JP2006008994A - Sliding film, sliding member, composition for sliding film, sliding device, swash-plate type compressor, process for forming sliding film, and process for producing sliding member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a swash-plate type compressor capable of exerting good seizing resistance even under severe sliding conditions. <P>SOLUTION: The present invention relates to a swash-plate type compressor provided with a swash plate (60) oscillating and rotating with the rotation of the main shaft, a piston (14) reciprocating within a cylinder bore due to the oscillation of the swash plate, and a pair of shoe (76) that is interposed on the joint between the swash plate and the piston. A sliding coating film is formed on the surface of the swash plate and/or the shoes. The sliding film contains a solid lubricant, a binder resin that retains the solid lubricant, and a low-melting-point material having a melting point lower than the glass transition temperature of the binder resin. The latent heat of the low-melting-point material absorbs heat generated upon seizing, thereby retarding the degradation of the binder resin. As a result, high seizure resistance can be obtained. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention comprises a sliding coating formed on a sliding surface, a sliding coating composition used for forming the sliding coating, a sliding member provided with the sliding coating, and the sliding member. The present invention relates to a sliding device, a swash plate compressor as an example of the sliding device, a method for forming the sliding coating, and a method for manufacturing the sliding member.

  Devices such as engines and swash plate compressors for air conditioners mounted on automobiles include sliding members that slide. Taking a swash plate compressor as an example, a piston that slides linearly and a cylinder bore that slides on it, a swash plate that slides on a rotating basis, a shoe that slides on it, and a bearing that supports the shaft while sliding on it It is. Usually, lubricating oil or the like is supplied to the sliding surface of such a sliding member so as to be actively lubricated. In the case of a swash plate compressor, the lubricity between sliding surfaces is basically maintained by a mist-like lubricating oil present in the compressor.

  However, there may be a case where the sliding surface is in a poorly lubricated state or a non-lubricated state immediately after the start or due to a sudden load fluctuation. Even in such a case, it is preferable to prevent seizure between the sliding surfaces and ensure stable sliding characteristics.

From such a viewpoint, for example, in the case of a swash plate type compressor, a sliding coating containing a solid lubricant is provided on the surface of the swash plate. Such a sliding coating is disclosed, for example, in Patent Documents 1 to 3 below. That is, in Patent Document 1, both surfaces are coated with a solid lubricant layer (sliding film) obtained by solidifying a solid lubricant such as MoS ₂ , polytetrafluoroethylene (PTFE), graphite (Gr) with a synthetic resin. A swashplate is disclosed. Patent Document 2 discloses a swash plate in which the solid lubricant layer is provided on the surface side where a large load acts during the compression stroke of the piston, and the opposite surface side is a sprayed layer. Patent Document 3 discloses a swash plate having both sides covered with a solid lubricant layer in which Ni, Fe, Cr, and Co are mixed in addition to MoS ₂ , PTFE, and Gr.
Japanese Patent Laid-Open No. 8-199327 JP 11-193780 A Japanese Patent Laid-Open No. 2003-183585

  However, in swash plate type compressors, etc., where a larger load than before has been applied between sliding members due to small size, weight reduction and other strict requirements, the above-mentioned solid lubricant layer is provided on the sliding surface. However, it is becoming difficult to ensure sufficient seizure resistance.

  The present invention has been made in view of such circumstances. That is, an object of the present invention is to provide a sliding coating that exhibits seizure resistance and the like superior to those of the conventional solid lubricant layer as described above. Further, it is an example of a sliding coating composition used for forming the sliding coating, a sliding member provided with the sliding coating, a sliding device composed of the sliding member, and the sliding device. An object is to provide a swash plate compressor. Furthermore, it aims at providing the formation method of the sliding film, and the manufacturing method of the sliding member.

  In addition, in the above-mentioned Patent Document 2, tin (Sn), lead (Pb), and indium (In) are also exemplified as solid lubricants contained in the sliding coating. There is no disclosure about the coating. Patent Document 2 merely handles these metals as one type of solid lubricant. Moreover, although there is disclosure that Sn-based plating or Sn-based thermal spraying is performed, they are merely considered as a ground treatment for a sliding coating containing a solid lubricant.

Patent Document 3 states that the Ni fine powder mixed in the solid lubricant layer has an action of promoting the adhesion of MoS ₂ and graphite (Gr) in the solid lubricant layer to the mating sliding surface. Disclosure. Such an action is completely different from the Sn of the present invention described later. Therefore, Sn and the like of the present invention described below are completely different from Ni and the like disclosed in Patent Document 3.

  Although the swash plate type compressor has been exemplified so far, the above description is the same for a vane type compressor, a scroll type compressor, and other types of compressors, and is not limited to the compressor and operates under severe conditions. The same applies to the sliding device in general.

As a result of extensive research and trial and error, the present inventor newly added a low melting point material such as Sn to the sliding coating in addition to the conventional solid lubricant. As a result, it was confirmed that the sliding coating exhibited excellent seizure resistance, and the present invention was completed.
(Sliding coating)
That is, the sliding coating of the present invention is a sliding coating excellent in sliding properties comprising a solid lubricant and a binder resin for holding the solid lubricant on the surface portion of the substrate, and further comprising the binder It is characterized by containing a low melting point material having a melting point lower than the glass transition temperature of the resin.

  When the sliding coating of the present invention is provided on the surface of the base material, the seizure resistance between the base material and the sliding counterpart material is improved as compared with the case where the conventional sliding coating is provided. The reliability and durability of the sliding device provided with the material are improved. In addition, according to the sliding coating of the present invention, not only the improvement of seizure resistance but also the improvement of the wear resistance of the sliding member and the reduction of the friction coefficient between the sliding surfaces can be expected. In the following description, the term “sliding characteristics” is used as appropriate, including not only seizure resistance but also wear resistance and a low friction coefficient.

  The reason why the sliding coating of the present invention exhibits excellent sliding characteristics is not clear. However, it is considered that the low melting point material included in the sliding coating of the present invention effectively absorbs at least frictional heat generated by sliding under severe lubricating conditions such as poor lubrication or non-lubrication. As a result, the deterioration of the sliding coating due to frictional heat is suppressed, and as a result of extending the life of the sliding coating, it is considered that the seizure resistance between the sliding members is improved. Hereinafter, this point will be described in detail.

  In the past, a solid lubricant was included to suppress seizure of the base material and its counterpart material (hereinafter, both are referred to as “sliding members” as appropriate) even in a poorly lubricated state or a non-lubricated state. A sliding coating has been provided. However, as described above, the operating condition and lubrication state of the sliding member have recently become more severe, and it has become difficult to ensure sufficient seizure resistance with conventional sliding coatings.

  As a reason for this, the present inventor considered early deterioration of the sliding coating due to the frictional heat. That is, more or less frictional heat is generated when the sliding member slides. If the lubricating oil is sufficiently supplied between the sliding surfaces, the lubricating oil film existing there reduces the friction coefficient between the sliding surfaces, disperses the surface pressure, and even the lubricating oil. Therefore, the frictional heat generated is small, and naturally the deterioration of the sliding coating hardly occurs.

