Whether the processing conditions of drilling are appropriate or not should be comprehensively judged by the factors such as machining accuracy, machining efficiency and drill life through trial cutting.
1.drill life and processing efficiency
On the premise of meeting the technical requirements of the workpiece to be processed, whether the drill bit is used properly should be comprehensively measured according to the service life and processing efficiency of the drill bit. The evaluation index of the service life of the drill can choose cutting distance; The evaluation index of machining efficiency can choose feed speed. For high speed steel bit, the service life of the drill bit is greatly affected by turnover rate and less affected by the feed per revolution. Therefore, the processing efficiency can be improved by increasing the feed per revolution, at the same time, it ensures a longer drill life. Because the heat resistance of the hard alloy drill bit is higher than high speed steel bit, turnover rate has little influence on the life of the drill bit. Therefore, the method of increasing turnover rate can be adopted to improve the processing efficiency of the hard alloy drill bit and ensure the life of the drill bit.
2.reasonable use of cutting fluid
The cutting of the drill bit is carried out in the hole with narrow space, so the types and injection methods of cutting fluid have a great influence on the life of the drill bit and the machining accuracy of the hole. Cutting fluid can be divided into two categories: water-soluble and non-water-soluble. Non-water-soluble cutting fluid has good lubrication, infiltration and adhesion resistance, and also has anti-rust effect. Water soluble cutting fluid has good cooling property, no smoke and no combustibility. Due to the consideration of environmental protection, water-soluble cutting fluid has been widely used in recent years. However, if the dilution ratio of water-soluble cutting fluid is improper or cutting fluid deteriorates, the service life of the tool will be greatly shortened, so attention must be paid in use. Whether water-soluble or non-water-soluble cutting fluid, the cutting fluid must reach the cutting point fully in use, and the flow rate, pressure, nozzle number, cooling method, etc. of cutting fluid must be strictly controlled.
