Cutting blade, and cutting blade manufacturing method

Abstract

To provide a cutting blade with a high strength and long life in a side face outer peripheral part of which a groove is formed.SOLUTION: A cutting blade has a toric cutting edge part containing a binder and abrasive grains dispersed and fixed in the binder. The cutting edge part has a first toric side face, a toric second side face, and an outer peripheral surface which is connected outer peripheries of the first side face and second side face respectively, and comprises a plurality of recesses that are exposed only on the outer peripheral surface. Preferably, the plurality of recesses are arranged along the outer periphery of the first side face, and are formed in the cutting edge part. Further, preferably, in one or more of the plurality of recesses, a filling material, which is softer compared to the cutting edge part, is provided.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a cutting blade used for cutting a workpiece such as a semiconductor wafer, and a method for manufacturing the cutting blade.

Background Art

[0002] In the manufacturing process of device chips used in electronic devices such as mobile phones and personal computers, first, a plurality of division planned lines (streets) intersecting each other are set on the surface of a wafer made of a material such as a semiconductor. Then, devices such as ICs (Integrated Circuits) and LSIs (Large-scale Integration) are formed in each region partitioned by the division planned lines. Thereafter, when the wafer is ground from the back side to be thinned and divided along the division planned lines, individual device chips are formed.

[0003] Furthermore, a technique is known in which a plurality of device chips are arranged at predetermined intervals on an electrode substrate, the back side of each device chip is sealed with a molding resin to produce a package substrate such as a CSP (Chip Size Package) or a QFN (Quad Flat Non-Leaded Package), and this is divided to form a packaged device (see Patent Document 1).

[0004] And a cutting device that cuts and divides a workpiece such as a wafer or a package substrate with an annular cutting blade is known. The cutting blade used in the cutting device has a cutting edge portion including a binder formed of metal, resin, or the like, and abrasive grains formed of diamond or the like dispersed and fixed in the binder. The cutting device performs cutting of the workpiece by cutting the cutting blade into the workpiece under predetermined processing conditions.

[0005] When a workpiece is cut with a cutting blade, the workpiece and the cutting edge portion are worn away and cutting chips are generated. The generated cutting chips get into both sides of the cutting blade that cuts the workpiece, gradually causing uneven wear on both side surfaces and the side corners of the cutting edge portion. When the workpiece is cut with a cutting blade that has uneven wear on the cutting edge portion, cutting marks of a shape reflecting the progress state of the uneven wear are formed on the workpiece. Since the uneven wear progresses gradually and the progress of the uneven wear is not uniform at various locations on the cutting edge portion, there has been a problem that the shape of the cutting marks formed on the workpiece is not stable.

[0006] Therefore, in a cutting device, when cutting a workpiece, cutting fluid such as pure water is supplied to the workpiece and the cutting blade to remove grinding chips. Further, in order to enhance the effect of removing cutting chips, a proposal has been made to form a plurality of grooves along the radial direction in the vicinity of the outer periphery of the side surface of the cutting blade (cutting edge portion) (see Patent Document 2). Also, it has been proposed to form an annular recess over the entire circumference on the outer peripheral surface of the cutting edge portion, and there is a possibility that this can suppress the entry of cutting chips into the side surface of the cutting blade (cutting edge portion) (see Patent Document 3).

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0008] However, in the method of forming a plurality of grooves along the radial direction in the vicinity of the outer periphery of the side surface of the cutting edge portion, since the grooves are exposed on both side surfaces of the cutting edge portion, the cutting chips that have entered the grooves get into the side surface of the cutting edge portion. That is, since the grooves serve as the progress path of the cutting chips to the side surface of the cutting edge portion, the effect of discharging the cutting chips is limited.

[0009] In addition, in the method of forming an annular recess extending over the entire outer peripheral surface of the cutting edge portion, linear convex portions reflecting the shape of the annular recess are formed on the cutting marks of the workpiece cut into the cutting edge portion. This is because the workpiece is cut in such a manner that not only the outer side but also the inner side (the bottom surface of the annular recess) of the annular recess on the outer peripheral surface of the cutting edge portion comes into contact with the workpiece. Moreover, since a sufficient space is not formed between the annular recess and the workpiece, the cutting chips are not effectively discharged.

[0010] The present invention has been made in view of such problems, and an object thereof is to provide a cutting blade capable of cutting a workpiece while efficiently discharging generated cutting chips, and a method for manufacturing such a cutting blade.

Means for Solving the Problems

[0011] According to one aspect of the present invention, there is provided a cutting blade having an annular cutting edge portion including a binder and abrasive grains dispersed and fixed in the binder, the cutting edge portion having an annular first side surface, an annular second side surface, and an outer peripheral surface connected to the outer peripheries of the first side surface and the second side surface, and characterized by including a plurality of recesses exposed only on the outer peripheral surface.

[0012] Preferably, the plurality of recesses are formed in the cutting edge portion side by side along the outer periphery of the first side surface.

[0013] Alternatively, preferably, a part of the plurality of recesses and another part of the plurality of recesses are not arranged side by side along the outer periphery of the first side surface.

[0014] More preferably, a soft filler is disposed in one or more of the plurality of recesses as compared with the cutting edge portion.

[0015] According to another aspect of the present invention, there is provided a method for manufacturing a cutting blade having an annular cutting edge portion including a binder and abrasive grains dispersed and fixed in the binder, the method comprising: a plate preparation step of preparing an annular first plate, an annular second plate, and an annular third plate; and an integration step of overlapping and integrating the first plate, the second plate, and the third plate to form the cutting edge portion, wherein the first plate is exposed on one side surface of the cutting edge portion, the third plate is exposed on the other side surface of the cutting edge portion, the second plate has an annular first side surface, an annular second side surface, and an outer peripheral surface connected to the outer periphery of each of the first side surface and the second side surface, the second plate has a notch portion penetrating from the first side surface to the second side surface and opening to the outer peripheral surface, and the notch portion of the second plate is exposed only on the outer peripheral surface of the cutting edge portion when the cutting edge portion is formed by the integration step.

[0016] Preferably, the method further comprises a filler disposing step of disposing a soft filler in the notch portion of the second plate as compared with the second plate, and the filler is integrated with the cutting edge portion.

[0017] According to still another aspect of the present invention, there is provided a method for manufacturing a cutting blade having an annular cutting edge portion including a binder and abrasive grains dispersed and fixed in the binder, the method comprising: a preparation step of preparing a blade body including the annular cutting edge portion having an annular first side surface, an annular second side surface, and an outer peripheral surface connected to the outer periphery of each of the first side surface and the second side surface; and a recess forming step of forming a plurality of recesses exposed only on the outer peripheral surface of the cutting edge portion of the blade body to form a cutting blade including the blade body.

[0018] Preferably, in the recess forming step, a laser beam is irradiated onto the outer peripheral surface of the cutting edge portion to form a plurality of the recesses.

[0019] More preferably, the method further comprises a filler disposing step of disposing a filler in the recesses.

[0020] Further, according to still another aspect of the present invention, there is provided a method for manufacturing a cutting blade having an annular cutting edge portion including a binder and abrasive grains dispersed and fixed in the binder, the method comprising: a plate preparation step of preparing an annular first plate and an annular second plate; and an integration step of overlapping and integrating the first plate and the second plate to form the cutting edge portion, wherein the second plate has an annular first side surface facing the first plate in the integration step, an annular second side surface not facing the first plate, and an outer peripheral surface connected to the outer perimeters of the first side surface and the second side surface, and the second plate has recesses exposed on the first side surface and the outer peripheral surface, and the recesses of the second plate are exposed only on the outer peripheral surface of the cutting edge portion when the cutting edge portion is formed by the integration step.

[0021] Preferably, the method further comprises a filler arrangement step of arranging a soft filler in the recesses of the second plate as compared with the second plate, and the filler is integrated with the cutting edge portion.

Advantages of the Invention

[0022] In one aspect of the present invention, a cutting blade has an annular cutting edge portion including a binder and abrasive grains dispersed and fixed in the binder. The cutting edge portion has an annular first side surface, an annular second side surface, and an outer peripheral surface connected to the outer perimeters of the first side surface and the second side surface. The outer peripheral surface is provided with a plurality of recesses (notches) exposed only on the outer peripheral surface.

[0023] When a workpiece is cut with a cutting blade having a plurality of recesses (notches) formed only on the outer peripheral surface of the cutting edge portion, the generated cutting chips are taken into the recesses. Since the cutting chips do not escape from the recesses to the side surface of the cutting edge portion, the cutting chips are efficiently discharged.

[0024] Further, unlike the case where an annular recess extending over the entire circumference is formed on the outer peripheral surface of the cutting edge portion, the inner side of the recess does not come into contact with the workpiece on the outer peripheral surface of the cutting edge portion, and a sufficient space is formed between the recess and the workpiece, so that the cutting chips are effectively discharged. Further, a recess corresponding to the shape of the recess is not formed at the bottom of the cutting mark.

[0025] Therefore, according to one aspect of the present invention, there are provided a cutting blade capable of cutting a workpiece while efficiently discharging generated cutting chips, and a method for manufacturing such a cutting blade.

Brief Description of the Drawings

[0026]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a perspective view schematically showing a part of a cutting device 2 on which a cutting blade according to the present embodiment is mounted and used. FIG. 1 includes a perspective view of a workpiece 1 to be processed by the cutting device 2. First, the workpiece 1 will be described.

