I finally found a solution but a verry bad solution. You could make the object 240x240 and than zoom out with the scale but than i must change every object and i did already so much that it is difficult now to change that. S has anybody experience with this.
For everyone the problem better described:
I have a ready Tilemap with a resolution of for example 240x240 each Tile. Of course when i open it with construct the tiles are to big. But if i scale it down with the image editor i lose the quality and there is no option to make it smaller with the size like with a sprite. Why there is no option like with the sprites. If i change the Tile width and height to 240x240 than the Tiles have the quality but are much to big. How can i than make them smaller without losing the quality.
Thank you so much for help