JP2003247546A - Wet type multi-layered sliding member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wet type multi-layered sliding member capable of reducing friction value further by supplying lubricating oil over the entire sliding surface. <P>SOLUTION: By setting the maximum height of the surface roughness of synthetic resin at 2.0-10.0 μm and the ten point average roughness at 0.3-1.5 μm, lubricating oil laid between the wet type multi-layered sliding member 1 and a shaft can be sufficiently supplied over the entire sliding surface of the wet type multi-layered sliding member 1, which leads to reduction of the friction value. By employing for a vehicle or the like a shock absorber using the wet type multi-layered sliding member 1 whose friction value is reduced, further improvement in the riding comfort of a vehicle or the like can be achieved. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention has a bearing structure in which the pores of a porous layer formed by sintering a metal powder on the surface of a backing metal are impregnated with synthetic resin to reciprocate in the axial direction. The present invention relates to a wet multi-layer sliding member that supports a shaft.

[0002]

2. Description of the Related Art In vehicles such as automobiles,
A shock absorber is provided as a shock absorber for absorbing a shock during traveling. A typical shock absorber is composed of a shaft that reciprocates in the axial direction and a sliding member that supports this shaft. The sliding surface used as the sliding member is formed of synthetic resin. Things are known. In order to improve the riding comfort of the vehicle in the shock absorber of this vehicle,
A lubricating oil is interposed between the synthetic resin and the shaft to reduce friction (reduce the friction value), and the surface roughness of the surface of the synthetic resin has a maximum height (Ry) of 12.0. ~ 2
0.0 μm and ten-point average roughness (Ra) of 2.0 to 4.0
It was μm.

[0003]

In recent years, there is an increasing demand for further improving the riding comfort of vehicles and the like, and for that purpose, the friction value of the shock absorber must be made lower. However, with the conventional sliding member having the above-mentioned surface roughness, the friction value cannot be lowered because the lubricating oil is not sufficiently distributed between the sliding member and the shaft, and there is a demand for improvement in riding comfort. On the other hand, the performance was not satisfactory. The present invention is
The present invention has been made in view of the above circumstances, and an object thereof is to provide a wet multi-layer sliding member capable of further lowering a friction value by making a lubricating oil spread over the entire sliding surface. To provide.

[0004]

In order to achieve the above-mentioned object, in the invention according to claim 1, a synthetic resin is provided in the pores of a porous layer formed by sintering a metal powder on the surface of a backing metal. A wet multilayer sliding member having a bearing structure impregnated with and supporting a shaft that reciprocates in the axial direction,
The maximum surface roughness of the synthetic resin is 2.0 to 10.0.
[mu] m and the ten-point average roughness is 0.3 to 1.5 [mu] m. With such a configuration, the lubricating oil interposed between the wet multilayer sliding member and the shaft can be sufficiently spread over the entire sliding surface of the wet multilayer sliding member, The friction value can be reduced. Thus, by using the shock absorber using the wet multi-layer sliding member with reduced friction value in a vehicle or the like, the riding comfort of the vehicle or the like can be further improved.

The invention according to claim 2 is characterized in that the synthetic resin is polytetrafluoroethylene. With this structure, the friction value can be further reduced and a wet multi-layer sliding member having high heat resistance can be formed. Therefore, the wet multi-layer sliding member can be used under severe operating conditions or high temperature environments. Can also be used below.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIG. FIG. 1 is a sectional view of a wet multilayer sliding member 1 according to the first embodiment.

The maximum height of surface roughness shown below (hereinafter referred to as Ry) is the sum of the absolute values of the distances between the peak line and the valley bottom line of the roughness curve within the reference length. In addition, the ten-point average roughness (hereinafter referred to as Ra) is the height of the peak of the roughness curve counted from the highest peak to the fifth highest peak within the reference length extracted from the roughness curve. The average value of the sum of the valleys and the average value of the sum of the depths of the valleys from the deepest valley bottom to the fifth valley are shown.

In FIG. 1, a wet multi-layer sliding member 1 is formed by laminating a back metal 2, a porous layer 3 and a sliding layer 4 in this order. The back metal 2 is made of steel with a thickness of 1.7 mm, and the porous layer 3 is obtained by sprinkling bronze powder on the surface of the back metal 2 to a thickness of 0.3 mm and sintering at 800 to 900 ° C. for 30 minutes. It is formed by performing.
In addition, the sliding layer 4 is made by adding any one of lead (hereinafter referred to as Pb), graphite (hereinafter referred to as Gr), Gr, and molybdenum disulfide (hereinafter referred to as MoS ₂ ) to a synthetic resin. The base synthetic resin is polytetrafluoroethylene (hereinafter,
(Displayed as PTFE). The Pb, Gr, and MoS ₂ added to the sliding layer 4 are added to improve the wear characteristics and friction characteristics of the synthetic resin.

