JP2000334665A - Grinding wheel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent an inner peripheral surface of an end face of a grinding wheel from being worn due to prostration of the workpiece, by guiding a workpiece along an end surface of an inner guide which is smoothly continued from a grinding surface and which does not produce a grinding force. SOLUTION: A grinding wheel 2 is composed of a cylindrical body 21 which contains abrasive, and an inner guide 22 which is fixed to the inner periphery of the body 21 and which does not contain abrasive. The inner guide 22 is adapted to guide a workpiece along a bore part of an end face 2a of the grinding wheel 2 without producing grinding force so as to prevent abrasion in the bore part. The end face 22a of the inner guide 22 has a concave curved surface continuous to the grinding surface 21a of the body 21 so as to smoothly guide the workpiece. Further, an outer guide 23 which does not contain abrasive, is secured to the outer periphery of the body 21 so that an end surface 23a of the outer guide 23 and the grinding surface 21a define together a continuous concave curved surface. The end surface 23a smoothly guides the workpiece between the grinding surface 21a and the workpiece guide so as to prevent the end face 2a from chipping. Further, both inner guide and outer guide have a hardness which is approximately equal to that of the body so that the dressing interval can be prolonged, thereby it is possible to aim at prolonging the service life of the grinding wheel.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a grinding wheel.
For example, the present invention relates to a grinding wheel having a concave-polished polishing surface on an end surface and used for polishing the end surface of a tapered roller for a tapered roller bearing.

[0002]

2. Description of the Related Art The above-mentioned grinding wheel is formed in a cylindrical shape,
The end surface has a polished surface. This polished surface is formed in a predetermined concave curved surface shape, and has a shape corresponding to the shape of the large end surface of the tapered roller, for example, a convex curved surface shape. The large end face of the work formed in the shape of a truncated cone of a tapered roller is pressed against the polishing surface and polished. At this time, the grinding wheel rotates,
At the same time, the work is sent along a feed track 90 as shown in FIG. This feed track 9
Reference numeral 0 denotes an arc shape curved in the direction perpendicular to the paper surface of FIG. 4, and the feed track 90 has a pair of work guides for introducing a work to a polishing surface of a grinding wheel 91 and for leading the work from the polishing surface. 92 are provided. The feed track 90 enters the outer peripheral portion of the polishing surface from one work guide 92, crosses the polishing surface from the outer peripheral portion to the outer peripheral portion through the inner peripheral portion, and reaches the other work guide 92. The work is pressed against the polishing surface and each work guide 92 in the feed track 90. In order to smoothly transfer the work between each work guide and the polishing surface, each work guide should be positioned as close as possible to the peripheral surface of the grinding wheel 91 which rotates.
It is preferable to position and fix it with high precision.

[0003]

However, it is difficult to position and fix the work guide with such high precision, and if the positioning precision is poor, the work may be placed on the outer periphery of the work guide and the polishing surface. In some cases, the polished surface may be chipped at the boundary portion between the polished surface and the polished surface. For this reason, the life of the grinding wheel has been shortened.

Further, since the inner peripheral edge of the polished surface is more likely to be worn than the remaining portion, in order to maintain the shape accuracy of the polished surface, the remaining portion is adjusted in accordance with the inner peripheral edge where wear progresses fastest. As a result, the life of the grinding wheel was shortened. The inner peripheral edge of the polished surface is easily worn out because the cut amount for the work is reduced at the outer peripheral edge of the polished surface to prevent the above-described chipping, whereas the inner peripheral edge of the polished surface (FIG. This is because it tends to be relatively large at the position of the work W7 of No. 4).

Further, at the inner peripheral edge of the polishing surface, a force applied to the work from the polishing surface (hereinafter referred to as "polishing force") acts strongly in a direction that promotes the falling of the work (tangential direction of the feed track). . As a result, when the work is inclined from the normal state, the inner peripheral edge of the polishing surface is strongly pressed, causing a great amount of wear. Therefore, an object of the present invention is to solve the above-mentioned technical problems and to provide a grinding wheel capable of extending the life.

[0006]

In order to achieve this object, a grinding wheel according to claim 1 is fixed to a cylindrical grinding wheel main body, an inner peripheral surface of the grinding wheel main body, and an abrasive material. And a cylindrical inner guide that does not include a grinding wheel, a grinding surface that forms a concave curved surface is formed on one end surface of the grinding wheel main body, and the end surface of the inner guide forms a concave curved surface that is continuous with the concave curved surface of the grinding surface. It is characterized in that at least a part of the polishing surface is guided.

