JP7108349B1 - drill bit - Google Patents

Abstract

A tip side drilling portion (12) is provided in an outer peripheral end region (12a), and a surface of a surface layer (12b) is provided in the outer peripheral end region (12a). The drilling member 12 is tilted at a first tilt angle α in a direction opposite to the rotational direction of the drill bit body 10 with respect to a perpendicular line P1 perpendicular to the plane F1. The cylindrical side drilling portion 13 is provided in the upper end region 13a, and the surface of the surface layer 13b is inclined at a second angle of inclination in the direction opposite to the rotation direction of the drill bit body with respect to a perpendicular line perpendicular to the surface of the upper end region. It consists of a digging member 13 inclined at β. The surface layer 13b of the drilling member of the cylindrical side drilling portion is provided in the vicinity of the surface layer 12b of the drilling member of the tip side drilling portion, and the tip of the surface layer 13b of the drilling member of the cylindrical side drilling portion is located on the drill bit body 10. In a plan view of the head portion 10a, the head portion 10a protrudes outward by a predetermined distance from the tip of the surface layer 12b of the excavating member of the tip side excavating portion. [Selection drawing] Fig. 2

Description

The present invention relates to drill bits.

2. Description of the Related Art Conventionally, in order to efficiently excavate hard rock such as granite on the seabed, there is a technique in which the arrangement of cutting members of a drill bit is devised.

US Pat. No. 4,098,362 discloses a rotary rock drill bit that includes a plurality of cutting elements or cutters attached to the crown of the drill bit. In this rotary rock drill bit, each cutting element includes a thin planar layer of polycrystalline diamond bonded to the crown of the bit at a rake angle of between -10 and -25 degrees. Also, in another embodiment, each cutting element is coupled to an elongated pin attached to one end of the drill crown and to the free end of the pin such that it is positioned at a rake angle of between -10 degrees and -25 degrees. and a thin layer of polycrystalline diamond. This minimizes the specific energy required to drill rocks such as Carthaginian marble and Valle granite.

Also, Japanese Patent Application Laid-Open No. 10-6228 (Patent Document 2) discloses an improved abrasive cutting element and drill bit. The abrasive cutting element of the drill bit includes an abrasive cutting layer and a metal substrate having a tangential chamfer at the interface therebetween, the plane of the tangential chamfer being about the plane of the surface of the cylindrical portion of the metal substrate. It forms an angle of 5 degrees to about 85 degrees. This is said to minimize the susceptibility of the diamond layer to fracture and spalling due to internal residual stresses in the abrasive cutting element.

Further, Japanese National Publication of International Patent Application No. 2001-515164 (Patent Document 3) discloses a drill bit partially reinforced with diamond. The drill bit comprises a bit body, at least one annular array of non-diamond reinforced buttons mounted on the bit body, and at least one annular array of diamond reinforced buttons mounted on the bit body radially outward of the unreinforced buttons. including. The total wear volume of the unreinforced buttons in at least one row of unreinforced buttons is greater than 75 percent of the total wear volume of the outermost annular row of reinforced buttons, and the number of unreinforced buttons in one of the rows of unreinforced buttons is , at least equal to the number of enhancement buttons in the outermost circular row of enhancement buttons. At least some of the unreinforced buttons have a greater wear volume than any of the reinforced buttons, and the radially outermost row of unreinforced buttons is axially forwardly displaced with respect to the adjacent row of reinforced buttons. This allows a significant amount of unreinforced button wear to occur before the unreinforced button needs to be remolded, thereby providing significant savings in time and money.

U.S. Pat. No. 4,098,362 JP-A-10-6228 Japanese Patent Publication No. 2001-515164

The drilling elements of drill bits used for drilling in the seabed or underground are usually provided with a thin planar layer of, for example, diamond, so that they can drill even in hard rock. The planar layer of the drilling member is easily worn or fractured due to continuous strong impacts from hard rock caused by the rotation of the drill bit. On the other hand, since the planar layer of the drilling member is composed of at least diamond as a raw material, the unit price of the drilling member is high. Connect. Therefore, there was a problem in extending the life of the drill bit.

Here, in the technique described in Patent Document 1, although it is possible to minimize the specific energy related to the impact depending on the angle of the cutting element, the cooperation of each cutting element improves the drilling efficiency of the entire drill bit. There is no description about extending the life of the drill bit.

Further, in the technique described in Patent Document 2, although hemispherical abrasive cutting elements are provided on the side surface of the head of the drill bit, there is no description of the cooperation of each abrasive cutting element.

Furthermore, in the technique described in Patent Document 3, the combination of the annular row of unreinforced buttons and the annular row of reinforced buttons promotes wear of the unreinforced buttons before they need to be remolded. , there is no description about cooperation of buttons for each position.

Accordingly, the present invention has been made to solve the above-mentioned problems, and by clarifying the excavation role of the excavating member at each position and dispersing the excavation load, the excavation efficiency of the drill bit as a whole is improved and the drill bit is improved. It is an object of the present invention to provide a drill bit capable of extending the life of a drill bit.

