JP3613500B2 - Piston ring coating - Google Patents

Description

【００４３】
（凝着摩耗試験）
実施例１〜５，比較例１〜７で得た各ピストンリング１のテストピースを、図２に示すように、実際のアルミニウム合金製ピストンからの切り出し材２を相手材として、表２に示す条件（試験温度は加熱ヒーター３により設定）で単体凝着摩耗試験を行い、摺動面１ｓでの凝着発生までの時間と、試験開始から５時間経過時点での相手材摩耗量を比較した。その結果を表３に示す。
【００４４】
【表２】

【００４５】
【表３】

【００４６】
表３より明らかなように、本発明実施例１〜５に係るものは、強化粒子であるＳｂ_２Ｏ_３を添加していない比較例１および比較例２、Ｓｂ_２Ｏ_３の添加量が本発明の範囲から外れる比較例３、さらに、Ｓｂ_２Ｏ_３を含めた添加成分全体の添加量が多く、ベースとなる耐熱性樹脂の割合が本発明の範囲から外れる比較例４、および比較例５に比べ、凝着発生までの耐久時間が大きく向上していることがわかる。
【００４７】
また、比較例６および比較例７は、凝着発生までの耐久時間は本発明実施例と同等であるが、相手材の摩耗量が本発明実施例と比較して著しく増加しており、これらのことから、本発明のピストンリング用被覆材は、従来の被覆材では得られない優れた性能を有していることがわかった。
【図面の簡単な説明】
【図１】本発明の実施例を示すピストンリングの一部拡大断面説明図である。
【図２】単体凝着摩耗試験の概要を示す断面説明図である。
【符号の説明】
１ ピストンリング
１ａ ピストンリング基材
１ｂ 被覆材
１ｓ 摺動面
２ ピストンからの切り出し材
３ 加熱ヒーター[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a coating material for a piston ring, and in particular, adhesion and wear due to direct contact with a base metal, ie, a piston made of an aluminum alloy, coated on a piston ring made of spring steel for an internal combustion engine. The present invention relates to a covering material for a piston ring that is suitable for preventing the above.
[0002]
[Prior art]
In recent years, as the performance of internal combustion engines has increased, the operating environment has become severe year by year.
[0003]
In general, pistons of these internal combustion engines are equipped with piston rings to ensure the airtightness of the combustion chamber and to control the appropriate lubricating oil in the cylinders. The aluminum alloy used as a material adheres to the surface of the piston ring, and the piston material may wear out. This causes a decrease in the airtightness of the combustion chamber and an increase in oil consumption. May cause problems.
[0004]
In order to prevent this, in some engines, a solid lubricant film with a heat-resistant resin binder on the upper and lower surfaces of the piston ring is aimed at preventing direct contact between the piston ring base material and the piston and improving the lubrication state. Is formed.
[0005]
As such a conventional solid lubricating coating, for example, a coating containing epoxy resin, polyamideimide resin or the like as a binder and appropriately containing a solid lubricant such as molybdenum disulfide, graphite, or PTFE (polytetrafluoroethylene) is known. ing.
[0006]
[Problems to be solved by the invention]
However, such a conventional solid lubricant film is effective in reducing friction on the sliding surface, especially when used under severe conditions such as high temperature and high load such as piston rings of high-power engines. In this case, the abrasion of the coating itself becomes intense, and sufficient durability cannot be obtained. As a result, adhesion and wear between the piston ring base material and the piston may occur at an early stage. There was a problem that there was.
[0007]
On the other hand, in order to improve the wear resistance of the coating, if carbon fibers or glass fibers are blended in the same way as general resin composite materials, the attack on the other material increases, and this is used as a coating material for piston rings. In such a case, there is a problem that the piston which is the counterpart material may be worn.
[0008]
For this reason, in the case of an aluminum alloy piston, under such severe conditions, it is a fact that higher cost measures such as anodizing the sliding surface of the piston with the piston ring must be adopted. there were.
[0009]
OBJECT OF THE INVENTION
The present invention has been made in view of such a conventional problem, and is less aggressive to the mating material. Further, the present invention has its own wear resistance even under severe sliding conditions such as high temperature and high load. By providing a coating material for a piston ring that can secure and prevent the occurrence of adhesion due to direct contact between the base material and the counterpart material and the significant wear of the base material and / or the counterpart material for a long time. The purpose is to realize low adhesion and wear performance at low cost without using a complicated mechanism.
[0010]
In order to achieve the above object, a piston ring covering material according to the present invention is a piston ring covering material based on a heat-resistant resin as described in claim 1, wherein the covering material is aluminum. It is formed on at least one surface of the front and back surfaces of the piston ring made of spring steel perpendicular to the reciprocating direction of the alloy piston, and 50% by weight or more thereof is made of a heat-resistant resin as a base material, and It is characterized in that it contains at least 5% by weight of antimony oxide having a particle diameter of 1 to 5 μm as reinforcing particles.
[0011]
And as for the coating material for piston rings which concerns on this invention, as described in Claim 2, the heat resistant resin as a base material shall be at least 1 sort (s) chosen from polyamideimide and a polyimide. be able to.
[0012]
Further, as described in claim 3, the piston ring covering material according to the present invention may contain a solid lubricant as a lubricity improving component. As described, the solid lubricant may include at least one selected from graphite, PTFE (polytetrafluoroethylene), MoS ₂ , and WS ₂ .
[0013]
Furthermore, as described in claim 5, the covering material for a piston ring according to the present invention is such that the base material is subjected to a phosphate treatment with a surface roughness Rmax of 1 to 10 μm as a base treatment. In that case, as described in claim 6, the phosphating treatment can be a manganese phosphate treatment.
[0015]
[Effects of the Invention]
