JP2008142795A - Saw blade - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a saw blade which suppresses heat storage of the blade when rotating at high speed while holding satisfactory strength of a substrate, and prevents occurrence of trembling of a hand and rubbing of a barrel part due to it so as to improve cutting performance of the saw blade. <P>SOLUTION: This saw blade is constituted by forming: crest parts 21 having circular arc cross section; and flat trough parts 22 alternately on both of front and rear side faces of the steel substrate except an ultra-abrasive grain layer 11 attaching part, a slit 25 forming part, a substrate hole part 27 forming part, and a fastening part 23 on a power tool by tilting them radially and backward from a front part in the direction of rotation of the substrate to form the corrugated substrate, and also by forming a plurality of deep groove parts continued to the trough parts, and a plurality of shallow groove parts adjacent to the slit forming part and the substrate hole part forming part on both of front and rear side faces of the ultra-abrasive grain layer attached to an outer peripheral fringe part of the substrate, respectively. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a grinding tool suitably used for cutting or cutting a work material made of hard and brittle materials such as various building materials such as concrete, stone, and tile, and castings, and more specifically, granite and marble. Made of natural stone, or artificial stone materials such as artificial marble, tiles, tiles, bricks, siding boards, and hard synthetic resins such as fiber reinforced plastics (FRP) and carbon fiber reinforced plastics (CFRP). The present invention relates to a superabrasive saw blade made of diamond abrasive grains or cBN abrasive grains for cutting a slab plate (flat plate) or the like with high accuracy.

  In recent years, in addition to various natural stones and artificial marble (hereinafter sometimes simply referred to as “stone”) as building materials, various hard materials as described above are widely used, and work materials made of these hard materials are used. As a grinding tool for cutting materials into desired dimensions and shapes, a superabrasive layer composed mainly of diamond abrasive grains and cBN abrasive grains is continuously and integrally formed on the outer peripheral edge of a disk-shaped steel substrate. Rim-type saw blades that are bonded together and segment-type saw blades that are formed by super-bonding superabrasive chips made of superabrasive grains and a binder at predetermined intervals are widely used. . These saw blades are usually fastened by being inserted into a spindle of a hand-held rotary electric tool such as a grinder or a sander in an orthogonal state with respect to the shaft center and used for manual operations such as cutting, but rotate at high speed. When cutting a workpiece with an electric power tool, it is difficult to avoid the phenomenon that the posture becomes unstable and the camera shakes, which causes the saw blade substrate to contact the workpiece. It was.

  When the substrate of the saw blade that rotates at such a high speed comes into contact with the work material, so-called body rubbing occurs, and heat generation and vibration due to friction are induced, resulting in a great influence on the accuracy of the cut surface. In addition, since thermal distortion occurs in the substrate and the tool life is shortened, such a phenomenon is required to be suppressed as much as possible, and various attempts have been made conventionally. For example, apart from the diamond abrasive layer formed on the outer peripheral edge of the saw blade, a ring-shaped inner diamond abrasive layer is formed on both sides of the inner side of the substrate, and the inner diamond abrasive grains. A saw blade (see, for example, Patent Document 1) is proposed in which a cut surface of a work material is ground by a layer, and at the same time, a direct contact between the substrate and the work material is avoided. .

  In addition, superabrasive grains such as diamond abrasive grains or cBN abrasive grains are electrodeposited and arranged on the outer peripheral edge of the substrate in a dense state, and at the same time both front and back sides of the intermediate area excluding the spindle fastening portion of the substrate In addition, a saw blade (see, for example, Patent Document 2) in which a plurality of superabrasive grain layer groups formed by abrasive grains of 3 or less per group are arranged at a specific interval is proposed, Compared to the case where the abrasive grains are densely arranged in the same area, by setting the abrasive density to 20 to 60%, the cutting depth of the abrasive grains on the side surface of the substrate is ensured, and the heat generated by the upper slip is effective. Has been reported to have been controlled.