A drill bit according to the present invention includes a drill bit body, a plurality of drilling members, a tip side drilling section, and a cylindrical side drilling section. The drill bit body has a longitudinal axis of rotation and is cylindrical. The drilling member is provided on the head of the drill bit body and has a face layer as a drilling edge. The tip-side drilling portion is provided in the outer peripheral end region of the tip plane of the head of the drill bit body, and the surface of the surface layer is aligned with a perpendicular line perpendicular to the surface of the outer peripheral end region. It consists of a drilling member inclined at a first angle of inclination within a range of 20 degrees to 50 degrees in a direction opposite to the direction of rotation of the drill bit body, and the side surface of the drilling member is covered and fixed. The cylindrical side drilling portion is provided in the upper end region of the cylindrical side surface of the head of the drill bit body, and the surface of the surface layer is aligned with the perpendicular line perpendicular to the surface of the upper end region of the drill bit. The excavating member is inclined at a second inclination angle within the range of 60 degrees to 90 degrees in the direction opposite to the rotation direction of the main body, and the side surface of the excavating member is covered and fixed to the excavating member. A surface layer is provided in the vicinity of the surface layer of the drilling member of the tip-side excavation section, and the tip of the surface layer of the drilling member is positioned to excavate the tip-side excavation section in a plan view of the head of the drill bit body. It protrudes outside by a predetermined distance from the tip of the surface layer of the member.

According to the present invention, by clarifying the excavation role of the excavating member at each position and distributing the excavation load, it is possible to improve the excavation efficiency of the entire drill bit and extend the life of the drill bit.

They are a side view perspective view (FIG. 1A) and a plan view perspective view (FIG. 1B) showing an example of a drill bit according to a first embodiment of the present invention. FIG. 4 is a side view showing an example of the positional relationship between the excavating member of the distal end side excavating portion and the excavating member of the cylindrical side excavating portion of the drill bit according to the first embodiment of the present invention; FIG. 3 is a plan view showing an example of the positional relationship between the excavating member of the distal end side excavating portion and the excavating member of the cylindrical side excavating portion of the drill bit according to the first embodiment of the present invention. A side view ( FIG. 4A ) showing an example of excavation by the excavating member of the tip side excavating portion in the drill bit according to the first embodiment of the present invention, and a side view ( FIG. 4A ) showing an example of excavating by the excavating member of the cylindrical side excavating portion ( FIG. 4B) and . FIG. 5A is a plan view (FIG. 5A) and a cross-sectional view (FIG. 5B) shows an example of a drill bit (sloping shoulder type drill bit) according to a second embodiment of the present invention. FIG. 6A is a plan view (FIG. 6A) and a cross-sectional view (FIG. 6B) shows an example of a drill bit (anchored shoulder type drill bit) according to a second embodiment of the present invention. 3 is a perspective photograph, a plane photograph, and a side photograph showing an example of Example 1-2 and Comparative Example 1. FIG. FIG. 8A shows an impulse evaluation result for each rotation speed in Example 1-2, and an energy evaluation result for each rotation speed in Example 1-2 (FIG. 8B). 2 is a photograph of a drilled hole in rock after drilling in Example 2. FIG. It is a perspective photograph, a plane photograph, and a side photograph showing an example of Example 2-4. Impulse evaluation results for each first tilt angle in Example 1-4 (FIG. 11A), and energy evaluation results for each first tilt angle in Example 1-4 (FIG. 11B). be. FIG. 12A is a perspective view (FIG. 12A) and a plan view (FIG. 12B) of Example 5. FIG. FIG. 13A is a perspective view (FIG. 13A) and a plan view (FIG. 13B) of Example 6. FIG. FIG. 14A is a rear perspective view of a prototype of Example 5-6, and a front view (FIG. 14B) showing an excavation test of Example 5-6. It is an evaluation result of the excavation speed for each rotation speed in Example 5-6.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention. It should be noted that the following embodiment is an example that embodies the present invention, and is not intended to limit the technical scope of the present invention.

<First embodiment of the present invention>
A drill bit 1 according to a first embodiment of the present invention comprises a drill bit body 10 and a plurality of drilling members 11, as shown in FIGS.

The drill bit body 10 has a longitudinal axis of rotation and is cylindrical. The drilling member 11 is provided on the head portion 10a of the drill bit body 10 and has a surface layer as a drilling edge. Here, the structure of the surface layer is not particularly limited, and examples thereof include a flat layer, a curved surface layer, a semicircular surface layer, and the like.

Moreover, the plurality of excavating members 11 includes a tip-side excavating portion 12 and a cylindrical-side excavating portion 13 . The tip-side drilling portion 12 is provided in the outer peripheral end region 12a of the tip plane of the head portion 10a of the drill bit body 10, and the surface of the surface layer 12b is perpendicular to the plane F1 of the outer peripheral end region 12a. , the excavation member 12 is inclined at a first inclination angle α in the range of 20 degrees to 50 degrees in the direction opposite to the rotation direction of the drill bit body 10, and the side surface of the excavation member is covered and fixed.

Here, the surface layer 12b of the excavating member 12 of the tip-side excavating portion 12 is configured as a planar layer. Further, the outer peripheral end region 12a means an end region near the outer periphery of the tip plane of the head 10a of the drill bit body 10. As shown in FIG. The surface F1 of the outer peripheral end region 12a includes a tangential plane forming a tangent line at a predetermined position (point) on the outer peripheral end region 12a in the vicinity of the surface layer 12b of the tip end side excavation portion 12 . In FIG. 2, in the vicinity of the surface layer 12b of the tip-side excavation portion 12, since the outer peripheral end region 12a is a flat surface, the surface F1 is a plane of the outer peripheral end region 12a. When 12a is a curved surface, the surface F1 becomes a tangential plane forming a tangent line at a predetermined position on the outer peripheral end region 12a in the vicinity of the planar layer 12b of the tip side excavation portion 12. Also, the tip side excavating section 12 is composed of three excavating members 12 .

