JP2011220151A - Sliding member and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sliding member and a method for manufacturing the same, to reduce friction loss by preventing insufficient supply of lubricating oil.SOLUTION: When a cylinder bore 10 is used as a sliding member in manufacturing the cylinder bore 10, a mask having a pattern extending in a sliding direction X is formed on a sliding surface 11, and a seizure-resistant coating 12 is formed on the sliding surface 11. By removing the mask, a flow path 13 extending in the sliding direction X is formed. The lubricating oil to be supplied to the sliding surface 11 can flow in the sliding direction X, thus smoothly supplying lubricating oil to the sliding surface 11. Moreover, in manufacturing the cylinder bore 10, the masking method is used, thus facilitating formation of the flow path extending in the sliding direction X on the sliding surface 11.

Description

  The present invention relates to a sliding member that slides with a mating member via an oil film and a method for manufacturing the same, and more particularly to an improvement in a flow path of an oil film formed on a sliding surface.

  In the field of sliding members, various techniques have been developed for the purpose of improving various characteristics of a sliding surface that slides with a mating member. For example, in the engine field, a cylinder bore is formed in a cylinder block as a sliding member. The cylinder bore slides with each part (a skirt part, a land part, or a ring part) of the piston. Lubricating oil is supplied from the lower surface of the piston between the cylinder bore and each part of the piston, and an oil film is formed there.

  The cylinder bore has a sliding surface that slides relative to each part of the piston via an oil film. An uneven shape is formed on the sliding surface, and a DLC film (Diamond-Like Carbon) is formed thereon (for example, Patent Document 1).

JP 2005-69008 A

  However, in the technique of Patent Document 1, it is difficult to interpose a desired amount of lubricating oil between the cylinder bore and each part of the piston, and the cylinder bore is required to reduce friction loss.

  The present inventor intends to continuously reduce friction loss, improve seizure resistance, and improve wear resistance by performing mirror finishing on the sliding surface of the cylinder bore and forming a DLC film thereon. Has proposed.

  The purpose of mirror finishing in the above technology is to reduce the oil film thickness and to suppress energy loss due to turbulent flow generation in the concave part of the sliding surface. There may be a shortage of supply. Specifically, under high load and high rotation conditions, the lubricating oil is not sufficiently supplied to the interface between the piston ring and the cylinder or the interface between the piston body and the cylinder, resulting in frequent direct contact between the components, resulting in friction. There is a risk of loss.

  Therefore, an object of the present invention is to provide a sliding member that can reduce friction loss and a manufacturing method thereof by preventing insufficient supply of lubricating oil.

  In order to solve the above problems, the present invention has intensively studied the shape of the flow path on the sliding surface of the cylinder bore. For example, when the extending direction of the flow path 2 of the lubricating oil is set in a direction perpendicular to the sliding direction X as in the cylinder bore 1 shown in FIG. 4A, the cylinder bore 3 shown in FIG. Thus, when the shape of the flow path 4 of the lubricating oil is set to a cross hatch shape by honing, for example, sliding with the mating member increases frictional resistance.

  On the other hand, if a material having seizure resistance is used as the material of the film formed on the sliding surface, the degree of freedom of the property of the sliding surface can be improved. In this case, as shown in FIG. When the extending direction of the lubricating oil flow path 6 in the cylinder bore 5 is set to the sliding direction X of the mating member, it is possible to prevent the supply of lubricating oil from being insufficient. As a result, the present invention was completed.

  The sliding member of the present invention has a seizure-resistant coating formed on the sliding surface that slides with the mating member, and a flow path through which lubricating oil flows. It is characterized by extending to.

  In the sliding member of the present invention, since the flow path formed in the sliding surface extends in the sliding direction, the lubricating oil supplied to the sliding surface can move in the sliding direction. . Therefore, since the lubricating oil can be smoothly supplied to the sliding surface, the friction loss with the mating member can be reduced.

  Various configurations can be used for the sliding member of the present invention. For example, at least one of a cylinder bore and a piston can be used as the sliding member. Specifically, when one of the cylinder bore and the piston is used as the sliding member, the other can be used as the mating member. In this case, the sliding surface of the mating member can also have the same configuration (film and flow path) as that of the sliding member. In this case, both the cylinder bore and the piston can be recognized as the sliding member of the present invention.

  For example, the coating has a first coating formed on the sliding surface and a second coating formed on the surface of the first coating, and a portion where the first coating is exposed constitutes the flow path. be able to. In this aspect, long-term reliability can be ensured as compared with the case where the surface of the substrate is exposed.

  For example, a Ni—SiC film containing 5 to 50% SiC in unit area ratio can be used as the coating. When the content ratio of SiC in the coating is less than 5% in unit area ratio, it becomes impossible to obtain toughness as a plating film. When the content ratio of SiC exceeds 50% in unit area ratio, the seizure resistance is deteriorated. Therefore, it is preferable that the content ratio of SiC in the coating is in the range of 5 to 50% in terms of unit area ratio. For example, it is preferable to use a DLC film (Diamond-Like Carbon film) as the coating. In this aspect, it is possible to continuously reduce friction loss, improve seizure resistance, and improve wear resistance.