The piston ring covering material of the present invention is, as described in claim 1, a piston ring covering material based on a heat-resistant resin, wherein the covering material is a reciprocating direction of an aluminum alloy piston. Is formed on at least one surface of the front and back surfaces of a piston ring made of spring steel orthogonal to the above, and 50% by weight or more thereof is made of a heat-resistant resin as a base material, and has a particle size of at least 1 as reinforcing particles. It has a structure containing 5% by weight or more of antimony oxide of ˜5 μm, but the coating material for piston rings according to the present invention can be used for a high temperature sliding part by using a heat resistant resin as a base material. Thus, by adding antimony oxide thereto, the coating is strengthened and excellent wear resistance is imparted.
[0016]
In addition, antimony oxide is not too hard compared to carbon fibers and glass fibers used in general resin composites, and the particle shape is nearly spherical and has no edges, so it is aggressive against other materials. Even when a relatively soft metal such as aluminum is combined as the mating sliding member, the wear is not accelerated.
[0017]
However, if the amount of antimony oxide added is less than 5% by weight, it is not possible to obtain a sufficient effect of improving wear resistance, and the amount of the heat-resistant resin forming a film as the base material is less than 50% by weight. Then, the bonding property of the film is insufficient, and there is a risk that the amount of wear increases.
[0018]
Furthermore, when the particle size of the antimony oxide particles to be added is less than 1 μm, the effect of improving the wear resistance is small. It can be difficult.
[0019]
As described in claim 2, the piston ring coating material of the present invention is such that the heat-resistant resin serving as the base material is at least one selected from polyamideimide and polyimide. However, since these resins are particularly excellent in heat resistance and also excellent in sliding properties, by using these as a base material, they can be suitably used for higher temperature sliding parts. Become.
[0020]
Further, as described in claim 3, the covering material for piston rings of the present invention can contain a solid lubricant as a lubricity improving component. As described above, the solid lubricant may include at least one selected from graphite, PTFE, MoS ₂ , and WS ₂ .
[0021]
In particular, when used in a severely lubricated environment, lubricity can be imparted by appropriately including a solid lubricant in the coating material, and friction loss during sliding can be reduced. In addition, the durability of the coating material itself can be further improved by reducing the frictional heat generation associated therewith. As solid lubricants, depending on sliding conditions, graphite that is particularly excellent in heat resistance, fluorine resin such as PTFE that is highly effective in reducing the friction coefficient at relatively low loads, and well-balanced lubrication in a wide temperature range By including at least one selected from MoS ₂ and WS ₂ exhibiting properties, the lubricity imparting action is further improved.
[0022]
Furthermore, as described in claim 5, the coating material for piston rings of the present invention is such that the base material is subjected to a phosphate treatment with a surface roughness Rmax of 1 to 10 μm as a base treatment. In this case, as described in claim 6, the phosphate treatment may be a manganese phosphate treatment.
[0023]
By performing the phosphate treatment as the ground treatment, the adhesion strength with the base material is further improved, and the coating material is further excellent in stability. In addition, as this phosphating treatment, a more effective base treatment layer can be obtained by using a manganese phosphate treatment that provides a dense, high-strength, heat-resistant treatment layer, and the stability of the coating material Is further increased.
[0024]
However, if the roughness of the phosphate treatment layer is less than Rmax 1 μm, the effect of improving the adhesion strength is not sufficient, and if it exceeds 10 μm, it becomes difficult to form a uniform film at the time of forming the coating material, and early peeling and falling off during sliding Cause.
[0025]
When applying the piston ring covering material of the present invention having the above-described excellent characteristics, at least one of the upper and lower surfaces (front and back surfaces in the direction orthogonal to the reciprocating direction of the piston) of the piston ring for an internal combustion engine By using it on the surface, adhesion and wear between the piston ring base material made of spring steel and the aluminum alloy piston can occur for a long time even under severe conditions such as high temperature and high load. Will be prevented.
[0026]
【The invention's effect】
The covering material for a piston ring according to the present invention is a covering material for a piston ring that uses a heat-resistant resin as a base material, as described in claim 1, and the covering material is a reciprocating motion of an aluminum alloy piston. It is formed on at least one of the front and back surfaces of a piston ring made of spring steel perpendicular to the direction, and 50% by weight or more is made of a heat-resistant resin as a base material, and at least a particle size as reinforcing particles Since it has a structure containing 5% by weight or more of antimony oxide of 1 to 5 μm, it can be used not only for a high temperature sliding part, but also has excellent wear resistance without increasing the aggressiveness to the mating material. Is provided, and it is possible to prevent the adhesion and wear between the base metal and the counterpart material over a long period of time.
[0027]
And as for the coating material for piston rings which concerns on this invention, as described in Claim 2, the heat resistant resin as a base material shall be at least 1 sort (s) chosen from polyamideimide and a polyimide. As a result, the heat resistance can be further increased, and a remarkable effect is obtained that it can be suitably used for a higher temperature sliding portion.
[0028]
