JP2002160169A - Integrated grinding wheel and grinding device using thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an integrated grinding wheel capable of reducing the cost by extending a working service life compared to a conventional grinding wheel employing a single crystalline diamond for a grinding grain and capable of improving processing accuracy (appearance) and product ratio while capable of grinding and processing a workpiece made of a hard material such as a glass lens. SOLUTION: This integrated grinding wheel 1 is provided with a grinding surface 13 made by binding and holding a grinding grain 11 with a binder 12 in a shape that a part or a whole of a target finishing surface of the workpiece 30 as the grinding object is reversely copied to a part of an outer surface thereof. The grinding grain 11 is constituted by polycristalline diamond or CBN.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a general grinding wheel for grinding a workpiece by transferring a grinding surface shape of the grinding wheel, and more particularly, to grinding a workpiece made of a hard material such as a glass lens. The present invention relates to a general-purpose grinding wheel used for a steel.

[0002]

2. Description of the Related Art A general grinding wheel is formed by binding and holding abrasive grains with a binder, and a part or all of a target finish surface of a workpiece to be ground is transferred to a part of its outer surface shape. It has a shaped grinding surface. In such a form grinding wheel, the shape of the ground surface is transferred to the workpiece by pressing the ground surface of the grinding wheel against the rotated workpiece (or pressing the workpiece against the ground surface of the grinding wheel). Thus, the surface of the workpiece can be ground. Mineral substances much harder than metal or the like are used for the abrasive grains of the grinding wheel, and the binder supports the abrasive grains acting as described above and functions to maintain the rigidity of the entire grinding wheel.

[0003] Generally, when the initial cutting edge on the grinding surface becomes dull due to wear, the abrasive force is increased and the abrasive force is peeled off from the binder or falls off, or the abrasive is appropriately crushed to form a new cutting edge. Continue to grind the blade by itself. As the abrasive grains, an appropriate substance according to the material of the workpiece is selected and used. However, when the workpiece is made of a hard material such as glass, a single crystal (artificial) diamond may be used. Many.

[0004]

However, in a general grinding wheel having a relatively large contact area with the workpiece during grinding, the abrasive grains that have come off from the binder during grinding and fall off the grinding surface (the ground surface). It is difficult to be discharged from the contact surface with the workpiece surface) and easily clogged. For this reason, when extremely hard single-crystal diamond is used for the abrasive grains, the surface of the workpiece may be deeply scratched and the processing (appearance) accuracy of the ground surface is reduced. Was causing it.

[0005] Further, during grinding, heat is generated by deformation of chips when they are scraped off by the cutting blade or by friction when the chips flow along the blade surface. A thermal effect is exerted on the binder through the grains, the abrasive grains are more likely to fall off than the binder, and the frequency of clogging is increased. For this reason, there is a problem that the trouble of applying a dresser (conditioner) to the blade surface of the grindstone increases, and the grinding efficiency does not increase. Further, since the abrasive grains fall off, the service life is shortened, and there is a problem that the cost required for grinding is increased by consuming time and money such as replacement of a grinding wheel.

SUMMARY OF THE INVENTION The present invention has been made in view of such a problem, and is intended to grind a workpiece made of a hard material such as a glass lens, while using a single crystal diamond as an abrasive. A general-purpose grinding wheel that can extend the service life and reduce the cost required for grinding compared to the conventional ones used, and can also increase the processing (appearance) accuracy of the grinding surface to improve the yield rate of production. And a grinding device.

[0007]

In order to achieve the above object, a form grinding wheel according to the present invention comprises abrasive grains bonded and held by a binder, and a part of the outer surface of which is to be ground. In a material having a ground surface in which part or all of a target finish surface of an object is transferred, abrasive grains are made of polycrystalline diamond or CBN (cubic boron nitride).

[0008] In the form grinding wheel having such a configuration,
When the abrasive grains are composed of polycrystalline diamond, the polycrystalline diamond is softer (brittle) than the monocrystalline diamond. However, polycrystalline diamond is more likely to crush and form a new cutting edge than to fall off due to the resistance received from the workpiece. The service life can be prolonged compared to a shaped grinding wheel. Also, the abrasive grains that fall off or crush during the grinding and enter between the ground surface and the workpiece surface are harder and have a larger particle diameter than the single crystal diamond that has fallen, whereas the crushed polycrystalline diamond is softer. Due to the small particle size, the surface of the workpiece is not so deeply scratched as the conventional one.

