Air spring for railroad car

An air spring for railroad cars, comprising:

• an air spring part formed by an upper support on a vehicle body side, an intermediate support arranged below the upper support, and a diaphragm made of an elastic material and extending between the upper support and the intermediate support;
• and
• an elastic mechanism formed by an elastic member interposed between said intermediate support and a lower support on a bogie side arranged below the intermediate support,
• said elastic member having an end in contact with said lower support formed as an enlarged end increasing in diameter as approaching said lower support in a vertical direction, an outer circumferential portion of this enlarged end being fitted in and bonded to an annular groove formed in said lower support, and said annular groove having an annular bottom inclined to decrease in height radially outwards to have an annular tapered bottom, an annular horizontal outer peripheral bottom that is horizontal and continuous with a radially outer side of said annular tapered bottom, and an outer circumferential wall has an angle which is perpendicular to an upper surface of the lower support, and an angle between the annular horizontal outer peripheral bottom and the annular tapered bottom is substantially different from the perpendicular outer circumferential wall angle.