JP7260971B2 - Electroformed whetstone - Google Patents

Description

The present invention relates to an electroformed grindstone.

2. Description of the Related Art Conventionally, an electroformed grindstone is known that includes a cylindrical portion having one end surface as a processing surface and a base adhered to the other end surface of the cylindrical portion (see, for example, Patent Document 1). In the electroformed whetstone disclosed in Patent Document 1, a plurality of openings are provided in the cylindrical portion to allow communication between the inner peripheral surface and the outer peripheral surface thereof.

Japanese Patent Application Laid-Open No. 2002-36123

The electroformed grindstone of Patent Document 1 is provided with a large number of openings that allow communication between the inner peripheral surface and the outer peripheral surface of the cylindrical portion, and is configured so that the working fluid flows through the large number of openings. However, as a result of providing a large number of openings, the area of the machined surface is reduced, resulting in a problem of reduced grinding efficiency.

On the other hand, when a ceramic member such as Al ₂ O ₃ , AlN, or SiC is ground, a highly viscous muddy substance is generated due to mixing of the ceramic debris generated during grinding with the working fluid. At this time, if the muddy matter cannot be efficiently discharged from the opening of the cylindrical portion, the inside of the cylindrical portion will be clogged with processing waste. As a result, there have been cases where the grinding efficiency is lowered and the grindstone is damaged due to the increased processing load. In particular, AlN generates alkaline ammonia when it reacts with moisture in the working fluid. Substances in which ammonia is turbid with machining waste or machining liquid have high viscosity and tend to condense, and there have been cases where they cannot be discharged well from the opening.

SUMMARY OF THE INVENTION In view of the above points, it is an object of the present invention to provide an electroformed grindstone capable of promoting the supply and discharge of working fluid and improving the grinding efficiency.

[1] In order to achieve the above object, the present invention
An electroforming grindstone for grinding a work piece of Al ₂ O ₃ , AlN or SiC ,
a cylindrical portion having a thickness of 0.3 mm or more and 1.0 mm or less;
at least one opening that extends continuously from the machined surface, which is one end surface of the cylindrical portion, toward the other end surface, and opens to the inner peripheral surface and the outer peripheral surface of the cylindrical portion;
When viewed from the processing surface side, the ratio of the length of the outer peripheral edge of the processing surface to the circumferential length of a virtual first circle passing through the entire outer peripheral edge of the processing surface is 50. % or more and 80% or less,
The ratio of the height of the opening along the axial direction of the cylindrical portion to the circumferential length of the portion of the first circle passing through the opening is 1.0 or more and 4.3 or less. characterized by

According to the present invention, the opening continuously extends from one end surface as the processing surface toward the other end surface. As a result, the machining fluid can easily enter the electroforming grindstone through the opening, and the machining fluid can be easily discharged through the opening.

Furthermore, according to the present invention, when viewed from the processing surface side, the length of the outer peripheral edge of the processing surface occupies the circumferential length of a virtual first circle passing through the entire outer periphery of the processing surface. The ratio is 50% or more and 80% or less, and the ratio of the height of the opening along the axial direction of the cylindrical portion to the circumferential length of the portion passing through the opening in the first circle is 1.0 or more and 4 .3 or less. As a result, the supply and discharge of the machining fluid are further promoted while ensuring the area of the machining surface and the strength of the electroformed grindstone. In addition, even if a highly viscous muddy substance is generated by mixing the machining waste generated by grinding with the working fluid, the muddy substance can be easily discharged together with the working fluid through the opening. It is possible to improve the grinding efficiency.

[2] Further, in the present invention, any number of 2 to 4 openings may be provided rotationally symmetrically with respect to the axis of the cylindrical portion. When two to four openings are provided, rotational balance of the electroformed whetstone can be improved by making the openings rotationally symmetrical, compared to one in which the openings are not rotationally symmetrical.

[3] In addition, in the present invention, in a virtual second circle passing through the entire outer peripheral surface in a cross section perpendicular to the axis of the cylindrical portion where the opening is present, the portion of the virtual second circle passing through the opening It is preferable that the length in the circumferential direction is longer than the length in the circumferential direction of the portion of the virtual first circle that passes through the opening. According to the present invention, the electroformed grindstone becomes shorter from the processing surface side due to wear due to grinding, but even if the electroformed grindstone becomes shorter, the area of the opening can be secured to some extent.

