Steel bar prestress tensioning machine

Abstract

The invention relates to a steel bar prestress tensioning machine, wherein a first driving mechanism can drive a tensioning assembly to move to enable a steel bar to have axial deformation. The tensioning assembly is provided with a tensioning big nut, and the tensioning big nut sleeves a tensioning screw and can slide to be clamped on a fixed end plate to prevent the steel bar from recovering from the deformation. The tensioning assembly further includes a bracket that can move synchronously with the tensioning big nut away from the fixed end plate during the tensioning process. The bracket can slide towards the fixed end plate with the tensioning big nut synchronously in the tensioning big nut screwing process. The bracket is further provided with a nut sleeve detachably connected with the tensioning big nut, a second driving mechanism for driving the nut sleeve to drive the tensioning big nut to rotate and a transmission assembly. Regardless of whether the tensioning big nut moves towards or away from the fixed end plate, the bracket can move together with the tensioning big nut, and the second driving mechanism arranged on the bracket can rotate the tensioning big nut continuously without sudden stop. The structure is simple and ingenious.

Description

technical field [0001] The invention relates to the field of construction engineering, in particular to a steel bar prestressed tensioning machine. Background technique [0002] Prestressed tension is to add tension in the component in advance, so that the prestressed tensioned component bears the tensile stress, and then makes it produce a certain deformation to cope with the load on the structure itself, including the load of the component's own weight, etc. form. [0003] In the existing production process of prefabricated piles or pipe piles, in order to obtain higher strength products, it is necessary to use a jack-type tensioning machine to carry out overall prestressed tension on the reinforced skeleton of the centrifugal square pile after mold closing. Applying pre-compressive stress before external load can improve the rigidity, bending resistance and rigidity of the structure itself, reduce vibration and elastic deformation, delay the time of cracks, and increase ...

AI Technical Summary

Problems solved by technology

When the steel bar in the pipe mold is stretched by the tensioning machine, the length will be extended in the axial direction. After the tensioning action is completed, the steel bar will inevitably retract to a certain extent. The existing technology is to manually twist and stretch The big nut in the machine makes it clamp with the tensioned end plate. When the steel bar retracts, the clamped large nut and the end plate will play a role in locking the retraction. Although manual screwing of the large nut can complete the clamping The task of stopping the retraction of steel bars, but the manual operation requires manual on-duty and the strength of the twist, which is time-consuming and laborious to operate, and is not suitable for the needs of automated production, and the human error is also relatively large

[0004] For this reason technical personnel have made certain improvements, as the Chinese invention patent that the patent number is CN201610113474.6 (public announcement number is CN105563636A) just discloses a kind of stretching machine, after its stretching action finishes, stretching oil cylinder maintains oil pressure , the compression cylinder works, so that the driving wheel and the driven wheel are attached to the tensioning nut, the driver of the driving wheel works and drives the driving wheel to rotate, and the driving wheel drives the tensioning nut to rotate, so that the tensioning nut is tightened toward the direction of the tensioning end plate And close to the tensioning end plate, because the tensioning nut will move axially along the tensioning screw rod during the rotation process, so the driving wheel should also be able to move synchronously with the tensioning nut, otherwise it will cause the driving wheel and the tensioning The big nut is misplaced and cannot drive the big tension nut to rotate further. Setting an additional cylinder on the tensioning machine can realize the driving wheel to follow the big nut to move axially along the tensioning wire rod, but it is difficult for the cylinder to ensure that the driving wheel and the big tension nut The nuts move equidistantly in the same time. When the driving wheel and the tensioning nut cannot move equidistantly within the same working time, there will be an axial displacement deviation between the driving wheel and the tensioning nut. The displacement deviation It will directly affect the distance between the tensioning nut and the tensioning end plate, and then affect the tensioning effect of the steel bar

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