WO2012036026A1

WO2012036026A1 - Grind stone, and method for producing same

Info

Publication number: WO2012036026A1
Application number: PCT/JP2011/070266
Authority: WO
Inventors: 博山副; 正拡糸井
Original assignee: 株式会社日進製作所
Priority date: 2010-09-17
Filing date: 2011-09-06
Publication date: 2012-03-22
Also published as: JP2012061583A

Abstract

A grind stone (1) attached to a tool on a machine tool is provided with: a grind stone base section (4); an abrasive grain section (3) which contains abrasive grains, is integrated with the grind stone base section (4), and comes into contact with a workpiece; and a cover section (5) covering at least a portion of the outer circumference of the abrasive grain section and the outer surface of the cover section (6) functioning as an attachment surface to which the aforementioned tool is attached. The cover section (5) and the grind stone base section (4) are integrally formed by being sintered. The cover section (5) is formed from a metal sheet material (10) which integrates with the grind stone base section (4) by being sintered.

Description

Grinding stone and method for producing grinding wheel

The present invention relates to a grindstone to be mounted on a tool of a machine tool and a method for producing the grindstone.

A whetstone is used for honing, for example. This honing is performed for the purpose of further smoothing the inner peripheral surface of a work (workpiece) obtained by grinding or the like and further improving the processing accuracy of the inner peripheral surface (see Patent Document 1). ). This honing process is a finishing process in which a fine-grained grindstone is brought into contact with the inner peripheral surface of a workpiece for grinding, and is one of precision finishing methods capable of obtaining an excellent workpiece surface together with lapping and superfinishing.

There is a honing machine as a machine tool that performs such honing. As a general structure of a honing machine, a tool for holding one to several grindstones (honing grindstones) is provided. Then, a relative rotational motion and a reciprocating linear motion are performed between the tool and the workpiece, and a grindstone mounted on the tool is brought into contact with the workpiece surface, and at the same time, a working fluid is applied to process the surface.

As shown in FIG. 9 (a), a conventional grindstone 90 is formed by providing an abrasive grain portion 92 on a grindstone base portion (grindstone base) 91, and these are integrated, Attached to the tool. The state where the grindstone 90 is attached to the tool will be described with reference to FIGS. 9B and 9C. The grindstone 90 is mounted in a groove 94 formed in the mandrel 93 of the tool.
Then, the mandrel 93 is inserted into the hole to be machined, and the honing machine is driven to reciprocate linearly in the longitudinal direction while rotating, for example, in the R direction. Done.

JP 2009-6448 A

During the honing process, a force in the rotation direction R acts between the groove 94 of the mandrel 93 and the grindstone 90, and the groove 94 receives a large contact force from the side surface of the grindstone 90 on the surface 94a facing the rotation direction.
Here, since the mandrel 93 is generally made of hardened steel, the side surface 92a of the abrasive grain portion 92 having abrasive grains comes into contact with the groove 94 (the surface 94a) of the mandrel 93, and a large contact force acts. If the state continues, there is a problem that the mandrel 93 is worn quickly.

Therefore, Patent Document 1 discloses the following grindstone. That is, as shown in FIG. 10 (a), the upper surface of the grindstone base portion 91 is cut to form an abrasive grain attaching groove 95, and as shown in FIG. It is arranged as a part (lower mold) of the mold 100, and the grindstone material powder 96 is filled in the groove 95 and fired in the mold 100. Thereby, the abrasive grain part obtained by baking the grindstone material powder 96 and the grindstone base part 91 are integrated. Thereafter, the grindstone surface of the abrasive grain portion is cut (not shown), and further, as shown in FIG. 10C, the grindstone base portion 91 is cut by a cutting tool 97 and finished to obtain a grindstone having a predetermined shape.
In this case, with reference to FIG. 10C, a wall 99 surrounding the abrasive grain portion 92 is formed on the grindstone base portion 91. This wall 99 which is a part of the grindstone unit 91 prevents the abrasive grains of the abrasive grain portion 92 from coming into direct contact with the groove 94 as shown in FIGS. 9B and 9C. 93 early wear can be suppressed. The reason why the wall 99 is thinly formed by the cutting tool 97 is to increase the ratio of the width of the grindstone surface to the entire width of the grindstone. By increasing this ratio, the life of the grindstone can be increased. .

However, in the case of the grindstone described in Patent Document 1, it is necessary to form the groove 95 by cutting the grindstone base 91 as shown in FIG. Further, it is impossible to form a thin portion (for example, 0.2 mm) at the cutting stage. For this reason, as shown in FIG. 10 (c), first, the portion 99 a to be the wall 99 is formed thick, and the portion 99 a that has been thickly formed after firing the abrasive grain portion 92 is removed by the cutting tool 97. The wall 99 is thinned by cutting. That is, according to the conventional technique, in order to form the thin wall 99 in the grindstone base portion 91 on the outer periphery of the side surface of the abrasive grain portion 92, many steps are required, and it is difficult to reduce the cost of the product.

Therefore, an object of the present invention is to provide a grindstone capable of reducing costs while having a structure capable of suppressing early wear on the tool side due to the grindstone, and a method for producing such a grindstone. .

