Anyone Know this Bean Flower?

I noticed this vine last fall with long bean pods all over it and thought it might be good for my back fence. Then this spring it made all these beautiful purple flowers!
So I took my camera for a walk and surreptitiously photographed this family's bean vine from across the street. (I'm sure I looked suspicious in my very large hat with a baby stroller, suddenly stopping to snap pics of their house.) Anyway, I wanted to ask if any of you know what it is.
Then, out of nowhere, I found a whole bunch more of it all over some trees in the wooded area between 51st Ave and the Metro. Invasive?

Sigh. It even smelled good.