JPH0121319B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a sampler for soft ground, which is used particularly for strata with strong viscosity in air drilling drilling operations.

[Technical background of the invention and its problems] A sampler used in an air drilling method that pumps air into a hole during drilling work to cool the tip of the drill bit inserted into the ground and to transport rock powder out of the hole. for,
Conventionally known devices consist of a sampler tube for drilling and sampling, and a casing for holding the inner wall of the drilled hole, with air being pumped between the two.

By the way, as a sampler of this type, there is an invention described in Japanese Patent Publication No. 56-4712.

However, the invention described in Japanese Patent Publication No. 56-4712 rotates both the inner sampler tube (drilling tube and rock core extractor) and the outer casing (hole storage tube), so the sampler tube rotates. This had the disadvantage that the sample was disturbed and difficult to collect. Furthermore, since the bit at the tip of the sampler tube is flat, the sample is further disturbed during rotation, making it difficult to collect the sample into the sampler tube. In addition, such disturbance of the sample causes the collapse of the borehole wall and increases the load applied to the casing, which becomes a major obstacle to the continuation of drilling, which has also been a problem.

To improve this point, Japanese Patent Application Laid-open No. 54-
An invention has also been proposed in which only the casing is rotated and the sampler tube is fixed, such as the invention described in Japanese Patent No. 5802. It is true that this invention has the advantage that the sample does not collapse or break compared to the above-mentioned invention, but since the fixed sampler tube is simply pressed into the ground, the excavation efficiency is poor, and the force required when pressing is low. There was also the drawback that the sample would collapse.

[Object of the Invention] The present invention was proposed in order to solve the problems of the prior art as described above, and its purpose is to provide a structure in which only the casing is rotated without rotating the sampler tube, and further, To provide a sampler for soft ground that allows smooth excavation and reduces sample collapse.

[Summary of the Invention] The sampler for soft ground according to the present invention rotates only the casing without rotating the sampler tube with the rotation of the rod by rotatably connecting the rotating shaft that rotates with the rod and the sampler tube. At the same time, the sampler tube is attached to the tip of the rotating shaft so that it can move up and down, and a spring is installed between the two, so that the sampler tube can be inserted into the ground while vibrating up and down. .

[Embodiment of the Invention] Hereinafter, an embodiment of the present invention will be specifically described with reference to the drawings.

FIG. 1 shows an example in which the sampler for soft ground of the present invention is applied to an air excavation device that uses foam.

In the figure, 1 is a boring machine for excavation, 2 is a rod thereof, and 3 is a sampler for soft ground of the present invention attached to the tip of the rod 2.
An air hose 5 for excavation extending from the main compressor 4 is connected to the upper end of the rod 2, and compressed air is supplied to the tip of the sampler 3 for soft ground through the air hose 5. A foam supplying air hose 7 extending from a foam generation compressor 6 is connected to the middle of this excavation air hose 5, and a foam generation device 8 is provided in the middle of this foam supplying air hose 7. The blowing agent is supplied to the

The sampler for soft ground of the present invention has a configuration as shown in FIG.

In the figure, a casing head 12 is provided at the upper end of the casing 11 so as to surround the rod 2.
The rod and casing 11 are connected by tightening and fixing a chuck 13 attached to the upper part of the casing head 12 to the rod 2. Below the casing head 12,
Distributor 14 via O-ring 14a
is provided, through which the rod 2 and the rotating shaft 15 in the sampler are connected. Here, the air sent into the rod 2 is sent only between the casing 11 and the rotating shaft 15.

A connecting rod 18 for the sampler tube 17 is attached to the lower end of the rotating shaft 15 via a bearing 16, so that the sampler tube 17 does not rotate as the rotating shaft 15 rotates.

The sampler tube 17 can be moved up and down within a certain range with respect to the rotating shaft 15 by means of the connecting rod 18, and is attached downwardly by a spring 19 provided between the sampler tube 17 and the rotating shaft 15. This spring 19 and the pressure relief valve 1 described later are
The sampler tube 17 is designed to move up and down by working with the sampler tube 7a.

The sampler tube 17 includes a transparent inner tube 20 and an outer tube 21 for maintaining strength.
It has a double structure that allows the inside and outside to be removed, and a cone point 22 with an acute angle is attached to the tip. A pressure release valve 17a connected to the casing 11 is provided at the base end having the rod 18, so that when a sample is collected in the sampler tube 17 and the pressure in the tube 17 increases, The pressure is released to the casing 11 side. Also, sampler tube 1
The tip of 7 and casing 11 is connected to casing 1
1 is always positioned above, so that the air ejected from between the two does not directly hit the rock core being collected. Also,
A metal crown 23 with a flat tip is attached to the tip of the casing 11.

