Blade case

Abstract

To provide a blade case combinedly usable as storage of a hub blade and storage of a pasting blade.SOLUTION: A blade case has a bottom plate, a storage part having a first side wall projecting from an inner surface of the bottom plate in an outer peripheral edge of the bottom plate, a fitting part projecting from the inner surface of the bottom plate in a central part of the bottom plate and fitting to a fitting hole of an annular base of a first or a second cutting blade and a first projection part arranged in an annular shape between the first side wall and the fitting part in the bottom plate, and a lid part having a top plate and a second side wall projecting from the inner surface of the top plate in the outer peripheral edge of the top plate, and an annular spacer detachable to the fitting part and arranged between the fitting part and the first projection part in a radial direction of the fitting part, provides a blade case removed from the fitting part when storing the second cutting blade, by preventing the cutting blade of the first cutting blade from contacting with the first projection part of the storage part, by contacting with the annular base of the first cutting blade by being installed in the fitting part when storing the first cutting blade.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a blade case capable of housing a cutting blade. [Background technology]

[0002] Semiconductor device chips are mounted on electronic devices such as mobile phones and PCs (Personal Computers). Semiconductor device chips are formed by dividing a workpiece, which is a wafer such as a single crystal silicon substrate on whose surface a number of devices such as ICs (Integrated Circuits) are formed, into individual devices.

[0003] When dividing a workpiece into a plurality of devices, for example, a cutting device is used. The cutting device has a spindle that can rotate at high speed, and a cutting blade is attached to the tip of the spindle. A typical cutting blade is known as a so-called hub blade (for example, see Patent Document 1).

[0004] The hub blade has an annular base (i.e., hub) made of a metal such as an aluminum alloy, and a cutting blade formed by electrochemical deposition on the outer periphery of one surface of the annular base. The cutting blade is, for example, a nickel (Ni) plating layer containing diamond abrasive grains. The hub blade is housed in a blade case during transportation, storage, etc. to prevent the cutting blade from being damaged (see, for example, Patent Document 2).

[0005] In addition to hub blades, washer blades (also called hubless blades) are also used as cutting blades. When attaching a washer blade to a spindle, the washer blade is sandwiched between a receiving flange fixed to the tip of the spindle and a pressing flange.

[0006] Washer blades are difficult to handle because the cutting edge is very thin. Therefore, an attached blade has been developed in which the washer blade is fixed to one surface of an annular base similar to that of the hub blade with an adhesive, and the annular base and the washer blade are integrated together (see, for example, Patent Document 3).

[0007] The application blade also needs to be stored in a blade case to prevent the cutting blade from being damaged during transportation, storage, etc., but there are circumstances in which the blade case used to store the hub blade described above cannot be used as is.

[0008] This situation will be described in more detail below. The bottom plate of the blade case for the hub blade is provided with an annular protrusion that supports the annular base of the hub blade so that the cutting edge of the hub blade does not come into contact with the blade case.

[0009] However, since the washer blade used in the application blade is designed to be sandwiched between the receiving flange and the holding flange as described above, the blade width of the washer blade (i.e., the width from the outer circumference to the inner circumference of the cutting blade) is larger than the blade width of the hub blade.

[0010] In contrast, the outer diameter of the cutting edge of the hub blade and the outer diameter of the cutting edge of the washer blade are substantially the same, and therefore the inner diameter of the cutting edge of the applicator blade (i.e., the washer blade) is smaller than the inner diameter of the cutting edge of the hub blade.

[0011] Therefore, if an application blade is housed in a blade case for a hub blade, the annular protrusion will collide with the inner peripheral portion of the cutting edge of the application blade, damaging the cutting edge of the application blade. However, if a blade case specifically for the application blade is manufactured separately from the blade case for the hub blade, a separate mold or the like is required, which increases costs. [Prior art documents] [Patent documents]

[0012] [Patent Document 1] JP 2000-87282 A [Patent Document 2] JP 2008-280073 A [Patent Document 3] JP 2012-135833 A Summary of the Invention [Problem to be solved by the invention]

[0013] The present invention has been made in consideration of the above problems, and its object is to provide a blade case that can be used to house both a hub blade and an application blade without damaging the cutting edge of the application blade. [Means for solving the problem]

