Third, the final drive unit is also the key to machine control. The machining accuracy that different drive units can achieve is different. When selecting the drive unit, the appropriate drive unit should be selected according to the precision requirements of the machined workpiece. (Optional for drive unit): The drive unit consists of two parts: the drive unit and the motor: 1. The purchase of the drive unit is mainly based on the selection of the drive unit. 2, the motor is a universal part, the performance difference only exists in different manufacturers and models. The drive motor can be mainly divided into three types: reactive step drive motor, hybrid (also called permanent magnet reaction) step drive motor and servo drive motor. The rotor of the reactive stepping drive motor has no winding, and the reaction torque generated by the excited stator winding realizes stepping operation. The rotor of the hybrid stepping motor uses permanent magnets, and the electromagnetic torque generated by the excitation and permanent magnets is stepped. The stepping motor is controlled by the pulse. The rotation direction of the motor can be changed by changing the order of energization. Changing the frequency of the pulse can change the rotation speed of the motor. Stepper motors have a certain step accuracy and no cumulative error. However, the efficiency of the stepping motor is low, the ability to drag the load is not large, the pulse equivalent cannot be too large, and the speed adjustment range is not large. At present, the stepping motor can be divided into two phases, three phases, and five equals. The commonly used five-phase stepping motor. In the past, stepper motors have dominated the market for a long time, but they are gradually being replaced by servo motors. At present, the commonly used servo motor is an AC servo motor. A photoelectric encoder is installed at the shaft end of the motor, and the rotor angle is used for frequency conversion control. From the lowest speed to the highest speed, the servo motor can run smoothly with low torque ripple. The servo motor has a long overload capability, a small moment of inertia and a large stall torque. The servo motor has a small starting frequency and can quickly accelerate from the lowest speed to the rated speed. The AC servo motor is used as the driving device to form a high-precision, high-performance semi-closed loop or closed-loop control system like the DC servo motor. Because the AC servo motor has a brushless structure, it requires almost no maintenance, and the volume is relatively small, which is beneficial to the improvement of the speed and power. DC servo motors have been replaced in a wide range. After the emergence of the all-digital AC servo system using high-speed microprocessor and dedicated digital signal processor (DSP), the original hardware servo control became software servo control, and some advanced algorithms in modern control theory were realized, which greatly improved The performance of the servo system, so the servo unit can greatly improve the processing efficiency and processing accuracy, but the price of the servo drive unit is also high. With the gradual improvement of servo control technology, the servo drive unit is gradually becoming the main force of the drive unit. The price of the servo drive unit is also gradually reduced. One uses pulse control, which is closed to the motor, but is not fed back to the CNC system. This driver can be called servo control of open loop control to some extent. The other uses the voltage control mode to control the speed of the motor through the voltage level. The feedback signal of the motor is fed back to the CNC system for position control through the driver. 3. When selecting the drive unit, also consider the proportion of the price of the drive unit in the entire CNC machine. The whole CNC machine tool has a lower price and generally selects the step drive unit, while the higher price machine selects the servo drive unit. However, when selecting the drive unit, it is also necessary to consider the matching problem between the drive unit and the numerical control system. When selecting the closed-loop control system, the closed-loop servo drive unit must be selected. AC servo systems outperform stepper motors in many performance aspects. However, in some occasions where the requirements are not high, stepper motors are often used to perform the motor. Therefore, in the design process of the control system, it is necessary to comprehensively consider the control requirements, cost and other factors, and select the appropriate control motor. Fourth, the function selection The above is based on the processing accuracy of the CNC system, in addition to, but also from the functional selection of the CNC system. 1) Control axis CNC system: The number of control axes is also the key to selection. According to the number of control axes, it can be divided into two-axis linkage, four-axis linkage, multi-axis linkage and the like. The more the number of control axes, the more complex the machine can process, but the higher the cost. At present, the wire cutting machine generally uses two linear moving axes to interlock, and the taper device has two additional linear moving axes. The high-end system has more axes, and the highest level of wire-cutting machine tool manufacturing is the five-axis linkage CNC system. Four axes are XYUV linear moving axes, one axis is the Z axis for the vertical axis, five axes. More complex space parts can be machined when linked. Of course, this requires high-end CNC systems, servo systems and software support, and the requirements for machine tools are also extremely high. The more control axes, the more the price of the CNC system grows. Therefore, when selecting the numerical control system, it is necessary to select according to the motion axis of the machine tool. The redundant control axis does not improve the control precision of the machine tool, but increases the cost of the numerical control system. 2) The graphic display function of the graphic display system, which is used to simulate the part processing process and display the cutting path of the real tool on the workpiece. You can select one plane in the Cartesian coordinate system, or you can select three-dimensional three-dimensional in different angles. The real-time display at the same time of processing can also be used for quick drawing of the machining process in the mechanical locking mode. It is an effective tool for checking the part processing program, improving programming efficiency and real-time monitoring. These kinds of problems are often encountered in the functional configuration of CNC wire-cutting machine tools. As a design and sales staff of CNC machine tools and investment buyers, they must clearly understand the various functional uses of the CNC system, according to the actual situation of the machine tool. For users to configure CNC machine tools that are economical, functional and cost-effective, reduce unnecessary waste. 40X60 Metal Building,30X40 Metal Building,General Steel Buildings,Metal Barns Guangdong Tianchen Steel Structure Engineering Co. Ltd. , https://www.tcsteeltech.com Previous page 1 2 Next page