JP2018031167A - Drilling tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drilling tool that uses a drilling bit having a protruded part made of a material containing diamond, thus enhancing durability compared to a conventional drilling tool, enabling the protruded part to be fixed solidly so as not to fall off due to heat or an impact during drilling, and thereby enabling stable drilling under a high temperature environment.SOLUTION: The drilling tool may be fitted on a rod of a drilling machine, and includes a drilling bit 20 having a plurality of recessed parts 24 provided on an outer surface, a protruded part fixing member 23 for each recessed part having a hollow part that may be fitted respectively to the recessed parts 24, and a protruded part 22 inserted such that a tip thereof protrudes from the hollow part and being made of a material containing diamond. The protruded part 22 is inserted into the hollow part of the respective protruded part fixing member 23 and the protruded part fixing member 23 is fitted to the respective recessed part 24, thus fixing the drilling tool so that the protruded part protrudes from an outer surface of the drilling bit 20.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a drilling tool for stably drilling a hole even in a high temperature environment.

  Generally, a drilling tool in which a chip made of a hard material such as cemented carbide or ceramics (hereinafter referred to as “carbide chip”) is implanted in a steel drilling bit is used. . The most common method of attaching this carbide tip is to drill a tip hole into which a carbide tip is fitted into a drill bit, and then to braze by fitting the carbide tip into the tip hole. There is a shrink fitting method.

  However, a tool with a cemented carbide tip fixed by the brazing method or shrink-fit method described above will be heated to a high temperature when processed for a long time or when the workpiece is at a high temperature. There was a problem that the hard chip was damaged or dropped out by thermal stress. For example, the pit of the blast furnace is closed again when the molten pig iron is discharged, and the next melting operation is started. The opening of the pit and the flattening of the opening at the time of closing (blocking) When the drilling bit is used to flatten the tip of the mud gun for use with the drilling bit, the bit must be brazed with a cemented carbide tip. When using a bit that has been shrink-fitted, the carbide tip will fall off immediately.

  In order to solve this problem, a method disclosed in Patent Document 1 is known as a fixing method in which a tip is not easily dropped in an excavation tool. In this method, an uneven shape is formed on the side surface of the base end portion of the chip, and welding is performed so as to cover the side surface.

  On the other hand, as a drilling tool made of a material containing diamond, there is a small bit (hereinafter referred to as “diamond bit”) made of a material containing diamond abrasive grains, which is used for a micro grinder or the like. Yes. However, these drilling tools are small as described above, and further, a material containing diamond abrasive grains is fixed to the surface near the tip of the base member by an electrodeposition method or a welding method. Therefore, there has been a problem that the drilling speed is remarkably reduced because the diamond abrasive grains fixed to the base member drop off and decrease as the diamond bit is used.

  In Patent Document 2, a non-diamond carbon material is placed in a pressure cell equipped with a means for indirectly heating, and heating and pressurization are performed, so that a diamond polycrystalline body can be directly converted without adding a sintering aid or a catalyst. And a polycrystalline diamond produced by the method are disclosed. Further, in Patent Document 2, the polycrystalline diamond produced by the above-described production method has no cleaving property like single crystal diamond and has stable strength and hardness with respect to loads in any direction. It describes that a material suitable for industrial use such as tools can be obtained.

  However, it is stable even in high-temperature environments, such as when deeply drilling the ground or the bottom of the sea floor using naturally produced diamonds or materials containing diamond polycrystals, or when the workpiece is hot. No drilling tool capable of drilling has been manufactured so far.

JP 2003-2108080 PR JP 2003-29297 A

  Stable drilling even in high-temperature environments, such as when drilling deeply on the ground or the bottom of the sea floor using diamonds produced naturally or materials containing diamond polycrystals, or when the workpiece is hot In order to configure a hole drilling instrument that can perform the drilling, it is necessary to have a configuration in which the protrusion does not fall off the hole drilling bit when the hole drilling instrument itself is heated to a high temperature. Therefore, there is a problem that it is not possible to use a generally used method of fitting a cemented carbide chip into a chip hole and brazing, or a shrink fitting method.