(1) A grindstone of the present invention is a grindstone mounted on a tool of a machine tool, and includes a grindstone base portion, an abrasive grain portion that includes abrasive grains and is integrated with the grindstone base portion, and contacts the workpiece. A covering portion that covers at least a part of the outer periphery of the grain portion and whose outer surface is a mounting surface to be mounted on the tool, wherein the covering portion and the grindstone base portion are integrated by sintering. To do.

According to the present invention, the covering portion covers at least a part of the outer periphery of the abrasive grain portion, and the outer surface of the covering portion serves as a mounting surface to be attached to the tool. In the portion covered with the portion, it is possible to prevent the abrasive grains from directly contacting the tool. For this reason, the early wear of the tool by a grindstone (abrasive part) can be controlled.
Furthermore, since the covering portion and the grindstone base portion are integrated by sintering, as in the prior art, in order to obtain a wall surrounding the outer periphery of the abrasive grain portion, the grindstone mounting groove is previously provided in the grindstone base portion. Is not required to be formed by cutting, and in order to reduce the thickness of the wall, it is not necessary to further cut the grindstone base portion after sintering the abrasive grain portion.
That is, according to the present invention, it is possible to thin the covering portion integrated with the grindstone base portion by sintering, thereby eliminating the need for twice cutting as in the prior art and reducing the cost of the grindstone. It becomes possible.
The grinding wheel base and the abrasive grain part are integrated, and the covering part and the grinding wheel base part are integrated by sintering, but the covering part is directly integrated with the grinding wheel base part (grinding stone In addition to the case where the covering portion is integrated on the outer peripheral side of the base portion, the covering portion includes a case where the covering portion is integrated with the grindstone base portion via the abrasive grain portion.

(2) Further, the covering portion is preferably made of a metal sheet material that is integrated with the grindstone base portion by sintering, and in this case, it is easy to form the covering portion thinly. Moreover, since the mounting surface of the grindstone mounted on the tool is constituted by the outer surface of the metal sheet material, the mounting surface can be a smooth surface.

(3) Moreover, although the material of the said coating | coated part may contain the material different from the said grinding wheel base part and the said abrasive grain part, the said coating | coated part uses the same material as the said grinding wheel base part and the said abrasive grain part. In this case, the bonding strength between the covering portion and the grindstone base portion is increased by sintering.

In addition, although the thickness of the said coating | coated part is good also as a range exceeding 50 micrometers and 200 micrometers or less, it is preferable that the thickness of the said coating | coated part is 20 micrometers or more and 50 micrometers or less. Since the width dimension of the mounting portion (for example, groove) of the tool on which the grindstone is mounted is a specified value, the width dimension of the entire grindstone is limited. For this reason, when the thickness of the covering portion is large (over 50 μm), the width dimension of the abrasive grain portion (grindstone surface) becomes narrow. In this case, the life of the grindstone may be reduced. Therefore, by setting the covering portion to the thickness (50 μm or less), the width of the abrasive grain portion can be secured and the life of the grindstone can be prevented from being reduced. If the thickness is less than 20 μm, the covering portion is too thin and there is a high possibility that abrasive grains contained in the abrasive portion (for example, an average particle size of 50 μm) are exposed through the covering portion. .

(4) Moreover, the grindstone main body composed of the grindstone base portion and the abrasive grain portion has a rod shape that is long in one direction, and the covering portion is formed on one side of the long side surfaces of the grindstone main body. It is preferable that the other surface of the long side surfaces is a surface where the covering portion is not formed and the abrasive grain portion is exposed.
Of the outer periphery of the abrasive grain portion of the grindstone mounted on the tool rotating in one direction, the surface facing the rotation direction of the tool does not come into contact with the tool mounting portion (for example, a groove) with a strong force during processing. For this reason, the surface facing the rotation direction of the tool is aligned with the surface where the abrasive grains are exposed without forming the coating portion, and the surface where the coating portion is formed is aligned with the surface facing away from the rotation direction. Then, you can attach the grindstone to the tool. Thus, the coating part may not be present on a part of the outer periphery of the abrasive grain part, and a part of the coating part can be omitted.

(5) Moreover, the grindstone main body composed of the grindstone base portion and the abrasive grain portion has a bar shape long in one direction, and the covering portions are formed on both side surfaces on the short side of the grindstone main body. Both side surfaces are preferably surfaces where the covering portion is not formed and the abrasive portion is exposed.
If the tool is only reciprocating linear motion, does not move in the rotational direction, and the grindstone is mounted on the tool with the longitudinal direction of the grindstone aligned with the direction of reciprocating linear motion, the tool reciprocates on the outer periphery of the abrasive grain. A surface facing in a direction orthogonal to the direction of linear motion does not contact the tool mounting portion (for example, a groove) with a strong force during processing. For this reason, if the grindstone is attached to the tool by aligning the surface facing the direction perpendicular to the direction of the reciprocating linear motion of the tool (both side surfaces on the long side) with the surface where the coating is not formed and the abrasive grain is exposed, Good. Thus, the coating part may not be present on a part of the outer periphery of the abrasive grain part, and a part of the coating part can be omitted.

