WO2023013264A1 - Oil ring - Google Patents

Oil ring Download PDF

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Publication number
WO2023013264A1
WO2023013264A1 PCT/JP2022/024541 JP2022024541W WO2023013264A1 WO 2023013264 A1 WO2023013264 A1 WO 2023013264A1 JP 2022024541 W JP2022024541 W JP 2022024541W WO 2023013264 A1 WO2023013264 A1 WO 2023013264A1
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WO
WIPO (PCT)
Prior art keywords
base material
segment
oil ring
segments
pair
Prior art date
Application number
PCT/JP2022/024541
Other languages
French (fr)
Japanese (ja)
Inventor
健太朗 河野
涼矢 清水
Original Assignee
Ｔｐｒ株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Application filed by Ｔｐｒ株式会社 filed Critical Ｔｐｒ株式会社
Priority to CN202280054486.XA priority Critical patent/CN117836542A/en
Publication of WO2023013264A1 publication Critical patent/WO2023013264A1/en

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02F—CYLINDERS, PISTONS OR CASINGS, FOR COMBUSTION ENGINES; ARRANGEMENTS OF SEALINGS IN COMBUSTION ENGINES
    • F02F5/00—Piston rings, e.g. associated with piston crown
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16J—PISTONS; CYLINDERS; SEALINGS
    • F16J9/00—Piston-rings, e.g. non-metallic piston-rings, seats therefor; Ring sealings of similar construction
    • F16J9/06—Piston-rings, e.g. non-metallic piston-rings, seats therefor; Ring sealings of similar construction using separate springs or elastic elements expanding the rings; Springs therefor ; Expansion by wedging
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16J—PISTONS; CYLINDERS; SEALINGS
    • F16J9/00—Piston-rings, e.g. non-metallic piston-rings, seats therefor; Ring sealings of similar construction
    • F16J9/26—Piston-rings, e.g. non-metallic piston-rings, seats therefor; Ring sealings of similar construction characterised by the use of particular materials

Definitions

  • the present invention relates to an oil ring provided with a pair of segments.
  • An internal combustion engine installed in a typical automobile adopts a configuration in which a combination of a piston ring (an example of a ring-shaped member) including a compression ring (pressure ring) and an oil ring is mounted in the ring groove of the piston.
  • the compression ring has a gas seal function that suppresses the outflow (blow-by) of combustion gas from the combustion chamber side to the crank chamber side by maintaining airtightness, and scrapes off excess oil that the oil ring could not scrape off. It has an oil seal function that suppresses oil rise.
  • the oil ring has an oil seal function that suppresses the outflow of oil to the combustion chamber side by scraping off excess engine oil (lubricating oil) adhering to the inner wall surface of the cylinder toward the crank. By adjusting the amount of oil so that it is properly retained on the inner wall surface, it has the function of preventing seizure of the compression rings and pistons that accompany the operation of the internal combustion engine.
  • the oil ring includes a pair of segments (also called side rails) arranged independently of each other in the axial direction of the oil ring and sliding on the inner wall surface of the cylinder, and a segment provided between the pair of segments.
  • a three-piece combination oil ring is widely used, which is combined with a spacer expander that urges a pair of segments against the inner wall surface of the cylinder.
  • Patent Document 1 discloses that in a pair of segments, the upper segment provided on the combustion chamber side and the lower segment provided on the crank chamber side have different outer peripheral surface shapes to reduce oil consumption and friction.
  • An oil ring is disclosed that reduces the
  • the upper segment located on the combustion chamber side slides under more severe conditions than the lower segment located on the crank chamber side. It tends to wear more than the lower segment.
  • the gap (side clearance) between the upper groove wall of the ring groove and the upper segment expands, which may deteriorate the oil sealing function of the oil ring.
  • the present invention has been made in view of the above problems, and an object thereof is to provide a technique capable of preventing deterioration of the oil seal function in an oil ring provided with a pair of segments.
  • the present invention employs the following configuration. That is, the present invention provides an oil ring to be assembled to a piston in an internal combustion engine, which is formed along the circumferential direction of the oil ring using an annular wire rod as a base material, and independently of each other in the axial direction of the oil ring. and a spacer expander arranged between the pair of segments.
  • the oil ring has higher wear resistance than the base material of the lower segment located on the crank chamber side in the internal combustion engine of the pair of segments.
  • the lower segment by making the wear resistance of the base material of the upper segment arranged on the combustion chamber side higher than the wear resistance of the base material of the lower segment arranged on the crank chamber side, the lower segment It can also reduce the wear of the upper segment that slides under severe conditions. As a result, deterioration of the oil seal function can be prevented.
  • the base material of the upper segment may have higher hardness than the base material of the lower segment.
  • the base material of the upper segment may have a hardness higher than that of the base material of the lower segment by 30 Hv or more.
  • the base material of the upper segment may have a higher carbide occupied area ratio on the surface than the base material of the lower segment.
  • the material of the base material of the upper segment and the material of the base material of the lower segment may be different.
  • FIG. 1 is a partial cross-sectional view of an internal combustion engine provided with an oil ring according to an embodiment
  • FIG. It is a schematic diagram which shows the structure of a reciprocating friction tester. It is a graph which shows a wear amount ratio. It is a graph which shows a wear amount ratio.
  • FIG. 1 is a partial cross-sectional view of an internal combustion engine 100 provided with an oil ring 40 according to an embodiment.
  • FIG. 1 shows a cross section perpendicular to the circumferential direction of the oil ring 40 .
  • a predetermined separation distance is secured between the inner wall surface 10a of the cylinder 10 and the outer peripheral surface 20a of the piston 20 mounted on the cylinder 10, so that the piston clearance PC1 is formed.
  • a ring groove 30 having a substantially rectangular cross section is formed in the outer peripheral surface 20 a of the piston 20 .
  • the ring groove 30 connects an upper wall 301 formed on the combustion chamber side, a lower wall 302 formed on the crank chamber side and facing the upper wall 301, and inner peripheral edges of the upper wall 301 and the lower wall 302. wall 303;
  • An oil ring 40 according to this embodiment is mounted in the ring groove 30 .
  • the oil ring 40 is a sliding member that is attached to the piston 20 by being fitted in the ring groove 30 and slides on the inner wall surface 10a of the cylinder 10 as the piston 20 reciprocates.
  • the oil ring 40 is a so-called three-piece combination oil ring, and includes a pair of segments 1 and 2 and a spacer expander 3 as shown in FIG.
  • the direction (axial direction) along the central axis of the oil ring 40 is defined as “vertical direction”.