  Moreover, when using the method disclosed by patent document 1, it is necessary to provide a fine uneven | corrugated shape in the side surface of the projection part which consists of a material containing a diamond, and to weld so that this side surface may be covered. However, a material containing diamond is difficult to be processed into a concavo-convex shape and cannot be firmly fixed by welding because it is not a material suitable for welding. For this reason, when used at the tip of a drilling bit to which an impact force and a rotational force are applied, there is a problem in that a protrusion made of a material containing diamond may be detached in the drilling.

  In addition, for the purpose of drilling deep in the ground for investigation (for example, up to the mantle), the surrounding temperature rises every time the ground is dug, and the drilling tool itself due to long drilling. However, when drilling is continued, there is a problem that there is a depth and high temperature environment that cannot be dug by existing drilling tools. Further, when drilling a deep hole in the ground, there is a problem that it takes a very high cost to pull up the bit that has been dug deeply when exchanging the drill bit. Therefore, there is a problem that there is a demand for a drilling tool that can drill deeper than existing drilling tools and has good durability.

  The present invention has been made in consideration of such points. For example, when a projecting portion made of a material containing diamond is used to deeply drill the ground or the bottom of the seabed, or when the workpiece is hot. Drilling holes that can be stably drilled even in high-temperature environments such as, and that are firmly fixed so that the projections attached to the drilling bit do not fall off due to impact or rotation due to drilling The purpose is to provide equipment.

  The drilling tool of the present invention can be attached to a rod of an excavator, and can be attached to each of the recesses with a drilling bit provided with a plurality of recesses on the outer surface, provided with a hollow portion. A plurality of projecting portion fixing members, and a plurality of projecting portions that are inserted into the hollow portions provided in the projecting portion fixing members so that their tips protrude. Each protrusion fixing member is attached to each recess of the drill bit so as to protrude from the outer surface of the hole bit, and the material of each protrusion includes diamond.

  According to such a drilling device, the protrusion made of a material containing diamond having excellent durability is formed into the recess provided on the outer surface of the drill bit using the protrusion fixing member provided with the hollow portion. By attaching the protrusion so that the protrusion protrudes, the protrusion made of a material containing diamond that is difficult to process and is not suitable for welding and cannot be firmly fixed by welding is firmly fixed to the drill bit. be able to. Also, it does not use a brazing material with a low melting point for fixing, and is different from the shrink-fitting method using thermal expansion. For example, when deeply drilling the ground or the bottom of the seabed, or when the workpiece is hot Even in a high temperature environment, the protrusions do not fall off and stable drilling can be performed.

  In the drilling device of the present invention, each projection has a shape that changes continuously or discontinuously so that the size of the cross-sectional shape of the proximal end is larger than the size of the cross-sectional shape of the distal end. Each of the protrusion fixing members may have a shape such that the inner surface of the hollow portion into which the protrusion is inserted and the outer surface of the protrusion are in contact with each other in at least a partial region. .

  In the drilling device of the present invention, each of the protrusions may have an elliptical shape or a polygonal cross-sectional shape.

  In this case, the cross-sectional shape of each projection is elliptical, and each projection is fixed to each projection so that the direction in which the major axis of the elliptical shape extends and the circumferential direction of the drill bit substantially coincide. It may be attached to the drilling bit by a member for use.

  In the drilling tool of the present invention, each of the recesses and each of the protrusion fixing members is shaped such that each of the protrusion fixing members is screwed into each of the recesses. The protrusion fixing member may be attached to each of the recesses by screwing.

  In the drilling device of the present invention, the size of the cross-sectional shape of each of the recesses is substantially the same as the size of the cross-sectional shape of each of the protrusion fixing members, and each of the protrusion fixing members is You may attach by welding inside the recessed part.

  In the drilling device of the present invention, each protrusion may be provided with fine irregularities on the whole or a part of at least one of the bottom surface and the side surface.

