1．Industry Overview

A crusher is a machine that pulverizes large-sized solid raw materials to a specific size, and achieves the purpose of pulverizing raw materials in the form of high-speed impact. Because of its simple structure, sturdiness, reliable operation and easy maintenance, crushers are still widely used in metallurgy, chemical industry, building materials, electric power, transportation and other industrial sectors. It is mainly used in the coarse, medium and fine crushing process of various ores and rocks with a compressive strength of 147-245MPa.

2．Working Principle and Control Requirements

1.How it works

The machine is composed of frame, eccentric shaft, large pulley, flywheel, movable jaw, side guard, toggle plate, toggle back seat, clearance adjustment screw, return spring, fixed jaw plate and movable jaw plate.

Ore is fed from the feed port and slides down along the sieve plate. The ore on the screen is crushed by the carbide hammer on the high-speed rotating rotor in the process of falling, and it flies to the first counterattack plate along the tangential direction at a high speed, so that the ore continues to be broken. The impact plate knocks the ore back and collides with other ore thrown out behind the rotor. Therefore, the ore is crushed by repeated impact in the first crushing chamber. After some ores are crushed to a certain particle size in the first crushing chamber, they are discharged into the second crushing chamber through the gap between the impact plate and the rotor, and continue to be repeatedly hit until the particle size becomes smaller before being discharged from the discharge port at the bottom of the crusher. .

2.Control Principle

It can be seen from the transmission system diagram: the transmission system consists of the motor A.B, the load roller and the belt; the motor A.B and the load are on the same belt, and the magnitude of the force on each point on the belt is the same, so the speed of the motor A and B is the same. The same is true. Therefore, the control requirement must be that the two motors run synchronously.

3．Electrical Control Diagram

4．Parameter Settings

Through high-frequency pulse signal, the host-auxiliary synchronization is realized. The host VFD FM is connected to the DI6 terminal of the auxiliary VFD.

Host VFD A Settings：

 Auxiliary VFD B Settings：

5．Program Features

1）The two VB VFDs use one host for speed regulation. Through pulse setting, the same operating frequency can be accurately given to the auxiliary VFD that is, the synchronous operation of the transmission structure is realized.

2） VB VFD adopts V/F control mode, excellent acceleration and deceleration performance, small starting current of the system, smooth transition between start and stop, and no impact on mechanical equipment.

3）To improve the production efficiency, the VFDr is used to adjust the operating frequency of the motor, so as to control the operating speed of the crusher to meet the particle size of the finished product after different pulverized materials.

4）Extend the service life of the equipment. The soft start function of the VFD makes the starting current of the motor start from zero, and the maximum value does not exceed the rated current, which reduces the impact on the power grid and the requirements for power supply capacity, and prolongs the service life of the equipment. The device has many protection functions, which can not only protect its own safety and normal use, but also greatly protect the safe operation of the front and rear equipment and save the maintenance cost of the equipment.