JP2736611B2 - Manufacturing method of plain bearings - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a sliding bearing, and more particularly to a method for manufacturing a sliding bearing used in an internal combustion engine. 2. Description of the Related Art Conventionally, as a method of manufacturing a plain bearing, A
A plating layer such as a Ni plating layer is formed on the surface of a lining material made of
2. Description of the Related Art There is known a method for manufacturing a plain bearing in which an overlay layer made of a system alloy, a Sn system alloy, or the like is formed. In this type of sliding bearing manufacturing method, the plating layer is
This is necessary to increase the adhesion strength between the lining material made of an Al- based alloy and the overlay layer made of a Pb-based alloy or the like. If a plating layer is formed between the two, the lining material and the overlay are interposed through the plating layer. The layers can be firmly connected. [0003] However, especially in recent automobile engines, cast shafts, for example, FCD70 are frequently used due to cost reduction, so that the overlay layer is worn out early due to burrs around the graphite. When the overlay layer is worn and the plating layer or the lining material is exposed, the seizure resistance is rapidly reduced and seizure occurs. Further, even a general forged shaft tends to be used at a high rotation speed and a high load, and the same problem occurs. The present invention has been made in view of such circumstances, and provides a method for manufacturing a plain bearing having excellent seizure resistance. [0004] That is, the present invention provides an Al
Forming a surface of a lining material made of a base alloy into an uneven surface of 2 to 20 μmRz by etching; and forming a plating layer made of a single or alloy of Ni, Cu, Cr, Fe on the uneven surface of the lining material. A step of forming the surface with a thickness of 0.01 to 2 μm so that the surface becomes an uneven surface following the uneven surface, and a step of forming an overlay layer having a thickness of 1 to 25 μm on the surface of the plating layer. It is intended to provide a method for manufacturing a plain bearing, characterized by having a bearing. According to the above manufacturing method, an uneven surface is formed on the surface of the lining material, a plating layer having the uneven surface is formed on the surface of the lining material, and an overlay layer is formed on the surface of the plating layer. Will be formed. The uneven surface of the lining material is 2 to 20 μm Rz, the thickness of the plating layer is in the range of 0.01 to 2 μm, and the thickness of the overlay layer is in the range of 1 to 25 μm. When the plating layer and the overlay layer are worn down to the convex surface, the plating layer and the overlay layer are left in the concave portions of the lining material, and therefore, the seizure resistance due to the remaining overlay layer is reduced. The occurrence of seizure can be prevented by preventing a significant decrease. DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiment. In FIG. 1A, a lining material 1 is made of an Al- based alloy, and a concave portion 2 is formed on its surface to form a concave-convex surface. doing. The uneven surface on the surface of the lining material 1 is formed by alkali, acid, or electrolytic etching, and has a roughness in a range of 2 to 20 μmRz, preferably in a range of 4 to 10 μmRz. 2μ roughness
If it is smaller than about mRz, it will be difficult to form the recess 2 covered with the plating layer 3 described below.
If the roughness is unnecessarily large, the fatigue resistance is reduced as described later, so that the maximum value is limited to 20 μmRz. As the Al- based alloy used for the lining material 1, an alloy composed of 3 to 20% of Sn, 10% or less of Si, and the balance of Al can be used in terms of% by weight. The following Cu and / or Mg, and additionally or alternatively 8% or less of Pb, further additionally or alternatively 0.1-1% Cr, Mn, Zr, V, Mo , Co, or Nb may be added. The lining material 1 can be manufactured by an appropriate method such as casting, casting rolling, sintering, and extrusion. In FIG. 1a, 5 indicates an Al matrix, 6 indicates Si, and 7 indicates Sn-Pb.