The present embodiment having the above configuration operates as follows.

First, as shown in FIG. 1, compressed air is sent to the soft ground sampler 3 through the excavation air hose 5 by the action of the main compressor 4, and at the same time,
Compressed air is sent from the foam generation compressor 6 to the foam generation device 8, and the foam generated here is supplied into the excavation air hose 5 through the foam generation air hose 7, and is used to clean soft ground together with the excavation compressed air inside the air hose 5. sampler 3. Then, when air and bubbles begin to be discharged from the drill tip 22, the boring machine 1 is started, and the rod 2 is thereby rotated, so that the sampler 3 for soft ground operates as follows.

That is, when the rod 2 starts rotating,
Casing 1 fixed with this and chuck 13
1 rotates together, and the metal crown 2 at the tip
Excavation will be carried out at 3. On the other hand, the sampler tube 17 has a rotary shaft 1 connected to the tip of the rod 2.
Since it is connected to the rod 5 by a bearing 16, it does not rotate even if the rod 2 rotates.
Therefore, although the casing 11 is inserted into the ground while rotating, the excavation of the sample within the casing 11 is performed by the drill tip 22, which is inserted into the ground together with the casing 11 and does not rotate. Therefore, since the sampler tube 17 does not rotate, disturbance of the sample is greatly reduced, and since the tip of the sampler tube is made at an acute angle, sampling of the sample becomes extremely easy. Furthermore, since the disturbance of the sample is reduced, the collapse of the borehole wall is also minimized, so that the load applied to the casing 11, which is a major hindrance in the drilling operation, can be reduced. Furthermore, the sampler tube 17 is movable up and down, and during excavation, the reaction force causes the sampler tube 17 to move upward, and the force of the spring 19 causes the sampler tube 17 to move downward again, which is repeated. can be collected more effectively. By the way, when a sample is collected in the sampler tube 17 and the pressure inside the tube 17 increases, pressure is released to the casing 11 side by the pressure release valve 17a, but this pressure release action also affects the pressure inside the sampler tube 17. Promotes vertical movement and works more effectively for sample collection.

On the other hand, the bubbles and air sent from Rod 2,
The distributor 14 sends the rock powder between the rotating shaft 15 and the casing 11 and ejects it from between the casing 11 and the tip of the sampler tube 17, thereby discharging the rock powder in the borehole.

In this way, in the present invention, since there is only one air flow path, if soil becomes clogged between the sampler tube 17 and the casing 11 during excavation, the pressure cage on the ground can be immediately removed. Since changes appear in the excavation status, the excavation status can be immediately determined, the work does not continue with excavation impossible, and samples can be reliably collected.

After collecting the sample, loosen the chuck 13 and
By removing the casing head 12 from the casing 11, these, the rod 2, and the sampler tube 17 are pulled up together. At this time, since the inside and outside of the sampler tube 17 can be removed,
By removing the outer tube 21, the sample collected inside the transparent inner tube 20 can be observed from the outside without changing. Also,
By leaving the casing 11 in the borehole, collapse of the borehole wall is prevented, so the drilling work can be continued by setting the rod 2 and sampler tube 17 again.

[Effects of the Invention] As explained above, according to the present invention, the sampler tube is inserted into the ground while being vibrated up and down by the spring, so that the insertion work of the sampler tube becomes smooth, and at the same time, when the tube is inserted, A sampler for soft ground with less sample collapse can be provided.

[Brief explanation of drawings]

FIG. 1 is an overall view showing an air excavation apparatus to which a sampler for soft ground according to the present invention is applied, and FIG. 2 is a sectional view showing an embodiment of the sampler for soft ground according to the present invention. 1... Bowling machine, 2... Rod, 3...
...Sampler for soft ground, 11...Casing,
12...Casing head, 13...Chick,
14... Distributor, 14a... O-ring, 15... Rotating shaft, 16... Bearing, 17
... Sampler tube, 17a ... Pressure relief valve, 18 ... Rod, 19 ... Spring, 20
...inner tube, 21...outer tube, 22...point, 23...metal crown.

Claims (1)

[Scope of Claims] 1. Used during the drilling work of the air drilling method, comprising a casing removably fixed to the tip of a rotating rod, and a sampler tube having a drill tip, the sampler tube being inserted into the casing. This is a sampler for soft ground that is attached to the tip of a rod that is rotatable.A rotary shaft that rotates together with the rod is provided inside the sampler, and the sampler is attached to the tip of the rotary shaft and is rotatable in the circumferential direction of the rotary shaft. The sampler tube is supported movably in the axial direction of the rotating shaft, and a spring is compressed between the tip of the rotating shaft and the sampler tube to bias the sampler tube in the axial direction of the rotating shaft. Sampler for soft ground.