CN212774152U

CN212774152U - Drag bit for drilling ovum gravel layer during construction of height-limited space

Info

Publication number: CN212774152U
Application number: CN202021814974.0U
Authority: CN
Inventors: 沈杜欣; 徐新战
Original assignee: Zhejiang Yitong Special Foundation Engineering Co ltd
Current assignee: Zhejiang Yitong Special Foundation Engineering Co ltd
Priority date: 2020-08-26
Filing date: 2020-08-26
Publication date: 2021-03-23
Anticipated expiration: 2030-08-26

Abstract

The utility model discloses a drag bit for drilling a gravel layer during construction of a height-limited space, which comprises a joint at the top, a core pipe positioned below the joint, a drill point positioned at the bottom end of the core pipe, a plurality of horizontal rib plates and a plurality of scrapers, wherein the inner end of each scraper and the inner end of each horizontal rib plate are fixed with the core pipe; the drill tip and the scraper are provided with a plurality of cutting teeth; the scraper drill bit also comprises an inner retainer ring and an outer retainer ring which are sleeved with each other in a sliding manner, and the outer end of each scraper and the outer end of each horizontal rib plate are welded with the inner retainer ring; the bottom ring surface of the inner retainer ring is also provided with a plurality of cutting teeth; the side wall of the inner retainer ring radially protrudes outwards to form a limiting convex ring, the side wall of the outer retainer ring radially protrudes inwards to form an upper retainer ring and a lower retainer ring, and the limiting convex ring is positioned between the upper retainer ring and the lower retainer ring. The scraper drill bit can prevent hole collapse when a gravel layer drills into the hole, the overall height of the drill bit during hoisting and installation can be effectively reduced, and normal installation and use in a height-limiting field are guaranteed.

Description

Drag bit for drilling ovum gravel layer during construction of height-limited space

Technical Field

The utility model relates to a pile foundation construction technical field specifically says a drag bit that creeps into ovum gravel layer and use when limit for height space construction pore-forming bored concrete pile.

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 comprises a joint which is arranged at the top and is used for being connected with a drill rod, a core pipe which is arranged below the joint, a drill point which is arranged at the bottom end of the core pipe, and a plurality of scrapers which are higher outside and lower inside, wherein the inner end of each scraper is fixed with the core pipe, the outer end of each scraper is welded with the same check ring, and a plurality of horizontal rib plates for reinforcing are arranged between the check ring and the core pipe.

The scraper drill bit in the prior art has excellent drilling efficiency in a common soil layer, but has larger hole collapse risk when drilling in a gravel layer, and although the scraper drill bit also synchronously adopts a mud retaining wall, the hole collapse usually occurs when mud does not form a stable mud skin. Therefore, a scheme of replacing a retaining ring with a small height with a steel casing with a large height is proposed to increase the height of the retaining wall, provide direct physical support for the hole wall for a period of time, enable slurry to have enough time to form firm mud skin on the hole wall, and obviously reduce the probability of hole collapse.

However, the drill bit replacing the steel casing described above has the following disadvantages in practical use: the ultra-high steel pile casing objectively increases the overall height of the drill bit, before drilling, the drill bit needs to be hoisted to the position below a power head of a pile machine, the ultra-high drill bit needs to be matched with a large-sized pile machine and a pile frame, the overhead cost, the labor intensity, the labor cost and the like can be increased, and particularly, when piling is carried out on certain height-limited places such as the position below an overhead bridge, the large-sized pile machine cannot be placed at all due to the height, so that the height-limited places are limited in use and cannot operate.

SUMMERY OF THE UTILITY MODEL

The to-be-solved technical problem of the utility model is to provide a hole of collapsing when the ovum gravel layer creeps into can prevent, can effectively reduce the whole height of drill bit when the handling installation again, ensure to creep into the drag bit that the ovum gravel layer was used when the limit for height space construction that can normally install and use in limit for height place.

