JP2009125918A - Grinding tool and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To widely achieve various grinding shapes without shortening the service life of a whole grinding wheel caused by the local wear of an abrasive grain layer. <P>SOLUTION: The grinding tool G1 is created by concentrically pinching a plurality of disc-like base metals 4, a tapered disc metal base 6R, a tapered disc metal base 6L, a disc-like base metal 5R, and a disc-like base metal 5L, having the abrasive grain layer formed on their outer peripheries between a flange 7R and a flange 7L, and integrally fastening them with screws 8 and nuts 10 penetrating through them in an arrangement direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a grinding tool and a technique effective when applied to a manufacturing technique of a grinding tool.

  As an example of the grinding process, for example, a centering process or a chamfering process of a lens can be given. This centering process is a process to make the optical axis of the lens coincide with the center of the outer periphery by grinding the outer periphery of the lens, and the chamfering process is to grind the boundary between the outer peripheral surface of the lens and the optical function surface. This is the process of forming a conical surface at the boundary.

Conventional centering methods are roughly classified into an optical centering method and a bell clamp method depending on the centering method performed before centering.
In the optical centering method, one surface of the lens is irradiated with inspection light and transmitted through or reflected by the lens to form an image. By visually observing this image, the eccentric state of the lens is detected to detect the center of the lens. I will put out.

  On the other hand, in the bell clamp system, a lens is sandwiched between the tapered surfaces of lens holders mounted on two spindle tips arranged opposite to each other on the same axis, and the two spindles are brought close to each other, whereby the lens is moved to a predetermined position. Slide to position to center.

As a centering method of a lens whose both surfaces are processed into a spherical shape or a planar shape by a bell clamp method, a technique disclosed in Patent Document 1 is known.
In other words, the bell clamp shaft is detachably connected to the lens drive motor and the correction motor via a clutch, and the rotational displacement of the bell clamp shaft is controlled by the correction motor prior to grinding by the lens drive motor. However, a technique is disclosed in which a lens outer peripheral shape is processed into an arbitrary non-circular shape by intermittently pressing a grindstone against the outer peripheral portion of the lens.

Hereinafter, a general conventional technique of the centering process of the bell clamp type used in Patent Document 1 will be described.
FIG. 7 shows the centering of the lens 1 and the left and right chamfering processes. (1) to (7) show the process sequence.

  The lens 1 is sandwiched between lens holders mounted on two spindle tips arranged opposite to each other on the same axis (not shown). A disc-shaped grindstone 2 having a drum-shaped peripheral side portion is attached to a rotatable grindstone shaft (not shown), and moves the grindstone shaft that is driven to rotate in the forward / backward direction and the left / right direction with respect to the lens 1, By rotating the lens 1, centering and left and right chamfering can be automatically performed.

(1) The grindstone 2 is in the initial position retracted.
(2) The grindstone 2 advances rapidly to a position approaching the lens 1.
(3) The lens 1 is centered by moving the grindstone 2 forward at a normal speed.

(4) The chamfering process on the right side of the lens 1 is performed by moving the grindstone 2 in the left direction.
(5) The grindstone 2 is slightly retracted.
(6) The chamfer on the left side of the lens 1 is processed by moving the grindstone 2 in the right direction.

(7) One cycle of machining is completed when the grindstone 2 moves backward at high speed.
Next, FIG. 8 shows a cross-sectional view of a grindstone used for centering in the prior art. The grindstone 3 is a grinding grindstone having an abrasive grain layer on the outer peripheral portion and the peripheral side portion. The disc-shaped base metal 3a includes an annular outer diameter processing portion 3b formed in the same direction as the axis of rotation of the base metal, and both sides thereof. The chamfered portion 3c and the chamfered portion 3d are inclined.

  Furthermore, the grindstone 3 has an insertion hole 3e for insertion into the grindstone mounting portion of the centering machine, and a fitting portion 3f for enabling installation without error with the grindstone mounting portion of the centering machine.

  The grinding stone layer fixes the abrasive grains by immersing the base metal formed in a disk shape as described above in an electroplating tank, filling the outer shape processing portion and the chamfering processing portion with diamond fine powder as abrasive grains, and electroplating. It is formed by a method called "electrodeposition", or a method called "metal bond" that bonds the grinding stone obtained by mixing and sintering the diamond powder that becomes the abrasive grains to the fine metal powder that becomes the binder, and then sintering it. is doing.