  In the hole drilling tool of the present invention, the diamond as the material of each of the protrusions may be made of a diamond single-phase polycrystal.

  According to the drilling tool of the present invention, durability can be improved as compared with the conventional drilling tool by using a protrusion made of a material containing diamond, and the protrusion can be affected by heat or impact during excavation. The hole can be firmly fixed to the drill bit so as not to drop off, and therefore the hole can be stably drilled even in a high temperature environment.

It is a side view of the drill bit of the drill tool by embodiment of this invention. It is a top view for showing arrangement of the projection part attached to the drill bit shown in FIG. It is a longitudinal cross-sectional view by the AOA line arrow of the drill bit shown in FIG. It is the longitudinal cross-sectional view which expanded the part to which the projection part shown to the upper right of FIG. 3 was attached. It is a longitudinal cross-sectional view which shows the state which decomposed | disassembled for each member the part to which the projection part shown in FIG. 4 was attached. It is a longitudinal cross-sectional view which shows the other example of the mechanism which attaches the projection part in embodiment of this invention. It is a top view which shows the other example of arrangement | positioning of the projection part attached to the drill bit of the drilling instrument in embodiment of this invention. It is a longitudinal cross-sectional view which shows the state which decomposed | disassembled for each member further another example of the mechanism which attaches the projection part in embodiment of this invention. It is a longitudinal cross-sectional view which shows the state which attached the projection part using the mechanism which attaches the projection part which concerns on another example shown in FIG. It is a longitudinal cross-sectional view which shows an example of the high temperature / high pressure cell used for the method of manufacturing a diamond polycrystal. It is a front view which shows the modification of arrangement | positioning of the projection part attached to the drill bit shown in FIG. It is a front view which shows the other modification of arrangement | positioning of the projection part attached to the drill bit shown in FIG. FIG. 12 is a front view showing a configuration in a case where chamfering is further performed on a corner portion of a cross-sectional shape of the protrusion in the modified example of the arrangement of the protrusion attached to the drill bit shown in FIG. 11. It is a front view which shows the structure at the time of chamfering to the corner | angular part of the cross-sectional shape of the said projection part in the modification of arrangement | positioning of the projection part attached to the drill bit shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings. 1 to 7 are views showing a drilling device according to the present embodiment. Among these, FIG. 1 is a side view of a drill bit of a drilling tool according to an embodiment of the present invention, and FIG. 2 is a diagram for illustrating the arrangement of protrusions attached to the drill bit shown in FIG. It is a top view. FIG. 3 is a longitudinal sectional view of the drill bit shown in FIG. 2 taken along the line A-O-A. 4 is an enlarged vertical cross-sectional view of a portion where the protrusion shown in the upper right of FIG. 3 is attached, and FIG. 5 is a state where the portion where the protrusion shown in FIG. 4 is attached is disassembled for each member. FIG. FIG. 6 is a longitudinal sectional view showing another example of the mechanism for attaching the protrusion in the embodiment of the present invention, and FIG. 7 shows the protrusion attached to the drill bit of the hole drilling tool in the present embodiment. It is a top view which shows the other example of arrangement | positioning.

  The drilling device according to the present embodiment is a hollow cylindrical member pipe rod (not shown), and is detachably attached to the tip of the pipe rod, and a plurality of blades and other projections 22 on the tip side. Are provided. Here, the rear end of the pipe rod can be attached to the excavator, and when the pipe rod is attached to the excavator, the excavator applies a striking force and a rotational force to the pipe rod. . Details of the configuration of the drill bit 20 and the projection 22 of such a drilling tool will be described below.

  As shown in FIG. 3 and the like, the drill bit 20 has a hollow shape whose rear end face is open, and the outer peripheral surface on the rear end side of the drill bit 20 is on the tip side of the pipe rod. An attachment portion 28 such as a male screw portion that can be detachably attached to the attached portion such as a provided female screw portion is provided. Further, as shown in FIGS. 1 and 2, six hole-growing powder (cutting chips) discharge grooves 25 are provided on the side surface of the hole-cutting bit 20. As shown in FIG. 2, each discharge groove 25 has an arc shape.