On the other hand, when the abrasive grains are made of CBN,
Since BN has a smaller thermal effect on the binder than single-crystal diamond, the workpiece is made of a sticky and difficult-to-cut material, and the contact time between the abrasive grains and the workpiece during grinding is prolonged, causing heat generation due to friction. Even when the temperature of the abrasive grains is high, the holding power of the abrasive grains by the binder does not decrease, and the abrasive grains do not fall off from the binder. The service life can be prolonged compared to a shaped grinding wheel. In addition, since the abrasive grains do not fall off even at such a high temperature, the frequency of clogging is reduced, and the work of applying a dresser (conditioner) to the blade surface of the grindstone is reduced, thereby improving the grinding efficiency. Note that polycrystalline diamond and CBN are hard abrasives next to single crystal diamond, and are sufficiently suitable for grinding a workpiece made of a hard material such as a glass lens.

As described above, in the form grinding wheel of the present invention, a work made of a hard material such as a glass lens can be ground into a predetermined shape, while a single crystal diamond is used as an abrasive. The service life can be extended as compared with the conventional one, and the cost required for grinding can be reduced. Also, polycrystalline diamond and CBN
Is not as hard as a single crystal diamond, so it peels off from the binder during grinding and falls off, even if it gets between the ground surface and the surface of the workpiece. It is possible to improve the processing (appearance) accuracy of the ground surface and to improve the production yield rate without causing damage.

Further, the grinding apparatus according to the present invention comprises a grinding wheel holding section (for example, a grinding wheel holding member 25 in the embodiment) for holding the above-mentioned form grinding wheel of the present invention, and a workpiece for holding a workpiece to be ground. A holding unit (for example, the work holder 40 in the embodiment) is provided, and in a state where the work held by the work holding unit is brought into contact with the grinding surface of the forming grinding wheel, the grinding wheel holding unit and the work It is configured to grind the workpiece by relatively rotating the holder. As described above, in the present grinding apparatus, the workpiece is ground using the above-described form grinding wheel according to the present invention, so that the cost required for the grinding can be reduced and the processing of the ground surface (appearance) Accuracy can be increased to improve the production non-defective rate.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. 1 and form-grinding wheel 1 illustrated in FIG. 2 (hereinafter, referred to as the grinding wheel 1) shows an embodiment of the present invention, substrates formed rotationally symmetrically with respect to the axis of rotational symmetry AX ₁ 20, provided in an annular shape on the upper surface 21 of the substrate 20, when the substrate 20 is rotated about its axis of rotational symmetry AX _1, to grind the workpiece 30 by rotating in this and to integrally And an abrasive layer 10.

Here, the shape of the outer peripheral surface 21 of the substrate 20
Is a cross section of the substrate 20 (the rotation target axis AX ₁Cross section through)
The shape of both ends is a cross-section (rotation center axis A
X_TwoInto a shape that is almost a transfer of one-sided shape
Has been established. On the other hand, the abrasive layer 10 is
It is provided on the peripheral surface 21 and is made of polycrystalline diamond.
Combines abrasive grains 11 made of CBN (cubic boron nitride)
(See FIG. 3).
See). This abrasive layer 10 is formed into a thin layer having a uniform thickness.
The ground surface 13, which is the outer surface thereof,
It has substantially the same shape as the peripheral surface 21. That is,
This grinding wheel 1 is an object to be ground on a part of its outer surface shape.
A form in which part or all of the target finish surface of the workpiece 30 is transferred
It has a grinding surface 13 in the shape of a circle.

The binder 1 for binding and holding the abrasive grains 11
2 is preferably a metal bond. Metal bond is mainly copper, brass and nickel, and is mainly used for bonding when diamond is used as abrasive grains. Metal-bonded grindstones are non-porous, have a large holding power for abrasive grains, and are excellent in heat diffusion. Therefore, they are suitable for grinding hard materials such as glass materials and hardened tools. It is particularly preferable that the metal bond is formed by electroless plating of nickel, cobalt, or the like. This electroless plating can form a plating film having better adhesion to the substrate than electroplating, can form a uniform plating film irrespective of the shape of the substrate, and can be used for non-plastic materials. There are advantages such as being applicable to conductive materials.