On the other hand, attempts have been made for a long time to apply special processing to the substrate itself to avoid the negative effects caused by so-called torso slipping, and typical saw blades are arranged radially on both sides of the substrate alternately from the axial center to the outer circumferential direction. And a diamond layer is continuously attached along the outer peripheral edge of the corrugated substrate, and a plurality of grooves are radially formed on the front and back sides of the diamond layer and connected to the concave portion of the corrugated substrate. A so-called rim type SD cutter (see, for example, Japanese Patent Application Laid-Open No. H10-228) is widely known in the art, and the air-cooling effect caused by the corrugated substrate acts to prevent the blade from accumulating heat. Since the discharge of chips proceeds smoothly by the groove portion connected to the concave portion and wear under the neck is effectively suppressed, it is widely used even now. Recently, apart from the diamond layer attached along the outer peripheral edge of the corrugated substrate, a plurality of island-shaped diamond layers are formed in the central portion of the substrate spaced from it, and the strength of the corrugated substrate is reinforced. A diamond saw blade (see, for example, Patent Document 4) is also proposed, and in addition to the radial unevenness, a diamond saw blade (for example, a ring-shaped groove formed so as to draw a concentric circle with respect to the axis of the substrate) And Patent Document 5) have been proposed, and it has been reported that the substrate is prevented from shaking due to rotation and strengthened.
JP-A-10-128673 JP 2001-121427 A Registered Design No. 1087498 WO / 30810 Publication JP 2004-358648 A

  In each of the above prior arts, the disc-shaped cutting cutters proposed in Patent Literature 1 and Patent Literature 2 are ground by the superabrasive layers formed on the both side surfaces of the substrate. As a result, it is possible to obtain a smooth and beautiful finished surface, but because the part that does not need to be ground is forcibly ground, resistance is added and obstructs straight cutting. As a result, there is a concern that the cutting efficiency is lowered. In addition, in the saw blade of Patent Document 5 in which ring-shaped grooves are formed on both side surfaces of the substrate, the ring-shaped grooves are formed concentrically with respect to the axis of the substrate. The air cooling effect given by the cutter and the diamond saw blade of Patent Document 4 cannot be expected, and the discharge of cutting waste and the like entering the ring-shaped groove does not remain, but the work material stops in the groove and stops. There remains a problem that is desired to be solved, for example, there is a concern that the grinding surface may be roughened by contact with the surface and cause so-called rubbing. Moreover, in the blades in Patent Documents 3 and 4, in addition to the air cooling effect provided by the corrugated substrate, the discharge of chips from the grooves formed in the diamond abrasive layer is effectively promoted, Although widely used in the field, the diamond abrasive layer serving as the blade portion is a so-called rim type saw blade that is continuously attached along the outer peripheral edge portion of the substrate. However, the bite is slightly inferior to the segment type, and it has been left as a problem to be improved.

  Accordingly, an object of the present invention is to provide a saw blade that improves the cutting performance by suppressing the heat accumulation of the blade during high-speed rotation while preventing the vibration of the blade and the body rubbing caused thereby while maintaining the substrate strength.

  In this situation, the present inventor has conducted intensive studies, and as a result, in order to prevent camera shake and torsion caused by it, ensuring the stability of the substrate during high-speed rotation is the most important factor, and for that purpose. If the shape of the slit formed on the substrate, the shape of the corrugation, and the shape of the groove provided in the superabrasive grain layer to be the blade are of a specific shape, the sharpness and blade as a blade while retaining the advantages of the corrugated substrate itself The present invention has been completed by finding that the strength of the substrate is improved in a well-balanced manner and that the stability of the substrate during high-speed rotation is ensured.

