JPH10246150A - Coating material for slide part and piston ring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating material for a slide part wherein an attack property to a mate material is small, even under a severe condition as in a high temperature high load, self wearing resistance can be ensured, adhesion generation due to direct contact between the base material and the mate material, according thereto, remarkable wearing of the base material and/or the mate material can be impeded for a long period. SOLUTION: In a coating material 1b for a slide part with a heat resistant resin serving as the base material, 50wt.% or more thereof is composed of heat resistant resin as the base material, and as at least a reinforcing particle, 5wt.% or more antimony oxide of 1 to 5μm grain size is contained.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coating material for a sliding portion, and more particularly to a coating material for a piston ring for an internal combustion engine.
The present invention relates to a coating material for a sliding portion which is suitable for preventing adhesion and abrasion due to direct contact between a base metal and a mating material, and a piston ring having the coating material formed on a surface thereof.

[0002]

2. Description of the Related Art In recent years, the operating environment of an internal combustion engine has become severer year by year as the performance of the engine increases.

[0003] Generally, the pistons of these internal combustion engines include:
A piston ring is installed to ensure the airtightness of the combustion chamber and to control the lubricating oil inside the cylinder. Especially in high-temperature and high-load conditions, the aluminum alloy used as the piston material is The phenomenon that the piston material is worn on the ring surface may occur, which may cause problems such as a decrease in airtightness of the combustion chamber and an increase in oil consumption.

In order to prevent this, in some engines, a heat-resistant resin is used as a binder on the upper and lower surfaces of the piston ring with the aim of preventing the direct contact between the piston ring base material and the piston and improving the lubrication state. A solid lubricating film is formed.

[0005] Conventionally, such a solid lubricating coating is made of, for example, molybdenum disulfide, graphite, PTFE using epoxy resin or polyamide imide resin as a binder.
It is known that a solid lubricant such as (polytetrafluoroethylene) is appropriately contained.

[0006]

However, such a conventional solid lubricating film is effective in reducing the friction of the sliding surface, but is subject to high temperature and high load, particularly, a piston ring of a high power engine. When used under such severe conditions, the wear of the coating itself progresses rapidly, and sufficient durability cannot be obtained. As a result, the adhesion between the piston ring base material and the piston is early. There is a problem that abrasion may occur.

On the other hand, if carbon fibers or glass fibers are blended in the same manner as a general resin composite material in order to improve the wear resistance of the coating, the aggressiveness of the mating material becomes large, and this increases the piston ring coating. When used as a material, there is a problem that a piston as a mating material may be worn.

Therefore, in the case of an aluminum alloy piston, under such severe conditions, higher cost measures such as anodizing the sliding surface of the piston with the piston ring must be adopted. Was the actual situation.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in view of such conventional problems, and has low aggressiveness to a mating material, and can be used under severe sliding conditions such as high temperature and high load. Of the base material and / or cohesion caused by direct contact between the base material and the mating material.
Or by providing a coating material for sliding parts that can prevent significant wear of the mating material for a long period of time,
The purpose is to realize the wear performance at low cost without using a complicated mechanism.

[0010]

In order to achieve the above object,
The sliding portion coating material of the present invention is, as described in claim 1, a sliding portion coating material having a heat-resistant resin as a base material, and 50% by weight or more of the sliding portion coating material as a base material. It is made of a heat-resistant resin, and has a particle size of at least 1 as reinforcing particles.
It is characterized by containing 5% by weight or more of 5 μm antimony oxide.

The coating material for a sliding portion according to the present invention is:
As described in claim 2, the heat-resistant resin as the base material can be at least one selected from polyamideimide and polyimide.

Further, the coating material for a sliding portion according to the present invention comprises:
As described in claim 3, a solid lubricant can be contained as a lubricity improving component. In this case, as described in claim 4, the solid lubricant is graphite. , PTFE (polytetrafluoroethylene), MoS ₂ , and WS ₂ .

Further, in the coating material for a sliding portion according to the present invention, 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, the phosphating treatment may be a manganese phosphate treatment, as described in claim 6.

Further, the piston ring according to the present invention is, as described in claim 7, claimed in claims 1 to 6.
Wherein the coating material for a sliding portion is formed on at least one of the front and back surfaces perpendicular to the reciprocating direction of the piston.