  However, when it becomes poorly lubricated or unlubricated, such an effect can hardly be expected, and even if the friction coefficient between the sliding surfaces is somewhat reduced by the solid lubricant, the frictional heat will not be generated after a predetermined time has elapsed. It suddenly increases and the temperature of the sliding coating starts to rise rapidly.

  The sliding coating is usually in a state where a solid lubricant is held on the surface of the sliding member by a binder resin. The heat resistance temperature of the binder resin is about 400 to 500 ° C. in the case of typical polyamideimide (PAI) having excellent heat resistance. However, when the temperature of the sliding coating increases due to frictional heat, even such a binder resin having excellent heat resistance is softened (including glass transition), deteriorated, and further destroyed. As a result, the retention of the solid lubricant on the surface of the sliding member is lost, and the sliding member comes into direct contact with the mating material without the sliding coating, and eventually seizes. It is thought that.

  Even in the case of the sliding coating of the present invention, the temperature of the sliding coating starts to rise rapidly under a severe sliding environment.

  However, in the case of the sliding coating of the present invention, a low melting point material having a melting point lower than the glass transition temperature of the binder resin is mixed in the sliding coating. When the temperature of the sliding coating starts to rise rapidly due to frictional heat, the low melting point material absorbs a large amount of frictional heat by latent heat much larger than the specific heat before the binder resin softens. As a result, the temperature rise of the sliding coating is suppressed, and the softening of the binder resin and the deterioration of the sliding coating are suppressed or delayed. Thus, the state in which the solid lubricant is firmly held on the surface of the sliding member is maintained for a longer time.

  In short, the sliding coating of the present invention has a low melting point material having a melting point lower than the glass transition temperature of the binder resin, so that the temperature rise of the sliding coating due to frictional heat is suppressed and delayed, and stable sliding by the sliding coating is achieved. Dynamic characteristics are maintained longer than before. As a result, it is considered that the seizure resistance between the sliding members is remarkably improved. However, such an effect is considered to be only one factor for the slide coating of the present invention to exhibit excellent seizure resistance, and the above-described mechanism enables the excellent slide of the slide coating of the present invention. Note that not all dynamic characteristics can be explained. As will be described later, when a specific component (sliding product forming element) is present on the sliding surface of the counterpart material, a new sliding product is formed by this and the low melting point material in the sliding coating of the present invention. The present inventor has confirmed that. The sliding product is considered not only to improve the seizure resistance but also to further improve the sliding characteristics such as reducing the friction coefficient between the sliding surfaces and improving the wear resistance.

The reason why the glass transition temperature of the binder resin is introduced as the threshold value of the melting point of the low melting point material in the present invention is that the glass transition temperature is an important characteristic indicating the heat resistance of the resin (particularly polymer). The present invention also conceptually includes components (for example, bearings) and the like that are substantially composed only of a sliding coating.
(Sliding member)
The present invention can also be grasped as a sliding member provided with the above-mentioned sliding coating.

That is, this invention is good also as a sliding member which consists of a base material and the sliding film of Claim 1 formed in the surface of this base material. A typical example of such a sliding member is a swash plate of a swash plate compressor.
(Sliding device and swash plate compressor)
The present invention can be grasped also as a sliding device provided with the above-mentioned sliding member.

  That is, this invention is good also as a sliding apparatus characterized by including the base material in which the said sliding film was formed in the surface, and the other party material which contacts the sliding film of this base material.

  Such a sliding device may be, for example, a swash plate type compressor, a compressor other than a swash plate type, or may not be a compressor. Here, a swash plate compressor will be described as a representative example of the sliding device. There are various types of swash plate compressors such as a variable displacement swash plate compressor, a fixed displacement swash plate compressor, a single-head swash plate compressor, and a double-head swash plate compressor.

Specific examples include a main shaft, a swash plate rotating with the main shaft, a cylinder block having a cylindrical cylinder bore extending in the axial direction and opened to the swash plate side, and engaging the swash plate with the swash plate A piston having an engaging portion that receives the oscillation of the swash plate and a head that is inserted and inserted into the cylinder bore and reciprocates in the cylinder bore in response to the oscillation of the swash plate; It is a swash plate type compressor provided with a pair of shoes slidably held by the engaging portion and slidably contacting the surface of the swash plate. In this case, it is preferable that the sliding coating of the present invention is formed on the surface of the swash plate and / or the shoe. The number of pistons may be singular or plural. There is a pair of shoes per piston, and if there are a plurality of pistons, a plurality of pairs of shoes are also formed.
(Sliding coating composition)
This invention can also be grasped | ascertained as a composition for sliding films used as the raw material at the time of forming the said sliding film.

That is, the present invention comprises a sliding coating comprising a solid lubricant, a binder resin, and a low melting point material having a melting point lower than the glass transition temperature of the binder resin, and the sliding coating is obtained. It may be a composition for use. Specific examples of such a sliding coating composition include a sliding coating or a sliding coating transfer film.
(Method of forming sliding coating)
The present invention can also be grasped as a method for forming the sliding coating.
(1) First, the present invention provides a coating material for a sliding coating in which a low melting point material having a melting point lower than the glass transition temperature of the binder resin and a solid lubricant are dispersed in the varnish of the binder resin on the surface of the base material. It is good also as the formation method of the sliding coating characterized by including the application | coating process to apply | coat and the baking process which heats and bakes the coating film formed after this application | coating process, and the said sliding coating is obtained.
(2) Next, according to the present invention, a transfer film printed with a paste in which a binder resin, a low melting point material having a melting point lower than the glass transition temperature of the binder resin, and a solid lubricant is printed is transferred to the surface of the substrate. A method for forming a sliding coating, comprising: a transfer step; and a firing step of heating and firing a transfer film formed on the surface of the substrate after the transfer step, and the sliding coating is obtained. Also good.
(Sliding member manufacturing method)
The present invention can be grasped as a manufacturing method of the above-mentioned sliding member.

  That is, this invention is good also as a manufacturing method of the sliding member characterized by obtaining the sliding member in which the sliding coating was formed in the surface of the base material by the formation method of the above-mentioned sliding coating.

The present invention will be described in more detail with reference to embodiments of the invention. The contents described in this specification including the following embodiments are not limited to the sliding coating according to the present invention, but include other sliding members, sliding coating compositions, sliding devices, swash plate compressors, It should be noted that the present invention can be appropriately applied to a method for forming a sliding coating and a method for manufacturing a sliding member. Also, it should be noted that which embodiment is the best depends on the target, required performance, and the like.
(1) Low melting point material The low melting point material has a melting point lower than the glass transition temperature of the binder resin of the sliding coating, and is selected and determined in relation to the binder resin. As a typical example of the low melting point material, a metal material such as a simple metal, an alloy, and an intermetallic compound is conceivable. Moreover, not only an inorganic material but organic material like a synthetic resin may be used. The low melting point material may be composed of a single type of those various materials, or may be composed of a plurality of types appropriately combining them.

