This article contains a listing of known keys that can be used with Kiosk and what they do. How to actually use these keys and other capabilities of Kiosk such as URL restrictions, creating assigning profiles, etc. is covered in the Introduction to Kiosk article.
In kdeglobals in the [KDE Action Restrictions] group:
The timeout is the time in seconds that the user must be idle for before the logout process is automatically started. Be careful with this capability as it can lead to data loss if the user has unsaved files open.
autologout goes here as