JP2006055913A - Carbide cutting blade specific to weeding and brushing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a carbide cutting blade specific to weeding and brushing, which allows re-grinding (re-toothing) thereof in the easiest manner as possible during weeding and brushing work in a forest land, and is available over a long period of time even after a plurality of times of re-grinding. <P>SOLUTION: According to the structure of the carbide cutting blade, a disk-shaped blade plate 1 has a number of teeth 2 on a circumference thereof. Each tooth is inclined rearward from the tip to form a gullet 3 of a tooth next thereto, and a hard chip 4 such as a tungsten carbide chip is attached to the tip of each tooth. The chip attached to the tip of the tooth has a slender shape, and it is arranged such that its long side extends along an upper side of the tooth and that its short side is located along a rake face 6, whereby a cutting edge 5 is formed at a longitudinal edge of the slender chip. Thus, by grinding the chips only by a slight quantity by a file, especially by a round file, the cutting edges 5 of the cutting blade are re-toothed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is an invention related to a cemented carbide cutting blade that is effective mainly for use in cutting down a forest.

  Brush cutters driven by an engine are widely used for cutting weeds on a flat ground, and for cutting down forests. Among these, a brush cutter used for cutting a forest is used under severe conditions in which not only vines and normal weeds but also a variety of things such as bushes and small shrubs are cut. In addition, since the work is performed deep inside the mountain, it is necessary to re-grind the cutting edge of the cutting blade plate at the site or to carry a spare cutting blade plate in order to damage the cutting blade plate. It was. Therefore, an all-steel cutting blade plate having a shape shown in FIG. 9, which can be re-polished relatively easily for cutting a forest, is widely used.

All-steel cutting blade plates have been used in various shapes depending on the application, but all-steel cutting blade plates have a disadvantage of poor durability. Therefore, for general weed cutting on flat ground, as shown in FIGS. 10 and 11 as a cutting blade plate for a brush cutter, tungsten carbide, titanium carbide, etc. are formed on the tooth profile B formed on the outer periphery of the disc-shaped blade plate A. Chip saws joined with hard chips C of No. 1 have been widely used. However, since the tip saw having excellent durability is difficult to re-grind at the same time, it has been rarely used for cutting a forest.
In the conventional chip saw shown in FIG. 10, as disclosed in Patent Documents 1 and 2, the chip C is bonded in such a manner that it is embedded obliquely rearward from the tip of the tooth profile B. The conventional chip saw shown in FIG. 11 has a chip C bonded to the front surface of the tooth profile B as disclosed in FIG. 5 of Patent Document 1 and Patent Document 3.
Japanese Utility Model Publication No. 03-23055 (FIGS. 1 and 5) Japanese Patent Laid-Open No. 7-312946 (FIG. 1) JP-A-8-71843 (FIG. 1)

With a cutting blade plate made of all steel, the cutting edge D is easily worn away, and it is necessary to re-grind (remake) the cutting edge D frequently in the cutting of a forest used under severe conditions. In this case, as shown by cross-hatching in FIG. 9, the cut portion E is cut out using a round file on the front surface portion of the tooth profile so that the rounded cutting edge is sharp.
The conventional tip saws shown in FIGS. 10 and 11 are more durable than all-steel cutting blades, but even a tip saw with excellent durability can be used for a long time or severely. The tip (blade edge) of the tip C, which is a cutting edge, is worn out by use under such conditions. At this time, in order to sharpen the cutting edge D rounded by abrasion, polishing is performed so that the upper side of the tooth profile B including the tip C or the front surface of the tooth profile B is largely cut as shown by cross hatching.

