WO2019070041A1

WO2019070041A1 - Sliding member

Info

Publication number: WO2019070041A1
Application number: PCT/JP2018/037279
Authority: WO
Inventors: 拓治原野; 敏彦毛利
Original assignee: Ntn株式会社
Priority date: 2017-10-04
Filing date: 2018-10-04
Publication date: 2019-04-11

Abstract

Provided is a sliding member having a sliding surface, the sliding member comprising a base body which is a sintered body of a compact containing metal powder, and a lubricating member which is a compact of a resin composition containing a thermoplastic resin and a carbon material, wherein the base body includes a housing portion for housing the lubricating member, at least a part of the sliding surface is composed of the lubricating member housed in the housing portion, and the lubricating members are also disposed around the inner periphery of openings at both end sides of the base body.

Description

Sliding member

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

The functions required for a sliding member in which a solid lubricant is embedded are becoming more and more severe year by year. Therefore, development of a solid lubricant which can maintain excellent slidability for a long time and which can be manufactured at low cost is required.

As a sliding member in which a solid lubricant is embedded, for example, in Patent Document 1, a through hole in the radial direction is formed in a cylindrical base, and the through hole is fired mainly containing artificial graphite as a solid lubricant. A sliding member in which a body is embedded has been proposed.

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, and the through hole of the base or 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 sintered body (calcined artificial graphite) is used as a solid lubricant, the carbon-based sintered body is less likely to be plastically deformed, and thus shaping by cutting is required to improve dimensional accuracy. There is a concern that the cost 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. There is also a need for a sliding member having better lubricating performance / sliding characteristics.

Then, this invention makes it a first object to provide the sliding member which has the outstanding lubricating performance / sliding characteristic.

The second object of the present invention is to provide a sliding member which can improve the working efficiency and the processing cost in manufacturing the sliding member.

Further, the present invention can improve the working efficiency and the processing cost in manufacturing the sliding member, and the possibility of the lubricating member (solid lubricant) falling off from the base of the sliding member is reduced while using the sliding member. The third object is to provide a sliding member.

The present invention provides a sliding member shown below.
[1] A lubricating member, which is a sliding member having a sliding surface, which is a molded body of a resin composition containing a base body which is a sintered body of a molded body containing metal powder, a thermoplastic resin and a carbon material And the base body has a housing portion for housing the lubricating member, and at least a part of the sliding surface is constituted by the lubricating member housed in the housing portion, and The sliding member, wherein the lubricating member is also disposed at the inner diameter of the small hole.

[2] A resin composition which is a sliding member having a sliding surface, and is a sintered body of a molded body containing Fe powder, Cu powder, Sn powder and graphite powder, a thermoplastic resin and a carbon material A lubrication member, which is a molded product of the object, the base body has a housing portion for housing the lubrication member, and at least a portion of the sliding surface is the lubrication received in the housing portion A sliding member comprising a member and wherein the lubricating member is disposed also at an inner diameter of the base.

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

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

[5] The sliding member according to [4], wherein the base has an open porosity of 10% to 50%.

[6] The sliding member according to any one of [1] to [5], wherein the base has a surface open area ratio of 10% to 50% on the inner surface of the housing portion.

[7] The sliding member according to any one of [1] to [6], 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 having excellent lubricating performance / sliding characteristics. Further, according to the present invention, it is possible to provide a sliding member which can improve the working efficiency and the processing cost in manufacturing the sliding member. Further, according to the present invention, the working efficiency and processing cost in manufacturing the sliding member can be improved, and the possibility of the lubricating member (solid lubricant) falling off from the base of the sliding member is reduced while using the sliding member. The sliding member can be provided.

It is a front view of a sliding member concerning an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line AA of FIG. It is a front view of a substrate concerning an embodiment of the present invention.

