JP3454650B2 - Sliding bearing material and its manufacturing method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slide bearing material and a method for producing the same, and more particularly to a lead bronze alloy or a copper alloy sintered material containing a bronze alloy as a main component so as to have a hard-soft mixed structure. The present invention relates to a plain bearing material adhered to a backing made of steel and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, there are two major requirements for copper bearing materials. That is, 1. High load capacity, excellent wear resistance, or seizure resistance. 2. Excellent sliding characteristics (low friction coefficient). Is.

The following measures have been taken to meet such requirements. The above 1. Regarding the above item, as a material measure, there is a method of improving the hardness of the material itself. For such a technique, for example, "Sliding characteristics of a lead bronze bearing to which a hard material is added" (Tribology Conference Proceedings (Nagoya) 1993-11, p639-64)
2) or “Powder and powder metallurgy” (40.8.199)
3, p780) and the like. In this case, a method of performing working and hardening in a manufacturing process, a method of improving density to prevent a decrease in hardness due to the presence of pores, and the like are implemented.

Further, a method of protecting the bearing material itself from a mating material that is in sliding contact is adopted by a method in which hard particles are dispersed in the tissue without changing the material itself. Regarding such a technique, for example, as disclosed in JP-A-5-279772, a hard Ni-B compound is dispersed in a brass alloy to improve wear resistance, or Japanese Patent Publication No. 7-2980. As disclosed in Japanese Patent Laid-Open Publication No. 20-34, the Al alloy has a Vickers hardness of 20.
Some disperse zero or more metal nitrides, metal carbides, metal phosphides and metal borides.

Next, the above 2. In order to improve the conformability, a soft metal layer such as lead or indium is coated on the surface of the sliding layer by plating or the like, as disclosed in JP-A-4-180599. Alternatively, as disclosed in JP-A-7-90551, there is one in which an overlay layer containing a soft alloy is formed in order to improve wear resistance and seizure resistance. This overlay reduces the frictional resistance generated by the metal contact of the protrusions on the metal surface portion at the beginning of sliding due to the low shearing force of the soft metal, and makes it easier to maintain the fluid lubrication by eliminating the protrusion portion due to plastic flow. To increase the service life.

In addition to the overlay, as a means for improving the conformability, it is conceivable that the sliding layer is impregnated with oil as disclosed in JP-A-3-89022. In addition, as another idea, JP-A-3-232 discloses a means for improving the load bearing capacity by containing oil.
As disclosed in Japanese Laid-Open Patent Publication No. 905, an iron plate having a plurality of independent projections or depressions is used, powder of a copper-based alloy sintering is sprinkled, sintered and rolled to perform low-density high-oil content firing. Forming a bonding gold layer and a high-density low-oil content sintered alloy layer,
A multilayer sintered sliding material has been proposed which can be used even under a condition where an impact load is applied.

[0007]

However, in order to obtain a bearing material, such as a bearing bush, which requires round bending, the following drawbacks have become clear. That is, 1. Since the material used for the overlay and the copper-based sliding material are separate material systems, two types of materials must be managed, which complicates the work process and increases the production cost. Further, the life is determined by the disappearance of the material used for the overlay, and the life generally tends to be short. 2. The above-mentioned material system can exert its sliding characteristics to some extent under the condition that lubricating oil exists, but in the boundary lubrication region,
In particular, seizure resistance is poor, and sufficient sliding characteristics cannot be obtained. 3. In the case of forming a dense and dense sintered layer by using a steel sheet with a convex portion, no measures are taken to accelerate the improvement of joining with the steel sheet.Therefore, when the round bending process is taken, the sintered layer peels from the steel sheet. Phenomenon occurs. 4. Further, in order to form a specific convex portion or concave portion on the surface of the steel sheet, a special production process is required at the time of manufacturing the steel sheet, resulting in high cost. In addition, there is a defect that some of the uneven shapes are difficult to manufacture and lack flexibility in manufacturing. 5. Furthermore, the material composition is basically the same for the sliding surface, although there is a difference in density. Depending on the operating conditions, the load resistance and sliding characteristics may not be sufficient due to the characteristics of the material. There is a case. 6. Sliding with fatigue such that load is applied cyclically
Under certain conditions, the type of sliding that contains solid lubricant inside
For moving materials, cracks develop around the solid lubricant and
Due to the frictional resistance of the product, it quickly exfoliates and wear is abnormally large.
Become The so-called life depends on the fatigue life of the sintered material.
It will be rate-limited. Finally, the convex part of the steel plate is the surface
The face appears on the part, the iron-based materials come into contact with each other, and seizure occurs.
It causes a problem that it will occur. Therefore, this kind of material
It is difficult to improve the life of the material due to its structural characteristics.

The present invention solves the above-mentioned problems and is excellent in conformability with a simple structure, and is excellent in wear resistance, load resistance and seizure resistance, and even under boundary lubrication conditions. It is an object of the present invention to provide a sufficiently usable sliding bearing material and a manufacturing method thereof that can be provided at low cost.

[0009]

To achieve these objects, the plain bearing material according to the present invention has a flat surface.
Of the steel backing and a copper-based alloy sintered layer bonded to the surface of the backing , the copper-based alloy sintered layer being a copper-based alloy sintered material excellent in load bearing performance. The mountains and the valleys
They are distributed in an alternating manner and in this distribution gap
Sintered copper alloy with excellent sliding characteristics is distributed and sintered
・ Rolled, high-density and low-density phases intersect
It is characterized in that they are distributed and formed on each other .

