Slide member and slide body

Abstract

To enhance abrasion resistance.SOLUTION: A sliding member 14 is composed of PTFE 16 that contains 2.4 wt.% or more and 15.6 wt.% or less of magnesium phosphate, 7.6 wt.% or more and 19.9 wt.% or less of barium sulfate, 0 wt.% or more and 10.0 wt.% or less of molybdenum disulfide, and 8.3 wt.% or more and 15.7 wt.% or less of fired clay.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a slide member and a slide body. [Background technology]

[0002] Conventionally, a technique has been disclosed in which a resin layer containing PTFE (polytetrafluoroethylene) as a main component is used as a sliding member from the viewpoint of improving abrasion resistance, etc. Also, a technique has been disclosed in which an additive is added to PTFE depending on the intended use of the sliding member. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-20568 [Patent Document 2] Japanese Patent Application Publication No. 8-41484 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the prior art, when the surface of the mating member such as a shaft member is rough, the amount of wear of the sliding member is large and wear resistance may not be obtained.

[0005] An object of the present invention is to provide a slide member and a slide body that can improve wear resistance. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems and achieve the object, a sliding body of the present invention comprises: A sliding member that slides against a sliding surface of a counter member having a surface roughness Ra of 0.3 or more and 0.7 or less, The sliding member is made of polytetrafluoroethylene resin containing 2.4% by weight or more and 15.6% by weight or less of magnesium phosphate, 7.6% by weight or more and 19.9% ​​by weight or less of barium sulfate, 0% by weight or more and 10.0% by weight or less of molybdenum disulfide, and 8.3% by weight or more and 15.7% by weight or less of calcined clay. [Effects of the Invention]

[0007] According to the present invention, it is possible to improve the wear resistance. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic view showing an example of a slide body according to an embodiment. [Figure 2A] FIG. 2A is an explanatory diagram of an example of the function of the sliding member. [Figure 2B] FIG. 2B is an explanatory diagram of an example of the action of the sliding member. [Figure 3A] FIG. 3A is a schematic diagram showing an example of an application form of a sliding body. [Figure 3B] FIG. 3B is a schematic diagram showing an example of an application form of the sliding body. [Figure 4A] FIG. 4A is an explanatory diagram of the abrasion resistance evaluation test. [Figure 4B] FIG. 4B is an explanatory diagram of the abrasion resistance evaluation test. [Figure 4C] FIG. 4C is an explanatory diagram of the abrasion resistance evaluation test. [Figure 4D] FIG. 4D is an explanatory diagram of the abrasion resistance evaluation test. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of a slide member and a slide body according to the present invention will be described in detail with reference to the accompanying drawings.

[0010] The sliding member of this embodiment is made of polytetrafluoroethylene resin (hereinafter referred to as PTFE) containing 2.4% by weight or more and 15.6% by weight or less of magnesium phosphate, 7.6% by weight or more and 19.9% ​​by weight or less of barium sulfate, 0% by weight or more and 10.0% by weight or less of molybdenum disulfide, and 8.3% by weight or more and 15.7% by weight or less of calcined clay.

[0011] Therefore, the sliding member of this embodiment can improve the wear resistance.

[0012] The reason why the above-mentioned effect is exhibited is not clear, but is speculated as follows: However, the present invention is not limited to the speculation below.

[0013] The slide member of this embodiment contains the above-mentioned amounts of calcined clay, magnesium phosphate, barium sulfate, and molybdenum disulfide in PTFE, which is the main component of the slide member. In the slide member of this embodiment, the content of calcined clay dispersed in PTFE is 8.3% by weight or more and 15.7% by weight or less, and the content of calcined clay, which is a hard material, is higher than in the prior art. It is believed that the hard material has the effect of micro-polishing and smoothing the surface of the mating shaft through sliding. Therefore, if the surface of the mating shaft is rough, it will become smoother than before sliding, and it is believed that this can suppress the progression of wear of the slide member itself.

[0014] Furthermore, the sliding member of this embodiment contains the calcined clay, magnesium phosphate, barium sulfate, and molybdenum disulfide in the above-mentioned amounts, which is thought to adjust the balance between low friction, wear resistance, and seizure resistance of the sliding member, thereby effectively improving the wear resistance.

