JP6718325B2 - Whetstone manufacturing jig and whetstone manufacturing method - Google Patents

Description

The present invention relates to a grindstone manufacturing jig for manufacturing a grindstone and a manufacturing method for manufacturing a grindstone using the grindstone manufacturing jig.

The grindstone is, for example, put a raw material in which powdery abrasive grains, a binder and a filler are mixed in a mold and molded into a desired shape by pressing, and then sintering at a predetermined temperature for a predetermined time. (See, for example, Patent Documents 1-3 below). Usually, the mold for containing the raw material is provided with a concave portion, and the raw material is put into the concave portion. Then, the grindstone is molded by pressing the raw material charged into the concave portion of the mold and accumulated.

JP, 2009-039835, A JP, 2006-142455, A JP-A-63-102876

However, when the raw material is put into the concave portion of the mold, air may remain in the concave portion to cause an air pocket. If the raw material stored in the recess is pressed in this state, the raw material may be ejected from the mold, which is dangerous. Further, in the related art, there is a problem that the work load is heavy because the mold frame is an obstacle when taking out the pressed and molded grindstone.

The present invention has been made in view of the above circumstances, and makes it possible to press the raw material of the grindstone put into the mold without ejecting it, and to easily obtain the pressed and molded grindstone It is an object.

The present invention is a grindstone manufacturing jig for manufacturing a grindstone by molding a powdery raw material of a grindstone by a press, and having a pillar at least a side surface of which is made of a magnetic material, and a fitting hole into which the pillar can be inserted. A magnet that is magnetically attached to a side surface of the mold and the pillar, is fitted into the pillar through one opening of the fitting hole, is positioned at a predetermined height position, and supports the mold with the one opening closed. A raw material of the grindstone is charged from the other opening of the fitting hole of the mold supported by the magnet, and then placed on the mold so as to close the other opening of the fitting hole. An upper plate, and the pillar and the upper plate are pressed toward each other so that the magnet moves along the side surface while supporting the mold, and the side surface and the inner surface of the fitting hole. The air in the fitting hole is exhausted from between and the raw material of the grindstone put into the fitting hole is pressed by the upper end surface of the column and the lower surface of the upper plate to mold the grindstone.

The present invention comprises a pressing means for pressing down the mold after pressing the raw material of the grindstone, the pressing means is a through hole penetrating the front and back in at least two places of the upper plate, and the through hole A pin to be inserted, the through hole is formed outside the fitting hole of the mold, and the through hole is blocked by the upper surface of the mold when the upper plate is placed on the mold. , The pin has a length of at least a thickness obtained by adding the thickness of the raw material of the grindstone after being pressed and the thickness of the upper plate, and after pressing the raw material of the grindstone into the through hole. The pin is inserted, and the pin is pushed down to push down the mold to obtain a pressed and molded grindstone.

Further, the present invention is a method for manufacturing a grindstone using the grindstone manufacturing jig, which comprises a magnetizing step of magnetically magnetizing the magnet to a predetermined height with respect to the side surface of the pillar, and the pillar. By inserting the fitting hole from the one opening, and supporting the mold by the magnet magnetically attached to the side surface, and the raw material of the grindstone from the other opening of the fitting hole. The step of charging the raw material of the grindstone to be charged , the step of mounting the upper plate on the mold, and the step of moving the upper plate and the column in the approaching direction , Pressing the raw material of the grindstone with the lower surface of the upper plate and the upper end surface of the column while discharging the air in the fitting hole from between the side surface and the mold on the side surface of the column. A mold lowering step of lowering the mold, an upper plate removing step of removing the upper plate to expose the pressed and molded whetstone, and a whetstone acquiring step of acquiring the pressed and whetstone.

The whetstone manufacturing jig according to the present invention includes a column having at least a side surface made of a magnetic material, a mold having a fitting hole for allowing the pillar to be inserted therethrough, and a side surface of the pillar being magnetically attached to one of the molds. A magnet that supports the mold that is inserted from the opening and is located at a predetermined height position and one of the openings is closed, and the raw material of the grindstone is input from the other opening of the insertion hole of the mold that is supported by the magnet. After that, an upper plate placed on the mold so as to close the other opening of the fitting hole is provided, and the magnet moves along the side face while supporting the mold to move the raw material of the grindstone put into the fitting hole. Since it is configured to press on the upper end surface of the pillar and the lower surface of the upper plate, when pouring the raw material of the grindstone into the insertion hole, air is discharged from the slight gap generated at the part where the side surface of the pillar and the formwork contact each other. Therefore, the air does not remain in the mold, and the possibility of the raw material spouting from the mold when the raw material of the grindstone is pressed can be reduced.

