Bent tubes and pipes are used for structural, decorative purposes or as passageways. There are different techniques that are followed based on the requirement and there are different machines which facilitate these processes. Pipe and tube busbar bending machine used in industries are usually pneumatic powered, human powered, electric servomotor or hydraulic addicted or driven. Apart from the machines and the processes, there are different types of tooling used in the bending machines. Given below is a brief on some tooling used.
A bend die is the forming tool that is used to make the specific radius of the bend. This die has two pieces namely the insert and the bend radius. While the insert radius is used to clamp the tube to the bend, the bend radius is the one that forms the arc of the bend when the tube is drawn around the die.
The clamp dies works along with the bend die to make sure that the tube is clamped to the bend die. This die moves in and out to allow feeding of the tube.
The pressure die is what is used to press the tube into the bend die and this is the tool that provides reaction force required for the bending moment. This die travels along with the tube as it is being formed. A boost cylinder is attached to the pressure die in order to prevent tube breakage and to assist the die through the bend.
Mandrel is a linked ball or a steel rod that is placed in the tube as it goes through the bending process. The main purpose of a mandrel is to offer more support to the tube and to prevent wrinkling or breakage of the tube throughout the bending process. There are different types of mandrels available such as the plug mandrel – a rock-solid rod, which is used in case of normal bends, a form mandrel – constitutes of the solid rod with a curved end and is used in cases where support is needed, a ball mandrel with/without cable – used on precise and critical bends.
The wiper die is used only in situations where using a mandrel alone is not enough to prevent wrinkling during the bending process. The wiper die actually works by wiping away wrinkles on the tube.