[0015] Therefore, it is presumed that the sliding member 14 of this embodiment can improve the wear resistance.

[0016] The sliding member and the sliding body of this embodiment will be described in detail below.

[0017] Fig. 1 is a schematic diagram showing an example of a slide body 10 according to the present embodiment. Fig. 1 shows a schematic cross-sectional structure of the slide body 10.

[0018] The slide body 10 includes a substrate 12 and a slide member 14. The slide body 10 is a laminate of the substrate 12 and the slide member 14 formed on the substrate 12.

[0019] The substrate 12 is a layer that provides mechanical strength to the slide body 10. The substrate 12 may also be called a backing metal or a backing metal layer. The substrate 12 may be a metal plate made of, for example, an Fe alloy, Cu, or Cu alloy. Alternatively, a wire mesh may be used as the substrate 12.

[0020] At least a portion of the substrate 12 on the side of the surface to be bonded to the slide member 14 may be formed by a sintered layer. The sintered layer is a sintered body of metal powder and is a porous layer having a plurality of pores. The metal powder constituting the sintered layer may be the same metal as that of the substrate 12, or may be a metal or material different from that of the substrate 12. The metal powder may be, for example, a mixed powder of metal powders such as copper alloys such as copper-tin, copper-lead-tin, and phosphor bronze, iron, copper, and tin. The structure including the sintered layer can improve the adhesion between the substrate 12 and the slide member 14.

[0021] Furthermore, at least a part of the region of the substrate 12 on the side of the surface that comes into contact with the sliding member 14 may be a roughened region. For the roughening treatment, shot blasting or the like may be used.

[0022] The sliding member 14 is a resin layer 15 laminated on a substrate 12 .

[0023] The slide member 14 is made of PTFE 16, magnesium phosphate 22, barium sulfate 24, and molybdenum disulfide 26. The magnesium phosphate 22, barium sulfate 24, and molybdenum disulfide 26 function as a solid lubricant 20 and are dispersed in the PTFE 16. In FIG. 1, the magnesium phosphate 22, barium sulfate 24, and molybdenum disulfide 26 are shown collectively as the solid lubricant 20 for the sake of simplicity. However, in reality, each of the magnesium phosphate 22, barium sulfate 24, and molybdenum disulfide 26 is dispersed in the PTFE 16.

[0024] The content of magnesium phosphate 22 relative to the total amount (100% by weight) of the slide member 14 is 2.4% by weight to 15.6% by weight, preferably 6.9% by weight to 12.0% by weight, and more preferably 6.9% by weight to 7.9% by weight.

[0025] When the sliding member 14 contains magnesium phosphate 22 in the above range, the ability of the PTFE 16 to form a lubricating film on the sliding surface of the sliding member 14 is promoted, thereby improving the wear resistance.

[0026] There are no limitations on the average particle size of magnesium phosphate 22. For example, the average particle size of magnesium phosphate 22 is in the range of 10 μm to 50 μm.

[0027] Examples of magnesium phosphate 22 include magnesium pyrophosphate (Mg2P2O7) and magnesium metaphosphate [Mg(PO3)2]. n Among them, magnesium metaphosphate is more preferable.

[0028] The content of barium sulfate 24 relative to the total amount (100% by weight) of the slide member 14 is 7.6% by weight or more and 19.9% ​​by weight or less, and preferably 9.8% by weight or more and 12.3% by weight or less.

[0029] By including barium sulfate 24 in the sliding member 14 in the above range, the wear resistance and load bearing capacity of the PTFE 16 can be further improved.

[0030] There are no limitations on the average particle size of barium sulfate 24. For example, the average particle size of barium sulfate 24 is 12 μm or less, preferably 1 μm or more and 12 μm or less, and more preferably 8 μm or more and 12 μm or less.

[0031] As the barium sulfate 24, either precipitated barium sulfate or elutriated barium sulfate may be used.

[0032] The content of molybdenum disulfide 26 relative to the total amount (100% by weight) of the slide member 14 is 0% by weight or more and 10.0% by weight or less, and preferably 4.7% by weight or more and 7.9% by weight or less.