Next, the manufacturing procedure of the grinding wheel 1 having such a configuration will be described with reference to an example in which the binder 12 is an electroless plating layer. For this, first, an appropriate test electroless plating solution containing polycrystalline diamond or CBN having an appropriate particle size (for example, about 12 to 25 μm) (for example,
Electroless plating solution mainly composed of nickel sulfate etc.)
A plating test is performed while rotating a stirrer (stirring machine) at various rotational speeds, and the relationship between the rotational speed of the stirrer and the abrasive content of the plating film formed at that time is confirmed. Then, on the formed outer peripheral surface 21 of the base material 20, a general base treatment such as a degreasing treatment, a masking treatment with a plating masking agent, a cleaning treatment, an activation treatment and the like is performed, and then a catalyst application treatment (for example, Immersion in a reducing agent such as an aqueous solution containing palladium chloride). However, when the base material 20 is formed of a material capable of reducing metal ions in the electroless plating solution (for example, iron, nickel, or the like), it is not necessary to perform a catalyst applying treatment at this time.

After the above pretreatment, a test piece for confirming the thickness of the plating film being deposited is placed in an electroless plating solution adjusted to have substantially the same composition as the test electroless plating solution. At the same time, the substrate 20 is immersed, and the stirrer in the electroless plating solution is rotated. However, initially, the stirrer is gently rotated so that the abrasive grains 11 do not enter the plating film, and the state of the outer peripheral surface 21 of the base material 20 is checked while checking the thickness of the plating film with a test piece. When a plating film having an appropriate thickness (usually 0.1 μm or more, preferably about 2 μm is appropriate) is deposited, the rotation speed of the stirrer is increased so that a specified amount of abrasive grains 11 are dispersed in the plating film. Let it.

Subsequently, while confirming the thickness of the plating film on a test piece, when a plating film having an appropriate thickness (for example, about 38 μm) according to the particle size of the abrasive grains 11 is further deposited, electroless plating is performed. The substrate 20 is pulled up from the liquid. Then, normal post-treatments such as washing, drying and masking removal are performed. By such a process, the outer peripheral surface 2 of the base material 20 is formed.
A grinding wheel 1 on which an abrasive grain layer 10 in which abrasive grains 11 made of polycrystalline diamond or CBN are bonded and held by a plating film (this plating film corresponds to a binder 12) is obtained.

In order to grind the workpiece 30 using the grinding wheel 1 obtained in this way, as shown in FIG. is rotated in AX ₁ around, rotates the workpiece 30 workpiece holder 40 which is held by a vacuum chuck or the like around its rotation center axis AX _2. Then, the workpiece 30 is pressed against the grinding wheel 1 while the grinding wheel 1 and the workpiece 30 are both rotated (or the grinding wheel 1 is pressed against the workpiece 30).
) And the surface of the workpiece 30 (workpiece surface) 3
1 is ground so as to follow the surface shape of the grinding wheel 1 (of the abrasive layer 10), and the shape of the grinding wheel 1 is transferred to the workpiece 30. During the grinding, in order to prevent heat generation on the grinding surface and to wash away chips to improve the processing (appearance) accuracy and the grinding efficiency of the grinding surface, the grinding surface (the surface between the grinding surface 13 and the work surface 31) is improved. The contact surface) with the grinding fluid 5 from the grinding fluid injection nozzle 50
1 is injected and supplied.

As described above, the workpiece 30 is formed by the main grinding wheel 1.
Can be ground into a predetermined shape. However, when the abrasive grains 11 fixed and held by the binder 12 are made of polycrystalline diamond, the conventional grinding wheels using a single crystal diamond as the abrasive grains are used. Can also extend the service life. This is due to the fact that polycrystalline diamond is softer (brittle) than single crystal diamond. That is, the single crystal diamond often falls off the binder rather than crushing due to the resistance received from the workpiece 30 during grinding,
While it is difficult to form a new cutting edge by itself, polycrystalline diamond is more likely to crush and form a new cutting edge than to fall off due to resistance from the workpiece 30. Grinding wheel 1
If the end of the service life is reached, the grinding operation is interrupted and the grinding wheel 1
Since time and cost are consumed for exchanging, for example, the grinding efficiency can be improved and the cost required for grinding can be reduced by the present invention.

Considering the case where the abrasive grains 11 fall or crush during grinding and enter between the ground surface 13 and the workpiece surface 31, the single crystal diamond that has fallen is hard and large, so Compared to a single crystal diamond, a fractured polycrystalline diamond is not as hard as a single crystal diamond and has a smaller particle size, but does not damage the workpiece 30 as deeply as a single crystal diamond. For this reason, the processing (appearance) accuracy of the ground surface can be improved, and the production yield can be improved.

On the other hand, when the abrasive grains 11 fixed and held by the binder 12 are CBN, especially when the workpiece 30 is a glass lens or the like made of a sticky material, the abrasive grains are made of single crystal diamond. The service life can be extended as compared with the conventional form grinding wheel using. This is C
Because BN has a smaller thermal effect on the binder than single-crystal diamond, the workpiece 30 is made of a sticky and difficult-to-cut material, and the contact time between the abrasive grains and the workpiece 30 during grinding increases. This is because even when the heat generated by friction increases and the abrasive grains become hot, the holding power of the abrasive grains 11 by the binder does not decrease and the abrasive grains 11 do not fall off the binder. In addition, these polycrystalline diamond and CBN
Is a hard abrasive next to single crystal diamond, and it is needless to say that it is sufficiently suitable for grinding a workpiece made of a hard material such as a glass lens.

Further, in the present grinding apparatus, since the workpiece 30 is ground using the above-described form grinding wheel 1 according to the present invention, the cost required for the grinding can be reduced and the ground surface can be reduced. The processing (appearance) accuracy can be enhanced to improve the production non-defective rate.

While the preferred embodiments of the present invention have been described above, the scope of the present invention is not limited to those described above. For example, in the above-described embodiment, the form grinding wheel of the present invention has a configuration in which a part of the outer surface shape transfers a part of a target finish surface of a workpiece to be ground.
A configuration in which a part of the outer surface shape transfers the entire target finish surface of the workpiece may be employed. The point is that the abrasive grains are bonded and held by a binder, and are formed grinding wheels that have a ground surface with a shape obtained by transferring part or all of the target finish surface of the workpiece to be ground to a part of the outer surface shape. I just need.

[0024]

As described above, in the form grinding wheel according to the present invention, a workpiece made of a hard material such as a glass lens can be ground into a predetermined shape while grinding the workpiece. The service life can be extended as compared with the conventional one using single crystal diamond, and the cost required for grinding can be reduced. Also, since polycrystalline diamond and CBN are not as hard as single crystal diamond, they are peeled off from the binder during grinding and fall off, and even if this enters between the ground surface and the surface of the workpiece, In addition, the processing (appearance) accuracy of the ground surface can be improved without causing deep scratches as compared with the above-mentioned conventional one, and the yield rate of good products can be improved.

In the grinding device according to the present invention,
Since the workpiece is ground using the above-mentioned form grinding wheel according to the present invention, the cost required for the grinding process can be reduced, and the processing (appearance) accuracy of the ground surface is improved to improve the yield rate of production. Can be done.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a forming grinding wheel according to the present invention.

FIG. 2 is a side sectional view showing the configuration of the form grinding wheel.

FIG. 3 is an enlarged view of the vicinity of a base material surface of a forming grinding wheel in which polycrystalline diamond is fixed by a plating layer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Form grinding wheel 10 Abrasive layer 11 Abrasive grains 12 Binder 13 Grinding surface 20 Substrate 25 Grindstone holding member (grindstone holding part) 30 Workpiece 40 Workpiece holder (workpiece holding part) 50 Grinding liquid injection nozzle 51 Grinding fluid

Claims (2)

[Claims] Claims: 1. An abrasive grain is bound and held by a binder,
In a forming grinding wheel having a ground surface having a shape obtained by transferring part or all of a target finish surface of a workpiece to be ground to a part of its outer surface shape, the abrasive grains are made of polycrystalline diamond or CBN. To form the grinding wheel. 2. A grinding wheel holding unit for holding a forming grinding wheel according to claim 1, and a work holding unit for holding a work to be ground, wherein the grinding surface of the forming grinding wheel is In a state where the workpiece held by the workpiece holding section is brought into contact with the workpiece holding section, the grindstone holding section and the workpiece holding section are relatively rotated to grind the workpiece. Grinding equipment.