JPH11293304A - Double-layered sintered sliding member and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a double-layered sintered sliding member with a simple structure excellent in conformability, excellent in wear resistance, load resistance and seizure resistance which and sufficiently capable under boundary lubricating conditions. SOLUTION: This member is composed of a back plate made of steel having a smooth surface and at least two kinds of sintered alloy layers jointed to the surface part of the back plate and different in compsn. and components with each other and at least one kind of sintered alloy layer among these sintered alloy layers is distributed so as to expose independently to the sliding direction in the state of being coexistent with the other sintered alloy in the sliding face.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-layer sintered sliding member for improving wear resistance under high surface pressure and preventing generation of abnormal noise, and a method for manufacturing the same. The present invention relates to a multilayer sintered sliding member in which at least two types of sintered alloy layers having different structures and components from each other are joined to a back metal, and a method of manufacturing the same at low cost.

[0002]

2. Description of the Related Art Generally, a sintered bearing member fulfills its function as a bearing material by making use of its porous property to impregnate it to provide self-lubricating performance.
As the types of the sintered bearing members, there are an iron-based sintered bearing member and a copper-based sintered bearing member, which are properly used depending on their use conditions. Among them, the iron-based sintered bearing member is difficult to seize with the shaft material, but has a relatively high load due to its high strength, and is used for low and medium speeds. On the other hand, a copper-based sintered bearing member is excellent in seizure resistance with a shaft material, but has a small load due to low strength, and is used for medium to high speeds.

[0003] As an intermediate between the iron-based sintered sliding material and the copper-based sintered sliding material, there is a material in which a copper-based material and an iron-based material are mixed.
It is hard to say that both good properties can be fully demonstrated.

[0004] From the viewpoints of seizure resistance, generation of abnormal noise during sliding, etc., copper-based sintered bearing materials are superior to iron-based sintered bearing materials. Used in some places. In addition, lead bronze or bronze,
And copper-lead-based materials are often used, and from the viewpoint of resource saving, a multi-layer sintered sliding material in which a copper-based material is integrated with an inexpensive iron-based backing material is well known. . These materials are selected to have a material configuration suitable for each sliding environment. That is, a copper-lead-based overlay or a material system with a high lead content is selected in a place where the load is small and lubrication characteristics are particularly important. On the other hand, even if some lubrication properties are sacrificed, the material system used where importance is placed on load-bearing properties is bronze, phosphor bronze, aluminum bronze, nickel bronze, etc. The suppressed material system is selected.

[0005] When the load-bearing performance is insufficient, a copper-based material having high strength (such as a high-strength brass material) is selected from the viewpoint of ease of seizure with iron materials. However, although high-strength brass is superior to iron in terms of seizure, it does not contain a material that improves lubricating properties inside, and is resistant to lubrication oil depletion. It cannot be said that the abrasion properties are sufficient. In addition, brass-based materials have difficulties during sintering, such as evaporation of zinc.

As a material having the same sliding characteristics as a sintered material and improved strength, a sliding member containing a large amount of solid lubricant and having a high density by hot pressing (for example, manufactured by Toshiba Tungaloy; SL alloy Although this sliding member has good sliding characteristics, the amount of the solid lubricant is too large and the strength is still insufficient.

In construction machines, the bearing materials discussed above use a large number of bearings, such as working machine bushes (high load, low speed), which cannot be adequately handled. At present, these bushes are used after being subjected to a hardening treatment such as quenching a surface portion of an iron-based material, and then to a surface treatment. Although grease is supplied as a lubricant, its life is short and it is necessary to constantly supply grease. Especially in the case of large models, the greasing interval is once a day. Therefore, many attempts have been made to improve the lubrication interval by changing the groove shape of the bush or increasing the number of grooves.

Apart from this, the following improvements have been attempted in lubrication methods, materials, etc., so that they can be used under severe conditions. (1) A grease to which a solid lubricant such as graphite is added to increase the viscosity and suppress seizure. (2) The bearing itself has a self-lubricating property such as oil lubrication. A specific example is an iron-based oil-impregnated bearing material. (3) A bearing material in which an iron-based material is changed to a copper-based material (for example, a high-strength brass material). (4) A mechanically drilled hole is formed in a high-strength brass material, and porous artificial graphite is embedded therein, and the bearing material is impregnated with oil (for example,
Oiles Industry; Oiles 500SP). (5) A copper-based sintered material containing 3% or more of graphite is joined to an iron plate having a convex portion or a concave portion to form a structure having a sparse and dense structure, and a material having self-lubricating properties by being oil-impregnated (for example, JP-A-3-232905). (6) A non-metallic resin bearing material in which Teflon fiber is wound inside and epoxy resin is arranged outside. (7) A bearing material in which an oil-impregnated resin is bonded to the inner surface of a metal pipe material to have self-lubricating properties (for example, OILES Industrial; OILES Drymet).

[0009]

However, despite such attempts, a bushing material having sufficient characteristics has not been obtained. Each of the above cases (1) to (7) will be discussed below. (1) In the case of adding a solid lubricant to grease,
The solid lubricant to be added is mainly composed of graphite and molybdenum disulfide from the viewpoint of cost, and the grease supply interval is slightly extended, but has not yet been substantially improved. Further, the supplied grease is exposed to the outside as the usage time increases, and there is a problem that the appearance quality is deteriorated because the color tone is particularly black. In conclusion, it is not a serious improvement. (2) In the case of an oil-containing bearing material made of an iron-based material, since the base material is porous, the pressure of the oil-impregnated oil does not increase, and the sliding mainly under so-called boundary lubrication in which metal-to-metal contact occurs. That is inevitable. About 25% of copper is contained to secure oil-impregnated pores to improve conformability, but in order to improve load resistance, the basic material is made of iron and the sag of the material itself is further reduced. Therefore, a quenching process is performed. As a result, the true contact area cannot be increased, the local surface pressure increases, and an environment is likely to occur in which seizure occurs easily with the shaft material. When used as a bush of a working machine, the situation is not so different from a grease lubricated product due to the ease of seizure between iron materials. In addition, when the adhesion occurs, the strength of the sintered structure is weak, so that the progress of abrasion has a remarkable weak point as compared with the iron material. In conclusion, no significant improvement has been achieved. (3) When the base material of the bush is made of a high-strength brass material, the ease of seizure and the occurrence of abnormal noise caused by the iron-iron combination are clearly improved. However, the lubrication mechanism is no different from the case of using an iron-based material, and although the lubrication interval is extended to some extent, it cannot be extended epoch-makingly. From the viewpoint of extending the greasing interval, it can be said that there is an effect. (4) The base material is a high-strength brass material of a copper-based material, and graphite is subjected to an oil-impregnating treatment, and the load resistance and seizure resistance are addressed by the high-strength brass material. On the other hand, the lubricating performance can be obtained by the graphite impregnated by the oil impregnated in the graphite and the progress of the abrasion, and it is a bush capable of extending the greasing interval. However, all the graphite embedding locations must be machined, and furthermore, a step of embedding graphite in oil and impregnating each one is necessary, which ultimately increases costs. From the above, it can be said that although effective, the cost is high. (5) In the case of a sintered material using an uneven iron plate, a high-density sintered material sintered on the convex iron plate becomes a load-bearing layer during sliding. The sliding condition of this portion is boundary lubrication and the friction force is relatively high. On the other hand, the material in this part has graphite added as a solid lubricant in an amount of 3% or more to provide a self-lubricating function, but does not have sufficient fatigue strength due to the presence of the solid lubricant. . Therefore, under the sliding conditions where fatigue is added, there occurs a problem that the phenomenon of peeling of the sliding material occurs. In conclusion, it can be said that fatigue strength is insufficient. (6) The resinous bearing material is made in a form depending on the lubrication characteristics of the Teflon material, and it can be said that the sliding characteristics are clearly excellent. However, since the material is resin, the amount of plastic deformation at the time of use is large, and there is a problem that rattling due to settling occurs. That is, the wear resistance is insufficient. (7) A bearing having self-lubricating properties by joining a resin having oil-impregnating properties to the inner surface of a metal pipe material. The main components of lubrication are resin and oil, and the friction coefficient is small. And has excellent lubrication properties. However, since the resin is mainly used, deformation due to plastic deformation of the resin component cannot be avoided, and the apparent abrasion amount tends to increase. In addition, when the load is large and the speed is large, that is, the so-called P * V value is large, a problem such as separation from a joint portion with a metal portion occurs due to deformation due to a difference in thermal expansion. In conclusion, the abrasion resistance is insufficient and the cost is high.

