An animation problem of fbx file created by scripting in Blender

Hi,

I have written a python script in Blender to make a simple animation. A cube is created, then becomes hidden at frame 5 and a cone is created exactly at that frame. Then the cone becomes hidden at frame 9. The created movie is attached.
The problem is that when I export this animations to Unity as a fbx file , I do not see any object and animations. Also there are four clips which their final frame is 4, while I adjusted final frame at 10 in Blender.
The inspector images of Unity have been attached.

I would be thankful if somebody could help,
Sima