[0033] By including the molybdenum disulfide 26 in the sliding member 14 in the content range described above, the lubricity of the PTFE 16 can be improved, and the wear resistance of the sliding member 14 can be improved.

[0034] There are no limitations on the average particle size of the molybdenum disulfide 26. For example, the average particle size of the molybdenum disulfide 26 is 0.5 μm or more and 2.5 μm or less, preferably 0.5 μm or more and 2.0 μm or less, and more preferably 1.0 μm or more and 2.0 μm or less.

[0035] The content of the calcined clay 18 relative to the total amount (100% by weight) of the sliding member 14 is 8.3% by weight or more and 15.7% by weight or less, and preferably 8.7% by weight or more and 11.0% by weight or less.

[0036] By including the calcined clay 18 in the sliding member 14 in the above content range, even if the surface of the mating member, such as a shaft member, is rough, the hard material minutely polishes and smoothes the surface of the mating shaft during sliding, thereby suppressing the progress of wear of the sliding member itself, thereby improving the wear resistance of the sliding member 14.

[0037] Furthermore, calcined clay 18 is obtained by subjecting clay to high-temperature treatment. The high-temperature treatment activates and porouss calcined clay 18, turning it into a material with excellent oil absorption properties. Therefore, when sliding member 14 contains calcined clay 18, the oil absorption effect of calcined clay 18 can improve the oil wettability of the sliding surface of sliding member 14. When the oil wettability of the sliding surface of sliding member 14 is improved, a lubricating oil film is more likely to be generated on the sliding surface of sliding member 14 under grease lubrication and in oil, improving the low friction properties of sliding member 14 and improving wear resistance.

[0038] There are no limitations on the average particle size of the calcined clay 18. For example, the average particle size of the calcined clay 18 is preferably 0.5 μm or more and 10 μm or less, more preferably 1.0 μm or more and 8.0 μm or less, and particularly preferably 1.5 μm or more and 6.0 μm or less.

[0039] The average particle diameters of the calcined clay 18 and the solid lubricant 20 may be measured by the following method. Specifically, for example, an electron image of the cross section of the sliding member 14 is obtained by photographing it with an electron microscope at an appropriate magnification (for example, 1000 times). The area of ​​the calcined clay 18 or solid lubricant 20 included in the obtained electron image is then measured by a general image analysis method and converted into the average diameter of a circle. By these processes, the average particle diameters of the calcined clay 18 and the solid lubricant 20 can be determined.

[0040] Calcined kaolin is an example of the calcined clay 18. Calcined kaolin is obtained by treating kaolin, a natural clay mineral, at high temperatures.

[0041] As the PTFE 16 that is the main component of the resin layer 15, for example, PTFE that is mainly used for molding as molding powder or fine powder may be used.

[0042] Examples of PTFE for molding powder include "Teflon (registered trademark) 7-J (trade name)" and "Teflon (registered trademark) 70-J (trade name)" manufactured by DuPont-Mitsui Fluorochemicals, "Polyflon M-12 (trade name)" manufactured by Daikin Industries, Ltd., and "Fluon G163 (trade name)" and "Fluon G190 (trade name)" manufactured by Asahi Glass Co., Ltd. Examples of PTFE for fine powder include "Teflon (registered trademark) 6CJ (trade name)" manufactured by DuPont-Mitsui Fluorochemicals, "Polyflon F201 (trade name)" manufactured by Daikin Industries, Ltd., and "Fluon CD076 (trade name)" and "Fluon CD090 (trade name)" manufactured by Asahi Glass Co., Ltd.

[0043] The content of PTFE 16 in slide member 14 may be the amount remaining after subtracting the total amount of solid lubricants 20 such as magnesium phosphate 22, barium sulfate 24, and molybdenum disulfide 26, and additional components such as fillers, from the total amount of slide member 14.

[0044] For example, the content of PTFE 16 in the slide member 14 is 40% by weight or more and 95% by weight or less, preferably 45% by weight or more and 80% by weight or less, and more preferably 50% by weight or more and 65% by weight or less, relative to the total amount of the slide member 14 (100% by weight).

