JPH0489890A - Solid lubricant and sliding member with the solid lubricant embedded therein - Google Patents

Abstract

PURPOSE:To improve the wettability and fluidity of a solid lubricant powder and thereby permit embedding or joining it in pores or grooves of a metal material regardless of their sizes, etc., by incorporating a lubricating oil that is liquid or pasty at room temperature and a synthetic resin binder in the solid lubricant powder. CONSTITUTION:A solid lubricant is obtained by incorporating 5-20wt.% lubricating oil that is liquid or pasty at room temperature and selected from mineral oils such as machine oils and engine oils, vegetable oils such as castor oil, synthetic oils such as ester oils and silicone oils, and grease and 15-50wt.% synthetic resin binder made of thermosetting synthetic resins, preferably epoxy resins, in a solid lubricant powder with an average size of 100 meshes, selected from graphite, molybdenum disulfide, polytetrafluoroethylene resins and boron nitride.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a solid lubricant containing a lubricating oil having wettability and fluidity, and a sliding member in which the solid lubricant is embedded.

[Conventional technology]

Conventionally, so-called solid lubricant-embedded sliding members, in which holes or grooves are formed in a metal base made of a copper-based or iron-based alloy, and a solid lubricant is embedded in the holes or grooves, have been used as various mechanical parts. ing.

The method for manufacturing the solid lubricant-embedded sliding member is as follows: (1) A graphite (solid lubricant) round bar with spiral protrusions formed on the outer circumferential surface is used as the core of a mold, and molten metal is poured into the mold. After casting, the core is removed by cutting and a solid lubricant (graphite) is exposed in a spiral on the sliding surface (Special Publication No. 39-2
506 Publication), ■ A solid lubricant pellet (cylindrical body) is glued and fixed to paper or plastic film that disappears by burning during casting of molten metal, and this is glued and fixed to the outer peripheral surface of a mandrel made of a shell sand mold. This can be used as the core of a mold (as described in Japanese Patent Publication No. 14381/1981), or a solid lubricant pellet can be adhesively fixed to the mandrel made of a shell sand mold, and this can be used as the core of a mold. Publication number 5449! ! 2) A method of casting molten metal in the mold and exposing solid lubricant pellets on the sliding surface (Japanese Patent Publication No. 52-5449)
2) A method in which holes are formed in a metal substrate and solid lubricant pellets coated with an adhesive are embedded and fixed in the holes.

[Problem that the invention seeks to solve]

Among the conventional manufacturing methods described above, method (2) uses graphite, which has good thermal conductivity, as a core, so it has the disadvantage that it is difficult to spread the molten metal sufficiently during casting, and the shape of the sliding member is limited. In addition, the method (2) has the disadvantage that the solid lubricant pellets may flake off or shift during casting, making it difficult to obtain a sliding member in which the face lubricant pellets are regularly arranged. The method ① above is generally used.

However, the above method (2) also has some problems.

That is, (a) since the size (hole diameter) of the hole provided in the metal substrate differs depending on the size of the metal substrate, the solid lubricant pellets embedded in the hole also have different dimensions that match the hole diameter. solid lubricant pellets. (b) The work of embedding the solid lubricant pellets coated with adhesive into the holes of the metal base is difficult to automate and requires manual work, resulting in extremely poor workability. (Since solid lubricant pellets cannot be used to embed and fix solid lubricant in the grooves provided on the inner surface of the C1 metal base, especially the cylindrical metal base, such as spiral grooves and ring-shaped grooves, Problems include the need to prepare a paste-like solid lubricant that has fluidity.

Additionally, although it is a secondary problem, the work of applying adhesive to the solid lubricant pellets described above (bl) may cause unexpected accidents such as rashes to the operator.

On the other hand, when considering the performance of sliding members, in sliding members embedded with solid lubricant, the embedded solid lubricant is supplied little by little to the sliding surface, forming a solid lubricant film there. , can be used for long periods of time without separately supplying lubricants such as grease, but its use is almost limited to low speed and high load areas, so for applications outside of the above range, grease or lubricating oil etc. It is necessary to use lubricants together.

Therefore, in sliding members embedded with solid lubricant used for applications outside the above range, grooves for grease reservoirs are formed on the sliding surfaces, or lubricating oil is supplied to the sliding surfaces by oil supply devices. Such measures are required.

