CN118686548A - Cage drill bit and submersible drilling rig - Google Patents

Abstract

The cage type drill bit comprises a drill point, a lower circular ring, an upper circular ring, a central tube, a cutting tool bit group, a connecting plate and an inclined rod, wherein the drill point is a triangular plate, the bottom edge of the triangular plate is fixedly arranged at the bottom of the lower circular ring, the cutting tool bit group is arranged in two rows on the inclined edge of the drill point, the lower circular ring and the upper circular ring are fixed through the connecting plate, the central tube is respectively fixed with the lower circular ring and the upper circular ring through a plurality of radially symmetrical lower spokes and upper spokes, and the inclined rod is obliquely arranged between the lower spokes and the upper spokes; the cutting tool bit groups are respectively arranged on two opposite surfaces of the inclined edge of the drill point, and the tool bits of each row of cutting tool bit groups are arranged at intervals along the length of the inclined edge of the drill point; the outer walls of the lower circular ring and the upper circular ring are respectively provided with a plurality of radially symmetrical supporting plates; the lower spoke and the upper spoke form an included angle in the projection direction. The cage type drill bit and the diving drill provided by the invention have the characteristics of simple structure, reliable hole forming, reliable guiding, smooth soil discharging and the like, the vertical precision of hole forming is ensured, and the construction efficiency of the cast-in-place pile is improved.

Description

Cage drill bit and submersible drilling rig

Technical Field

The invention belongs to the technical field of foundation construction, and in particular relates to a cage drill bit and a submersible drilling rig.

Background Art

As a traditional method of pile foundation construction, bored piles have the advantages of high bearing capacity, no soil extrusion during construction, good adaptability to various geologies, simple construction and low purchase cost. They are widely used in urban construction, highway and railway, bridge and tunnel construction projects. In the soft clay strata widely distributed along the southeast coast of Bohai Sea in my country, submersible drilling rigs are generally used with three-wing cage drill bits for foundation treatment.

The three-wing cage drill bit of the prior art has the following problems: 1) Since the three obliquely arranged wing rods on which the cutting bit is installed are respectively welded to the front end of the outer wall of the central tube and the bottom of the drill bit lower retaining ring, when encountering underground obstacles, backfill soil and other unfavorable geological conditions during the drilling process, the three wing rods will be twisted and deformed, causing deviation in the verticality of the hole, affecting the hole quality and construction efficiency; 2) When the drill bit drills holes in clay soil, mud strips and mud blocks will be formed, which will be suspended around the ends of each wing rod and the cutting bit under the action of the injected mud, resulting in the ineffective cutting and crushing of the soil layer; 3) Since the submersible drilling rig relies on the outer ring of the cage to protect the hole wall during the drilling process, the drill bit will be deformed when encountering uneven soft and hard strata, causing the hole to collapse and shrink.

Summary of the invention

The main purpose of the present invention is to overcome the shortcomings of the prior art and provide a cage drill bit and a submersible drill rig, which have the characteristics of simple structure, reliable hole formation, reliable guidance, smooth soil discharge and good overall rigidity, so as to achieve simultaneous cutting and drilling of multiple cutter heads in the length direction of the two beveled edges of the drill tip, and the support plates on the outer walls of the lower and upper circular rings can effectively protect the walls of the holes, improve the impact resistance of the cutting head group during the rotary cutting process, ensure the vertical accuracy of the holes, and further improve the construction efficiency of the cast-in-place piles.

The present invention is achieved through the following technical solutions:

A cage drill bit, characterized in that it includes a drill tip, a lower circular ring, an upper circular ring, a center tube, a cutting bit group, a connecting plate, and an inclined rod; the drill tip is a triangular plate, and its bottom edge is fixedly arranged at the bottom of the lower circular ring; the cutting bit group is respectively arranged in two rows on the two oblique sides of the drill tip; the lower circular ring and the upper circular ring are fixed by a connecting plate; the center tube is fixed to the lower circular ring and the upper circular ring by a plurality of radially symmetrical lower spokes and upper spokes respectively; the inclined rod is obliquely arranged between the lower spokes and the upper spokes.

