JP2012237150A - Drilling bit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a drilling bit that allows efficient arrangement of house-shaped chips made of cemented carbide to allow an efficient decrease in amount of cemented carbide to be used while maintaining drilling performance.SOLUTION: A drilling bit is provided in which five house-shaped chips 2a to 2e made of cemented carbide are radially arranged on a chip mounting surface 12 of a metal base 1. While displacing the position by rotation at which the five house-shaped chips 2a to 2e of cemented carbide hit, an impact is given by vibration in a forward-backward direction to a subject to be drilled, thereby performing drilling. Among the five house-shaped chips 2a to 2e of cemented carbide, short chips 2b and 2e of cemented carbide are shorter in a longitudinal direction than long chips 2a, 2c and 2d of cemented carbide. The five house-shaped chips 2a to 2e of cemented carbide have their respective outer ends 2a1 to 2e1 that are arranged along the outer peripheral side of the chip mounting surface 12 at which a drilling load (a drilling amount) is relatively high.

Description

  The present invention is used, for example, by being mounted on the tip of a rock drill or rock bolt, and a plurality of cemented carbide house-shaped chips made of cemented carbide are arranged radially on the chip mounting surface of the base metal. The present invention relates to a perforation bit that performs perforation (perforation) by impacting a target to be perforated by vibration in the front-rear direction while shifting the position where a plurality of cemented carbide house-shaped chips hit by rotation.

  A drill bit in which a plurality of cemented carbide house-shaped tips made of a cemented carbide called a house shape (also called chisel shape) is provided on an iron base metal is, for example, a tip of a rock drill or a rock bolt The piercing object is impacted by the vibration in the front-rear direction while shifting the position where the plurality of cemented carbide house-shaped chips hit by rotation. In such a perforated bit, a plurality of cemented carbide house-type chips are fixed to the chip mounting surface, which is the tip of the pedestal, by brazing, and the outer peripheral side surface of the base metal is recessed to discharge slime. Forming grooves is a basic form (see, for example, Patent Documents 1 and 2). When a drill bit employing such a cemented carbide house-shaped tip is used by being attached to the tip of a rock bolt, for example, the shaft center of the drill bit is approximately 10 times as many as several hundred revolutions per minute. Depending on the maximum outer diameter of the drilling bit, it oscillates in the front-rear direction, hits the drilled object such as rock, and discharges slime from the discharge groove toward the rear end of the lock bolt. Proceed by forming a long hole with a hole diameter.

Japanese Patent Laid-Open No. 11-170035 Japanese Utility Model Publication No. 6-67593

  By the way, on the chip mounting surface, the closer to the outer peripheral side from the center, the longer the movement (rotation) distance when the base metal rotates, and the larger the area responsible for perforation by impact, the larger the perforation (cutting) in the house-shaped chip. Hole) It is indispensable and it is indispensable that it is a cemented carbide house type chip.

  However, since the cemented carbide house-type chip is made of an expensive cemented carbide, the cost reduction effect is greater as the number of cemented carbide house-type chips is smaller. In particular, a self-drilling lock bolt in which a drill bit is connected to the tip of the lock bolt is a one-time use type in which the lock bolt and the drill bit are embedded in the ground as they are, and therefore it is required to reduce costs as much as possible. Yes.

  On the other hand, on the center side of the chip mounting surface, the closer to the center, the shorter the movement (rotation) distance when the base metal rotates, and the smaller the area responsible for perforation by hitting, the perforation (cutting) on the chip. Hole) Even if the load is small and the cemented carbide house type chip is omitted, or even a chip softer than the cemented carbide house type chip, the drilling ability is not significantly affected.

  Accordingly, an object of the present invention is to provide a drill bit that can efficiently dispose the cemented carbide house-type chip while maintaining the drilling capability, thereby efficiently reducing the amount of cemented carbide used. .

