CN211924078U

CN211924078U - Drag bit for drilling into gravel layer

Info

Publication number: CN211924078U
Application number: CN202020595248.8U
Authority: CN
Inventors: 梁亦邱; 沈杜欣; 徐新战
Original assignee: Zhejiang Yitong Foundation Engineering Co ltd
Current assignee: Zhejiang Yitong Special Foundation Engineering Co.,Ltd.
Priority date: 2020-04-20
Filing date: 2020-04-20
Publication date: 2020-11-13
Anticipated expiration: 2030-04-20

Abstract

The utility model discloses a drag bit for drilling a gravel layer, which comprises a joint at the top for butting with a drill rod, a core pipe fixed at the lower end of the joint and a drill point fixed at the lower end of the core pipe; the lower end of the core pipe is also fixed with a plurality of scrapers; each scraper has an included angle with the vertical plane, and the outer ends of all the scrapers are welded with the same steel casing; the upper end of the steel casing is fixed with the upper end of the core pipe through a plurality of reinforcing rib plates; a plurality of cutting teeth are arranged on the lower edges of the drill tip and the scraper; the bottom end of the steel casing is also provided with a plurality of cutting teeth. The drill bit has high drilling efficiency and can prevent hole collapse.

Description

Drag bit for drilling into gravel layer

Technical Field

The utility model relates to a pile foundation construction technical field specifically says a scraper bit that when constructing the bored concrete pile drilling ovum gravel layer was used.

Background

The hole-forming bored concrete pile is a well-developed pile foundation technology, and is constructed by the steps of forming holes by a drilling machine, synchronously mud protecting walls, cleaning the holes after the holes are drilled to the elevation of the bottom of the holes, then putting a reinforcement cage down, and pouring and tamping concrete.

The conventional scraper drill bit is generally adopted for drilling holes in a conventional soil layer and comprises a joint, a core pipe, a drill point and a plurality of inclined scrapers, wherein the joint is arranged at the top and used for being connected with a drill rod, the core pipe is arranged below the joint, the drill point is arranged at the bottom end of the core pipe, the plurality of inclined scrapers are arranged, the inner end of each scraper is inclined in a high-outer-low mode, the inner end of each scraper is fixed with the core pipe, the outer ends of all the scrapers are welded with the same check ring, and a plurality of horizontal rib plates for.

The prior scraper drill bit has excellent drilling efficiency in common soil layers, but has obvious insufficient efficiency when drilling in gravel layers. This is because each blade is inclined in a manner that the inside is higher than the outside when viewed from the front, but the blade is positioned on a plane perpendicular to the ground when viewed from the thickness direction, in other words, the blade is a positive blade positioned on a vertical plane, and the gravel layer is generally a mixed form of small gravel and soil, and when the positive blade drills, the positive blade is difficult to be embedded below each gravel, so the positive blade is easy to slip on the gravel, and the drilling efficiency is low; moreover, the gravel layer has the biggest risk of easy hole collapse, and although the scraper drilling also adopts the mud protecting wall synchronously, the hole collapse happens when the mud does not form a stable mud skin.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model is to provide a creep into scraper bit that the hole that creeps into ovum gravel layer usefulness that efficient and can prevent to collapse is crept into.

The technical proposal of the utility model is that a drag bit for drilling a gravel layer comprises a joint at the top for butting with a drill rod, a core pipe fixed at the lower end of the joint and a drill point fixed at the lower end of the core pipe; the lower end of the core pipe is also fixed with a plurality of scrapers; each scraper has an included angle with the vertical plane, and the outer ends of all the scrapers are welded with the same steel casing; the upper end of the steel casing is fixed with the upper end of the core pipe through a plurality of reinforcing rib plates; a plurality of cutting teeth are arranged on the lower edges of the drill tip and the scraper; the bottom end of the steel casing is also provided with a plurality of cutting teeth.

Compared with the prior art, the scraper drill bit for drilling the ovum gravel layer with the structure has the following advantages.