Referring to FIG. 1, the sliding member 1 has a cylindrical shape, and an axis 2 (indicated by a dashed line) as a mating material is inserted in the inner periphery thereof. The sliding member 1 includes a base 4 which is a sintered body of a molded body containing metal powder. A lubricating member (solid lubricant) 3, which is a molded product of a resin composition containing a thermoplastic resin and a carbon material, is disposed in the inside diameter (both) small holes 13 of the substrate 4.

In the present specification, “inner diameter of the base 4” means the vicinity of one end of the inner diameter portion of the base 4 in contact with the shaft 2. Specifically, one end of the lubricating member 3 integrated with the base 4 is extended outward at the side surface of the substantially cylindrical sliding member 1 (bearing 1) main body, for example, substantially It is formed in the shape of a hollow disc or annular ring. One end of the base 4 is, for example, substantially annular on the inner diameter side of the side surface of the main body of the sliding member 1 (bearing 1) having a substantially cylindrical shape corresponding to the hollow disc shape / annular rod shape. The shape is indented into the

Further, in the present specification, “inner diameter and small diameter end of base 4” means the vicinity of both ends of the inner diameter portion of the base 4 in contact with the shaft 2. Specifically, both ends of the lubricating member 3 integrated with the base 4 are extended outward at the side surface of the substantially cylindrical sliding member 1 (bearing 1) main body, for example, as a pair It is formed in a substantially hollow disc shape / annular bowl shape. Corresponding to the pair of hollow disk-like / annular bowl-like shapes, both ends of the base 4 are, for example, a pair on the inner diameter side of the side surface of the substantially cylindrical sliding member 1 (bearing 1) main body. The shape is indented in a substantially annular shape. With such a structure, when the base 4 is inserted into an injection mold and injection molding is performed using a resin composition to form the sliding member 1 (bearing 1), the lubricating member 3 reliably It is integrated with the base 4.

In the case of “inside small diameter” or “inside small diameter”, the minimum diameter of “inside small diameter” or “inside small diameter” is equal to the smallest diameter of the base 4 and / or the smallest diameter of the lubricating member 3. Further, the maximum diameter of the “inner diameter small opening” or the “inner diameter small small diameter opening” is equal to the maximum diameter of the lubricating member 3.

The radial dimension D ₁ of “the inner diameter portion of the base 4” may be, for example, 0.1% to 10% of the inner diameter D ₀ of the base 4. The axial dimension L ₁ of “the inner diameter portion of the base 4” may be, for example, 2.5% to 10% of the axial length dimension L ₀ of the base 4, and the axial length dimension L of the base 4 is preferably 3.5% to 7.5% of the _0, and particularly preferably 4% to 6% of the axial length _{L 0} of the substrate 4. Further, the radial dimension D ₁ of the “inner diameter and small diameter portion of the base 4” may be, for example, 0.1% to 10% of the inner diameter size D ₀ of the base 4. Axial dimension L ₁ of the "inner diameter both small of the substrate 4" may be, for example, 5% to 20% of the axial length L ₀ of the substrate 4, the axial length L ₀ of the substrate 4 And preferably 8% to 12% of the axial length dimension L ₀ of the substrate 4.

If the above% is smaller than the predetermined value, the dimensions of the inner diameter (both) small mouths become smaller, and there is a tendency that the reliable integration of the lubricating member 3 and the base 4 becomes difficult. When the above% is larger than the predetermined value, the size of the inner diameter (both) small mouth becomes too large and the volume of the base 4 decreases, as a result, for example, the strength of the sliding member 1 (bearing 1) provided with the base 4 decreases. Are concerned.

The outer peripheral surface 12 of the sliding member 1 is fixed to the inner peripheral surface of a housing (not shown) by means such as press fitting or adhesion, and supported so that the shaft 2 inserted in the inner periphery of the sliding member 1 can rotate or slide. Ru. In addition to rotating or sliding the shaft 2 in this manner, the shaft 2 can be made stationary and the sliding member 1 can be rotated or slid.

