JP2000205266A - Low-friction long-life sliding material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To continue a good sliding characteristic for a long period without using lubricating oil by providing recesses on the sliding surface of a base material, and uniformly applying a low-friction material over the whole sliding surface including the recesses. SOLUTION: Recesses are uniformly dispersed so that the recess area ratio for the unit are 400 mm2 becomes 20% or above at any portion on the sliding surface of a base material, and a low-abrasion material is uniformly applied to the whole surface including the recesses. If the area ratio is below 20%, the reducing effect of the friction coefficient is not sufficient. The base material is made of a sintered body of a metal fused material or metal powder, and a fluororesin is used for the low-friction material. The contact area between the portion other than the recesses of the base material and a mating member is reduced, the low-friction material in the recesses is invariably supplied to a new face even when the low-friction material is abraded, and the film of the low-friction material is always formed and held on the sliding surface. Good sliding performance is maintained for a long period, and the film of the low-friction material protects the surface of the base material and can suppress the base material itself from being abraded.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention has a low coefficient of friction,
The present invention relates to a low-friction, long-life sliding material that exhibits excellent sliding performance over a long period of time.

[0002]

2. Description of the Related Art
In general, a method of applying a lubricating oil to a sliding surface has been performed in order to impart a good sliding property to the sliding surface of the sliding material.
However, in this case, there is a problem that the lubricating oil is lost as the sliding is repeated, the sliding performance cannot be prevented from gradually decreasing, and the lubricating oil must be replenished periodically.

On the other hand, the sliding material is formed of a sintered body, and the pores thereof are impregnated with a lubricating oil.
Also in this case, there arises a problem that the lubricating oil contained in the sintered body is scattered as steam due to a rise in temperature and the surrounding environment is polluted.

An object of the present invention is to provide a low-friction, long-life sliding material that can maintain good sliding performance over a long period of time without using such a lubricating oil.

[0005]

According to the low friction and long life sliding material of claim 1 of the present application, a recess is provided on the sliding surface of the base material,
The low friction material is uniformly applied over the entire sliding surface including the recess.

[0006] low friction and high lifetime sliding member according to claim 2, in low friction and high lifetime sliding material according to claim 1, dents per unit area 400 mm ² at any part of the sliding surface of the base material The dents are uniformly dispersed so that the area ratio of the dents is 20% or more.

The low-friction, long-life sliding material according to claim 3 is the low-friction, high-life sliding material according to any one of claims 1 and 2,
The dent is a groove.

According to a fourth aspect of the present invention, there is provided a low-friction and long-life sliding material according to any one of the first and second aspects.
The dent is a dimple-shaped dent.

The low-friction, long-life sliding material according to claim 5 is the low-friction, high-life sliding material according to any one of claims 1 to 4,
It is characterized in that the base material is made of a molten metal material.

The low-friction, high-life sliding material according to claim 6 is the low-friction, high-life sliding material according to any one of claims 1 to 4,
The substrate is constituted by a sintered body of a metal powder.

A low-friction, high-life sliding material according to a seventh aspect of the present invention is the low-friction, high-life sliding material according to the sixth aspect, wherein the base material has pores filled with the low-friction material. Features.

The low-friction, long-life sliding material according to claim 8 is the low-friction, high-life sliding material according to any one of claims 1 to 7,
The low friction material is a fluorine resin.

According to a ninth aspect of the present invention, there is provided a low friction and long life sliding material according to the eighth aspect, wherein the low friction material comprises a polytetrafluoroethylene resin or tetrafluoroethylene. It is a combined resin.

[0014]

As described above, according to the present invention, a dent is provided on the sliding surface of the base material, and a low-friction material is uniformly applied to the entire surface including the dent (claim 1). . Here, a solid lubricant can be suitably used as the low friction material.

As a means for imparting good sliding performance to the sliding material, it is conceivable to simply apply a low friction material to a smooth sliding surface, but in this case, the sliding material has good sliding performance at first. Even if the sliding is repeated for a long time, the low friction material on the surface is peeled off and lost, and the sliding performance is reduced.

