NC machining is the most widely used machining method at present, and it is also the basic skill that every machining worker must master. After startup, workpiece clamping, workpiece touch number, tool preparation and processing parameter setting, it enters the startup processing link. In this link, we will summarize what problems need the attention of operators.
Tool and feed speed
Before starting to execute each program, all tools must be carefully checked to ensure that they are consistent with the tools specified in the programming instructions. At the beginning of processing, the feed speed should be adjusted to the minimum, and the methods of single section execution, rapid positioning and tool dropping should be adopted. Attention must be paid to the feeding, and the hand should be placed on the stop key. If problems are found, it must be stopped immediately. During machining, pay attention to the moving direction of the tool to ensure safe feeding, and then slowly increase the feeding speed until it reaches the appropriate value. At the same time, add coolant or cold air to the tool and workpiece to reduce the cutting temperature.
Precautions for rough machining
When rough machining the workpiece, the position of the operator should not be too far away from the control panel, so as to ensure that the machine can be shut down and checked in time in case of abnormal phenomena. Pull the table again after roughening to make sure that the workpiece is not loose. If there is any, the workpiece must be corrected and touched again. In the processing process, we should constantly optimize the processing parameters according to the processing conditions to achieve the best results.
Because roughening is a very critical process, after processing, the main dimension value should be measured to see whether it is consistent with the drawing requirements. It can be removed after passing the self inspection, and must be sent to the inspector for special inspection.
Precautions for drilling processing
Drilling on the machining center is divided into three steps. First, the center drill must be used to locate the hole, then drill with a drill bit 0.5 to 2 mm smaller than the hole size in the drawing, and finally finish machining with a suitable drill bit.
Precautions for reaming
Similar to drilling, reaming the workpiece is also divided into three steps. First, locate the hole with a central drill, then drill with a drill bit 0.5 to 3 mm smaller than the hole size in the drawing, and finally ream with a reamer. When reaming, pay attention to control the spindle speed within 70 to 180 revolutions per minute, neither lower than the lower limit nor higher than the upper limit.
Precautions for boring processing
Boring the workpiece is divided into four steps. The first step is to use the center drill for positioning, the second step is to use a drill bit that is 1 to 2 mm smaller than the hole size in the drawing, the third step is to use a rough boring cutter or milling cutter to process to a machining allowance of only about 0.3 mm on one side, and the last step is to use a fine boring cutter with pre adjusted size for fine boring, and the fine boring allowance cannot be less than 0.1 mm.
Precautions for direct NC operation
Before DNC NC machining, the workpiece should be clamped, the zero position should be set, and then the machining parameters should be set. Open the processing program for data transmission processing in the computer for inspection, then let the computer enter the DNC state, and enter the file name of the correct processing program. Next, press the "tape" key and the program start key on the machining machine tool, and then the machine tool controller will display the flashing words "LSK". At this time, press the enter keyboard on the computer to carry out DNC data transmission processing.