Referring to FIG. 2, the sliding member 1 includes a sliding surface 11 and a base 4 which is a sintered body of a compact including metal powder. In the present specification, the term "metal" means any element of the periodic table excluding carbon, nitrogen, oxygen, sulfur, fluorine, chlorine, bromine, iodine, hydrogen and a rare gas. The sliding member 1 includes the lubricating member 3 which is a molded body of a resin composition containing a thermoplastic resin and a carbon material. The lubricating member 3 is preferably an injection molded body of the resin composition. The sliding surface 11 includes the inner surface 3 a of the lubricating member 3 and the inner peripheral surface 4 a of the base 4. The inner surface 3a of the lubricating member 3 and the inner peripheral surface 4a of the base 4 are substantially flush with each other, and the sliding surface 11 (bearing surface portion 11) is formed.

Referring to FIG. 3, the base 4 has a housing 4 c for housing the lubricating member 3. The lubricating member 3 is housed in the housing portion 4c. Thereby, at least one part of the sliding face 11 is comprised by the lubricating member 3 accommodated in the accommodating part 4c. The base 4 is provided with a concave cylindrical mating surface 4b. The mating surface 4 b is in close contact with the outer surface of the lubricating member 3.

In FIG. 3, a pair of substantially hollow disk-shaped / annular bowl-shaped ends of the lubricating member 3 are connected to connect both ends of six (plural) substantially rectangular flat plates constituting the inner side surface 3a. 6 (plural) substantially rectangular flat groove-shaped accommodation on the inner peripheral side of the base 4 corresponding to the six (plural) substantially rectangular flat coupling portions. Although the configuration in which the portion 4 c is provided is illustrated, a pair of substantially hollow disc-like / annular bowl-like coupling portions connecting the lubricating member 3 and a housing portion on the inner peripheral side of the base 4 The number of 4c is not limited to this, and at least a part of the sliding surface may be configured by the lubricating member 3. For example, a plurality of substantially rectangular flat grooved housing portions 4c are provided on the inner peripheral side of the base body 4, and a pair of substantially hollow hollow parts of the lubricating member 3 are provided corresponding to the plurality of substantially rectangular flat grooved housing portions 4c. It is preferable that the lubricating member 3 be provided with a plurality of substantially rectangular flat plate-like coupling portions which connect the disc-like / ring-like bowl-like ends and which constitute the inner side surface 3a.

Here, to describe the substantially rectangular flat groove shape of the housing portion 4c depth D ₂ of the substrate 4, on the basis of the minimum diameter of the base body 4, approximately along the outermost diameter of the substrate 4 in the radial direction of the substrate 4 It means the dimension of the receiving groove depth directed to the outer peripheral side of the base 4. The depth D ₂ has a plurality of thicknesses of coupling portions in which the substantially rectangular plate which constitutes the inner surface 3a with connecting a pair of ends in which the substantially hollow disk-shaped / circular flange-like lubricating member 3 Approximately equal to the height dimension.

Accommodating portion depth _{D 2} of 4c in which the substantially rectangular flat groove-like substrate 4 is, for example, 0.1% to 10% of the inner diameter _{D 0} of the substrate 4, it is 0.1 to 5% Is preferred. The thickness of the substantially rectangular flat coupling portion of the lubricating member 3 is, for example, 0.1% to 10% of the inner diameter D ₀ of the lubricating member 3 and 0.1% to 5%. Is preferred.

Less than substantially rectangular flat groove and the depth D ₂ is above a predetermined percentage of the accommodating portion 4c of the substrate 4, and approximately the thickness of the coupling portion where the rectangular plate is above a predetermined lubricating member 3 If the value is smaller than the value of%, the amount of the resin composition disposed / embedded in the housing portion 4c is reduced, and as a result, there is a concern that the lubricating property / sliding property may be deteriorated. The thickness dimension is reduced, and the reliable integration of the lubricating member 3 and the base 4 tends to be difficult. Furthermore, approximately the depth D ₂ of the housing portion 4c in which the rectangular flat groove is greater than the predetermined percentage of the base body 4, and the wall thickness of the coupling portion in which the substantially rectangular plate-shaped lubricant member 3 If the value is larger than the above-mentioned predetermined value, the minimum thickness dimension in the radial direction of the base 4 is reduced, and as a result, for example, the strength of the sliding member 1 (bearing 1) provided with the base 4 may be reduced. The member 3 is filled into the substantially rectangular flat grooved housing portion 4c of the base 4 more than necessary, as a result, waste of the resin composition is increased.