  A plurality of recesses 24 having a substantially circular cross-sectional shape are provided on the outer surface (indicated by reference numerals 20a and 20b in FIG. 2) of the tip side of the drill bit 20, and an inner surface of each recess 24 will be described later. An attached portion 24a such as a female screw portion for enabling attachment of the protrusion fixing member 23 is formed. The depth of each recess 24 is such that when the bottom of each projection 22 comes into contact with the bottom surface of each recess 24, the projection 22 protrudes from the outer surface on the tip side of the drill bit 20. . As will be described later, by attaching the attachment portion 23a such as the male screw portion of each protrusion fixing member 23 to the attachment portion 24a such as the female screw portion of each recess 24, the bottom portion of each protrusion 22 becomes the respective recess 24. It is configured to be pressed and fixed to the bottom surface of. Surface processing and / or roughening treatment may be performed on the bottom surface of each recess 24 so that the surface has fine irregularities.

  Each protrusion fixing member 23 has a mounting portion 23a such as a male screw portion formed on the outer surface thereof, and a hollow portion provided therein. In the present embodiment, the cross-sectional shape of the hollow portion substantially matches the cross-sectional shape in the vicinity of the middle portion of each protrusion 22 in the vertical direction (vertical direction in FIG. 5). Further, the inner surface 23b of each protrusion fixing member 23 may be subjected to surface processing and / or roughening treatment so that the surface has fine irregularities.

  The thickness of each protrusion fixing member 23 is formed to be smaller than the depth of each recess 24, and the depth of each recess 24 is formed on the bottom surface of each recess 24 as described above. The size of the projection 22 protrudes from the outer surface of the drill bit 20 when the bottom part comes into contact. Thereby, it can attach so that the front-end | tip of each protrusion part 22 may protrude from the upper surface of each protrusion part fixing member 23. FIG.

  Each protrusion 22 is made of a material containing diamond (for example, a single diamond), and each protrusion 22 is pulled out from the protrusion fixing member 23 when inserted into each protrusion fixing member 23. It has no shape. In the present embodiment, each protrusion 22 has a small warhead shape in which the cross-sectional shape of the tip is small and the cross-sectional shape gradually increases in diameter toward the base end. In other words, the side surface 22 a of each protrusion 22 is inclined with respect to the direction orthogonal to the bottom surface of each recess 24. As described above, in the present embodiment, the cross-sectional shape of the hollow portion of the protrusion fixing member 23 is substantially the same as the cross-sectional shape in the vicinity of the middle portion of each protrusion 22 in the vertical direction (vertical direction in FIG. 5). Therefore, the cross-sectional shape of the hollow portion of the protrusion fixing member 23 is inclined so as to engage with the side surface 22a of each inclined protrusion 22. For this reason, the inclined side surface 22 a of each protrusion 22 is fitted to the inner surface 23 b of the hollow portion of each protrusion fixing member 23.

  As described above, the height of each protrusion 22 is such that the tip of each protrusion 22 protrudes beyond the outer surface of the drill bit 20 when the bottom of the protrusion 22 abuts against the bottom surface of each recess 24. It has become. As a result, the attachment portion 23a such as a male screw portion provided on the outer periphery of each protrusion fixing member 23 to which each protrusion 22 is fitted is attached to the inner surface of each recess 24 provided in the drill bit 20. When the protrusion fixing member 23 is fixed to the drill bit 20, the bottom of each protrusion 22 and the bottom surface of each recess 24 are fixed to each other. It comes to be pressed and fixed.

