JP2944919B2 - Aluminum bearing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sliding bearing used for automobiles, industrial machines and the like, and more particularly to an aluminum bearing suitable for high load and high speed rotation.

[0002]

2. Description of the Related Art Conventional aluminum bearings 1 include, for example, those shown in FIGS.
That is, a bearing alloy 2 ′ such as an aluminum-tin-based or aluminum-lead-based alloy and a steel back metal 4 are joined via a pure aluminum-based joining layer 30 of 99.00% or more. This pure aluminum-based bonding layer 30 is made of a bearing alloy 2 ′.
In order to prevent the lubricating components contained therein, such as tin and lead, from directly intervening at the bonding interface 4a with the back metal 4 and hinder the bonding between the bearing alloy 2 'and the back metal 4, it is provided as a medium contact layer. Can be Further, the pure aluminum-based bonding layer 30 also has a role as a bonding layer for bonding the bearing alloy 2 ′ and the back metal 4 at the same time. Specifically, the aluminum-based bearing 1 includes a pure aluminum-based bonding layer 3 between the bearing alloy 2 ′ and the back metal 4.
It is manufactured by pressure contact with a roll with 0 interposed.

[0003] A lubricating metal component such as tin, lead or the like is not interposed on the surface of the back metal 4, and an aluminum-based bearing alloy 2 'is used.
In order to fix the different kinds of materials having completely different mechanical properties, ie, the back metal 4 and the steel, by applying a predetermined bonding strength by roll pressing, the relative slip generated between the two during the pressing is absorbed, and the An appropriate bonding layer that firmly adheres the alloy 2 ′ to the back metal 4 is essential. Therefore, as a necessary condition of the bonding layer, it is required that the bonding layer be rich in ductility and easily adhere to the back metal 4. As a material satisfying such requirements, a pure aluminum-based bonding layer 30 has been conventionally used.

[0004] On the other hand, there is also known an aluminum bearing in which a nickel plating layer is used as a bonding layer between the bearing alloy 2 'and the back metal 4, and the bearing alloy 2' and the back metal 4 are bonded via the nickel plating layer. Have been. According to this, although the nickel plating layer prevents direct contact between the back metal 4 and tin, lead, and the like in the bearing alloy 2 ', the nickel layer has poor ductility, so that sufficient bonding strength cannot be obtained. There are technical issues.

Therefore, in order to obtain a strong bond, it is essential to use a pure aluminum-based bonding layer 30.
In order to increase the load applied to the aluminum bearing 1,
The problem caused by the soft and low-strength pure aluminum-based bonding layer 30 has become apparent. That is, when repeatedly subjected to a high load at a high temperature, the pure aluminum-based bonding layer 30 undergoes plastic deformation, causing slippage between the aluminum-based bearing alloy 2 ′ and the back metal 4, and cracking in the bearing alloy 2 ′. And the failure occurs when the bearing alloy 2 ′ layer is broken. However, this is an unavoidable problem since the intermediate bonding layer 30 is required to be made of pure aluminum having no strength. It is physically impossible to achieve both sufficient ductility and sufficient strength by pure aluminum itself. Was thought to be. In order to cope with such a problem, a patent (Japanese Patent Application Laid-Open No. 5-99229) in which the bonding layer is made of aluminum alloy instead of pure aluminum can be seen. However, aluminum alloy still has poor ductility, and the bonding force is relatively high. It has to fall.