Further, the cylindrical side drilling portion 13 is provided in the upper end region 13a of the cylindrical side surface of the head portion 10a of the drill bit body 10, and the surface of the surface layer 13b is aligned with the perpendicular line P2 perpendicular to the plane F2 of the upper end region 13a. , the drilling member 13 is inclined at a second inclination angle β within the range of 60 to 90 degrees in the direction opposite to the rotational direction of the drill bit body 10 .

Here, the surface layer 13b of the excavating member 13 of the cylindrical side excavating portion 13 is configured as a plane layer. The upper end region 13a means an upper end region of the cylindrical side surface of the head 10a of the drill bit body 10 near the outer periphery. The surface F2 of the upper end region 13a includes a tangent plane forming a tangent line at a predetermined position (point) on the upper end region 13a in the vicinity of the surface layer 13b of the cylindrical side excavation 13, as described above. In FIG. 3, since the upper end region 13a is flat, its surface F2 is the plane of the upper end region 13a. In the vicinity of the plane layer 13b of the portion 13, it becomes a tangent plane forming a tangent line at a predetermined position on the upper end region 13a. The cylindrical side excavating section 13 is composed of three excavating members 13 corresponding to the three excavating members 12 of the distal end side excavating section 12, and the side surfaces of the excavating members are covered and fixed.

Further, the plane layer 13b of the excavating member 13 of the cylindrical side excavating section 13 is provided in the vicinity of the plane layer 12b of the excavating member 12 of the tip side excavating section 12, and the plane layer 13b of the excavating member 13 of the cylindrical side excavating section 13 The tip 13b1 (cutting edge) of the head 10a of the drill bit body 10 is projected outward by a predetermined distance d from the tip 12b1 (cutting edge) of the flat layer 12b of the excavating member 12 of the tip-side excavating portion 12 in plan view. ing. Here, a plan view means a surface seen from a direction opposite to the direction in which the head portion 10a of the drill bit body 10 advances.

Further, the fact that the plane layer 13b of the excavating member 13 of the cylindrical side excavating section 13 is provided in the vicinity of the plane layer 12b of the excavating member 12 of the distal end side excavating section 12 means that the plane layer of the excavating member 13 of the cylindrical side excavating section 13 is 13b exists within a predetermined distance from the plane layer 12b of the excavating member 12 of the distal end side excavating portion 12. For example, in FIG. The layer 13b is located at a position opposite to the rotational direction of the drill bit body 10 with respect to the planar layer 12b of the drilling member 12 of the tip-side drilling section 12, and extends from the plane of the head 10a of the drill bit body 10 to the side surface. It is provided at an oblique position. As a result, by clarifying the excavation role of the excavating member 11 at each position and distributing the excavation load, it is possible to improve the excavation efficiency of the drill bit 1 as a whole and extend the life of the drill bit 1.

That is, when the head portion 10a of the drill bit 10 is rotated and collided with the rock R (hard rock), the flat layer 12b of the drilling member 12 of the tip-side drilling portion 12 is first crushed by the rock R as shown in FIG. 4A. , destroying the rock R and starting excavation. That is, the tip 12b1 of the flat layer 12b of the excavating member 12 of the tip-side excavating portion 12 collides with the rock R, and excavation is performed up to the trajectory of the tip 12b1 of the flat layer 12b of the excavating member 12 of the tip-side excavating portion 12. The excavation of the excavating member 12 of the distal excavating portion 12 corresponds to crushing excavation.

Here, in the flat layer 12b of the excavating member 12 of the distal end side excavating portion 12, the first inclination angle α is within the range of 20 degrees to 50 degrees, so that the rock R is efficiently excavated and excavated. It is possible to reduce the excavation burden on the planar layer 12b of the member 12. Further, it is more preferable that the first inclination angle α is within the range of 20 degrees to 45 degrees.

Now, as the excavation of the flat layer 12b of the excavating member 12 of the distal end side excavating portion 12 progresses, the cylindrical side excavating portion is located in the vicinity of the lower portion of the planar layer 12b of the excavating member 12 of the distal end side excavating portion 12 (near the upper portion in FIG. 4A). The flat layer 13b of the excavating member 13 of 13 is provided, and the tip 13b1 of the flat layer 13b of the excavating member 13 of the cylindrical side excavating portion 13 is the tip of the flat layer 12b of the excavating member 12 of the tip side digging portion 12. 4B, the flat layer 13b of the excavating member 13 of the cylindrical side excavating portion 13 starts excavating the side surface of the excavated portion of the rock R. .

In other words, when the excavating member 12 of the tip-side excavating portion 12 excavates to some extent, the excavating member 13 of the cylindrical-side excavating portion 13 excavates the side face R2 of the excavating portion R1 excavated by the excavating member 12 of the tip-side excavating portion 12. It will be. Here, since the tip 13b1 of the flat layer 13b of the excavating member 13 of the cylindrical side excavating portion 13 starts colliding with the side surface R2 of the excavating portion R1, the tip 13b1 of the flat layer 13b of the excavating member 13 of the cylindrical side excavating portion 13 Further excavation is performed to the trajectory of

Here, in the flat layer 13b of the excavating member 13 of the cylindrical side excavating portion 13, the second inclination angle β is within the range of 60 degrees to 90 degrees, so that the rock R is efficiently excavated and excavated. It is possible to reduce the excavation burden on the planar layer 13b of the member 13. When the second inclination angle β is 90 degrees, for example, the excavating member 13 of the cylindrical side excavating portion 13 corresponds to a dome-shaped button bit (button chip bit). In this case, as shown in FIG. 3, the uppermost surface of the surfaces of the curved layer 13b of the button bit is located at a predetermined position above the upper end region 13a (here Then, the tangential plane F2 constitutes the tangential line at the bottom), and is inclined at 90 degrees in the direction opposite to the direction of rotation of the drill bit body 10 with respect to the perpendicular line P2 perpendicular to the tangential plane F2.

