Member

Abstract

To provide a member which achieves improvement of friction characteristics on a contact surface.SOLUTION: A member 10 is a member which contacts with and moves relative to the mating member 50. The member 10 includes a base part 11 and a plurality of protruding parts 12 which are scattered on a surface 11A of the base part 11. The protruding part 12 has a protruding end surface 12A which makes surface contact with the mating member 50. When the member 10 moves relative to the mating member 50, objects adhering to the mating member 50 are scraped by at least one of the protruding parts 12 and the scraped objects are stored between the protruding parts 12.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a member that comes into contact with a counter member and moves relatively thereto. [Background technology]

[0002] Patent Document 1 discloses a movable scroll having a pressure-receiving portion in the form of a floating island. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-219809 A Summary of the Invention [Problem to be solved by the invention]

[0004] For contact surfaces such as sliding surfaces and guide surfaces, improvements in friction characteristics, such as a reduction in the friction coefficient, are desired in order to support a load and ensure smooth relative motion.

[0005] The present disclosure has been made in consideration of the above-mentioned conventional situation, and has as its object to provide a member having improved friction characteristics at a contact surface. [Means for solving the problem]

[0006] [1] A member that moves relative to a counter member by contacting the counter member, The present invention comprises a base and a plurality of protrusions scattered on a surface of the base, The protruding portion has a protruding end surface that comes into planar contact with the counter member, When the member moves relative to the counter material, at least one of the multiple protrusions scrapes off material adhering to the counter material, and the scraped-off material is stored between the multiple protrusions. [Brief description of the drawings]

[0007] [Figure 1] FIG. 2 is a plan view of the sliding member of the first embodiment. [Diagram 2] (A) is an enlarged view showing a part of Fig. 1. (B) is a longitudinal sectional view showing (A) taken along line BB. [Diagram 3] FIG. 11 is a vertical cross-sectional view for illustrating a state in which something transferred to a counter material is scraped off. [Figure 4] 4 is a cross-sectional view taken along line IV-IV in FIG. 3, for illustrating a schematic manner in which something adhering to a counter material is scraped off. FIG. [Diagram 5] 1A is a schematic diagram showing a state before contact with a counter material, and FIG. 1B is a schematic diagram showing a state after transfer to the counter material due to contact. [Figure 6] FIG. 13 is a schematic diagram illustrating how the formation of protrusions distributes contact over the entire contact surface, thereby suppressing adhesion growth on the soft-side surface. [Figure 7] FIG. 11 is a plan view of a sliding member according to a second embodiment. [Figure 8] FIG. 11 is a plan view of a sliding member according to a third embodiment. [Figure 9] 1 is a cross-sectional view for explaining a schematic manner in which something transferred to a counter material is scraped off. FIG. [Figure 10] FIG. 1 is a diagram showing the results of Experimental Example 1-3. [Figure 11] 1 is a graph showing changes in friction coefficient over time in Experimental Examples 2, 4, and 5. [Figure 12] FIG. 1A is a plan view of a test piece of Experimental Example 8. FIG. 1B is a plan view of a test piece of Experimental Example 9. FIG. 1C is a plan view of a test piece of Experimental Example 10. FIG. 1D is a plan view of a test piece of Experimental Example 11. [Figure 13] 13 is a graph showing changes in friction coefficient over time in Experimental Examples 6 and 5. [Figure 14] 1 is a graph showing changes in friction coefficient over time in Experimental Examples 6 and 7. [Figure 15] 1 is a graph showing changes in friction coefficient over time in Experimental Examples 6 and 8. [Figure 16] 1 is a graph showing changes in friction coefficient over time in Experimental Examples 9 and 11. [Figure 17] (A) Observation images of the test piece (Disk) and the mating material (Ring) of Experimental Example 13. (B) Observation image of the convex portion and the cross-sectional curve of the convex portion. [Figure 18] 1 is a graph showing changes in friction coefficient over time in Experimental Examples 12 and 13. [Figure 19] 1A is an observation image of the test piece (disk) and the mating material (ring) of Experimental Example 14. (B) is an observation image of a convex portion and a cross-sectional curve of the convex portion. [Figure 20] (A) Observation images of the test piece (Disk) and the mating material (Ring) of Experimental Example 15. (B) Observation image of the convex portion and the cross-sectional curve of the convex portion. [Figure 21] 1 is a graph showing changes in friction coefficient over time in Experimental Examples 14 and 15. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] Additionally, preferred examples of the present disclosure will be described. [2] The member is a sliding member that slides against the counter member, the mating member has a sliding surface that comes into contact with the plurality of protruding end surfaces, The member according to [1], wherein the sliding surface of the counter member is harder than the protruding end surface. [3] The sum of the areas of the protruding end faces of the plurality of protruding portions is A, When the surface area of ​​the base is B, (A / B)×100≦30 The component described in [1] or [2] satisfies the above. However, it is preferable to set the allowable contact load so that the contact pressure (= applied load / A) does not exceed 1 / 15 of the yield stress of this member (corresponding to the soft material described below). [4] The member described in any one of [1] to [3], wherein the protruding end surface has an elliptical shape in a plan view. [5] The member described in [4], wherein the minor axis direction of the ellipse of the protruding end surface is aligned with the direction of relative movement with respect to the counter member. [6] The member described in any one of [1] to [3], wherein the protruding height of each of the plurality of protrusions is 0.01 mm or more and 1 mm or less.