  • the combustion chamber side (upper side in FIG. 1) of the internal combustion engine 100 is defined as “upper side”
  • the opposite side, that is, the crank chamber side (lower side in FIG. 1) is defined as “upper side”. defined as 'lower side'.
  • the term “peripheral direction” refers to the circumferential direction of the oil ring 40
  • the term “radial direction” refers to the radial direction of the oil ring 40.
  • the “axial direction” refers to the axial direction of the oil ring 40 .
  • the state in which the oil ring is attached to the piston attached to the cylinder of the internal combustion engine as shown in FIG. 1 is referred to as the "used state”.
  • the term “barrel shape” refers to a surface shape that is curved so as to be convex radially outward including the apex, which is the maximum diameter of the piston ring, and the apex is in the axial direction of the ring It includes a "symmetrical barrel shape” located in the center of the width and an “eccentric barrel shape” in which the apex is located closer to the crankcase than the center of the axial width of the ring.
  • the term “tapered shape” refers to a surface shape that is inclined so as to increase in diameter toward the crank chamber.
  • the pair of segments 1 and 2 are annularly formed along the circumferential direction of the oil ring 40, and are provided independently of each other and separated from each other in the axial direction.
  • the upper segment 1, which is one of the pair of segments 1 and 2 is provided on the upper side (combustion chamber side) of the internal combustion engine 100, and the other, the lower segment 2, is provided on the lower side of the internal combustion engine 100. side (crank chamber side).
  • the upper segment 1 includes a base material 1a formed in an annular shape from a segment wire and an outer coating 1b formed on the outer peripheral surface of the base material 1a. .
  • the upper segment 1 has an outer peripheral surface 11 , an inner peripheral surface 12 , an upper surface 13 and a lower surface 14 .
  • An outer coating 1b is formed on the outer peripheral surface 11 .
  • the upper surface 13 and the lower surface 14 define the axial width of the upper segment 1 .
  • the upper segment 1 is provided so that the upper surface 13 faces the upper wall 301 of the ring groove 30 in use, and slides on the inner wall surface 10a of the cylinder 10 using the outer peripheral surface 11 as a sliding surface.
  • the lower segment 2 includes a base material 2a formed in an annular shape from a segment wire and an outer coating 2b formed on the outer peripheral surface of the base material 2a.
  • the lower segment 2 has an outer peripheral surface 21 , an inner peripheral surface 22 , an upper surface 23 and a lower surface 24 .
  • An outer coating 2 b is formed on the outer peripheral surface 21 .
  • the upper surface 23 and the lower surface 24 define the width of the lower segment 2 in the axial direction.
  • the lower segment 2 is provided so that the lower surface 24 faces the lower wall 302 of the ring groove 30 in use, and slides on the inner wall surface 10a of the cylinder 10 using the outer peripheral surface 21 as a sliding surface.
  • the spacer expander 3 is provided between a pair of segments 1 and 2 and has self-tension so that it expands in use. Therefore, the upper segment 1 and the lower segment 2 are urged radially outward by the spacer expander 3, and the outer peripheral surface 11 of the upper segment 1 and the outer peripheral surface 21 of the lower segment 2 press the inner wall surface 10a of the cylinder 10. do. As a result, an oil sealing function is obtained, and an oil film is formed so that the engine oil present on the inner wall surface 10a of the cylinder 10 has an appropriate thickness.
  • the shape of the spacer expander according to the present invention is not particularly limited.
  • the outer peripheral surfaces 11, 21 of the pair of segments 1, 2 have a symmetrical barrel shape with low friction.
  • the shape of the pair of segments is not limited to that shown in FIG.
  • the outer peripheral surface of the upper segment located on the upper side of the pair of segments may have an eccentric barrel shape with excellent oil scraping performance
  • the outer peripheral surface of the lower segment located on the lower side may have a symmetrical barrel shape with low friction.
  • both outer peripheral surfaces may have an eccentric barrel shape.
  • the outer peripheral surface of the upper segment may have a symmetrical barrel shape, and the outer peripheral surface of the lower segment may have an eccentric barrel shape.
  • the outer peripheral surface 11 of the upper segment 1 may be tapered for excellent oil scraping performance, or both outer peripheral surfaces may be tapered.
  • the outer peripheral surface of the upper segment may be tapered, and the outer peripheral surface of the lower segment may be symmetrical barrel-shaped.
  • the base material 1a of the upper segment 1 and the base material 2a of the lower segment 2 are different. More specifically, the material of the base material 1a and the material of the base material 2a are different from each other.
  • the base material 1a of the upper segment 1 is made of SWRH72A and has a hardness of 450 Hv or more and 550 Hv or less.
  • the base material 2a of the lower segment 2 is made of SUS440B and has a hardness of 300 Hv or more and 420 Hv or less.
  • the hardness of the base material 1a is higher than that of the base material 2a, and the difference therebetween is 30 Hv or more and 150 Hv or less.
  • the material of the base material of the segment is not limited to the above.
  • SUS, SWRH and the like are exemplified as the material of the base material of the segment.
  • martensitic stainless steel, silicon chromium steel, aluminum alloy, or the like may be used as the base material.
  • the difference in hardness between the substrate 1a and the substrate 2a may be 270 Hv or less, 200 Hv or less, or 180 Hv or less.
  • the outer coating 1b and the outer coating 2b according to this example are formed as DLC coatings with high abrasion resistance.
  • the outer coating is not limited to the DLC treatment coating, and includes at least one layer of a nitriding coating, a Ni-P plating coating, a chromium plating coating, a PVD coating, and a DLC coating. may be formed as
  • the outer coating 1b of the upper segment 1 and the outer coating 2b of the lower segment 2 may have different configurations.
  • the outer coating is not an essential configuration in the present invention, and either or both of the upper segment and the lower segment may not have the outer coating.
  • the axial end faces (upper surface 13 and lower surface 14) of the upper segment 1 and the axial end faces (upper surface 23 and lower surface 24) of the lower segment 2 are coated with a coating, a resin coating, a chemical conversion coating, an oxidation coating, and a nitriding coating.
  • a surface treatment film including at least one layer of a treatment film, a Ni—P plating treatment film, a chromium plating treatment film, a PVD treatment film, and a DLC treatment film may be formed.
  • coating film refers to a film formed by applying paint.
  • a "resin coating” refers to a coating formed of a resin material.
  • Examples of the "coating film” and “resin coating” include a resin coating film made of water-based or oil-based resin paint.
  • “Chemical conversion coating” refers to a coating formed by chemical conversion treatment. Examples of chemical conversion treatments include triiron tetraoxide treatment (blackening), phosphate treatment, and chromate treatment. Examples of phosphate treatment include manganese phosphate treatment, zinc phosphate treatment, and iron phosphate treatment.
