JP2013136138A - Chip saw for metal cutting - Google Patents

Abstract

PROBLEM TO BE SOLVED: To effectively suppress the breakage of a chip of a saw blade even if an inner surface bead continuously formed in an arc welded steel pipe, an electric resistance welded steel pipe or the like is cut, to easily break the inner surface bead, and furthermore, to decrease the cutting resistance of the steel pipes.SOLUTION: A chip saw for cutting a metal includes saw blades 43 projected at an external periphery of a disc-shaped base metal 42 at a predetermined interval, chips 45 fixed to notch-shaped pedestals 44 formed at the front side of each saw blade 43, and chip chambers 46 disposed between the adjacent saw blades 43. The saw blades 43 are formed approximately in square shapes when seen from the front side and the top surface 43a thereof are extended in the circumferential direction of the base metal 42. The chips 45 have inclined surfaces 43b formed at both side edges of a top flank surface 45a and the saw blades 43 also have inclined surfaces 43b formed at both side edges of the top surface 43a.

Description

  The present invention relates to a metal cutting tip saw suitable for cutting a welded steel pipe having a bead on the inner surface of the pipe.

  In arc welded steel pipes and ERW steel pipes, beads are formed on the inner and outer surfaces of the steel pipe during manufacture, and the outer beads are easily cut and removed by bringing a cutting tool of a dedicated cutter into contact with the outer surface of the steel pipe. be able to. On the other hand, the bead on the inner surface of the steel pipe is usually cut through an internal bead with a cutting tool such as a trimmer and cut with the cutting tool, and then the bead is finely cut in the steel pipe with a bead chopper. In general, the bead cannot be completely finely cut. Therefore, with this kind of metal cutting tip saw, the inner bead which is left in the pipe when the steel pipe is cut into a predetermined length is not cut. Will be cut at the same time.

JP 2000-84731 A JP 2000-218431 A JP 2008-178925 A JP-A-6-246535

  However, as shown in FIG. 12, this type of conventional tip saw 51 easily discharges chips generated during cutting of a steel pipe from a blade chamber 54 between saw blades 53 projecting from the base metal 52 at regular intervals. In order to do this, in the blade chamber 54, the tip surface 58 of the tip 55 of the saw blade 53 and the opposing surface 56 thereof are respectively rotated in the rotational direction of the tip saw 51 with respect to the center line CL extending from the center of the tip saw 51 to the outer peripheral direction. The upper inlet opening 54a of the blade chamber 54 is widened by setting the angles α1 and α2 to be inclined, so that when the steel pipe described in the previous section is cut together with the inner surface bead, the inner surface bead makes the tip 55 early. The tip saw 51 has a short life, and the number of cuts in the steel pipe varies greatly depending on the internal bead entering into the blade chamber 54 described above. There was also a title.

  In addition to this, in a relatively small-diameter tip saw used for a hand-held small-sized cutting machine or the like, a tip rear portion of the saw blade is made larger than usual and a projection is provided on the portion. The tip saw was intended to prevent excessive cutting into the workpiece and improve the strength of the base metal, and did not contribute to prevention of tip breakage due to the above-described inner bead.

  It is an object of the present invention to effectively suppress breakage of a tip in a saw blade even when cutting an arc welded steel pipe, an electric resistance welded steel pipe or the like together with a continuous inner surface bead in the pipe, and cutting at that time An object of the present invention is to provide a chip saw capable of suppressing resistance.

  According to the first aspect of the present invention, saw blades protrude from the outer periphery of the disk-shaped base metal at a predetermined interval, and a chip is fixed to a notch-shaped base formed on the front side of each saw blade. In a saw with a blade chamber between saw blades, the saw blade has a substantially rectangular shape when viewed from the front whose top extends in the circumferential direction of the base metal, and the tip is inclined on both side edges of the top flank. And a cutting saw for metal cutting in which inclined surfaces are also formed on both side edges of the top surface of the saw blade.

