A pressurizing apparatus comprising: a cam member having an outer circumferential surface, in which a spiral lead cam groove is formed, and a pressurizing member including a plurality of projections (R1, R2, R11, R12, R13, R14, R15, R16, R17, R18) inserted into the lead cam groove , and configured to move along an axis of rotation of the cam member when the cam member rotates, wherein two or more projections define a row, characterized in that the lead cam groove consists of a large lead cam groove inclined at a first angle relative to a plane orthogonal to the axis of rotation, and a small lead cam groove inclined at a second angle that is smaller than the first angle relative to the plane orthogonal to the axis of rotation, the large lead cam groove and the small lead cam groove being continuously connected to form the lead cam groove , and wherein the cam member and the pressurising member are so configured that, when the plurality of projections (R1, R2, R11, R12, R13, R14, R15, R16, R17, R18) are inserted into the large lead cam groove , the projection (R1, R2, R11, R12, R13, R14, R15, R16, R17, R18) located at one end side of a row comes into contact with one of two side surfaces of the large lead cam groove and the projection (R1, R2, R11, R12, R13, R14, R15, R16, R17, R18) located at another end side of the row comes into contact with the other one of the two side surfaces of the large lead cam groove , and when the plurality of projections (R1, R2, R11, R12, R13, R14, R15, R16, R17, R18) are inserted into the small lead cam groove , each of the plurality of projections (R1, R2, R11, R12, R13, R14, R15, R16, R17, R18) comes into contact with at least one of one side surface and the other side surface of two side surfaces of the small lead cam groove . a cam member having an outer circumferential surface, in which a spiral lead cam groove is formed, and a pressurizing member including a plurality of projections (R1, R2, R11, R12, R13, R14, R15, R16, R17, R18) inserted into the lead cam groove , and configured to move along an axis of rotation of the cam member when the cam member rotates, wherein two or more projections define a row, characterized in that the lead cam groove consists of a large lead cam groove inclined at a first angle relative to a plane orthogonal to the axis of rotation, and a small lead cam groove inclined at a second angle that is smaller than the first angle relative to the plane orthogonal to the axis of rotation, the large lead cam groove and the small lead cam groove being continuously connected to form the lead cam groove , and wherein the cam member and the pressurising member are so configured that, when the plurality of projections (R1, R2, R11, R12, R13, R14, R15, R16, R17, R18) are inserted into the large lead cam groove , the projection (R1, R2, R11, R12, R13, R14, R15, R16, R17, R18) located at one end side of a row comes into contact with one of two side surfaces of the large lead cam groove and the projection (R1, R2, R11, R12, R13, R14, R15, R16, R17, R18) located at another end side of the row comes into contact with the other one of the two side surfaces of the large lead cam groove , and when the plurality of projections (R1, R2, R11, R12, R13, R14, R15, R16, R17, R18) are inserted into the small lead cam groove , each of the plurality of projections (R1, R2, R11, R12, R13, R14, R15, R16, R17, R18) comes into contact with at least one of one side surface and the other side surface of two side surfaces of the small lead cam groove . <EOS>