JP2007030045A - Knife edge replacement type drill - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To replace a knife edge member 3, to lengthen the life of the knife edge of a shank by effectively preventing the abrasion of a part near the knife edge, and further to reduce the general cost. <P>SOLUTION: In a tool replacement type core drill, a short cylindrical knife edge member 3 is removably fitted to a mount part 2 formed on the tip of the cylindrical shank body 1. A hard tool material member 9 is fixed to the vicinity of the mount part 2 of the shank body 1, and the hard tool material member 9 is exposed to the surface of the shank body 1. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a blade-tip exchange type drill used for drilling concrete or the like.

  Generally, a drill is used as a means for drilling concrete or the like. The tip of a cylindrical core drill or solid drill body is equipped with a cutting edge member that holds diamond grains with a binder material, and the drill is rotated by pressing the cutting edge member against the surface of the concrete to create a hole of the required size. It is something to wear.

As such a drill, as shown in Patent Document 1, it is used in a dry drill apparatus in which a grinding material is supplied to a cutting site together with a cooling gas, and diamond particles are bonded to the tip of a cylindrical core as a binder material. A core drill formed by fixing the cutting tip held in the above, wherein the cutting tip is integrally formed in an annular shape, and the tip surface of the cutting tip that contacts the surface to be cut is formed in a series of flat shapes. Are known. Further, as shown in Patent Document 2, the upper end includes a shank connected to the rotary tool, the lower end edge has a tool portion made of a diamond tip, and a spiral diamond abrasive grain layer is formed on the outer peripheral surface of the shank. What is formed is known. Furthermore, as shown in Patent Document 3, there is known one in which a tip portion including a blade edge member is replaceable.
Japanese Patent Publication No. 8-18327 JP 2004-268434 A Special table 2001-527469

  However, the drill described in Patent Document 1 is disadvantageous in terms of cost because the cutting edge cannot be replaced, and therefore the entire bit needs to be replaced when the tool is worn.

  Further, the drill bit described in Patent Document 2 is disadvantageous in terms of manufacturing cost because it provides a diamond abrasive layer on the outer periphery of the shank. Moreover, the cutting edge cannot be replaced, which is disadvantageous in terms of cost.

  Furthermore, in the drill described in Patent Document 3, the cutting edge can be replaced each time it is worn, but as shown in FIG. 11, wear occurs in the portion A near the cutting edge of the shank. Since this portion is a portion necessary for keeping the straight travel when the drill enters the concrete, the straight travel performance is impaired when worn. Therefore, when the blade edge is replaced several times, the shank portion A is also worn, and the shank must be replaced. For this reason, the total cost cannot be reduced.

  The present invention solves the above-mentioned problems, can replace the blade edge member, can effectively prevent wear of the portion near the blade edge of the shank, can extend its life, and further reduce the overall cost It is an object of the present invention to provide a cutting edge replaceable drill.

  In order to solve the above-mentioned problem, a blade-tip replaceable drill according to the present invention is a blade-tip replaceable drill in which a short cylindrical blade member is detachably attached to a mounting portion formed at the tip of a cylindrical shank body. A super hard member is fixed to the attachment portion or the vicinity thereof, and the super hard member is exposed on the surface of the shank.

  In addition, it is preferable to form the said super-hard member in a ring shape.

  The super hard member may be a double ring formed on an inner ring made of the same material as the shank body, and the double ring may be fixed to the shank attachment portion or the vicinity thereof.

  Moreover, it is preferable that the shank is divided into a shank main body and an attaching portion at or near the attaching portion, and the shank main body and the attaching portion are integrally fixed via the super hard member.

  Further, the super-hard member may be fixed at intervals in the circumferential direction of the shank, or may be disposed spirally on the shank.

  In addition, a plurality of the super hard members may be provided.

  Further, one or both of the shank body and the blade edge member may be solid instead of being cylindrical.