Further, as described in claim 3, the piston ring covering material according to the present invention contains a solid lubricant as a lubricity improving component, thereby reducing friction loss during sliding. It becomes possible to further improve the durability of the coating material itself. Further, as described in claim 4, the solid lubricant is at least one selected from graphite, PTFE, MoS ₂ , and WS _2. By including the seed, the above-described effect can be further improved, which is a remarkable effect.
[0029]
Furthermore, as described in claim 5, the coating material for a piston ring according to the present invention is such that the base material is subjected to a phosphate treatment with a surface roughness Rmax of 1 to 10 μm as a base treatment. Thus, the adhesion to the base metal can be further enhanced, and it becomes possible to obtain a coating material with further excellent stability. By using manganese oxide treatment, it is possible to obtain a ground treatment layer that is denser, higher in strength, and excellent in heat resistance, and can be further improved in stability of the coating material. The effect is brought about.
[0030]
When applying the piston ring covering material of the present invention having such excellent characteristics, the front and back surfaces of the piston ring made of spring steel for an internal combustion engine in the direction orthogonal to the reciprocating direction of the aluminum alloy piston of the piston ring By forming and using it on at least one surface, the piston ring base material made of spring steel and the aluminum alloy piston are used even under severe conditions such as high-power engines and high loads. A remarkable effect is achieved in that it is possible to prevent the occurrence of adhesion, wear, and the progress thereof for a long time at an unprecedented level.
[0031]
【Example】
Next, examples will be described together with comparative examples.
[0032]
Examples 1-5
A PAI (polyamideimide) resin is selected as a heat-resistant resin as a base material, and this is dissolved in n-methyl-2-pyrrolidone and xylene as a solvent, and antimony oxide (Sb) having an average particle size of 3 μm as reinforcing particles. ₂ O ₃ ) and a solid lubricant selected from graphite, PTFE, MoS ₂ and WS ₂ were prepared so as to have the compositions shown in Examples 1 to 5 in Table 1.
[0033]
Next, after the surface adjustment such as degreasing is performed on the upper surface of the piston ring base material made of spring steel, manganese phosphate treatment with a surface roughness Rmax of about 5 μm is performed. After spraying and drying, a test of the piston ring 1 in which a coating material 1b having a film thickness of about 10 μm is formed on the upper surface of the piston ring substrate 1a as shown in FIG. I got a piece.
[0034]
Comparative Examples 1 and 2
The same PAI resin as used in the above example was dissolved in n-methyl-2-pyrrolidone and xylene as a solvent, and a solid lubricant such as graphite was blended so as to have the composition shown in Comparative Examples 1 and 2 in Table 1. Solution was made.
[0035]
Next, after the surface adjustment such as degreasing is performed on the upper surface of the piston ring base material made of spring steel, manganese phosphate treatment with a surface roughness Rmax of about 5 μm is performed. After spraying and drying, the piston is heated and fired at about 180 to 220 ° C., and a coating material 1b having a film thickness of about 10 μm is formed on the upper surface of the piston ring base 1a as shown in FIG. A test piece of ring 1 was obtained.
[0036]
Comparative Examples 3-5
In the same PAI resin as used in the above example, n-methyl-2-pyrrolidone, xylene dissolved in a solvent, antimony oxide (Sb ₂ O ₃ ) having an average particle size of 3 μm as reinforcing particles, and a solid such as graphite A solution in which the lubricant was blended so as to have the composition shown in Comparative Examples 3 to 5 in Table 1 was prepared.
[0037]
Next, after the surface adjustment such as degreasing is performed on the upper surface of the piston ring base material made of spring steel, manganese phosphate treatment with a surface roughness Rmax of about 5 μm is performed. After spraying and drying, the piston is heated and fired at about 180 to 220 ° C., and a coating material 1b having a film thickness of about 10 μm is formed on the upper surface of the piston ring base 1a as shown in FIG. A test piece of ring 1 was obtained.
[0038]
Comparative Example 6
The same PAI resin as used in the above example was dissolved in n-methyl-2-pyrrolidone and xylene as a solvent. Carbon fiber as a reinforcing component and a solid lubricant such as graphite are shown in Comparative Example 6 in Table 1. A solution formulated to have a composition was prepared.
[0039]
Next, after the surface adjustment such as degreasing is performed on the upper surface of the piston ring base material made of spring steel, manganese phosphate treatment with a surface roughness Rmax of about 5 μm is performed. After spraying and drying, the piston is heated and fired at about 180 to 220 ° C., and a coating material 1b having a film thickness of about 10 μm is formed on the upper surface of the piston ring base 1a as shown in FIG. A test piece of ring 1 was obtained.
[0040]
Comparative Example 7
Comparative Example 7 in Table 1 shows the same PAI resin as used in the above examples dissolved in n-methyl-2-pyrrolidone and xylene as a solvent, glass fiber as a reinforcing component, and solid lubricant such as graphite. A solution formulated to have a composition was prepared.
[0041]
Next, after the surface adjustment such as degreasing is performed on the upper surface of the piston ring base material made of spring steel, manganese phosphate treatment with a surface roughness Rmax of about 5 μm is performed. After spraying and drying, the piston is heated and fired at about 180 to 220 ° C., and a coating material 1b having a film thickness of about 10 μm is formed on the upper surface of the piston ring base 1a as shown in FIG. A test piece of ring 1 was obtained.
[0042]
[Table 1]