Now, conventionally, in a normal drill bit, for example, the drilling member 12 of the tip side drilling section 12 is configured to drill even the drilling portion R1 of the rock R and its side face R2. The excavation load on the excavating member 12 of the excavating part 12 increases, causing wear and crushing of the planar layer 12b of the excavating member 12 .

In the present invention, the excavating member 12 of the tip side excavating section 12 is in charge of excavating the first excavating portion R1 of the rock R, and then the excavating member 13 of the cylindrical side excavating portion 13 is in charge of excavating the excavated portion R1 of the rock R. He is in charge of excavating the side surface R2. Thus, the excavating role of the excavating members at each position of the excavating member 12 in the outer peripheral end region 12a on the tip plane of the head 10a of the drill bit body 10 and the excavating member 13 in the upper end region 13a on the cylindrical side surface of the head 10a. can be clarified to disperse the excavation load. As a result, concentration of the drilling load on the drilling member at a specific position can be avoided, and the drilling efficiency of the entire drill bit 1 can be improved and the life of the drill bit 1 can be extended. With such a configuration, the drilling speed of the drill bit 1 as a whole is improved with respect to a constant thrust (N) (kgf), which contributes to shortening the drilling time at the site.

In addition, since the side surface R2 of the excavated portion R1 of the rock R is intensively excavated by the excavating member 13 of the cylindrical excavating portion 13, the side surface R2 of the excavated portion R1 with respect to the side surface of the head portion 10a of the drill bit body 10 Therefore, even if the head 10 of the drill bit 1 continues to rotate during drilling, the outer peripheral side surface of the head 10 does not shake. As a result, the excavated portion R1 of the rock R can be formed neatly.

Further, the excavating members 12 and 13 of the distal end side excavating portion 12 and the cylindrical side excavating portion 13 are fixed so as to cover the side surfaces thereof. For example, this corresponds to providing a recessed pedestal (groove) (hollow) in which the excavating members 12 and 13 of the tip-side excavating portion 12 and the cylindrical-side excavating portion 13 are fitted. As a result, even if the head 10a of the drill bit body 10 rotates and the flat layers 12b, 13b of the drilling members 12, 13 strongly collide with the rock R, the side surfaces of the drilling members 12, 13 are covered and fixed. As a result, the fixing strength of the excavating members 12 and 13 to the rock R can be maintained, and the dropping of the excavating members 12 and 13 can be reliably prevented.

Here, the configuration of the drill bit body 10 is not particularly limited, but for example, as shown in FIGS. Holes 10b and discharge grooves 10c may be provided as appropriate.

The construction of the excavating members 11, 12, and 13 is not particularly limited, but for example, a cylindrical construction having a flat layer can be mentioned. can be mentioned. The plane layer is composed of, for example, cemented carbide or wear-resistant material in addition to polycrystalline diamond.

Further, the number of drilling members 11, 12, and 13 is not particularly limited, and can be appropriately changed according to the size of the drill bit body 10 and the object to be drilled. Of course, in addition to the excavating members 12 and 13 of the distal end side excavating portion 12 and the cylindrical side excavating portion 13, another excavating member 11 may be appropriately arranged.

There are no particular restrictions on how the excavating members 11, 12, and 13 are fixed. For example, when the excavating members 11, 12, and 13 are cylindrical, a cylindrical pedestal to which the cylinder can be attached is provided on the drill bit. By being provided on the head portion 10a of the main body 10, the side surfaces of the excavating members 11, 12, 13 can be covered and fixed.

By the way, regarding the fixing method of the excavating members 11, 12, 13, as shown in FIG. It is preferable that the sides of the excavating members 11, 12, 13 are covered and fixed by brazing the excavating members 11, 12, 13 from their side surfaces to their bottom surfaces to the recessed pedestal 10d. As a result, the drilling members 11, 12 and 13 can be firmly fixed to the drill bit body 10. As shown in FIG.

Here, the dimension r1 of the recess of the pedestal 10d is not particularly limited, but for example, it is longer than the diameter dimension r2 of the excavating members 11, 12, 13 by a predetermined length (eg, 0.1 mm to 0.5 mm). After filling the recesses of the pedestal 10d with wax, the bottom surfaces of the excavating members 11, 12, and 13 are pushed in to fill the excavating members 11, 12, and 13 from the side surfaces to the bottom surfaces with the wax. 12 and 13 can be firmly fixed. There is no particular limitation on the type of brazing, but examples include nickel brazing, titanium brazing, cobalt brazing, copper brazing, tin brazing, silver brazing, and combinations thereof. In order to fix the excavating members 11, 12, and 13 more firmly, for example, it is preferable to further provide a groove portion 10e in which wax is accumulated in the bottom surface of the concave portion of the base 10d. Here, the shape of the groove portion 10e is not particularly limited.