[0010] The present invention solves the above-mentioned problems, and is excellent in conformability with a simple structure, excellent in abrasion resistance, load resistance, and seizure resistance, and can be sufficiently performed under boundary lubrication conditions. Another object of the present invention is to provide a simple multilayer sintered sliding member and a manufacturing method capable of manufacturing the sliding member at low cost.

[0011]

In order to achieve such an object, a multilayer sintered sliding member according to the present invention comprises a steel back metal having a smooth surface and a surface of the back metal. A multi-layer sintered sliding member comprising at least two types of sintered alloy layers having different structures and components from each other, wherein at least one type of the sintered alloy layers is And are distributed so as to be exposed independently of the sliding direction in a state of being mixed with other sintered alloy layers on the sliding surface.

At least one of the at least two types of sintered alloy layers is a high-density low-oil-impregnated sintered alloy layer having excellent load-bearing performance, and at least one other is a low-density high-oil-impregnated layer having excellent oil-impregnating performance. It is preferable to use an oil-impregnated sintered alloy layer (porous sintered sliding material), and to further dispose a resin material having excellent oil-impregnating performance.

Further, by adding a gelling agent to the oil-impregnated oil, when the sliding conditions become severe and heat is generated, the gel is melted and the oil is supplied, so that the self-lubrication is maintained. Will have.

It is desirable that the high-density low-oil-impregnated sintered alloy layer having excellent load-bearing capacity has an area ratio of 30% to 60%. When the area ratio of the load-bearing layer on the sliding surface is 30% or less, the lubricating property can be maintained, but the load-bearing surface is insufficient. If it is 60% or more, the oil content that can be secured is small, and the lubricating ability is insufficient.
It was set to 0%. The size of the high-density low-oil-impregnated sintered alloy layer is continuously 3 mm to 2 mm with respect to the trajectory in the sliding direction.
It must be 0 mm long. That is, the minimum dimension was set to 3 mm from the economical viewpoint of manufacturing. Meanwhile, 2
If it is 0 mm or more, the oil as a lubricating component is not sufficiently distributed, so the maximum upper limit is set to 20 mm. As one example, the form of the load-bearing layer is circular or elliptical, and is arranged such that there is always some load-bearing layer in the sliding direction independently of the sliding surface (for example, (In a staggered manner at an angle of 60 ° with respect to the sliding direction), it is preferable to exist in a form coexisting with a sintered alloy layer of another material. As a sintered alloy of another material system, firstly, a sintered alloy layer having excellent oil-impregnating performance and having a porosity of 20% or more and 70% or less, and in some cases,
1% to 20% of solid lubricant for the second sintered alloy layer
Sintered alloys with rich self-lubrication. The sliding bearing material according to the present invention is a sliding member characterized by including these two or three sintered layers.

As described above, the load-bearing layer is arranged so as to exist at least continuously in the sliding direction, and the oil-bearing layer containing a specific amount of oil and the load-bearing layer are formed on the sliding surface. In the sliding direction, by arranging them so that they are mixed, while maintaining sufficient load-bearing characteristics,
A bearing member having sufficient lubrication characteristics can be provided. In particular, when the load is large, the area ratio of the load-bearing layer is increased to 60%, and when the load is small and the speed is large, the area of the load-bearing layer is reduced to 20%. By taking a large area, it is possible to make the material structure suitable for the sliding conditions. Further, in addition to these structures, it is also possible to form a layer in which the amount of the solid lubricant is increased as the third layer. In the worst case, even if the oil is depleted, the lubrication performance can be improved by the solid lubricant. , And a material that can withstand load fluctuations can be obtained.

The above-mentioned sintered alloy is preferably a copper-based sintered alloy, particularly when the mating material is an iron-based material, as a load-bearing material. The copper-based sintered alloy is selected depending on its use. In particular, under heavy load conditions, high-strength high-strength brass, silzine bronze, aluminum bronze, brass, nickel bronze, nickel silver, and other age-hardenable copper alloys (C
u-Ni-Si alloy (Corson alloy), Cu-Ni-S
n alloy, Cu-Ti-Si alloy, Cu-Ti-Ni alloy, Cu-Cr alloy, Cu-Ti alloy).

However, due to difficulties in production, high-strength brass containing zinc, nickel silver, silzin bronze, and brass are
It does not fall into the category of the mentioned copper-based sintered alloy. Under a condition where the load is small, phosphor bronze, bronze, lead bronze, and the like can be applied as the copper-based sintered alloy. A copper-based sintered alloy to which iron is added is also applicable in some cases, but if it is not sufficiently alloyed and remains in the structure in the form of iron particles,
This part is not suitable because it becomes the starting point of adhesion with the partner material.

[0018] The sintered alloy responsible for the oil-impregnating performance, as for the alloy component system, in principle, when iron is the partner material,
Bearings in which iron constitutes the matrix material are susceptible to seizure, but are not particularly limited when the oil content is high (high porosity) because the strength is not sufficient and severe seizure does not occur. The same applies to resin-based cases.

In the case of the third layer containing a solid lubricant,
When the amount of the solid lubricant is large, there is no particular limitation, but the amount of the solid lubricant is small, for example, 1 to 5
In the range of%, when an iron-based material is used as a mating material, it is not preferable to use iron as a constituent element of the third layer.

