JP2005098294A - Swash plate and method for its manufacture - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a swash plate excellent in sliding property for a long period of time not only in the initial stage of operation of an automotive air conditioner, and a method for its manufacture, so as to solve a problem of a conventional swash plate made by coating resin with sliding property on bearing alloy layers, that is, the conventional swash plate is susceptible to seizing with long-term use although it is excellent in sliding property in the initial stage of operation of automotive air conditioner. <P>SOLUTION: The swash plate has a Cu-plated solid lubricant uniformly dispersed in the matrix of a sintered bronze powder. The sintered alloy layer is densified, and the surface of the bearing alloy layer is coated with a resin with sliding property. In a method of manufacturing the swash plate, a mixture of a bronze powder and a Cu-plated solid lubricant are temporarily sintered, and the temporarily sintered mass is pulverized. The pulverized powder is sintered on both sides of a disk steel plate. After sintering of the pulverized powder on both sides of the steel plate to form the bearing alloy layers, the bearing alloy layers are pressed and densified. After densification, the bearing alloy layers are annealed, again pressed, and then coated with the resin with sliding property. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a swash plate used for a car air conditioner and a manufacturing method thereof.

  In general, a compressor for a vehicle air conditioning system that uses a swash plate is called a swash compressor. A swash compressor (hereinafter simply referred to as a compressor) rotates a swash plate (swash plate) attached to the main shaft to convert the piston into a reciprocating motion with a shoe abutting the swash plate, and sucks refrigerant. -Repeat compression and discharge. A conventional swash plate is made by attaching a bearing alloy to a disk-shaped steel plate to provide slidability.

  FIG. 1 is a perspective view of a swash plate used for a compressor. The swash plate S has sliding portions 2 and 3 formed on both surfaces of a disk-shaped steel plate 1. The sliding portion is a bearing alloy. In the center of the swash plate S, a hole 4 is formed to be inserted and attached to the rotating shaft.

  FIG. 2 is an enlarged view of a main part of the compressor. A piston 6 is installed in the cylinder 5 so as to freely reciprocate. The cylinder 5 is divided into a left cylinder chamber 7 and a right cylinder chamber 8 by the piston 6. A left suction valve 9 and a left discharge valve 10 are installed in the left cylinder chamber 7, and a right suction valve 11 and a right discharge valve 12 are installed in the right cylinder chamber 8. A swash plate S is disposed at the center of the piston 6 between the left shoe 13 and the right shoe 14. The swash plate is attached in an inclined state with respect to the rotating shaft 15, and a left bearing alloy 16 and a right bearing alloy 17 are attached to both surfaces of the swash plate.

  Here, the movement of the swash plate and the piston when the car air conditioner is used will be briefly described.

  During the operation of the compressor, the swash plate S also rotates with the rotation of the rotating shaft 15. However, since the swash plate is mounted inclined with respect to the rotating shaft, the piston 6 sandwiching the swash plate is as indicated by an arrow A. Is reciprocated. A left shoe 13 and a right shoe 14 are installed at a portion where the piston 6 sandwiches the swash plate S, and these shoes slide on the surfaces of the bearing alloys 16 and 17 attached to the swash plate S.

  In the compressor, the swash plate rotates at a high speed (more than 8,000 revolutions per minute), so a very large load is applied to the portion where the swash plate contacts the shoe. Therefore, during use, the swash plate must not peel from the steel plate and the bearing alloy, and the bearing alloy must not be damaged or worn. For this reason, the swash plate must have excellent mechanical strength such as high bonding strength between the steel plate and the bearing alloy and high hardness of the bearing alloy. Of course, the swash plate must also have excellent slidability.

  In the past, the swash plate was obtained by simply attaching a bearing alloy to the surface of a disk-shaped steel plate. For the application of the bearing alloy, a method of spraying the bearing alloy or sintering the bearing alloy powder is employed.

  The swash plate obtained by the method of joining by thermal spraying does not have sufficient joining strength between the steel plate and the bearing alloy, and the bearing alloy may peel from the steel plate during use. The peeling by this thermal spraying method is due to the fact that the bonding is not metallurgical bonding but mechanical bonding. In other words, the thermal spraying method is a mechanical joining in which a molten bearing alloy is blown off with a high-pressure gas and applied to a steel plate, and the bearing alloy is bitten into the steel plate with the momentum.

