JPH09303373A - Laminated sliding member and sliding bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated sliding member and a sliding bearing in which both antinomic characteristics such as fatigue resistant property and surface performance can be obtained at a high level. SOLUTION: This laminated sliding member is formed in such a way that as a surface layer, an alloy B consisting of Sn, less than 6 to 15%; one or two selected from Pb and Sb, 0.1 to 10%; Si, 0.1-4.5%; one or two selected from Cu and Cr, 0.1-2.0%; respectively in weight%, and substantially Al for the rest, is laminated on a Cu-Pb series high lead bronze bearing alloy A consisting of Pb, 5 to 50%; Sn, 5 % or below, respectively in weight %, and substantially Cu for the rest. A back plate is arranged on the rear surface of the laminated sliding member.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bearing used as a structural part of various mechanical devices such as automobiles, machine tools, agricultural machines and the like, and a laminated sliding member and a sliding bearing suitable as materials for sliding members. is there.

[0002]

2. Description of the Related Art In recent years, Kelmet (a general term for Cu-Pb-based high lead bronze bearing alloys) has been widely used as a bearing alloy for internal combustion engines, particularly from the viewpoint of heat resistance, wear resistance, fatigue resistance and the like. .

[0003]

However, although Kelmet is excellent in fatigue resistance and the like, it is inferior in seizure resistance as it is. Therefore, it was necessary to form a Pb-Sn overlay layer on the surface.

However, in the high speed and high load range, Pb-S
Experiments have confirmed that those having an n-type overlay layer on the surface show a remarkable increase in friction as compared to a bearing alloy having an Al-based alloy surface layer having good thermal conductivity.

According to the conventional wisdom, in the high speed / high load range, when the temperature of the lubricating oil becomes high, the oil viscosity decreases, and the oil film becomes thin, and as a result, the friction as the shearing resistance of the oil decreases. At this time, the difference in bearing material has no effect.

As a result of some research conducted by the present inventors on the frictional behavior of the bearing when the temperature of the lubricating oil becomes high, the viscosity decreases as the temperature of the oil becomes high, and the oil film However, it was found that the oil film pressure was increased, and as a result, the oil viscosity under high pressure was significantly increased, which in turn increased the friction as the shear resistance of the oil. Further, under such a condition, the local high oil film pressure naturally impairs the fatigue resistance of the bearing.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of such conventional problems, and it is effective to lower the temperature of the oil film, which is the starting point of the mechanism, in order to reduce friction in a high speed / high load range. For that purpose, it is important to increase the thermal conductivity of the bearing alloy, which is also irrelevant in the past, which also plays a role of quickly removing the local heat generation of the intervening oil. Is based on that.

By increasing the thermal conductivity of the bearing alloy by improving the thermal conductivity of the surface layer, the friction loss in the lubricating oil in the high speed / high load range can be significantly reduced as compared with the conventional sliding bearing.

Further, in addition to improving the strength of the bearing alloy, by using the bearing of the present invention having high thermal conductivity to reduce the intervening oil film pressure, the fatigue resistance is improved and the surface performance is at a level unprecedented. Can be achieved with.

Therefore, an object of the present invention is to provide a laminated sliding member and a sliding bearing which can obtain both anti-fatigue properties and surface properties, which are trade-off characteristics, at a high level which has never been obtained.

[0011]

A laminated sliding member according to the present invention has a P content of% by weight, as defined in claim 1.
b: 5 to 50%, Sn: 5% or less, the balance being substantially Cu
On a Cu-Pb-based high lead bronze bearing alloy A which is a Kelmet alloy consisting of Sn as a surface layer in a weight percentage of Sn: 6 to
Less than 15%, one or two selected from Pb and Sb: 0.1 to 10%, Si: 0.1 to 4.5%, C
one or two selected from u and Cr: 0.1 to
It is characterized in that an alloy B having a composition of 2.0% and the remainder being substantially Al is laminated.

In the embodiment of the laminated sliding member according to the present invention, as described in claim 2, the alloy B may be subjected to heat treatment for strain relief. .