[0028] The workpiece 1 is, for example, a circular wafer made of a semiconductor material such as silicon. A plurality of division planned lines 3 called streets that intersect each other are set on the surface 1a side thereof. Devices 5 such as ICs and LSIs are formed in each region partitioned by the division planned lines 3. When the workpiece 1 is divided along the division planned lines 3, individual device chips can be manufactured. Alternatively, the workpiece 1 is a package substrate such as a CSP or QFN, and when this is divided, package devices can be formed.

[0029] However, there are no restrictions on the material, shape, structure, etc. of the workpiece 1, and it may be composed of materials such as resin and metal, or may be a rectangular substrate. The workpiece 1 is divided by being cut with a cutting blade in the cutting device 2.

[0030] When the workpiece 1 is carried into the cutting device 2, the workpiece 1 is integrated with the adhesive tape 7 and the annular frame 9 to form a frame unit 11. Then, the workpiece 1 is carried into the cutting device 2 and cut in the state of the frame unit 11.

[0031] The frame unit 11 includes the annular frame 9 and the adhesive tape 7 attached so as to close the opening of the annular frame 9. The adhesive tape 7 exposed at the opening of the annular frame 9 is adhered to the back surface 1b side of the workpiece 1. That is, the workpiece 1 is supported by the annular frame 9 via the adhesive tape 7. When the workpiece 1 is divided in this state, the individual chips formed continue to be supported by the annular frame 9 via the adhesive tape 7. That is, when the frame unit 11 is formed, the workpiece 1 and the chips can be easily handled.

[0032] Next, the cutting device 2 will be described. The cutting device 2 includes a chuck table 4 that sucks and holds the workpiece 1 via the adhesive tape 7, and a cutting unit 6 that cuts the workpiece 1 sucked and held by the chuck table 4 with a cutting blade 8. The cutting blade 8 has an annular cutting edge portion 10 including a bonding material and innumerable abrasive grains dispersed and fixed in the bonding material on the outer periphery.

[0033] The bonding material is composed of, for example, resinoid, metal material, vitrified bond, etc. For example, as the resinoid, thermosetting resins such as phenolic resin, epoxy resin, and polyimide resin can be mentioned. For the bonding material composed of a metal material, Cu, Sn, Co, Fe, Ni, W, Ti, etc. are used as the main components. Further, the abrasive grains dispersed and fixed in the bonding material are composed of diamond, cBN (cubic boron nitride), etc. The bonding material is formed, for example, by mixing abrasive grains into a material such as a resin material and sintering the obtained mixture.

[0034] The cutting device 2 includes a chuck table 4 and a cutting unit 6, and a moving mechanism (machining feed mechanism) (not shown) that can move the chuck table 4 and the cutting unit 6 relative to each other along the machining feed direction (X-axis direction). When the cutting blade 8 is rotated and the cutting edge portion 10 is cut into the workpiece 1 along the division planned line 3, the workpiece 1 is cut and divided.

[0035] Here, a more detailed structure of the cutting unit 6 will be described with reference to FIG. 2. FIG. 2 is an exploded perspective view schematically showing the cutting unit 6. The cutting unit 6 includes a spindle housing 12 fixed to a moving mechanism (not shown) of the cutting device 2 and the like. The proximal end side of the spindle 14 is rotatably accommodated in the spindle housing 12, and further, a rotation drive source (not shown) such as a motor for rotating the spindle 14 is accommodated.

[0036] The distal end side of the spindle 14 protrudes forward from the spindle housing 12. An opening 16 is formed at the distal end portion of the spindle 14, and a screw groove is provided on the inner wall surface of the opening 16. A flange-shaped mount 18 is attached to the distal end portion of the spindle 14. The mount 18 includes a flange portion 20 that extends radially outward and a boss portion 22 that protrudes forward from the center of the surface (front surface) of the flange portion 20.

[0037] At the center of the mount 18, a through hole 24 penetrating the mount 18 in the front - rear direction is formed. Also, on the rear - face side of the flange portion 20 inside the through hole 24, a fitting portion (not shown) into which the tip of the spindle 14 can be fitted is formed. When the tip of the spindle 14 is fitted into the fitting portion and the fixing bolt 26 is tightened through the washer 28 and the through hole 24 into the opening 16, the mount 18 is fixed to the spindle 14. Note that a thread corresponding to the thread groove of the opening 16 is provided on the outer peripheral surface of the fixing bolt 26.

[0038] The surface on the outer - peripheral side of the flange portion 20 is a contact surface 30 that contacts the back side of the cutting blade 8. This contact surface 30 is formed in an annular shape when viewed from the axial direction of the spindle 14. The boss portion 22 is formed in a cylindrical shape, and a thread 32 is provided on its outer peripheral surface. A circular opening 8a through which the boss portion 22 is inserted is formed at the center of the cutting blade 8. By inserting the boss portion 22 through this opening 8a, the cutting blade 8 contacts the contact surface 30 of the flange portion 20.

[0039] In a state where the cutting blade 8 is in contact with the contact surface 30, an annular front flange 34 is mounted on the front side of the cutting blade 8. An opening 34a is formed at the center of the front flange 34, and the boss portion 22 of the mount 18 is fitted into this opening 34a. Note that the back surface on the outer - peripheral side of the front flange 34 is a contact surface (not shown) that contacts the side surface of the cutting blade 8. This contact surface is provided at a position corresponding to the contact surface 30 of the mount 18.

[0040] After the front flange 34 is mounted on the boss portion 22, an annular fixing nut 36 is tightened onto the tip of the boss portion 22. Thereby, the front flange 34 is pressed against the mount 18 side, and the cutting blade 8 is clamped between the mount 18 and the front flange 34. Note that an opening 36a is formed in the fixing nut 36, and a thread groove (not shown) that is tightened onto the thread 32 formed at the tip of the boss portion 22 is provided on the inner wall surface of this opening 36a.

[0041] On the front surface of the spindle housing 12, a blade cover 38 (see Fig. 1) for accommodating a cutting blade 8 or the like mounted on the spindle 14 is provided. As shown in Fig. 1, a pair of substantially L-shaped nozzles 40 that sandwich the lower part of the cutting blade 8 in the front-rear direction are fixed to the blade cover 38. Cutting water is supplied to the nozzles 40 from the outside through a water suction port 42 provided in the blade cover 38.

[0042] On the tip side of the nozzle 40, a plurality of injection ports (not shown) are formed so as to face the cutting blade 8. When the cutting water is injected from the injection ports while the cutting blade 8 cuts the workpiece 1, the cutting blade 8 and the workpiece 1 can be cooled and cleaned.

[0043] When cutting the workpiece 1, first, the chuck table 4 is rotated around an axis perpendicular to the upper surface so that the extension direction of the division planned line 3 coincides with the machining feed direction (X-axis direction). Then, the cutting blade 8 is positioned above the end of the division planned line 3, and the rotation of the spindle 14 is started to rotate the cutting blade 8.

[0044] After that, the cutting unit 6 is lowered so that the lower end of the cutting blade 8 reaches the adhesive tape 7 below the back surface 1b of the workpiece 1. Then, when the workpiece 1 is machined and fed along the X-axis direction, the workpiece 1 is cut and a cutting groove 3a is formed along the division planned line 3. After cutting the workpiece 1 along one division planned line 3, the cutting unit 6 is indexed and fed in the Y-axis direction perpendicular to the X-axis direction, and the workpiece 1 is similarly machined along another division planned line 3.

[0045] In this way, the workpiece 1 is processed one after another. After processing the workpiece 1 along all the division planned lines 3 along one direction, the chuck table 4 is rotated to align the division planned lines 3 along the other direction with the machining feed direction. Then, the workpiece 1 is successively cut along the division planned lines 3 along the other direction. When the workpiece 1 is cut along all the division planned lines 3 and the cutting grooves 3a are formed, the workpiece 1 is divided into individual chips.

[0046] When the workpiece 1 is cut with the cutting blade 8, the workpiece 1 and the cutting edge portion 10 are worn out and cutting chips are generated. The generated cutting chips get into both sides of the cutting blade 8 that cuts the workpiece 1, and gradually cause uneven wear on both side surfaces and the side surface corners of the cutting edge portion 10. When the workpiece 1 is cut with the cutting blade 8 in which uneven wear has occurred on the cutting edge portion 10, a cutting mark (cutting groove 3a) of a shape reflecting the progress state of the uneven wear is formed on the workpiece 1. Since the uneven wear gradually progresses and the progress of the uneven wear is not uniform at various locations on the cutting edge portion 10, there has been a problem that the shape of the cutting mark formed on the workpiece 1 is not stable.

[0047] Therefore, when cutting the workpiece 1, cutting fluid such as pure water is supplied from the nozzle 40 to the workpiece 1 and the cutting blade 8 to remove grinding chips. In particular, the cutting blade according to the present embodiment is configured as described below so that the workpiece 1 can be cut while efficiently discharging the generated cutting chips. Hereinafter, the cutting blade 8 according to the present embodiment will be described in detail.

[0048] FIG. 3(A) is a plan view schematically showing a side surface of the cutting edge portion 10 of the cutting blade 8. Further, FIG. 4(A) is a plan view schematically showing an enlarged side surface of the cutting edge portion 10. The cutting blade 8 according to the present embodiment has an annular cutting edge portion 10 including a binder and abrasive grains dispersed and fixed in the binder.

