WO2018062357A1

WO2018062357A1 - Slide member

Info

Publication number: WO2018062357A1
Application number: PCT/JP2017/035131
Authority: WO
Inventors: 拓治原野; 敏彦毛利
Original assignee: Ntn株式会社
Priority date: 2016-09-28
Filing date: 2017-09-28
Publication date: 2018-04-05

Abstract

Provided is a slide member (1) having a sliding surface, at least part of which is constituted of the surface of a lubricating member (3), said sliding member comprising: a base (4) which is a sintered compact of a molded body including metal powder and which is integrated with the lubricating member (3); and the lubricating member (3) which is a resin composition containing an injection-molded body of a polyarylene sulfide-based resin and a carbon material.

Description

Sliding member

The present invention relates to a sliding member having a sliding surface.

The functions required for sliding members embedded with solid lubricants are becoming increasingly severe year by year. Therefore, development of a solid lubricant that can maintain excellent slidability for a long period of time and can be manufactured at low cost is demanded.

As a sliding member in which a solid lubricant is embedded, for example, in Patent Document 1 (Japanese Patent Laid-Open No. 2013-14645), a radial through hole is formed in a cylindrical base body, and a solid lubricant is formed in the through hole. There has been proposed a sliding member in which a fired body mainly composed of artificial graphite is embedded.

JP 2013-14645 A

However, in order to form a radial through hole in the base and embed the solid lubricant in the through hole, it is necessary to fix the solid lubricant to the base with high accuracy. Since it is necessary to process the solid lubricant fitted thereto with high accuracy, there is room for improvement from the viewpoint of work efficiency and processing cost. In particular, when a carbon-based fired body (fired artificial graphite) is used as the solid lubricant, the carbon-based fired body is difficult to plastically deform. There is a concern that costs will increase further. In addition, in the structure in which the solid lubricant is embedded in the through hole, there is a concern that the solid lubricant may fall out of the base of the sliding member during use of the sliding member.

Therefore, the first object of the present invention is to provide a sliding member that can improve the working efficiency and processing cost in manufacturing the sliding member. In addition, the present invention can improve the working efficiency and processing cost in manufacturing the sliding member, and the sliding member in which the risk of the solid lubricant falling off the base of the sliding member during use of the sliding member is reduced. Is the second purpose.

The present invention provides the following sliding member and method for manufacturing the sliding member.
[1] A sliding member having a sliding surface, wherein at least a part of the sliding surface is constituted by a surface of a lubricating member, and is a sintered body of a molded body containing metal powder, and the lubricating member And a lubricating member that is an injection-molded body of a resin composition containing a polyarylene sulfide-based resin and a carbon material.

[2] The lubricating member having a sliding surface, wherein at least a part of the sliding surface is constituted by a surface of the lubricating member, and is a sintered body of a molded body containing metal powder. A sliding body comprising: a base body having a housing portion for housing a resin; and an injection-molded body of a resin composition comprising a polyarylene sulfide resin and a carbon material, wherein the lubricating member is disposed in the housing portion Element.

[3] The sliding member according to [1] or [2], wherein the content of the carbon material in the resin composition is approximately 5% by mass or more and approximately 70% by mass or less.

[4] The sliding member according to any one of [1] to [3], wherein the base body has internal holes, and the internal holes are impregnated with a lubricating oil.

[5] The sliding member according to any one of [1] to [4], wherein the base body has an open porosity of approximately 5% to approximately 50%.

[6] The sliding member according to any one of [1] to [5], wherein the substrate has a surface area ratio of approximately 10% to approximately 50%.

[7] The sliding member according to [2], wherein the base body has a surface area ratio of approximately 10% to approximately 50% on the inner surface of the housing portion.

[8] The sliding member according to any one of [1] to [7], wherein the carbon material is at least one selected from the group consisting of carbon nanofibers, carbon black, and graphite.

[9] A sliding member having a sliding surface, wherein at least a part of the sliding surface is constituted by a surface of a lubricating member, and is a sintered body of a molded body containing metal powder, and the lubricating member And a lubricating member that is an injection-molded body of a resin composition containing a thermoplastic resin and a carbon material.

[10] The lubricating member having a sliding surface, wherein at least a part of the sliding surface is constituted by a surface of the lubricating member, and is a sintered body of a molded body containing metal powder. A sliding member, comprising: a base body having a housing portion for housing the resin; and an injection-molded body of a resin composition comprising a thermoplastic resin and a carbon material, and the lubricating member disposed in the housing portion.

[11] The sliding member according to [9] or [10], wherein the content of the carbon material in the resin composition is approximately 5% by mass or more and approximately 70% by mass or less.

[12] The sliding member according to any one of [9] to [11], wherein the base body has internal holes, and the internal holes are impregnated with a lubricating oil.

[13] The sliding member according to any one of [9] to [12], wherein the base body has an open porosity of approximately 5% to approximately 50%.

[14] The sliding member according to any one of [9] to [13], wherein the base body has a surface porosity of approximately 10% to approximately 50%.

[15] The sliding member according to [10], wherein the base body has a surface area ratio of approximately 10% to approximately 50% on the inner surface of the housing portion.

[16] The sliding member according to any one of [9] to [15], wherein the carbon material is at least one selected from the group consisting of carbon nanofibers, carbon black, and graphite.

[17] A method for manufacturing a sliding member having a sliding surface, wherein at least a part of the sliding surface is formed by a surface of a lubricating member, and sintering a molded body containing metal powder, And a step of integrating the lubricating member with the base body by injecting a resin composition containing a carbon material and a thermoplastic resin.

[18] A method for manufacturing a sliding member having a sliding surface, wherein at least a part of the sliding surface is constituted by a surface of a lubricating member, wherein a molded body containing metal powder is sintered, A step of manufacturing a substrate having a housing portion for housing a lubricating member; and a resin composition containing a carbon material and a thermoplastic resin is injected into the housing portion, thereby arranging the lubricating member in the housing portion. And a method for producing the sliding member.

[19] The method for manufacturing a sliding member according to [17] or [18], wherein the content of the carbon material in the resin composition is approximately 5% by mass or more and approximately 70% by mass or less.

[20] The method for manufacturing a sliding member according to any one of [17] to [19], further including a step of impregnating the internal holes with a lubricating oil, wherein the base body has internal holes.

[21] The method for manufacturing a sliding member according to any one of [17] to [20], wherein the substrate has an open porosity of approximately 5% to approximately 50%.

[22] The method for manufacturing a sliding member according to any one of [17] to [21], wherein the substrate has a surface area ratio of approximately 10% to approximately 50%.

[23] The method for manufacturing a sliding member according to [18], wherein the base body has a surface area ratio of approximately 10% to approximately 50% on the inner surface of the housing portion.

[24] The method for manufacturing a sliding member according to any one of [17] to [23], wherein the carbon material is at least one selected from the group consisting of carbon nanofibers, carbon black, and graphite.

According to the present invention, it is possible to provide a sliding member that can improve the working efficiency and processing cost in manufacturing the sliding member. Further, according to the present invention, it is possible to improve the working efficiency and processing cost in manufacturing the sliding member, and reduce the possibility of the solid lubricant falling off from the base of the sliding member during use of the sliding member. A moving member can be provided.