Firstly, because the scraper and the vertical plane form an included angle, namely the scraper is an inclined scraper, the scraper has a certain inclination angle during drilling, so that the scraper can be embedded into the bottom of small-particle gravel to dig up the gravel, thereby avoiding skidding and obviously improving the drilling efficiency in the gravel layer; more importantly, the drill bit uses the steel casing to replace a check ring, the height of the casing is obviously enhanced, and the direct physical support lasting for a certain time is provided for the hole wall, so that the mud has enough time to form firm mud skin on the hole wall, the probability of hole collapse is obviously reduced, and the steel casing with large height also has better centralizing effect, and the drill bit is ensured to vertically drill downwards; finally, because the cutting teeth firmer than the alloy teeth are arranged below the drill tip and the scraper, the front ends of the cutting teeth are also sharper, the stirring effect on compact pebble is obviously better, the efficiency for prying small-particle pebbles is higher, and the drilling efficiency is further enhanced; moreover, the cutting teeth are additionally arranged at the bottom end of the steel casing, so that the drilling efficiency is further enhanced.

Preferably, the steel casing is composed of an upper casing and a lower casing, an upper convex ring is arranged at the lower end of the upper casing in a radially inward protruding mode, a lower convex ring is arranged at the upper end of the lower casing in a radially inward protruding mode, and the upper convex ring and the lower convex ring are connected through bolts; the core pipe consists of an upper pipe and a lower pipe, wherein the lower end of the upper pipe is provided with an upper flange, the upper end of the lower pipe is provided with a lower flange, and the upper flange and the lower flange are also connected through bolts; the inner end of each scraper is welded with the lower pipe, and the outer end of each scraper is welded with the inner wall of the lower protective cylinder; the inner end of each reinforcing rib plate is welded with the upper pipe, and the outer end of each reinforcing rib plate is welded with the inner wall of the upper protective cylinder; thus, the structure is characterized in that each part of the drill bit is divided into two parts, namely, the scraper, the drill tip, the lower core tube and the lower steel casing which are easy to wear are integrated at the lower part and welded into a whole, so that the overall firmness of the lower structure is enhanced, more importantly, the lower structure is easy to replace as a whole after being damaged, and the replacement can be completed only by detaching the bolts of the two convex rings and the two flanges, and the structure is simple and convenient; the upper part of the core pipe, the upper part of the steel protective cylinder and the reinforcing rib plate which are not easy to damage are also welded into a whole, so that the firmness of the steel protective cylinder is enhanced as much as possible.

Preferably, the upper pipe is welded with a plurality of reinforcing rib plates with different heights, and four reinforcing rib plates are uniformly distributed along the circumferential direction; when viewed from the overlooking direction, each reinforcing rib plate is staggered by 45 degrees with the reinforcing rib plate of the next layer; the structure is preferable based on the previous step, and each part which is not easy to wear at the upper part forms a whole without replacement, so that a plurality of reinforcing rib plates can be added, the strength and the stability of each height of the steel casing are improved, a stronger retaining wall and a straightening effect are obtained, and the problem of cost and material waste during replacement after wear is avoided.

Drawings

Fig. 1 is a schematic view of the construction of example 1 of a drag bit for drilling a pebble bed according to the present invention.

Fig. 2 is a schematic view of the structure of fig. 1 after being deflected by a certain angle.

Fig. 3 is a schematic view of the construction of example 2 of the drag bit of the present invention for drilling a gravel layer.

Fig. 4 is a schematic view of the structure of fig. 3 after being deflected by a certain angle.

Fig. 5 is a schematic view of a drag bit for drilling a gravel layer according to example 2 of the present invention, with an upper casing removed.

Fig. 6 is a schematic view of the structure of fig. 5 after being deflected by a certain angle.

The drawing shows that 1, a joint, 2, a core pipe, 2.1, an upper pipe, 2.2, a lower pipe, 3, a drill tip, 4, a scraper, 5, a steel protective cylinder, 5.1, an upper protective cylinder, 5.2, a lower protective cylinder, 6, a reinforcing rib plate, 7, a cutting pick, 8, an upper convex ring, 9, a lower convex ring, 10, a bolt, 11, an upper flange, 12 and a lower flange.

Detailed Description

The invention will be further explained with reference to the drawings and the specific embodiments.