  Further, at least one of the side surface 22a and the bottom of each protrusion 22 has a surface processing or roughening treatment (for example, blasting) so that the entire surface or a part of the surface thereof has fine irregularities, Or both. As a result, the side surface 22a of each projection portion 22 and the inner side surface 23b of the hollow portion of each projection portion fixing member 23 are compared with the projection portions 22 each having a smooth side surface 22a made of a conventional cemented carbide or the like. And the frictional force acting between the bottom of each protrusion 22 and the bottom of each recess 24 increases. Therefore, the rotation of each projection 22 attached to the drilling bit 20 due to impact force or rotational force at the time of drilling (that is, each axis centered on the axis passing through the tip and the center of the bottom of each projection 22) The rotation of the protrusions 22 is suppressed, and the protrusions 22 can be made difficult to drop off from the protrusion fixing members 23. Further, the effect of preventing the rotation and dropping of each projection 22 is the contact between the region having fine irregularities on the side surface 22a of each projection 22 and the inner side surface 23b of the hollow portion of each projection fixing member 23. The larger the contact area between the area and the area having the fine irregularities at the bottom of each protrusion 22 and the bottom surface of each recess 24, the higher the effect. It is preferable to provide fine irregularities in a wider area of the side surface 22a and the bottom of the protrusion 22.

  In addition to the effect obtained by providing fine irregularities in at least a part of the surface of each protrusion 22 as described above, the cross-sectional shape of each protrusion 22 is made elliptical as described above. Further, the performance of the drilling tool using each projection 22 can be further improved. More specifically, when the cross-sectional shape of each projection 22 is a perfect circle, the frictional force acting between the side surface 22a of each projection 22 and the inner side surface 23b of the hollow portion of the projection fixing member 23. In addition, each protrusion 22 is prevented from rotating and dropping by the pressing force and the frictional force and pressing force acting between the bottom of each protrusion 22 and the bottom surface of the recess 24. In the case where the cross-sectional shape of 22 is an elliptical shape, in addition to the frictional force and pressing force acting in the case of a perfect circle shape, when each projection 22 and each projection fixing member 23 are fitted, A force (hereinafter referred to as “cross-section”) that prevents the protrusions 22 from rotating due to a geometric shape in which each protrusion 22 cannot freely rotate with respect to each protrusion fixing member 23. The rotation of each protrusion 22 is prevented by the shape of Is called a power ".) It is possible to further suppress to rotate and fall off of the protrusions 22 utilized.

  In addition to the frictional force and the pressing force, in order to obtain the combined effect of preventing the rotation and dropping of each protrusion 22 using the force that prevents the rotation of each protrusion 22 depending on the shape of the cross section. The cross-sectional shape of each protrusion 22 is not necessarily an elliptical shape. Even if the cross-sectional shape of each protrusion 22 is a shape other than a circular shape, for example, a polygonal shape such as a square shape or a hexagonal shape, or a star shape, the cross-sectional shape of each protrusion 22 and this cross-sectional shape When each projection fixing member 23 having a hollow portion formed so as to substantially coincide with each other is fitted, the sectional shape of each projection 22 becomes the sectional shape of the hollow portion of each projection fixing member 23. It is only necessary to have a geometric shape that cannot be freely rotated.

  Further, when the cross-sectional shape of each protrusion 22 does not have a corner like a polygon or the like, and the cross-sectional shape is composed of a smooth curve such as an ellipse, each protrusion 22 is a polygon. Since there is no portion that easily wears due to impact force or rotational force at the time of drilling such as a corner in the shape, the rotation and dropping of each protrusion 22 can be further prevented.

  Further, a discharge hole 26 for discharging high-pressure air or high-pressure air and water supplied from a pipe rod attached to the rear end of the drill bit 20 is provided on the front end surface 20a of the drill bit 20. Yes.

  Further, the pipe rod is attached to the excavator. When the excavator applies a striking force and a rotational force to the pipe rod, the drill bit 20 attached to the tip of the pipe rod causes a hole in the ground. Is to be excavated.

  In addition, as in another example of a mechanism for attaching each protrusion 22 as shown in FIG. 6, an attachment portion such as a screw portion or attached portion is attached to the inner surface of each recess 24 and the outer surface of each protrusion fixing member 23. No protrusions may be formed, and each protrusion fixing member 23 may be attached to each recess 24 by welding (the welding location is indicated by reference numeral 23c in FIG. 6). In this case, in order to weld the outer surface of each protrusion fixing member 23 and the inner surface of each recess 24 without transferring heat generated during welding to each protrusion 22, each recess 24. Further, it is preferable that the size of the cross-sectional shape of each protrusion fixing member 23 is larger than that in the case of attaching with a screw or the like.