[0049] Note that the cutting blade 8 may include a hub base (not shown) formed of a metal that fixes the cutting edge portion 10 to the outer periphery. The cutting blade 8 including the hub base is called a hub blade. On the other hand, as shown in FIG. 3(A) and the like, the cutting blade 8 that does not include a hub base and is composed of the cutting edge portion 10 is called a washer blade. Hereinafter, the cutting blade 8 according to the present embodiment will be described by taking the washer blade as an example. However, the cutting blade 8 is not limited to the washer blade.

[0050] The cutting edge portion 10 is formed in an annular thin plate shape. The cutting edge portion 10 has an annular first side surface 10c and an annular second side surface 10d. A through hole 10a penetrating from the first side surface 10c to the second side surface 10d is formed at the center of the cutting edge portion 10. Further, the cutting edge portion 10 has an outer peripheral surface 10b connected to the outer periphery 10e of the first side surface 10c and the outer periphery 10f of the second side surface 10d.

[0051] And the cutting edge portion 10 of the cutting blade 8 according to the present embodiment includes a plurality of recesses 44 exposed only on the outer peripheral surface 10b. In FIG. 3, the formation positions of these recesses 44 are indicated by broken lines. The recesses 44 are manufactured, for example, by electrical discharge machining or laser machining on the cutting edge portion 10 of the cutting blade 8 in which the recesses 44 are not formed. However, the formation method of the recesses 44 is not limited to these. Details will be described later.

[0052] When the workpiece 1 is cut with the cutting blade 8 in which a plurality of recesses 44 exposed only on the outer peripheral surface 10b are formed in the cutting edge portion 10, the generated cutting chips are taken into these recesses 44. That is, the recesses 44 function as a storage space for temporarily storing the cutting chips, and have a function of excluding the cutting chips from the first side surface 10c, the second side surface 10d, and the outer peripheral surface 10b of the cutting edge portion 10.

[0053] For example, when the recesses 44 are also exposed on the first side surface 10c or the second side surface 10d of the cutting edge portion 10, unlike the present embodiment, the cutting chips taken into the recesses 44 will leak out to the first side surface 10c or the second side surface 10d. In this case, the leaked cutting chips become a cause of uneven wear of the cutting edge portion 10, causing a deterioration in the quality of the machining performed with the cutting blade 8.

[0054] On the other hand, when the plurality of recesses 44 are exposed only on the outer peripheral surface 10b, the cutting chips do not escape from these recesses 44 to the side surface side of the cutting edge portion 10, so uneven wear of the cutting edge portion 10 is suppressed. And when the recesses 44 into which the cutting chips have entered as the cutting blade 8 rotates pass through the workpiece 1, the cutting chips are discharged from the recesses 44. Therefore, in the cutting blade 8 according to the present embodiment, the cutting chips generated when the workpiece 1 is cut are efficiently discharged from the cutting marks (cutting grooves).

[0055] In each figure, for the convenience of explanation, the shape, size, etc. of each structure are emphasized and shown. Therefore, the dimensions, etc. of each part of the cutting edge portion 10 of the cutting blade 8 according to the present embodiment are not limited to the shape, size, etc. of each part in each figure. Here, the dimensions, etc. of each part of the cutting edge portion 10 of the cutting blade 8 according to the present embodiment, particularly the size of the concave portion 44, will be described.

[0056] However, depending on the combination of each value that can be adopted within the ranges indicated by the following items, it may not be possible to realize the cutting edge portion 10 having a predetermined performance. Since the size ranges of the following items affect each other so as to be able to realize the cutting edge portion 10 having a predetermined performance, depending on the value adopted for one item, the following numerical ranges for other items may be further limited. Therefore, in the following items, values are adopted so as not to cause contradictions with each other and to be able to realize the cutting edge portion 10 having a predetermined performance.

[0057] First, the thickness of the cutting edge portion 10 (the distance between the first side surface 10c and the second side surface 10d) is preferably 0.10 mm or more and 0.60 mm or less, and typically is 0.12 mm. The width of the concave portion 44 (the length in the thickness direction of the cutting edge portion 10) is preferably 0.03 mm or more and 0.50 mm or less, and is set to a value smaller than the thickness of the cutting edge portion 10, and typically is 0.03 mm.

[0058] Furthermore, the width of the concave portion 44 will be described from another perspective. The width of the concave portion 44 is preferably 20% or more of the thickness of the cutting edge portion 10. This is because when it is less than 20% of the thickness of the cutting edge portion 10, the amount of cutting chips entering the concave portion 44 is insufficient with respect to the amount of generated cutting chips, and the effect of discharging the cutting chips by the concave portion 44 is limited. However, the width of the concave portion 44 may be less than 20% of the thickness of the cutting edge portion 10 in some cases.

[0059] Further, the width of the recess 44 is preferably equal to or less than a value obtained by subtracting 0.04 mm from the thickness of the cutting edge portion 10. If the width of the recess 44 exceeds the value obtained by subtracting 0.04 mm from the thickness of the cutting edge portion 10, there will be no sufficient thickness of the bonding material remaining between the recess 44 and both side surfaces 10c and 10d of the cutting edge portion 10, and the strength of the cutting edge portion 10 will extremely decrease in the vicinity of the recess 44. In this case, chipping will occur in the cutting edge portion 10 while cutting the workpiece 1 with the cutting blade 8, and the cutting quality will deteriorate. Moreover, if the recess 44 is connected to the first side surface 10c or the second side surface 10d of the cutting edge portion 10, the chip discharging effect of the recess 44 will also deteriorate.

[0060] Further, the length of each recess 44 (the length in the circumferential direction of the cutting edge portion 10, the length in the direction along the outer circumference 10e of the first side surface 10c) is preferably 1 mm or more, and typically 20 mm. If the length of the recess 44 is less than 1 mm, the chip discharging effect will be limited, and when the cutting edge portion 10 is worn out while repeatedly cutting the workpiece 1 with the cutting blade 8, the recess 44 will easily disappear.

[0061] Further, the depth of the recess 44 is preferably 0.01 mm or more and 2.00 mm or less, and typically 0.02 mm. If the depth of the recess 44 is less than 0.01 mm, the chip discharging effect will be limited. On the other hand, if the depth of the recess 44 exceeds 2.00 mm, sufficient strength cannot be ensured for the cutting edge portion 10 in the portion between the recess 44 and both side surfaces 10c and 10d of the cutting edge portion 10, and chipping will easily occur in the cutting edge portion 10 at this portion.

[0062] Further, the number of recesses 44 formed in the cutting edge portion 10 is preferably 1 or more, more preferably 2 or more, and typically 8. Even if only one recess 44 is formed in the cutting edge portion 10, a limited chip discharging effect will occur. And when the number of recesses 44 is 2 or more, the cutting blade 8 can rotate stably as described below.

[0063] Also, the number of the recesses 44 is preferably less than the value obtained by multiplying the outer diameter (mm) of the cutting edge portion 10 by 1.5. If the number of the recesses 44 is equal to or more than this value, the length of each recess 44 has to be about 1 mm or less, and the effect of discharging the cutting chips is limited.

[0064] Here, the formation positions (arrangements) of the plurality of recesses 44 in the cutting edge portion 10 will be described in detail. As shown in FIG. 3, the arrangement of the plurality of recesses 44 is preferably determined to be rotationally symmetric along the circumferential direction of the cutting edge portion 10. In this case, when the cutting blade 8 is rotated to cut the workpiece 1 with the cutting blade 8, the center of gravity position of the cutting edge portion 10 does not change and the rotation is stable. Therefore, the workpiece 1 can be machined with high quality.

[0065] Moreover, FIG. 4(A) is a plan view schematically showing the outer peripheral surface 10b of the cutting edge portion 10 of the cutting blade 8 according to the present embodiment. As shown in FIG. 4(A), the plurality of recesses 44 are preferably formed in the cutting edge portion 10 side by side along the outer periphery 10e of the first side surface 10c. The plurality of recesses 44 arranged in this way are relatively easy to form.

[0066] Here, when a plurality of recesses 44 are formed in the cutting edge portion 10, the mechanical strength of the cutting edge portion 10 decreases. When the distance between the recess 44 and both side surfaces 10c and 10d is short, the mechanical strength of the cutting edge portion 10 particularly decreases. Therefore, it is desirable to make the distance between both side surfaces 10c and 10d of the cutting edge portion 10 and each recess 44 as large as possible. When the plurality of recesses 44 are formed in the cutting edge portion 10 side by side along the outer periphery 10e of the first side surface 10c, the distance between each recess 44 and both side surfaces 10c and 10d can be maximized, and the strength of the cutting edge portion 10 becomes relatively high. However, the plurality of recesses 44 do not necessarily have to be arranged side by side along the outer periphery 10e of the first side surface 10c.

[0067] In order to enhance the mechanical strength of the cutting edge portion 10 in which the concave portion 44 is formed on the outer peripheral surface 10b, a soft filler may be disposed in one or more of the plurality of concave portions 44 as compared with the cutting edge portion 10. The filler is composed of, for example, a resin material. FIG. 5(B) includes a plan view schematically showing a filler 54 according to an example. The filler 54 will be described in detail in the manufacturing method of the cutting blade described below.