  That is, the present invention is a segment type saw blade in which a superabrasive layer composed of diamond abrasive grains or cBN abrasive grains is intermittently attached to a peripheral edge of a circular steel substrate at a predetermined interval. In the circular steel substrate, the outer peripheral edge portion is equally divided in the circumferential direction, and a plurality of slits having a through-hole at the base end, and a substantially long length that equally pierces the intermediate portion of the substrate between the slits A plurality of circular substrate hole portions are formed so as to be inclined radially from the front to the rear in the rotation direction of the substrate, respectively, and the superabrasive layer attaching portion, the slit forming portion, and the substrate hole portion of the steel substrate. Formed on both sides of the front and back, excluding the forming part and the fastening part to the power tool, by alternately inclining ridges with a circular arc section and substantially flat valleys, and inclining radially from the front to the back in the direction of substrate rotation To obtain a corrugated substrate. Grooves are formed on the front and back side surfaces of the superabrasive grain layer attached to the outer peripheral edge of the outer circumferential edge part at equal pitches in the circumferential direction and alternately on the front and back sides, and the groove part includes a deep groove part connected to the trough part, A saw blade comprising a slit forming portion and a shallow groove portion adjacent to the substrate hole forming portion is provided.

  Further, according to the present invention, a first corrugation in which a middle mountain portion and a flat middle valley portion having an arcuate cross section are alternately formed between the slit forming portion and the fastening portion to the power tool, and the formation of the substrate hole portion. The second corrugated portion in which the small ridges having a circular arc shape and the flat ridge portions are alternately formed between the fastening portion and the fastening portion to the power tool are shorter than the middle valley portion and the middle valley portion, and the substrate is rotated. The saw blade is provided so as to be inclined radially from the front to the rear in the direction.

  In addition, the present invention provides the saw blade, wherein the plurality of slits are formed by dividing the outer peripheral edge portion into four equal parts in the circumferential direction.

  Further, the present invention provides the saw blade, wherein the deep groove portion and the shallow groove portion are formed to be inclined substantially radially from the front to the rear in the rotation direction of the substrate.

  According to the present invention, the shallow groove portion includes 2 to 4 first groove portions adjacent to the slit forming portion and 2 to 5 second groove portions adjacent to the substrate hole forming portion. The saw blade is provided.

  Further, the present invention provides the saw blade, wherein a chamfering process is performed on a through hole formed at the base end of the slit.

  In the present invention, the superabrasive layer attaching portion is formed to be slightly thinner than the plate thickness of the portion other than the superabrasive layer attaching portion in the substrate, The saw blade is characterized in that the saw blade is formed to be slightly thicker than the thickness of the portion other than the superabrasive layer attachment portion of the substrate.

  Further, in the present invention, the means for attaching the superabrasive layer to the steel substrate is simultaneous sintering in which formation of the superabrasive layer and bonding to the steel substrate are simultaneously performed. The saw blade is provided.

  The saw blade of the present invention suppresses heat accumulation of the blade during high-speed rotation while maintaining the substrate strength, ensures stability in the rotation direction, prevents hand shake and the resulting rubbing, and improves cutting performance. That is, when the saw blade is fastened to a spindle of a rotary electric tool such as a grinder or a sander in an orthogonal state, and the cutting work is manually performed on a work material such as a stone, hand shake is effectively suppressed. , Can continue stable work.

  In the present invention, by making the substrate form a special corrugated substrate partially composed of crests and troughs, the substrate strength is improved and the reliability in terms of safety as a saw blade is ensured. Increasing the surface area of the substrate increases the amount of heat dissipation, and the air cooling effect during high-speed rotation works synergistically to effectively suppress the heat storage of the blade, which can have a positive impact on cutting performance. it can.

  In addition, the substantially oval substrate hole formed in the substrate, together with the through hole formed at the base end of the slit, reduces the contact area with the work material on the flat surface of the substrate, and suppresses heat storage, which is good This contributes to maintaining good cutting performance.

  Further, the cutting waste is smoothly discharged by the deep groove portion of the superabrasive grain layer formed continuously with the valley portion of the corrugated substrate, while the superabrasive grains are in the vicinity of the slit forming portion and the substrate hole forming portion. Shallow grooves are formed on both side surfaces of the layer, suppressing a decrease in strength of the superabrasive layer in a well-balanced manner, and the cut surface of the work material is accurately ground without impairing the cutting performance. Wear is prevented in advance.

  In addition, the notch of the superabrasive grain layer, which is the tip of the slit formed in the substrate, and the grooves formed on both front and back sides of the superabrasive grain layer act synergistically in the biting into the work material. This contributes to maintaining the sharpness over a long period of time.