The arrangement of the excavating members 12 and 13 of the tip-side excavating portion 12 and the cylindrical-side excavating portion 13 is not particularly limited. The drilling members 13 of the cylindrical side drilling portion 13 are evenly arranged radially from the center of the tip plane, and are evenly arranged in the circumferential direction on the outer peripheral surface of the cylindrical side surface of the head 10a of the drill bit body 10. is not limited to

In addition, the tip 13b1 of the flat layer 13b of the excavating member 13 of the cylindrical side excavating portion 13 protrudes to the outside with respect to the tip 12b1 of the flat layer 12b of the excavating member 12 of the tip side excavating portion 12. Although not limited, it is preferably in the range of 0.5 mm to 3.0 mm, for example. As a result, the side face R2 of the excavation portion R1 excavated by the excavating member 12 of the distal end side excavating portion 12 immediately collides with the excavating member 13 of the cylindrical side excavating portion 13, so that the excavation of the distal end side excavating portion 12 is shifted from the excavation of the cylindrical side excavating portion. It is possible to efficiently switch to the drilling of No. 13, and it is possible to further improve the drilling efficiency of the drill bit 1 as a whole.

Here, the closer the flat layer 13b of the excavating member 13 of the cylindrical side excavating portion 13 is to the position of the flat layer 12b of the excavating member 12 of the distal end side excavating portion 12, the more it contributes to the dispersion of the excavation load. preferable.

<Second embodiment of the present invention>
Now, in the first embodiment of the present invention, three excavating members 12 of the distal end side excavating portion 12 and three excavating members 13 of the cylindrical side excavating portion 13 are configured as the minimum required, but not limited to this, Other configurations are possible.

For example, in the drill bit according to the second embodiment of the present invention (referred to as a sloping shoulder drill bit), as shown in FIG. 4 are evenly arranged radially from the center of the tip plane. Here, the corners of the outer peripheral end region 12a of the head portion 10a of the drill bit body 10 are formed in an R shape, and the excavating member 12 of the distal end side drilling portion 12 is formed in the R-shaped portion (shoulder portion) of the outer peripheral end region 12a. (corner part). Further, four drilling members 13 of the cylindrical side drilling portion 13 are evenly arranged in the circumferential direction on the outer peripheral surface of the cylindrical side surface of the head portion 10a of the drill bit body 10 . In FIG. 5, four drilling members 12 of the distal end side drilling section 12 and four drilling members 13 of the cylindrical side drilling section 13 are arranged, but four or more may be arranged according to the configuration of the drill bit. Also good.

Here, the plane layer 13b of the excavating member 13 of the cylindrical side excavating section 13 is provided in the vicinity of the plane layer 12b of the excavating member 12 of the distal end side excavating section 12, and the plane of the excavating member 13 of the cylindrical side excavating section 13 is provided. A tip 13b1 of the layer 13b protrudes outward by a predetermined distance d from the tip 12b1 of the flat layer 12b of the excavating member 12 of the tip-side excavating portion 12 in a plan view of the head 10a of the drill bit body 10 .

Here, in the second embodiment of the present invention, a plurality of excavating members 11 are further arranged on the tip plane and the cylindrical side surface of the head portion 10a of the drill bit body 10, but the excavating role of the excavating member 11 at each position In order to clarify and disperse the excavation load, the following configuration is adopted.

For example, when the plurality of drilling members 11 and 12 are provided on the tip plane of the head portion 10a of the drill bit body 10, when the head portion 10a of the drill bit body 10 rotates, the plane layers of the plurality of drilling members 11 and 12 are formed. Each is partially overlapped in the radial direction of the head 10a of the drill bit body 10 so that the planar layers of the plurality of drilling members 11 and 12 cover the entire tip plane of the head 10a of the drill bit body 10. It is As a result, by rotating the head portion 10a of the drill bit body 10, the planar layers of the plurality of excavating members 11 and 12 can evenly collide with the rock, and the excavating load is concentrated on the excavating members 11 and 12 at specific positions. can be avoided.

Also, the number of the plurality of excavating members 11, 12, 13 is configured to increase along the radial direction of the head portion 10a of the drill bit body 10. As shown in FIG. As a result, the rotational speed (peripheral speed) of the head 10a of the drill bit body 10 increases as it goes radially of the head 10a of the drill bit body 10. Since the number of the plurality of drilling members 11, 12, 13 increases along the way, the drilling load of the plurality of drilling members 11, 12, 13 at a specific position in the radial direction of the head 10a of the drill bit body 10 is distributed. becomes possible. As a result, the planar layers of the plurality of excavating members 11, 12, 13 at specific positions can be made to evenly collide with the rock, avoiding concentration of the excavating load on the excavating members 11, 12, 13 at specific positions. It becomes possible to

Further, the height of the tips of the planar layers of the drilling members 11, 12 and 13 is configured to decrease toward the center of the head portion 10a of the drill bit body 10. As shown in FIG. For example, the tip 11a2 of the planar layer 11a1 of the first drilling member 11a provided in the central region of the plane of the head 10a of the drill bit body 10 is closer to the center of the head 10a of the drill bit body 10 than the second drilling member. The tip 11b2 of the planar layer 11b1 of 11b is higher than the tip 11b2 by a predetermined height h. That is, the tip 11b2 of the planar layer 11b1 of the second excavating member 11b on the center side is lower than the tip 11a2 of the planar layer 11a1 of the first excavating member 11a on the outer peripheral end side. As a result, when the head 10a of the drill bit 10 is rotated and collided with the rock R, the flat layer 11a1 of the first drilling member 11a first breaks the rock R, and then the second drilling member The flat layer 11b1 of 11b sequentially excavates the next portion of the excavated portion excavated by the first excavating member 11a (the portion near the central region of the head portion 10a of the drill bit 10). In this way, the tips of the planar layers of the plurality of drilling members 11 arranged on the plane of the head 10a of the drill bit body 10 are lowered stepwise toward the center of the head 10a of the drill bit body 10. (By increasing the height step by step as the outer circumference of the head 10a of the drill bit body 10 is approached), the excavating role of the excavating member 11 at each position can be clarified and the excavating load can be distributed.

