data at each position in the moving route of the torch 16. During the welding, the recognition of the groove shape by the laser sensor 26 is performed, as is the automatic formation of the welding conditions suitable for the groove shape; therefore, the welding is possible applicable in real time to a change in the groove and also, with the recognition result stored for the groove shape of one layer, a welding plan is made for the next layer based on such storage, enabling automatic welding from the initial layer to the finish.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for thick layer multi-layer welding, and more particularly to a method and an apparatus using a laser sensor.
The present invention relates to a thick-plate multi-layer build-up welding method and apparatus suitable for automatically performing multi-layer build-up welding adapted to a groove shape from a first layer to a finished layer of a thick plate.

[0002]

2. Description of the Related Art Conventionally, the following two methods are known as a thick plate multi-layer overlay welding method by a robot using a laser sensor.

[0003] First, a welding sensor adapted to each groove shape is calculated while detecting each groove cross-sectional shape by a laser sensor during welding, and a robot is determined based on the conditions (target position of welding torch, welding speed, etc.). This is a method of welding while controlling the welding. This is called real-time tracking.

Second, a groove shape is first detected by a laser sensor over the entire welding line, whereby the entire groove shape on the welding line is grasped. Thereafter, the groove shape is adapted on the detected welding line. This is a method of making a welding plan for the next layer and performing welding. The groove shape is sensed by a laser sensor each time the welding of each layer is completed, and this is repeated for each layer to perform multi-layer welding. This is called dry pass sensing.

[0005]

However, in the former real-time tracking, the groove shape is always detected during welding, so that, for example, even if the welding line is curved,
It is possible to perform welding according to it, but since the laser sensor does not record each detected groove cross-sectional shape, as welding progresses in welding thick plates and approaches the finished layer, the laser sensor There is a problem that it is difficult to grasp the groove cross-sectional shape and it is difficult to continue welding automatically.

In the latter dry pass sensing,
If the welding line is a straight line, the groove cross-sectional shape is detected by the laser sensor even near the start and end positions of the welding line, and the entire groove cross-sectional shape on the welding line can be predicted based on that. When the line is a curve, it is necessary to detect all groove cross-sectional shapes on the welding line. Therefore, in the method of repeatedly detecting the groove shape by the laser sensor before welding each layer, extra time is required for detection separately from welding. In addition, during welding, welding is performed as planned in advance in the welding plan, and the groove cross-sectional shape is not detected by the laser sensor. , It lacks responsiveness and cannot be welded following the detection work.

SUMMARY OF THE INVENTION The present invention focuses on the above-mentioned conventional problems, and makes it possible to automatically perform multi-layer build-up welding of a thick plate continuously for each layer while reflecting the immediately preceding groove cross-sectional shape. It is an object of the present invention to provide a multi-layer overlay welding method and apparatus.

[0008]

In order to achieve the above object, a thick plate multi-layer overlay welding method according to the present invention comprises the steps of: moving a welding torch around a groove of a thick plate welding point; In the method of performing multi-layer build-up welding, the groove to be welded before welding is detected by a sensor encircling with the welding torch to detect groove cross-sectional shape data, and the current welding is performed under welding conditions adapted to the groove cross-sectional shape. At the same time, the groove shape section detected by the sensor is stored, and the welding conditions for the next layer are set based on the groove shape data stored after the welding of the current welding layer, and the next layer is welded. By repeating this continuously for each layer, multi-layer welding suitable for the groove shape from the first layer to the finished layer of the thick plate is automatically performed.

[0009] The thick plate overlay welding apparatus according to the present invention comprises a welding torch operated by welding condition setting means;
A groove section detection sensor that is moved ahead in front of the welding torch, and a storage holding unit that stores a groove section shape along a torch moving path from the groove section detection sensor,
Planning means for planning welding conditions for the next layer by referring to groove shape data along the torch movement path stored during welding of the current welding layer at the time of completion of the current welding layer during each layer welding by the welding torch, A control means for operating a welding torch via the welding condition setting means so as to match welding conditions adapted to the groove cross-sectional shape detected by the groove cross-section detection sensor.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of a method and an apparatus for thick build-up welding according to the present invention will be described in detail with reference to the drawings. As an example of this welding method, an example of a thick-plate multi-layer overlay welding apparatus in which a head plate of a pressure vessel is to be welded will be described.

FIG. 1 is an explanatory diagram of a welding operation state of a circumferential welding apparatus according to an embodiment as a thick-plate multilayer overlay welding apparatus. As shown in the figure, the circumferential welding apparatus is for welding a head plate 12 to an end of a cylindrical pressure vessel main body 10, and rotates the cylindrical pressure vessel main body 10 to which the head plate 12 is temporarily attached around its axis. It has a rotatable support 14 for supporting it. Thereby, the welding line is defined as a circle having a constant radius centered on the axis on a plane orthogonal to the axis of rotation of the container body 10.

