CN113618204A

CN113618204A - K-TIG welding system and method

Info

Publication number: CN113618204A
Application number: CN202110863911.7A
Authority: CN
Inventors: 欧阳凯; 张新明; 樊云博; 鲍亮亮; 刘文明
Original assignee: China Construction Industrial and Energy Engineering Group Co Ltd
Current assignee: China Construction Industrial and Energy Engineering Group Co Ltd
Priority date: 2021-07-29
Filing date: 2021-07-29
Publication date: 2021-11-09
Anticipated expiration: 2041-07-29
Also published as: CN113618204B

Abstract

The invention discloses a K-TIG welding system, which is different from a traditional TIG fixed wire feeding mode, can automatically identify the width of a large arc of the K-TIG, and sets high and low wire feeding speed areas in the wire feeding process according to the detected value of the arc width so as to perform swinging wire feeding and achieve the aim of one-time welding forming. The invention can effectively utilize the high-energy melting welding wire of the K-TIG welding electric arc to fill the welding seam, thereby effectively solving the welding defects of poor molten pool fluidity, undercut and the like during K-TIG welding and realizing one-time forming of the welding seam. The invention has the advantages of stable welding process, high welding seam quality, lower welding deformation and residual stress, no slag removal after welding, wide application in the welding of materials such as low carbon steel, stainless steel, nickel-based alloy and the like, and increased K-TIG welding production efficiency.

Description

K-TIG welding system and method

Technical Field

The invention belongs to the technical field of K-TIG welding, and particularly relates to a K-TIG welding system and a K-TIG welding method.

Background

The traditional argon arc welding equipment for medium and heavy plates of low-carbon steel, stainless steel, nickel-based alloy and the like has low welding filling efficiency and welding speed not higher than 180 mm/min. The K-TIG welding technology utilizes large current (more than 300A) to generate larger arc pressure, and carries out one-step penetration welding on a medium and thick plate, and because welding materials are not added, the gravity of a molten pool and the larger arc are not added, the undercut phenomenon is easily generated during the welding seam forming.

In various product equipment such as petrochemical industry pipelines, pressure vessels and the like, one-time cover surface welding is needed after one-time K-TIG welding, welding equipment needs to be replaced in the process, interlayer temperature needs to be controlled in special materials such as stainless steel and the like, equipment cost and time cost are increased to a certain extent, and how to realize the real one-time welding seam forming technology of the K-TIG welding is to be perfected.

On the other hand, the K-TIG welding arc is wider, the front width of a one-time welding seam can reach more than 12mm, the diameter of a welding wire for automatic welding is generally about 2mm, and the traditional argon arc welding centering wire feeding mode obviously cannot meet the requirement of one-time welding seam forming of the K-TIG welding. The K-TIG welding speed is as fast as 300mm/min, the molten pool is large in volume and low in fluidity, and the welding wire is difficult to spread to fill the whole welding seam after being melted, so that the defects of undercut, incapability of forming one-time welding seams and the like exist in the process of welding medium plate materials by the K-TIG welding.

Disclosure of Invention

Aiming at the technical problems in the prior art, the invention provides a K-TIG welding system and a K-TIG welding method so as to achieve the purpose of forming a one-time welding seam in K-TIG welding.

The invention provides a K-TIG welding system, which comprises an image acquisition system, an image processing system, a control system, a swing mechanism, a wire feeding mechanism and a welding mechanism, wherein the image acquisition system is connected with the image processing system through a cable;

the image processing system is used for detecting an arc width value under the welding current according to the arc image acquired by the image acquisition system and transmitting the arc width value to the control system; the control system is used for dividing the electric arc into a high wire feeding area and a low wire feeding area according to the electric arc width value and generating swing width so as to control the swing mechanism and the wire feeding mechanism to swing and feed wires.

Preferably, the image acquisition system is a high dynamic industrial camera.

Preferably, the wire feeder comprises a wire feeder connected with a wire guide nozzle through a wire guide rod.

Preferably, the swing mechanism comprises a swing device, a swing center sensor and a wire guide rod clamping mechanism; the oscillator is used for controlling the ball screw to convert rotary motion into linear motion through the servo driving system, and numerically controls and adjusts the oscillation frequency, the oscillation width and the oscillation retention time of the yarn guide nozzle.