[0015]

The coating material for a sliding portion of the present invention is, as described in claim 1, a coating material for a sliding portion having a heat-resistant resin as a base material, of which 50% by weight or more. Is composed of a heat-resistant resin as a base material, and contains at least 5% by weight or more of antimony oxide having a particle size of 1 to 5 μm as reinforcing particles. By using a heat-resistant resin as a base material, it can be used for sliding parts at high temperatures. By adding antimony oxide to the base material, the coating is strengthened and excellent wear resistance is imparted.

Further, antimony oxide is not too high in hardness as compared with carbon fiber or glass fiber used in general resin composite materials, has a nearly spherical particle shape, and has no edge, so that it can be used as a counterpart material. Is less aggressive, and even when a relatively soft metal such as aluminum is combined as the mating sliding member, the wear is not promoted.

However, if the amount of antimony oxide is less than 5% by weight, a sufficient effect of improving the abrasion resistance cannot be obtained, and the amount of the heat-resistant resin forming the film as the base material is less than 50%. When the amount is less than the weight percentage, the bonding property of the coating is insufficient, and the amount of wear of the coating itself may be increased.

If the particle size of the added antimony oxide particles is less than 1 μm, the effect of improving the abrasion resistance is small. May be difficult to form.

According to a second aspect of the present invention, there is provided the coating material for a sliding portion, wherein the heat-resistant resin serving as the base material is at least one kind selected from polyamideimide and polyimide. However, since these resins are particularly excellent in heat resistance and also have excellent sliding properties, by using them as a base material, they can be suitably used for higher temperature sliding parts. It can be used.

Further, the sliding portion coating material of the present invention may contain a solid lubricant as a lubricity improving component as described in claim 3. As described in Item 4, the solid lubricant may include at least one selected from graphite, PTFE, MoS ₂ , and WS ₂ .

In particular, when used in an environment where lubrication is severe, lubricating properties can be imparted by appropriately adding a solid lubricant to the coating material, and friction loss during sliding can be reduced. Further, the durability of the coating material itself can be further improved by reducing the frictional heat generated thereby. As the solid lubricant, graphite which is particularly excellent in heat resistance, fluorine resin such as PTFE which is highly effective in reducing the friction coefficient under a relatively low load, depending on the sliding conditions, lubrication with good balance in a wide temperature range Mo showing sex
By including at least one selected from S ₂ and WS _2, the effect of imparting such lubricity is further enhanced.

Further, as described in claim 5, the coating material for a sliding portion of the present invention has a base material 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 can be a manganese phosphate treatment.

By performing a phosphate treatment as a base treatment, the adhesion strength to the base material is further improved, and a coating material having further excellent stability can be obtained. In addition, by using a manganese phosphate treatment that provides a dense, high-strength, and heat-resistant treatment layer as the phosphate treatment, a more effective base treatment layer can be obtained, and the stability of the coating material can be improved. Is even higher.

However, the roughness of the phosphating layer is Rmax
When the thickness is less than 1 μm, the effect of improving the adhesion strength is not sufficient,
If it exceeds μm, it becomes difficult to form a uniform coating when forming the coating material, which causes early peeling and falling off during sliding.

When applying the coating material for a sliding portion of the present invention having the above-described excellent characteristics, the upper and lower surfaces of the piston ring for the internal combustion engine (the piston By forming and using at least one of the front and back surfaces in a direction perpendicular to the reciprocating direction, the adhesion between the piston ring base material and the piston can be prevented even under severe conditions such as high temperature and high load. Wear will be prevented for a long period of time.

[0026]

According to the present invention, the coating material for a sliding portion according to the present invention is a coating material for a sliding portion having a heat-resistant resin as a base material. The above consists of a heat-resistant resin as a base material, and at least 5 wt% of antimony oxide having a particle size of 1 to 5 μm as reinforcing particles.
Since it has a configuration containing the above, it can be used not only for high-temperature sliding parts, but also has excellent abrasion resistance without increasing aggressiveness to a mating material, and can be used for a long time with the base metal. A remarkably excellent effect that adhesion and abrasion with a counterpart material can be prevented is brought about.

Further, the coating material for a sliding portion according to the present invention comprises:
As described in claim 2, by setting the heat-resistant resin as the base material to be at least one selected from polyamideimide and polyimide, the heat resistance can be further improved. This has a remarkable effect that it can be suitably used for higher temperature sliding parts.