As described above, after the sliding material is formed on the iron backing metal, the end face portion is cut into required dimensions according to specifications, and then processed into a bearing shape by round bending, and then the end face portions are joined. The inner and outer diameters are processed to finish the product. At this time, an intermediate material is provided between the sintered layer and the back metal to buffer the stress generated at the time of round bending in order to prevent the sintered layer located on the inner diameter side from peeling off from the back metal surface portion. It is also possible. In this case, the intermediate material is preferably mainly made of an iron material in order to improve the bonding performance with the backing metal. Particularly, when the load-bearing layer is a copper-based sintered material, copper-
Iron-based intermediate layer is good.

In this case, a sintering step for joining the intermediate material to the steel sheet surface is required. Finally, the bearing is completed by performing an oil impregnation process. A gelling agent may be added to the oil-containing oil depending on the conditions of use.

As one example including all of these elements, there is an intermediate layer made of iron-copper on the surface of a steel back metal, and a high-density load-bearing layer mainly composed of a copper-based sintered material. When,
A sliding plate material is manufactured in which an oil-impregnated layer made of a porous sintered material and a lubricating layer containing a solid lubricant are present in a form mixed in a sliding surface portion. After manufacturing in this way,
After cutting according to the specifications, round bending is performed, and after joining the end faces, the inner diameter side and the outer diameter side are machined to produce a bearing member.

Further, in order to prevent the movement of the oil-containing oil from the sliding surface due to gravity or the like during long-term use,
The lubrication interval was extended by adding a gelling agent to the oil-impregnated oil and causing it to gel in the oil-impregnated layer, melting by the heat generated on the sliding surface, and exerting the lubrication effect. A bearing member can be manufactured.

The oil impregnation treatment mentioned here is carried out as follows. That is, the oil used for the oil impregnation treatment is prepared by adding an appropriate amount of a gelling agent at room temperature in advance, heating the oil, vacuum impregnating the sintered member, and cooling to room temperature.
After cooling, the removed bearing member is used as a bearing member after removing the oil component from the surface portion.

As means for securing the oil content, an organic material (for example, wax or the like) which disappears during sintering is arranged in an arbitrary form on a smooth iron plate in advance, and the sintered material is sprayed and baked thereon. By tying, a low-density place can be set in a specific portion. At this time, by setting the sintering temperature low, excessive shrinkage can be suppressed.

Next, the following various methods can be mentioned as a method for producing the multilayer sintered sliding member according to the present invention.

The first production method comprises the following steps: (a) a first step of spraying a metal mixture forming an intermediate layer on the surface of a steel back metal having a smooth surface; A second step of sintering the obtained component, (c) a metal forming powder for forming a high-density low-oil-impregnated sintered alloy layer is formed on the surface of the component obtained in the second step by using a required forming mold. (D) a fourth step of sintering the composition obtained in the third step, and (e) a high density of protrusions on the surface of the composition obtained in the fourth step. The fifth step of rolling the material,
(F) spraying a metal mixture forming a low-density and high oil-impregnated sintered alloy layer on the surface of the component obtained in the fifth step;
6th step, (g) 7th step of sintering the composition obtained in the 6th step, (h) 8th step of rolling the low density material present on the surface of the composition obtained in the 7th step And (i) a ninth step of impregnating the composition obtained in the eighth step with oil.

In the second manufacturing method, (a) a metal mixed powder for forming a high-density low-oil-impregnated sintered alloy layer is formed on a surface portion of a steel back metal having a smooth surface by using a required forming mold. (B) a second step of sintering the composition obtained in the first step, and (c) a high density of protrusions on the surface of the composition obtained in the second step. To cover the material
In addition, these high-density materials are covered with a slit plate so that a new slit can be formed between the high-density materials, and a metal mixed powder that forms a low-density and high-oil-impregnated sintered alloy layer is provided on the surface side of the slit plate. A third step of spraying, (d) this third step
A fourth step of sintering the composition obtained in the step, (e) a fifth step of spraying an oil-containing resin material on the surface of the composition obtained in the fourth step, and rolling the surface; and f) A sixth step of impregnating the composition obtained in the fifth step with oil.

Further, the third manufacturing method comprises the steps of: (a) using a required mold to form a metal mixed powder for forming a high-density low-oil-impregnated sintered alloy layer on the surface of a steel back metal having a smooth surface; (B) a second step of sintering the composition obtained in the first step, and (c) a low-density, high-oil-impregnated bond to the surface of the composition obtained in the second step. A third step of spraying a metal mixed powder forming a gold layer, (d) a fourth step of sintering the composition obtained in the third step, and (e) a surface portion of the composition obtained in the fourth step And (f) a sixth step of impregnating the composition obtained in the fifth step with oil. In the third manufacturing method, it is preferable that sintering is performed again after the fifth step and rolling is performed after this sintering.

Further, the fourth manufacturing method is as follows: a) A metal mixed powder for forming a high-density low-oil-impregnated sintered alloy layer is formed on a surface portion of a steel back metal having a smooth surface by using a required forming mold. A first step of spraying, (b) a second step of sintering the component obtained in the first step, and (c) a high-density material existing in a protruding manner on the surface of the component obtained in the second step. (D) a fourth step of spraying a metal mixed powder for forming a low-density and high oil-impregnated sintered alloy layer on the surface of the structure obtained in the third step; A fifth step of sintering the composition obtained in the step, (f) a sixth step of rolling the surface of the composition obtained in the fifth step, and (g) re-forming the composition obtained in the sixth step. A seventh step of sintering and rolling after this sintering, and (h) impregnating the component obtained in the seventh step with oil It is characterized in further comprising an eighth step of.

In each of these manufacturing methods, after the final rolling step, the component obtained in the rolling step is formed into a cylindrical shape, the end faces are joined together, and the inner and outer diameter parts are machined. A step of forming the bearing may be provided, and the step of impregnating the bearing with oil may be provided after this step. In each of these manufacturing methods, it is preferable to use cardboard as the forming die. In some cases, a punching metal or the like can be used.

According to the present invention, the following effects can be obtained. To provide a material having seizure resistance, abrasion resistance and self-lubricating properties by arranging a sintered material and an oil-impregnated resin material having different compositions and structures on the surface of a flat steel sheet, and a gelled oil or fat. Can be. On the steel sheet surface part, a copper alloy layer of relatively high hardness with excellent seizure resistance and excellent load resistance is arranged so as to be continuously present in the sliding direction, and also excellent in lubrication By simultaneously arranging a porous iron-based and copper-based sintered material having oil-impregnating performance or an oil-impregnated resin material as a layer, a bearing member having self-lubricating properties can be manufactured. By incorporating a gelling agent into the oil to be impregnated, the viscosity of the oil impregnated during use of the bearing decreases, causing a dripping phenomenon due to gravity and shortening the life due to oil shortage. Problems can be avoided. In addition, it has a sliding layer composed of at least three types of materials: a load-bearing layer, a self-lubricating layer, and an oil-impregnated layer. A bearing material having durability and durability can be provided. With the above-described sliding bearing, a bearing for a working machine with an extended greasing interval can be manufactured.

