JP2004204588A - Geological sampler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a geological sampler preventing the intrusion of cuttings into a sample. <P>SOLUTION: A core bit 3 constituting the geological sampler has a cutting edge 13 formed with a cylindrical inner excavating face, outer excavating face and an annular tip excavating face inclining inwardly to make the respective tips of the inner excavating face and outer excavating face continuous. The cutting edge has at least two tip groups of a plurality of preceding tips 17 forming the inner excavating face and preceding tip excavating face, and a plurality of succeeding tips 18 forming the outer excavating face and succeeding tip excavating face behind the preceding tips 17. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a geological sampler, and more particularly, to a sampler that utilizes the high-speed drilling performance of a rotary percussion drill to improve the working efficiency and the accuracy of a geological survey.
[0002]
[Prior art]
A rotary percussion drill is a drill that gives a rotating force and a hitting force to a bit for drilling, and is therefore known as a drill capable of high-speed drilling regardless of the type of stratum. On the other hand, in recent years, soil pollution has become a social problem, and geological samples are being sampled for a preliminary survey of purification measures.
[0003]
If this geological sample is sampled by using a rotary percussion drill, high-speed sampling can be performed, and the cost of soil contamination investigation can be reduced. However, in a soil contamination survey, if a chemical disturbance occurs in a geological sample, it is not possible to grasp a correct state of the contamination. Therefore, in order to realize high-speed sampling, the sampler must satisfy the following requirements.
[0004]
(1) The sample must not contain any debris. (2) The sample can be taken into the sampling tube quickly and without any resistance. (3) The sample is not distorted and the sample in the sample tube is disturbed. (4) The sample does not fall out of the collection tube.
[Problems to be solved by the invention]
The present invention has been made based on the technical background as described above, and achieves the following objects.
SUMMARY OF THE INVENTION An object of the present invention is to provide a geological sampler in which excavation is prevented from being mixed into a sample.
Another object of the present invention is to provide a geological sampler that can quickly and easily take a sample into a collection tube.
Still another object of the present invention is to provide a geological sampler which prevents twisting of the sampling tube and prevents the sample in the sampling tube from being disturbed.
Still another object of the present invention is to provide a geological sampler in which a sample is prevented from dropping from a sampling pipe.
[0006]
[Means for Solving the Problems]
The present invention employs the following means to achieve the above object.
That is, the present invention provides a geological system including a mantle tube, a core bit connected to a tip portion of the mantle tube and excavated by a rotary impact force, and a sampling tube that is integrated from the mantle tube to the core bit and is incorporated in an inner periphery thereof. A sample sampler,
The core bit has a cutting edge that forms a cylindrical inner digging surface and an outer digging surface, respectively, and an inwardly inclined annular tip digging surface that continues between the tips of the inner digging surface and the outer digging surface,
The cutting edge includes a plurality of leading chips that form the inner digging surface and the leading digging surface in advance, and a plurality of leading chips that are behind the leading chip and form the distal digging surface by trailing the outer digging surface. A geological sampler having at least two chip groups with the following chip.
[0007]
More specifically, the shank of the core bit on which each of the tips is implanted has an acute end in an axial cross section, and the tip of the preceding tip and the tip of the shank are substantially at the same position. The diameter of the cylindrical shape forming the outer excavation surface by the core bit is larger than the outer diameter of the mantle tube, and an excavation passage is formed on the outer periphery of the core bit from its front end to its rear end.
[0008]
Further, the present invention provides a geological system comprising: a mantle tube, a core bit connected to a distal end portion of the mantle tube and excavated by a rotary impact force, and a sample collection tube that is integrated from the mantle tube to the core bit and is incorporated in the inner periphery thereof. A sample sampler,
A step having an annular cavity for receiving the tip of the sampling tube is formed on the inner periphery of the core bit,
A geological sampler according to claim 1, wherein a rear end of the sampling tube is rotatably supported by the mantle tube.
