JP6941476B2 - Resin material for sliding members and sliding members - Google Patents

Description

The present invention relates to a resin material for a sliding member and a sliding member using the same.

As a resin material used for a sliding member, a resin material in which graphite is added to a binder resin is known. For example, Patent Document 1 describes a resin material containing graphite particles having a shape close to a sphere.

Japanese Patent No. 5683571

In the technique described in Patent Document 1, since the size of the additive is relatively large, there is a problem that the surface roughness of the processed surface becomes rough when the additive falls off from the processed surface during cutting. was there.

On the other hand, the present invention provides a technique for suppressing the roughness of the surface roughness after cutting.

The present invention contains a binder resin and an additive contained in the binder resin, and the additive contains a solid lubricant and hard particles, and the average particle size of the additive is 5 μm or less. Provided is a resin material for a certain sliding member.

The average particle size of each of the additives may be 3 μm or less.

The binder resin may contain polyimide.

The solid lubricant may be graphite and the hard particles may be clay.

The binder resin may be contained in an amount of 85% by volume or more.

The additive may not contain _{MoS 2.}

The present invention also provides a sliding member having a base material and a resin coating layer formed on the base material using any of the above resin materials for sliding members.

According to the present invention, it is possible to suppress the roughness of the surface roughness after cutting.

The figure which illustrates the cross-sectional structure of the sliding member 1 which concerns on one Embodiment. The schematic diagram which shows the surface shape at the time of cutting.

1. 1. Configuration FIG. 1 is a diagram illustrating a cross-sectional structure of a sliding member 1 according to an embodiment. The sliding member 1 is, for example, a sliding member used in a fuel injection pump. The sliding member 1 has a base material 11, a sintered layer 12, and a resin coating layer 13. The base material 11 is a layer for imparting the shape and mechanical strength of the sliding member 1. The base material 11 is made of, for example, steel. The sintered layer 12 is a layer for improving the adhesion between the resin coating layer 13 and the base material 11, and is formed of a metal powder, for example, copper or a copper alloy powder.

The resin coating layer 13 is formed of a resin material for sliding members. This resin material contains a binder resin 131 and an additive 132 dispersed in the binder resin 131. As the binder resin 131, for example, a thermosetting resin, more specifically, at least one of a polyimide (PI) resin and a polyamide-imide (PAI) resin is used. From the viewpoint of improving fatigue resistance, it is preferable to use PI resin rather than PAI resin, and among PI resins, those with high strength (here, "high strength" means those having a tensile strength of 150 MPa or more). Is preferably used. From the viewpoint of improving fatigue resistance, the content of the binder resin in the resin coating layer 13 is preferably high, for example, 80% by volume or more, more preferably 83% by volume or more, and 85% by volume. % Or more, more preferably 90% by volume or more.

The additive 132 is a substance for improving the characteristics of the resin coating layer 13, and contains, for example, at least one of a solid lubricant 1321, hard particles 1322, and a silane coupling agent (silane coupling agent is not shown). Omitted). The solid lubricant 1321 is an additive for reducing the coefficient of friction of the resin coating layer 13, and contains, for example, at least one of _{graphite and MoS 2.} Since MoS ₂ may easily aggregate in the resin layer, it is preferable to use _{graphite as the solid lubricant 1321 and not MoS 2.} When graphite is used as the solid lubricant 1321, the degree of graphitization is preferably high, for example, 95% or more, and more preferably 99% or more, from the viewpoint of reducing the friction coefficient. The hard particles 1322 are substances for improving the seizure resistance and abrasion resistance of the resin coating layer 13, and include, for example, at least one of clay, mullite, and talc. The silane coupling agent is a substance for strengthening the bond between the binder resin 131 and the solid lubricant 1321.

From the viewpoint of improving fatigue resistance, the content of the additive is preferably small, for example, the total content is preferably 20% by volume or less, more preferably 17% by volume or less, and 15% by volume or less. More preferably, it is more preferably 10% by volume or less. From the viewpoint of reducing the friction coefficient, the content of the solid lubricant is preferably high, for example, 9% by volume or more. From the viewpoint of reducing the total amount of additives, the content of the solid lubricant is preferably small, for example, 18% by volume or less. From the viewpoint of improving seizure resistance and wear resistance, it is preferable that the content of the hard material (hard particles) is large, for example, 0.5% by volume or more. From the viewpoint of reducing the total amount of additives, the content of the solid lubricant is preferably small, for example, 3% by volume or less. In order to add both the solid lubricant and the hard material, the content of the solid lubricant is preferably 9% by volume or more and 17% by volume or less, and more preferably 14% by volume or less. The content of the hard material is preferably 0.5% by volume or more and 3% by volume or less. The content of the silane coupling agent is preferably, for example, 0.1% by weight or more, more preferably 0.2% by weight or more, based on the binder resin. From the viewpoint of cost reduction, the content of the silane coupling agent is preferably, for example, 5% by weight or less, and more preferably 3% by weight or less, based on the binder resin.

From the viewpoint of reducing the surface roughness after cutting, the particle size of the additive 132 used as a material is preferably small. For example, the average particle size of the additive 132 is the average of the metal powder used for the sintered layer 12. It is preferably smaller than the particle size. Further, both the solid lubricant 1321 and the hard particles 1322 preferably have an average particle size of 5 μm or less or less than 5 μm, and more preferably 3 μm or less or less than 3 μm.