The laminated plain bearing according to the present invention is characterized in claim 3.
As described in (1), the laminated sliding member according to claim 1 or 2 is characterized in that a back metal is provided on the back surface.

In the embodiment of the laminated sliding bearing according to the present invention, as described in claim 4, the back metal can be a steel plate.
Between alloy A and alloy B, pure Al
Intervening layers and / or alloy A and alloy B as claimed in claim 6.
And an Al alloy layer containing no Sn, Pb, or Sb may be interposed between and.

[0015]

The laminated sliding member according to the present invention, as defined in claim 1, has a Pb of 5 to 50% by weight.
%, Sn: 5% or less, and a balance of Sn: 6 to less than 15% by weight as a surface layer on a Cu-Pb-based high lead bronze bearing alloy A which is a Kelmet alloy whose balance is substantially Cu.
One or two selected from Pb and Sb: 0.1
-10%, Si: 0.1 to 4.5%, one or two selected from Cu and Cr: 0.1 to 2.0%, and an alloy B having the balance substantially Al is laminated. The reason for limiting each component and numerical value will be described below together with the action of each element.

First, the reasons for limiting the components and numerical values of alloy A will be described together with the action of each element.

(A-1) Pb: 5 to 50% Pb is effective as a lubricating component and serves to improve seizure resistance. In the case of alloy A, this is used as a lower layer and alloy B is used. When the alloy B is laminated as a surface layer, the conformability and the foreign matter embedding property are not required, and it is added to prevent seizure when the alloy B is worn. However, if the addition amount is less than 5%, the effect is small, and if it exceeds 50%, Cu
The strength of the matrix decreases, the fatigue resistance tends to deteriorate, and the thermal conductivity decreases, increasing friction loss in high temperature lubricating oil, which is one of the features of the laminated sliding member and sliding bearing of the present invention. The ability to suppress is impaired.

(A-2) Sn: 5% or less Sn forms a solid solution in the Cu matrix and strengthens it, and at the same time improves the corrosion resistance. However, if the addition amount exceeds 5%, the elongation is reduced and the density strength during lamination is lowered,
Sliding performance or bearing performance is degraded.

Next, the reasons for limiting the components and numerical values of alloy B will be explained together with the action of each element.

(B-1) Sn: 6 to less than 15%, Pb,
One or two selected from Sb: 0.1 to 10
% Sn, Pb, and Sb are effective as lubricating components and have excellent seizure resistance. Further, the compatibility of the alloy B used as the surface layer and the foreign matter embedding property are enhanced.

However, when Sn is less than 6% and the total amount of Pb and Sb is less than 0.1%, the effect is small, and Sn is 15%.
As described above, when the total amount of Pb and Sb exceeds 10%, the thermal conductivity decreases, and an increase in friction loss in high temperature lubricating oil, which is one of the features of the laminated sliding member and the sliding bearing of the present invention, is increased. The ability to suppress is impaired.

(B-2) Si: 0.1 to 4.5% Si contributes to the improvement of seizure resistance of the alloy B as the surface layer, but if less than 0.1%, its effect is small. If it exceeds 5%, the conformability and workability such as rolling deteriorate.

(B-3) One or two selected from Cu and Cr: 0.1 to 2.0% Cu and Cr improve the load resistance and heat resistance of the alloy B as the surface layer. However, if less than 0.1%, the effect is small,
If it exceeds 2.0%, the conformability and workability such as rolling deteriorate.

Next, with respect to the method for producing the alloy B used as the surface layer in the laminated sliding member according to the present invention,
Usually, a method of rolling a plate-like cast material is used.
If it exceeds 4%, segregation occurs in the casting method and it is difficult to form a uniform material structure. Therefore, the plate material may be made by powder rolling or sintering, or it can be directly laminated on the alloy A by thermal spraying. is there.

Then, as described in claim 2,
The alloy B may be subjected to a heat treatment for strain removal, if necessary.

The laminated plain bearing according to the present invention is characterized by claim 3.
As described in claim 1, the laminated sliding member according to claim 1 or 2 has a structure in which a back metal is provided on the back surface. By adopting such a structure, fatigue resistance and surface Both of the trade-off characteristics of performance will be obtained at a high level that has never been seen before.

