JPS6230277B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sliding device member having a smooth anodic oxide coating on its sliding surface.

Aluminum alloy is a metal that is lightweight and has good workability, but it has poor wear resistance, so it is used as a sliding equipment member 1 having a sliding surface 3 on which a sealing member 2 slides as shown in FIG. It has been considered unsuitable for pressure cylinders, bearings, etc. However, in recent years, with the demand for weight reduction of automobiles and the like, research has been conducted on the use of aluminum alloys for equipment members having sliding surfaces.

Generally, anodic oxidation treatment is used as a surface strengthening method for aluminum alloys, but in order to increase the strength of aluminum and improve workability, silicon 4 is added as shown in Figures 9 and 10. When the aluminum alloy 5 is anodized, the surface roughness of the anodic oxide film 12 becomes an uneven surface with a ten-point average roughness of about 5 to 50μ, and the sliding surface 3 of the sliding equipment member 1 has the following properties: Totally unusable. Therefore, in some cases, the anodic oxide film 12 is formed extremely thick and the surface is smoothed using a grindstone, abrasive paper cloth, or the like. However, in order to obtain a thicker anodic oxide film 12 corresponding to the thickness removed, extra power is required, which is not preferable in terms of energy saving. Furthermore, the polishing process requires a lot of time and effort in order to remove the hard anodic oxide film, which poses a labor-saving problem.

Therefore, the present invention solves the above problem by pressing a pressing member against the sliding part of a sliding equipment member made of an aluminum alloy, and then applying anodization treatment to form a smooth anode on the sliding surface. The object of the present invention is to provide a sliding device member having an oxide film.

An embodiment of the present invention will be described below based on the accompanying drawings. In FIG. 2, the sliding device member before processing is cast from an aluminum alloy 5 containing silicon 4 (step A). The aluminum alloy 5 mentioned above includes all aluminum alloys, including aluminum alloys containing copper, silicon, magnesium, nickel, titanium, etc. The experimental results described below show that the effect is sometimes remarkable in aluminum alloy 5 containing silicon. The structure of the material at this time is as shown in FIG. In other words, the silicon 4
are mixed together as needle-shaped crystals.

Next, the material of this sliding device member is machined (step B) to form a sliding surface 3 on which the sealing member 2 slides, as shown in FIG. Further, the aluminum alloy 5 is coated on the sliding surface 3 of the sliding device member 1.
A pressing member 6 (see FIGS. 4 and 5), which is harder than the above, is used to perform pressing processing (step C) as described later. The condition near the surface of the material at this time is
As shown in FIG. 6, the silicon 4 is crushed into fine particles 4'. At this time, there is an appropriate range for the amount of pressing processing (referred to as finishing allowance); if it is less than 0.01 mm, the amount of strain on the aluminum alloy surface is insufficient, and the silicon particles distributed near the surface cannot be crushed, and the aluminum alloy There is no miniaturization of silicon particles. If the finishing allowance is 0.05 mm or more, the stress generated on the aluminum alloy surface will be greater than the yield point of the aluminum alloy, and the aluminum alloy will become rough and exposed. For this reason, the finishing allowance is set at 0.01 to 0.05 mm. The pressing member 6 is not particularly limited, but is preferably one that can press the surface to be treated, such as a sliding surface, with uniform pressure. For example, Figures 4 and 5
As shown in the figure, a roller 7, a frame 8, an adjuster nut 9, a lock nut 10, and a rotating shaft 1.
It may consist of 1. Thereafter, the sliding surface 3 of the sliding device member 1 formed in this way is subjected to an anodizing treatment (step D) to form an anodic oxide film 1.
2', it is possible to obtain a sliding device member 1 with a smooth surface, low roughness, and a sliding surface 3 that does not require post-processing, as shown in FIGS. 7 and 8. . The reason is as follows. When the aluminum alloy 5 containing silicon is anodized (step D), as shown in FIGS. 9 and 10, countless pores and cracks are formed in the anodic oxide film formed by the silicon 4 near the surface. causing the sliding surface 3
The surface becomes uneven with a ten-point average roughness of about 5 to 50 microns.

However, when the sliding surface 3 of the sliding device member 1 made of such an aluminum alloy 5 is pressed by the pressing member 6, as shown in FIG. Alloy components such as No. 4, which inhibit the formation of an anodic oxide film and are difficult to cause plastic deformation, are crushed into fine particles and can be transformed into a surface on which an anodic oxide film is easily formed (see FIG. 6). When the sliding equipment member 1 processed to such a surface is anodized (step D), pores and cracks are significantly reduced.
It is possible to obtain an anodic oxide film having a smooth surface with a ten-point average roughness of about 2 to 5 μm and less unevenness.