[4] Further, in the present invention, the contour lines that define the openings in the outer peripheral surface and the inner peripheral surface include a straight portion extending from the processing surface to the other end surface side and and the straight portion of the outline defining the opening extends in a circumferential direction with respect to the axis of the cylindrical portion when viewed from a direction perpendicular to the axial direction of the cylindrical portion. It can also be configured to extend obliquely. According to the present invention, since the direction in which the opening extends when viewed from the processing surface side can be aligned with the rotation direction of the electroformed tool, the impact applied to the electroformed grindstone during grinding is reduced, and the electroformed grindstone is damaged. can be suppressed.

[5] Further, in the present invention, it is preferable that contour lines defining the openings in the outer peripheral surface and the inner peripheral surface have curved lines on the other end surface side. According to the present invention, since the other end side of the contour defining the opening has a curved line, stress concentration at the corner is less likely to occur than when the contour is composed only of straight lines. , the strength of the electroformed grindstone can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS The perspective view which shows typically the electroforming grindstone of 1st Embodiment. The perspective view which shows typically the electroforming grindstone of 2nd Embodiment. Explanatory drawing which shows typically the electroforming grindstone of 3rd Embodiment. Explanatory drawing which shows typically the electroforming grindstone of 4th Embodiment. Explanatory drawing which shows typically the electroforming grindstone of 5th Embodiment. Explanatory drawing which shows the electroforming grindstone of an Example and a comparative example.

An electroformed grindstone according to an embodiment of the present invention will be described with reference to the drawings.

[First embodiment]
Referring to FIG. 1, an electroformed grindstone 1 of the first embodiment includes a cylindrical portion 2 and a columnar base 3 . One end surface 2a of the cylindrical portion 2 is open and functions as a processing surface for grinding in contact with a workpiece. The other end face 2b of the cylindrical portion 2 is adhered to one end face of the base 3. As shown in FIG.

The thickness of the cylindrical portion 2 is set within a range of 0.3 mm or more and 1.0 mm or less. The cylindrical portion 2 is provided with one opening portion 4 extending continuously from one end surface 2a as a processing surface toward the other end surface 2b and opening to the inner peripheral surface and the outer peripheral surface of the cylindrical portion 2. ing.

A first circle 5 is a virtual circle that passes through the entire outer peripheral edge of one end surface 2a as the processing surface when the cylindrical portion 2 is viewed from the processing surface side, which is the one end surface 2a side. The length of the outer peripheral edge of one end face 2a as the processing surface (the length in the circumferential direction of the portion excluding the opening 4) is set to 50% or more and 80% or less of the circumference of the first circle 5. ing. By setting the length of the outer peripheral edge of one end face 2a to 50% or more and 80% or less of the virtual first circle 5, the contact area with the workpiece can be increased to a certain extent, and the grinding efficiency can be improved. can be achieved.

The opening 4 is defined by the circumferential length of the portion passing through the opening 4 in the virtual first circle 5 (the circumferential width of the end of the opening 4 on the one end surface 2a side). 4 is set so that the height ratio in the axial direction of the electroformed grindstone 1 is 1.0 or more and 4.3 or less.

By configuring in this way, while ensuring the strength of the electroformed grindstone 1, a sufficient size of the opening 4 is ensured, so that during grinding, the working fluid can be supplied and processed through the opening 4. It is possible to efficiently discharge the machining liquid and machining waste. Further, even if the opening 4 becomes vertically elongated in the axial direction and the length of the opening 4 of the electroforming grindstone 1 in the axial direction becomes shorter due to wear during processing, the opening area of the opening 4 should be maintained to some extent. , and a relatively long service life of the electroformed grindstone 1 can be ensured.

The contour lines defining the opening 4 on the outer and inner peripheral surfaces of the cylindrical portion 2 are curved at the edge portion 4a on the other end surface 2b side. As a result, compared to the case where the outline defining the opening 4 is formed only by straight lines, stress concentration at the corners is less likely to occur, and the strength of the electroformed grindstone can be improved.

Next, a method for manufacturing the electroformed grindstone 1 of this embodiment will be described.

First, #200 diamond is dispersed in a nickel plating bath to form a plated layer having a thickness of 0.3 mm to 1 mm on a metal substrate. Then, the cylindrical portion 2 is formed by removing the metal base material.