The technical scheme of the utility model is that the scraper drill bit for drilling the gravel layer during the construction of the height-limited space comprises a joint at the top, a core pipe positioned below the joint, a drill point positioned at the bottom end of the core pipe, a plurality of horizontal rib plates and a plurality of scrapers, wherein the inner end of each scraper and the inner end of each horizontal rib plate are fixed with the core pipe; the drill tip and the scraper are provided with a plurality of cutting teeth; the scraper drill bit also comprises an inner retainer ring and an outer retainer ring which are sleeved with each other in a sliding manner, and the outer end of each scraper and the outer end of each horizontal rib plate are welded with the inner retainer ring; the bottom ring surface of the inner retainer ring is also provided with a plurality of cutting teeth; the side wall of the inner retainer ring radially protrudes outwards to form a limiting convex ring, the side wall of the outer retainer ring radially protrudes inwards to form an upper retainer ring and a lower retainer ring, and the limiting convex ring is positioned between the upper retainer ring and the lower retainer ring.

Compared with the prior art, the scraper drill bit for drilling the gravel layer in the construction of the height-limited space with the structure has the following advantages.

In the initial state, in the process of hoisting a drill bit below a power head of a pile machine before hole forming operation, the upper clamping ring is placed on the limiting convex ring under the action of gravity, so that the heights of the two retaining rings are mutually overlapped, the integral height of the retaining rings is halved, and the integral height of the drill bit is correspondingly greatly reduced, so that the space below the power head of the pile machine is enough for hoisting the drill bit, the drill bit can be matched with a small pile machine and a pile frame, the work cost, the labor intensity and the labor cost are reduced, the method is particularly suitable for construction operation below a height-limited site such as a viaduct, and the problem that the adaptive pile machine in the prior art cannot be placed too; and this drill bit creeps into in the ovum gravel layer, interior retaining ring continues to go down along with the drill bit body and bores, and outer retaining ring receives the friction hindrance pause of the hole side soil body at former height, make two retaining rings take place highly to relative motion, pulled open, thereby make the dado highly compare increase one time when overlapping, provide the direct physics nature support that lasts a period to the hole wall, make mud have sufficient time to form firm mud skin at the pore wall, obviously reduced the probability that the ovum gravel layer collapsed the hole.

Preferably, the bottom ring surface of the outer retainer ring is also provided with a plurality of cutting teeth; the bottom ring surface of the limit convex ring is provided with a plurality of upper ratchets, and the top ring surface of the lower clamping ring is provided with a plurality of lower ratchets used for meshing the upper ratchets; the specific process of the drill bit drilling is as follows: interior retaining ring bores down along the drill bit body, and outer retaining ring receives the soil body resistance along the height to the stagnation, like this, spacing bulge loop can constantly descend and draw close with lower snap ring, supports until both to lean on completely, and last ratchet between the two also just meshes with lower ratchet and targets in place to make outer retaining ring can follow interior retaining ring and drill bit drilling rod synchronous rotation. The purpose of designing like this is because the pore wall of the step that the difference of inside and outside retaining ring external diameter can form constitutes the hindrance to boring down to the outer retaining ring, and just because outer retaining ring has obtained rotatory power, combines with the pick of outer retaining ring base ring face for outer retaining ring has also possessed stronger drilling efficiency, can overcome the hindrance of step pore wall, and the boring down smoothly, and then guarantees the holistic efficiency of boring of drill bit.

Drawings

Fig. 1 is a schematic structural diagram of the utility model when two retaining rings of the drag bit for drilling into a gravel layer during construction of a height-limiting space are overlapped.

Fig. 2 is the structure schematic diagram of the utility model which is used after half of the outer retainer ring is removed when two retainer rings of the drag bit for drilling into the gravel layer during the construction of the height-limiting space are overlapped.

Fig. 3 is a schematic structural diagram of the scraper drill bit for drilling into the gravel layer during the construction of the height-limiting space.

Fig. 4 is the structure schematic diagram of the utility model which is used after half of the outer retainer ring is removed when the two retainer rings of the drag bit for drilling the ovum gravel layer during the construction of the height-limiting space are opened.

Fig. 5 is a schematic structural diagram of the utility model which is formed after half of the outer retainer ring and the whole inner retainer ring are removed when the two retainer rings of the drag bit for drilling the gravel layer during the construction of the height-limiting space are opened.

The drawing shows that 1, joints, 2, a core pipe, 3, a drill tip, 4, a horizontal rib plate, 5, a scraper, 6, an outer retainer ring, 7, a cutting tooth, 8, an inner retainer ring, 9, a limiting convex ring, 10, an upper retainer ring, 11, a lower retainer ring, 12, an upper ratchet, 13 and a lower ratchet.