FIG. 6 shows a conventional pure aluminum-based bonding layer 30.
1 shows a structure of a material of an aluminum-based bearing 1 having the following. In the figure, the maximum thickness of the pure aluminum-based bonding layer 30 is T, the maximum height of the surface of the back metal 4 (the bonding interface 4a between the pure aluminum-based bonding layer 30 and the back metal 4) is Rmax, and the surface of the back metal 4 (pure). The maximum rolling undulation of the bonding interface 4a) between the aluminum bonding layer 30 and the back metal 4 is W _EM , and the thickness of the shear stress generating layer is S. Maximum height Rmax is JISBO6
01, and when the extracted portion is sandwiched between two straight lines parallel to the average line of the portion extracted by the reference length from the cross-sectional curve (joining interface 4a), the interval between the two straight lines is defined as the direction of the longitudinal magnification of the cross-sectional curve. This value is expressed in μm. In addition, the rolling wave maximum undulation W _EM is JISBO601.
The stylus of radius R is defined by the cross-sectional curve (joining interface 4a).
And the curve drawn by the center of the stylus is determined as a rolling circular undulation curve, and is the maximum undulation height of the rolling circular undulating curve. Note that the relationship between the maximum height Rmax and the rolling circle maximum undulation W _EM is such that when the irregularity of the surface of the back metal 4 as the measurement surface is smooth and the radius R of the stylus is sufficiently small,
If Rmax = W _{EM and} the irregularity of the surface of the back metal 4 changes relatively sharply and the radius R of the stylus is relatively large, Rmax
x> W _EM .

In the case of the conventional material, T> Rmax
And T> _WEM . That is, as shown in FIG. 6, the surface (bonding interface 4a) of the back metal 4 has roughness and undulation, but the interface 2′a between the upper surface of the pure aluminum-based bonding layer 30 and the bearing alloy 2 ′. Has a slight undulation but is almost flat, and since the pure aluminum-based bonding layer 30 is thicker than the unevenness of the back metal 4,
Most of the unevenness is absorbed, and a pure aluminum layer S having a predetermined height exists along the interface 2′a of the bearing alloy 2 ′. The present inventors have found that the pure aluminum layer S continuous in the circumferential direction in the pure aluminum-based bonding layer 30 becomes a layer in which a low-strength shear stress is generated. The pure aluminum layer S undergoes plastic deformation, and the aluminum-based bearing alloy 2 ′
And the back metal 4 caused slipping, cracking occurred in the bearing alloy 2 ', and led to the destruction of the bearing alloy 2' layer.

FIG. 7 shows the mechanical background in the case where slip occurs in the pure aluminum layer S in the pure aluminum-based bonding layer 30 and the aluminum-based bearing alloy 2 ′ layer is broken.
This will be described with reference to FIG. Under boundary lubrication conditions that cause oil shortage under high speed and high load, the rotational force of the shaft (not shown)
It acts as a tangential pulling force P on the surface (sliding surface) of the cylindrical bearing alloy 2 ′, propagates in the bearing alloy 2 ′, reverses the stress direction in the pure aluminum-based bonding layer 30, and 4, a tensile force P 'is generated in the pure aluminum-based bonding layer 30, and as a result, a shear stress is generated in the weakest pure aluminum-based bonding layer 30. Therefore, when the bearing alloy 2 'is broken,
Cracks propagate in the continuous pure aluminum layer S in the pure aluminum-based bonding layer 30 to cause separation from the bearing alloy 2 ', and the separated bearing alloy 2' is scattered, and in some cases, the shaft is seized. Develop.

As shown in FIG. 8, in a bearing 1 'having a bonding layer 30' made of nickel plating or the like, when a pulling force P is generated on the surface of the bearing alloy 2 ', the nickel plating and the bearing alloy 2 An extremely large shear stress (P ₁ + P ₂ ) acts on the joint interface 2′a with the ′, and if a shear stress greater than the allowable stress acts, it is easily separated from the interface 2′a.

An object of the present invention is to provide an aluminum-based bearing 1 in a circumferential direction while using a pure aluminum-based bonding layer 30 to prevent a reduction in bonding strength between an aluminum-based bearing alloy 2 ′ layer and a backing metal 4. The continuous pure aluminum layer S is prevented from being formed, and the interlayer slip generated between the bearing alloy 2 ′ layer and the back metal 4 when a high load is repeatedly applied is suppressed. As a result, the load bearing capacity of the aluminum-based bearing 1 is reduced. Is to promote sex.

