Openable and closed drill bit

Abstract

An open-close drill bit, comprising a hollow drill body and a central movable wing hinged with the hollow drill body, the hollow drill body is provided with three or more blades, and at least one cutting tooth is provided on the blades, The central movable fin is provided with at least one cutting tooth and is positioned on the hollow drill bit body by a spring positioning pin. There is a groove for installing the central movable fin on the hollow drill bit body, and one end of the central movable fin is connected to the In the groove of the hollow drill bit body, the other end is provided with a positioning groove, and the positioning groove is used for the positioning of the spring positioning pin when the central movable fin is closed. The groove is a semi-open groove structure. The hinged structure is at the open end of the groove; therefore, the present invention has a simple structure and is convenient for loading and unloading, and is used to solve the problem that the drill bit body is easily deformed when it encounters a hard rock during the drilling construction of the lower screen pipe inside the drill pipe. A technical problem that prevents the center fins of the drill from opening properly.

Description

technical field [0001] The present invention relates to the technical field of drill bits, in particular to an openable and closable drill bit, which is used in the drilling process through the center of the drill rod without lifting casings or instruments, and is especially suitable for gas drainage drills in soft and outburst coal seams. Drill pipe center down screen pipe process is carried out in hole construction. Background technique [0002] In the utility model patent "Detachable Core Drill Bit for Drilling" (ZL: 200820028443.1) filed by the applicant earlier, the problem of lowering the pipe through the central through hole of the drill pipe without mentioning the drill is solved. The drill bit can be drilled into a hole and then lowered into the screen pipe through the inner hole of the drill pipe to keep the gas drainage channel unblocked. Left in the hole, the inner core cannot be reused, resulting in material waste. The utility model patent "a articulated core ...

AI Technical Summary

Problems solved by technology

[0005] The object of the present invention is to provide an openable and closable drill bit, which has a simple structure and is convenient for loading and unloading, and is used to solve the problem that when the drill encounters hard rock, the force on the drill bit body is relatively large and it is easy to cause Deformation causes the technical problem that the center fin of the drill bit cannot be opened normally

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