(A) is a front view of the sliding member manufactured by the 1st Embodiment of this invention, (b) is sectional drawing in the BB line of (a) figure. It is a front view of a base. It is sectional drawing of the metal mold | die which shows the insert molding state of a base | substrate and a lubricating member. It is the top view which looked at the fixed type | mold of the said metal mold | die from the C direction of FIG. It is a front view of the sliding member manufactured by other embodiment which concerns on this invention.

Referring to FIGS. 1 (a) and 1 (b), the sliding member 1 has a cylindrical shape, and a shaft 2 (shown by a chain line) as a mating member is inserted into the inner periphery thereof. The sliding member 1 includes a base 4 provided with an inner peripheral surface 4a and a concave cylindrical surface 4b, and an alignment of the inner surface 3a and the base 4 that are disposed in the housing 4c of the base 4 and exposed on the inner peripheral surface. And a lubricating member 3 having an outer surface 3b in close contact with the surface 4b. As shown in FIG. 1A, the inner surface 3 a of each lubricating member 3 and the inner peripheral surface 4 a of the base body 4 can constitute, for example, a bearing surface portion 11 having a perfectly circular cross section. An outer peripheral surface 12 of the bearing 1 is fixed to an inner peripheral surface of a housing (not shown) by means such as press fitting or adhesion, and a shaft 2 inserted into the inner periphery of the bearing 1 is rotatably supported. As described above, the shaft 2 can be the rotating side, the shaft 2 can be the stationary side, and the bearing 1 can be the rotating side. FIG. 1A illustrates a configuration in which five lubrication members 3 are provided, but the number of lubrication members 3 is not limited to this, and at least a part of the sliding surface is the surface of the lubrication member 3. It only has to be configured.

Hereinafter, the sliding member according to the present invention will be described in detail while showing embodiments.
[First Embodiment]
The sliding member according to the present embodiment includes a base 4 obtained by compression-molding raw material powder containing metal powder using a mold, and heating and sintering the molded body (metal powder molded body), and Lubricating member which is a resin composition arranged as an injection-molded body in the accommodating portion 4c of the base body 4 by injection molding a resin composition containing a polyarylene sulfide resin and a carbon material using the base body 4 as an insert part 3 is included. Preferably, the polyarylene sulfide-based resin is the main component (the heaviest component by weight) of the resin composition.

Hereinafter, a bearing is taken as an example of the sliding member according to the present invention and will be described with reference to FIGS.

(1) Base 4
Referring to FIG. 1, base 4 is a sintered body obtained by sintering a molded body containing metal powder in accordance with a normal manufacturing process employed when manufacturing a bearing. The base body 4 includes a housing portion 4 c for housing the lubricating member 3. A molded body containing metal powder can be obtained, for example, by compression-molding raw material powder containing metal powder as a main component (a component having the largest weight ratio) using a molding die. By heating and sintering a molded body (metal powder molded body) obtained by compression molding, it is possible to obtain a base body 4 having a housing portion 4c for housing the lubricating member 3.

Referring to FIG. 2, a molded body 4 ′ (metal powder molded body) having a shape corresponding to the substrate 4 is molded by filling the molding die with raw material powder and compressing. The metal powder molded body 4 ′ is formed with a recess 4 a ′ corresponding to the housing portion 4 c of the base body 4 at the time of molding.

Next, metal powder molding is performed by heating at a sintering temperature necessary to sinter the metal powder molded body 4 ′ (for example, about 750 to 900 ° C. if the metal powder molded body 4 ′ is copper iron-based). The body 4 'is sintered.

The sintered metal powder molded body 4 ′ is transferred to a sizing process for correcting the dimensions, and the dimensions of each surface portion (inner peripheral surface, outer peripheral surface, and both end surfaces) are corrected by recompression in the mold. Is done. Under the present circumstances, the bearing surface part 11 of high roundness can be obtained by correcting the dimension of the internal peripheral surface 4a used as the bearing surface part 11 at least. Thereby, stable bearing performance can be obtained. Thus, the bearing surface portion 11 is finally finished in the sizing process, and the base body 4 including the housing portion 4c for housing the lubricating member 3 can be obtained.

Examples of the metal powder used to manufacture the substrate 4 include a copper-based material having copper as a main component (the most component by weight ratio), an iron-based material having iron as a main component (the most component by weight ratio), Metal powders of any kind of metal including copper-iron-based materials containing copper and iron as main components (the largest component by weight) can be used. In addition, metal powders of special metals such as aluminum-bronze can be used.

When copper iron-based metal powder is used, metal powder in which iron powder, copper powder, and low melting point metal powder are mixed can be used. The low-melting point metal is a component for melting itself at the time of sintering to advance liquid phase sintering, and a metal having a lower melting point than copper is used. Specifically, a metal having a melting point of 700 ° C. or lower, for example, a metal containing tin (Sn), zinc (Zn), or phosphorus (P) can be used. Among these, it is preferable to use tin having good compatibility with copper. The low melting point metal can be added by alloying with other metal powders in addition to adding the simple powder to the mixed powder.

In addition to the above metal powder, a sintering aid such as calcium fluoride and a lubricant such as zinc stearate may be added as necessary, and graphite powder as a solid lubricant powder may be added. By adding graphite powder, graphite particles can be dispersed in the sintered structure of the base 4 after sintering. Therefore, the lubricity in the part formed with the base | substrate 4 among the bearing surface parts 11 can be improved.

Here, specifically, the ratio of the metal (element) constituting the substrate 4 is, for example, a mixed powder of Fe powder, Cu powder, and Sn powder, and in this embodiment, graphite powder is further mixed. The blending ratio of each powder is, for example, Cu powder: approximately 10 to 30% by mass, specifically 10 to 30% by mass (preferably approximately 15 to 20% by mass, specifically 15 to 20% by mass), Sn Powder: about 0.5 to 3.0% by mass, specifically 0.5 to 3.0% by mass (preferably about 1.5 to 2.0% by mass, specifically 1.5 to 2%. 0 mass%), graphite powder: approximately 0.5 to 7.0 mass%, specifically 0.5 to 7.0 mass% (preferably approximately 0.5 to 3.0 mass%, specifically 0.5 to 3.0% by mass), and the rest is Fe powder. If the amount of Cu powder is too small, the slidability of the inner peripheral surface 4a of the sliding surface portion 11 is lowered, and if it is too large, there is a problem in the wear resistance of the inner peripheral surface 4a of the sliding surface portion 11. The range.

Next, the Sn powder is blended to form a Cu—Sn alloy structure for bonding the Fe structures of the substrate 4 by melting the Cu powder during the sintering of the compact 4 ′ (green compact). Has been. Therefore, if the amount of Sn powder is too small, the strength of the substrate 4 cannot be sufficiently increased. However, if the amount of Sn powder is too large, the cost of the substrate 4 may be increased. From the above, the blending ratio of Cu powder and Sn powder is in the above range.