The above-mentioned grindstone manufacturing jig is provided with a pushing-down means for pushing down the mold after pressing the raw material of the grindstone, so that the mold is pushed down to a position where the mold does not interfere when taking out the pressed and molded grindstone, and then the grindstone is pressed. It can be exposed on the upper end surface of the pillar, and the pressed and molded grindstone can be easily obtained.

Further, the method for manufacturing a grindstone according to the present invention includes a magnetizing step of magnetically attaching a magnet to a side surface of a pillar at a predetermined height, and a fitting hole is fitted into the pillar from one opening, and a magnet is attached to the side surface. Form support process of supporting the form by the attached magnet, grinding stone raw material feeding process of feeding the raw material of the grinding stone from the other opening of the insertion hole, and placing the upper plate on the form Step, pressing step to move the upper plate and the pillar in the direction of approaching and press the raw material of the grindstone with the lower surface of the upper plate and the upper end surface of the pillar, and the form lowering to lower the form along the side of the pillar Step, because the upper plate removal process of removing the upper plate to expose the pressed and molded whetstone, and the whetstone acquisition process of obtaining the pressed and molded whetstone, when performing the whetstone raw material charging step, Air can be discharged from a slight gap generated in a portion where the side surface of the column and the mold are in contact with each other, and the air does not remain in the mold. Therefore, it is possible to reduce the risk that the raw material will be ejected from the mold when the pressing step is performed.
Furthermore, after performing the pressing process, proceed to the mold lowering process, so press down the mold to a position where the mold does not interfere when taking out the pressed and molded grindstone, then remove the upper plate and acquire the grindstone The process can be carried out and the pressed and molded whetstone can be easily obtained.

It is an exploded perspective view showing composition of a whetstone manufacturing jig. It is a perspective view which shows a magnetic sticking process. It is a perspective view which shows a formwork support process. It is a perspective view which shows a grindstone raw material charging process. It is a perspective view which shows an upper plate mounting process and a press process. It is a perspective view which shows a form pushing down process. It is a perspective view which shows an upper plate removal process and a grindstone acquisition process. It is a perspective view which shows the structure of the modification of a formwork.

1 Grinding Stone Manufacturing Jig The grinding stone manufacturing jig 1 shown in FIG. 1 is a jig for manufacturing a grinding stone used when pressing and molding powder raw material of the grinding stone, and shows a state in which each member is disassembled. ing. The whetstone manufacturing jig 1 has a pillar 2 at least a side surface 20 of which is made of a magnetic material, a mold 4 having a fitting hole 43 into which the pillar 2 can be inserted, and a side surface 20 of the pillar 2 which is magnetically attached to the pillar 2. A magnet 5 that is inserted from one opening of the insertion hole 43 and is located at a predetermined height position and supports the mold 4 whose one opening is closed, and an upper plate 6 that is placed on the upper surface 40 of the mold 4. It has and.

The pillar 2 is formed in a square pillar shape, for example, and stands upright on the press table 3. The press table 3 is a workbench that receives a predetermined load via the pillar 2. The material of the pillar 2 is not particularly limited, but at least the side surface 20 may be made of a magnetic material. The magnet 5 has, for example, a rectangular parallelepiped shape. Although the number of the magnets 5 shown in this embodiment is four, the number is not limited to this. For example, at least two magnets 5 may be magnetically attached to the side surfaces 20 of the columns 2 facing each other. Further, the side surface 20 of the column 2 may be provided with a block for positioning the magnet 5 at a predetermined height position, or may be provided with a scale for placing the magnet 5 at a predetermined height position. .. The pillar 2 may be formed in a cylindrical shape. In this case, it is advisable to form the surface of the magnet 5 on the side that is magnetically attached to the side surface 20 of the columnar pillar 2 into an arc surface.