[0045] The slide member 14 of this embodiment may further contain additional components from the viewpoint of further improving the wear resistance. However, it is preferable that the slide member 14 does not contain silicate. This is because silicate is soft and may reduce the wear resistance.

[0046] The additional component may include, for example, at least one filler selected from spherical carbon, glass spheres, carbon fiber, graphite fiber, glass fiber, resin powder, resin fiber, metal powder, and metal fiber.

[0047] The content of the filler in the sliding member 14 is preferably 10% by weight or less relative to the total weight of the sliding member 14 (100% by weight).

[0048] By including the filler in the sliding member 14, the strength and wear resistance of the sliding member 14 can be improved.

[0049] (Method for manufacturing sliding body) The slide body 10 of this embodiment is manufactured, for example, by the following steps.

[0050] A raw material mixture made of the constituent materials of the slide member 14 having the above-described configuration is applied onto the substrate 12 to form a resin material layer on the substrate 12. Known conditions may be used for application. For example, the raw material mixture may be applied by spraying, tumbling, roll transfer, printing, or the like.

[0051] Alternatively, the substrate 12 having a roughened surface or the substrate 12 having a sintered layer formed thereon may be impregnated with the above-mentioned raw material mixture to form a resin material layer on the substrate 12. The thickness of the sintered layer is, for example, 0.1 mm or more and 0.3 mm or less.

[0052] Then, the resin material layer applied onto the substrate 12 is baked. Known baking conditions may be used. For example, the resin material layer is baked by holding it at 350°C to 450°C. By this baking process, the sliding member 14 is formed on the substrate 12. There are no limitations on the thickness of the sliding member 14 formed on the substrate 12. The thickness of the sliding member 14 is, for example, 10 μm or more and 60 μm or less, and preferably 20 μm or more and 40 μm or less.

[0053] (Action of sliding body) Next, an example of the operation of the sliding member 14 of this embodiment will be described.

[0054] 2A and 2B are explanatory diagrams showing an example of the function of the sliding member 14. FIG.

[0055] As described above, the slide member 14 of this embodiment is made of PTFE 16 containing 2.4% by weight or more and 15.6% by weight or less of magnesium phosphate, 7.6% by weight or more and 19.9% ​​by weight or less of barium sulfate, 0% by weight or more and 10.0% by weight or less of molybdenum disulfide, and 8.3% by weight or more and 15.7% by weight or less of calcined clay.

[0056] In the slide member 14 of this embodiment, the content of the calcined clay 18 dispersed in the PTFE 16 is 8.3% by weight or more and 15.7% by weight or less, and the content of the calcined clay 18, which is a hard material, is higher than in the prior art. Therefore, even if the surface of the mating material, such as the shaft member 30, is rough, the hard material minutely polishes and smoothes the surface of the mating shaft during sliding, which is thought to suppress the progress of wear of the slide member 14 itself.

[0057] 2A, it is assumed that the surface roughness of the sliding surface C2 of the shaft member 30 that comes into contact with the sliding member 14 is rough. The term "rough surface roughness of the sliding surface C2 of the shaft member 30" means that the sliding surface C2 of the shaft member 30 is rough enough to wear down the sliding surface C1 of the resin layer made of PTFE 16 that does not contain the calcined clay 18 or the solid lubricant 20 by a predetermined amount or more. Specifically, the term "rough surface roughness of the sliding surface C2 of the shaft member 30" means that the surface roughness Ra of the sliding surface C2 of the shaft member 30 is in the range of 0.3 to 0.7.

[0058] Here, a comparative sliding member is assumed in which the content of calcined clay 18 dispersed in PTFE 16 of sliding member 14 does not satisfy the above content of calcined clay 18 of the present embodiment. In this case, the amount of wear on the sliding surface of the comparative sliding member with shaft member 30 is large due to the rough sliding surface C2 of shaft member 30, and wear resistance may not be obtained.

