Does qm importdisk automaticly convert from qcow2 to raw?

As you pass the storage it will convert it into the default format for that storage. See format for overruling.
Code:
man qm
qm importdisk <vmid> <source> <storage> [OPTIONS]

       Import an external disk image as an unused disk in a VM. The image format has to be supported by qemu-img(1).

       <vmid>: <integer> (1 - N)
           The (unique) ID of the VM.

       <source>: <string>
           Path to the disk image to import

       <storage>: <string>
           Target storage ID

       --format <qcow2 | raw | vmdk>
           Target format
 
As you pass the storage it will convert it into the default format for that storage. See format for overruling.
Code:
man qm
qm importdisk <vmid> <source> <storage> [OPTIONS]

       Import an external disk image as an unused disk in a VM. The image format has to be supported by qemu-img(1).

       <vmid>: <integer> (1 - N)
           The (unique) ID of the VM.

       <source>: <string>
           Path to the disk image to import

       <storage>: <string>
           Target storage ID

       --format <qcow2 | raw | vmdk>
           Target format

Ok. Thanks Alwin :)