  Considering typical polyimide (PI) and polyamideimide (PAI) excellent in heat resistance as the binder resin, their glass transition temperature (Tg) is about 200 to 500 ° C. Based on this, an example of a low melting point material is given below. The numerical value in parentheses is the melting temperature.

  Among the simple metals, there are simple low melting point metals such as indium (In: 157 ° C.), tin (Sn: 232 ° C.), bismuth (Bi: 271 ° C.), and lead (Pb: 327 ° C.). Of course, the low melting point material may be an alloy of these low melting point metals. Examples of Sn alloys (eutectic composition) include Sn-52In (118 ° C.), Sn-58Bi (139 ° C.), Sn-37Pb (183 ° C.), Sn-3.5Ag (221 ° C.), Sn— 0.7 Cu (227 ° C.) and the like. Furthermore, there are Sn-3Ag-0.5Cu (217-220 ° C.) and Sn-3Ag-2Bi-1In (209-217 ° C.). The numerical value in the parenthesis indicates “solidus temperature to liquidus temperature”, and each alloy composition is indicated by mass% (total: 100 mass%).

  As described above, various low melting point materials can be considered, but the low melting point material is preferably one or more of Sn alone, Sn alloy, or Sn compound. These Sn-based materials have a low melting point and a large latent heat. Sn is an element that can be obtained at a relatively low cost and has a small environmental load.

  Since the ratio of the low melting point material in the sliding coating is appropriately determined according to the specification of the sliding coating and the type and ratio of the solid lubricant and binder resin to be used, it is difficult to generally specify. When the entire sliding coating is 100% by mass, the lower limit of the low melting point material is preferably 0.1% by mass, 0.2% by mass, 0.5% by mass, and further 2% by mass, and the upper limit is 60%. It is good that they are mass%, 50 mass%, and 40 mass%. These upper and lower limits can be combined as appropriate.

  If even a little low melting point material is present in the sliding coating, the durability of the sliding coating can be improved and the seizure resistance can be improved, but if it is too small, the effect is small. On the other hand, an excessive amount of the low melting point material is not preferable because the solid lubricant and the binder resin are relatively reduced and the characteristics of the sliding coating itself are deteriorated.

  Since the low-melting-point material is preferably uniformly dispersed in the sliding coating or in the vicinity of the surface layer, the low-melting-point material is in the form of (fine) particles at least in an initial state that is not overheated by sliding or the like. preferable. The detailed form such as the particle size and aspect ratio is not particularly limited, but it is appropriately selected in consideration of the specification of the sliding coating, the availability of the low melting point powder, the cost, and the like. For example, the particle diameter of the low melting point material is preferably about 0.1 to 100 μm, 0.1 to 50 μm, 0.5 to 20 μm, and further about 1 to 5 μm. A low melting point material having a too small particle size is difficult to obtain and is expensive. On the other hand, a low melting point material having an excessively large particle size is not preferable because it protrudes from the sliding coating. That is, the low melting point material may have a maximum particle size equal to or less than a desired thickness of the sliding coating. However, depending on the specifications of the sliding member and sliding device, the sliding member once formed may be used after being polished, etc. "The maximum particle size of the low melting point material is less than the film thickness of the sliding coating" It is not necessarily an essential requirement.

  The raw material powder used as the low melting point material may be either a mechanically pulverized powder or an atomized powder, and the production method thereof is not limited.

  However, even when a powdery low melting point material is used, it is not necessary for the low melting point material to retain the form of the raw material stage in the sliding coating. The surface of the low melting point material may be changed by grinding or polishing the surface after the sliding coating is formed. The sliding coating may be heated at a temperature lower than the glass transition temperature of the binder resin, and the low melting point material may be in a state of being diffused in the sliding coating as a whole or partially melted.

  The low-melting-point material is not limited to such a form in the sliding coating, and it may be possible to change the form of the material. For example, it is assumed that Sn powder is used as the raw material powder for the low melting point material to form a sliding coating in which Sn particles are dispersed. Then, when the sliding coating is heated or the like thereafter, the Sn may react with other elements to form a compound or form an alloy or the like. This new product (including a sliding product described later) is also included in the low melting point material of the present invention as long as it has a melting point lower than the glass transition temperature of the binder resin. That is, the low-melting-point material in the present invention does not need to maintain the starting material as it is in the sliding coating, and may be changed after the sliding coating is formed. For example, low-melting-point alloys such as Sn-0.7Cu and Sn-3.5Ag described above can be considered as the new product. In the stage of forming the sliding coating, for example, an appropriate amount of Cu or Ag powder is mixed together with Sn powder. Thereafter, Sn, Cu, and Ag form a Sn—Cu alloy or a Sn—Ag alloy at the stage of firing the binder resin of the sliding coating or using the sliding coating, It may be.

It is considered that the total amount of frictional heat received by the low melting point material in the sliding coating before the glass transition temperature of the binder resin is greatly influenced by the content of the low melting point material. However, as long as the heat is received for a short time, the particle size distribution of the low melting point material is considered to affect the temperature rise of the sliding coating. Therefore, it is preferable to adjust the ratio and form of the low melting point material in the sliding coating according to the required specifications of the sliding coating.
(2) Binder resin The binder resin fixes and holds the solid lubricant and the low melting point material on the substrate surface. The type of the binder resin is not particularly limited, but it is more preferable that the binder resin itself has excellent sliding characteristics.

  As the binder resin, for example, a thermosetting resin, a thermoplastic resin, a non-thermoplastic resin, a crystalline resin, or an amorphous resin can be appropriately selected according to the specification of the sliding coating. For example, polyamideimide (PAI, Tg = 280 ° C.), polyimide (PI, Tg = 410 ° C.), polyether ether ketone (PEEK resin, Tg = 143 ° C.), epoxy resin, phenol resin, unsaturated polyester , Liquid crystal polyarates (LCP, Tg = 360 ° C.), polyethersulfone (PES, Tg = 230 ° C.), polyether imide (PEI, Tg = 217 ° C.), etc. (numbers in parentheses are glass transition temperatures Tg) .) In particular, PAI or the like is suitable as a binder resin having excellent sliding characteristics such as wear resistance, heat resistance, and economical efficiency.

  The binder resin need not be a single type of resin, and may be a mixture of multiple types of resins. Furthermore, instead of a single resin, reinforcing resin may be strengthened by dispersing reinforcing particles in the resin. In order to improve the conformability of the solid lubricant, the low-melting-point material, and the reinforcing particles in the binder resin, a coupling agent may be used as appropriate. Further, when dispersing a solid lubricant or the like in the binder resin, a solvent or the like may be used.

  The ratio of the binder resin in the sliding coating may be considered as the remainder other than an appropriate amount of solid lubricant, low melting point material, and the like. However, for example, when the entire sliding coating is 100% by volume, the lower limit of the binder resin may be 20% by volume or 30% by volume, and the upper limit may be 80% by volume or 70% by volume. . These upper and lower limits can be combined as appropriate.