[Means for solving problems]

The present inventors have solved the above-mentioned manufacturing and performance problems by: (1) being able to be embedded without being restricted by the size, shape, etc. of holes or grooves provided in the metal base; (2) lubrication by lubricating oil; The following three technical issues were identified as the need to satisfy both the lubrication effects of a solid lubricant and the ability to bond to holes or grooves in metal substrates. We believed that the above-mentioned problems could be solved at once, and as a result of intensive research, we found that a solid lubricant made by blending a lubricating oil agent and a synthetic resin binder with solid lubricant powder has wettability and fluidity. However, even though it contains a lubricant, it can be embedded in the hole or groove provided in the metal substrate without any restrictions on the size, shape, etc., and it is possible to join to the hole or groove. The present invention was discovered by confirming that all of the above-mentioned technical problems were satisfied.

That is, the present invention relates to a solid lubricant having wettability and fluidity, which is composed of a solid lubricant powder as a main component, and a lubricating oil agent that is liquid or paste-like at room temperature and a synthetic resin binder, and a solid lubricant having wettability and fluidity. This is a sliding member in which a chemical agent is embedded in holes or grooves in a metal base.

In the above-mentioned configuration, the solid lubricant powder that is the main component refers to a substance that acts as a solid lubricant by itself, and in the present invention, pastes such as natural graphite and coke powder are themselves carbonized by heating and combustion. It is molded using a binder such as graphitized coal tar pitch, and then
Artificial graphite obtained by firing at a temperature of 0°C, impregnating it with an impregnating agent such as pitch, and heat-treating it at a temperature of 2500 to 3000°C to graphitize. ■Natural scaly graphite, Quiche graphite, after aging. Expanded graphite washed with water and instantly expanded in the C-axis direction at high temperature; ■molybdenum disulfide; ■polytetrafluoroethylene resin (PTFE); and ■one or more of boron nitride (BN). be done.

These solid lubricants have an average particle size of 100 mesh (150μ
m) powder is used.

Examples of lubricating oils that are liquid or paste at room temperature include mineral oils such as machine oil and engine oil, vegetable oils such as castor oil, synthetic oils such as ester oil and silicone oil, and grease. The appropriate blending ratio of the lubricant used when the above is selected is 5 to 20% by weight, and if it is blended in excess of 20% by weight, the lubricant may be mixed during fluid filling into the holes or grooves of the metal substrate, which will be described later. The amount of bleed-out increases, and this is interposed at the bonding interface between the solid lubricant and the hole or groove of the metal substrate, weakening the bonding strength of the solid lubricant to the hole or groove of the metal substrate. As a result, solid lubricant may be drawn out from holes or grooves.

In addition, when the amount is less than 5% by weight, the strength of the solid lubricant itself is increased, and the bonding strength to the holes or grooves of the metal substrate is increased. Synthetic resin binders, which have a small amount of exudation and are difficult to expect to improve sliding performance with lubricants, have the role of bonding expanded graphite powder together and bonding solid lubricants containing lubricating oil to holes or grooves in metal substrates. Thermosetting synthetic resins such as epoxy resins, phenol resins, and polyester resins play a role, and epoxy resins are particularly preferably used in the present invention.

As the epoxy resin, a room temperature curing liquid epoxy resin and a thermosetting liquid or powder epoxy resin can be used.

Specifically, room temperature curing liquid epoxy resins include:
One example is "Cemedine" (trade name), which is commercially available from Cemedine.

In addition, thermosetting liquid epoxy resins include "Technodyne" (trade name), commercially available from Taoka Chemical Co., Ltd., and "Epicote" (trade name), a liquid epoxy resin commercially available from Yuka Shell Epoxy Co., Ltd. Liquid epoxy resins include Asahi Kasei Industries' latent curing agent "Repacure" (trade name) or Ajinomoto Co.'s "Amicure" (trade name).

An example of a thermosetting powder epoxy resin is "Ebiform" (trade name) manufactured by Somar Co., Ltd., and this powder epoxy resin can also be used to adjust the flow of the liquid epoxy resin.

The appropriate blending ratio of this synthetic resin binder is 15 to 50% by weight.

The solid lubricant having the above-mentioned structure (component composition) is produced as follows.