Then, the cylindrical portion 2 is adhered to the cylindrical base 3 . Next, an opening 4 is formed in the cylindrical portion 2 to complete the electroforming grindstone 1 of the present embodiment.

According to the electroforming grindstone 1 of the present embodiment, the opening 4 continuously extends from one end surface 2a as a processing surface toward the other end surface 2b, and a relatively small opening as in the conventional art. The size of one opening 4 can be made relatively large compared to one in which is dispersed in a plurality of. This makes it easier for the working fluid to enter the cylindrical portion 2 of the electroforming grindstone 1 through the opening 4 . Therefore, even if the rotational speed of the electroforming grindstone 1 is increased, the machining fluid can be appropriately supplied to the machining portion of the workpiece. Furthermore, even if a highly viscous and cohesive muddy substance is generated by mixing the processing waste generated by the grinding process with the working fluid, the muddy substance does not stay inside the opening 4 and the opening is large. It is discharged from the part 4, and the reduction in grinding efficiency can be suppressed.

[Second embodiment]
FIG. 2 shows an electroforming grindstone 1 of a second embodiment. The electroforming grindstone 1 of the second embodiment is configured in the same manner as the first embodiment except that there are two openings 4 . The two openings 4 are arranged at regular intervals in the circumferential direction so that the cylindrical portion 2 is rotationally symmetrical. By providing the opening 4 so as to be rotationally symmetrical, compared with the case where the opening 4 is provided so as not to be rotationally symmetrical, the rotational balance when the electroforming grindstone 1 is rotated is improved. can be done.

Also in the electroforming grindstone 1 of the second embodiment, similarly to the first embodiment, the opening 4 continuously extends from one end surface 2a as a processing surface toward the other end surface 2b. The size of one opening 4 can be made relatively large compared to a plurality of relatively small openings such as . This makes it easier for the working fluid to enter the cylindrical portion 2 of the electroforming grindstone 1 through the opening 4 . Therefore, even if the rotational speed of the electroforming grindstone 1 is increased, the machining fluid can be appropriately supplied to the machining portion of the workpiece.

[Third embodiment]
FIG. 3 shows an electroforming grindstone 1 of a third embodiment. The electroformed grindstone 1 of the third embodiment is configured in the same manner as the second embodiment, except that the circumferential width of the opening 4 includes a region that gradually increases toward the other end face 2b. there is

The fact that the width of the opening 4 in the circumferential direction gradually increases toward the edge portion 4a on the side of the other end face 2b means that the axis of the cylindrical portion 2 where the opening 4 exists In a virtual second circle 6 passing through the entire outer peripheral surface of the cylindrical portion 2 in a cross section perpendicular to the , the circumferential length of the portion passing through the opening 4 is It can be said that it is configured to be longer than the circumferential length of the portion passing through the opening 4 .

By configuring the width of the opening 4 in the circumferential direction so as to gradually increase toward the edge portion 4a on the side of the other end surface 2b, even if the electroformed grindstone 1 becomes shorter due to wear accompanying the grinding process, the opening remains open. The opening area of the portion 4 can be maintained wide to some extent, and the life of the electroforming grindstone 1 can be maintained relatively long.

Further, in the electroforming grindstone 1 of the third embodiment, similarly to the first embodiment, the opening 4 continuously extends from one end surface 2a as a processing surface toward the other end surface 2b. , the size of one opening 4 can be made relatively large compared to a conventional one in which relatively small openings are dispersed. This makes it easier for the working fluid to enter the cylindrical portion 2 of the electroforming grindstone 1 through the opening 4 . Therefore, even if the rotational speed of the electroforming grindstone 1 is increased, the machining fluid can be appropriately supplied to the machining portion of the workpiece. Furthermore, even if a highly viscous and cohesive muddy substance is generated by mixing the processing waste generated by the grinding process with the working fluid, the muddy substance does not stay inside the opening 4 and the opening is large. It is discharged from the part 4, and the reduction in grinding efficiency can be suppressed.