Further, the graphite powder is blended so that the base 4 remains as free graphite and functions as a solid lubricant in the base 4. Therefore, if the blending ratio of the graphite powder is too small, the effect as a solid lubricant will be low. However, if it is too large, the specific gravity of graphite is smaller than that of Fe and Cu. Since the deterioration and deterioration of the powder filling property are caused, the above range is set.

(2) Lubricating member 3
In order to arrange the lubricating member 3 in the housing portion 4c of the base body 4, a resin composition containing a polyarylene sulfide-based resin and a carbon material is injection-molded using the base body 4 as an insert part. Thereby, the plurality of lubricating members 3 are integrated with the base body 4. More specifically, a plurality of lubricating members 3 are arranged as injection molded bodies in the accommodating portion 4c of the base 4 (hereinafter also referred to as an insert molding process).

Referring to FIG. 3, the insert molding process can be performed by using a molding die 20 including a fixed mold 21 and a movable mold 22. The fixed die 21 is provided with a cylindrical portion 21a, and the inner peripheral surface 4a of the base body 4 is formed on the outer peripheral surface of the cylindrical portion 21a. A gate 21 b is provided on a molding surface 21 c that forms an end surface of the lubricating member 3 in the fixed mold 21. In the present embodiment, a plurality (five in the illustrated example) of gates 21b are arranged at equal intervals in the circumferential direction on the molding surface 21c of the fixed die 21 (see FIG. 4). The type of the gate is not limited to the dotted gate as in the illustrated example, and may be, for example, an annular film gate.

In the insert molding process, first, the base body 4 is inserted into the cylindrical portion 21a of the fixed mold 21 and arranged. In this state, the cavity 23 is formed by clamping the movable mold 22 and the fixed mold 21. At this time, the base 4 is sandwiched between the fixed mold 21 and the movable mold 22 from both sides in the axial direction. The cavity 23 corresponds to the accommodating portion 4 c of the base body 4.

Next, a resin composition containing a polyarylene sulfide resin and a carbon material is injected into the cavity 23 from the runner 21d through the gate 21b. As a result, the cavity 23 is filled with the molten resin composition. When the resin composition filled in the cavity 23 is cooled and solidified, the lubricating member 3 is disposed on the inner peripheral surface 4a of the base body 4, and the bearing 1 is manufactured.

According to the above embodiment, for example, a resin composition containing a polyarylene sulfide-based resin, which is a thermoplastic resin, as a main component (a component having the largest weight ratio) and further containing a carbon material is injected into the housing portion 4c. Thereby, it becomes possible to manufacture the bearing 1 in which the lubricating member 3 is disposed in the housing portion 4c efficiently and continuously in large quantities. Since the bearing 1 can be manufactured efficiently and continuously in large quantities, the manufacturing cost of each bearing 1 can be reduced. Further, the lubricating member 3 is disposed in the housing portion 4 c of the base body 4. Therefore, due to the anchor effect of the polyarylene sulfide resin contained in the lubricating member 3, the bonding force between the base body 4 and the lubricating member 3 is enhanced on the mating surface 4b (inner surface of the accommodating portion 4c). Thereby, the possibility that the lubricating member 3 may fall off from the base 4 of the bearing 1 during use of the bearing 1 can be reduced.

(3) Polyarylene sulfide-based resin The polyarylene sulfide-based resin (hereinafter referred to as PAS resin) used in the present invention is a synthetic resin generally represented by the following general formula (1). Ar in the following general formula (1) is an arylene group, and examples of Ar include those represented by the following general formulas (2) to (7).

[N is a natural number representing the number of repeating units -Ar-S-. ]

[Q represents a halogen selected from F, Cl and Br, or CH ₃ , and m represents an integer of 1 to 4. ]

As the PAS resin used in the present invention, a polyphenylene sulfide resin (hereinafter referred to as PPS resin) in which Ar in the general formula (1) is the general formula (2) can be preferably used.

The PAS resin preferably has a repeating unit (—Ar—S—) content of 70 mol% or more, more preferably 90 to 100 mol%. The content rate of a repeating unit here means the ratio of the repeating unit which occupies for 100% of all the monomers which comprise PAS resin. When a PAS resin having a repeating unit content of less than 70 mol% is used, it is difficult to obtain stability such as reduction in dimensional change in the lubricating member 3 based on low water absorption when the lubricating member 3 is formed. There is a tendency.

In order to obtain the PAS resin, a well-known method can be used. For example, halogen-substituted aromatic compounds and alkali sulfides disclosed in Japanese Patent Publication Nos. 44-27671 and 45-3368 are disclosed. A reaction with an aromatic compound and sulfur chloride in the presence of a Lewis acid catalyst, as disclosed in Japanese Patent Publication No. Sho 46-27255, or as disclosed in US Pat. No. 3,274,165 Although it is synthesized by a condensation reaction of thiophenols in the presence of an alkali catalyst or a copper salt, a specific method can be arbitrarily selected according to the purpose.

As a specific method, sodium sulfide and p-dichlorobenzene may be reacted in an amide solvent such as N-methylpyrrolidone or dimethylacetamide or a sulfone solvent such as sulfolane. It should be noted that, within a range that does not affect the crystallinity of the PAS resin, for example, components represented by the following general formulas (8) to (12) can be included in the PAS resin to form a copolymer component. The addition amount of the components represented by the following general formulas (8) to (12) is less than 30 mol%, preferably less than 10 mol% and 1 mol% or more with respect to 100% of all monomers constituting the PAS resin. Can do.

[R represents an alkyl group other than a methyl group, a nitro group, a phenyl group, an alkoxy group, or the like. ]

Also, the PAS resin is preferably of a cross-linked type or has a partial cross bond, that is, a partial cross-link. A PAS resin having a partial cross-linking is also called a semi-crosslinked or semi-linear PAS. The cross-linked PAS resin increases the molecular weight of the polymer to a necessary level by performing a heat treatment in the presence of oxygen during the production process of the polymer. In the crosslinked PAS resin, some polymer molecules have a two-dimensional or three-dimensional crosslinked structure through oxygen to each other. For this reason, it is excellent in that it maintains high rigidity even under a high temperature environment as compared with the linear PAS resin described below, and has little creep deformation and resistance to stress relaxation. As described above, the cross-linked or semi-cross-linked PAS resin is superior in heat resistance, creep resistance and wear resistance as compared with a linear (non-cross-linked) PAS resin. Therefore, there is an advantage that the occurrence of burrs is less in the injection-molded molded product than in the linear PAS resin.

On the other hand, since the linear PAS resin does not include a heat treatment step in the polymer production process, the polymer molecule does not include a crosslinked structure, and the molecule is a one-dimensional linear chain. In general, linear PAS resins are characterized by low rigidity and somewhat higher toughness and elongation than cross-linked PAS resins. The linear PAS resin is excellent in mechanical strength from a specific direction. Further, the linear PAS resin has an advantage that since the polymer has high purity and low moisture absorption, the dimensional change is small and the electrical insulation is not deteriorated even in a high temperature and high humidity atmosphere. In addition, since the linear PAS resin can reduce the melt viscosity by adjusting the molecular weight, for example, the fluidity of the resin composition in which a large amount of a carbon material or the like is mixed with the linear PAS resin is reduced. In addition to a decrease in yield during injection molding, it is avoided that injection molding itself is difficult.

