CN102155166A - Radial spinning drill - Google Patents

Abstract

The invention relates to a radial spinning drill bit. The ball tooth is welded on the front end of the central shaft, the spiral blade is welded on the central shaft, and forms a spiral section together with the central shaft, the central shaft is connected with the radial spinning section, and the radial spinning section is threaded with the gauge section. The axis of the helical section is collinear with the axis of the gage section, and the end of the gage section is formed by connecting the drill pipe or the down-the-hole hammer through threads. It overcomes the defect of large axial displacement of the soil caused by the conical compacting drill bit, and solves the technical problem of squeezing the soil below the drill bit, resulting in slower and slower drilling speed. The radial spinning section consists of several disc-shaped cams. Composition, when drilling, with the change of the radial direction of the cam, the soil is spun and pushed by the cam to the periphery of the hole wall, which is beneficial to the radial plastic flow of the soil and avoids the formation of a dense area in front of the conical drill bit. The extrusion drilling speed has been greatly improved, the drilling depth has been increased and the hole wall has been strengthened at the same time. The concave part between the cams releases the moisture between the soil particles, which plays a role in lubricating the drill bit and reducing frictional resistance.

Description

Radial Spinning Drill

Technical field:

The invention relates to a drill bit for extrusion drilling, in particular to a drill bit for helical-radial spinning drilling in which soil layers are extruded to form holes.

Background technique:

In recent years, due to the advantages of no soil discharge, long pure drilling time, good for hole wall reinforcement, environmental protection, and energy saving during the drilling process, the extrusion drilling technology has been used in rock-soil anchorage, trenchless pipeline laying, and foundation engineering construction. and other fields have been widely used. Squeeze drilling technology usually uses a conical drill bit, and the stress that the drill bit acts on the soil is evenly distributed along the conical surface, and the direction is perpendicular to the conical surface. Therefore, in addition to the horizontal component force that squeezes the soil to the surrounding of the hole wall, a downward vertical component force is also generated, which makes the soil at the front end of the drill bit move downward, and the soil is compressed and compacted gradually, and the hardness becomes stronger. bigger and bigger. As the formation depth increases, the volume of the hardened soil below the drill bit continues to increase, and the footage speed becomes slower and slower until finally no footage is obtained. Although the torque of the engineering drilling rig is large, the torque only serves to overcome the friction of the soil on the drilling tool and ensure the direction of the drilling, and is not directly used to crush and squeeze the soil. Therefore, the radial extrusion effect on the soil is small, so that extrusion drilling can only be used for shallow formation construction.

Invention content:

The object of the present invention is to provide a radial spinning drill bit capable of directly extruding the soil to the peripheral side of the hole wall in view of the above-mentioned deficiencies in the prior art.

The purpose of the present invention is achieved through the following technical solutions:

The radial spinning drill bit is made of button 1 welded on the front end of the central shaft 2, the spiral blade 3 is welded on the central shaft 2, and together with the central shaft 2 forms a helical segment 4, and the central shaft 2 is welded, splined or The thread is connected to the radial spinning section 5, the radial spinning section 5 is threaded or welded to the gauge section 6, the axis of the spiral section 4 is in line with the axis of the gauge section 6, and the end of the gauge section 6 passes through the thread and the drill Rod or down-the-hole hammer connection structure.

The radial spinning section 5 is formed by threading or welding more than one or even N cams with different base circle diameters.

The length of each level of the cam is 5-100cm, the end surface of each level of cam is stepped, the diameter of the base circle of each level of cam is increased or reduced by 5-30cm relative to the diameter of the adjacent cam base circle, and the maximum radial angle of each level of cam is staggered by 60° -120°, the bending moment of each cam is balanced.

The pitch of the helical blade 3 is 5-100cm.

Beneficial effects: the invention overcomes the defect that the existing conical compacting drill bit causes large axial displacement of the soil, and solves the problem that the conical compacting drill bit squeezes the soil below the drill bit, resulting in slower and slower drilling speed Difficult, with spiral-radial spinning and gage design. The front part of the drill bit is designed as helical drilling, which cuts into the soil layer under the action of drilling pressure and rotation, and makes the soil rise along the helical blades to the gap formed between the radial spinning section and the hole wall. The radial spinning section is composed of several sections of disc-shaped cams. When drilling, the soil body is equivalent to being subjected to spinning as the radial direction of the cams changes, and is pushed to the periphery of the hole wall by the cams, which is beneficial to the radial plastic flow of the soil body and avoids The formation of a dense zone ahead of the conical bit. Significantly increasing the extrusion drilling speed is beneficial to increase the extrusion drilling depth and better strengthen the hole wall. The recesses between the cams have a certain space, which is easy to release the water between the soil particles, which plays the role of lubricating the drill bit and reducing frictional resistance.

Description of drawings:

Figure 1 is a front view of a radial spinning drill bit;

Fig. 2 is a sectional view of section A-A in accompanying drawing 1:

1 ball tooth, 2 central shaft, 3 helical blade, 4 helical section, 5 radial spinning section, 6 gauge section.

①,②,③...⑤...N cam

Detailed ways:

Below in conjunction with accompanying drawing and embodiment do further detailed description:

The radial spinning drill bit is made of button 1 welded on the front end of the central shaft 2, the spiral blade 3 is welded on the central shaft 2, and together with the central shaft 2 forms a helical segment 4, and the central shaft 2 is welded, splined or The thread is connected to the radial spinning section 5, the radial spinning section 5 is threaded or welded to the gauge section 6, the axis of the spiral section 4 is in line with the axis of the gauge section 6, and the end of the gauge section 6 passes through the thread and the drill Rod or down-the-hole hammer connection structure.