  • a “nitriding coating” refers to a coating formed by infiltrating nitrogen into a metal surface by nitriding.
  • “Oxidation treatment film” refers to a film formed by oxidizing a metal surface by oxidation treatment. Examples of oxidation treatment include alumite treatment.
  • Ni—P plating film refers to a film formed by electroless Ni—P plating.
  • chromium-plated film refers to a film formed by chromium plating. Chrome plating is also called industrial chrome plating.
  • PVD physical vapor deposition
  • a “DLC (Diamond Like Carbon) treated coating” refers to an amorphous hard carbon coating mainly composed of hydrocarbons and allotropes of carbon.
  • the wear resistance of the base material 1a of the upper segment 1 arranged on the combustion chamber side is higher than the wear resistance of the base material 2a of the lower segment 2 arranged on the crank chamber side.
  • the base material 1a and the base material 2a are made of different materials so as to be higher than the abrasion resistance.
  • the material of the base material 1a is SWRH72A
  • the material of the base material 2a of the lower segment 2 is SUS440B, so that the hardness of the base material 1a is higher than that of the base material 2a.
  • FIG. 2 is a schematic diagram showing the configuration of the reciprocating friction tester.
  • a reciprocating friction test using a reciprocating friction tester is performed using a pin-on plate type reciprocating friction tester whose outline is shown in FIG.
  • the upper test piece used in the reciprocating motion friction test is a pin which is assumed to be the base material of the segment, and the material of the pin is the same as the wire material for the segment.
  • the pin used for the upper test piece has a diameter of 8 mm, and the tip (sliding surface) of the pin is mirror-finished so as to have a radius of curvature of 18 mm.
  • a plate (equivalent to AC8A material) that resembles a piston is used as the lower test piece.
  • FIG. 3 is a graph showing the results of the reciprocating friction test, showing the wear amount ratio.
  • the oil ring 40 is configured such that the wear resistance of the base material 1a of the upper segment 1 is higher than the wear resistance of the base material 2a of the lower segment 2.
  • 2 are made of different materials.
  • the material of the base material 1a is a SWRH material having higher hardness than the SUS material that is the material of the base material 2a.
  • the oil ring 40 according to the embodiment can be suitably used for gasoline engines and engines using low-viscosity oil in which there are many chances of direct contact between the segments and the inner wall of the ring groove.
  • the internal combustion engine to which the oil ring according to the present invention is applied is not limited to these.
  • the material of the base material 1a of the upper segment 1 and the material of the base material 2a of the lower segment 2 are made different so that the hardness of the base material 1a is higher than that of the base material 2a. By making it higher, the wear resistance of the base material 1a is made higher than the wear resistance of the base material 2a.
  • the difference in hardness between the base material 1a and the base material 2a is not particularly limited. It is preferable to make it higher than 30Hv.
  • the pair of segments 1 and 2 are made different in surface color by making the base materials of the pair of segments 1 and 2 different. Thereby, the identifiability of the pair of segments 1 and 2 can be improved.
  • Modification 1 In the oil ring 40 of Modification 1, while the material of the base material 1a of the upper segment 1 and the material of the base material 2a of the lower segment 2 are the same, the wear resistance of the base material 1a of the upper segment 1 is higher than that of the lower segment.
  • the hardness of the base material of the pair of segments 1 and 2 is made different from each other so that the wear resistance of the base material 2a of the pair of segments 1 and 2 is higher than that of the base material 2a of the pair of segments.
  • the hardness can be varied by varying the manner of heat treatment.
  • the wear resistance of the upper segment 1 is increased and deterioration of the oil seal function is prevented. be able to.
  • the difference in hardness between the base material 1a and the base material 2a is not particularly limited, but the hardness of the base material 1a of the upper segment 1 is preferably higher than that of the base material 2a of the lower segment 2 by 30 Hv or more.
  • the oil ring 40 of Modified Example 2 is configured such that the base material surfaces of the pair of segments 1 and 2 are arranged such that the wear resistance of the base material 1a of the upper segment 1 is higher than the wear resistance of the base material 2a of the lower segment 2.
  • the carbide occupied area ratio (carbide precipitation rate) in is different from each other.
  • the carbide occupied area ratio refers to the ratio of the area of carbide occupying the surface of the segment.
  • the carbide occupied area ratio can be obtained, for example, by acquiring an image of the substrate surface with a metallurgical microscope after etching treatment with a marble reagent, binarizing the acquired image, and calculating the area ratio of the white portion.
  • the method for calculating the carbide occupied area ratio is not limited to this.
  • the base material 1a of the upper segment 1 and the base material 2a of the lower segment 2 are made of stainless steel with different carbon and chromium contents. More specifically, the base material 1a of the upper segment 1 is made of 17 chromium SUS material, which is martensitic stainless steel containing a large amount of chromium, and the base material 2a of the lower segment 2 is made of stainless steel with a slightly low chromium content. 13 chromium SUS material, which is steel, is used as the material. However, the material of the segment according to the present invention is not limited to this.
  • the carbide occupied area ratio of the base material 1a of the upper segment 1 is 7.2% to 15.3% by the above calculation method, and the carbide occupied area ratio of the base material 2a of the lower segment 2 is 0.2. % to 2.0%. That is, in Modification 2, the substrate 1a of the upper segment 1 has a higher carbide occupied area ratio than the substrate 2a of the lower segment 2, and the difference is 5.2% or more.
  • the material of the base material 1a of the upper segment 1 and the material of the base material 2a of the lower segment 2 may be the same.
  • the size of the carbides can be changed by, for example, different heat treatment methods, and the carbide occupied area ratios can be varied.
  • the upper segment 1 and the lower segment 2 may be made of different base material materials so that the carbide occupied area ratios are different from each other.
  • the pair of segments 1 and 2 are arranged such that the carbide occupied area ratio of the base material 1a of the upper segment 1 is higher than the carbide occupied area ratio of the base material 2a of the lower segment 2.
  • the substrates are made different from each other.
  • the carbide occupied area ratio of the base material 1a of the upper segment 1 higher than the carbide occupied area ratio of the base material 2a of the lower segment 2
  • the wear resistance of the upper segment 1 is improved and the deterioration of the oil seal function is prevented. be able to.
  • the difference in the carbide occupied area ratio between the base material 1a and the base material 2a is not particularly limited.
  • the surface colors of the pair of segments 1 and 2 are made different from each other by making the carbide occupied area ratios of the base material surfaces of the pair of segments 1 and 2 different. Thereby, the identifiability of the pair of segments 1 and 2 can be improved.