  Also, through holes are provided at the base end of the slit, and chamfering is performed around the through holes, resulting in impacts in severe grinding operations that are weak points of the substrate slit in the segment type. Effectively suppress the generation of cracks.

  In addition, no consideration is given to the formation of the slits in the substrate so as to prevent a reduction in the strength of the substrate in the slit formation. Although the segment type saw blade is excellent in cutting performance, in addition to the impact in the rotation direction and the like due to the slit formed in the substrate, the bending strength in the lateral direction (substrate thickness) is generally weak. This may adversely affect the safety surface and cutting performance during use, but in the corrugated shape of the steel substrate in the present invention, the corrugated processing reaching the superabrasive layer attachment part is performed, Consideration is given so that the strength of the substrate is greatly improved and sufficient bending strength is maintained.

  As described above, the saw blade according to the present invention compensates for the strength reduction between the substrate and the superabrasive layer due to the slits and grooves, and has excellent durability while maintaining the excellent effect brought about by the corrugated substrate. A segment-type superabrasive saw blade is realized to ensure safe and efficient cutting, and at the same time, the tool life of the saw blade itself is guaranteed over a long period of time.

  BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the best mode for carrying out the present invention will be described in more detail with reference to the accompanying drawings and embodiments. However, the present invention is not limited thereto and can be freely performed within the scope of the gist of the present invention. Design changes are possible.

  1 is a front view of a saw blade according to an embodiment of the present invention, FIG. 2 is a side view of the saw blade of FIG. 1, and FIG. 3 is a cross-sectional view taken along line A-B-C-D in FIG. 4 is an enlarged sectional view taken along line FF in FIG. 1, FIG. 5 is an enlarged sectional view taken along line GG in FIG. 1, and FIG. 6 is taken along line EE in FIG. It is the expanded sectional view seen.

  The saw blade in the present invention is formed from diamond abrasive grains or cBN abrasive grains through slits made of key grooves or U grooves formed at predetermined intervals in the circumferential direction on the outer peripheral edge of a disk-shaped steel substrate. As a so-called segment type saw blade obtained by intermittently attaching a superabrasive grain layer (hereinafter also referred to simply as “abrasive grain layer”) along the outer peripheral edge, for example, a disc grinder, a sander For example, it is suitable for cutting work materials made of hard and brittle materials such as concrete and stone. Provided.

  In the saw blade 1 according to the present invention, as shown in FIG. 1, the outer peripheral edge of a disc-shaped steel substrate 2 is divided into equal parts to form four slits 25. Is provided with a substantially circular elliptical hole 26 (through-hole) that is eccentric from the center of the slit 25 in the rearward direction of rotation and penetrates the substrate 2, and is intermediate between the slit 25 and the slit 25. A substantially oval substrate hole 27 is formed through the portion equally, and the slit 25 and the substrate hole 27 are formed so as to be inclined radially from the front to the rear in the rotation direction of the substrate, respectively. ing. The through hole is not limited to the elliptical hole, and may be a circular hole, for example.

  Further, the substrate 2 excluding the attachment portion 13 of the superabrasive grain layer 11 at the outer peripheral edge of the substrate 2, the formation portion of the slit 25, the formation portion of the substrate hole 27 and the fastening portion 23 to the electric tool. On both the front and back sides, as shown in an enlarged view in FIG. 5, the crests 21 having an arcuate cross section and the substantially flat troughs 22 are alternately inclined in a radial direction from the front to the rear in the rotation direction of the substrate. In addition, the width of the substrate 2 is gradually increased from the axial center to the outer peripheral direction, and the substrate 2 is formed from the outer peripheral end of a fastening portion (hereinafter simply referred to as “fastening portion”) 23 to the power tool. A plurality of waveforms 41 reaching the outer peripheral edge are formed.