  According to a second aspect of the present invention, in the metal cutting tip saw according to the first aspect, the top surface of each saw blade is gradually increased from the rear end portion to the rear end, and the height of the rear end of the saw blade is increased. The height position is lower than the top height position of the tip facing the blade chamber.

  According to the tip saw according to the present invention, the cutting performance of the welded steel pipe is further improved, and it is possible to effectively prevent the inner bead from entering from the inlet opening of the blade chamber. Since the inclined surfaces are formed on both side edges of the top surface of the saw blade corresponding to the shape, when the welded steel pipe is cut by the tip saw, the top of the saw blade comes into contact with the welded steel pipe and the cutting performance is deteriorated. Is effectively prevented.

BRIEF DESCRIPTION OF THE DRAWINGS It is a whole front view of the chip saw which concerns on embodiment, Comprising: The chip surface angle with respect to the centerline and the chip | tip opposing surface angle are shown. FIG. 3 is an enlarged front view of an outer peripheral portion of the chip saw according to the first embodiment. It is a front view which expands and shows the blade chamber part in the outer periphery of the chip saw which concerns on Embodiment 1. FIG. It is an enlarged view of the chip | tip part in the same chip saw, (a) is a front view, (b) is a side view on the rake face side, and (c) is a plan view. It is front sectional drawing which shows the cutting condition of the steel pipe by the tip saw of embodiment. It is a plane sectional view showing the cutting situation of the steel pipe by the tip saw of an embodiment similarly. It is front sectional drawing which shows the condition from generation | occurrence | production of the chip in a blade chamber to discharge | emission in the cutting | disconnection of the steel pipe by the tip saw of embodiment similarly. It is an enlarged front view of the outer peripheral part of the chip saw which concerns on Embodiment 2. FIG. It is a front view which expands and shows the blade chamber part in the outer periphery of the tip saw which concerns on the same embodiment. It is an enlarged plan view of the outer peripheral part of the chip saw according to the embodiment. It is an expansion perspective view of the saw blade part in the outer periphery of the chip saw which concerns on the same embodiment. It is a front view which expands and shows the blade chamber part in the outer periphery of the conventional chip saw. It is a front view which expands and shows the blade chamber part of the tip saw which concerns on a comparative example. It is an enlarged view of the chip | tip part in the chip saw which concerns on a comparative example, Comprising: (a) is a front view, (b) is a side view by the side of a rake face, (c) is a top view.

  Next, although embodiment of this invention is described according to drawing, this invention is not limited to this embodiment.

  (Embodiment 1)

  As shown in FIG. 1 and FIG. 2, in the tip saw 1 of this embodiment, a saw blade 3 protrudes from the outer periphery of a disk-shaped base metal 2 at a constant interval, and the tip saw rotating direction (arrow) in the saw blade 3 is shown. An L-shaped pedestal portion 4 is formed on the side surface as viewed from the front side, and a vertical rectangular chip 5 is fixed to the pedestal portion 4 by brazing or the like, and the space between the saw blades 3 is a blade chamber 6. It has become.

  The outer diameter D of the tip saw 1 is 250 mm or more, and the opening width W2 at the entrance of the blade chamber 6 is in the range of 0.6 to 1.2% of the outer diameter D.

  Further, the saw blade 3 in the tip saw 1 of the present embodiment has a substantially horizontal rectangle when viewed from the front, and the tip surface 5a of the tip 5 is based on a center line CL extending from the center C of the tip saw 1 in the outer peripheral direction. It is provided in the form of a minus angle α1 inclined in the opposite direction (arrow A direction) to the rotation direction of the tip saw, and the facing surface 6a of the tip 5 in the blade chamber 6 is also opposite to the rotation direction of the tip saw (arrow A). In the negative angle α2 inclined in the direction). As shown in FIG. 3, the top surface of the saw blade 3 has a shape that gradually increases from the rear end portion 3b to the rear end 3a.

