Telescopic tail beam

The utility model provides a telescopic tail beam used for hydraulic supports, which not only can be suitable for cutting height variation, but also can not be smashed bent by roof pressure. The utility model is composed of an inclined beam 1, a sleeve pipe 2 and a core pipe 5, the inclined beam 1 is welded with the sleeve pipe 2, the sleeve pipe 2 is provided with an upper, a middle and a lower pin holes and is connected with the core pipe 5 via a pin 3, and the sleeve pipe is in vertical direction. The core pipe 5 is hinged with the inclined beam 1 via a base 6 and an oil cylinder 7. When the hydraulic support is applied with the roof pressure, the inclined beam can mainly bear a lateral pressure, and the sleeve pipe 2 and the core pipe 5 bear a longitudinal pressure; when the cutting height is changed, the oil cylinder 7 can vertically stretches so as to drive the core pipe 5 to stretch. Therefore, the utility model can get the purpose of automatic adjusting height.