  Further, in the space formed between the formation portion of the slit 25 and the fastening portion 23 in the substrate 2, as shown in FIGS. 1 and 3, a middle mountain portion 28 having a circular arc shape and a substantially flat middle valley portion 29 are respectively provided. The first corrugation 42 is formed over three rows, and the space formed between the formation portion of the substrate hole portion 27 and the fastening portion 23 is shorter than the middle mountain portion 28 and the middle valley portion 29 as shown in FIG. The second corrugated portion 210 and the substantially flat small valley portion 211 are formed in two rows, respectively, and the small and large peak portions and valley portions are substantially central portions of the substrate from the front in the rotation direction. A waveform is formed so as to incline radially toward the rear and gradually widen from the axial center toward the outer periphery. Thus, the substrate 2 constitutes a so-called corrugated substrate 2 on which a partial waveform composed of the waveform 41, the first waveform 42 and the second waveform 43 is formed.

  Grooves 51 are formed on the front and back sides of the superabrasive grain layer 11 attached to the outer peripheral edge of the corrugated substrate 2 at equal pitches in the circumferential direction and alternately at the front and back (see FIGS. 1 and 2). Consists of a deep groove portion 12 a continuous with the valley portion and a shallow groove portion 12 b adjacent to the formation portion of the slit 25 and the substrate hole formation portion 27. That is, the outer peripheral edge of the corrugated substrate 2 is separated by the slits 25, and the abrasive layer 11 is intermittently attached to form a blade portion. As shown in enlarged views in FIGS. 1, 2 and 4, the deep groove 12b is connected to the valley formed in the substrate 2, and the shallow groove 12a is formed in the vicinity of the slit 25 and the substrate hole 27 forming portion. A plurality of slanted portions are formed so as to be inclined radially from the front to the rear in the rotation direction.

  The shallow groove portion 12a includes two to four first groove portions adjacent to the slit 25 forming portion and two to five second groove portions adjacent to the substrate hole forming portion. In this example, as shown in FIG. 2, the shallow groove portion 12a includes a groove a and a groove b formed on the left side surface in FIG. 2 adjacent to the formation portion of the slit 25, and a groove formed on the right side surface in FIG. b, three first grooves of the groove c adjacent to b, a groove e and a groove d formed on the left side in FIG. 2 adjacent to the substrate hole forming part 27, and a groove g formed on the right side in FIG. And four second groove portions of the groove f.

  By forming a plurality of grooves formed on both side surfaces of the abrasive grain layer 11 as shallow grooves 12a in the vicinity of the slit 25 forming portion and the substrate hole 27 forming portion, the slit 25 or the substrate hole 27 is formed. Compensating for the strength reduction of the substrate caused by the formation, and forming the groove portion 12b deeper than that in the portion connected to the trough portion 22, it is possible to reduce the biting of the cutting edge into the work material in the portion where the slit 25 is not formed In addition to contributing to maintaining a sharp sharpness, it is possible to maintain good cutting performance and a good finish on the ground surface by improving chip discharge.

The superabrasive layer mounting portion 13 of the steel substrate 2, superabrasive which compared to the thickness t ₁ of the portion other than the superabrasive layer mounting portion 13 of the substrate 2 is slightly thin, is attached The grain layer 11 is formed to be slightly thicker at t ₂ than the plate thickness t ₁ of the portion other than the superabrasive layer attaching part 13 in the substrate 2. That is, compared to the thickness t ₁ of the steel substrate 2, for slightly thicker the thickness t ₂ of the abrasive grain layer 11, the predetermined clearance 3 as shown in FIG. 3 is formed. The clearance 3 creates a gap between the substrate 2 and the work material, so that so-called cylinder displacement is prevented in advance, and both the cutting performance and the finish of the grinding work surface are maintained in a good state.

  In the corrugated substrate 2 according to the present invention, a chamfered portion 26a is formed in the elliptical hole 26 formed at the base end of the slit 25 by chamfering the periphery of the hole as shown in an enlarged view in FIG. The chamfered portion 26a and the elliptical hole 26 act synergistically to effectively suppress the generation of cracks from the slit forming portion, which is a fatal problem in the segment type substrate.