  In addition, when each projection fixing member 23 is attached to each recess 24 by welding by using another example of a mechanism for attaching the projection 22 as shown in FIG. Each projection fixing member 23 may be fixed to each recess 24 by welding once along the circumference where the side surface and the inner side surface of each recess 24 come into contact with each other. Each protrusion fixing member 23 may be fixed to each concave portion 24 by welding several portions on the circumference where the side surface contacts the inner side surface of each concave portion 24.

  In addition, when the cross-sectional shape of each protrusion part 22 is not a perfect circle shape (for example, when it is an elliptical shape), each protrusion part 22 is attached to the drill bit 20 by arrangement | positioning as shown in FIG. Specifically, it is attached so that the direction in which the long axis of the elliptical shape that is the cross-sectional shape of each protrusion 22 extends and the circumferential direction of the drill bit 20 substantially coincide. Thereby, for example, the drilling performance can be improved as compared with the case where the direction in which the long axis of the elliptical shape extends and the radial direction of the drill bit 20 are substantially matched.

The diamond used in the drilling tool of the present invention is a polycrystalline body composed of diamond obtained by conversion and sintering from a carbon material having a graphite-type layer structure under an ultrahigh pressure and high temperature without adding a sintering aid or a catalyst. A polycrystalline diamond having an average particle diameter of 100 nm or less and a purity of 99% or more may be used. In this case, the polycrystalline diamond has an average particle diameter of 20 nm or less, a hardness of 70 GPa or more, and (111) of (220) diffraction intensity (I ₍₂₂₀₎ ) of X-ray diffraction in an arbitrary direction of the polycrystalline body. ) The ratio I ₍₂₂₀₎ / I ₍₁₁₁₎ to the diffraction intensity (I ₍₁₁₁₎ ) may be 0.1 or more.

An example of the method for producing the polycrystalline diamond will be described with reference to a longitudinal sectional view of a high-temperature and high-pressure cell used in the method for producing the polycrystalline diamond shown in FIG. The outside of the high-temperature and high-pressure cell is a container made of lanthanum chromite (LaCrO ₃ ), and the sample 61 is accommodated inside. In this example, two samples 61 can be set in a high-temperature high-pressure cell. This sample 61 is made of non-diamond carbon, for example, graphite, which is a raw material for diamond, in a predetermined shape. The shape of the sample 61 is almost the same as that of the synthesized polycrystalline body. Here, graphite is formed in a cylindrical shape, and FIG. 10 shows a cross section cut in half along the axis of the cylinder. Around the sample 61, a powder 62 of sodium chloride, which is an alkali halide substance, is disposed, and the periphery thereof is wrapped with magnesium oxide 63 (MgO). Furthermore, a heater 64 made of rhenium (Re) is provided outside the layer of magnesium oxide 63, and a heat insulating material 65 made of zirconia (ZrO ₂ ) is provided outside the heater 64. By causing an electric current to flow through a heater made of a refractory metal such as rhenium to generate heat, the sample 61 is effectively and stably heated while being indirectly heated. Further, since sodium chloride powder 62, which is an alkali halide material that is stable even at high temperatures, is disposed between the sample 61 and the heater 64, the sample 61 or the produced diamond polycrystal is insulated from the heater 64. At the same time, the surface is protected even during pressurization. Electrodes 66 made of molybdenum (Mo) are provided above and below the high-temperature and high-pressure cell, and electric power for heating the heater 64 is supplied from the outside. A pressure medium 67 of magnesium oxide or cobalt oxide is provided around the heat insulating material 65, and a pressure medium 68 of lanthanum chromite (LaCrO ₃ ) is provided above and below the electrode 66, respectively. A tungsten-rhenium thermocouple 69 for measuring the temperature of the sample 61 is provided almost at the center of the high-temperature and high-pressure cell. As shown in FIG. 10, a sample 61 and various pressure media are loaded, and this high-temperature high-pressure cell is put into a multi-anvil pressurizing device and pressurized. The load applied by the pressurizing device is applied to the sample as almost hydrostatic pressure through the pressure medium of the high-temperature and high-pressure cell. At the same time, the sample 61 is heated by supplying power to the heater 64 through the electrode 66. The pressure applied to the sample can be obtained from the load applied by a pressurizing device output from a load cell or the like, the angle and area of the pressing surface, and the temperature of the sample 61 can be grasped by a thermocouple 69 provided nearby. The sample 61 is synthesized into a polycrystal by holding at a predetermined temperature and pressure for a certain period of time. After the synthesis, for example, maintaining the temperature at about 600 ° C. and reducing the pressure is particularly effective for obtaining a high-quality sintered body.