[0009]
More specifically, the annular space is formed by the step having a step surface inclined outward. A retainer is integrally fitted to the rear end of the sampling tube, and a rolling bearing is interposed between the retainer and the outer tube. The retainer is provided with an air vent having a check valve. An annular seal member is interposed between the outer periphery of the sampling tube and the inner periphery of the core bit near the tip of the sampling tube.
[0010]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is an axial cross-sectional view showing the whole of a geological sampler according to the present invention, and is divided into two parts along a line AA for convenience of the drawing. The sampler 1 includes a mantle tube 2, a core bit 3, and a sampling tube 4.
[0011]
The mantle tube 2 has screws 5 and 6 on the outer circumference at the front end and the inner circumference at the rear end. A core bit 3 and a rod sub 7 are screwed onto the outer periphery of the distal end portion and the inner periphery of the rear end portion of the outer tube 2, respectively. A drill rod of a rotary percussion drill (not shown) is connected to the rear end of the rod sub 7 by a screw 8.
[0012]
2 is a front view of the core bit, FIG. 3 is a sectional view taken along line BB of FIG. 2, and FIG. 4 is a sectional view taken along line BC of FIG. The shank 9 of the core bit 3 has a hollow cylindrical shape, and a screw 10 for screwing with the screw 5 of the mantle tube 2 is provided on the inner peripheral surface thereof. Further, a step 11 is provided on the inner peripheral surface of the shank 9 on the tip side of the screw 10, and a step 12 is further provided on the tip side. The tip of the outer tube 2 screwed to the shank 9 is in contact with one of the steps 11. The other step 12 will be described later.
[0013]
FIG. 5 is a sectional view showing an excavated surface formed in the ground by excavation by the cutting edge 13 of the core bit 3. That is, the cutting edge 13 of the core bit 3 forms a cylindrical inner digging surface 14 and an outer digging surface 15 by excavation, and a tip digging surface 16 that connects between the tips of the inner digging surface 14 and the outer digging surface 15 respectively. The tip excavation surface 16 is an inclined excavation surface inclined inward.
[0014]
In order to form such excavated surfaces 14, 15, 16, the cutting edge 13 has a plurality of leading chips 17 and trailing chips 18, respectively. The leading tip 17 is a tip that precedes the inner digging surface 14 and the tip digging surface 16 shown in FIG. 5, and is planted at the tip of the shank 9 at intervals in the circumferential direction. The tip of the axial section of the shank 9 is acute, and the tip of the leading tip 17 and the tip of the shank 9 are substantially at the same position (see FIG. 3). The trailing tip 18 behind the leading tip 17 is the tip that forms the outer digging surface 15 and the trailing digging surface 16 shown in FIG. 5 and is spaced circumferentially at the tip of the shank 9. It is planted.
[0015]
Each of the leading tip 17 and the trailing tip 18 has a tip angle of 90 ° or more and less than 180 ° forming the cutting edge 19 (see FIG. 2). The tip angle α of the cone including the tip excavation surface 16 formed by the leading tip 17 and the trailing tip 18 is 75 to 90 degrees (see FIG. 5).
[0016]
The diameter of the cylinder forming the outer digging surface 15 is larger than the outer diameter of the mantle tube 2. The core bit 3 has two excavation passages 20 and 21 extending from the front end to the rear end. The cutting waste path 20 is formed by cutting the outer periphery of the shank 9 between the leading tip 17 and the trailing tip 18 from the tip to the middle. The digging discharge path 21 is formed by cutting the outer periphery of the shank 9 from the front end to the rear end between the digging discharge paths 20 and 20. The cuttings cut by the chips 17, 18 are discharged to the rear end side of the core bit 3 through the cutting discharge paths 20, 21 in order or only through the cutting discharge path 21.
[0017]
The sampling tube 4 is a tube made of a synthetic resin. The sampling tube 4 extends from the mantle tube 2 to the core bit 3 and is incorporated in the inner periphery thereof (see FIG. 1). FIG. 6 is an enlarged sectional view showing the tip of the core bit 3 into which the tip of the sampling tube 4 is incorporated. The above-mentioned step 12 has an annular step surface 22 which is inclined outward. That is, the step 12 has a Z-shaped cross section. Since the step 12 has such a step surface 22, an annular space 23 is formed on the inner periphery of the core bit 3.
