In the realm of stamping and shearing production lines, the decoiler plays a crucial role as a frequently used unwinding device, positioned at the front end of the production process. Its primary function is to feed and unwind coil materials, ensuring smooth operations. Depending on the coil’s weight, two types of decoilers are employed – the standard decoiler for regular coils and the hydraulic decoiler for particularly heavy coils weighing over 2 tons.
Key Components of the Hydraulic Decoiler
The hydraulic decoiler comprises several key components, each contributing to its efficient operation:
1. Main Body of the Decoiler
The decoiler’s main body is meticulously crafted by welding shaped steel, A3 steel plates, and #45 steel forged bearing seats. After welding, the surface undergoes fine polishing, followed by annealing and stress relief treatment to prepare the bearing holes. The back plate is machined with precision using a CNC machining center, ensuring a tight fit of the overall body.
2. Expanding and Contracting Mandrel Assembly
The expanding and contracting mandrel is a critical part of the hydraulic decoiler. It consists of a main shaft, a backing wheel, a four-cone shaft, a fan-shaped material support plate, a drawbar, an expanding and contracting cylinder, and a rotating joint. The main shaft is made of 40Gr round steel with a diameter of 85mm, which undergoes ultrasonic (UT) flaw detection, quenching heat treatment, and surface nitriding heat treatment to achieve a working surface diameter of 125mm. The drawbar and the four fan-shaped material support plates are forged from alloy steel 42CrMo, also subjected to finishing and quenching heat treatment for added durability.
3. Motor and Reducer Assembly
The main motor of the hydraulic decoiler is directly connected to the cycloidal pinion reducer, while the coil drum is driven by a belt. Protective covers are equipped on the transmission parts, and the speed is efficiently controlled by a “Delta” variable frequency speed controller.
4. Hydraulic System
The hydraulic system of the decoiler includes a hydraulic station, pressure valves, high-pressure oil pipes, rotating joints, and expanding and contracting oil cylinders. All hydraulic equipment adopts Taiwan’s renowned brand, ensuring reliability and performance. The expanding and contracting oil cylinder pulls the wedge-shaped slide to move, driving the supporting connecting rod to achieve the coiling and uncoiling function of the coil drum.
5. Optional Loading Trolley
For loading heavy coils onto the decoiler, an optional loading trolley is available. The coil is placed on the loading trolley, which can be easily controlled by a handle to slide along the base guide rail. An approach switch ensures automatic alignment between the coil and the expanding and contracting mandrel, facilitating the automatic feeding of the coil.
Enhancing Unwinding Efficiency with the Hydraulic Decoiler
The hydraulic decoiler’s vertical cantilever design and AC variable frequency motor-driven operation through a cycloidal pinion reducer and belt transmission result in efficient unwinding operations. The four-cone structure of the expanding and contracting mandrel, with a cone angle of 14° and equipped with a rotating oil cylinder and rotary seal at the tail, ensures stable and smooth unwinding.
Moreover, the pressure arm’s polyurethane-coated pressing wheel, controlled by a cylinder for compression, provides a secure grip on the coil, preventing slippage during the unwinding process. Additionally, the positioning of the expanding and contracting mandrel during loading is achieved through four Type-A material stoppers, further optimizing the coil feeding process.