(6) Further, the present invention provides a grinding wheel base part, an abrasive grain part that includes abrasive grains and is integrated with the grinding wheel base part, and contacts at least a part of the outer periphery of the abrasive grain part. A method of manufacturing a grindstone including a covering portion to be a mounting surface to be mounted on a tool, wherein the coating material constituting the covering portion is set outside on the inner side of the mold, and the grinding wheel base portion is provided on the inner side. And a preparatory step in which the grindstone material constituting the abrasive grain portion is disposed, and a firing step of firing the coating material and the grindstone material obtained in the preparatory step.
According to this invention, the grindstone as described in said (1) can be manufactured. That is, inside the mold, the coating material and the grindstone material are baked to integrate the coating material with the grindstone platform. The coating material covers the outer periphery (at least a part thereof) of the abrasive grain portion, and the outer surface of the coating material becomes a mounting surface to be mounted on the tool.

(7) Further, the coating material is provided in the groove formed on the inner surface of the mold, and the coating material in the groove is not compressed by the pressing mold inserted into the inner surface of the mold. It is preferable to heat and bake the filled grindstone material while compressing.
In this case, since the coating material is provided in the groove formed on the inner surface of the mold, the filled coating material can be compressed by the pressing die without compressing the coating material in the groove.

(8) Moreover, it is preferable that the said covering material consists of metal sheet | seat raw materials. In this case, it is easy to form the covering portion thinly. And a grindstone base part and the coating | coated part which consists of metal sheet materials can be integrated by baking of the grindstone material which comprises a grindstone base part and an abrasive grain part.
(9) Alternatively, the coating material may be a metal layer obtained by applying a paint or paste containing metal powder to the inner peripheral surface of the mold. In this case, it is easy to form the coating portion thinly, and a metal layer obtained by applying a paint or paste containing metal powder to the inner peripheral surface of the mold can be used as the coating portion.

According to the grindstone of this invention, it can prevent that an abrasive grain contacts a tool directly with a coating | coated part, and can suppress the early wear of the tool by a grindstone. And even if it does not perform the conventional cutting process, a thin coating | coated part is obtained and the cost of a grindstone can be reduced.
According to the method for producing a grindstone of the present invention, the grindstone as described above can be produced.

It is a perspective view which shows one Embodiment of the grindstone of this invention. It is explanatory drawing of the tool which mounted | wore with the grindstone, (a) is a top view, (b) is sectional drawing of a BB arrow. It is an image figure which isolate | separates and demonstrates a grindstone main body and a coating | coated part. It is explanatory drawing of the manufacturing method of a grindstone. It is explanatory drawing of the manufacturing method of a grindstone, and has shown the baking preparation process. It is explanatory drawing of the manufacturing method of a grindstone, and has shown the baking preparation process. It is explanatory drawing of the manufacturing method of a grindstone, and has shown the baking process. It is explanatory drawing of the grindstone of another form. It is explanatory drawing of the conventional grindstone. It is explanatory drawing of the manufacturing method of the conventional grindstone.

[1. About the whetstone)
FIG. 1 is a perspective view showing an embodiment of the grindstone of the present invention. In the present embodiment, the grindstone 1 will be described for honing, but the grindstone of the present invention can be used for other machining.
A honing machine is a machine tool that performs honing. As shown in FIG. 2, the honing machine includes a honing tool 31 (hereinafter referred to as a tool 31) at the tip of the rotation spindle, and the honing tool 31 has a mandrel 32. Then, the grindstone 1 is mounted on the mandrel 32.
A groove 33 is formed in the mandrel 32, and the grindstone 1 is fixed in a state of being fitted in the groove 33. Moreover, the grindstone 1 can be removed from the groove 33 and can be exchanged. In this embodiment, a single grindstone 1 is attached to the tool 31, but a plurality of grindstones 1 may be attached.

The groove 33 opens from the center hole of the mandrel 32 toward the radially outer side. The grindstone 1 is mounted in the groove 33 in a state of protruding outward in the radial direction, and the grindstone surface 7 which is the upper surface (outer surface) of the grindstone 1 contacts a workpiece (not shown) to perform processing. .
Further, as shown in FIG. 2B, an expansion rod 32a is provided inside the mandrel 32. The lower surface (inner surface) of the grindstone 1 has a shape that matches the contact surface of the expansion rod 32a, and these surfaces are inclined surfaces. Therefore, by moving the expansion rod 32a in the axial direction by a grindstone cutting device (not shown) of the honing machine, the grindstone 1 that is in contact with the expansion rod 32a is moved in the radial direction by the wedge action of the surface (inclined surface). Can be moved.

