JP2609987B2 - Superabrasive grindstone and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a superabrasive grindstone in which a superabrasive layer such as diamond or cubic boron nitride (CBN) is fixed on the outer peripheral surface of a disk-shaped base. In particular, the present invention relates to a structure in which the performance of the base during high-speed rotation is improved.

[0002]

2. Description of the Related Art A super-abrasive grinding wheel of this kind has a grinding wheel peripheral speed of 8%.
It is used for high-speed grinding at 0 m / s or more. In order to withstand such high-speed grinding, the base holding the superabrasive layer is required to have the following characteristics.

[0003] Sufficient strength against the stress generated by high-speed rotation. Deformation caused by the above-mentioned stress should be small.
.

Conventionally, as a base material of a superabrasive grindstone,
Metal materials such as steel have been used, but such metal materials have a large specific gravity with respect to the elastic modulus, and tensile fibers
Incorporation by specific modulus such as (a value obtained by dividing the modulus of elasticity in density)
However, there is a limit to increase the height of the base, and there is a problem that the amount of deformation of the base during high-speed rotation is large.

For this reason, recently, application to a base material such as carbon fiber reinforced plastic (hereinafter abbreviated as CFRP) having a high specific modulus has been attempted. This CFRP has a specific elastic modulus in the fiber direction several times higher than that of steel, a coefficient of thermal expansion that is sufficiently smaller than that of steel, and a density that is about 1/5 that of steel. There is. The base made of CFRP having this characteristic can reduce the amount of deformation during rotation and can perform high-speed grinding, due to the high specific elastic modulus, as compared with steel.

[0006]

SUMMARY OF THE INVENTION Here, the super-abrasive
Among the required properties of stone, the most important factor for grinding performance
Is used for the structure in which the abrasive layer is placed on the outer peripheral surface of the base.
Is the outer peripheral displacement of the grinding wheel that enables ultra-high precision machining,
This is the displacement of the outer circumference as a base, and the change of the outer circumference with respect to the rotation speed.
Is small. This peripheral displacement is the specific elastic modulus of the base.
Is uniquely determined by In this regard, the bullet above
Long fibers with high modulus are arranged in the circumferential direction,
FRP hardened with fluorinated resin, especially CFRP mentioned above,
Although extremely advantageous, the following problems remain.

[0007] High performance materials typified by CFRP are more expensive than steel materials.
Generally expensive. Generally, FRP is easily damaged and can be attached to a grinding machine.
Lacks reliability.

In addition, even when the entire base is formed of CFRP, the number of bases is small due to the increase in the peripheral speed of the grinding wheel.
As the outer peripheral displacement increases, the inner peripheral displacement of the base also increases. In particular, the tendency becomes more remarkable as the inner diameter becomes larger than the outer diameter of the base. For this reason, even if the peripheral speed can be increased from the viewpoint of the displacement amount or breakage of the entire grindstone, a large gap is generated at the fitting portion between the inner diameter surface of the deformable grindstone and the mounting shaft of the grinder during rotation. However, there is a problem that the range of the usable number of rotations is limited due to the rotation imbalance caused by the rotation.

Accordingly, the present invention provides an outer periphery of a disk-shaped base.
The above-mentioned super-abrasive grindstone composed of a superabrasive layer fixed to the surface
With the object of solving the above problems, it is an object of the present invention to provide a superabrasive grindstone and a method for manufacturing the same, which enable stable use at high speed rotation by reducing the displacement of the inner diameter side and the outer diameter side of the base. I have.

[0010]

In order to solve the above-mentioned problems, the invention according to claims 1 to 3 relates to a superabrasive grinding wheel.
According to the first aspect of the present invention, the base is formed of an inner diameter side member and an outer diameter side member having different specific elastic moduli, and the specific elastic modulus of the outer diameter side member is set higher than that of the inner diameter side member. to and
In both cases, the outer diameter side member and inner diameter side member are
Difference between the outer diameter of the outer member and the outer diameter of the inner member
The structure was integrated by fitting with the above interference.

The invention according to claim 2 is the invention according to the above invention.
The elastic modulus of the inner diameter side member is calculated from the elastic modulus of the outer diameter side member.
The configuration was also set high.

In each of the above-mentioned inventions,
The inner member is made of a metal material, and the outer member is made of carbon fiber.
It can be made of reinforced plastic.
3).

