JP5388751B2 - Method for regenerating worn core bit and core bit regenerated thereby - Google Patents

Description

  The present invention relates to a core bit used for cutting asphalt concrete, cement concrete and the like into a circle. More specifically, the present invention relates to a method for regenerating a core bit worn by cutting as described above and a core bit regenerated by the method.

  For example, when repairing a paved road surface such as asphalt concrete, a core bit having a large diameter such as 1 to 2 m is used to cut the paved road surface around a manhole metal frame into a circle (see Patent Document 2). .

  As the core bit, a structure in which a plurality of cutting tips are fixed to the end of a cylindrical shank at a predetermined interval by brazing, laser welding, or other welding methods is well known. It is used by being attached to various types of core drills so that it can rotate around the axis and move in the axial direction. Usually, at the cutting location, lubrication between the cutting tip and the workpiece, cooling of the cutting tip, cutting tip, etc. Water is supplied for cleaning the shavings sludge adhering to (see Patent Documents 1 to 3).

  The cylindrical shank of the core bit is usually formed from a carbon steel material or the like having the required physical properties and thickness, and the cutting tip is often a diamond tip formed by mixing diamond abrasive grains and a binder and sintering. Etc. are formed. Both of these cylindrical shanks and cutting tips wear with the cutting use of the core bit on the workpiece. In this case, the cutting tips are particularly in the thickness direction (shank radial direction) and the height direction (shank axis). The cylindrical shank also wears in the thickness direction on both the inner and outer surfaces, particularly near the end portion, and becomes thin as the cutting tip wears in the thickness direction.

  For the core bit near the end of the cylindrical shank and the cutting tip as described above, for example, when the wear in the thickness direction near the end of the cylindrical shank is within an allowable limit, the cylindrical shank is left as it is. If the worn cutting tip is reusable by replacing it with a new cutting tip and the wear in the thickness direction near the end of the cylindrical shank exceeds the allowable limit, Prior to tip replacement, the cylindrical part, including the excessively worn part of the cylindrical shank, can be reused by cutting and removing it to the required length within the allowable length of the cylindrical shank. Has been played.

  However, in the conventional method of regenerating the core bit, the cylindrical shank worn near the end tends to cause stagnation of sludge generated around the cutting tip or poor discharge due to continuous use or reuse. The progress of wear in the thickness direction in the vicinity of the part is further accelerated, and the service life of the cylindrical shank is likely to be shortened, and when the core bit is regenerated, the worn cutting tip is replaced with a new cutting tip, or the cylindrical shank is excessive. The used worn cutting tips that are removed from the cylindrical shank and recovered when the cylindrical part including the worn part is cut off are disposed of as non-reusable, resulting in resource loss and environmental adverse effects. There was a problem such as.

Japanese Utility Model Publication No. 46-37712 Japanese Patent Publication No. 61-52283 No. 02-30255

  In view of the above-mentioned problems of the prior art, it is an object of the present invention to prolong the service life of a cylindrical shank worn near the end and to further reuse a used worn cutting tip. It is an object of the present invention to provide a reproduced core bit and a reproduced core bit.

  The method for regenerating a core bit according to the present invention that solves the above-described problem is that, as described in claim 1, a plurality of cutting tips are fixed to the end of a cylindrical shank at a required interval, and can be rotated around an axis. And a core bit that is attached to a core drill device so as to be movable in the axial direction and is used for cutting a workpiece into a circle, wherein the core bit is near the end of the cylindrical shank or near the end of the cylindrical shank and the cutting tip. In the method for regenerating worn core bits, a plurality of swarf discharge blades are inclined around the outer surface near the worn end of the cylindrical shank toward the end of the cylindrical shank with respect to the direction of rotation of the core bit. Including a blade fixing step for fixing at intervals, the generated shavings sludge is generated together with the rotation of the core bit when the workpiece is cut by the rotation of the regenerated core bit. The shavings ejection blade pivots about the axis, is characterized in that it has to be pushed proximally of the cylindrical shank.