In FIG. 1, the grindstone 1 of the present embodiment has a rod shape that is long in one direction, and the grindstone 1 includes a grindstone body 2 and a covering portion 5. FIG. 3 is an image diagram illustrating the grindstone body 2 and the covering portion 5 separately. In FIG. 3, for ease of explanation, the grindstone main body 2 and the covering portion 5 are virtually separated, but the covering portion 5 is integrated with the grindstone main body 2 by firing. In the actual grindstone 1, it is impossible to separate the grindstone body 2 and the covering portion 5.
As will be described later, the grindstone main body 2 is made of a sintered body obtained by firing a powdered grindstone material in a mold, and is a grindstone base portion (a portion fixed to the tool 31 (the groove 33 of the mandrel 32)). (Base metal layer) 4 and an abrasive grain part (abrasive grain layer) 3 that is integrated with the grinding wheel base part 4 and contacts the workpiece. Although the abrasive grain part 3 contains an abrasive grain, the grindstone base part 4 does not contain an abrasive grain.

The covering portion 5 is a portion that is integrated with the grindstone main body 2 (the grindstone base portion 4) when the grindstone main body 2 is sintered, and covers the outer periphery of the side surface of the grindstone main body 2. Further, as shown in FIG. 2B, the outer peripheral surface 6 of the covering portion 5 becomes a mounting surface (a part of the mounting surface) that comes into contact with (is mounted on) the groove 33 of the tool 31.
And in this embodiment, the coating | coated part 5 has covered the side surface outer periphery of the grindstone main body 2 over the perimeter substantially. That is, the covering portion 5 covers the entire side surface of the grindstone platform 4 and the entire side surface except the upper portion of the abrasive grain portion 3. In addition, the coating | coated part 5 should just cover at least one part of the side surface outer periphery of the abrasive grain part 3, and the form in the case of covering a part is demonstrated later (refer FIG. 8 (a) (b)).
In addition, after completion of the grindstone 1, the abrasive grains present on the side surfaces of the abrasive grain part 3 partially penetrate into the inner peripheral side of the covering part 5, but this covering part 5 is being manufactured (before sintering). Then, it is a part which does not contain an abrasive grain.

The abrasive grain portion 3 is formed by bonding minute abrasive grains with a binding material. As an abrasive grain, common things, such as WA (white alumina type | system | group) and GC (green silicon carbide type), or superabrasive grains, such as a diamond and CBN, are used, and can be changed according to the objective. Further, as the bonding material, a sintered metal material such as a metal bond, a vitrified bond, or a resinoid bond is used, and can be changed according to the purpose. In the present embodiment, a metal bond containing a copper alloy powder is used as the bonding material.

The grindstone unit 4 is made of a sintered metal material such as a metal bond, a vitrified bond, or a resinoid bond as a main material, and preferably includes the same material as that of the abrasive grain unit 3. That is, the grindstone base part 4 contains the bonding material of the abrasive grain part 3 as a main material, and in this embodiment, a metal bond containing a copper alloy powder is used.
Since the grindstone base part 4 is also made of a sintered metal material, the abrasive grain part 3 and the grindstone base part 4 are integrally joined by a sintering action during firing of the grindstone main body 2, and the abrasive grain part 3 and the grindstone base part 4. And the strength increases. In particular, the grindstone base portion 4 includes a sintered metal material equivalent in strength and linear expansion coefficient to the bonding material of the abrasive grain portion 3, thereby homogenizing the strength of the grindstone body 2 as a whole, and the grindstone. The distortion in the whole main body 2 can be suppressed small.

The covering portion 5 is made of a metal sheet material (metal foil), and the covering portion 5 is integrated with the grindstone body 2 (the grindstone base portion 4 and the abrasive grain portion 3) by sintering. The thickness of the sheet material is the thickness of the covering portion 5. Considering the durability of the manufactured grindstone 1, the width of the grindstone body 2 is preferably as large as possible in the entire width of the grindstone 1, so that the sheet material is preferably thin. For example, the thickness of the sheet material The thickness is preferably 20 μm or more and 50 μm or less.

Moreover, it is preferable that the coating | coated part 5 contains the same material as the grindstone base part 4 and the abrasive grain part 3. FIG. That is, in this embodiment, since the grindstone base portion 4 and the abrasive grain portion 3 are made of copper alloy powder, the covering portion 5 is made of a sheet material (copper alloy foil) containing a copper alloy that is the same material. Is preferred. Thereby, joining with the coating | coated part 5 and the grindstone main body 2 is made | formed by the sintering action at the time of baking of the grindstone main body 2, the joining strength of the coating | coated part 5 and the grindstone base part 4, and the coating | coated part 5 and an abrasive grain part. The bonding strength with 3 is increased. In particular, the covering portion 5 includes the bonding material of the grindstone main body 2 and a sintered metal material that is equivalent in strength and linear expansion coefficient, thereby homogenizing the strength of the grindstone 1 as a whole and straining the grindstone 1 as a whole. It can be kept small.
In addition, the coating | coated part 5 should just consist of a material which bears a certain amount of abrasion, and may contain the material different from the grindstone base part 4 and the abrasive grain part 3. FIG. For example, the coating | coated part 5 may contain another metal other than pure aluminum or an aluminum alloy. Examples of combinations of materials of the abrasive grain part 3, the grinding wheel base part 4 and the covering part 5 include the abrasive grain part 3 (copper alloy), the grinding wheel base part 4 (copper alloy), and the covering part 5 (pure aluminum or aluminum alloy). There are combinations.