On the other hand, the invention according to claims 4 to 6 is characterized in that
The invention according to claim 4 relates to a method of manufacturing a grindstone.
Two members that can be fitted outside and have different specific elastic modulus
Use a member with a large ratio on the outer diameter side to
The difference between the displacement of the inner diameter of the outer member and the outer diameter of the inner member
Assemble the disk-shaped base by press-fitting with the above interference, and
A super-abrasive layer is fixed to the outer peripheral surface of the base to form a whetstone
It was a configuration.

In the present invention, the above two members are elastically
The elasticity of the member is different from that of the inner diameter side.
The above configuration can be adopted (Claim 5).
Pressing both members with adhesive applied to the mating surface of the material
After fitting, assembling the base, curing the above adhesive
(Claim 6).

[0015]

First, the outer periphery of the base, which is the first object of the present invention.
Explaining the point of suppressing displacement, high specific elastic modulus
Lower than A and A for a base composed of material A alone
When considering a base composed of B having a specific elastic modulus, A
A and B are each used as an outer diameter member and B as an inner diameter member.
When rotated by itself, the outer diameter side member A is more
The radial displacement naturally increases. This means that the A base is the outer diameter side.
It is the same even if it is divided on the inner diameter side. That is, the same material
If, inner diameter displacement and the inner diameter side member of the outer diameter side member of the outer diameter change position
Increase the outer diameter of the inner diameter member as the initial interference by the difference.
When press fitting, the outer diameter of the outer diameter side member at the time of press fitting is
Depending on the case, the sum of the expansion and the single rotational displacement
The meter is equal to the rotational displacement for a single piece.

Here, A is an outer diameter member, and B is an inner diameter member.
The difference in deformation during single rotation is given as the initial interference.
Then, the base is integrated by press-fitting them.
That is the first invention.

According to the present invention, a single A group having a high specific modulus
A composite base with almost the same outer diameter displacement as the base can be provided
In addition, the deformation difference when A and B rotate independently is smaller than the same material.
During initial press-fit on the corner base with less initial interference
Can also be reduced.

[0018] Further , this makes it possible to use expensive CFRP or the like.
The material having a high specific elastic modulus is only the outer diameter side member of A.
In addition to the above,
Proven metal materials can be applied,
High reliability.

In addition to the above, the elastic modulus of A is smaller than that of B.
In the second invention, the displacement at the time of press fitting is A
This displacement is overwhelmingly large, and this displacement is the outer diameter displacement during rotation.
This has the effect of further reducing. Also, regarding the inner diameter displacement of B
Considering that, the displacement at the time of press-fit increases the rotational displacement conversely
In this case, the displacement of the inner diameter of B is also small.
The second task was to mount the base and grinder.
The fitting portion with the shaft is also highly reliable.

In the present invention, the outer diameter side member is CFRP,
If the radial side member is made of metal material, the base and grinder mounting shaft
Is more reliable.

[0021]

FIG. 1 shows a superabrasive grindstone of an embodiment.
The grindstone 1 is composed of a base 2 on a disk and a superabrasive layer 3 arranged on the outer periphery of the base 2.

The base 2 has a ring-shaped inner diameter side member 4.
And the outer diameter side member 5, the inner diameter side member 4 is formed of steel, and the outer diameter side member 5 is formed of CFRP.

The inner diameter side member 4 and the outer diameter side member 5 are coated with an adhesive on the outer peripheral surface and the inner peripheral surface, respectively. 4 are press-fitted to each other by giving a margin equal to or greater than the difference in outer diameter displacement, and after the fitting, the adhesive is cured to be integrally fixed. Then, the outer diameter side member 5 to which the inner diameter side member 4 is fixed.
The super-abrasive layer 3 made of diamond or CBN is fixed to the outer peripheral surface of the substrate.

FIG. 2 shows another embodiment. In the superabrasive grinding wheel 11 of this example, the inner diameter side member 14 is further formed by two ring-shaped parts 16 and 17, and the ring-shaped parts 16 and
An outer diameter side member 15 made of CFRP is press-fitted to the outside of the member 17.

The ring-shaped parts 16 and 17 have an inner part 16 made of steel, an outer part 17 made of a duralumin-based aluminum alloy, and an outer part 17.
After the interference of the inner diameter of the inner part 16 and the outer diameter of the inner part 16 is larger than the difference between the inner diameter and the inner diameter, the fitting surface is press-fitted with an adhesive applied.

