JPS6153437B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a vane type air pump, and more particularly to a combination of a vane and a mating member with which the vane slides.

It is known that alumite treatment on the surface of Al alloy improves its wear resistance. Utility Model Application No. 50-33712 proposes the use of aluminum treated with alumite and further impregnated with Teflon as the vane material for vane type air pumps. However, carbon materials are superior to vane materials in terms of weight, compatibility with the mating material, and properties such as not damaging the mating material and not wearing out itself, so carbon vanes are mainly used. . Therefore, it has been conventional practice to make the vanes of vane-type air pumps made of carbon, and to use a mating material such as a casing with an alumite-treated or chromium-plated Al--Si alloy. However, when the surface of the mating material is alumite-treated, there is a problem that the primary Si particles are exposed on the surface due to the polishing process performed after the alumite treatment, causing wear to the carbon vane and increasing frictional resistance. Even chrome plated ones have the disadvantage of high frictional resistance.

Therefore, an object of the present invention is to provide an air pump in which the wear resistance of the vanes and the mating member is improved and the frictional resistance is reduced.

That is, the present invention provides a variable volume vane type air pump in which the material of the vane is carbon, the mating material such as a casing with which the tip of the vane slides is made of an Al-Si alloy, and the surface of the mating material is It is characterized in that an anodic oxide film is formed on the surface of the anodic oxide film, and Si particles exposed on the surface of the anodic oxide film are removed by a Si removal treatment.

According to the present invention, a carbon material is used as the vane, and the counterpart material, that is, the casing is made of Al.
-Si alloy is used. This Al-Si alloy is alumite-treated to improve its wear resistance, and the Si particles on the surface are removed by the subsequent Si-removal treatment, which reduces wear on the carbon vane and improves its wear resistance. Frictional resistance, that is, driving resistance of the air pump can be reduced. In a preferred embodiment, the Si removal after alumite treatment is
This process consists of a physical treatment using a thorough polishing process and a chemical treatment to elute Si particles on the surface. If the amount of Si contained in the Al-Si alloy is large, most of it will be removed by the polishing process. Ru. In chemical treatment
Si is removed using, for example, a hydrofluoric acid aqueous solution. In this case, it is better to use a relatively dilute hydrofluoric acid aqueous solution;
For Al-Si alloys containing 19% Si, fluoric acid 10
Si may be removed by treating with a 5% aqueous solution for about 10 seconds and a 5% aqueous solution for about 40 seconds. Moreover, a mixed aqueous solution of hydrofluoric acid and nitric acid can also be used. The mating material of the present invention is typically made by die casting, molding, or sand casting of an Al--Si alloy, and is subjected to alumite treatment, followed by polishing and the above-mentioned Si removal treatment. In addition, a preferable vane lateral structure is made by compacting and firing carbon powder coated with a binder of pitcher resin to form a carbon block, and then impregnating it with resin, and is a composite containing 10% or less of resin. be. In addition, carbon is bonded with resin and molded,
It can also be produced by carbonizing the resin by firing and then further impregnating the resin into the pores generated by the carbonization of the resin. In this case as well, the resin content is kept to 10% or less.

Embodiments of the present invention will be described below with reference to the drawings.

1, an air pump 10 according to the present invention is shown. The pump 10 includes a casing 12
The rotor 14 is housed inside and rotates at an eccentric position. A plurality of radially extending vanes 16 are arranged on the rotor 14 at equal intervals. The amount of protrusion of the vane 16 from the rotor 14 is variable, and the amount of protrusion from the casing 12 is changed according to the rotation of the rotor 14.
The inner surface and the tip move while making contact, and the casing 1
The air inside 2 is discharged.

In the present invention, carbon is used as the material for the vane 16, and the casing 12 is made of an Al-Si alloy, and an anodized film is formed on the inner surface that makes sliding contact with the vane 16.
Particles are removed by a desilicon treatment.

With respect to the vane type air pump having such a structure, pump driving experiments were conducted by changing the material of the casing 12, that is, the mating material.

The casing material according to the present invention used in this experiment was made by casting Al-Si alloys with various Si contents.
It was subjected to T6 heat treatment, the required processing was performed, the surface was anodized, and then, after polishing, it was immersed in a hydrofluoric acid aqueous solution to remove Si.

Experimental conditions Pump capacity: 400c.c. Vane: carbon vane Rotation speed: 6000rpm Driving time: 10Hr The experimental results are shown in FIGS. 2 and 3.

FIG. 2 shows the relationship between the pump and drive torque corresponding to the frictional resistance between the vane and the mating material, and the amount of Si contained in the Al base material of the mating material. In the figure, line a indicates the Al-Si alloy in which Si is not removed, line b indicates that Si is removed before alumite treatment, and line c indicates the method according to the present invention. This is in accordance with the following. In the cases shown by lines a and b, the driving torque increases depending on the amount of Si in the base material. In addition, these devices have a large driving torque as a whole. This is thought to be due to the fact that Si particles are exposed on the surface of the oxide film formed by alumite treatment by subsequent polishing, and the line b indicates that after alumite treatment. This is thought to be the result of a combination of the fact that the surface of the oxide film is partially chipped due to polishing and the surface becomes rough, and that Si particles that could not be removed by the Si removal treatment before the alumite treatment protrude. What is shown by line c
The driving torque is uniformly low regardless of the Si content. Referring to FIG. 3, the relationship between the amount of vane wear and the amount of Si in the base material is shown. Lines a, b, and c in the figure are similar to those in FIG. 2. In this case as well, in the cases shown by lines a and b, the amount of wear of the carbon vanes is large, and the amount of wear tends to increase depending on the Si content. In addition,
The vane wear in Figure 3 has a tendency that is opposite to that shown by line a and line b compared to the case of drive torque in Figure 2. This is thought to be due to the strong influence of surface roughness of the material shown in b. In the case shown by line c, the amount of wear of the carbon vane is low overall, and the influence of changes in Si content is small.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of an air pump according to the invention;
FIG. 2 is a graph showing the relationship between the driving torque of the pump and the amount of Si in the base material, and FIG. 3 is a graph showing the relationship between the amount of vane wear and the amount of Si in the base material. Explanation of symbols, 10... Air pump, 12...
Casing, 14... rotor, 16... vane.

Claims (1)

[Claims] 1. In a variable volume vane type air pump, the material of the vane is carbon, the mating material with which the tip of the vane slides is an Al-Si alloy, and an anodized film is formed on the surface of the mating material. At the same time, the Si-free particles exposed on the surface of the anodic oxide film are removed.
An air pump characterized by having been removed by Si treatment.