Here, when magnetically attaching the magnet 5 to the side surface 20 of the pillar 2, the magnet 5 is attached to the side surface 20 of the pillar 2 by orienting the longitudinal direction of the magnet 5 in a direction intersecting the extending direction of the pillar 2. Good to wear. As a result, the magnet 5 is magnetically attached in a state of protruding from the side surface 20 of the column 2 like a protrusion, so that the mold 4 can be supported from below by the magnet 5 in this state. Further, the magnet 5 can move vertically along the side surface 20 of the column 2 while supporting the mold 4.

The mold 4 is a member for molding the raw material of the powdery grindstone into a predetermined shape, and has, for example, a block shape. A fitting hole 43 that penetrates the upper surface 40 and the lower surface 41 is formed in the center of the mold 4. The fitting hole 43 has a quadrangular prism shape in conformity with the shape of the pillar 2, and the front and back sides are open so that the pillar 2 can be penetrated. The fitting hole 43 is slightly larger than the outer shape of the column 2. The fitting hole 43 is fitted into the pillar 2 from one opening (lower opening in the figure), one opening is closed by the upper end surface 21, and the lower surface 41 of the mold 4 is magnetically attached to the side surface 20. When supported by the magnet 5, a recess surrounded by the inner side surface 42 of the mold 4 and the upper end surface 21 of the column 2 is formed. The raw material of the grindstone is put into this recess. When the raw material of the grindstone is put into the concave portion, a slight gap is formed in a portion where the side surface 20 of the column 2 and the inner side surface 42 of the form 4 are in contact with each other, so that only air is discharged from the gap. The shape, material, size, etc. of the mold 4 are not particularly limited, and the shape and size of the fitting hole 43 may be appropriately changed according to the shape and size of the column 2.

The upper plate 6 is formed in a flat plate shape, and has an area large enough to close at least the other opening (the upper opening in the drawing) of the fitting hole 43. The upper plate 6 may close the other opening of the fitting hole 43 with the lower surface 61 of the upper plate 6 after charging the raw material of the grindstone into the recess from the other opening of the fitting hole 43 of the mold 4 supported by the magnet 5. it can. Then, the upper surface 60 of the upper plate 6 in this state is pressed by, for example, a pressing machine to press the raw material of the grindstone by the upper end surface 21 of the pillar 2 and the lower surface 61 of the upper plate 6 into a predetermined shape. It can be molded.

Further, the grindstone manufacturing jig 1 is provided with a pushing-down means 7 for pushing down the mold 4 after pressing the raw material of the grindstone. The pushing-down means 7 is provided with a through hole 71 that penetrates the front and back at at least two places of the upper plate 6, and a pin 70 that is inserted into the through hole 71. The through hole 71 is formed outside the fitting hole 43 of the mold 4 and is covered by the upper surface 40 of the mold 4 when the upper plate 6 is placed on the mold 4. The pin 70 has a length equal to or greater than the sum of the thickness of the raw material of the grindstone after being pressed and the thickness of the upper plate 6. In the pushing-down means 7 configured in this way, when the upper frame 6 is placed on the mold 4 and the mold 70 is pushed down by the pin 70 through the through hole 71, the pressed and molded grindstone is taken out. The mold 4 can be positioned at a position where the mold 4 does not get in the way (at least at a position lower than the upper end surface 21 of the pillar 2), and the pressed and molded grindstone can be exposed.

As described above, in the grindstone manufacturing jig 1 according to the present invention, at least the side surface 20 of the pillar 2 is formed, the mold 4 having the fitting hole 43 into which the pillar 2 is inserted so as to penetrate, and the side surface 20 of the pillar 2. The magnet 5 that is magnetically attached to the pillar 2, is fitted into the pillar 2 through one opening of the fitting hole 43, is located at a predetermined height position, and supports the mold 4 whose one opening is closed, and the upper surface 40 of the mold 4. The upper plate 6 placed on the upper surface 6 of the pillar 2 and the magnet 5 moved along the side surface 20 while supporting the mold 4 and the raw material of the grindstone thrown into the recess from the fitting hole 43 and the upper surface 21 of the pillar 2. Since it is configured to press with the lower surface 61 of the plate 6, when the raw material of the grindstone is put into the concave portion from the fitting hole 43, a slight amount is generated in a portion where the side surface 20 of the column 2 and the inner side surface 42 of the form 4 come into contact with each other. The air can be discharged from such a gap, and the air does not remain in the concave portion of the mold 4. Thereby, it is possible to reduce the possibility that the raw material is spouted from the mold 4 when the raw material of the grindstone is pressed.
Further, since the grindstone manufacturing jig 1 is provided with the pushing-down means 7 that pushes down the mold 4 after pressing the raw material of the grindstone, the mold 4 is placed at a position where the mold 4 does not interfere when taking out the pressed and molded grindstone. After pressing down, the grindstone can be exposed on the upper end surface 21 of the pillar 2, and the pressed and molded grindstone can be easily obtained.