In order to achieve the above object, a perforated bit according to the present invention comprises a plurality of cemented carbide house-shaped tips made of cemented carbide arranged radially on a chip mounting surface of a base metal, and the plurality of cemented carbides by rotation. A drilling bit for drilling by piercing an object to be drilled by vibration in the front-rear direction while shifting the position where the house-shaped chip hits, wherein some of the cemented carbides out of the plurality of cemented carbide house-shaped chips The house type chip has a shorter length in the longitudinal direction than other cemented carbide house type chips, and the outer ends of each of the plurality of cemented carbide house type chips are arranged along the outermost periphery of the chip mounting surface. A piercing bit characterized in that
In this way, the outer ends of the plurality of cemented carbide house-type chips are arranged on the outer peripheral side of the chip mounting surface having a large drilling load (drilling amount), while the chip mounting surface having a small drilling load (drilling amount) is arranged. On the center side, the inner end of the cemented carbide house-shaped tip having a short length in the longitudinal direction is not lined up, and only the inner end of the cemented carbide house-shaped tip having a longer length is arranged, so that the drilling ability is maintained. However, the amount of the cemented carbide can be efficiently reduced by arranging the cemented carbide house type chip efficiently.
Here, the chip mounting surface is further continuous from the inner end of the cemented carbide house-shaped chip having a short length in the longitudinal direction to the center of the chip mounting surface among the plurality of cemented carbide house-shaped chips. Then, a base metal integrated house-shaped chip integrally formed with the base metal may be provided.
As a result, a plurality of cemented carbide house-shaped chips are arranged at predetermined intervals on the outer peripheral side of the chip mounting surface having a large drilling load (drilling amount), while the chip mounting surface having a small drilling load (drilling amount) is arranged on the center side of the chip mounting surface. As necessary, since a plurality of cemented carbide house-shaped chips having a long length and a base metal integrated house-shaped chip are arranged side by side, the drilling ability on the center C side of the chip mounting surface is more than when no base metal integrated house-shaped chip is provided. It is possible to efficiently reduce the amount of cemented carbide used by efficiently arranging the cemented carbide house-type chips while securing the above.
Here, the plurality of cemented carbide house-shaped chips are divided into at least a long cemented carbide house-shaped chip and a short cemented carbide house-shaped chip according to the length in the longitudinal direction, and the long cemented carbide The alloy house-type chips and the short cemented carbide house-shaped chips are alternately disposed, and the smaller the number of the long cemented carbide house-shaped chips and the short cemented carbide house-shaped chips. When there is no more, the remaining one may be arranged continuously.
In this case, since the long cemented carbide house-shaped chip and the short cemented carbide house-shaped chip are alternately arranged, it becomes possible to drill with good balance in combination with the rotation of the base metal. .
Of the plurality of cemented carbide house-shaped tips, one cemented carbide house-shaped tip has a longitudinal length from an outer end to an inner end of the cemented carbide house-shaped tip, It is substantially the same as the radius of the chip mounting surface, the outer end portion of the cemented carbide house-shaped chip is located on the outermost periphery of the chip mounting surface, and the inner end portion of the cemented carbide house-shaped chip is the chip You may make it arrange | position so that it may be located in the center of a mounting surface.
In this case, the inner end of one cemented carbide house-type chip is located at the center of the chip mounting surface, so the chip can be installed while reducing the amount of cemented carbide by using a short cemented carbide house-type chip. The drilling ability in the central part of the surface can be improved.

  In the perforated bit of the present invention, among the plurality of cemented carbide house-shaped chips provided radially on the chip mounting surface of the base metal, some cemented carbide house-shaped chips are more than other cemented carbide house-shaped chips. Since the length in the longitudinal direction is short and the outer end portions are arranged substantially along the outer peripheral side of the chip mounting surface, there is a longer length on the outer peripheral side of the chip mounting surface with a large drilling load (drilling amount). Regardless of the length of the direction, the outer end of each cemented carbide house type chip is lined up, while the center side of the chip mounting surface with a small drilling load (drilling amount) has a long length in the cemented carbide house type Since only the inner end portions of the chips are arranged, it is possible to efficiently arrange the cemented carbide house-shaped chips while maintaining the drilling ability, thereby efficiently reducing the amount of the cemented carbide used.

