JPH10176204A - Sliding bearing material and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an inexpensive sliding bearing material having simple constitution and excellent in fitness, wear resistance, load resistance, burning resistance and sufficiently usable even in a boundary lubricating condition by joining and forming a copper base alloy sintered layer composed of a high dense phase geometrically distributed and a low dense phase arranged in the dustributed gaps of the high dense phase on a steel-made backing metal. SOLUTION: On the backing metal 1 composed of a flat surface steel plate, copper base alloy powder 3 is spread in waving state through e.g. a corrugated edge scraping plate 2 and sintered in a sintering furnace 4 under reduced atmosphere to form the high density sintered alloy layer 3a having geometrically distributed high load resistant characteristic. On this sintered alloy layer 3a, copper base alloy powder 3 different in components from the alloy powder 3, and as necessary, containing solid lubricator such as graphite, MoS2 is spread into the gaps through a scraping plate 2' and sintered to form the low density sintered layer 3b excellent in sliding characteristic, and further, fats and oils are impregnated when needed. Successively, the prepared sintered layer A is rolled by rolling rollers 5 and formed to a high density, and a round bending work is executed to obtain the sliding bearing 10 excellent in the wear resistance, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sliding bearing material and a method for producing the same, and more particularly, to a lead-bronze alloy or a copper-based alloy sintered material containing a bronze alloy as a main component so as to have a hard / soft mixed structure. In addition, the present invention relates to a sliding bearing material adhered to a steel back metal and a method for producing the same.

[0002]

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

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

[0004] In addition, a method of protecting the bearing material itself from a mating member that is in sliding contact with the material by dispersing hard particles in the tissue without changing the material itself has been adopted. As for 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, As disclosed in Japanese Unexamined Patent Publication No.
Some disperse zero or more metal nitrides, metal carbides, metal phosphides and metal borides.

Next, 2. As disclosed in Japanese Patent Application Laid-Open No. 4-180599, the sliding layer surface is coated with a soft metal layer such as lead or indium by plating or the like in order to improve conformability. Also, as disclosed in Japanese Patent Application Laid-Open No. 7-90551, an overlay layer containing a soft alloy is formed to improve abrasion resistance and seizure resistance. This overlay reduces the frictional resistance generated by the metal contact of the projections on the metal surface at the initial stage of sliding by the low shearing force of soft metal, and eliminates the projections by plastic flow to easily maintain fluid lubrication. To extend the life.

[0006] In addition to overlay, as means for improving conformability, as disclosed in Japanese Patent Application Laid-Open No. 3-89022, it is conceivable to use oil in a sliding layer. As another idea, Japanese Patent Application Laid-Open No. 3-232 discloses a means for impregnating oil and improving load resistance.
As disclosed in Japanese Unexamined Patent Publication No. 905, a plurality of independent convex or concave iron plates are used, and a copper-based alloy sintering powder is sprayed, and sintering and rolling are performed to obtain a low density and high oil content Forming a bonded gold layer and a high density, low oil content sintered alloy layer,
A multi-layer sintered sliding material that can be used even under a condition where an impact load acts is proposed.

[0007]

However, in order to obtain a bearing material such as a bearing bush that requires round bending, such as a bearing bush, the following disadvantages have become apparent. That is, 1. The material used for the overlay and the copper-based sliding material are separate material systems, and two types of materials must be managed, complicating the work process and increasing the production cost. Further, the life is determined by the loss of the material used for the overlay, and the life tends to be short as a whole. 2. The above-mentioned material system can exhibit a certain sliding property under the condition that lubricating oil is present, 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 coarse-dense sintered layer by using a steel sheet with a convex part, in particular, no measures have been taken to promote the improvement of bonding with the steel sheet. Phenomenon occurs. 4. Further, forming a specific convex portion or concave portion on the surface of the steel sheet requires a special production process at the time of manufacturing the steel sheet, which increases the cost. In addition, there is a drawback that the manufacturing process is difficult depending on the uneven shape, and the manufacturing process lacks flexibility. 5. Furthermore, in terms of material composition, the sliding surface is basically the same material, albeit with different densities. Depending on the conditions of use, the load resistance and sliding characteristics are insufficient due to the characteristics of the material. It may be.