With the above configuration, the grindstone main body 2 is embedded and integrated in the covering portion 5, the upper surface of the abrasive grain portion 3 of the grindstone main body 2 is exposed, and the upper surface becomes the grindstone surface 7. And the outer periphery of the side surface of the abrasive grain part 3 and the grindstone base part 4 is covered with the covering part 5. Further, as shown in FIG. 1, the grindstone surface 7 is in a state of protruding from the upper surface 5 a of the covering portion 5 by a predetermined height h.

As shown in FIG. 2A, the outer peripheral contour shape of the grindstone 1 in plan view is a shape that matches the inner peripheral contour shape of the groove 33 of the mandrel 32 in plan view.
As shown in FIG. 2B, the inner surface of the groove 33 is present at the same radial position as the abrasive grain portion 3 of the grindstone 1 with the grindstone 1 mounted in the groove 33. In this state, when the tool 31 is rotated in the rotation direction R, if the covering portion 5 is not present, the abrasive grain portion 3 is directly applied to the surface 33a of the inner surface of the groove 33 in the rotation direction R. It will come into contact. However, in this invention, since the coating | coated part 5 has covered this abrasive grain part 3, the abrasive grain of the abrasive grain part 3 does not contact the said surface 33a directly. That is, the covering portion 5 can function as a protective wall for the groove 33. For this reason, although the mandrel 32 consists of steel (for example, hardening steel), it can suppress that the groove | channel 33 of the mandrel 32 is worn by the abrasive grain part 3 of the grindstone 1.

And the thickness of the coating | coated part 5 is 20 micrometers or more and it is preferable that it is 50 micrometers or less. This is because the width dimension of the groove 33 is a specified value, and the width dimension of the entire grindstone 1 is limited. That is, when the thickness of the covering portion 5 is large (exceeding 50 μm), the width dimension of the abrasive grain portion 3 (the grindstone surface 7) becomes narrow. In this case, the life of the grindstone 1 is reduced. However, by setting the covering portion 5 to be thin (50 μm or less), the width of the abrasive grain portion 3 (the grinding wheel surface 7) can be secured, and the life of the grinding stone 1 can be prevented from being reduced. In addition, when the lifetime of the coating | coated part 5 is likely to become shorter than the lifetime of the abrasive grain part 3, it is good also considering the thickness of the coating | coated part 5 as more than 50 micrometers (200 micrometers or less).
And if the thickness of the coating | coated part 5 shall be less than 20 micrometers, the coating | coated part 5 is too thin and a part of abrasive grain (for example, particle diameter of an average of 50 micrometers) is contained in the abrasive | grain part 3. The possibility of being exposed through is increased.

According to the grindstone 1 having the above configuration, the covering portion 5 covers the outer peripheral surfaces of the abrasive grain portion 3 and the grindstone base portion 4, and the outer peripheral surface 6 of the covering portion 5 contacts the groove 33 of the mandrel 32. It becomes the mounting surface. For this reason, it can prevent that an abrasive grain contacts the groove | channel 33 directly in the part covered with the coating | coated part 5 among the abrasive grain parts 3 containing an abrasive grain. Therefore, early wear of the mandrel 32 by the abrasive grain portion 3 can be suppressed.

[2. About the manufacturing method of the grindstone)
The manufacturing method of the said grindstone 1 is demonstrated with reference to FIGS.
As shown in FIG. 4, a belt-shaped metal sheet material (metal foil) 10 is formed into an oval annular shape, and as shown in FIG. 5, the sheet material 10 extends along the inner peripheral surface 21 of the mold 20. Provide. Then, as shown in FIG. 5 and FIG. 6, in this mold 20, the sheet material 10 is set as the outside, and the powdered grinding stone material 11 (12, 13) constituting the grinding wheel body 2 is filled inside and fired. To do.
In addition, the sheet | seat raw material 10 can be cut out from the roll by which the metal strip | belt was wound, for example. That is, in accordance with the dimension of the outer periphery of the side surface of the grindstone main body 2, a metal strip is cut into a predetermined length, which is used as a sheet material 10, and this sheet material 10 is formed into an oval ring.

As shown in FIG. 7, the mold 20 includes an annular mold body 22, and a lower mold 23 and an upper mold 24 as push molds, and the sheet material 10 and the powder in a space surrounded by these molds. The grindstone material 11 is disposed, and the grindstone 1 is fired.
The sheet material 10 is provided along the inner peripheral surface 21 of the annular mold body 22. In particular, as shown in FIG. 5, a shallow groove 25 is formed in the inner peripheral surface 21 of the mold body 22. An annular shape is formed along the peripheral surface 21, and the sheet material 10 is provided along the groove 25. That is, the sheet material 10 is in a state of being fitted in the groove 25.