[0009] The members according to the embodiment will be described in detail below. In this specification, when a numerical range is described using "-", the lower limit and the upper limit are included unless otherwise specified. For example, the description "10-20" includes both the lower limit "10" and the upper limit "20". In other words, "10-20" has the same meaning as "10 or more and 20 or less".

[0010] 1 to 4, a sliding member 10 that slides against a counterpart member 50 will be described as an example of a member. The sliding member 10 in FIG.

[0011] In the sliding member 10 of this embodiment, lubricating components such as lubricating oil and grease may not be present between the sliding surface of the sliding member 10 and the sliding surface 50A of the counterpart material 50. The performance of the sliding surface (sliding contact surface) is reduced by wear. Since the sliding surface of the sliding member 10 of this embodiment has good friction characteristics, the sliding surface can be extended in life even without the presence of lubricating components. Depending on the application, etc., a lubricating component may be present between the sliding surface of the sliding member 10 and the sliding surface 50A of the counterpart material 50. The performance of the sliding surface (sliding contact surface) is also reduced by the deterioration of the lubricating components. Since the sliding member 10 of this embodiment has reduced frictional wear of the sliding surface, the deterioration of the lubricating components can also be suppressed, and the sliding surface can be further extended in life.

[0012] The mating member 50 has a sliding surface 50A that contacts the multiple protruding end faces 12A. The sliding surface 50A of the mating member 50 is preferably a smooth surface. That is, the sliding surface 50A of the mating member 50 is preferably configured as a surface that does not have a convex portion or a concave portion. From the viewpoint of improving the friction characteristics, the sliding surface 50A of the mating member 50 is preferably harder than the protruding end faces 12A. The hardness of the sliding surface 50A can be made harder than the protruding end faces 12A by appropriately selecting the material of the mating member 50. For example, when the multiple protruding portions 12 are made of a metal material, ceramics or a metal material harder than the multiple protruding portions 12 may be selected as the material of the mating member 50. For example, when the multiple protruding portions 12 are made of a resin material, a metal material harder than the multiple protruding portions 12 may be selected as the material of the mating member 50.

[0013] The surface 11A of the base 11 is disposed opposite to the sliding surface 50A of the counter member 50. The surface 11A of the base 11 preferably extends parallel to the sliding surface 50A of the counter member 50 in a cross-sectional view. For example, when the sliding surface 50A of the counter member 50 is flat, the surface 11A of the base 11 may be a flat surface parallel to the sliding surface 50A. When the sliding surface 50A of the counter member 50 is arc-shaped in a cross-sectional view, the surface 11A of the base 11 may be arc-shaped concentric with the sliding surface 50A in a cross-sectional view.

[0014] The material of the base 11 is not particularly limited. The base 11 is formed of, for example, a metal material. Examples of the metal material include copper-based metals, zinc-based metals, aluminum-based metals, iron-based metals, titanium-based metals, stainless steel-based metals, magnesium-based metals, and nickel-based metals. The metal material may be a pure metal, or an alloy containing two or more metal components. Among these, one or more metals selected from copper-based metals (brass, bronze) and aluminum-based metals (e.g., A5052) are preferable because of their softness.

[0015] The multiple protrusions 12 are scattered on the surface 11A of the base 11. In this embodiment, as shown in Fig. 1, the multiple protrusions 12 are scattered evenly on the surface 11A of the base 11. The multiple protrusions 12 are made of the same metal material as the base 11 and are provided integrally with the base 11, for example.

[0016] Each protrusion 12 has a protruding end surface 12A that contacts the mating material 50 in a planar manner. Such a protrusion 12 can be formed, for example, by processing the surface 11A of the base 11 into a smooth surface and removing a part of the processed surface (a part other than the protrusion 12). Examples of processing for removing a part of the surface include laser processing, electrolytic polishing, and fine cutting. Note that even if the protruding end surface 12A and the sliding surface 50A of the mating material 50 are smooth surfaces, they have minute unevenness that is invisible to the naked eye. "Contacting the mating material in a planar manner" is not limited to a configuration in which the entire area of ​​the protruding end surface 12A contacts the sliding surface 50A of the mating material 50, but also includes a configuration in which a virtual surface includes multiple contact parts between the protruding end surface 12A and the sliding surface 50A.

[0017] The shape and dimensions of each protrusion 12 are not particularly limited. The protrusion heights of the multiple protrusions 12 are preferably the same from the viewpoint of improving frictional characteristics. The protrusion height of each protrusion 12 is preferably about the same as the maximum diameter of the protrusion end face 12A from the viewpoint of improving frictional characteristics. For example, the protrusion height of each protrusion 12 is preferably 60% or more of the maximum diameter of the protrusion end face 12A, and is preferably 140% or less of the maximum diameter of the protrusion end face 12A. In addition, the protrusion height of each protrusion 12 may be as follows. The protrusion height of each protrusion 12 is preferably 0.01 mm or more, more preferably 0.1 mm or more, even more preferably 0.3 mm or more, and particularly preferably 0.5 mm or more. The upper limit of the protrusion height of each protrusion 12 is not particularly limited, and is usually 1 mm or less. In this embodiment, as shown in FIG. 2(A), the protrusion end face 12A has a circular shape in a plan view. The diameter of the protruding end surface 12A in the moving direction is preferably 0.05 mm or more and 5 mm or less, more preferably 0.10 mm or more and 2 mm or less, and further preferably 0.15 mm or more and 1 mm or less.