As described above, the cutting blade plate made of all steel needs to be re-polished frequently, and the conventional tip saw accurately cuts the cutting part E in a relatively large range of the tip C that is hard and wear-resistant. Therefore, it was necessary to polish the material and it was difficult to re-grind it easily at the work site. Therefore, realignment of the carbide cutting blade used for undercutting should be done in a well-equipped place where the machine can accurately set the angle of the cutting edge, side angle, tip clearance angle, etc. It is normal to carry a spare tip saw. This has been a drawback that the burden on the equipment of the worker is increased accordingly. Further, the conventional tip saw has a disadvantage that it is not economical because one tip saw cannot be used for a long time because the tip C is greatly scraped off by re-polishing.
In view of the above-mentioned disadvantages of the prior art, the present invention has a small amount of chips to be excised by a single polishing, and can be re-polished (re-adjusted) by hand as easily as possible. An object of the present invention is to provide a cemented carbide cutting blade exclusively for undercutting that can withstand and can be used for a long time. In particular, in view of the fact that mountain forest workers are skilled in reworking cutting blade plates made of all steel, it is necessary to provide a carbide cutting blade dedicated to undercutting that can be repolished by that technique. It is the purpose.

  In order to achieve the above object, the cemented carbide blade for undercutting according to the first aspect of the present invention forms a large number of teeth 2 and 2 on the outer periphery of a disc-shaped blade plate 1. The shape of the tooth profile 2 is such that the upper side (outer peripheral edge) is inclined rearward from the tip to form the galette 3 of the next tooth profile 2, and the tip of each tooth profile 2 is made of a hard material such as tungsten carbide or titanium carbide. The chip 4 is joined. The tip 4 to be joined to the tip of each tooth profile 2 is an elongated tip, the longitudinal direction of the tip is arranged in the direction along the upper side of the tooth profile 2, that is, the circumferential direction, and the short side is the scooping surface 6 at the tip of the tooth profile 2. The blade edge 5 is formed at the front end in the longitudinal direction of the elongated chip 4. The gallet 3 which is a void in front of the tooth profile 2 has a size and shape through which a file, mainly a round file, passes, and the tip portion of the chip 4 exposed on the scooping surface 6 can be polished by the file.

  In the invention according to claim 2, the long side dimension along the upper side of the tooth profile 2 of the chip 4 serving as the flank 7 is 3 mm or more, and the short side dimension of the chip serving as the scooping surface 6 is 1.5 to 2.5 mm. The clearance angle β, which is the chip joining direction, is less than 20 degrees.

  According to the third aspect of the present invention, a horizontal angle γ is formed on the cutting edge 5 which is a cutting edge at the tip of the tip 4 arranged on the outer periphery of the blade plate 1, and the horizontal angle γ is inclined alternately left and right, and the tip 4 The blade edge 5 is formed with a clam that protrudes from the thickness surface of the blade plate 1.

  According to the cemented carbide cutting blade for undercutting according to the first aspect of the present invention, when the cutting edge 5 is worn, the front end portion of the tooth profile, that is, the scooping surface is re-polished with a file. At this time, since the tip appearing on the scooping surface is the short side of the elongated tip 4, the tip 5 is sharpened by cutting a small amount of the tip 4 that is hard and difficult to polish. It can be easily rebuilt. For this reason, when cutting down forests, etc., cutting-off cutting work can be carried out while properly redressing the wear of the cutting edge 5 while using a cutting-edge cemented carbide blade with excellent sharpness and durability. Thus, it is not necessary to carry a spare cutting blade plate as in the conventional tip saw, and the cutting operation can be efficiently performed. In addition, the carbide cutting blade for undercutting according to the present invention requires only a small amount of the tip to be cut when re-setting, so that re-setting can be performed many times as compared with the conventional tip saw, which is extremely economical. .

  The invention according to claim 2 relates to a specific shape of the chip. By making the long side dimension of the chip not less than 3 millimeters and the short side in the range of 1.5 to 2.5 millimeters, polishing is easy and It has sufficient cutting edge strength and can withstand multiple times of re-polishing. That is, as a result of the inventors' research, the time required for reshaping (repolishing) is shortened by setting the above dimensions, and the performance (sharpness / durability) as a lower cutting blade is 1.5 mm thick in the radial direction of the chip. It has been proved to be fully effective. Further, by setting the clearance angle in the range of 0 to 20 degrees, chipping of the cutting edge that is the tip of the tip, that is, chipping can be prevented.