[0018]
The distal end of the sampling tube 4 is received in the annular space 23 without contacting the step surface 22. An O-ring 24 as an annular sealing member is interposed between the outer periphery of the sampling tube 4 and the inner periphery of the core bit 3 near the tip of the sampling tube 4.
[0019]
Referring again to FIG. 1, a retainer 25 is integrally fitted to the inner periphery of the rear end of the sample collection tube 4. A rear portion of the retainer 25 protruding from the sample collection tube 4 forms a cylindrical portion 26. The retainer 25 is provided with an axial hole 27 in the center and a radial hole 28 in the cylindrical portion 26. These holes 27 and 28 are air vent holes, and the hole 27 is provided with a check valve 29.
[0020]
The cylindrical portion 26 is fitted between the distal end of the rod sub 7 and the outer tube 2 integrated with each other by the screw 6. A rolling bearing 30 is interposed between the cylindrical portion 26 and the rod sub 7, that is, the outer tube 2 integrated with the rod sub 7. By the rolling bearing 30, the cylindrical portion 26 is rotatable relative to the outer tube 2, but is supported so as not to move in the axial direction.
[0021]
Next, the operation of the above-mentioned geological sampler will be described. A drill rod of a rotary percussion drill is connected to the rod sub 7, and a rotational force and a striking force are applied to the core bit 3. Thereby, the leading tip 17 and the trailing tip 18 of the core bit 3 excavate the ground so as to form the excavation surface shown in FIG. That is, the leading tip 17 cuts and forms a sample 31 (see FIG. 5) having the inner excavation surface 14 as an outer periphery, and takes the sample 31 into the core bit 3. In addition, the trailing tip 18 forms an excavation hole wall that is the outer excavation surface 15.
[0022]
At that time, since the tip excavation surface 16 formed by the leading tip 17 and the trailing tip 18 is an inwardly inclined annular inclined surface, the cutting waste is given a tendency to move to the outer peripheral side of the core bit 3. As a result, the shavings are discharged between the mantle tube 2 and the borehole wall through the shaving discharge paths 20 and 21 without entering the core bit 3. Therefore, no shavings are mixed into the sample. In addition, because the sample is not subject to consolidation by digging debris, in the case of sampling for soil contamination survey, ground air and groundwater originally contained in the contaminated geological sample can be secured without being squeezed out. A highly accurate survey can be performed.
[0023]
The sample taken into the core bit 3 enters the sample collection tube 4. At this time, the check valve 29 is opened by the piston action due to the intrusion of the sample, and the air in the sample collection tube 4 is pushed out, so that the sample can smoothly enter. Further, as shown in FIG. 6, since the tip of the sampling tube 4 is received in the annular space 23 of the step 12, that is, the step 12 and the tip of the sampling tube 4 overlap with each other. The sample taken into the core bit 3 smoothly moves into the sampling tube 4.
[0024]
Even if the sample flows to the outer peripheral side of the collection tube 4, the gap formed between the step surface 22 and the tip of the collection tube 4 functions like a labyrinth mechanism, and the sample will flow to the outer peripheral side of the collection tube 4. Can be prevented. Even if the sample flows to the outer peripheral side of the collection tube 4, since the O-ring 24 is disposed between the outer periphery of the collection tube 4 and the inner periphery of the core bit 3, the sample is There is no clogging on the outer circumference. Therefore, relative rotation of the sample collection tube 4 with respect to the mantle tube 2 by the rolling bearing 30 is ensured. Thereby, twisting of the sample collection tube 4 can be prevented, and disturbance of the sample can be prevented.
[0025]
Further, when the sampler is lifted to the ground, the check valve 29 is closed to ensure airtightness in the sample collection tube 4, so that the sample can be prevented from dropping from the sample collection tube 4. Thus, when the sample is soil contaminated with a volatile substance, the chance of contact with the atmosphere can be reduced, and the accuracy of the investigation can be increased.
