JPS6330175A - Automatic profiling device for narrow gap submerged arc welding machine - Google Patents

Abstract

PURPOSE:To execute automatic profiling with high accuracy without being subjected to a thermal influence of a welding torch, by using the up-and-down, and the right and left profile detectors of an indirect contact type, executing a visual observation and monitoring by a monitor television and driving the welding torch upward and downward, and to the right and left, at the time of bringing a U-shape narrow groove of a thick wall steel plate, to submerged arc welding. CONSTITUTION:At the time of bringing a U-shape narrow gap 27 of a thick wall steel plate base material of >=300mm, to submerged arc welding by a welding torch 6, a groove side face profiling right and left profile detector 4, and an up-and-down profile detector 21 for profiling a gap bottom part, of an indirect contact pipe are driven simultaneously by a motor 5 and a motor 22, respectively. Its detecting signal is received by a control board, welding is observed visually by a television by a monitor television camera 2, and welding is executed by driving the welding torch 6 of a welding head 7 right and left, and up-and-down driving devices 14, 15 in accordance with a signal from the control board. Both the detectors 4, 21 for a gap are an indirect contact type, therefore, a weld joint having a high quality can be formed without being influenced by a high temperature of the welding torch 6.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention provides an automatic narrow gap submerged arc welding machine for performing multilayer welding by submerged welding by providing a U-shaped groove in thick steel plates and thick cast steel. The present invention relates to a copying device.

(Prior Art) In recent years, as welded structures have become larger, efforts have been made to improve the performance and save energy of welded joints. Among them, the narrow gap welding method has been developed because it is easy to reduce welding man-hours, welding materials, welding distortion, etc., and the narrow gap submerged arc welding method (hereinafter referred to as NG-3AW) and the narrow gap MIG method are being developed. etc. have been put into practical use.

A U-shaped groove is provided for thick-walled steel plates and thick-walled cast steel, and NG-3
When performing multilayer welding by AW, the groove angle is 9th.
As shown in the figure, a narrow angle of 2° to 4° is used.

There are two types of bevel tracing sensors used in the automatic tracing system of the NG-3AW: a contact type and a non-contact type.
There is a stylus method that converts displacement into an electrical quantity even if it is detected by an electrical contact, and although the mechanism is simple, there is a limit to tracing accuracy.Non-contact methods include an electromagnetic method and an image processing method using a television. However, the electromagnetic method does not allow close proximity of the arc, and the television method allows for real-time detection but is extremely costly, and contact sensors are commonly used, but they are still in the development stage.

Conventional copying devices are mainly left-right copying devices for shallow development. For example, when constructing a groove in a pressure vessel with a plate thickness of about 60 mm, the welding torch height must be adjusted approximately 3 to 3 times per round.
This was done manually according to the height of 5 mm + weld bead, and left and right scanning was manually adjusted using a simple scanning method that combined a detector consisting of a scanning roller. The vertical scanning detector doubles as a left and right scanning detector, and does not reach the point where it can copy the bottom of a thick groove.

Therefore, groove tracing control in narrow gap welding has been at the discretion of the welding operator.

(Problems to be solved by the invention) When performing NG-3AW on a thick cylindrical plate with a wall thickness of 300 mm and an outer diameter of about 2000 mm, a preheating temperature of 100 to 150°C is required for the purpose of preventing cold cracking. Although it is necessary to operate equipment near the nozzle to maintain groove accuracy, high-temperature preheating hinders the welding operator's ability to maintain concentration.

Welding defects occur due to misalignment of the core wire, and when a welding defect occurs, the groove needs to be reworked because local repair is impossible due to the narrow groove, the groove rework cost is high, and the groove tracing accuracy is reduced. This has a large effect on welding quality, welding workability, and welding costs, and in particular, a large number of welding workers are required to ensure stable quality.