  According to the third aspect of the present invention, not only undercutting thin things such as weeds and vines, but also cutting shrubs that are somewhat thick and small-diameter standing trees that have been conventionally cut using a hand saw or the like. it can.

Hereinafter, preferred embodiments of a cemented carbide cutting blade according to the present invention will be described with reference to the accompanying drawings.
FIG. 1 is a front view of a cemented carbide blade exclusively for lower cutting according to the present invention, and a part thereof is enlarged and displayed. FIG. 2 is an enlarged front view of only a part of the cemented carbide cutting blade for lower cutting, and FIG. 3 is a schematic diagram showing a chip joining process.

  A large number of tooth shapes 2 and 2 are formed on the outer peripheral edge of the blade plate 1 formed in a disc shape with a steel material such as special tool steel, and the tip 4 is joined to the tip portion of each tooth shape. The tooth profile 2 formed on the outer peripheral edge of the blade plate 1 is such that the front surface of the projecting tooth profile 2 is substantially arc-shaped, and gently slopes backward from the apex to form the galette 3. Continuing to the front. An elongated hard tip 4 is joined to the apex portion of the tooth profile 2 along the upper side of the tooth profile 2 by welding or brazing.

  In order to join a hard tip 4 such as tungsten carbide or titanium carbide to the top of the front end of the tooth profile 2, as shown in FIG. 3 (a), a tip seat 8 for disposing the tip 4 on the front end top of the tooth profile 2 is formed. In addition, the elongated chip 4 is joined to the chip seat 8 in such a manner that the long side is along the upper side of the tooth profile. In the state where the chip is bonded to the chip seat as shown in FIG. 3B, the upper side of the chip 4, that is, the clearance surface 7 and the front end surface of the chip, that is, the scooping surface 6 are polished, and the state shown in FIG. Complete a carbide cutting blade for undercutting.

  The tooth shape of the cemented carbide blade for undercutting completed in this way is as shown in FIG. 2. The elongated tip 4 extends along the upper side of the tooth shape at the front end top portion of the tooth shape 2 having a generally arcuate scooping surface 6 as shown in FIG. The galette 3 in front of the scooping surface 6 is shaped so that a round file can be passed. The tip of the tip 4 is a sharp cutting edge 5 that is a cutting edge, and a front end surface (short side) following the cutting edge 5 forms a scooping surface 6 and an upper surface (long side) forms a flank 7. By forming the scooping surface 6 on the front surface of the tooth profile 2 in a substantially arcuate shape, a scooping angle α having a constant angle is formed on the cutting edge 5. The larger the angle α is, the sharper it is, but it is set in the range of 0 to 25 degrees in relation to the strength. The upper surface (long side) of the tip 4 forms a flank 7, but a constant flank angle β is formed on the cutting edge 5 because of the gentle inclination to the rear. The clearance angle β is preferably set in the range of 0 to 20 degrees in relation to the strength.

  With the above-described configuration, the present invention can complete a cemented carbide cutting blade with a sharp cutting edge 5 for use in cutting. This carbide cutting blade for undercutting has excellent durability because the elongated tip 4 is strongly joined to the tooth profile 2 at the long side, so there is little possibility of falling off due to cutting resistance or impact on the cutting edge 5. It can be. However, if the crushed angle α and the clearance angle β are increased, the force for dropping the chip is reduced if the creased angle α and clearance angle β are decreased, and the strength can be improved.

  Even if it is a hard cutting blade for undercutting that is hard to wear out, the cutting edge 5 is worn out roundly by use, and the sharpness becomes dull. In such a case, the cutting edge 5 can be re-polished using a diamond round file. That is, as shown by a two-dot chain line in FIG. 5 (a), a round file 9 is inserted into the galette 5 and reciprocated in a direction intersecting the blade plate 1, whereby a two-dot chain line in FIG. 5 (b). The front end portion of the tooth profile 2 shown can be cut out to form a new cutting edge that functions as a sharp cutting edge. That is, the blade plate 1 itself is cut away in the inclination direction of the galette 3 by the round file 9, so that the front end of the tooth profile 2 is retracted. However, since the upper side of the tooth profile 2 is also inclined rearward, as a result, the tooth profile 2 having the same shape is maintained and the overall diameter is slightly reduced.

