Round Bar Laser Engraving Robot

The high-temperature laser marking robot is applied to the bar production line. It is located at the end of the chain conveyor and performs online laser marking on the end face of the rolled piece with a size of Ø50mm to Ø160mm.

The system mainly includes a robot spraying system, character recognition system, electronic control, etc.

 

1. Working principle of the laser marking robot

Special high-temperature-resistant paint is evenly and continuously fed into the spray gun pipeline by a pneumatic diaphragm pump, and then the spray gun is controlled by the robot to spray the primer on the end face. The 3D vision system recognizes the center and distance of the end face and guides the robot to perform laser melting. Beam spray printing, followed by taking pictures of the end face of laser spraying, and identifying characters for archiving.

 

2. System workflow:

• During the process, the chain conveyor runs to the working area (the interlocking signal equipment shall be provided by the supplier);
• The robot moves to the spraying area;
• The robot recognizes the bar placement position (center position and distance);
• The robot performs the work of spraying the primer;
• The robot performs the laser coding action;
• The robot returns to its original position and waits for the signal of the arrival of the next group of bars.

 

3. Main technical features

1) The spraying system with a new structure is specially designed for the high operating rate and harsh environmental conditions of steel mills. A low ambient temperature inside the nozzle head is ensured by forced air cooling.

2) The font and font size can be adjusted, the spraying speed is fast, and all uppercase and lowercase letters, numbers, and special symbols can be sprayed.

3) Design and manufacture according to standardized modules, and high-precision coupling with industrial robots. The whole system has high reliability and a low maintenance rate. The control system (standard configuration is Siemens S7-1200) has a standard interface that can be connected to the factory host computer and is connected to the system designated by Party A. The labeling content is transmitted through the upper computer PLC or the secondary network, and the equipment automatically labels according to the signal;

4) Remote monitoring system to realize fault self-diagnosis.

5) Remote semi-automatic operation mode: the label content is manually input or modified in the control room, and the equipment automatically labels according to the signal;

6) Short-distance manual operation mode: used for manual debugging or maintenance of equipment on site.

 

4. Equipment technical specifications and performance indicators:

1) The high-temperature lettering and spraying robot is a fully automatic high-tech product. Its main feature is that it is suitable for bars under high-temperature conditions, and the high temperature can reach 1000°C for spraying and marking. The marking machine uses a 6-degree-of-freedom robot and servo control technology, which can flexibly adjust the spraying posture and can spray graphics, symbols, and text on flat and curved surfaces. It is stable in online use, and its advanced technology has reached the level of similar foreign products.

2) Spray guns and high-temperature protection devices designed for high operating rates and harsh environmental conditions in steel mills. It has high reliability and a low maintenance rate. The high-temperature-resistant material is matched with forced water-air cooling to ensure that the nozzle maintains a lower ambient temperature and prolongs its service life. Guarantee the long-term stable operation of the printing system.

3) Font, word spacing, and font size settings; when the billet temperature does not exceed 1000°C, the high-temperature coating can meet the actual process requirements, and the font is clear and easy to distinguish without falling off.

4) Multiple detection and protection measures fully avoid equipment damage caused by equipment failure, human operation, etc., reduce maintenance costs and improve production efficiency.

 

5. The basic composition of the overall equipment:

1) The system consists of the following parts:

the descaling system, robot, high-temperature mobile focus laser marking machine assembly, numbering head assembly, paint, and cleaning agent delivery system, paint storage system, cleaning agent storage system, pneumatic part, electric control part, safety protection, monitoring system, and coding recognition system.

2) Mechanical part

The overall equipment consists of a robot, a box, and a supporting column. The height of the equipment adapts to the change in the height of the end surface of the material.
The system design uses a six-axis industrial robot as the action platform, which can achieve the function of multi-angle free listing. The system is equipped with domestic and foreign first-line brand robots.

3) Electrical control part

The electric control part is mainly a PLC control system and a servo drive system. It has the overall action of printing, communication, material distribution signal, and jet printing machine.

4) Control software

The software is divided into two parts: PLC control software and recognition software. PLC software controls communication with on-site equipment, printing actions, etc. The identification software is associated with the PLC to identify the head position information of the slab and the edge information of the slab and interact with the first-level and second-level data on-site.

a. The programming language and system control language adopted by the system operating software are common programming and control languages.

b. The software adopts a full Chinese software interface, friendly design, and easy operation.

c. It can set parameters, automatically receive the data of the second and third-level systems on-site or manually enter the data to print the signage, and can automatically print the two-dimensional code and barcode information. It has manual data entry or automatic access to the network for users. choose.

d. Mode switching function, which can switch between fully automatic, semi-automatic, and manual modes on the software interface, and users can choose according to their needs.

e. Automatic detection and alarm function, when the equipment fails, the operating software will automatically alarm and give certain fault prompts and maintenance assistance.