A biaxial moving manipulator 18 is provided on the side of the rotary support 14 so that the welding torch 16 can be moved in the horizontal and vertical directions in a plane including the welding line. It can be placed at the position to follow.
That is, the manipulator 18 has a horizontal arm 24 attached to an elevating slider 22 that can move along the column 20, and the horizontal arm 24 is mounted on the elevating slider 22 so as to be horizontally movable. The welding torch 16 is attached to the distal end of the horizontal arm 24. The above configuration enables the welding torch 16 to move on a plane including the welding line.
At the end of the horizontal arm 24, a laser sensor 26 for detecting a groove cross-sectional shape, which is a welded portion, is mounted. The laser sensor 26 is installed at a certain distance from the welding torch 16. ing. In this case, the laser sensor 26 is installed in front of the welding torch 16 in a forward position in the welding progress direction, and detects a groove-shaped cross section before welding.

The welding torch 16 is attached to the distal end of the horizontal arm 24. At the distal end of the arm, the welding torch 16 can be independently moved in two orthogonal directions and rotated about one axis. FIG. 2 shows a skeleton of the torch drive shaft unit 30. A vertical axis 28Z is provided at the tip of the horizontal arm 24,
A horizontal X-axis 28X that moves up and down using this as a guide is provided. A crank portion 28XC is formed on the horizontal X axis 28X, and a horizontal Y
The shaft 28Y is fixed. The welding torch 16 is attached so as to be movable in the axial direction along the horizontal Y axis 28Y. Thereby, the welding torch 16 is connected to the manipulator 18.
In this state, the welding distance can be varied by moving up and down with respect to the welding groove 32 (elevation of the horizontal X axis with respect to the vertical axis 28Z), and weaving can be performed during welding (horizontal Y). The pressure vessel 10 can be rotated by the rotary support 14 to change the welding site of the groove 32. These are operated by an actuator not shown. In addition, the laser sensor 26 is provided at the corresponding position, and in particular, the tip of the horizontal X axis 28X is irradiated with a measurement laser beam toward the groove 32, and the built-in mirror is used to cut the sectional direction of the groove 32. (Horizontal Y axis 28Y direction).

As shown in FIG. 2, the welding torch 16 and the laser sensor 26 are provided with a butt groove 32 of a work comprising the pressure vessel body 10 to be welded and the end plate 12.
At this time, the work rotation direction (arrow A)
On the other hand, the laser torch 26 is arranged ahead of the laser sensor 26, and the welding torch 16 is arranged behind.

In addition to the above-described drive system, a controller 34 and a welding power source device 36 are provided as welding condition setting means for setting various control conditions for performing a welding process (FIG. 1). FIG. 4 shows a system block diagram of the controller 34. As shown, the controller 34
Is a host computer 3 for each axis of the torch 3-axis drive unit 30.
The servo amplifier 4 is controlled by the axis control board 40 inserted in
2 is controlled. The host computer 38 performs all management including the teaching pendant 44, the welding power source 36, and the wire feeding device 46. In addition, a laser sensor controller 48 for controlling the laser sensor 26 is provided, and processing after the control of the laser sensor 26 and the reception of the cross-sectional shape data from the laser sensor 26 (analysis of the groove cross-sectional shape data and based on the result thereof). Generation of welding conditions).

The basic sequence of the welding performed by the above-described apparatus configuration is one-pass welding that makes one round on the circumference. At this one-pass welding, the laser sensor 26 pre-reads the groove cross-sectional shape of the work. Then, the welding conditions are calculated in accordance with the groove shape, and one-pass welding is performed under the welding conditions by controlling each axis of the robot and the welding power source. That is, the welding of one layer is constituted by one pass or several pass welding, but the groove shape data is recorded simultaneously with the detection of the groove cross-sectional shape in the first pass of each layer,
When that layer is completed, the remaining groove shape is estimated based on the recorded groove shape data, and the number of remaining layers and the number of passes of the next layer are planned. Based on this plan, the next layer is welded in each pass as before. By repeating this for each layer, multi-layer welding from the first layer to the finished layer is automatically performed. At this time, the logic for calculating the welding conditions from the first layer to the intermediate layer and to the finished layer is automatically switched in accordance with the remaining groove shape.

The specific welding process will be described with reference to the flowchart of FIG. This welding sequence is basically performed for each round, and firstly, as preparation work, work data (outer diameter, plate thickness, groove type, etc.) is input by key input by an operator. In response, the host computer 38 sets the origin of each axis (step 100). This origin setting is necessary only when the power is turned on. And 1
In order to start welding of the layer, the operator manually moves the two axes (Y, Z) of the torch axis drive unit 30 to the groove measurement start point (step 110). The groove shape measurement position, which is the position of the welding torch 16 after this movement, becomes the reference position for the subsequent welding sequence. Thereafter, the welding start switch is turned on (step 120), and in response thereto, the laser sensor controller 48 turns on the laser sensor 26 (step 130). Thus, the detection of the groove shape is started, and the host computer 38 moves the torch 16 while searching for the welding start point with the laser sensor, and stops at the detected welding start point (step 140).