2 Method for Manufacturing Grinding Stone Next, a method for manufacturing a grindstone using the grindstone manufacturing jig 1 will be described with reference to FIGS. First, the pillar 2 standing on the press table 3 is prepared.

(1) Magnetization step As shown in FIG. 2, the magnet 5 is magnetized at a predetermined height position with respect to the side surface 20 of the column 2. In this embodiment, the magnet 5 is magnetically attached to each of the side surfaces 20 of the pillar 2 with the longitudinal direction of the magnet 5 oriented in the direction intersecting with the extending direction of the pillar 2. As a result, each magnet 5 is projected like a protrusion on each side surface 20 of the pillar 2. The predetermined height position may be changed appropriately according to the thickness of the grindstone to be manufactured.

(2) Formwork Supporting Step As shown in FIG. 3, the fitting hole 43 of the formwork 4 is fitted into the pillar 2 from one opening, and the formwork 4 is formed by the magnet 5 magnetically attached to the side surface 20 of the pillar 2. Support. Specifically, as shown by the chain double-dashed line in the form 4, by inserting the fitting hole 43 into the post 2 from one opening, the inner side surface 42 of the form 4 runs along the side surface 20 of the post 2. And moves to a predetermined height position, one opening of the fitting hole 43 is closed by the upper end surface 21 of the column 2, and the mold 4 is supported by each magnet 5. As a result, a recess 400 surrounded by the upper end surface 21 of the pillar 2 and the inner side surface 42 of the mold 4 is formed.

(3) Grinding Stone Raw Material Feeding Process As shown in FIG. 4, the powdery grinding stone raw material 8 is charged through the other opening of the fitting hole 43, and a predetermined amount of the raw material 8 is stored in the recess 400. The raw material 8 is a mixture in which the abrasive grains and the bond material are mixed by stirring with a stirrer, for example. The type of abrasive grains is not particularly limited, and examples thereof include alumina abrasive grains and diamond abrasive grains. The type of bond material is not particularly limited, and examples thereof include vitrified bond and resin bond. Here, when the raw material 8 is charged into the recess 400 from the other opening of the fitting hole 43, a slight gap is generated in a portion where the inner side surface 42 of the mold 4 and the side surface 20 of the column 2 come into contact with each other, and therefore air is generated. Only the gas is discharged through the gap. On the other hand, the raw material 8 stored in the recess 400 is not discharged through the gap.

(4) Upper Plate Placing Step After performing the grindstone raw material charging step, as shown in FIG. 5, the upper surface 40 of the mold 4 and the lower surface 61 of the upper plate 6 are opposed to each other, and the upper plate is placed on the mold 4. Place 6. As a result, the other opening of the fitting hole 43 shown in FIG. 4 can be closed by the lower surface 61 of the upper plate 6.

(5) Pressing Step Subsequently, the upper plate 6 is pressed downward by using, for example, a mechanical pressing machine. Specifically, the pressing machine presses the upper surface 60 of the upper plate 6 toward the press table 3 to move the upper plate 6 and the column 2 in the direction of approaching each other, and the lower surface 61 of the upper plate 6 and the column 2 are moved. The raw material 8 stored in the recess 400 of the mold 4 shown in FIG. At this time, since air pockets are not generated in the recess 400, the possibility that the raw material 8 is ejected to the outside of the mold 4 during pressing is reduced. In this way, by pressing the raw material 8 for a predetermined time, the raw material 8 is molded into a block shape in the concave portion 400 of the mold 4.

(6) Formwork lowering step Next, as shown in FIG. 6, the formwork 4 is pushed down by the pushing-down means 7. First, the two pins 70 are inserted into the two through holes 71, and the lower ends of the pins 70 are brought into contact with the upper surface 40 of the mold 4. After that, for example, by pressing the two pins 70 with the above-mentioned pressing machine, the lower ends of the pins 70 push down the mold 4 downward, and along the side surface 20 of the pillar 2 the magnet 5 and the mold 4 are at least supported by the pillar 2. It is lowered to a position lower than the upper end surface 21 of the. Thereby, the upper plate removing step and the grindstone acquiring step, which will be described later, can be performed without removing the form 4 from the pillar 2. In the form lowering step, an operator may push the pin 70 downward to drop the form 4 along the side surface 20 of the pillar 2 together with the magnet 5 without using a press machine.

