JPH11236709A - Inside pipe rotating prevention core tube sampler making use of magnet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable an inside pipe for storing a sample (core) to surely prevent the rotation thereof. SOLUTION: An inside pipe rotating prevention core tube sampler is equipped with a sampler head 2 having a joint section 2a1 for connecting with a boring rod 21, a sampler body 4 mounted to the lower end of the sampler head 2 and formed of a non-magnetic substance, an outside pipe 6 with the edge of a blade mounted to the sampler body 4 in a detachable manner, inside pipes 8 and 10 stored in the outside pipe in a rotatable manner, and a rotating prevention mechanism 12 for mechanically preventing the rotation of the inside pipes to the outside pipe by interlocking with a boring hole wall. A magnetic substance 13 having a chuck piece 15 for interlocking with the boring hole wall and provided to the sampler body 4 in a rotatable manner and a magnetic substance 17 fixed to the inside pipe are pulled against each other to control the rotation of the inside pipe.

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 sample, that is, a sampler, for sampling a ground (sampling) for the purpose of geological investigation. In the core tube sampler constituted by the above, the mechanism for forcibly stopping the rotation of the inner tube for accommodating the sample (core) is improved.

[0002]

2. Description of the Related Art As this type of sampler, a double-core tube sampler composed of an outer tube with a cutting edge (bit) for excavating the ground and an inner tube for storing a ground sample, or a double-tube inner sampler is used. The known triple core tube sampler is known. For example, Japanese Patent Publication No. 63-26240 discloses a double core tube sampler. In both cases, the basic structure is the same. Rotation and penetration force are transmitted from the boring machine to the outer pipe via the rod, and the cutting edge of the outer pipe rotates and excavates while scraping the ground. Water and muddy water are pumped from the excavation pump on the ground through the inside of the rod, and discharged from the cutting edge of the outer tube to the outside through the gap between the outer tube and the inner tube of the sampler. The shaved ground debris mixes with the digging water and muddy water, rises in the borehole, and is carried to the ground. As the excavation progresses, the ground sample cut into a cylindrical shape is stored in the inner tube. The inner tube for storing the sample is rotatable with respect to the outer tube by a ball bearing or the like. The triple core tube is a mechanism in which the second inner tube is rotatably housed in the rotatable inner tube via a ball bearing, so that the rotating force of the outer tube does not reach the second inner tube further. It is like that.

[0003] When sampling the ground with a core tube sampler, the most important thing is that the inner tube does not rotate with the outer tube. The conventional sampler has a structure in which a ball bearing is interposed between an outer tube and an inner tube, so that the rotational force of the outer tube is not transmitted to the inner tube. Therefore, even if the outer pipe rotates, the inner pipe is always rotatable with respect to the outer pipe. When the cutting edge of the outer pipe tip rotates at the time of sampling and excavates while shaving the ground, the ground becomes a core (in the inner pipe). (Ground sample cut into a columnar shape). The core being excavated has its circumference cut off, but the bottom of the core is connected to the unexcavated ground. Since the outer peripheral surface of the core housed in the inner tube is in contact with the inner surface of the inner tube, rotation of the inner tube is suppressed by these frictional resistances. Therefore, the rotation inhibiting force of the inner pipe depends on the strength of the connection between the ground and the core bottom.

[0004]

In the conventional double-core tube or triple-core tube sampler, the rotation of the inner tube cannot be suppressed unless the ground has a certain strength. If the inner tube rotates easily during the sampling operation, the outer peripheral surface of the core to be collected is rubbed by the inner surface of the inner tube, and the core is worn or broken. In addition, in the excavation path for excavation, the inner pipe is slightly shorter than the outer pipe edge at the sampler tip,
Drill launch and core always come into contact at this part. The core worn or broken by the rotation of the inner pipe comes into contact with the drilling water and becomes more brittle, flows out of the inner pipe with the drilling water, and the core collection rate is greatly reduced. Therefore, it is not suitable for soil with low solidification such as sand, gravel and weathered soil.

A main object of the present invention is to surely prevent rotation of an inner tube for accommodating a sample (core) and to improve the sampling rate regardless of the ground strength.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a boring machine.
In order to reliably prevent the inner pipe from rotating together with the outer pipe against the rotational force that can be transmitted from the outer pipe to the inner pipe for some reason from the outer pipe that is given a rotational force by the machine, ball bearings must be installed as in the past. Based on the finding that it is not enough to intervene and it is necessary to mechanically prevent the rotation of the inner tube, the rotation of the inner tube was forcibly stopped using the hole wall of the boring hole Things.

