xiehe model

Since the machining center is far more refined than ordinary machine tools, it is more expensive than ordinary machine tools and has more constraints. Therefore, it is more important to choose a machine tool reasonably or not. The correct selection is the key to make good use of the machining center and make the machining center effective. When purchasing a machining center, it is especially important to carefully examine these five points:

1. Rigidity of the machining center

Since the rigidity of the machining center will directly affect the production efficiency and the machining accuracy of the machine tool, the machining speed of the machining center is much higher than that of ordinary machine tools, and the power of the motor is also higher than that of ordinary machine tools of the same specification, so the rigidity of its structural design is also much higher than that of ordinary machine tools. When ordering, it can be checked according to the maximum value of process requirements, allowable torque, power, axial force and feed force, and the value provided by the manufacturer. In order to obtain the high rigidity of the machine tool, it is often not limited to the size of the part, but a machine tool with a size 1 to 2 larger than the size of the part is selected.

2. Machining accuracy of the machining center

Machining accuracy directly affects your product quality. When many people deny that your machine tool is not accurate enough, it will directly affect the purchaser's decision. It should be noted that machining accuracy and machine tool accuracy are two different concepts. It is wrong to regard the position accuracy on the manufacturer's sample or product certificate as the machining accuracy of the machine tool. The positional accuracy marked on the sample or certificate is the accuracy of the machine tool itself, while the machining accuracy is the sum of errors caused by various factors in the entire process system including the allowable error of the machine tool itself. When selecting the model, you can refer to the evaluation method of the process capability kp as the basis for the selection of the accuracy. Generally speaking, the calculation result should be greater than 1.33.

3. Selection of CNC system of machining center

The CNC system is the core brain of the machining center operation. The CNC functions are divided into basic functions and selection functions. The basic functions must be provided, and the optional functions will only be provided by the manufacturer after the user selects these functions. The functions of the CNC system must be selected according to the performance requirements of the machine tool. When ordering, the required functions must be ordered and cannot be omitted. At the same time, to avoid waste caused by low utilization rate, attention should also be paid to the correlation between functions. Among the available CNC systems, performance varies widely. It should be selected according to needs, and high indicators should not be pursued one-sidedly, so as to avoid waste. When selecting multiple machine tools, try to choose the CNC system of the same manufacturer, so that operation, programming and maintenance are more convenient.

4. The number of coordinate axes and the number of linkage axes

Both the number of coordinate axes and the number of linkage axes should meet the processing requirements of typical workpieces, and the number of coordinate axes is also a sign of the grade of the machine tool. In general, for a machine tool of the same manufacturer, same specification, and same precision, adding a standard coordinate axis will increase the cost by about 35%. Although increasing the number of axes can enhance the function of the machine tool, it is still necessary to pay attention to the balance of process requirements and funds.

5. Automatic tool changer and tool magazine capacity

The selection of the dynamic tool changer mainly considers the tool change time and reliability. Short tool change time can improve productivity, but the tool change time is short, the general tool change device has complex structure, high failure rate, and high cost. Excessive emphasis on tool change time will greatly increase the cost and increase the failure rate. According to statistics, about 50% of the failures of the machining center are related to the automatic tool changer. Therefore, under the premise of meeting the requirements of use, try to choose an automatic tool changer with high reliability to reduce the failure rate and the cost of the whole machine.

The working quality and tool magazine capacity of the automatic tool changer will directly affect the performance and quality of the machining center. The capacity of the tool magazine is based on the principle of meeting the needs of a complex machining part for tools.