Further, if necessary, a back metal can be provided on the back surface of the lining material 1, and the back metal can be adhered directly or through an adhesion layer such as a Ni plating layer or a pure Al layer. Next, a plating layer 3 made of a simple substance or an alloy of Ni, Cu, Cr, Fe is formed on the surface of the lining material 1, that is, on the uneven surface, and the plating layer 3 is formed on the uneven surface of the lining material 1. The inner surface of the recess 2 is covered with a plating layer 3. The plating layer 3 is formed by wet plating such as electroplating,
Alternatively, it is formed by dry plating such as sputtering or ion plating. At this time, the plating layer 3
Is preferably formed by electroplating. According to the electroplating, since the plating layer 3 can be made to conform to the uneven surface of the lining material 1 satisfactorily, it is easy to secure a concave portion following the concave portion 2 on the surface of the plating layer 3,
In addition, it is easy to form the plating layer 3 with few plating defects such as pinholes. If the thickness of the plating layer 3 is too small, the lining material 1 and the overlay layer 4 cannot be sufficiently adhered to each other. If the thickness is too large, the plating layer 3 is completely filled in the recess 2 and the plating layer 3 Since it becomes difficult to form the covered recess 2, 0.0
The range is about 1 to 2 μm, preferably 0.01 to 0.9 μm, and more preferably 0.1 to 0.9 μm. Further, a Pb-based overlay layer 4 is formed on the surface of the plating layer 3, that is, on the uneven surface.
Is filled in the recess 2 whose inner surface is covered with the plating layer 3 and is in close contact with the plating layer 3, and has a smooth surface. As the Pb-based alloy used for the overlay layer 4, one obtained by adding one or more of Pb to 15% or less of Sn, 15% or less of In, 5% or less of Cu, and 5% or less of Sb is used. it can. This overlay layer 4
Is wet plating such as electroplating, or sputtering,
It can be formed by dry plating such as ion plating, and its thickness is in the range of 1 to 25 μm. FIG. 2A shows a conventional method of manufacturing the same type of plain bearing, and a portion corresponding to the portion shown in FIG.
The same reference numerals are denoted by '. As can be understood from the figure, the difference from the present invention is that the plating layer 3 'is completely filled in the recess 2' and the surface of the plating layer 3 'has a smooth surface. The point is that an overlay layer 4 'is formed on the layer 3'. That is, conventionally, the surface of the lining material 1 'is formed as smooth as possible in order to ensure fluid lubrication, and the plating layer 3' is formed thick to completely fill the recess 2 'with the plating layer 3'. Thus, the influence of the roughness of the lining material 1 'is reduced so that the surface of the plating layer 3' is formed to be smoother. In other words, the concave portion 2 'is not formed as actively as the concave portion 2 of the present invention, but is a concave portion which is formed to such an extent that the surface of the lining material 1' is formed as smooth as possible. The height is about 1 μmRz or less, and at most about 1.5 μmRz. In the sliding bearing manufactured by the manufacturing method of the present invention described above,
As shown in FIG. 1B, even if the plating layer 3 and the overlay layer 4 are worn down to the convex surface of the lining material 1, the plating layer 3 and the overlay layer 4 remain in the recess 2 so that FIG. As shown in FIG. 1c, the lining material 1,
The plating layer 3 and the overlay layer 4 are exposed. Therefore, the overlay layer 4 suppresses a decrease in seizure resistance, and the Si added and precipitated in the lining material 1.
When a hard component such as 6 improves wear resistance, and the material forming the plating layer 3 is hard Ni or Cr,
They also function to improve wear resistance. Therefore, at the start of the use of the method of manufacturing a plain bearing, the overlay layer 4 can achieve an improvement in initial conformability, a reduction in one-sided contact, and a reduction in friction, and the plating layer 3 and the overlay layer 4 can be formed in a convex shape of the lining material 1. Even if the surface is worn, good seizure resistance and wear resistance can be maintained. On the other hand, in the conventional method of manufacturing a plain bearing, when the overlay layer 4 'is worn, as shown in FIGS. 2b and 2c, the plating layer 3' is exposed on the entire sliding surface, or furthermore, the plating layer 3 '. When the abrasion occurs, the lining material 1 'is exposed, so that seizure resistance is significantly reduced. Next, effects of the present invention will be described based on test results. The test results shown in FIG. 3 show that the product 1 of the present invention produced by the method of the present invention and the comparative material 1
4 shows the results of measuring the baking surface pressure under the following test conditions. (Test conditions) Test machine: Journal type baking test machine Rotation speed: 1300 rpm (speed 2.7 m / s) Lubricating oil: 10 W-30 Oil temperature: 140 ° C. Mating shaft: FCD70 (Hv 200 to 250) Shaft roughness: 0. 5~0.6μmRz load pattern: 1 in the first 60 minutes 50 Kg / cm ^2, the next 45 minutes 100 Kg / cm ^2, thereafter every 45 minutes
Increase by 00Kg / cm ² until burning. The product 1 of the present invention used in the present test was prepared by adding Al -1 to a back metal made of SPCC.
