A combined multi-stage drill bit device

Abstract

A combined multi-stage drill bit device comprises a drill pipe, a first-stage drill, a second-stage drill, a third-stage drill sleeve, a connecting drill, a cover sealing drill and a positioning bolt.The first-stage drill is arranged at the top end of the drill pipe, and the first-stage drill is in fixed threaded connection with the drill pipe. The second-stage drill is arranged on the top section of the drill pipe, and the second-stage drill is in fixed threaded connection with the drill pipe. The third-stage drill is arranged at the bottom section of the drill pipe and is arranged at the bottom end of the second-stage drill to realize threaded fixation of the three-stage drill and the drill pipe. The connecting drill achieves fixing of the first-stage drill, the second-stage drill and athird-stage drill through clamped connection. The cover sealing drill is arranged at the bottom end of the third-stage drill, the positioning bolt penetrates through a cover sealing drill positioninghole and extends into a drill pipe positioning hole, and the cover sealing drill, the third-stage drill and the drill pipe are fixed through threaded connection. A drill bit is long in service life,the parts are convenient to dismount and replace, cutting step holes can be formed at a time, and the cutting aperture is smooth and attractive.

Description

technical field [0001] The invention relates to the field of drill tools, in particular to a combined multistage drill device. Background technique [0002] The main structural forms of drill bits are twist drills, flat drills, center drills, deep hole drills and casing drills. For drilling step holes, ordinary drills need to be drilled many times repeatedly, and the processing process is cumbersome. Various forms of combination drill bits are provided in the prior art, and the drill bits of this form can realize drilling of stepped holes or direct drilling of larger diameter holes. In the prior art, the structure of the combined drill bit is complicated, and it is fixed by plugging in the form of a multi-level drill bit. During the drilling process, a small hole is drilled, and then the drill bit with a gradually increasing diameter is used to expand the hole layer by layer. To achieve the hole size, the drill bit of each layer combination is directly in contact with the ...

AI Technical Summary

Problems solved by technology

In the prior art, the structure of the combined drill bit is complicated, and it is fixed by plugging in the form of a multi-level drill bit. During the drilling process, a small hole is drilled, and then the drill bit with a gradually increasing diameter is used to expand the hole layer by layer. To achieve the hole size, the drill bit of each layer combination is directly in contact with the object. During the process of reaming, it is easy to cause serious wear of the drill bit, and when the drilling process is affected by lateral external force or uneven force, it is easy to cause the drill bit to be damaged. Part of the cutter head is damaged, which affects the service life of the cutter head, and the drill bit needs to be replaced frequently, which increases the cost of use and is low in economy

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