Various types of tracing methods, such as contact sensors and non-contact sensors, have been tried in the past for left-right scanning detectors, but in the case of deep groove welding, there is a misalignment between the scanning position and the welding arc position, and this has not been put to practical use. In addition, in the case of visible arc such as MIG welding that does not use flux, there are methods such as image processing using a television camera, but this has not yet been controlled. Furthermore, there are cases where the vertical scanning detector is used as a left/right scanning detector, but it has not reached the point where it can copy the bottom of a thick-walled groove.

The automatic copying device of the narrow gap NG-3AW machine, which is equipped with upper and lower copying simultaneously, stabilizes quality and improves welding workability.

Although it was requested to reduce welding costs, there was a problem with the groove tracing accuracy due to groove tracing control, and it was still a trial and error process, so it has not been widely used.

(Means for Solving the Problems) The present invention aims to provide an apparatus capable of eliminating and improving unresolved problems in copying apparatuses of the prior art, and the present invention is directed to providing an apparatus capable of eliminating and improving unresolved problems in copying apparatuses of the prior art. The above objects can be achieved by providing a method as described in the scope. That is, it is an automatic tracing device for a narrow gap submerged arc welding machine that performs multilayer welding by submerged welding by providing a U-shaped groove in thick-walled steel plates and thick-walled cast steel; a drivable left-right scanning detector that copies the bottom of the U-shaped bevel and a drivable vertical scanning detector that copies the bottom of the U-shaped bevel; a control panel that receives signals from displacements detected by the left-right scanning detector and the vertical scanning detector; The system that received the signal? Under the control of the III panel, the left and right scanning detectors and the vertical scanning detector are caused to follow the displacement.The left and right scanning drive motors and the vertical scanning drive motors are controlled simultaneously by the control panel; the welding torch left and right drive motor and the welding torch vertical drive. Welding torch left and right drive means and welding torch up and down drive means that drive the motor and control the torch to a predetermined position; and a welding torch up and down drive means that drives the motor and controls the torch in a predetermined position; and a monitor television that monitors the welding torch that welds the bottom of the groove using the television camera; and while monitoring the monitor television, the left and right copying drive motor, the vertical copying drive motor, and the welding torch left and right drive. an operation panel that manually drives the motor and welding torch vertical drive motor; and a counter that frames the welding head and smoothly drives the welding and nods to smoothly drive the welding torch vertically. A welding torch vertical drive motor that is provided with a weight and drives the welding head up and down, and a welding mechanism frame that includes a welding torch drive means, and a welding torch left and right drive motor that drives the welding mechanism frame left and right, and a welding torch left and right drive. The present invention relates to an automatic tracing device for a narrow gap submerged arc welding machine, which has a fixed plate including means;

Next, the present invention will be explained in detail.

The device of the present invention is an automatic copying device for the NG-5AW machine, which has indirect contact type left and right, top and bottom sensor monitor televisions, and is capable of welding cylinders up to 300 mm in wall thickness and uses automatic groove copying control.

The present invention will be described with reference to FIG. 1, which is a perspective view showing an overall schematic view of an embodiment of an automatic copying apparatus of the present invention.

As shown in FIG. 1, the device of the present invention includes a left and right tracing detector 4 that can be driven to trace the side surfaces of a U-shaped groove 27 provided in a base material 11, and a left-right tracing detector 4 that can be driven to trace the bottom of the U-shaped groove 27. a control panel 20 shown in FIG. 2 that receives signals from the displacement detected by the vertical scanning detector 21, the horizontal scanning detector 4, and the vertical scanning detector 21; and control from the control panel 20 that receives the signals. A left and right scanning drive motor 5 causes the left and right scanning detector 4 and the vertical scanning detector 21 to follow the displacement. Welding torch left and right drive means 25 for controlling the welding torch 6 to a predetermined position by driving the welding torch left and right drive motor 14 and the welding torch vertical drive motor 15 under the control of the vertical scanning drive motor 22 and, at the same time, the control panel 20. Welding torch vertical drive means 23, and the left and right scanning detector 4. Vertical scanning detector 21
A television camera 2 and a lighting 3 are installed on a cantilever beam 1 fixed to a welding head 17 carrying a welding torch 6. As shown in FIG.
Weld the bottom of the welding torch 6 Welding The wire 8 protruding from the welding torch 6 does not cover the flux 13 supplied from the flux nozzle 7 at an appropriate magnification to monitor the bare area. Figure 2 printed in the direction.