(7) Upper Plate Removing Step As shown in FIG. 7, the upper plate 6 and the pins 70 are removed from the mold 4. At this time, since the mold 4 is supported by the magnet 5 on the side surface 20 at a position lower than the upper end surface 21 of the pillar 2, when the upper plate 6 and the pin 70 are removed from the upper surface 40 of the mold 4, press The grindstone 80 molded into a block shape can expose the grindstone 80 on the upper end surface 21 of the pillar 2.

(8) Grinding Stone Obtaining Step Subsequently, the pressed and molded whetstone 80 is obtained. Since the mold 4 is in a position that does not interfere with the removal of the grindstone 80, the grindstone 80 can be easily obtained from the upper end surface 21 of the column 2. Then, the obtained grindstone 80 is sintered at a predetermined temperature for a predetermined time.

As described above, the method of manufacturing a grindstone according to the present invention includes a magnetizing step of magnetically attaching the magnet 5 to the side surface 20 of the pillar 2 at a predetermined height, and a fitting hole 43 for the pillar 2. Form supporting step for supporting the form 4 by the magnet 5 which is fitted into the side wall 20 and is attached to the side surface 20, a grindstone raw material introducing step for introducing the raw material 8 of the grindstone from the other opening of the fitting hole 43, and the form 4 The upper plate placing step of placing the upper plate 6 on the upper plate, and the upper plate 6 and the pillar 2 are moved in a direction of approaching each other to move the lower plate 61 of the upper plate 6 and the upper end surface 21 of the pillar 2 to the raw material 8 of the grindstone. A pressing step of pressing, a mold lowering step of lowering the mold 4 along the side surface 20 of the column 2, an upper plate removing step of removing the upper plate 6 to expose the pressed and molded grindstone 80, and a pressing process. Since a grindstone obtaining step of obtaining the molded grindstone 80 is provided, when performing the grindstone raw material charging step, from a slight gap generated in a portion where the side surface 20 of the pillar 2 and the inner side surface 42 of the form 4 come into contact with each other. The air can be discharged, and the air does not remain in the recess 400 of the mold 4. Therefore, it is possible to reduce the possibility that the raw material 8 is spouted from the mold 4 when performing the pressing process.
Further, after the pressing process is performed, the process goes to the form lowering process. Therefore, the form 4 is pushed down to a position where the form 4 does not get in the way when the pressed and molded grindstone 80 is taken out, and then the upper plate removing process is performed. And the grindstone acquisition step can be performed, and the grindstone 80 can be easily acquired.

The form 9 shown in FIG. 8 is a modification of the form 4 described above. The mold 9 includes four plate members 90, and the ends of each plate member 90 are connected to each other by bolts 95 to form a block shape as a whole. Although not shown, a through hole through which the bolt 95 penetrates is formed at the end of each plate member 90, and this through hole may be formed as an elongated hole. The mold 9 thus formed has a fitting hole 94 penetrating the upper surface 91 and the lower surface 92 in the center thereof, as in the above-described mold 4. The fitting hole 94 has a quadrangular prism shape in conformity with the shape of the pillar 2 described above, and the front and back sides of the fitting hole 94 are open so that the pillar 2 can be penetrated. The fitting hole 94 is slightly larger than the outer shape of the column 2. The fitting hole 94 is fitted into the pillar 2 through one opening (a lower opening in the drawing), one opening is closed by the upper end surface 21, and the lower surface 92 of the mold 9 is magnetically attached to the side surface 20. When supported by the magnet 5, a recess surrounded by the inner surface 93 of the mold 9 and the upper end surface 21 of the column 2 is formed. When the raw material of the grindstone is put into the concave portion, a slight gap is formed in a portion where the side surface 20 of the column 2 and the inner side surface 93 of the mold 9 are in contact with each other, so that only air is discharged from the gap. Therefore, air does not remain in the concave portion of the mold 9, and it is possible to reduce the possibility that the raw material will blow out from the mold 9 when the raw material of the grindstone is pressed.