Further, when the base material is a metal and the mating member is also a metal member, if the low-friction material is peeled and lost, the metals come into contact with each other to cause seizure,
In some cases, the state becomes substantially impossible to slide.

However, in the present invention, since a low friction material is applied to the sliding surface after forming the concave on the sliding surface, the contact area between the base material itself (parts other than the concave) and the mating member is small. In addition, even if the low friction material on the sliding surface is worn out, the low friction material held inside the recess is always supplied to the new surface, and a film of the low friction material is always formed on the sliding surface and retained Therefore, according to the present invention, good sliding performance is maintained for a long time. Further, the film of the low friction material protects the surface of the base material and can suppress the wear of the base material itself.

It is desirable that the recess has a depth of 0.1 mm or more. If the depth is shallower than this, the dent disappears immediately when the sliding surface wears out, making it difficult to maintain good sliding performance over a long period of time. However, it is desirable that the depth of the recess is set to 10 mm or less.

In the present invention, in any part of the sliding surface of the substrate, the area ratio of the dent per unit area of 400 mm ² is 20%.
It is desirable that the depressions are uniformly dispersed and formed as described above (claim 2). When the area ratio of the dent is less than 20%, the effect of reducing the friction coefficient is not sufficient, and when the surface pressure applied to the sliding surface is large (for example, 1 kgf / cm ² or more),
It is difficult to sufficiently suppress abrasion of the substrate surface.

In the present invention, the area ratio of the recesses per unit area is desirably 95% or less. If the area ratio is more than 95%, processing of the substrate surface becomes difficult and the processing cost increases. Besides, the area of the substantial sliding surface (the sliding surface other than the recess) of the substrate is small. And when supporting a large load on the sliding surface,
That is, when the surface pressure applied to the sliding surface is large, it becomes difficult to withstand a large surface pressure due to a decrease in the supporting force of the base material,
There is a risk of deformation. A more desirable area ratio of the depression is 90% or less.

In the present invention, the recess can be a groove (claim 3). This groove can be formed in various cross-sectional shapes. For example, this can be a V-shaped groove having a V-shaped cross section or a U-shaped groove having a U-shaped cross section. When the V-shaped groove and the U-shaped groove are used, the groove can be formed on the surface of the base material easily and at low cost by using an ordinary tool.

This groove can be formed with a groove depth of 0.2 to 10 mm, and the distance between the grooves is 0.4 to 10 mm.
mm. Further, based on the sliding direction of the mating member with respect to the sliding material, a large number of grooves can be formed vertically and horizontally, that is, in a lattice shape, or each groove crosses the sliding direction at a predetermined angle. It can also be formed in a twill pattern.

In the present invention, the depression may be a dimple-shaped depression (claim 4). In this case, such a depression can be formed as a spherical depression.
The spherical dent has a diameter of 0.2 to 10 mm and a depth of 0.2 to
A recess of 10 mm can be formed.

In the present invention, the base material can be made of a molten metal material. In this way, a low-friction sliding material can be obtained at low cost. On the other hand,
In the present invention, such a base material may be constituted by a sintered body of a metal powder (claim 6).

When the base material is made of a sintered body, the pores of the base material can be filled with and held by a low-friction material (claim 7). The friction coefficient of the surface can be reduced more effectively, and even when the surface of the base material is worn out, the low friction material held in the pores can be replenished to the new surface, and good sliding performance can be maintained for a long time. Can be sustained.

In the present invention, a fluorine resin can be suitably used as the low friction material.
Further, as the fluorine resin, a polytetrafluoroethylene resin or a copolymer resin using tetrafluoroethylene can be suitably used (claim 9).

PFA, FEP, P
Examples thereof include CTFE, ETFE, ECTFE, PVDF, PVF, and the like. In addition, ultrahigh-molecular-weight polyethylene, carbon, graphite, MoS ₂ , WS _{2 and the} like can be used alone or in combination.

As the metal substrate, steel, cast iron, Ni-base alloy, Al alloy, Cu alloy or other metals can be used, or the substrate can be made of ceramics or other materials.