[0018] The area ratio of the protruding end surface 12A is not particularly limited. The area ratio of the protruding end surface 12A can be calculated as (A / B)×100, where A is the sum of the areas of the protruding end surfaces in the multiple convex portions, and B is the area of ​​the surface 11A of the base 10. From the viewpoint of improving friction characteristics, the area ratio of the protruding end surface 12A preferably satisfies the following formula (1), more preferably satisfies the following formula (2), and even more preferably satisfies the following formula (3). The lower limit of (A / B)×100 is not particularly limited, and can be, for example, 1 or more, 2 or more, or 2.5 or more. (A / B) × 100≦30 (1) (A / B) × 100≦15 (2) (A / B) × 100≦7 (3) However, it is preferable to set the allowable contact load so that the contact pressure (=applied load / A) does not exceed 1 / 15 of the yield stress of the sliding member 10 .

[0019] A method for calculating the area ratio of the protruding end faces 12A will be specifically described with reference to FIG. 1. The total area A of the protruding end faces 12A can be calculated by calculating the area of ​​each protruding end face 12A and adding up the areas. The area B of the surface 11A of the base 11 is the area of ​​the sliding surface in the sliding member 10. In the sliding member 10 of FIG. 1, the area B can be calculated as the area of ​​the region R1 of the entire surface 11A of the base 11, which forms an annular ring. That is, the area B of the surface 11A of the base 11 corresponds to the area of ​​the surface of the base 11 facing the sliding surface 50A. From the above, the area A and area B can be calculated to calculate the area ratio of the protruding end faces 12A.

[0020] As shown in Fig. 3 and Fig. 4, when the sliding member 10 moves relative to the counter material 50, at least one of the multiple convex parts 12 scrapes off the object S attached to the counter material 50, and the scraped off object S is accommodated between the multiple convex parts 12. In Fig. 3 and Fig. 4, the moving direction of the counter material 50 is depicted by a hollow arrow. Specific examples of the object S attached to the counter material 50 will be described later.

[0021] It can be confirmed, for example, by observing the sliding member 10 and the mating member 50 after the relative movement that the object S adhering to the mating member 50 has been scraped off and that the scraped off object S is housed between the plurality of protrusions 12. The confirmation method will be specifically described in the examples described later with reference to Example 13 shown in Figs. 15(A)(B), Example 14 shown in Figs. 17(A)(B), and Example 15 shown in Figs. 18(A)(B).

[0022] In the member of the present disclosure, the manner of relative movement with respect to the counter member is not particularly limited. Conditions such as the distance of relative movement and the presence or absence of a lubricant component may be appropriately set according to the application of the member. For example, in the sliding member of Experimental Example 12-15 described later, a ring-on-disk test (test load: 100 N, test speed: 0.25 m / s, lubricant: none) can be set. In addition, in the present disclosure, a configuration in which the matter attached to the counter member is scraped off and the scraped off matter is accommodated between a plurality of protrusions can be realized, for example, by adjusting the area ratio of the protruding end face 12A or the hardness difference between the protruding end face 12A and the sliding surface 50A of the counter member 50. Specifically, the above configuration is easily realized by reducing the area ratio of the protruding end face 12A. In addition, the above configuration is easily realized by making the sliding surface 50A of the counter member 50 harder than the protruding end face 12A.

[0023] The operation and effect of the present embodiment will be described with reference to Figs. 5 and 6. According to the present embodiment, the friction characteristics can be improved. Although the reason is not clear, the reason is assumed. Note that the present disclosure is not limited to the interpretation based on the reason.

[0024] As shown in FIG. 5, the generation of the transferred matter when the sliding member is a soft material having a soft surface and the counter member is a hard material having a hard surface will be described. The sliding member in FIG. 5 does not have multiple convex parts, unlike the present embodiment. As shown in FIG. 5(A), when the counter member moves and comes into contact with the sliding member, a transfer layer is formed on the convex parts of the hard surface having the unevenness, and a wedge is formed in front of the moving direction of the counter member (see FIG. 5(B)). The transfer layer and the wedge are examples of the above-mentioned "substance S attached to the counter member 50", and hereinafter are also simply referred to as the transferred matter. As shown in Fig. 6, assuming that the surface of the mating material is smooth and the processing hardness of the surface of the sliding member on which multiple protrusions are formed is lower than the hardness of the surface of the mating material, the protrusions formed on the surface of the sliding member act as edges that scrape off the transferred material from the mating material, and serve to reduce the size of the transferred material. In Fig. 6, the transferred material scraped off by the protrusions is called "scrapped off transfer". In this way, it is presumed that the multiple protrusions suppress the growth of the transferred material from the mating material, thereby reducing the friction coefficient and suppressing wear.

[0025] As shown in Fig. 6, when the convex parts scrape off the transferred material from the counter material and the scraped off transferred material is contained between the multiple convex parts, the intrusion of the scraped off transferred material into the contact surface ahead in the moving direction of the convex parts (left side of the paper in Fig. 6) can be suppressed. The synergistic effect of the suppression of the intrusion of the transferred material into the contact surface and the elastic deformation (deflection or buckling) of the convex parts can favorably inhibit the growth of the adhesion part.

[0026] As described above, according to this embodiment, for example, the growth of adhesion, which is a cause of increased frictional resistance and wear in sliding contact with a hard flat surface, can be suitably suppressed by the multiple protrusions 12. Furthermore, material transferred to the counter material 50 is scraped off ahead in the moving direction of the protrusions 12, and the scraped off material is accommodated between the multiple protrusions 12, thereby being removed from the contact area and suppressing the growth of adhesion.

