Stable liquid expansion mandrel structure

The utility model discloses a stable type liquid expansion mandrel structure which comprises a mandrel body and a thin-wall sleeve, the mandrel body comprises a mandrel and an annular boss, two sets of adjusting mechanisms are arranged outside the thin-wall sleeve, each adjusting mechanism comprises a clamping assembly and an adjusting assembly, each clamping assembly comprises an inclined plate, and each adjusting assembly comprises an inclined plate. A supporting plate is fixedly arranged outside the inclined plate, the adjusting assembly comprises a triangular plate, a moving groove is formed in the triangular plate, and a screw rod is fixedly arranged on the surface of the inclined plate; by means of the designed adjusting mechanism, a workpiece with the larger inner diameter can be conveniently fixed to the thin-wall sleeve in the using process, the workpiece with the larger inner diameter can be fixed by adjusting the position of the supporting plate, the using cost is reduced, and the applicability of