[0029]

Next, embodiments of the present invention will be described in detail. <Experimental example 1> Width 100 mm, length 200 mm, thickness 20
A metal substrate (material: SS400) as a base material having a thickness of 1 mm is provided on one surface (one surface on the sliding side) with depressions of various forms shown in Table 1, and the surface including the depressions is provided with polytetrafluoroethylene (PTFE). Resin is applied in the following coating thickness, that is, a thickness (the thickness from the surface of the apex is 0.1 to 0.2 mm) enough to hide the apex of the protrusion of the substrate, and the sliding material test piece 1
0 (see FIG. 1), and using this, a friction coefficient measurement test was performed by the method shown in FIG.

[0030]

[Table 1]

That is, the indenter 12 (width 1
20 mm and a length of 40 mm), a load W (40 kg) was further applied on the indenter 12, and in this state, the indenter 12 was reciprocated by the air cylinder 14 at a moving speed of 100 mm / sec. The coefficient of friction after the test and the coefficient of friction after the test were performed 10,000 times were measured.

The application of the PTFE resin was performed as follows. That is, the substrate was immersed in a liquid in which the PTFE resin powder was dispersed in a dispersion medium, and the dispersion of the PTFE resin was applied to the surface of the substrate. Next, it is dried at 100 ° C.
After holding at 40 ° C. for about 10 minutes, a heat treatment was performed at 370 ° C. for 30 minutes to remove the dispersion medium and dissolve the particles of the PTFE resin, followed by cooling to solidify the PTFE resin.

Further, in order to fill the recesses with the PTFE resin, PTFE resin powder of 0.3 μm was pressed with a roll and heated again at 380 ° C. for 30 minutes to fix the PTFE resin to the uneven surface of the substrate. In addition, isopropanol (IPA) was used as a dispersion medium of the PTFE resin,
μm PTFE resin powder was dispersed at a concentration of 20% by weight. The results are shown in Table 1.

However, the dent area ratio in Table 1 was measured at 10 arbitrary positions on a 400 mm ² sliding surface, and the range and the average value were shown. In addition, the form (planar form) of each dent of Invention Examples 1 to 13 and Comparative Examples 1 and 2 is also shown in FIGS. 2 and 3. However, these figures show a part having a unit area of 400 mm ² (20 mm square), and a black part in the figures shows a dent.

As shown in the results of Table 1, Comparative Example 1 in which the surface was coated with PTFE resin but no depression was provided, that is, Comparative Example 1 in which the substrate surface was flat, and In Comparative Example 2 where the PTFE resin was not applied, but the coefficient of friction after 10,000 times was greater than 0.75, the friction coefficient of any of the inventive examples was larger. When it is 0.6 or less, the sliding performance over a long period is improved. In particular, in the case of Invention Examples 1 to 11 in which the area ratio of the dent per unit area satisfies the condition of 20% or more, the friction coefficient after 10,000 times is less than or equal to the desired target value 0.3 or less over a long period. It can be seen that good sliding performance is exhibited.

The area ratio of the dents per unit area is 20%.
The above Comparative Examples 1 to 11 are superior in long-term sliding performance as compared with Invention Examples 12 and 13 which do not satisfy the condition of Claim 2, that is, the condition that the area ratio of the dent is 20% or more in any part. You can see that

<Experimental Example 2> P43 having the chemical composition shown in Table 2
0L powder (-100 mesh) is produced by a water spray method, 1% by weight of zinc stearate (lubricant) is added to the powder, and the molding pressure is 1.5 t / cm using a 50 × 70 mm plate-shaped test piece mold. ^2. Press molding was performed.

[0038]

[Table 2]

At this time, R (radius) is 0.2 mm at an interval of 0.7 mm and R 0.2 at an interval of 2.0 mm on the upper punch surface of the mold.
mm, a convex portion 16a of R0.4 mm at 1.1 mm intervals,
16b and 16c (see FIG. 4), and a comparative example having a flat surface on which such a convex portion was not formed.

Next, the green compact was heated at 500 ° C. for 30 minutes.
After dewaxing (delubrication) under the conditions, 1150 ° C x 60m
Vacuum sintering was performed under the conditions of “in” to obtain a sintered body. The grill at this time
5.27 g / cm³(67.8%)-5.36
g / cm ³(68.8%). Also their sintering
The body accurately corresponds to the convex parts 16a, 16b, 16c of the mold
The dents retained on the surface.