SUMMARY OF THE INVENTION The present invention solves the above-mentioned problems, and has excellent conformability with a simple structure, excellent abrasion resistance, load resistance, and seizure resistance, and can be used under boundary lubrication conditions. An object of the present invention is to provide a slide bearing material that can be sufficiently used, and to provide a manufacturing method thereof that can be provided at a low cost.

[0009]

In order to achieve such an object, a sliding bearing material according to the present invention comprises a steel backing,
A sliding bearing material having a copper-based alloy sintered layer bonded to the back metal, wherein a high-density phase and a low-density phase are geometrically distributed and formed in the copper-based alloy sintered layer. It is characterized by the following.

Further, in the present invention, the copper-based alloy sintered layer is provided with a copper-based alloy sintered material having an excellent load-bearing performance geometrically distributed in the copper-based alloy sintered layer. It is characterized in that a base alloy sintered material is arranged and joined to the back metal surface.

In the bearing material, it is preferable that the copper-based alloy sintered layer is made of one selected from the group consisting of a copper-lead alloy, a lead-bronze alloy, and a bronze alloy. Lubricity can be reasonably maintained by including a solid lubricant such as graphite or molybdenum disulfide in the low-density phase of the copper-based alloy layer. In addition, by allowing the low-density phase of the copper-based alloy sintered layer to contain oil, the sliding characteristics can be reasonably maintained.

According to the present invention, in order to obtain the above-described sliding bearing material, a kind of copper-based alloy sintered powder material is geometrically distributed on the surface of a steel backing metal, and after sintering, the copper-based alloy A copper-based alloy sintered powder material having characteristics different from that of the sintered powder material is covered with the former sintered body of the copper-based alloy sintered powder material, or sprayed so as to have the same height, and the sintering operation is performed again. And then rolling, so that a dense phase and a low-density phase, or phases having different components are geometrically distributed and formed in the copper-based alloy sintered layer. It is a manufacturing method.

In the manufacturing method, when forming the copper-based alloy sintered layer on the back metal surface, first, a copper-based alloy sintered material having excellent load-bearing performance is dispersed in a geometric pattern and sintered. Then, a sintering operation is performed again by spraying a copper-based alloy sintered material having excellent sliding properties to the gaps between the sintered layers of the sintered copper-based alloy sintered material. The sintering operation of the above-described copper alloy sintered material having excellent load bearing performance and the copper alloy sintered material having excellent sliding characteristics may be performed in the reverse order.

In the above-mentioned manufacturing method, when the copper-based alloy sintered layer is formed on the back metal surface, the copper-based alloy sintered material layer having been geometrically sintered on the back metal surface is subjected to the following step. Spray to cover with the base alloy sintering material, or scatter to the same height, and control the sintering temperature to increase the joint strength of both sintering materials, By forming the high-density portion and the low-density portion in a geometric pattern and performing oil impregnation, a sliding bearing material excellent in load resistance and seizure resistance can be obtained.

It is preferable that the geometrical spraying of the copper-based alloy sintered material on the back metal is performed so that a high-density portion is not continuous in a sliding direction as a product bearing. The dispersing positions may exist independently, or irregularities may be formed in a wavy manner. In addition, the copper alloy sintering material is independently sprayed and sintering is performed by using a sintering auxiliary plate having a large number of holes with a required interval distribution. The mold release agent of the copper-based alloy sintered material is applied and used. After sintering, the sintering auxiliary plate is removed and reused. With this configuration, a convex portion having a shape conforming to the shape of the hole provided in the sintering auxiliary plate can be formed, and since the sintering auxiliary plate can be used repeatedly, workability and economic efficiency can be improved. The shape of the sintering auxiliary plate does not necessarily need to remain after sintering. For example, paper or resin may be used. In this case, since the projections are formed by simple cleaning after sintering, it can be said that the method is excellent in terms of workability.

[0016]

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

Further, in the production of the sliding bearing material of the present invention, it is extremely simple to sinter sintered materials of required different materials and join them to the backing metal by means of geometric spraying means and supplementary spraying means. Through a working process, a high-density portion and a low-density portion can be formed on the sliding surface by arbitrarily sintering, and a product that satisfies the requirements as a sliding bearing can be obtained economically.