Furthermore, the cutting bit groups are respectively arranged on two opposite surfaces of the bevel of the drill tip, and the individual bits of each row of the cutting bit groups are spaced apart along the length direction of the bevel of the drill tip, so as to improve the cutting strength of the tool body.

Furthermore, a groove is provided in the middle of the bottom edge of the drill tip, and the groove faces the outlet of the central tube to facilitate the injection of slurry.

Furthermore, the outer walls of the lower circular ring and the upper circular ring are both provided with radially symmetrical supporting plates for hole forming and wall protection.

Furthermore, the upper spokes and the lower spokes form a certain angle in the projection direction of the central tube.

A submersible drilling rig comprises a cage drill bit as described in any one of the above items.

Compared with the prior art, the beneficial effects of the present invention are:

1) This technical solution adopts the method of welding a fixed drill tip at the bottom of the existing cage drill bit lower retainer, shortening the length of the center tube and the total length of the cage drill bit, effectively improving the overall rigidity of the drill bit and ensuring the stability of drilling; the cutting head groups are respectively arranged on two opposite surfaces of the bevel of the drill tip, and the heads of each row of cutting head groups are arranged at intervals, which improves the impact resistance of the cutting head group during the rotary cutting process, avoids the situation of the head breaking and falling off, achieves stable and reliable soil cutting, and further improves the efficiency of drilling operations;

2) This technical solution adopts the method of setting multiple supporting plates on the outer walls of the upper and lower retaining rings, which effectively protects the wall of the hole during the rotation of the cage drill bit, thereby ensuring the vertical accuracy of the hole; at the same time, it increases the service life of the upper and lower retaining rings, which is conducive to improving construction efficiency;

3) This technical solution adopts a plurality of inclined rods to be set in the inner cavity of the upper and lower retaining rings, which is conducive to the smooth discharge of soil when the two rows of cutting head groups on the inclined edge of the drill tip rotate and drill, further effectively improving the working efficiency.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic structural diagram of a cage drill bit according to the present invention;

FIG2 is a top view of FIG1;

FIG3 is a bottom view of FIG1 ;

Fig. 4 is a cross-sectional view taken along the line A-A of Fig. 2;

Among them, 10-drill tip, 102-groove, 11-lower ring, 12-upper ring, 13-center tube, 14 cutter head, 15-connecting plate, 114-lower spoke, 124-upper spoke, 33-support plate, 44-oblique rod.

DETAILED DESCRIPTION

The cage drill bit and the submersible drill rig of the present invention are further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention.

This embodiment discloses a cage drill bit, which includes seven parts: a drill tip 10 , a lower ring 11 , an upper ring 12 , a center tube 13 , a cutting head assembly, a connecting plate 15 , and an inclined rod 44 .

1-4, the lower ring 11 and the upper ring 12 are respectively welded firmly to the outer wall of the central tube 13 through four radially symmetrical lower spokes 114 and upper spokes 124, and each lower spoke 114 and upper spoke 124 forms an angle of 45° in the axial projection direction of the central tube 13;

The lower end surface of the lower ring 11, the lower edge of the lower spoke 144, and the bottom end of the center tube 13 are arranged in the same plane, so that when the drill tip 10 is welded to the bottom of the lower ring 11, they are completely fitted and flush with each other, ensuring the welding strength between the various components, thereby improving the overall strength of the cage drill bit and extending its service life;

The inclined rod 44 is arranged between the lower spoke 114 and the upper spoke 124 in a clockwise rotation direction and in an oblique direction. The lower end of the inclined rod is welded to the joint of the lower spoke 114 and the outer wall of the central tube 13, and the upper end is welded to the joint of the upper spoke 124 and the upper ring 12. In this way, when the cage drill bit rotates clockwise to cut the stratum, the soil is smoothly discharged from the hole by means of the space formed between each inclined rod 44 and the central tube 13.