  • the abrasion resistance of the base material of the segment according to Modification 2 was evaluated by the reciprocating friction test described above.
  • a reciprocating friction test was performed on each of the pins representing the base material 1a of the upper segment 1 as an upper test piece C and the pin representing the base material 2a of the lower segment 2 as an upper test piece D to compare the amount of wear.
  • the material of the upper test piece C was the same 17 chromium SUS material as the base material 1a
  • the material of the upper test piece D was the same 13 chromium SUS material as the base material 2a.
  • the carbide occupied area ratio of the upper test piece C was set to 7.2% to 15.3% by the above calculation method, and the carbide occupied area ratio of the upper test piece D was set to 0.2% to 2.0%.
  • FIG. 4 is a graph showing the results of the reciprocating friction test, showing the wear amount ratio. As shown in FIG. 4, the upper test piece C of the upper segment 1 having a larger carbide occupied area ratio had higher wear resistance than the upper test piece D of the lower segment 2 .

Abstract

An oil ring according to the present invention includes: a pair of segments that are formed following a perimeter direction of the oil ring and that are provided arrayed in the axial direction of the oil ring, independent from each other, with an annular wire rod as a base material of each; and a space expander that is disposed between the pair of segments. Of the pair of segments, the base material of an upper-side segment that is situated on a combustion chamber side in an internal combustion engine has higher wear resistance than the base material of a lower-side segment of the pair of segments that is situated on a crank chamber side in the internal combustion engine.

Description

オイルリングoil ring
　本発明は、一対のセグメントを備えるオイルリングに関する。 The present invention relates to an oil ring provided with a pair of segments.
　一般的な自動車に搭載される内燃機関は、コンプレッションリング（圧力リング）とオイルリングとを含むピストンリング（リング状部材の一例）の組み合わせをピストンのリング溝に装着した構成を採用している。コンプレッションリングは、気密を保持することで燃焼室側からクランク室側への燃焼ガスの流出（ブローバイ）を抑制するガスシール機能や、オイルリングが掻き落とし切れなかった余分なオイルを掻き落とすことでオイル上がりを抑制するオイルシール機能を有する。オイルリングは、シリンダ内壁面に付着した余分なエンジンオイル（潤滑油）をクランク側に掻き落とすことでオイルの燃焼室側への流出（オイル上がり）を抑制するオイルシール機能や、潤滑油膜がシリンダ内壁面に適切に保持されるようにオイル量を調整することで内燃機関の運転に伴うコンプレッションリングやピストンの焼き付きを防止する機能を有する。 An internal combustion engine installed in a typical automobile adopts a configuration in which a combination of a piston ring (an example of a ring-shaped member) including a compression ring (pressure ring) and an oil ring is mounted in the ring groove of the piston. The compression ring has a gas seal function that suppresses the outflow (blow-by) of combustion gas from the combustion chamber side to the crank chamber side by maintaining airtightness, and scrapes off excess oil that the oil ring could not scrape off. It has an oil seal function that suppresses oil rise. The oil ring has an oil seal function that suppresses the outflow of oil to the combustion chamber side by scraping off excess engine oil (lubricating oil) adhering to the inner wall surface of the cylinder toward the crank. By adjusting the amount of oil so that it is properly retained on the inner wall surface, it has the function of preventing seizure of the compression rings and pistons that accompany the operation of the internal combustion engine.
　ここで、オイルリングとしては、互いに独立してオイルリングの軸方向に並んで設けられてシリンダ内壁面を摺動する一対のセグメント（サイドレールとも呼ばれる）と、一対のセグメント同士の間に設けられて一対のセグメントをシリンダの内壁面へ付勢するスペーサエキスパンダとを組み合わせた、３ピースの組合せオイルリングが広く用いられている。これに関連して、特許文献１には、一対のセグメントにおいて燃焼室側に設けられる上側セグメントとクランク室側に設けられる下側セグメントとで外周面形状を異ならせることで、オイル消費量及びフリクションを低減するオイルリングが開示されている。 Here, the oil ring includes a pair of segments (also called side rails) arranged independently of each other in the axial direction of the oil ring and sliding on the inner wall surface of the cylinder, and a segment provided between the pair of segments. A three-piece combination oil ring is widely used, which is combined with a spacer expander that urges a pair of segments against the inner wall surface of the cylinder. In relation to this, Patent Document 1 discloses that in a pair of segments, the upper segment provided on the combustion chamber side and the lower segment provided on the crank chamber side have different outer peripheral surface shapes to reduce oil consumption and friction. An oil ring is disclosed that reduces the
国際公開第２０１９／００８７８０号WO2019/008780 特開２０１９－１２４２８８号公報JP 2019-124288 A
　上下一対のセグメントを備えるオイルリングの場合、燃焼室側に配置される上側セグメントの方がクランク室側に配置される下側セグメントよりも過酷な状況下で摺動するため、上側セグメントの方が下側セグメントよりも摩耗し易い傾向にある。長期間の使用により上側セグメントの上面が大きく摩耗すると、リング溝の上溝壁と上側セグメントとの隙間（サイドクリアランス）が拡大することでオイルリングのオイルシール機能が低下する可能性がある。 In the case of an oil ring comprising a pair of upper and lower segments, the upper segment located on the combustion chamber side slides under more severe conditions than the lower segment located on the crank chamber side. It tends to wear more than the lower segment. When the upper surface of the upper segment wears significantly due to long-term use, the gap (side clearance) between the upper groove wall of the ring groove and the upper segment expands, which may deteriorate the oil sealing function of the oil ring.
　本発明は、上述の問題に鑑みてなされたものであり、その目的は、一対のセグメントを備えるオイルリングにおいて、オイルシール機能の低下を防ぐことが可能な技術を提供することである。 The present invention has been made in view of the above problems, and an object thereof is to provide a technique capable of preventing deterioration of the oil seal function in an oil ring provided with a pair of segments.
　上記課題を解決するために、本発明は、以下の構成を採用した。即ち、本発明は、内燃機関におけるピストンに組み付けられるオイルリングであって、環状の線材を基材として前記オイルリングの周長方向に沿うように形成され、互いに独立して前記オイルリングの軸方向に並んで設けられる一対のセグメントと、前記一対のセグメント同士の間に配置されるスペーサエキスパンダと、を備え、前記一対のセグメントのうち前記内燃機関において燃焼室側に位置する上側セグメントの基材の方が、前記一対のセグメントのうち前記内燃機関においてクランク室側に位置する下側セグメントの基材よりも耐摩耗性が高い、オイルリングである。 In order to solve the above problems, the present invention employs the following configuration. That is, the present invention provides an oil ring to be assembled to a piston in an internal combustion engine, which is formed along the circumferential direction of the oil ring using an annular wire rod as a base material, and independently of each other in the axial direction of the oil ring. and a spacer expander arranged between the pair of segments. The oil ring has higher wear resistance than the base material of the lower segment located on the crank chamber side in the internal combustion engine of the pair of segments.
