JP4611112B2 - Improved double core tube sampler - Google Patents

Description

  The present invention relates to an improved double core tube sampler for increasing the excavation rate in a rocking or ground coring.

  A double core tube sampler is widely used as a device for coring (core collection) of rock and ground. A double core tube sampler generally has a double tube structure of an outer tube and an inner tube, and digs rock and ground while supplying water to the tip.

  A bit made of hard metal is provided at the tip of the double core tube sampler to dig rock and ground, and a bit using diamond is called a diamond bit. Conventional diamond bits are roughly classified into two types: surface set bits and impregnated bits. In the former type, diamond particles are set on the surface of the matrix, and in the latter type, diamond powder and matrix powder are kneaded and cast.

  In general, the double core tube sampler is configured to accommodate the collected core in a bag while digging, and a tube ring is used to hold the upper end of the bag. Various tube rings have been proposed, and the present inventor has also proposed a novel tube ring (see Patent Document 1).

Japanese Patent Application No. 2003-345145

  However, it is difficult to say that the conventional diamond bit can excavate all the rocks from hard rock to soft rock. On the other hand, the tube ring described in Patent Document 1 was fortunately well received, but further improvements are desired.

  Accordingly, an object of the present invention is to provide an improved double core tube sampler that overcomes the problems of the conventional double core tube sampler and increases the digging rate in the coring and enables efficient coring.

  The rock that is the target of excavation by the bit is composed of various rocks classified into sedimentary rocks, igneous rocks, and metamorphic rocks, and their hardness, rock quality, etc. are diverse. When the rock is excavated with the bit, the outer peripheral edge and the inner peripheral edge of the bit are worn, but depending on the rock of the rock to be excavated, the manner of wear (the degree of wear, the wear location, etc.) is different. On the other hand, at the site of geological survey, using a file or the like in advance, the outer peripheral edge and / or inner peripheral edge of the bit is artificially worn in a mode corresponding to the rock of the rock so that the degree of adhesion with the rock is increased. In other words, it is empirically known that excavation can be performed efficiently. The present inventor has developed a novel diamond bit by paying attention to the empirical fact that a good excavation can be realized by wearing the outer periphery and / or inner periphery of the bit in a manner corresponding to the rock.

An improved double core tube sampler according to claim 1 is a bit having a large number of protrusions formed by continuously providing gaps at equal intervals in the circumferential direction at the tip of a cylindrical body. Each projecting portion is formed by mixing and sintering industrial diamond powder and a matrix, and the planar shape of each projecting portion has a ratio of circumferential dimension / diameter dimension. Or it is selected so that it may become a substantially rectangular shape below it, or other arbitrary shapes inscribed in this rectangular shape.

An improved double core tube sampler according to claim 2 of the present application is the sampler of claim 1, further comprising a tube ring that holds an upper end of a bag that accommodates the collected core, wherein the tube ring has a cylindrical core. And a sponge filter portion disposed on the outer periphery of the core portion.

  The improved double core tube sampler according to claim 3 of the present application is the sampler of claim 2, wherein a protrusion for preventing movement or displacement of the filter portion with respect to the core portion is provided on an outer periphery of the core portion. It is characterized by that.

  According to the improved double core tube sampler bit of the present invention, a good excavation rate can be obtained for all rocks from hard rock to soft rock. In addition, according to the improved double core tube sampler tube ring of the present invention, the inner tube surface is cleaned during coring, the core is smoothly raised, and the bag may be damaged. Can be avoided as much as possible.

  Next, an improved double core tube sampler according to a preferred embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a longitudinal sectional view of an improved double core tube sampler 10 according to a preferred embodiment of the present invention. In FIG. 1, reference numeral 12 indicates a bit forming the first feature of the present invention.

  The bit 12 of the present invention is of the type classified as the above-mentioned impregnated bit. The bit 12 includes a number of protrusions 16 disposed at the tip of a cylindrical main body 14. As shown in FIG. 3, the protrusion 16 has a substantially rectangular (strictly fan-shaped) planar shape having a circumferential dimension (width) of A and a diameter dimension (thickness) of B. On both sides of the protrusion 16, the protrusions 16 having the same shape are arranged in the circumferential direction with a gap 18 therebetween. In other words, a large number of protrusions 16 are formed by continuously providing the gap 18 at one end of the main body 14 of the bit 12 at equal intervals in the circumferential direction.

  The protrusion 16 is formed by mixing and sintering industrial diamond powder and a matrix (for example, tungsten carbide, copper alloy, or a mixture thereof).

