JP3267577B2 - Core extraction equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a core collecting device used for ground survey. More specifically, the present invention relates to a core extracting device capable of extracting a core in a good condition regardless of the hardness of the ground.

[0002]

2. Description of the Related Art Conventional typical core collecting devices include:
With a drill bit at the lower end of the rotating outer pipe,
There is known a structure in which an inner tube for taking in a core is provided inside an outer tube, a fluid passage is provided between the outer tube and the inner tube, and an outlet of the passage is provided on an inner peripheral surface of a bit.

In hard ground, the core is not easily deformed when it is sampled, but on the other hand, the bit is liable to be damaged and burned due to a large friction with the bit, and the core is easily burned and deteriorated. . Therefore, when the above-mentioned apparatus is used, the bit is prevented from being damaged and burnt out while using a liquid as a fluid to collect the core in a good condition. However, even in the case of a hard ground, when there is soft earth and sand between the rocks, the earth and sand flow or collapse due to the liquid, and the core becomes inaccurate.

[0004] The soft and damp ground has a core that is easily deformed, but has little friction with the bit due to the moisture, so that the bit is hardly burnt and the core is hardly burnt.
When using the above device, gas was used as the fluid, and the gas could be collected without deforming the core by flowing the gas at a weak pressure so that the outlet was not clogged with mud. Bit burnout and core deterioration due to frictional heat could not be prevented. On the other hand, when a liquid was used as the fluid, burning of the bit and deterioration of the core could be prevented, but the core was inevitably deformed by the impact of the liquid.

Further, in soft and dry ground, the core is easily deformed and the friction with the bit is relatively large, so that the bit is easily burnt out and the core is also easily burnt. When a liquid was used as the fluid when the above-described apparatus was used, both deterioration of the core due to frictional heat and burning of the bit could be prevented, but the core collapsed due to the impact of the liquid. In addition, when gas was used as the fluid, the shape and deterioration of the core and the burnout of the bit all occurred, and this was useless at all.

[0006]

SUMMARY OF THE INVENTION The present invention has been developed in view of the above-mentioned circumstances, and has as its object to be able to take out a core in as good a condition as possible, regardless of the ground, and to extend a bit for a long period of time. To provide a coring device that can be used over a wide range of applications.

[0007]

According to the first aspect of the present invention,
An outer tube with a bit is suspended from the rotating boring rod via a head for the outer tube, and the inner tube for taking in the core is placed inside the outer tube via a fluid passage, and the rotation of the outer tube is prevented. In a coring device in which a non-rotatable holding device is provided and an outlet of a fluid passage is provided on the inner peripheral surface side of the bit, a plurality of through holes communicating with the fluid passage are formed along the circumferential direction of the outer peripheral surface of the bit. It is provided at intervals .

In this case, the fluid is dispersed and discharged from the plurality of through holes and the outlet. The fluid discharged from the outlet is dispersed in a small amount irrespective of liquid or gas, so that the core does not collapse. The fluid discharged from the through-hole flows into a region different from the region where the core is collected, and thus does not adversely affect the core.

When a liquid is used as the fluid, the liquid discharged from the outlet flows into the inner peripheral surface of the bit to moisten the surface of the core, thereby reducing the friction generated when the core is taken into the inner tube. . Also, the liquid discharged from the outlet hangs down along the inner peripheral surface of the bit, and the liquid discharged from the plurality of through holes hangs down along the outer peripheral surface of the bit,
Cools the tip of the bit where heat tends to accumulate directly.

When gas is used as the fluid, the gas discharged from the outlet not only prevents the outlet from being clogged with mud but also synergizes with the gas discharged from the plurality of through holes. Indirectly cool the tip of the bit. It should be noted that the gas discharged from the outlet and the gas discharged from the plurality of through-holes, even if each in a small amount, become a considerable amount if they are combined, so that the cooling effect is high.

A plurality of through-holes and an outlet may be formed in a state where the amount of fluid passing through the outlet is larger than that through the plurality of through-holes. with not only wetting the surface of the core, because the core tends to collapse by the liquid pressure, to collect core in good condition, further, a plurality of through holes and the outlet mentioned above, a plurality of through It is desirable that the outlet is formed to have a smaller amount of fluid passage than the hole.