If the binder resin is too small, the solid lubricant or the low-melting-point material will drop off, and the wear resistance of the sliding coating will decrease. On the contrary, when the binder resin is excessive, the amount of the solid lubricant and the low melting point material are relatively insufficient, and the sliding characteristics of the sliding coating are deteriorated. It is preferable that the ratio of the binder resin is appropriately adjusted depending on the type, the solid lubricant used, the specifications of the sliding coating, and the like.
(3) Solid lubricant The type of solid lubricant is not limited, and the solid lubricant is not limited to a single type of solid lubricant, and a plurality of types of solid lubricants may be mixed and used. By using a plurality of types of solid lubricants, the sliding characteristics of each solid lubricant are complemented, and a sliding coating with excellent sliding characteristics can be obtained as a whole.

Examples of such solid lubricants include polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), tetrafluoroethylene hexafluoropropylene copolymer (FEP), molybdenum disulfide (MoS ₂ ), and tungsten disulfide (WS). ₂ ), calcium fluoride (CaF ₂ ), graphite (Gr), boron nitride (BN) and the like.

  The ratio of the solid lubricant in the sliding coating varies depending on the specifications of the sliding coating. For example, when the entire sliding coating is 100% by volume, the lower limit may be 20% by volume or even 30% by volume. The upper limit may be 80% by volume or even 70% by volume. These upper and lower limits can be combined as appropriate.

The solid lubricant is particularly preferably composed of one or more of PTFE, MoS ₂ or graphite, and more preferably, these three are blended simultaneously. The ratio of each solid lubricant is preferably 10 to 40% by volume of PTFE, 5 to 30% by volume of MoS ₂ , and 10 to 30% by volume of graphite when the entire sliding coating is 100% by volume. As the binder resin in that case, for example, 50 to 80% by volume of PAI is preferable.

If the amount of solid lubricant is too small, the sliding characteristics of the sliding coating will be reduced, and if the amount of solid lubricant is excessive, the proportion of binder resin and low melting point material in the sliding coating will be relatively reduced. The wear resistance and the like of the sliding coating is reduced due to the falling off of the solid lubricant. The optimum range of the solid lubricant is preferably adjusted as appropriate depending on the type of the lubricant and the specifications of the sliding coating.
(4) Base material, mating material and sliding member The base material is the base of the sliding member. The sliding member has a sliding surface in which at least one surface of the base material is covered with a sliding coating. The material of the base material may be any material such as aluminum alloy, magnesium alloy, steel, cast iron, ceramics, resin, etc., and may be any shape such as plate shape, cylindrical shape, and spherical shape.

  In order to improve the adhesion between the surface of the substrate and the sliding coating, the surface of the substrate is made to have an appropriate surface roughness (roughening) by cutting, shot peening, anodizing treatment, etc., or sprayed onto the surface. A layer may be provided.

  The counterpart material is a member that performs relative motion while being in sliding contact with the sliding member. The surface properties and materials are not limited, but a sliding coating as in the present invention may be formed as in the case of the substrate. The material and shape are the same as in the case of the base material. In this specification, for the sake of convenience, the surface of the substrate having the sliding coating of the present invention formed thereon is called the “sliding member” of the present invention. Also called “moving member”.

  Since the sliding member of the present invention exhibits excellent sliding characteristics, it is suitable as a member used under severe sliding conditions. For example, shafts, bearing races, internal combustion engine pistons, swash plates and shoes of swash plate compressors for automobile air conditioners.

Although the required sliding characteristics vary depending on the use of the sliding member, the thickness of the sliding coating of the present invention is preferably 0.1 to 120 μm, 5 to 100 μm, and more preferably 5 to 60 μm. If the sliding coating is too thin, stable sliding characteristics cannot be secured in the long term, and if the sliding coating is too thick, it takes a long time to form the sliding coating, resulting in high costs.
(5) Sliding product As described above, the sliding coating of the present invention exhibits excellent seizure resistance as compared with conventional sliding coatings. It is done. However, the present inventor repeatedly conducted various tests and analyzes, and it was confirmed that a new sliding product was formed on the sliding surface under specific sliding conditions. It is thought that this sliding product contributes more or less to further improving the sliding characteristics between the sliding members. Specifically, the sliding product further reduces the friction coefficient between the sliding surfaces and promotes the wear resistance of the sliding coating, and in addition to improving the seizure resistance described above, the sliding coating slides. It is thought that the characteristics, reliability and durability are further improved.

  This sliding product is considered to be a new alloy or compound (including an intermetallic compound) formed by reacting with a low-melting-point material (or a part of its constituent components). The sliding product forming element that reacts with the low melting point material to form a sliding product may be contained together with the low melting point material in the sliding coating, or the sliding contact of the counterpart material that is in sliding contact with the sliding coating. It may exist near the surface. However, it is preferable that the sliding coating contains both of the low melting point material and the sliding product forming element, because the sliding product is formed regardless of the components of the counterpart material.

  When the sliding product forming element exists on the counterpart material side, movement of constituent elements of the sliding product occurs between the base material side and the counterpart material side. For example, when a sliding product is formed on the sliding surface of the counterpart material, the constituent components in the sliding coating on the base material side have moved to the counterpart material. The same applies to the reverse case. The sliding product may be formed on the side of the base material provided with the sliding coating, may be formed on the counterpart material side, or may be formed on both sides. Furthermore, the sliding product may be in the form of a film that covers the entire sliding surface, may be in the form of a film that partially covers the sliding surface, or may be scattered on the sliding surface. Absent.

  As an example of such a sliding product, there is a Ni alloy or a Ni compound of a low melting point metal made of Sn, Pb, In or Bi and Ni which is a sliding product forming element. For example, when the low melting point material contains Sn and the sliding product forming element is Ni, the sliding product is a Sn—Ni compound or the like. Taking a swash plate compressor as an example, when a sliding coating with Sn as a low melting point material is formed on the surface of the swash plate, and Ni plating is formed on the surface of the shoe sliding with the swash plate, An Sn-Ni compound layer may be formed as a new sliding product.

A further example is the formation of a (secondary) sliding product layer. When the solid lubricant contains Sn and MoS ₂ particles, a sliding product layer containing Sn—S—Mo is formed on the surface of the sliding coating at an early stage by friction, and the sliding product layer slides. In some cases, it was considered that the wear resistance of the dynamic coating was further improved. In addition, a some sliding product may be formed sequentially. In this case, these sliding products are called a primary sliding product, a secondary sliding product, etc. in order, and are distinguished for convenience (the sliding product on the sliding surface side has a higher order). .
(6) Sliding coating composition, sliding coating forming method or sliding member manufacturing method The sliding coating composition of the present invention comprises components necessary for forming a sliding coating, that is, a solid lubricant, It contains at least a binder resin and a low melting point material. Other components may be contained depending on the specifications of the sliding coating. Moreover, the composition for sliding films takes the form according to the formation method of a sliding film. For example, when a sliding coating is applied and formed on the surface of a substrate, the sliding coating composition becomes a sliding coating paint in which a binder resin is varnished. When the sliding coating is formed by a transfer method, the sliding coating composition is, for example, a sliding coating paste so that the transfer film can be easily screen-printed.

