CoArc arc spraying equipment

CoArc type arc spraying system is Praxair Daihatsu's "new generation" arc spraying system, which can fully meet the various needs of sprayers for arc spraying. This new system offers several breakthroughs in arc spray technology, taking arc spray technology to a whole new level. These new technological breakthroughs in the CoArc system can be said to be revolutionary. It not only improves the stability and reproducibility of coating quality, but also indicates that the development of arc spraying system will start a new stage. The main technical features of the CoArc system are introduced as follows.

1. Introduced touch screen operation interface terminal OIT and PLC control for the first time

The basic components of a CoArc arc spray system are a CoArc console, an arc spray power supply and an arc spray gun. The console of the CoArc system is equipped with a powerful operation interface terminal with a touch screen, and a programmable logic controller (PLC) is used for process control. Arc spray control system.

The CoArc System's OIT (Operator Interface Terminal) console is a color touchscreen in a rugged industrial housing. The removable, user-friendly "touch screen" operator interface is powerful and greatly simplifies arc spray operation.

The programming is based on the intuitive pattern symbols on the touch screen, and the setting and monitoring of process parameters are relatively simple. Complicated jobs can be completed with simple operations at runtime. The OIT console can communicate directly with the PLC. Operators can see and control all parameters from the console, while having direct access to process development and maintenance procedures. The operator can also change the display language of the program.

The operation interface terminal OIT with touch screen is powerful, and the PLC programmable logic controller used for process control is extremely stable and reliable. The combination of the two makes the electrical control of the CoArc system reach a new height.

It is the first initiative of Praxair Daihatsu to introduce the touch screen operation interface terminal OIT and PLC controller into the arc spraying equipment at the same time, which greatly improves the function of the control system and ensures the reliability and stability of the control system.

2. For the first time in the arc spraying, the computer closed-loop control of the "gun head" air pressure

It is well known that the performance of compressed air is extremely important for arc spraying. The atomization of the wire droplet, the size of the atomized particles and their particle size distribution, the velocity of the particles, the shape of the spraying beam, and many other key technical performance indicators are inseparable from the performance of the compressed air.

The performance of compressed air includes many aspects such as pressure, flow rate, and airflow pattern flowing through the nozzle, which are closely related to the fluid dynamics characteristics of the compressed air in the gun. Since the birth of the electric arc spraying process, Praxair Daihatsu's R&D department has been concerned with the compressed air of the spray gun and its control. After continuous efforts, a variety of new spray guns have been researched and developed, such as the ArcJet system (arc jet flow assembly) that can improve the gas flow characteristics in the spray gun and greatly increase the particle velocity; the 9000 arc spray gun with large air flow characteristics, etc. However, only the CoArc system truly controls the compressed air.

The basic principle of the CoArc system to implement closed-loop control of the compressed air of the spray gun is: to detect the pressure of the air through the pressure sensor installed on the head of the 9935 spray gun, and this signal is fed back to the computer to compare with the preset value, and then through the compression of the input end of the spray gun The control of the air ensures that the pressure of the "tip" is consistent with the set value. Since the feedback signal is taken from the compressed air outlet on the spray gun head, the computer-controlled actuator implements control at the compressed air inlet of the spray gun, thereby ensuring that the pressure of the compressed air flowing through the spray gun remains constant.

The pressure of the compressed air at the gun head remains unchanged, which ensures that the airflow characteristics of the spray gun remain unchanged, thereby ensuring stable atomization of the wire, stable particle size distribution and stable spraying beam shape.

This new technology developed by Praxair Daihatsu captures the key parameter of the compressed air pressure of the nozzle, and then effectively controls it. This is a revolutionary breakthrough of the CoArc system for the key technology of arc spraying.

3. For the first time in arc spraying, one control platform is used to control multiple systems

The CoArc system developed by Praxair Daihatsu is a new type of modular system. Its design idea is to use an electrical control system to control and operate a variety of arc spray guns, thus greatly improving the flexibility and adaptability of the CoArc system. It can operate the famous 8830 air-operated spray gun, the lightweight BP400 "push wire" spray gun, and the advanced DC servo motor driven 9935 spray gun. It can be configured with either 353CV power supply or enhanced 353ECV power supply. the
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The basic configuration of a complete CoArc system is a CoArc console, a 353ECV power supply and a 9935 arc spray gun and its associated pipes and cables. The CoArc system is a configurable system that, in addition to operating a wide variety of spray guns, can also add a variety of optional components to increase its functionality. This system can be used as an independent unit for spraying operations, and can also be combined with other options to form a spraying system suitable for the target workpiece. Therefore, the customer has a system, and can build a variety of spraying equipment according to the needs of the work, so that the work can be done well and cheaply. For example, you can choose BP400 spray gun, which uses fan-shaped spray beam to spray aluminum and zinc for anti-corrosion engineering; you can also choose 9935 spray gun, which uses concentrated beam to spray high melting point metal on large workpieces to obtain good reproducibility high reliability coating. For various spraying jobs, you can get the most ideal equipment configuration.

