Partition member for cooling passage of internal combustion engine, cooling structure of internal combustion engine, and method for forming the cooling structure

A partition member that divides a groove-like cooling passage formed in a cylinder block of an internal combustion engine into a plurality of passages in a direction defined by a depth of the cooling passage, wherein a cooling heat medium flows through the cooling passage, the cooling passage having a bottom surface and a pair of opposing inner surfaces that define a width of the cooling passage, the partition member comprising:

• a spacer having a thickness that is less than the width of the cooling passage, wherein the spacer has a lower end arranged on the bottom surface of the cooling passage, and a pair of side surfaces each facing one of the inner surfaces;
• and
• a separating member arranged in the cooling passage, wherein the separating member has two members each fixed to one of the side surfaces of the spacer, wherein, before the partition member is arranged in the cooling passage, each of the two members has a width wider than the width created between the inner surface of the coolant passage and the side surface of the spacer when the partition member is arranged in the cooling passage, and wherein the separating member is elastically deformable such that the width of the separating member can be reduced to a size that allows the separating member to be arranged in the cooling passage;
• wherein:
• the cooling passage extends continuously to encompass all cylinder bores formed in the cylinder block, the separating member having an opening at a position that corresponds to a part of the cooling passage in a circumferential direction,
• the spacer extends along the entire circumference of the cooling passage, and the spacer has a guide wall at a position that corresponds to the opening of the separating member, the guide wall guiding the cooling heat medium to a cooling passage of a cylinder head, and
• the separating member is coupled with an upper end surface of the spacer, and the guide wall extends toward the cylinder head relative to the separating member.