Каталог Tungaloy глубокое сверление 1

Coolant

operations. Therefore, it is very important to choose the correct type of coolant and use it appropriately.

Coolant plays an essential role in lubricating tools,	on such characteristics as thermal conductivity and relative
cooling cutting edges, chips and guide pads, as well as	heat. Coolant with good cooling ability increases tool life, but
evacuating chips when drilling. It also improves tool life,	water-soluble coolant is not preferred in deep hole drilling
surface finish and cutting accuracy when continuously	because it reduces effectiveness. If water-soluble coolant is
supplied during the machining process.	used, the recommended concentration is 10% (dilution rate
	1/10) or more.
1) Lubrication
Lubrication of cutting edges and guide pads is necessary in	3) Chip evacuation
deep hole drilling. For efficient lubrication, it is recommended	Coolant helps push chips through the back end of the
to use EP (Extreme Pressure) additives which contain sulfur or	boring bar (for STS) or inner tube (for DTS) until the chips are
chlorine.	separated from the workpiece in general cutting conditions.
	The flow and the pressure of coolant are also important in
2) Temperature reduction	order to control chip evacuation.
The ability to cool down the cutting edge and chips depends
	Double tube system Single tube system
	Oil Guide
Workpiece	Double tube Guide Outer Drill Workpiece

bush pressure Bar

material Drill tube Chip material Drill bush tube Inner connector Chip

Sealing head rest

head box head tube box

No need for sealing

A coolant unit is also important to obtain the best effect	Maintaining coolant temperature is important to keeping
from the coolant.	stable cutting conditions, chip formation and cutting accuracy.
	The temperature should be lower than 40°C (100°F) for EP
1) Coolant pressure and volume should be fixed and	additives to provide sufficient lubrication. Therefore, the
continuous.	coolant temperature should be kept between 30 - 40°C (90 -
An ideal coolant unit is the one which can set any valve of	100°F) throughout the cutting operation.
coolant pressure and volume and monitor the condition with
gauges. A system that can detect trapped chips by a pressure	3) Filtering
gauge and the screw pumps with an inverter controller are	Unwanted particles are contained in coolant after the cutting
both recommended.	operations, thus filtration is necessary to remove them. The
	filter size should be selected carefully to catch particles but not
2) Coolant temperature should be maintained.	EP additives. Filter size depends on the coolant, but around 10
Coolant is heated by factors, such as:	- 20 μm is generally suggested. For iron-based workpieces, a
- Cutting edge	magnetic separator is helpful as it decreases the frequency of
- Friction on guide pad	filter maintenance.

- Contact time of heated chips and coolant - Pump Flow chart of coolant in deep hole drilling Pressure gauge Flow

gauge Motor

head box Dirty tank Clean tank