Since the depth of the groove 25 is set to the same thickness as the sheet material 10, the inner peripheral surface 21 of the mold main body 22 with the sheet material 10 positioned in the groove 25 as shown in FIG. 5. And the inner peripheral surface 10a of the sheet material 10 constitute the same smooth annular inner peripheral surface.
For this reason, the lower mold 23 having the same contour shape as the inner peripheral surface 21 of the mold main body 22 is fitted to the inner peripheral surface 21 of the mold main body 22, and a part (lower part) of the sheet material 10 is It will be in the state externally fitted to a part (upper outer peripheral surface 23b) of the mold 23. That is, the upper part of the lower mold 23 is in a state in which the lower part of the sheet material 10 is sandwiched between the mold main body 22 and the sheet material 10 can be restrained.

Then, as described above, the sheet material 10 is set as the outside, and the powdered whetstone material 11 constituting the whetstone body 2 is filled therein. Specifically, as shown in FIG. 5, the grindstone material 12 constituting the grindstone base 4 is filled with the upper surface 23 a of the lower mold 23 as the bottom surface. As described above, the grindstone material 12 can be various sintered metal materials constituting the grindstone base portion 4, but in the present embodiment, powder of a copper alloy is mainly included. And this grindstone material 12 is provided so that it may become flat, and the grindstone material 12 is temporarily pressed using a push die (or upper mold | type 24) depending on the case.

After that, as shown in FIG. 6, a powdered grindstone material 13 constituting the abrasive grain portion 3 is filled on the flat grindstone material 12. As described above, the grindstone material 13 can be various materials constituting the abrasive grain portion 3. In the present embodiment, the grindstone material 13 includes fine abrasive grains and a powder of a binding material. In the present embodiment, As the powder, a copper alloy powder is mainly contained. And this grindstone material 13 is provided so that it may become flat, and the grindstone material 13 is temporarily pressed using a pressing die (or upper mold | type 24) depending on the case.
The above is the preparatory process, and in this preparatory process, the sheet material (coating material) 10 constituting the covering part 5 is set outside on the inside of the mold 20, and the grindstone base part 4 and the abrasive grain part 3 are set inside thereof. It is set as the state which has arrange | positioned the

grindstone materials

12 and 13 to comprise.

Then, as shown in FIG. 7, the grindstone material 11 (12, 13) is heated by the lower mold 23 and the upper mold 24 in the vertical direction with a heater or the like outside the figure while being pressed, and the grindstone material 11 is fired. To do. That is, this step is a firing step for firing the sheet material (coating material) 10 and the grindstone material 11 obtained in the preparation step.
By this firing step, the grindstone main body 2 is formed as a sintered body by the grindstone material 11 in the mold 20, and the sheet material 10 is integrated with the grindstone main body 2 by the sintering of the grindstone main body 2. 10 becomes the coating | coated part 5 which covers the side surface outer periphery of the grindstone main body 2. As shown in FIG.
In addition, in FIG. 7, the part which protrudes from the lower surface of the grindstone main body 2 among the parts which were the sheet | seat raw material 10 is cut out after mold removal. Further, as shown by a two-dot chain line in FIG. 7, in order to make the bottom surface (lower surface) side of the grindstone 1 into a predetermined shape (inclined surface), the lower part of the grindstone 1 that has been demolded after firing is machined. It may be excised.

According to the above manufacturing method, the grindstone 1 shown in FIG. 1 can be manufactured.
Since the sheet material 10 is positioned in the groove 25 of the mold body 22, the sheet material in the groove 25 is inserted by the lower mold 23 and the upper mold 24 inserted along the inner peripheral surface 21 of the mold body 22. Without compressing 10 from both sides in the vertical direction, only the powdered grinding wheel material 11 filled inside the sheet material 10 can be compressed from both sides in the vertical direction, heated and fired.

Furthermore, in this embodiment, since the coating material which finally becomes the coating portion 5 is made of the metal sheet material 10, it is easy to form the coating portion 5 thin by adopting the thin sheet material 10. Become.
Further, since the outer periphery of the side surface of the grindstone 1 becomes a mounting surface of the grindstone 1 to be mounted in the groove 33 of the mandrel 32, it is preferable to make it a smooth surface. Therefore, as in the present embodiment, the covering portion 5 is formed by the sheet material 10 having a smooth surface, and the outer periphery of the side surface of the grindstone 1 is molded by the groove 25 having the smooth surface. The outer periphery can be made a smooth surface without machining.

In the said embodiment, as shown in FIG. 5, although the coating material provided along the inner peripheral surface 21 of the metal mold | die 20 was made into the sheet raw material 10, the other manufacturing method for manufacturing the grindstone 1 of FIG. The coating material may be a paint or paste containing metal powder. That is, a metal layer obtained by applying a paint or paste containing metal powder to the inner peripheral surface 21 of the mold body 22 may be used as the coating material.
In this case, it is preferable that the metal powder contains the same material (for example, copper alloy powder) as the grindstone base part 4 and the abrasive grain part 3, as in the embodiment. The metal layer may be provided in the groove 25 formed in the inner peripheral surface 21 of the mold body 22 (first half of the preparation process).
Then, the latter half of the preparation step (FIGS. 5 and 6) and the firing step (FIG. 7) for firing are the same as in the above embodiment.
In this case, the coating portion 5 of the grindstone 1 in FIG. 1 can be formed by a metal layer obtained by applying a paint or paste containing metal powder to the inner peripheral surface of the mold 20.