Here, the arrangement of the first excavating member 11a and the second excavating member 11b is not particularly limited. For example, as shown in FIG. It is provided along an extension line formed by the arrangement of the side excavating portion 13 and the excavating member 13 . Further, on the extended line below the excavating member 13 of the cylindrical side excavating portion 13, there is another excavating member in which the tip of the flat layer protrudes outward by a predetermined distance from the tip 13b1 of the flat layer 13b of the excavating member 13. is provided.

As another configuration, in the drill bit according to the second embodiment of the present invention (referred to as an anchor shoulder type drill bit), as shown in FIG. , the tip 11b2 of the planar layer 11b1 of the second excavating member 11b is higher than the tip 11b2 by a predetermined height h, and the tip 12b1 of the planar layer 12b of the excavating member 12 of the tip-side excavating portion 12 is located above the first excavating portion. The tip 11a2 of the planar layer 11a1 of the member 11a is higher than the tip 11a2 by a predetermined height i. In this way, the tip of the planar layer of the drilling member arranged along the radial direction of the head 10a of the drill bit body 10 is lowered stepwise toward the center of the head 10a of the drill bit body 10. (By increasing the height stepwise as the outer circumference of the head 10a of the drill bit body 10 is approached), the excavation load can be further dispersed.

Here, the flat layer 12b of the drilling member 12 of the tip side drilling section is provided in the vicinity of the plane layer 13b of the drilling member 13 of the cylindrical side drilling section. An outer peripheral end portion 12a of 10a is configured in an R shape, and a third excavating member 11c other than the excavating member 12 of the tip-side excavating portion is provided at a position other than the position where the excavating member 12 of the tip-side excavating portion is provided. is arranged in the R-shaped portion of the In this manner, the excavating member provided in the R-shaped portion of the outer peripheral end portion 12a may be provided in addition to the excavating member 12 in the tip side excavating portion.

The second embodiment of the present invention shown in FIGS. 5 and 6 is appropriately provided with discharge holes and discharge grooves. The discharge holes and discharge grooves are provided to discharge gravel and stones after crushing rocks to the outside. The head 10a of the drill bit body 10 is provided as appropriate, taking into consideration the flow rate and direction in which stones are discharged.

Further, in the first embodiment of the present invention, the shape of the head portion 10a of the drill bit main body 10 was cylindrical, but as in the sloping shoulder type drill bit of the second embodiment of the present invention, the head portion 10a is shaped like the outer peripheral end. The shoulder portion of the outer peripheral end region 12a may be rounded to form a hemispherical shape, or like the anchor shoulder type drill bit of the second embodiment of the present invention, the shoulder portion of the outer peripheral end region 12a may be rounded and the drill The center of the head portion 10a of the bit body 10 may be lowered to form a hollow shape.

Here, the second embodiment of the present invention may be further modified to other configurations. For example, the drilling member 13 of the cylindrical side drilling portion is configured as a button bit (a cemented carbide button), and the cemented carbide button strikes the rock R at the same time as the drill bit body 10 rotates, thereby reducing axial vibration. You can prevent it. Further, apart from the excavating member 13 of the cylindrical side excavating portion, a cemented carbide button may be provided on the cylindrical side surface of the head portion 10a to prevent shaft shaking. The number of cemented carbide buttons is not particularly limited and is designed as appropriate. Moreover, there is no particular limitation on the installation position of the cemented carbide button.

Further, for example, an elongated cemented carbide guide pad along the rotation axis of the head portion 10a may be provided on the cylindrical side surface of the head portion 10a to prevent shaft deflection. The number of cemented carbide guide pads is not particularly limited and is designed as appropriate. Moreover, there is no particular limitation on the installation position of the cemented carbide guide pad.

Further, for the plurality of excavating members 11, 12, and 13, the corners of the planar layers may be rounded and the edges may be rounded to prevent cracking during excavation.

Further, since the rotational speed of the shoulder portion of the outer peripheral end region 12a of the tip plane of the head 10a is extremely high, excavating members 11 and 12 are required as the rotational speed increases. Therefore, the number of excavating members 11 and 12 provided in the shoulder portion of the outer peripheral end region 12a may be increased compared to the other portions.

In addition, since the rotation speed near the center of the tip plane of the head 10a is almost zero, excavation by the excavating member 11 provided near the center works very disadvantageously. Therefore, the excavating member 11 near the center may be prevented from cracking during excavation by rounding the corners of the planar layer or providing a supplementary cemented carbide button near the center.

Also, in order to cope with high temperature heating of the head 10a during excavation, the head 10a may be replenished with fresh water. Further, in order to adjust the dynamic balance of the head 10a when the head 10a rotates, a weight or a hole is appropriately provided on the cylindrical side surface of the head 10a so as to prevent shaft shake. may be configured.

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

<Drill bit evaluation method and evaluation results>
A drill bit 1 shown in FIGS. 1 to 3 was produced as a prototype. Here, as shown in FIG. 7, a drill bit in which the first inclination angle α of the flat layer 12b of the excavating member 12 in the distal end side excavation portion 12 is set to 0 degrees is taken as Comparative Example 1, and the first inclination angle α is set to Example 1 is a drill bit of 20 degrees, and Example 2 is a drill bit of 40 degrees. Here, the diameter of the cylinder of the drill bit body 10 is assumed to be 61.00 mm, and the diameter of the plane layer 12b of the drilling member 12 of the distal end side drilling section 12 and the plane layer 13b of the drilling member 13 of the cylindrical side drilling section 13 are set to 13 mm. .44 mm and the second tilt angle β was 70 degrees. Also, the predetermined distance d was set to 1.41 mm.