[0027] The technology of the present disclosure is considered to be effective not only for the slide member 10 but also for sliding contact surfaces in many mechanical systems and the like. The technology of the present disclosure is applicable to various members and can significantly improve performance related to friction and wear, and therefore has extremely high industrial applicability.

[0028] <Embodiment 2> 7, the sliding member 110 according to the second embodiment differs from the sliding member 10 in the arrangement of the multiple protrusions 12. The same components as those in the sliding member 10 are given the same reference numerals and detailed description thereof will be omitted.

[0029] The plurality of protrusions 12 are scattered on the surface 11A of the base 11. In this embodiment, the plurality of protrusions 12 are scattered in a region R2 divided on the surface 11A of the base 11. The number, position, and area of ​​the divided regions R2 are not particularly limited. The number and position of the regions R2 may be appropriately set so that the sliding member 110 and the mating member 50 can be in stable contact with each other. For example, the region R2 in FIG. 7 is divided into three and provided at positions spaced 120° apart on the annular base 11. The region between the regions R2 and R2 is a non-existence region where the plurality of protrusions 12 are not present. In other words, the region between the regions R2 and R2 is a surface at the same height as the bottom surface of the recess between the protrusions 12. The area of ​​the region R2 may be appropriately set in consideration of the size of each protrusion 12 and the load on each protrusion 12 so that the sliding member 110 and the mating member 50 can be in stable contact with each other. 7 can be set to, for example, 10% to 60% of the area of ​​the surface 11A of the base 11, and is preferably 40% or less, and more preferably 30% or less, from the viewpoint of reducing the area ratio A / B. Note that the area of ​​the region R2 in which the multiple protrusions 12 are provided may be calculated by calculating the area of ​​each region R2 surrounding a group of multiple protrusions 12 and adding up the areas.

[0030] The area ratio of the protruding end face 12A is not particularly limited, and can be in the same range as the area ratio of the protruding end face 12A in the first embodiment. A method for calculating the area ratio of the protruding end face 12A will be specifically described with reference to FIG. 7. The total area A of the protruding end faces 12A may be calculated by calculating the area of ​​each protruding end face 12A and adding up the areas. The area B of the surface 11A of the base 11 is the area of ​​the sliding surface in the sliding member 110. In the sliding member 110 of FIG. 7, the area B can be calculated as the area of ​​the region R1 of the entire surface 11A of the base 11 that forms an annular ring. That is, the area B of the surface 11A of the base 11 corresponds to the area of ​​the surface facing the sliding surface 50A side in the base 11. In the sliding member 110 of FIG. 7, a plurality of convex portions 12 are provided in the divided region R2 in the surface 11A of the base 11. As described above, the area A and the area B can be calculated to calculate the area ratio of the protruding end face 12A.

[0031] When the above-mentioned area ratio of the multiple protrusions 12 is the same, according to a configuration in which the multiple protrusions 12 are scattered in the region R2 divided on the surface 11A of the base 11, the sliding distance can be extended compared to a configuration in which the multiple protrusions 12 are scattered evenly on the surface 11A of the base 11. Although the mechanism is unclear, it is speculated that the contact area with the counter material 50 can be reduced by scattering the multiple protrusions 12 in the region R2 divided on the surface 11A of the base 11.

[0032] <Embodiment 3> 8 and 9, a sliding member 210 according to the third embodiment differs from the sliding member 10 in the shape of a protruding end surface 212A. The same components as those in the sliding member 10 are given the same reference numerals and detailed description thereof will be omitted.

[0033] In this embodiment, the protruding end surface 212A has an elliptical shape in a plan view. The minor axis direction of the protruding end surface 212A is along the direction of relative movement with respect to the counterpart material 50. That is, the minor axis direction of the ellipse is along the circumferential direction of the annular base portion 11. The diameter (minor axis) of the protruding end surface 12A in the movement direction is preferably 0.01 mm or more and 2.5 mm or less, more preferably 0.05 mm or more and 1 mm or less, and even more preferably 0.10 mm or more and 0.6 mm or less. The major axis of the protruding end surface 12A is longer than the minor axis and is 5 mm or less, more preferably 2 mm or less, and even more preferably 1.2 mm or less.

[0034] Each of the protruding portions 212 can be configured in the same manner as each of the protruding portions 12 described above. For example, the protruding height of the protruding portion 212 can be the same as the protruding height of the protruding portion 12 described above. The area ratio of the protruding end surface 212A can be the same as the area ratio of the protruding end surface 12A described above.

[0035] The configuration in which the protruding end surface 212A has an elliptical shape in a plan view can contribute to improving the friction characteristics more than, for example, a configuration in which the protruding end surface 212A has a rectangular shape in a plan view. Although the reason for this is unclear, it is presumed that the scraped off material can be moved along the side surface of the convex portion 212, and the intrusion of the scraped off material into the contact surface can be suppressed. Also, the configuration in which the minor axis direction of the ellipse of the protruding end surface 212A is aligned with the direction of relative movement with respect to the counter member 50 can make the friction more stable than, for example, a configuration in which the major axis direction of the ellipse of the protruding end surface is aligned with the direction of relative movement with respect to the counter member 50.

[0036] <Other embodiments> The present disclosure is not limited to the above-described embodiments, and the following embodiments, for example, are also included within the technical scope.