  As a result of using the re-polished cemented carbide cutting blade shown in FIG. 5 (b), if the cutting edge 5 of the tip 4 is further worn, the round file 9 is used as described above. By re-polishing the front end portion of the tooth profile 2, the cutting edge 5 can be regenerated again. Then, by repeating this operation, the tip 4 is gradually shortened, and eventually a relatively small tip 4 is joined to the front end top portion of the tooth profile 5 as shown in FIG. Thus, in the present invention, the horizontally elongated chip 4 can be re-polished many times until the chip 4 becomes short, which is extremely economical.

  The thickness T of the chip 4 to be bonded to the tooth profile 2 of the blade plate 1 can maintain a sufficient bonding strength by making the thickness T substantially the same as the thickness t of the blade plate 1. It can also be larger than the thickness t. Further, as a carbide cutting blade for a brush cutter, it is not always necessary to form a horizontal angle on the cutting edge of the tip 4, but by forming a horizontal angle γ and a set width w on the tip 4, In this way, even a small standing tree can be cut.

  That is, in the embodiment shown in FIG. 4 (a), the tip 4 having the thickness T larger than the thickness t of the blade plate 1 is joined to the center of the thickness of the blade plate 1, thereby the tip 4 from both the front and back sides of the blade plate 1. Protrudes by a certain thickness. Further, as a result of forming the horizontal angle γ alternately on the left and right sides of the cutting edge 5 of the chip 4, the cutting edge 5 of the chip 4, specifically, the sharp tip of the cutting edge, that is, the cutting edge protrudes from the surface of the blade plate 1 alternately on the left and right. Therefore, the thickness protruding from the surface of the blade plate 1 becomes the set width w and functions as a saw tooth. In addition, the horizontal angle γ for functioning as a saw blade is in the range of 5 to 20 degrees, and the clam width w is about 0.2 to 0.3 millimeters, so that almost all of the trees that are generated by cutting down the forest except for thick standing trees are used. It turned out that it can cope with the mowing work.

The embodiment shown in FIG. 4B shows an embodiment in which the chip 4 having a thickness T smaller than that shown in FIG. In this embodiment, when the chip 4 is bonded to the blade plate 1, the side surface of the chip is bonded to the blade plate 1 while being shifted in the plane direction alternately so that a certain dimension protrudes from the surface of the blade plate 1. A horizontal angle γ is formed so that the tip of the blade edge 4 protruding from the surface becomes the cutting edge. Thereby, the protrusion dimension from the blade board 1 of the chip | tip 4 becomes the set width w, and functions as a sawtooth.
Thus, by securing the set width w so that the chip 4 functions as a sawtooth, a small standing tree or the like that has been conventionally cut using a hand saw can be cut without difficulty. .

  The re-grinding (re-shaping) of the cemented carbide blade according to the present invention can be performed by polishing the front end portion of the tooth profile 2 through a round file through the galette 3 portion as described above. The round file 9 used in this case is a known one having diamond particles attached to the surface of a round bar, and passes through the galette 3 portion of the blade plate 1 as shown in FIG. In addition, the front end face of the tooth profile 2 can be polished by reciprocating in a direction coinciding with the horizontal angle γ.

  The hard chip 4 can be polished by using the round file 9 to which the diamond particles are adhered. However, in the manual polishing operation, the blade plate 1 softer than the chip 4 is largely excised, and the tooth profile 2 The shape may be deformed. In preparation for such a situation, the present inventor devised that the guide cover 10 is attached to the round file 9 for use. That is, as shown in FIG. 8, the guide cover 10 has a cylindrical shape that is attached to a file portion to which diamond particles of the round file 9 are attached, and has a window hole 11 in a part thereof. The chip 4 is polished as shown in FIG. 7 using a round file equipped with the guide cover 10. At this time, the root portion of the gallet softer than the tip 4 is protected by the guide cover 10, and the front surface of the tooth profile 2 including the tip 4 is effectively cut off by the exposed file portion of the round file 9 to expose the bottom portion. It is possible to prevent excessive shaving.