[0010] In the prior SL bearing material, the copper-based alloy sintered layer, is preferably one made by one selected from the group consisting of copper-lead alloy and lead bronze alloy and bronze alloy.

Further, by adding a solid lubricant such as graphite or molybdenum disulfide to the low density phase in the copper alloy layer, the lubricity can be reasonably maintained. In addition, sliding properties can be reasonably maintained by allowing oil to be impregnated in the low-density phase of the copper-based alloy sintered layer.

According to the present invention, in order to obtain the above-mentioned plain bearing material, a kind of copper-based alloy sintered powder material is provided on the surface of a steel backing metal having a flat surface such that peaks and valleys alternate. After distribution , after sintering, a copper-based alloy sintered powder material having characteristics different from those of the copper-based alloy sintered powder material is covered on the sintered body of the former copper-based alloy sintered powder material, Alternatively, spray to the same height, add the sintering operation again, and then roll to obtain a high-density phase and a low-density phase, or a phase with a different composition, in the copper-based alloy sintered layer. The manufacturing method is characterized in that the distribution is formed alternately .

In the above-mentioned manufacturing method, when the copper-based alloy sintered layer is formed on the surface of the steel backing metal, first, the copper-based alloy sintered material having excellent load-carrying performance is alternated between peaks and valleys.
And then sinter and then sinter the copper-based alloy sintered material, which has excellent sliding characteristics, into the gap between the sintered copper-based alloy sintered materials and sinter again. Try to do the operation. The above-mentioned copper-based alloy sintered material having an excellent load-bearing performance and the copper-based alloy sintered material having an excellent sliding property may be sintered in reverse order.

Further, in the above manufacturing method, when the copper-based alloy sintered layer is formed on the surface of the back metal, the surface of the steel back metal is formed.
On the copper-based alloy sintered material layer that has been sintered in a pattern in which peaks and valleys alternate , spread so as to cover it with the copper-based alloy sintered material in the next step, or make it the same height. spraying to, as well as to enhance the bonding strength of both sintered material by controlling the sintering temperature, sintering layer and the high density part and a low density portion mountains
A sliding bearing material having excellent load resistance and seizure resistance can be obtained by forming a pattern in which ridges and valleys alternate and performing an oil impregnation treatment. Further, when the sliding condition is accompanied by a cyclic load change, in the above-mentioned manufacturing method, a copper-based alloy sintered material which is sprinkled so as to cover the copper-based alloy sintered material excellent in load resistance is used. The binder is removed by machining in the final finishing step, and the sliding surface has a structure in which a copper-based sliding material excellent in load resistance and a copper-based sliding material excellent in sliding characteristics are mixed. At this time, it is preferable that the load-bearing copper-based alloy sintered material does not contain iron, which easily causes adhesion with the iron material. As a result, the sliding copper-based alloy sliding material having inferior fatigue strength is removed, and a material having a sufficient life against cyclic load fluctuations can be provided. When the sliding material is sprinkled at the same height as the load bearing layer, the rolling step is followed by machining in consideration of shrinkage during the subsequent sintering. In this case, it can be manufactured without processing.

Peaks and valleys on the back metal of the copper-based alloy sintered material
It is preferable that the spraying such that and are alternated is performed so that the high density portion is not continuous in the sliding direction as the product bearing. This spraying position exists independently, and wavy unevenness may be formed. Further, in order to independently spray and sinter the copper-based alloy sintered material, a sintering auxiliary plate having a large number of holes formed at a required interval distribution is used. It is used by applying a release agent of a copper alloy sintered material, and after sintering, this sintering auxiliary plate is removed and reused. By doing so, a convex portion having a shape corresponding to the shape of the hole provided in the sintering auxiliary plate can be formed, and since the sintering auxiliary plate can be repeatedly used, workability and economy are improved. The sintering auxiliary plate does not necessarily have to retain its shape after sintering, and for example, paper or resin may be used. In that case,
Since the convex portions are formed by simple cleaning after sintering, it can be said that this method is excellent in terms of workability.

[0016]

As described above, the sliding bearing material of the present invention can be formed by mixing the high density portion and the low density portion of the sintered material on the sliding surface, and the distribution thereof can be set arbitrarily. As a certain sliding bearing, a material that satisfies the conventionally demanded high load resistance, excellent wear resistance or seizure resistance, and excellent sliding characteristics (low friction coefficient) can be easily provided.

Further, in the manufacture of the sliding bearing material of the present invention, the required different sintered materials are classified into ridges and valleys.
Through the extremely simple processing process of joining to the back metal with the geometrical spraying means for spraying alternately and the complementary spraying means, the high density part and the low density part can be distributed in any desired manner on the sliding surface. It has become possible to economically obtain a product that can be formed by sintering and that satisfies the requirements as a sliding bearing.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Next, a general outline of manufacturing the sliding bearing material according to the present invention will be described with reference to the drawings.

[Example 1 (see FIGS. 1 and 2)] (First Step) As a back metal, a flat steel plate whose surface is degreased and washed is prepared. (Second step) By weight ratio, a uniform mixed powder of 10% tin, 10% lead and the balance copper or alloy powder is prepared.

