What are the common drill bit clamping methods used in CNC machining centers

The commonly used drill bit clamping methods for CNC machining centers include:

 

1. Spring chuck of CNC machining center: The clamping part of the tool handle is longer, which can obtain higher clamping force. The core of the conical part of the fastening bolt is inconsistent with the core of the threaded part, which can form unilateral contact and have a negative impact on the oscillation accuracy.

2. The drilling chuck head of CNC machining center: uses three claws on the handle that can be opened and closed to achieve the clamping of the drill bit. The oscillation accuracy is poor, exceeding 0.05mm, and the clamping force is only about 1/4 of the spring chuck. When using a hard alloy drill bit for high-speed cutting, sliding may sometimes occur.

3. Lateral locking tool holder of CNC machining center: applied to drill bits with flat surfaces on straight shanks. Simply clamp the screws on the side of the drill bit to use, with low cost and simple structure. It has strong clamping force and is suitable for heavy cutting processing.

4. The Morse taper shank tool holder of CNC machining centers has two types: flat tail type and traction screw type. The pressing cone angle is relatively loose, and the contact quality of the cone surface directly affects the vibration accuracy. It is applied to Morse taper shank tools.

5. The self tightening drill chuck of CNC machining center: This is a clamping method that does not use a handle to control the opening and closing of the clamping jaws, but directly rotates the shell by hand. To improve the clamping force, a mechanism with internal steel balls is adopted, which can automatically increase the clamping force as the cutting resistance increases. (Note) It cannot be used for high-precision hole processing using high-speed steel drills.

6. The heat shrinkable tool holder of CNC machining center: It is used to clamp the drill bit through heating and cooling treatment, with excellent accuracy, rigidity, and clamping force.

7. Hydraulic chuck of CNC machining center: a method of clamping the tool handle using the elastic deformation generated by the metal cylinder under hydraulic pressure. Its balanced force and comprehensive contact can bring good oscillation accuracy.

If the CNC machining center does not use the clamping method with drill bit characteristics, normal drilling processing cannot be carried out.