　本発明によると、燃焼室側に配置される上側セグメントの基材の耐摩耗性をクランク室側に配置される下側セグメントの基材の耐摩耗性よりも高くすることで、下側セグメントよりも過酷な状況下で摺動する上側セグメントの摩耗を低減することができる。その結果、オイルシール機能の低下を防ぐことができる。 According to the present invention, by making the wear resistance of the base material of the upper segment arranged on the combustion chamber side higher than the wear resistance of the base material of the lower segment arranged on the crank chamber side, the lower segment It can also reduce the wear of the upper segment that slides under severe conditions. As a result, deterioration of the oil seal function can be prevented.
　また、本発明において、前記上側セグメントの基材の方が前記下側セグメントの基材よりも硬度が高くてもよい。 Further, in the present invention, the base material of the upper segment may have higher hardness than the base material of the lower segment.
　また、本発明において、前記上側セグメントの基材の方が前記下側セグメントの基材よりも硬度が３０Ｈｖ以上高くてもよい。 Further, in the present invention, the base material of the upper segment may have a hardness higher than that of the base material of the lower segment by 30 Hv or more.
　また、本発明において、前記上側セグメントの基材の方が、前記下側セグメントの基材よりも表面における炭化物占有面積率が高くてもよい。 Further, in the present invention, the base material of the upper segment may have a higher carbide occupied area ratio on the surface than the base material of the lower segment.
　また、本発明において、前記上側セグメントの基材の材料と前記下側セグメントの基材の材料とが異なっていてもよい。 Further, in the present invention, the material of the base material of the upper segment and the material of the base material of the lower segment may be different.
　本発明によれば、一対のセグメントを備えるオイルリングにおいて、オイルシール機能の低下を防ぐことができる。 According to the present invention, it is possible to prevent deterioration of the oil seal function in an oil ring having a pair of segments.
実施形態に係るオイルリングを備える内燃機関の部分断面図である。1 is a partial cross-sectional view of an internal combustion engine provided with an oil ring according to an embodiment; FIG. 往復動摩擦試験機の構成を示す模式図である。It is a schematic diagram which shows the structure of a reciprocating friction tester. 摩耗量比を示すグラフである。It is a graph which shows a wear amount ratio. 摩耗量比を示すグラフである。It is a graph which shows a wear amount ratio.
　以下、図面を参照しながら、本発明の好ましい実施の形態について説明する。なお、以下の実施形態に記載されている構成は、特に記載がない限りは発明の技術的範囲をそれらのみに限定する趣旨のものではない。 Preferred embodiments of the present invention will be described below with reference to the drawings. It should be noted that the configurations described in the following embodiments are not meant to limit the technical scope of the invention only to them unless otherwise specified.
　［全体構成］
　図１は、実施形態に係るオイルリング４０を備える内燃機関１００の部分断面図である。図１では、オイルリング４０の周長方向に直交する断面が図示されている。図１に示すように、内燃機関１００では、シリンダ１０の内壁面１０ａとシリンダ１０に装着されたピストン２０の外周面２０ａとの間に所定の離間距離が確保されることにより、ピストン隙間ＰＣ１が形成されている。また、ピストン２０の外周面２０ａには、略矩形状の断面を有するリング溝３０が形成されている。リング溝３０は、燃焼室側に形成された上壁３０１と、クランク室側に形成されて上壁３０１に対向する下壁３０２と、上壁３０１と下壁３０２の内周縁同士を接続する接続壁３０３とを有する。このリング溝３０には、本実施形態に係るオイルリング４０が装着されている。 [overall structure]
FIG. 1 is a partial cross-sectional view of an internal combustion engine 100 provided with an oil ring 40 according to an embodiment. FIG. 1 shows a cross section perpendicular to the circumferential direction of the oil ring 40 . As shown in FIG. 1, in the internal combustion engine 100, a predetermined separation distance is secured between the inner wall surface 10a of the cylinder 10 and the outer peripheral surface 20a of the piston 20 mounted on the cylinder 10, so that the piston clearance PC1 is formed. formed. A ring groove 30 having a substantially rectangular cross section is formed in the outer peripheral surface 20 a of the piston 20 . The ring groove 30 connects an upper wall 301 formed on the combustion chamber side, a lower wall 302 formed on the crank chamber side and facing the upper wall 301, and inner peripheral edges of the upper wall 301 and the lower wall 302. wall 303; An oil ring 40 according to this embodiment is mounted in the ring groove 30 .
　オイルリング４０は、リング溝３０に装着されることでピストン２０に組み付けられ、ピストン２０の往復運動に伴ってシリンダ１０の内壁面１０ａを摺動する摺動部材である。オイルリング４０は、所謂３ピース型の組合せオイルリングであり、図１に示すように、一対のセグメント１，２とスペーサエキスパンダ３とを備える。 The oil ring 40 is a sliding member that is attached to the piston 20 by being fitted in the ring groove 30 and slides on the inner wall surface 10a of the cylinder 10 as the piston 20 reciprocates. The oil ring 40 is a so-called three-piece combination oil ring, and includes a pair of segments 1 and 2 and a spacer expander 3 as shown in FIG.