  According to the core bit regenerated by the method of regenerating the core bit, when the workpiece is cut by the rotation of the core bit, the generated chip sludge is turned around the axis by the rotation of the core bit. Is pressed toward the base of the cylindrical shank in the gap between the cutting cross-section of the cylindrical shank and the outer surface of the cylindrical shank. The progress of wear in the thickness direction in the vicinity of the end portion of the steel sheet is suppressed.

  The shavings discharge blade is fixed around the outer surface near the worn end of the cylindrical shank by brazing, welding, etc. over a plurality of single or double or spiral arrangements as necessary. Is done. As long as the shavings discharge blade can achieve the above action, there is no particular limitation on the shape, the inclination angle, etc. In order to enhance the discharging action of shavings sludge accompanying turning, for example, the end is a base of a cylindrical shank. It may be curved or bent in the direction.

  In the method for regenerating the worn core bit, the circular cutting of the workpiece by the rotation of the core bit is smoothly performed with a required cutting width. It is usually preferred to be able to swivel with a turning radius that does not exceed the cutting radius by the insert. In practice, however, even if there is a swarf discharge blade having a turning radius that exceeds the cutting radius of the cutting tip, such swarf discharging blade will wear as the cutting progresses and repeats, and the turning radius eventually becomes Is substantially equal to the cutting radius of the cutting tip, so that there is no major problem in cutting work.

  In the method of reclaiming a worn core bit, if the wear of the cutting tip is close to the allowable limit or the allowable limit is reached, the worn cutting tip as described in claim 3, if necessary. A chip replacement process is performed to replace the chip with a new cutting chip.

  In addition, there is no particular restriction on the material of the shavings discharge blade, but since it can come into contact with an object to be cut and its shavings sludge, diamond abrasive grains and a binder are mixed in the same manner as the cutting tip. It is preferably formed from a sintered material or the like. As the swarf discharging blade, for example, as in claim 4, a used cutting tip that is worn and collected by cutting use may be diverted, and in this case, the used worn cutting tip may be diverted. This will contribute to the effective use of resources and the reduction of environmental load through reuse and recycling. Further, since the used cutting tip is usually curved in an arc shape so as to be fixed along the end of the cylindrical shank, this is used as a shavings discharge blade as described above. When it is fixed around the outer surface near the worn edge, the curved concave portion faces the base direction of the cylindrical shank, which contributes to an increase in the discharging action of shaving sludge accompanying turning. Can do. The used worn cutting tip is, for example, when the worn cutting tip is replaced with a new cutting tip when the core bit is regenerated, or the cylindrical portion including the excessively worn portion of the cylindrical shank is integrated with the cutting tip over the required length. It is removed and collected when cutting and removing.

  According to the core bit regeneration method, a plurality of cutting tips are fixed to the end of the cylindrical shank at a required interval, and the core drill is rotatable about the axis and movable in the axial direction. A core bit that is attached to the machine and used to cut a workpiece in a circular shape, and the core bit near the end of the cylindrical shank or near the end of the cylindrical shank and the worn cutting tip is reusable. A plurality of shavings discharge blades are fixed around the outer surface near the worn end of the cylindrical shank at a required interval by being inclined in the direction of the end of the cylindrical shank with respect to the rotation direction of the core bit. , A regenerated core bit is obtained. In the core bit regenerated in this way, when the workpiece is cut by the rotation, the generated shaving sludge is pressed toward the base of the cylindrical shank by the shaving discharge blade that rotates around the axis along with the rotation of the core bit. Will be.

  In the regenerated core bit, the wear of the cylindrical shank is such that the plurality of swarf discharge blades can swivel with a turning radius not exceeding the cutting radius of the cutting tip, as obtained with the reclaiming method of claim 2. And may be fixed around the outer surface near the edge, and the worn cutting tip may be replaced with a new cutting tip as obtained by the regeneration method according to claim 3, and As obtained by the reclaiming method described above, used cutting tips that have been worn and recovered by cutting use may be diverted as the swarf discharging blade.