The radial spinning section 5 is formed by threading or welding more than one or even N cams with different base circle diameters. The axial dimension of each cam is 5-100cm, the end face of each cam is stepped, the base circle diameter of each cam is increased or reduced by 5-30cm relative to the adjacent cam base circle diameter, and the maximum radial angle of each cam is staggered by 60° -120°, the bending moment of each cam is balanced. The pitch of the helical blade 3 is 5-100cm.

When drilling, the drill bit cuts into the soil layer under the action of drill pressure and rotation, and the soil rises along the helical blade to the gap formed between the radial spinning section and the hole wall. Under the action of the cam spinning, the soil is squeezed around the hole wall, and the soil produces radial plastic flow, which avoids the formation of a dense area in front of the conical drill bit.

Example 1

The radial spinning drill bit is made of button 1 welded on the front end of the central shaft 2, the spiral blade 3 is welded on the central shaft 2, and together with the central shaft 2 forms a helical segment 4, and the central shaft 2 is welded, splined or The thread is connected to the radial spinning section 5, the radial spinning section 5 is threaded or welded to the gauge section 6, the axis of the spiral section 4 is in line with the axis of the gauge section 6, and the end of the gauge section 6 passes through the thread and the drill Rod or down-the-hole hammer connection structure.

The radial spinning section 5 is formed by threading or welding 5 cams with different base circle diameters. The axial dimension of each cam is 80cm, and the end surface of each cam is stepped. The diameter of the base circle of each cam is 5-15cm larger or smaller than that of the adjacent cam. The maximum radial angle of each cam is staggered by 120°. The bending moment on the stage cam is kept in balance. The pitch of the helical blade 3 is 100cm.

The number and pitch of the helical blades 3 can be adjusted as required. The radial spinning section 5 is composed of several cams with different base circle diameters. As shown in Figure 1, the end faces of each cam can be stepped or evenly transitioned. The centerline of the helical blade 3 coincides with the centerline of the gauge section 6 to ensure the effective transmission of drilling pressure.

Example 2

The radial spinning drill bit is made of button 1 welded on the front end of the central shaft 2, the spiral blade 3 is welded on the central shaft 2, and together with the central shaft 2 forms a helical segment 4, and the central shaft 2 is welded, splined or The thread is connected to the radial spinning section 5, the radial spinning section 5 is threaded or welded to the gauge section 6, the axis of the spiral section 4 is in line with the axis of the gauge section 6, and the end of the gauge section 6 passes through the thread and the drill Rod or down-the-hole hammer connection structure.

The radial spinning section 5 is formed by threading or welding 8 cams with different base circle diameters. The axial dimension of each cam is 30cm, and the end surface of each cam is stepped. The diameter of the base circle of each cam is 5-21cm larger or smaller than that of the adjacent cam. The maximum radial angle of each cam is staggered by 90°. The bending moment on the stage cam is kept in balance. The pitch of the helical blade 3 is 80cm.

The number and pitch of the helical blades 3 can be adjusted as required. The radial spinning section 5 is composed of several cams with different base circle diameters. As shown in Figure 1, the end faces of each cam can be stepped or evenly transitioned. The centerline of the helical blade 3 coincides with the centerline of the gauge section 6 to ensure the effective transmission of drilling pressure.

Example 3

The radial spinning drill bit is made of button 1 welded on the front end of the central shaft 2, the spiral blade 3 is welded on the central shaft 2, and together with the central shaft 2 forms a helical segment 4, and the central shaft 2 is welded, splined or The thread is connected to the radial spinning section 5, the radial spinning section 5 is threaded or welded to the gauge section 6, the axis of the spiral section 4 is in line with the axis of the gauge section 6, and the end of the gauge section 6 passes through the thread and the drill Rod or down-the-hole hammer connection structure.

The radial spinning section 5 is formed by threading or welding 10 cams with different base circle diameters. The axial dimension of each cam is 25cm, and the end surface of each cam is stepped. The bending moment on the stage cam is kept in balance. The pitch of the helical blade 3 is 60cm.

The number and pitch of the helical blades 3 can be adjusted as required. The radial spinning section 5 is composed of several cams with different base circle diameters. As shown in Figure 1, the end faces of each cam can be stepped or evenly transitioned. The centerline of the helical blade 3 coincides with the centerline of the gauge section 6 to ensure the effective transmission of drilling pressure.

Claims (4)

1. spinning drill bit radially, it is characterized in that, be by the front end of ball tooth (1) welding-on in central axis (2), helical blade (3) is welded on the central axis (2), and form spiral section (4) jointly with central axis (2), central axis (2) is connected with spinning section (5) radially by welding, spline or screw thread, radially section (6) is threaded or welds spinning section (5) with protecting directly, spiral section (4) axis with protect footpath section (6) axis conllinear, the end of protecting footpath section (6) is hammered into shape with drilling rod or down-the-hole by screw thread and is connected and composed.

2. according to the described radially spinning of claim 1 drill bit, it is characterized in that, radially spinning section (5) be by more than one so that N the different cam of base circle diameter (BCD) constitute by screw thread or welding.

3. according to the described radially spinning of claim 2 drill bit, it is characterized in that, every grade of axial dimension 5-100cm of described cam, every grade of cam face is stepped, the relative adjacent cams base circle diameter (BCD) of every grade of cam base circle diameter increases or dwindles 5-30cm, every grade of cam maximum radial place angle staggers 60 °-120 °, and every grade of suffered moment of flexure of cam keeps balance.

4. according to the described radially spinning of claim 1 drill bit, it is characterized in that the pitch of helical blade (3) is 5-100cm.

Images