Read the angle of a physic object after collision and set up new one

Hi, I wish to control the velocity and the angle of a object with a constant velocity. My purpose is limit the angle between a minimum and maximum after collision without change the speed. Game is in 2D, so just control two vectors, right and up. I’ve playing getting the velocity and normals but not sure but maths experience. Somebody can gimme an idea?
Thanks in advance.