Examples of a method of forming a crosslink in the PAS resin or forming a partial crosslink include, for example, a method in which a polymer having a low polymerization degree is polymerized and then heated in an atmosphere in which air exists, a crosslinker or a branching agent is used. There is a method of adding.

The apparent melt viscosity of the PAS resin is preferably in the range of 1000 poise to 10,000 poise. If the apparent melt viscosity is too low, the strength of the lubricating member 3 can be reduced. On the other hand, if the apparent melt viscosity becomes too high, the moldability may be lowered and the molten resin material will not easily enter the open pores on the surface of the substrate 4. Therefore, the anchor effect may be reduced.

The melt viscosity of the crosslinkable PAS resin can be 1000 to 5000 poise, and preferably 2000 to 4000 poise. If the melt viscosity is too low, mechanical properties such as creep resistance can be lowered at a high temperature of 150 ° C. or higher. Moreover, when melt viscosity is too large, moldability may be inferior. The melt viscosity can be measured with a Koka flow tester under the conditions of a measurement temperature of 300 ° C., an orifice having a hole diameter of 1 mm, a length of 10 mm, a measurement load of 20 kg / cm ² , and a preheating time of 6 minutes. .

The PAS resin having a partially cross-linked bond has a thermal viscosity change rate of −50% to 150% after 6 minutes of preheating and 30 minutes after the preheating under the above melt viscosity measurement conditions. It is preferable. The rate of change is expressed by the following formula.
[Change rate = (P30−P6) / P6 × 100 (P6: measured value after 6 minutes of preheating, P30: measured value after 30 minutes of preheating)].

Examples of the PAS resin having a partial cross-linking that satisfies the above conditions include, for example, T4, T4AG, TX-007, etc. manufactured by Toprene. The weight average molecular weight of the PAS resin is preferably 20000 to 45000, and more preferably 25000 to 40000. When the weight average molecular weight is smaller than 20000, the heat resistance tends to be inferior, and when the weight average molecular weight is larger than 45,000, the moldability for complicated precise dimensional accuracy tends to be inferior. The weight average molecular weight in the present invention indicates a weight average molecular weight in terms of polystyrene measured by gel permeation chromatograph (GPC method) after dissolving the PAS resin in a solvent. It implements on the conditions shown in the Example.

The molecular weight of the PAS resin is preferably 13,000 to 30000 in terms of number average molecular weight in view of injection moldability, and more preferably 18000 to 25000 in terms of number average molecular weight in consideration of fatigue resistance and high molding accuracy. When the number average molecular weight is less than 13,000, the molecular weight is too low and the fatigue resistance tends to be inferior. On the other hand, when the number average molecular weight exceeds 30000, although fatigue resistance is improved, it may be necessary to contain, for example, carbon fiber in order to achieve necessary mechanical strength such as impact strength. For example, when 10 to 50% by mass of carbon fiber is contained, the melt viscosity at the time of molding exceeds the above upper limit (10000 poise). Therefore, it tends to be difficult to ensure the molding accuracy of the lubricating member 3 during injection molding. The number average molecular weight in the present invention indicates the number average molecular weight in terms of polystyrene measured by gel permeation chromatograph (GPC method) after dissolving the PAS resin in a solvent. It implements on the conditions shown in the Example of this.

The melting point of the PAS resin is, for example, about 220 to 290 ° C., preferably 280 to 290 ° C. In general, since the melting point of the PPS resin is about 285 ° C., it is preferable to use the PPS resin as the PAS resin. Further, since the PAS resin has low water absorption, the lubricating member 3 containing the PAS resin tends to reduce dimensional changes due to water absorption. Therefore, the bearing 1 having the lubrication member 3 containing the PAS resin tends to have excellent stability that the seizure in the lubrication member 3 hardly occurs and the dimensional change due to water absorption is reduced.

(4) Carbon material As a carbon material mix | blended with a resin composition, graphite, carbon nanofiber, carbon black, etc. are mentioned, for example. Examples of the form of the carbon material include powder. As the carbon material powder, for example, graphite powder can be used, and specifically, any of natural graphite powder and artificial graphite powder can be used. Natural graphite powder has a feature of excellent lubricity because it is in the form of scales. On the other hand, artificial graphite powder has a feature that it is excellent in formability because it is in a lump shape. The carbon material powder is not limited to the graphite powder, which is a crystalline powder, but may be an amorphous powder such as pitch powder or coke powder. When carbon nanofibers are used as the carbon material, the mechanical strength such as the bending elastic modulus of the lubricating member 3 can be improved. Carbon nanofibers are broadly classified into pitch systems and PAN systems, and any of them can be used. For example, carbon nanofibers having an average fiber diameter of 20 μm or less and an average fiber length of 0.02 to 0.2 mm can be used.

A binder can also be included in the carbon material powder (for example, graphite powder). As the binder, resin binder powder can be used, and as the resin binder powder, for example, phenol resin powder can be used. It is preferable to add a molding aid, a lubricant, a modifier, or the like as necessary to uniformly mix the carbon material powder and the binder.

As the raw material powder constituting the lubricating member 3, in addition to using the mixed powder of the carbon material powder and the resin binder powder as described above, a granulated powder obtained by granulating the carbon material powder in the presence of the resin binder can also be used. The granulated powder has a larger specific gravity and higher fluidity than a single resin binder powder or carbon material powder. Therefore, it becomes easy to supply the resin composition containing the granulated powder to the molding die, and it becomes possible to accurately mold into a predetermined shape.

In the bearing 1, the lubricating member 3 constituting a part of the bearing surface portion 11 serves as a carbon material supply source. The carbon material supplied from the lubricating member 3 spreads over the entire bearing surface portion 11 by the relative movement of the bearing surface portion 11 and the shaft 2. Thereby, the lubrication effect by a carbon material can be acquired in the bearing surface part 11 whole.

(5) Other materials The resin composition may include other fillers in addition to the polyarylene sulfide-based resin and the carbon material. Examples of other fillers include fibers such as glass fiber, aramid fiber, alumina fiber, aromatic polyamide fiber, polyester fiber, boron fiber, silicon carbide fiber, boron nitride fiber, silicon nitride fiber, metal fiber, and the like. Knitted fabric, minerals such as calcium carbonate, talc, silica, clay, mica, inorganic whiskers such as aluminum borate whisker and potassium titanate whisker, various heat resistant resins such as polyimide resin and polybenzimidazole Can be used. By including these fillers, the friction and wear characteristics of the lubricating member 3 can be improved and the linear expansion coefficient can be reduced. If necessary, additives such as a mold release agent, a flame retardant, a weather resistance improver, an antioxidant, and a pigment may be appropriately added.