[0018]

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

Example 1 (See FIGS. 1 and 2) (First Step) A flat steel plate whose surface is degreased and cleaned is prepared as a backing metal. (Second step) A uniform mixed powder or alloy powder composed of 10% tin, 10% lead, and the balance copper is prepared by weight ratio.

(Third Step) The mixed powder (alloy powder) 3 prepared in the second step is rubbed on the surface of the backing metal 1 by using a rubbing plate 2 having a rubbed cut surface, and peaks and valleys are alternately formed. Spray to be present in. At this time, when the ridge portion is formed into a bush by round bending as a product, the bush is scattered so as not to be continuously present in the sliding direction. That is, a shape in which the direction of the mountain crosses the sliding direction diagonally,
Or spray it vertically (Figs. 1 and 2
(A)). The method of forming the peaks and valleys may be such that after the mixed powder is uniformly dispersed, a roller having a groove shape is pressed against the surface of the mixed powder to be rolled.

(Fourth Step) The back metal 1 on which the mixed powder 3 spread on the surface in a geometric pattern is sintered is adjusted to a reducing atmosphere and the temperature is controlled from 850 ° C. to 900 ° C. Then, the mixture powder 3 is held for 30 to 60 minutes to perform sintering of the mixed powder 3 and sintering bonding to the back metal 1 (see FIG. 2B).

(Fifth Step) On the back metal 1 on which the sintered alloy layer 3a has been integrated in the previous step, the mixed powder 3 is further leveled by a scraping plate 2 'so that the valleys are filled and uniform. (See FIG. 2 (c)).

(Sixth step) Mixed powder 3 uniformly dispersed
The back metal 1 filled with is adjusted to a reducing atmosphere and the temperature is set to 8
In a sintering furnace 4 controlled from 50 ° C. to 900 ° C., 30 to 6
After holding for 0 minute, the mixed powder is sintered and bonded to the back metal by sintering (see FIG. 2D).

(Seventh Step) In the previous step, the sintered alloy layers 3a, 3
The back metal 1 integrated with b is applied to a rolling roller 5 to increase the density of the bonded sintered alloy layer A (see FIG. 2E).

(Eighth Step) The back 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. for 30 to 60 minutes to improve the bonding force between the sintered alloy layers 3a and 3b and the bonding force to the back metal 1. Thereafter, the density of the sintered alloy layer A is further increased again by 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 disposed on the inner portion, and the butted ends are joined to form a required dimension. The outer periphery and the inner periphery are machined so as to satisfy the above conditions to obtain a sliding bearing 10 having both hard and soft phases without delamination and excellent in wear resistance (FIG. 2 (f)).

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

(Third Step) A sintering auxiliary plate 6 coated with a sintering bonding inhibitor is placed on the surface of the back metal 1 (see FIG. 3A). This sintering auxiliary plate 6 has a large number of holes 6 'in a required distribution.
Is made of an empty steel plate. The mixed powder of the copper-based alloy sintered sliding material a is sprayed on the sintering auxiliary plate 6 so that only the hole 6 ′ of the sintering auxiliary plate 6 is filled with the mixed powder ( FIG. 3 (b)). As the sintering bonding inhibitor, for example, flaky graphite powder is used.

(Fourth Step) Sintering auxiliary plate 6 and mixed powder a
Is placed in a sintering furnace 4 in which a reducing atmosphere is controlled, and at a temperature of 800 ° C. to 900 ° C., 10 to 60
Sintering (primary sintering) is performed for one minute (see FIG. 3C), and then the sintering auxiliary plate 6 is removed. As a result, the protrusions of the sintered alloy body 3a having an arbitrary shape can be dispersed and joined at an arbitrary position on the back metal surface (see FIG. 3D).

(Fifth Step) The intermediate obtained in the fourth step is rolled by a rolling roller 5 to obtain the sintered alloy 3a.
(See FIG. 4B). Roller rolling may not be performed depending on the sintering material, sintering density and dimensions.