According to this configuration, since the inner peripheral portion of the grinding wheel is constituted by the inner guide containing no abrasive, the grinding force does not act on the inner peripheral portion of the end surface of the grinding wheel, so that the work can be prevented from falling down. In addition, it is possible to prevent an increase in wear caused by the fall. In addition, the inner guide receives the surface to be polished of the work with a concave curved surface that is continuous with the polishing surface, so that the work can smoothly transition at the boundary between the polishing surface and the end surface of the inner guide, and also prevent the work from falling down from this point it can.

[0008] A grinding wheel according to a second aspect of the present invention is the grinding wheel according to the first aspect, wherein the inner guide is mainly composed of a resin-based material and has a hardness similar to that of the grinding wheel main body. . According to this configuration, since the inner guide and the end face of the grinding wheel body are surely and uniformly worn, when dressing the end face of the grinding wheel, the entire end face of the grinding wheel can be uniformly dressed with a single dressing blade. Easy to work with.

[0009] Here, the main component of the resin material is:
This is intended to include a case where the inner guide is formed only of a resin-based material. The resin-based material may be any material containing a resin. For example, the resin-based material may be a single resin material, or may be a resin material and an inorganic or organic filler having no abrasive power. In addition, examples of the material of the inner guide include, but are not limited to, an epoxy-based resin alone or a mixture of an epoxy-based resin and cryolite.

[0010] The hardness of the inner guide is, on the Rockwell hardness scale L scale, ± of the hardness of the grinding wheel body.
Hardness within 20 is required. The hardness of the grinding wheel main body is changed within the range of Rockwell hardness meter L scale 50 to 120 in accordance with the type of work and the required quality after polishing. It is necessary to adjust the hardness of the inner guide to within ± 20 with respect to the hardness of the grinding wheel body.

According to a third aspect of the present invention, there is provided a grinding wheel including a cylindrical grinding wheel main body, and a cylindrical outer guide fixed to an outer peripheral surface of the grinding wheel main body and containing no abrasive. A polishing surface forming a concave curved surface is formed on one end surface of the outer guide, and the end surface of the outer guide forms a concave curved surface continuous with the concave curved surface of the polishing surface, and guides the polished surface of the work to the polishing surface. It is.

According to this configuration, when the work is transferred from the position close to the outer periphery of the grinding wheel to the polishing surface, the work is transferred to the polishing surface via the end surface of the outer guide that does not exert a polishing force. Can be migrated to. The same applies when the work moves from the polished surface to the above-described position. As described above, since the work at the time of transition does not rattle, chipping does not occur on the outer peripheral portion of the grinding wheel.

A grinding wheel according to a fourth aspect of the present invention is the grinding wheel according to the third aspect, wherein the outer guide is mainly composed of a resin material and has a hardness similar to that of the grinding wheel main body. . According to this configuration, since the outer guide and the end face of the grinding wheel main body are surely and uniformly worn, when dressing the end face of the grinding wheel, the entire end face of the grinding wheel can be uniformly dressed with a single dressing blade. Easy to work with.

Here, the material and hardness of the outer guide include:
The material and hardness of the inner guide described in the operation of claim 2 can be used.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a grinding wheel according to an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a sectional view of a grinding wheel according to an embodiment of the present invention. The grinding wheel 2 has a cylindrical shape, and one end surface 2a is formed as a concave curved surface that is rotationally symmetric about the central axis 2b. Further, the other end surface of the grinding wheel 2 is formed in a flat shape, and a disk-shaped mounting member 3 for driving the grinding wheel 2 to rotate around the center axis 2b is fixed thereto.

The grinding wheel 2 includes a cylindrical grinding wheel main body 21 containing an abrasive, a cylindrical inner guide 22 fixed to the inner peripheral surface 21b of the grinding wheel main body 21 and containing no abrasive.
A cylindrical outer guide 23 fixed to the outer peripheral surface 21c of the grinding wheel main body 21 and containing no abrasive is provided. The end surface 2a of the grinding wheel 2 includes an end surface 22a of the inner guide 22, a polishing surface 21a of the grinding wheel main body 21, and an end surface 23 of the outer guide 23.
a are arranged from the inside in the radial direction to the outside. Each of the surfaces 21a, 22a, and 23a is formed as a concave curved surface, and each concave curved surface is continuous with a concave curved surface adjacent to each other and forms one large concave curved surface as a whole.

