A casing for soft soil rotary drilling

Abstract

The utility model discloses a casing protection cylinder for soft soil rotary drilling, which comprises a cylinder body, a cutting strip in the shape of spiral rising is arranged on the outer lateral wall of the cylinder body, the cutting strip is located in the slot provided on the lateral wall of the cylinder body, a plurality of cutting edges are arranged at equal intervals inside the cutting strip, the cutting edges penetrate through the sliding groove provided on the lateral wall of the cylinder body, and the cutting edges slide inside the sliding groove, and a cutting part is arranged on both sides of the cylinder body corresponding to the two ends of the cutting edges. Through the arrangement of the slidable cutting edges, the extension length of the cutting edges can be adaptively adjusted according to the different soil breaking positions, the overall rotary drilling efficiency is improved, the cutting edges can be conveniently taken out, the cut earth and stones can be timely discharged outside the wall, and the casing protection cylinder is suitable for soft soil and easy necking strata.

Description

Technical Field

[0001] This utility model relates to the field of rotary drilling technology, specifically to a casing for rotary drilling in soft soil. Background Technology

[0002] In pile driving construction for building construction, rotary drilling rigs typically require the use of casings. When encountering complex geological conditions such as soft soil, silt, or sand, the casing protects the pile hole from collapse and prevents mud, sand, and water from entering. Additionally, when the groundwater level is high, the casing isolates groundwater, keeping the pile hole dry and facilitating drilling. Furthermore, the casing protects the pile location and surrounding area from damage, ensuring the smooth progress of pile foundation construction.

[0003] The length and type of casing should be selected appropriately based on the rotary drilling strata. The casing length should be determined according to geological conditions and construction requirements, generally 3-6 meters is appropriate. The inner diameter of the casing should be consistent with the pile diameter to ensure construction quality and safety. For soft soil strata, an outer wall with a spiral soil removal system, such as spiral fins, should be selected. Discontinuous, low-pitch spiral steel strips are welded or integrally machined onto the outer wall of the casing. These fins differ from continuous auger drill rods; their function is scraping and lifting, not complete conveying.

[0004] However, the current casing's outer spiral fins are relatively fixed in position, which may cause the casing to jam when it is lifted. Furthermore, the removal of shredded soil and rock from the casing's outer wall is also limited. In short, it is crucial to ensure the quality and stability of the casing when using it, and the current casing structure for rotary drilling in soft soil requires further improvement.

[0005] A utility model patent with publication number CN217896479U provides a steel casing for rotary drilling piles, relating to the field of building construction technology. It includes a casing body and a rotary drilling cylinder, the latter being located at the lower end of the casing body. The diameter of the lower opening of the rotary drilling cylinder is smaller than the diameter of the rotary drilling rig's drill bit. It also includes a rotation stop groove on the inner wall of the rotary drilling cylinder and a rotation stop block on the outer periphery of the rotary drilling rig's drill bit. When the rotary drilling cylinder is fitted onto the rotary drilling rig's drill bit and the rotation stop block is accommodated within the rotation stop groove, the rotary drilling rig's drill bit can drive the rotary drilling cylinder to rotate. This utility model can be installed on the drill bit of a rotary drilling rig. The rotary drilling rig's rotation during drilling can cause this device to descend together, ensuring that the device can maintain the borehole immediately and prevent borehole collapse, thus facilitating rotary drilling pile construction. However, it still cannot effectively solve the aforementioned problems. Utility Model Content

[0006] To address the aforementioned problems, this utility model provides a casing for rotary drilling in soft soil.

[0007] The technical solution of this utility model is: A casing for rotary drilling in soft soil includes a casing body. The outer wall of the casing body is provided with a spirally ascending cutting strip. The cutting strip is located in a slot provided in the side wall of the casing body. A plurality of cutting edges are arranged at equal intervals inside the cutting strip. The cutting edges penetrate a sliding groove provided in the side wall of the casing body and slide inside the sliding groove. Both ends of the cutting edges are provided with cutting parts corresponding to the inner and outer sides of the casing body.

[0008] Furthermore, a ring of soil-breaking blades is provided at equal intervals at the bottom of the cylinder.

[0009] Note: Soil breaking is assisted by a soil breaking blade.

[0010] Furthermore, the length of the cylinder is 3~6m, the pitch of the cutting strip is 0.5~1.5m, and the helix angle of the cutting strip is 15~25°.

[0011] Explanation: By properly controlling the pitch and helix angle of the cutting strip, we can ensure that the soil removal efficiency is improved and avoid excessive cutting.