  The film thickness of the coating can be set within a range of 0.1 to 10 μm. When the film thickness is less than 0.1 μm, the yield strength is insufficient from the viewpoint of long-term reliability. When the film thickness exceeds 10 μm, the amount of consumption of the lubricating oil increases.

  Since it is difficult to form the flow path of the sliding member having the above shape by means of honing, boring or the like, the manufacturing method of the sliding member of the present invention uses a masking technique. That is, the manufacturing method of the sliding member of the present invention is a manufacturing method of a sliding member having a flow path through which lubricating oil flows on a sliding surface that slides with the mating member, and the sliding member that slides with the mating member. By forming a mask having a pattern extending in the sliding direction on the moving surface, forming a film having seizure resistance on the sliding surface after forming the mask, and sliding the mask by removing the mask after forming the film. A flow path extending in the direction is formed.

  In the manufacturing method of the sliding member of the present invention, since the above-described masking technique is used, the flow path extending in the sliding direction can be easily formed on the sliding surface. In the sliding member obtained by the above, the same effect as the sliding member of the present invention can be obtained.

  The manufacturing method of the sliding member of the present invention can use various configurations. For example, the mirror surface processing can be performed on the sliding surface before the mask is formed. In this aspect, the sliding surface and the cast hole in the vicinity thereof can be crushed and the sliding surface can be smoothed by mirror finishing. Accordingly, defects such as a casting hole can be sufficiently removed, and thus cracks in the coating and peeling of the coating can be prevented. As a result, durability reliability can be improved. Further, since it is not necessary to hit the sliding surface with a hammer or the like, the occurrence of distortion can be suppressed, and as a result, the quality of the product can be improved. Further, for example, another film having seizure resistance can be formed on the sliding surface before forming the mask.

  According to the sliding member or the manufacturing method thereof of the present invention, it is possible to obtain an effect such that friction loss with the counterpart member can be reduced.

The schematic structure of the sliding surface of the cylinder bore which concerns on 1st Embodiment of this invention is represented, (A) is a front view of the sliding surface 11, (B) is sectional drawing of the 1B-1B line of (A), (C ) Is a cross-sectional view taken along line 1C-1C in FIG. (A)-(E) represent the example of the shape of the flow path formed in the sliding face of FIG. 1, and is a schematic partial block diagram of a sliding face. The schematic structure of the sliding surface of the cylinder bore which concerns on 2nd Embodiment of this invention is represented, (A) is a front view of the sliding surface 11, (B) is sectional drawing of the 3B-3B line of (A), (C ) Is a cross-sectional view taken along line 3C-3C in FIG. (A)-(C) represents schematic structure of the sliding surface of a sliding member, (A), (B) is the shape of the flow path of a prior art example, (C) is the shape of the flow path of the example of this invention. It is a front view.

(1) First Embodiment Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a schematic configuration of a sliding surface 11 of a cylinder bore 10 according to a first embodiment of the present invention, where (A) is a front view of the sliding surface 11 and (B) is a line 1B-1B in (A). (C) is sectional drawing of the 1C-1C line | wire of (A). Reference numeral 1 in FIG. 1 is a cylinder block in which a cylinder bore 10 is formed.

  The cylinder bore 10 (sliding member) has a sliding surface 11 that slides with a piston (not shown). A coating 12 having seizure resistance is formed on the sliding surface 11. Examples of the material of the coating 12 include DLC, Ni—SiC (nickel-silicon carbide), CrN (chromium nitride), Au (gold), Ag (silver), and Cu (copper) having high seizure resistance.

  DLC is suitable as a material for the coating 12 because it has excellent seizure resistance and low friction. When using DLC, for example, a DLC film is formed by plasma CVD or PVD. When using CrN, for example, a CrN film is formed by vapor deposition.

  The sliding surface 11 is formed with a groove-like flow path 13 through which lubricating oil flows. The flow path 13 extends in the sliding direction X. In the flow path 13, the smooth inner peripheral surface of the base material (cylinder block 1) of the cylinder bore 10 is exposed. FIG. 2 shows an example of the shape of the flow path 13 of FIG. 1, and (A) to (E) are schematic partial configuration diagrams of the sliding surface 11. The shape of the flow path 13 should just be extended in the sliding direction X, and various aspects can be used for it. In FIG. 2, the length in the sliding direction X is shortened for the convenience of illustration.

  For example, the channel 13A shown in FIG. 2A extends linearly along the sliding direction. In the flow path 13B shown in FIG. 2B, the upper end portion and the lower end portion do not extend to the upper end and the lower end of the cylinder bore 10 and are not opened. Thereby, the negative pressure in the cylinder bore 10 can be ensured reliably. In the flow path 13 </ b> C shown in FIG. 2C, the wide portions 21 and the narrow portions 22 are alternately formed along the sliding direction X.