It is a top view of the drill bit of embodiment of this invention. (A), (b) is the front view and II sectional view taken on the line of the drill bit of embodiment shown in FIG. 1, respectively. It is a figure which shows the state which connected the lock bolt to the drill bit of embodiment of this invention, and is drilling as a self-drilling lock bolt. It is a top view which shows the other example of the punch bit of embodiment of this invention. (A), (b) is a top view which shows the further another example of the punching bit of embodiment of this invention, respectively.

  Next, an embodiment of a punch bit according to the present invention will be described. The drill bit according to the present embodiment is, for example, a rock drill or a rock bolt, in particular, attached to the tip of the lock bolt, and a plurality of cemented carbide house-shaped chips made of cemented carbide are base metal chip mounting surfaces. A perforation bit that is radially arranged on the top and performs perforation by impacting the object to be perforated by vibrations in the front-rear direction while shifting the position where a plurality of cemented carbide house-shaped chips hit by rotation.

  FIG. 1 is a plan view of a drill bit A according to an embodiment. FIGS. 2A and 2B are a front view and a cross-sectional view taken along line I-I, respectively, of the drill bit A according to the embodiment shown in FIG.

  The drill bit A of the embodiment is attached to the tip of the lock bolt, and as described above, a plurality of cemented carbide house-shaped chips 2a to 2e made of cemented carbide are on the chip mounting surface 12 of the base metal 1. The drill bit is drilled by impacting the drilled object by vibration in the front-rear direction while shifting the position where the plurality of cemented carbide house-shaped chips 2a to 2e hit by rotation. The number of rotations of the perforation bit A is, for example, about 200 rotations per minute, and the number of strikes caused by vibration in the front-rear direction is about 1,800 times per minute, which is nine times the number of rotations. When the perforation bit A is rotated by 40 degrees by the hitting, the position where the house-shaped chips 2a to 2e hit is rotated, and the punching bit A is rotated once by nine hits.

  As shown in FIGS. 2 (a) and 2 (b), the base metal 1 includes a connecting surface 11 to which tip portions (not shown) such as a rock drill and a rock bolt are connected, and an axis of the drill bit A. Straightness is achieved during drilling (drilling) between the chip mounting surface 12 in which a plurality of cemented carbide house-shaped chips 2a to 2e are arranged on a plane perpendicular to the direction, and the connecting surface 11 and the chip mounting surface 12. 5 guide surfaces 13a1 to 13a5 having peripheral side surfaces with the center C of the perforation bit A as an axis to maintain, and a plurality of discharge grooves that are recessed from the guide surfaces 13a1 to 13a5 and that discharge slime generated during perforation. And outer peripheral side surface 13 provided with discharge groove surfaces 13b1 to 13b5 forming 13b11 to 13b51.

  As shown in FIG. 1B, the connecting surface 11 has a rock drill rod having a hollow hole (not shown) for sending compressed air and a tip of a rock bolt made of a hollow rod (not shown). A connecting hole 11a such as a screw hole is formed. At the tip of the connecting hole 11a, a compressed air reservoir 11a2 for branching compressed air sent through a hollow hole (not shown) such as a rock drill or a rock bolt to the blow holes 13b12 to 13b52. Is provided.

  The chip mounting surface 12 has five cemented carbide house-shaped chips 2a to 2e at the same angle with respect to the center C of the perforated bit, that is, approximately 72 degrees, and the center of the five cemented carbide house-shaped chips 2a to 2e. They are arranged apart from each other and are fixed by brazing or the like. The cemented carbide house-type chips 2a to 2e are double-edged, and the double-edged blades have tips formed at acute angles.

  Here, the cemented carbide house type | mold chips 2a-2e are comprised from cemented carbide alloys, such as tungsten carbide, for example. Therefore, the cemented carbide house-type chips 2a to 2e are expensive, and it is required to reduce the amount of the cemented carbide as much as possible in the drill bit for the self-drilling lock bolt that is supposed to be used only once. ing.