(Third step) The mixed powder (alloy powder) 3 prepared in the second step is rubbed on the surface of the backing metal 1 using a rubbed plate 2 having a corrugated rubbed surface, and peaks and valleys alternate. To be present in. At this time, when the mountain portion is made into a bush by round bending as a product, it is sprayed so as not to continuously exist in the sliding direction. That is, a shape in which the direction of the mountain crosses diagonally with respect to the sliding direction,
Alternatively, spray it vertically (see FIGS. 1 and 2).
(See (a)). Regarding the method of forming the peaks and valleys, the mixed powder may be uniformly sprayed, and then a roller having a groove shape may be pressed against the mixed powder spraying surface to roll.

(Fourth step) The backing metal 1 on which the mixed powder 3 is scattered on the surface in a geometric pattern is adjusted to a reducing atmosphere and the temperature is controlled from 850 ° C. to 900 ° C. in a sintering furnace 4. Then, it is held for 30 to 60 minutes to sinter the mixed powder 3 and sinter and bond it to the backing 1 (see FIG. 2B).

(Fifth Step) On the backing metal 1 in which the sintered alloy layer 3a is integrated in the previous step, the mixed powder 3 is further smoothed by a scraping plate 2'so that the valleys are filled and become uniform. And spray (see FIG. 2 (c)).

(Sixth step) The mixed powder 3 uniformly dispersed
Adjust the backing metal 1 filled with the
In the sintering furnace 4 controlled from 50 ° C to 900 ° C, 30 to 6
Hold for 0 minutes to sinter the mixed powder and sinter-bond to the back metal (see FIG. 2 (d)).

(Seventh step) In the previous step, the sintered alloy layers 3a and 3a
The back metal 1 in which b is integrated is applied to the rolling roller 5 to increase the density of the joined sintered alloy layer A (see FIG. 2 (e)).

(Eighth step) The backing metal 1 for improving the density of the sintered alloy layer A is placed in the sintering furnace 4, and the temperature is 850 ° C.
To 900 ° C. and hold for 30 to 60 minutes to improve the bonding force between the sintered alloy layers 3 a and 3 b and the bonding force to the backing metal 1. After that, the density of the sintered alloy layer A is further increased through the rolling roller 5 and the wear resistance is improved by work hardening by plastic working.

(Ninth Step) The material formed as described above is round-bent so that the sintered alloy layer A is arranged on the inner side, and both ends to be joined are joined together to obtain a required size. The outer circumference and the inner circumference are machined so as to satisfy the above condition, and thus a plain bearing 10 having both hard and soft phases without peeling and excellent in wear resistance is obtained (FIG. 2 (f)).

Next, a manufacturing method by a method of using a sintering auxiliary material and two kinds of copper alloy sintered materials for forming a sintered alloy layer will be described. [Example 2 (see FIGS. 3 to 6)] (First Step) As the backing metal 1, a steel sheet whose surface has been washed is prepared. Its size shall correspond to the size of the bearing to be manufactured. (Second step) Two kinds of copper-based alloy powder are prepared. For example, the first type; as the copper-based alloy sintered sliding material a, by weight ratio, tin 5 to 15%, iron 5 to 20%, graphite 1 to 3%,
A uniform mixed powder consisting of 1 to 3% silica and the balance copper is prepared. Second type; as the copper alloy sintered sliding material b,
By weight, tin 5-20%, graphite 5-20%, silica 1-
A uniform mixed powder consisting of 3% and the balance copper is prepared.

(Third step) A sintering auxiliary plate 6 coated with a sintering joining inhibitor is set on the surface of the backing metal 1 (see FIG. 3 (a)). This sintering auxiliary plate 6 is provided with a large number of holes 6'at a required distribution.
It is made of steel plate with holes. The mixed powder of the copper-based alloy sintered sliding material a is sprinkled on the sintering auxiliary plate 6 so that only the hole 6 ′ of the sintering auxiliary plate 6 is filled with the mixed powder ( See FIG. 3B). As the sinter-bonding inhibitor, for example, flake graphite powder is used.

(Fourth step) Sintering auxiliary plate 6 and mixed powder a
10 to 60 at a temperature of 800 ° C. to 900 ° C. by placing the backing metal 1 filled with the metal in a sintering furnace 4 in which a reducing atmosphere is controlled.
Sintering (primary sintering) is performed for a minute (see FIG. 3C), and then the auxiliary sintering plate 6 is removed. As a result, the convex portion of the sintered alloy body 3a having an arbitrary shape can be dispersedly bonded to an arbitrary position on the surface of the back metal (see FIG. 3D).

(Fifth Step) The intermediate body obtained in the fourth step is rolled by the rolling roller 5 to obtain the sintered alloy body 3a.
To improve the density (see FIG. 4B). Note that roller rolling may not be performed depending on the sintering material, the sintering density, and the size.

(Sixth step) The mixed powder b is sprinkled on the surface of the backing metal 1 where the independent sintered alloy body 3a having an arbitrary shape is joined at an arbitrary position (see FIG. 4 (c)). . As for the spraying state, there are cases where the sintered alloy body 3a of the mixed powder a is covered with the mixed powder b (see FIG. 6A) or not covered (see FIG. 6B). In the former case, the sliding surface is a copper-based alloy of the mixed powder b, and in the latter case, the material of the mixed powder a and the material of the mixed powder b are mixed on the surface of the sliding surface.

