Power requirements of CNC machine tools

As we all know, high-speed machining technology is developing rapidly, and it is CNC machine tools that promote this development trend. How to make good use of the performance of CNC machine tools and maintain the accuracy of machine tools is very important.

Power supply is the energy support part to maintain the normal operation of the system. The direct result of its failure or failure is to stop or destroy the whole system. In addition, some running data, setting data and processing programs of CNC system are generally stored in RAM memory, which is maintained by the backup battery or lithium battery of power supply after the system is powered off. Therefore, the downtime is relatively long, and plugging or unplugging the power supply or memory may cause data loss, making the system unable to run.

At the same time, because the CNC equipment adopts three-phase AC 380V power supply, safety is also an important part of the preliminary work of CNC equipment installation. Based on the above reasons, the power supply used for numerical control equipment has the following requirements:

1. Power grid voltage fluctuation should be controlled between+10% ~- 15%. In China, the power supply fluctuates greatly, the quality is poor, there are hidden interferences such as high-frequency pulses, and there are also human factors (such as sudden power failure). During the peak hours of electricity consumption, such as going to work at day and night or about an hour before leaving work, the deviation is often more, even reaching 20%. Make the machine tool alarm and fail to work normally, and damage the power supply system of the machine tool. Even lead to the loss of related parameter data. This phenomenon occurs in CNC machining centers or turning centers and other machine tools with high frequency, which should be paid attention to.

It is suggested that AC stabilized power supply system with automatic compensation and adjustment function should be configured in the workshop where CNC machine tools are concentrated. A single CNC machine tool can be solved by configuring AC voltage stabilizer separately.

2. It is recommended to connect mechanical and electrical equipment to a single power supply. If it is necessary to use other power sources to supply power to some parts of electrical equipment (such as electronic circuits and electromagnetic clutches), these power sources should be taken from equipment (such as transformers and frequency converters). ) as far as possible is a part of mechanical and electrical equipment. For large and complex machines, including many machines working together in a cooperative way and occupying a lot of space, more than one attraction power supply may be needed, depending on the configuration of the field power supply.

Unless the electromechanical equipment is directly connected to the power supply through the plug/socket, it is recommended to directly connect the power cord to the power supply terminal of the power-off switch. If this is not possible, a separate terminal board shall be provided for the power cord.

The handle of the power cut-off switch should be accessible and installed between 0.6m ~ 1.9m above the easy-to-operate position. The upper limit is suggested to be 1.7M, which can quickly cut off the power supply in an emergency and reduce losses and casualties.

3. Requirements of CNC equipment for compressed air supply system CNC machine tools generally use a large number of pneumatic components, so the workshop should be connected with a clean and dry compressed air supply system network. Its flow and pressure should meet the requirements. The compressed air machine should be installed far away from the CNC machine tools. According to the plant layout and gas consumption, the compressed air supply system pipe network should consider installing frozen air in coal machines, air filters, gas storage tanks, safety valves and other equipment.

4. Requirements of CNC equipment for working environment Precision CNC equipment generally requires a constant temperature environment. Only under the condition of constant temperature can the accuracy and machining degree of the machine tool be guaranteed. Ordinary CNC machine tools have no specific requirements for room temperature, but a lot of practice shows that the failure rate of CNC system increases greatly when the room temperature is too high.

Humid environment will reduce the reliability of CNC machine tools, especially the humid environment with large acid gas, which will rust printed circuit boards and connectors and increase the electrical failure of machine tools. Therefore, some users in the south should take measures to dehumidify the environment of CNC machine tools in summer and rainy season.

1) The working environment temperature should be between 0℃ and 35℃, avoiding direct sunlight on CNC machine tools, and the room should be equipped with good lighting equipment.

2) In order to improve the accuracy of the machined parts and reduce the thermal deformation of the machine tool, if conditions permit, the CNC machine tool can be installed in a relatively closed workshop with air conditioning equipment.

3) The relative humidity of the working environment should be less than 75%. CNC machine tools should be installed far away from liquid splashing and prevent the workshop from dripping.

4) Stay away from the environment with too much dust and corrosive gas.