[0037] (1) The member is not limited to a member made of a metal material. The member may be a member made of a resin material, a member made of a rubber material, etc. In addition, the hardness difference between the member and the mating material can be appropriately set depending on the application, etc. (2) The member is not limited to a sliding member, so long as it is a member that moves relative to a counter member by contacting the counter member. Examples of the member include various members having a sliding contact surface that supports a load and realizes smooth relative movement. Specifically, a guide member having a guide surface as a sliding contact surface is exemplified. Also, a member having a surface that is a sliding contact surface is exemplified. A member having a surface that is a sliding contact surface is excellent in surface friction characteristics, so that dirt and the like can be easily removed by rubbing against the counter member. Such a configuration is also useful for boots and bicycle parts that are prone to getting dirty with mud and the like. (3) The sliding surface may be a surface of the sliding member based on a curved surface. An example of such a sliding surface is the outer peripheral surface of a cylindrical member. When the sliding surface of the sliding member is a surface based on a curved surface, it is preferable that the sliding surface of the counter member is also a surface based on a curved surface extending parallel to the sliding surface of the sliding member. (4) The shape, dimensions, and area ratio of the protruding end face of the convex portion can be appropriately changed depending on the material, application, etc. of the member. (5) The frictional characteristics improved by the multiple protrusions are not limited to a reduction in the friction coefficient. When the member of the present disclosure moves relative to the counter material, at least one of the multiple protrusions scrapes off material adhering to the counter material, and the scraped off material is accommodated between the multiple protrusions, so that the member is also effective in improving frictional characteristics other than a reduction in the friction coefficient. The frictional characteristics improved by the multiple protrusions may be, depending on the performance required of the member, a reduction in the fluctuation range of the friction coefficient, a maintenance of a predetermined friction coefficient for a long period of time, and the like. EXAMPLES

[0038] The present disclosure will be specifically described below with reference to examples. Experimental Examples 4-8 and 10-15 are examples. Experimental Examples 1-3 and 9 are comparative examples, and are indicated with an "*" in Table 1. However, the present disclosure is not limited to these examples.

[0039] 1. Experimental Examples 1-3 (1) Preparation of test specimens A brass disk with an inner diameter of 20 mm, an outer diameter of 44 mm, and a thickness of 7 mm was prepared. In Experimental Example 1, a laser processing machine was used to form multiple recesses on one end surface of the disk under the following conditions: one irradiation, power of 60% (18 W), feed speed of 150 mm / s-500 mm / s, and laser irradiation frequency of 45 kHz. This processing allowed the formation of recesses with a depth of 0.3 mm or more. In Experimental Example 2, multiple recesses were formed on one end surface of the disk in a similar manner. In Experimental Example 3, laser processing was not performed and the surface was left flat. The configurations of Experimental Examples 1-3 are as follows. <Experimental Example 1> Concave: circular, diameter 0.5mm Placement: Staggered, evenly scattered over the surface of the base -Protruding end surface area ratio: 50% <Experimental Example 2> Convex part: circular, diameter 0.5 mm Placement: Staggered, evenly scattered over the surface of the base -Protruding end surface area ratio: 50% <Experimental Example 3> ·Flat surface

[0040] (2) Friction test method The counter material was a carbon steel ring (SUJ2), which is harder than brass. The counter material surface (sliding surface) was flat. The ring-on-disc test was carried out under the following conditions. Test load: 100N Test speed: 0.25m / s Lubricant: None

[0041] (3) Results In Experimental Example 1, braking stopped in 1 minute. In Experimental Example 2, braking stopped in 2 minutes 32 seconds. In Experimental Example 3, braking stopped in 2 minutes 48 seconds. Figure 10 shows the sliding surface of the test piece (Disk) and the sliding surface of the mating material (Ring) after the test. In Experimental Example 1, the shapes of the multiple concave parts had almost disappeared, and it was confirmed that the contact surface with the mating material (Ring) had worn away. In Experimental Example 2, the shapes of the multiple convex parts were confirmed, but the contact surface with the mating material (Ring) had worn away. In Experimental Examples 1 and 2, it was not observed that the material attached to the mating material was scraped off and that the scraped off material was accommodated between the multiple convex parts.

[0042] The graph in Fig. 10 shows the change over time in the friction coefficient of Experimental Examples 1 to 3. The horizontal axis represents the sliding distance (m), and the vertical axis represents the friction coefficient. Comparing the graphs in Fig. 10, Experimental Examples 1 and 2 did not show any improvement in friction characteristics compared to Experimental Example 3.

[0043] In all of the experimental examples 1 to 3, adhesion of wear powder was observed on the sliding surface of the mating material (ring). Based on the results of the experimental examples 1 to 3, we hypothesized that the wear powder adhered to the mating material (ring) was the cause of the deterioration of the friction characteristics, and conducted experimental examples 4 and 5 in which spaces capable of accommodating wear powder were provided between multiple protrusions.

[0044] 2. Experimental Examples 4 and 5 (1) Preparation of test specimens In Experimental Examples 4 and 5, the area ratio of the protruding end faces (volume of the protruding portions) was made smaller than that of Experimental Example 2, so that wear powder could be accommodated between the multiple protruding portions. The test pieces of Experimental Examples 4 and 5 were prepared in the same manner as the test piece of Experimental Example 2, except that the area ratio of the protruding end faces was changed. The configurations of Experimental Examples 4 and 5 are as follows. <Experimental Example 4> Convex part: circular, diameter 0.5 mm Arrangement: staggered (see Figure 2(A)), evenly scattered on the surface of the base -Protruding end surface area ratio: 12.5% <Experimental Example 5> Convex part: circular, diameter 0.5 mm Placement: Staggered, evenly scattered over the surface of the base -Protruding end surface area ratio: 6.25%

[0045] (2) Friction test method A ring-on-disk test was carried out in the same manner as in Experimental Example 1-3.