  When the sliding coating is formed on the surface of the substrate using the sliding coating, for example, the coating is applied to the substrate with the sliding coating adjusted to an appropriate viscosity according to the coating method using a solvent or the like. The process consists of a firing step of firing the coating film after the coating step. The coating process can be performed by brush painting, spray coating, immersion in a paint bath, or the like. More specifically, a known coating method such as a roller, roll coater, air spray, airless spray, electrostatic coating, electrodeposition coating, or screen printing may be used.

  The firing step is a step of heating the coating applied to the substrate surface under a predetermined condition to form a strong sliding coating and bringing the sliding coating into close contact with the substrate surface. This baking step may also serve as a drying step for drying the coating film after the coating step. In addition, the binder resin made of a thermosetting resin is cured by crosslinking and the like in this baking process.

  When a sliding film is formed on the surface of a substrate by a transfer method, for example, a transfer film forming step in which a sliding film paste is screen-printed on a mount to form a transfer film, and the transfer film is formed on the surface of the substrate. And a baking step of baking the transfer film transferred to the surface of the substrate.

Although the method for forming the sliding coating has been described, the manufacturing method for the sliding member can be similarly considered.
(7) Sliding device The sliding device of the present invention is a device comprising a sliding member in which the sliding coating of the present invention is formed on a sliding surface, and a mating material that slides on the sliding member. A wide variety of such sliding devices can be considered. For example, there are an engine, various pumps, a swash plate compressor for an air conditioner, and the like only for automobiles. Hereinafter, a swash plate compressor, which is a refrigerant compressor of a vehicle air conditioner, will be taken as an example, and the case where the sliding coating of the present invention is formed on the swash plate will be described in detail with reference to the drawings.

  FIG. 1 shows a cross section of a swash plate compressor C which is an embodiment of the sliding device of the present invention. In the swash plate compressor C, a housing 21 is formed by a front housing 16, a cylinder block 10 and a rear housing 18 in order from the left side of the figure, and a rotary shaft 50, a swash plate 60, a single-head piston 14 (hereinafter referred to as a piston 14) are formed therein. And an electromagnetic control valve 90 and the like.

  A plurality of cylindrical cylinder bores 12 extending in the axial direction are formed in the cylinder block 10 so as to surround the axial center in an annular shape. A piston 14 is fitted in each cylinder bore 12 so as to be able to reciprocate. A front housing 16 is attached to one end face of the cylinder block 10 in the axial direction, and a rear housing 18 is attached to the other end face via a valve plate 20.

  A suction chamber 22 and a discharge chamber 24 are provided between the rear housing 18 and the valve plate 20, and are connected to a refrigeration circuit (not shown) via a suction port 26 and a supply port 28, respectively. The valve plate 20 is provided with a suction hole 32, a suction valve 34, a discharge hole 36, a discharge valve 38, and the like.

  The rotating shaft 50 is pivotally supported at the center of the cylinder block 10 in the axial direction. One end of the rotating shaft 50 is connected to a drive source (not shown). A swash plate 60 is attached to the rotary shaft 50 so as to be relatively movable and tiltable in the axial direction. A through hole 61 passing through the center line is formed in the swash plate 60, and the rotary shaft 50 passes through the through hole 61. The inner diameter of the through-hole 61 is gradually increased in the vertical direction (FIG. 1) toward the opening on both ends, and the cross-sectional shape of both ends forms a long hole. A rotating plate 62 is fixed to the rotating shaft 50 and is supported by the front housing 16 via a thrust bearing 64.

  The swash plate 60 is rotated integrally with the rotary shaft 50 by a hinge mechanism 66 and can be tilted with movement in the axial direction. The hinge mechanism 66 includes a support arm 67 fixedly provided on the rotating plate 62, a guide pin 69 fixedly provided on the swash plate 60, and slidably fitted in a guide hole 68 of the support arm 67; The through hole 61 of the swash plate 60 and the outer peripheral surface of the rotating shaft 50 are included.

  The piston 14 includes an engaging portion 70 that is engaged with the outer periphery of the swash plate 60 and a head 72 that is provided integrally with the engaging portion 70 and is slidably inserted into the cylinder bore 12. Become. The head 72 is hollow and lightweight. The head 72, the cylinder bore 12, and the valve plate 20 jointly form a compression chamber. The engaging portion 70 is engaged with the outer peripheral portion of the swash plate 60 via a pair of spherical crown shoes 76. The piston 14 is referred to as a single-head piston because the head 72 is provided only on one side of the engaging portion 70.

  The piston 14 reciprocates as the swash plate 60 rotates. Specifically, the rotational movement of the swash plate 60 is converted into the reciprocating linear movement of the piston 14 via the shoe 76. In the suction stroke in which the piston 14 moves from the top dead center to the bottom dead center, the refrigerant gas in the suction chamber 22 is sucked into the compression chamber in the cylinder bore 12 through the suction hole 32 and the suction valve 34. In the compression stroke in which the piston 14 moves from the bottom dead center to the top dead center, the refrigerant gas in the compression chamber in the cylinder bore 12 is compressed and discharged to the discharge chamber 24 through the discharge hole 36 and the discharge valve 38. As the refrigerant gas is compressed, an axial compression reaction force acts on the piston 14. The compression reaction force is received by the front housing 16 via the piston 14, the swash plate 60, the rotating plate 62 and the thrust bearing 64.

  An air supply passage 80 is provided through the cylinder block 10. The air supply passage 80 connects the discharge chamber 24 and a swash plate chamber 86 formed between the front housing 16 and the cylinder block 10. An electromagnetic control valve 90 is provided midway in the air supply passage 80. The current supply to the solenoid 92 of the electromagnetic control valve 90 is controlled according to information such as a cooling load by a control device (not shown) mainly composed of a computer.

  A discharge passage 100 is provided inside the rotary shaft 50. The discharge passage 100 is opened at one end into a support hole 102 provided in the center of the cylinder block 10 and at the other end is opened into the swash plate chamber 86. The support hole 102 communicates with the suction chamber 22 through the discharge port 104.

  The swash plate compressor C is a variable displacement type. The pressure in the swash plate chamber 86 is controlled using the pressure difference between the discharge chamber 24 on the high pressure side and the suction chamber 22 on the low pressure side. As a result of adjusting the difference between the pressure in the swash plate chamber 86 and the pressure in the compression chamber in the cylinder bore 12 acting before and after the piston 14, the inclination angle of the swash plate 60 is changed, and the stroke of the piston 14 is changed. The discharge capacity of the machine is adjusted. The pressure control of the swash plate chamber 86 is performed by the swash plate chamber 86 being connected to or shut off from the discharge chamber 24 in accordance with the excitation and demagnetization control of the electromagnetic control valve 90.