[0068] Next, an example of a method for manufacturing a cutting blade having a plurality of concave portions on the outer peripheral surface of the cutting edge portion will be described. In the manufacturing method of the cutting blade described below, a plurality of annular plates are prepared, and the cutting edge portion is formed by integrating them. The number of plates serving as constituent members of the cutting edge portion can be appropriately changed. First, a case where three plates are integrated to form the cutting edge portion will be described as an example.

[0069] FIG. 5(A) is a plan view schematically showing the first side surfaces 46a and 50a of the first plate 46 and the third plate 50, and FIG. 5(B) is a plan view schematically showing the first side surface 48a of the second plate 48. In this manufacturing method, the first plate 46, the second plate 48, and the third plate 50 are integrated to form the cutting edge portion.

[0070] FIG. 6(A) is a plan view schematically showing the outer peripheral surface 56c of the cutting edge portion 56 formed by integrating the first plate 46, the second plate 48, and the third plate 50. As shown in FIG. 6(A), when forming the cutting edge portion 56, the first plate 46 is exposed on one side surface 56a of the cutting edge portion 56, and the third plate 50 is exposed on the other side surface 56b of the cutting edge portion 56. The second plate 48 is sandwiched between the first plate 46 and the third plate 50.

[0071] Here, each of the plates 46, 48, and 50 has a first side surface 46a, 48a, 50a and a second side surface 46b, 48b, 50b having the same shape and size as the side surfaces 56a and 56b of the cutting edge portion 56 whose formation is planned. Further, in each plate 46, a through hole having the same diameter as the through hole formed in the center of the cutting edge portion 56 whose formation is planned penetrates through the two side surfaces.

[0072] And each of the plates 46, 48, 50 further has outer peripheral surfaces 46c, 48c, 50c connected to the outer perimeters of the first side surfaces 46a, 48a, 50a and the second side surfaces 46b, 48b, 50b, respectively. The thickness of each of the plates 46, 48, 50 (the width of the outer peripheral surfaces 46c, 48c, 50c) is determined so as to be the same as the thickness of the cutting edge portion 56 when totaled.

[0073] Also, as shown in FIG. 5(B), the second plate 48 has a notch portion 52 that penetrates from the first side surface 48a to the second side surface 48b and opens to the outer peripheral surface 48c. This notch portion 52 serves as a recess when the cutting edge portion 56 is formed. The number and arrangement of the notch portions 52 of the second plate 48 are determined so as to correspond to the number and arrangement of the recesses in the cutting edge portion 56 to be formed. On the other hand, the first plate 46 and the third plate 50 do not have such notch portions.

[0074] Next, each step of the method for manufacturing the cutting blade will be described. FIG. 16(A) is a flowchart showing the flow of each step of the method for manufacturing the cutting blade. In the method for manufacturing the cutting blade, first, a plate preparation step S10 of preparing an annular first plate 46, an annular second plate 48, and an annular third plate 50 is performed.

[0075] Here, there is no particular limitation on the method of preparing each of the plates 46, 48, 50. For example, countless abrasive grains are mixed into the powder that becomes the material of the binder, and this is put into a mold corresponding to the shape and size of each of the plates 46, 48, 50, and the powder put into the mold is compacted. Thereby, each of the plates 46, 48, 50 can be formed. Here, the powder put into the mold may be heated and fired.

[0076] Here, a method for manufacturing each of the plates 46, 48, and 50 using a mold will be described. FIG. 14 is a perspective view schematically showing a press molding machine 120 used for manufacturing the first plate 46 (the third plate 50). First, the press molding machine 120 will be described. The press molding machine 120 includes a mold 122 that houses powder in a predetermined shape, and a pressing portion 124 that presses the powder housed in the mold 122.

[0077] The mold 122 has a circular and concave accommodation space 126 exposed on the upper surface 122a, and a cylindrical portion 128 is provided at the center of the bottom surface of the accommodation space 126. An annular groove 130 is formed around the cylindrical portion 128. The depth of the annular groove 130 exceeds the thickness of the first plate 46 (the third plate 50) to be manufactured.

[0078] The diameter of this cylindrical portion 128 is set to a size corresponding to the inner diameter of the first plate 46 to be manufactured. And the outer diameter of the annular groove 130 is set to a size corresponding to the outer diameter of the first plate 46 to be manufactured. The pressing portion 124 is formed, for example, in a cylindrical or cylindrical shape. The diameter of this pressing portion 124 is set to a size corresponding to the outer diameter of the annular groove 130 of the mold 122.

[0079] When manufacturing the first plate 46 with the press molding machine 120, first, powder that is a material of the binder constituting the first plate 46 and abrasive grains are put into the annular groove 130 of the mold 122. At this time, vibration may be applied to the mold 122 so that no bubbles remain in the powder inside the annular groove 130 and the upper end of the powder has a uniform height, thus adjusting the state of the powder.

[0080] Next, the pressing portion 124 is inserted into the accommodation space 126 of the mold 122 from above, and the powder is pressed by the lower surface 124a of the pressing portion 124. FIG. 15(A) includes a cross-sectional view schematically showing how the powder 136 is pressed by the press molding machine. When the powder 136 is pressed by the pressing portion 124, the powder 136 is pressed into a shape that reflects the shape of the annular groove 130. Note that the powder 136 may be heated and sintered together with the press molding machine 120 in this state.

[0081] After that, the pressing part 124 is taken out from the mold 122, and the solidified powder body 136 is taken out from the mold 122. This solidified powder body 136 becomes the first plate 46. Note that the third plate 50 is manufactured by the press molding machine 120 in the same manner as the first plate 46.

[0082] When manufacturing the second plate 48, a press molding machine 138 (see FIG. 15(C)), which has a configuration different from that of the press molding machine 120 shown in FIG. 15(A), may be used. FIG. 15(C) includes a cross-sectional view schematically showing the press molding machine 138. Among the components of the press molding machine 138 shown in FIG. 15(C), the components similar to those of the press molding machine 120 shown in FIG. 15(A) are given the same reference numerals as those of the corresponding components in FIG. 15(A) in FIG. 15(C). And the description of these components is omitted.

[0083] In the press molding machine 138, a dummy member 134 is disposed inside the annular groove 130. The dummy member 134 is a member that occupies a space where it is desired that the powder body 136 does not enter. The dummy member 134 has a height approximately the same as the thickness of the second plate 48 to be manufactured, and has the same shape as the notch 52 of the second plate 48. And the dummy member 134 is arranged in the annular groove 130 in the same number as the notches 52 in the second plate 48 to be manufactured, and in the direction and position corresponding to each notch 52.

[0084] The dummy member 134 may be fixed to the mold 122. Or, the mold 122 may be manufactured by cutting from a metal disk, or the mold 122 may be cut out so that the dummy member 134 is arranged in the annular groove 130. When the powder body 136 is put into the mold 122 in which the dummy member 134 is arranged in the annular groove 130 and the powder body 136 is pressed and compacted by the pressing part 124, the second plate 48 having the notch 52 can be manufactured.

[0085] In addition, when the thicknesses of the respective plates 46, 48, and 50 are the same, three annular plates may be manufactured or procured. Two of the plates may be used as the first plate 46 and the third plate 50, and a notch 52 may be formed in the remaining one plate to prepare the second plate 48. The second plate 48 is manufactured, for example, by performing machining such as mechanical machining, electrical discharge machining, laser machining, etc. on the plate used as the raw material to form the notch 52. However, the thicknesses of the respective plates 46, 48, and 50 may be different from each other, and they may be prepared individually.

[0086] Next, an integration step S30 of overlapping and integrating the first plate 46, the second plate 48, and the third plate 50 to form the cutting edge portion 56 is performed. More specifically, in the integration step S30, the second side surface 46b of the first plate 46 is brought into contact with the first side surface 48a of the second plate 48, and the second side surface 48b of the second plate 48 is brought into contact with the first side surface 50a of the third plate 50.

[0087] At this time, the first side surface 46a of the first plate 46 and the second side surface 50b of the third plate 50 are exposed to the outside. And the notch 52 of the second plate 48 is partially blocked by the first plate 46 and the third plate 50. And the notch 52 is exposed only on the outer peripheral surface 48c side of the second plate 48.

[0088] In the integration step S30, after overlapping the three plates 46, 48, and 50, the laminate is heated and sintered. Thereby, the three plates 46, 48, and 50 are integrated, and the cutting edge portion 56 is formed. Here, the sintering temperature may be appropriately determined according to the type of the binder material contained in the plates 46, 48, and 50. Also, the integration method is not limited to sintering, and the respective plates 46, 48, and 50 may be integrated by an adhesive or a brazing material.

[0089] FIG. 6(A) is a plan view schematically showing the outer peripheral surface 56c of the formed cutting edge portion 56, and FIG. 6(B) is a plan view schematically showing an enlarged outer peripheral surface 56c of the formed cutting edge portion 56. As shown in each figure, the notch portion 52 formed in the second plate 48 becomes a recess exposed only on the outer peripheral surface 56c of the cutting edge portion 56.

[0090] An annular hub portion made of a metal material such as aluminum may be attached to the formed cutting edge portion 56, whereby a hub blade is formed as a cutting blade. Alternatively, a hub portion may not be attached to the formed cutting edge portion 56. In this case, it means that the cutting blade (washer blade) composed only of the cutting edge portion 56 is manufactured by the integration step S30.