[0011]

SUMMARY OF THE INVENTION The present invention has been made in view of such conventional technical problems, and has the following configuration. Configuration of the first aspect of the invention, aluminum-based bearing behind <br/> gold 4 made of steel with intervening pure aluminum-based bonding layer 3 Ru is Yotsute joining a bearing alloy 2 Roll Bonding
Fraud and mitigating risk pure aluminum-based maximum thickness of the bonding layer 3 T in,
JIS surface roughness of the bonding interface 4a between the bonding layer 3 and the backing 4 (BO601), the maximum height as stipulated in the surface waviness (BO610) Rmax, the rolling circle maximum waviness and _{W EM,}
An aluminum-based bearing that satisfies at least one of T <Rmax and T <W _EM .

[0012]

According to the first aspect of the present invention, the occurrence of slip in the pure aluminum-based joining layer 3 and the destruction of the two aluminum-based bearing alloys can be suppressed well. That is,
Under high speed and high load, the rotational force of the shaft acts as a large force that pulls the surface of the bearing alloy 2 in the tangential direction, propagates in the bearing alloy 2 layer, and the stress direction is reversed in the pure aluminum-based joining layer 3 However, a shear stress is generated in the weakest pure aluminum-based bonding layer 3 to cause interlayer slip. However, since the irregularities of the bearing alloy 2 and the back metal 4 mesh with each other via the pure aluminum-based bonding layer 3, the shear stress acting on the pure aluminum-based bonding layer 3 is reduced, and the pure aluminum-based bonding layer 3 is broken. Is suppressed well,
Further, the bonding between the back metal 4 and the bearing alloy 2 is also ensured by pure aluminum. As a result, the load bearing capacity of the aluminum-based bearing 1 is improved, cracks propagate in the pure aluminum-based bonding layer 3, and the bearing alloy 2 is separated, and the separated bearing alloy 2 is scattered and develops into seizure of the shaft. Is prevented.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. 1 to 4 show one embodiment of the present invention.
1 shows an aluminum bearing according to an embodiment. In FIG. 1, reference numeral 1 denotes an aluminum bearing having a semi-cylindrical shape. The aluminum bearing 1 includes a bearing alloy 2 serving as a sliding friction surface, a pure aluminum bonding layer 3, and a steel back metal 4.
And The bearing alloy 2 is made of aluminum-tin,
An aluminum-lead-based, aluminum-silicon-based, or aluminum-magnesium-based alloy, and the pure aluminum-based bonding layer 3 is formed of 99.00% or more of pure aluminum (aluminum in the 1000s according to JIS). The bearing alloy 2 and the back metal 4 are joined by a roll pressure welding with a pure aluminum-based joining layer 3 interposed therebetween.

The pure aluminum bonding layer 3 of the aluminum bearing 1 has a structure shown in FIG. That is, the maximum thickness of the pure aluminum-based bonding layer 3 is T,
As a surface maximum (pure aluminum-based bonding interface 4a between the bonding layer 3 and the backing 4) (specified in JISBO601) height Rmax, the rolling circle maximum waviness (defined in JISBO610) W _EM, T <Rmax and T <W _At least one of the conditions of _EM is satisfied.

Not only the interface 4a of the back metal 4 with the pure aluminum-based bonding layer 3 but also the interface 2a of the pure aluminum-based bonding layer 3 with the bearing alloy 2 has a predetermined roughness and undulation, respectively. The state in which the convex portion between the two interfaces 4a and 2a enters the opposing concave portion is set so that the thickness of the pure aluminum-based bonding layer 3 is smaller than the unevenness of the back metal 4. This is achieved by preventing the unevenness of the hard back metal 4 from being absorbed. The unevenness of both interfaces 4a, 2a is obtained by grinding the surface of the back metal 4 immediately before joining by a grinding belt to which predetermined abrasive grains are adhered to the back metal 4 to positively form the predetermined unevenness. After that, it can be formed by roll pressing. Therefore, the pure aluminum-based bonding layer 3
There is no portion extending in the circumferential direction of the semi-cylindrical aluminum bearing 1 as a planar layer having a predetermined thickness. As a result, there is no continuous weak aluminum layer (S) having a low strength, and there is no continuous layer in the pure aluminum-based bonding layer 3 in which shear stress in the circumferential direction is generated.