[0012] As a specific shape in which the amount of fluid passing through the outlet is smaller than that of the plurality of through-holes, it is possible to simply set the area of the through-hole and the outlet. The plurality of through holes may be horizontally or outwardly inclined upward, and the outlet may be horizontally or inwardly downwardly inclined.However, when the amount of fluid discharged from the outlet is small, the outlet is clogged with mud. to stop it so easily, as the invention described in claim 2, in the invention according to the first aspect, further, with a shape that is inclined to the the outlet inwardly upwardly, outwardly through holes It is desirable that the shape be inclined downward.

There are two reasons why this is desirable. one,
Fluid flowing from above to below is difficult to flow because the traveling direction changes greatly in the horizontal and upward directions, and has the property of flowing naturally downward. The other is that when the exit has a shape that is inclined horizontally or inward downward, the mud naturally enters the exit using the lifting force of the core, but when the shape is inclined inward upward, The reason for this is that the mud does not easily enter because the power of the core is not transmitted.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in FIGS. 1 and 2, a coring apparatus has a boring rod 1, an outer tube 2, and an inner tube 3 as main components.

The boring rod 1 rotatably supports the outer tube 2 and supports the inner tube 3 in the outer tube 2 in a state where the rotation of the outer tube 2 is not transmitted. More specifically, the outer tube head 5 is provided below the rotating rod body 4.
The outer tube 2 is screwed around the outer peripheral portion of the outer tube head 5 and suspended therefrom. The support shaft 6 is suspended at the center of the outer tube head 5 and the inner tube head 7 is mounted on the support shaft 6 with a bearing. 8, the inner pipe 2 is screwed down to the outer peripheral portion of the inner pipe head 7, and is provided vertically. A space serving as a fluid passage 9 is provided between the outer pipe 2 and the inner pipe 3. . Although not shown in the drawings, the pressure of the fluid flowing through the fluid passage 9 is set in the range of 0.1 to 7.0 kg / cm ² when digging up to 70 m, and when digging deeper than that. Is a higher pressure.

The outer tube 2 is formed by screwing a plurality of unit tubes in the vertical direction and connecting them, screwing the uppermost unit tube to the outer tube head 5, and screwing the bit 10 to the lowermost unit tube. Things. The bit 10 is provided with a step 11 protruding inward along the circumferential direction of the lower end, and a plurality of through holes 12 communicating with the fluid passage 9 at intervals along the circumferential direction of the outer peripheral surface of the lower end. It is provided open. While the outer tube 2 is embedded in the ground and the core is being taken in, a gap serving as the outlet 13 of the fluid passage 9 is formed in an annular shape between the upper surface of the step portion 11 and the lower end surface of the inner tube 3. When the core is taken out by pulling out the outer tube 2, the lower end of the inner tube 3 is supported on the step portion 11. The upper surface of the step portion 11 and the lower end surface of the inner pipe 3 are formed in a tapered shape that is inclined inward and upward, respectively, so that most of the fluid flows out of the through hole 12 and the rest flows out of the outlet 13. The shape is continuous with the upper surface of the step portion 11, that is, the shape is inclined outward and downward. The diameter of the through hole 12 is 0.5 to 3.0 cm, the vertical distance between the outlets 13 is 0.5 to 2.0 cm, and the distance between the fluid passages 9 is 0.5 to 2.0 cm.

The inner tube 3 is screwed down with an inner tube 16 for accommodating a collecting tube 15 for taking in the core contained in the bag 14 into the inner tube head 7 and is suspended therefrom. To the inner tube 16
And a sleeve tube 18 for holding the bag 14 is removably fitted to a lower portion of the extension tube 17, and a core lifter case 19 for supporting the core so that it cannot fall down is fitted to a lower portion of the sleeve tube 18. It is fitted so that it can be inserted and removed.

