JP2007061957A - Band saw blade - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a band saw blade which prevents a blade bottom part from being hardened by coating hard material between cutting edges, and from early being broken by inducing crack from the blade bottom part due to bending or torsional stress concentrated and loaded on a main body, especially the blade. <P>SOLUTION: In a bimetal band saw, the band saw blade 1 is composed of a body part 3 and a cutting edge part 2. The cutting edge part 2 is accurately welded to the body part 3 by an electron beam or the like at a welded part 4, the blade bottom 7 and the welded part 4 are separated, and a hard material 6 is coated on the cutting edge part 2. Non-coated part 8, where a hard material 6 of at least 1 mm or more is not coated on the part of the blade bottom part 5, is provided between the cutting edge 2a and the successive cutting edge 2b in order to reduce crack from the blade bottom part 5 of cutting edge 2o, 2a, 2b, 2c, 2d, 2e. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a band saw blade for metal cutting, and particularly to a bimetal band saw composed of a body portion and a cutting blade portion.

  The conventional band saw blade is made of high-hardness high-speed tool steel or cemented carbide, and the body is made of spring steel. The bimetal is joined at the weld by electron beam welding or leather beam welding. Band saws are the mainstream. Recently, there has been an increase in the hardness of hard work materials and difficult-to-cut materials, and the tendency of high-speed cutting of general steel materials. Along with this, band saw blades with a hard coating coated on the cutting edge have also become widespread.

As a band saw blade coated with such a hard material, in Patent Document 1, a hard material is coated on the back portion of the band saw blade body and hardened, or a band width of 0.15 with a saw width W on the back side of the band saw blade body and the back of the body portion. A band saw blade coated with a hard material and cured is disclosed. In Patent Document 2, a hard cutting edge coated with a hard material is provided with a width of at least 0.2 mm from the bottom of the cutting edge when viewed from the side of the band saw blade body, and each hard cutting edge is discontinuously covered. A constructed band saw blade is disclosed.
JP 2003-211322 JP Utility Model Registration No. 2603622

The band saw blade coated with the hard material of Patent Document 1 has a hard coating continuously coated on the back of the band saw blade body and / or the back surface of the body part. When viewed from the side, the hard coating remains on the bottom of the blade from the rake face. However, the lifespan of the band saw blade has shifted from bending due to abrasion of the band saw blade to breakage of the main body from the blade bottom. In both Patent Documents 1 and 2, since the hard coating remains on the bottom of the blade from the rake face when viewed from the bottom side of the band saw blade, the band saw blade is mounted on the band saw and the band saw blade is bent. When used while twisting, the bending and torsional stress concentrates and acts on the main body, especially the blade bottom, and if it is hard-covered between the cutting blade and the cutting blade, the blade bottom becomes harder than the uncoated product. The bending and torsional fatigue strength of the steel decreased, causing cracks from the blade bottom and causing early breakage.
Moreover, by continuously coating the hard coating on the back of the saw blade body and / or the back surface of the body blade with a hard coating, it was possible to increase the hardness of these parts and improve the wear resistance. However, when a hard coating is continuously coated on the back of the body of the band saw blade or the back of the body and / or the back of the body of the blade, although the wear of the blade edge is slight, the band saw blade is repeatedly bent as described above, Due to repeated fatigue during twisting, a crack was induced on the back part of the band saw blade body and / or the back surface of the body part, causing the body part to break. However, both Patent Documents 1 and 2 have no suggestion or disclosure for solving the problem.

The problem of the present invention is that when the band saw blade is mounted on the band saw machine and used while bending and twisting the band saw blade, the blade bottom is hardened by hard coating between the cutting blade and the cutting edge, and the bending portion is bent to the main body portion, particularly the blade bottom portion. It is an object of the present invention to provide a band saw blade in which torsional stress concentrates and acts to induce cracks from the blade bottom and prevent early breakage.
Another problem of the present invention is that when a band saw blade is mounted on a band saw machine and used while the band saw blade is bent and twisted, the band saw blade body back portion and / or the trunk portion due to repeated fatigue when the band saw blade is repeatedly bent and twisted. The object is to provide a band saw blade that induces cracks on the back side surface and does not break early.

  For this reason, this invention is a bimetal band saw which consists of a trunk | drum and a cutting-blade part, Comprising: A blade bottom and a welding part space apart, The element periodic table group 3b element, 4a-6th in the said cutting blade part In a bimetal band saw coated with a hard material composed of one or more of group element nitride, carbide, carbonitride, oxide, oxycarbide, oxynitride, and oxycarbonitride, the cutting edge blade In order to reduce cracks from the bottom, the portion that becomes the blade bottom between the cutting edge and the next cutting edge is provided with an uncoated portion that does not cover the hard material by at least 1 mm, and the hard material is discontinuously coated. The above-described problem of the present invention is solved by a band saw blade characterized by the above.

