FIBER BUNDLE CONDENSING DEVICE OF SPINNING MACHINE

A fiber bundle condensing device (11) of a spinning machine includes: a suction pipe (15) having a suction slit (27); and an air-permeable transport belt (16) wound on the suction pipe (15). The suction slit (27) has an upstream end (31). The upstream end (31) has: an introduction surface (31c) that is located on a bottom roller (13a) side of delivery roller pair (13) under a common tangent (L) to the delivery roller pair (13) at a nip point (P1) and defines a flow path of air to introduce the air into the suction slit (27); and a flow expansion surface (31b) obliquely intersecting the introduction surface (31c), located between an outer surface and an inner surface of the suction pipe (15), and expanding the flow path. A first angle (θ1) between a first imaginary line (D1) along the introduction surface (31c) and the common tangent (L) is smaller than a second angle (θ2) between a second imaginary line (D2) along the flow expansion surface (31b) and the common tangent (L).