  According to the present invention, when drilling the concrete with the above-mentioned drill, the super hard member is exposed at a portion where the wear is most severe except for the cutting edge member, and this portion is not easily worn. If the outer diameter is kept constant, it is naturally difficult to wear between the cutting edge member which is hard to be worn and the super hard member. For this reason, the replacement frequency of the shank is reduced, the life of the drill can be extended, and the overall cost can be reduced.

  1 and 2 show a part of a shank of a core drill as a cutting edge exchange type drill, and reference numeral 1 denotes a shank body. The shank body 1 is formed in a cylindrical shape made of metal (usually iron), and a mounting portion 2 is formed by a male screw at the tip. In addition, although the whole shank main body 1 may be the same diameter, as FIG. 3 shows, the structure which makes the outer diameter of the vicinity of the attaching part 2 a little larger diameter may be sufficient.

  Reference numeral 3 denotes a blade member. The blade member 3 is formed in a short cylindrical shape, and a cutting blade 4 is formed at a tip portion thereof. The cutting blade 4 is a sintered body in which diamond grains are embedded, has a slightly larger outer diameter, and has a cutting groove 8 formed therein. The opposite side of the blade edge member 3 is slightly smaller in diameter than the cutting blade 4 and is formed to have substantially the same diameter as the shank body 1, and a female screw 5 is formed at the end thereof. The blade member 3 is integrally coupled by screwing the female screw 5 into the male screw of the mounting portion 2 of the shank body 1. The cutting blade 4 and the shank body 1 may have the same diameter. Further, as a means for attaching the blade member 3 to the attachment portion 2 of the shank body 1, as shown in FIG. 3, a right angle formed by a longitudinal groove 6a and a transverse groove 6b on the outer surface of the attachment portion 2 of the shank body 1 as shown in FIG. The key groove 6 is formed, a protrusion 7 is formed on the inner surface of the blade member 3, and the protrusion 7 is engaged with the vertical groove 6a of the key groove when the blade member 3 is fitted into the mounting portion 2 of the shank body 1. In addition, after moving in the axial direction, it may be configured to be further rotated in the orthogonal direction at the insertion end and fixed in the transverse groove 6b.

  Next, a ring-shaped super-hard member 9 made of a super-hard alloy is fixed in the vicinity of the shank mounting portion 2. The super-hard member 9 has the same outer diameter as the shank body 1 and is exposed to be flush with the surface of the shank body 1.

  In order to fix the super-hard member 9 in the above position, the shank is usually divided into the shank body 1 and the mounting part 2 at or near the mounting part 2, and the shank body 1 and the mounting part 2 are separated from each other. What is necessary is just to fix integrally through the super-hard member 9.

  As a method for fixing the super-hard member 9, a means such as welding, brazing, or pressure welding may be used. Further, the super-hard member 9 and the shank body 1 may be processed into a screw shape and fixed by screwing.

  Further, since only the surface layer portion is important in the super-hard member 9, particularly when the thickness of the shank is large, the super-hard member 9 is made of the same material as the shank body 1 as shown in FIG. 3 or FIG. A multi-layered ring formed on the inner ring 10 may be used, and the multi-layered ring may be fixed in the vicinity of the mounting portion 2 of the shank.

  Furthermore, the number of super-hard members 9 is not limited to one. As shown in FIG. 5, two (or more) super-hard members 9 may be provided. The more the number of super-hard members 9, the higher the wear prevention effect.

  Moreover, as shown in FIG. 6, a center drill 11 can be formed at the center of the shank. In this case, since the straightness is further ensured by the center drill 11, the wear on the surface behind the shank blade member 3 can be suppressed to a small level.

  Furthermore, the shank body 1 and the blade member 3 are not limited to those formed in a cylindrical shape. As shown in FIG. 7, the solid cutting edge member 3 may be screwed and fixed to a screw hole (attachment portion 2) formed at the center of the solid shank body 1. Either the shank body 1 or the blade member 3 may be solid and the other may be cylindrical.

  By the way, the super hard member 9 may be provided on the mounting portion 2 as shown in FIG.

  The super-hard member 9 is not limited to a ring-shaped member. As shown in FIG. 8, they may be fixed at intervals in the circumferential direction, or may be formed in a spiral shape as shown in FIG.