5) Laser printing part

The laser printing part is mainly to mark the end face of the slab. The equipment is mainly composed of a laser generator, a laser crystal mirror, and a cooler, and the data transmission fiber is realized, and the whole is installed in a stainless steel box.
Driven by the manipulator, the end face of the round steel or square steel is scanned, and the spatial position coordinates of the center of each round steel or square steel are given through data processing to realize automatic steel finding, and the depth and distance information of the feedback control system realizes automatic focusing.

Laser marking head: Driven by the manipulator, mark the end face of steel parts one by one.
High-temperature spraying gun: under the drive of the manipulator, the primer is sprayed on the end surface of the steel part.

6) Cooling system

The entire equipment is designed with a separate cooling system. The jet printer is cooled by a cooler, and the front of the equipment is designed for heat insulation.

7) Paint supply spraying system

The paint supply system includes a paint and cleaning agent delivery system, a paint storage system, a cleaning agent storage system, and a pneumatic part.

The pneumatic diaphragm pump is used as the core part of the paint supply and cleaning control system. The paint is pumped from the paint barrel into the paint pipeline through the diaphragm pump and supplied to the spray gun. During the working process of the paint control system, the pressure inside the barrel is kept at the same level as the atmospheric pressure outside the barrel. unanimous.
The bucket is filled with high-temperature paint for spraying.

8) Composition of character recognition:

The character recognition system includes image segmentation and neural network technology, which can accurately recognize the sprayed characters. The character recognition system uses a high-definition industrial camera to obtain the image of the sprayed character. After image preprocessing, character positioning, and segmentation, the character is recognized, and the result is generated as a report, which is sent to the system designated by Party A which is responsible for the interface work. Party A is obliged to cooperate. It is used for single-piece tracking and feedback on whether the spray number characters are correct or not.

The character recognition system includes a character video image acquisition module, an image processing and character recognition module, and a data management and transmission module. The image processing and character recognition module is the core working module. The high-definition camera takes photos containing sprayed characters and transmits them to the character recognition central processor through the industrial Ethernet for character recognition, and the recognition results are transmitted to the buyer’s system. It is composed of a camera light source part, electrical control cable part, protective cooling part, control software, network communication equipment, system host, and so on.

9) Monitoring system part

The monitoring computer is installed in the operating room, which mainly realizes the management of the identification data. Through the specially designed management software, the system can receive the identification data transmitted from the secondary network system, and the operator can select the corresponding identification information according to the identification requirements of the production site. If there are special requirements, the operator can also choose to manually modify, delete, and other operations.

 

6. Working mode of the automatic rod marking robot

(1) Automatic mode—transmit to the high-temperature engraving and spraying robot system through the upper-level PLC; realize automatic continuous spraying.

(2) Semi-automatic mode – input by the operator through the computer on the terminal of the jet printer (the input characters meet the specified format requirements), after the material reaches the printing position and stops, the jet printer will automatically or manually control the jet printer to spray the material print;

(3) On-machine maintenance mode – full manual control, this method is generally used for on-site emergency or online debugging and maintenance. —According to the on-site printing requirements, set the release function, and realize manual release for billets that do not need to be printed;

 

7. Main technical parameters

Steel specification: Φ50～160mm;

Marking process: mark on the stand in rows one by one;

Steel temperature: ≤800℃;

Marking range: 150×150mm;

Logo rhythm: about 23 seconds/group;

The maximum stroke of the mechanical arm: is 2050mm;

Primer temperature resistance: 900°C;

Primer curing temperature: 200°C, long-term operation without clogging;

QR code logo size:

Φ50～70mm: 12×12mm, character height 2mm;
Φ70～100mm: 16×16mm, character height 3mm;
Φ100～160mm: 18×18mm, character height 4mm;

Quantity: 2 sets (one set for Zone A and one for Zone B)

 

8. Spray number requirements

1) Spray number position
Bar end face, spray white primer + laser printing

2) Character types
QR code; numbers: 0-9, letters: a-z, A-Z and special symbols and Chinese characters

3) Number of characters
Set according to customer requirements