  When re-grinding the scooping surface 6 with the round file 9, consideration is given so that the scooping angle α of the blade edge 5 does not become too large, for example, 25 degrees or more. This can be polished to an optimum rake angle by selecting the diameter of the round file to be used. For example, when polishing a carbide cutting blade exclusively for lower cutting where the height of the tooth profile 2 is 5.5 mm. Can be achieved by using a round file with a diameter of 7 millimeters.

  The cutting blade plate made of all steel needs to be re-adjusted frequently because the cutting edge is worn quickly. For example, when performing a general forest cutting operation using a cutting blade plate made of all steel, which is a conventional blade, it is necessary to remake every 1 to 1.5 hours, but only for cutting according to the present invention With a carbide cutting blade, the work could be continued for about 7 to 12 hours. This means that a day's work can be continued. Further, the grinding amount of the blade plate by one re-dressing operation is 0.5 to 1 mm in the conventional blade, but the blade plate by one re-alignment operation of the cemented carbide cutting blade for undercut according to the present invention ( The grinding amount of the tip) was about 0.1 to 0.3 mm.

  In the illustrated embodiment, the shape of the galette 5 is a shape that can be polished by a round file, but a shape that allows a semi-round file or a flat file to pass through, and can be polished by a file other than a round file. It may be.

FIG. 1 is a front view showing an example of a cemented carbide cutting blade for lower cutting according to the present invention, Fig. 2 is an enlarged view of only a part of a carbide cutting blade dedicated to undercutting, FIG. 3 is a schematic diagram showing the process of joining the chip to the blade plate. FIG. 4 is an enlarged view of only a part seen from the thickness direction of the carbide cutting blade dedicated to undercutting, FIG. 5 is a schematic diagram showing the grinding process of the tooth profile, FIG. 6 is a schematic diagram showing a tooth profile polishing work state by a round file, FIG. 7 is a schematic diagram showing a grinding operation state of a tooth profile using a guide cover for a round file. FIG. 8 is a perspective view showing an example of a round file with the guide cover removed. FIG. 9 is a front view showing an example of a conventional all-steel cutting blade plate, FIG. 10 is a front view showing an example of a conventional cutter saw for a brush cutter, FIG. 11 is a front view illustrating another example of a conventional brush saw tip saw.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Blade plate, 2 ... Tooth profile, 3 ... Galette, 4 ... Tip, 5 ... Cutting edge, 6 ... Scuff surface, 7 ... Flank, 8 ... Tip seat, 9 ... Round file, 10 ... Guide cover, 11 ... Window hole , Α… the crawl angle, β… the clearance angle, γ… the lateral angle, w… the clam width.

Claims (3)

  A number of tooth forms are formed on the outer periphery of the disc-shaped blade plate, and the upper side of the tooth form is inclined rearward from the tip to form a gallet of the next tooth shape, and tungsten carbide is formed at the tip of each tooth shape. In cemented carbide cutting blades that join hard tips such as tips, place the longitudinal direction of the elongated tip along the top side of the tooth profile at the tip of each tooth profile, and place the short side on the scooping surface of the tooth profile tip. A tip is formed at the tip of the elongated tip in the longitudinal direction and the size and shape of the file through which the file passes through the gallet in front of the tooth profile, and the tip of the tip exposed as a scooping surface is polished by the file Carbide cutting blade dedicated to undercutting, characterized by being made possible.   The tip has a long side dimension of 3 mm or more along the upper side of the tooth profile as the flank surface, a short side dimension of 1.5 to 2.5 mm as the scoop surface, and a clearance angle of less than 20 degrees in the chip joining direction. The cemented carbide cutting blade for undercut according to claim 1, wherein   A horizontal angle is formed on the blade tip at the tip of the tip that is arranged on the outer periphery of the blade plate, the horizontal angle is alternately inclined to the left and right, and a crest is formed on the tip so that the blade edge protrudes from the thickness surface of the blade plate. The cemented carbide blade exclusively for lower cutting according to claim 1, wherein:

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