The extension tube 17 has a protruding piece 20 protruding inward along a circumferential direction at an intermediate height thereof, and the sampling tube 15 is placed on the protruding piece 20. The sleeve tube 18 includes an insertion portion 21 that protrudes deep into the extension tube 17, and forms a cylindrical pocket 22 that opens upward between the outer peripheral surface of the insertion portion 21 and the inner peripheral surface of the extension tube 17. , In the pocket 22,
The peripheral wall of the bag 14 for wrapping the core is loaded. The core lifter case 19 has a taper in which a lower inner circumference is narrower than an upper inner circumference, and a core lifter 23 having a C-shaped cross section that holds a lower end portion of the core is fitted to an inner circumferential surface of the core lifter case 19 so as to be able to move up and down. are doing. Note that the lower end surface of the core lifter case 19 is the lower end surface of the inner tube 3 described above.

In the above-described core collecting apparatus, the outlet 13
Is formed between the lower end of the inner tube 3 and the step portion 11 of the bit 10, but the bit 10 is formed without using the lower end of the inner tube 3.
May be formed on the inner peripheral surface.

[0020]

According to the first aspect of the present invention, when a liquid is used as a fluid when the liquid is used for hard ground, the liquid is dispersed and discharged to the outside of the bit and the inner peripheral surface of the bit. In comparison with the bit, the amount of liquid flowing into the bit is smaller, but the friction with the bit is still smaller, preventing the core from deforming due to the friction, and a large amount of liquid discharged from multiple through holes and outlets The bit can be cooled directly by the liquid to prevent core deterioration and bit burnout. Also, even in the case of hard ground having soft earth and sand between rocks, the amount of liquid flowing into the bit is small,
The core can be collected in good condition without flowing or collapsing just because the soil gets wet. Furthermore, if gas is used as the fluid when used on soft and damp ground, the core will be moistened in advance and the friction will be small, so it will not lose its shape, and the gas discharged from multiple through holes and outlets When the amounts of the bits are adjusted, a large amount can be taken, so that a large amount of bit heat can be taken away and the bits and the core can be prevented from burning. In addition, when using on soft and dry ground, if a liquid is used as the fluid, the impact of a small amount of liquid will not cause the core to collapse, and will also wet the surface to reduce friction, and reduce the frictional shape of the core. The collapse can be prevented, and the core can be prevented from being deteriorated by the heat and the bit can be burned out by a large amount of liquid discharged from the plurality of through holes and the outlet. Therefore, the core can be collected in as good a condition as possible on any ground.
The bit can be used for a long time.

Further, since the amount of fluid passing through the outlet is smaller than that of the plurality of through holes, the core can be collected in a better condition. Further, the mud that has flowed back into the outlet is naturally discharged through a plurality of through holes through which a large amount of fluid passes.

According to a second aspect of the present invention, the outlet is formed to be inclined inwardly upward and the through hole is formed to be inclined downward and outward so that the fluid is hardly discharged from the outlet and discharged from the through hole. By making the outlet which is easy to be clogged with mud when the flow rate is reduced, the above-mentioned shape makes it difficult for mud to enter, the core can be collected in an ideal state.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a lower portion of a coring device of the present invention.

FIG. 2 is a longitudinal sectional view showing an upper part of the coring device of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Boring rod 2 Outer tube 3 Inner tube 5 Outer tube head 9 Fluid passage 10 Bit 12 Through hole 13 Exit

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) E21B 25/00 E02D 1/04

Claims (2)

(57) [Claims] An outer tube (2) provided with a bit (10) is attached to an outer tube head (5) on a rotating boring rod (1).
And an inner tube (3) for taking in the core is disposed inside the outer tube (2) via a fluid passage (9) and is unable to rotate with respect to the rotation of the outer tube (2). And holding the outlet (1) of the fluid passage (9) on the inner peripheral surface side of the bit (10).
In the coring apparatus provided with 3), a plurality of through-holes (12) communicating with the fluid passage (9) are provided at intervals along the circumferential direction of the outer peripheral surface of the bit (10) . The through hole (12) and the outlet (13) are connected to a plurality of through holes.
The amount of fluid passing through the outlet (13) is smaller than that in (12).
A coring device, characterized in that the coring device is formed in a state where it becomes difficult. 2. The core collecting apparatus according to claim 1, wherein
Further, the outlet (13) is inclined inward and upward.
And the through hole (12) is inclined outward and downward.
A coring device, characterized in that the coring device has a shape that is different from that of the core.