| 摘要 |
According to the present invention, a coupling structure of a piercing head includes: a milling spindle which is coupled to a fixing part with a bearing to be rotated; a boring spindle which is coupled to the inner side of the milling spindle to be rotated along with it and to be transported back and force; a flange which is coupled to one side of the fixing part; a piercing head which has a fixing body and a rotating body that is fixed to the fixing body and selectively coupled to the milling spindle; a locking key assembly body which has a rod that is installed to be ascended and descended between the fixing part and the flange, a pusher that is connected and interlocked with the rod and has a protruded part at its end part, a locking key that is installed in a space between the flange and the one end of the rotating body and has a concave grove on one side which is engaged with the protruded part of the pusher for interlocking, a bolt that is coupled to one end of the rotating body penetrating through the locking key, and a coil spring that is installed on outer circumference of the bolt. According to the present invention, as the rotating body can be selectively coupled to or decoupled from the milling spindle by installing the transportable locking key, a high-speed boring work can be performed even when the piercing head is installed and, therefore, the work efficiency can be improved. |