However, according to the prior art as described above, there are the following technical problems.
The annular outer diameter processing portion 3b of the grindstone 3 is designed wider than the width of the centering portion of the lens. However, since the grindstone is linearly advanced toward the rotation axis of the lens 1 during the centering process, the outer diameter processing portion 3b has an action region 3g acting on the centering process as shown in FIG. A non-acting region 3h that does not act is generated.

  For this reason, when mass production processing of the lens 1 is performed, different distributions are generated in the abrasive wear state in the outer diameter processing portion 3b, and when a part of the working region 3g reaches the end of its life, the entire outer diameter processing portion 3b has a lifetime. Therefore, there is a technical problem that it must be replaced with a new grindstone 3.

  In recent years, an aspherical lens is increasingly used due to the high accuracy of the optical system. Many aspherical lenses are made by a molding method in which a mold shape is transferred to a lens surface by pressing a lens material softened at a high temperature with a mold obtained by processing a desired shape with high accuracy.

A lens made by this molding method has a larger amount of centering than a lens made by conventional grinding and polishing methods, and the amount of grinding at the chamfered portion is significantly different.
For this reason, when mass production processing is performed using the above-described conventional grindstone 3, wear of abrasive grains of the annular outer diameter processing portion 3b and the inclined chamfering processing portion 3c and the chamfering processing portion 3d protruding on both sides thereof. A difference will arise in a state. Since the above-described prior art grindstone 3 has an integral shape, it is determined that the entire grindstone 3 has reached the end of its life when the outer diameter processed portion reaches the end of its life, and must be replaced with a new grindstone 3. There are challenges.

  Furthermore, recently, various products using optical systems have been required to be compact. Therefore, the optical system is also required to be compact in accordance with it. In order to make the optical system compact, it is necessary to devise various methods for assembling the lens into the lens frame. The outer diameter of the lens is stepped compared to a simple shape having a flat outer periphery and a chamfer. There are many needs to finish in complicated shapes such as providing parts.

In the case of the grindstone 3 used for the conventional centering process, when the complicated shape as described above is processed on the lens outer periphery, a dedicated grindstone is designed and manufactured according to the outer peripheral shape required for each type of the lens 1. Therefore, there is a technical problem that the versatility of the grindstone is impaired, the lead time and cost are increased, and the storage location of the grindstone is increased.
JP 52-13196 A

  SUMMARY OF THE INVENTION An object of the present invention is to provide a grinding tool and a grinding tool manufacturing technique capable of realizing various grinding shapes for general use without causing a reduction in the life of the entire grindstone due to local wear of the abrasive layer. There is.

A first aspect of the present invention is a plurality of base metal having an abrasive layer,
Fixing means for fixing a plurality of the base metal integrally;
A grinding tool is provided.

  The 2nd viewpoint of this invention provides the manufacturing method of the grinding tool which creates a grinding tool by combining the some base metal which has an abrasive grain layer.

  According to the present invention, there is provided a grinding tool and a grinding tool manufacturing technique capable of realizing various grinding shapes for general use without causing a reduction in the life of the entire grindstone due to local wear of the abrasive layer. be able to.

In the first aspect of the present embodiment, a grinding tool is created by combining at least two disk-shaped base metal having an abrasive grain layer on the outer peripheral portion or the peripheral side portion.
Further, in the second aspect, in the first aspect, at least one of the abrasive grain layers is configured to hold the abrasive grains on the surface by electrodeposition.

In the third aspect, in the first aspect, at least one of the abrasive grain layers is produced by baking a mixture of abrasive grains in a binder.
According to the first aspect of the present embodiment, by creating a grinding tool by combining a base metal having at least two or more abrasive layers, for example, wear occurs in the abrasive layer of one base metal and the lifetime is increased. In this case, by replacing the base metal that has reached the end of its life with a new one or another base metal that does not have a problem with the abrasive layer, the other base metal parts can be used continuously, There is no lifetime.

Further, by preparing in advance various types of base metal having an abrasive layer, it becomes possible to create a grinding tool by selecting and combining base metals corresponding to the lens shape to be processed.
According to the invention of the second aspect of the present embodiment, the shape accuracy of the processed surface can be maintained over a long period of time by holding the abrasive layer by electrodeposition in the first aspect described above. Become.