The concave curved surface is, for example, a spherical surface, and the center of the spherical surface is arranged on the center axis 2 b of the grinding wheel 2. The concave curved surface has a shape corresponding to the convex curved shape of the large end surface of the tapered roller as the work. The grinding wheel body 21
It contains abrasive grains as an abrasive and a binder holding the abrasive grains. The abrasive is, for example, alumina-based abrasive grains, and the binder may be a thermosetting resin, a vitreous material, or the like.

The inner guide 22 and the outer guide 23 are made of the same resin material. This resin material is mainly composed of an epoxy resin, has a Rockwell hardness similar to that of the grinding wheel main body 21, and has the same degree of wear resistance. For example, when dressing a single dressing blade uniformly along the entire end surface of the grinding wheel 2, the grinding wheel main body 21, the inner guide 22, and the outer guide 23 are uniformly worn and a step is formed on the dressed surface. When the workpiece is fed along the end surface 2a of the grinding wheel 2, the grinding wheel main body 21, the inner guide 22, and the outer guide 23 are uniformly worn during polishing. Each side 21a, 2
No step is formed at the boundary between 2a and 23a.

Next, a polishing apparatus 1 using the main grinding wheel 2
Will be described with reference to a schematic diagram showing a schematic configuration of FIG.
The polishing device 1 is for polishing a large end surface of a tapered roller for a tapered roller bearing into a convex curved surface having a spherical surface, and processes a substantially frustoconical work. The polishing apparatus 1 includes the above-described grinding wheel 2 that is rotationally driven by a first driving unit 11 around a center axis 2b, and a rotation axis 1 that intersects the center axis 2b.
And a holder 13 that holds the plurality of works W by being rotationally driven by the second drive means 12 around the portion 2a.

The holder 13 includes a pair of disks 14 and 15 that rotate about the rotation axis 12a. These disks 14 and 15 are disc-shaped main parts 14d and 15d.
And shaft portions 14a, 15a extending along the rotation axis 12a from the central portions of the main portions 14d, 15d and drivingly connected to the second driving means 12, and being close to each other at the outer peripheral edges of the main portions 14d, 15d. And the annular projections 14b, 15b projecting in opposite directions. Opposite end faces of the annular protrusions 14b and 15b are
c, 15c, and a plurality of works W made of tapered rollers are held between the holding surfaces 14c, 15c. The holding surfaces 14c and 15c are formed of conical tapered surfaces that are inclined in opposite directions to each other, and come into contact with the peripheral surface of the work W that is formed of a conical surface.

The center axis WC of the plurality of works W held between the holding surfaces 14c, 15c is radially centered on an intersection P between the plane A and the rotation axis 12a in a plane A orthogonal to the rotation axis 12a. It is arranged in. In addition, the plurality of workpieces W are, for example, regulated in a circumferential interval on an arc in the plane A centered on the intersection P by the retainer 16 having an axis passing through the center hole thereof. It is held evenly around the circumference. The large end surface of the work W is directed radially outward of the disks 14 and 15 and is arranged at a predetermined radial position. A circle passing through the radial position and included in the plane A with the intersection P as the center is made to pass substantially along the end surface 2a of the grinding wheel 2, in particular, through the inner peripheral edge of the end surface 22 a. Center axis 2b
Intersects the intersection P.

The second driving means 12 is provided as a pair and drives the pair of disks 14 and 15 respectively. A pair of disks 1
The workpieces 4 and 15 hold the plurality of works W in a freely rotatable manner around the center axis WC of the work W, and rotate the plurality of works W by the peripheral speed difference between the holding surfaces 14c and 15c caused by the relative rotation. I try to make it. Further, the above-described peripheral speed difference is set so that the work W revolves around the rotation axis 12a.