A solid lubricant having wettability and fluidity can be obtained by blending and mixing a lubricating oil agent with a solid lubricant powder adjusted to an average particle size of 150 mesh, and then adding a synthetic resin binder to the mixture and kneading it.

The thus obtained solid lubricant having wettability and fluidity is flow-filled into holes or grooves provided in a metal substrate at room temperature or under heating, and then the binder is cured at room temperature or under heating. By bonding a solid lubricant containing a lubricant to the holes or grooves of the metal base, a sliding member in which the solid lubricant containing a lubricant is embedded can be obtained.

Compression molding, transfer molding, injection molding, and other methods are used to fluidly fill the solid lubricant into the holes or grooves of the metal base.In the case where the sliding member has a plate shape, the solid lubricant is A method can be adopted in which the material is formed into a plate shape in advance, placed on a plate-like sliding member (metallic base) provided in a hole or groove, and fluidized and filled by press molding.

FIG. 1 is a longitudinal cross-sectional view showing an example of a solid lubricant fluid filling device, in which reference numeral 1 indicates a holder equipped with a cylindrical portion 11, and numeral 2 indicates an outer peripheral surface inside the cylindrical portion 11 of the holder 1. 3 is a sliding member material having a plurality of holes 21 formed so as to overlap each other in the circumferential direction, into which the material 2 is restrained and inserted;
4 is a guide tool having a flow passage 31 inserted into the inner surface of the material 2 with a minute annular gap S between the material 2 and the inner diameter surface of the material 2;
A container 5 is fitted into the upper end of the cylindrical portion 11 of the holder 1 and has a flow path 41 that communicates with the flow path 31; The lubricant 6 is a pressing tool fitted into the container 4 so as to be movable in the vertical direction.

FIG. 2 is a longitudinal cross-sectional view showing a sliding member embedded with a solid lubricant obtained in the above Example The holes 72 are solid lubricants fluidly filled and bonded to the holes 71.

[For production]

(2) Since the solid lubricant has wettability and fluidity, it can be embedded in the holes or grooves provided in the sliding member without being restricted by the size, shape, etc. of the holes or grooves.

■Since the solid lubricant itself contains a lubricant, when a sliding member embedded with the solid lubricant slides with a mating material, the solid lubricant is applied to the sliding surface of the sliding member. Since the contained lubricant is supplied, the wettability is maintained by the lubricant, and the lubrication effect is performed by the solid lubricant and the lubricant. Not only can it be used under high speed and high load conditions, but it can also be used in applications outside of these conditions without the need to supply a separate lubricant.

〔Example〕

Hereinafter, the solid lubricant of the present invention and the sliding member embedded with the solid lubricant will be described in detail based on Examples thereof.

<Example: I> As a solid lubricant powder, ■ Artificial graphite prepared by crushing a porous artificial graphite molded body (manufactured by IBIDEN) with a bulk specific gravity of 1, 55 g/cm3, and a porosity of 45% and adjusting the average particle size to 100 mesh. Powder 58% by weight,■
43% by weight of the artificial graphite powder and polytetrafluoroethylene resin (PTFE) powder ("Yunon" manufactured by Nippon Halker Co., Ltd.)
(Product name) 15% by weight, ■ 43% by weight of the artificial graphite powder and 1 molybdenum disulfide powder
5% by weight, mineral oil (manufactured by Idemitsu Kosan Co., Ltd.) was used as a lubricant.
15% by weight of Dafun Super Multi (trade name J) was added and mixed to obtain a mixture of solid lubricant powder and lubricant.

Next, 16% by weight of a thermosetting liquid epoxy resin (trade name: "mhi]-" manufactured by Showa Shell Chemical Co., Ltd.) as a synthetic resin binder and a latent curing agent (trade name "mhi]-" manufactured by Asahi Kasei Industries, Ltd.) were added to this mixture as a synthetic resin binder.
A solid with wettability and fluidity is obtained by blending 5% by weight of Tsunohonia (trade name) and 6% by weight of a powdered epoxy resin (manufactured by Somar Co., Ltd., "Epiform (trade name)") for flow rate adjustment. Got the lubricant.