  A flow path 13D shown in FIG. 2D has a curved shape (for example, a meandering shape). In the flow path 13E shown in FIG. 2 (E), a plurality of independent recesses 23 are formed along the sliding direction X. In this case, the adjacent recesses 23 are alternately arranged so as not to be positioned in a straight line. In the flow paths 13C and 13D, similarly to the flow path 13B, the upper end portion and the lower end portion may not be opened. Moreover, you may combine the shape of FIG. 2 (A)-2 (E) suitably.

  A method for manufacturing the cylinder bore 10 having the above configuration will be described. First, a cylinder block 1 made of, for example, Al is obtained by casting using a mold. Next, the cylinder bore 10 having the sliding surface 11 is formed by boring the cylinder block 1.

  Subsequently, mirror surface processing (for example, plastic processing) is performed on the sliding surface 11 of the cylinder bore 10 to crush the cast hole generated during casting and to smooth the sliding surface 11 of the cylinder bore 10. In plastic working, for example, a roller burnishing method is used.

  Subsequently, a mask having a pattern extending in the sliding direction X is formed on the sliding surface 11, and a film 12 having seizure resistance is formed on the sliding surface 11. Next, the flow path 13 extending in the sliding direction X is formed by removing the mask.

  In the first embodiment, since the flow path 13 formed in the sliding surface 11 extends in the sliding direction, the lubricating oil supplied to the sliding surface 11 moves in the sliding direction X. Can do. Therefore, since the lubricating oil can be smoothly supplied to the sliding surface 11, the friction loss with the piston can be reduced. Further, since the masking technique is used in the manufacture of the cylinder bore 10, the flow path 13 extending in the sliding direction X can be easily formed on the sliding surface 11.

(2) Second Embodiment In the second embodiment, the portion where the surface of the cylinder bore base material (cylinder block) is exposed as a flow path is different from the first embodiment in that the entire surface of the cylinder bore base material is used. The point which forms the film which has seizure resistance differs, and the structure (for example, the shape of the flow path shown in FIG. 2) similar to 1st Embodiment can be used other than that. Note that in the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and descriptions thereof are omitted.

  FIG. 3 shows a schematic configuration of the sliding surface 11 of the cylinder bore 30 according to the second embodiment of the present invention, (A) is a front view of the sliding surface 11, and (B) is a line 3B-3B of (A). (C) is sectional drawing of the 3C-3C line | wire of (A). A coating 31 (first coating, other coating) having seizure resistance is formed on the entire sliding surface 11, and a coating 32 having seizure resistance slides on the surface of the coating 31 (first coating). It is formed along the direction X. The portion where the coating 31 is exposed constitutes a groove-like flow path 33 through which the lubricating oil flows. The flow path 33 extends along the sliding direction X. The material of the films 31 and 32 can be the same material as that of the film 12, and the materials of the films 31 and 32 may be the same or different.

  A method for manufacturing the cylinder bore 30 having the above configuration will be described. First, after the mirror surface processing is performed on the sliding surface 11 of the cylinder bore 30 as in the first embodiment, the coating 31 having seizure resistance is formed on the entire sliding surface 11 of the cylinder bore 30. Next, a mask having a pattern extending in the sliding direction X is formed on the coating 31, and a coating 32 having seizure resistance is formed on the coating 31. Next, the flow path 33 extending in the sliding direction X is formed by removing the mask.

  In the second embodiment, not only the effects of the first embodiment can be obtained, but also the surface of the base material of the cylinder bore 30 is not exposed, so long-term reliability can be ensured.

  DESCRIPTION OF SYMBOLS 10, 30 ... Cylinder bore (sliding member), 11 ... Sliding surface, 12 ... Coating (other coating, 1st coating), 31 ... Coating (other coating, 1st coating), 32 ... Coating (2nd coating) ), 13, 13A to 13E, 33...

Claims (9)

On the sliding surface that slides with the mating member, a film having seizure resistance is formed, and a flow path through which the lubricating oil flows is formed,
The sliding member characterized in that the flow path extends in a sliding direction.   The sliding member according to claim 1, wherein the sliding member is at least one of a cylinder bore and a piston. The coating has a first coating formed on the sliding surface and a second coating formed on the surface of the first coating,
The sliding member according to claim 1 or 2, wherein a portion where the first coating film is exposed constitutes the flow path.   The sliding member according to any one of claims 1 to 3, wherein a Ni-SiC film containing 5 to 50% SiC by unit area ratio is used as the coating.   The sliding member according to claim 1, wherein the coating is a DLC film.   The sliding member according to any one of claims 1 to 5, wherein the film thickness is in a range of 0.1 to 10 µm. In the manufacturing method of the sliding member having a flow path through which the lubricating oil flows on the sliding surface sliding with the counterpart member,
On the sliding surface, a mask having a pattern extending in the sliding direction is formed,
After forming the mask, forming a film having seizure resistance on the sliding surface,
After the coating is formed, the mask is removed to form the flow path extending in the sliding direction.   The method for manufacturing a sliding member according to claim 7, wherein the sliding surface is mirror-finished before the mask is formed.   9. The method for manufacturing a sliding member according to claim 7, wherein another film having seizure resistance is formed on the sliding surface before forming the mask.

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