The design of CoArc console incorporates new technologies and is equipped with multiple sets of efficient actuators. Such as the lubricating oil adder for the 8830 air motor and the controller for the servo motor on the new 9935 spray gun. There is also an optional push/pull function. The driving mechanism of the push wire feeding is located in the control cabinet. When the distance between the wire reel and the spray gun is greater than 15 meters (50ft), the wire pushing mechanism can be activated to implement long-distance push/pull combined wire feeding. The ingeniously designed and exquisitely crafted piping system in the CoArc system also reduces pressure drop in the air supply system, resulting in better air supply flow and control to the spray gun. CoArc system is also equipped with data acquisition function, which can help customers implement effective quality control, production management and cost control.

It is the first initiative of Praxair Daihatsu to use one control platform in the arc spraying system to control multiple spraying systems built according to the needs. It greatly improves the flexibility and adaptability of the equipment and brings users Great convenience and considerable benefits.

4. The new control technology comprehensively improves the quality and reproducibility of arc spraying

The CoArc system takes arc spraying to a whole new level by providing closed-loop control of the spraying process. The main hallmarks of this new level are:

(1) Implement comprehensive closed-loop control over the arc spraying process.
Since the technical difficulty of closed-loop control of wire feeding speed is not very high, general arc spraying equipment has this function. The closed-loop control of the compressed air of the spray gun is very difficult, and it has always been a difficult problem that the arc spraying equipment wants to solve but has not solved. Praxair Daihatsu has solved this problem by adopting the closed-loop control technology of the "gun head" pressure. Therefore, the control technology of the arc spraying process is fundamentally improved, so that it can carry out closed-loop control on the entire spraying process, rather than certain process parameters.

(2) The control function is more comprehensive.
In addition to controlling the "tip" gas pressure and controlling wire feed speed, the CoArc system also monitors and controls the voltage at the power supply or at the torch tip. As we all know, high-current spraying equipment (arc and plasma) should not use too long cables. Even with a resistance of 0.01 ohms, the spray gun must have a considerable voltage drop when the current is hundreds of amperes. Therefore, directly controlling the voltage on the gun can control the spraying process more stably.
Because the CoArc system implements a comprehensive closed-loop control of the spraying process, it can make the conveying and melting of the wire material more stable, the quality of the droplet atomization is better, the particle size distribution of the particles is more ideal, and the particle injection speed is faster. The quality and reproducibility of arc sprayed coatings has also reached unprecedented heights.

5. Further expand the application of arc spraying and lead the development direction of arc spraying

Because arc spraying uses electric arc to melt wire, its energy utilization rate is extremely high, and all particles are completely melted, the temperature of particles is also high, and the particles in the coating can be firmly bonded to each other , so the bonding strength of arc sprayed coatings is also high, especially those coatings with high melting point materials. Arc sprayed metal coating has extremely high resistance to peeling, falling off and cracking. The bonding strength of most arc sprayed coatings is much greater than that of flame sprayed coatings and plasma sprayed coatings of the same material.

However, the general arc spraying equipment has a simple structure, low control system configuration, difficult to stabilize the process parameters during spraying, and the quality and reproducibility of the coating cannot be guaranteed, thus greatly limiting the application of arc spraying. At present, most arc spraying equipment is used for spraying aluminum and zinc for large area anticorrosion, or for occasions where the requirements are not high and the working conditions are not severe.

Because the CoArc system implements computer closed-loop control on the main process parameters of arc spraying, the arc spraying process has all the characteristics of fine process control, and the quality and reproducibility of the coating have been qualitatively improved. Therefore, the CoArc system has the conditions to expand to the application field with high requirements and severe working conditions, thus greatly expanding the application field of the arc spraying process.

At present, the application field of electric arc spraying is continuously expanding. For example, the aviation machinery department has adopted BondArc75B nickel-aluminum wire to spray and repair jet engine flanges. The bonding bottom layer of large ceramic coating rollers has abandoned the use of high-cost plasma spraying coatings, and instead uses arc spraying Alcro and Al1800 wire materials. Such bonding bottom layers are not only extremely low in cost (about one fifth of the former ), the bonding strength is also stronger than that of plasma spraying, and what is more interesting is that the arc spraying coating has better recovering performance, which can improve the deposition efficiency of the ceramic surface layer and its bonding strength with the bonding bottom layer.

The new CoArc arc spraying system starts from a brand-new perspective, wholeheartedly considers the users, pays attention to the inherent technical characteristics of arc spraying in equipment development, implements a comprehensive closed-loop control of arc spraying process for the first time, and raises arc spraying to a brand new On a horizontal level, the quality and reproducibility of arc sprayed coatings have been qualitatively improved. At the same time, the CoArc arc spraying system has also achieved sufficient leadership in many technologies, which will lead the development of the world's arc spraying technology for a long period of time in the future.