In the grindstone 1 manufactured by the manufacturing method according to each of the above embodiments, the covering portion 5 becomes a portion integrated with the grindstone main body 2 by sintering the grindstone main body 2 made of a sintered body. Therefore, as in the conventional case shown in FIG. 10C, in order to obtain the wall 99 surrounding the outer periphery of the abrasive grain portion 92, the abrasive grain portion mounting groove 95 (see FIG. 10A) is previously formed in the grindstone base portion 91. ) By cutting, and in order to make the wall 99 thinner, the grinding wheel base 91 is further moved by the cutting tool 97 (see FIG. 10C) after the sintering of the abrasive grain 92. There is no need to cut.
That is, according to the present invention, the covering portion 5 is integrated simultaneously with the sintering of the grindstone body 2, and the covering portion 5 is installed on the inner peripheral surface 21 of the mold 20, for example, a metal sheet material 10. By doing, the coating | coated part 5 can be formed thinly. For this reason, the conventional two-time cutting process is unnecessary, and the cost of the grindstone 1 can be reduced.

Moreover, since the coating | coated part 5 is integrated by sintering of the grindstone main body 2 which has the abrasive grain part 3 and the grindstone base part 4, the intensity | strength as the grindstone 1 whole becomes high, and the grindstone 1 is made long-life. And
And in the said manufacturing method, using the sheet | seat raw material 10 as an outer peripheral member, the grindstone material 11 of a powder is baked inside this sheet | seat raw material 10, and the abrasive grain part 3, the grindstone base part 4, and the coating | coated part 5 are integrated. . That is, the grindstone 1 in which the abrasive grain part 3, the grindstone base part 4, and the covering part 5 are integrated can be obtained by one firing.

[3. About other types of grinding wheels)
In the above embodiment, as described with reference to FIGS. 1 and 3, the outer periphery of the side surface of the grindstone main body 2 is almost entirely covered with the covering portion 5, but depending on the use of the grindstone 1, the grindstone main body 2. A part of the outer periphery of the side surface may be covered.
For example, when the tool of the machine tool (honing machine) only reciprocates linearly in the longitudinal direction of the grindstone main body 2 and does not rotate, as shown in FIG. The coating | coated part 5 may be provided only in the both sides of the direction. Note that the directions of arrows X and Y in FIG.

That is, the covering portions 5 are formed on both side surfaces on the short side of the grindstone main body 2, and the both side surfaces 15 on the long side are surfaces where the covering portion 5 is not formed and the abrasive grains 3 are exposed. Both side surfaces 15 on the long side are surfaces facing the direction orthogonal to the operation direction (arrow X, Y direction) of the tool on the outer periphery of the side surface of the grindstone main body 2, and are not provided with the covering portion 5 and are abrasive grain portions. 3 is an exposed surface.
In this case, of the outer periphery of the side surface of the grindstone body 2, the side surface 15 that faces in the direction orthogonal to the operation direction of the tool does not contact the groove of the tool with a strong force during processing (for example, honing processing). May not be present, and a part of the covering portion 5 can be omitted.

In another embodiment, for example, a tool of a machine tool (honing machine) reciprocates linearly in the longitudinal direction (long direction) of the grindstone body 2 and rotates in the short direction. However, when the rotation is in one direction, as shown in FIG. 8B, the covering portions 5 may be provided only on both sides in the longitudinal direction of the grindstone body 2 and on one side in the short direction. . In addition, the arrow X, Y direction of FIG.8 (b) is the direction of the reciprocation of a tool, and the arrow R direction is a rotation direction.

That is, the covering portion 5 is formed on one of the long side surfaces of the grindstone body 2, and the other surface 17 of the long side surfaces of the grindstone body 2 is the covering portion 5. It is the surface where the abrasive grains 3 are not formed. The surface 17 on the other side where the covering portion 5 is not formed is a surface facing the rotation direction of the tool in the outer periphery of the side surface of the grindstone main body 2, and is a surface on which the abrasive grain portion 3 is exposed without the covering portion 5. It is.
In this case, the surface 17 of the grindstone body 2 that faces the rotation direction of the tool does not come into contact with the groove of the tool with a strong force during machining (for example, honing), and therefore the covering portion 5 is present. There is no need, and a part of the covering portion 5 can be omitted.

[4. About the whetstone disclosed for reference)
In the embodiment (FIG. 5), the case where the coating material to be the coating portion 5 is the sheet material 10 has been described. That is, the member to be the covering portion 5 is the sheet material 10 that is a structure having a three-dimensional shape before being attached to the mold 20. In addition to this, the grindstone disclosed as a reference (reference invention) is formed by molding the grindstone body 2 having the abrasive grain portion 3 and the grindstone base portion 4 as a sintered body using a mold, and then covering the outer peripheral surface thereof. A part 5 is provided.