[0033]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a multi-layer sintered sliding member according to the present invention.

(Example 1) FIG. 1 shows a manufacturing process of a multilayer sintered sliding bearing member according to Example 1. Hereinafter, each step will be sequentially described.

(Step 1) As shown in FIG.
A steel plate 1 having a flat surface is prepared and cut into a length of 300 mm. In the case of a polished steel plate, it can be used after degreasing as it is, but when an oxide film is formed, the oxide film is removed by polishing and then degreased. The thickness of the steel plate was selected to be 6 mm.

(Step 2) A metal mixed powder 2 for forming an intermediate layer is prepared. The metal mixed powder 2 has the following configuration in terms of size and weight ratio, and after weighing, mixed with a V-type mixer for 30 minutes. Reduced iron powder of 150 μm or less; 70% electrolytic copper powder of 100 μm or less; 25% atomized tin powder of 50 μm or less; 5%

(Step 3) As shown in FIG.
The metal mixed powder 2 corresponding to the intermediate layer mixed in the step 2 is evenly spread on the surface of the steel sheet 1 prepared in the step 1. The spray thickness is 2 mm.

(Step 4) As shown in FIG.
The sintering temperature of the steel sheet with the metal mixed powder 2 sprayed on the surface is set to 8
The sintering is performed by passing through a continuous sintering furnace 3 having a temperature of 50 ° C. to 900 ° C. and a holding time of 10 minutes to 30 minutes. Thus, joint sintering to the back metal (steel plate) is performed simultaneously with sintering of the mixed powder. As a result, the thickness of the sintered product after sintering is 7.5 m.
m.

(Step 5) Next, the materials for the high-density sintered body are mixed in a weight ratio as follows. Atomized copper powder having a size of 100 μm or less; 80% Atomized nickel powder having a size of 100 μm or less; 1
0% atomized tin powder with a size of 100 μm or less; 10%

(Step 6) As shown in FIG.
The metal powder 4 for the high-density sintered body mixed in the step 5 is
Spray on the surface of the sintered product manufactured in the above. This spraying is performed so that a large number of circles having a diameter of 10 mm are independently distributed over the intermediate layer. Specifically, for example, a resin plate 5 having a hole formed in a punched metal shape having a thickness of 3 mm is placed on the intermediate layer 2, and a metal powder 4 for high density is sprayed on the hole. The holes in this plate are
60 ° staggered, φ10, pitch 12.5, aperture ratio 6
2.5% was used. After spraying so that the height is uniform, scrape off. By this operation, height 3mm
This means that the high-density mixed powder 4 was sprayed.

(Step 7) As shown in FIG.
The plate on which the metal powder for high density has been sprayed in step 6 is sintered in the sintering furnace 3. The sintering temperature at this time is from 850 ° C to 900
° C, and the holding time was 10 minutes to 30 minutes. At the time of sintering, the resin inserted at the same time as sintering burned and did not exist on the sintered surface.

(Step 8) Removed from the sintering furnace (FIG. 1)
(Refer to FIG. 1F) Then, the high-density material which is present in a protruding state independently on the sintered surface is rolled by the rolling mill 6 (see FIG. 1G). This rolling process results in a total thickness of 9.5.
mm. As a result, the density of the high-density material is reliably improved, and the bonding with the intermediate layer is ensured.
In addition, the dimensional adjustment is performed in consideration of the next sintering.

(Step 9) Material is mixed with the material rolled in Step 8 in order to further spray a material for forming an oil-containing layer. At this time, the following materials were prepared by weight ratio. Electrolytic copper powder of 150 μm or less; 70% atomized tin powder of 150 μm or less; 5% reduced iron powder of 150 μm or less; 25%

(Step 10) As shown in FIG. 1 (h), the material 7 mixed in the step 9 is sprayed on the sintered plate manufactured in the step 8. Thereafter, as shown in FIG. 1 (i), the sintering plate that was sprayed was sintered in the sintering furnace 3. The temperature of the sintering furnace 3 at this time was 850 ° C. to 900 ° C., and the holding time was 10 minutes to 30 minutes. The spray thickness at this time was 2.5 mm, and the total thickness was 10 mm.

(Step 11) The material sintered in step 10 was rolled so as to have a thickness of 9.7 mm and a total rolled thickness of 8.5 mm (see FIG. 1 (j)).
Finally, 0.5mm from outer circumference, 0.5mm from inner circumference
We decided to leave a shaving allowance.

(Step 12) After cutting the sintered material rolled in step 11 to a required length, as shown in FIG.
A round bending process was performed so that the inner diameter was 80 mm and the outer diameter was 95 mm. Thereafter, as shown in FIG.
The end faces were joined, the inner diameter surface and the outer diameter portion were processed, and the bearing 8 was manufactured. Finally, a sliding bearing in which a copper-based high-density sintered layer and a copper-based low-density sintered layer having different components were mixed on the sliding surface was manufactured. further,
Finally, by immersing in heated oil and evacuating the atmosphere contained in the sintered body by evacuating the atmosphere,
The oil was impregnated by restoring pressure.

(Embodiment 2) FIG. 2 shows a manufacturing process of a multilayer sintered sliding bearing member according to Embodiment 2. Hereinafter, each step will be sequentially described.

(Step 1) As shown in FIG. 2A, a steel plate 11 having a flat surface and a thickness of 6 mm was prepared, and
Cut to 0 mm length. In the case of polished steel plate, use it without degreasing. If an oxide film exists on the surface, the oxide film is removed by polishing and then degreased.

(Step 2) Next, the material for the high-density sintered body and the material for the self-lubricating sintered material are mixed by a V-type mixer for 30 minutes so as to have the following weight ratio. (1) High-density sintered material 100% or less copper-10% tin-0.2% phosphorus atomized alloy powder; 98% 50% or less tin atomized powder; 2% (2) Sintered material having self-lubricating properties Electrolytic copper powder of 150 μm or less; 60% atomized nickel powder of 150 μm or less; 10% atomized tin powder of 150 μm or less; 10% artificial graphite particles of 200 μm or more and 500 μm or less; 20%

(Step 3) As shown in FIG.
The mixed powder 12 mixed in the step 2 is sprayed on the surface of the steel sheet 11 prepared in the step 1. The method of spraying is as follows: First, at an angle of 45 ° with respect to the longitudinal direction, 5 mm
A steel plate (first slit steel plate) 13 having a width of 5 mm and having a slit is placed on the steel plate 11 prepared in the step 1.
Next, the mixed powder 12 mixed in the step 2 is put into the cavity of the slit portion, and the surface portion is scraped off. In addition, the steel plate 13 having the slit groove is formed by applying graphite to the surface so as not to join the material during sintering. Alternatively, a material obtained by subjecting a ferritic stainless steel to a surface oxidation treatment may be used.

(Step 4) As shown in FIG.
The steel sheets combined in step 3 are sintered in a sintering furnace 14 controlled at 830 ° C to 860 ° C. At this time, the sintering furnace 14
May be any of a continuous type and a batch type, and the sintering time is set to a maximum temperature holding time of 10 minutes to 30 minutes.
Minutes is enough.