When the raw material of the grindstone is pressed using the mold 4 and the mold 9 shown in the present embodiment, the side surface 20 of the pillar 2, the inner side surface 42 of the mold 4 and the inner side surface 93 of the mold 9 come into contact with each other. The raw material of the abrasive grains may enter into a slight gap between the portions, and the side face 20 and the inner side faces 42, 93 may be scraped by the raw material of the abrasive grain to increase the gap. The shapes of the side surface 20 of the pillar 2 and the inner side surface 42 of the form 4 are difficult to correct and therefore need to be replaced, but the shape of the inner side surface 93 of the form 9 can be corrected and can be replaced. You don't have to. That is, in the mold 9, the bolts 95 are removed, the plate members 90 are disassembled, and the flatness of the inner side surfaces 93 is reproduced by performing, for example, surface grinding on the inner side surfaces 93, and then each plate is again. Since the ends of the members 90 can be connected to each other by the bolts 95, the suitable fitting holes 94 for the columns 2 can be re-formed, and the form 9 can be reused.

The grindstone manufactured by the grindstone manufacturing jig 1 according to the present embodiment has, for example, a cutting blade for cutting the workpiece, a dresser boat for dressing the grindstone, and a thickness for grinding the workpiece. A grinding wheel or the like can be used.

1: Grinding stone manufacturing jig 2: Pillar 20: Side surface 21: Upper end surface 3: Press table 4: Form 40: Upper surface 41: Lower surface 42: Inner side surface 43: Fitting hole 400: Recess 5: Magnet 6: Upper plate 60: Upper surface 61: Lower surface 7: Push-down means 70: Pin 71: Through hole 8: Raw material 80: Grinding stone 9: Form 90: Plate member 91: Upper surface 92: Lower surface 93: Inner side surface 94: Fitting hole 95: Bolt

Claims (3)

A whetstone manufacturing jig for manufacturing a whetstone by molding a powdery raw material of a whetstone by a press,
At least a side surface made of a magnetic material,
A mold having a fitting hole into which the pillar is fitted so as to penetrate therethrough,
A magnet that is magnetically attached to a side surface of the pillar, is fitted into the pillar through one opening of the fitting hole, is located at a predetermined height position, and supports the mold in which the one opening is closed;
The raw material of the grindstone is charged from the other opening of the fitting hole of the mold supported by the magnet, and then placed on the mold so as to close the other opening of the fitting hole. And an upper plate,
By pressing the pillar and the upper plate in a direction of approaching each other, the magnet moves along the side surface while supporting the mold, and the magnet is moved from between the side surface and the inner side surface of the fitting hole. A grindstone manufacturing jig for forming a grindstone by discharging air and pressing the raw material of the grindstone put into the fitting hole by the upper end surface of the column and the lower surface of the upper plate. After pressing the raw material of the grindstone, a pressing means for pressing down the mold is provided,
The pushing-down means includes through holes penetrating the front and back sides at at least two places of the upper plate,
A pin to be inserted into the through hole,
The through hole is formed outside the fitting hole of the mold, and the through hole is closed by the upper surface of the mold when the upper plate is placed on the mold.
The pin has a length equal to or greater than the sum of the thickness of the raw material of the grindstone after being pressed and the thickness of the upper plate,
2. The pressed grindstone is obtained by pressing the raw material of the grindstone, inserting the pin into the through hole, and pushing down the pin to push down the mold frame. The whetstone manufacturing jig described. A method for manufacturing a grindstone using the grindstone manufacturing jig according to claim 1,
A magnetizing step of magnetizing the magnet to a predetermined height with respect to the side surface of the pillar;
A mold supporting step of fitting the fitting hole into the pillar from the one opening and supporting the mold by the magnet magnetically attached to the side surface,
A grinding stone raw material charging step of charging the raw material of the grinding stone from the other opening of the fitting hole,
An upper plate placing step of placing the upper plate on the mold,
The upper plate and the pillar are moved toward each other to discharge air in the fitting hole from between the side surface and the inner side surface of the fitting hole, and the lower surface of the upper plate and the upper end surface of the pillar. And a pressing step of pressing the raw material of the grindstone,
A form lowering step of lowering the form along the side surface of the pillar,
An upper plate removing step of removing the upper plate to expose the pressed and molded grindstone;
A method for manufacturing a whetstone, comprising a whetstone obtaining step of obtaining a pressed and molded whetstone.

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