(Sixth Step) The mixed powder b is sprayed 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. 4C). . The state of dispersion may be a case where the sintered alloy body 3a of the mixed powder a is covered with the mixed powder b (see FIG. 6A) or a case where it is 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 back metal 1 on which the mixed powder b has been sprayed as described above is placed in a sintering furnace 4 in which a reducing atmosphere is controlled, at a temperature of 850 ° C. to 900 ° C. for 30 minutes to 60 hours. Sintering is performed for a minute (FIG. 5A). As a result, the mixed powder b
It is bonded to the sintered alloy body 3a of the mixed powder a, and is also sintered to the back metal 1.

(Eighth Step) The back metal 1 to which the sintered alloy layer A 'of the mixed powder a and the mixed powder b is joined is rolled by the rolling roller 5 to improve the density (see FIG. 5B). In particular, at the time of rolling by the rolling roller 5, mutual bonding of the sintered alloy bodies 3a and 3b of the mixed powder a and the mixed powder b is ensured.

(Ninth Step) The back metal 1 having the surface on which the sintered alloy layer A 'made of the mixed powder a and the mixed powder b is applied is again placed in the sintering furnace, and is heated at a temperature of 850 ° C. to 900 ° C. , 3
By sintering for 0 to 60 minutes, the sintering of the sintered alloy layer A 'is advanced to increase the adhesive force with the backing metal 1 or to bond the sintered alloy body 3a of the mixed powder a and the mixed powder b to each other. The sinter bonding with the metal body 3b is promoted. In particular, the sintered alloy 3 of the mixed powder a in this sintering temperature range is controlled by controlling the components.
Since a liquid phase is generated in both the sintered alloy body 3b of the mixed powder a and the mixed powder b, the bonding of the sintered bodies further progresses. After the sintering is completed, rolling is performed by the roller to further increase the density of the sintered alloy layer and to smooth the surface.

(Tenth Step) The multilayer sintered sliding material (intermediate product) manufactured by the above process is round-bent so that the sliding material portion (sintered alloy layer) is arranged inward. Processing is performed and the end faces are joined by welding or the like. (Eleventh step) The member subjected to the round bending is machined to the desired length and surface roughness at the outer and inner peripheral portions, and the manufacture of the slide bearing is completed (see FIG. 5 (c)).

(Twelfth Step) The sintered body, which is the sintered alloy layer of the sliding bearing obtained in the eleventh step, has a difference in density between the convex part and the other part. Some parts have a low density and have a density configuration that allows oil impregnation, and depending on the use situation as a bearing, they are subjected to oil impregnation processing before use.

In the case of the two types of copper-based alloy powder described above,
Basically, it is a copper-tin-based bronze alloy system, but it is not always necessary to use the same alloy system. For example, in the case of a bronze-brass system, bronze-lead bronze system, bronze-iron system, brass -In the case of iron-based, copper-based-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-described material system). is there. From a manufacturing perspective, by sintering the sintering temperature according to each alloy system, it is possible to manufacture bearings with composite phases with various sliding characteristics with controlled joint strength and wear resistance. Will be possible.

In any of the above-mentioned cases, a single process is performed using a process of forming convex portions or concave portions having different densities or components arranged in a geometric pattern on a flat back metal on a sliding surface. Conventional materials (materials with a single structure macroscopically) by changing from a simple structure to a heterogeneous structure
A bearing material having excellent sliding characteristics different from the above can be easily manufactured. In order to enhance the sliding characteristics, it is preferable to use a solid lubricating inorganic material such as molybdenum disulfide in a copper-based alloy powder that forms a low-density phase in the above-described 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 a sliding material having an arbitrary component depending on use conditions. A bearing can be manufactured in which layers are arranged at arbitrary locations,
By controlling the hardness and density of these sliding material layers in the sintering process and the rolling process, they can be used as bearing materials having a sliding surface excellent in load resistance and wear resistance.

[0040]

[Example 1]

(First step) As a back metal, a carbon steel sheet 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. The mixture was mixed for 30 minutes to obtain a mixed powder (a) (copper: 80%, tin: 1).
0%, lead: 10%). In the same process, 15% of atomized tin powder, 30% of atomized iron powder passing through 250 mesh, 10% of graphite powder passing through 100 mesh, and the remainder were mixed with atomized copper powder passing through 250 mesh,
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 the mixture is cut by a corrugated cutting plate so that peaks and valleys are alternately present. After the round bending in the process of manufacturing the bearing material, the ridge portion is cut off so as not to be at least parallel to the sliding direction as the bearing. At this time, the height of the peak was 5 mm, and the valley was cut off so that the mixed powder did not exist.

