Openable-closeable drill bit

Abstract

An openable-closed drill bit comprises a hollow drill bit body and a central moving wing hinged to the hollow drill bit body. The hollow drill bit body is provided with at least three knife wings, each knife wing is provided with a cutting tooth at least, the central moving wing is provided with at least one cutting tooth and positioned to the hollow drill bit body through a spring positioning pin, a groove for mounting the central moving wing is formed in the hollow drill bit body, one end of the central moving wing is connected in the groove of the hollow drill bit body through a hinging structure while the other end of the same is provided with a positioning groove, the positioning groove allows the spring positioning pin to be clamped therein for positioning when the central moving wing is closed, the groove is of a half-open groove structure, and the hinging structure is positioned at one open end of the groove. Therefore, the openable-closeable drill bit is simple in structure and convenient to mount and demount and is used for solving the technical problem that the central wing of the drill bit cannot be normally opened caused by the fact that the drill bit body is highly stressed and is prone to deforming when the drill bit comes across hard rock during drilling of a lower sieve pipe in a drill column.

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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