The core tube sampler of the present invention has a sampler head provided with a connecting portion for connecting to a boring rod, a sampler body attached to the lower end of the sampler head, and a blade attached to the lower end of the sampler body and having a blade at the tip. An outer tube, an inner tube housed in the sampler body and the outer tube, and a rotation preventing mechanism for preventing rotation of the inner tube with respect to the outer tube, wherein the sampler body is formed of a non-magnetic material, The mechanism includes an outer member rotatably supported on the outer periphery of the sampler body, an inner member fixed to the inner tube, a chuck portion in which the outer member is engaged with a borehole wall, and a first magnet. Wherein the interior member comprises a second magnet arranged to attract the first magnet, the chuck portion of the circumscribing member engages with the boring hole wall, and the first magnet of the circumscribing member By the second magnet inscribed member attract each other through the sampler body, it is intended to prevent the rotation of the inner tube relative to the boring hole walls.

The chuck portion includes a chuck piece supported on the outer periphery of an exterior member rotatably supported by a sampler body via a bearing so as to protrude and retract from an outer diameter position of the sampler body, and a sampler for holding the chuck piece. A spring member for biasing the body so as to partially protrude from the outer diameter position is a main component.

More specifically, a plurality of independent chuck pieces are radially arranged, tapered ends are formed at both axial ends of the chuck pieces, and tapered ends of the chuck pieces are formed at both axial sides of the chuck pieces. Place a thrust collar with a tapered surface corresponding to the part,
By applying an elastic force in the axial direction to the thrust collar with a spring member, the chuck pieces are urged in the expanding direction, and a plurality of chuck pieces independent of each other are radially arranged, and each chuck piece is provided with an external force. There is one provided with a spring member for giving a direction elastic force. "Spring member"
Any member that has the above-mentioned effects may be used, and a coil spring, a leaf spring, an air cushion member, a hydraulic cylinder, or the like can be applied.

It is preferable that the chuck piece has a shape in which a portion protruding from the outer tube outer diameter position generates a large frictional resistance between the boring hole wall in the rotation direction of the outer tube and a small frictional force in the axial direction. For example, there is a plate-shaped one in which a portion protruding from the outer diameter position of the outer tube extends in the axial direction.

The first magnet and the second magnet engage the outer member and the inner member by magnetic force. Both magnets may be constituted by a single magnet, but in order to effectively suppress the rotation of the inner tube, the above-mentioned first magnet has magnetic poles alternately N and S in the circumferential direction, and N · in the circumferential direction so that the magnet attracts the first magnet
It is preferable that the magnetic poles have magnetic poles alternately with S. For example, in an exterior member or an interior member, a plurality of magnets are arranged in the circumferential direction such that N poles and S poles are alternately formed, or a circular magnet having N / S alternating magnetic poles in the circumferential direction. It may be. The “magnet” includes a permanent magnet and an electromagnet.

The present invention can be applied to both a double-core tube sampler and a triple-core tube sampler. In the latter case, the inner tube has a double structure.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a core tube sampler according to 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. The core tube sampler of this embodiment includes a sampler head 2, a sampler body 4 integrally connected to the sampler head 2, an outer tube 6 having a cutting edge detachably attached to a lower end of the sampler body 4, and a sampler body 4. The inner pipe shaft 8 and the inner pipe 10 rotatably accommodated in the outer pipe 6 and the boring hole wall 20a engage with the boring hole wall 20a.
And a rotation prevention mechanism 12 for mechanically suppressing rotation of the inner pipe shaft 8 and the inner pipe 10 with respect to the rotation direction.

The sampler head 2 has a hole 2a formed at the center thereof, and a boring rod 21 is connected to a connecting portion 2a1 formed at the upper end of the hole 2a. The sampler head 2 is connected to the sampler body 4 at the lower end. The connection with the sampler body 4 has a detachable connection relationship using, for example, a screw.