Further, the sliding portion coating material according to the present invention contains a solid lubricant as a lubricity improving component as described in claim 3 to thereby provide friction during sliding. The durability of the coating material itself can be further improved together with the reduction of the loss, and the solid lubricant is made of graphite or PTF.
At least one selected from E, MoS ₂ , and WS ₂
By including seeds, a remarkable effect that the above effects can be further improved is brought about.

Further, the coating material for a sliding portion according to the present invention is:
As described in claim 5, the base material has been subjected to a phosphate treatment with a surface roughness Rmax of 1 to 10 μm as a base treatment, thereby further improving the adhesion to the base metal. It is possible to obtain a coating material having higher stability, and as described in claim 6, the phosphate treatment is a manganese phosphate treatment, so that a denser coating can be obtained. Thus, a ground treatment layer having high strength and excellent heat resistance can be obtained, and a remarkably excellent effect that the stability of the coating material can be further enhanced can be obtained.

When the coating material for a sliding portion of the present invention having such excellent characteristics is applied, the reciprocating direction of the piston of the piston ring for an internal combustion engine is determined as described in claim 7. By forming and using at least one of the front and back surfaces in the direction perpendicular to each other, adhesion between the piston ring base material and the piston can be achieved even under severe conditions such as high temperature and high load such as a high power engine. It is possible to prevent the occurrence and progress of abrasion at an unprecedented level for a long period of time.

[0031]

Next, examples will be described together with comparative examples.

Examples 1 to 5 PAI (polyamide imide) resin was selected as a heat-resistant resin as a base material, and was dissolved in n-methyl-2-pyrrolidone and xylene as a solvent. Antimony oxide (Sb ₂ O ₃ ) with a particle size of 3 μm
And a solid lubricant selected from graphite, PTFE, MoS ₂ , and WS ₂ so as to have a composition shown in Examples 1 to 5 in Table 1 to prepare a solution.

Next, after surface adjustment such as degreasing is performed on the upper surface of the piston ring base material made of spring steel, the surface roughness R
A manganese phosphate treatment with a max of about 5 μm is performed, and the solution prepared above is spray-coated and dried,
Heating and baking at about 180-220 ° C, as shown in FIG.
A test piece of the piston ring 1 having a coating material 1b with a film thickness of about 10 μm formed on the upper surface of the piston ring substrate 1a was obtained.

Comparative Examples 1 and 2 The same PAI resin as used in the above Examples was used for n-methyl-2.
-In a solution of pyrrolidone and xylene as a solvent,
A solution was prepared by mixing a solid lubricant such as graphite so as to have the composition shown in Comparative Examples 1 and 2 in Table 1.

Next, after surface adjustment such as degreasing is performed on the upper surface of the piston ring base material made of spring steel, the surface roughness R
A manganese phosphate treatment with a max of about 5 μm is performed, and the solution prepared above is spray-coated and dried,
As shown in FIG. 1, a test piece of the piston ring 1 in which the coating material 1b having a thickness of about 10 μm was formed on the upper surface of the piston ring substrate 1a as shown in FIG. .

COMPARATIVE EXAMPLES 3-5 The same PAI resin used in the above Examples was replaced with n-methyl-2
-In a solution of pyrrolidone and xylene as a solvent,
Antimony oxide having an average particle size of 3 μm (S
b ₂ O ₃ ) and a solid lubricant such as graphite were prepared so as to have a composition shown in Comparative Examples 3 to 5 in Table 1.

Next, after surface adjustment such as degreasing is performed on the upper surface of the piston ring base material made of spring steel, the surface roughness R
A manganese phosphate treatment with a max of about 5 μm is performed, and the solution prepared above is spray-coated and dried,
As shown in FIG. 1, a test piece of the piston ring 1 in which the coating material 1b having a thickness of about 10 μm was formed on the upper surface of the piston ring substrate 1a as shown in FIG. .

COMPARATIVE EXAMPLE 6 The same PAI resin used in the above example was replaced with n-methyl-2
-In a solution of pyrrolidone and xylene as a solvent,
A solution was prepared in which carbon fiber as a reinforcing component and a solid lubricant such as graphite were mixed so as to have a composition shown in Comparative Example 6 in Table 1.