[0012] Furthermore, the slide groove is provided with a limiting groove, which includes several interconnected circular slots. The slots at both ends are respectively connected to the inner and outer sides of the slide groove. A limiting ball is provided in the middle of the cutting edge, and the limiting ball is engaged with the slot. When the cutting edge is squeezed from the front and back, the limiting ball slides in each slot.

[0013] Description: The sliding cutting edge can adaptively adjust its extension length according to the different soil breaking locations. When it is close to the bottom soil breaking location, the cutting edge is squeezed into the chute under greater pressure, improving rotary drilling efficiency. After rotary drilling a certain distance, the cutting edge near the ground surface is squeezed by the soil and rocks inside the cylinder and extends out of the chute, promoting soil removal. This adaptive adjustment improves the overall rotary drilling efficiency, facilitates removal, and can promptly discharge the shredded soil and rocks outside the wall. It is suitable for soft soil and easily necked strata.

[0014] Furthermore, there are three slots. When the limiting ball engages with the innermost slot, 1 / 3 to 1 / 2 of the cutting part is located outside the slot.

[0015] Explanation: By properly controlling the length of the cutting section, a certain cutting effect can be achieved in all states.

[0016] Furthermore, the distance between two adjacent cutting edges is 2 to 8 cm.

[0017] Note: By appropriately selecting the spacing between the two cutting edges, clogging of the groove can be avoided.

[0018] Furthermore, the top edge of the cylinder is provided with several L-shaped grooves for engaging with the drill bit.

[0019] Note: The L-shaped groove is used for clamping and installation with the drill bit.

[0020] Furthermore, the limiting ball is a rubber ball.

[0021] Explanation: The rubber ball can achieve displacement after compression.

[0022] The beneficial effects of this utility model are: This utility model discloses a casing for rotary drilling in soft soil. By setting a sliding cutting edge, the extension length of the cutting edge can be adaptively adjusted according to different soil breaking locations. When approaching the bottom layer of soil, the cutting edge is squeezed into the groove under greater pressure, improving rotary drilling efficiency. After rotary drilling a certain distance, the cutting edge near the ground surface is squeezed by the soil and rocks inside the casing and extends out of the groove, promoting soil removal. This adaptive adjustment improves the overall rotary drilling efficiency, facilitates removal, and can promptly discharge the shredded soil and rocks outside the casing. It is suitable for soft soil and easily necked strata. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the external structure of a casing for rotary drilling in soft soil according to this utility model. Figure 2 This is a schematic diagram of the cutting strip structure of a casing for rotary drilling in soft soil according to this utility model; Figure 3 This is a schematic diagram of the internal structure of the groove of a casing for rotary drilling in soft soil when the cutting edge is located in the middle. Figure 4 This is a schematic diagram of the internal structure of the casing sleeve for rotary drilling in soft soil when the cutting edge is located at the innermost side.

[0024] Among them, 1-cylinder, 11-groove, 2-cutting strip, 3-cutting edge, 31-cutting part, 32-limiting ball, 4-sliding groove, 41-limiting groove, 42-empty groove, 5-soil breaking blade, 6-L-shaped groove. Detailed Implementation

[0025] Example 1 like Figures 1-3As shown, a casing for rotary drilling in soft soil includes a casing 1. The outer wall of the casing 1 is provided with a spirally ascending cutting strip 2. The cutting strip 2 is located in a slot 11 provided in the side wall of the casing 1. A plurality of cutting blades 3 are arranged at equal intervals inside the cutting strip 2. The cutting blades 3 penetrate the sliding groove 4 provided in the side wall of the casing 1 and slide inside the sliding groove 4. Both ends of the cutting blades 3 are provided with cutting parts 31 corresponding to the inner and outer sides of the casing 1. A ring of soil-breaking blades 5 is provided at equal intervals at the bottom of the casing 1. A plurality of L-shaped grooves 6 for engaging with the drilling tool are provided at the top edge of the casing 1. like Figure 1 As shown, the length of cylinder 1 is 4m, the pitch of cutting strip 2 is 1m, and the helix angle of cutting strip 2 is 20°; like Figures 2-4 As shown, the slide groove 4 is provided with a limiting groove 41 inside. The limiting groove 41 includes several interconnected circular cross-section empty grooves 42. The empty grooves 42 at both ends are connected to the inner and outer sides of the slide groove 4 respectively. A limiting ball 32 is provided in the middle of the cutting edge 3. The limiting ball 32 is engaged with the empty groove 42. When the cutting edge 3 is squeezed back and forth, the limiting ball 32 slides in each empty groove 42. There are 3 empty grooves 42. When the limiting ball 32 is engaged with the innermost empty groove 42, 1 / 3 of the cutting part 31 is located outside the slot 11. The distance between two adjacent cutting edges 3 is 6cm. The limiting ball 32 is a rubber ball.