(Fourth Step) The steel sheet having the mixed powder (a) spread on the surface in a corrugated manner in the previous step is placed in a sintering furnace adjusted to a reducing atmosphere and sintered at a temperature of 850 ° C. for 30 minutes ( Primary sintering), and sintering of the mixed powder (a) and bonding to the back metal were performed simultaneously.

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

(Sixth Step) Next, the mixed powder (b) is sprayed on the surface of the back metal processed up to the fifth step so that the tip of the convex portion of the sintered alloy layer (a ') is peeped. Then, scraping is performed so as to cover the back metal portion of the concave portion so that the spraying surface becomes flat. Thereafter, the material is placed in a sintering furnace adjusted to a reducing atmosphere at a temperature of 870 ° C. for 30 minutes and sintered, and bonded to a sintered alloy layer (a ′) and bonded to a back metal; Then, the mixed powder (b) is sintered.

(Seventh Step) The back metal joined to the sintered alloy layer (a ′) and the sintered alloy layer (b ′) obtained in the previous sixth step is subjected to roller rolling to reduce the density of the sintered alloy layer. Enhance. The thickness of the sintered alloy layer after the rolling was 2.5 mm.

(Eighth Step) The back metal integrally joined with the sintered alloy layer is placed in the sintering furnace, and is heated at 850 ° C. for 3 minutes.
After sintering (secondary sintering) for 0 minutes, the sintering of the sintered alloy layer proceeds, and the bonding force with the back metal and the mutual interaction between the sintered alloy layer (a ′) and the sintered alloy layer (b ′) The bonding strength between them is also improved. Thereafter, the sintered product is rolled by a rolling roller to improve the density of the sintered alloy layer and flatten the surface with high precision. The final sintered alloy layer thickness is 2mm
And an intermediate product was obtained.

(Ninth Step) The intermediate product provided with the flattened sintered alloy layer is subjected to round bending so that the inside becomes a sintered surface, and the wound both ends are joined. Then, by machining, the inner diameter, outer diameter, and end are cut to a desired size, and a sliding bearing is completed.

(Tenth Step) The sliding bearing having the multilayer structure is subjected to an oil impregnation treatment. In the sliding bearing, no pores were observed in the sintered alloy layer (a ') under a microscopic structure, and the density was almost close to the true density. This sintered alloy layer (a ')
, The sintered alloy layer (b ′) showed an oil content of 34%.

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

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

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

(Fourth Step) This press-formed body is arranged on the back metal surface so that holes are periodically arranged in a geometrical pattern, and an iron plate coated with graphite to prevent sintering is placed on the weight. Put as. (Fifth step) The back metal on which the compact and the weight are placed is
Place in a sintering furnace controlled in a reducing atmosphere,
Sinter for 0 minutes. By this operation, sintering of the green compact is promoted and bonding to the back metal is performed. The thickness of the sintered body (compact molded body) after sintering was 3.3 mm.

(Sixth Step) After the completion of sintering, weights (iron plates) are removed from the sintered body, and rolling is performed by a rolling roller in order to improve the sintering density. This rolling reduced the thickness of the sintered body to 3.1 mm.

(Seventh Step) The mixed powder (d) is sprayed onto the back metal surface of the sintered body joint obtained in the above step so as to have a uniform height. (Eighth step) The back metal on which the mixed powder (d) uniformly spread is placed is adjusted to a reducing atmosphere, and the temperature is set to 850 ° C.
And held for 60 minutes in a controlled sintering furnace to perform sintering of the mixed powder (d) and sinter bonding to the back metal and the sintered layer (c ′).

(Ninth Step) The back metal integrally joined 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 the sintered layer is improved.

(Tenth Step) The back metal having the improved sintering density is placed in the sintering furnace, and the temperature is controlled at 850 ° C. and is maintained for 60 minutes. And the bonding force between the sintered alloy layers (d ') and the back metal is further increased.