[0046] (3) Results Braking stopped in 3 minutes 45 seconds in Experimental Example 4. Braking stopped in 10 minutes 50 seconds in Experimental Example 5. In Experimental Examples 4 and 5, it was observed that the material adhering to the counter material was scraped off and that the scraped off material was accommodated between multiple protrusions.

[0047] The graph in FIG. 11 shows the change over time in the friction coefficient for Experimental Example 2 (area ratio 50%), Experimental Example 4 (area ratio 12.5%), and Experimental Example 5 (area ratio 6.25%). The horizontal axis represents the sliding distance (m), and the vertical axis represents the friction coefficient. Comparing the graphs in FIG. 11, it was found that Experimental Example 4 and Experimental Example 5 were able to improve friction characteristics such as a reduced friction coefficient, an increased sliding distance, and stable friction compared to Experimental Example 2.

[0048] From a comparison of Experimental Examples 2, 4, and 5, it was found that the smaller the area of ​​the contact surface with the counter material, the lower the friction coefficient and the longer the sliding distance. Therefore, based on the hypothesis that reducing the area of ​​the contact surface with the counter material can further contribute to improving the friction characteristics, Experimental Examples 6-8 were carried out in which multiple convex parts were divided and arranged on the surface of the base.

[0049] 3. Experimental Examples 6-8 (1) Preparation of test specimens In Experimental Examples 6-8, multiple protrusions (staggered arrangement) similar to those in Experimental Example 5 (area ratio 6.25%) were arranged in three divided regions on the surface of the base, with an area ratio of 2%. The test piece in Experimental Example 6 was prepared in the same manner as the test piece in Experimental Example 5, except that the multiple protrusions were arranged as shown in FIG. 7. The test piece in Experimental Example 7 was prepared in the same manner as the test piece in Experimental Example 6, except that the diameter of the protrusions was 0.2 mm. The test piece in Experimental Example 8 was prepared in the same manner as the test piece in Experimental Example 6, except that the multiple protrusions were arranged with a larger interval in the movement direction than in Experimental Example 6, as shown in FIG. 12(A). The configurations of Experimental Examples 6-8 are as follows. <Experimental Example 6> Convex part: circular, diameter 0.5 mm Arrangement: staggered, scattered within divided areas on the surface of the base (see Figure 7) -Protruding end surface area ratio: 2% <Experimental Example 7> Convex part: circular, diameter 0.2 mm Arrangement: staggered, scattered within divided areas on the surface of the base -Protruding end surface area ratio: 2% <Experimental Example 8> Convex part: circular, diameter 0.2 mm Arrangement: Arrangement with larger spacing in the direction of movement than staggered arrangement, scattered within divided areas on the surface of the base (see Figure 12(A)) -Protruding end surface area ratio: 2%

[0050] (2) Friction test method A ring-on-disk test was carried out in the same manner as in Experimental Example 1-3.

[0051] (3) Results In Experimental Example 6, braking did not stop until 33 minutes 33 seconds, so the test was stopped halfway through. In Experimental Example 7, braking did not stop until the specified time, so the test was stopped halfway through. In Experimental Example 8, braking stopped at 15 minutes 46 seconds. In Experimental Examples 6 to 8, it was observed that the material attached to the mating material was scraped off and the scraped off material was stored between multiple protrusions.

[0052] The graph in Figure 13(A) shows the change over time in the friction coefficient for Experimental Example 6 (area ratio 2%, divided), and the graph in Figure 13(B) shows the change over time in the friction coefficient for Experimental Example 5 (area ratio 6.25%). In both cases, the horizontal axis represents the sliding distance (m) and the vertical axis represents the friction coefficient. Comparing the graphs in Figure 13(A) and Figure 13(B), it was found that by arranging multiple convex parts within the divided areas, it was possible to improve friction characteristics such as an increase in the sliding distance. The graph in Figure 14(A) shows the change over time in the friction coefficient for Experimental Example 6 (diameter 0.5 mm), and the graph in Figure 14(B) shows the change over time in the friction coefficient for Experimental Example 7 (diameter 0.2 mm). In both cases, the horizontal axis represents the sliding distance (m) and the vertical axis represents the friction coefficient. Comparing the graphs in Figure 14(A) and Figure 14(B), it is clear that by reducing the diameter of the convex portion (protruding end face), it is possible to improve friction characteristics such as reducing the friction coefficient and stabilizing wear. The graph in Figure 15(A) shows the change over time in the friction coefficient for Experimental Example 6 (staggered arrangement), and the graph in Figure 15(B) shows the change over time in the friction coefficient for Experimental Example 7 (arrangement with large spacing in the movement direction). In both cases, the horizontal axis represents the sliding distance (m) and the vertical axis represents the friction coefficient. Comparing the graphs in Figure 15(A) and Figure 15(B), it was found that by making the arrangement of the protrusions more uniform (for example, by using a staggered arrangement), it is possible to improve friction characteristics such as extending the sliding distance and stabilizing wear.