The sampler body 4 is a cylindrical member made of a non-magnetic material, and the rotation preventing mechanism 12 is attached to the intermediate portion 4a. The intermediate portion 4a includes an inner tube portion 4a1 and an outer tube portion 4a.
a2, and is connected to the outer tube 6 at the lower end of the inner space 4a1. The outer tube portion 4a2 is open in a region where the chuck piece 12a as an engagement member of the rotation preventing mechanism 12 projects, and a cover 4c is provided in the opening portion 4b to prevent inflow of muddy water or the like. The cover 4c is provided rotatably with respect to the sampler body 4.

The outer tube 6 is a hollow cylindrical member having a plurality of blades 6a at its tip, and is attached to the lower end of the sampler body 4.

The sampler head 2, the sampler body 4, and the outer tube 6 are integrally connected, and the sampler head 2 at the upper end is formed.
With the boring rod 21 connected to the connecting portion 2a1, the boring rod 21 is lowered into the boring hole 20 dug with a predetermined diameter. Accordingly, the sampler head 2, the sampler body 4, and the outer tube 6 receive the fitting input and the rotational force of the boring rod 21, and excavate the boring hole 20 while rotating, thereby shaving the bottom of the hole into a cylindrical shape.

The inner tube shaft 8 and the inner tube 10 are accommodated in hollow portions of the sampler body 4 and the outer tube 6.

The inner tube shaft 8 is a hollow shaft member and is rotatably connected to the sampler body 4 via a bearing 22. The lower end of the inner pipe shaft 8 projects into the outer pipe 6 and is connected to the inner pipe head 9. The lower end of the inner tube head 9 is connected to the inner tube 8. The inner tube 8 is a hollow cylindrical member,
The lower end of the inner tube 8 is open inside the lower end of the outer tube 6.

The upper end of the inner tube shaft 8 is inserted into the hole 2 a of the sampler head 2, and the hollow portion 8 a of the inner tube shaft 8 is inserted through the hole 2 a of the sampler head 2 into the boring rod 21. The inner pipe shaft 8 communicates with the water passage 21a and has an opening 8b at the lower end thereof.
b. As a result, the boring rod 2
1, the hollow portion 8a of the inner tube shaft 8, the inner portion 6b of the outer tube,
A water passage leading to the outer tube cutting edge 6a is formed. Drilling water is pumped into this water passage by a pump on the ground. The drilling water is spouted from the cutting edge 6a of the outer tube 6 to the outside of the core tube sampler, mixed with the shaved ground debris, and discharged to the ground.

The rotation of the inner pipe shaft 8 and the inner pipe 10 with respect to the boring hole wall 20a (relative to the ground) is mechanically suppressed by the action of the rotation preventing mechanism 12. As a result, the ground sample (core) 25 that has been cut into a cylindrical shape by the outer tube 6 is stored in the hollow portion 10a of the inner tube 10 in a favorable state and collected.

FIG. 2 is an enlarged view of the rotation preventing mechanism 12 in the present embodiment.

The rotation preventing mechanism 12 is provided between the upper and lower wheel members (13, 14) rotatably disposed on the outer periphery of the inner tube portion 4a1 in the sampler body intermediate portion 4a, and the upper and lower wheel members (13, 14). Chuck piece 15 arranged in
A spring member 16 disposed at the upper end of the upper foil member 13 and an inner foil member 17 disposed at a portion corresponding to the upper foil member 13 on the outer peripheral surface of the inner pipe shaft 8.
And

The upper and lower wheel members (13, 14) are donut-shaped members, and are rotatably disposed on the outer periphery of the inner tube portion 4a1 of the sampler body via bearings 23, 24, respectively. The upper foil member 13 (hereinafter, referred to as the upper foil member 13) has a circular magnet 13a at an upper end, and has a conical surface 13 having a diameter reduced in the axial direction on an outer peripheral surface at a lower end.
b. An engaging portion 13c for attaching the chuck piece 15 is formed in a radial direction of the conical surface 13b.
As shown in FIG. 4, the circular magnet 13a has N poles and S poles alternately formed along the circumference. The upper end of the upper wheel member 13 is in contact with the spring member 16 via the bearing 23.

The lower wheel member 14 (hereinafter referred to as the lower wheel member 14) has a conical surface 14b whose diameter is reduced in the axial direction on the outer peripheral surface at the upper end. An engaging portion 14 for incorporating the chuck piece 15 at a position corresponding to the engaging portion 13c of the upper wheel member 13 in the radial direction of the conical surface 14b.
c is formed. The lower end of the lower wheel member 14 is rotatably fixed to the sampler body intermediate portion 4a via a bearing 24.

