Combined bit

Abstract

The invention relates to a combined bit, comprising a rod body, an inner cutter body consisting of an inner cutter head and an inner cutter handle, wings and an outer cutter body consisting of an outer cutter body and an outer cutter handle, wherein the middle part of the rod body is provided with a grouting channel, and the inner cutter body is fixed at the lower end part of the rod body; the number of the wings is 2-6 and are uniformly distributed and fixed on the peripheral surface of the lower part of the rod body along the length direction thereof vertical to the direction of an axial central line of the rod body, and the outer cutter body is fixed on the wings; the inner cutter head in the inner cutter body and the outer cutter head in the outer cutter body are respectively welded the inner cutter handle with the outer cutter handle into a whole; the front ends of the inner cutter head and the outer cutter head are respectively provided with an inner cutting edge and an outer cutting edge; and the installation directions of the inner cutter body and the outer cutter body are rotating directions leading the inner cutter head and the outer cutter head to be installed toward the rod body. The combined bit realizes synchronous drilling and cutting of the inner cutter head and the outer cutter head, improves the operating efficiency multiply, has high bonding strength of the cutter heads and the cutter handles, reduces the wear condition of the cutter heads and the wings, and guarantees the quality of continuous walls after drilling holes.

Description

technical field

[0001] The invention relates to a composite drill bit capable of penetrating strata, especially sandy soil strata, which can be widely used in underground deep foundation projects such as underground facilities of high-rise buildings, foundation pit enclosure of subway stations, reinforcement of river dams and improvement of soft soil foundations, etc. need. Background technique

[0002] In the construction process of underground foundation projects such as urban high-rise buildings, deep foundation pit enclosure of subway stations, anti-seepage reinforcement of river dykes and soft soil foundation improvement and reinforcement, a large number of SMW construction method equipment is currently used to construct underground diaphragm walls, that is, multi-axis drilling rigs are used. The technology of continuously drilling, mixing soil and cement slurry in situ and inserting section steel to build underground retaining and waterproof walls, which plays the role...

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