  Moreover, since the swash plate obtained by the conventional sintering method has a low alloy density, the swash plate may dent during use or cause baking. Therefore, the applicant of the present invention has proposed a swash plate in which bearing alloy powder is sintered on the surface of a disk-shaped steel plate and the alloy density is increased, and a manufacturing method thereof (Patent Document 1). The swash plate of Patent Document 1 has a feature that the alloy density is higher than the alloy density (80% or less) of the swash plate obtained by a conventional sintering method with an alloy density of 85% or more, and therefore, it is difficult to cause baking.

  The swash plate obtained in Patent Document 1 has a surface made only of a bearing alloy, but has been sufficiently usable for conventional compressors. However, the swash plate obtained in Patent Document 1 has not been sufficiently slidable with respect to those that are further enhanced in function and are subjected to high-speed and high-load loads such as today's compressors. Therefore, recently, in order to improve the slidability of the swash plate, a surface coated with a resin having excellent slidability has been used.

  A number of swash plates coated with resin have been proposed. For example, in Patent Document 2, a copper alloy is sintered on the surface of a steel plate to form a bearing alloy layer, and the bearing alloy layer is coated with a slidable resin. In Patent Document 3, a copper alloy layer is formed on a steel plate by plating, spraying, cladding, sintering, etc., and the surface of the alloy layer is coated with any one of slidable resin, molybdenum disulfide, and graphite. .

Japanese Patent Laid-Open No. 2003-21056 JP 2002-180961 A Japanese Patent Laid-Open No. 11-13638

  In Patent Document 1, in order to improve the disadvantages of the conventional sintering method, that is, the indentation or baking during use, voids were eliminated by performing primary pressing on the sintered steel sheet. . As a result, in Patent Document 1, the alloy density of the bearing alloy layer is increased, and dents and baking during use are not caused. However, as described above, in a swash plate in which bearing alloy layers are formed on both surfaces of a steel plate and then the primary press is performed to increase the alloy density, as described above, it is necessary to use a swash plate as a sliding plate. There was a problem with mobility.

  Further, the applicant of the present invention uniformly mixes 100 parts by volume of the Cu—Sn alloy powder and 1 to 50 parts by volume of the Cu-plated solid lubricant, pre-sinters them to make a sintered ingot, We have also proposed a swash plate in which the pulverized powder obtained by pulverizing sinter is sintered into a steel plate and is less prone to baking. In the present invention, a solid lubricant plated with Cu is further added to the invention of Patent Document 1 to reduce friction and make baking difficult. Although the present invention is excellent in practical use, as described above, further excellent sliding properties are required for use in today's compressors.

  On the other hand, a swash plate with a bearing alloy layer coated with a slidable resin shows better slidability for high speed than a swash plate with a bearing alloy formed on a steel plate. It can be said that. However, a conventional swash plate coated with a slidable resin has a problem in life in that good slidability is maintained for a long time. In other words, the slidable resin coated on the surface of the bearing alloy layer is present between the bearing alloy and the shoe in the initial operation of the air conditioner, so that the slidable resin improves the slidability. Thereafter, the slidable resin is scraped off by the shoe with the passage of time, so that most of the slidable resin disappears and remains slightly between the irregularities of the bearing alloy. Therefore, after the initial operation of the car air conditioner, the shoe is received by the slidable resin and the bearing alloy that are slightly left between the irregularities of the bearing alloy layer. At this time, the swash plate having poor sliding property causes baking.

  By the way, the bearing alloy used for the former swash plate was lead bronze containing lead like LBC-3. In lead bronze, metallic lead is dispersed in a bronze matrix, and the lead exhibits excellent slidability as a solid lubricant. However, if lead accumulates in the human body, its use is becoming regulated because it may lead to lead poisoning, and lead bronze is no longer used in swash plates. Therefore, as a substitute for lead bronze bearing alloys, lead-free bronze bearing alloys made of Cu and Sn have been used for swash plates. Since the lead-free bronze bearing alloy is less slidable than the conventional lead-bronze bearing alloy, a swash plate in which a slidable resin is coated on the bearing alloy layer of bronze powder can be considered. Even when good slidability was exhibited by the slidable resin, after that, when the slidable resin disappeared, baking would occur immediately.

  Although the present invention uses a lead-free bronze bearing alloy, it can maintain excellent sliding characteristics for a long time even after the slidable resin disappears, and the portion that comes into contact with the chute may be recessed during use. The object of the present invention is to provide a swash plate and a method for manufacturing the same.