Each work W is sent on a circular feed trajectory 18 consisting of the orbit of the work. As shown in FIG. 3, the work is applied to the end surface 2 a of the grinding wheel 2 in order to polish a large end surface of the work in a part of a feed track 18 (in FIG. 3, curved in a direction perpendicular to the paper surface). Sent along the track 1
The remaining area 8 is guided by the work guide 17. The work guide 17 has an annular shape in which a part of the work W is cut away, and its inner peripheral surface is arranged close to the outer peripheral portion of the holding body 13, and the large end surface of the work W extends along the inner peripheral surface. .

The pair of disks 14 and 15 are urged by urging means 19 to approach each other, and
The large end surface of the work is pressed against the end surface 2a of the grinding wheel 2 and the work guide 17 by the tapered surfaces c and 15c. In the polishing apparatus 1, when the grinding wheel 2 is rotated, the grinding wheel main body 21, the inner guide 22, and the outer guide 23 rotate integrally. The work is sent on the feed track 18 while rotating. In the meantime, the work can be pressed against the end face 2a of the grinding wheel 2 and a convex curved surface shape can be formed on the work by the polishing surface 21a.

This will be described in detail. The work enters the outer peripheral portion of the end surface 23a of the outer guide 23 from a part 17a of the work guide 17, and the end surface 23a of the outer guide 23 changes the surface to be polished of the work from the work guide 17 to the inner peripheral portion.
Guide to 1a. During this time, the work is supported by the end surface 23a of the inner guide 23, but is not polished. The work is polished by the polishing surface 21a of the grinding wheel main body 21.

Then, the end surface 22a of the inner guide 22 moves the polished surface of the work to one position (work W2) of the polished surface 21a.
(The position where the workpiece W4 is located), and is guided through the inner peripheral edge of the end face 2a of the grinding wheel 2 to another location (the location where the workpiece W4 is located) that is circumferentially separated from the above-described one position. During this time, the work is supported by the end face 22a of the inner guide 22, but is not polished. At the inner peripheral edge of the end face 22a of the inner guide 22, only the radially outer portion of the work W3 is supported by the end face 22a of the inner guide 22. The inner guide 22 may support the entire work at the inner peripheral edge portion, or may support at least a part of the work.

Thereafter, the work is further polished by the polishing surface 21a. Next, the end surface 23a of the outer guide 23 guides the polished surface of the work from the outer peripheral edge of the polished surface 21a to the other portion 17b of the work guide 17. The work exits the work guide 17 via the outer peripheral portion of the end face 2a of the grinding wheel 2. As described above, according to the present embodiment, since the inner peripheral portion of the grinding wheel 2 is configured by the inner guide 22 containing no abrasive,
As a result that the polishing force does not work on the inner peripheral portion of the end face 2a of the grinding wheel 2,
It is possible to prevent the work from falling down due to the polishing force at the inner peripheral portion, and to prevent an increase in wear caused by the falling down.

The end surface 22a of the inner guide 22 receives the surface to be polished of the work by a concave curved surface continuous with the polishing surface 21a, so that the work can be smoothly formed at the boundary between the polishing surface 21a and the end surface 22a of the inner guide 22. Migration can be performed, and from this point the work can be prevented from falling down. Further, when the cutting amount of the work is increased toward the inner circumference, the end face 2 of the grinding wheel 2
Even if the wear of “a” becomes relatively large near the inner circumference, the end face 22 a of the inner guide 22 does not have a polishing action, and therefore there is no possibility that the processing accuracy of the work is reduced.

Also, by providing the outer guide 23,
When the work W1 (see FIG. 3) moves from the work guide 17 located close to the outer periphery of the grinding wheel 2 to the polishing surface 21a, it moves to the polishing surface 21a via the end surface 23a of the outer guide 23. , Can transition smoothly. This is because the end surface 23a forms a concave curved surface continuous with the polishing surface 21a and does not exert a polishing force. In addition, the work is moved in the opposite direction from the polishing surface 21a to the work guide 1.
The same is true when going out after moving to 7. in this way,
Since the work at the time of transfer does not rattle, chipping does not occur on the outer peripheral portion of the grinding wheel 2.

Further, since the polishing force does not act on the end face 23a of the outer guide 23, even if the positioning accuracy between the work guide 17 and the end face 2a of the grinding wheel 2 is not sufficiently high, the work is loose. Sticking can be prevented.
Accordingly, the positioning of the work when the work is placed on the end surface 2a of the grinding wheel 2, for example, the positional accuracy of assembling the work guide 17 to the grinding wheel 2 does not need to be high.