  According to the third aspect of the present embodiment, the shape accuracy of the machined surface is finished with high precision by using the abrasive grain layer in the first aspect as a grindstone produced by mixing and firing abrasive grains in a binder. It becomes possible.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
(Embodiment 1)
FIG. 1 is an exploded perspective view showing an example of a configuration of a grinding tool according to an embodiment of the present invention. FIGS. 2 and 3 are side views illustrating components of the grinding tool according to the present embodiment taken out. It is sectional drawing.

FIG. 4 is a side view of a lens that has been centered and chamfered using the grinding tool of the first embodiment.
FIG. 5 is a perspective view of an example of a method for using the grinding tool in the first embodiment.

  FIG. 1 shows the overall configuration of a grinding tool G1 according to the first embodiment, and FIGS. 2 and 3 show a disk-shaped base metal 4, a disk-shaped base metal 5R and a disk that constitute the grinding tool G1 according to the present embodiment. The cross sections of the shaped base metal 5L, the tapered disk base metal 6R and the tapered disk base metal 6L are shown.

  In the present embodiment, the boundary between the planar outer peripheral surface 21 of the lens 20 as shown in FIG. 4 and each of the optical functional surface 20a and the optical functional surface 20b is formed as a 45 ° conical large chamfered portion 22 and a small chamfered portion. The grinding tool G1 for processing the surface of the chamfered portion 23 will be described as an example.

  As shown in FIG. 1, the grinding tool G1 according to the present embodiment includes a disk-shaped base metal 4 (base metal) and a plurality of tapered disk base metals 6R (with the disk-shaped base metal 4 interposed therebetween) A base metal), a tapered disk base metal 6L (base metal), a disk-shaped base metal 5R (base metal), a disk-shaped base metal 5L (base metal), a flange 7R, and a flange 7L.

As illustrated in FIG. 2, each of the cylindrical disk-shaped base metal 4, the disk-shaped base metal 5 </ b> R, and the disk-shaped base metal 5 </ b> L has an abrasive layer 16 on each outer peripheral surface 15.
Each of the disk-shaped base metal 4, the disk-shaped base metal 5R, and the disk-shaped base metal 5L is formed with a grindstone mounting hole 13 that can be inserted into a centering machine grindstone shaft (not shown) with high accuracy through the center. Yes.

Further, each of the disk-shaped base metal 4, the disk-shaped base metal 5R, and the disk-shaped base metal 5L is provided with a fastening hole 14 through which a fastening screw 8 (fixing means) can be inserted.
The above-mentioned abrasive grain layer 16 is constituted by fixing abrasive grains to the outer peripheral surface 15 of the disk-shaped base metal 4, the disk-shaped base metal 5R, and the disk-shaped base metal 5L. For example, diamond, boron nitride cubic (CBN), or the like is used. These abrasive grains are fixed to the outer peripheral surfaces of the disk-shaped base metal 4, the disk-shaped base metal 5R, and the disk-shaped base metal 5L with an electrodeposited metal such as Ni or Cu.

As illustrated in FIG. 3, the tapered disk base metal 6 </ b> R and the tapered disk base metal 6 </ b> L have a truncated cone shape having different diameters at both end faces, and have an abrasive grain layer 16 on the outer peripheral slope 17.
The outer peripheral slope 17 is formed to be inclined, for example, by 45 degrees with respect to the side surface. Further, the tapered disk base 6R and the tapered disk base 6L are provided with a grindstone mounting hole 13 and a fastening hole 14 similar to the disk-shaped base 4, the disk-shaped base 5R and the disk-shaped base 5L.

  The abrasive layer 16 of the taper disk base 6R and the taper disk base 6L is electrodeposited with abrasive grains on the outer peripheral slope 17 in the same manner as the disk-shaped base 4, the disk-shaped base 5R and the disk-shaped base 5L. For example, diamond or boron nitride cubic (CBN) is used as the abrasive. These abrasive grains are fixed to the outer peripheral inclined surface 17 of the tapered disk base metal 6R and the tapered disk base metal 6L by an electrodeposited metal such as Ni or Cu.

The outer diameter 6a on the small diameter side of the taper disk base 6R and the taper disk base 6L is finished to be equal to the outer diameter 4a of the disk-shaped base 4.
On the other hand, the outer diameter dimension 5a of the disk-shaped base metal 5R and the disk-shaped base metal 5L is finished to be equal to the outer diameter dimension 6b of the large-diameter side of the tapered disk base metal 6R and the tapered disk base metal 6L.