Furthermore, it is preferable that the lubricating member 3 be disposed in the inside diameter and the small end 13 of the base 4. The lubricating member 3 having the above-described structure is formed as one unit and integrated with the base 4.

With such a structure, when the base 4 is inserted into an injection mold and injection molding is performed using a resin composition, and the bearing 1 (sliding member 1) is formed, the lubricating member 3 reliably It is integrated with the base 4. Thereby, the bearing 1 (sliding member 1) is provided in which the risk of the lubricating member 3 falling off the base 4 of the bearing 1 (sliding member 1) is reduced during use of the bearing 1 (sliding member 1). Ru.

Hereinafter, a bearing 1 will be described as an example of the sliding member 1 according to the present invention, with reference to FIGS. 1 to 3.

(1) Substrate 4
Referring to FIG. 1, the substrate 4 is a sintered body obtained by sintering a molded body containing metal powder in accordance with a normal manufacturing process adopted in manufacturing a bearing. In the usual manufacturing process, for example, a step of obtaining a metal powder compact by compression molding raw material powder containing metal powder as the main component (the component with the largest weight ratio) using a mold, and the metal powder molding A body is heated and sintered at a temperature of, for example, about 750 to 900 ° C. to obtain a sintered metal powder compact, and a sizing process for correcting the dimensions of the sintered metal powder compact Etc.

The metal powder used to produce the substrate 4 is, for example, a copper-based material containing copper as the main component (the most component in weight ratio), an iron-based metal containing iron as the main component (the most component in weight ratio), Metal powders of any type of metal can be used, including copper-iron based copper and iron as the main components (the most abundant component by weight). Besides, metal powder of special metal such as aluminum-bronze type can also be used.

When a copper-iron-based metal powder is used, elements such as iron powder, copper powder, and metal powder mixed with low melting point elements such as low melting metal powder can be used. The low melting point element such as a low melting point metal is a component for melting itself during sintering to advance liquid phase sintering, and a low melting point element such as a metal having a melting point lower than that of copper is used. Specifically, an element such as a metal having a melting point of 700 ° C. or less, such as tin (Sn), zinc (Zn), phosphorus (P) or the like can be used, and among these, tin having a good compatibility with copper is used Is preferred. The low melting point element such as the low melting point metal can be added by mixing the single powder into the mixed powder or alloying with another metal powder.

In addition to the above metal powder, if necessary, a sintering aid such as calcium fluoride or a lubricant such as zinc stearate may be added, and further, a graphite powder as a lubricating member powder may be added. By adding the graphite powder, the graphite particles can be dispersed in the sintered structure of the base 4 after sintering, so that the lubrication of the portion of the bearing surface 11 (sliding surface 11) formed by the base 4 Can be enhanced. Here, specifically, the metal (element) powder constituting the substrate 4 may be, for example, a mixed powder of Fe powder, Cu powder and Sn powder, and in the present embodiment, a graphite powder is further added to this mixed powder. Be mixed.