  Therefore, in the perforated bit A of this embodiment, for example, as shown in FIGS. 1A and 1B and FIGS. 2A and 2B, five cemented carbide house-shaped chips 2a to 2e are provided. Of these, the two cemented carbide house-type chips 2b and 2e are made shorter in the longitudinal direction than the other three cemented carbide house-type chips 2a, 2c and 2d. This is only an example, and the length of three cemented carbide house-type chips out of the five cemented carbide house-shaped chips 2a to 2e may be shortened, or four cemented carbide house chips. The length of the shaped chip may be shortened. Hereinafter, the cemented carbide house-shaped chips 2b, 2e having a short length in the longitudinal direction are referred to as short cemented carbide chips, and the cemented carbide house-shaped chips 2a, 2c, 2d having a long length in the longitudinal direction are referred to as It will be abbreviated as a long cemented carbide chip.

  In the perforated bit A of the embodiment, the outer end portions 2a1 to 2e1 of the five cemented carbide house-type chips 2a to 2e are respectively located at the upper end portions of the guide surfaces 13a1 to 13a5 that are the outermost periphery of the chip mounting surface 12. Are arranged on substantially the same circumference. In addition, some unevenness | corrugation of arrangement | positioning of the outer side edge part 2a1-2e1 is the range of an error.

  On the other hand, the outer ends 2a1 to 2e1 of the five cemented carbide house-type chips 2a to 2e are arranged on the same circumference along the upper ends of the guide surfaces 13a1 to 13a5 which are the outermost periphery of the chip mounting surface 12. Since the inner ends 2a2, 2c2, 2e2 of the long cemented carbide chips 2a, 2c, 2d approach the center C of the chip mounting surface 12, the inner ends of the short cemented carbide chips 2b, 2e are arranged. 2b2 and 2f2 are located away from the center C.

  Therefore, in the perforation bit A of the present embodiment, all the cemented carbide house-type chips are provided on the outermost periphery of the chip mounting surface 12 having a long movement (rotation) distance, that is, a wide perforation range and a large perforation load (amount of perforation). While the outer end portions 2a1 to 2e1 of 2a to 2e are lined up, a short cemented carbide is disposed on the center C side of the chip mounting surface 12 where the movement (rotation) distance is short, that is, the drilling range is narrow and the drilling load (punching amount) is small. The inner ends 2b2 and 2f2 of the chips 2b and 2e are not lined up, and only the inner ends 2a2, 2c2 and 2e2 of the long cemented carbide chips 2a, 2c and 2d are arranged.

  Thereby, according to the piercing bit A of the present embodiment, it is possible to efficiently dispose the cemented carbide house-shaped chip while maintaining the piercing capability, and to efficiently reduce the amount of the cemented carbide used. And can provide an inexpensive perforated bit.

  Further, according to the drill bit A of the present embodiment, since the shape of the outer peripheral side surface 13 of the base metal 1 is not changed, the number and area of the guide surfaces 13a1 to 13a5 are the same as before, and the drill bit A is not blurred. Therefore, it is possible to efficiently drill (drill) while ensuring straightness.

  Therefore, in the drill bit A of the embodiment, there is a gap between the inner ends 2b2 and 2f2 of the short cemented carbide chips 2b and 2e and the center C side of the chip mounting surface 12, and therefore the drill bit A of the embodiment. Then, the base metal integrated house-shaped chips 12b and 12e formed integrally with the base metal 1 continuously from the inner ends 2b2 and 2f2 of the short cemented carbide chips 2b and 2e to the center C of the chip mounting surface 12 are formed. Yes. Here, the base metal integrated house-shaped chip 12b and the base metal integrated house-shaped chip 12e are continuous at the center C of the chip mounting surface 12.

