Method for direct screwing of components, in particular for flow drilling screws and device for direct screwing of components

A method for direct screwing or flow hole screwing of structural components, the method comprising the following steps:

• producing a feed and a feed force by using a non-pneumatic feed drive and transmitting the feed and the feed force to a screw shaft;
• setting the screw shaft in a rotational movement;
• setting a high rotational speed of the rotational movement and setting a high feed force by using the non-pneumatic feed drive for producing a hole in a structural component in a first process stage;
• switching over to a lower feed force and a slower rotational speed at a defined switchover point with penetration of the structural component for forming a thread in the hole in a second process stage;
• and
• monitoring a parameter correlated at least with the feed force and using a characteristic value or a characteristic change of a value of the parameter to define the switchover point.

A device for direct screwing or flow hole screwing of structural components, the device comprising:

• a rotatably drivable screw shaft configured to be moved in an axial direction to exert a feed;
• a non-pneumatic feed drive for generating a feed and a feed force and for transmitting said feed and said feed force to said screw shaft;
• and
• a control unit for controlling a flow hole screwing procedure, said control unit setting a high rotational speed of said screw shaft and a high feed force produced by said non-pneumatic feed drive in a first process stage and switching over to a lower feed force and a slower rotational speed at a defined switchover point for a second process stage;
• and
• said control unit monitoring a parameter correlated at least with said feed force and defining said switchover point upon reaching a characteristic value or upon a characteristic change of a value of said parameter.