As described above, in the grinding wheel 2, the wear of the end surface 2a of the grinding wheel 2 at the inner peripheral portion and the chipping at the outer peripheral portion can be suppressed, so that the shape accuracy of the end surface 2a of the grinding wheel 2 is maintained. Therefore, it is possible to lengthen the dress interval when performing dress work regularly, and it is not necessary to cut the polishing surface 21a more than necessary at the time of dressing, so that the life of the grinding wheel 2 can be extended. it can.

In particular, when the grinding wheel 2 includes both the inner guide 22 and the outer guide 23, the life can be more reliably extended, which is preferable. The inner guide 22 and the outer guide 23
Even if only at least one of them is used, an effect corresponding to that can be obtained. Further, the inner guide 22 and the outer guide 23 have the same degree of wear resistance by being adjusted to a hardness similar to that of the grinding wheel main body 21. Thereby, at the time of polishing, each end face of the inner guide 22, the outer guide 23 and the grinding wheel main body 21 is surely and uniformly worn, so that the wear of the end face 2a of the grinding wheel 2 can be made uniform in the radial direction. In addition, since it has the same degree of wear resistance, when the end face 2a of the grinding wheel 2 is dressed, the entire end face 2a of the grinding wheel 2 can be uniformly dressed with a single dressing blade. Since the work can be performed similarly to a conventional grinding wheel without the inner guide 22 and the outer guide 23, the work is easy.

Here, the inner guide 22 which can obtain this function is provided.
The material of the outer guide 23 may be any material having a resin-based material as a main component. Here, the substance containing a resin-based material as a main component includes a substance composed of only a resin-based material. The resin-based material may be any material containing a resin. For example, the resin-based material may be a single resin material, or may be a resin material and an inorganic or organic filler having no abrasive power. The material of the inner guide 22 and the outer guide 23 in the present embodiment is a material in which 50 parts by weight of epoxy resin and 50 parts by weight of cryolite are uniformly mixed. Further, in the inner guide 22 and the outer guide 23, the type and the mixing ratio of the resin material and the filler may be changed in order to obtain a hardness similar to that of the grinding wheel main body 21.

In the hardness of the inner guide 22, the hardness close to that of the grinding wheel main body 21 is required to be within ± 20 of the hardness of the grinding wheel main body 21 in the Rockwell hardness meter L scale. In addition, the grinding wheel main body 21
Is 50 to 120 on a Rockwell hardness tester L scale depending on the type of work and the required quality after polishing.
In this case, it is necessary to adjust the hardness of the inner guide 22 within a range of ± 20 with respect to the changed hardness of the grinding wheel main body. The hardness of the outer guide 23 is also required to be the above-described hardness.

The radial dimensions of the inner guide 22 and the outer guide 23 are preferably as thin as possible in order to enlarge the polished surface 21a. In particular, the radial thickness (width) of the inner guide 22 only needs to be at least a dimension (for example, 1 mm) that can support the work, and is more preferably 50% or less of the diameter of one work. The reason is that the feed track 18 of the work passes through the inner peripheral edge of the end face 2a. Therefore, when the thickness of the inner guide 22 exceeds 50% of the above-described diameter, the thickness is reduced to 50% of the diameter.
%, The effect of preventing the work from falling is the same, but the polished surface 21a is smaller.
Specifically, the width of the inner guide 22 is approximately 40% of the diameter of the large end face of the tapered roller (the workpiece W) (2 mm). The part can fully support the work.

The thickness (width) of the outer guide 23 in the radial direction is 1
It is preferable that the diameter be in a range of not less than half the diameter of one work and not more than the diameter of one work. For example,
The width is set to a size (5 mm) substantially equal to the diameter of the large end surface of the tapered roller which is the surface to be polished of the work. When the thickness of the outer guide 23 is equal to or more than half of the above-mentioned diameter, when the work is placed on the end face 2a of the grinding wheel 2, the work is moved after the center of the work is transferred from the work guide 17 to the end face 23a. Can enter the polishing surface 21,
It is preferable to stabilize the work, and the outer guide 23
The work can be further stabilized as the thickness becomes greater than or equal to one-half of the above-mentioned diameter dimension and becomes the above-mentioned diameter dimension. When the thickness of the outer guide 23 has the above-described diameter, the end surface 23a of the outer guide 23
Can securely place the entire work and hold it stably, and can guide the work smoothly and reliably between the work guide 17 and the polishing surface 21a. However, the thickness of the outer guide 23 is equal to or larger than the above-described diameter. However, the stability is the same, but the polished surface is relatively narrow, which is not preferable.