  The flange 7R and the flange 7L have a base metal fixing surface 11 and an abutting surface 12 for making contact with the centering machine grindstone shaft. Further, the flange 7R and the flange 7L are provided with a wheel mounting hole 13 for fastening and the same as the disk-shaped base metal 4, the disk-shaped base metal 5R, the disk-shaped base metal 5L, the taper disk base metal 6R, and the taper disk base metal 6L. A hole 14 is provided.

The screw 8 is a screw that can penetrate the fastening hole 14 and has a sufficient length, and the washer 9 and the nut 10 are each of a size that allows the screw 8 to be fastened.
Each component of grinding tool G1 of this embodiment mentioned above is assembled as follows.

  First, the taper disk base metal 6R and the taper disk base metal 6L are arranged so as to hold the central disk-shaped base metal 4. At this time, the tapered disk base metal 6R and the tapered disk base metal 6L are arranged so that the side surface 6c of the small diameter side outer diameter dimension 6a faces the disk-shaped base metal 4.

  Subsequently, the disk-shaped base metal 5R and the disk-shaped base metal 5L are arranged so as to hold the side of the outer diameter 6b of the tapered disk base metal 6R and the taper disk base metal 6L, and further, the flange 7R and the flange 7L is arranged such that the base metal fixing surface 11 is in contact with the disk-shaped base metal 5R and the disk-shaped base metal 5L.

  Subsequently, the screw 8 passes through the fastening hole 14 of the flange 7L, the disk-shaped base metal 5L, the taper disk base metal 6L, the disk-shaped base metal 4, the taper disk base metal 6R, the disk-shaped base metal 5R, and the flange 7R. After inserting and further inserting the washer 9, the nut 10 is used for fastening.

  Accordingly, the plurality of disk-shaped base metal 5L, the tapered disk base metal 6L, the disk-shaped base metal 4, the taper disk base metal 6R, and the disk-shaped base metal 5R having the abrasive layer 16 are provided between the flange 7L and the flange 7R. Thus, a grinding tool G1 having an appearance and function equivalent to that of a conventional grinding tool having an electrodeposition layer on the outer peripheral surface of a base metal having a monolithic structure is obtained.

  The above-mentioned abrasive grain layer 16 may of course be provided by adhering a metal bond grindstone or a resin bond grindstone obtained by firing a mixture of a binder and fine abrasive powder to the base metal surface, in addition to fixing the abrasive grains by electrodeposition.

Or you may form the abrasive grain layer 16 of another kind for every above-mentioned each base metal comprised so that decomposition | disassembly was possible.
Next, an example of the processing action of the grinding tool G1 of the present embodiment will be described.

  As illustrated in FIG. 5, the grinding tool G <b> 1 of the first embodiment configured as described above has a posture in which the axis of the grindstone mounting hole 13, that is, the rotation drive axis is parallel to the optical axis of the lens 20. In the rotated state, the outer peripheral surface 21 is formed coaxially with the optical axis by pressing the abrasive layer 16 of the disc-shaped base metal 4 at the center portion against the outer peripheral surface 21 of the lens 20 to be processed. Is done.

  Further, in the same posture, the entire grinding tool G1 is translated in the direction of the rotation axis, and the abrasive layer 16 of the taper disk base 6R is pressed against the corner of the boundary between the outer peripheral surface 21 and the optical function surface 20a. Thus, the large chamfered portion 22 is formed.

Similarly, the chamfered portion 23 is formed by moving the abrasive grain layer 16 of the tapered disk base 6L against the boundary between the outer peripheral surface 21 and the optical functional surface 20b by moving in the opposite direction.
In the present embodiment, the grinding tool G1 used for processing the lens 20 having the outer peripheral surface 21 and the large chamfered portion 22 and the small chamfered portion 23 at the boundary portion has been described as an example. The stepped shape is transferred to the outer peripheral surface 21 of the lens 20 by arranging the disk-shaped base metal adjacently in a staircase shape, and holding and fastening with the flange 7R and the flange 7L to create the grinding tool G1. Is possible.

  That is, by preparing various base metal shapes having an abrasive grain layer on the outer periphery or the peripheral side surface, a grinding tool G1 corresponding to various processing shapes of the outer peripheral surface 21 of the lens 20 can be created by a desired combination of base metals. Is possible.