As shown in fig. 1 to 2, the embodiment 1 of the drag bit for drilling a gravel layer of the present invention includes a joint 1 for butt-jointing with a drill rod at the top, a core tube 2 fixed to the lower end of the joint 1, and a drill tip 3 fixed to the lower end of the core tube 2. Four scrapers 4 are fixed at the lower end of the core tube 2, and each scraper 4 forms an included angle with the vertical plane, in other words, each scraper 4 is an inclined scraper which is not in the vertical plane. The outer ends of all the scrapers 4 are welded with the same steel casing 5; the upper end of the steel casing 5 is fixed with the upper end of the core pipe 2 through four reinforcing rib plates 6 at the same height. The lower edges of the drill tip 3 and the scraper 4 are provided with a plurality of cutting teeth 7; the bottom end of the steel casing 5 is also provided with a plurality of cutting teeth 7. In this embodiment, the core tube 2 is an integral core tube 2, and the steel casing 5 is also an integral steel casing 5.

As shown in fig. 3 to 6, the drag bit of the present invention of example 2 for drilling a gravel layer is different from the previous example in that: the steel casing 5 and the core pipe 2 are both split.

Specifically, the steel casing 5 consists of an upper casing 5.1 and a lower casing 5.2, an upper convex ring 8 is radially and inwardly protruded at the lower end of the upper casing 5.1, a lower convex ring 9 is radially and inwardly protruded at the upper end of the lower casing 5.2, and the upper convex ring 8 and the lower convex ring 9 are connected through a bolt 10; the core pipe 2 is composed of an upper pipe 2.1 and a lower pipe 2.2, an upper flange 11 is arranged at the lower end of the upper pipe 2.1, a lower flange 12 is arranged at the upper end of the lower pipe 2.2, and the upper flange 11 and the lower flange 12 are also connected through a bolt 10.

In the embodiment, the inner ends of four scrapers 4 are welded with the lower pipe 2.2, and the outer ends of the four scrapers 4 are welded with the inner wall of the lower protective cylinder 5.2; the inner end of each reinforcing rib plate 6 is welded with the upper pipe 2.1, and the outer end of each reinforcing rib plate 6 is welded with the inner wall of the upper protective barrel 5.1.

Further, the difference from the previous embodiment is that the reinforcing floor 6 is a plurality of reinforcing floors 6 distributed at different heights. Four reinforcing rib plates 6 are still arranged in each channel and are uniformly distributed along the circumferential direction; each rib 6 is shifted by 45 degrees from the rib 6 of the next layer in a plan view.

Claims

1. A drag bit for drilling a gravel layer comprises a joint (1) which is arranged at the top and is used for butting with a drill rod, a core pipe (2) fixed at the lower end of the joint (1) and a drill point (3) fixed at the lower end of the core pipe (2); the lower end of the core tube (2) is also fixed with a plurality of scrapers (4); the method is characterized in that: each scraper (4) forms an included angle with the vertical plane, and the outer ends of all the scrapers (4) are welded with the same steel casing (5); the upper end of the steel protective cylinder (5) is fixed with the upper end of the core pipe (2) through a plurality of reinforcing rib plates (6); a plurality of cutting teeth (7) are arranged on the lower edges of the drill tip (3) and the scraper (4); the bottom end of the steel casing (5) is also provided with a plurality of cutting teeth (7).

2. A drag bit for drilling a layer of egg gravel according to claim 1 wherein: the steel casing (5) consists of an upper casing (5.1) and a lower casing (5.2), an upper convex ring (8) is radially and inwardly protruded at the lower end of the upper casing (5.1), a lower convex ring (9) is radially and inwardly protruded at the upper end of the lower casing (5.2), and the upper convex ring (8) and the lower convex ring (9) are connected through a bolt (10); the core pipe (2) is composed of an upper pipe (2.1) and a lower pipe (2.2), the lower end of the upper pipe (2.1) is provided with an upper flange (11), the upper end of the lower pipe (2.2) is provided with a lower flange (12), and the upper flange (11) and the lower flange (12) are also connected through a bolt (10); the inner end of each scraper (4) is welded with the lower pipe (2.2), and the outer end is welded with the inner wall of the lower protective cylinder (5.2); the inner end of each reinforcing rib plate (6) is welded with the upper pipe (2.1) and the outer end is welded with the inner wall of the upper protective barrel (5.1).

3. A drag bit for drilling into an egg gravel layer as claimed in claim 2 wherein: a plurality of reinforcing rib plates (6) with different heights are welded on the upper pipe (2.1), and four reinforcing rib plates (6) are uniformly distributed along the circumferential direction; when viewed from the top, each reinforcing rib (6) is staggered from the next reinforcing rib (6) by 45 degrees.