  In the swash plate compressor of this embodiment, the swash plate inclination angle changing device for changing the inclination angle of the swash plate includes the above-described hinge mechanism 66, cylinder bore 12, piston 14, suction chamber 22, discharge chamber 24, and support. The hole 56, the air supply passage 80, the swash plate chamber 86, the electromagnetic control valve 90, the discharge passage 100, the discharge port 104, a control device (not shown), and the like.

  The cylinder block 10 and the piston 14 are made of an aluminum alloy, and the outer peripheral surface of the piston 14 is coated with a fluororesin. The fluororesin coating improves the seizure resistance by avoiding direct contact with the same kind of metal, and makes the fitting gap (clearance) between the cylinder bore 12 as small as possible.

  The engaging portion 70 of the piston 14 is generally U-shaped, and has a pair of arm portions 120 and 122 extending in parallel to each other in a direction orthogonal to the central axis of the head 72, and the base ends of these arm portions 120 and 122. And a connecting portion 124 to be connected. Concave spherical surfaces 128 serving as shoe holding surfaces are formed on the side surfaces of the arm portions 120 and 122 facing each other. These two concave spherical surfaces 128 are located on the same spherical surface.

  As shown in FIG. 2, the shoe 76 has a spherical crown shape having a spherical surface portion 132 in which one of the outer surfaces is generally a convex spherical surface and a flat surface portion 138 in which the other surface is generally flat. The pair of shoes 76 is slidably held on the concave spherical surface 128 of the piston 14 at the spherical surface portion 132, and contacts the sliding surfaces 140 and 142 that are both side surfaces of the outer peripheral portion of the swash plate 60 at the flat surface portion 138. The outer peripheral part of the swash plate 60 is clamped from both sides. The pair of shoes 76 is designed so that the convex spherical surface of the spherical surface portion 132 is positioned on the same spherical surface in that state. That is, the shoe 76 has a spherical crown shape that is smaller than the hemisphere by approximately half the thickness of the swash plate 60.

  The base material 160 of the swash plate 60 is made of ductile cast iron (FCD700, FCD600, FCD500, etc.), and is made of carbon steel for mechanical structures (S45C, S55C, etc.), various chromium molybdenum steels (SCM), etc., or a copper alloy. Also good.

A solid lubricant layer 166 that is a sliding coating according to the present invention is formed on both side surfaces 162 and 163 of the substrate 160. The solid lubricant layer 166 includes a mixture of MoS ₂ , which is a solid lubricant, graphite (Gr) and polytetrafluoroethylene (PTFE), Sn fine powder which is a low melting point material, and polyamideimide which is a binder resin ( PAI). The thickness of the solid lubricant layer 166 is about 10 to 20 μm. The solid lubricant layer 166 shown here is merely an example, and other types can be used as appropriate according to the specifications of the swash plate compressor C.

  The solid lubricant layer 166 is formed as follows, for example. The liquid paint (sliding film paint) composed of the constituent components of the solid lubricant layer 166 described above is uniformly attached to the outer surface of the substrate 160 by spraying or transfer processing (screen printing, roll coat paint). The spray process is a method in which the base material 160 is fixed and the paint is sprayed onto the base material 160 so as to adhere uniformly. The coating film formed after spraying or the like is cured by baking. Ultimately, the surface is polished to form a solid lubricant layer 166 adjusted to a predetermined size and a predetermined surface roughness.

  Due to the presence of the solid lubricant layer 166, the swash plate 60 having sufficient sliding resistance such as seizure resistance and low friction can be obtained. As a result, even if the swash plate compressor C is operated under severe conditions such as a non-lubricated state or a poorly lubricated state, seizure between the swash plate 60 and the shoe 76 (between the sliding members) is avoided, and the swash plate compressor High durability and reliability of C are ensured.

  A sliding coating similar to that of the solid lubricant layer 166 may be formed on the inner peripheral surface of the cylinder bore 12 or the surface of the head portion 72 of the piston 14, or the outer peripheral surface of the shoe 76 or the concave portion of the engaging portion 70. It may be formed on the surface of the spherical surface 128.

  The pair of shoes 76 are often made of SUJ2 (high carbon chromium bearing steel), but may be, for example, an aluminum alloy surface plated with Ni. Specifically, Ni—P, Ni—B, Ni—P—B, Ni—P—B—W, and the like are formed on a base material made of an aluminum alloy such as an Al—Si alloy equivalent to A4032 containing silicon. A Ni-based plating film may be formed. This coating may be a single coating or a plurality of different or similar coatings.

  The sliding coating such as the solid lubricant layer 166 and the Ni plating coating may cover the entire surface of the base material, or may cover only a portion having severe sliding conditions.

Although the variable displacement swash plate compressor has been described as an embodiment of the sliding device of the present invention, it goes without saying that the sliding device of the present invention is not limited thereto. In the case of a compressor which is one of the sliding devices, the capacity may be variable or fixed, and the compression method may be a reciprocating type (swash plate type, wobble type, etc.) or a rotary type (vane type, scroll type, etc.). In the case of an air conditioner compressor, the type of refrigerant is not limited. It may be an alternative chlorofluorocarbon or CO ₂ or the like.

The sliding member provided with the sliding coating of the present invention was actually manufactured as follows, and the sliding characteristics of the sliding coating were evaluated.
(Preparation of sliding coating)
PFE resin varnish, which is a binder resin, PTFE powder (average particle size: 0.2 to 100 μm), graphite (Gr) powder (average particle size: 0.3 to 10 μm), and MoS ₂ powder (solid lubricant) The average particle size: 3 to 40 μm) and each metal powder (average particle size: 5 to 20 μm) as a low melting point material were added, and the mixture was stirred and dispersed to produce a paint for sliding coating.

The blending ratio was PAI: 34.49%, PTFE: 20.73, when the entire formed sliding coating (excluding the low melting point material) was 100% by mass (hereinafter simply expressed as “%”). %, Graphite: 10.85%, MoS ₂ : 33.93%. The types and blending amounts of the low melting point materials are shown in Table 1.
(Production method of sample material)
Assuming application of a swash plate compressor to a swash plate, an annular disc (φ95 × φ16 × t6 mm) made of cast iron (FCD700) was prepared as a base material. After degreasing and washing the surface of this base material, the above-mentioned various coating materials for sliding coating were spray-coated while adjusting the coating amount (coating process). The base material with the coating film formed on the surface was put into a heating furnace in the air atmosphere, heated at 200 ° C. for 1 hour, dried and fired (firing process). After cooling the substrate, the surface of the sliding coating was polished to make the thickness of the sliding coating about 10 μm. The surface roughness at this time was JIS Rz 1.0 to 3.2 μm. Thus, a sliding member (test material) having a surface coated with the sliding coating was obtained.