(6) Content of carbon material The content of the carbon material blended in the resin composition is set in a suitable range in order to ensure the sliding characteristics of the sliding surface of the lubricating member 3, and is approximately 5% by mass or more. Approximately 70% by mass or less, specifically 5% by mass or more and 70% by mass or less, preferably approximately 10% by mass or more and approximately 60% by mass or less, specifically 10% by mass or more and 60% by mass or less, more preferably approximately 40% by mass. It is not more than mass%, specifically not more than 40 mass%. When the compounding amount of the carbon material in the resin composition is less than about 5% by mass, specifically when it is less than about 10% by mass, more specifically when it is less than 10% by mass, the compounding amount of the carbon material is small. Therefore, the effect of improving the sliding characteristics of the sliding surface by the carbon material tends to hardly appear. When the compounding amount of the carbon material in the resin composition exceeds approximately 70% by mass, specifically exceeds approximately 60% by mass, more specifically exceeds 60% by mass, the fluidity of the resin composition is increased. In addition to a decrease in yield rate during injection molding, it tends to be difficult to perform injection molding itself. The content of the carbon material blended in the resin composition is preferably within the above range in order to avoid a decrease in the yield rate during injection molding while ensuring sliding characteristics, and is approximately 40% by mass or less. Specifically, it is more preferably 40% by mass or less.

(7) Impregnation of lubricating oil Since the bearing 1 has innumerable internal holes, the internal holes of the bearing 1 that have undergone the insert molding process can be impregnated with lubricating oil. For example, after the bearing 1 that has undergone the insert molding process is immersed in lubricating oil in a reduced pressure environment, the internal holes of the bearing 1 can be impregnated with lubricating oil by returning to atmospheric pressure. The lubricating oil is not particularly limited as long as it is widely used for bearings. For example, mineral oil such as spindle oil, refrigerator oil, turbine oil, machine oil, dynamo oil, polybutene, poly-α-olefin, alkyl, etc. Hydrocarbon synthetic oils such as naphthalene and alicyclic compounds, or ester oils of natural oils and polyols, esters such as phosphate esters and diester oils, polyglycol oils, silicone oils, polyphenyl ether oils, alkyl diphenyl ether oils In addition, non-hydrocarbon synthetic oils such as alkylbenzene and fluorinated oil, liquid grease, and the like may be used.

(8) Open porosity of the base 4 The open porosity of the base 4 is determined by the fact that the lubricating oil functions as a lubricity imparting agent when the internal pores of the bearing 1 subjected to the insert molding process are impregnated with the lubricating oil. In order to improve the sliding characteristics, it is set within a suitable range. The open porosity of the substrate 4 is approximately 5% or more, specifically 5% or more, preferably approximately 10% or more, specifically 10% or more, more preferably approximately 15% or more, specifically 15%. That's it. The open porosity of the substrate 4 is approximately 50% or less, specifically 50% or less, preferably approximately 40% or less, specifically 40% or less, more preferably approximately 30% or less, specifically. 30% or less, more preferably about 25% or less, specifically 25% or less. When the open porosity is less than about 5% (specifically, 5%), the total amount of lubricating oil impregnated in the internal pores of the substrate 4 is small. Therefore, it tends to be difficult for the bearing 1 to exhibit excellent lubricating performance based on the lubricating oil over a long period of time. Further, when the open porosity exceeds approximately 50% (specifically, 50%), it becomes difficult to form the base 4 and the formability of the base 4 is lowered. As a result, it is difficult to form the base body 4 with high productivity, and it tends to be difficult to produce the bearing 1 including the base body 4 at low cost. In order to form the bearing 1 with high productivity while allowing the base 4 to exhibit excellent lubricating performance based on the lubricating oil, the open porosity of the base 4 is preferably within the above range. The “open porosity” is expressed as a percentage of the internal pores that can be impregnated with respect to the volume of the substrate 4, and is obtained by dividing the volume of oil after complete impregnation by the volume of the substrate 4 and multiplying by 100. . The open porosity can be measured by the Japanese Industrial Standard “Sintered Metal Material—Density, Oil Content and Open Porosity Test Method (JIS Z 2501: 2000)”.

(9) Oil content of base 4 The internal pores of the base 4 are impregnated with a lubricating oil such as mineral oil or synthetic oil as a lubricant. Therefore, when the base 4 rotates with respect to the shaft 2, the lubricating oil held in the internal pores of the base 4 oozes out from the surface opening of the inner peripheral surface 4a of the base 4, and the inner peripheral surface 4a (sliding surface portion 11). And an oil film of lubricating oil is formed between the outer peripheral surface of the shaft 2. Thereby, wear of the sliding surface portion 11 is suppressed or prevented. The oil content of the entire substrate 4 is about 5 vol% or more, specifically 5 vol% or more, preferably about 10 vol% or more, specifically 10 vol% or more, more preferably about 15 vol% or more, specifically 15 vol%. That's it. Further, the oil content of the whole substrate 4 is about 50 vol% or less, specifically 50 vol% or less, preferably about 40 vol% or less, specifically 40 vol% or less, more preferably about 30 vol% or less, specifically 30 vol% or less, more preferably about 25 vol% or less, specifically 25 vol% or less. When the oil content is about 5 vol%, specifically about 10 vol%, more specifically about 15 vol%, and more specifically below 15 vol%, the desired lubrication characteristics can be stably maintained over a long period of time. I can't demonstrate it. When the oil content is about 50 vol%, specifically about 40 vol%, more specifically about 30 vol%, more specifically about 25 vol%, more specifically about 25 vol%, the internal porosity is increased. Furthermore, there is a possibility that the mechanical strength required for the substrate 4 as a whole cannot be ensured.

Further, if the lubricating oil impregnated in the internal pores of the base body 4 is too low in viscosity, the lubricating oil will easily flow out to the outside, and the oil film rigidity will be low and the wear suppressing effect of the sliding surface portion 11 will be insufficient. there is a possibility. On the other hand, if the lubricating oil is too viscous, there is a possibility that the amount of lubricating oil oozing out from the surface opening of the sliding surface portion 11 will be insufficient, and an oil film having a predetermined thickness and rigidity may not be formed. From this point of view, the lubricating oil has a kinematic viscosity at 40 ° C. of about 5 mm ² / s or more, specifically 5 mm ² / s or more, preferably about 30 mm ² / s or more, specifically 30 mm ² / s. More preferably, it is about 50 mm ² / s or more, more specifically 50 mm ² / s or more. The lubricating oil has a kinematic viscosity at 40 ° C. of about 600 mm ² / s or less, specifically 600 mm ² / s or less, preferably about 550 mm ² / s or less, specifically 550 mm ² / s or less, More preferably, it is about 500 mm ² / s or less, specifically 500 mm ² / s or less.

It should be noted that the internal pores of the substrate 4 may be impregnated with liquid grease instead of the above lubricating oil. As the liquid grease, for example, a lubricating oil having a kinematic viscosity at 40 ° C. within the above range is used as a base oil, and a soap-based thickener such as lithium soap or a non-soap-based thickener such as urea is added thereto. Things can be used.