[0091] In any case, in the manufacturing method of the cutting blade described above, the notch portion 52 of the second plate 48 is exposed only on the outer peripheral surface 56c of the cutting edge portion 56 when the cutting edge portion 56 is formed by the integration step S30. Then, when the workpiece 1 is cut using the formed cutting blade, the generated grinding chips enter the notch portion (recess) 52 and are discharged from the side surfaces 56a and 56b of the cutting edge portion 56. Therefore, uneven wear of the cutting edge portion 56 is suppressed by the grinding chips.

[0092] When forming the cutting edge portion 56 using three plates 46, 48, and 50, the plates 46, 48, and 50 do not necessarily need to have the same properties such as constituent materials, material composition ratios, and structures. For example, the second plate 48 may be softer than the first plate 46 and the third plate 50, may contain pores in the binder, or may have a porous structure. Also, it is preferable that the first plate 46 and the third plate 50 have the same shape, size (thickness), constituent material, etc.

[0093] Here, in the cutting edge portion 56, a filler 54 (see FIG. 5(B)) may be disposed in the notch portion 52. The filler 54 is preferably a member softer than the second plate 48. Alternatively, it is preferably a member softer than the first plate 46 and the third plate 50. From another perspective, the filler 54 is preferably a member softer than the cutting edge portion 56.

[0094] And the manufacturing method of the cutting blade described so far may further include a filler disposing step S20 of disposing a filler 54 softer than the second plate 48 in the notch portion 52 of the second plate 48. In the filler disposing step S20, the filler 54 is disposed in some or all of the notch portions 52 of the second plate 48. Then, the filler 54 is integrated with the cutting edge portion 56.

[0095] When the notch portion (recess) 52 of the cutting edge portion 56 is filled with the filler 54, the mechanical strength of the cutting edge portion 56 is higher than when nothing is disposed in the notch portion 52. The filler 54 includes, for example, a main material composed of a resinoid, a metal material, a vitrified bond, etc., and a filler mixed into the main material.

[0096] Examples of the resinoid used for the main material include thermosetting resins such as phenol resin, epoxy resin, and polyimide resin. As the main material composed of a metal material, one of Cu, Sn, Co, Fe, Ni, W, Ti, etc. may be used, or two or more of these may be used in combination.

[0097] In addition, as the filler mixed and used in the main material, for example, particles such as diamond particles, cBN particles, C-based abrasive grains (abrasive grains mainly composed of silicon carbide (SiC)), A abrasive grains (abrasive grains mainly composed of alumina), carbon, MoS2, and ceramic fine particles can be used. As the ceramic fine particles, for example, Al2O3, SiO2, SiC, TiC, TiCN, TiN, etc. can be used. The filler 54 is formed, for example, by mixing a filler into a main material and sintering the mixture.

[0098] The blending ratio of the main material in the filling 54 is preferably 40% by weight or more and 100% by weight or less, and more preferably 50% by weight or more and 80% by weight or less. Typically, it is about 60% by weight. However, the blending ratio of the main material is not limited thereto. The materials of the main material and the filler, and the mixing ratio of the main material can be appropriately selected within the range where the filling 54 is softer than the cutting edge portion 56.

[0099] Here, the filling 54 may be disposed, for example, in the notch 52 of the second plate 48 before being overlapped with the first plate 46 and the third plate 50. That is, the filling disposition step S20 may be performed before the integration step S30. In the integration step S30, the second plate 48 in which the filling 54 is disposed in the notch 52 is sandwiched between the first plate 46 and the third plate 50 and integrated. In this case, the disposition of the filling 54 in the notch 52 is not obstructed by the first plate 46 and the third plate 50.

[0100] Further, the filling 54 may be disposed, for example, in the notch 52 of the second plate 48 overlapped with the first plate 46 and the third plate 50. That is, the filling disposition step S20 may be performed simultaneously with the integration step S30. And the filling 54 may be disposed in the notch 52 after the three plates 46, 48, 50 are overlapped and before integration such as sintering or adhesion is performed. In this case, the filling 54 can be fixed by heating the filling 54 simultaneously with the sintering or the like of the three plates 46, 48, 50.

[0101] Alternatively, when the filler arrangement step S20 is carried out simultaneously with the integration step S30, the filler 54 may be arranged in the notch (recess) 52 after the three plates 46, 48, 50 are stacked, the integration such as sintering or adhesion is carried out, and the cutting edge portion 56 is formed. And after the notch 52 is filled with the filler 54, the cutting edge portion 56 may be heated and the filler 54 may be fixed to the notch 52. In this case, regardless of the conditions such as sintering of the three plates 46, 48, 50, the filler 54 can be fixed under the conditions optimal for the fixation of the filler 54.

[0102] Here, a method of arranging the filler 54 in the notch 52 (the recess of the cutting edge portion 56) will be described. For example, a filler 54 shaped to correspond to the shape of the notch 52 (the recess of the cutting edge portion 56) is prepared, and the arrangement is carried out by inserting this into the notch 52. Alternatively, a fluid in which the material of the filler 54 is dispersed in a dispersion medium is prepared, and the fluid is caused to flow into each notch 52. Then, the filler 54 may be arranged in the notch 52 by heating this fluid to remove the dispersion medium.

[0103] Furthermore, another method of arranging the filler 54 will be described. FIG. 7 is a plan view schematically showing an annular filler member 58 formed of the constituent material of the filler 54. The annular filler member 58 has an annular support portion 62, and the inner diameter of the annular support portion 62 exceeds the outer diameter of the cutting edge portion 56 (the diameter of the outer peripheral surface 56c of the cutting edge portion 56, the diameter of the outer peripheral surface 48c of the second plate 48).

[0104] And a plurality of protrusions 60 are provided on the inner periphery of the annular support portion 62 of the annular filler member 58 in an arrangement corresponding to the arrangement of the recesses in the cutting edge portion 56 (the arrangement of the notches 52 in the second plate 48). The position, size, and shape of each protrusion 60 are determined to correspond to the position, size, and shape of the recess in the cutting edge portion 56 (the notch 52 of the second plate 48).

[0105] The annular filling member 58 is attached to the second plate 48 such that each protrusion 60 is fitted into each notch 52 of the second plate 48. The attachment of the annular filling member 58 to the second plate 48 is performed, for example, before sandwiching the second plate 48 between the first plate 46 and the third plate 50.

[0106] Then, the second plate 48 to which the annular filling member 58 is attached is integrated with the first plate 46 and the third plate 50 to form an integral body. Thereafter, by removing the annular support portion 62 of the annular filling member 58 from the integral body, the connection of each protrusion 60 via the annular support portion 62 is released, and the protrusions 60 remain as the filling 54 in the plurality of recesses (the plurality of notches 52) of the cutting edge portion 56.

[0107] Note that the removal of the annular support portion 62 is performed, for example, by bringing the integral body into contact with a grindstone member from the outer periphery while rotating the integral body in the circumferential direction. When the annular support portion 62 of the rotating annular filling member 58 comes into contact with the grindstone member, the annular support portion 62 is scraped off from the outer periphery. Also, the removal of the annular support portion 62 may be performed by separating the protrusions 60 and the annular support portion 62 with a cutting tool such as a cutter.

[0108] The filling 54 disposed in the notch (recess) 52 by any method is fixed to the cutting edge portion 56 by a method such as adhesion or sintering. Note that even when the filling 54 is disposed in the notch (recess) 52, the effect of discharging cutting chips by the notch (recess) 52 can be sufficiently achieved.

[0109] The filling 54 is softer than the binder constituting the cutting edge portion 56 and is easily worn. Therefore, when the workpiece 1 is cut with a cutting blade having the cutting edge portion 56 in which the filling 54 is disposed in the notch (recess) 52, the wear of the filling 54 progresses faster than the surroundings. Therefore, a space sufficient for the cutting chips generated by cutting to enter is always formed, and the effect of discharging the cutting chips is achieved.

[0110] Alternatively, when the workpiece 1 is cut with the cutting blade, the cutting chips enter the notch 52 by pushing aside the soft filler 54. Therefore, the cutting chips can sufficiently enter the notch (recess) 52 where the filler 54 is disposed, resulting in a cutting chip discharge effect.

[0111] In the manufacturing method of the cutting blade described so far, the cutting edge portion 56 is formed by integrating three annular plates 46, 48, and 50. However, the number of annular plates used to form the cutting edge portion 56 is not limited to three. For example, the cutting edge portion may be formed by integrating two annular plates, or the cutting edge portion may be formed by integrating four or more annular plates.

[0112] Also, for example, a plurality of the above-described first plates 46 and a plurality of second plates 48 may be alternately laminated to form an integral body, and one of the first plates 46 may be exposed on one side surface of the integral body, and the other of the first plates 46 may be exposed on the other side surface of the integral body to form the cutting edge portion. Even in this case, a cutting edge portion having a plurality of recesses exposed only on the outer peripheral surface can be formed from this integral body.

[0113] Next, a method for manufacturing a cutting blade by forming a cutting edge portion of the cutting blade using two plates, namely the first plate and the second plate, will be described. FIG. 8(A) is a plan view schematically showing a side surface 64a of the first plate 64, and FIG. 8(B) is a plan view schematically showing a side surface 66a of the second plate 66. Next, in the manufacturing method of the cutting blade to be described, the cutting edge portion 70 shown in FIG. 9(A) is formed by integrating the first plate 64 and the second plate 66.