(Step 5) As shown in FIG.
After sintering, the slit plate is removed. At this time, the sintered body is contracted, and the slit steel plate 13 can be easily removed. By this operation, a number of slits running obliquely are formed on the steel plate. In addition, the width of the sintered body (convex portion) is 3 mm, and the slit interval is 7 mm.

(Step 6) A steel plate having a cavity so as to cover the projections on the steel plate manufactured up to the step 5 and further having a slit hole formed therein so that a new slit can be formed between the projections. (Second slit steel plate) 15 is prepared. This steel plate is placed on the steel plate manufactured in step 5, and the mixed powder 16 for a self-lubricating sintered body is sprayed through a slit (FIG. 2).
(E)). It is needless to say that the steel plate 15 used here is preferably a steel plate which has been coated with graphite to prevent sintering. The slit interval of the second slit steel plate 15 was 5 mm.

(Step 7) As shown in FIG.
The component assembled in step 6 is sintered in the sintering furnace 14 including the second slit steel plate 15 at a temperature of 850 ° C. to 900 ° C. The sintering holding time is 10 minutes to 30 minutes.

(Step 8) As shown in FIG. 2 (g), after sintering, the second slit steel plate 15 is removed. As a result, the first flat steel plate 11 is provided with a sintered body 17 for load resistance.
And a sintered body 18 containing a solid lubricant having self-lubricating properties
Are alternately arranged in the longitudinal direction. The load-bearing sintered body 17 had a width of 3 mm and a height of 3 mm, and the solid lubricant-containing sintered body 18 had a width of 4 mm and a height of 4 mm.

(Step 9) As shown in FIG. 2 (h), the steel sheet produced in the step 8
And rolling is performed by a rolling mill 20. As a result, since the surface has irregularities, the resin component is bonded to the sintered plate. The thickness after rolling was 8.3 mm.

(Step 10) Next, in order to further improve the bonding property of the sintered plate material coated with the resin component, a calcination treatment is performed in a heat retaining furnace.

(Step 11) Next, rolling is carried out by a rolling mill for adjusting the height of the sintered body. As a result, the thickness of the slide bearing material finally became 8.0 mm. Finally, the cutting allowance on the inner diameter side was 0.25 mm, and the cutting allowance on the outer diameter side was 0.25 mm. FIGS. 3A and 3B are a schematic diagram and a cross-sectional view of the bearing material thus manufactured, respectively.

(Step 12) After cutting the sintered material rolled in step 11 to a required length, a round bending process is performed so that the inner diameter is 80 mm and the outer diameter is 95 mm. After that, the end faces are joined, the inner diameter surface and the outer diameter surface are processed, and finally, the copper-based high-density sintered layer on the sliding surface and the copper-based self-lubricating material A sliding bearing in which three types of materials, that is, a lubricating layer and an oil-containing resin layer, were mixed was produced. Thereafter, the oil-impregnated low-density sintered body was subjected to an oil-impregnating treatment to complete a bearing material (see FIG. 2 (i)).

(Embodiment 3) FIG. 4 shows a manufacturing process of a multilayer sintered sliding bearing member according to Embodiment 3. Hereinafter, each step will be sequentially described.

(Step 1) As shown in FIG. 4A, a steel plate 21 having a flat surface and a thickness of 6 mm was prepared, and
Cut to 0 mm length. In the case of a polished steel sheet, it can be used after being degreased as it is, but if an oxide film is formed, the oxide film is removed by polishing and then degreased.

(Step 2) A material for a high-density sintered body and a material for a low-density sintered body are mixed by a V-type mixer for 30 minutes so as to have the following weight ratio. (1) Material for high-density sintered body: Ferromolybdenum powder of 100 μm or less; Ferroline powder of 70% 50 μm or less; Atomized tin powder of 2% 100 μm or less; Copper 8% phosphorus powder of 5% 50 μm or less; 2% 100 μm The following atomized copper powder; 20% silica powder of 50 μm or less; 1% (2) low-density and high oil-impregnated sintering material Reduced iron powder of 50 μm or less; 10% atomized tin powder of 150 μm or less; 10% activated carbon powder of 100% or less 5% diatomaceous earth powder of 100 μm or less; 2% micro-balloons of 50 μm or less; 3% of atomized copper powder of 100 μm or less; did.

(Step 3) As shown in FIG.
The mixed powder for sintering for low density mixed in the step 2 is sprayed on the surface of the steel plate 21 prepared in the step 1. How to spray
Using an auxiliary plate 22 in which a hole is formed in a cardboard with a punch, the auxiliary plate 22 is placed on the surface of a steel plate 21, and a sintering material powder 23 is sprayed on the auxiliary plate 22 and cut off. As a result, the steel plate 21
Above, the auxiliary plate 22 and the sintering material powder 23 are present in the holes formed in the auxiliary plate 22. The hole of this cardboard had a diameter of φ10, a staggered pattern of 60 ° with a pitch of 15, and an open ratio of 40%.

(Step 4) As shown in FIG.
The steel sheet combined in step 3 is sintered in the sintering furnace 24. At this time, since the cardboard shrinks during sintering, a graphite plate is placed as a weight. The sintering temperature at this time is 850 ° C. to 9
00 ° C., and the holding time is 10 minutes to 30 minutes.

(Step 5) Since carbonized cardboard and a sintered layer are present on the plate sintered in step 4, the carbonized cardboard is removed.

(Step 6) A sintered material for high density is further sintered and joined to the material after the primary sintering. In other words, a high-density sintered layer is formed by sintering around a low-density oil-impregnated layer existing as a projection on a steel plate. That is, FIG.
As shown in (e), the sintering alloy powder 25 for high density is evenly spread on the steel plate 21 manufactured in the step 5. The height of the projections was 2.8 mm, and the spraying height was such that the projections were slightly covered, that is, the overall height was 10 mm.

(Step 7) As shown in FIG. 4 (f), the steel sheet uniformly dispersed in the step 6 is secondarily sintered in the sintering furnace 24. The sintering temperature at this time is 850 ° C. to 900 ° C.
And the holding time was 10 minutes to 30 minutes.

(Step 8) As a result of the operations up to step 7, a bearing material in which a low-density oil-impregnated layer is present in an independent form on the surface of the steel sheet and is surrounded by a high-density sintered layer. Be produced. Since the high-density portion is sintered only once, the density is not sufficient. Therefore, rolling for physically improving the density is performed (see FIG. 4 (g)). By this rolling, the thickness after sintering is changed from 9.2 mm to 8.5 finally.
mm.

(Step 9) For the material whose density has been increased by rolling, tertiary sintering was performed in order to more reliably improve the strength. The sintering conditions at this time are as follows:
C. to 900 ° C., and the sintering retention time is 10 minutes to 30 minutes.