High strength brass casting (J Is-) 1220 as metal base
5) was cut to obtain a cylindrical base with an inner diameter of 60 mm, an outer diameter of 80 mm, and a length of 80 mm, and holes with a diameter of 10 mm were formed in the cylindrical base so that they overlapped each other in the circumferential direction of the cylindrical base. 54 pieces were formed and used as a sliding member material (bearing bushing material).

The outer circumferential surface of the sliding member material is restrained, and a solid lubricant having the above-mentioned composition is made to flow from the inner surface of the material using the fluid filling device shown in FIG. 1 while being pressurized at a pressure of 50 kg/cm2 at room temperature. The pores of the material were densely filled.

Next, the sliding member material holding the solid lubricant in the pores of the material was held in a heating furnace heated to 80° C. for 60 minutes to primary harden the synthetic resin binder.
The solid lubricant containing the lubricating oil is bonded to the pores of the material by holding the synthetic resin binder in a heating furnace heated to a temperature of A sliding member (bearing bushing) was obtained.

<Example: ■> As a solid lubricant, ■Bulk specific gravity 0-7g/cm3. 58% by weight of expanded graphite powder prepared by crushing an expanded graphite sheet with a thickness of 0.5 mm (F Nika Film manufactured by Nippon Carbon Co., Ltd., product name part) and adjusting the average particle size to 100 meshes, ■43% by weight of the above expanded graphite powder and PTFE. 15% by weight of resin powder (same as in Example I above), 43% by weight of expanded graphite powder described above, and 15% by weight of artificial graphite powder (same as in Example 15% by weight (same as Example I) was added and mixed to obtain a mixture of solid lubricant powder and lubricant.

Next, 16% by weight of a thermosetting liquid epoxy resin (same as in Example I above) as a synthetic resin binder, 5% by weight of a latent curing agent (same as in Example I above) and a flow rate adjustment agent were added to this mixture. Powdered epoxy resin (same as above Example ■) 6
% by weight and kneaded to obtain a solid lubricant having wettability and fluidity.

After producing a sliding member material using the same high-strength brass casting as in Example I above as a metal base, in Example 2 above, the solid lubricant was tightly packed into the pores of the material in the same manner. It was filled with fluid.

Thereafter, a sliding member in which a solid lubricant was embedded was obtained in the same manner as in Example I above.

<Example 2■> As solid lubricant powder, ■70% by weight of molybdenum disulfide powder, ■60% by weight of molybdenum disulfide powder and 10% by weight of PTFE resin powder (same as in Example ■ above), ■Molybdenum disulfide powder 60% by weight of boron nitride powder and 10% by weight of boron nitride powder, and 8% by weight of mineral oil (same as in Example I above) was added as a lubricant and mixed to obtain a mixture of solid lubricant powder and lubricant. Ta.

Next, 17% by weight of a thermosetting liquid epoxy resin (same as in Example I above) and 5% by weight of a latent curing agent (same as in Example I above) were added to this mixture as a synthetic resin binder,
A solid lubricant having wettability and fluidity was obtained by kneading.

After preparing a sliding member material using the same high-strength brass casting as in Example I above as a metal base, the solid lubricant was densely applied to the pores of the material in the same manner as in Example I above. Fluid filled.

Thereafter, a sliding member in which a solid lubricant was embedded was obtained in the same manner as in Example 2 above.

Next, the results of testing the bonding strength of the solid lubricant to the hole and the sliding characteristics of the sliding member with respect to the sliding member embedded with the solid lubricant obtained in the above-mentioned Examples will be described.

(Joint strength test) The bond strength is determined by applying a bush pull gauge to the solid lubricant embedded in the hole of the sliding member and measuring the force (kgf/cm") to pull out the solid lubricant from the hole. The value was taken as the bonding strength.

(Sliding property test) As for the sliding property, the coefficient of friction and amount of wear were measured under the following test conditions.

Test conditions ■ Load 500kgf/cm2 Speed 1m/
min Compatible material Carbon 1IIL (S45C) for mechanical structures Reciprocating swing test Stroke 200 Test cycle 100 x 10' (400 km) Test conditions Load 10 kgf/cm Speed 40 m/m
in Compatible material Carbon M (S45C) for mechanical structures Reciprocating swing test Stroke 200mm Test cycle 100 x 10' (400km) The test results are shown in the table below.

