JP2881369B2 - Composite plating and sliding member using 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 composite plating used in a surface treatment method for imparting lubricity to a material surface, and an improvement of a sliding member using the same.

[0002]

2. Description of the Related Art As shown in FIG. 4, in a CD pickup device, a shaft member 1 is required to follow the movement of an optical disk.
The servo is always applied to the lens holder 3 which is slidably supported and supports the objective lens 2, and the position is corrected in the focus or track direction. This movement requires high speed and accuracy, but for that purpose, the sliding resistance (coefficient of friction, dimensional accuracy) of the shaft member 1 supporting the lens holder 3 must be extremely small.
Therefore, conventionally, as a surface treatment method for providing lubrication to the shaft member 1, for example, a BN
A processing method of applying (boron nitride) composite plating or PTFE (polytetrafluoroethylene) composite plating has been applied.

[0003]

The BN composite plating used in the surface treatment method has a high coefficient of friction. On the other hand, the PTFE composite plating has a problem in that the coefficient of friction can be suppressed low, but the cost of the chemical solution is high. In addition, as a wet surface modification method for imparting lubricity to the material surface, boron nitride, calcium fluoride, PT
There is a method using composite plating in which FE or the like is dispersed. However, since the composite plating by the above method is based on electroless or electrolytic Ni-P, it is very difficult to uniformly disperse the dispersant, and therefore, various dispersion accelerators for dispersing the dispersant are used. ing.

[0004]

An object of the present invention is to eliminate the need for a dispersion-promoting chemical solution for a dispersant which imparts lubricity to the material surface, and to reduce the amount of
A main object of the present invention is to provide a composite plating capable of obtaining a friction coefficient substantially equal to that of P-PTFE, and a sliding member using the same.

[0005]

Means for Solving the Problems To achieve the above object, the composite plating of the present invention has a gist that swelling mica is added as a dispersant to a base material such as nickel. The gist of the sliding member according to the present invention is that mica composite plating in which mica containing fluorine or swellable mica containing fluorine is added as a dispersing material to a base material such as nickel is applied.

Here, the swellable mica is a synthetic mica that, when immersed in water, absorbs water and swells, and then cleaves to become ultrafine particles. Further, the swellable mica containing fluorine is a fluorine-based mica in which OH ⁻ constituting a part of the crystal lattice is replaced with F ⁻ as bound water in the mica. As a typical example,
NaMg ₂ Li (SiO ₄ O ₁₀ ) F ₂ , NaMg ₂₅ (Si _{4
O 10) F 2, LiMg 2} Li (Si 4 O 10) F 2 and the like.

[0007]

The swelling mica in the composite plating according to the above constitution is:
Since mica itself has lubricity, a highly lubricious coating can be obtained by using this mica composite plating. Further, according to the use of mica composite plating using mica containing fluorine (fluorinated mica) or swelling mica containing fluorine (fluorinated swelling mica) as a dispersing material, the friction coefficient at almost the same level as that of the PTFE composite plating is obtained. Is obtained. In particular, in the case of composite plating using swelling mica as a dispersant, a special dispersion accelerator is not required since mica itself has dispersibility in an aqueous solution or the like.

[0008]

The composite plating according to the present invention is based on, for example, a nickel hypophosphite solution (Ni-P), to which swelling mica or fluorine-based mica or fluorine-based swelling mica is added as a dispersant. Obtained easily.

FIG. 1 is a diagram showing a surface treatment process for applying Ni-P-mica plating to the shaft member 1 shown in FIG. 4 as an embodiment of the present invention. First, after the surface of the sliding member (shaft member) is washed by a process of washing with water, pickling, and washing with water, electroless Ni is used.
-Apply P plating. This is to improve the adhesion of the next Ni-P-mica plating.

[0010] Next, a plating material (about 90 ° C, PH5 to 5) obtained by adding the above electroless Ni-P plated sliding member to a nickel hypophosphite solution (Ni-P) and adding mica as a dispersing agent.
5.5) dipped in the substrate and electrolessly plated with Ni-P-mica. In this electroless plating step, a mica composite plating film (2 to 3 μm) having lubricity is obtained.

The sliding member obtained in the above-mentioned surface treatment step is:
As compared with the case of the conventional surface treatment method using various types of composite plating, it was confirmed that the dynamic friction coefficient was almost equivalent to that of Ni-P-PTFE.

FIG. 2 is a graph showing the results of a mounting test (temporal friction coefficient characteristics) of a shaft member having a mica composite plating film according to the present invention and a conventional product. FIG.
Shows mounting test results of only conventional products.

As is clear from the graph of FIG.
The shaft member subjected to P-mica plating is Ni-P-SiC,
Compared to a shaft member provided with a coating of Ni-P-BN or the like, the shaft member has excellent friction characteristics over time, and it is recognized that the dynamic friction coefficient is almost the same as that of Ni-P-PTFE.

[0014]

As is apparent from the above description, the composite plating according to the present invention is obtained by adding swellable mica as a dispersing material to a base material such as nickel. A low-cost lubricating film can be formed. In addition, since mica, which is a dispersing agent, has swelling properties, when it is dispersed in a plating solution, uniform dispersion is possible without using a special dispersion accelerator, and workability can be greatly improved. In addition, according to the use of fluorine-based mica or composite plating in which fluorine-based swelling mica is dispersed, a sliding member having a reduced friction coefficient can be easily obtained. Further, according to the mica composite plating, a film free from color unevenness can be obtained.

[Brief description of the drawings]

FIG. 1 is a surface treatment process diagram for obtaining a sliding member using the composite plating of the present invention.

FIG. 2 is a graph showing the friction characteristics over time of a sliding member subjected to composite plating of the present invention and a conventional product.

FIG. 3 is a graph showing the friction characteristics over time of various conventional products.

FIG. 4 is a sectional view of a main part of the optical pickup device.

[Explanation of symbols]

 1 Shaft member 2 Objective lens 3 Lens holder

Claims (3)

(57) [Claims] 1. Composite plating characterized by adding swellable mica as a dispersing agent to a base material such as nickel. 2. A sliding member having a mica composite plating obtained by adding mica containing fluorine to a base material such as nickel as a dispersing material. 3. A sliding member having a surface coated with mica composite plating obtained by adding swellable mica containing fluorine as a dispersing material to a base material such as nickel.