Next, after surface adjustment such as degreasing is performed on the upper surface of the piston ring base material made of spring steel, the surface roughness R
A manganese phosphate treatment with a max of about 5 μm is performed, and the solution prepared above is spray-coated and dried,
As shown in FIG. 1, a test piece of the piston ring 1 in which the coating material 1b having a thickness of about 10 μm was formed on the upper surface of the piston ring substrate 1a as shown in FIG. .

COMPARATIVE EXAMPLE 7 The same PAI resin used in the above example was replaced with n-methyl-2
-In a solution of pyrrolidone and xylene as a solvent,
A solution was prepared by mixing glass fiber as a reinforcing component and a solid lubricant such as graphite so as to have a composition shown in Comparative Example 7 in Table 1.

Next, after surface adjustment such as degreasing is performed on the upper surface of the piston ring base material made of spring steel, the surface roughness R
A manganese phosphate treatment with a max of about 5 μm is performed, and the solution prepared above is spray-coated and dried,
As shown in FIG. 1, a test piece of the piston ring 1 in which the coating material 1b having a thickness of about 10 μm was formed on the upper surface of the piston ring substrate 1a as shown in FIG. .

[0042]

[Table 1]

(Adhesive Wear Test) Examples 1 to 5 and Comparative Example 1
The test piece of each piston ring 1 obtained in FIGS.
As shown in Table 2, a single piece adhesion wear test was performed under the conditions shown in Table 2 (the test temperature was set by the heater 3) with the cut material 2 actually cut from the aluminum alloy piston as the mating material. Was compared with the amount of wear of the mating member 5 hours after the start of the test. Table 3 shows the results.

[0044]

[Table 2]

[0045]

[Table 3]

As is clear from Table 3, Example 1 of the present invention
Those of the 5, Comparative Example without the addition of _Sb 2 _{O 3} is a reinforcing particles 1 and Comparative Example 2, _Sb 2 _{O 3} addition amount Comparative Example 3 outside the scope of the present invention, furthermore, Sb ₂ O
Comparative Example 4, in which the total amount of the additional components including No. ₃ was large and the proportion of the base heat-resistant resin was out of the range of the present invention,
Also, it can be seen that the durability time until the occurrence of adhesion is greatly improved as compared with Comparative Example 5.

In Comparative Examples 6 and 7, the durable time until the occurrence of adhesion is equal to that of the inventive example, but the wear amount of the mating material is significantly increased as compared with the inventive example. From these facts, it was found that the coating material for a sliding portion of the present invention has an excellent performance that cannot be obtained by a conventional coating material.

[Brief description of the drawings]

FIG. 1 is a partially enlarged 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 Coating material 1s Sliding surface 2 Cutting material from piston 3 Heater

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masahiko Shioda 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture Nissan Motor Co., Ltd. (72) Inventor Katsuhiro Kishi 2 Takaracho, Kanagawa-ku, Yokohama-shi, Kanagawa Nissan Automobile Stock In company

Claims (7)

[Claims] 1. A coating material for a sliding portion comprising a heat-resistant resin as a base material, wherein 50% by weight or more of the coating material is made of a heat-resistant resin as a base material, and at least reinforcing particles have a particle size of 1 to 5 μm. A coating material for a sliding portion, comprising 5% by weight or more of antimony oxide of the present invention. 2. The coating material for a sliding portion according to claim 1, wherein the heat-resistant resin as the base material is at least one selected from polyamideimide and polyimide. 3. The coating material for a sliding portion according to claim 1, further comprising a solid lubricant as a lubricity improving component. 4. A solid lubricant comprising graphite, PTF
At least one selected from E, MoS ₂ , and WS ₂
The coating material for a sliding part according to claim 3, comprising a seed. 5. A base material having a surface roughness Rmax as a base treatment.
The coating material for a sliding portion according to any one of claims 1 to 4, wherein a phosphate treatment of 1 to 10 µm has been performed. 6. The coating material for a sliding part according to claim 5, wherein the phosphate treatment is a manganese phosphate treatment. 7. A piston, wherein the coating material for a sliding portion according to claim 1 is formed on at least one of front and back surfaces orthogonal to a reciprocating direction of the piston. ring.