The wet multi-layer sliding member 1 is manufactured by first adding Pb, Gr or G to a predetermined amount of PTFE dispersion.
A resin composition for impregnation coating is prepared by adding any one of r and MoS ₂ and mixing them uniformly. After coating the prepared resin composition on the porous layer 3, the pores of the porous layer 3 are impregnated and coated by roll rolling. After the resin composition is impregnated and coated in the pores of the porous layer 3, the resin composition is baked, and the thickness of the wet multi-layer sliding member 1 is made uniform by roll rolling. A wet multi-layer sliding member 1 having dimensions is formed. Then, this wet multi-layer sliding member 1 is cut into a predetermined size, and bending is performed so that the sliding layer 4 becomes the inner surface, whereby the cylindrical wet multi-layer sliding member 1 is manufactured.

The wet multi-layer sliding member 1 produced has a surface roughness Ry of the sliding layer 4 of 2.0 to 10.0 μm and Ry.
When a is 0.3 to 1.5 μm, when a lubricating oil is interposed between the wet multilayer sliding member 1 and the shaft supported by the wet multilayer sliding member 1, the wet multilayer The lubricating oil can be sufficiently spread over the entire sliding surface of the sliding member 1, and the friction value can be reduced. If the surface roughness Ry exceeds 10.0 μm or Ra exceeds 1.5 μm, it becomes difficult for the lubricating oil existing at the valley bottom of the roughness curve to reach the contact surface with the shaft, that is, the crest of the roughness curve. The flow of lubricating oil over the entire moving surface becomes stagnant. For this reason, the lubricating oil cannot be sufficiently spread over the entire sliding surface, and the friction value becomes high. Conversely, the surface roughness Ry is 2.0 μm or Ra is 0.3.
If it is less than μm, the gap between the wet multi-layer sliding member 1 and the shaft becomes too small, which makes it difficult for the lubricating oil to intervene, and in this case also the friction value becomes high.

When the wet multilayer sliding member 1 is bent as described above, the synthetic resin between the bronze powder of the porous layer 3 and the bronze powder exudes on the surface of the sliding layer 4, As a result, the surface roughness of the sliding layer 4 becomes rough. This surface roughness becomes coarser as the particle size of the bronze powder of the porous layer 3 becomes larger because the amount of synthetic resin exuded increases, but the porous layer 3
By setting the particle size of the bronze powder to 100 μm or less, the surface roughness Ry can be 2.0 to 10.0 μm and Ra can be 0.3 to 1.5 μm. Also, by performing post-processing such as cutting or polishing after bending the wet multilayer sliding member 1, similarly, the surface roughness Ry is 2.0 to 10.0 μm and Ra is 0. .3 to 1.
It can be 5 μm. In addition, the test sample in the present embodiment shown below has a surface roughness Ry of 2.0 to 10.0 μm by performing the ironing process and the cutting process after the bending process of the wet multilayer sliding member 1. And Ra is 0.3 to
It was set to 1.5 μm.

Next, Table 1 and Table 2 show the friction value test conducted by a reciprocating sliding tester using test samples of a plurality of wet multilayer sliding members 1 having different compositions of the sliding layer 4. Will be described with reference to. Table 1 shows the test results when the test was performed by changing the composition of the sliding layer 4, and Table 2 is a table showing the conditions of the reciprocating sliding test for measuring the friction value.

As test samples for conducting the test, test samples having different compositions of the sliding layer 4 shown in Examples 1 to 3 of Table 1 were used. In addition, as test samples for comparison, Comparative Examples 1 to 3
The test samples having different compositions of the sliding layer 4 (shown in Comparative Example 2 and Comparative Example 3) were used. Of the test samples shown in Table 1,
PTFE was used for all of Examples 1 to 3 and Comparative Examples 1 to 3 as a base synthetic resin, and Pb was added as an additive in Example 1 and Comparative Example 1 to Example 2, Comparative Example 2 and Comparative Example. In Example 3, Gr was added, and in Example 3, Gr and MoS ₂ were added.

The test method was carried out using a reciprocating sliding tester under the conditions shown in Table 2. Specifically, a cylindrical wet multilayer sliding member 1 as a test sample is fitted into a housing to which a load cell is attached, and a shaft inserted through the wet multilayer sliding member 1 is filled with shock absorber oil. The friction value between the wet multi-layer sliding member 1 and the shaft when sliding back and forth in the oil tank was measured by a load cell.

[0015]

[Table 1]

[0016]

[Table 2]

From the test results on the friction coefficient and the wear amount shown in Table 1, the following facts were found. The surface roughness Ry of the sliding layer 4 is 2.0 to 10.0 μm and Ra is 0.3 to
The friction values of Examples 1 to 3 falling within the range of 1.5 μm are 6.0 to 8.9 kgf, whereas the surface roughness Ry and Ra of the sliding layer 4 are not within the above range. The friction values of Comparative Examples 1 to 3 are 10.8 to 12.4k.
It is gf. Thus, the surface roughness Ry of the sliding layer 4 is 2.0 to 10.0 μm and Ra is 0.3 to 1.5.
By setting the thickness within the range of μm, the friction value can be significantly reduced.

Looking at this individually, Example 1 and Comparative Example 1
In comparison between Example 2 and Comparative Examples 2 and 3, even in the case of the sliding layer 4 having the same composition, the surface roughness Ry and Ra are in the above ranges. By doing so, the friction value can be significantly reduced.