[0016] Thus, according to satisfy aluminum-based bearing 1 in at least one of T <Rmax and T <W _EM, not that the shear stress across a single layer made of pure aluminum, bearing alloy The two layers and the irregularities of the back metal 4 mesh with each other to make the structure extremely difficult to slip. In practice, not only in the circumferential direction of the aluminum-based bearing 1 but also in the center axis direction, the unevenness of the bearing alloy 2 layer and the back metal 4 is engaged via the pure aluminum-based bonding layer 3 so that the structure is less slippery. I'm sorry. However, the maximum relationship between the height Rmax and rolling circle maximum swell W _EM is, usually, Rmax ≧ W
_Since it is _EM , if T <Rmax is satisfied, a form in which the two layers of the bearing alloy and the back metal 4 are unevenly engaged can be provided. However, in order to sufficiently provide the unevenly engaged state, T
It is desired to satisfy <W _EM .

According to the aluminum bearing 1, slipping occurs in the pure aluminum bonding layer 3,
Destruction of the two layers of the aluminum-based bearing alloy is successfully suppressed. That is, under the boundary lubrication condition where the oil has run out under high speed and high load, the rotational force of the shaft is
Acts as a large force that pulls the surface of the bearing alloy in the tangential direction, propagates in the two layers of the bearing alloy, and the stress direction is reversed in the pure aluminum-based bonding layer 3. It tends to occur. However, at least in the circumferential direction of the aluminum-based bearing 1, the irregularities of the bearing alloy 2 and the back metal 4 are engaged with each other via the pure aluminum-based bonding layer 3.
The shear stress acting on the backing metal 4 and the bearing alloy 2 is secured by the pure aluminum, and the destruction of the pure aluminum-based bonding layer 3 is reduced. As a result, a crack is prevented from propagating in the pure aluminum-based bonding layer 3 to cause separation of the bearing alloy 2, and the separated bearing alloy 2 is scattered to cause burning of the shaft.

[0018]

Example 1 First, aluminum bearings 1 having the structures shown in Tables 1 and 2 were prepared. The method of making the alloy is a predetermined aluminum-tin bearing alloy 2 (Al-13% by weight).
Sn-2% by weight Pb-3% by weight Si-1% by weight Cu) was continuously cast, the upper and lower surfaces were chamfered, and then cold-rolled, and finally, pure aluminum series shown in Tables 1 and 2 was obtained. Bonding layer 3
1.2mm, 0.9mm,
Pure aluminum with a thickness of 0.6 mm and 0.3 mm (JI
SA1050 alloy) and finally 1.5m thick
m was pressed against the back metal 4 by a roll to prepare a test sample. At this time, the bonding interface 4a of the backing metal 4, the maximum height Rmax and the rolling circle maximum waviness W _EM are both in the finished material 25μ
m. That is, by pressing the pure aluminum having the above thickness into pressure, a conventional product (sample Nos. 1, 2, 6, and 7) in which the thickness of the pure aluminum-based bonding layer 3 in Tables 1 and 2 is 45 μm and 30 μm is obtained. The pure aluminum-based bonding layer 3 has a maximum thickness T of 2
Sample Nos. 0 μm and 15 μm were used. 4,5,9,10
As obtained. On the other hand, a sample in which a nickel plating layer was formed instead of the pure aluminum-based bonding layer 3 was also used as the sample No. 3,8
As a conventional product. Table 1 shows that the product of the present invention has T <
Test results when Rmax is satisfied are shown, and Table 2 shows test results when the product of the present invention satisfies T < _WEM .

[0019]

[Table 1]

[0020]

[Table 2]

These prepared samples were evaluated by the following two methods. One is a shear test to check the shear bonding force, and the other is a fatigue test to comprehensively evaluate bearing performance.