Next, the green compact was subjected to PT
The PTFE resin impregnation treatment was performed, and the PTFE resin application treatment was performed on the surface including the dents. The comparative example is PTFE
Was only impregnated. That is, the substrate was immersed in a liquid in which a PTFE resin powder was dispersed in a dispersion medium, degassed under reduced pressure, and the pores of the sintered body of the substrate were impregnated with the PTFE resin dispersion. Next, it is dried at 100 ° C.
After holding at 40 ° C. for about 10 minutes, heat treatment is performed at 370 ° C. for 30 minutes to remove the dispersion medium and dissolve the PTFE resin particles remaining in the pores.
The E resin was solidified.

In order to further fill the recesses with the PTFE resin, 0.3 μm PTFE resin powder was pressed with a roll.
Heat treatment was again performed at 380 ° C. for 30 minutes to fix the PTFE resin to the uneven surface of the substrate. In addition, isopropanol (IPA) was used as a dispersion medium of the PTFE resin, and a particle size of 0.
3 μm PTFE resin powder was dispersed at a concentration of 20% by weight.

Test piece 1 of the sliding material thus obtained
Using 0, a measurement test of the friction coefficient was performed in the same manner as in Experimental Example 1. The thickness of the PTFE resin applied to the surface of the substrate was the same as in Experimental Example 1. The results are shown in Table 3. In addition, FIG. 5 shows the shapes of the recesses of Invention Examples 14, 15, and 16 in Table 3. The display method is the same as that of the first experimental example.

[0044]

[Table 3]

From the results shown in Table 3, it can be seen that the friction coefficient after 10,000 times of the example of the present invention is 0.3 or less, which is a desirable value, and excellent sliding performance is maintained over a long period of time. I understand.

Although the embodiment of the present invention has been described in detail above, this is merely an example, and the present invention can be configured in variously modified forms without departing from the gist thereof.

[Brief description of the drawings]

FIG. 1 is a diagram showing a method of a measurement test of a friction coefficient performed in an experimental example of the present invention.

FIG. 2 is a diagram illustrating a form of a dent in Invention Examples 1 to 8.

FIG. 3 is a diagram illustrating a form of a dent in Inventive Example 9 to Comparative Example 2.

FIG. 4 is a view showing a shape of a convex portion of a punch surface of a mold used in Experimental Example 2.

FIG. 5 is a diagram illustrating a form of a depression on the substrate surface of each invention example in Experimental Example 2.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takazumi Shimizu 37-29, Kitamon, Takada, Ichinomiya-shi, Aichi Prefecture (72) Inventor Kazuo Yanagihara 1-10-10 Tatsumiminami, Okazaki-shi, Aichi F-term (reference) 3J011 LA01 PA02 QA05 SB19 SC04 SC05

Claims (9)

[Claims] 1. A low-friction, long-life sliding material characterized in that a depression is provided on a sliding surface of a base material, and a low-friction material is uniformly applied over the entire sliding surface including the depression. 2. The low-friction and long-life sliding material according to claim 1, wherein the area ratio of the dents per unit area of 400 mm ² is 20% or more in any part of the sliding surface of the base material. A low-friction, long-life sliding material characterized in that the depressions are uniformly dispersed. 3. The low-friction and long-life sliding material according to claim 1, wherein the recess is a groove. 4. The low-friction, long-life sliding material according to claim 1, wherein the depression is a dimple-shaped depression. 5. The low-friction, long-life sliding material according to claim 1, wherein the base material is made of a metal-melted material. . 6. The low-friction, high-life sliding material according to claim 1, wherein the base is made of a sintered body of a metal powder. Sliding material. 7. The low-friction, high-life sliding material according to claim 6, wherein the base material is filled with pores of the low-friction material. 8. The low-friction, high-life sliding material according to claim 1, wherein the low-friction material is a fluorine-based resin. 9. The low-friction and long-life sliding material according to claim 8, wherein the low-friction material is a polytetrafluoroethylene resin or a copolymer resin using tetrafluoroethylene. High life sliding material.