The counterpart material that was in sliding contact with the base material was a spherical crown member assuming a shoe of a swash plate compressor. The sliding surface of this mating member has a circular shape of φ13.5 mm. This counterpart material is made of an aluminum alloy (Al-12Si-4Cu: mass%), and the sliding surface is subjected to electroless Ni plating with a thickness of about 50 μm. In addition, a mating material made of SUJ2 (JIS), which is a bearing steel, whose surface is not plated was also prepared.
(Dry rock test)
By the dry lock test apparatus shown in FIG. 3, the seizure time until the base material on which the sliding coating is applied (hereinafter simply referred to as “swash plate”) and the Ni-plated counterpart material (hereinafter simply referred to as “shoe”) are seized. Was measured. This test apparatus slides both in a non-lubricated state (dry state) in a predetermined atmosphere while applying a predetermined load between the swash plate and the shoe. Thereby, the state very close to the non-lubricated state in the actual machine (swash plate compressor) is reproduced.

Specifically, the test was performed in two test atmospheres of CO ₂ gas and alternative chlorofluorocarbon (R134a). The vertical load applied from the upper side of the two shoes was 200 kgf (1961 N). The swash plate and the shoe are in flat contact with each other, and the surface pressure between them is about 2 MPa. The sliding speed was 10.4 m / sec. This is the average speed on the contact center circle between the swash plate and the shoe. In other words, the swash plate was slid by rotating at 3000 rpm while fixing the shoe. A thermocouple for measuring the temperature of the shoe was embedded in the ball seat holding the shoe.

  Judgment as to whether or not the image sticking occurred was made by observing a change in the torque of the drive motor required when rotating the swash plate at a constant speed. That is, the time change of the torque was continuously measured, and it was determined that seizure occurred when the torque increased rapidly (15 kgf · cm).

Tables 1 and 2 show the results of measuring the seizing time by each sliding coating. Table 1 shows the seizing time when the type and content of the low-melting-point material in the sliding coating and the content (the entire sliding coating is 100% by mass) are changed in a test atmosphere of ₂ MPa CO ₂ gas. It is a thing. Table 2 shows how the seizure time varies depending on the type of shoe and the test atmosphere when Sn-based low melting point materials having particularly excellent sliding properties are used in Table 1. .

In Table 2, the test material No. 11 shows the specimen No. in Table 1. 1 and test material No. 14 is the test material No. 2 and test material No. 17 is a specimen No. 6 and the specimen No. No. 20 is a specimen No. 7 and test material No. 23 is a specimen No. 8 and the test material No. No. 26 is a specimen No. Each is the same as 9. Further, FIG. 4 shows a graph of the burn-in time in Table 2. In FIG. 4, there are a plurality of ● because there is variation in the burn-in time even in the test under the same conditions. In correspondence with them, Table 2 also shows a plurality of burn-in times.
(Ring on block test)
With the ring-on-block test apparatus shown in FIG. 5, the temporal change of the frictional force was measured for the test piece of the sliding member in which the sliding coating was applied to the base material. In this test apparatus, a prismatic block-shaped test piece is slid while applying a predetermined load to a cylindrical mating member in a non-lubricated state (dry state) in a predetermined atmosphere. The frictional force acting on the sliding surface is measured. The test piece used here is a 6.5 × 7.0 × 6.0 mm prism block (FIG. 5) cut out from an annular disc (the aforementioned swash plate) covered with a sliding coating (thickness of about 20 μm). The outer peripheral surface of the counterpart material is in sliding contact with the sliding coating of the test piece. The counterpart material is made of φ35 mm chromium steel (JIS SCR420 equivalent material), its surface is carburized, and the surface roughness is polished to about Rz 1.7 μm. Two types of test pieces were prepared, one containing 20% by mass of Sn, which is a low melting point material, and one not containing a low melting point material.

This ring-on-block test was performed for 10 minutes in an air atmosphere. The vertical load applied to the test piece from above was 0.87 kgf (8.5 N). The sliding speed was constant at 100 mm / sec. In other words, the test was performed by rotating the mating member at a constant speed of 54 rpm while fixing the test piece. However, before this test, a break-in operation was performed in advance at the above sliding speed with a vertical load of 0.22 kgf (2.2 N) × 1 minute and then a vertical load of 0.44 kgf (4.3 N) × 1 minute. . As the test progresses, the sliding area between the test piece and the counterpart material increases, so the surface pressure also decreases. However, from the observation of the surface after the test, the surface pressure between the two is 10 kgf. / Cm ² (1 MPa) is estimated.

  FIG. 6 shows a graph showing the time change of the frictional force obtained by the ring-on-block test. FIG. 4A shows the case where there is no low melting point material in the sliding coating, and FIG. 4B shows the case where Sn is contained in the sliding coating.

Further, when the sliding surface of each test piece after the ring-on-block test was observed, the wear width when the low melting point material was not included in the sliding coating was 1.69 mm. When this is converted, the wear depth corresponds to about 20.3 μm. On the other hand, when the sliding coating contains Sn 20%, the wear width is 1.32 mm, which corresponds to a wear depth of about 12.4 μm. Each wear depth is shown in comparison with FIG.
(SEM analysis and EPMA analysis)
SEM (Scanning Electron Microscope) shows the sliding surface of the swash plate and shoe after the dry rock test using the specimen containing 28% Sn in the sliding coating (same conditions as specimen No. 14 in Table 2). ) Observation and EPMA (Electron Probe Micro Analyzer) analysis. The observed sliding surface is the one before seizure 150 seconds after the start of the test. FIG. 8 shows an SEM photograph of the sliding coating, and FIG. 9 shows an EPMA photograph thereof.

As a result of the above analysis, it was confirmed that in the sliding coating on the swash plate side, Sn is not in the form of particles but is widely distributed in the sliding coating (FIG. 9). Further, Sn and Ni—Sn compounds (sliding products) were also confirmed on the surface of the shoe plated with Ni. Furthermore, a new (secondary) sliding product layer (Sn—S—Mo compound) is formed on the surface of the Ni—Sn compound by MoS ₂ and Sn transferred from the sliding coating. It was also confirmed.
(Evaluation)
As is apparent from Tables 1 and 2 and FIG. 4, the seizure time is extended by 4 to 5 times the conventional time because the sliding coating contains the low melting point material. The tendency for the seizure resistance to be improved by the sliding coating of the present invention was basically the same even when the counterpart material and the sliding atmosphere were changed. As a cause of this, first, when the particulate low melting point material is melted and distributed widely in the sliding coating (see FIG. 9), it absorbs frictional heat and suppresses the thermal degradation of the sliding coating and its life. It is thought that was extended. Furthermore, as can be seen from FIG. 4, when the sliding coating contains Sn as a low melting point material and Ni plating is applied to the surface of the counterpart material, it has become clear that the effect of improving the seizure resistance is particularly remarkable. . As can be seen from the results of the above-mentioned EPMA analysis, the sliding product (Ni—Sn compound) newly formed on the shoe surface, which is the counterpart material, and further formed on the surface of the Ni—Sn compound are the reasons for this. The influence of the secondary sliding product layer is considered. This sliding product or secondary sliding product layer is present on the sliding surface, and as a result of reducing the coefficient of friction between the sliding surfaces, the seizure resistance may be improved. This can be sufficiently inferred from the results of FIG. 6 and FIG. In other words, in the case of the conventional sliding coating containing no low melting point material (FIG. 6 (a)), the frictional force suddenly increased and fluctuated after sliding in the unlubricated (dry) state for about 5 minutes. . This is thought to be due to burn-in. On the other hand, in the case of the sliding coating of the present invention containing a low melting point material (FIG. 6B), the frictional force (that is, the friction coefficient) was stable throughout the test and hardly fluctuated. This is presumably because, despite the sliding in a non-lubricated (dry) state, stable sliding characteristics were maintained and seizure did not occur.