Next, specific experimental examples of the present invention will be shown, but the present invention is not limited thereto.

In this experiment, an aluminum casting alloy (JISH5202) was cast and formed (process A) and then machined (process B).
AC2B cylinder 1 (outer diameter 30mm, inner diameter 19mm, length
180 mm) using a pressing member 6 called a so-called roller vanishing with a tool diameter of 19 mm, in which six rollers 7 are arranged in the axial direction around a rotating shaft 11 as shown in FIGS. 4 and 5. and rotation speed 1400
Pressing processing C was performed on the inner surface of the cylinder 3 with a finishing allowance of 0.025 mm while rotating at a rotation rate of 0.025 mm. The inner surface roughness at this time was 0.5μ or less as a ten-point average roughness.
Thereafter, this cylinder 1 was degreased with trichlene, dried, and then anodized (step D) under the following conditions to form an anodic oxide film 12' having a thickness of 10 μm.

Electrolytic bath composition: 30% by weight sulfuric acid Bath temperature: 20°C Current density: 1.5 A/dm ² The film 12' thus obtained is extremely smooth as shown in Figures 7 and 8, and has a 10-point score. The average roughness was 2μ. On the other hand, a conventional comparative example is as follows. Cylinder 1 made of aluminum casting alloy AC2B (outer diameter 30 mm) was cast and formed (step A) using the same aluminum alloy (JISH5202) as in the example, and then machined (step B).
mm, inner diameter 19 mm, length 180 mm), the inner surface 3 was polished to adjust the surface to a ten-point average roughness of 0.5 μ or less. Thereafter, this cylinder 1 was degreased with trichlene and dried, and then subjected to anodizing treatment (step D) under the following conditions to form an anodic oxide film 12' having a thickness of 10 μm.

Electrolytic bath composition: 30 wt% sulfuric acid Bath temperature: 20°C Current density: 1.5 A/dm ^2The cross section of the anodic oxide film 12' thus obtained has extremely large irregularities, as shown in Figs. 9 and 10. The ten-point average roughness was 5μ.

A sliding device member 1 having a surface-reinforced sliding surface 3 made of the aluminum alloy 5 obtained as described above has a hard anodic oxide coating 1 on the sliding surface 3.
2', it has sufficient wear resistance. Furthermore, unlike an anodic oxide film whose sliding surface is smoothed by polishing with a grindstone or abrasive paper cloth, there is no risk of damage to the sliding surface 3 due to residual polishing debris. Furthermore, since there is no need to form an extra anodic oxide film corresponding to the amount of polishing, the anodizing process time can be shortened and extra electrical energy consumption can be avoided, compared to polishing work. The pressing operation C by the pressing member 6 is easy and can be mass-produced at low cost. Furthermore, since silicon particles are finely dispersed in the film, it has excellent corrosion resistance and lubricity.

[Brief explanation of the drawing]

The figures from FIG. 1 to FIG. 8 show an example of a sliding device member whose sliding surface has been subjected to a smooth anodizing treatment according to the present invention and its manufacturing method. A cross-sectional view of the member, FIG. 2 is a schematic diagram showing the manufacturing process according to the present invention in an easy-to-understand manner, FIG. 3 is a tissue diagram of the material before pressing in FIG. 2, and FIG. 4 is a front view of the pressing member. Figure 5 is an enlarged cross-sectional view taken along line A-A in Figure 4, Figure 6 is a structural diagram of the material after pressing in Figure 2, and Figure 7 shows the state of formation of the anodic oxide film. Fig. 8 is an enlarged cross-sectional photograph of the anodic oxide film on the sliding surface after pressing the pressing member corresponding to Fig. 7, and Fig. 9 shows the anodic oxide film applied without the conventional pressing process. An enlarged view showing the generated state,
FIG. 10 shows the anodic oxide film 1 of the conventional pressing member without pressing process, which corresponds to FIG. 9.
2' is an enlarged cross-sectional photograph. 1: Sliding device member, 2: Seal member, 3: Sliding surface, 4: Silicon, 5: Aluminum alloy containing silicon, 6: Pressing member, 7: Roller,
8: Claim, 9: Adjustment nut, 10: Lock nut, 11: Rotating shaft, 12: Anodic oxide film.

Claims (1)

[Claims] 1. In a sliding device member made of an aluminum alloy containing silicon and having a sliding surface into which a seal member is slidably inserted, the silicon distributed near the sliding surface is pressed harder than the aluminum alloy. Finishing allowance is 0.01 while rotating the parts.
By pressing at ~0.05 mm, the material is crushed into smaller pieces than the thickness of the anodic oxide film, and the sliding surface is anodized at a low current density to contain fine silicon particles in a dispersed state. Sliding equipment parts with anodized coating.