(10) Surface Opening Ratio of Base 4 The surface opening ratio of the base 4 on the mating surface 4b, which is the inner surface of the housing portion 4c, is the polyarylene contained in the lubricating member 3 disposed in the housing portion 4c of the base 4. Due to the anchor effect of the sulfide-based resin, the range is set within a suitable range in order to increase the bonding force between the base 4 and the lubricating member 3. The surface area ratio is preferably 10% or more and 50% or less. When the surface open area ratio is less than 10%, the amount of the polyarylene sulfide resin contained in the lubricating member 3 entering the surface pores of the mating surface 4b is reduced. Therefore, the anchor effect of polyarylene sulfide resin tends to decrease. Moreover, when the surface area ratio exceeds 50%, it tends to be difficult to mold the housing portion 4c. In order to form the bearing 1 with high productivity while increasing the bonding force between the base 4 and the lubricating member 3, the surface porosity of the base 4 is preferably within the above range. The “surface aperture ratio” is the ratio (area ratio) of the total area of surface apertures per unit area of the surface. In addition, for the sake of convenience, the surface area ratio here is calculated, for example, by taking an image (for example, 500 times) taken with a metal microscope such as Nikon Corporation: ECLIPSE ME600 as image data and calculating the area of the pore portion. You can ask for it.

(11) Material of shaft 2 The material of the shaft is not particularly limited, and various materials such as SS steel, SC steel, SCM steel, SUJ steel, and SUS steel can be used. The hardness of the steel may be about HRC 30 to 60 (HB 286 to 654), or about HB 140 to 220, and the hardness after quenching may be about HRC 55 to 70, preferably HRC 55 to 60, or HRC 60 to 65. Good. In this way, a slide bearing device including the sliding member 1 and the shaft 2 may be configured.

In the above embodiment, the case where the inner surface 3a of the lubricating member 3 and the inner peripheral surface 4a of the base body 4 are arranged in the same cylindrical surface and the bearing surface portion 11 is configured by these is shown, but the present invention is not limited thereto. . Hereinafter, although other embodiment of this invention is described, description is abbreviate | omitted about the point which overlaps with said embodiment.

[Other Embodiments]
Referring to FIG. 5, the bearing 1 is arranged such that the inner side surface 3 a of the lubricating member 3 is arranged on the inner diameter side with respect to the inner peripheral surface 4 a of the base 4, and the bearing surface portion 11 is constituted only by the inner side surface 3 a of the lubricating member 3. It may be manufactured. In this case, the inner side surfaces 3a of the plurality of lubricating members 3 are preferably arranged on the same cylindrical surface.

Further, the lubricating member 3 may be disposed only in a partial region in the axial direction in addition to the entire axial length of the bearing 1 as shown in FIG. 1B, for example, a plurality of locations separated in the axial direction. You may arrange in.

Further, in the bearing 1, the shaft 2 does not necessarily slide with respect to the entire bearing surface portion 11. For example, a limited partial region of the bearing surface portion 11 may slide with the shaft 2. Specifically, when the shaft 2 is in a horizontal posture, the shaft 2 may drop due to gravity and slide with the bearing surface portion 11 in the lower region of the bearing surface portion 11. In that case, the position and shape of the lubricating member 3 in the bearing 1 are designed so that the lubricating member 3 is located in the sliding region with the shaft 2, or the circumferential phase of the bearing 1 is adjusted so that the shaft 2 can always slide with the lubricating member 3. As a result, a high lubrication effect can be obtained, so that the shaft 2 can be supported in an oilless state in which no lubricating oil is interposed between the bearing surface portion 11 and the like, for example. Of course, it can also be used in a state where lubricating oil is interposed between the bearing surface portion 11 and the shaft 2, and in this case, the lubricating effect is further enhanced. In the present embodiment, lubricating oil is interposed between the bearing surface portion 11 and the shaft 2, and the internal holes of the substrate 4 are impregnated with oil. In this case, the oil rises from the surface (inner side surface 3a) of the substrate 4 due to the temperature rise accompanying the rotation of the shaft 2, and this oil is supplied to the sliding region between the bearing surface portion 11 and the shaft 2 to slide. An excellent slidability is maintained by reliably avoiding oil film breakage in the region.

Further, the present invention is not limited to a bearing that supports the relative rotation of the shaft, but can also be applied to a bearing that supports the axial movement of the shaft. Further, the present invention is not limited to a cylindrical sliding member, and can be applied to a sliding member having another shape (for example, a semi-cylindrical shape or a rectangular parallelepiped shape).

Hereinafter, the sliding member and the manufacturing method thereof according to the present invention will be described in detail with reference to embodiments.

[Second Embodiment]
The sliding member manufactured by the manufacturing method according to the present embodiment is the following sliding member.

A sliding member having a sliding surface, wherein at least a part of the sliding surface is constituted by a surface of a lubricating member, and is a sintered body of a molded body containing metal powder, and integrated with the lubricating member A sliding member comprising: a base to be formed; and the lubricating member which is an injection-molded body of a resin composition containing a thermoplastic resin and a carbon material.

The manufacturing method of the sliding member according to the present embodiment is a method of manufacturing the sliding member in which the lubricating member 3 is disposed in the housing portion 4c of the base body 4 by using injection molding.
The process of obtaining the base | substrate 4 by compressing and molding the raw material powder which uses a metal powder as a main component (the most component by weight ratio) using a shaping | molding die, and heating and sintering a molded object (metal powder molded object). (Substrate manufacturing process), and
A step of placing the resin composition in the housing portion 4c of the substrate 4 as the lubricating member 3 by injection molding with a resin composition containing a carbon material and a thermoplastic resin using the substrate 4 as an insert part (insert molding step); Are included in this order.

Hereinafter, the steps will be described with reference to FIGS. 1 to 4 by taking a bearing as an example of the sliding member according to the present invention.

(1) Substrate manufacturing process Referring to FIG. 1, this process accommodates the lubricating member 3 by sintering a molded body containing metal powder in accordance with a normal manufacturing process employed when manufacturing a bearing. This is a process of manufacturing the base 4 provided with the accommodating portion 4c for the purpose. A molded body containing metal powder can be obtained, for example, by compression-molding raw material powder containing metal powder as a main component (a component having the largest weight ratio) using a molding die. By heating and sintering a molded body (metal powder molded body) obtained by compression molding, it is possible to obtain a base body 4 having a housing portion 4c for housing the lubricating member 3.

Here, specifically, the ratio of the metal (element) constituting the substrate 4 is, for example, a mixed powder of Fe powder, Cu powder, and Sn powder, and in this embodiment, graphite powder is further mixed. The blending ratio of each powder is, for example, Cu powder: approximately 10 to approximately 30% by mass, specifically 10 to 30% by mass (preferably approximately 15 to approximately 20% by mass, specifically 15 to 20% by mass). Sn powder: approximately 0.5 to approximately 3.0% by mass, specifically 0.5 to 3.0% by mass (preferably approximately 1.5 to approximately 2.0% by mass, specifically 1. 5 to 2.0% by mass), graphite powder: about 0.5 to about 7.0% by mass, specifically 0.5 to 7.0% by mass (preferably about 0.5 to about 3.0% by mass) %, Specifically 0.5 to 3.0 mass%), and the rest is Fe powder. If the amount of Cu powder is too small, the slidability of the inner peripheral surface 4a of the sliding surface portion 11 is lowered, and if it is too large, there is a problem in the wear resistance of the inner peripheral surface 4a of the sliding surface portion 11. The range.