[0114] FIG. 9(A) is a plan view schematically showing an outer peripheral surface 70c of the cutting edge portion 70 formed from the first plate 64 and the second plate 66. FIG. 9(A) includes a plan view schematically showing an outer peripheral surface 64c of the first plate 64 and a plan view schematically showing an outer peripheral surface 66c of the second plate 66.

[0115] As shown in FIGS. 8(A) and 9(A), the first plate 64 includes two side surfaces 64a and 64b and an outer peripheral surface 64c connected to both side surfaces 64a and 64b, and no structures such as notches or grooves are formed on the outer peripheral surface 64c.

[0116] As shown in FIGS. 8(B) and 9(A), the second plate 66 includes two side surfaces 66a and 66b and an outer peripheral surface 66c connected to both side surfaces 66a and 66b. More specifically, the second plate 66 has an annular first side surface 66a facing the first plate 64 in the integrated step S30, an annular second side surface 66b not facing the first plate 64, and an outer peripheral surface 66c connected to the outer periphery of each of the first side surface 66a and the second side surface 66b.

[0117] The second plate 66 has grooves (recesses) 68 exposed on the first side surface 66a and the outer peripheral surface 66c. That is, a plurality of grooves (recesses) 68 exposed on the first side surface 66a facing the first plate 64 are formed on the outer peripheral surface 66c. On the other hand, the plurality of grooves (recesses) 68 do not open to the second side surface 66b that does not face the first plate 64.

[0118] When forming the cutting edge portion 70, first, the first plate 64 and the second plate 66 are prepared. The second plate 66 is manufactured, for example, by a press molding machine 132 (see FIG. 15(B)). In the press molding machine 132, a dummy member 134 is disposed inside the annular groove 130. The dummy member 134 is a member that occupies a space where the entry of the powder 136 is to be prevented.

[0119] The shape and size of the dummy member 134 are the same as those of the groove 68 provided in the second plate 66 to be manufactured. The dummy member 134 is arranged in the annular groove 130 in the same number as the grooves 68 in the second plate 66 to be manufactured, and in the orientation and position corresponding to each groove 68.

[0120] When the powder 136 is placed in the mold 122 with the dummy member 134 disposed in the annular groove 130 and the powder 136 is pressed and compacted by the pressing portion 124, the second plate 66 having the groove 68 can be manufactured. FIG. 15(B) is a cross-sectional view schematically showing the press molding machine 132 according to the modified example.

[0121] Next, the integration step S30 is performed. First, the first plate 64 and the second plate 66 are overlapped so that the first side surface 66a of the second plate 66 where the groove 68 is exposed is in contact with the first plate 64. In this state, the first plate 64 and the second plate 66 are integrated by a method such as sintering or adhesion. Then, the cutting edge portion 70 is formed.

[0122] FIG. 9(B) is a plan view schematically showing an enlarged outer peripheral surface 70c of the formed cutting edge portion 70. As shown in FIG. 9(B), the opening on the first side surface 66a side of the groove 68 is blocked by the first plate 64. And the groove 68 becomes the recessed portion 72 exposed only on the outer peripheral surface 70c of the cutting edge portion 70. That is, the groove 68 (recessed portion 72) of the second plate 66 is exposed only on the outer peripheral surface 70c of the cutting edge portion 70 when the cutting edge portion 70 is formed by the integration step S30. At this time, the recessed portion 72 is not exposed on the side surfaces 70a, 70b of the cutting edge portion 70.

[0123] Note that a plurality of grooves may be formed in the first plate 64 in addition to the second plate 66. For example, the first plate 64 has grooves (recessed portions) exposed on the side surface (second side surface 64b) facing the second plate 66 and the outer peripheral surface 64c. That is, a plurality of grooves (recessed portions) exposed on the second side surface 64b facing the second plate 66 are formed on the outer peripheral surface 64c. On the other hand, the plurality of grooves (recessed portions) do not open on the side surface (first side surface 64a) that does not face the second plate 66.

[0124] When a groove is formed in the first plate 64, the opening on the second side surface 64b side of this groove is blocked by the second plate 66 when performing the integration step S30. Then, the groove becomes a recess that is exposed only on the outer peripheral surface 70c of the cutting edge portion 70. That is, this groove (recess) of the first plate 64 is exposed only on the outer peripheral surface 70c of the cutting edge portion 70 when the cutting edge portion 70 is formed by the integration step S30. At this time, the groove (recess) is not exposed on the side surfaces 70a, 70b of the cutting edge portion 70.

[0125] In this case, in the integration step S30, the groove 68 of the second plate 66 and the groove of the first plate 64 may face each other. In this case, when the integration step S30 is performed, a plurality of large recesses in which both grooves are integrated are formed in the cutting edge portion 70. Also in this case, since the groove 68 of the second plate 66 is not exposed on the side surfaces 70a, 70b of the cutting edge portion 70, it can be said that it is exposed only on the outer peripheral surface 70c. That is, the recess (groove 68) of the cutting edge portion 70 being exposed only on the outer peripheral surface 70c is synonymous with not being exposed on the side surfaces 70a, 70b, and the connection of the groove of the first plate 64 and the groove 68 of the second plate 66 is not excluded.

[0126] Alternatively, in the integration step S30, the groove 68 of the second plate 66 and the groove of the first plate 64 do not have to face each other. In this case, when the integration step S30 is performed, recesses originating from the respective grooves are formed in the cutting edge portion 70 so as to be arranged in a zigzag along the outer peripheral surface 70c. The significance of such a plurality of recesses that are not arranged along the outer peripheral surface 70c is as shown separately.

[0127] When cutting the workpiece 1 with a cutting blade having a cutting edge portion 70, the generated cutting chips enter the groove 68 (recess 72) and are efficiently discharged from the side surface of the cutting edge portion 70. Therefore, uneven wear due to cutting chips hardly occurs in the cutting edge portion 70. In this way, it is also possible to form the cutting edge portion 70 using two plates 64, 66 instead of three plates. Also, it is possible to form the cutting edge portion using four or more plates. Details will be described later.

[0128] Next, a modified example of the cutting blade according to the present embodiment will be described. FIG. 10(A) is a plan view schematically showing a side surface 74c of a cutting edge portion 74 of a cutting blade according to the modified example. The cutting edge portion 74 shown in FIG. 10(A) has an inner peripheral surface 74a, an outer peripheral surface 74b, and two side surfaces 74c connected to the inner peripheral surface 74a and the outer peripheral surface 74b. And the cutting edge portion 74 includes a plurality of recesses 76 exposed only on the outer peripheral surface 74b.

[0129] The cutting edge portion 74 shown in FIG. 10(A) has a large feature in the shape of the recess 76. In FIG. 10(A), centers 84 of the inner peripheral surface 74a and the outer peripheral surface 74b in a plane parallel to the side surface 74c of the cutting edge portion 74 are shown. And among the inner surfaces other than the bottom surface 82 of the recess 76, the inner surfaces 78, 80 not along the two side surfaces 74c are made parallel to the radial direction 86 of the cutting edge portion 74 passing through the center 84.

[0130] When machining the workpiece 1 with a cutting blade having the cutting edge portion 74, the cutting edge portion 74 is gradually consumed from the outer peripheral surface 74b side, the diameter of the cutting edge portion 74 gradually becomes smaller, and the circumferential length (the length of the outer peripheral surface 74b) of the cutting edge portion 74 gradually becomes smaller. And when the inner surfaces 78, 80 of the recess 76 are along the radial direction 86, at this time, the circumferential length of the recess 76 exposed on the outer peripheral surface 74b (the distance between the two inner surfaces 78, 80 on the outer peripheral surface 74b) also gradually becomes smaller.

[0131] Here, the reduction rate of the circumferential length (the length of the outer peripheral surface 74b) of the cutting edge portion 74 accompanying the consumption of the cutting edge portion 74 and the reduction rate of the circumferential length of the recess 76 (the distance between the two inner surfaces 78, 80 on the outer peripheral surface 74b) are the same. Therefore, the ratio of the circumferential length of the recess 76 to the circumferential length of the cutting edge portion 74 is independent of the consumption of the cutting edge portion 74 and is constant.

[0132] If the inner surfaces 78 and 80 of the recess 76 are not along the radial direction 86, as the cutting edge portion 74 wears, the ratio of the circumferential length of the recess 76 to the circumferential length of the cutting edge portion 74 changes, and the cutting performance of the cutting edge portion 74 changes. On the other hand, when the ratio of the circumferential length of the recess 76 to the circumferential length of the cutting edge portion 74 is constant, the change in the cutting performance of the cutting edge portion 74 due to wear is extremely small. Therefore, the cutting edge portion 74 shown in Fig. 10(A) has an extremely small change in cutting ability due to wear.

[0133] Next, another modification of the cutting blade according to the present embodiment will be described. Fig. 10(B) is a plan view schematically showing a side surface 88c of a cutting edge portion 88 of a cutting blade according to the modification. The cutting edge portion 88 shown in Fig. 10(B) has an inner circumferential surface 88a, an outer circumferential surface 88b, and two side surfaces 88c connected to the inner circumferential surface 88a and the outer circumferential surface 88b. And the cutting edge portion 88 is provided with a plurality of recesses 90a and 90b exposed only on the outer circumferential surface 88b.