[0059] On the other hand, in the slide member 14 of this embodiment, the content of calcined clay 18 dispersed in PTFE 16 is 8.3% by weight or more and 15.7% by weight or less, and the content of calcined clay 18, which is a hard material, is higher than in the prior art. Therefore, even if the surface of a mating material such as the shaft member 30 is rough, it is thought that the calcined clay 18 slightly polishes the rough sliding surface C2 of the mating material during sliding of the slide member 14, thereby smoothing the sliding surface C2 of the shaft member 30 (see FIG. 2B). Therefore, it is thought that the slide member 14 of this embodiment can suppress the amount of wear of the slide member 14 itself.

[0060] Furthermore, the slide member 14 of this embodiment contains the above-mentioned amounts of calcined clay 18, magnesium phosphate 22, barium sulfate 24, and molybdenum disulfide 26. Therefore, it is believed that the balance between low friction, wear resistance, and seizure resistance of the slide member 14 can be adjusted, and wear resistance can be effectively improved.

[0061] Therefore, it is presumed that the slide member 14 of this embodiment and the slide body 10 including the slide member 14 can improve the wear resistance.

[0062] (Application form) Next, an example of an application of the sliding body 10 will be described.

[0063] 3A and 3B are schematic diagrams showing an example of an application form of the slide body 10. For example, as shown in FIG. 3A, the slide body 10 is applied to a bushing for a shift fork of a manual transmission.

[0064] As shown in FIG. 3B, the slide body 10 is used in a steering mechanism of a vehicle such as an automobile, where the sliding speed is low and grease lubrication is required. For example, the slide body 10 is applied to an arc-shaped bearing used in a support yoke portion attached to a rack-and-pinion power steering system, where low friction and wear resistance are important. Therefore, by applying the slide body 10 of this embodiment, the wear resistance of the slide bearing can be effectively improved.

[0065] Specifically, for example, the sliding device includes a shaft member 30 and a sliding body 10. The shaft member 30 is a cylindrical member and functions as a shaft. The sliding body 10 is, for example, annular or arc-shaped with the sliding member 14 disposed on the inner circumferential surface side of the substrate 12, and the shaft member 30 is disposed inside. That is, the sliding body 10 functions as, for example, a bushing (FIG. 3A) or an arc-shaped bearing (FIG. 3B).

[0066] The sliding device is not limited to the form shown in Fig. 3. For example, the shaft member 30 and the sliding body 10 may be flat. [Example]

[0067] The present invention will be specifically explained below with reference to examples, but the present invention is not limited to these examples.

[0068] The following slide body 10 and comparative slide bodies were produced and evaluated for wear resistance.

[0069] Example 1 -Adjustment of base material 12- A 1.5 mm thick backing steel plate (SPCC (JIS)) was prepared. The surface of the backing steel plate was sanded, and then phosphor bronze powder was scattered on the degreased backing steel plate. The scattered phosphor bronze powder was sintered at 920°C to 950°C to prepare a substrate 12 in which a 0.1 mm to 0.3 mm thick sintered layer was formed on the backing steel plate.

[0070] - Adjustment of sliding material (resin layer) - A raw material mixture having the composition shown in Example 1 in Table 1 was prepared as a raw material mixture made up of constituent materials of the slide member 14. The prepared raw material mixture was then impregnated and coated on the sintered layer of the substrate 12 using a roll to form a resin material layer. The resin material layer was then fired at 350°C to 420°C to form the slide member 14 of Example 1 on the substrate 12. The formed slide member 14 had a thickness of 0.01 mm to 0.06 mm. Through these processes, the slide body 10 of Example 1 was produced.

[0071] (Examples 2 to 14, Comparative Examples 1 to 7) The slide bodies 10 of Examples 2 to 14 and the comparative slide bodies of Comparative Examples 1 to 7 were produced in the same manner as in Example 1, except that raw material mixtures of the constituent materials of the slide member 14 were prepared to have the compositions shown in Examples 2 to 14 and Comparative Examples 1 to 7 in Table 1, respectively.

[0072] [Table 1]

[0073] -evaluation- -Wear resistance- The wear resistance of the slide members 14 and the comparative slide members 10 of Examples 1 to 14 and Comparative Examples 1 to 7 was evaluated.