[0053] 4. Experimental Examples 9-11 (1) Preparation of test specimens The test piece of Experimental Example 9 was prepared in the same manner as the test piece of Experimental Example 2, except that radial convex portions were formed as shown in FIG. 12(B). The test piece of Experimental Example 10 was prepared in the same manner as the test piece of Experimental Example 9, except that multiple dotted convex portions were formed as shown in FIG. 12(C). The test piece of Experimental Example 11 was prepared in the same manner as the test piece of Experimental Example 10, except that the width of the multiple dotted convex portions was increased as shown in FIG. 12(D). The configurations of Experimental Examples 9-11 are as follows. <Experimental Example 9> Convex part: 0.1mm wide radial shape Arrangement: Arranged at 5° intervals (see Figure 12(B)) -Protruding end surface area ratio: 7.1% <Experimental Example 10> Convex part: 0.5mm long x 0.1mm wide rectangular dotted line, dot pitch 1.39mm Arrangement: Radially spaced at 5° intervals (see Figure 12(C)) -Protruding end surface area ratio: 3.4% <Experimental Example 11> Convex part: 0.5mm long x 0.2mm wide rectangular dotted line, dot pitch 1.39mm Arrangement: Radial arrangement at 10° intervals (see Figure 12(D)) -Protruding end surface area ratio: 3.4%

[0054] (2) Friction test method A ring-on-disk test was carried out in the same manner as in Experimental Example 1-3.

[0055] (3) Results In Experimental Example 9, the friction was not stable, so the test was stopped at 12 minutes 47 seconds. In Experimental Example 10, the friction was more stable than in Experimental Example 9, but the test was stopped when the friction coefficient exceeded 0.2 (at 47 seconds). In Experimental Example 11, the test was stopped at 12 minutes 9 seconds. In Experimental Examples 10 and 11, it was observed that material adhering to the counter material was scraped off and that the scraped off material was housed between multiple convex portions.

[0056] The graph in Figure 16(A) shows the change over time in the friction coefficient for Experimental Example 9 (radial line), and the graph in Figure 16(B) shows the change over time in the friction coefficient for Experimental Example 11 (dotted line). In both cases, the horizontal axis represents the sliding distance (m) and the vertical axis represents the friction coefficient. Comparing the graphs in Figure 16(A) and Figure 16(B), it was found that a configuration in which multiple protrusions are scattered is more effective at improving friction characteristics such as wear stabilization than a configuration in which protrusions exist in a line.

[0057] 5. Experimental Examples 12 and 13 (1) Preparation of test specimens The test piece of Experimental Example 12 was prepared in the same manner as the test piece of Experimental Example 11, except that the convex portion was formed in an elliptical shape and the major axis was arranged along the sliding direction (direction of relative movement). The test piece of Experimental Example 13 was prepared in the same manner as the test piece of Experimental Example 11, except that the convex portion was formed in an elliptical shape and the minor axis was arranged along the sliding direction (direction of relative movement), as shown in Fig. 8. The configurations of Experimental Examples 12 and 13 are as follows. <Experimental Example 12> Convex part: elliptical shape with major axis of 0.5 mm x minor axis of 0.25 mm, major axis aligned with the sliding direction (horizontal) Placement: Placed on a radial line at 10° intervals -Protruding end surface area ratio: 3.5% <Experimental Example 13> Convex part: elliptical shape with major axis 0.5 mm x minor axis 0.25 mm, minor axis aligned with the sliding direction (vertical) Placement: Placed on a radial line at 10° intervals -Protruding end surface area ratio: 3.5%

[0058] (2) Friction test method A ring-on-disk test was carried out in the same manner as in Experimental Example 1-3. The test time was set to 4 minutes.

[0059] (3) Results For Experimental Example 13, the sliding surface of the test piece (Disk) and the sliding surface of the counter material (Ring) after the test are shown in FIG. 17(A). In Experimental Example 13, the shape of the multiple convex parts of the test piece was maintained, and there was almost no wear. In addition, on the sliding surface of the counter material, the adhesion was scraped off, and it was observed as an arc-shaped line. FIG. 17(B) shows an observation image of the convex part and a cross-sectional curve of the convex part. The cross-sectional curve in the lower row is a cross-sectional curve in the left-right direction of the convex part in the upper row. The movement direction of the counter material is the right direction of the paper in FIG. 17(B). It was observed that the wear powder was accommodated on the left side of the convex part, and was higher than the right side of the convex part. The same situation was observed for Experimental Example 12. That is, in Experimental Examples 12 and 13, it was observed that the adhesion of the counter material was scraped off, and the scraped off part was accommodated between the multiple convex parts.

[0060] The graph in Figure 18(A) shows the change over time in the friction coefficient for Experimental Example 12 (ellipse, horizontally long), and the graph in Figure 18(B) shows the change over time in the friction coefficient for Experimental Example 13 (ellipse, vertically long). In both cases, the horizontal axis represents the sliding distance (m) and the vertical axis represents the friction coefficient. In Experimental Example 12, the friction coefficient was low at 0.16 or less up to a sliding distance of 60 m, and the wear was also stable. Experimental Example 12 had excellent wear characteristics. In Experimental Example 13, the friction coefficient was even lower at 0.12 or less up to a sliding distance of 60 m, and the wear was even more stable. Experimental Example 13 had particularly excellent wear characteristics.

[0061] 6. Experimental Examples 14 and 15 (1) Preparation of test specimens The test piece of Experimental Example 14 was prepared in the same manner as the test piece of Experimental Example 13, except that the material was bronze. The test piece of Experimental Example 15 was prepared in the same manner as the test piece of Experimental Example 13, except that the material was an aluminum-magnesium alloy (A5052). The configurations of Experimental Examples 14 and 15 are as follows. <Experimental Example 14> ·bronze Convex part: elliptical shape with major axis 0.5 mm x minor axis 0.25 mm, minor axis aligned with the sliding direction (vertical) Placement: Placed on a radial line at 10° intervals -Protruding end surface area ratio: 3.5% <Experimental Example 15> Aluminum-magnesium alloy (A5052) Convex part: elliptical shape with major axis 0.5 mm x minor axis 0.25 mm, minor axis aligned with the sliding direction (vertical) Placement: Placed on a radial line at 10° intervals -Protruding end surface area ratio: 3.5%

[0062] (2) Friction test method A ring-on-disk test was carried out in the same manner as in Experimental Example 1-3. The test time was 4 minutes. A carbon steel ring (SUJ2), which is harder than brass and A5052, was used as the mating material.