(Step 10) After sintering, rolling was carried out in order to adjust the thickness and improve the strength of the load-bearing layer by work hardening. The thickness after sintering expanded to 8.7 mm, and was rolled again to 8.5 mm. In this way, a final allowance of 0.5 mm for the inner periphery and 0.5 mm for the outer periphery was obtained. FIGS. 5 (a) and 5 (b) show a schematic diagram and a sectional view of the bearing material thus manufactured, respectively.

(Step 11) As shown in FIG. 4 (h), the sintered plate after the final rolling is cut to a required length.
A round bending process is performed so that the inner diameter becomes 80 mm and the outer diameter becomes 95 mm. Thereafter, the end faces were joined, the inner diameter surface and the outer diameter surface were processed, and a bearing was manufactured. By the inner diameter surface processing, a bearing having a sliding surface in which an independent copper-based oil-impregnated sintered alloy and a continuous iron-based high-density sintered alloy layer were mixed was manufactured. Thereafter, the oil-impregnated sintered alloy layer portion was subjected to oil-impregnating treatment by a vacuum device to complete the bearing.

(Embodiment 4) Next, the manufacturing process of the multilayer sintered sliding bearing member according to Embodiment 4 will be described.

(Step 1) A steel plate having a flat surface is prepared.
Cut to a length of 00 mm. In the case of a polished steel sheet, it can be used after degreasing as it is, but when an oxide film is formed on the surface by performing a surface treatment, the surface layer is removed by polishing and then degreased. The steel plate thickness was 6 mm.

(Step 2) The material for the high-density sintered body and the material for the oil-containing sintered body were mixed for 30 minutes using a V-type mixer. The composition is as follows by weight ratio. (1) Atomized copper powder having a size of 100 μm or less for high-density sintered bodies; 80% NiB powder having a size of 100 μm or less; 10% NiP powder having a size of 100 μm or less; 5% atomized tin powder having a size of 100 μm or less; % (2) Reduced iron powder having a size of 100 μm or less for oil impregnation; 75% Artificial graphite powder having a size of 150 μm or less; 15% Atomized bronze powder having a size of 100 μm or less; 10%

(Step 3) The mixed powder for high density mixed in the step 2 was sprayed on the steel plate prepared in the step 1 so that a large number of circles having a diameter of 15 mm were independently distributed. Specifically, for example, a steel plate in which holes of φ10 are punched in a staggered shape at a pitch of 12.5 in a 60 ° zigzag shape in a punching metal shape having a thickness of 3 mm is placed on the above-mentioned steel plate, and the mixed powder is sprayed into the hole. Furthermore, it is scraped off so that the height becomes uniform. Here, the aperture ratio of the punched metal plate was 62.5%. By this operation, the high-density mixed powder having a height of 4.5 mm was uniformly dispersed and dispersed on the back metal surface.

(Step 4) Next, a sintering process is performed in a sintering furnace on the set of steel sheets combined in Step 3. The sintering conditions at this time are 850 ° C. to 900 ° C. as the sintering temperature,
The holding time is between 10 minutes and 30 minutes.

(Step 5) After sintering, the set punching metal was removed. The convex portion formed on the surface of the back metal has a cylindrical shape of φ9, and has a height of about 9.6 mm.
Met. The high-density material that is present in a protruding state independently on the sintering surface is rolled and densified by a rolling mill. With this process,
The high-density material surely improves the density, and also improves the bondability with the steel plate serving as the backing metal. As a result of the rolling process, the thickness is 8.
5 mm was reached. In addition, the convex cylindrical part has an average diameter of φ1
Had changed to 1. As a result, the area ratio of the entire convex portion is 72.
% Has been reached. Thus, by rolling performed after sintering,
The feature of this method is that the area ratio of the entire convex portion can be controlled by increasing the diameter of the convex portion forming body.

(Step 6) The mixed powder for oil impregnation is further sprayed on the sintered plate produced in step 5. The spray height is 9.
At 0 mm, the protrusion after the rolling process was hidden.

(Step 7) The sintered plate on which the mixed powder for oil impregnation was sprayed in step 6 was held in a sintering furnace controlled at a temperature of 850 ° C. to 900 ° C. for 10 minutes to 30 minutes to perform sintering. . The sintering furnace may be either a reducing gas atmosphere furnace or a vacuum atmosphere furnace.

(Step 8) The thickness of the material after sintering is 8.8 m.
m, which was rolled to 8.5 mm.

(Step 9) The sintered material after rolling is sintered again. By this treatment, a liquid phase is partially formed in the sintered layer, thereby improving the bondability with the steel sheet and improving the structure of the consolidated layer. The total thickness after sintering was changed to 8.6 mm.

(Step 10) After sintering, final rolling for dimensional adjustment is performed. As a result of rolling, the overall dimensions are 8.5m
m.

(Step 11) The sintered material produced in step 7 was cut to a required length, and round-bent so as to have a diameter of 80 × 95. The end faces are joined, and the inner diameter side and the outer diameter side are processed. 0.5 mm for both the inner and outer diameter sides
The shaving allowance.

(Step 12) Finally, an oil component to be supplied to the inner diameter side is prepared. An engine oil # 30 is prepared, and a gelling agent (for example, Ajinomoto; GPI) is prepared. This was added to oil at 1% and heated to 100 ° C. Thereafter, graphite powder having an average particle size of 5 μm was added and mixed well in order to improve the load resistance of the oil. The bearing member was immersed in the oil thus obtained, and the atmosphere was evacuated to impregnate the oil.

(Step 13) The oil adhering to the surface was removed from the bearing taken out of the oil impregnating device to produce a bearing.
On the other hand, by using a highly viscous grease, it can be used as a substitute for gelling oil.

(Example 5) A sliding test was performed on the bearing members manufactured as described above. The test conditions are shown below.

(1) Configuration of Testing Machine In this test, as shown in FIG.
The bearing member 31 is slid at a specific swing angle by the electric motor 33 while applying a load with the hydraulic cylinder 32 from above. A thermometer is attached to the rear of the bearing material to measure the temperature change during sliding. The control is a load amount, a swing angle, and the number of swings. The evaluation is the amount of wear after a specific number of swings, the variation and value of the friction coefficient, and the presence or absence of abnormal noise.

(2) Test conditions i) "Performance evaluation" Test specimen material type; Example 1 material Example 2 material Example 3 material Example 4 material Comparative material (high-strength brass material) Conventional material (iron-based; (Inner surface induction hardened material) ・ Lubrication: Apply grease to the inner surface of the bearing and conduct a sliding test. After that, grease will not be supplied in principle. In the case of the material of Example 4, grease is applied to the metal sliding portion. Load: The load was gradually reduced to the surface pressure with the apparent projected area of the bearing material as the reference area. Surface pressure is 10MPa, 20MPa
a, 30MPa, 40MPa, 50MPa, 60MP
a, 70MPa, 80MPa, 90MPa, 100MP
As a, the number of swings is 2,000 times at each surface pressure, and when there is no abnormality in the friction coefficient, a sliding test is performed with a larger load (the final test is completed at 100 MPa).・ Number of swings: 2000 times for each surface pressure.・ Swinging speed: 11 times / minute ・ Evaluation: Abnormality of friction coefficient and occurrence of abnormal noise were judged as burn-in. The immediately preceding surface pressure is the maximum allowable surface pressure. ii) "Durability evaluation" Load: 30 MPa Number of swings: Last 100,000 times Lubrication: Initial grease only Table 1 shows the test results performed under these test methods and test conditions.