  FIG. 4A is a partially enlarged view of the protruding portion 16 of the bit 12. When a rock is dug by a bit, generally, the outer peripheral edge and the inner peripheral edge of the tip of the bit are worn. The wear mode (degree of wear, wear location, etc.) differs depending on the type of bedrock, and when the wear mode is the best mode for the bedrock, the tip of the bit is in close contact with the bedrock and the efficiency of digging is improved. It is known to be very good. As a result of various trials, the inventor found that when A / B is 1 or less (that is, A / B ≦ 1), the outer peripheral edge and the inner peripheral edge of the protrusion 16 are the best for the rock during excavation. It was found that it was worn out.

  When A / B ≦ 1, the reason why the outer peripheral edge and the inner peripheral edge of the protrusion 16 wear in the best manner is a part that has not been clarified academically. It is difficult to say, but it is presumed that the following phenomenon occurs. That is, as shown in FIG. 4A, when the bit rotates in the direction of the arrow, the location where the bit protrusion 16 and the rock collide becomes the corner edge at the outer periphery and the corner edge at the inner periphery. Therefore, it seems that the wear starts from the corner edge and gradually wears along the outer peripheral edge and the inner peripheral edge. However, when the protrusion 16 is made to satisfy A / B ≦ 1, the corner edge at the outer peripheral edge Since the number of corner edges at the inner peripheral edge increases, it is assumed that the wear proceeds so that the degree of adhesion with the rock is increased (FIG. 4B is a diagram illustrating an aspect of wear. Is).

  Next, the tube ring which makes the 2nd characteristic of this invention is demonstrated. As described above, the tube ring 20 is an instrument for holding the upper end of the bag that accommodates the collected core. The tube ring 20 includes a cylindrical core portion 22 and a filter portion 24 disposed on the outer periphery of the core portion 22. The filter part 24 is made of sponge, and the core part 22 is made of an appropriate material such as a synthetic resin material. The bag and filter part 24 is fixed to the core part 22 by a rubber band 26 or the like.

  It is preferable to provide one or a plurality of protrusions 22a on the outer surface of the core part 22 so that the bag and the filter part 24 fixed to the outer surface do not move or shift with respect to the core part 22 (FIG. 5 ( c)).

  FIG. 6 is a series of views showing a state where coring is performed using a double core tube sampler provided with the tube ring 20. As shown in FIG. 6, as the core is raised, the filter portion 24 of the tube ring 20 is raised in contact with the inner surface of the inner tube, so the inner surface of the inner tube is cleaned. In addition, since the sponge-made filter portion 24, which is an elastic body, is in contact with the inner surface of the inner tube, the gravel is easily taken into the filter portion 24, thereby smoothly raising the core. Furthermore, since the bag and the filter part 24 are fixed to the core part 22 by a rubber band 26 or the like, sand gravel or the like does not enter the bag and falls into the cavity inside the core part 22 to avoid a situation where the bag is damaged. can do.

  The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the invention described in the claims, and these are also included in the scope of the present invention. Needless to say, it is something.

  For example, in the above-described embodiment, the protruding portion 16 of the bit 12 is described as having a substantially rectangular planar shape having a circumferential dimension A and a diameter dimension B. However, any shape inscribed in the rectangle (for example, The protrusion 16 may be formed so as to have a planar shape such as a circle, an ellipse, or a polygon (see FIG. 7).

It is length direction sectional drawing of the double core tube sampler which concerns on preferable embodiment of this invention. It is a perspective view of the bit with which the front-end | tip of the sampler of FIG. 1 is mounted | worn. FIG. 3 is a plan view of the bit of FIG. 2. FIG. 4A is a partially enlarged view of the protruding portion of the bit, and FIG. 4B is a view showing various wear states of the protruding portion of the bit. 5 (a) is a perspective view showing the tube ring attached state, FIG. 5 (b) is a side view showing the tube ring attached state, and FIG. 5 (c) shows a core portion provided with a protrusion. FIG. It is a series of figures which showed the state which is performing the coring using the double core tube sampler of this invention. It is the figure which showed the deformation | transformation form of the protrusion part of a bit.

Explanation of symbols

10 Double core tube sampler 12 Bit 14 Body 16 Projection 18 Clearance 20 Tube ring 22 Core 24 Filter

Claims (3)

An improved double core tube sampler,
At the tip of the cylindrical main body, provided with a bit having a large number of protrusions formed by continuously providing gaps spaced equidistantly in the circumferential direction ,
Each of the protrusions is formed by mixing and sintering industrial diamond powder and a matrix,
The planar shape of each of the protrusions is selected to be a substantially rectangular shape having a ratio of circumferential dimension / diametrical dimension of 1 or less, or any other shape inscribed in the rectangle. A sampler. The tube ring further includes a tube ring that holds the upper end of the bag that accommodates the collected core, and the tube ring includes a cylindrical core portion and a sponge filter portion disposed on the outer periphery of the core portion. The sampler according to claim 1 . The sampler according to claim 2, wherein a protrusion for preventing movement or displacement of the filter part with respect to the core part is provided on an outer periphery of the core part.

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