  Further, the substantially oval substrate hole 27 formed in the substrate 2 reduces the contact area with the work material on the flat surface of the substrate 2 together with the elliptical hole 26 formed at the base end of the slit 25, thereby storing heat. This contributes to maintaining good cutting performance.

  In the saw blade 1 according to the present invention configured as described above, the mounting hole 24 is inserted into the spindle (not shown) of the rotary electric tool as described above in a state orthogonal to the axis thereof, It is fastened and fixed by a lock nut through the fastening portion 23 of the substrate 2 and is generally used for cutting work on a work material by manual work.

  The substrate 2 in the present invention is usually a circular plate-like body made of carbon tool steel, and the corrugation forming means is applied by a known cold working, specifically, a carbon tool processed to a predetermined dimension. A corrugated steel substrate 2 according to the present invention is formed by subjecting a circular plate-shaped body made of steel to rolling, punching, or other machining using a predetermined die in a predetermined temperature range. Is done. Moreover, as long as the joining means of the abrasive grain layer 11 with respect to the obtained steel board | substrate 2 is a method in which both are firmly fixed, it does not deny adopting conventionally well-known methods, such as welding and brazing, suitably. Kneading superabrasive grains made of diamond abrasive grains or cBN abrasive grains and various bond matrices made of cobalt, bronze, iron, nickel, tungsten carbide or various mixtures thereof at various mixing ratios through various binders Adopting a so-called simultaneous sintering method that simultaneously forms the superabrasive layer 11 and bonds the superabrasive layer 11 to the steel substrate 2 reduces the manufacturing cost by simplifying the process, This is desirable for ensuring stable quality.

  A plate material made of a commercially available carbon tool steel with a plate thickness of 1.4 mm is prepared as a raw material, and cold rolling processing, punching processing and press processing by a press are performed on the raw material, and an inner diameter of 20 mm is provided at the center as shown in FIG. The disc-shaped steel substrate 2 having an outer diameter of 89 mm provided with a fastening portion 23 having a diameter of 35 mm is formed at the periphery of the mounting hole 24, and the outer peripheral edge of the substrate 2 is divided into four equal parts. The groove width of the central portion where the substantially circular elliptical hole 26 penetrating the substrate 2 is provided at the base end is 1.7 mm, and slits 25 that are radially inclined from the front to the rear in the rotation direction of the substrate are formed. Substantially oblong substrate holes 27 are formed so as to pass through the intermediate portion of the substrate 2 between the slits 25 slightly wider from the axial center toward the outer peripheral direction, and are inclined radially from the front to the rear in the rotation direction of the substrate. . Next, on both side surface portions of the substrate 2 excluding the formation portion of the slit 25 and the substrate hole portion 27 and the fastening portion 23, as shown in an enlarged view in FIG. The substrate 2 is alternately and gradually inclined from the front to the rear in the rotation direction, and gradually increases in width from the axial center toward the outer periphery. In the space formed between the forming portion of the slit 25 and the fastening portion 23 in the substrate 2 to form a plurality of corrugations reaching the outer peripheral edge portion, as shown in FIG. 1 and FIG. Are formed in three rows, and the space formed between the formation portion of the substrate hole portion 27 and the fastening portion 23 includes the middle mountain portion 28 and the intermediate mountain portion 28 as shown in FIG. Cross section shorter than Nakatani 29 The arc-shaped small ridges 210 and the substantially flat small valleys 211 are formed in two rows, respectively, and the small and medium ridges and valleys are inclined radially from the front to the rear in the rotation direction at the substantially central portion of the substrate. A corrugated substrate 2 having a partially corrugated shape according to the present embodiment was formed by forming a waveform that gradually widened from the center toward the outer peripheral direction.

  The corrugated substrate forming means according to the present embodiment employs cold rolling using a predetermined die in a predetermined temperature range, but the present invention is not limited to this, and the target corrugated substrate is Any method can be selected as long as it can be obtained. Further, during the cold rolling process, the joint portion (abrasive layer attachment portion) of the abrasive grain layer 11 at the outer peripheral edge of the corrugated substrate 2 is simultaneously rolled to reduce the thickness of the joint part to 0. 0. By processing 2 mm thinner, the strength of the outer peripheral edge of the substrate was improved together with the bonding strength of the abrasive layer 11. Further, a chamfering process was performed around the elliptical hole 26 formed at the base end of the slit 25 to form a chamfered portion 26a as shown in FIG. By providing the chamfered portion 26a, generation of cracks from the slit 25 forming portion was effectively suppressed.

