Gun Drill-Gun Drilling Technology

Gun Drill-Gun Drilling Technology:

How to use gun drill?

Used in the production tank gun drill straight up. According to the diameter of the gun drill and drive through part of the shank and blade cooling holes in the case, gun drill can be made integral and welded types. The cooling fluid from the surface of the hole after the knife spray. Gun drill can have one or two circular cooling hole, or a single kidney-shaped hole.

Standard gun drill diameter of 1.5mm to 76.2mm processed holes, drilling depth of up to 100 times the diameter. Special custom gun drill machinability aperture 152.4mm, depth of 5080mm deep hole.
Although the gun drill feed per revolution is low, but the amount of feed per minute than the big twist drill (feed per minute is equal to the amount of feed per revolution multiplied by the speed of the tool or the workpiece).

As the blade is carbide manufacture, so the gun drill cutting speed than the high-speed steel drill bit to be much higher. This increases the gun drill feed rate per minute. In addition, when using high-pressure coolant, its chips from the hole in the effective discharge of the processed without drilling process on a regular basis back in the knife to discharge chips.

About gun drill system:
Accordance with the system engineering theory, taken alone any drilling system technology factors are one-sided. However, different tools and drilling equipment manufacturers in different parts of the system, so no one take responsibility for system consistency. As the gun drill processing system architecture is not unified, it is often unpredictable failure of the gun drill. Potential failure, including drill breakage and excessive wear of the blade. These failures will lead to deterioration in the quality of the hole to be machined, resulting in poor surface roughness, big beat and axis offset. In the automotive industry, which failed to make deep holes into the bottleneck process.
The above-mentioned adverse outcomes are often considered to be the tool manufacturer quality products, it is not right. When the gun drill machining inclined hole, its operators and field technicians should be aware that using a dedicated guide sleeve, and to ensure adequate coolant, and to drill sets the distance between the bottom and the surface does not exceed 0.5mm, drill sleeve and the spindle concentricity of less than 0.005mm. Should be used with Carbide drill sets or high-alloy tool steel, precision gun drill drill sleeve, its hardness is 63 ~ 65HRC, the bore surface roughness is 16 ~ 32μm, the maximum allowable difference in diameter axis 0.002 degrees mm, the maximum allowable runout of the front surface of 0.005mm. Here is the proper use of the automobile industry is not an instance of gun drill:When the drill sleeve and drill the difference between the axis of rotation axis through the large, gun drill will usually fail, such as the drill point of impact, this impact due to the fragile carbide tip can not bear the bend caused by different heart stress caused by the blade fracture.
If the workpiece is rotated instead of rotating drill, this will become even worse, because this pressure will re-acting on the tip of the different parts. When pressure is applied to the weakest part (the tip angle), the tip will break.
On the tool length. When the gun drill length increases, the rigidity of the tool down. When the center is not good, the gun drill shank will not transfer more force to bend the tip, the tip is not damaged, but will cause shank vibrate, leading to fatigue failure.
Drill sleeve and drill through the gap between the tool failure caused by the General Assembly. At this point the gun drill cut a lot of the side edge of the workpiece material, because the cutting edge of the posterior horn of 0 °, so the side of too much cutting edge caused rupture.Coolant supply is not sufficient reason for failure is caused by the tool. It will accumulate in the chip chip slot, the plug by squeezing the chip formation, so that excessive torque acting on the gun drill, gun drill when the V-groove is blocked, the head will shank separation. At this point the user is usually considered to be the gun manufacturers for gun drill drill arbor welding is not strong with the head caused by head and shank separation. However, the manufacturer can not control the installation of the gun drill and specific operation of the system. If the problem occurs in the processing, should be sent to sales representatives to understand the situation and fill out the reasons for failure analysis tables.