Heat exchanger for vehicle

A heat exchanger for a vehicle, comprising:

• a heat radiating portion provided with a first connecting line, a second connecting line and a third connecting line formed alternately by a stacked plurality of plates, and receiving first, second and third operating fluids into the first, second and third connecting lines, respectively, the first, second and third operating fluids heat-exchanging with each other while passing through the first, second and third connecting lines, wherein the first, second and third operating fluids supplied into the first, second and third connecting lines are not mixed with each other while circulated;
• a bifurcating portion configured to bypass one of the first, second and third operating fluids around the heat radiating portion according to a temperature of the one operating fluid;
• a valve unit mounted at an inflow hole forming the bifurcating portion, selectively opening or closing one of the first second and third connecting lines by expansion or contraction of a deformable material filled therein to selectively direct the one operating fluid to the heat radiating portion or the bifurcating portion according to a temperature of the one operating fluid;
• and
• a plurality of inflow holes for the first, second and third operating fluids to flow into the heat radiating portion and the bifurcating portion;
• and
• a plurality of exhaust holes for the first, second and third operating fluid to flow out of the heat radiating portion and the bifurcating portion.