A monitor television 19 shown in FIGS. 4 and 5.

While monitoring the monitor television 19, the left and right scanning drive motors 5. Vertical copying drive motor 22 and welding torch left and right copying drive motor 14. The operation panel 10 shown in FIG. 2 for manually driving the welding torch upper and lower tracing drive motors 15, the welding head 17, and the welding head 17 are constructed to smoothly drive the welding throat 17 and the welding torch. Counterweight 2 that can smoothly drive vertical copying of 6
4, a welding torch vertical tracing drive motor 15 for vertically driving the welding head 17, and a welding torch vertical driving means 2.
The welding mechanism frame 16 is equipped with a welding mechanism frame 16 including
This device has a welding torch left and right drive motor 14 that drives the welding torch left and right, and a fixed plate that includes a welding torch left and right drive means 25.

The left and right scanning detector has a U-shaped groove 2 as shown in FIG.
7. A copying roller 28 provided at the tip of a sensor arm 18 having a pin 12 provided on the upper side surface; A striker is installed on the opposite side of the copying roller 28 centering on the pin 12.
29 is provided, and the movement of the copying roller 28 is detected by the sensor arm 1.
8, the striker 29 is moved and a signal is sent from the contact sensor 30 to the control panel shown in FIG. It has a contact type sensor 30 that simultaneously drives the welding torch left and right drive motor 14 under the control of the control panel 20 to control the welding torch 6 to a predetermined position, and a spring that adjusts the degree of contact of the copying roller 28. 31, a limit striker 32 for preventing overrun in the left and right direction, and a limit switch 33.

As shown in FIG. 7, the above-mentioned vertical scanning detector
7 Sensor arm 1 having a pin 12 disposed at the bottom
8 and the copying roller 28 provided at the tip of the pin 12
A striker 29 is provided on the opposite side of the copying roller 28 with the center at . A signal is sent to the control panel 20 shown in FIG. 2. Under the control of the control panel 20, the vertical copying drive motor 22 is driven, and at the same time, under the control of the control panel, the welding torch vertical drive motor 15 is driven to move the welding torch 6 to a predetermined position. A bar 31 that has a contact sensor 30 that controls the position and adjusts the degree of contact of the copying roller 28, and a limit striker that prevents overrun in the vertical direction.
32, Rimisoto Sui Nochi 33 is structured.

Vertical scanning detector 2 of an embodiment of the automatic copying device of the present invention
The vertical effective stroke of 1 is 300mm.

The effective stroke in the left and right direction of the left and right copying detector 4 is 30mm.
, The effective stroke of the 7-contact torch copying left and right drive means 25 is 350 mm, similarly) 8-contact torch vertical drive means 23
The effective stroke was 400 mm.

FIG. 2 is a system diagram of the apparatus of the present invention. The horizontal and vertical displacements detected by the left-right scanning detector 4 and the vertical scanning detector 21 are input into the control panel 20, thereby driving the left-right scanning drive motor 5 and the vertical scanning drive motor 22, and at the same time, the welding torch left-right driving motor. 14 and the welding torch vertical drive motor 15, the displacement between the scanning surface detected by the left-right scanning detector 4 and the vertical scanning detector 21 is corrected, and the welding torch is controlled to the correct position.

FIG. 3 is a sectional view showing the positional relationship between the television camera 2 and the groove. The welding operator should check that the symbol m shown in FIG.
monitor the naked parts of the body.

FIG. 4 shows the case of one pass per layer, and the welding torch 6 is located at the center of the U-shaped groove.

