How to install a safety barrier-post in garage, between house and vehicle
You can rent a core drill for under 200 dollars including the dimond bit. You would need to make a substantially larger diameter hole than the pipe because you need concrete around it, not just in it.

This is a picture of a very serious bollard 

https://www.concreteconstruction.net/how-to/creating-a-bollard_o

If you are really worried about a teen driver or similar crashing into your bed, go with the example in the picture. A reasonable compromise with a fair amount of stopping power would be 2" pipe in a 6" hole at least a couple of feet deep. Most of the bolt down ones are just for show unless, you get some really serious anchors bolting down through a very thick peice of metal and deep into the concrete spread out on a large bolt pattern.