  The blade portion was formed by the abrasive grain layer 11 being intermittently attached to the outer peripheral edge portion of the corrugated substrate 2 formed as described above by the slit 25. Is a mixed powder obtained by mixing a bond matrix composed of cobalt + bronze mixed metal powder and diamond abrasive grains having a concentration of 15% with respect to the bond matrix in the presence of a volatile binder. Is pressed on the abrasive layer bonding portion at the outer peripheral edge of the substrate 2, heated to 900 ° C. in a furnace, and then cooled, so as to simultaneously process the forming of the segment chips and the bonding of the segment chips. A diamond saw blade 1 according to this example as shown in FIGS. 1 to 6 was obtained by the simultaneous sintering method. The abrasive layer 11 bonded to the outer peripheral edge of the substrate 2 is alternately inclined on both the front and back side surfaces of the substrate 2 as shown in FIGS. As shown in FIG. 2 or FIG. 4 in an enlarged manner, the groove is formed as a shallow groove 12a in which the portion adjacent to the slit 25 and the substrate hole 27 formed in the substrate 2 is shallow. The other portion, that is, the portion connected to the valley portion 22 was formed as a deep groove portion 12b. By making the groove formed in the abrasive grain layer 11 shallow at a portion adjacent to the slit 25 and the substrate hole 27, it is often possible to compensate considerably for the strength reduction of the substrate caused by the slit 25 and the substrate hole 27. Proven in a cutting test. Further, as shown in FIG. 3, the abrasive layer 11 to be attached is 0.2 mm thick on one side with respect to the plate thickness of the substrate 2, that is, by providing 0.2 mm of clearance 3 with respect to the substrate 2. Since a gap was provided between the workpiece and the work material, it effectively functioned to suppress so-called rubbing.

  As described above, the abrasive grain layer 11 consisting of segment chips intermittently on the outer peripheral edge of the steel substrate 2 partially corrugated on the front and back side surfaces of the substrate 2 as shown in FIGS. A segment type saw blade 1 according to this example was obtained. The obtained saw blade 1 was fastened and fixed to the spindle of the grinder, and a straight cutting test was repeated on a concrete flat plate having a thickness of 60 mm and a compressive strength of 35 MPa. A cutting speed of 900 mm per minute is ensured at 000 / min, and it is demonstrated that a total cutting of 500 m is possible, and stability in the rotational direction accompanying the rotation of the grinder is ensured, and vibration of the tool is effectively suppressed. The deep groove 12b of the abrasive grain layer 11 provided continuously to the valley 22 formed in the substrate 2 and the shallow groove 12a formed in addition to the groove 22 formed on the substrate 2 without any friction due to camera shake are combined. Powder discharge is effectively promoted and a grinding surface with excellent machining accuracy can be obtained repeatedly, and heat storage on the cutting surface is effective due to the air cooling action unique to corrugated substrates It was confirmed that the life performance of the saw blade 1 was greatly improved.

  As a material for forming the circular substrate according to the present invention, usually commercially available carbon tool steel is preferably used, but is not particularly limited as long as it has a certain rigidity and mechanical strength. It can be used by appropriately selecting from steel. The saw blade formed by the present invention is not particularly limited as long as it is a segment type saw blade having an outer diameter of 100 mm or more and less than 400 mm, and can be applied to a wide variety of saw blades.