In each of the above-mentioned superabrasive grinding wheels 1 and 11, as the material forming the inner diameter side members 4 and 14, various metal materials can be used in addition to the above-mentioned steel and aluminum alloy. Is not limited.

On the other hand, the outer diameter side members 5 and 15 are made of a material having a higher specific elastic modulus than the metal material. When CFRP is used, carbon fiber woven fabric is laminated at a constant angle in the circumferential direction. Pseudo-isotropic CFRP bonded with resin (hereinafter referred to as pseudo-isotropic CFRP), or carbon fiber continuous in one direction wound in the circumferential direction (or helical direction) and bonded with resin (Hereinafter referred to as “circumferentially wound CFRP”), and a circular cross-type CFRP obtained by combining a circumferential yarn and a radial yarn of carbon fiber can be used.

Next, various experimental examples performed to see the effects of the above embodiment will be described.

<Experimental Example 1> In the superabrasive grain 1 shown in FIG.
5C, the outer diameter side member 5 was made of pseudo-isotropic CFRP, the inner diameter side member 4 was made of S45C, and the outer diameter side member 5 was made of a circular cross CFRP. The test was performed.

Pseudo isotropic CFRP used for outer diameter side member 5
Table 1 below shows the physical property values of the CFRP and the circular cloth CFRP.

[0031]

[Table 1]

Each dimension value of the grindstone is determined by the inner radius a of the base 2 = 7.
6.2 mm, outer radius b of base 2 = 212 mm, boundary radius c of inner and outer diameter members 4 and 5 = 100 mm, outer radius d of grindstone 1 =
It was set to 220 mm.

The inner diameter side member 4 and the outer diameter side member 5 are shown in Table 2.
Then, a vitrified bond CBN layer was bonded as an abrasive layer 3 to the outer peripheral surface of the outer diameter side member 5 after giving the interference shown in FIG.

[0034]

[Table 2]

In the test, the prototype grindstone was rotated at a speed of 300 m / s, the displacement of the outer periphery was detected at that time, and the appearance of the grindstone after rotation was observed.

As a result of the test, the outer peripheral displacement of each grindstone showed values as shown in Table 3 below, and no abnormality was observed in the appearance of the grindstone after rotation.

[0037]

[Table 3]

<Experimental Example 2> In the superabrasive grinding wheel 1 shown in FIG. 1, the inner diameter side member 4 was a duralumin based aluminum alloy, and the outer diameter side member 5 was a circumferential elastic modulus at a density of 1.6 g / cm ^3. 19,000 kg / mm ²
A grindstone was manufactured as a circumferentially wound CFRP.

In FIG. 1, the inner radius a of the base is a = 7.
6.2 mm, outer radius b = 212 mm, boundary radius c = 177 mm
After the inner diameter side member 4 and the outer diameter side member 5 are press-fitted together with an interference of φ0.1 mm, a vitrified bond CBN layer is bonded to the outer peripheral surface of the outer diameter side member 5 to reduce the outer radius d of the grindstone to 220 mm. Finished.

The superabrasive grindstone manufactured as described above is
As a result of a high-speed rotation test at a peripheral speed of m / s, the outer peripheral displacement of the grindstone showed a value of 0.13 mm, and no abnormality was observed in the appearance of the grindstone before and after the rotation test.

<Experimental Example 3> In the superabrasive grinding wheel 11 having a four-layer structure shown in FIG. 2, the inner radius a of the base is 76.2 mm, the outer radius b is 212 mm, the outer radius of the grinding wheel d is 220 mm, and the inner radius is Inner part 1 of side member 14
6 is made of S55C, the outer part 17 is made of a duralumin-based aluminum alloy, and the outer diameter side member 15 is 1.6 g in density.
A grindstone formed of a circumferentially wound CFRP having a circumferential elasticity of 19,000 kg / mm ^{2 at} a pressure of / cm ³ .

The boundary diameter c ₁ between the inner part 16 and the outer part 17 of the inner diameter side member 14 is 100 mm, and the interference is φ0.1.
mm, the boundary diameter c ₂ between the outer part 17 and the outer diameter side member 15 is 177 mm, and the interference is φ0.25 mm. After each member is press-fitted and adhered, the vitrified bond CBN layer is formed on the outer peripheral surface of the outer diameter side member 15. Were glued and finished.