[0014] According to one aspect of the present invention, there is provided a blade case, the blade case being capable of accommodating either a first cutting blade having an inner diameter of a first size and fixed to one surface with an adhesive, the first cutting blade having an inner diameter larger than the inner diameter of the first size and fixed to one surface without the adhesive, among a plurality of cutting blades each having an annular base including an attachment hole provided at a radial center portion thereof and an annular cutting blade including abrasive grains and a binder provided on one surface of the annular base, the first cutting blade having an inner diameter of a first size and fixed to the one surface with an adhesive, and the second cutting blade having an inner diameter larger than the inner diameter of the first size and fixed to the one surface without the adhesive, the blade case comprising a bottom plate, a first side wall protruding from an inner surface of the bottom plate along a thickness direction of the bottom plate at an outer circumferential edge thereof, a fitting portion protruding from an inner surface of the bottom plate along a thickness direction of the bottom plate at a central portion thereof and fitting into the mounting hole of the annular base, and a fitting portion provided in an annular shape on the bottom plate between the first side wall and the fitting portion and contacting the cutting blade of the second cutting blade. a top plate, a lid portion having a second side wall protruding from an inner surface of the top plate along the thickness direction of the top plate at the outer periphery of the top plate, and a hinge portion connected to the first side wall and the second side wall and functioning as a rotation axis when rotating the storage portion and the lid portion to open and close, wherein the storage portion is detachable from the fitting portion and further has an annular spacer provided between the fitting portion and the first convex portion in the radial direction of the fitting portion, the annular spacer being attached to the fitting portion and contacting the annular base of the first cutting blade when the first cutting blade is stored in the blade case, thereby preventing the cutting edge of the first cutting blade from contacting the first convex portion of the storage portion, and being removed from the fitting portion when the second cutting blade is stored in the blade case.

[0015] Preferably, the annular spacer comprises a non-metallic material, has a hardness lower than that of the annular base, and is elastically deformable.

[0016] Preferably, the accommodating portion has a second convex portion provided on the bottom plate between the fitting portion and the first convex portion, and a top surface of the first convex portion protrudes further than a top surface of the second convex portion.

[0017] Preferably, the first cutting blade is an attached blade in which a washer blade having the abrasive grains fixed with the binder is fixed to one surface of the annular base with the adhesive, and the second cutting blade is a hub blade in which a cutting blade having the abrasive grains fixed with a metal plating layer as the binder is fixed to the annular base. Effect of the Invention

[0018] The storage section of a blade case in one embodiment of the present invention has an engagement section that can be fitted into the mounting holes of the annular bases of both the first cutting blade (the above-mentioned application blade) and the second cutting blade (the above-mentioned hub blade), and an annular spacer that can be attached and detached to the engagement section.

[0019] The annular spacer is attached to the fitting portion when the first cutting blade is housed in the blade case. Then, when the fitting portion fits into the mounting hole of the annular base of the first cutting blade, the annular spacer comes into contact with the annular base of the first cutting blade, thereby preventing contact between the cutting edge of the first cutting blade and the housing portion.

[0020] On the other hand, when the second cutting blade is housed in the blade case, the annular spacer is removed from the fitting portion. When the fitting portion fits into the mounting hole of the annular base of the second cutting blade, the first protrusion provided on the housing portion comes into contact with the annular base of the second cutting blade, thereby preventing contact between the cutting edge of the second cutting blade and the housing portion.

[0021] In this way, by utilizing an annular spacer for the first cutting blade and not utilizing an annular spacer for the second cutting blade, the same blade case can be used to house both the first cutting blade and the second cutting blade. [Brief description of the drawings]

[0022] [Figure 1] FIG. 2 is a perspective view of the blade case excluding the annular spacer. [Diagram 2]FIG. [Diagram 3] 11 is a perspective view showing how the attachment blade is housed in the blade case using the annular spacer. FIG. [Figure 4] 11 is a partial cross-sectional side view showing how the application blade is housed in the blade case using the annular spacer. FIG. [Diagram 5] FIG. 5(A) is a partially sectional side view of a blade case in which an application blade is housed using an annular spacer, and FIG. 5(B) is a partially enlarged view of FIG. 5(A). [Figure 6] 11 is a perspective view showing how the hub blades are housed in the blade case without using an annular spacer. FIG. [Figure 7] 11 is a partial cross-sectional side view showing how the hub blades are housed in the blade case without using an annular spacer. FIG. [Figure 8] FIG. 8(A) is a partially sectional side view of a blade case in which hub blades are housed, and FIG. 8(B) is a partially enlarged view of FIG. 8(A). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] An embodiment according to one aspect of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a perspective view of a blade case 2 excluding an annular spacer 2a (see Fig. 3) described below. With reference to Fig. 1, the structure of the blade case 2 excluding the annular spacer 2a will be described.