  In swash plates using lead-free bronze bearing alloys, it is known that a solid lubricant in place of lead may be included in order to improve slidability, but this is a solid lubricant for bearing alloys. When graphite or molybdenum disulfide is mixed with bronze and sintered, these solid lubricants are not metals, so they are not metallicly bonded to the bronze powder and are simply dispersed in a bronze matrix. Become. In such a swash plate in which the solid lubricant is dispersed in a bronze matrix in an unstable state, the solid lubricant peels off from the bronze during operation and disappears easily, and the sliding property is lost and baking is performed. Get up. Therefore, if the solid lubricant can be metallically bonded to the bronze powder, the present inventors will be in a stable state in the bronze matrix. The solid lubricant will not easily peel off even if it comes into contact, and if a lubricating resin is coated on a bearing alloy layer with a high alloy density, the bearing alloy will not easily dent even if the lubricating resin disappears, etc. This invention was completed paying attention to.

  The invention of claim 1 is that a mixed powder obtained by uniformly mixing 100 parts by volume of an alloy powder composed of Sn 5 to 20% by mass and the balance Cu and 1 to 50 parts by volume of a Cu-plated solid lubricant powder is formed on a disk-shaped steel plate. A swash plate characterized in that it is sintered to form a bearing alloy layer, the bearing alloy layer is densified, and the surface of the bearing alloy layer is coated with a slidable resin. It is.

  A second aspect of the present invention is the swash plate according to the first aspect, wherein the bearing alloy layer has an alloy density of 85% or more.

  A third aspect of the present invention is the swash plate according to the first aspect of the present invention, wherein the Cu-plated solid lubricant powder is either graphite powder or molybdenum disulfide powder.

  A fourth aspect of the present invention is the swash plate according to the first aspect, wherein the slidable resin is at least one selected from polyamideimide, polyimide, and polytetrafluoroethylene.

The invention of claim 5 is characterized in that, in the invention of claim 1, the slidable resin contains at least one kind of graphite powder, molybdenum disulfide, and polytetrafluoroethylene as a solid lubricant. It is a swash plate.
A sixth aspect of the present invention is the swash plate according to the first aspect, wherein the slidable resin contains at least one kind of graphite powder, molybdenum disulfide, and polytetrafluoroethylene. is there.

  In the invention of claim 6, (a) 100 volume parts of Cu-based alloy powder consisting of 5 to 20% by mass of Sn and the balance Cu and 1 to 50 volume parts of Cu-plated solid lubricant powder are mixed. Mixing step for obtaining mixed powder; (b) pre-sintering step for sintering the mixed powder in a reducing atmosphere at 750 to 850 ° C. to obtain a sintered lump; (c) 300 μm or less of the sintered lump with a pulverizer (D) After uniformly dispersing the pulverized powder on one surface of the steel sheet, the pulverized powder and the pulverized powder and the steel sheet are heated by heating the steel sheet in a reducing atmosphere at 800 to 880 ° C. A primary sintering step of joining and forming a bearing alloy layer on one side of the steel sheet; (e) after uniformly dispersing the pulverized powder on the other side of the primary sintered steel sheet, the steel sheet is heated to 800-880 ° C. By heating in a reducing atmosphere, the pulverized powder and the pulverized powder and the steel plate are joined together to form a bearing alloy layer on the other surface of the steel plate. Secondary sintering step to be formed; (f) primary pressing step of densifying the bearing alloy layer by pressing the bearing alloy layers formed on both surfaces of the steel plate; (g) a steel plate having a densified bearing alloy layer; An annealing step of heating in a reducing atmosphere at 880 ° C .; (h) a secondary pressing step of pressing the annealed bearing alloy layer again to a predetermined hardness; (i) slidability on the bearing alloy layers on both sides of the steel plate A method for producing a swash plate, comprising: a coating step for adhering a resin.

  Since the swash plate of the present invention uses a lead-free bronze alloy, there is no concern about lead pollution. In addition, the swash plate of the present invention is obtained by mixing and sintering bronze alloy powder and Cu-plated solid lubricant, so that the bronze alloy powder and the surface of the solid lubricant are metallically joined and in use. Not only does the solid lubricant not peel off, it also has good slidability over a long period of time due to the presence of a stable solid lubricant. Furthermore, the swash plate of the present invention has a densified bearing alloy layer obtained by mixing and sintering bronze alloy powder and Cu-plated solid lubricant, so that even if the shoe comes into direct contact with the alloy layer, There is no dent by pressing. The swash plate of the present invention exhibits excellent slidability in the initial operation because the surface of the bearing alloy layer having good slidability is coated with a slidable resin.