As the back metal in this case, a steel plate can be used as described in claim 4, and the use of the steel plate provides the bearing with the rigidity required.

If the amount of Sn in alloy B increases, the adhesion with alloy A may deteriorate depending on the cladding conditions. In this case, as described in claims 5 and 6, between the alloy A and the alloy B, pure A of about 1 to 15 μm is provided.
The 1 layer and / or the Al alloy layer not containing Sn, Pb, or Sb may be interposed for improving the adhesion.

[0029]

As described in claim 1, the laminated sliding member according to the present invention has a Pb of 5 to 50% by weight.
%, Sn: 5% or less, and a balance of Sn: 6 to less than 15%, Pb, Sb as a surface layer on a Kelmet alloy (Cu-Pb-based bearing alloy) A whose balance is substantially Cu.
One or two selected from among: 0.1 to 10%,
Si: 0.1 to 4.5%, one or two kinds selected from Cu and Cr: 0.1 to 2.0%, and a structure in which an alloy B composed of the balance substantially Al is laminated Therefore, both anti-fatigue properties such as fatigue resistance and surface performance are realized at unprecedented high levels, and especially under high temperature lubrication conditions, improvement of fluid lubrication performance improves fatigue resistance. , And suppression of temperature rise due to reduction of frictional heat generation are significantly superior to conventional sliding members.

In the embodiment of the laminated sliding member according to the present invention, as described in claim 2, the alloy B is subjected to heat treatment for strain relief, It is possible to obtain a remarkably excellent effect that a sliding member having excellent toughness and stability can be obtained.

The laminated slide bearing according to the present invention has a structure in which a backing is provided on the back surface of the laminated sliding member according to claim 1 or 2 as described in claim 3. Therefore, both anti-fatigue properties such as fatigue resistance and surface performance have been achieved at a high level that has never been achieved, and especially under high temperature lubrication conditions, fluid lubrication performance improves fatigue resistance and The remarkable effect that the suppression of the temperature rise of the oil film due to the improvement of the heat removal property of the alloy is remarkably superior to the conventional plain bearings is brought about.

In the embodiment of the laminated slide bearing according to the present invention, as described in claim 4, the back metal is a steel plate, so that the strength required for the bearing can be obtained. And a pure Al layer is interposed between the alloy A and the alloy B as described in claim 5, and / or the alloy A as described in claim 6. Between Sn and alloy B, Sn, Pb, S
By interposing the Al alloy layer not containing b, the remarkably excellent effect that the adhesion between the alloy A and the alloy B can be further improved is brought about.

[0033]

Next, examples will be described together with comparative examples.

Examples 1 to 4 and Comparative Examples 1 to 4 First, Examples 1 to 1 shown in the column of alloy A (lower layer) in Table 1
4, after the Cu-Pb-based alloy having the composition of Comparative Examples 1 to 4 is melted, it is continuously poured onto the steel plate, and immediately after the pouring, water is cooled from the lower surface of the steel plate to rapidly cool, Cast Kelmet alloy (Cu-
A Pb-based high lead bronze bearing alloy) was laminated to produce a laminated material.

On the other hand, Al-Sn having the composition of Examples 1 to 4 and Comparative Examples 1 to 4 shown in the column of alloy B (surface layer) in Table 1
A series alloy was cast by a continuous casting as a plate-shaped material having a thickness of 20 mm, the upper and lower surfaces of each cast billet were cut by 1 mm, and then cold rolled to a thickness of 1 mm. In this state, a heat treatment at 200 to 300 ° C. was performed to remove the strain.

Next, the above laminated material is subjected to dimensional adjustment, and the contact surfaces of the laminated material and the alloy B are cleaned, respectively, and then the alloy A of the laminated material is used as a lower layer and the alloy B is used as a surface layer to perform cladding. It was

Subsequently, the surface was further mechanically removed. As a result, the thickness of the steel plate as the back metal was about 1.20 mm, the layer thickness of alloy A as the lower layer was about 0.25 mm, and the surface layer was A plain bearing having a layer thickness of alloy B of about 0.05 mm and a total thickness of about 1.5 mm was obtained.