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

The intermediate product manufactured as described above is
Circular bending so that the sliding layer (sintered alloy layer) is arranged on the inner part, join the bent both ends, and machine the inner and outer diameters to meet the required dimensions. In this way, a sliding bearing having both hard and soft phases free from peeling and having excellent wear resistance is manufactured.

Example 3 (First Step) A 3 mm thick carbon steel plate is degreased and washed as a back metal to clean the surface. (Second Step) After the lead bronze powder passing through the 200 mesh is sprayed on the upper surface of the steel plate, the lead bronze is cut by a corrugated cut-off plate so that the peaks and valleys intersect. The height of the peak of the powder at this time is set to 4 mm. The valley is in a state where the backing metal can be seen.

(Third Step) A steel sheet having lead bronze powder sprayed on the surface in the preceding step is placed in a sintering furnace adjusted to a reducing atmosphere and sintered at 850 ° C. for 30 minutes (primary sintering). And
The powder is sintered and bonded to the back metal. At this time, the height of the sintered body was such that the peak portion was shrunk to 3 mm.

(Fourth Step) The back metal whose surface is joined to the sintered body in a corrugated manner is rolled by a rolling roller. The height of the peak of the sintered body is reduced to 2 mm by rolling.

(Fifth Step) The powder to be further sintered is sprayed on the back metal to which the sintered body having the improved density of the mountain portion by the rolling is joined. The powder used was the above-mentioned lead bronze powder, which was sprayed so that the surface became uniform. Spray height is 4m
m.

(Sixth Step) The back metal on 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 sintering of the secondary sintered body itself is advanced. (Seventh Step) The thickness of the portion of the sintered body of the material after sintering was reduced to 3.5 mm.

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

(Ninth Step) The back metal to which the sintered alloy layer having a desired thickness by rolling is bonded is placed at a temperature of 790 ° C. for 30 minutes in a sintering furnace adjusted to a reducing atmosphere. After sintering, the bonding of the alloy powder which has newly mechanically adhered by rolling in the sintered structure by rolling is more reliably performed.

(Tenth Step) The intermediate product manufactured through the above steps is round-bent and then machined to produce a wound bush, as in the previous embodiment.

Next, a description will be given of a test example in a case where the sliding bearing material provided with the multi-phase sintered sliding layer manufactured according to the above-described embodiment is used for a working machine of a hydraulic shovel.

[Testing Method of Bush of Working Machine] The work of loading the earth and sand was carried out using the bushing of the second embodiment in the hydraulic cylinder bearing portion of the working machine of the hydraulic shovel. As a comparative example, a similar test was performed on a conventionally used iron bush. (Test conditions)-Lubrication: Apply grease only at the beginning of the test. -Test time: 200 hours-Partner material: S53C induction hardened product (axis) The test results performed 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) are mounted on the bush portions used one by one on the left and right sides of the machine. The sliding angles can be considered to be the same. Therefore, from the test results, it can be said that the example material 2 has significantly improved abrasion resistance as compared with the conventional material. In particular, in the conventional material, adhesion occurred between the bush and the shaft, and the shaft was also worn. Of course, there was no abnormality in the shaft for Example Material 2.

The sliding characteristics were evaluated by the following test methods. (Test Method) A bush-shaped test piece and a shaft-shaped test piece are prepared. The shaft is passed through the bush, and the shaft is rocked at a specific angle while applying a load with a hydraulic cylinder from above the bush. Measure the torque that acts during rocking and convert to a coefficient of friction. The load was further increased after the specified number of swings, and the limit was set when abnormal fluctuations in the friction coefficient and the resonance phenomenon (squealing) between the bush and the shaft occurred, and the load immediately before the limit was evaluated as the allowable maximum load. .

(Test conditions) Material type of test piece: Example material 1, Conventional material (iron-based inner surface height)
Frequency hardened material), iron-based oil-impregnated bearing material-Test specimen shape: (1) Bush: outer diameter 95 mm, inside
Diameter 80mm, height 40mm (2) Shaft: outer diameter 80mm, length 300mm ・ Load: 100kg / cm^Two, 200kg / c
m^Two, 300kg / cm^Two, 400kg / cm^Two  500kg / cm^Two, 600kg / cm^Two, 700kg
/ Cm^Two, 800kg / cm^Two 900kg / cm^Two, 1000kg / cm^Two And The load is the total load of the hydraulic cylinder.
It is divided by the apparent area covered.・ Oscillation angle: 100 degrees ・ Number of oscillations: 2000 times under each load condition ・ Speed: 0.17 m / min ・ Lubrication: Initial grease lubrication only
As shown in FIG.