The bottom length of the drill tip 10 is respectively adapted to the outer diameters of the lower ring 11 and the upper ring 12. The groove 102 in the middle of the bottom of the drill tip is formed into a U shape or a rectangle. Since the groove is located at the outlet of the central tube 13, it is convenient for the external slurry to be smoothly injected into the hole through the inner hole of the central tube 13.

A plurality of radially symmetrical support plates 33 are welded on the outer walls of the lower circular ring 11 and the upper circular ring 12, respectively. The outer surface of the support plates is provided with a wear-resistant layer, which effectively improves the wear resistance thereof, can effectively protect the hole wall, prevent the hole wall from collapsing or shrinking, and ensure the quality of the bored pile.

When the cage drill bit of the present invention is used, the center tube 13 is fixedly connected to the power head of the down-the-hole drill, and the power head is driven to drive the cage drill bit to rotate clockwise. The two rows of cutting heads located on the oblique side of the drill tip 10 drill down to cut the stratum. At the same time, the external grouting system injects slurry through the hollow drill rod and the center tube 13. The cut soil is smoothly discharged into a hole under the action of the pressure slurry and the simultaneous rotation of each oblique rod 44, and finally the drilling operation of the cast-in-place pile is completed.

The present invention also relates to a submersible drilling rig, comprising the above-mentioned cage drill bit.

The cage drill bit and the submersible drill rig of the present invention have the characteristics of simple structure, reliable hole formation, reliable guidance and good overall rigidity, and can realize simultaneous cutting and drilling by the respective cutter heads of the two-row cutting head group on the bevel edge of the drill tip, and the supporting plates located on the outer walls of the lower circular ring and the upper circular ring can effectively protect the wall of the hole formed, and the impact resistance of the cutting head group in the process of rotary cutting can ensure the vertical accuracy of the hole formed, and effectively improve the efficiency of cast-in-place pile construction.

Various changes and improvements may be made to the present invention without departing from the overall concept of the present invention. However, as long as they are identical or equivalent to the present invention, they also fall within the protection scope of the present invention.

Claims (6)

1. The cage type drill bit is characterized by comprising a drill point (10), a lower circular ring (11), an upper circular ring (12), a central tube (13), a cutting tool bit group, a connecting plate (15) and an inclined rod (44); the drill point (10) is a triangular plate, and the bottom edge of the triangular plate is fixedly arranged at the bottom of the lower circular ring (11); the cutting blade sets are respectively provided with two rows on two bevel edges of the drill point (10); the lower circular ring (11) and the upper circular ring (12) are fixed through a connecting plate (15); the central tube (13) is fixed with the lower circular ring (11) and the upper circular ring (12) through a plurality of radially symmetrical lower spokes (114) and upper spokes (124) respectively; the diagonal rods (44) are obliquely arranged between the lower spokes (114) and the upper spokes (124).

2. Cage bit according to claim 1, characterized in that the cutting bit groups are arranged on two opposite sides of the hypotenuse of the drill tip (10), respectively, and that the individual bits (14) of each row of cutting bit groups are arranged at intervals along the length of the hypotenuse of the drill tip (10) for increasing the cutting strength of the cutter body.

3. Cage drill bit according to claim 1, characterized in that the middle of the bottom edge of the drill tip (10) is provided with a groove (102) which is right at the outlet of the central tube (13) for facilitating the injection of slurry jet.

4. Cage bit according to claim 1, characterized in that the outer walls of the lower ring (11) and the upper ring (12) are provided with radially symmetrical support plates (33) for hole-forming retaining walls.

5. Cage bit according to claim 1, characterized in that the upper spokes (124) form an angle with the lower spokes (114) in the projection direction of the central tube (13).

6. A submersible drilling rig comprising a cage drill bit according to any of claims 1-5.