That is, the grindstone 1 provided with such a covering portion 5 will be described with reference to FIG. 1, as in the above-described embodiment, the grindstone base portion 4 that does not include abrasive grains that become parts fixed to the tool, and the abrasive grains. A grindstone main body 2 made of a sintered body having an abrasive grain portion 3 that is integrated with the grindstone base portion 4 and comes into contact with the workpiece, and an outer circumferential surface that covers at least a part of the outer circumference of the abrasive grain portion 3 is the tool. And a coating portion 5 that does not include abrasive grains that serve as a mounting surface. And in this reference invention, the said coating | coated part 5 consists of a film body by which film | membrane formation was carried out with respect to at least one part of the outer periphery of the abrasive grain part 3. FIG.

Examples of the film body include a coating film and a metal film formed by surface treatment such as plating or vapor deposition. In this case, the grindstone body 2 having the abrasive grain portion 3 and the grindstone base portion 4 is molded as a sintered body using a mold 20 similar to that shown in FIG. The said film | membrane is formed in the side surface outer periphery of the grindstone main body 2 which consists of a knot.
Even in the case of this grindstone, the covering portion 5 covers at least a part of the outer periphery of the grindstone main body 2, and the outer peripheral surface of the covering portion 5 becomes a mounting surface to be attached to the tool, as in the above embodiment. In the portion of the abrasive grain portion 3 including the abrasive grains that is covered with the covering portion 5, the abrasive grains can be prevented from coming into direct contact with the tool. For this reason, the early wear of the tool by the abrasive grain part 3 can be suppressed.
Furthermore, the coating part 5 formed as a film can be made thin, so that the conventional two-time cutting process is unnecessary, and the cost of the grindstone can be reduced. The above is the reference invention.

Further, the grindstone of the present invention is not limited to the illustrated form, but may be of other forms within the scope of the present invention. For example, in the above-described embodiment, the grindstone is described as a honing grindstone. However, the grindstone is not limited to this, and may be a grindstone for other purposes. Moreover, the whole shape of the grindstone 1 may be other. Furthermore, although the case where the tool (mandrel 32) is mounted with a single grindstone 1 has been described, a plurality of grindstones 1 may be mounted. Moreover, although the heating means at the time of baking the grindstone material 11 which comprises the grindstone main body 2 was demonstrated in the case of a heater, it may be based on another mechanism.

1: Whetstone, 2: Whetstone main body, 3: Abrasive part, 4: Whetstone base part, 5: Covering part, 6: Outer peripheral surface (outer surface) of covering part, 10: Sheet material, 11: Whetstone material, 12: Whetstone Materials: 13: Grinding stone material, 20: Mold, 22: Mold body, 23: Lower mold (push mold), 24: Upper mold (push mold), 25: Groove, 31: Honing tool (tool)

Claims

A grindstone mounted on a tool of a machine tool,
A grinding wheel base part, an abrasive grain part that includes abrasive grains and that is integrated with the grinding wheel base part and contacts the workpiece, and an outer surface that covers at least a part of the outer periphery of the abrasive grain part is a mounting surface that is attached to the tool. A covering portion;
The grindstone, wherein the covering portion and the grindstone base portion are integrated by sintering.
The grindstone according to claim 1, wherein the covering portion is made of a metal sheet material integrated with the grindstone base portion by sintering.
The grindstone according to claim 1 or 2, wherein the covering portion includes the same material as the grindstone base portion and the abrasive grain portion.
The grindstone main body composed of the grindstone base and the abrasive grain is a rod-like shape that is long in one direction,
The covering portion is formed on one of the long side surfaces of the grindstone body, and the other surface of the long side surfaces is not formed with the covering portion. The grindstone according to any one of claims 1 to 3, wherein the abrasive grain portion is an exposed surface.
The grindstone main body composed of the grindstone base and the abrasive grain is a rod-like shape that is long in one direction,
The covering portion is formed on both side surfaces on the short side of the grindstone body, and both side surfaces on the long side are surfaces where the covering portion is not formed and the abrasive grain portion is exposed. The grindstone according to claim 1.
A grinding wheel base part, an abrasive grain part that includes abrasive grains and that is integrated with the grinding wheel base part and contacts the workpiece, and an outer surface that covers at least a part of the outer periphery of the abrasive grain part is a mounting surface that is attached to the tool. A method of manufacturing a grindstone comprising a covering portion,
Inside the mold, the coating material constituting the coating part is the outside, a preparation step in which the grinding stone material constituting the grinding wheel base part and the abrasive grain part is arranged inside thereof,
And a firing step of firing the coating material and the grindstone material obtained in the preparation step.
Providing the coating material in the groove formed on the inner surface of the mold,
The method for manufacturing a grindstone according to claim 6, wherein the filled grindstone material is heated and fired while being compressed without compressing the coating material in the groove by a pressing die inserted into the inner surface of the mold. .
The method for manufacturing a grindstone according to claim 6 or 7, wherein the coating material is made of a metal sheet material.
The method for manufacturing a grindstone according to claim 6 or 7, wherein the coating material is a metal layer obtained by applying a paint or paste containing metal powder to the inner peripheral surface of the mold.