The mixing ratio of each powder is, for example, Cu powder: approximately 10 to 30 mass%, specifically 10 to 30 mass% (preferably approximately 15 to 20 mass%, specifically 15 to 20) based on the total mass. Mass%), Sn powder: approximately 0.5 to 3.0 mass%, specifically 0.5 to 3.0 mass% (preferably approximately 1.5 to 2.0 mass%, specifically 1 .5 to 2.0% by mass), graphite powder: approximately 0.5 to 7.0% by mass, specifically 0.5 to 7.0% by mass (preferably approximately 0.5 to 3.0% by mass) Specifically, the content is made 0.5 to 3.0% by mass), and the remainder is made into Fe powder. If the mixing ratio of Cu powder is too small, the sliding property of the inner peripheral surface 4a of the sliding surface 11 decreases, and if it is too large, a problem occurs in the wear resistance of the inner peripheral surface 4a of the sliding surface 11. Range of Further, by making the Fe powder, the Cu powder, the Sn powder and the graphite powder into the above mixture ratio, the base 4 made of the iron-copper based sintered alloy having excellent lubricating performance / sliding property / abrasion resistance is obtained. It is formed. For example, graphite dispersed in a base 4 made of iron-copper based sintered alloy contributes to lubricity as free graphite. The sliding member of the present invention preferably contains Fe powder, Cu powder, Sn powder and graphite powder from the viewpoints of use in high surface pressure and low speed regions without oiling and improvement of wear resistance. It is a sintered compact of a molded object. Thus, for example, by forming the base 4 made of the iron-copper based sintered alloy containing graphite, for example, a slide having the inner peripheral surface 4a having excellent lubricating performance / sliding property / abrasion resistance. A dynamic member 1 (bearing 1) is provided.

(2) Lubricating member 3
The lubricating member 3 is a formed body of a resin composition containing a thermoplastic resin and a carbon material. The lubricating member 3 is preferably an injection-formed body of the above-described resin composition. The inclusion of the carbon material can impart excellent sliding characteristics to the bearing 1, and the inclusion of the thermoplastic resin can reduce the cost required for manufacturing the lubricating member 3. The lubricating member 3 can be disposed / embedded as an injection-molded body in the housing portion 4c of the base 4 by injection molding the resin composition containing a thermoplastic resin and a carbon material, for example, using the base 4 as an insert part. (Hereafter, it is also called an insert molding process.). With reference to FIGS. 2 and 3, by arranging / embedding lubricating member 3 in housing portion 4 c, inner side surface 3 a of lubricating member 3 is at least one of sliding surface 11 (bearing surface portion 11) of bearing 1. Make up the department. In the bearing 1 according to the present invention, for example, since the lubricating member 3 can be disposed / embedded in the housing portion 4c of the base 4 by an insert molding process, the working efficiency and the processing cost in manufacturing the bearing 1 (sliding member 1) Improvement is expected. In addition, the method of arranging / embedding the lubricating member 3 in the accommodating part 4c of the base | substrate 4 is not limited to the said insert molding process, It can also be arrange | positioned / embedding by a well-known method.

According to the above embodiment, since the lubricating member 3 is disposed / embedded in the housing portion 4c of the base body 4, the anchoring effect of the thermoplastic resin contained in the lubricating member 3 makes the mating surface 4b (inside the housing portion 4c On the surface), it is considered that the bonding force between the base 4 and the lubricating member 3 is enhanced, and the possibility of the lubricating member 3 falling off the base 4 of the bearing 1 is reduced while the bearing 1 is in use. That is, the bearing 1 (sliding member 1) is provided in which the risk of the lubricating member 3 falling off the base 4 of the bearing 1 (sliding member 1) is reduced during use of the bearing 1 (sliding member 1). It is expected.

(3) Thermoplastic resin For example, as a thermoplastic resin to be a main component (for example, it may be the largest component by weight ratio but is not limited thereto) of the resin composition, for example, polyamide (PA) , Polycarbonate (PC), polybutylene terephthalate (PBT), polyacetal (POM), liquid crystal polymer (LCP), wholly aromatic polyester, polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyamideimide (PAI), poly Ether imide (PEI), polyimide (PI), polytetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), ethylene-tetrafluoroethylene copolymer ( Such as ETFE) A resin containing a fluorine resin (polyfluorinated olefin resin), an olefin resin such as polyethylene, or the like may be used. Specifically, it is preferable to use, for example, a thermoplastic resin which can be injection-molded as the thermoplastic resin. For example, in addition to polyphenylene sulfide (PPS) being a resin material whose price is kept low appropriately, it is possible to mix a large amount of carbon material, because it has a low melt viscosity at the time of injection molding, etc. It is. Each of these synthetic resins described above may be used alone or in combination of two or more kinds.