  In another swash plate manufacturing method of the present invention, the solid lubricant can be uniformly dispersed without being unevenly distributed, and the solid lubricant can be firmly held against the lead-free bearing alloy powder. The swash plate manufacturing method of the present invention can increase the alloy density of the bearing alloy containing the solid lubricant and coat the surface with the increased alloy density with a lubricious resin, so of course during initial operation. In the subsequent operation, a swash plate having good slidability over a long period of time can be obtained.

  In the swash plate of the present invention, a mixture of a bronze alloy powder made of Cu and Sn and a solid lubricant plated with Cu is sintered on a steel plate to form a bearing alloy layer. The bearing alloy layer is densified, and the bearing alloy layer is further coated with a slidable resin. The bronze alloy powder used in the present invention cannot obtain sufficient hardness when the Sn content in the bronze alloy is less than 5% by mass, and becomes brittle when the Sn content exceeds 20% by mass.

  In a swash plate in which a bearing alloy is simply sintered on the surface of a steel plate, the portion with which the shoe contacts may be recessed in an annular shape as if it were a car bag. This is because a sintered swash plate has a porous bearing alloy layer and is pushed by a shoe contacting at high speed and high pressure, and the porous portion is crushed. Therefore, in the swash plate of the present invention, the sintered porous portion is crushed and densified so that it is not dented by the shoe. The porous part only for sintering has an alloy density of 80% or less, and at this alloy density, the swash plate is recessed during use. When the alloy density in the bearing alloy layer of the swash plate is 85% or more, there is no dent during use.

  The solid lubricant used in the swash plate of the present invention is a Cu-plated graphite powder, molybdenum disulfide powder, or a mixture thereof, and the mixing ratio of the solid lubricant is 1 to 100 parts by volume of bronze alloy powder. 50 parts by volume. If the mixing ratio is less than 1 part by volume, sufficient sliding characteristics cannot be obtained, and seizure occurs early. However, when the mixing ratio of the solid lubricant exceeds 50 parts by volume, the mechanical strength of the bearing alloy cannot be obtained.

  As the slidable resin used in the present invention, any resin can be used as long as it has excellent slidability. Suitable slidable resins for use in the present invention are polyamide resins, polyimide resins, polyamideimide resins, and polyterolafluoroethylene resins (PTFE), which are used alone or in combination. You can also.

  When a solid lubricant is contained in the slidable resin, the slidability is further improved. Suitable solid lubricants for use in the present invention are PTFE, molybdenum disulfide, graphite, and the like. The solid lubricant may be only one kind, but if two or more kinds are mixed and contained, the slidability is further improved.

  Lubricating resin coated on the bearing alloy layer suitable for the present invention includes 20-80 vol% of slidable resin such as polyamide resin, polyimide resin, polyamideimide resin, 5-10 vol% of MOS2, and 30-30 of graphite. It is preferable to use a sliding resin coating agent to which 80 to 20 vol% of a mixture of three components of a solid lubricant of 70 vol% and PTFE of 20 to 65 vol% is added.

  When the temperature in the preliminary sintering step in the method for producing a swash plate of the present invention is lower than 750 ° C., the bonding strength between the powders is not sufficient. However, when the pre-sintering temperature is higher than 850 ° C., Cu plated with the solid lubricant diffuses and disappears in the bronze alloy powder, and the bronze alloy powder and the solid lubricant cannot be joined and separated.

The sintered ingot obtained by this preliminary sintering is pulverized into a powder form by a pulverizer such as a mill. Cu
Since the specific gravity of the plated solid lubricant and the bronze alloy powder are different, the Cu plated solid lubricant cannot be mixed with the bronze alloy powder evenly by mechanical stirring. However, when the mixed powder is pre-sintered and then pulverized, the solid lubricant is present uniformly throughout. The particle size of this pulverized powder is 300 μm or less. When the powder particle size is larger than 300 μm, it breaks and falls off the bronze matrix. The size of the pulverized powder suitable for use in the present invention is about 100 μm.

If the sintering temperature after the pulverized powder is dispersed on the steel sheet is lower than 800 ° C, the bonding strength between the alloy powders and between the alloy powder and the steel sheet will not be sufficient, and if it exceeds 880 ° C, The intermetallic compound is generated and the bonding strength is lowered.