[0024] The blade case 2 includes a housing portion 4 and a lid portion 6. The housing portion 4 and the lid portion 6 are connected to each other by a hinge portion 8. The housing portion 4, the lid portion 6 and the hinge portion 8 are integrally formed from a synthetic resin such as polypropylene.

[0025] The storage section 4 has a bottom plate 10. The bottom plate 10 includes an inner surface 10a and an outer surface 10b. The direction from the outer surface 10b to the inner surface 10a is parallel to a thickness direction 10c of the bottom plate 10. A first side wall 12 is provided on the outer peripheral edge of the bottom plate 10 so as to protrude from the inner surface 10a.

[0026] The space inside the inner surface 12a of the first side wall 12 serves as an accommodation space for accommodating a cutting edge 17 (see FIG. 2) of the application blade 11 or a cutting edge 25 (see FIG. 6) of the hub blade 21, which will be described later.

[0027] When the storage section 4 is viewed in a plane, the area defined by the inner surface 12a of the first side wall 12 is larger than the area defined by the outer peripheral edge of the cutting blade 17 of the application blade 11, and is also larger than the area defined by the outer peripheral edge of the cutting blade 25 of the hub blade 21.

[0028] A cylindrical fitting portion 14 protruding from the inner surface 10a along the thickness direction 10c is provided at the center of the bottom plate 10. The diameter of the outer peripheral side surface 14a of the fitting portion 14 is approximately equal to the diameter of the mounting hole 13c (see FIG. 2) of the annular base 13 of the application blade 11 and the diameter of the mounting hole 13c (see FIG. 7) of the annular base 23 of the hub blade 21.

[0029] The shape of the fitting portion 14 is not limited to a cylinder. The fitting portion 14 may be formed of a plurality of pins, a plurality of claws, etc. arranged in a ring shape, or may be formed of a polygonal prism. In this case, the plurality of pins, a plurality of claws, etc. arranged in a ring shape form an outer diameter that is approximately equal to the diameter of the mounting hole 13c, and the diameter of the circumscribing circle of the polygonal prism is approximately equal to the diameter of the mounting hole 13c.

[0030] An annular convex portion (first convex portion) 16 is provided between the first side wall 12 and the fitting portion 14 on the bottom plate 10. Note that instead of the annular convex portion 16, a plurality of convex portions (first convex portions) arranged in a discrete manner in a ring shape may be provided.

[0031] The outer diameter of the outer peripheral side surface 16a of the annular convex portion 16 is larger than the inner diameter 17b of the cutting edge 17 of the applying blade 11 (see Fig. 5(B) and Fig. 7), but smaller than the inner diameter 25b of the cutting edge 25 of the hub blade 21 (see Fig. 7).

[0032] In the bottom plate 10, a bottom upper platform portion (second convex portion) 18 is provided between the fitting portion 14 and the annular convex portion 16. A top surface 18a of the bottom upper platform portion 18 is lower than a top surface 16b of the annular convex portion 16 in the thickness direction 10c (see FIG. 5(B)). That is, the top surface 16b of the annular convex portion 16 protrudes more than the top surface 18a of the bottom upper platform portion 18.

[0033] In addition, instead of the bottom upper platform portion 18, a plurality of convex portions (second convex portions) arranged in a circular manner in a discrete manner in approximately the same area as the area in which the bottom upper platform portion 18 is provided may be provided, as long as they have the same function as the bottom upper platform portion 18.

[0034] 1, a first claw portion 20 is provided on a part of the first side wall 12 of the storage section 4 in a manner protruding outward from the first side wall 12. The above-mentioned hinge portion 8 is connected to another part of the first side wall 12 located on the opposite side to the part of the first side wall 12, with the fitting portion 14 sandwiched therebetween. The storage section 4 is connected to the lid section 6 via the hinge portion 8.

[0035] The lid portion 6 has a top plate 22. The top plate 22 includes an outer surface 22a and an inner surface 22b. The direction from the outer surface 22a to the inner surface 22b is parallel to a thickness direction 22c of the top plate 22. A second side wall 24 is provided on the outer periphery of the top plate 22 so as to protrude from the inner surface 22b.