The invention also discloses a welding method based on the K-TIG welding system, which comprises the following steps:

s1, presetting swing frequency, swing stay time and high and low wire feeding speeds in a control system; after the arc striking of the welding mechanism is stable, an image acquisition system acquires an arc image, and an image processing system processes the arc image, detects an arc width value under the welding current and transmits the arc width value to a control system;

s2, dividing an arc into four areas equally by the control system according to the arc width value, wherein the arc is 1.5mm away from the bottom of the arc and takes the center of a welding seam as the center, the two ends of the arc are high-speed wire feeding areas, the middle of the arc is a low-speed wire feeding area, and meanwhile, the swing width is generated;

and S3, controlling the swing mechanism by the control system according to the generated swing width, preset swing frequency and swing dwell time, controlling the wire feeding mechanism according to the generated high and low wire feeding areas and preset high and low wire feeding speeds, and performing swing wire feeding until the welding is finished.

Preferably, in S1, the specific method for processing the arc image by the image processing system is as follows: and carrying out image filtering algorithm processing on the arc image, carrying out average calculation on the gray value of each point of a certain window by adopting a neighborhood average method, and replacing the gray value of the central point by the obtained average value.

Preferably, in S1, the arc width at 1.5mm from the bottom of the arc at the welding current is detected.

Compared with the prior art, the invention has the beneficial effects that:

1. based on the defect that the existing K-TIG welding medium and thick plate is difficult to form at one time, the invention collects the width range value of the K-TIG welding arc through a high dynamic industrial camera, the control system automatically adjusts the swinging wire feeding width according to the detection value of the arc width, and sets high and low wire feeding speed areas according to the appearance of the K-TIG welding seam, thereby achieving the purpose of forming the K-TIG welding seam at one time, solving the problem of undercut defect after the K-TIG welding, replacing the face welding process and saving the production time. Different swing wire feeding widths are obtained according to different welding currents, and the device has the advantages of high intelligence, strong self-adaptive capacity, perfect welding bead and the like.

2. The invention saves time and equipment cost, the prior K-TIG welding medium and heavy plate also needs to be subjected to one-section facing welding, the facing welding process is generally MIG or TIG, and one more welding power supply equipment needs to be used.

3. The arc combustion is stable in the welding process, no splashing exists, slag removal is not needed after welding, and energy is saved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a schematic structural diagram of a welding system in an embodiment of the invention.

Fig. 2 is a schematic flow chart of a welding method according to an embodiment of the invention.

FIG. 3 is a schematic diagram of arc image processing according to an embodiment of the present invention.

FIG. 4 is a sectional view of the high and low speed filament feeding areas in the embodiment of the present invention.

In the figure, 1, a welding power supply, 2, an argon gas bottle, 3, a medium plate, 4, a K-TIG welding pool, 5, a K-TIG welding arc, 6, a tungsten electrode, 7, a wire guide nozzle, 8, a high-speed photographic camera, 9, a water cooling machine, 10, a wire feeding oscillator, 11, a servo motor, 12, a wire feeding machine, 13, a control system, 14, an image processor, 15, a fixed beam, 16 and a wire guide rod.

Detailed Description

The following examples are provided to further understand the present invention, not to limit the scope of the present invention, but to provide the best mode, not to limit the content and the protection scope of the present invention, and any product similar or similar to the present invention, which is obtained by combining the present invention with other prior art features, falls within the protection scope of the present invention.

Example 1

Referring to fig. 1, a K-TIG welding system includes a high-speed camera 8, an image processor 14, a control system 13, a wire feed oscillator 10, a wire feeder, and a K-TIG welding device.

The wire feeder comprises a wire feeder 12, the wire feeder 12 being connected to the godet nozzle 7 via a godet bar 16.

The wire feeding oscillator 10 comprises an oscillator, an oscillation center sensor and a wire guide rod clamping mechanism; the oscillator is used for controlling the ball screw through the servo motor 11 to convert the rotary motion into linear motion and numerically controlling and adjusting the oscillation frequency, the oscillation width and the oscillation retention time of the yarn guide nozzle 7. In the welding process, the swing width numerical value signal is determined by the arc width value; the swing center sensor always ensures that the swing width takes the center of the welding seam as a midpoint; the wire guide rod clamping mechanism fills the welding wire into the welding seam through a certain wire feeding angle.

The K-TIG welding equipment comprises a tungsten electrode 6, wherein the tungsten electrode 6 is respectively connected with a welding power supply 1, an argon gas bottle 2 and a water cooling machine 9.

The control system 13 is respectively connected with the wire feeder 12, the servo motor 11 and the image processor 14, and the image processor 14 is connected with the high-speed photographic camera 8; the wire feeding oscillator 10, the servo motor 11 and the high-speed camera 8 are all mounted on a fixed beam 15, and the wire guide rod 16 is arranged in the wire guide rod clamping mechanism.