　以下、図１に示すように、オイルリング４０の中心軸に沿う方向（軸方向）を「上下方向」と定義する。また、オイルリング４０の軸方向のうち、内燃機関１００における燃焼室側（図１における上側）を「上側」と定義し、その反対側、即ち、クランク室側（図１における下側）を「下側」と定義する。また、以下のオイルリング４０の説明において、特に指定しない限りは、「周長方向」とはオイルリング４０の周長方向のことを指し、「径方向」とはオイルリング４０の径方向のことを指し、「軸方向」とはオイルリング４０の軸方向のことを指す。また、本明細書では、図１に示すように内燃機関のシリンダに装着されたピストンにオイルリングが組み付けられた状態を「使用状態」と称する。また、本明細書において、「バレル形状」とは、ピストンリングにおいて最大径となる頂部を含んで径方向外側に凸状となるように湾曲した面形状のことを指し、頂部がリングの軸方向幅における中央に位置する「対称バレル形状」や頂部がリングの軸方向幅における中央よりもクランク室側に位置する「偏心バレル形状」を含むものとする。また、本明細書において、「テーパ形状」とは、クランク室側に向かうに従って拡径するように傾斜した面形状のことを指す。 Hereinafter, as shown in FIG. 1, the direction (axial direction) along the central axis of the oil ring 40 is defined as "vertical direction". Further, in the axial direction of the oil ring 40, the combustion chamber side (upper side in FIG. 1) of the internal combustion engine 100 is defined as "upper side", and the opposite side, that is, the crank chamber side (lower side in FIG. 1) is defined as "upper side". defined as 'lower side'. In the following description of the oil ring 40, unless otherwise specified, the term "peripheral direction" refers to the circumferential direction of the oil ring 40, and the term "radial direction" refers to the radial direction of the oil ring 40. , and the “axial direction” refers to the axial direction of the oil ring 40 . Further, in this specification, the state in which the oil ring is attached to the piston attached to the cylinder of the internal combustion engine as shown in FIG. 1 is referred to as the "used state". Further, in this specification, the term “barrel shape” refers to a surface shape that is curved so as to be convex radially outward including the apex, which is the maximum diameter of the piston ring, and the apex is in the axial direction of the ring It includes a "symmetrical barrel shape" located in the center of the width and an "eccentric barrel shape" in which the apex is located closer to the crankcase than the center of the axial width of the ring. Further, in this specification, the term “tapered shape” refers to a surface shape that is inclined so as to increase in diameter toward the crank chamber.
　一対のセグメント１，２は、オイルリング４０の周長方向に沿うように環状に形成されており、互いに独立して軸方向に離間して設けられている。図１に示すように、一対のセグメント１，２の一方である上側セグメント１は、内燃機関１００において上側（燃焼室側）に設けられ、他方である下側セグメント２は、内燃機関１００において下側（クランク室側）に設けられる。 The pair of segments 1 and 2 are annularly formed along the circumferential direction of the oil ring 40, and are provided independently of each other and separated from each other in the axial direction. As shown in FIG. 1, the upper segment 1, which is one of the pair of segments 1 and 2, is provided on the upper side (combustion chamber side) of the internal combustion engine 100, and the other, the lower segment 2, is provided on the lower side of the internal combustion engine 100. side (crank chamber side).
　図１に示すように、上側セグメント１は、セグメント用の線材により環状に形成された基材１ａと、基材１ａの外周面に成膜された外周被膜１ｂと、を含んで構成されている。上側セグメント１は、外周面１１、内周面１２、上面１３、及び下面１４を有する。外周面１１には、外周被膜１ｂが形成されている。上面１３と下面１４とによって、上側セグメント１の軸方向における幅が規定される。上側セグメント１は、使用状態において上面１３がリング溝３０の上壁３０１に対向するように設けられ、外周面１１を摺動面としてシリンダ１０の内壁面１０ａを摺動する。 As shown in FIG. 1, the upper segment 1 includes a base material 1a formed in an annular shape from a segment wire and an outer coating 1b formed on the outer peripheral surface of the base material 1a. . The upper segment 1 has an outer peripheral surface 11 , an inner peripheral surface 12 , an upper surface 13 and a lower surface 14 . An outer coating 1b is formed on the outer peripheral surface 11 . The upper surface 13 and the lower surface 14 define the axial width of the upper segment 1 . The upper segment 1 is provided so that the upper surface 13 faces the upper wall 301 of the ring groove 30 in use, and slides on the inner wall surface 10a of the cylinder 10 using the outer peripheral surface 11 as a sliding surface.
　図１に示すように、下側セグメント２は、セグメント用の線材により環状に形成された基材２ａと、基材２ａの外周面に成膜された外周被膜２ｂと、を含んで構成されている。下側セグメント２は、外周面２１、内周面２２、上面２３、及び下面２４を有する。外周面２１には、外周被膜２ｂが形成されている。上面２３と下面２４とによって、下側セグメント２の軸方向における幅が規定される。下側セグメント２は、使用状態において下面２４がリング溝３０の下壁３０２に対向するように設けられ、外周面２１を摺動面としてシリンダ１０の内壁面１０ａを摺動する。 As shown in FIG. 1, the lower segment 2 includes a base material 2a formed in an annular shape from a segment wire and an outer coating 2b formed on the outer peripheral surface of the base material 2a. there is The lower segment 2 has an outer peripheral surface 21 , an inner peripheral surface 22 , an upper surface 23 and a lower surface 24 . An outer coating 2 b is formed on the outer peripheral surface 21 . The upper surface 23 and the lower surface 24 define the width of the lower segment 2 in the axial direction. The lower segment 2 is provided so that the lower surface 24 faces the lower wall 302 of the ring groove 30 in use, and slides on the inner wall surface 10a of the cylinder 10 using the outer peripheral surface 21 as a sliding surface.
　図１に示すように、スペーサエキスパンダ３は、一対のセグメント１，２の間に設けられ、使用状態において拡径するように自己張力を有している。そのため、上側セグメント１及び下側セグメント２がスペーサエキスパンダ３によって径方向の外側へ付勢され、上側セグメント１の外周面１１及び下側セグメント２の外周面２１がシリンダ１０の内壁面１０ａを押圧する。これより、オイルシール機能が得られ、シリンダ１０の内壁面１０ａに存在するエンジンオイルが適切な厚さになるように油膜が形成される。なお、本発明に係るスペーサエキスパンダの形状は特に限定されない。 As shown in FIG. 1, the spacer expander 3 is provided between a pair of segments 1 and 2 and has self-tension so that it expands in use. Therefore, the upper segment 1 and the lower segment 2 are urged radially outward by the spacer expander 3, and the outer peripheral surface 11 of the upper segment 1 and the outer peripheral surface 21 of the lower segment 2 press the inner wall surface 10a of the cylinder 10. do. As a result, an oil sealing function is obtained, and an oil film is formed so that the engine oil present on the inner wall surface 10a of the cylinder 10 has an appropriate thickness. The shape of the spacer expander according to the present invention is not particularly limited.