  The regenerated core bit according to the present invention is rotatably attached to a rotational drive shaft that is movable in the axial direction of the core drill device, as described in Patent Document 1 or 3 or the like, or described in Patent Document 2, for example. In the core drill device, it is attached to a fixed shaft fixed in a non-rotatable manner so as to be rotatable about the axis and movable in the axial direction, and is used for circular cutting of an object to be cut. If necessary, an extension tube or the like having a required length is provided on the core bit.

  As described above, according to the first aspect of the invention, it is possible to extend the service life of the cylindrical shank worn near the end by the action of promoting the discharge of the shaving sludge by the turning of the shaving discharge blade. A core bit reproducing method can be provided.

  According to the second aspect of the present invention, in the regenerating method of the core bit, since the swarf discharging blade swirls at a turning radius that does not exceed the cutting radius by the cutting tip, the circular shape of the object to be cut by the rotation of the regenerated core bit. Cutting can be performed smoothly with a required cutting width.

  According to the invention of claim 3, in the regenerating method of the core bit, not only the shavings discharge blade is fixed to the cylindrical shank but also the worn cutting tip is replaced with a new cutting tip. Function can be improved.

  According to the fourth aspect of the present invention, in the method of regenerating the core bit, the used cutting tip that has been worn and recovered by cutting use as the shavings discharge blade is diverted. It can contribute to the effective use of resources and the reduction of environmental load by recycling and recycling.

  According to the fifth aspect of the present invention, a plurality of chips sludge generated around the cutting tip during the rotary cutting of the core bit are fixed around the outer surface near the worn end of the cylindrical shank at a predetermined inclination and interval. The turning of the shavings discharge blade promotes the discharge by receiving a pressing force toward the base of the cylindrical shank, that is, the opposite end in the gap between the cutting cross section of the workpiece and the outer surface of the cylindrical shank. Therefore, it is possible to reduce the stagnation of sludge and the discharge failure around the cutting tip and to suppress the progress of wear in the thickness direction near the end of the cylindrical shank.

FIG. 1 (A) is a front view showing a longitudinal section near the end where the thickness of the core bit is exaggerated before cutting use, and FIG. 1 (B) is a perspective view near the end of the core bit shown in FIG. 1 (A). . FIG. 2 (A) is a front view showing a longitudinal section near the end of the cylindrical shank and the end of the core bit with the cutting tip worn out by cutting use of the core bit shown in FIG. 1 (A). 2 (B) is a front view showing a longitudinal section in the vicinity of the end portion exaggerating the thickness of the core bit obtained by regenerating the worn core bit shown in FIG. 2 (A) by introducing a shaving discharge blade, and FIG. FIG. 3 is a front view showing a longitudinal section in the vicinity of an end portion exaggerating the thickness of the core bit obtained by replacing the cutting tip with a new cutting tip when the core bit is regenerated by introducing the chip discharging blade as shown in FIG.

Hereinafter, the present invention will be specifically described with reference to the drawings.
1 (A) and 1 (B), a core bit 1 before being used for cutting is formed by fixing a plurality of cutting tips 2 to end portions of a cylindrical shank 3 by brazing or laser welding at a required interval. Yes. The cylindrical shank 3 is made of, for example, a carbon steel pipe or a carbon steel plate bent into a cylindrical shape, and the cutting tip 2 is made of, for example, a rectangular parallelepiped diamond tip curved along the end of the cylindrical shank 3. And a radial thickness D exceeding the thickness d of the cylindrical shank 3.

  The core bit 1 shown in FIG. 2 (A) is a state in which both the members of the cutting tip 2 and the cylindrical shank 3 are worn by the cutting use of the core bit 1 shown in FIGS. 1 (A) and 1 (B). belongs to. That is, the cutting tip 2 wears and shrinks particularly in the thickness direction (radial direction) and the height direction (axial direction), and the cylindrical shank 3 wears in the thickness direction on both the inner and outer surfaces, particularly in the vicinity of the end 3a. The taper is thin.