[0036] The space inside the inner surface 24a of the second side wall 24 becomes a storage space for storing the annular base 13 of the application blade 11 or the annular base 23 of the hub blade 21. A recess 26 in the shape of an arched door is provided in the center of the top plate 22 of the lid portion 6 so as to protrude from the inner surface 22b along the outer surface 22a.

[0037] A second claw portion 28 is provided on a portion of the second side wall 24 in a manner protruding inwardly of the second side wall 24. In addition, the above-mentioned hinge portion 8 is connected to another portion of the second side wall 24 located on the opposite side to the portion of the second side wall 24, with the recess 26 therebetween.

[0038] The hinge portion 8 is a film-like region made of the same material as the housing portion 4 and the lid portion 6. The hinge portion 8 functions as a rotation axis when the housing portion 4 and the lid portion 6 are rotated to open and close the blade case 2.

[0039] When the storage section 4 is closed, for example, by rotating the lid section 6 around the hinge section 8, the inner surface 24a of the second side wall 24 comes into contact with the outer surface of the upper end section of the first side wall 12. Furthermore, when the storage section 4 is closed, the first claw section 20 and the second claw section 28 are engaged with each other, thereby maintaining the blade case 2 in a closed state.

[0040] On the other hand, the blade case 2 can be opened by disengaging the first claw portion 20 and the second claw portion 28 and then rotating the lid portion 6 around the hinge portion 8. This opens the storage spaces of the storage portion 4 and the lid portion 6. Next, the application blade (first cutting blade) 11 stored in the blade case 2 will be described.

[0041] 2 is an exploded perspective view of the application blade 11. The application blade 11 has an annular base 13. The annular base 13 is formed using a metal such as an aluminum alloy. The annular base 13 has one annular surface 13a and another surface 13b located on the opposite side to the one surface 13a in the thickness direction of the annular base 13.

[0042] A cylindrical mounting hole 13c is provided in the center of the annular base 13 in the radial direction 13d so as to penetrate the annular base 13. The annular base 13 is mounted on the above-mentioned spindle (not shown) using the mounting hole 13c.

[0043] An annular recess 13e is provided outside the mounting hole 13c and inside the inner diameter of the one surface 13a in the radial direction 13d of the annular base 13. The annular recess 13e has an inner diameter larger than the outer diameter of the annular spacer 2a (see FIG. 5(B)).

[0044] An adhesive 15 made of resin or the like is provided on the annular surface 13a. In Fig. 2, the area where the adhesive 15 is provided is indicated by an arrow. An annular cutting blade 17 is fixed to the surface 13a by the adhesive 15. The cutting blade 17 is provided concentrically with the annular base 13 on the surface 13a.

[0045] The cutting blade 17 is a so-called washer blade (also called a hubless blade) that includes abrasive grains such as diamond grains and a bonding material for fixing the abrasive grains, such as a vitrified bond, a resin bond, a metal bond, or an electroformed bond.

[0046] When a vitrified bond, a resin bond, or a metal bond is used as the binder, the cutting blade 17 is formed by mixing powdered abrasive grains with the binder, and then performing compression molding, sintering, or the like.

[0047] When electroforming bond is used as the bonding material, a base made of a metal such as an aluminum alloy is immersed in a plating bath containing abrasive grains such as diamond grains and an electrolyte such as nickel sulfate or nickel nitrate. The area other than the annular area (i.e., the area corresponding to the shape of the cutting blade 17) on the outer periphery of the base is masked.

[0048] A nickel electrode is also immersed in the plating bath. The masked base is electrically connected to the negative terminal (i.e., negative electrode) of a DC power supply, and the nickel electrode is electrically connected to the positive terminal (i.e., positive electrode) of the DC power supply, to form a cutting blade 17 with abrasive grains fixed by a nickel plating layer. The base is then removed to separate the cutting blade 17 from the base.

[0049] The cutting blade 17 has a thickness of, for example, 15 μm or more and 600 μm or less. The cutting blade 17 includes a circular opening 17a. The opening 17a has an inner diameter 17b of a first size larger than the diameter of the mounting hole 13c.