Examples 5 to 6 Cu-Pb alloy powders having the compositions of Examples 5 to 6 shown in the column of alloy A (lower layer) in Table 1 were continuously applied on a steel sheet in a reducing atmosphere. After spraying and sintering at a temperature of 750 to 900 ° C., this was pressed and then sintered and pressed again, and a sintered Kelmet alloy (Cu-Pb type high lead bronze bearing alloy) was laminated on the steel plate. A laminated material was produced.

On the other hand, Al-Sn alloys having the compositions of Examples 5 to 6 shown in the column of alloy B (surface layer) in Table 1 were cast by continuous casting as a plate material having a thickness of 20 mm, and each cast billet. The upper and lower surfaces were cut by 1 mm and then cold rolled to a thickness of 1 mm. 200-30 in this state
The strain was removed by heat treatment at 0 ° C.

Next, the above laminated material is subjected to dimensional adjustment, and the contact surfaces of the laminated material and the alloy B are cleaned, respectively, and then the alloy A of the laminated material is used as a lower layer and the alloy B is used as a surface layer to perform cladding. It was

Subsequently, the surface was further mechanically removed. As a result, the thickness of the steel plate as the back metal was about 1.20 mm, the layer thickness of alloy A as the lower layer was about 0.25 mm, and the surface layer was A plain bearing having a layer thickness of alloy B of about 0.05 mm and a total thickness of about 1.5 mm was obtained.

Comparative Examples 5 and 6 Cu-Pb type alloys having the compositions of Comparative Examples 5 and 6 shown in the column of alloy A (lower layer) in Table 1 were melted and then continuously poured onto a steel plate. Immediately after pouring, water was cooled from the lower surface of the steel sheet to quench it, thereby producing a laminated material in which a cast kelmet alloy (Cu-Pb-based high lead bronze bearing alloy) having a dendrite structure was laminated on the steel sheet. Then, the laminated material was subjected to dimensional adjustment, and as a result, the thickness of the steel plate as the back metal was about 1.20 mm, and the layer thickness of the cast kelmet was about 0.3.
A plain bearing with a total thickness of about 1.5 mm in mm was obtained.

Comparative Example 7 An Al—Sn alloy having the composition of Comparative Example 7 (same as Examples 1 and 5) shown in the column of alloy B (surface layer) in Table 1 was continuously cast into a plate shape with a thickness of 20 mm. It was cast as a material, the upper and lower surfaces of the cast billet were cut by 1 mm, and then cold-rolled to a thickness of 1 mm. 200-30 in this state
The strain was removed by heat treatment at 0 ° C.

After that, the alloy B was clad on the steel plate to be the back metal, and the surface was mechanically removed. As a result, the thickness of the steel plate as the back metal was about 1.2 mm and Layer thickness is about 0.3 mm and total thickness is about 1.5 mm
Got a plain bearing.

Comparative Example 8 A Cu-Pb alloy having the composition of Comparative Example 8 shown in the column of Alloy A (lower layer) in Table 1 was melted, and then continuously poured onto a steel plate, after pouring. Immediately, the lower surface of the steel sheet was rapidly cooled by water cooling to produce a laminated material in which a cast kelmet alloy (Cu-Pb-based high lead bronze bearing alloy) having a dendrite structure was laminated on the steel sheet. Then, after dimensional adjustment of this laminated material, pretreatment such as degreasing is performed on the surface of Kelmet, and Pb containing 10 wt% Sn and 2 wt% Cu is further applied thereto.
—Sn—Cu plating was applied to a thickness of 20 μm to obtain a slide bearing having a total thickness of about 1.5 mm.

[0046]

[Table 1]

(Seizure resistance test) Examples 1 to 6 and Comparative Example 1
2 and each of the plain bearings obtained in Comparative Examples 5 to 8 had a width of 35
A test piece having a length of 35 mm and a length of 35 mm was cut out, and a seizure resistance test was performed using a Suzuki abrasion tester under the conditions shown in Table 2. Table 3 shows the results.