  In the present invention, in order to reduce cracks from the cutting edge, the part that becomes the cutting edge between the cutting edge and the next cutting edge is provided with an uncoated portion that does not cover the hard material by at least 1 mm. When the blade is mounted on the band saw machine and used while bending and twisting the band saw blade, the blade bottom is hardened by hard coating between the cutting blade and the cutting edge becomes hard, and bending and torsional stress concentrate and act on the main body, especially the blade bottom. The present invention provides a band saw blade that induces cracks from the bottom of the cutting blade and prevents early breakage.

  Preferably, the back portion of the trunk portion is subjected to the same curing treatment as the cutting edge coated with the hard substance, but includes an untreated portion, and is applied as a discontinuous curing treatment so that back pressure is applied to the trunk portion back portion during cutting. While acting to increase the abrasion resistance of the back surface when it acts, repeated bending of the band saw blade, repeated fatigue during twisting induces cracks in the band saw blade back part and / or the back part of the body part and causes early breakage The band saw blade which prevented this was provided.

  The best mode for carrying out the present invention will be described. FIG. 1A is a partial side view of a band saw blade according to the first embodiment of the present invention, FIG. 1B is a top view of FIG. 1A and shows a cutting edge and a blade bottom, and FIG. FIG. 2 (d) is a right side cross-sectional view taken along the line DD in FIG. 2 (a), and FIG. ) Is an enlarged view of part A, and includes the third embodiment of the present invention, and FIG. 9B is an enlarged view of part B of FIG.

  The band saw blade 1 of the first embodiment for carrying out the present invention shown in FIG. 1 and FIG. 2 is composed of a body portion 3 and a cutting edge portion 2, and the cutting edge portion 2 is a high-speed tool steel (a cemented carbide). The body 3 is made of special spring steel with high elastic limit and high bending torsional fatigue strength, and the cutting edges 2o, 2a, 2b, 2c, 2d, 2e ... are in the body 3 The band saw blade 1 is a bimetal band saw that is precisely welded with a weld bead portion 4 with an electron beam or the like. The band saw blade dimensions of the first embodiment of the present invention are the saw width W, the saw thickness t, the pitch P, and the set width T, which are specifications for cutting steel materials. The blade bottom 7 and the welded portion 4 are separated and cut. The blade part 2 has one or more kinds of nitrides, carbides, carbonitrides, oxides, oxycarbides, oxynitrides, oxycarbonitrides of Group 3b elements, Groups 4a to 6a of the Periodic Table of Elements In a bimetal band saw coated with a hard material 6 shown in gray consisting of two or more kinds, in order to reduce cracks from the blade bottom 5 of the cutting edges 2o, 2a, 2b, 2c, 2d, 2e. ), An uncoated portion 8 that does not cover the hard substance 6 shown in gray at least 1 mm or more is provided in the portion that becomes the blade bottom portion 5 between the cutting edge 2a and the next cutting edge 2b. As shown in FIG. 1A, when viewed from the side, a large number of cutting edges 2o, 2a, 2b, 2c, 2d, 2e,. As shown in gray in FIGS. 2 (a) and 2 (b), the hard coating 6 is applied only to the high-speed tool steel forming the cutting edge part 2 and the part involved in the cutting of the weld bead part 4. FIG. When viewed from the side, at least the blades 2o, 2a, 2b, 2c, 2d, 2e,... And the hard coating 6 between the blade portions are discontinuous at the uncoated portion 8. 2B, the hard coating 6 is applied only to the cutting edges (parts of the high-speed tool steel) 2a, 2b... And the weld bead part 4 and not to other parts. An uncoated portion 8 was provided. Further, there may be a configuration in which there is an uncoated portion 8 with hard coating in the vicinity including the blade bottom 7 without performing hard coating on a part of the blade bottom portion 5, and at least discontinuous.

  The band saw blade 1 according to the second embodiment of the present invention is the same as the cutting blade part 2 coated with a hard substance, as shown in the back view of the band saw blade body part viewed from the direction C in FIG. 1 (c). Although the hardening process is performed, the unprocessed part 10 is included, and it is applied to the trunk back part 9 as a discontinuous hardening process, so that it is resistant to rubbing wear on the back surface when back pressure is applied during cutting. If a hard material is continuously applied to the band saw blade back 9, the main body will bend due to the torsion and bending when mounted on the band saw, but the body back 9 will not be cured. The treatment part 10 is provided irregularly, and the body back 9 is hardened discontinuously in the untreated part 10, so that the body breaks due to the back part starting point due to the twisting and bending action when mounted on such a band saw machine. Can be prevented.

  The band saw blade 1 of the third embodiment of the present invention shown in FIG. 2 (a) has cutting edges 2a, 2b coated with a hard material 6 at least of the cutting edges 2a, 2b when viewed from the side of the band saw blade body 3. Provided with a width of 0.2mm from the bottom of the blade 7 to suppress the progress of wear of the blade edge during cutting, further prevent chip welding and reduce the frictional resistance of the rake face. It became a long life.