A 0.25 mm thick lining material made of 2Sn-1.5Pb-3Si-1Cu-0.2Cr is pressed against the surface, and then the surface of the lining material is 6 μm thick by alkali etching.
After forming an irregular surface of mRz, 0.3 mm by electroplating.
A Ni plating layer having a thickness of μm is formed, and an overlay layer having a thickness of 5 μm made of Pb-7.5Sn-5.5In-0.1Cu is formed on the Ni plating layer by electroplating. On the other hand, the comparative material 1 was obtained by removing the plating layer and the overlay layer from the product 1 of the present invention while stopping the etching performed on the surface of the lining material of the product 1 of the present invention. The etching of the surface of the lining material of the product 1 was stopped, and the thickness of the plating layer was increased to 2.5 μm. The comparative material 3 was the product of the present invention 1 from which the plating layer was omitted. The plating layer of Inventive Product 1 was 1 μm thick, and the overlay layer was omitted. In the comparative materials 1 to 4, the other configurations are the same as those of the product 1 of the present invention. When the cross-sectional shape was measured, the product 1 of the present invention had the cross-sectional shape shown in FIG. 1A, but the comparative material 2 had the cross-sectional shape shown in FIG. 2A. As is clear from the test results shown in FIG.
When the overlay layer and the plating layer were worn out, the product 1 of the present invention had the cross-sectional shape shown in FIG.
4, a greater seizure resistance can be obtained. On the other hand, particularly, in the comparative material 4, the plating layer is in direct contact with the mating shaft, and also in the comparative material 2, the overlay layer is worn out early and the plating layer comes into sliding contact with the mating shaft, so that the seizure resistance is inferior. The result is. On the other hand, the comparative materials 1 and 3 have the lining material in sliding contact with the mating shaft, so that the lining material itself exhibits the seizure resistance. Next, the test results shown in FIG.
4 shows the results of measuring the wear amount under the following test conditions for Nos. 4 to 4. (Test conditions) Testing machine: Reciprocating dynamic load testing machine Rotation speed: 2300 rpm Surface pressure: 0 ± 1000 Kg / cm ² Lubricating oil: 10 W-30 Oil temperature: 140 ° C. Partner shaft: FCD70 (Hv200-250) Shaft roughness: 0 0.8 to 1.0 μmRz As shown in the test results in FIG. 4, the comparative material 4 in which the plating layer is in direct contact with the mating shaft has a small amount of abrasion because the plating layer is hard, but it is seized early and cannot be measured. . Similarly, the comparative material 2 in which the overlay layer wears out early and the plating layer comes into sliding contact with the mating shaft also shows the same state of wear as the product 1 of the present invention until the overlay layer wears out. When the plating layer comes into sliding contact with the mating shaft due to wear, seizure occurs and measurement becomes impossible. On the other hand, the comparative material 3 having no plating layer has a small adhesion strength between the overlay layer and the lining material, so that the overlay layer is worn so that the overlay layer is peeled off. Therefore, the amount of wear rapidly increases after the start of the test. Thereafter, since the lining material comes into sliding contact with the mating shaft, the amount of wear increases at a substantially constant gradient based on the material of the lining material. Further, in the comparative material 1 having neither the plating layer nor the overlay layer, the wear amount increases at a substantially constant gradient based on the material of the lining material from the start of the test. On the other hand, the product 1 of the present invention has a relatively large amount of wear until the overlay layer is worn, but after the plating layer and the overlay layer are worn to the cross-sectional state shown in FIG. Since the sliding contact is made by the layer and the overlay layer, the amount of wear increases at a smaller gradient than the comparative materials 1 and 3 in which only the lining material comes into sliding contact. The amount of wear is reduced. Next, FIG. 5 shows the test results of measuring the baking surface pressures of the products 2 to 4 of the present invention under the test conditions described above. The present invention products 2 to 4 each have a Ni plating layer as a plating layer of the present invention product 1,
The Cr plating layer, Fe plating layer, and Cu plating layer were changed, and the other conditions were the same. As shown in the test results of the same figure, all of the products 2 to 4 of the present invention have excellent seizure resistance compared with the comparative materials 1 to 4. In addition, the test results shown in FIG. 6 show that the thickness of the plating layer was variously changed in the product 1 of the present invention,
It shows the result of measuring the surface pressure for printing under the above test conditions. From this result, the maximum value of the thickness of the plating layer is about 2 μm as described above. On the other hand, the minimum value of the thickness of the plating layer is such that if the thickness is too small, it becomes difficult to reliably cover the entire surface of the uneven surface of the lining material 1 with the plating layer, and variations occur between products. Therefore, the minimum value of the thickness of the plating layer is 0.01μ
m. Further, the test results shown in FIG. 7 show the results obtained by varying the surface roughness of the lining material 1 in the above-described product 1 of the present invention under various test conditions and measuring the baked surface pressures. From this result, if the roughness is too small, it becomes difficult to realize the state of FIG. 1B and the state of FIG.