From the viewpoint of improving the fatigue resistance of the resin coating layer 13, the average particle size of the solid lubricant 1321 used as a material is preferably small, for example, it is preferably twice or less the average particle size of the hard particles 1322. More preferably, it is smaller than the average particle size of the hard particles 1322.

FIG. 2 is a schematic view showing the surface shape at the time of cutting. FIG. 2A shows an example using the resin material according to the prior art, and FIG. 2B shows an example using the resin material according to the present embodiment. FIG. 2 schematically shows a cross section perpendicular to the sliding surface. In the example of FIG. 2A, the solid lubricant as an additive is relatively large, about 10 μm. Therefore, if the solid lubricant falls off from the surface during cutting, the surface after processing has irregularities having a size of about 10 μm. On the other hand, in the example of FIG. 2B according to the present embodiment, the solid lubricant 1321 which is the additive 132 is 3 μm or less, which is small. Therefore, even if the solid lubricant 1321 falls off from the surface during cutting, the unevenness generated on the surface after processing is about 3 μm in size.

2. Examples The inventors of the present application prepared test pieces of a sliding member under various conditions, and evaluated the surface roughness of these test pieces after cutting.

2-1. Preparation of test piece As a base material, a steel plate (SPCC (JIS)) having a thickness of 1.5 mm was used. Copper alloy powder (average particle size 100 μm) was sprayed on the base material to a thickness of 100 μm, and then sintered by heating to 930 ° C. in a reducing atmosphere without reduction. A precursor solution for forming a resin layer having the composition shown in Table 1 was prepared, and this precursor solution was applied onto the sintered layer by a knife coating method. After coating, it was dried in the range of room temperature to about 200 ° C. for about 60 to 90 minutes. Then, the temperature was raised to about 300 ° C. and firing was performed for about 30 to 90 minutes.

In Experimental Example 1, graphite having an average particle size (d50 based on volume) of 1.5 μm and a degree of graphitization of 99% was used. Further, as the high-strength PI resin, a resin having a tensile strength of 195 MPa, an elongation of 90%, an elastic modulus of 3.8 GPa, and a glass transition temperature of 285 ° C. was used. In Experimental Example 2, graphite having an average particle size of 12.5 μm and a graphitization degree of 90% was used. As MoS ₂ , an average particle size of 1.5 μm was used. Further, the PI resin has a tensile strength of 119 MPa, an elongation of 47%, and a glass transition temperature of 360 ° C., and the PAI resin has a tensile strength of 112 MPa, an elongation of 17%, an elastic modulus of 2.7 GPa, and glass. The one having a transition temperature Tg of 288 ° C. was used. In Experimental Example 1, a silane coupling agent having a chemical formula of 3 (H ₃ CO) SiC ₃ H ₆ −NH−C ₃ H ₆ Si (OCH ₃ ) ₃ was used. In Table 1, the content of the silane coupling agent is shown as a weight ratio with respect to the high-strength PI resin. In Experimental Examples 1 and 2, the clay, the structure formula of Al ₂ O ₃ · 2SiO _2, average particle size was used in 3 [mu] m.

2-2. Evaluation of Surface Roughness After Cutting After cutting the surface of the test pieces of Experimental Example 1 and Experimental Example 2 with a lathe, the surface roughness (10-point average roughness) was used with a roughness meter (Surfcorder SE-3400) manufactured by Kosaka Research Institute. RzJIS and maximum height Rmax) were measured. The surface roughness was measured for 8 test pieces for Experimental Example 1 (Example) and 10 test pieces for Experimental Example 2 (Comparative Example), and the average value was calculated. Table 2 shows the measurement results of the surface roughness. As can be seen from Table 2, the surface roughness of Experimental Example 1 was improved.

The various materials used in the above-mentioned examples and their compositions are merely examples, and the present invention is not limited thereto. Further, the specific structure of the sliding member is not limited to that illustrated in FIG. For example, the sintered layer 12 may be omitted, and the resin coating layer 13 may be formed directly on the base material 11. Further, the application of the sliding member 1 is not limited to that used in the fuel injection pump, and may be used in various bearings, compressors, and the like.

1 ... Sliding member 11 ... Base material 12 ... Sintered layer 13 ... Resin coating layer 131 ... Binder resin 132 ... Additive

Claims (6)

A binder resin containing at least one of thermosetting polyimide and thermosetting polyamide-imide,
Containing with the additive contained in the binder resin,
The additive is
With graphite
Includes at least one of non- organized clay, mullite, talc,
A resin material for sliding members in which the average particle size of all of the additives is 5 μm or less. The resin material for a sliding member according to claim 1, wherein the average particle diameter of each of the additives is 3 μm or less. The resin material for a sliding member according to claim 1 or 2, wherein the binder resin is contained in an amount of 85% by volume or more. The resin material for a sliding member according to any one of claims 1 to 3, wherein the resin material does not contain MoS _2. With the base material
The sintered layer formed on the base material and
A sliding member having a resin coating layer formed on the sintered layer using the resin material for the sliding member according to any one of claims 1 to 4. With the base material
A sliding member having a resin coating layer directly formed on the base material using the resin material for the sliding member according to any one of claims 1 to 4.

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