[0063] (3) Results For Experimental Example 14, the sliding surface of the test piece (Disk) and the sliding surface of the counter material (Ring) after the test are shown in FIG. 19(A). In Experimental Example 14, the shape of the multiple convex parts of the test piece was maintained, and there was almost no wear. In addition, on the sliding surface of the counter material, the adhesion was scraped off, and it was observed as an arc-shaped line. FIG. 19(B) shows an observation image of the convex part and a cross-sectional curve of the convex part. The cross-sectional curve in the lower row is a cross-sectional curve in the left-right direction of the convex part in the upper row. The movement direction of the counter material is the right direction of the paper in FIG. 19(B). It was observed that the wear powder was stored on the left side of the convex part, and was higher than the right side of the convex part. That is, in Experimental Example 14, it was observed that the adhesion of the counter material was scraped off, and the scraped off material was stored between the multiple convex parts.

[0064] In the observation image of the protrusions in Figure 19(B), elemental analysis of the material deposited on the left side of the protrusions detected copper (Cu) and zinc (Zn) elements. This result suggests that the material contained between the multiple protrusions includes wear powder and the like derived from the brass test piece.

[0065] For Experimental Example 15, the sliding surface of the test piece (Disk) and the sliding surface of the counter material (Ring) after the test are shown in FIG. 20(A). In Experimental Example 15, the shape of the multiple convex parts of the test piece was maintained, and there was almost no wear. In addition, on the sliding surface of the counter material, the adhesion was scraped off, and it was observed as an arc-shaped line. FIG. 20(B) shows an observation image of the convex part and a cross-sectional curve of the convex part. The cross-sectional curve in the lower row is a cross-sectional curve in the left-right direction of the convex part in the upper row. The movement direction of the counter material is the right direction of the paper in FIG. 20(B). It was observed that the wear powder was accommodated on the left side of the convex part, and was higher than the right side of the convex part. That is, in Experimental Example 15, it was observed that the adhesion of the counter material was scraped off, and the scraped off material was accommodated between the multiple convex parts.

[0066] The graph in Figure 20(A) shows the change over time in the friction coefficient for Experimental Example 14 (ellipse, vertically long, bronze), and the graph in Figure 20(B) shows the change over time in the friction coefficient for Experimental Example 15 (ellipse, vertically long, aluminum-magnesium alloy). In both cases, the horizontal axis represents the sliding distance (m) and the vertical axis represents the friction coefficient. In Experimental Example 14, the friction coefficient was low at 0.06 or less from a sliding distance of 10 m to 60 m, and wear was also stable. Experimental Example 14 had excellent wear characteristics. In Experimental Example 15, the friction coefficient was low at 0.10 or less up to a sliding distance of 60 m, and wear was also stable. Experimental Example 15 had excellent wear characteristics.

[0067] 7. Summary The characteristics of each experimental example are summarized in Table 1. In the "Scrape-off / Storage" column in Table 1, if it was observed that "when moving relative to the counter material, at least one of the multiple convex parts scrapes off material adhering to the counter material, and the scraped-off material is stored between the multiple convex parts," it is marked as "observed," and if it was not observed, it is marked as "not observed." "-" indicates that no observation was made.

[0068] [Table 1]

[0069] It was found that when the test piece moves relative to the opposing material, at least one of the multiple convex portions scrapes off material adhering to the opposing material and the scraped-off material is accommodated between the multiple convex portions, thereby improving the friction characteristics. According to this embodiment, a member having improved friction characteristics at the contact surface can be provided.

[0070] The present invention is not limited to the above-described embodiments, and various modifications and variations are possible within the scope of the claims of the present disclosure. [Explanation of symbols]

[0071] 10, 110, 210... sliding member (member), 11... base, 11A... surface, 12, 212... convex portion, 12A, 212A... protruding end surface, 50... mating member, 50A... sliding surface, R1, R2... region

Claims

1. A member that moves relative to a counter member by contacting the counter member, The present invention comprises a base and a plurality of protrusions scattered on a surface of the base, The protruding portion has a protruding end surface that comes into planar contact with the counter member, When the member moves relative to the opposing material, at least one of the multiple protrusions scrapes off material adhering to the opposing material, and the scraped-off material is stored between the multiple protrusions.

2. The member is a sliding member that slides against the counter member, the mating member has a sliding surface that comes into contact with the plurality of protruding end surfaces, The member according to claim 1 , wherein the sliding surface of the counter member is harder than the protruding end surface.

3. The sum of the areas of the protruding end faces of the plurality of protruding portions is A, When the surface area of ​​the base is B, (A / B)×100≦30 The member according to claim 1 or claim 2, which satisfies the above.

4. The member according to claim 1 or 2, wherein the protruding end surface has an elliptical shape in a plan view.

5. The member according to claim 4 , wherein the minor axis direction of the ellipse of the protruding end surface is aligned with a direction of relative movement with respect to the counter member.

6. 3. The member according to claim 1, wherein the protruding height of each of the plurality of protrusions is 0.01 mm or more and 1 mm or less.

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