First, a test method for checking the shear bonding force is as follows.
Each sample (No. 1 to 10) was cut into a size of 1 mm in width and 15 mm in length, and was set in a shear test jig as shown in FIGS. That is, the backing metal 4 is fixed to the first jig 6 with the fixing screw 7 in a state where the bearing alloy 2 is projected, the second jig 8 is engaged with the bearing alloy 2, and the bearing alloy 2 and the backing metal 4 are joined together. The pure aluminum-based bonding layer 3 at the bonding interface 4a was sheared. Then, a rolling force N was applied to the second jig 8, and the maximum value of the stress when the pure aluminum-based bonding layer 3 (or the nickel plating layer) was sheared was defined as the shearing stress. The results are shown in Tables 1 and 2. The unit of the shear stress was kgf / mm ² .

On the other hand, a so-called underwood tester was used for the fatigue test. This is a test machine that fixes a sliding bearing to a connecting rod and applies an eccentric load to the shaft in almost the same way as the actual engine conditions. Time). The test conditions are described below.

Surface pressure 800 kgf / cm ² Number of rotations 3500 rpm Mating material FCD70 Roughness 0.8 to 1.5 S Oil used SAE30 Oil temperature 150 ° C. ± 5 ° C. Each of the above tests was carried out with n = 5 for each sample. Are shown in Tables 1 and 2 as data.

The results shown in Tables 1 and 2 show that the maximum thickness T of the pure aluminum-based bonding layer 3 of the present invention <the bonding layer 3
The maximum height of the bonding interface 4a between the metal and the back metal 4 is Rmax, and the maximum thickness T of the pure aluminum-based bonding layer 3 <the maximum rolling undulation _WEM of the conventional product No.
1, 2, 6, 7 and nickel-plated bond products (Sample N
o. 3 and 8) show that the bonding strength found from the shear stress is weak, and therefore the product of the present invention has a large shear stress and a fatigue time of 130 to 150 in comparison with a short time of only 75 to 95 hours in the underwood test. Time has been significantly improved. In other words, it is supported that such a rational improvement of the joining interfaces 2a and 4a dramatically improves the load bearing capacity of the aluminum-based bearing 1.

[0026]

As will be understood from the above description,
ADVANTAGE OF THE INVENTION According to the aluminum-type bearing which concerns on this invention, the joining strength represented by the shear stress of a joining interface is improved remarkably compared with the conventional product which does not satisfy | fill predetermined conditions, and withstands a load of 80.
A sliding bearing having an effective fatigue strength even under a high load condition of 0 kgf / cm ² can be manufactured. In other words, the bearing capacity of aluminum bearings has dramatically improved,
In particular, it is possible to provide an aluminum bearing suitable for high load and high speed rotation.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an aluminum-based bearing according to one embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view showing a main part of the same.

FIG. 3 is a schematic diagram showing a shear test jig.

FIG. 4 is an enlarged sectional view showing a main part of the same.

FIG. 5 is a sectional view showing a conventional aluminum bearing.

FIG. 6 is an enlarged cross-sectional view showing a main part of the same.

FIG. 7 is a stress distribution diagram of an aluminum bearing having a pure aluminum bonding layer.

FIG. 8 is a stress distribution diagram of an aluminum bearing having a nickel plating layer.

[Description of References] 1: Aluminum bearing, 2: Bearing alloy, 3: Pure aluminum bonding layer, 4: Back metal, T: Maximum thickness, Rmax:
Maximum height, W _EM : Rolling circle maximum undulation.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Takeshi Sakai 1-687, Minemachi, Narashino-shi, Chiba NDC Corporation (56) References JP-A-56-133371 (JP, A) JP-A-7-133825 (JP, A) JP-A-2-38714 (JP, A) JP-A-7-259856 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F16C 33/00-33 / 28 C22C 21/00

Claims (1)

(57) [Claims] A bearing alloy (2) is roll-welded to a steel back metal (4) with a pure aluminum-based bonding layer (3) interposed therebetween.
Oite the aluminum-based bearing Ru is Yotsute bonding, JIS surface roughness of the bonding interface of the maximum thickness of the pure aluminum-based bonding layer (3) T, the bonding layer (3) and backing (4) (4a) is (BO601), the maximum height as stipulated in the surface waviness (BO610) Rmax, the rolling circle maximum waviness and _{W EM,} aluminum-based bearing and satisfies at least one of T <Rmax and T _{<W EM} .