  In this way, the outer ends 2a1 to 2e1 of the five cemented carbide house-shaped chips 2a to 2e are arranged at predetermined intervals on the outermost periphery of the chip mounting surface 12 with a large drilling load (amount of drilling), The inner end portions 2a2, 2c2, and 2e2 of the long cemented carbide chips 2a, 2c, and 2d and the base metal integrated house-shaped chip 12b are appropriately disposed on the center C side of the chip mounting surface 12 with a small drilling load (drilling amount). , 12e are arranged, so that the five cemented carbide house-shaped chips 2a to 2e are secured while ensuring the drilling ability on the center C side of the chip mounting surface 12 as compared with the case where the base metal integrated chips 12b and 12e are not provided. Can be arranged efficiently to reduce the amount of cemented carbide used efficiently. In the present invention, whether or not the base metal integrated chips 12b and 12e are formed is arbitrary.

  In the perforated bit A of the embodiment, the long cemented carbide chips 2a, 2c, 2d and the short cemented carbide chips 2b, 2e are alternately arranged on the chip mounting surface 12, and several Since the long cemented carbide chips 2a, 2c, and 2d, which have a large amount, remain, the long cemented carbide chips 2c and 2d are continuously arranged.

  As a result, the long cemented carbide chips 2a, 2c, 2d and the short cemented carbide chips 2b, 2e are alternately arranged on the chip mounting surface 12 within the possible range. In combination with this, it becomes possible to perforate with good balance.

  FIG. 3 is a diagram illustrating a state in which drilling is performed in the form of a self-drilling lock bolt formed by connecting a lock bolt B to the drill bit A of the embodiment.

  As shown in FIG. 3, in the perforated bit A of the embodiment, the shape of the outer peripheral side surface 13 of the base metal 1 becomes thinner from the tip mounting surface 12 on the front end side toward the connecting surface 11 side on the rear end side. When the self-drilling lock bolt is to be pulled back as compared with the base metal in which the step perpendicular to the axial center direction of the drill bit A is formed. The slime can easily move between the drilling wall and the drill bit A or the lock bolt B, the pull-back operation of the self-drilling lock bolt becomes smooth, and the operability (workability) is improved.

  Thus, since the self-drilling lock bolt in which the drill bit A of the embodiment is connected to the tip of the lock bolt B is used once, as described above, this embodiment in which the amount of cemented carbide is reduced is used. This perforation bit A is effective in terms of cost.

  In the perforated bit A of the present embodiment, the five cemented carbide house-shaped chips 2a to 2e have been described as having two lengths in the longitudinal direction for convenience of explanation. However, the length in the longitudinal direction of the cemented carbide house-shaped chip may be three or four or more, and the number of cemented carbide house-shaped chips is three. Of course, the number may be four, six, or more.

  For example, as shown in FIG. 4, of the three long cemented carbide chips 2a, 2c, 2d ′, only one long cemented carbide chip 2d ′ has a length in the longitudinal direction that is the radius of the chip mounting surface 12. The outer end 2d1 ′ of the long cemented carbide tip 2d ′ is positioned on the outermost periphery of the chip mounting surface 12, and the inner end 2d2 ′ of the long cemented carbide tip 2d ′ is the tip. Of course, it may be arranged so as to be located at the center C of the mounting surface 12.

  In this case, since the inner end 2d2 ′ of one long cemented carbide chip 2d ′ is located at the center C of the chip mounting surface 12, the cemented carbide is formed by the short cemented carbide house-shaped chips 12b and 12e. The drilling ability in the center C portion of the chip mounting surface 12 can be improved while reducing the amount of use.

  Further, like the perforated bit A ′ shown in FIG. 5A, four cemented carbide house-shaped chips 2a, 2b, 2c and 2e are arranged at an angle of approximately 90 degrees, or FIG. Of course, six cemented carbide house-type chips 2a to 2c and 2e to 2g may be disposed at an angle of approximately 60 degrees, as shown in the perforated bit A "shown in FIG.

  Specifically, in the case of the perforated bit A ′ shown in FIG. 5A, two long cemented carbide chips 2a, 2c out of the four cemented carbide house-shaped chips 2a, 2b, 2c, 2e. And short cemented carbide chips 2b, 2e are alternately arranged, and there is a gap between the inner ends 2b2, 2e2 of the short cemented carbide chips 2b, 2e and the center C side of the chip mounting surface 12. The base metal integrated house-shaped chips 12b and 12e are formed integrally with the base metal 1 continuously from the inner ends 2b2 and 2e2 of the short cemented carbide chips 2b and 2e to the center C of the chip mounting surface 12. doing. Here, the base metal-integrated house-shaped chip 12b and the base metal-integrated house-shaped chip 12e are continuous at the center C of the chip mounting surface 12 so that there is no gap.