The host computer 38 issues a one-round welding start command (step 150), turns on the arc from the detected welding start point, rotates the work on the rotary support 14 and starts welding. During welding, in the laser sensor controller 48, the groove shape is detected by the laser sensor, and the generation logic of the welding conditions (including the target position of the torch, the weaving condition, etc.) adapted to the groove shape is executed (step 160). ), The correction value of the target position and the correction value of the welding condition are output to the host computer 38 at a predetermined cycle. This laser sensor controller 48
The host computer 38 controls the torch drive shaft unit 30 and the welding power source device 36 based on the correction values from (step 170).

At this time, the laser sensor controller 48 stores groove shape detection data for one round. When the work makes one rotation, the host computer 38 stops welding (step 180) and moves the welding torch 16 to the standby position. Here, the operator is torch 1
Inspect 6 and clean the nozzle if necessary.

Only when the first pass welding of each layer is completed,
The welding plan of the next layer is executed based on the groove cross-sectional shape data for one round stored in the laser sensor controller 48, the number of passes of the next layer, the welding condition generation logic of the next layer ( An initial layer, an intermediate layer, a finished layer, and the like are determined (step 190).

By repeating such a one-round welding sequence from the first layer to the finished layer, as shown in FIG. 6, it is possible to automatically perform thick plate overlay welding.

As described above, according to the present embodiment, the groove section immediately after welding is detected by the laser sensor 18 at the time of welding orbiting by the welding torch 16, and this detection data is stored, and the data is stored when the next layer is welded. It can be used to set the welding conditions of each layer, so that the welding process of each layer can be performed continuously, greatly shortening the work time of multilayer welding of thick plate welding such as cylindrical pressure vessels Can be.

[0023]

As described above, the present invention relates to a welding torch operated by a welding condition setting means, a groove section detecting sensor which is moved ahead of the welding torch, and a groove section detecting sensor. Memory holding means for storing a groove cross-sectional shape along the torch moving path from the detection sensor, and at the time of completion of the current welding layer upon welding of each layer by the welding torch, along the torch moving path stored during welding of the current welding layer. Planning means for planning welding conditions for the next layer with reference to the groove shape data obtained, and the welding condition setting means so as to match welding conditions adapted to the groove cross-sectional shape detected by the groove cross-section detection sensor. Control means for activating the welding torch through the tool.During welding, the welding is performed while recognizing the groove shape by the laser sensor and automatically generating welding conditions adapted to the groove shape. Real-time adaptive welding is possible for the motion, and the groove shape recognition result is stored in the previous layer, and based on this, the welding plan for the next layer is created. Thus, the effect that the automatic welding can be performed is obtained.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an overall configuration of a thick plate overlay welding apparatus according to an embodiment.

FIG. 2 is a skeleton diagram of a mounting portion of the welding torch and the laser sensor of the apparatus.

FIG. 3 is an explanatory view of an arrangement of a welding torch and a laser sensor.

FIG. 4 is a configuration block diagram of a controller of the apparatus.

FIG. 5 is a flowchart of a welding process according to the embodiment.

FIG. 6 is a sectional view of a groove portion of a welding result.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Pressure vessel main body 12 End plate 14 Rotation support stand 16 Welding torch 18 Manipulator 20 Prop 22 Lifting slider 24 Horizontal arm 26 Laser sensor 28X Horizontal X axis 28Y Horizontal Y axis 28Z Vertical axis 30 Torch drive shaft part 32 Groove part 34 Controller 36 Welding Power supply device 38 Host computer 40 Axis control board 42 Servo amplifier 44 Teaching pendant 46 Wire supply device 48 Laser sensor controller

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B23K 101: 12 (72) Inventor Shintaro Ogawa 3-1-1, Tama, Tamano-shi, Okayama Mitsui Engineering & Shipbuilding Co., Ltd. Tamano Works (72) Inventor Yoshihiro Higo 3-1-1 Tama, Tamano-shi, Okayama Mitsui Engineering & Shipbuilding Co., Ltd.

Claims (2)

[Claims] 1. A method for performing a multi-layer build-up welding on a groove by moving a welding torch around a groove at a thick plate welding point, wherein the welding before welding is performed by a sensor that rotates together with the welding torch. Detected groove cross-sectional shape data to be
The current welding is performed under the welding conditions adapted to the groove cross-sectional shape, the groove shape cross-section detected by the sensor is stored, and the following groove shape data is stored based on the groove shape data stored after welding of the current welding layer. Welding of the next layer is performed by setting the welding conditions of the layers, and this is repeated continuously for each layer, so that multi-layer welding suitable for the groove shape from the first layer of the thick plate to the finished layer is automatically performed. A thick plate overlay welding method characterized by being performed. 2. A welding torch operated by a welding condition setting means, a groove section detection sensor which is moved ahead of the welding torch, and a path along a torch moving path from the groove section detection sensor. A memory holding means for storing a groove cross-sectional shape, and at the time of completion of the current weld layer at the time of each layer welding by the welding torch, referring to groove shape data along the torch movement path stored during welding of the current weld layer, and Planning means for planning welding conditions for the layers, and control means for operating a welding torch via the welding condition setting means so as to match welding conditions adapted to the groove cross-sectional shape detected by the groove cross-section detection sensor. A thick plate build-up welding apparatus comprising: