JP2008142805A - Grinding wheel, grinding wheel pellet and manufacturing method of optical element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily judge a life span of a grinding wheel. <P>SOLUTION: An abrasive grain part 20 is constituted of an intermediate layer 21 and an abrasive grain layer 22 formed on an upper surface of the intermediate layer 21. The intermediate layer 21 is formed by nickel electroless plating containing PTFE particles 21a having high lubricating ability and the abrasive grain layer 22 is formed by electroless nickel plating containing diamond abrasive grains 22a. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a grinding wheel, a grinding stone pellet, and an optical element manufacturing method.

  A grinding wheel using a plating film as a binder includes a base plate and an abrasive layer formed by plating containing abrasive grains on the surface of the base plate.

  This grinding wheel is used for grinding and polishing a workpiece such as a lens, like a resin bond grindstone and a metal bond grindstone. The abrasive layer gradually wears due to grinding and polishing, and the wheel life is exhausted when the surface of the platform is exposed.

In addition, a grindstone using a resin bond or a metal bond as a binder is attached to the surface of the base plate, and a part of the surface of the base plate is exposed (see Japanese Patent Application Laid-Open No. 10-249734). Wear can be judged visually.
JP-A-10-249734

  However, in a grinding wheel using a plating film as a binder, the abrasive grain layer is laminated on the entire surface of the platen, so it is difficult to visually determine the life of the grinding wheel. If the surface of the tray (base) is exposed when the workpiece is ground or polished, the surface of the workpiece will not be damaged, but if the surface of the tray is exposed during processing, The surface of the object is deeply scratched or the workpiece is cracked. In addition, since the base plate itself is damaged, the base plate may not be reused.

  The present invention has been made in view of such circumstances, and an object thereof is to make it possible to easily determine the life of a grindstone.

  In order to solve the above-mentioned problem, the invention of claim 1 is formed by plating on the surface of the platform, the surface of the platform, the intermediate layer containing a solid lubricant, and formed on the surface of the intermediate layer by plating. A grinding wheel comprising an abrasive grain layer containing abrasive grains.

  According to a second aspect of the present invention, in the grinding wheel according to the first aspect, the solid lubricant is PTFE particles.

  According to a third aspect of the present invention, in the grinding wheel according to the first or second aspect, the intermediate layer and the abrasive layer are formed by an electroless plating method.

  A fourth aspect of the present invention is a method of manufacturing an optical element using the grinding wheel according to any one of the first to third aspects.

  The invention according to claim 5 is a substrate, an intermediate layer formed by plating on the surface of the substrate and containing a solid lubricant, and an abrasive layer formed by plating on the surface of the intermediate layer and containing abrasive grains It is provided with the following.

  The invention described in claim 6 is a grinding wheel characterized by comprising a base plate and a plurality of wheel stone pellets according to claim 5 fixed to the base plate.

  A seventh aspect of the present invention is a method of manufacturing an optical element using the grinding wheel according to the fifth or sixth aspect.

  According to this invention, the life of the grindstone can be easily determined.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a conceptual diagram showing a cross section of a grinding wheel according to an embodiment of the present invention.

  The grinding wheel 1 includes a base plate 10 and an abrasive grain portion 20 for grinding a lens (not shown).

  For example, the grinding wheel 1 rotates around the shaft portion 11 of the base plate 10 to grind a workpiece such as a lens or an optical element. The shaft portion 11 is formed with a female screw portion 11a for screwing a male screw portion of a shaft of a motor (not shown).

  A metal having high mechanical rigidity is suitable as a material for the tray 10. Specific examples of the material include iron, brass, aluminum, and stainless steel that can be easily pretreated for plating. In the case of forming an intermediate layer 21 to be described later using electroless plating, it is not particularly necessary to apply any catalyst to the base plate 10, and iron in which the base plate 10 itself becomes a catalyst and electroless plating is deposited is particularly preferable. Is suitable. In addition, you may use plastic resin materials, such as PEEK (polyetheretherketone), polyamide, and PPS (polyphenylene sulfide).

  The surface 10a of the tray 10 has a shape corresponding to the finished shape of the lens or optical element to be processed. In this embodiment, the surface 10a of the base plate 10 has a shape corresponding to a planar optical element.

  The abrasive grain portion 20 includes an intermediate layer 21 and an abrasive grain layer 22 formed on the upper surface of the intermediate layer 21.

  The intermediate layer 21 contains PTFE (polytetrafluoroethylene) particles (solid lubricant) 21a. The coefficient of friction of the PTFE particles 21a is very low and below ice. In addition, the coefficient of static friction is lower than the coefficient of dynamic friction, and the coefficient of friction (0.04) is lower than that of other solid lubricants such as graphite and molybdenum disulfide at high loads and low speeds. The intermediate layer 21 is formed by electroless plating.

  The abrasive layer 22 covers the intermediate layer 21. The abrasive grain layer 22 contains diamond abrasive grains (abrasive grains) 22a. The abrasive layer 22 is formed by electroless plating.

  Next, a method for manufacturing the grinding wheel 1 will be described.

  2A to 2E are diagrams for explaining the manufacturing process.

  First, the tray 10 is washed with electrolyzed water. In addition, the diameter of the base plate 10 is 220 mm. Moreover, stainless steel was used as the material of the base plate 10 (see FIG. 2A).

  Next, a masking jig (not shown) is attached to the back surface of the base plate 10 to perform masking 30 (see FIG. 2B).

  Next, the plate 10 is dipped in an alkaline aqueous solution, degreased by the saponification action of the alkaline aqueous solution (removal of organic matter such as fingerprints and oils and dust attached due to electrostatic action), and activation treatment with acid Are performed sequentially.

  Thereafter, it is soaked in a palladium replacement solution containing hydrochloric acid and palladium chloride as main components for 60 seconds, and a palladium layer is formed on the surface 10a of the tray 10 as a catalyst layer for smoothly performing electroless plating. The same applies to brass. Moreover, in the case of aluminum, the base plate 10 is immersed in a zinc substitution liquid, and the zinc layer used as a catalyst is formed in the surface 10a of the base plate 10. FIG. In the case of iron having catalytic properties, this catalyst layer forming process is omitted.

  Next, the platen 10 is dipped in an electroless nickel plating solution 40a containing PTFE particles 21a, and a nickel plating film is formed on the surface 10a of the platen 10 by electroless plating. This nickel plating film becomes the intermediate layer 21.

  The electroless nickel plating solution 40a is charged with 4.5 g of PTFE particles 21a per liter including a dispersant. The stirring conditions of the stirrer 41 are set so that a predetermined amount (for example, 20 vol%) of PTFE particles 21a is uniformly distributed in the electroless nickel plating solution 40a. When immersed in a plating solution 40a heated to 90 ° C. for 1 hour, a nickel plating film having a thickness of 10 μm was formed (see FIG. 2C).

  The electroless plating solution 40a containing the PTFE particles 21 is, for example, Nimron (manufactured by Uemura Kogyo Co., Ltd.) or Kaniflon (manufactured by Nippon Kanisen Co., Ltd.).

  Thereafter, ultrasonic cleaning (not shown) and water washing by immersion are performed to remove the PTFE particles 21a adhering to the base plate 10 and the jig.

  Next, the platen 10 is immersed in an electroless nickel plating solution 40b containing diamond abrasive grains 22a, and a nickel plating film is formed on the surface of the intermediate layer 21 by electroless plating.

  The electroless nickel plating solution 40b is charged with 0.1 g of diamond abrasive grains 22a having a particle size of 2.0 to 4.0 μm per liter. The stirring conditions of the stirrer 41 are set so that a predetermined amount (for example, 10 vol%) of diamond abrasive grains 22a is uniformly distributed in the electroless nickel plating solution 40b. When immersed in a plating solution heated to 90 ° C. for 2 hours, a nickel plating film having a thickness of 30 μm was formed (see FIG. 2D). This nickel plating film becomes the abrasive grain layer 22.

  Thereafter, the tray 10 is taken out from the electroless nickel plating solution 40b, washed with water, and then dried to remove the masking 30. As a result, the grinding wheel 1 is completed (see FIG. 2 (e)).

  Next, a processing experiment using the grinding wheel 1 was performed, and the effect of the intermediate layer 21 was confirmed.

A plane lens made of quartz and having a diameter of 270 mm was used as a workpiece. The processing conditions are as follows.
Grinding device: Ogino Elliptical Motion Grinding conditions Grinding wheel rotation speed: 300rpm
Lens rotation speed: 50 rpm
Gauge pressure: 0.2 MPa
Grinding fluid: water-soluble grinding stock solution diluted with water Grinding concentration Stock solution: water = 1: 3

  The amount of wear of the workpiece and the surface of the grinding wheel 1 were examined when processed for 1 minute each under the above conditions. The average amount of wear of the workpiece per minute when processed for 15 minutes from the start of processing was 30 μm. Moreover, the average amount of wear of the workpiece per minute when machining for 16 minutes was 10 μm. At this time, idling occurred in the motor that rotates the grinding wheel 1 and the motor that rotates the lens. Note that idling can be visually confirmed. When idling occurred, no scratches or the like were found on the surface of the workpiece.

  When the surface of the grinding wheel 1 is observed with a microscope, the abrasive grain layer 22 is not observed, and the surface 10a of the base plate 10 is not exposed. It was found that polishing was suppressed. Processing may be stopped by judging this time as the life of the grinding wheel 1.

  According to this embodiment, when the abrasive grain layer 22 is worn out during grinding of the workpiece, idling of the motor caused by the self-lubricating property of the intermediate layer 21 can be easily detected, so that the life of the grinding wheel Can be easily determined. Moreover, since the scratches and cracks of the plate 10 itself can be prevented by idling, the grinding wheel 1 (the plate 10) can be reused.

In addition, when using electroplating for formation of the abrasive grain layer 22, since the presence or absence of a catalyst layer does not become a problem, what is necessary is just to put in a plating solution immediately after washing with water. The thickness of the abrasive layer 22 can be controlled by the amount of current flowing in the plating solution (current × time) (for example, 5 A / 100 cm ² , 30 minutes). The content of the diamond abrasive grains 22a can be controlled by keeping the amount of the diamond abrasive grains 22a charged into the plating solution and the stirring condition of the stirrer constant.

  Moreover, although the said embodiment demonstrated the grinding grindstone 1 in which the abrasive grain part 20 (the intermediate | middle layer 21 and the abrasive grain layer 22) is directly formed in the surface 10a of the base plate 10, it is cylindrical on the base plate 10 via an adhesive agent. When the present invention is applied to a grinding wheel configured by attaching a plurality of grinding wheel pellets (not shown) above, an intermediate layer and an abrasive layer may be formed on the surface of the grinding wheel pellets on a cylinder. .

FIG. 1 is a conceptual diagram showing a cross section of a grinding wheel according to an embodiment of the present invention. 2A to 2E are diagrams for explaining the manufacturing process.

Explanation of symbols

  1: grinding wheel, 10: platform, 21: intermediate layer, 21a: PTFE particles (solid lubricant), 22: abrasive layer, 22a: diamond abrasive (abrasive).

Claims (7)

A plate and
An intermediate layer formed on the surface of the platen by plating and containing a solid lubricant,
A grinding wheel comprising: an abrasive layer formed by plating on the surface of the intermediate layer and containing abrasive grains.   2. The grinding wheel according to claim 1, wherein the solid lubricant is PTFE particles.   The grinding wheel according to claim 1 or 2, wherein the intermediate layer and the abrasive layer are formed by an electroless plating method.   A method for producing an optical element, wherein the grinding wheel according to claim 1 is used. A substrate;
An intermediate layer formed on the surface of the substrate by plating and containing a solid lubricant;
A grinding stone pellet, comprising: an abrasive layer formed by plating on the surface of the intermediate layer and containing abrasive grains.   A grinding grindstone comprising a base plate and a plurality of grinding stone pellets according to claim 5 fixed to the base plate.   A method for producing an optical element, wherein the grinding wheel according to claim 5 or 6 is used.

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