[Fourth embodiment]
FIG. 4 shows an electroforming grindstone 1 of a fourth embodiment. In the electroforming grindstone 1 of the fourth embodiment, the edge portion 4a of the opening 4 on the side of the other end surface 2b is formed in a circular shape having a larger diameter than the circumferential width of the opening 4 on the side of the one end surface 2a. The configuration is the same as that of the second embodiment except that

In other words, the edge portion 4a of the opening 4 on the side of the other end surface 2b is formed in a circular shape having a diameter larger than the circumferential width of the opening 4 on the side of the one end surface 2a. In a virtual second circle 6 passing through the entire outer peripheral surface of the cylindrical portion 2 in a cross section perpendicular to the axis of the cylindrical portion 2 where the opening 4 exists, the circumferential length of the portion passing through the opening 4 It can be said that the length is longer than the length in the circumferential direction of the portion passing through the opening 4 in the virtual first circle.

By forming the edge portion 4a of the opening 4 on the side of the other end surface 2b into a circular shape having a larger diameter than the circumferential width of the opening 4 on the side of the one end surface 2a, the electroformed grindstone 1 is ground. The opening area of the opening 4 can be maintained wide to some extent even if it becomes shorter due to wear associated with this, and the life of the electroforming grindstone 1 can be maintained relatively long.

Further, in the electroforming grindstone 1 of the fourth embodiment, similarly to the first embodiment, the opening 4 continuously extends from one end surface 2a as a processing surface toward the other end surface 2b. , the size of one opening 4 can be made relatively large compared to a conventional one in which relatively small openings are dispersed. This makes it easier for the working fluid to enter the cylindrical portion 2 of the electroforming grindstone 1 through the opening 4 . Therefore, even if the rotational speed of the electroforming grindstone 1 is increased, the machining fluid can be appropriately supplied to the machining portion of the workpiece. Furthermore, even if a highly viscous and cohesive muddy substance is generated by mixing the processing waste generated by the grinding process with the working fluid, the muddy substance does not stay inside the opening 4 and the opening is large. It is discharged from the part 4, and the reduction in grinding efficiency can be suppressed.

[Fifth embodiment]
FIG. 5 shows an electroforming grindstone 1 of a fifth embodiment. The electroformed grindstone 1 of the fifth embodiment is the same as that of the second embodiment, except that the opening 4 extends obliquely in the circumferential direction with respect to the axis of the electroformed grindstone 1. It is configured.

Also in the electroforming grindstone 1 of the fifth embodiment, similarly to the first embodiment, the opening 4 continuously extends from one end surface 2a as a processing surface toward the other end surface 2b. The size of one opening 4 can be made relatively large compared to a plurality of relatively small openings such as . This makes it easier for the working fluid to enter the cylindrical portion 2 of the electroforming grindstone 1 through the opening 4 . Therefore, even if the rotational speed of the electroforming grindstone 1 is increased, the machining fluid can be appropriately supplied to the machining portion of the workpiece.

Furthermore, even if a highly viscous and cohesive muddy substance is generated by mixing the processing waste generated by the grinding process with the working fluid, the muddy substance does not stay inside the opening 4 and the opening is large. It is discharged from the part 4, and the reduction in grinding efficiency can be suppressed. In addition, since the direction in which the opening 4 extends when viewed from the side of one end face 2a can be aligned with the rotational direction of the electroformed tool 1, the impact applied to the electroformed grindstone 1 during grinding can be reduced. Damage can be suppressed.

[Examples and Comparative Examples]
FIG. 6 shows the dimensions and evaluation of more specific Examples 1-9 and Comparative Examples 1-3.

Using the electroforming tools 1 of Examples 1 to 9 and Comparative Examples 1 to 3, concentric grooves were formed on the surface of a disk-shaped silicon carbide (SiC) sintered body (300 mm in diameter and 8 mm in thickness) as a work piece. was ground, and the presence or absence of defects such as breakage and breakage of the electroforming tool 1 when the total processing distance reached 200 m and 300 m was confirmed, and those with no defects were evaluated as good. Grinding conditions were set so that the cutting speed, feed speed, and peripheral speed were the same in Examples 1 to 9 and Comparative Examples 1 to 3.

The cylindrical portion 2 is set to have an axial length of 20 mm and a thickness of 0.5 mm. Examples 1 to 7 and Comparative Examples 1 to 3 have one opening 4 , Example 8 has two openings 4 , and Example 9 has four openings 4 .

