摘要 |
A tube expander includes an oil-discharging device for discharging a predetermined amount of oil into the tubes of a heat exchanger mounted on the tube expander which is movably mounted between tube-expanding mandrels of the tube expander and the heat exchanger. The oil-discharging device is provided with a plurality of oil-discharging nozzles each constructed of a pipe-shaped nozzle main body having an end expander bullet that can be inserted into a tube, an oil-discharging hole arranged between the nozzle main body and the expander bullet for discharging the oil, an annular sleeve mounted around the circumferential surface of the main body for reciprocal movement relative thereto, the annular sleeve having an end contact part for abutting against an opening end of the tube, the annular sleeve sealing the oil-discharging hole of the nozzle main body by means of a resilient member, and a stopper provided on an end of the expander bullet to receive the sleeve on the end of the expander bullet.
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