(4) Carbon Material The carbon material blended in the resin composition may be, for example, at least one selected from the group consisting of carbon nanofibers, carbon black and graphite. A powder form can be mentioned as a form of a carbon material. For example, graphite powder can be used as the carbon material powder, and specifically, both natural graphite powder and artificial graphite powder can be used. Natural graphite powder is characterized by being excellent in lubricity because it is scaly. On the other hand, the artificial graphite powder has a feature of being excellent in moldability because it is in a massive form. The carbon material powder is not limited to graphite powder which is crystalline powder, and amorphous powder such as pitch powder and coke powder can also be used. When carbon nanofibers are used as the carbon material, mechanical strength such as flexural modulus of the lubricating member 3 can be improved. Carbon nanofibers are roughly classified into pitch-based and PAN-based, but 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 (e.g., graphite powder). Resin binder powder can be used as the binder, and phenol resin powder can be used as the resin binder powder, for example. It is preferable to uniformly mix the carbon material powder and the binder by adding a molding aid, a lubricant, a modifier or the like as necessary.

As the raw material powder constituting the lubricating member 3, besides the mixed powder of the carbon material powder and the resin binder powder as described above, it is also possible to use a granulated powder obtained by granulating the carbon material powder under coexistence of resin binder powder. . Granulated powder has a higher specific gravity and higher fluidity than a single resin binder powder or carbon material powder, so that it becomes easy to supply a resin composition containing it to a molding die, and it is precisely molded into a predetermined shape. It is possible to

In the bearing 1, the lubricating member 3 that constitutes a part of the bearing surface portion 11 is a carbon material supply source. The carbon material supplied from the lubricating member 3 spreads over the entire bearing surface 11 due to the relative movement between the bearing surface 11 and the shaft 2, so that the lubricating effect of the carbon material can be obtained in the entire bearing surface 11. Thereby, the sliding member 1 (bearing 1) which has the outstanding lubricating performance / sliding characteristic is provided.

(5) Other Materials In addition to the thermoplastic resin and the carbon material, the resin composition may contain other fillers. As other fillers, for example, 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 Cloth-like, minerals such as calcium carbonate, talc, silica, clay, mica etc., inorganic whiskers such as aluminum borate whiskers, potassium titanate whiskers, thermosetting resins such as polyimide resin, etc. polybenzimidazole etc. The various heat resistant resin etc. of can be used. By including these fillers, it is possible to improve the friction and wear characteristics of the lubricating member 3 and to reduce the linear expansion coefficient. If necessary, additives such as a mold release agent, a flame retardant, a weather resistance improver, an antioxidant, and a pigment may be added as appropriate.

(6) Inner diameter (both) edge 13
A lubricating member 3 is disposed in the inner diameter (both) small holes 13. Thereby, in addition to radial sliding (rotation), also at the time of axial sliding (sliding), the carbon material supplied from the lubricating member 3 disposed in the inner diameter (both) small opening 13 comprises the bearing surface portion 11 and the shaft 2 It is expected that the lubricating effect by the carbon material can be obtained in the entire bearing surface portion 11 by spreading over the entire bearing surface portion 11 by the relative movement of

The method of arranging the lubricating member 3 in the inner diameter (both) small holes 13 is not particularly limited, but, for example, in the insert molding step, the lubricating member 3 is arranged in the small diameter holes 13 as an injection molded body of a resin composition. It is also good. Alternatively, after the lubricating member 3 is disposed in the housing portion 4 c in the insert molding process, the lubricating member 3 may be disposed in the inner diameter (both) small holes 13 by a method other than injection molding. Inside diameter (both) lubricating member 3 arranged small 13 has a shape corresponding to the inner peripheral shape of the substrate 4 (the inside diameter (both) small 13), dimensions of L ₁ and the radial direction of the axial above It has D ₁ .