[0089]

[Table 1]

From these test results, it can be said that the bearing materials shown in the examples have excellent characteristics in terms of abnormal friction coefficient and generation of abnormal noise. In the conventional material, a remarkable change in the coefficient of friction was observed at 30 MPa. When the test was interrupted and the sliding surface was observed, the sliding surface was rough, and the shaft and the bearing part were partially adhered to the sliding part. The situation was observed. In the case of the high-strength brass material, the bearing member vibrated at a surface pressure of 50 MPa, and abnormal noise began to be generated. The coefficient of friction was in a state of rising and falling periodically, with a large fluctuation.

From these test results, it was clarified that the conventional material and the high-strength brass material did not have sufficient load-bearing capacity. Therefore, in the same testing machine, the surface pressure was fixed at 30 MPa, the number of swings was increased, and a change in the amount of wear at that time was investigated. The result is
It is shown in Table 2.

[0092]

[Table 2]

From these results, all bearing materials tend to have a large amount of wear until the number of oscillations of 10000, at which initial wear is observed, and thereafter shift to the steady wear region. Of these, the high-strength brass material is greased every time the wear amount is measured. Among these materials, in Examples 1, 2 and 3, the oil impregnated leaked out from the end portion of the bearing material.

The coefficient of friction during the test was as in Examples 1, 2,
In each of 3 and 4, the value was in the range of 0.04 to 0.06, and the temperature of the bearing material was also 40 ° C to 50 ° C. On the other hand, in the case of a high-strength brass material, the friction coefficient is 0.1 to
0.12, the temperature of the bearing material is 110 ° C ~ 1
Heat was generated up to about 20 ° C.

When the sliding surface was observed after the test,
In all of Examples 1, 2, 3, and 4, there was no trace of the sliding surface being rough. On the other hand, in the case of high-strength brass material, it changes color to copper,
The inside was rough.

In the case of Examples 1, 2, 3 and 4, the shaft was discolored slightly blackish, but the sliding surface had rather improved surface roughness (3S changed to about 1S). On the other hand, in the case of the high-strength brass material, the copper alloy material was transferred to the shaft surface, and its color was a dark copper color.

[0097] From the above results, it was clarified that, in each case, the abrasion resistance of the working material was remarkably superior to that of the high-strength brass material. In particular, when the gelling agent is added to the oil-containing oil, the necessary amount dissolves due to the heat generated during sliding, and the friction coefficient is reduced to suppress heat generation. This indicates that there is a possibility that the oil-impregnating performance can be maintained over a period of time.

(Example 6) In this example, the content of a phosphide or a boride contained in a high-density low-oil-impregnated sintered alloy layer as a member for improving strength and abrasion resistance was investigated. .

(Step 1) A steel plate having a flat surface is prepared.
It was cut to a length of 00 mm. In the case of a polished steel plate, it can be used after degreasing as it is, but when an oxide film is formed on the surface by performing a surface treatment, a degreasing treatment is performed after removing a surface layer by polishing. The thickness of the steel plate is 6m
m.

(Step 2) The materials for the high-density sintered body were mixed with a V-type mixer to the following level. The mixed powder was sprayed on a steel plate by 5 mm, and sintering was performed. The sintering atmosphere was vacuum and the sintering temperature was 850 ° C. Next, the sintered body after the primary sintering was rolled until the thickness of the sintered layer became 2 mm, and the secondary sintering was further performed. The sintering conditions at that time are the same as in the primary sintering. The back metal portion of the sintered body thus obtained was removed by machining, processed into a tensile test piece, and the tensile strength was measured. The test results are shown in Table 3.

[0101]

[Table 3]

A high-density material portion that requires load-bearing capacity requires hardness and strength. Particularly in a sliding condition in which a shear force acts, the strength factor is a necessary requirement for improving the wear resistance. As is clear from the above test results, from the viewpoint of hardness, particularly strength, when the total weight of phosphide and boride is 5% or less,
It can be seen that the strength is high (290 MPa or more). Therefore, it is preferable that the total addition amount of both is 5% at the maximum.

[Brief description of the drawings]

FIG. 1 is a manufacturing process diagram of Example 1.

FIG. 2 is a manufacturing process diagram of Example 2.

FIGS. 3A and 3B are a schematic view (a) and a cross-sectional view (b) of a bearing material manufactured in Example 2. FIG.

FIG. 4 is a manufacturing process diagram of the third embodiment.

FIGS. 5A and 5B are a schematic view (a) and a cross-sectional view (b) of a bearing material manufactured in Example 3. FIG.

FIG. 6 is a configuration diagram of a test machine for a sliding test.

[Explanation of symbols]

 1, 11, 21 Steel plate 2, 4, 7, 12, 16 Metal mixed powder 3, 14 Sintering furnace 5 Resin plate 6, 20 Rolling mill 8 Bearing 13 First slit steel plate 15 Second slit steel plate 17, 18 Sintered body 19 resin 22 auxiliary plate

Claims (25)