  As described above in detail, the saw blade according to the present invention exhibits the sharpness peculiar to the segment cutter while maintaining advantages such as the rotational direction stability and air cooling effect peculiar to the corrugated substrate, and excellent chip discharge. As a result, the cutting performance is remarkably improved. Further, by adding a specific improvement to the shape of the slit formed on the substrate and the groove portion of the abrasive layer, the tool life as a saw blade was greatly improved by compensating for the strength reduction of the substrate. In addition, the saw blade according to the present invention is suitable for various work materials including hard and brittle materials such as concrete and stone, although it can be mass-produced by a relatively simplified process such as a simultaneous sintering method. It can be used for cutting and cutting operations efficiently and with high accuracy, and it can be used in a wide range of industries because it can provide functionally superior grinding tools at a relatively low cost. There is expected.

It is a front view which shows the saw blade of one Example which concerns on this invention. It is a side view which shows the saw blade of the Example. FIG. 2 is a cross-sectional view taken along the line A-B-C-D in FIG. 1. It is the FF line expanded sectional view of FIG. It is the GG line expanded sectional view of FIG. It is the EE line expanded sectional view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Saw blade 11 Superabrasive grain layer 12 Groove part 12a Shallow groove part 12b Deep groove part 2 Steel substrate 21 Mountain part 22 Valley part 23 Fastening part 24 Mounting hole 25 Slit 26 Elliptical hole 27 Substrate hole part 28 Middle mountain part 29 Middle valley part 210 Small mountain part 211 Otanibe 3 Clearance

Claims (8)

  A segment type saw blade in which a superabrasive layer consisting of diamond abrasive grains or cBN abrasive grains is intermittently attached to a peripheral edge portion of a circular steel substrate at a predetermined interval. A plurality of slits having a through-hole at the base end and a plurality of substantially oval substrate holes that equally pierce through the intermediate portion of the substrate between the slits by equally dividing the outer peripheral edge of the substrate made in the circumferential direction. Are formed in such a manner as to be inclined radially from the front to the rear in the direction of rotation of the substrate, to the superabrasive layer attaching portion, the slit forming portion, the substrate hole forming portion and the electric tool of the steel substrate. A corrugated substrate is formed by alternately forming crests having a circular arc cross section and substantially flat troughs on both front and back sides excluding the fastening portion of the substrate, and inclining radially from the front to the back in the rotation direction of the substrate. Attached to the outer peripheral edge of the corrugated substrate Grooves are formed on the front and back side surfaces of the superabrasive grain layer at equal pitches in the circumferential direction and alternately on the front and back sides, and the groove parts include deep groove parts that are continuous with the valley parts, slit formation parts, and substrate hole parts. A saw blade comprising a shallow groove adjacent to the forming portion.   Between the formation part of the slit and the fastening part to the electric power tool, a first corrugation in which a cross-section arc-shaped middle mountain part and a flat middle valley part are alternately formed, and the board hole part formation part and the electric tool Between the fastening portions, a second corrugation in which a small ridge portion having a circular arc cross section and a flat small valley portion are alternately formed is shorter than the middle valley portion and the middle valley portion, respectively, from the front to the rear in the rotation direction of the substrate. The saw blade according to claim 1, wherein the saw blade is radially inclined.   The saw blade according to claim 1 or 2, wherein the plurality of slits are obtained by dividing the outer peripheral edge portion into four equal parts in the circumferential direction.   The saw blade according to any one of claims 1 to 3, wherein the deep groove portion and the shallow groove portion are formed so as to be inclined substantially radially from the front to the rear in the rotation direction of the substrate.   5. The shallow groove portion includes 2 to 4 first groove portions adjacent to the slit forming portion and 2 to 5 second groove portions adjacent to the substrate hole forming portion. The saw blade according to any one of the above.   The saw blade according to any one of claims 1 to 5, wherein a chamfering process is performed on a through hole formed in the slit base end.   The superabrasive layer attaching part is formed slightly thinner than the plate thickness of the part other than the superabrasive layer attaching part in the substrate, and the superabrasive grain layer to be attached is the superabrasive layer in the substrate. The saw blade according to any one of claims 1 to 6, wherein the saw blade is formed slightly thicker than a plate thickness of a portion other than the abrasive layer attaching portion.   The means for attaching the superabrasive layer to the steel substrate is simultaneous sintering in which formation of the superabrasive layer and bonding to the steel substrate are simultaneously performed. The saw blade according to any one of 1 to 7.

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