The chuck piece 15 is provided with a plurality of plate-like members independent of each other and radially erected in the axial direction at equal intervals in the circumferential direction.

The outer end of the chuck piece 15 has an end 15a parallel to the axis, and a notch 15a1 is formed at the top and bottom. With such a shape, the engagement force of the chuck piece 15 is large in the rotation direction of the outer tube 6 and small in the axial direction, so that it is engaged with the boring hole wall 20a with a sufficient engagement force in the rotation direction. And does not hinder the fitting operation into the boring hole 20.

The inner end of the chuck piece 15 is vertically tapered (13b, 1) of the upper and lower foil members (13, 14).
4b), a tapered end corresponding to the engaging portion (13c, 13c) of the upper and lower wheel members (13, 14) is formed on the tapered end.
An engaged portion (15b, 15b) corresponding to 14c) is formed. The chuck piece 15 is erected in the axial direction of the core tube sampler by engaging with the engaging portions (13c, 14c) of the upper and lower wheel members (13, 14), and the upper and lower wheel members (13, 14). Is a member that slides in the radial direction on the tapered surfaces (13b, 14b).

As shown in FIG. 3, the engaging portions (13c, 14c) of the upper and lower wheel members (13, 14) and the engaging portions (15b, 15b) of the chuck piece 15 have stoppers. Therefore, it is possible to prevent the chuck piece 15 from coming off to the outer diameter side.

The chuck piece 15 partially protrudes outward through a slit formed in the cover 4c. The cover 4c is a cylindrical member, and the sampler body outer tube portion 4a2
The upper and lower foil members (13, 1)
The upper and lower foil members (1) are provided by ribs attached to (4).
3, 14).

The spring member 16 is provided in the sampler body inner tube 4.
a1 is a coil spring mounted on the outer periphery of a1. Spring member 1
6 is sandwiched between the upper end (bearing 23) of the upper foil member 13 and the sampler body 4. The spring member 16 urges the upper foil member 13 downward, and the upper and lower foil members (1)
The chuck piece 15 sandwiched between (3, 14) is slid to the outer diameter side. As a result, the outer end 15a of the chuck piece 15 passes through the slit of the cover 4c and engages with the bowling hole wall 20a with an engaging force proportional to the urging force of the spring member 16. When the chuck piece 15 is engaged with the boring hole wall 20a, the upper and lower wheel members (1) are engaged.
In (3, 14), the rotation with respect to the boring hole wall 20a is suppressed.

The inner foil member 17 is a donut-shaped member, has a circular magnet 17a, and is fixed to the outer periphery of the inner pipe shaft 8 at a position corresponding to the location of the upper foil member 13. As shown in FIG. 4, the circular magnet 17a of the upper foil member 13 is attracted to the circular magnet 17a of the inner foil member 17 so as to attract each other.
The north pole and the south pole are alternately arranged in the circumferential direction corresponding to. As shown in FIG. 4, the circular magnet 17 of the inner foil member 17 is used.
a and the circular magnet 13a of the upper wheel member 13 exert magnetic force on each other via the sampler body. For this reason, the sampler body is made of a non-magnetic material such as stainless steel that does not affect the magnetic field.

Even when the inner foil member 17 receives a force in the rotating direction, the magnetic poles of the inner foil member 17 and the corresponding magnetic poles of the upper foil member 13 attract each other, and repel with the magnetic poles adjacent to each other. Since they fit, rotation of the inner wheel member 17 with respect to the upper wheel member 13 is suppressed. Since the inner wheel member 17, the inner tube shaft 8, the inner tube head 9, and the inner tube 10 are integrally formed, the rotation of the inner wheel member 17 is suppressed by suppressing the rotation of the inner wheel member 17.

That is, as described above, the rotation preventing mechanism 12 engages the chuck piece 15 with the boring hole wall 20a to thereby form the upper and lower wheel members (13, 14).
Of the circular magnet 1 of the upper foil member 13.
The rotation of the inner foil member 17, the inner pipe shaft 8, and the inner pipe 10 with respect to the boring hole wall 20a is forcibly suppressed by the attraction of the circular magnet 3a and the circular magnet 17a of the inner foil member 17. As described above, the inner tube 10 becomes a stationary member with respect to the ground due to the operation of the rotation preventing mechanism 12, so that the core tube sampler according to the present embodiment can collect a good ground sample regardless of the strength of the ground. .