　図１に示すように、本実施形態に係るオイルリング４０では、一対のセグメント１，２の外周面１１，２１をフリクションの低い対称バレル形状としている。但し、本発明において、一対のセグメントの形状は図１に示すものに限定されない。例えば、一対のセグメントのうち上側に位置する上側セグメントの外周面をオイル掻き性能に優れた偏心バレル形状とし、下側に位置する下側セグメントの外周面をフリクションの低い対称バレル形状としてもよいし、両方の外周面を偏心バレル形状としてもよい。これにより、フリクションの増加を抑制しつつも内燃機関１００のオイル消費量を低減することができる。また、上側セグメントの外周面を対称バレル形状とし、下側セグメントの外周面を偏心バレル形状としてもよい。また、上側セグメント１の外周面１１をオイル掻き性能に優れたテーパ形状としてもよく、両方の外周面をテーパ形状としてもよい。また、上側セグメントの外周面をテーパ形状とし、下側セグメントの外周面を対称バレル形状としてもよい。 As shown in FIG. 1, in the oil ring 40 according to the present embodiment, the outer peripheral surfaces 11, 21 of the pair of segments 1, 2 have a symmetrical barrel shape with low friction. However, in the present invention, the shape of the pair of segments is not limited to that shown in FIG. For example, the outer peripheral surface of the upper segment located on the upper side of the pair of segments may have an eccentric barrel shape with excellent oil scraping performance, and the outer peripheral surface of the lower segment located on the lower side may have a symmetrical barrel shape with low friction. , both outer peripheral surfaces may have an eccentric barrel shape. As a result, it is possible to reduce the oil consumption of the internal combustion engine 100 while suppressing an increase in friction. Alternatively, the outer peripheral surface of the upper segment may have a symmetrical barrel shape, and the outer peripheral surface of the lower segment may have an eccentric barrel shape. In addition, the outer peripheral surface 11 of the upper segment 1 may be tapered for excellent oil scraping performance, or both outer peripheral surfaces may be tapered. Alternatively, the outer peripheral surface of the upper segment may be tapered, and the outer peripheral surface of the lower segment may be symmetrical barrel-shaped.
　本実施形態に係るオイルリング４０は、上側セグメント１の基材１ａと下側セグメント２の基材２ａとを異ならせている。より詳しくは、基材１ａの材料と基材２ａの材料とが互いに異なっている。上側セグメント１の基材１ａは、ＳＷＲＨ７２Ａを材料として形成されており、その硬度が４５０Ｈｖ以上５５０Ｈｖ以下である。一方、下側セグメント２の基材２ａは、ＳＵＳ４４０Ｂを材料として形成されており、その硬度が３００Ｈｖ以上４２０Ｈｖ以下である。基材１ａの硬度の方が基材２ａの硬度よりも高く、その差は３０Ｈｖ以上１５０Ｈｖ以下である。但し、セグメントの基材の材料は上記に限定されない。セグメントの基材の材料としては、ＳＵＳやＳＷＲＨなどが例示される。また、マルテンサイト系ステンレス鋼やシリコンクロム鋼、アルミニウム合金などを基材の材料として用いてもよい。その場合の基材１ａと基材２ａの硬度の差は、２７０Ｈｖ以下であってよく、２００Ｈｖ以下であってよく、１８０Ｈｖ以下であってよい。 In the oil ring 40 according to this embodiment, the base material 1a of the upper segment 1 and the base material 2a of the lower segment 2 are different. More specifically, the material of the base material 1a and the material of the base material 2a are different from each other. The base material 1a of the upper segment 1 is made of SWRH72A and has a hardness of 450 Hv or more and 550 Hv or less. On the other hand, the base material 2a of the lower segment 2 is made of SUS440B and has a hardness of 300 Hv or more and 420 Hv or less. The hardness of the base material 1a is higher than that of the base material 2a, and the difference therebetween is 30 Hv or more and 150 Hv or less. However, the material of the base material of the segment is not limited to the above. SUS, SWRH and the like are exemplified as the material of the base material of the segment. Also, martensitic stainless steel, silicon chromium steel, aluminum alloy, or the like may be used as the base material. In that case, the difference in hardness between the substrate 1a and the substrate 2a may be 270 Hv or less, 200 Hv or less, or 180 Hv or less.
　本例に係る外周被膜１ｂ及び外周被膜２ｂは、耐摩耗性の高いＤＬＣ処理被膜として形成されている。なお、外周被膜は、ＤＬＣ処理被膜に限定されず、窒化処理被膜、Ni－Pめっき処理被膜、クロムめっき処理被膜、ＰＶＤ処理被膜、及びＤＬＣ処理被膜のうち少なくとも何れか１つの層を含む硬質被膜として形成されてもよい。なお、上側セグメント１の外周被膜１ｂと下側セグメント２の外周被膜２ｂとで構成を異ならせてもよい。また、本発明において外周被膜は必須の構成ではなく、上側セグメントや下側セグメントの何れか又は両方が外周被膜を有さなくてもよい。また、上側セグメント１の軸方向端面（上面１３や下面１４）や下側セグメント２の軸方向端面（上面２３や下面２４）には、塗膜、樹脂被膜、化成処理被膜、酸化処理被膜、窒化処理被膜、Ni－Pめっき処理被膜、クロムめっき処理被膜、ＰＶＤ処理被膜、及びＤＬＣ処理被膜のうち少なくとも何れか１つの層を含む表面処理被膜が形成されていてもよい。なお、「塗膜」とは、ペイント（塗料）の塗布により形成された膜のことを指す。また、「樹脂被膜」とは、樹脂材料により形成された被膜のことを指す。「塗膜」や「樹脂被膜」の例としては、水性又は油性の樹脂ペイントによる樹脂塗膜などが挙げられる。「化成処理被膜」とは、化成処理により形成された被膜のことを指す。化成処理の例としては、四三酸化鉄処理（黒染め）、リン酸塩処理、クロム酸塩処理などが挙げられる。また、リン酸塩処理の例としては、リン酸マンガン処理、リン酸亜鉛処理、リン酸鉄処理などが挙げられる。「窒化処理被膜」とは、窒化処理により金属表面に窒素を浸透させることで形成される被膜のことを指す。「酸化処理被膜」とは、酸化処理により金属表面を酸化させることで形成される被膜のことを指す。酸化処理の例としては、アルマイト処理などが挙げられる。「Ni－Pめっき処理被膜」とは、無電解Ni－Pめっきにより形成された被膜のことを指す。また、「クロムめっき処理被膜」とは、クロムめっきにより形成された被膜のことを指す。クロムめっきは工業用クロムめっきとも呼ばれる。また、「ＰＶＤ（physical vapor deposition）処理被膜」とは、ＰＶＤ法により形成された被膜のことを指す。また、「ＤＬＣ（Diamond Like Carbon）処理被膜」とは、主として炭化水素や炭素の同素体により構成される非晶質の硬質炭素被膜のことを指す。 The outer coating 1b and the outer coating 2b according to this example are formed as DLC coatings with high abrasion resistance. In addition, the outer coating is not limited to the DLC treatment coating, and includes at least one layer of a nitriding coating, a Ni-P plating coating, a chromium plating coating, a PVD coating, and a DLC coating. may be formed as The outer coating 1b of the upper segment 1 and the outer coating 2b of the lower segment 2 may have different configurations. In addition, the outer coating is not an essential configuration in the present invention, and either or both of the upper segment and the lower segment may not have the outer coating. Further, the axial end faces (upper surface 13 and lower surface 14) of the upper segment 1 and the axial end faces (upper surface 23 and lower surface 24) of the lower segment 2 are coated with a coating, a resin coating, a chemical conversion coating, an oxidation coating, and a nitriding coating. A surface treatment film including at least one layer of a treatment film, a Ni—P plating treatment film, a chromium plating treatment film, a PVD treatment film, and a DLC treatment film may be formed. The term "coating film" refers to a film formed by applying paint. A "resin coating" refers to a coating formed of a resin material. Examples of the "coating film" and "resin coating" include a resin coating film made of water-based or oil-based resin paint. "Chemical conversion coating" refers to a coating formed by chemical conversion treatment. Examples of chemical conversion treatments include triiron tetraoxide treatment (blackening), phosphate treatment, and chromate treatment. Examples of phosphate treatment include manganese phosphate treatment, zinc phosphate treatment, and iron phosphate treatment. A "nitriding coating" refers to a coating formed by infiltrating nitrogen into a metal surface by nitriding. “Oxidation treatment film” refers to a film formed by oxidizing a metal surface by oxidation treatment. Examples of oxidation treatment include alumite treatment. “Ni—P plating film” refers to a film formed by electroless Ni—P plating. In addition, the term "chromium-plated film" refers to a film formed by chromium plating. Chrome plating is also called industrial chrome plating. Also, the term "PVD (physical vapor deposition) treated coating" refers to a coating formed by the PVD method. A "DLC (Diamond Like Carbon) treated coating" refers to an amorphous hard carbon coating mainly composed of hydrocarbons and allotropes of carbon.
