Non-Conventional Robotic Welding Methods
Despite the growing number of robotic applications, robotic welding remains the most common. The automation of welding with robots dates back to 1962 when GM implemented the UNIMATE robot for spot welding. The traditional welding processes of arc welding and spot welding have been the main focus of robotic welding automation. However, advancements in technology along with the adoption of robots in less traditional industries has led to the automation of non-conventional welding methods with robots. Manufacturers are also welding more diverse materials from metals to polymers to composites, which is fueling the growth of non-conventional robotic welding methods. Below is a look at the three fastest growing non-conventional welding processes for robotic automation.
Laser WeldingOut of the three non-conventional welding methods, laser welding is the most well-known for robotic automation. Automating laser welding involves integrating a robot with a laser cutting head for the EOAT. During welding a laser beam is emitted onto a workpiece producing concentrated heat to create a narrow and deep weld. Laser welding can be automated by six-axis robots. The FANUC Arcmate 120ic is ideal for laser welding automation. Robotic laser welding can be used to weld a variety of metals and unlike most welding processes it can be used to weld dissimilar metals together.
One of the main advantages of laser welding is that it is a non-contact welding method. The ABB 2400 can laser weld workpieces up to a foot away. Robotic laser welding is ideal for delicate or hard to reach workpieces because of its no contact approach. It is also an extremely flexible method since it can weld dissimilar metals together.
Electron Beam WeldingElectron beam welding involves joining metals together through kinetic energy produced from a stream of electrons. An electron gun is integrated with an industrial robot for the automation of EBW. When the industrial robot applies the electron gun to a metal workpiece, the kinetic energy from the electrons heats and melts the metal. The one caveat to robotic EBW is welding must occur within a vacuum chamber which can limit workpiece size. The Motoman MA1900 is capable of automating EBW processes.
One of the advantages of EBW is its incredible power which allows for the welding of thick metals. It is also able to produce some of the purest and cleanest welds due to the use of a vacuum chamber which completely protects the weld pool.
Ultrasonic WeldingThe automation of ultrasonic welding with articulated robots has tripled in the past decade. This robotic welding method has been implemented across the automotive and electronics industries. Ultrasonic welding robots can be used for both metal and plastic workpieces. This method creates welds through ultrasonic vibrations which are generated through electrical voltage to melt and join workpieces. Ultrasonic welding is typically automated with a six-axis industrial robot. Ultrasonic weld heads serve as the EOAT that is integrated with the robot. These tend to be on the heavy side so a medium to high payload robot will be needed.
The main advantage of ultrasonic welding is that it can weld plastic in addition to metal. Another advantage is the fast cycle times reaching up to 60 cycles per minute.