[0036]

As described above, according to the present invention, the sampler body is formed of a non-magnetic material, and the rotation preventing mechanism includes the circumscribing member rotatably supported on the outer periphery of the sampler body,
An inner member fixed to the inner tube is provided, the outer member is provided with a chuck member and a first magnet, the inner member is provided with a second magnet, the chuck portion of the outer member is engaged with a bore hole wall,
In addition, since the first magnet of the outer member and the second magnet of the inner member attract each other via the sampler body, the rotation of the inner tube with respect to the wall of the boring hole can be forcibly suppressed.

According to the present invention, since the rotation of the inner tube of the core tube sampler is reliably prevented without being affected by the strength of the ground, the sampling rate is greatly improved. Therefore, if the core tube sampler of the present invention is used,
With conventional samplers, it is possible to sample sand, gravel, weathered soil, and hard / soft ground that are difficult to sample.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a core tube sampler according to an embodiment of the present invention.

FIG. 2 is an enlarged longitudinal sectional view of a rotation preventing mechanism according to the embodiment of the present invention.

FIG. 3 is a longitudinal sectional view of the chuck piece according to the embodiment of the present invention.

FIG. 4 is a sectional view of a circular magnet according to the embodiment of the present invention.

[Explanation of symbols]

 2 Sampler head 4 Sampler body 6 Outer tube 8 Inner tube shaft 9 Inner tube head 10 Inner tube 12 Rotation prevention mechanism 13 Upper foil member 13a Circular magnet 14 Lower foil member 15 Chuck piece 16 Spring member 17 Inner foil member 17a Circular magnet

Claims (9)

[Claims] A sampler head having a connection portion for connecting to a boring rod; a sampler body attached to a lower end of the sampler head; an outer tube attached to a lower end of the sampler body and having a blade at a tip; An inner tube housed in the body and the outer tube; and a rotation preventing mechanism for preventing rotation of the inner tube with respect to the outer tube. The sampler body is formed of a non-magnetic material. An outer member rotatably supported on the outer periphery of the sampler body, an inner member fixed to the inner tube, a chuck portion in which the outer member is engaged with a boring hole wall, and a first magnet. Wherein the interior member comprises a second magnet arranged to attract the first magnet, wherein the chuck portion of the circumscribing member engages with a boring hole wall;
A core tube sampler, wherein the rotation of the inner tube with respect to the bore hole wall is suppressed by attracting the first magnet of the outer member and the second magnet of the inner member to each other. 2. A chuck piece, wherein the chuck portion is supported on the outer periphery of an exterior member rotatably supported by a sampler body via a bearing so as to protrude and retract from an outer diameter position of the sampler body, and a chuck. The core tube sampler according to claim 1, further comprising a spring member for urging the piece so as to partially protrude from an outer diameter position of the sampler body. 3. A plurality of independent chuck pieces are radially arranged, tapered ends are formed at both axial ends of the chuck pieces, and tapered ends of the chuck pieces are formed at both axial sides of the chuck pieces. 3. The core tube according to claim 2, wherein a thrust collar having a tapered surface is disposed, and the chuck member is urged in a direction of expanding the chuck piece by applying an axial elastic force to the thrust collar by a spring member. Sampler. 4. The core tube sampler according to claim 2, wherein a plurality of chuck pieces independent of each other are arranged radially, and a spring member for giving an outward elastic force is provided for each chuck piece. 5. A portion of the chuck piece protruding from the outer diameter of the outer tube is formed to have a large frictional resistance between the boring hole wall in the rotation direction of the outer tube and a small axial resistance. The core tube sampler according to claim 2, wherein 6. The core tube sampler according to claim 5, wherein the portion of the chuck piece projecting from the outer diameter position of the outer tube has a plate shape extending in the axial direction. 7. The first magnet has magnetic poles alternately N and S in the circumferential direction, and the second magnet has magnetic poles alternately in the circumferential direction so as to attract the first magnet. 7. The core tube sampler according to claim 1, wherein: 8. The core tube sampler according to claim 7, wherein both the first magnet and the second magnet are circular magnets having alternating N and S magnetic poles in the circumferential direction. 9. An inner tube according to claim 1, wherein said inner tube has a double structure.
To 8 core tube samplers.