  Further, as described above, as a result of mass production processing of centering and chamfering of the lens 20 using the grinding tool G1 described in the present embodiment, for example, a small-diameter disk-shaped base metal 4 located in the center portion. When the abrasive layer 16 is worn out and the processing quality is deteriorated, the screw 8 for fastening is removed, and a new disk-shaped base metal 4 manufactured in the same manner as the disk-shaped base metal 4 is inserted, reassembled and fastened. Thus, the grinding tool G1 having the good abrasive layer 16 can be easily regenerated.

  Similarly, since the machining amount of the large chamfered portion 22 is larger than the machining amount of the small chamfered portion 23, in the mass production process, the wear amount of the abrasive layer 16 of the tapered disk base metal 6R for machining the large chamfered portion 22 is increased. The life of the portion of the taper disk base 6R is expected to expire before the taper disk base 6L. However, in the case of the grinding tool G1 of the present embodiment, the life of the abrasive layer 16 is exhausted. The use can be continued by exchanging only the tapered disk base 6R, and it is not necessary to replace or discard the entire grinding tool G1.

  In addition, the wear amount of each base metal can be made uniform by changing the assembly position of the base metal of the same shape before the end of life, or by reversing the assembly posture of each base metal and mounting it by mistake. You can also.

That is, the entire life of the grinding tool G1 is not affected by local wear of the abrasive layer 16.
As described above, according to the present embodiment, the bases of necessary shapes such as the disk-shaped base metal 4, the disk-shaped base metal 5L, the disk-shaped base metal 5R, the taper disk base metal 6L, the taper disk base metal 6R, and the like. Since the grinding tool G1 having a grinding function surface having a desired shape can be created by combining gold, the grinding tool G1 can have versatility.

  Furthermore, even if some abrasive layers 16 are worn out and reach the end of their lives, only the corresponding base metal can be replaced, so other base metals other than the base metal can be used continuously. In addition to reducing the management cost of the grinding tool G1, the required time (lead time) for producing the grinding tool G1 is shortened, and the amount of metal material used for the base metal is also reduced. It is also effective in reducing environmental load.

That is, according to the present embodiment, various grinding shapes can be realized on a general basis without reducing the life of the entire grindstone due to local wear of the abrasive layer.
(Embodiment 2)
FIG. 6 is an exploded perspective view showing a configuration example of a grinding tool according to another embodiment of the present invention.

In addition, in the grinding tool G2 of the second embodiment illustrated in FIG. 6, elements common to the configuration of the grinding tool G1 described above are denoted by the same reference numerals, and redundant description is omitted.
In the grinding tool G2 of the second embodiment, the positioning pin insertion holes 18 are formed in each of the disk-shaped base metal 4, the disk-shaped base metal 5R, the disk-shaped base metal 5L, the taper disk base metal 6R, and the taper disk base metal 6L. It is configured to penetrate at a predetermined position with high accuracy.

  And after inserting the knock pin 19 in this positioning pin insertion hole 18 and assembling the base metal with high accuracy (for example, high coaxiality) in advance, each base metal is held between the flange 7R and the flange 7L. .

Thereafter, the screw 8 is inserted into the fastening hole 14, and the entire grinding tool G 2 is fastened using the washer 9 and the nut 10.
In the grinding tool G2 of the second embodiment, the base metals can be assembled with high accuracy with high coaxiality, and therefore the grinding tool G2 can be assembled with high accuracy without rotational vibration.

That is, in the centering process of the lens 20, if rotational runout occurs in the grinding tool, it may cause defects such as chipping on the ground surface or a decrease in roundness.
In the grinding tool G2 according to the second embodiment, as described above, a high-precision positioning pin insertion hole 18 is provided in advance at a predetermined position of the base metal, and the base metal is connected to each other using the positioning pin insertion hole 18 as a counter. By assembling, the grinding tool G2 is constituted by the base metals coupled to each other without any eccentricity, so that the grinding tool G2 is a highly accurate grinding tool G2 having no eccentricity, and the quality of the lens 20 to be processed is not deteriorated.

According to the grinding tool G2 of the second embodiment, the grinding tool G2 can be assembled with high precision, and the lens 20 can be ground with high precision.
As described above, according to each embodiment of the present invention, it is possible to provide a versatile lens centering and chamfering grinding tool by combining base metal of a desired shape. Only the base metal that has reached the end of its life due to wear of the abrasive grains can be replaced, and the base metal having a workable abrasive grain layer can be used continuously.

  That is, it is possible to provide a grinding tool and a grinding tool manufacturing technique capable of realizing various grinding shapes on a general basis without reducing the life of the entire grindstone due to local wear of the abrasive layer.

