Каталог Iscar сверла ружейные и для глубокого сверления 2022 - страница 94

DEEP DRILLING - BTA SYSTEM USER GUIDE Coolant Successful deep hole drilling is achieved by an STS - Double tube system optimal combination of the tool, the machine andthe coolant. Coolant plays an essential role inWorkpieceOuter Double tubematerialtubeconnector achieving secure and cost-efficient deep hole drilling Drill Guide operations. Therefore, it is very important to choose head bush Inner Chip the correct type of coolant and use it appropriately. tube box Coolant Coolant plays an essential role in lubricating tools, cooling cutting edges, chips and guide pads, as well as evacuating chips when drilling. It also improves No need for sealing tool life, surface finish and cutting accuracy when continuously supplied during the machining process. Coolant unit A coolant unit is also important to obtain 1 Lubrication the best effect from the coolant. Lubrication of cutting edges and guide pads is necessary in deep hole drilling. For efficient lubrication, 1 Coolant pressure and volume should it is recommended to use EP (Extreme Pressure) be fixed and continuous. additives which contain sulfur or chlorine. An ideal coolant unit should be able to set any valve of coolant pressure and volume and monitor the condition 2 Temperature reduction with gauges. A system that can detect trapped chips The ability to cool down the cutting edge and by a pressure gauge and the screw pumps with chips depends on such characteristics as an inverter controller are both recommended. thermal conductivity and relative heat. Coolant with good cooling ability increases tool life, but 2 Coolant temperature should be maintained. water-soluble coolant is not preferred in deephole drilling because it reduces effectiveness. IfCoolant is heated by factors, such as: water-soluble coolant is used, the recommended • Cutting edge concentration is 10% (dilution rate 1/10) or more. • Friction on guide pad • Contact time of heated chips and coolant 3 Chip evacuation • Pump Maintaining coolant temperature is important to Coolant helps push chips through the back end of the keeping stable cutting conditions, chip formation boring bar (for STS) or inner tube (for DTS) until the chips and cutting accuracy. The temperature should are separated from the workpiece in general cutting be lower than 40°C (100°F) for EP additives to conditions. The flow and the pressure of coolant are provide sufficient lubrication. Therefore, the coolant also important in order to control chip evacuation. temperature should be kept between 30 - 40°C STS - Single tube system (90 - 100°F) throughout the cutting operation. Workpiece material Guide Oil 3 Filtering Drill Drill bushheadtubeSealingpressureheadBarChiprestbox Unwanted particles are contained in coolant after thecutting operations, thus filtration is necessary to remove them. The filter size should be selected carefully to catch particles but not EP additives. Filter size depends on the coolant, but around 10 - 20 μm is generally suggested. For iron-based workpieces, a magnetic separator is helpful as it decreases the frequency of filter maintenance. Flow chart of coolant in deep hole drilling Pressure gauge Flow gauge Motor M Pump P M Chipbreaker P Drill head Drill tubeWorkpiece Filter Chiller OilpressureheadChipbox Dirty tank Clean tank 278 ISCAR