  The above-described method for producing a diamond polycrystalline body synthesizes a polycrystalline body having a high purity from a raw material having a high purity without adding a catalyst or a sintering aid, so that a polycrystalline body having high transparency and excellent physical properties can be obtained. The effect is obtained. In addition, the polycrystalline diamond obtained by this manufacturing method is an extremely well-sintered polycrystalline sintered body, which is not cleaved like single crystal diamond and has a stable strength against any load in any direction. -It has a hardness.

  According to the drilling tool of the present embodiment configured as described above, each projection 22 is made of a material containing diamond, and each projection 22 has a cross-sectional shape of the hollow portion of each projection. The projection fixing member 23 is fitted to each recess 24 provided in the drill bit 20, and is fitted to each projection fixing member 23 that substantially coincides with the intermediate portion in the vertical direction of the portion 22. . As described above, heat is not used for fixing each protrusion 22 and it is mechanically firmly fixed. For example, when deeply drilling the ground or the sea floor, Even in a high temperature environment such as a high temperature, each protrusion 22 does not fall out of the drill bit 20 and stable drilling can be performed.

  In addition, the hole drilling instrument by this Embodiment is not limited to the aspect as mentioned above, A various change can be added.

  As in the modification shown in FIG. 11, when the cross-sectional shape of each protrusion 22 is a quadrangular shape, the extending direction of the diagonal line of the quadrilateral shape and the circumferential direction of the drill bit 20 are substantially the same. Each protrusion 22 is attached to the drill bit 20. This can improve the hole drilling performance of the hole drilling tool.

  In addition, when the cross-sectional shape of each protrusion 22 is a hexagonal shape as in another modification shown in FIG. 12, the diagonal line having the longest length among the plurality of diagonal lines of the hexagonal shape is Each protrusion 22 is attached to the drill bit 20 so that the extending direction and the circumferential direction of the drill bit 20 substantially coincide. As a result, for example, among the plurality of hexagonal diagonal lines, the drilling performance is improved as compared with the case where the longest diagonal line extends and the radial direction of the drill bit 20 substantially coincides with each other. Can be made.

  The arrangement of the projections 22 when attaching the projections 22 to the drill bit 20 is not necessarily limited to the above-described example, and the most or relatively sharp portion (in the cross-sectional shape of each projection 22 ( For example, what is necessary is just to attach each protrusion part 22 so that the direction to which the four corners are facing and the circumferential direction of the drill bit 20 may coincide with each other. In this case as well, the drilling performance can be improved as compared with the case where the direction in which the most or relatively sharp part is facing and the direction perpendicular to the circumferential direction of the drill bit 20 are substantially matched. Can do.

  Furthermore, as shown in FIGS. 11 and 12, the cross-sectional shape of each protrusion 22 and each protrusion fixing member 23 is easily worn due to impact force or rotational force during drilling, such as a corner portion. 13 and FIG. 14, each protrusion is formed by chamfering a curved portion such as a corner, which is easily worn, and curving the portion to prevent wear. The rotation and dropping of 22 can be further prevented.