Detailed Description

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

As shown in fig. 1-5, the utility model discloses creep into the drag bit that ovum gravel layer was used during limit for height space construction, it includes the top be used for with the drilling rod be connected joint 1, be located the core pipe 2 of joint 1 below, weld at the drill point 3 of core pipe 2 bottom, many horizontal floor 4 and many scraper 5, in this embodiment, horizontal floor 4 is 4, scraper 5 also is 4, horizontal floor 4 and scraper 5 all along circumference evenly distributed. The drag bit also comprises an inner retainer ring 8 and an outer retainer ring 6 which are mutually slidably sleeved and coaxial.

The inner end of each scraper 5 is welded and fixed with the core tube 2, and the outer end of each scraper 5 is welded with the inner surface of the side wall of the inner retainer ring 8. The inner end of each horizontal rib plate 4 is welded and fixed with the core pipe 2; and the outer end of each horizontal rib plate 4 is welded with the inner surface of the side wall of the inner retainer ring 8. The horizontal rib 4 is higher than the scraper 5.

The outer surface of the side wall of the inner retainer ring 8 is radially and outwardly protruded with a limit convex ring 9, and the limit convex ring 9 is simultaneously positioned at the upper edge of the side wall of the inner retainer ring 8. An upper snap ring 10 and a lower snap ring 11 are arranged on the inner surface of the side wall of the outer retainer ring 6 in an inward radial direction, and a limiting convex ring is arranged between the upper snap ring 10 and the lower snap ring 11.

The bottom of the drill tip 3 and the lower edge of the scraper 5 are provided with a plurality of cutting teeth 7; the bottom ring surface of the inner retainer ring 8 is also provided with a plurality of cutting teeth 7; the bottom ring surface of the outer retainer ring 6 is also provided with a plurality of picks 7.

The bottom ring surface of the limit convex ring 9 is provided with a plurality of upper ratchets 12, and the top ring surface of the lower retainer ring 11 is provided with a plurality of lower ratchets 13 which are used for being engaged with the upper ratchets 12 in a one-way mode. The upper ratchets 12 and the lower ratchets 13 are uniformly distributed along the circumferential direction, and the unidirectional meshing means that when the inner retainer ring 8 drills downwards along with the drill bit, the downwards drilling direction can ensure that the upper ratchets 12 on the bottom ring surface of the limiting convex ring 9 can be just meshed with the lower ratchets 13 on the top ring surface of the lower retainer ring 11, so that the circumferential rotation of the two retainer rings is limited.

Claims

1. A scraper drill bit for drilling a gravel layer during construction of a height-limited space comprises a joint (1) at the top, a core pipe (2) positioned below the joint (1), a drill point (3) positioned at the bottom end of the core pipe (2), a plurality of horizontal rib plates (4) and a plurality of scrapers (5), wherein the inner end of each scraper (5) and the inner end of each horizontal rib plate (4) are fixed with the core pipe (2); the drill tip (3) and the scraper (5) are provided with a plurality of cutting teeth (7); the method is characterized in that: the drag bit also comprises an inner retainer ring (8) and an outer retainer ring (6) which are sleeved with each other in a sliding way, and the outer end of each drag (5) and the outer end of each horizontal rib plate (4) are welded with the inner retainer ring (8); the bottom ring surface of the inner retainer ring (8) is also provided with a plurality of cutting teeth (7); the side wall of the inner retainer ring (8) radially protrudes outwards to form a limiting convex ring (9), the side wall of the outer retainer ring (6) radially protrudes inwards to form an upper retainer ring (10) and a lower retainer ring (11), and the limiting convex ring (9) is positioned between the upper retainer ring (10) and the lower retainer ring (11).

2. The drag bit for drilling a gravel layer during construction of a limited height space according to claim 1, wherein: the bottom ring surface of the outer retainer ring (6) is also provided with a plurality of cutting teeth (7); the bottom ring surface of the limit convex ring (9) is provided with a plurality of upper ratchets (12), and the top ring surface of the lower clamping ring (11) is provided with a plurality of lower ratchets (13) which are used for being meshed with the upper ratchets (12).