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How to choose the correct robot for spraying

With the continuous development and improvement of modern spraying technology, the reform of spraying technology is going on at any time. Now the requirements of automatic industrial production is gradually raised, the principle of safety production and environmental protection need to be done in the daily production, so it is inevitable that spraying robot should be widely used. As an important part of industrial production, spraying robot is a kind of advanced coating equipment with advantages in flexibility, working scope, spraying quality, spraying efficiency and material utilization. It can be used for more complex coating processes. However, how to choose the correct robot for spraying become the essential part in the coating automation progress.

Industrial robot is a very hot product in recent years, of which categories are various and application should vary in different needs. The specialization in the specific area is what exactly we need now to optimize the quality and maximize the profits. Therefore, it’s important to know the way to choose correct robot and avoid the waste. First of all, it is necessary to know the function and application area of the robots, which depend on the core software package. Then, it comes to the number of axles of robots. The more axles the robot have, more flexible and costlier it will be. The number of axles depends on the complexity of motion the robot needs to finish, that is, how many steps the motion should be divided into. Lastly, the size of robots (including load-bearing capacity and arm-span distance) means a lot.

Spraying robot is specialized in coating industry, and its wrist load is mostly 3-10 kg. It is unnecessary to choose large load capacity for spraying robot, because a spray gun is 450 grams and four are only within 3 kg. The greater the load is, the thicker robot wrist will be designed. Thick wrist structure is not conducive to spray coatings, so spraying robot wrist load are normally designed in 3 to 5 kg (it should be designed larger under the circumstance of installing large-diameter rotatory cup).

Wrist driving motor for spraying robot should be rear-mounted (at the end of the horizontal arm), so as to minimize the size and weight of the wrist and make speed and accelerated speed faster. In addition, it will be more conductive to avoid negative phenomena in the electrostatic spraying, because there is no electric at the front end. Spraying robot is very different from ordinary robot in structure.

The high-end spraying robot also adopts oblique structure, then what actually is oblique structure? Most of the industrial robots we see belong to straight structures, where the rotation centers intersect at 90 degrees. A 90-degree intersection of the wrist does not guarantee that the axle can rotate around 360 degrees, so some axles cannot reach the full range of motion. While the robot axles in oblique wrist structure will not effect the rotating degree and are able to reach to the place in the wider range. Accordingly, the wrist whose intersection degree of axles central line is greater than 90 can be generally called the oblique structure. There is more than a dozen pairs of precise gears in the arms, and most of them are designed in the hollow type for pipes easy to pass through.

 

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After knowing the mechanical structure of spraying robot, there are many kinds of control software and programming for spraying robot, such as: traditional programming, off-line programming, dragging & teaching programming, intelligent vision automatic programming.

  1. Traditional programming: it means to program by man inputting word by word. It suits for single product and mass production because it will cost so much in changing the program. The price of this kind of robots also is reasonable. However, if you have many types of products with complex shapes, this kind of robots will not satisfy your needs to a great extent.
  2. Off-line programming: it means that there is a professional software for coating process with the robot. With this kind of robot, all we have to do is to input the 3D drawing of product, and then the software will generate the spraying path and parameters automatically. However, there are full of inferior software in coating area nowadays, and the practical and professional coating software is costly for industry use.
  3. Dragging & teaching programming: the robot with that function can be taught by man dragging its arms and teaching it how to move and operate. It is easy for programming and operating, and can be applied to some products which need a lot of complicated motion for robot spraying.
  4. Intelligent vision automatic programming: it can be the future of the really intelligent and automatic coating robot. It is said that automatic spraying by intelligent vision has been achieved for some plate-type products. Whereas, the intelligent vision system and software cost more than the robot, so it is unworthy for industry at present at least.

In conclusion, choosing a correct robot should be according to your product type and production output. Spraying robots with traditional programming will be fit for mass production and products of less types; while products of more types should adopt other programming way according to specific situation. In a word, the less the robot costs at the beginning, the more possible there may be problems then; the more you may spend on your transformation and upgrading to automation, the less disappointed you will be in the future. However, it doesn’t mean it will cost a lot.

 

 


Post time: Feb-26-2020