  In the method for producing a swash plate of the present invention, when bronze powder and Cu plating solid lubricant are mixed and pre-sintered, and when sintered powder obtained by pre-sintering is sintered into a steel plate The reason why the reducing atmosphere is used is that the surface of the bearing alloy powder and the steel plate is oxidized during heating, and the oxide film prevents metallic bonding. When pre-sintering or sintering is performed in a reducing atmosphere, the bearing alloy powder and the steel plate are prevented from being oxidized during heating, and the oxide on the metal surface oxidized before heating is reduced and removed. Ensure the bonding between the alloy powder and the steel plate. The reducing atmosphere used in the present invention is an atmosphere filled with hydrogen gas, ammonia decomposition gas (hydrogen 75%, nitrogen 25%) or the like.

  In the method for producing a swash plate of the present invention, the bearing alloy layer on the steel plate is primarily pressed to densify the bearing alloy surface. A suitable pressing force on the bearing alloy layer is 150 to 250 tons.

After densifying the bearing alloy surface, annealing is performed at 840 ° C to 880 ° C. Annealing here is to reduce the bearing alloy layer that has been work hardened by primary pressing to an appropriate hardness,
The purpose is to increase the bonding strength by re-sintering the peeled portion generated by pressing. Annealing temperature is 84
If the temperature is lower than 0 ° C, sufficient annealing cannot be performed. However, if the temperature is higher than 880 ° C, the hardness of the steel sheet decreases and the mechanical strength becomes weak.

And secondary pressing is performed with respect to the bearing alloy layer after annealing. In the secondary pressing here, the hardness that has been lowered in the annealing process is increased to a predetermined hardness, and further pressed to a predetermined thickness. Hardness in the secondary pressed, H _V 100 to 140 are suitable. If a predetermined thickness can be obtained only by this secondary pressing, the next process may be performed as it is. However, when it is difficult to obtain a predetermined thickness by the secondary pressing, the secondary pressing may be performed slightly thicker than the predetermined thickness and then cut by a lathe.

  In the coating of the slidable resin, the surface of the bearing alloy layer is preferably roughened with fine irregularities in order to strengthen the adhesion between the surface of the bearing alloy layer and the slidable resin. When the surface of the bearing alloy is roughened, the surface area is increased, the adhesive strength is increased, and the slidable resin is more firmly bonded by an anchor effect of being entangled with the roughened bearing alloy surface. As a means for roughening the surface of the bearing alloy layer, there is a surface cutting process using a lathe as described above. When the bearing alloy layer is cut with a lathe, the lathe bite mark remains like a groove on the record board. As other means for roughening the surface of the bearing alloy layer, sandblasting, etching, or the like can be employed.

  The method for producing the swash plate of the present invention will be described below. ai explain each process in the manufacturing method of the swash plate concerning this invention.

Manufacturing method of swash plate (a) Mixing step: Cu-plated graphite powder is mixed at a ratio of 4 parts by volume with respect to 100 parts by volume of the composite bronze gold powder consisting of 10% by mass of Sn and the remaining Cu.
(B) Temporary sintering step: The mixed powder obtained in the mixing step is heated in a reducing atmosphere at 800 ° C. to produce a sintered ingot.
(C) Grinding step: The sintered mass is pulverized with a hammer mill to produce a powder having a particle size of about 100 μm.
(D) Primary sintering process: Steel plate with a thickness of 5.0mm and diameter 80mm (S45C) After uniformly dispersing the pulverized powder on one side with a thickness of 0.8mm, the steel plate on which the pulverized powder has been applied is heated in a reducing atmosphere. Heating is performed at 860 ° C in a furnace to primarily sinter the powder, and the powder and steel plate.
(E) Secondary sintering step: After uniformly dispersing the pulverized powder on the other surface of the primary sintered steel sheet with a thickness of 0.8 mm, the steel sheet on which the pulverized powder is dispersed is heated in a reducing atmosphere. Heat at medium 860 ° C to secondary-sinter the powder and powder and steel plate.
(F) Primary pressing step: The bearing alloy layers on both surfaces of the steel sheet are pressed by a press at 200 tons to densify the bearing alloy layers.
(G) Annealing step: A material in which the bearing alloy layer is densified is annealed by heating at 860 ° C. for 15 minutes in a reducing furnace.
(H) Secondary pressing step: The bearing alloy layer that has been densified and annealed is pressed at 180 tons by pressing. Hardness here is H _V 100. Then, the thickness of the bearing alloy layer is adjusted by cutting with a precision lathe and the surface of the bearing alloy layer is appropriately roughened.
(I) Sliding resin coating process: A suspension made of a mixture of polyamideimide, which is a sliding resin, and a mixture of three solid lubricants of PTFE, MoS2, and graphite on the surfaces of both bearing alloy layers. It was applied and then baked at 180 ° C. in a heating furnace.