Further, as shown in Example 3, even when 5% by volume of MoS ₂ is added as an additive in addition to 5% by volume of Gr, the surface roughness Ry and Ra fall within the above ranges. As a result, the friction value can be set to the same level as in the first and second embodiments, and the friction value can be significantly reduced as compared with the comparative examples 1 to 3.

As described above, the surface roughness Ry of the sliding layer 4 is 2.0 to 10.0 μm and Ra is 0.3 to 1 irrespective of the amount and type of the additive added to the synthetic resin. By setting the thickness within the range of 0.5 μm, the friction value can be greatly reduced as compared with the case where the friction value does not fall within this range. By using a shock absorber using a wet multi-layer sliding member having a reduced friction value in a vehicle or the like, the riding comfort of the vehicle or the like can be further improved.

In the above embodiment, the values of Ry are 7.8 μm, 2.5 μm and 5.3 μm, and the values of Ra are 1.2 μm, 0.4 μm and 1.0 μm.
However, the value of Ry is 2.0 μm or 10.
Even when the value of 0 μm and Ra was 0.3 μm or 1.5 μm, good results were obtained as in the above case.

[0022]

As is apparent from the above description, in the invention according to claim 1, the lubricating oil interposed between the wet multi-layer sliding member and the shaft is used for the wet multi-layer sliding member. The friction value can be reduced because it can be sufficiently spread over the entire sliding surface. Thus, by using the shock absorber using the wet multi-layer sliding member with reduced friction value in a vehicle or the like, the riding comfort of the vehicle or the like can be further improved.

Further, in the invention according to claim 2, since the wet multi-layer sliding member which can further reduce the friction value and has high heat resistance can be formed, the wet multi-layer sliding member is operated under severe conditions. It can also be used under conditions and high temperature environments.

[Brief description of drawings]

FIG. 1 is a sectional view of a sliding member.

[Explanation of symbols]

1 Wet multi-layer sliding member 2 back money 3 Porous layer 4 Sliding layer

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] November 14, 2002 (2002.11.
14)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction content]

[0002]

2. Description of the Related Art In vehicles such as automobiles,
A shock absorber is provided as a shock absorber for absorbing a shock during traveling. A typical shock absorber is composed of a shaft that reciprocates in the axial direction and a sliding member that supports this shaft. The sliding surface used as the sliding member is formed of synthetic resin. Things are known. In order to improve the riding comfort of the vehicle in the shock absorber of this vehicle,
A lubricating oil is interposed between the synthetic resin and the shaft to reduce friction (reduce the friction value), and the surface roughness of the surface of the synthetic resin has a maximum height (Ry) of 12.0. ~ 2
0.0 μm and arithmetic mean roughness (Ra) of 2.0 to 4.0
It was μm.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

[0004]

In order to achieve the above-mentioned object, in the invention according to claim 1, a synthetic resin is provided in the pores of a porous layer formed by sintering a metal powder on the surface of a backing metal. A wet multilayer sliding member having a bearing structure impregnated with and supporting a shaft that reciprocates in the axial direction,
The maximum surface roughness of the synthetic resin is 2.0 to 10.0.
μm and the arithmetic mean roughness is 0.3 to 1.5 μm. With such a configuration, the lubricating oil interposed between the wet multilayer sliding member and the shaft can be sufficiently spread over the entire sliding surface of the wet multilayer sliding member, The friction value can be reduced. Thus, by using the shock absorber using the wet multi-layer sliding member with reduced friction value in a vehicle or the like, the riding comfort of the vehicle or the like can be further improved.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

The maximum height of surface roughness shown below (hereinafter referred to as Ry) is the sum of the absolute values of the distances between the peak line and the valley bottom line of the roughness curve within the reference length. In addition, the arithmetic mean roughness (hereinafter, referred to as Ra) indicates the arithmetic mean value of the absolute values of the altitudes within the reference length extracted from the roughness curve.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Name of item to be corrected] 0015

[Correction method] Change

[Correction content]

[0015]

[Table 1]

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Hajime Kachi             Daidome, 2 Sanaru-cho, Kita-ku, Nagoya-shi, Aichi             Within Taru Industry Co., Ltd. (72) Inventor Kotaro Kashiyama             Daidome, 2 Sanaru-cho, Kita-ku, Nagoya-shi, Aichi             Within Taru Industry Co., Ltd. F-term (reference) 3J011 JA01 KA07 LA01 MA02 QA05                       SC05                 3J069 AA50 CC18 DD02

Claims (2)

[Claims] 1. A wet composite having a bearing structure in which the pores of a porous layer formed by sintering metal powder on the surface of a backing metal are impregnated with a synthetic resin and supporting a shaft that reciprocates in the axial direction. In the layer sliding member, the maximum height of the surface roughness of the synthetic resin is 2.0 to 10.0.
The wet multi-layer sliding member is characterized in that it has a ten-point average roughness of 0.3 to 1.5 μm. 2. The wet multi-layer sliding member according to claim 1, wherein the synthetic resin is polytetrafluoroethylene.