Method of manufacturing foam molded article

A method of manufacturing a foam molded article, comprising:

• an extrusion step of extruding a molten, kneaded resin containing a foaming agent through an annular slit between a die core and a die shell surrounding the die core to form a cylindrical foam parison and extruding the foam parison between a pair of split molds;
• a lower-pinching step of pinching the foam parison between lower pinchers disposed under the split molds;
• and
• a molding step of molding the foam parison by closing the split molds, after the lower-pinching step, wherein
• H/D is 1.33 to 3.33 and L/D is 0.33 to 2.00 where D represents a diameter of the die core;
• H represents a distance between a lower surface of the die core and an upper surface of each of the split molds;
• and L represents a distance between a lower surface of each of the split molds and an upper surface of the corresponding lower pincher, and wherein
• the diameter of the die core is between 50 mm and 300 mm,
• the foam molded article is a tubular object including a main channel and a sub-channel connected to the main channel,
• an angle between the main channel and the sub-channel is 45 to 90°, and
• a section which forms an angle of 0 to 45° with an extrusion direction of the foam parison, of the foam molded article has a blow ratio of 0.5 to 0.8.