It is preferable that the radial dimension of the inner guide 22 be smaller than the radial dimension of the outer guide 23. This is because, in the above-described feed path 18, the work passes through the inner guide 22 for a longer time than the outer guide 23, so that the inner guide 22 is made relatively small, so that the polishing surface 21a has an effect. The polishing can be made large in size and can be polished efficiently.

The grinding wheel 2 can be used for purposes other than polishing the large end face of the tapered roller of the tapered roller bearing. Further, the concave curved surface may be a concave curved surface other than a spherical surface. In the above-described embodiment, the feed path 18
At a position where the tangential direction of the wheel and the tangential direction of the grinding wheel 2 coincide with each other, the work is supported only on the end face 22a of the inner guide 22, but a part of the work slightly straddles the polishing surface 21a. No problem.

In addition, various design changes can be made without changing the gist of the present invention.

[0040]

According to the first aspect of the present invention, the work is guided by the end face of the inner guide which smoothly continues from the polishing surface and does not generate a polishing force, so that the inner peripheral portion of the end face of the grinding wheel is provided. Wear caused by the work falling down can be prevented, and the life of the grinding wheel can be extended.

According to the second aspect of the present invention, if the inner guide has a resin-based material as a main component and a hardness similar to that of the grinding wheel main body, the dressing operation is easy. According to the third aspect of the present invention, the end surface of the outer guide can smoothly move the work passing therethrough between a position close to the outer periphery of the grinding wheel and the polishing surface. As a result, it is possible to extend the life of the grinding wheel.

According to the fourth aspect of the invention, if the outer guide has a resin-based material as a main component and a hardness similar to that of the grinding wheel main body, the dressing operation is easy.

[Brief description of the drawings]

FIG. 1 is a sectional view of a grinding wheel showing one embodiment of the present invention.

FIG. 2 is a schematic diagram of a schematic configuration of a polishing apparatus using the grinding wheel shown in FIG.

FIG. 3 is a view of the grinding wheel shown in FIG. 1 as viewed from an end face side.

FIG. 4 is a diagram showing a feed trajectory of a workpiece in a conventional grinding wheel, viewed from an end face side.

[Explanation of symbols]

 2 grinding wheel 2a end face 21 grinding wheel main body 21a polished surface 21b inner peripheral surface 21c outer peripheral surface 22 inner guide 22a end surface 23 outer guide 23a end surface

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazuya Aikawa 2-3-1-20 Yoshiura Shinmachi, Kure City, Hiroshima Prefecture Inside Kure Norton Co., Ltd. (72) Inventor Kenichi Suga 2-3-20 Yoshiura Shinmachi, Kure City, Hiroshima Prefecture No. Cle Norton Co., Ltd. F-term (reference) 3C063 AA02 AB05 BB03 BC03 BG01 BG10 EE01

Claims (4)

[Claims] 1. A grinding wheel main body, and a cylindrical inner guide fixed to an inner peripheral surface of the grinding wheel main body and containing no abrasive material, wherein a concave curved surface is formed on one end surface of the grinding wheel main body. A grinding wheel, wherein a grinding surface to be formed is formed, and an end surface of the inner guide forms a concave curved surface that is continuous with the concave curved surface of the polishing surface, and guides at least a part of the surface to be polished of the work. 2. The grinding wheel according to claim 1, wherein the inner guide is mainly composed of a resin-based material and has a hardness similar to that of the grinding wheel main body. 3. A grinding wheel main body, and a cylindrical outer guide fixed to an outer peripheral surface of the grinding wheel main body and containing no abrasive material, and having a concave curved surface on one end surface of the grinding wheel main body. A grinding wheel, wherein a grinding surface is formed, and an end surface of the outer guide forms a concave curved surface which is continuous with the concave curved surface of the polishing surface, and guides a surface to be polished of the work to the polishing surface. 4. The grinding wheel according to claim 3, wherein the outer guide is mainly composed of a resin-based material and has a hardness similar to that of the grinding wheel main body.