Cutting rod, cutting bit and cutting tool

Abstract

The present invention provides a drilling rod, a drill and a drilling tool thereof. In the drilling rod, a mounting unit (2) which protrudes frontwards and extends along the first axial line is provided. The mounting unit is provided with a parallel male thread portion having a constant minimum distance from the first axial line at a section perpendicular to the first axis line and a male thread cut portion connected to the rear end side of the parallel male thread portion and having a minimal distance that enlarges, furthermore, the mounting unit is formed to that the minimal distance does not reduce from the front end side to the back end side. The rear end of the male thread cut portion is disposed on a plane where the distance from the first axial lien gradual enlarges from the parallel male thread portion towards the rear end side.

Description

technical field [0001] The present invention relates to a drill pipe, a drill bit, and a drilling tool used for drilling foundations and sandy soils in civil engineering such as tunnels, various works such as anchoring and foundation piles, and gravel operations. The present application claims priority from Japanese Patent Application No. 2005-355888 filed on December 9, 2005, the contents of which are incorporated herein by reference. Background technique [0002] As a drilling tool for drilling ground, sand and other drilled objects, a drilling tool composed of a drill bit having a plurality of button-shaped drill points and a drill rod supporting the drill bit is used, wherein the button-shaped drill bit The tip is made of a hard material such as cemented carbide. A mounting hole with a female thread on the inner peripheral surface is perforated at the rear end of the drill bit. At the front end of the drill rod, a mounting portion having a male thread on the outer peri...

AI Technical Summary

Problems solved by technology

However, in conventional drilling tools, the diameter of the attachment part of the drill rod is set small in order to ensure the wall thickness of the drill bit. , in the case of increasing the drilling speed, the load acting on the drilling tool increases, and there is a risk of damage to the drill pipe due to this load

On the other hand, in the case of increasing the diameter of the drill rod, the wall thickness of the drill bit becomes thinner, so there is a problem of bit breakage

In particular, when the drill rod is broken, the drill bits and the like remain at the bottom of the drilled hole, and it takes a lot of time and labor to repair the accident, so it is not economical.

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