JP2003064976A - Core tube sampler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a core tube sampler capable of forcedly controlling the rotation of an inner pipe for storing a core and adopting the good core in spite of the strength of a stratum. SOLUTION: An outer pipe 2 having a metal crown 5 for boring the stratum is mounted to an outer pipe head 1 connected to the lower end of a boring rod 4 and propelled while rotating the outer pipe head, and for the core tube sampler for storing the inner pipe 14 storing the core in the outer pipe 2 in a rotatable manner, a weight 13 is stored in the outer pipe 2, at the same time, the weight 13 is supported on the outer pipe head 1 in a state to relatively rotate to the outer pipe 2, the inner pipe 14 is mounted to the lower end of the weight 13, and the rotation of the inner pipe 14 is controlled by adding the weight of the weight to the inner pipe 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for collecting a geological sample (core), that is, a sampler, in the sampling (sampling) of a stratum that is carried out for the purpose of geological survey. The inner tube that houses the core in the core tube sampler composed of the tube and the tube is prevented from rotating.

[0002]

2. Description of the Related Art As a core tube sampler of this type, a double core tube sampler (for bedrock) composed of an outer tube having a cutting edge (bit) for drilling a formation and an inner tube for accommodating a core, or A triple core tube sampler (for soft) with a double inner tube is known. For example, Japanese Examined Patent Publication No. 63-26240 discloses a double core tube sampler.

These core tube samplers have the same basic structure, and a conventional double core tube sampler is shown in FIG. 2 and described below. A conventional double core tube sampler (hereinafter simply referred to as a sampler) includes an outer tube head 1, an outer tube 2 and an inner tube 3 as main components.

The outer tube head 1 is connected to the lower end of a boring rod 4 which is rotationally driven by a boring machine (not shown) installed on the ground, and the boring rod 4 applies rotation and propulsive force.

The outer pipe 2 has an upper end fixed to the outer pipe head 1 and a metal crown 5 fixed to the lower end. The metal crown 5 is for removing the stratum into a cylindrical shape,
It is formed in a cylindrical shape and has a hard cutting edge (bit) 6 on the lower end surface.

The inner tube 3 is housed inside the outer tube 2 and is supported by the outer tube head 1 in a state of rotating relative to the outer tube 2. That is, the bearing case 9 is supported by the spindle 7 fixed to the central portion of the lower surface of the outer tube head 1 via the bearing 8, and the inner tube connecting head 1 is attached to the lower surface of the bearing case 9.
0 is attached, and the upper end of the inner pipe 3 is fixed to the inner pipe connecting head 10. Reference numeral 11 is a lifter case fixed to the lower end portion of the inner pipe 3, and is provided with a core lifter 12 for preventing the core from falling off.

The conventional sampler is constructed as described above. In order to collect the core of the formation, the sampler is lowered into the hole excavated with a predetermined diameter, and when the sampler reaches the bottom of the hole, the boring machine is started. At the same time, rotation and propulsion force are applied to the outer pipe head 1 via the boring rod 4, and at the same time, drilling water is pumped to the outer pipe head 1 from a water pump (not shown) on the ground via the boring rod 4.

When the outer tube head 1 is rotated and propulsive force is applied, the outer tube 2 is propelled while rotating, and the stratum is shaving in a cylindrical shape by the cutting edge 6 of the metal crown 5 fixed to the lower end of the outer tube 2. At the same time, the ground formation scraped into a cylindrical shape is housed in the inner pipe 3 as a core. that time,
The drilling water pumped to the outer pipe head 1 passes through the gap between the outer pipe 2 and the inner pipe 3 and is ejected from the lower end of the metal crown 5 to the outside of the outer pipe 2 and mixed with scraped slime (geological debris). The gap between the hole wall that has been excavated and the outer pipe 2 rises and is discharged to the ground. Then, by collecting the sampler on the ground at the stage where the core is excavated to a predetermined depth, the core shaved off in a cylindrical shape can be housed in the inner pipe 3 and collected.