[0050] In this example, the inner diameter 17b of the opening 17a is equal to or larger than the inner diameter of the surface 13a and equal to or smaller than the outer diameter of the surface 13a. For example, the inner diameter of the surface 13a is 32 mm, and the inner diameter 17b of the opening 17a is 40 mm.

[0051] When fixed to the annular base 13, the cutting blade 17 protrudes outward from the outer periphery of the annular base 13 in the radial direction 13d of the annular base 13 (see Figs. 3 and 4). The length of the cutting blade 17 protruding outward from the outer periphery of the annular base 13 is the blade tip extension of the application blade 11.

[0052] When the joining blade 11 is housed in the blade case 2, an annular spacer 2a that is detachable from the fitting portion 14 is provided in the housing portion 4. The joining blade 11 is housed in the blade case 2 by utilizing the annular spacer 2a.

[0053] FIG. 3 is an oblique view showing how the application blade 11 is accommodated in the blade case 2 using the annular spacer 2a, and FIG. 4 is a partially cross-sectional side view showing how the application blade 11 is accommodated in the blade case 2 using the annular spacer 2a.

[0054] The annular spacer 2a is made of a non-metallic material. In this embodiment, the annular spacer 2a is made of synthetic rubber, but the annular spacer 2a may be made of natural rubber, synthetic resin, natural resin, elastomer, synthetic sponge, natural sponge, or the like.

[0055] In particular, the annular spacer 2a is more flexible than the metallic annular base 13, and has a lower hardness than the annular base 13. The annular spacer 2a is easily deformed when an external force is applied thereto by hand, and returns to its original shape when the external force is removed (i.e., it is elastically deformable).

[0056] However, the hardness, volume, etc. of the annular spacer 2a are designed in advance so that even if the annular spacer 2a is compressed by an external force when the attachment blade 11 is housed in the blade case 2, the thickness of the annular spacer 2a does not become smaller than the protrusion amount 16c (see Figure 5 (B)) of the top surface 16b of the annular convex portion 16 relative to the top surface 18a of the bottom upper base portion 18.

[0057] Furthermore, when no external force is applied, the thickness of the annular spacer 2a is thinner than the protrusion 14b of the fitting portion 14 from the top surface 18a of the bottom upper base portion 18 (see Figure 4), and thicker than the protrusion 16c of the top surface 16b of the annular convex portion 16 relative to the top surface 18a of the bottom upper base portion 18 (see Figure 5(B)).

[0058] In this example, the thickness of the annular spacer 2a when no external force is applied is about 1.5 mm, which is thinner than the protrusion amount 14b (about 6 mm) and thicker than the protrusion amount 16c (about 0.5 mm). The annular spacer 2a does not have a permanent magnet, a ferromagnetic material, or the like inside or on its outer surface, and does not have an adhesive part such as an adhesive material on its outer surface.

[0059] The annular spacer 2a is annular, and has an opening 2b in its radial center, the opening 2b having approximately the same diameter as the diameter of the outer peripheral side surface 14a of the fitting portion 14. By using such an annular spacer 2a, scratches and damage to the annular base 13 of the applying blade 11 when the applying blade 11 is housed in the blade case 2 can be reduced.

[0060] When the joining blade 11 is housed in the blade case 2 using the annular spacer 2a, first, the annular spacer 2a is inserted into the fitting portion 14. As a result, the annular spacer 2a is provided between the fitting portion 14 and the annular protrusion 16 in the radial direction of the fitting portion 14.

[0061] Next, the orientation of the application blade 11 is adjusted so that the cutting blade 17 faces the storage section 4, and then the application blade 11 and the storage section 4 are brought relatively close to each other, thereby attaching the fitting section 14 to the mounting hole 13c of the annular base 13.

[0062] That is, the fitting portion 14 is inserted into the annular base 13. Then, with the annular recess 13e of the annular base 13 supported by the annular spacer 2a, the storage portion 4 is closed by, for example, rotating the lid portion 6 with the hinge portion 8 as a fulcrum.

[0063] FIG. 5(A) is a partially sectional side view of the blade case 2 in which the application blade 11 is housed using the annular spacer 2a, and FIG. 5(B) is a partially enlarged view of the right half of FIG. 5(A).

[0064] When stored, as shown in Figure 5(A), the first claw portion 20 and the second claw portion 28 engage with each other, and as shown in Figure 5(B), the top surface 14c of the fitting portion 14 contacts the bottom surface of the recess 26 of the lid portion 6, and the inner surface 22b of the top plate 22 contacts the other surface 13b of the annular base 13.