[0026] Example 2 The difference between this embodiment and Embodiment 1 is that: The length of cylinder 1 is 3m, the pitch of cutting strip 2 is 0.5m, and the helix angle of cutting strip 2 is 15°.

[0027] Example 3 The difference between this embodiment and Embodiment 1 is that: The length of cylinder 1 is 6m, the pitch of cutting strip 2 is 1.5m, and the helix angle of cutting strip 2 is 25°.

[0028] Example 4 The difference between this embodiment and Embodiment 1 is that: When the limiting ball 32 engages with the innermost slot 42, 1 / 3 of the cutting part 31 is located outside the slot 11, and the distance between two adjacent cutting edges 3 is 2cm.

[0029] Example 5 The difference between this embodiment and Embodiment 1 is that: When the limiting ball 32 engages with the innermost slot 42, half of the cutting part 31 is located outside the slot 11, and the distance between two adjacent cutting edges 3 is 8cm.

[0030] Working principle: The sliding cutting edge 3 can adaptively adjust its extension length according to the different soil-breaking locations. First, after the cylinder 1 is connected to the drill bit, rotary drilling begins. When the bottom of the cylinder 1 approaches the bottom soil layer, the soil-breaking blade 5 and the drill bit drill synchronously to break the soil. The cutting strip 2 assists in soil breaking and chip removal. At this time, several cutting edges 3 located below are subjected to greater pressure and are squeezed into the groove 4. The limiting ball 32 is squeezed into the innermost empty groove 42 and held in place. The cutting part 31 retracts into the slot 11. Figure 3 The state becomes Figure 4 This improves the efficiency of rotary drilling by adjusting the drilling conditions. After rotary excavation has progressed a certain distance, the cutting edge 3 near the ground surface is compressed by increasing soil and rock inside the cylinder 1, causing it to extend out of the groove 4. The limiting ball 32 is compressed into the outermost empty groove 42 and remains fixed. The cutting part 31 extends out of the slot 11, and... Figure 4 The state becomes Figure 3 This state facilitates soil removal, achieves adaptive adjustment, improves overall rotary drilling efficiency, facilitates extraction, and enables timely removal of shredded soil and rock from outside the wall. It is suitable for soft soil and easily necked strata.

Claims

1. A casing for rotary drilling in soft soil, characterized in that, The device includes a cylindrical body (1), on which a spirally ascending cutting strip (2) is provided on the outer wall of the cylindrical body (1). The cutting strip (2) is located in a slot (11) provided on the side wall of the cylindrical body (1). A plurality of cutting edges (3) are arranged at equal intervals inside the cutting strip (2). The cutting edges (3) penetrate through a sliding groove (4) provided on the side wall of the cylindrical body (1) and slide inside the sliding groove (4). Both ends of the cutting edges (3) are provided with cutting parts (31) on the inner and outer sides of the cylindrical body (1).

2. The casing for rotary drilling in soft soil according to claim 1, characterized in that, The bottom of the cylinder (1) is provided with a ring of soil-breaking blades (5) at equal intervals.

3. The casing for rotary drilling in soft soil according to claim 1, characterized in that, The length of the cylinder (1) is 3~6m, the pitch of the cutting strip (2) is 0.5~1.5m, and the helix angle of the cutting strip (2) is 15~25°.

4. The casing for rotary drilling in soft soil according to claim 1, characterized in that, The slide (4) is provided with a limiting groove (41) inside. The limiting groove (41) includes several interconnected hollow grooves (42) with circular cross sections. The hollow grooves (42) at both ends are connected to the inner and outer sides of the slide (4). The cutting edge (3) is provided with a limiting ball (32) in the middle. The limiting ball (32) is engaged with the hollow groove (42). When the cutting edge (3) is squeezed from front to back, the limiting ball (32) slides in each hollow groove (42).

5. A casing for rotary drilling in soft soil according to claim 4, characterized in that, There are 3 slots (42). When the limiting ball (32) engages with the innermost slot (42), 1 / 3 to 1 / 2 of the cutting part (31) is located outside the slot (11).

6. A casing for rotary drilling in soft soil according to claim 4, characterized in that, The distance between two adjacent cutting edges (3) is 2~8cm.

7. A casing for rotary drilling in soft soil according to claim 1, characterized in that, The top edge of the cylinder (1) is provided with several L-shaped grooves (6) for engaging with the drill bit.

8. A casing for rotary drilling in soft soil according to claim 4, characterized in that, The limiting ball (32) is a rubber ball.

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