(7) Content of Carbon Material The content of the carbon material blended in the resin composition is set to a suitable range for securing the sliding characteristics of the sliding surface of the lubricating member 3, and the content is The content is, for example, 10% by mass or more and 40% by mass or less depending on the type of the thermoplastic resin and the like. When the compounding amount of the carbon material in the resin composition is less than a predetermined mass%, the effect of improving the sliding property of the sliding surface by the carbon material tends to be difficult to appear because the compounding amount of the carbon material is small. When the compounding amount of the carbon material in the resin composition exceeds a predetermined mass%, the fluidity of the resin composition is lowered to lower the yield rate at the time of injection molding, and it becomes difficult to carry out the injection molding itself There is a tendency. The content of the carbon material blended in the resin composition is preferably in the above-described range in order to prevent the decrease in the yield rate during injection molding while securing the sliding characteristics.

(8) Impregnation of Lubricating Oil Since the bearing 1 has innumerable internal holes, the internal holes of the bearing 1 that has undergone the insert molding process can also be impregnated with lubricating oil. For example, the internal holes of the bearing 1 can be impregnated with the lubricating oil by immersing the bearing 1 that has undergone the insert molding process in the lubricating oil in a reduced pressure environment and then returning to atmospheric pressure. The lubricating oil is not particularly limited as long as it is generally used for bearings, for example, spindle oil, refrigeration oil, turbine oil, machine oil, mineral oil such as dynamo oil, polybutene, poly-α-olefin, alkyl Hydrocarbon-based synthetic oils such as naphthalene and alicyclic compounds, or ester oils of natural fats and oils, phosphoric acid esters, diester oils, polyglycol oils, silicone oils, polyphenyl ether oils, alkyl diphenyl ether oils, alkyl benzenes, A non-hydrocarbon-based synthetic oil such as a fluorinated oil may be used.

(9) Open Porosity of the Base 4 The open porosity of the base 4 is determined by impregnating the internal pores of the bearing 1 that has undergone the insert molding step with oil, and the oil functions as a lubricant to make the slide of the bearing 1 In order to improve dynamic characteristics, it is set in a suitable range, preferably 10% or more and 50% or less. If the open porosity is less than 10%, the total amount of oil impregnated in the internal pores of the substrate 4 is small, and it is difficult to make the bearing 1 exert excellent lubricating performance based on the lubricating oil over a long period of time is there. If the open porosity exceeds 50%, molding of the substrate 4 becomes difficult and the moldability of the substrate 4 decreases, as a result, it becomes difficult to mold the substrate 4 with high productivity, and the substrate 4 is provided. It tends to be difficult to produce the bearing 1 at low cost. In order to form the bearing 1 with high productivity while causing the base 4 to exhibit excellent lubricating performance based on lubricating oil, the open porosity of the base 4 is preferably within the above range. The “open porosity” is a percentage representing the internal pores capable of being 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 according to "Sintered metal material-density, oil content and open porosity test method (JIS Z 2501: 2000)" of Japanese Industrial Standard.

(10) Surface open area ratio of the base 4 The surface open area ratio of the base 4 at the mating surface 4 b which is the inner surface of the housing 4 c is thermoplasticity contained in the lubricating member 3 disposed in the housing 4 4 c of the base 4. The anchor effect of the resin is set in a range suitable for enhancing the bonding strength between the base 4 and the lubricating member 3, and is preferably 10% to 50%. If the surface porosity 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, and the anchoring effect of the thermoplastic resin tends to be reduced. In addition, when the surface open area ratio exceeds 50%, molding of the housing portion 4c tends to be difficult. In order to form the bearing 1 with high productivity while enhancing the bonding force between the base 4 and the lubricating member 3, the surface open area ratio of the base 4 is preferably within the above range. The "surface open area ratio" is the ratio (area ratio) of the total area of the surface open per unit area of the surface. The “surface open area ratio” can be determined by, for example, taking in an image (for example, 500 times) taken with a metallurgical microscope such as ECLIPSE ME600 manufactured by Nikon as image data into a computer and calculating the area of the pore portion.