[0134] In the cutting edge portion 88 of the cutting blade according to this modification, the depths of the recesses 90a and 90b are not constant. For example, in the cutting edge portion 88 shown in Fig. 10(B), a plurality of relatively shallow recesses 90a and a plurality of relatively deep recesses 90b are formed. In this case, when the cutting edge portion 88 wears while repeatedly cutting the workpiece 1 with the cutting blade having the cutting edge portion 88, each of the recesses 90a and 90b gradually becomes shallower, the inner surfaces 92a and 94a of the recess 90a gradually become smaller, and the inner surfaces 92b and 94b of the recess 90b gradually become smaller.

[0135] And when the wear of the cutting edge portion 88 progresses to a certain extent, the bottom surface 96a and the outer circumferential surface 88b become the same surface, the inner surfaces 92a and 94a of the shallow recess 90a disappear, that is, the shallow recess 90a disappears. On the other hand, at this stage, the bottom surface 96b of the deep recess 90b does not become the same surface as the outer circumferential surface 88b, and the deep recess 90b remains in the cutting edge portion 88.

[0136] Here, as described with reference to FIG. 2, the cutting unit 6 of the cutting apparatus has a rotational drive source that rotates the spindle 14 to which a cutting blade is attached. And in the cutting apparatus, while cutting the workpiece 1, the load applied to this rotational drive source is monitored. Based on the load applied to this rotational drive source, the degree of wear of the cutting edge portion 88 can be detected.

[0137] More specifically, when the shallow recess 90a disappears due to wear of the cutting edge portion 88, the contact area of the outer peripheral surface 88b of the cutting edge portion 88 with the workpiece 1 increases, so the load applied to the rotational drive source that rotates the spindle 14 rapidly increases. Therefore, when the load applied to the rotational drive source increases, it can be determined that the wear of the cutting edge portion 88 has progressed to the extent that the shallow recess 90a disappears. In this case, although it is desirable to replace the cutting blade, it is not necessary to immediately stop the cutting of the workpiece 1 being processed. Since the deep recess 90b remains and the chip discharge effect continues to occur, the cutting of the workpiece 1 may be continued while the deep recess 90b remains.

[0138] On the other hand, when no significant increase is observed in the load of the rotational drive source that rotates the spindle 14, it can be determined that all the recesses 90a and 90b remain in the cutting edge portion 88 and a sufficient chip discharge effect is occurring. In short, based on the load applied to the rotational drive source, the degree of wear of the cutting edge portion 88 can be detected.

[0139] Note that in FIG. 10(B), a case is shown where the same number of shallow recesses 90a and deep recesses 90b are formed in the cutting edge portion 88, but the shallow recesses 90a and the deep recesses 90b are not limited to the same number. It is preferable that the cutting edge portion 88 is formed with a number of shallow recesses 90a equal to or more than the minimum number that causes a detectable increase in the load of the rotational drive source when the shallow recess 90a disappears due to wear of the cutting edge portion 88. If the number of shallow recesses 90a is reduced, the number of deep recesses 90b can be increased accordingly, so that the chip discharge effect in the cutting edge portion 88 after the shallow recess 90a disappears can be maintained relatively high.

[0140] Also, within a range where it is possible to determine the consumption amount of the cutting edge portion 88, the number of types of recesses formed in the cutting edge portion 88, the number and shape of recesses of each type, may be appropriately determined. For example, when it is desired to detect the progress of wear of the cutting edge portion 88 in multiple stages, recesses having different depths corresponding to the number of stages where detection is desired may be formed in the cutting edge portion 88. For example, if four types of recesses with different depths are formed in the cutting edge portion 88, the progress of wear of the cutting edge portion 88 can be determined in four stages.

[0141] Next, a further modification example of the cutting blade according to the present embodiment will be described. FIG. 11 is a plan view schematically showing a side surface 100c of a cutting edge portion 100 of a cutting blade according to the modification example. Also, FIG. 12(A) is a plan view schematically showing an outer peripheral surface 100b of the cutting edge portion 100, and FIG. 12(B) is a plan view schematically showing an enlarged outer peripheral surface 100b of the cutting edge portion 100.

[0142] The cutting edge portion 100 shown in FIG. 11 and the like has an inner peripheral surface 100a, an outer peripheral surface 100b, and a first side surface 100c and a second side surface 100d connected to the inner peripheral surface 100a and the outer peripheral surface 100b. And the cutting edge portion 100 includes a plurality of recesses 102a, 102b exposed only on the outer peripheral surface 100b.

[0143] In the cutting edge portion 100, a part of the plurality of recesses 102a, 102b and another part of the plurality of recesses 102a, 102b are not arranged along the outer periphery of the first side surface 100c. Explaining from another perspective, the plurality of recesses 102a and the plurality of recesses 102b are not arranged along the outer periphery of the first side surface 100c of the cutting edge portion 100.

[0144] Explaining from yet another perspective, in the cutting edge portion 100, a plurality of recesses 102a arranged along the outer periphery of the first side surface 100c at a position relatively close to the first side surface 100c and a plurality of recesses 102b arranged along the outer periphery of the first side surface 100c at a position relatively close to the second side surface 100d are formed.

[0145] In order to sufficiently produce the effect of discharging cutting chips over the entire width of the outer peripheral surface 100b of the cutting edge portion 100, it may be considered to form a recess that is long (wide) in the width direction of the outer peripheral surface 100b in the cutting edge portion 100. However, in this case, if a wide recess is formed in the cutting edge portion 100, the thickness of the bonding material of the cutting edge portion 100 around the recess becomes thinner accordingly, and the mechanical strength of the cutting edge portion 100 decreases.

[0146] Therefore, it is preferable that a plurality of recesses 102a and a plurality of recesses 102b are formed in the cutting edge portion 100 so as not to be arranged along the outer periphery of the first side surface 100c of the cutting edge portion 100. In this case, the regions where the recesses 102a and the recesses 102b exhibit the effect of discharging cutting chips are different. And both of them act integrally to produce the effect of discharging cutting chips over the entire width of the outer peripheral surface 100b. On the other hand, since the widths of the individual recesses 102a and 102b can be made small, a cutting edge portion 100 with sufficiently high strength can be realized.

[0147] Such a situation is more prominent as the thickness of the cutting edge portion 100 (the width of the outer peripheral surface 100b) is larger. That is, according to the configuration in which a part of the plurality of recesses 102a and 102b and another part of the plurality of recesses 102a and 102b are not arranged along the outer periphery of the first side surface 100c, a cutting edge portion 100 having sufficient strength and a large thickness can be realized.

[0148] In addition, in FIG. 12(A) etc., the case where two types of recesses 102a and 102b having different positions in the width direction of the outer peripheral surface 100b of the cutting edge portion 100 are formed in the cutting edge portion 100 is shown. However, the number of types of recesses having different positions in the width direction of the outer peripheral surface 100b is not limited to 2, and three or more types of recesses may be formed in the cutting edge portion 100.

[0149] Next, a method for manufacturing a cutting blade having a cutting edge portion formed with a plurality of types of recesses at different positions in the width direction of the outer peripheral surface will be described. This cutting blade can be manufactured, for example, by using two types of annular plates. FIG. 13(A) is a plan view schematically showing the outer peripheral surface 104b of the cutting edge portion 104 of the cutting blade to be manufactured, and FIG. 13(B) is a plan view schematically showing an enlarged view of the outer peripheral surface 104b of the cutting edge portion 104.

[0150] The cutting edge portion 104 is composed of four annular plates having the same inner diameter and outer shape as the cutting edge portion 104. That is, the cutting edge portion 104 includes a first plate 106, a second plate 108, a third plate 110, and a fourth plate 112. Then, the respective plates 106, 108, 110, and 112 are stacked and integrated in this order.

[0151] Here, each of the plates 106, 108, 110, and 112 has a first side surface and a second side surface having the same shape and size as the side surfaces 104c and 104d of the cutting edge portion 104 where formation is planned. Further, in each of the plates 106, 108, 110, and 112, a through-hole having the same diameter as the through-hole formed at the center of the cutting edge portion 104 where formation is planned is formed at the center so as to penetrate between the two side surfaces.

[0152] And the thickness (width of the outer peripheral surface) of each of the plates 106, 108, 110, and 112 is determined so as to have the same thickness as the thickness of the cutting edge portion 104 when totaled. Further, the first plate 106 and the fourth plate 112 are configured in the same manner as the first plate 46 described with reference to FIG. 5(A). Further, the second plate 108 and the third plate 110 are configured in the same manner as the second plate 48 described with reference to FIG. 5(B), and have a notch portion that penetrates from the first side surface to the second side surface and opens to the outer peripheral surface.

[0153] The flow of each step of the method for manufacturing a cutting blade having the cutting edge portion 104 can be explained by the flowchart shown in FIG. 16(A). First, the first plate 106, the second plate 108, the third plate 110, and the fourth plate 112 are prepared (plate preparation step S10).

[0154] Next, the first plate 106, the second plate 108, the third plate 110, and the fourth plate 112 are overlapped and integrated to form the cutting edge portion 104 (integration step S30). At this time, the orientations of the second plate 108 and the third plate 110 are adjusted so that the cutout portions of the second plate 108 and the third plate 110 do not overlap each other.