By the way, the most important thing when sampling the stratum with the sampler is that the inner tube 3 does not rotate together with the outer tube 2. The conventional sampler has a structure in which a bearing 8 is interposed between the outer tube 2 and the inner tube 3,
The rotational force of the outer tube 2 is prevented from being transmitted to the inner tube 3. Therefore, even if the outer tube 2 rotates, the inner tube 3 is always rotatable with respect to the outer tube 2, and the outer tube head 1 is rotated and propelled by the metal crown 5 of the outer tube 2 during sampling. When the formation is dug, the core scraped into a columnar shape is smoothly stored in the inner pipe 3. The core under excavation is
Although the peripheral surface has been scraped off, the bottom surface is connected to the unexcavated strata to maintain a self-supporting state, and the peripheral surface is the inner pipe 3
Since it is in contact with the inner surface of the inner tube 3, a holding force for the inner tube 3 is generated to prevent the inner tube 3 from rotating. Therefore, the inner pipe 3
The rotation inhibiting force of No. 1 depends on the strength of the formation, and in a soft formation, the rotation inhibiting force of the inner pipe 3 is weak, which causes the inner pipe 3 to co-rotate following the rotation of the outer pipe 2.

[0010]

In the conventional sampler, since the rotation restraining holding force of the inner tube 3 cannot be secured unless the formation strength is strong and the formation is uniform, the uneven ground mixed with soft ground, sand, gravel, etc. It was difficult to sample in the different strata. The reason is that in order to prevent the outer tube 2 and the inner tube 3 from rotating together, the conventional structure in which the bearing 8 is interposed between the outer tube 2 and the inner tube 3 is not sufficient. Yes, if there is a change in soil quality or hardness of the stratum at the time of sampling, the inner pipe 3 can be held in a hard place, but the inner pipe 3 cannot be held in a soft place, and the rotation inhibiting holding force of the inner pipe 3 is lost and the outer pipe is lost. This is because the inner pipe 3 rotates following the rotation of the pipe 2.
When the inner tube 3 rotates during the sampling operation, the peripheral surface of the core to be sampled is rubbed against the inner surface of the inner tube 3, and the core is worn or broken, so that a good core cannot be sampled.

The present invention has been proposed in view of the above-mentioned problems of the prior art, and a core tube capable of collecting a good core regardless of the strength of the formation by suppressing the rotation of the inner tube for accommodating the core. The purpose is to provide a sampler.

[0012]

In order to achieve the above-mentioned object, the present invention provides an outer tube head, which is connected to a lower end of a boring rod and is propelled while rotating, having a metal crown for drilling a formation. In a core tube sampler that rotatably accommodates an inner tube for accommodating a geological sample in the outer tube, a weight is accommodated in the outer tube, and the weight is provided in the outer tube head relative to the outer tube. The inner tube is attached to the lower end of the weight.

Further, the present invention is characterized in that the inner pipe is formed of a transparent synthetic resin, and the inner pipe is detachably attached to the weight.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows an embodiment in which the present invention is applied to a double core tube sampler. Incidentally, the same parts as those of the conventional one shown in FIG.

As shown in FIG. 1, the sampler of this embodiment comprises an outer tube head 1 connected to the lower end of a boring rod 4 which is rotationally driven by a boring machine (not shown) installed on the ground, and an outer tube. An outer tube 2 having an upper end fixed to the head 1 and a metal crown 5 at the lower end, and housed inside the outer tube 2 and supported by the outer tube head 1 in a state of rotating relative to the outer tube 2. The weight 13 and the inner tube 14 housed inside the outer tube 2 and detachably attached to the lower end of the weight 13.

The weight 13 suppresses the rotation of the inner pipe 14 that follows the rotation of the outer pipe 2 by applying the weight to the inner pipe 14, and the upper end portion is screwed to the weight mounting head 15. At the same time, the weight mounting head 15 is fixed to the lower surface of the bearing case 9, and the bearing case 9 is supported by the spindle 7 fixed to the central portion of the lower surface of the outer tube head 1 via the bearing 8.
It is supported by the outer tube head 1 while rotating relative to the outer tube 2. The weight of the weight 13 is set according to the diameter of the core to be sampled. For example, the diameter of the core to be sampled is φ5
When it is 0 mm, it is 20 to 25 kg, and when the diameter of the core to be sampled is 70 mm, it is 25 to 30 kg.