The image processor 14 is used for detecting the arc width value under the welding current according to the arc image collected by the high-speed camera 8 and transmitting the arc width value to the control system 13; the control system 13 is used for dividing the arc into a high wire feeding area and a low wire feeding area according to the arc width value, and generating a swing width so as to control the wire feeding oscillator 10 and the wire feeding mechanism to swing and feed wires.

Referring to fig. 1 to 4, the welding method of the K-TIG welding system, taking butt welding of Q235 steel plates with a thickness of 10mm as an example, includes the following steps:

s1, setting the swing frequency to be 80T/min, the swing stay time to be 0.1S, the high wire feeding speed to be 1.2m/min and the low wire feeding speed to be 0.5m/min in the control system 13 in advance; after arc striking is stable by adopting the K-TIG welding equipment at the welding current of 520A and the welding speed of 4.4mm/s, the high-speed camera 8 collects an arc image of a K-TIG welding arc 5 in a K-TIG welding pool 4, the image processor 14 quickly processes the obtained arc image, the principle is as shown in figure 3, namely, the arc image is processed by an image filtering algorithm, because the arc area of the arc image of the K-TIG welding has larger gray difference with the surrounding space, the gray value of each point of a certain window is averagely calculated by adopting an averaging method, the gray value of the central point is replaced by the average value obtained in the neighborhood, the edge, the outline, the brightness and the like of the arc image are enhanced, and the K-TIG welding arc outline is conveniently picked up. For the processed arc image, the arc width value at 1.5mm from the arc bottom was detected as 11.2mm, and the signal was transmitted to the control system 13. This process makes control system 13 can be autonomic according to welding conditions automatic selection swing send a width, guarantees that welding wire swing width does not exceed electric arc width scope and continuously melts and fills in the welding seam, has the higher advantage of flexibility ratio, intelligent degree.

S2, referring to fig. 4, the control system 13 divides the arc into four regions equally at a distance of 1.5mm from the bottom thereof with the center of the weld as the center, with both ends being high-speed wire feeding regions and the middle being low-speed wire feeding regions, according to the weld forming characteristics of Q235 steel and the arc width value being 11.2mm, and the swing width generated by the control system 13 is 5.6 mm. According to different arc width ranges generated by different welding currents, the intelligent wire feeding method based on the arc width division has the advantages of high precision, perfect weld forming, simple structure, strong practicability and the like.

S3, the control system 13 controls the wire feeding oscillator 10 according to the generated swing width of 5.6mm, the preset swing frequency of 80T/min and the swing dwell time of 0.1S, controls the wire feeding mechanism according to the generated high and low wire feeding areas, the preset high wire feeding speed of 1.2m/min and the preset low wire feeding speed of 0.5m/min, and performs swing wire feeding until welding is completed, the undercut defects on two sides of the obtained welding seam disappear, and one-time welding seam forming of K-TIG welding is realized.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all equivalent structures made by using the contents of the present specification and the drawings can be directly or indirectly applied to other related technical fields, and are within the scope of the present invention.

Claims

1. A K-TIG welding system is characterized by comprising an image acquisition system, an image processing system, a control system, a swing mechanism, a wire feeding mechanism and a welding mechanism;

2. The K-TIG welding system of claim 1, wherein the image acquisition system is a high-motion industrial camera.

3. The K-TIG welding system of claim 1, wherein the wire feeder comprises a wire feeder coupled to a wire guide nozzle via a wire guide rod.

4. The K-TIG welding system of claim 3, wherein the swing mechanism comprises a wobbler, a swing center sensor, and a guidewire rod clamping mechanism; the oscillator is used for controlling the ball screw to convert rotary motion into linear motion through the servo driving system, and numerically controls and adjusts the oscillation frequency, the oscillation width and the oscillation retention time of the yarn guide nozzle.

5. A welding method based on the K-TIG welding system according to any one of claims 1 to 4, characterized by comprising the following steps:

6. The welding method of claim 5, wherein in S1, the image processing system processes the arc image by: and carrying out image filtering algorithm processing on the arc image, carrying out average calculation on the gray value of each point of a certain window by adopting a neighborhood average method, and replacing the gray value of the central point by the obtained average value.

7. A welding method as defined in claim 5, characterized in that in S1, the arc width at a distance of 1.5mm from the bottom of the arc is detected at the welding current.