Sonic Corp., the drive-in restaurant chain known for carhops, chili-cheese coneys and a bevy of beverages, is coming to the Chicago area this summer, part of an effort to expand beyond its Sun Belt roots.

Sonic announced Wednesday that four restaurants are slated to open near Chicago by the end of the year, the first two this summer in Country Club Hills and Aurora. Sonic outlets in Algonquin and Lockport are scheduled to open in the fall and winter, respectively.

Within the next six years, the company expects to have 40 to 50 restaurants in the Chicago area, said Drew Ritger, Sonic's senior vice president of development. Sonic has at least 30 restaurants in Illinois, but the closest one to Chicago is in Peoria.