Figure 5 shows the case of 1 layer and 2 buses, and welding torch 6 in the first pass.
This shows a state in which the position is shifted from the left side of the U-shaped groove to the right side, and the symbol n shown in the figure is shifted by 4 to 6 mm. Similarly, the welding torch 6 is placed at a position shifted to the left from the right side of the U-shaped groove in the 2-bath. In this case, during automatic welding, the welding torch 6 is automatically copied by the welding torch copying drive device, but the welding torch 6 is automatically copied to a predetermined position by a remote control by switching to manual operation using the operation panel 10.

When using the device of the present invention, the contact sensors of the left and right and top and bottom scanning detectors are of indirect contact type, so the contact sensors are not affected by welding heat, and by reducing the size of the scanning roller and sensor arm, the bottom of the U-shaped groove can be NG-3 which improves the tracing accuracy by copying directly above the weld bead of
AW allows remote control from start to finish of welding without the influence of high-temperature preheating while visually monitoring the monitor TV from start to finish of welding. ■ When welding one pass layer, only one operator can perform high-temperature work. Preheating management reduces the physical and mental strain on workers due to long welding hours, greatly improving welding workability.

Construction management was sufficient, making it possible to stabilize quality and reduce welding costs.

Next, the present invention will be explained with reference to examples.

(Example) The chemical composition 1 mechanical properties and heat treatment conditions of the 5FVQ2B material used as a tower link material are shown in Table 1, and the shape of the welded object and narrow groove joint are shown in Figure 8 [al, (b) ). By configuring the shape of the narrow gap joint so that it is in contact with the copying roller 28 as shown in Figure 8 (bl), the copying roller 28 influences the flux 13 when submerged arc welding is performed on the upper part of the narrow gap 27. In addition, when the copying roller 28 and the welding torch 6 are lifted up by the television camera 2, the welding torch 6 can be prevented from being visible due to the pattern matching, and automatic welding can be performed up to the upper end of the narrow gap.

Normally we use 70kg/m2 welding material, but due to inventory we used 60kg/mm" class KB-120XKW.
-1008 was used. Chemical composition 5 mechanical properties of weld metal are shown in Table 2.

Welding is done using wire diameter φ4. Large coil 75kg and 25kg
Welding was carried out by two welders using a roll. The welding conditions are shown in Table 3.

The object to be welded was placed on a turning roller, and NG-3AW was applied while rotating it. The welding workers and welding operators were always in front of the monitor TV on the floor, and the other workers were in charge of supplying flux, grinding the slag, cleaning the slag, and instructing the timing of the transition between two baths and one layer. . The welding was completed smoothly without arc interruption or other problems, no defects were observed, and penetration was uniform.