  In this embodiment, the bottom portion 6b of the blade chamber 6 has a concave arc shape, and the tip facing surface 6a rising upward from the bottom portion 6b is substantially linear, and from the tip facing surface 6a to the top portion 3a of the saw blade 3. The leading corner 7 has a convex arc shape.

  (Embodiment 2)

  As shown in FIGS. 8 to 11, the tip saw 41 of the present embodiment has the same overall shape as the tip saw 1 of the first embodiment. However, in the tip saw 41 of the present embodiment, the pedestal 44 of the saw blade 43 is used. The top height position H1 of the tip 45 fixed to the top is higher than the top height position H2 of the saw blade 43, and the difference G between the height positions H1 and H2 is less than the thickness of the inner surface bead. The top flank 45 a has a substantially mountain shape having inclined surfaces K that descend on both sides when viewed from the rake face S side (in the direction of arrow E) of the blade chamber 46, and the top flank 45 a of the saw blade 43 that follows the top flank 45 a of the tip 45. Inclined surfaces 43b are also formed on both side edges of the top surface 43a. Further, the top surface 43a of the saw blade 43 is gradually increased from the rear end portion 40b to the rear end 40a in order to easily break the inner surface beads, chips and the like.

  In the tip saw 41 of the present embodiment, the inclined surface 43b is provided over the entire length on both side edges of the top surface 43a of the saw blade 43, but may not be provided over the entire length but may be provided partially.

  Next, the cutting test of the welded steel pipe was done using the tip saws of the following examples and comparative examples according to the present invention. Cutting conditions are as follows: peripheral speed 300 m / min at initial cutting, feed speed 10.0 mm / sec, peripheral speed 550 m / min at pipe cutting, feed speed 30.0 mm / sec, peripheral speed 400 m / min The feed rate was 10.0 mm / sec, and the cutting conditions were changed at the time of cutting the tip saw into the welded steel pipe, at the time of cutting the pipe, and at the time of cutting through.

  Example 1

  As shown in FIGS. 3 and 4, the tip saw according to the embodiment of the present invention has an outer diameter of 550 mm, a blade width W1 of 3.5 mm, a base metal thickness T of 3.0 mm, a number of blades of 90 z, and a blade chamber inlet. The opening width W2 is 4.4 mm (ratio to the tip saw outer diameter = 0.8%), the tip surface inclination angle α1 is −7 degrees, the tip facing surface angle α2 is −7 degrees, and the rake face rake angle α3 is A tip saw having a clearance of -15 degrees, a clearance angle α4 of 8 degrees, and a difference between the top height position of the tip and the top height position of the saw blade of 0.3 mm is manufactured, and STKM13A, φ89.1 × 3 is manufactured using the tip saw. A 5 ton welded steel pipe having an inner surface bead cut and connected with a cutting tool in the pipe was cut.

  As a result, 200 to 300 cuts (average number of cuts = 250 cuts) were possible.

  As shown in FIG. 5, the cutting of the welded steel pipe with the tip saw of the present embodiment is performed by cutting the welded steel pipe P from the F1 side into the F2 side and cutting the welded steel pipe P toward the F2 side. Since the inlet opening 6 c of the blade chamber 6 has a predetermined narrow width as described above, the inner bead B of the steel pipe P does not enter the blade chamber 6, and as a result, the steel pipe P formed by the tip saw 1 does not enter the blade chamber 6. Cutting is performed smoothly and breakage of the chip 5 is effectively suppressed. Further, as described above, the inner surface bead B that is prevented from entering the blade chamber 6 is easily broken by the top surface of the saw blade 3 that gradually increases from the rear end portion 3b to the rear end 3a. The

  In addition, as shown in FIG. 6, even if the inner bead B enters the blade chamber 6 of the tip saw 1, the inner bead B only enters vertically with respect to the tip saw 1 so as to penetrate the tip saw 1. Since the steel pipe P is broken and discharged from the blade chamber 6, the steel pipe P can be stably and efficiently cut without damaging the tip 5.