[0026]
The annular space 23 for receiving the tip of the sampling tube 4 is not limited to the above embodiment. FIG. 7 is a cross-sectional view showing another embodiment. In this embodiment, an annular groove 23 is formed in the step surface 22 of the step 12 to form an annular space. According to this embodiment, the same effect as described above can be obtained.
[0027]
The above embodiments are merely examples, and the present invention can be variously modified. For example, in the above-described embodiment, the cutting edge is configured by two chip groups of a leading chip and a trailing chip. However, an intermediate chip may be provided between the leading chip and the trailing chip to form three chip groups.
[0028]
【The invention's effect】
As described above, according to the present invention, cuttings can be mixed into the sample.
In addition, the sample can be taken into the collection tube quickly and without any difficulty. Further, it is possible to prevent the collection tube from being twisted, and prevent the sample in the collection tube from being disturbed. Further, it is possible to prevent the sample from dropping from the collection tube.
[Brief description of the drawings]
FIG. 1 is an axial sectional view showing an entire geological sampler according to the present invention.
FIG. 2 is a front view of a core bit.
FIG. 3 is a sectional view taken along line BB of FIG. 2;
FIG. 4 is a sectional view taken along line BC of FIG. 2;
FIG. 5 is a sectional view showing an excavated surface formed in the ground by a cutting edge of a core bit.
FIG. 6 is an enlarged sectional view showing a tip of a core bit into which a tip of a sample collection tube is incorporated.
FIG. 7 is a view similar to FIG. 6, but showing another embodiment.
[Explanation of symbols]
1: sampler 2: mantle tube 3: core bit 4: sampling tube 7: rod sub 9: shank 12: step 13: cutting edge 14: inner digging surface 15: outer digging surface 16: tip digging surface 17: leading tip 18: trailing Tip 19: Blade edge 20: Excavation discharge path 21: Excavation discharge path 22: Step surface 23: Annular space 24: O-ring 25: Retainer 26: Cylindrical portion 27: Axial hole 28: Radial hole 29 ： Check valve 30 ： Bearing

Claims (8)

A geological sample sampler comprising: a mantle tube, a core bit connected to a tip portion of the mantle tube and excavated by a rotary impact force, and a sample collection tube installed on the inner periphery of the mantle tube from the mantle tube to the core bit,
The core bit has a cutting edge that forms a cylindrical inner digging surface and an outer digging surface, respectively, and an inwardly inclined annular tip digging surface that continues between the tips of the inner digging surface and the outer digging surface,
The cutting edge includes a plurality of leading chips that form the inner digging surface and the leading digging surface in advance, and a plurality of leading chips that are behind the leading chip and form the distal digging surface by trailing the outer digging surface. A geological sampler having at least two chip groups with a subsequent chip. The shank of the core bit in which each of the tips is implanted has a sharp end in an axial cross section, and the tip of the preceding tip and the tip of the shank are substantially at the same position. Geological sampler. The diameter of the cylindrical shape forming the outer digging surface by the core bit is larger than the outer diameter of the mantle tube, and the outer periphery of the core bit is formed with a digging discharge path from a front end to a rear end thereof. The geological sampler according to claim 1. A geological sample sampler comprising: a mantle tube, a core bit connected to a tip portion of the mantle tube and excavated by a rotary impact force, and a sample collection tube installed on the inner periphery of the mantle tube from the mantle tube to the core bit,
A step having an annular cavity for receiving the tip of the sampling tube is formed on the inner periphery of the core bit,
The geological sampler according to claim 1, wherein a rear end of the sampling tube is rotatably supported by the mantle tube. The geological sample sampler according to claim 4, wherein the annular space is formed by the step having a step surface inclined outward. 6. The geological sampler according to claim 4, wherein a retainer is integrally fitted to a rear end portion of the sampling tube, and a rolling bearing is interposed between the retainer and the outer tube. 7. The geological sampler according to claim 6, wherein the retainer is provided with an air vent having a check valve. The annular seal member is interposed between the outer periphery of the collection tube and the inner periphery of the core bit near the tip of the sample collection tube. Geological sampler.

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