This prototype was connected to a rotating connection part of a commercially available large drilling machine, and the rotation speeds were set to 100 rpm, 260 rpm, and 360 rpm, respectively. The rocks to be excavated were hard rocks including granite. A commercially available compact compression load cell was installed on the rock, and the thrust (maximum pressing force) (N) was measured from this load cell when the drill bit collided with the rock and drilled. Also, the excavation time from the start of excavation to the completion of excavation is measured, and the impulse (N·sec = 1/1000 KN·sec) is calculated by multiplying the thrust (N) and the excavation time (sec) to confirm the excavation burden. did. Also, the excavation speed (m/sec) is calculated by dividing the excavation distance (m) by the excavation time (sec), and the energy during excavation is calculated by multiplying the impulse (N·s) by the excavation speed (m/sec). (J) was calculated, and the excavation energy burden was confirmed.

FIG. 8A shows evaluation results of the impulse for each rotation speed in Example 1-2. Here, in Comparative Example 1, since the first inclination angle α was 0, the excavation member 12 of the tip end side excavation portion 12 did not have an excavation capability in the first place. On the other hand, as shown in FIG. 8A, in Example 1-2, as the number of rotations increases from 100 rpm to 360 rpm, the impulse decreases and the excavation burden is reduced. Furthermore, in Example 2, it was found that the impulse was remarkably reduced at any number of rotations, and the excavation burden was reduced.

FIG. 8B shows the evaluation results of the energy for each rotational speed in Example 1-2. As shown in FIG. 8B, in Example 1-2, as the number of rotations increases from 100 rpm to 360 rpm, the energy decreases and the excavation burden is reduced. Furthermore, in Example 2, compared with Example 1, lower energy was exhibited regardless of the number of revolutions, and it was found that the excavation load was well distributed.

FIG. 9 shows a photograph of the drilled hole in the rock after drilling in Example 2. As shown in FIG. 9, the bottom of the excavated hole has a step of about 0.5 mm. This is precisely because the tip 13b1 of the flat layer 13b of the excavating member 13 in the cylindrical side excavating portion 13 protrudes from the tip 12b1 of the flat layer 12b of the excavating member 12 in the tip side digging portion 12 by a predetermined distance d. because he was Incidentally, in Example 1-2, even if the head of the drill bit continued to rotate during drilling, there was no axial deflection of the outer peripheral side surface of the head. It is considered that the excavation of the planar layer 13b of the excavating member 13 in the cylindrical-side excavating portion 13 contributes to the stable excavation of the drill bit as a whole.

Next, the drill bit 1 was produced by changing the first inclination angle α for the above prototype. As shown in FIG. 10, in contrast to Example 2 of the drill bit having the first inclination angle α of 40 degrees, the drill bit of Example 3 having the first inclination angle α of 50 degrees was used. A drill bit with an inclination angle α of 30 degrees was used as Example 4. Here, the diameter of the cylinder of the drill bit body 10, the diameter of the plane layer 12b of the drilling member 12 of the tip-side drilling section 12, the diameter of the plane layer 13b of the drilling member 13 of the cylindrical-side drilling section 13, and the second inclination angle β and the predetermined distance d are the same as described above.

The prototype of Example 2-4 was connected to the rotary connection part of a large drilling machine, the rotation speed was set to 100 rpm, 260 rpm, and 360 rpm, respectively, and the rock to be excavated was set to rock containing granite, and the above-mentioned Similarly, the thrust (maximum pressing force) (N), excavation time (sec), and excavation speed (m/sec) were measured, and from these measured values, the impulse (N sec = 1/1000 KN sec)) and the energy (J) at the time of excavation were calculated.

FIG. 11A shows evaluation results of the impulse for each first tilt angle α in Examples 1-4. As shown in FIG. 11A, when the first inclination angle α is in the range of 20 degrees to 45 degrees, the more the rotation speed increases from 100 rpm to 260 rpm and 360 rpm, the more the impulse decreases and the excavation load is reduced. It is understood that

FIG. 11B shows the energy evaluation results for each first tilt angle α in Example 1-4. As shown in FIG. 11B, when the first inclination angle α is in the range of 20 degrees to 45 degrees, the energy decreases and the excavation load is dispersed as the rotational speed increases from 100 rpm to 260 rpm and 360 rpm. It is understood that progress is being made.

Next, the drill bit 1 shown in FIGS. 5 and 6 was produced as a scaled-up prototype. Here, in FIGS. 12A and 12B, the shoulder-shaped drill bit shown in FIG. In the sloping shoulder type drill bit 1, as described above, the four drilling members 12 of the tip side drilling portion are arranged radially evenly from the center of the tip plane of the head 10a, and the drilling members 13 of the cylindrical side drilling portion are Four of them are evenly arranged in the circumferential direction on the outer peripheral surface of the cylindrical side surface of the head portion 10a, and are provided directly below the excavating member 12 of the tip side excavating portion. A first digging member 11a and a second digging member 11b are provided from the digging member 12 of the tip side digging portion toward the center of the tip plane of the head 10a. The diameter of the head 10a is 150 mm, the length of the head 10a is about 270 mm and the number of digging members is 29.