[0043]
(Adhesive wear test)
As shown in FIG. 2, the test pieces of the piston rings 1 obtained in Examples 1 to 5 and Comparative Examples 1 to 7 are shown in Table 2 with the cut material 2 from the actual aluminum alloy piston as the counterpart material. A single adhesion wear test was performed under the conditions (the test temperature was set by the heater 3), and the time until the occurrence of adhesion on the sliding surface 1s was compared with the wear amount of the mating material after 5 hours from the start of the test. . The results are shown in Table 3.
[0044]
[Table 2]

[0045]
[Table 3]

[0046]
As is apparent from Table 3, Comparative Examples 1 and _{2 to} which the reinforcing particles Sb ₂ O ₃ are not added are added in the present Examples 1 to 5, and the added amount of Sb ₂ O ₃ is the present amount. Comparative Example 3 deviating from the scope of the invention, and Comparative Example 4 and Comparative Example 5 in which the amount of the entire additive component including Sb ₂ O ₃ is large and the ratio of the heat-resistant resin serving as the base deviates from the scope of the present invention. It can be seen that the durability time until the occurrence of adhesion is greatly improved.
[0047]
In Comparative Example 6 and Comparative Example 7, the durability time until the occurrence of adhesion is the same as that of the example of the present invention, but the wear amount of the counterpart material is remarkably increased as compared with the example of the present invention. From the above, it was found that the piston ring coating material of the present invention has excellent performance that cannot be obtained by the conventional coating material.
[Brief description of the drawings]
FIG. 1 is a partially enlarged cross-sectional explanatory view of a piston ring showing an embodiment of the present invention.
FIG. 2 is an explanatory cross-sectional view showing an outline of a single adhesion wear test.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Piston ring 1a Piston ring base material 1b Cover material 1s Sliding surface 2 Cutting material from piston 3 Heating heater

Claims (6)

A piston ring covering material based on a heat resistant resin, wherein the covering material is formed on at least one of the front and back surfaces of a piston ring made of spring steel perpendicular to the reciprocating direction of an aluminum alloy piston. A piston ring coating comprising 50% by weight or more of a heat-resistant resin as a base material and containing at least 5% by weight of antimony oxide having a particle diameter of 1 to 5 μm as reinforcing particles Wood. 2. The covering material for a piston ring according to claim 1, wherein the heat resistant resin as the base material is at least one selected from polyamide imide and polyimide. 3. The covering material for a piston ring according to claim 1 or 2, comprising a solid lubricant as a lubricity improving component. 4. The covering material for a piston ring according to claim 3, wherein the solid lubricant contains at least one selected from graphite, PTFE, MoS ₂ and WS ₂ . The coating material for a piston ring according to any one of claims 1 to 4, wherein the base material is subjected to a phosphate treatment with a surface roughness Rmax of 1 to 10 µm as a base treatment. The coating material for a piston ring according to claim 5, wherein the phosphate treatment is a manganese phosphate treatment.

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