On the other hand, as compared with the above-mentioned prototype grinding wheel, as shown in FIG. 3, in the grinding wheel 21 of the conventional structure in which the super-abrasive grain layer 23 is fixed to the outer periphery of the base 22 formed in a single structure, Using a vitrified bond CBN layer for 23, two types of comparative grindstones in which the base 22 was formed of a single material of S45C and pseudo-isotropic CFRP, respectively, were manufactured.

In this case, the dimensions of the grinding wheel 21 having the conventional structure are as follows.
The inner radius a of the base was 76.2 mm, the outer radius b was 212 mm, and the outer radius d of the grindstone was 220 mm.

A high-speed rotation test was performed using the prototype grinding wheel manufactured as described above and a comparative grinding wheel, and high-speed performance was compared.

As a result of the test, the speed of the comparative grinding wheel using a single material of S45C as a base material was impossible at 200 m / s or more due to rotational imbalance, and the base material was a single material of pseudo-isotropic CFRP. The comparison grindstone is 250m / s
At the point of time, the CBN layer was peeled off and destroyed.

On the other hand, the prototype grinding wheel of the embodiment
Even at a peripheral speed of 0 m / s, the outer peripheral displacement remained at 0.11 mm, and no abnormality was observed in the appearance of the grindstone before and after the rotation test.

[0048]

As described above, according to the present invention, both the displacement on the inner diameter side and the displacement on the outer diameter side of the base of the superabrasive grindstone can be reduced. Unbalance and generation of stress on the abrasive layer can be prevented, and there is an effect that the super-abrasive wheel can exhibit stable processing performance.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a grindstone of an embodiment.

FIG. 2 is a perspective view showing another embodiment.

FIG. 3 is a perspective view showing a whetstone having a conventional structure.

[Explanation of symbols]

 1, 11 Whetstone 2, 12 Base 3, 13 Superabrasive layer 4, 14 Inner diameter side member 5, 15 Outer diameter side member 16 Inner part 17 Outer part

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Nobuhiro Sakurada 1 in Shinnakahara-cho, Isogo-ku, Yokohama-shi, Kanagawa Japan (56) References JP-A-1-3011074 (JP, A) Hei 3-256674 (JP, A)

Claims (6)

(57) [Claims] To 1. A disc-like base outer peripheral surface of the superabrasive grinding wheel formed by fixing the superabrasive layer, the upper Kimotodai, different inner diameter side member having specific elastic modulus and the outer diameter side member , The specific elastic modulus of the outer diameter side member is set higher than that of the inner diameter side member , and the outer diameter side member and the inner diameter side member are set.
Is the inner diameter and outer diameter of the outer diameter side member when the grinding wheel is in use.
A superabrasive grindstone characterized by being fitted and integrated with a tightening allowance equal to or greater than the difference in displacement of the member outer diameter . 2. The superabrasive grinding wheel according to claim 1, wherein the elastic modulus of the inner diameter side member is set higher than the elastic modulus of the outer diameter side member. 3. The superabrasive grinding wheel according to claim 1, wherein the inner diameter side member of the base is formed of a metal material, and the outer diameter side member is formed of carbon fiber reinforced plastic. 4. A superabrasive layer is fixed on the outer peripheral surface of a disk-shaped base.
A method of manufacturing a superabrasive grinding wheel formed by wearing, the two members having different specific modulus fittable in an inner outside, a large member of specific modulus and the outer diameter side, in use rotation of the grinding wheel outer diameter side member inner diameter of the displacement and to the inner diameter side member outer diameter difference was press-fitted in the above interference of the displacement of the assembled base of the disc-shaped, the superabrasive layer on an outer peripheral surface of the base A method for producing a superabrasive grinding wheel, comprising forming a grinding wheel by sticking. 5. The method for manufacturing a superabrasive grindstone according to claim 4, wherein the two members have different elastic moduli, and the member having a high elastic modulus is located on the inner diameter side. The method according to claim 6, wherein said two members, the adhesive press-fitted in the coated state to the fitting surface, to claim 4 or 5, characterized in that curing the adhesive after the assembly of the base A method for producing a superabrasive grinding wheel as described in the above.