(Effects of the Invention) The automatic copying device for NG SAW welding machines according to the present invention has contact sensors for left/right and top/bottom copying detectors that are indirect contact types, so the contact sensors are not affected by force, contact heat, and copying is possible. By making the shape of the roller and sensor arm smaller, it traces directly above the weld bead at the bottom of the U-shaped groove, improving tracing accuracy.The NG-3AW, with a wall thickness of up to 300 mm, can visually monitor the monitor from the start to the end of welding. However, there is no effect of high-temperature preheating, and remote work can be performed from the start to the end of welding, reducing the physical and mental burden on the worker due to long hours of high-temperature welding work, and greatly improving welding work efficiency. As a result, preheating management and construction management can be adequately performed, quality can be stabilized, and welding costs can be reduced, which is extremely effective.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an overall schematic diagram of an embodiment of an automatic copying device for an NG-3AW welding machine according to the present invention. FIG. 2 is a system diagram of the apparatus of the present invention. FIG. 3 is a sectional view showing the positional relationship between the television camera and the groove. FIG. 4 is a diagram showing the monitor screen when welding one layer and one bus. FIG. 5 is a diagram showing a monitor screen during one-layer two-pass welding. FIG. 6 is an overall schematic diagram of the left-right copying device of the present invention. FIG. 7 is an overall schematic diagram of the vertical copying device of the present invention. Figures 8(a) and (bl are longitudinal cross-sectional views showing the shape of the welded object and narrow-gap joint used in the examples, respectively. Figure 9 shows the narrow-gap welded object when performing multilayer welding with NG-3AW) It is a diagram showing a longitudinal cross-sectional view of an object. l... Beam, 2... Camera, 3... Illumination. 4... Left and right scanning detector, 5... Left and right scanning drive motor. 6...・Wire, 9...Scale, 10...Operation panel. 11...Base metal, 12-...Pin, 13...Flux 114...Welding torch left and right drive motor. 15...Welding torch Vertical drive motor. 16... Welding mechanism frame, 17... Welding head. 18... Sensor arm, 19... Monitor TV. 20... System? 111 board, 21... Vertical copying detector 1
22... Vertical copying drive motor, 23... Welding torch vertical drive means 124... Counter weight 25...
- Welding torch left and right drive means, 26... fixed plate. 27... U-shaped bevel, 28... Copying roller. 29... Striker-930... Contact sensor. 31...Spring, 32...Limit striker-13
3...Limit switch.

Claims (1)

[Scope of Claims] 1. An automatic tracing device for a narrow gap submerged arc welding machine that performs multilayer welding by submerged welding by providing a U-shaped groove in thick-walled steel plates and thick-walled cast steel, comprising: A drivable left and right scanning detector that copies the side surface of the U-shaped groove and a drivable vertical scanning detector that copies the bottom of the U-shaped groove; A control panel receives the signal; Under control from the control panel that receives the signal, the left and right scanning detectors and the vertical scanning detector are controlled by a left and right scanning drive motor, a vertical scanning drive motor that causes the vertical scanning detector to follow the displacement, and at the same time, by control of the control panel, Welding torch left and right drive means and welding torch up and down drive means that drive a welding torch left and right drive motor and a welding torch up and down drive motor to control the torch to a predetermined position; the left and right scanning detector, the vertical scanning detector and the welding torch; a television camera and lighting provided on a beam fixed to a mounted welding head; a monitor television that monitors a welding torch for welding the bottom of the groove with the television camera; and a monitor television that monitors the welding torch that welds the bottom of the groove with the television camera; , an operation panel for manually driving the vertical profiling drive motor, the welding torch left and right drive motor, and the welding torch vertical drive motor respectively; A welding torch that is equipped with a counterweight that can smoothly drive the welding head vertically, and a welding mechanism frame that includes a vertical drive motor that drives the welding head vertically and a welding mechanism frame that includes a welding torch drive means, and that drives the welding mechanism frame left and right. An automatic tracing device for a narrow gap submerged arc welding machine, comprising: a fixed plate including a left and right drive motor and a welding torch left and right drive means; 2. The left and right copying detector includes a copying roller provided at the tip of a sensor arm having a pin disposed on the side surface of the U-shaped groove; and a striker provided on the opposite side of the copying roller with the pin as the center. ; A contact type sensor that converts the movement of the copying roller into rotational displacement via a pin by a sensor arm to move a striker, and sends a signal from the contact type sensor to a control panel;
2. The device according to claim 1, comprising: a spring for adjusting the degree of contact of the copying roller; a limit striker for preventing overrun in the left-right direction; and a limit switch. 3. The vertical copying detector includes a copying roller provided at the tip of a sensor arm having a pin disposed at the bottom of the U-shaped groove; and a striker provided on the opposite side of the copying roller with the pin in the center. ; A contact sensor that converts the movement of the copying roller into rotational displacement via a pin using a sensor arm to move the striker, and sends a signal from the contact sensor to the control panel; A spring that adjusts the degree of contact of the copying roller and the left/right direction. 2. The device according to claim 1, comprising: a limit striker for preventing overrun; and a limit switch.