[0074] 4A to 4D are explanatory diagrams of the abrasion resistance evaluation test.

[0075] In the wear resistance test, sample S is attached to base D, and with load I applied to base D, shaft J is caused to slide against sample S by reciprocating.

[0076] The shaft J is an example of the shaft member 30 and corresponds to a sliding counterpart material. The sample S corresponds to each of the slide bodies 10 of Examples 1 to 14 and the comparative slide bodies of Comparative Examples 1 to 7. For the sample S, the slide body 10 and the comparative slide body each formed into an arc plate shape are used, and the slide member 14 and the comparative slide member are attached to a base so that the sliding surfaces C1 thereof face the shaft J.

[0077] FIG. 4A is a schematic diagram of the wear resistance evaluation test as viewed from a direction along the extension direction of axis J. FIG. 4B is a cross-sectional view taken along line AA in FIG. 4A. FIG. 4C is a schematic diagram showing the shape of sample S. As shown in FIG. 4C, sample S had an arcuate plate shape with a radius of R13 mm, a height of 9.5 mm, a length in the arc direction of 30 mm, and a length in the axial direction of 32 mm. FIG. 4D is a cross-sectional view taken along line BB in FIG. 4C.

[0078] As shown in FIGS. 4A to 4D, sample S was attached to base D, and a load was applied to base D to press sample S against the periphery of shaft J with a shaft diameter of 26 mm. Then, a wear resistance test was performed by sliding shaft J in a reciprocating motion in the extension direction of shaft J (left and right direction in FIG. 4). The test conditions for the wear resistance test were as follows:

[0079] Wear resistance test conditions Axis J reciprocating stroke: 20mm Sliding speed: 55mm / s Evaluation time: 3 hours Load: 3500N Load type: static load Oil temperature: Room temperature Lubrication method: Grease application Oil type: Kyodo Yushi Mori White LSG Shaft J material: S45C Shaft J hardness: HRC24~30 Surface roughness of shaft J: Ra: 0.3~0.7

[0080] Then, the wear resistance test was carried out under the above-mentioned test conditions for each sample S of the slide bodies 10 of Examples 1 to 14 and the comparative slide bodies of Comparative Examples 1 to 7, and the wear amount of the sample S was evaluated. The evaluation results are shown in Table 1.

[0081] As shown in Table 1, the slide bodies 10 of Examples 1 to 14 exhibited reduced wear amounts compared to the comparative slide bodies of Comparative Examples 1 to 7. Therefore, the evaluation results showed that the slide bodies 10 of Examples 1 to 14 had improved wear resistance compared to the comparative slide bodies of Comparative Examples 1 to 7.

[0082] It should be noted that the various materials and their compositions used in the above-described examples are merely examples, and the present invention is not limited thereto. The slide member 14 according to the present invention may further contain inevitable impurities. Furthermore, the specific structures of the slide member 14 and the slide body 10 are not limited to those exemplified in FIGS. 1 to 3, etc. [Explanation of symbols]

[0083] 10 Slider 12 Base material 14 Sliding member 16 PTFE 18 Calcined Clay 22 Magnesium Phosphate 24 Barium sulfate 26 Molybdenum disulfide

Claims

1. A sliding member that slides against a sliding surface of a mating member having a surface roughness Ra of 0.3 or more and 0.7 or less, 2.4% by weight or more and 15.6% by weight or less of magnesium phosphate; 7.6% by weight or more and 19.9% ​​by weight or less of barium sulfate; 0% by weight or more and 10.0% by weight or less of molybdenum disulfide; 8.3% by weight or more and 15.7% by weight or less of calcined clay; A sliding member made of a polytetrafluoroethylene resin containing

2. silicate-free, The sliding member according to claim 1 .

3. The polytetrafluoroethylene resin is Further containing at least one filler selected from spherical carbon, glass spheres, carbon fibers, graphite fibers, glass fibers, resin powder, resin fibers, metal powder, and metal fibers in a total filling amount of 10 wt% or less; The sliding member according to claim 1 .

4. A substrate; The slide member according to claim 1 provided on the substrate; A sliding body comprising:

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