[0155] When the four plates 106, 108, 110, and 112 are integrated, the cutout portion of the second plate 108 is blocked by the first plate 106 and the third plate 110, and becomes a recess 114a that is exposed only on the outer peripheral surface 104b of the cutting edge portion 104. At the same time, the cutout portion of the third plate 110 is blocked by the second plate 108 and the fourth plate 112, and becomes a recess 114b that is exposed only on the outer peripheral surface 104b of the cutting edge portion 104.

[0156] As a result, a cutting blade having a cutting edge portion 104 is manufactured in which some of the recesses 114a and some of the other recesses 114b are not arranged along the outer periphery of the side surfaces 104c and 104d. In the manufacturing method of the cutting blade including the cutting edge portion 104, the filler disposing step S20 may be further performed. That is, a filler may be disposed in the recesses 114a and 114b.

[0157] As described above, in the cutting blade according to the present embodiment, the cutting edge portion includes a plurality of recesses (cutout portions) exposed only on the outer peripheral surface. When machining a workpiece with a cutting blade in which a plurality of recesses (cutout portions) exposed only on the outer peripheral surface are formed in the cutting edge portion, the generated cutting chips are taken into these recesses. And since the cutting chips do not escape from this recess to the side surface side of the cutting edge portion, the cutting chips are efficiently discharged.

[0158] Further, unlike the case where an annular recess extending over the entire circumference is formed on the outer peripheral surface of the cutting edge portion, the inside of the recess does not come into contact with the workpiece on the outer peripheral surface of the cutting edge portion, and a sufficient space is formed between the recess and the workpiece. Therefore, the cutting chips are effectively discharged. Also, a recess corresponding to the shape of the recess is not formed at the bottom of the cutting mark.

[0159] In the above embodiment, the case where the cutting edge portion of the cutting blade is formed by overlapping and integrating a plurality of plates has been mainly described. However, one aspect of the present invention is not limited to this. The cutting blade according to one aspect of the present invention may be formed by machining the cutting edge portion of a conventional cutting blade. Next, a modified example of the manufacturing method of the cutting blade according to one aspect of the present invention will be described.

[0160] FIG. 16(B) is a flowchart for explaining the flow of each step of the manufacturing method of the cutting blade according to the modified example. In this manufacturing method of the cutting blade, first, a preparation step S40 of preparing a blade body including an annular cutting edge portion having an annular first side surface, an annular second side surface, and an outer peripheral surface connected to the outer periphery of each of the first side surface and the second side surface is performed. In this preparation step S40, for example, a conventional cutting blade is prepared as the blade body.

[0161] Next, a recess forming step S50 of forming a cutting blade including the blade body by forming a plurality of recesses exposed only on the outer peripheral surface of the cutting edge portion of the blade body is performed. In the recess forming step S50, for example, machining is performed on the cutting edge portion to form recesses in the cutting edge portion. Alternatively, in the recess forming step S50, a laser beam is irradiated onto the cutting edge portion to perform laser processing to form recesses in the cutting edge portion.

[0162] When performing laser processing on the cutting edge portion, a laser beam is irradiated onto the outer peripheral surface of the cutting edge portion. The irradiated laser beam has, for example, a wavelength of 355 nm, a repetition frequency of 30 kHz or more and 40 kHz or less. Then, the laser beam may be scanned so that the laser beam and the irradiated region move at a relative speed of 200 mm / sec or more and 400 mm / sec or less. However, the irradiation conditions of the laser beam are not limited to this.

[0163] In addition, in this method for manufacturing a cutting blade, after the recess forming step S50, a filler disposing step S60 of disposing a filler in the recess may be further performed. Disposing a filler in the recess increases the mechanical strength of the cutting edge portion.

[0164] In addition, the structures, methods, etc. according to the above embodiments can be appropriately changed and implemented without departing from the scope of the object of the present invention.

Explanation of Reference Numerals

[0165] 1 Workpiece 1a Surface 1b Back surface 3 Division planned line 3a Cutting groove 5 Device 7 Adhesive tape 9 Annular frame 11 Frame unit 2 Cutting device 4 Chuck table 6 Cutting unit 8 Cutting blade 8a Opening 10 Cutting edge portion 10a Through hole 10b Outer peripheral surface 10c, 10d Side surfaces 10e, 10f Outer periphery 12 Spindle housing 14 Spindle 16 Opening 18 Mount 20 Flange portion 22 Boss portion 24 Through hole 26 Fixing bolt 28 Washer 30 Contact surface 32 Thread 34 Front flange 34a Opening 36 Fixing nut 36a Opening 38 Blade cover 40 Nozzle 42 Water intake 44 Recess 46, 48, 50 Plate 46a, 48a, 50a First side 46b, 48b, 50b Second side 46c, 48c, 50c Outer peripheral surface 52 Notch 54 Filling 56 Cutting edge 56a, 56b Side 56c Outer peripheral surface 58 Annular filling member 60 Protrusion 62 Annular support 64, 66 Plate 64a, 64b, 66a, 66b Side 64c, 66c Outer peripheral surface 68 Groove 70 Cutting edge 70a, 70b Side 70c Outer peripheral surface 72 Recess 74 Cutting edge 74a Inner peripheral surface 74b Outer peripheral surface 74c Side 76 Recess 78, 80 Inner surface 82 Bottom surface 84 Center 86 Radial direction 88 Cutting edge 88a Inner peripheral surface 88b Outer peripheral surface 88c Side 90a, 90b Recess 92a, 92b, 94a, 94b Inner surface 96a, 96b Bottom surface 100, 104 Cutting edge 100a Inner peripheral surface 100b, 104b Outer peripheral surface 100c, 100d, 104c, 104d Side 102a, 102b Recess 106, 108, 110, 112 Plate 114a, 114b Recess 120, 132, 138 Press former 122 Mold 122a Upper surface 124 Pressing part 124a Lower surface 126 Accommodation space 128 Cylindrical part 130 Annular groove 134Dummy member 136 Powder

Claims

1. A cutting blade having an annular cutting edge portion including a binder and abrasive grains dispersed and fixed in the binder, wherein the cutting edge portion has an annular first side surface, an annular second side surface, and an outer peripheral surface connected to the outer peripheries of the first side surface and the second side surface, and is characterized by including a plurality of recesses exposed only on the outer peripheral surface.

2. The cutting blade according to claim 1, wherein the plurality of recesses are formed in the cutting edge portion side by side along the outer periphery of the first side surface.

3. The cutting blade according to claim 1, wherein a part of the plurality of recesses and another part of the plurality of recesses are not arranged side by side along the outer periphery of the first side surface.

4. The cutting blade according to any one of claims 1 to 3, wherein a soft filler is disposed in one or more of the plurality of recesses as compared with the cutting edge portion.

5. A method for manufacturing a cutting blade having an annular cutting edge portion including a binder and abrasive grains dispersed and fixed in the binder, the method comprising: a plate preparation step of preparing an annular first plate, an annular second plate, and an annular third plate; and an integration step of overlapping and integrating the first plate, the second plate, and the third plate to form the cutting edge portion, wherein the first plate is exposed on one side surface of the cutting edge portion, the third plate is exposed on the other side surface of the cutting edge portion, the second plate has an annular first side surface, an annular second side surface, and an outer peripheral surface connected to the outer peripheries of the first side surface and the second side surface, and has a notch portion penetrating from the first side surface to the second side surface and opening to the outer peripheral surface, and the notch portion of the second plate is characterized by being exposed only on the outer peripheral surface of the cutting edge portion when the cutting edge portion is formed by the integration step.

6. The method for manufacturing a cutting blade according to claim 5 further includes a filler disposition step of disposing a soft filler in the notch portion of the second plate, wherein the filler is integrated with the cutting edge portion.

7. A method for manufacturing a cutting blade having an annular cutting edge portion including a binder and abrasive grains dispersed and fixed in the binder, the method comprising: A preparation step of preparing a blade body including an annular cutting edge portion having an annular first side surface, an annular second side surface, and an outer peripheral surface connected to the outer periphery of each of the first side surface and the second side surface; A recess forming step of forming a cutting blade including the blade body by forming a plurality of recesses exposed only on the outer peripheral surface of the cutting edge portion of the blade body, characterized in that the manufacturing method of the cutting blade comprises the steps of:

8. The method for manufacturing a cutting blade according to claim 7, wherein in the recess forming step, a laser beam is irradiated onto the outer peripheral surface of the cutting edge portion to form a plurality of the recesses.

9. The method for manufacturing a cutting blade according to any one of claims 7 or 8, further comprising a filler disposing step of disposing a filler in the recesses.

10. A method for manufacturing a cutting blade having an annular cutting edge portion including a binder and abrasive grains dispersed and fixed in the binder, A plate preparation step of preparing an annular first plate and an annular second plate; An integrating step of overlapping and integrating the first plate and the second plate to form the cutting edge portion, The second plate has an annular first side surface facing the first plate in the integrating step, an annular second side surface not facing the first plate, and an outer peripheral surface connected to the outer periphery of each of the first side surface and the second side surface, and has recesses exposed on the first side surface and the outer peripheral surface, The method for manufacturing a cutting blade, characterized in that the recesses of the second plate are exposed only on the outer peripheral surface of the cutting edge portion when the cutting edge portion is formed by the integrating step.

11. The method further comprises a filler disposing step of disposing a filler softer than the second plate in the recesses of the second plate, The method for manufacturing a cutting blade according to claim 10, wherein the filler is integrated with the cutting edge portion.

Images