Reducing drilling rig

Abstract

The invention discloses a reducing drilling rig, which comprises a drilling rig pipe body, a spiral cutting wing consisting of a wing piece and a first cutting pick, and a front end drill bit consisting of a front end seat plate and a second cutting pick; the spiral cutting wing is arranged at the outer wall of the pipe body of the drilling rig in a radiating form; the wing piece is a spiral pieceof which upper part is conical and the lower part is cylindrical; the outside diameter of the conical free end at the lower part is risen along its rotation direction and gradually increased in the conical form; every first cutting pick is fixedly connected to the free end at the outside of the wing piece, two adjacent first cutting picks are arranged equally at the arc face of the free end of the wing piece and outwards expanded; several first cutting picks are risen at 360 degrees around the rotation direction of the wing piece and then arranged at intervals along the arc face of the outside free end of the wing piece; the front end drill bit is fixed on the outer end face of the drilling rig pipe body through a front end seat plate, two lines of second cutting picks are outwards inclined to fix at the lower side of the front end seat plate. The reducing drilling rig is featured by high intensity of cutting bit, wide adaptation scale, wear-resistance and reliability, and can realizemultilayered cutting and drilling, and effectively improve the drilling and rock breaking ability and construction working efficiency.

Description

technical field [0001] The invention belongs to the field of building foundation construction machinery, in particular to a variable-diameter drilling tool matched with a long helical drilling machine. Background technique [0002] With the development of large bridges, intercity railways, expressways, mountain tunnels, underground space development and urban pipe gallery projects, bored piles occupy the main construction technology and scheme used in infrastructure construction. In the prior art, the long helical drilling machine is used for drilling and stirring, and the drill bits connected with the long helical drill rod generally have the following categories: 1) The flat bottom drill bit inlaid with the ordinary alloy cutter head has unreasonable structure, contact Because of the large surface and low strength of the cutter body, it can meet the requirements of drilling and excavating piles for general soil and sandy soil foundations, but the rock breaking ability is l...

AI Technical Summary

Problems solved by technology

In the prior art, the long helical drilling machine is used for drilling and stirring, and the drill bits connected with the long helical drill rod generally have the following categories: 1) The flat bottom drill bit inlaid with the ordinary alloy cutter head has unreasonable structure, contact Because of the large surface and low strength of the cutter body, it can meet the requirements of drilling and excavating piles on general soil and sandy soil foundations, but the rock breaking ability is low.

2) Conical rock drill bits, which use cemented carbide block cutter heads arranged at intervals on the conical helical blades wound around the outer wall of the drill rod to perform drilling and improve the rock-breaking ability of the drilling tool, but this type of drilling tool still has the following problems: a ) Carbide cutter heads are arranged at intervals along the entire helical blade. Excessive quantity will greatly increase the manufacturing cost, and the economic performance is unreasonable; There is a problem of blade breaking; c) The cemented carbide cutter head is made of cemented carbide block with a Rockwell hardness below HRC75, which is suitable for drilling and breaking rocks in general hard formations, sand pebbles, soft stones, pebbles and sub-hard rocks. , but when drilling various types of hard rock with rock uniaxial saturated compressive strength exceeding 35MPa, there will be problems such as difficult rock breaking, fast drill bit wear and low construction efficiency; The axial direction is set in parallel (that is, each cutting head is vertical to the blade surface). When the drill bit breaks rock, it is limited by the angle setting, which affects the rock breaking ability and drilling performance

To sum up, the above-mentioned defects of various drill bits in the existing long helical drilling machines greatly reduce the rock-breaking performance of the drilling tools, affect the progress of the project, cause an increase in project cost, and low operating efficiency, thereby restricting the further development of the foundation construction industry. develop

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