  Further, the super hard member 9 is not limited to a super hard alloy. For example, the super hard member 9 obtained by performing ceramic spraying in the vicinity of the mounting portion 2 of the shank body may be used.

  As described above, when the core drilling is performed on the concrete, the most severe wear except the cutting edge member 3 is the peripheral portion of the cutting edge member 3 having the largest displacement in the circumferential direction during rotation due to the elasticity of the drill. It is. However, since the super-hard member 9 is exposed in this portion, it hardly wears even if it contacts the concrete surface. Therefore, if the outer diameter of the core drill is kept constant at the position of the super hard member 9, it is naturally difficult to wear between the cutting edge member 3 and the super hard member 9 which are hard to wear.

  Actually, a drilling experiment was performed on concrete using the core drill shown in FIG. When the cutting edge member 3 is worn and can no longer be used, it is replaced and drilled until it is replaced 3 to 4 times. The wear between the cutting edge member 3 and the super hard member 9 is extremely small, and the cutting edge member 3 is replaced. It was in a state where it could be used continuously. Further, as indicated by the line a in the table of FIG. 10, even when drilling continued for 14 m, the wear between the blade edge member and the super hard member was only 0.03 mm. On the other hand, the cutting edge exchange type core drill not provided with the super hard member was as shown by the line b. Therefore, it was confirmed that the wear of the portion close to the blade edge of the shank can be effectively prevented and the replacement frequency of the shank is lowered, so that the life of the core drill can be greatly extended and the overall cost can be further reduced.

  In addition, the part from the tip to the part where the super hard member 9 is provided is a part necessary for keeping the core drill straight when entering the concrete, and since this part is not easily worn, the straightness during drilling is long. Good period is secured.

It is a longitudinal cross-sectional view of the blade-tip-exchangeable core drill according to the present invention. It is a disassembled perspective view of a part of the shank of the core drill. It is a longitudinal cross-sectional view which shows the other attachment aspect of the blade member with respect to a shank main body. It is a longitudinal cross-sectional view which shows the other fixed aspect of a super-hard member. It is a longitudinal cross-sectional view which shows another fixing aspect of a super-hard member. It is a longitudinal cross-sectional view which shows the other example of a core drill. It is a longitudinal cross-sectional view which shows the other example of a core drill. It is explanatory drawing which shows the other arrangement | positioning aspect of a super-hard member. It is explanatory drawing which shows the other arrangement | positioning aspect of a super-hard member. It is a table | surface figure which shows the result of a drilling experiment. It is a longitudinal cross-sectional view which shows the part which is easy to wear with a core drill.

Explanation of symbols

1 Shank body 2 Mounting part 3 Cutting edge member 9 Super hard member

Claims (8)

  In a blade-replaceable drill in which a short cylindrical blade member is detachably mounted on a mounting portion formed at the tip of a cylindrical shank body, a super-hard member is fixed to or near the mounting portion of the shank body. A blade-tip replaceable drill characterized in that a hard member is exposed on the surface of the shank body.   The cutting edge replacement type drill according to claim 1, wherein the super-hard member is formed in a ring shape.   The super-hard member is a double ring formed on an inner ring made of the same material as the shank body, and the double ring is fixed at or near the mounting portion of the shank body. Item 3. The blade-tip replaceable drill according to Item 2.   The shank is divided into a shank main body and an attaching portion at or near the attaching portion, and the shank main body and the attaching portion are integrally fixed via the super hard member. The cutting edge replacement type drill described in 1.   2. The blade tip replaceable drill according to claim 1, wherein the super-hard member is fixed at intervals in a circumferential direction of the shank body.   The blade tip exchange drill according to claim 1, wherein the super-hard member is spirally disposed on the shank body.   The blade tip replaceable drill according to claim 1, 2 or 6, wherein a plurality of the super hard members are arranged. The blade-tip-replaceable drill according to any one of claims 1 to 7, wherein one or both of the shank main body and the blade member are solid instead of being cylindrical.

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