[0074]

[Table 2]

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

From the above test results, it was found that the bearing materials manufactured in Example Material 1 and Example Material 2 were lubricated only at the initial stage, and were not lubricated at all. It shows an excellent value in terms of characteristics, and can be said to be a material that can sufficiently exhibit the function as a bearing. This means that, in view of the fact that grease is being lubricated every 100 hours using the iron bush in the working machine of a hydraulic shovel, the sliding bearing material according to the present invention has Can be greatly extended, or a greasing operation can be omitted.

[Test of Metal Bearing] Evaluation of sliding material
The following test was performed on the material manufactured in Example 3.
The sliding characteristics were evaluated with a machine. (Test conditions) ・ Test machine structure: Pin-desk type constant-speed sliding test ・ Specimen material type: Example 3 material, LBC3 sintered material (uniform
Spraying-sintering material), partner material (S53C induction hardened product)
(Surface roughness: 3S) ・ Lubrication: EO30, 200cc / min ・ Speed: 10m / sec ・ Load: 100kg / cm^Two To 800 kg / cm^TwoMa
And 100kg / cm ^TwoIncrease the load every 10 minutes
Let Changes in friction coefficient and wear amount at that time
And a determination of burn-in is made. Load just before burning
Weight is the maximum allowable load. These test methods and tests
Table 3 shows the test results performed under the conditions.

[0078]

[Table 3]

Example 3 in which a density difference was formed in the sliding phase
Has better familiarity compared to 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, according to the gist of the present invention, the load due to mutual sliding on a flat portion is used as a planar sliding material. Can also be adopted for the support member. Further, as the sintering auxiliary plate described in the above examples, a steel plate having a thickness corresponding to the height necessary for mounting the mixed powder of the sintering material,
By using a number of round holes and square holes and other small holes of any shape at the required pitch, and by using other net-shaped plates, etc., the distribution of portions with different densities in the obtained sintered alloy layer and The arrangement and the like can be set arbitrarily, which contributes to improving workability. The sintering auxiliary plate does not necessarily need to be made of metal, and can sufficiently fulfill its role even with paper or resin.

[0081]

As described above, the present invention has the following effects. 1) A copper-based alloy sintered layer in which phases with different densities and components are geometrically arranged is formed on the sliding part of the bearing. Due to this difference in density, high load resistance and wear resistance are achieved in the high density part. Alternatively, a bearing material that can achieve seizure resistance and excellent sliding characteristics in a low-density portion and that exactly satisfies the requirements as a sliding bearing can be provided without difficulty. 2) In addition, since the distribution state of the high-density portion (phase) and the low-density portion (phase) of the copper-based sintered alloy layer can be arbitrarily set, optimal conditions can be set according to the use conditions. Thus, a bearing that can be adapted to bad conditions that cannot be predicted conventionally can be obtained. 3) If necessary, in order to further improve the sliding characteristics, it is possible to mix a solid lubricating material with a low-density phase that enhances the sliding characteristics, or impregnate with a fat or oil. 4) When manufacturing, it is possible to easily manufacture products under arbitrary conditions without requiring complicated processing and steps, and it has an effect of reducing product cost.

[Brief description of the drawings]

FIG. 1 is a view showing one embodiment of a manufacturing process of a sliding bearing material according to the present invention.