From Examples 1 to 9 in FIG. 6, the outer peripheral edge of one end face 2a with respect to the circumferential length (L1) of the virtual first circle 5 passing through the entire outer peripheral edge of one end face 2a as a processing surface The ratio of the length (L2) is 50% or more and 80% or less, and the height (H) of the opening 4 along the axial direction is the portion of the first circle 5 that passes through one opening 4 If the value obtained by dividing by the length in the circumferential direction is 1.0 or more and 4.3 or less, problems such as breakage of the electroformed grindstone 1 occur even when the total processing distance reaches 200 m. Therefore, it can be seen that the life of the electroforming tool 1 is sufficiently ensured. A possible reason for this is that each of the openings 4 is formed with a size sufficient to sufficiently discharge cutting waste together with the working fluid.

On the other hand, as shown in Comparative Example 1, when the ratio of L2/L1 exceeds 80%, cutting chips are not sufficiently discharged from the opening 4, and the load applied to the electroformed grindstone 1 during cutting increases, resulting in total machining. Breakage occurred when the distance reached 200 m. Further, as shown in Comparative Example 2, the value obtained by dividing the height (H) of the opening 4 by the circumferential length of the portion of the first circle 5 passing through one opening 4 is 4.3. , breakage occurred due to insufficient strength of the cylindrical portion 2 . Furthermore, as shown in Comparative Example 3, the value obtained by dividing the height (H) of the openings 4 by the circumferential length of the portion of the first circle 5 that passes through one opening 4 is 1.0. below, the machining fluid is not sufficiently supplied through the opening 4, and the cutting chips are not sufficiently discharged together with the machining fluid, so the load applied to the electroforming grindstone 1 during cutting increases, and the total machining distance When reached 200 m, breakage occurred.

In Examples 2, 4, and 7, the value obtained by dividing the height (H) of the opening 4 by the circumferential length of the portion of the first circle 5 passing through one opening 4 is relatively small, The life was reached before the total processing distance reached 300m.

In Examples 1 to 9, the SiC sintered body was used as the work piece, but the electroformed grindstone 1 can also be used for processing the AlN sintered body or the Al ₂ O ₃ sintered body as the work piece. can be done. In particular, AlN generates alkaline ammonia when it reacts with moisture in the working fluid. Substances in which ammonia is turbid with processing waste or processing liquid are highly viscous and tend to agglomerate. It was confirmed that even if the total machining distance exceeded 200 m, problems such as breakage did not occur when machining was performed under the same conditions as in Examples 1 to 9.

1 Electroforming grindstone 2 Cylindrical portion 2a One end surface (processing surface)
2b other end 3 base 4 opening 4a edge portion 5 virtual first circle 6 virtual second circle

Claims (5)

An electroforming grindstone for grinding a work piece of Al ₂ O ₃ , AlN or SiC ,
a cylindrical portion having a thickness of 0.3 mm or more and 1.0 mm or less;
at least one opening that extends continuously from the machined surface, which is one end surface of the cylindrical portion, toward the other end surface, and opens to the inner peripheral surface and the outer peripheral surface of the cylindrical portion;
When viewed from the processing surface side, the ratio of the length of the outer peripheral edge of the processing surface to the circumferential length of a virtual first circle passing through the entire outer peripheral edge of the processing surface is 50. % or more and 80% or less,
The ratio of the height of the opening along the axial direction of the cylindrical portion to the circumferential length of the portion of the first circle passing through the opening is 1.0 or more and 4.3 or less. An electroformed whetstone characterized by The electroforming grindstone according to claim 1,
2 to 4 of the openings are provided rotationally symmetrically with respect to the axis of the cylindrical portion. The electroforming grindstone according to claim 1 or claim 2,
In a virtual second circle passing through the entire outer peripheral surface in a cross section perpendicular to the axis of the cylindrical portion where the opening is present, the circumferential length of the portion passing through the opening is the virtual an electroformed whetstone characterized by being longer than the circumferential length of a portion of the first circle that passes through the opening. The electroforming grindstone according to any one of claims 1 to 3,
contour lines defining the opening on the outer peripheral surface and the inner peripheral surface have a straight portion extending from the processing surface to the other end surface side and a curved line on the other end surface side;
The linear portion of the outline defining the opening extends at an angle in the circumferential direction with respect to the axis of the cylindrical portion when viewed from a direction perpendicular to the axial direction of the cylindrical portion. An electroformed whetstone characterized by: The electroforming grindstone according to any one of claims 1 to 4,
An electroformed grindstone, wherein outlines defining the openings in the outer peripheral surface and the inner peripheral surface are curved on the other end surface side.

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