  Furthermore, as shown in FIG. 7, according to the tip saw 1 according to the present invention, the chips J generated when the steel pipe P is cut are formed in a circular arc shape from the narrow blade chamber inlet opening 6 c in the tip saw 1. It enters inside, is easily broken in the narrow blade chamber 6, and is discharged out of the blade chamber 6 as the tip saw 1 rotates. At this time, in the tip saw 1 according to the present invention, the tip surface 5a is set at a minus angle in which the tip surface 5a is inclined in the direction opposite to the rotation direction of the tip saw 1 (arrow A direction). It is easily discharged out of the blade chamber 6. Moreover, such an effect is exhibited in any of the tip saws of the present invention.

  (Example 2)

  As shown in FIGS. 3 and 4, the tip saw according to the embodiment of the present invention has an outer diameter of 550 mm, a blade width W1 of 3.5 mm, a base metal thickness T of 3.0 mm, a blade count of 140 z, and a blade chamber inlet. The opening width W2 is 4.4 mm (ratio to the tip saw outer diameter = 0.8%), the tip surface inclination angle α1 is −7 degrees, the tip facing surface angle α2 is −7 degrees, and the rake face rake angle α3 is A tip saw having a clearance of -15 degrees, a clearance angle α4 of 8 degrees, and a difference between the top height position of the tip and the top height position of the saw blade of 0.3 mm is manufactured, and STKM13A, φ89.1 × 3 is manufactured using the tip saw. A 5 ton welded steel pipe having an inner surface bead cut and connected with a cutting tool in the pipe was cut.

  As a result, 400-500 cuts (average number of cuts = 450 cuts) were possible.

  (Comparative example)

  As shown in FIGS. 13 and 14, the outer diameter is 550 mm, the blade width W1 is 3.5 mm, the base metal thickness T is 3.0 mm, the number of blades is 90 z, and the opening width W2 at the blade chamber inlet is 11.0 mm (tip saw). (Ratio to outer diameter = 2.0%), the inclination angle α1 of the chip surface 65a is 0 degree, the back surface angle α2 of the facing surface 66a of the chip 65 is +10 degrees, the rake angle α3 of the rake face is −15 degrees, and the clearance angle α4 Produced an 8 degree tip saw, and the tip saw was used to cut a STKM13A, φ89.1 × 3.5t welded steel pipe having an inner surface bead cut and connected in the pipe.

  As a result, 3 to 250 cuts (average number of cuts = 150 cuts) were possible.

  Comparing the number of cuts of the welded steel pipe with the tip saws of the examples and comparative examples described above, the number of cuts of the comparative example saws varies from 3 to 250, and the average number of cuts is about 150. And proved to have a low lifetime.

  On the other hand, in the tip saws of Example 1 and Example 2 according to the present invention, it is proved that the average number of cuts is as large as 350 to 550, the variation in the number of cuts is small, and a stable and long life can be secured. It was.

  The tip saw of the present invention can be expected to be widely used in cutting a welded steel pipe having an inner surface bead because the life is greatly extended compared to the conventional case and a stable number of cuts can be secured.

DESCRIPTION OF SYMBOLS 1 Tip saw 2 Base metal 3 Saw blade 5 Tip 5a Tip surface 6 Blade chamber 6a Tip opposed surface D Tip saw outer diameter W1 Blade width W2 Blade chamber inlet opening width

Claims (2)

  Saw blades protrude from the outer circumference of the disk-shaped base metal at a predetermined interval, chips are fixed to a notch-shaped base formed on the front side of each saw blade, and a space between adjacent saw blades is a blade chamber. In the tip saw, the saw blade has a substantially rectangular shape when viewed from the front whose top extends in the circumferential direction of the base metal, and the tip is formed with inclined surfaces on both side edges of the top flank, and the top of the saw blade A metal cutting tip saw with inclined surfaces formed on both side edges of the surface.   The top surface of each saw blade is gradually higher from the rear end portion toward the rear end, and the height position of the saw blade rear end is formed lower than the top height position of the opposing chip across the blade chamber. The tip saw for metal cutting according to claim 1, wherein

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