[0048]

[Table 2]

[0049]

[Table 3]

As is clear from Table 3, Example 1 of the present invention
It can be seen that the slide bearings of Nos. 6 to 6 have seizure resistance equivalent to or higher than that of the slide bearing of Comparative Example 8, which has been considered to have excellent seizure resistance.

On the other hand, the sliding bearings of Comparative Examples 1 and 2 in which the component of the alloy B as the surface layer is out of the present invention are inferior to the sliding bearings of the examples of the present invention in seizure resistance and correspond to alloy B. It can be seen that the sliding bearing of Comparative Example 5 in which the surface layer is not provided and the Kelmet alloy A is used as the surface layer is further inferior in seizure resistance.

Further, as in Comparative Example 5, the sliding bearing of Comparative Example 6 in which the alloy A is the surface layer and the composition of which is out of the present invention has remarkably inferior seizure resistance. It can be seen that even if the same surface layer as that of the plain bearing is provided, it is difficult to maintain the sliding performance required for the bearing when the surface layer is worn.

(High temperature friction property) Each of the plain bearings obtained in Examples 1 to 6 and Comparative Example 8 was processed into a half bearing shape, and a bearing unit testing machine developed by a part of the inventors (Japan Society of Mechanical Engineers). 71st
National Conference Lecture Collection Vol. D, 1993 p3
32-334), the frictional force when the sliding surface became high temperature was measured under the conditions shown in Table 4. Sliding surface is 130 ° C
Table 5 shows the friction torque at that time.

[0054]

[Table 4]

[0055]

[Table 5]

As is clear from Table 5, Example 1 of the present invention
It can be seen that the plain bearings Nos. 6 to 6 have better friction characteristics than the plain bearing of Comparative Example 8 having the Pb-Sn-Cu overlay layer on the surface.

(Fatigue Resistance Test) Examples 1 to 6 and Comparative Examples 1 to 1
Each slide bearing obtained in Example 5 and Comparative Example 7 was processed into a half bearing shape so as to be applied as an engine part, and an underwood test was conducted under the conditions shown in Table 6. The results are shown in Table 7.

[0058]

[Table 6]

[0059]

[Table 7]

As is clear from Table 7, Comparative Example 1 in which the components of the surface layer (alloy B) are out of the present invention and Comparative Examples 3 and 4 in which the components of the lower layer (alloy A) are out of the present invention, and further alloy B The sliding bearing of the sliding bearing 5 of Comparative Example 5 in which the surface layer corresponding to the above was not used and the sliding bearing of Comparative Example 5 in which the Kelmet alloy was used as the surface layer, and the sliding bearing of Comparative Example 7 in which the lower layer was not provided were more fatigue resistant than the sliding bearings of the Examples. Is inferior.

From these three types of test results, it is clear that the sliding bearing according to the present invention simultaneously achieves seizure resistance, fatigue resistance and reduction of friction loss in high temperature lubricating oil. It was found that the bearing alloy had performances that were impossible.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masahiko Shioda 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Prefecture Inside Nissan Motor Co., Ltd. (72) Inventor Kenshi Ushijima 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Inside the corporation

Claims (6)

[Claims] 1. Pb: 5 to 50%, Sn: 5 by weight
% Or less, and the balance being substantially Cu, on a Cu-Pb-based high lead bronze bearing alloy A, as a surface layer, by weight%, S
n: 6 to less than 15%, 1 selected from Pb and Sb
Type or 2 types: 0.1 to 10%, Si: 0.1 to 4.5
%, Cu, or one or two selected from Cr:
Alloy B consisting of 0.1 to 2.0% and the balance substantially Al
A laminated sliding member comprising: 2. The laminated sliding member according to claim 1, wherein the alloy B is heat-treated for strain relief. 3. A laminated slide bearing, wherein a back metal is provided on the back surface of the laminated slide member according to claim 1. 4. The laminated sliding bearing according to claim 3, wherein the back metal is a steel plate. 5. The laminated slide bearing according to claim 3, wherein a pure Al layer is interposed between alloy A and alloy B. 6. Sn, Pb, S between alloy A and alloy B
The laminated slide bearing according to claim 3, wherein an Al alloy layer not containing b is interposed.