(2) Insert molding step This step is a step of injection molding with a resin composition containing a carbon material and a thermoplastic resin, using the base 4 as an insert part, in order to place the lubricating member 3 in the housing portion 4c of the base 4. It is. In this way, the plurality of lubricating members 3 are integrated with the base body 4. More specifically, this is a process in which the plurality of lubricating members 3 are arranged in the housing portion 4 c of the base body 4.

Referring to FIG. 3, this step can be performed by using a molding die 20 having a fixed die 21 and a movable die 22. The fixed die 21 is provided with a cylindrical portion 21a, and the inner peripheral surface 4a of the base body 4 is formed on the outer peripheral surface of the cylindrical portion 21a. A gate 21 b is provided on a molding surface 21 c that forms an end surface of the lubricating member 3 in the fixed mold 21. In the present embodiment, a plurality (five in the illustrated example) of gates 21b are arranged at equal intervals in the circumferential direction on the molding surface 21c of the fixed die 21 (see FIG. 4). The type of the gate is not limited to the dotted gate as in the illustrated example, and may be, for example, an annular film gate.

Next, a molten resin composition containing a carbon material and a thermoplastic resin is injected into the cavity 23 from the runner 21d through the gate 21b. As a result, the cavity 23 is filled with the molten resin composition. When the resin composition filled in the cavity 23 is cooled and solidified, the lubricating member 3 is disposed on the inner peripheral surface 4a of the base body 4, and the bearing 1 is manufactured.

According to the above-described embodiment, for example, the lubricating member 3 is contained in the housing portion 4c by injecting a resin composition containing a thermoplastic resin as a main component (a component having the largest weight ratio) and further including a carbon material into the housing portion 4c. It is possible to manufacture the bearings 1 arranged in the above efficiently and in large quantities. Since the bearings 1 can be manufactured in large quantities, the manufacturing cost of each bearing 1 can be reduced. In addition, since the lubricating member 3 is disposed in the housing portion 4c of the base body 4, due to the anchor effect of the thermoplastic resin contained in the lubricating member 3, the mating surface 4b (the inner surface of the housing portion 4c) and the base body 4 The coupling force with the lubricating member 3 is increased. Therefore, it is possible to reduce the possibility that the lubricating member 3 falls off the base 4 of the bearing 1 during use of the bearing 1.

Examples of the thermoplastic resin that is the main component (the component having the largest weight ratio) of the resin composition include polyamide (PA), polycarbonate (PC), polybutylene terephthalate (PBT), polyacetal (POM), and wholly aromatic polyester. Liquid crystal polymer (LCP) such as a liquid crystal polymer, polyarylene sulfide resin (eg, may be polyphenylene sulfide (PPS)), polyetheretherketone (PEEK), polyamideimide (PAI), polyetherimide (PEI) ), Polyimide (PI), polytetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), and ethylene-tetrafluoroethylene copolymer (ETFE). Fluororesin (polyvinylidene-olefin resin), include resins, including olefin resin such as polyethylene. Each of these synthetic resins may be used alone or may be a polymer alloy in which two or more kinds are mixed. When the thermoplastic resin contains a polyarylene sulfide-based resin, the sliding member according to the above embodiment can be manufactured by the manufacturing method according to the present embodiment.

Examples of the carbon material blended in the resin composition include graphite, carbon nanofiber, and carbon black. Examples of the form of the carbon material include powder. As the carbon material powder, for example, graphite powder can be used, and specifically, any of natural graphite powder and artificial graphite powder can be used. Natural graphite powder has a feature of excellent lubricity because it is in the form of scales. On the other hand, artificial graphite powder has a feature that it is excellent in formability because it is in a lump shape. The carbon material powder is not limited to the graphite powder, which is a crystalline powder, but may be an amorphous powder such as pitch powder or coke powder.

In order to achieve the required mechanical strength such as impact strength, it may be necessary to contain, for example, carbon fiber. For example, 10 to 50% by mass of carbon fiber is contained.

By adding carbon nanofibers as the carbon material, mechanical strength such as flexural modulus can be improved, and by adding the carbon material powder, sliding to the shaft 2 and the cylindrical portion 21a of the molding die 20 can be achieved. The dynamic characteristics are improved. Carbon nanofibers are broadly classified into pitch systems and PAN systems, and any of them can be used. For example, carbon nanofibers having an average fiber diameter of 20 μm or less and an average fiber length of 0.02 to 0.2 mm can be used.

The resin composition may contain other fillers in addition to the thermoplastic resin and the carbon material. Examples of other fillers include fibers such as glass fiber, aramid fiber, alumina fiber, aromatic polyamide fiber, polyester fiber, boron fiber, silicon carbide fiber, boron nitride fiber, silicon nitride fiber, metal fiber, and the like. What is knitted into cloth, minerals such as calcium carbonate, talc, silica, clay and mica, inorganic whiskers such as aluminum borate whisker and potassium titanate whisker, polyimide resin and polybenzimidazole can be used. By including these fillers, the friction and wear characteristics of the lubricating member 3 can be improved and the linear expansion coefficient can be reduced. If necessary, additives such as a mold release agent, a flame retardant, a weather resistance improver, an antioxidant, and a pigment may be appropriately added.

The content of the carbon material blended in the resin composition is set in a suitable range for ensuring the sliding characteristics of the sliding surface of the lubricating member 3, and is approximately 5% by mass or more and approximately 70% by mass or less. 5 mass% to 70 mass%, preferably about 10 mass% to about 60 mass%, specifically 10 mass% to 60 mass%, more preferably about 50 mass% or less, specifically 50% by mass or less, more preferably approximately 40% by mass or less, specifically 40% by mass or less. When the compounding amount of the carbon material in the resin composition is less than about 5% by mass, specifically when it is less than about 10% by mass, more specifically when it is less than 10% by mass, the compounding amount of the carbon material is small. Therefore, the effect of improving the sliding characteristics of the sliding surface by the carbon material tends to hardly appear. When the compounding amount of the carbon material in the resin composition exceeds approximately 70% by mass, specifically exceeds approximately 60% by mass, more specifically exceeds approximately 50% by mass, particularly specifically 50%. When it exceeds mass%, the fluidity of the resin composition is lowered, the yield rate during injection molding is lowered, and the injection molding itself tends to be difficult. The content of the carbon material blended in the resin composition is preferably within the above range in order to avoid a decrease in the yield rate during injection molding while ensuring sliding characteristics, and is approximately 40% by mass or less. Specifically, it is more preferably 40% by mass or less.

Since the bearing 1 has an infinite number of internal holes, the internal holes of the bearing 1 that have undergone the insert molding process can be impregnated with oil. Specifically, after the bearing 1 that has undergone the insert molding step is immersed in lubricating oil in a reduced pressure environment, the internal voids of the bearing 1 are impregnated with oil by returning to atmospheric pressure. The lubricating oil is not particularly limited as long as it is widely used for bearings. For example, mineral oil such as spindle oil, refrigerator oil, turbine oil, machine oil, dynamo oil, polybutene, poly-α-olefin, alkyl, etc. Hydrocarbon synthetic oils such as naphthalene and alicyclic compounds, or ester oils of natural oils and polyols, esters such as phosphate esters and diester oils, polyglycol oils, silicone oils, polyphenyl ether oils, alkyl diphenyl ether oils In addition, non-hydrocarbon synthetic oils such as alkylbenzene and fluorinated oil, liquid grease, and the like may be used.