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

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

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

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

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Backing metal 2 Corrugated scraping plate 2 'Scratch plate 3 Mixed powder of copper alloy sintered material 3a, 3b, 3c, 3d Sintered alloy layer 4 Incinerator 5 Roller roller 6 Sintering auxiliary plate 6' Sintering auxiliary plate Hole 10 Bearing

Claims (13)

[Claims] 1. A sliding bearing material having a steel back metal and a copper-based alloy sintered layer joined to the back metal, wherein the copper-based alloy sintered layer has a high density phase and a low density phase. A sliding bearing material characterized in that: 2. A copper-based alloy sintered material having an excellent load-bearing performance, wherein a copper-based alloy sintered material having an excellent load-bearing performance is geometrically distributed, and a copper-based alloy sintered material having an excellent sliding property is provided in the distribution gap. The sliding bearing material according to claim 1, wherein 3. The sliding bearing material according to claim 1, wherein the copper-based alloy sintered layer is made of one selected from the group consisting of a copper-lead alloy, a lead-bronze alloy, and a bronze alloy. 4. The sliding bearing material according to claim 1, wherein the copper-based alloy sintered layer contains a low-density phase containing a solid lubricant such as graphite or molybdenum disulfide. 5. The sliding bearing material according to claim 1, wherein a portion of a phase having a low density in the copper-based alloy sintered layer is impregnated with oil or fat. 6. A copper-based alloy sintered powder material having a characteristic different from that of the copper-based alloy sintered powder material after sintering by dispersing a kind of copper-based alloy sintered material on the surface of the steel back metal. Powder material,
The former sintered body of the copper-based alloy sintered powder material is covered or sprayed so as to have the same height, a sintering operation is added again, and then rolling is performed. A method for producing a sliding bearing material, wherein a high-density phase and a low-density phase or a phase having different components are geometrically distributed and formed. 7. When forming the copper-based alloy sintered layer on the back metal surface, first, a copper-based alloy sintered material excellent in load-bearing performance is sprayed on a geometric pattern and sintered, and then sliding is performed. 7. The sintering operation is performed again by spraying a copper-based alloy sintered material having excellent characteristics to gaps between sintered layers of the sintered copper-based alloy sintered material. 3. The method for producing a slide bearing material according to claim 1. 8. When forming the copper-based alloy sintered layer on the back metal surface, first, a copper-based alloy sintered material excellent in sliding properties is sprayed on a geometric pattern and sintered, and then a load bearing capacity is applied. 7. The sintering operation is performed again by spraying a copper-based alloy sintered material having excellent performance to a gap portion of a sintered layer of the sintered copper-based alloy sintered material. 3. The method for producing a slide bearing material according to claim 1. 9. A sintering auxiliary plate having a large number of holes formed at required intervals is arranged on a back metal surface to geometrically distribute the copper alloy sintered powder material. The hole of the auxiliary plate is filled with a copper-based alloy sintered powder material, and after sintering, the sintering auxiliary plate is removed, and a sintered body is independently formed on the back metal. The method for producing a sliding bearing material according to any one of the above. 10. A sintering auxiliary plate made of a flammable material, such as paper or resin, having a large number of holes formed at a required interval to distribute the copper-based alloy sintered powder geometrically. Is placed on the backing metal surface, the hole of this sintering auxiliary plate is filled with a copper-based alloy sintered powder material, and the sintered body is separated by removing the residue of the sintering auxiliary plate that has disappeared after sintering. The method for producing a sliding bearing material according to any one of claims 6 to 8, wherein the sliding bearing material is formed. 11. Forming a high-density phase and a low-density phase of a copper-based alloy sintered layer distributed and formed on the back metal surface,
Roller rolling after sintering of the copper alloy sintering powder material to be sprayed first, then spraying and sintering other copper alloy sintering powder material, and then roller rolling again to obtain a high-density phase The method for producing a sliding bearing material according to claim 6, wherein the low-density phase is mixedly formed. 12. When the copper-based alloy sintering layer is formed on the back metal surface, the copper-based alloy sintering in the next step is performed on the copper-based alloy sintering material layer that has been sintered in a geometric pattern on the back metal surface. Spreading to cover with the material, or spraying to make the same height, by controlling the sintering temperature to increase the bonding strength of both sintered materials, and the sintered layer and the high density part The method for producing a sliding bearing material according to any one of claims 6 to 10, wherein the low-density portion and the low-density portion are formed in a geometric pattern and subjected to an oil-impregnating treatment. 13. The geometric spraying of the copper alloy sintered powder material on the back metal so that a high-density portion is not continuous in a sliding direction of a mating material as a product bearing. 12. The method for producing a sliding bearing material according to any one of claims 11 to 11.