  The band saw blade 1 of the first embodiment for carrying out the present invention shown in FIG. 1 and FIG. 2, wherein the hard material is a nitride or carbonitride of a group 4a to 6a metal in the TICN-based periodic table A band saw blade with a hard cutting edge coated with a hard material selected from the above was made. A body fatigue test was conducted to perform a body bending test repeatedly. As shown in Fig. 3 (a), the in-house bending tester grips the band saw 1 on the chuck at intervals of 220mm span, and performs a repeated bending test on the body with a ± 30mm stroke in the lateral direction using a drive unit (not shown). It was. Fig. 3 (b) shows the number of times the main body is repeatedly bent until the 10 new coatings of the present invention and 10 conventional coatings are broken, and Fig. 3 (c) shows the data of Fig. 3 (b) in a graph. . If the conventional coating has a hard coating between the cutting edges on the bottom of the blade and the one with no hard coating on the bottom 5 between the cutting edges of the product of the present invention, the bending fatigue life of the invention is the conventional product. Compared to 23%.

Band saw blade using high alloy high-speed blade material: endless belt length 5300mm × plate width 41mm × plate width 1.3mm × 2/3 piles per inch (2.54cm), existing coating and new coating products Prototyped. The work material was SKD 61 φ300mm, and the cutting performance test was carried out under the machining conditions; cutting speed = 45m / min and cutting rate = 28cm ² / min. The new coating product was compared to the conventional coating product. The life was improved by about 25%, and the life form was changed from the bending life of the main body from the conventional origin of the bottom of the blade to the bending life, and the result of shifting to the normal wear of the blade edge and the effect of coating treatment of the blade edge was obtained.

In the band saw blade of the first embodiment of the present invention, in order to reduce cracks from the cutting blade bottom, the portion that becomes the blade bottom between the cutting blade and the next cutting blade is not coated with a hard material at least 1 mm or more. Since the band saw blade is mounted on the band saw machine, and the band saw blade is bent and twisted, it is hard-covered between the cutting edge and the cutting edge to harden the bottom of the blade. A band saw blade that prevents bending and torsional stress from concentrating and acting to induce cracks from the blade bottom and prevent early breakage is provided.
In the band saw blade of the second embodiment of the present invention, the body portion is subjected to the same hardening treatment as that of the cutting blade coated with the hard substance on the back portion thereof, but includes an untreated portion and is cut as a discontinuous hardening treatment. The back of the band saw blade and / or the back of the trunk due to repeated bending of the band saw blade and repeated fatigue during twisting while strengthening the abrasion resistance of the back surface when back pressure acts on the back of the trunk A band saw blade is provided that induces cracks on the sides and prevents early breakage.

(A) is a partial side view of the band saw blade of the first embodiment of the present invention, (b) is a top view of (a) showing the cutting edge and the blade bottom, and (c) is from the C direction of (a). FIG. 5B is a right side cross-sectional view taken along the line DD of FIG. 5A, including the second embodiment of the present invention in the seen trunk back view. (A) is the A section enlarged view of Drawing 1 (a), and contains the 3rd embodiment of the present invention, and (b) is the B section enlarged view of Drawing 1 (b). (A) shows the specifications of in-house bending tester, (b) shows the data of the number of times the main body is repeatedly bent until breakage of 10 new coatings of the present invention and 10 conventional coatings, and (c). The data of (b) is shown by a graph.

Explanation of symbols

DESCRIPTION OF SYMBOLS REPRESENTING MAJOR PARTS OF THE DRAWING 1 ・ ・ Band saw blade, 2 ・ ・ Cutting edge, 2o, 2a, 2b, 2c, 2d, 2e ・ ・ Cutting blade, 3 ・ ・ Body part 4 5 .. Bottom of the blade, 6 .. Hard material, 7.. Bottom of the blade, 8 .. Uncovered part 9 .. Back part of the body, 10.

Claims (4)

  A bimetal band saw consisting of a body part and a cutting edge part, wherein the blade bottom and the welded part are spaced apart, and the cutting edge part has a periodic table element group 3b element, a nitride of group 4a to 6a element, In bimetal band saws coated with a hard material consisting of one or more of carbide, carbonitride, oxide, oxycarbide, oxynitride, oxycarbonitride, reduce cracks from the bottom of the cutting edge Therefore, a band saw that is provided with an uncoated portion that does not cover the hard material at least 1 mm or more at a portion that becomes a blade bottom portion between the cutting blade and the next cutting blade, and the hard material is discontinuously coated. blade.   The cutting edge coated with the hard material is provided with a width of at least 0.2 mm from the bottom of the cutting edge when viewed from the side of the band saw blade body, and each hard cutting edge is coated discontinuously. The band saw blade according to claim 1.   3. The body back portion is subjected to the same curing treatment as that of the cutting blade coated with the hard substance, but includes an untreated portion and is performed as a discontinuous curing treatment. Band saw blade.   2. The cutting edge portion is made of high-hardness high-speed tool steel or cemented carbide, and the barrel portion is made of spring steel having a high elastic limit with high bending and torsional fatigue strength. A band saw blade according to claim 2 or claim 3.