[0065] The application blade 11 housed in the blade case 2 is restricted in its movement in a direction parallel to the inner surfaces 10a, 22b by the fitting portion 14, and is restricted in its movement in the thickness directions 10c, 22c by the housing portion 4, the annular spacer 2a and the lid portion 6.

[0066] That is, the applying blade 11 is held in the blade case 2. In particular, the annular spacer 2a comes into contact with the annular base 13, thereby preventing the cutting blade 17 of the applying blade 11 from coming into contact with the top surface 16b of the annular protrusion 16. That is, damage to the cutting blade 17 can be prevented.

[0067] Next, a description will be given of the case where the hub blade (second cutting blade) 21 is housed in the blade case 2. Fig. 6 is a perspective view showing the state where the hub blade 21 is housed in the blade case 2 without using the annular spacer 2a, and Fig. 7 is a partially sectional side view showing the state where the hub blade 21 is housed in the blade case 2 without using the annular spacer 2a.

[0068] The hub blade 21 has an annular base 23. The annular base 23 has approximately the same diameter as the annular base 13 of the application blade 11. For example, the above-mentioned annular base 13 having a thickness 13f is manufactured by reducing the thickness 23f of the annular base 23. Therefore, for the same or corresponding configuration as the annular base 13, the same reference numerals as those of the annular base 13 are used for the annular base 23.

[0069] An annular cutting blade 25 is provided on one surface 13a of the annular base 23. An inner diameter 25b of an opening 25a of the cutting blade 25 of the hub blade 21 is larger than an inner diameter 17b of an opening 17a of the cutting blade 17 of the application blade 11 (the first size described above).

[0070] The difference between the inner diameter 25b of the opening 25a of the cutting blade 25 and the inner diameter 17b of the opening 17a of the cutting blade 17 is due to the difference in the manufacturing method of the cutting blade 25 and the cutting blade 17. To briefly explain the manufacturing method of the cutting blade 25, first, a mask is applied to the area other than the annular area on the outer periphery of one surface 13a of the annular base 23. Next, the cutting blade 25 is formed only in this annular area by electrochemical deposition.

[0071] As a result, the cutting blade 25, to which abrasive grains such as diamond are fixed by a metal plating layer such as a nickel plating layer as a binder, is formed in a state in which it directly contacts the one surface 13a. Therefore, in the hub blade 21, the cutting blade 25 is fixed to the one surface 13a without the adhesive 15.

[0072] The cutting blade 25 protrudes outward from the outer periphery of the annular base 23 in the radial direction 23d of the annular base 23. The inner diameter 25b of the cutting blade 25 is larger than the outer diameter of the annular protrusion 16. The thickness of the cutting blade 25 is a predetermined value, for example, not less than 12 μm and not more than 360 μm.

[0073] When the hub blade 21 is housed in the blade case 2, first, the annular spacer 2a is removed from the fitting portion 14, or it is confirmed that the annular spacer 2a has been removed from the fitting portion 14.

[0074] Next, the front and back orientation of the hub blade 21 is adjusted so that the cutting blade 25 faces the storage portion 4, and the hub blade 21 and the storage portion 4 are brought relatively close to each other, thereby attaching the fitting portion 14 to the mounting hole 13c of the annular base 23.

[0075] Then, with one surface 13a of the annular base 23 supported by the annular protrusion 16, the housing portion 4 is closed, for example, by rotating the lid portion 6 around the hinge portion 8 as a fulcrum. Fig. 8(A) is a partially cross-sectional side view of the blade case 2 housing the hub blade 21, and Fig. 8(B) is a partially enlarged view of Fig. 8(A).

[0076] When stored, as shown in Figure 8(A), the first claw portion 20 and the second claw portion 28 engage with each other, and as shown in Figure 8(B), the top surface 14c of the fitting portion 14 contacts the bottom surface of the recess 26 of the lid portion 6, and the inner surface 22b of the top plate 22 contacts the other surface 13b of the annular base 23.

[0077] The hub blade 21 is restricted in its movement in a direction parallel to the inner surfaces 10a, 22b by the fitting portion 14, and is restricted in its movement in the thickness directions 10c, 22c by the housing portion 4 and the lid portion 6. In other words, the hub blade 21 is held within the blade case 2.