  A core bit 1 shown in FIG. 2B is obtained by regenerating the worn core bit 1 shown in FIG. 2A by the reproduction method according to the present invention. That is, a plurality of shavings discharge blades 4 are inclined by an angle θ in the direction of the end of the cylindrical shank 3 with respect to the rotation direction α of the core bit 1 around the outer surface of the end 3a of the cylindrical shank 3 that is worn. Thus, the life of the core bit 1 which is fixed at a required interval and thus worn is increased. In this case, if necessary, the plurality of swarf discharging blades 4 may be fixed so as to be able to turn at a turning radius r1 that does not exceed the cutting radius R1 of the cutting tip 2. As the shavings discharge blade 4, the used cutting tips 2 that are worn and recovered by cutting use are diverted from the viewpoint of effective use of waste, circulation use, reduction of environmental load, and the like. Is arranged so that the curved concave surface faces the base direction (upward in the drawing) of the cylindrical shank 3 in a bucket shape so as to enhance the discharging action of the shavings sludge.

  Further, the core bit 1 shown in FIG. 2C is obtained by regenerating the worn core bit 1 shown in FIG. 2A by a reproduction method in which another process is added to the reproduction process shown in FIG. 2B. . That is, the worn cutting tip 2 is replaced with a new cutting tip 2, and a plurality of shavings discharge blades 4 made of used cutting tips 2 that have been worn out and collected are processed as shown in FIG. Similarly, the cylindrical shank 3 is cylindrical so as to be able to turn around the outer surface near the worn end 3a of the cylindrical shank 3 with a rotation radius r2 that does not exceed the cutting radius R2 of the cutting tip 2 and with respect to the rotational direction α of the core bit 1. The core bit 1 which is fixed at a required interval in a posture inclined by an angle θ in the direction of the end of the shanks 3 is used to extend the life of the core bit 1.

α Rotation direction of the core bit θ Tilt angle of the chip discharging blade d Cylindrical shank thickness D Radial thickness of the cutting tip R1, R2 Cutting radius of the cutting tip r1, r2 Rotating radius of the chip discharging blade 1 Core bit 2 Cutting tip 3 Cylindrical shank 3a Near end of cylindrical shank 4 Shavings discharge blade

Claims (5)

  A plurality of cutting tips are fixed to the end of a cylindrical shank at a required interval, and are used to cut a work piece into a circle by attaching it to a core drill device so that it can rotate around the axis and move in the axial direction. In the method of reclaiming a core bit that is near the end of the cylindrical shank or near the end of the cylindrical shank and the cutting tip is worn, a plurality of chip discharge blades are arranged near the worn end of the cylindrical shank. The blade includes a blade fixing step that is inclined around the outer surface of the core bit in the direction of the end of the cylindrical shank with respect to the direction of rotation of the core bit and fixed at a required interval. The swarf sludge is pressed toward the base of the cylindrical shank by the swarf discharge blade that rotates around the axis along with the rotation of the core bit. Worn core bits reproducing method being characterized in that as.   In the blade fixing step, the plurality of shavings discharge blades are inclined around the outer surface near the worn end of the cylindrical shank toward the end of the cylindrical shank with respect to the direction of rotation of the core bit and The method for regenerating a worn core bit according to claim 1, wherein the worn core bit is fixed at a required interval so as to be able to turn with a turning radius not exceeding the cutting radius.   The method for regenerating a worn core bit according to claim 1, further comprising a chip replacement step of replacing the worn cutting chip with a new cutting chip.   The method for regenerating a worn core bit according to any one of claims 1 to 3, wherein a used cutting tip that has been worn and recovered by cutting is used as the shavings discharge blade.   The core bit reproduced | regenerated by the reproduction | regeneration method of the core bit in any one of Claims 1-4.

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