Needless to say, the present invention is not limited to the configuration exemplified in the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.
For example, the fixing means for fixing a plurality of base metals integrally is not limited to a screw or the like. For example, a fitting structure provided on a side surface of the base metal, a screw-in structure, a strong permanent magnet, or the like is used. You can also
(Additional remark 1) The grinding tool which creates a grinding tool by combining at least 2 base metal which has an abrasive grain layer in the grinding tool which performs the outer diameter and chamfering of workpieces, such as a lens.
(Appendix 2) The grinding tool according to (Appendix 1), wherein at least one of the base metals has abrasive grains on the surface thereof by electrodeposition.
(Appendix 3) The grinding tool according to (Appendix 1), wherein at least one of the base metals has a grindstone produced by mixing and baking abrasive grains in a binder.

It is a disassembled perspective view which shows an example of a structure of the grinding tool which is one embodiment of this invention. It is the sectional side view which took out and illustrated the component of the grinding tool which is one embodiment of this invention. It is the sectional side view which took out and illustrated the component of the grinding tool which is one embodiment of this invention. It is a side view of the lens used for centering and chamfering of the embodiment of the present invention. It is a perspective view of an example of the usage method of the grinding tool in Embodiment 1 of this invention. It is a disassembled perspective view which shows the structural example of the grinding tool which is other embodiment of this invention. It is explanatory drawing which shows the centering of a lens and the chamfering process of right and left in the reference technique of this invention in order of a process. It is sectional drawing of the grinding tool used for the centering of a lens and the chamfering process of right and left in the reference technique of this invention. It is sectional drawing explaining the technical subject of the grinding tool of the reference technique of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lens 2 Grinding wheel 3 Grinding wheel 3a Base metal 3b Outer diameter processing part 3c Chamfering processing part 3d Chamfering processing part 3e Insertion hole 3f Contacting part 3g Action area 3h Non-action area 4 Disc-shaped base metal 4a Outer diameter 5L Disk-shaped base metal 5R disk-shaped base metal 5a outer diameter 6L tapered disk base 6R taper disk base 6a small diameter outer diameter 6b large diameter outer diameter 6c side face 7L flange 7R flange 8 screw 9 washer 10 nut 11 base metal fixing surface 12 Abutting surface 13 Wheel mounting hole 14 Fastening hole 15 Outer peripheral surface 16 Abrasive grain layer 17 Outer peripheral slope 18 Positioning pin insertion hole 19 Knock pin 20 Lens 20a, 20b Optical functional surface 21 Outer peripheral surface 22 Large chamfered portion 23 Small chamfered portion G1, G2 grinding tool

Claims (10)

A plurality of base metals having an abrasive layer;
Fixing means for fixing a plurality of the base metal integrally;
A grinding tool comprising: The grinding tool according to claim 1,
At least one of the base metals has the abrasive layer formed by electrodeposition. In the grinding tool according to claim 1 or 2,
At least one of the abrasive layers of the base metal is produced by firing a mixture of a binder and abrasive grains. The grinding tool according to claim 1,
Each of the bases has a rotationally symmetric shape, and the fixing means includes a screw that passes through and fastens a plurality of the bases arranged in parallel with the rotational axis. A grinding tool. The grinding tool according to claim 4, wherein
A grinding tool comprising, as the fixing means, a knock pin that penetrates the plurality of base metals together with the screws and positions the plurality of base metals coaxially.   A grinding tool manufacturing method comprising creating a grinding tool by combining a plurality of base metals having an abrasive layer. In the manufacturing method of the grinding tool according to claim 6,
A method of manufacturing a grinding tool, wherein the abrasive layer is formed on at least one of the base metal by electrodeposition. In the manufacturing method of the grinding tool of Claim 6 or Claim 7,
A method for producing a grinding tool, comprising: producing at least one abrasive layer of the base metal by mixing abrasive grains in a binder and firing the mixture. In the manufacturing method of the grinding tool according to claim 6,
Forming each base metal in a rotationally symmetric shape, arranging the plurality of base metals coaxially with a rotation axis, and fastening the plurality of base metals together with screws penetrating in parallel to the rotation axis; A manufacturing method of a grinding tool. In the manufacturing method of the grinding tool according to claim 9,
A method for manufacturing a grinding tool, wherein the plurality of base metals are coaxially positioned using knock pins that penetrate the plurality of base metals.