(Seventh step) The backing metal 1 on which the mixed powder b has been dispersed is placed in a sintering furnace 4 in a controlled reducing atmosphere at a temperature of 850 ° C. to 900 ° C. for 30 minutes to 60 minutes. Sintering for a minute (FIG. 5A). As a result, the mixed powder b is
It is joined to the sintered alloy body 3a of the mixed powder a and also to the backing metal 1 by sintering.

(Eighth step) The backing metal 1 to which the sintered alloy layers A'of the mixed powder a and the mixed powder b are joined is rolled by the rolling roller 5 to improve the density (see FIG. 5 (b)). Particularly, during the rolling by the rolling roller 5, the joining of the sintered alloy bodies 3a and 3b of the mixed powder a and the mixed powder b is ensured.

(Ninth Step) The backing metal 1 having the surface thereof coated with the sintered alloy layer A ′ of the mixed powder a and the mixed powder b is placed in the sintering furnace again, and the temperature is set to 850 ° C. to 900 ° C. Three
After sintering for 0 to 60 minutes, the sintering of the sintered alloy layer A ′ is promoted to enhance the adhesive force with the backing metal 1, or the sintered alloy body 3a of the mixed powder a and the sintered powder b are fired and bonded. The sinter joining with the metal body 3b is promoted. Particularly, by controlling the components, the sintered alloy body 3 of the mixed powder a in this sintering temperature range
Since a liquid phase is generated in both the sintered alloy body 3b of a and the mixed powder b, the bonding between the sintered bodies further proceeds. After the completion of sintering, the material is rolled by the roller to further increase the density of this sintered alloy layer and smooth the surface.

(Tenth Step) The multilayer sintered sliding material (intermediate product) manufactured by the above-mentioned process is circularly bent so that the sliding material portion (sintered alloy layer) is arranged inward. Processing is performed and the end face portions are joined by welding or the like. (Eleventh step) The member subjected to the round bending process is machined to have the desired length and surface roughness on the outer and inner peripheral parts, and the manufacture of the sliding bearing is completed (see FIG. 5 (c)). At this time, the sliding axis
Depending on the usage conditions of the bridge, it is possible to control the dimensions during round bending and
And is located above the sintered alloy body 3a due to machining cost.
When the sintered layer of the mixed powder b
There is a match. In addition, as shown in the sixth step, the mixed powder is previously mixed.
When b is sprinkled so as to have the same height as the sintered alloy body 3a
In the case of two types, two types of materials slide the type that shows the face on the sliding surface
It can be manufactured without processing the surface.

(Twelfth Step) In the sintered body which is the sintered alloy layer of the sliding bearing obtained in the eleventh step, there is a density difference between the convex portion and the non-convex portion. Some of the parts have a low density and have a density configuration that allows oil to be impregnated. Depending on the usage as a bearing, they are subjected to an oil impregnation treatment before use.

In the case of the above-mentioned two kinds of copper alloy powder,
Basically, it is a copper-tin-based bronze alloy system, but not necessarily the same alloy system, for example, in the case of bronze-brass system, bronze-lead bronze system, bronze-iron system, brass. In the case of iron-based, copper-aluminum-based, or as described above, the amount can be changed also in the additive material (lead amount, graphite amount, silica amount in the above-mentioned material system). is there. From the viewpoint of manufacturing, it is possible to manufacture a bearing having a composite phase having various sliding characteristics in which the bonding strength and the wear resistance are controlled by sintering the sintering temperature according to each alloy system. It will be possible.

Further, in any of the above-mentioned cases, a single process is performed by using a process of forming convex portions or concave portions having different densities or components and arranged in a geometric pattern on a backing metal forming a plane. Conventional materials (materials that have a single microstructure) by changing from a different structure to a different structure
A bearing material having excellent sliding characteristics different from that can be easily manufactured. Further, in order to improve the sliding property, it is possible to mix an inorganic material having solid lubricity such as molybdenum disulfide into copper-based alloy powder that forms a low-density phase in the above process. it can.

The sliding bearing material having the above-mentioned structure has a sliding material layer having an arbitrarily designed density distribution on its sliding surface and, depending on the use conditions, a sliding material having an arbitrary component. Bearings can be manufactured in which the layers are placed anywhere
By controlling the hardness and density of these sliding material layers in the sintering process and the rolling process, they can be used as a bearing material having a sliding surface having excellent load resistance and wear resistance.

[0040]

[Example 1]

(First step) As a back metal, a carbon steel plate having a thickness of 5 mm is degreased and washed, and then roughened by sandblasting.

(Second Step) 10% of atomized tin powder passing through 250 mesh, 10% of atomized lead powder passing through 250 mesh, and 80% of atomized copper powder passing through 250 mesh were weighed, and were weighed by a V-type mixer. Mixed for 30 minutes to obtain mixed powder (a) (copper: 80%, tin: 1
0%, lead: 10%). In the same process, atomized tin powder 15%, atomized iron powder 30% that passes 250 mesh, graphite powder 10% that passes 100 mesh, and the balance copper atomized copper powder that passes 250 mesh are mixed,
A mixed powder (b) was obtained.