[Claims] 1. A multilayer sintered sliding member comprising a steel back metal having a smooth surface and at least two types of sintered alloy layers joined to the surface of the back metal and having different structures and components from each other. Wherein at least one of the sintered alloy layers is distributed so as to be independently exposed to the sliding direction on the sliding surface while being mixed with other sintered alloy layers. A multilayer sintered sliding member characterized in that: 2. The multi-layer sintered sliding member according to claim 1, wherein a resin material having lubricating properties is further provided on a surface portion of the back metal. 3. The multi-layer sintered sliding member according to claim 1, wherein the porosity of the at least two types of sintered alloy layers in the structure is 10% to 50% as a whole. 4. At least one of the at least two types of sintered alloy layers is a high-density low-oil-impregnated sintered alloy layer, and at least one other is a low-density high-oil-impregnated sintered alloy layer. 4. The multilayer sintered sliding member according to any one of 1, 2, and 3. 5. The high-density low-oil-impregnated sintered alloy layer has a plurality of portions having a length of at least 3 mm to 20 mm in a sliding direction and a circular, elliptical or band-like surface shape of a sliding surface,
The multi-layer sintered sliding member according to claim 4, wherein any one of the portions is disposed so as to be always located in the sliding direction. 6. The multilayer sintered sliding member according to claim 4, wherein an area ratio of the high-density low-oil-impregnated sintered alloy layer to the entire sliding surface is 30% to 60%. 7. The multi-layer sintered sliding member according to claim 4, wherein the porosity of the low-density high-oil-impregnated sintered alloy layer is adjusted to 20% to 70%. 8. The multi-layer sintered sliding member according to claim 4, wherein the porosity of the high-density low-oil-impregnated sintered alloy layer is adjusted to 10% or less. 9. The low-density and high-oil-impregnated sintered alloy layer contains at least one solid lubricant such as graphite and molybdenum disulfide.
The multilayer sintered sliding member according to any one of claims 4 to 8, wherein the seed is contained in an amount of 1% to 20%. 10. The high-density low-oil-impregnated sintered alloy layer contains at least one of a phosphide, a boride and an oxide in an amount of 1% or more.
The multilayer sintered sliding member according to any one of claims 4 to 9, which contains 5%. 11. The low-density and high-oil-impregnated sintered alloy layer includes vermiculite, foam glass, activated carbon, diatomaceous earth, charcoal,
5. The composition according to claim 4, wherein at least one of the porous forming members such as bone powder, coral powder, wood powder and wax is contained in an amount of 1% to 10%.
The multilayer sintered sliding member according to any one of claims 10 to 10. 12. The multilayer sintered sliding member according to claim 4, wherein the high-density low-oil-impregnated sintered alloy layer is a copper-based sintered alloy layer. 13. A steel back metal having a smooth surface, an iron-copper alloy-based sintered layer mainly composed of iron formed on the surface of the back metal, and an iron-copper alloy-based sintered layer A multi-layer sintered sliding member comprising at least two types of sintered alloy layers having different structures and components formed on the upper surface of the sintered alloy layer, wherein at least one type of sintered alloy layer among these sintered alloy layers Are distributed so as to be exposed independently of the sliding direction in the sliding surface in a state of being mixed with other sintered alloy layers on the sliding surface. 14. At least one of the at least two types of sintered alloy layers is a high-density low-oil-impregnated sintered alloy layer, and at least one other is a low-density high-oil-impregnated sintered alloy layer. The high-density low-oil-impregnated sintered alloy layer has a length of at least 3 mm to 20 mm in the sliding direction, and has a large number of circular, elliptical, or band-shaped surface portions on the sliding surface, and any one of those portions. 14. The multilayer sintered sliding member according to claim 13, wherein the portion is arranged so as to be always located in the sliding direction. 15. The multi-layer sintered sliding member according to claim 14, wherein the low-density high-oil-impregnated sintered alloy layer contains oil containing a gelling agent. 16. The oil after addition of the gelling agent contains at least one solid lubricant such as lead, graphite, molybdenum disulfide and the like.
The multi-layer sintered sliding member according to claim 15, wherein the seed is contained at 2% to 10%. 17. A multilayer sintered sliding member comprising a steel back metal having a smooth surface, and at least two types of sintered alloy layers joined to the surface of the back metal and having different structures and components from each other. Is cut into a predetermined length, and the front and back sides are machined to form a flat sliding member. 18. A multilayer sintered sliding member comprising a steel back metal having a smooth surface, and at least two types of sintered alloy layers joined to the surface of the back metal and having different structures and components from each other. Is cut into a predetermined length, processed into a bearing shape by round bending, the end faces are joined, and the inner and outer diameters are machined to form a cylindrical bearing. Knot sliding member. (A) a first step of spraying a metal mixture forming an intermediate layer on a surface portion of a steel back metal having a smooth surface, and (b) firing the component obtained in the first step. A second step of bonding, (c) a third step of spraying a metal mixed powder for forming a high-density low-oil-impregnated sintered alloy layer on the surface of the component obtained in the second step using a required forming mold. (D) a fourth step of sintering the composition obtained in the third step, (e)
A fifth step of rolling a high-density material existing in a protruding manner on the surface of the component obtained in the fourth step; (f) applying a low-density high-oil-impregnated A sixth step of spraying the metal mixture forming the bonding gold layer, (g) a seventh step of sintering the composition obtained in the sixth step, (h)
An eighth step of rolling the low-density material present on the surface of the component obtained in the seventh step and (i) a ninth step of impregnating the component obtained in the eighth step with oil. A method for producing a multilayer sintered sliding member. 20. (a) a first step of spraying a metal mixed powder for forming a high-density low-oil-impregnated sintered alloy layer on a surface portion of a steel back metal having a smooth surface using a required forming mold; (B)
A second step of sintering the composition obtained in the first step,
(C) These high-density materials are formed so as to cover the high-density materials existing in the form of protrusions on the surface of the component obtained in the second step, and to form new slits between the high-density materials. A third step of covering with a slit plate and spraying a metal mixed powder for forming a low-density and high oil-impregnated sintered alloy layer on the surface side of the slit plate; and (d) sintering the composition obtained in the third step. A fourth step of (e) spraying an oil-containing resin material on the surface of the component obtained in the fourth step and rolling the surface; and (f) a fifth step of (f) obtained in the fifth step. A method for manufacturing a multilayer sintered sliding member, comprising: a sixth step of impregnating a component with oil. 21. (a) a first step of spraying a metal mixed powder for forming a high-density low-oil-impregnated sintered alloy layer on a surface portion of a steel back metal having a smooth surface using a required forming mold; (B)
A second step of sintering the composition obtained in the first step,
(C) a third step of spraying a metal mixed powder forming a low-density and high oil-impregnated sintered alloy layer on the surface of the composition obtained in the second step, and (d) a composition obtained in the third step. A fourth step of sintering, (e) a fifth step of rolling a high-density portion present on the surface of the composition obtained in the fourth step, and (f) an oil in the composition obtained in the fifth step. A method for producing a multilayer sintered sliding member, comprising: a sixth step of impregnating the sliding member. 22. The method according to claim 21, wherein sintering is performed again after the fifth step, and rolling is performed after the sintering. 23) a) a first step of spraying a metal mixed powder for forming a high-density low-oil-impregnated sintered alloy layer on a surface portion of a steel back metal having a smooth surface by using a required forming die; b) a second step of sintering the composition obtained in the first step;
(C) a third step of rolling a high-density material existing in a protruding manner on the surface of the structure obtained in the second step, and (d) a low-density high surface on the surface of the structure obtained in the third step. A fourth step of spraying a metal mixed powder forming an oil-impregnated sintered alloy layer, (e)
A fifth step of sintering the composition obtained in the fourth step,
(F) a sixth step of rolling the surface of the component obtained in the fifth step, and (g) a second step of re-sintering the component obtained in the sixth step and rolling after the sintering. 7. A method for producing a multilayer sintered sliding member, comprising: a seventh step and (h) an eighth step of impregnating the component obtained in the seventh step with oil. 24. After the final rolling step, the component obtained in the rolling step is formed into a cylindrical shape, the end faces are joined to each other, and the inner diameter part and the outer diameter part are machined to form a bearing. The method for manufacturing a multilayer sintered sliding member according to any one of claims 19 to 23, further comprising a step, wherein the step of impregnating the bearing with oil is provided after the step. 25. The method according to claim 19, wherein the forming die is cardboard.
24. The method for producing a multilayer sintered sliding member according to any one of 24.