Has a minimum value of about 2 μm as described above. On the other hand, the maximum value of the surface roughness of the lining material 1 can be maintained in a good condition with respect to the printing surface pressure even if the roughness becomes large. However, when the depth of the concave portion 2 becomes deeper than necessary, it becomes difficult to form a plating layer on the entire inner surface thereof, which causes a decrease in adhesion strength, and the concave portion 2 is filled with an overlay. Even if it is, it is extremely soft as compared with the lining material, so that it is substantially the same as a hollow state. In such a state, stress concentration when a dynamic load is repeatedly applied becomes large, so that cracks are easily generated at the bottom of the concave portion, which adversely affects fatigue resistance. This tendency is especially true for 150
It was remarkable in a high temperature state of ~ 200 ° C. Therefore, the maximum value of the surface roughness of the lining material 1 was determined in consideration of the above points, and the maximum value was 20 μmRz. As described above, according to the present invention, it is possible to produce a plain bearing having excellent seizure resistance and wear resistance as compared with a conventional plain bearing of the same kind. Can be

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1a is a sectional view showing one embodiment of the present invention. FIG. 1B is a cross-sectional view showing a state in which the overlay layer 4 and the plating layer 3 in FIG. 1A have been worn down to the convex surface of the lining material 1; FIG. 1c is a plan view of FIG. 1b. FIG. 2a is a sectional view of a conventional plain bearing corresponding to FIG. 1a. FIG. 2b is a sectional view of a conventional plain bearing corresponding to FIG. 1b. FIG. 2c is a plan view of FIG. 2b. FIG. 3 is a test result diagram showing the result of measuring the surface pressure for printing. FIG. 4 is a test result diagram showing a result of measuring a wear amount. FIG. 5 is a test result diagram showing the results of measuring the baking surface pressure with different types of plating layers. FIG. 6 is a test result diagram showing the result of measuring the baking surface pressure while changing the thickness of the plating layer. FIG. 7 is a test result diagram showing the result of measuring the sintering surface pressure while varying the surface roughness of the lining material. [Explanation of Signs] 1 lining material 2 recess 3 plating layer 4
… Overlay layer

Continuation of front page    (72) Inventor Tatsuhiko Fukuoka               3-65 Midorigaoka, Toyota-shi, Aichi               Industrial Co., Ltd. (72) Inventor Yoshio Kumada               3-65 Midorigaoka, Toyota-shi, Aichi               Industrial Co., Ltd.                (56) References JP-A-62-124321 (JP, A)                 JP-A-58-94631 (JP, A)                 JP-A-57-61934 (JP, A)

Claims (1)

(57) [Claims] Forming a surface of a lining material made of an Al- based alloy on an uneven surface of 2 to 20 μmRz by etching; and forming Ni, Cu, C on the uneven surface of the lining material.
a step of forming a plating layer made of a simple substance or an alloy of r and Fe with a thickness of 0.01 to 2 μm so that the surface becomes an uneven surface following the uneven surface;
Forming an overlay layer having a thickness of ２５25 μm. 2. The method according to claim 1, wherein the thickness of the plating layer is in the range of 0.01 to 0.9 m. 3. The method according to claim 1, wherein the plating layer is formed by electroplating.