(Third Step) First, the mixed powder (a) is sprayed on a steel flat plate to an appropriate thickness, and then scraped off by a corrugated scraping plate so that peaks and valleys are alternately present. After the round bending in the process of manufacturing the bearing material, the mountain portion is scraped off so as not to be at least parallel to the sliding direction of the bearing. At this time, the height of the crests was 5 mm, and the valleys were scraped off so that the mixed powder did not exist.

(Fourth Step) The steel sheet on the surface of which the mixed powder (a) was sprayed in a corrugated form in the previous step was placed in a sintering furnace adjusted to a reducing atmosphere and sintered at a temperature of 850 ° C. for 30 minutes ( Primary sintering), and the mixed powder (a) was sintered and bonded to the back metal at the same time.

(Fifth Step) The backing metal to which the sintered alloy layer has been joined in the previous step is rolled by a rolling roller. Regarding the height of the sintered alloy layer at this time, the height after sintering was 4.3 mm, but it was rolled to a thickness of 3.5 mm.

(Sixth step) Next, the mixed powder (b) is sprayed on the surface of the backing metal processed up to the previous fifth step so that the tip of the convex portion of the sintered alloy layer (a ') can be seen. Then, scrape it so as to cover the back metal part of the recess so that the spray surface becomes flat. After that, the material is placed in a sintering furnace adjusted to a reducing atmosphere at a temperature of 870 ° C. for 30 minutes to sinter, to bond to a sintered alloy layer (a ′) and to a backing metal, Then, the mixed powder (b) is sintered.

(Seventh step) The backing metal having the sintered alloy layer (a ') and the sintered alloy layer (b') obtained in the previous sixth step joined thereto is roller-rolled to reduce the density of the sintered alloy layer. Increase. The thickness of the sintered alloy layer after this rolling was 2.5 mm.

(Eighth Step) The backing metal integrally bonded with the sintered alloy layer is placed in the sintering furnace and heated at a temperature of 850 ° C. for 3 hours.
Sintering (secondary sintering) for 0 minutes progresses the sintering of the sintered alloy layer, and the bonding force with the backing metal and the sintered alloy layer (a ′) and the sintered alloy layer (b ′) mutually. It also improves the bond strength between them. After that, this sintered product is rolled by a rolling roller to improve the density of the sintered alloy layer and to flatten the surface accurately. The final thickness of the sintered alloy layer is 2 mm
And an intermediate product was obtained.

(Ninth Step) An intermediate product having a flattened sintered alloy layer is subjected to a round bending process so that the inner side becomes a sintered surface, and both ends of the winding are joined. Then, by machining, the inner diameter, the outer diameter, and the end are cut to finish to a desired size, and the slide bearing is completed.

(Step 10) The sliding bearing having the multi-layer structure is subjected to oil impregnation treatment. In the plain bearing, no pores were observed in the sintered alloy layer (a ′) microscopically, and the sintered alloy layer (a ′) had almost a true density. This sintered alloy layer (a ')
The sintered alloy layer (b ′) of the above had an oil content of 34%.

In this way, on the sliding surface of the sliding bearing thus obtained, the stripes of the yellow bronze phase and the porous bronze phase containing a lot of dark yellow graphite are alternately arranged on the inner diameter sliding surface side. It is a complex organization.

Example 2 (First Step) A steel plate having a smooth surface is prepared as a backing metal. (Second step) 10% tin, 20% iron, 1 graphite by weight
%, And the balance is copper to form a uniform mixed powder (c).
In addition, a uniform mixed powder (d) composed of 15% tin, 10% graphite and the balance copper is prepared in the same weight ratio.

(Third Step) The mixed powder (c) was press-formed into a plate shape having a hole in the inner diameter and capable of being arranged periodically. Molding pressure at this time is 3t
/ Cm ² , the thickness of the molded body was 3.5 mm.

(Fourth step) This press-formed body was arranged on the surface of the back metal so that the holes were periodically arranged in a geometrical arrangement, and an iron plate coated with graphite for preventing sintering was weighed. Put as. (Fifth step) The backing metal on which the green compact and the weight are placed,
Place in a sintering furnace controlled to a reducing atmosphere, and hold at 850 ° C for 3
Sinter for 0 minutes. By this operation, the green compact is sintered and is joined to the back metal. The thickness of the sintered body (compacted powder compact) after sintering was 3.3 mm.

(Sixth step) The weight (iron plate) is removed from the sintered body after the completion of sintering, and rolling is performed by a rolling roller in order to improve the sintered density. By this rolling, the thickness of the sintered body portion became 3.1 mm.

(Seventh Step) The mixed powder (d) is sprinkled on the surface of the back metal of the sintered body obtained in the above step so as to have a uniform height. (Eighth step) The back metal covered with the uniformly mixed powder (d) was adjusted to a reducing atmosphere and the temperature was 850 ° C.
Then, the mixed powder (d) is sintered and bonded to the back metal and the sintered layer (c ') for 60 minutes.

(Ninth Step) The backing metal integrally bonded with the sintered alloy layer is rolled by a rolling roller to improve the bondability between the sintered layer (c ′) and the sintered layer (d ′), And improve the sintered layer.

