Nesting type wrench clamping mechanism

The invention discloses a nesting type wrench clamping mechanism which is a mechanism for clamping a bolt when a wrench is used for screwing up the bolt. The mechanism is composed of a fixing sleeve, sleeves, a center column, reset springs, contact switches and the like. The center column and the sleeves in all specifications are nested into the fixing sleeve, and reset springs are installed at the lower portions of the center column and the sleeves in all specifications. When the bolt is clamped, a clamping mechanism is arranged on a bolt hexagonal head in a sleeving manner, the hexagonal head jacks the sleeves with the sizes equal to or smaller than that of the hexagonal head, and the rest of the sleeves is clamped; and when the center column or the sleeve is pressed down, the corresponding contact switch is closed, and the bolt specification can be identified. The nesting type wrench clamping mechanism has the beneficial effects that the clamping mechanism adapts to bolts in different specifications by pre