Further, as can be seen from the results of Table 2 and FIG. 4, when a sliding coating containing Sn is provided, the conventional alternative chlorofluorocarbon (R134a) is used even in a harsh environment such as a _{high surface} pressure (2 MPa) CO ₂ gas atmosphere. It was also confirmed that very good seizure resistance, equivalent to or better than the gas atmosphere, was developed. It has been confirmed that such high seizure resistance can be sufficiently obtained even when Sn is about 2% as well as when Sn is contained 28% or more.

  In addition, even if it was Sn type material, Sn-20% Cu (liquidus temperature: 545 degreeC) whose melting | fusing point was much higher than the glass transition temperature of binder resin (PAI) was mixed in the sliding film. In this case, the above-described effects were not obtained, and only the seizure resistance comparable to that of the conventional sliding coating that did not contain any low melting point material or the like was shown.

  Furthermore, when the surface temperature of the shoe was measured with a thermocouple in the dry rock test, the temperature rise when the sliding coating contains a low melting point material compared to when the sliding coating does not contain a low melting point material. Was moderate. As this factor, as described above, it is considered that the endothermic effect of the frictional heat due to the melting of the low melting point material was exhibited, the friction coefficient was stabilized by the sliding product, and the like.

It is sectional drawing of the swash plate type compressor which is one Embodiment of the sliding apparatus of this invention. It is an expanded sectional view which shows the sliding contact state of the swash plate and a shoe. It is the outline | summary of the dry lock test apparatus used in order to evaluate the seizure resistance of a sliding film. It is the dispersion | distribution figure which plotted the burning time of the sliding member about various sliding coatings. It is the outline | summary of the ring on block test apparatus used in order to evaluate the frictional force of a sliding film. It is a graph which shows the time change of the frictional force by a ring-on-block test, The figure (a) is a case where a low melting point material is not included in a sliding film, The figure (b) is Sn20% in a sliding film. Is included. It is the bar graph which contrasted the maximum wear depth formed on the surface of the test piece after a ring on block test. It is a SEM photograph of the sliding film (Sn28% containing) after a dry lock test. It is a characteristic X-ray image of Sn by EPMA of the sliding coating (containing Sn 28%) after the dry lock test (showing the same part as FIG. 8).

Explanation of symbols

10 Cylinder block 12 Cylinder bore 14 Single-head piston 60 Swash plate (base material, sliding member)
70 engaging part 72 head 76 shoe (partner material)
166 Solid lubricant layer (sliding film)
C Swash plate compressor (sliding device)

Claims (18)

A sliding coating excellent in sliding properties comprising a solid lubricant and a binder resin that holds the solid lubricant on the surface portion of the substrate,
The sliding coating further comprises a low melting point material having a melting point lower than the glass transition temperature of the binder resin.   The sliding coating according to claim 1, wherein the low-melting-point material is made of one or more of a simple metal, an alloy, or a compound.   The low melting point material is one or more simple substances of a low melting point metal composed of tin (Sn), lead (Pb), indium (In) or bismuth (Bi), an alloy containing one or more kinds of the low melting point metal, The sliding film according to claim 1, comprising at least one of compounds containing at least one low melting point metal.   The sliding coating according to claim 1, wherein the low melting point material is 0.1 to 60% by mass with respect to 100% by mass as a whole.   The sliding coating according to claim 1, further comprising a sliding product forming element capable of reacting with the low melting point material to form a new sliding product having excellent sliding characteristics on the sliding surface. The low melting point material includes at least one low melting point metal composed of Sn, Pb, In or Bi,
The sliding product forming element is Ni;
The sliding coating according to claim 5, wherein the sliding product is a Ni alloy or a Ni compound composed of at least one low melting point metal and Ni. A substrate;
A sliding member comprising the sliding coating according to claim 1 formed on the surface of the substrate.   The sliding member according to claim 7, wherein the sliding member is a swash plate of a swash plate compressor. A substrate on which the sliding coating according to claim 1 is formed;
A sliding device comprising: a mating material in sliding contact with the sliding coating of the substrate. A main shaft, a swash plate rotating together with the main shaft, a cylinder block having a cylindrical cylinder bore extending in the axial direction and opened to the swash plate side, and engaging the swash plate to swing the swash plate A piston having a receiving engagement portion, a piston connected to the engagement portion and inserted into the cylinder bore and reciprocating in the cylinder bore in response to the swing of the swash plate; and an engagement portion of the piston A swash plate compressor comprising a pair of shoes that are slidably held and slidably contact the surface of the swash plate,
A swash plate type compressor, wherein the sliding coating according to claim 1 is formed on a surface of the swash plate and / or the shoe. The sliding coating is formed on one surface of the swash plate or the shoe,
On the surface of the swash plate or the shoe that is in sliding contact with the other sliding coating, a sliding product capable of reacting with the low melting point material in the sliding coating to form a new sliding product having excellent sliding characteristics. 11. The swash plate compressor according to claim 10, wherein a moving product forming element is present. The low melting point material includes Sn,
The sliding product forming element is Ni;
The swash plate compressor according to claim 11, wherein the sliding product is a Sn-Ni compound. The solid lubricant in the sliding coating consists of one or more of polytetrafluoroethylene (PTFE), molybdenum disulfide (MoS ₂ ) or graphite (Gr),
The swash plate compressor according to claim 12, wherein the binder resin in the sliding coating is made of polyamideimide (PAI). A solid lubricant,
A binder resin,
A low melting point material having a melting point lower than the glass transition temperature of the binder resin,
A sliding coating composition according to claim 1, wherein the sliding coating composition is obtained.   The composition for a sliding coating according to claim 14, which is a coating for sliding coating or a transfer coating for sliding coating. A coating step in which a coating material for a sliding coating in which a low melting point material having a melting point lower than the glass transition temperature of the binder resin and a solid lubricant is dispersed in the binder resin varnish is applied to the surface of the substrate;
A heating step of heating and baking the coating film formed after the coating step,
A method for forming a sliding coating, wherein the sliding coating according to claim 1 is obtained. A transfer step of transferring a transfer film, which is a paste obtained by mixing a binder resin and a low melting point material having a melting point lower than the glass transition temperature of the binder resin, and a solid lubricant, to the surface of the substrate;
A baking step of heating and baking the transfer film formed on the surface of the substrate after the transfer step,
A method for forming a sliding coating, wherein the sliding coating according to claim 1 is obtained.   18. A method for producing a sliding member, wherein a sliding member having a sliding coating formed on a surface of a substrate is obtained by the method for forming a sliding coating according to claim 16.

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