Back tong for top-drive drilling unit

Abstract

The invention discloses a back tong of a top-driving well drilling device. The back tong comprises a back tong shell and a pair of tongs consisting of a left tong head and a right tong head; the back tong also comprises a tong head float mounting seat which can move right and left along the shell; one side of an inner cavity of the float mounting seat is provided with a hydraulic cylinder; the hydraulic cylinder float right and left through the pressure change of inner oil liquid; and the pair of the tong heads are connected with the float mounting seat and the sidewall of the hydraulic cylinder respectively. When the back tong of the top-driving well drilling device is shackled, the back tong can realize the effects of the reliable clamping of the back tong and the even and consistent locking force of the left tong head and the right tong head, and avoid the problems that the back tong is worn and a drill stem is scratched and needs mechanical strengthening; and when the shackling isfinished and is loosened, the back tong can keep proper distance with the drill stem, has the same clearance with the drill stem, prolongs the service cycle and replacement cycle of the back tong so that the whole top-driving well drilling device is safer and more reliable.

Description

Technical field [0001] The invention relates to the technical field of machinery, in particular to a top drive drilling device back clamp. Background technique [0002] In recent years, with the continuous development of drilling equipment and in order to better meet the needs of drilling special wells, top drive drilling devices have been developed. The device combines a faucet with a motor to drive the drill tool and drill bit to rotate on the upper part of the derrick space. At the same time, it is equipped with a drill pipe up-and-down device, which can complete a variety of drilling operations. Because the top drive drilling device is a new type of oil drilling equipment, it has the function of making up and breaking up, which can perform up and down operations at any height of the derrick, and the completion of the up and off function is through the back clamp of the top drive drilling device This is achieved by clamping the drill pipe while hydraulic power drives the spin...

AI Technical Summary

Problems solved by technology

[0007] In view of this, the object of the present invention is to provide a top-driven drilling device back tong to solve the problem that the drilling device back tong in the prior art is easy to cause wear and scratches on the drill pipe, thereby reducing the service life of the back tong

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