(Tenth Step) The backing metal for improving the sintered density was placed in the sintering furnace and maintained at 850 ° C. for 60 minutes to maintain the sintered alloy layer (c ′). The bonding force between the sintered alloy layer (d ′) and the sintered alloy layer (d ′) is improved, and the bonding force between both sintered alloy layers and the back metal is further increased.

(Eleventh step) Thereafter, a rolling operation is performed with a rolling roller to improve the molding density and the strength,
Obtain intermediate products of plain bearing materials.

The intermediate product manufactured as described above is
Round bending is performed so that the sliding layer (sintered alloy layer) is arranged on the inner part, the bent both ends are joined, and the inner diameter and outer diameter are machined so as to satisfy the required dimensions. Thus, a sliding bearing having both hard and soft phases that do not cause peeling and having excellent wear resistance is manufactured.

Example 3 (First Step) As a backing metal, a carbon steel plate having a thickness of 3 mm is degreased and cleaned to clean the surface. (Second step) Lead bronze powder passing through 200 mesh is sprinkled on the upper surface of the steel plate, and then scraped off by a corrugated scraping plate so that peaks and valleys intersect each other. At this time, the height of the peak of the powder is set to 4 mm. The valley should be such that the background of the back metal can be seen.

(Third step) The steel sheet on the surface of which the lead bronze powder was dispersed in the previous step was placed in a sintering furnace adjusted to a reducing atmosphere and sintered at a temperature of 850 ° C for 30 minutes (primary sintering). Then
Sintering of the powder and bonding to the back metal are performed. At this time, the height of the sintered body was such that the peak portion contracted to 3 mm.

(Fourth Step) A backing metal having a sintered body joined in a corrugated form on its surface is rolled by a rolling roller. The height of the mountain portion of the sintered body is 2 mm by rolling.

(Fifth Step) A powder for further sintering is sprinkled on the backing metal to which the sintered body having the density of the mountain portion improved by rolling is joined. The powder used is the above-mentioned lead bronze powder, which is sprinkled so that the surface is even. Spray height is 4m
to be m.

(Sixth Step) The back metal, to which the lead bronze powder was uniformly dispersed, was sintered (secondary sintering) in a sintering furnace adjusted to a reducing atmosphere at a temperature of 850 ° C. for 30 minutes. . By this operation, the primary sintered body and the secondary sintered body are joined, and the secondary sintered body itself is sintered. (Seventh step) In the material that had been sintered, the thickness of the sintered body portion had shrunk to 3.5 mm.

(Eighth Step) Next, the backing metal to which the primary sintered phase and the secondary sintered phase are joined is rolled by a rolling roller.
By this rolling, the thickness of the sintered body was reduced to 3 mm.

(Ninth Step) The backing metal to which the sintered alloy layer having a desired thickness by rolling is joined is placed in a sintering furnace adjusted to a reducing atmosphere at a temperature of 790 ° C. for 30 minutes. Sintering and rolling further ensure the joining of the alloy powder mechanically produced by rolling in the sintered structure.

(Tenth Step) The intermediate product produced through the above steps is subjected to round bending as in the above-mentioned embodiment and then machined to produce a wound bush.

Next, a test example will be described in which the sliding bearing material provided with the multi-phase sintered sliding layer manufactured by the above-mentioned embodiment is used in a working machine for a hydraulic excavator.

[Testing Method for Working Machine Bushing] The bushing of Example 2 was used as the bushing in the hydraulic cylinder bearing portion of the working machine of the hydraulic excavator, and the loading work of earth and sand was performed. As a comparative example, the same test was performed on a conventionally used iron-based bush. (Test conditions) -Greasing: Apply grease only at the beginning of the test. -Test time: 200 hours-Counterpart material: S53C induction hardened product (shaft) The test results conducted under the above test conditions are as shown in Table 1.

[0070]

[Table 1]

The bearing material of Example 2 (hereinafter referred to as Example material 2) and the conventional material (iron-based material) were attached to the bush portions, one on the left and one on the right of the machine. The sliding angles can be considered to be the same. Therefore, from the test results, it can be said that the material of Example 2 has significantly improved wear resistance as compared with the conventional material. In particular, in the conventional material, adhesion occurs between the bush and the shaft, and the shaft is also worn. Of course, there was no abnormality in the shaft for Example material 2.

The sliding characteristics were evaluated by the following test method. (Test method) A bush-shaped test piece and a shaft-shaped mating test piece are prepared. Pass the shaft through the bush, and swing the shaft at a specific angle while applying a load from above the bush with a hydraulic cylinder. Measure the torque that acts while swinging and convert it into a friction coefficient. The load is further increased after a certain number of swings, and the limit is set when there is an abnormal fluctuation in the friction coefficient and when the bush and shaft cause a resonance phenomenon (squeaking), and the load immediately before that is evaluated as the maximum allowable load. .