  In the case of the perforated bit A ″ shown in FIG. 5B, three long cemented carbide chips 2a, 2c, 2f out of the six cemented carbide house-shaped chip chips 2a-2c, 2e-2g. And three short cemented carbide chips 2b, 2e, 2g are alternately arranged, and the inner ends 2b2, 2e2, 2g2 of the short cemented carbide chips 2b, 2e, 2g and the center C of the chip mounting surface 12 are arranged. Is formed integrally with the base metal 1 continuously from the inner ends 2b2, 2e2, 2g2 of the short cemented carbide chips 2b, 2e, 2g to the center C of the chip mounting surface 12 so that there is no gap between them. The base metal integrated house-shaped chips 12b, 12e, and 12g are formed, and the base metal integrated house-shaped chips 12b, 12e, and 12g are continuous at the center C of the chip mounting surface 12, and the gap is empty. I do n’t want to.

A, A ', A "Drilling bit B Lock bolt 1 Base 11 Connection surface 11a Connection hole 12 Chip mounting surface 13 Outer peripheral surface 13a1 to 13a5 Guide surface 13b1 to 13b5 Discharge groove surface 13b11 to 13b51 Discharge groove 13b12 to 13b52 Blow hole 2a 〜2g Cemented carbide house type chip 2a, 2c, 2d, 2d ′, 2f Long cemented carbide chip 2b, 2e, 2g Short cemented carbide chip 2a1, 2b1, 2c1, 2d1, 2d1 ′, 2e1, 2f1, 2g1 Outer end 2a2, 2b2, 2c2, 2d2, 2d2 ', 2e2, 2f2, 2g2 Inner end 12b, 12e, 12g Base metal integrated house type chip

Claims (4)

A plurality of cemented carbide house-shaped tips made of cemented carbide are arranged radially on the chip mounting surface of the base metal, and are rotated by vibrations in the front-rear direction while shifting the position where the plurality of cemented carbide house-shaped tips hit by rotation. A drilling bit that drills by impacting a drilling object,
Among the plurality of cemented carbide house-shaped chips, some cemented carbide house-shaped chips have a shorter length in the longitudinal direction than other cemented carbide house-shaped chips, and the plurality of cemented carbide house-shaped chips. Each outer end is disposed along the outermost periphery of the chip mounting surface,
A piercing bit characterized by that. The perforated bit according to claim 1,
The chip mounting surface further includes
A base metal integrally formed with the base metal continuously from the inner end of the cemented carbide house type chip having a short length in the longitudinal direction to the center of the chip mounting surface among the plurality of cemented carbide house type chips. Provide an integrated house-shaped chip,
A piercing bit characterized by that. The punch bit according to claim 1 or 2,
The plurality of cemented carbide house-shaped tips are:
According to the length in the longitudinal direction, it is divided into at least a long cemented carbide house-shaped chip and a short cemented carbide house-shaped chip,
The long cemented carbide house-shaped chip and the short cemented carbide house-shaped chip are alternately arranged,
When there is no longer one of the long cemented carbide house-shaped chip and the short cemented carbide house-shaped chip, the remaining one is continuously disposed.
A piercing bit characterized by that. In the drill bit according to any one of claims 1 to 3,
Among the plurality of cemented carbide house-shaped tips, one cemented carbide house-shaped tip is:
The length in the longitudinal direction from the outer end to the inner end of the cemented carbide house-shaped chip is substantially the same as the radius of the chip mounting surface, and the outer end of the cemented carbide house-shaped chip is the chip. Located at the outermost periphery of the mounting surface, and disposed so that the inner end of the cemented carbide house-shaped chip is positioned at the center of the chip mounting surface,
A piercing bit characterized by that.

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