Hereinafter, although other embodiments of the present invention are described, explanation is omitted about a point which overlaps with the above-mentioned embodiment.

Other Embodiments
The lubricating member 3 may be disposed over the entire axial length of the bearing 1 as shown in FIG. 2 or may be disposed only in a partial region in the axial direction, for example, even when disposed at a plurality of axially separated locations Good.

Further, in the bearing 1, the shaft 2 does not necessarily slide with respect to the entire bearing surface portion 11, and 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 the horizontal posture, the shaft 2 may be depressed by gravity and slide on the bearing surface portion 11 in the lower region of the bearing surface portion 11. In that case, by designing the position and the shape of the lubricating member 3 in the bearing 1 or adjusting the phase of the bearing 1 in the circumferential direction so that the lubricating member 3 is positioned in the sliding region with the shaft 2 It is possible to always slide 2 with the lubricating member 3. Since a high lubricating effect can be acquired by this, it becomes possible to support the axis | shaft 2 in the oil-less state which does not interpose lubricating oil between the bearing surface parts 11, 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, a lubricating oil is interposed between the bearing surface portion 11 and the shaft 2, and the internal pores of the base 4 are impregnated with the oil. In this case, the oil exudes from the surface (inner peripheral surface 4 a) of the base 4 due to the temperature rise caused by 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. The excellent slidability is maintained by reliably avoiding oil film breakage in the moving region.

Furthermore, the present invention is not limited to the bearing that supports the relative rotation of the shaft, but can be applied to a bearing that supports the axial movement of the shaft. Further, the present invention is not limited to the cylindrical sliding member, but can be applied to sliding members of other shapes (for example, semi-cylindrical or rectangular parallelepiped). The sliding member of the present invention can be used, for example, as a sliding member used for office equipment, automobiles, accessories and the like.

Reference Signs List 1 sliding member (bearing), 2 axis, 3 lubricating member, 3a inner side surface, 4 base, 4a inner peripheral surface, 4b mating surface, 4c accommodation portion, 11 sliding surface (bearing surface portion), 12 outer peripheral surface, 13 inner diameter Both sides (inner diameter side).

Claims

A sliding member having a sliding surface, wherein
A substrate which is a sintered body of a molded body containing metal powder,
And a lubricating member, which is a molded product of a resin composition containing a thermoplastic resin and a carbon material,
The base body has an accommodating portion for accommodating the lubricating member,
At least a part of the sliding surface is constituted by the lubricating member housed in the housing portion, and
The lubricating member is disposed also in the inner diameter portion of the base body,
Sliding member.
A sliding member having a sliding surface, wherein
A substrate which is a sintered body of a compact containing Fe powder, Cu powder, Sn powder and graphite powder;
And a lubricating member, which is a molded product of a resin composition containing a thermoplastic resin and a carbon material,
The base body has an accommodating portion for accommodating the lubricating member,
At least a part of the sliding surface is constituted by the lubricating member housed in the housing portion, and
The lubricating member is disposed also in the inner diameter portion of the base body,
Sliding member.
The sliding member according to claim 1 or 2 whose content rate of said carbon material in said resin composition is 5 mass% or more and 70 mass% or less.
The substrate has an internal void,
The sliding member according to any one of claims 1 to 3, wherein lubricating oil is impregnated in the internal cavity.
The sliding member according to claim 4, wherein the base has an open porosity of 10% or more and 50% or less.
The sliding member according to any one of claims 1 to 5, wherein the base has a surface open area ratio of 10% to 50% on an inner surface of the housing portion.
The sliding member according to any one of claims 1 to 6, wherein the carbon material is at least one selected from the group consisting of carbon nanofibers, carbon black and graphite.