(Test conditions) -Type of test piece material: Example material 1, conventional material (iron-based inner surface height
Induction hardening material), iron-based oil-impregnated bearing material ・ Shape of test piece: (1) Bushing: 95 mm outside diameter, inside
Diameter 80 mm, height 40 mm (2) Shaft: outer diameter 80mm, length 300mm ・ Load: 100 kg / cm², 200 kg / c
m², 300 kg / cm², 400 kg / cm² 500 kg / cm², 600 kg / cm², 700 kg
/ Cm², 800 kg / cm² 900 kg / cm², 1000 kg / cm² And The load is the total load from the hydraulic cylinder.
It is divided by the apparent area that is covered. · Swing angle: 100 degrees ・ Number of swings: 2000 times under each load condition ・ Speed: 0.17m / min ・ Lubrication: Only grease lubrication at the initial stage The test results conducted under these test methods and test conditions are shown in the table.
It was as shown in 2.

[0074]

[Table 2]

Among the evaluation results, in the case of the conventional material (iron-based), a remarkable change in the friction coefficient was observed at a load of 300 kg / cm ² , and when the sliding surface was observed after discontinuing the test, the bushing was partially found. It was found that the shaft material had caused adhesion. In the case of the oil-impregnated bearing, squeal was generated at 200 kg / cm ² . The coefficient of friction increased and decreased and wobble was remarkable. For example materials,
Without such a case, the low coefficient of friction was maintained even at 1000 kg / cm ² .

From the above test results, the bearing materials manufactured in Example material 1 and Example material 2 are only lubricated at the initial stage and are not lubricated at all thereafter. It shows excellent values in terms of properties, and can be said to be a material that can fully exhibit its function as a bearing. This means that, in the present situation, in a hydraulic excavator working machine, in view of the fact that grease lubrication is performed every 100 hours using the iron-based bush, the sliding bearing material according to the present invention has a lubrication interval. It is possible to greatly extend the amount of oil used, or to eliminate the greasing work.

[Test of Metal Bearing] As evaluation of sliding material
And the test shown below for the material produced in Example 3
The sliding characteristics were evaluated by a machine. (Test condition) ・ Tester structure: Pin-desk type constant speed sliding test -Type of test piece material: Example 3 material, LBC3 sintered material (uniform
Scatter-sintered material, mating material (S53C induction hardened product)
(Surface roughness: 3S)) ・ Lubrication: EO30,200cc / min ・ Speed: 10m / sec ・ Load: 100 kg / cm² To 800 kg / cm²Well
At 100 kg / cm ²The load is increased every 10 minutes
Let Change of friction coefficient and change of wear amount at that time
Judgment is further made to determine burn-in. Load just before burning
The weight is the maximum allowable load. These test methods and tests
Table 3 shows the test results conducted under the conditions.

[0078]

[Table 3]

Example 3 in which a density difference was formed in the sliding phase
Has better compatibility than LBC3 (conventional material),
It is possible to maintain fluid lubrication up to high loads.

In the above description, a bearing formed by round bending is described. However, based on the gist of the present invention, a load caused by mutual sliding on a flat portion as a planar sliding material. It can also be used as a support member. Further, as the sintering auxiliary plate described in the above examples, a steel plate having a thickness corresponding to the height required to fill the mixed powder of the sintering material,
By using a large number of round holes, square holes or other small holes of any shape at a required pitch, or by using a plate formed in a net shape, etc., the distribution of parts of different density in the obtained sintered alloy layer and Arrangement can be set arbitrarily and contributes to improve workability. The sintering auxiliary plate does not necessarily have to be made of metal, and paper or resin can sufficiently fulfill its role.

[0081]

As described above, the present invention has the following effects. 1) bearing sliding portions, the different phases of the density and component peaks and valleys
A copper-based alloy sintered layer that is geometrically arranged so that and alternate with each other is formed, and due to this difference in density, high load resistance, wear resistance or seizure resistance is obtained in the high density portion,
It has become possible to provide reasonably a bearing material that can achieve excellent sliding characteristics in the low-density portion, exactly satisfying the requirements for a sliding bearing. 2) In addition, the high density portion (phase) and the low density portion (phase) of the copper-based sintered alloy layer can be set in any distribution state, which makes it possible to set the optimum conditions for the situation of use. Therefore, it is possible to obtain a bearing that can adapt to adverse conditions that could not be predicted in the past. 3) If necessary, in order to further improve the sliding characteristics, it is possible to mix the solid lubricating material in a low density phase that enhances the sliding characteristics, or to impregnate oil and fat. 4) In manufacturing, there is an effect that a product under arbitrary conditions can be easily manufactured and a product cost can be reduced without requiring complicated processing and steps.

[Brief description of drawings]

FIG. 1 is a diagram showing one embodiment of a process for producing a sliding bearing material according to the present invention.

FIG. 2 is a process drawing showing an example of a manufacturing process of a plain bearing material according to the present invention.

FIG. 3 is a process drawing showing another example of the manufacturing process of the sliding bearing material according to the present invention.

FIG. 4 is a process drawing showing another example of the manufacturing process of the sliding bearing material according to the present invention.

FIG. 5 is a process drawing showing another example of the manufacturing process of the sliding bearing material according to the present invention.

FIG. 6 is a schematic cross-sectional view showing a constitutional aspect of a copper-based alloy sintered layer.