  Using the swash plate of the example obtained by the above method and the swash plate manufactured by the manufacturing method including the steps shown in Table 1, the friction coefficient and the durability test were performed. The results are shown in Table 1.

表の見方 ○：その工程を含む。 ×：その工程を含まない。

How to read the table ○: Including the process. X: The process is not included.

Test method 1. Friction coefficient: Using a thrust tester as shown in FIG. 3, the torque is measured in a dry state, and the friction coefficient is calculated from the torque.
The test method is to place a shoe on three points on a swash plate (on a circle with a diameter of 69 mm), apply a load of 20 kg along with the shoe, and rotate the shoe by 4000 rpm. At this time, the torque applied to the swash plate is measured, and the friction coefficient is calculated by the following equation.
Friction coefficient = torque / load x length (radius of swash plate)
2. Durability: At the time of the above torque measurement, 4000 rpm, 1 minute is set as one time, and the number of times until the temperature of the swash plate reaches 200 ° C. is measured to obtain the number of durability cycles.

  The coefficient of friction was 0.137 for the swash plate of the example and was several steps better than that of 0.295 to 0.193 for the swash plate of Comparative Examples 1 to 3 whose surface was not resin-coated. In addition, the durability of the swash plate of the example is 14 times, no solid lubricant is mixed in the alloy layer, and the durability is 20 times or more better than that of the comparative example 4 in which the formed alloy layer is not densified. Showed sex.

  The swash plate of the present invention has excellent slidability for a long period of time as well as during initial operation, so it will be well suited for compressors for car air conditioners that will be subjected to severe conditions of higher speeds and loads in the future. Is possible.

Perspective view of swash plate Main section enlarged view of compressor Simplified test of thrust tester

Explanation of symbols

S Swash plate 1 Steel plate 2, 3 Sliding part 2 Hole

Claims (6)

Bearing alloy in which a mixed powder in which 100 parts by volume of Sn 5 to 20% by mass of the alloy powder consisting of the remaining Cu and 1 to 50 parts by volume of the Cu-plated solid lubricant powder are uniformly mixed is sintered on a disk-shaped steel plate The swash plate is characterized in that a layer is formed, the bearing alloy layer is densified, and the surface of the bearing alloy layer is coated with a slidable resin. The swash plate according to claim 1, wherein the bearing alloy layer has an alloy density of 85% or more. The swash plate according to claim 1, wherein the Cu-plated solid lubricant powder is either graphite powder or molybdenum disulfide powder. The swash plate according to claim 1, wherein the slidable resin is at least one selected from a polyamide resin, a polyimide resin, a polyamideimide resin, and a polytetrafluoroethylene resin. The swash plate according to claim 1, wherein the slidable resin contains at least one kind of graphite powder, molybdenum disulfide, and polytetrafluoroethylene as a solid lubricant. (A) A mixing step of mixing 100 parts by volume of Cu-based alloy powder composed of 5 to 20% by mass of Sn and the balance Cu and 1 to 50 parts by volume of Cu-plated solid lubricant powder to obtain a mixed powder;
(B) Temporary sintering step of sintering the mixed powder in a reducing atmosphere at 750 to 850 ° C. to obtain a sintered mass;
(C) A pulverization step of pulverizing the sintered ingot to a powder of 300 μm or less with a pulverizer;
(D) After uniformly dispersing the pulverized powder on one side of the steel sheet, the steel sheet is heated in a reducing atmosphere at 800 to 880 ° C., thereby joining the pulverized powder to each other and the pulverized powder and the steel sheet. A primary sintering step to form an alloy layer;
(E) After uniformly dispersing the pulverized powder on the other surface of the primary sintered steel sheet, the pulverized powder and the pulverized powder and the steel sheet are heated by heating the steel sheet in a reducing atmosphere at 800 to 880 ° C. A secondary sintering step in which a bearing alloy layer is formed on the other surface of the steel sheet by joining;
(F) a primary pressing step of pressing the bearing alloy layers formed on both surfaces of the steel sheet to densify the bearing alloy layers;
(G) An annealing process in which the steel sheet with a dense bearing alloy layer is heated in a reducing atmosphere at 840 to 880 ° C;
(H) a secondary pressing step of pressing the annealed bearing alloy layer again to a predetermined hardness;
(I) a coating step for attaching a slidable resin on the bearing alloy layers on both surfaces of the steel sheet;
A method for producing a swash plate, comprising:

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