The other drilling members 11 are such that when the head 10a rotates, each planar layer of the plurality of drilling members 11, 12, 13 partially overlaps in the radial direction of the head 10a such that the plurality of drilling members 11, 12 , 13 are configured to cover the entire tip plane of the head 10a. Also, when the plurality of excavating members 11 and 12 are provided on the tip plane of the head 10a, the number of the plurality of excavating members 11 and 12 is configured to increase along the radial direction of the head 10a. there is An excavating member 11 is also provided directly below the excavating member 13 of the cylindrical side excavating portion.

13A and 13B, the anchor shoulder type drill bit shown in FIG. The dovetail shoulder drill bit 1 is provided with a drilling member 12 for the tip side drilling portion and a drilling member 13 for the cylindrical side drilling portion, as in the stroke shoulder drill bit 1 described above. In addition, a plurality of excavating members 11 are also provided, and in the plurality of excavating members 11 and 12 provided on the tip plane of the head 10a, the height of the tip of the planar layer of the excavating members 11 and 12 is the center of the head 10a. It is configured so that it becomes lower as it goes to. An excavating member 11 is also provided directly below the excavating member 13 of the cylindrical side excavating portion.

As shown in FIG. 14A, this prototype was transported to a land drilling test site, and as shown in FIG. Each was set at 180 rpm. The rock to be excavated was a granite (granite) rock of 600 mm×600 mm×600 mm. As for the excavation conditions, after excavating a pilot hole to a depth of 100 mm to 150 mm at a rotation speed of 60 rpm, main excavation was continuously performed to a depth of about 500 mm. As the excavation depth progressed, the rotation speed was increased and the thrust (kgf) was increased, and the excavation time (min) was measured at each rotation speed to measure the excavation speed (cm/min). When the rotation speed is 60 rpm, the thrust is 1,800 kgf-1,900 kgf, when the rotation speed is 120 rpm, the thrust is 2,700-3,000 kgf, and when the rotation speed is 180 rpm, the thrust is 3. 500 kgf to 3,600 kgf.

FIG. 15 shows the evaluation results of the excavation speed for each rotational speed in Example 5-6. As shown in FIG. 15, in Example 5-6, as the number of rotations increases, the excavation speed increases and the excavation load is reduced, resulting in improved excavation efficiency. Here, in Example 5-6, the excavation speed exceeds 4 cm/min when the number of revolutions reaches 120 pm. On the other hand, it is considered that the required characteristics of a drill bit for hard rock are a rotation speed of 60 rpm to 120 rpm and a drilling speed of about 4 cm/min. Surprisingly, therefore, the drilling speed of Example 5-6 is significantly improved at a rotational speed of 120 pm, compared to the required drilling speed for hard rock, and the drilling efficiency of Example 5-6 is , was found to sufficiently satisfy the required properties for hard rock.

Thus, it was found that the drilling efficiency of the drill bit 1 as a whole was improved by clarifying the drilling role of the drilling member 11 at each position and dispersing the drilling load. In addition, it is believed that the life of the drill bit 1 will be extended due to the reduction in impulse and energy.

As described above, the drill bit according to the present invention is useful not only for submarine exploration but also for mining, oil, gas, construction, and hot spring drilling. By distributing the load, it is effective as a drill bit capable of improving the drilling efficiency of the entire drill bit and extending the life of the drill bit.

REFERENCE SIGNS LIST 1 drill bit 10 drill bit body 11 drilling member 12 tip side drilling section 13 cylindrical side drilling section

Claims (3)

a cylindrical drill bit body having a longitudinal axis of rotation;
a plurality of drilling members provided on the head of the drill bit body and having surface layers as drilling blades;
In the tip plane of the head of the drill bit body, the surface of the surface layer provided in the outer peripheral end region is aligned in the direction of rotation of the drill bit body with respect to a perpendicular line perpendicular to the surface of the outer peripheral end region. and in the opposite direction, 20 degrees~45 degreesa tip side excavating portion configured by an excavating member inclined at a first inclination angle within the range of and fixed to cover the side surface of the excavating member;
Among the cylindrical side surfaces of the head of the drill bit body, the surface layer is provided in the upper end region, and the surface of the surface layer is positioned in the direction opposite to the direction of rotation of the drill bit body with respect to a perpendicular line perpendicular to the surface of the upper end region. a drilling member inclined at a second angle of inclination in the range of 60 degrees to 90 degrees in the direction of the drilling member and fixed over the side surface of the drilling member, the face layer of the drilling member being aligned with the tip Provided in the vicinity of the surface layer of the excavating member of the side excavating section, the tip of the surface layer of the excavating member is the tip of the surface layer of the excavating member of the tip-side excavating section in a plan view of the head of the drill bit body. than, within the range of 0.5 mm to 3.0 mma cylindrical side excavation projecting outwardly a distance;
equipped with ,
Each of the tip side excavation portion and the cylindrical side excavation portion is fixed by covering the side surface of the excavation member by brazing from the side surface to the bottom surface of the excavation member to a recessed pedestal provided in advance. to be
drill bit. The dimension of the recess of the pedestal is longer than the diameter dimension of the excavating member by a length of 0.1 mm to 0.5 mm. filling the drilling member from the side to the bottom with wax by pressing;
A drill bit according to claim 1. A groove portion in which wax is accumulated is further provided on the bottom surface of the recessed portion of the pedestal,
After filling the recess of the pedestal with wax, the bottom surface of the excavating member is pushed in to fill the excavating member from the side surface to the bottom surface with the wax.
A drill bit according to claim 1.

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