(The following is a blank space) From the test results, the bonding strength (extraction force) of the solid lubricant of the example to the hole of the sliding member showed a value lower than that of the conventional technology shown in the comparative example.

This test result was as expected, and the fact that we were able to bond a solid lubricant containing a lubricant with a bonding strength of 50 kgf/cm2 is based on the sliding property test result, that is, the solid lubricant embedded type. It demonstrated performance equivalent to or better than conventional technology not only in the low-speed, high-load range (test conditions ■ above), which is the appropriate application for sliding members, but also in applications outside this range (test conditions ■ above). Considering this, the bonding strength in the example means that there is no problem in using the sliding member.

In the sliding member of Comparative Example (2), the coefficient of friction gradually increased with the passage of test time in the test under test condition (3), and the amount of wear suddenly increased at a test stroke of 300 km. Also,
In the test under test condition (3), immediately after the start of the test, both the friction coefficient and the amount of wear increased rapidly at Ikm of the test stroke, so the test was discontinued.

The sliding member of Comparative Example ■ exhibited almost the same performance as the sliding members of Examples I to Example ■ in the test under test condition ■, but in the test under test condition ■, the test stroke was 20.
At 0 km, the grease applied to the sliding surface squeezes out (
The test was discontinued because the bearing temperature, friction coefficient, and wear amount suddenly increased at the test stroke of 300 km.

On the other hand, since the solid lubricant of the example contains a lubricant, it can be used not only in the low speed and high load area, which is the appropriate application for solid lubricant-embedded sliding members, but also in applications outside of this area. , demonstrated stable performance without the need to supply a separate lubricant.

〔effect〕

The present invention having the above-described configuration has the following unique effects.

■Since solid lubricants have wettability and fluidity, they can be embedded into holes or grooves provided in metal substrates without any restrictions, greatly expanding the range of applications for sliding parts. can.

■Since solid lubricants contain lubricating oil, they can be used not only in the low-speed, high-load range, which is the appropriate application for solid lubricant-embedded sliding members, but also in applications outside of these ranges. There is no need to separately supply lubricant such as grease, and it can be used under a wide range of conditions.

■Since the solid lubricant is flow-filled and embedded into holes or grooves provided in the metal base, there is no need for conventional adhesive application and embedding work, greatly improving workability and making adhesive application work easier. Problems caused by this, such as rash on workers, are completely eliminated.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an example of a fluid filling device for solid lubricant, and FIG. 2 is a longitudinal sectional view showing a sliding member in which solid lubricant is embedded. 7. Sliding member 71. Hole 72. Solid lubricant

Claims (8)

[Claims] (1) A solid lubricant having wettability and fluidity, which is mainly composed of solid lubricant powder, and is blended with a lubricating oil agent that is liquid or paste-like at room temperature and a synthetic resin binder. (2) 5 to 20% by weight of lubricant and 1% of synthetic resin binder
The solid lubricant according to claim 1, characterized in that the solid lubricant contains 5 to 50% by weight. (3) The solid lubricant according to claim 1 or 2, wherein the solid lubricant powder is selected from one or more of graphite, molybdenum disulfide, polytetrafluoroethylene resin, and boron nitride. (4) The lubricant is selected from one or more of mineral oils such as machine oil and engine oil, vegetable oils such as castor oil, synthetic oils such as ester oil and silicone oil, and grease. The solid lubricant according to item 1. (5) The solid lubricant according to any one of claims 1 to 4, wherein the synthetic resin binder comprises a thermosetting synthetic resin. (6) A solid lubricant having wettability and fluidity, which is composed mainly of solid lubricant powder and mixed with a lubricating oil agent and a synthetic resin binder, is flow-filled into holes or grooves provided in a metal substrate. 1. A sliding member embedded with a solid lubricant, characterized in that the sliding member is embedded in a solid lubricant and is bonded to a hole or groove of the metal base. (7) The solid lubricant having wettability and flowability is 5 to 20% by weight of lubricant, 15 to 50% by weight of synthetic resin binder,
7. A sliding member embedded with a solid lubricant according to claim 6, wherein the remainder is solid lubricant powder. (8) The sliding member embedded with a solid lubricant according to claim 6 or 7, wherein the sliding surface of the metal base in which the holes or grooves are formed has a flat, cylindrical, or spherical surface.