  In the present embodiment, the end of the bottom surface of each protrusion fixing member 23 has substantially the same height as the end of each recess 24, but may protrude slightly or be dented. In this case, the hole drilling device is excellent in aesthetics, and the early wear of each protrusion fixing member 23 is unlikely to occur.

  Moreover, the thread part provided in each protrusion part fixing member 23 may be comprised from the multiple thread | screw. In this case, each protrusion fixing member 23 can be separated from the drill bit 20 with a small number of rotations. In addition, since the allowable stress is increased due to the multi-thread structure of the screw, it is possible to enhance the durability of each protrusion fixing member 23 to which a strong impact or the like is given during drilling.

  Further, each protrusion fixing member 23 is screwed into a mounting portion 24a such as a female screw portion provided on the inner side surface of each recess 24, so that a tool such as a spanner is applied to the bottom surface thereof. You may provide engaging means, such as a wrench flat and a pin hole for engagement. This facilitates screwing and detachment of each protrusion fixing member 23, and can improve the convenience of the drilling tool.

  Moreover, the side surface 22a of each protrusion part 22 and the inner surface 23b of the hollow part of each protrusion part fixing member 23 do not need to have an inclined side surface over the whole. Instead, for example, as shown in FIGS. 8 and 9, a flange 22 b may be provided at the base end of each protrusion 22. Also in this case, by using each protrusion fixing member 23 that matches the shape of each protrusion 22, the bottom of the flange 22 b can be pressed and fixed to the bottom of each recess 24.

20 Drilling bit 20a Tip surface 20b Inclined surface 22 Protruding portion 22a Side surface 22b Flange portion 23 Protruding portion fixing member 23a Mounting portion 23b Inner side surface 23c Welding portion 24 Recessed portion 24a Mounted portion 25 Discharge groove 26 Discharge hole 28 Mounting portion 61 Sample 62 Sodium chloride powder 63 Magnesium oxide 64 Heater 65 Heat insulating material 66 Electrodes 67, 68 Pressure medium 69 Thermocouple

Claims (8)

A drilling bit that can be attached to a rod of an excavator and has a plurality of recesses on the outer surface;
A plurality of protrusion fixing members that are attachable to each of the recesses and provided with a hollow portion;
A plurality of protrusions that are inserted into the hollow portions provided in the protrusion fixing members, so that their tips protrude;
With
The protrusion fixing members are attached to the recesses of the drill bit so that the protrusions protrude from the outer surface of the drill bit, and the material of the protrusion includes diamond. Drilling equipment.   Each of the protrusions has a shape that changes continuously or discontinuously so that the size of the cross-sectional shape of the base end is larger than the size of the cross-sectional shape of the tip. The hole drilling device according to claim 1, wherein the inner surface of the hollow portion into which each projection is inserted and the outer surface of each projection are in contact with each other in at least a partial region.   The drilling tool according to claim 1 or 2, wherein each of the protrusions has an elliptical shape or a polygonal cross-sectional shape.   The cross-sectional shape of each of the protrusions is elliptical, and each of the protrusions is cut by the protrusion fixing member so that the direction in which the major axis of the elliptical shape extends and the circumferential direction of the drill bit substantially coincide. The drilling tool according to claim 3, wherein the drill bit is attached to a hole bit.   Each of the recesses and each of the protrusion fixing members are shaped such that each of the protrusion fixing members is screwed into each of the recesses, and each of the protrusion fixing members is screwed. The drilling device according to any one of claims 1 to 4, wherein the drilling device is attached to each of the recesses.   The size of the cross-sectional shape of each of the recesses is substantially the same as the size of the cross-sectional shape of each of the protrusion fixing members, and each of the protrusion fixing members is attached to the inside of each of the recesses by welding. The drilling tool according to any one of claims 1 to 4.   Each of the projections is provided with fine irregularities on at least one of the bottom surface and the side surface of the whole or a part of the region. Hole instrument.   The drilling tool according to any one of claims 1 to 7, wherein diamond as a material of each of the protrusions is made of a single-phase polycrystalline diamond.

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