The inner pipe 14 is formed of a transparent synthetic resin, such as acrylic resin, in a cylindrical shape. The inner pipe connecting head 16 is fixed to the upper end of the inner pipe 14 and the inner pipe connecting head 16 is screwed to the lower end surface of the weight 13. By being combined, it is detachably attached to the weight 13.

In this embodiment, the weight 13 is supported by the outer tube head 1 in a state of rotating relative to the outer tube 2, and the inner tube 14 for accommodating the core at the lower end of the weight 13 is supported.
Is installed. Therefore, the weight of the weight 13 is applied to the inner pipe 14 without being influenced by the rotation of the outer pipe 2, and the rotation of the inner pipe 14 that follows the rotation of the outer pipe 2 is forcibly forced by the action of the residual force of the weight 13. Be deterred. This allows
It is possible to suppress the rotation of the inner pipe 14 without being influenced by the strength of the formation, and the core scraped off by the metal crown 5 of the outer pipe 2 into a cylindrical shape is stored in the inner pipe 14 in a good state, Collected.

Further, in this embodiment, since the inner pipe 14 is made of a transparent synthetic resin and the inner pipe 14 is detachably attached to the weight 13, the core can be removed even if the sampled core is not taken out from the inner pipe 14. Can be investigated. Further, since the core can be inspected without taking out the sampled core from the inner pipe 14, the core can be carried and stored in the state of being housed in the inner pipe 14, and the handling is easy.

The present invention is not limited to the above embodiment, but within the scope of the invention described in the claims,
It goes without saying that various changes can be made. For example, although the above embodiment is applied to the double core tube sampler, it can also be applied to the triple core tube sampler.

In the above embodiment, the inner pipe 14 made of transparent synthetic resin is attached, but the inner pipe 14 made of other than transparent synthetic resin can be attached.

[0023]

As described above, according to the present invention, the outer pipe head having the metal crown for boring the formation is attached to the outer pipe head which is connected to the lower end of the boring rod and propels while rotating. In the core tube sampler that rotatably accommodates the inner tube that stores the stratum sample in the tube,
Since the weight is accommodated in the outer pipe, the weight is supported by the outer pipe head in a state of rotating relative to the outer pipe, and the inner pipe is attached to the lower end of the weight, the rotation of the outer pipe is affected. Instead, the weight of the weight is applied to the inner pipe, and the rotation of the inner pipe that follows the rotation of the outer pipe can be forcibly suppressed by the action of the residual force of the weight. As a result, the inner tube can be prevented from rotating without being affected by the strength of the formation, and the core can be collected in a good condition. Therefore, it becomes possible to sample a non-uniform stratum mixed with soft ground, sand, gravel, etc., which is said to be difficult to collect cores with a conventional sampler.

Further, since the inner tube for collecting the core is formed of transparent synthetic resin and the inner tube is detachably attached, the core can be investigated without removing the sampled core from the inner tube. The core can be carried and stored in a state where it is housed in the inner tube, and it is easy to handle.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a core tube sampler of the present invention.

FIG. 2 is a vertical cross-sectional view of a conventional core tube sampler.

[Explanation of symbols] 1 Outer tube head 2 outer tube 4 Bowling rod 5 metal crown 6 cutting edge (bit) 7 spindles 8 bearings 9 Bearing case 13 weights 14 Inner tube 15 Weight mounting head 16 Inner pipe connection head

Claims (2)

[Claims] 1. An outer tube head equipped with a metal crown for drilling a formation is attached to an outer tube head which is connected to a lower end of a boring rod and is propelled while rotating, and an inner tube for accommodating a formation sample is provided in the outer tube. In a rotatably accommodated core tube sampler, a weight is accommodated in the outer tube, and the weight is supported by the outer tube head in a state of rotating relative to the outer tube, and the weight is supported by a lower end of the outer tube. A core tube sampler with an inner tube attached. 2. The core tube sampler according to claim 1, wherein the inner tube is formed of a transparent synthetic resin, and the inner tube is detachably attached to the weight.