[0078] In particular, the annular protrusion 16 comes into contact with one surface 13a of the annular base 23 attached to the fitting portion 14 without coming into contact with the cutting edge 25 of the hub blade 21. This prevents the cutting edge 25 of the hub blade 21 from being damaged.

[0079] The blade case 2 of this embodiment can accommodate any one of a plurality of cutting blades (that is, the application blade 11 and the hub blade 21) by selectively using the annular spacer 2a.

[0080] In other words, by using the annular spacer 2a for the joining blade 11 and not using the annular spacer 2a for the hub blade 21, the same blade case 2 can be used to house the joining blade 11 and the hub blade 21.

[0081] In addition, the structures, methods, and the like according to the above-described embodiments can be modified as appropriate without departing from the scope of the object of the present invention. [Explanation of symbols]

[0082] 2: blade case, 2a: annular spacer, 2b: opening 4: Storage section, 6: Lid section, 8: Hinge section 10: bottom plate, 10a: inner surface, 10b: outer surface, 10c: thickness direction 11: Application blade (first cutting blade) 12: First side wall, 12a: Inner surface 13: Annular base, 13a: One surface, 13b: Other surface, 13c: Mounting hole 13d: radial direction, 13e: annular recess, 13f: thickness 14: Fitting part, 14a: Outer circumferential side, 14b: Projection amount, 14c: Top surface 15: Glue 16: annular convex portion (first convex portion), 16a: outer peripheral side surface, 16b: top surface, 16c: protrusion amount 17: cutting blade, 17a: opening, 17b: inner diameter 18: Bottom platform (second convex part), 18a: Top surface 20: 1st claw part 21: Hub blade (second cutting blade) 22: top plate, 22a: outer surface, 22b: inner surface, 22c: thickness direction 23: annular base, 23d: radial direction, 23f: thickness 24: second side wall, 24a: inner surface 25: cutting blade, 25a: opening, 25b: inner diameter 26: Recess 28:Second claw part

Claims

1. A blade case, The blade case can accommodate either a first cutting blade having an inner diameter of a first size and fixed to one surface with an adhesive, and a second cutting blade having an inner diameter larger than the inner diameter of the first size and fixed to one surface without the adhesive, among a plurality of cutting blades each having an annular base including a mounting hole provided in the radial center and an annular cutting blade provided on one surface of the annular base and including abrasive grains and a binder, The blade case comprises: a housing section having a bottom plate, a first side wall protruding from an inner surface of the bottom plate along a thickness direction of the bottom plate at an outer peripheral edge of the bottom plate, a fitting section protruding from the inner surface of the bottom plate along the thickness direction of the bottom plate at a central portion of the bottom plate and fitting into the mounting hole of the annular base, and a first protrusion provided annularly on the bottom plate between the first side wall and the fitting section, and contacting the annular base of the second cutting blade without contacting the cutting edge of the second cutting blade; a cover portion having a top plate and a second side wall protruding from an inner surface of the top plate along a thickness direction of the top plate at an outer peripheral edge of the top plate; a hinge portion connected to the first side wall and the second side wall and functioning as a rotation axis when the storage portion and the lid portion are rotated to open and close; Equipped with The storage section includes: a ring-shaped spacer that is detachable from the fitting portion and is provided between the fitting portion and the first protrusion in a radial direction of the fitting portion, The annular spacer comprises: When the first cutting blade is housed in the blade case, the first cutting blade is attached to the fitting portion and comes into contact with the annular base of the first cutting blade, thereby preventing the cutting edge of the first cutting blade from coming into contact with the first protrusion of the housing portion; A blade case which is detached from the fitting portion when the second cutting blade is housed in the blade case.

2. 2. The blade case according to claim 1, wherein the annular spacer is made of a non-metallic material, has a hardness lower than that of the annular base, and is elastically deformable.

3. the housing portion has a second protrusion provided on the bottom plate between the fitting portion and the first protrusion, 2. The blade case according to claim 1, wherein a top surface of the first protrusion protrudes further than a top surface of the second protrusion.

4. the first cutting blade is an attached blade in which a washer blade having the abrasive grains fixed with the bonding material is fixed to the one surface of the annular base with the adhesive, The blade case according to any one of claims 1 to 3, characterized in that the second cutting blade is a hub blade in which the cutting edge, to which the abrasive grains are fixed by a metal plating layer as the bonding material, is fixed to the annular base.

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