[Explanation of symbols]

1 back money 2 corrugated scraping plate 2'scraper 3 Mixed powder of copper alloy sintered material 3a, 3b, 3c, 3d Sintered alloy layer 4 incinerator 5 Rolling roller 6 Sintering auxiliary plate 6'hole of auxiliary sintering plate 10 bearings

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-3-232905 (JP, A) JP-A-2-138406 (JP, A) JP-A-1-312014 (JP, A) JP-A-61-1 127801 (JP, A) JP-A-53-31245 (JP, A) JP-A-52-42228 (JP, A) JP-A-62-116705 (JP, A) JP-A-48-69754 (JP, A) JP 53-44409 (JP, A) JP 50-79407 (JP, A) JP 4-135096 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) B22F 7/02

Claims (12)

(57) [Claims] 1. A steel backing having a flat surface and a backing of the backing
A sliding bearing material having a copper-based alloy sintered layer bonded to the surface , wherein the copper-based alloy sintered layer is a copper-based alloy sintered material excellent in load bearing performance.
The binder is distributed so that the peaks and valleys alternate.
In addition, a copper-based alloy sintered material with excellent sliding characteristics is placed in this distribution gap.
A plain bearing material which is distributed , sintered and rolled, and has a high density phase and a low density phase alternately distributed. 2. The sliding bearing material according to claim 1 , wherein the copper-based alloy sintered layer is made of one kind selected from the group consisting of a copper-lead alloy, a lead-bronze alloy, and a bronze alloy. Wherein said copper-based alloy sintered layer, the lower phase density, graphite, sliding bearing material according to claim 1 or 2 containing a solid lubricant such as molybdenum disulfide. 4. A sliding bearing material according to claim 1 or 2 oil is impregnated in a portion of the less dense phase in the copper-based alloy sintered layer. 5. A kind of copper-based alloy sintered powder material is distributed on a surface of a steel backing metal having a flat surface such that peaks and valleys are alternately arranged, and after sintering, the copper-based material is sintered. Sintered copper-based alloy powder having different characteristics from the alloy-sintered powder material covers the former sintered body of copper-based alloy powder powder or is sprayed to the same height and sintered again. Sliding characterized in that a high density phase and a low density phase or phases having different components are alternately distributed and formed in the copper-based alloy sintered layer by applying an operation and then rolling. Bearing material manufacturing method. 6. When forming the copper-based alloy sintered layer on the surface of the steel backing metal, first of all, a copper-based alloy sintered material having an excellent load-bearing performance is spread in a pattern in which peaks and valleys alternate. And then sinter, and then spread the copper-based alloy sintered material with excellent sliding properties to the gaps of the sintered layer of the above-mentioned sintered copper-based alloy sintered material and perform the sintering operation again. The method for manufacturing a plain bearing material according to claim 5 , wherein 7. When forming the copper-based alloy sintered layer on the surface of the steel back metal, a copper-based alloy sintered material having excellent sliding properties is first spread in a pattern in which peaks and valleys alternate. And then sinter, and then spread the copper-based alloy sintered material with excellent load-bearing performance to the gap part of the sintered layer of the sintered copper-based alloy sintered material and perform the sintering operation again. The method for manufacturing a plain bearing material according to claim 5 , wherein 8. The peaks and valleys of the copper-based alloy sintered powder material intersect.
In order to distribute them in a mutually alternating manner , a sintering auxiliary plate in which a large number of holes are drilled at a required interval distribution is arranged on the surface of the steel backing metal, and the copper-based alloy is baked in the holes of this sintering auxiliary plate. The sliding bearing material according to any one of claims 5 to 7 , wherein the powdered powder material is filled, the sintering auxiliary plate is removed after sintering, and the sintered body is independently formed on the back metal. Production method. 9. The copper-based alloy sintered powder material intersects peaks and valleys.
In order to distribute them in a mutually alternating manner , a sintering auxiliary plate made of a combustible material such as paper or resin in which a large number of holes are perforated at a required spacing is arranged on the surface of the steel backing metal, and A sintered body is independently formed by filling the pores of the sintering auxiliary plate with a copper-based alloy sintering powder material and removing the residue of the sintering auxiliary plate that has disappeared after sintering. Item 5
8. The method for manufacturing the sliding bearing material according to any one of 7 . 10. A copper-based alloy sintered powder material, which is previously sprayed to form a high-density phase and a low-density phase of a copper-based alloy sintered layer distributed and formed on the surface of the steel backing metal. 6. Rolling after the sintering of step 1, then spraying another copper-based alloy sintered powder material, sintering operation, and then rolling again to form a high density phase and a low density phase together . 9. The method for manufacturing the sliding bearing material according to 6 or 8 . 11. Upon formation of the copper-based alloy sintered layer on the steel back metal surface, the peaks and valleys on the steel back metal surface exchange
Spray the copper-based alloy sintered material layer that has been sintered so as to be mutually covered so as to cover it with the copper-based alloy sintered material in the next step, or spray it so that it has the same height as the sintering temperature. The joint strength of both sintered materials is increased by controlling the temperature of the sintered material, and the high density portion and the low density portion of the sintered layer alternate between peaks and valleys.
The method for producing a plain bearing material according to any one of claims 5 to 9 , wherein the plain bearing material is formed as described above and is subjected to an oil impregnation treatment. 12. The scattering of the copper-based alloy sintered powder material such that peaks and valleys alternate with respect to the back metal is such that the high-density portion is not continuous in the sliding direction of the mating material as the product bearing. The method for producing a plain bearing material according to any one of claims 5 to 10 , wherein the slide bearing material is formed by spraying.