The open porosity of the base body 4 is suitable for improving the sliding characteristics of the bearing 1 because the oil functions as a lubricity imparting agent when the internal pores of the bearing 1 subjected to the insert molding process are impregnated with oil. Set to range. The open porosity of the substrate 4 is approximately 5% or more, specifically 5% or more, preferably approximately 10% or more, specifically 10% or more, more preferably approximately 15% or more, specifically 15%. That's it. The open porosity of the substrate 4 is approximately 50% or less, specifically 50% or less, preferably approximately 40% or less, specifically 40% or less, more preferably approximately 30% or less, specifically. 30% or less, more preferably about 25% or less, specifically 25% or less. When the open porosity is less than about 5% (specifically, 5%), the total amount of oil impregnated in the internal pores of the substrate 4 is small. Therefore, it tends to be difficult for the bearing 1 to exhibit excellent lubricating performance based on the lubricating oil over a long period of time. Further, when the open porosity exceeds approximately 50% (specifically, 50%), it becomes difficult to form the base 4 and the formability of the base 4 is lowered. As a result, it becomes difficult to mold the substrate 4 with high productivity. For this reason, it tends to be difficult to produce the bearing 1 including the base body 4 at low cost. In order to form the bearing 1 with high productivity while allowing the base 4 to exhibit excellent lubricating performance based on the lubricating oil, the open porosity of the base 4 is preferably within the above range. The “open porosity” is expressed as a percentage of the internal pores that can be impregnated with respect to the volume of the substrate 4, and is obtained by dividing the volume of oil after complete impregnation by the volume of the substrate 4 and multiplying by 100. . The open porosity can be measured by the Japanese Industrial Standard “Sintered Metal Material—Density, Oil Content and Open Porosity Test Method (JIS Z 2501: 2000)”.

The internal pores of the substrate 4 are impregnated with a lubricating oil such as mineral oil or synthetic oil as a lubricant. Therefore, when the base 4 rotates with respect to the shaft 2, the lubricating oil held in the internal pores of the base 4 oozes out from the surface opening of the inner peripheral surface 4a of the base 4, and the inner peripheral surface 4a (sliding surface portion 11). And an oil film of lubricating oil is formed between the outer peripheral surface of the shaft 2. Thereby, wear of the sliding surface portion 11 is suppressed or prevented. The oil content of the entire substrate 4 is about 5 vol% or more, specifically 5 vol% or more, preferably about 10 vol% or more, specifically 10 vol% or more, more preferably about 15 vol% or more, specifically 15 vol%. That's it. Further, the oil content of the whole substrate 4 is about 50 vol% or less, specifically 50 vol% or less, preferably about 40 vol% or less, specifically 40 vol% or less, more preferably about 30 vol% or less, specifically 30 vol% or less, more preferably about 25 vol% or less, specifically 25 vol% or less. When the oil content is about 5 vol%, specifically about 10 vol%, more specifically about 15 vol%, and more specifically below 15 vol%, the desired lubrication characteristics can be stably maintained over a long period of time. I can't demonstrate it. When the oil content is about 50 vol%, specifically about 40 vol%, more specifically about 30 vol%, more specifically about 25 vol%, more specifically about 25 vol%, the internal porosity is increased. Furthermore, there is a possibility that the mechanical strength required for the substrate 4 as a whole cannot be ensured.

The surface porosity of the mating surface 4b, which is the inner surface of the housing portion 4c, of the base body 4 is lubricated with the base body 4 by the anchor effect of the thermoplastic resin contained in the lubricating member 3 disposed in the housing portion 4c of the base body 4. In order to increase the coupling force with the member 3, it is set within a suitable range. The surface aperture ratio is preferably 10% or more and 50% or less. When the surface area ratio is less than 10%, the amount of the thermoplastic resin contained in the lubricating member 3 entering the surface pores of the mating surface 4b is reduced. Therefore, the anchor effect of the thermoplastic resin tends to decrease. Moreover, when the surface area ratio exceeds 50%, it tends to be difficult to mold the housing portion 4c. In order to form the bearing 1 with high productivity while increasing the bonding force between the base 4 and the lubricating member 3, the surface porosity of the base 4 is preferably within the above range. The “surface aperture ratio” is the ratio (area ratio) of the total area of surface apertures per unit area of the surface. In addition, for the sake of convenience, the surface area ratio here is calculated, for example, by taking an image (for example, 500 times) taken with a metal microscope such as Nikon Corporation: ECLIPSE ME600 as image data and calculating the area of the pore portion. You can ask for it.

The material of the shaft is not particularly limited, and various materials such as SS steel, SC steel, SCM steel, SUJ steel, and SUS steel can be used. The hardness of the steel may be about HRC 30 to 60 (HB 286 to 654), or about HB 140 to 220, and the hardness after quenching may be about HRC 55 to 70, preferably HRC 55 to 60, or HRC 60 to 65. Good. In this way, a slide bearing device including the sliding member 1 and the shaft 2 may be configured.

1 sliding member (bearing), 2 shaft, 3 lubrication member, 3a inner surface, 3b outer surface, 4 base, 4 'molded body, 4a inner peripheral surface, 4a' recess, 4b mating surface, 4c housing portion, 11 bearing Surface portion (sliding surface portion), 12 outer peripheral surface, 20 molding die, 21 fixed mold, 21a cylindrical portion, 21b gate, 21c molding surface, 21d runner, 22 movable mold, 23 cavity.

Claims

A sliding member having a sliding surface, wherein at least a part of the sliding surface is constituted by a surface of a lubricating member;
A sintered body of a molded body containing metal powder, and a base body integrated with the lubricating member;
The lubricating member which is an injection-molded article of a resin composition comprising a polyarylene sulfide-based resin and a carbon material;
A sliding member.
A sliding member having a sliding surface, wherein at least a part of the sliding surface is constituted by a surface of a lubricating member;
A base body having a housing portion for housing the lubricating member, which is a sintered body of a molded body containing metal powder;
An injection molded body of a resin composition comprising a polyarylene sulfide-based resin and a carbon material, the lubricating member disposed in the housing portion,
A sliding member.
The sliding member according to claim 1 or 2, wherein a content of the carbon material in the resin composition is approximately 5% by mass or more and approximately 70% by mass or less.
The substrate has internal voids;
The sliding member according to any one of claims 1 to 3, wherein the internal hole is impregnated with a lubricating oil.
The sliding member according to any one of claims 1 to 4, wherein the base body has an open porosity of approximately 5% or more and approximately 50% or less.
The sliding member according to any one of claims 1 to 5, wherein the base body has a surface porosity of approximately 10% or more and approximately 50% or less.
The sliding member according to claim 2, wherein the base body has a surface area ratio of approximately 10% to approximately 50% on the inner surface of the housing portion.
The sliding member according to any one of claims 1 to 7, wherein the carbon material is at least one selected from the group consisting of carbon nanofibers, carbon black, and graphite.