　［耐摩耗性について］
　一般に、上下一対のセグメントを備えるオイルリングの場合、燃焼室側に配置される上側セグメントの方がクランク室側に配置される下側セグメントよりも過酷な状況下で摺動するため、上側セグメントの方が下側セグメントよりも摩耗し易い傾向にある。そのため、長期間の使用により上側セグメントの上面（燃焼室側の面）が大きく摩耗すると、リング溝の上溝壁と上側セグメントとの隙間（サイドクリアランス）が拡大することでオイルリングのオイルシール機能が低下し、内燃機関の高回転域でのオイル消費が増大する懸念がある。 [About wear resistance]
Generally, in the case of an oil ring comprising a pair of upper and lower segments, the upper segment located on the combustion chamber side slides under more severe conditions than the lower segment located on the crank chamber side. tend to wear more than the lower segment. Therefore, if the upper surface of the upper segment (surface on the side of the combustion chamber) wears significantly due to long-term use, the gap (side clearance) between the upper groove wall of the ring groove and the upper segment expands, and the oil seal function of the oil ring is lost. There is a concern that oil consumption will increase in the high speed range of the internal combustion engine.
　これに対して本実施形態に係るオイルリング４０は、燃焼室側に配置される上側セグメント１の基材１ａの耐摩耗性がクランク室側に配置される下側セグメント２の基材２ａの耐摩耗性よりも高くなるように、基材１ａと基材２ａとで材料を異ならせている。具体的には、基材１ａの材料をＳＷＲＨ７２Ａとし、下側セグメント２の基材２ａの材料をＳＵＳ４４０Ｂとすることで、基材１ａの硬度を基材２ａの硬度よりも高くしている。これにより、上側セグメント１の摩耗を低減し、オイルシール機能の低下を防ぐことができる。 On the other hand, in the oil ring 40 according to the present embodiment, the wear resistance of the base material 1a of the upper segment 1 arranged on the combustion chamber side is higher than the wear resistance of the base material 2a of the lower segment 2 arranged on the crank chamber side. The base material 1a and the base material 2a are made of different materials so as to be higher than the abrasion resistance. Specifically, the material of the base material 1a is SWRH72A, and the material of the base material 2a of the lower segment 2 is SUS440B, so that the hardness of the base material 1a is higher than that of the base material 2a. As a result, wear of the upper segment 1 can be reduced, and deterioration of the oil seal function can be prevented.
　往復動摩擦試験機を用いた往復動摩擦試験により、セグメントの基材の耐摩耗性を評価した。図２は、往復動摩擦試験機の構成を示す模式図である。往復動摩擦試験機による往復動摩擦試験は、図２に概要を示すピンオンプレート式往復動摩擦試験機を用いて行う。往復動摩擦試験に際して用いた上試験片は、セグメントの基材に見立てたピンであり、ピンの材料にはセグメント用線材と同じものを使用する。なお、この上試験片に用いたピンは、直径が８ｍｍであり、ピンの先端部（摺動面）は、曲率半径が１８ｍｍとなるように鏡面仕上げされたものを用いる。また、下試験片はピストンを見立てたプレート（ＡＣ８Ａ材相当）を用いる。 The wear resistance of the base material of the segment was evaluated by a reciprocating friction test using a reciprocating friction tester. FIG. 2 is a schematic diagram showing the configuration of the reciprocating friction tester. A reciprocating friction test using a reciprocating friction tester is performed using a pin-on plate type reciprocating friction tester whose outline is shown in FIG. The upper test piece used in the reciprocating motion friction test is a pin which is assumed to be the base material of the segment, and the material of the pin is the same as the wire material for the segment. The pin used for the upper test piece has a diameter of 8 mm, and the tip (sliding surface) of the pin is mirror-finished so as to have a radius of curvature of 18 mm. A plate (equivalent to AC8A material) that resembles a piston is used as the lower test piece.
　往復動摩擦試験では、可動ブロックによって下試験片をストロークさせることで上試験片に対して下試験片を摺動させた。上試験片と下試験片との摺動界面にはチュービングポンプやエアディスペンサーを用いて潤滑油を供給した。この際の試験条件を以下に示す。
＜試験条件＞
・ストローク：５０ｍｍ
・荷重：５０Ｎ
・速度：２００ｃｙｃｌｅ／ｍｉｎ
・潤滑油：０Ｗ－２０
　上側セグメント１の基材１ａを見立てたピンを上試験片Ａとし、下側セグメント２の基材２ａを見立てたピンを上試験片Ｂとして、夫々について往復動摩擦試験を行い、摩耗量を比較した。上試験片Ａの材料には基材１ａと同じＳＷＲＨ７２Ａを用い、上試験片Ｂの材料には基材２ａと同じＳＵＳ４４０Ｂを用いた。図３は、往復動摩擦試験の結果を示すグラフであって、摩耗量比を示すグラフである。測定の結果、上試験片Ａと上試験片Ｂの摩耗量比は、図３に示す通り、上試験片Ａ：上試験片Ｂ＝０．２：１．０となった。これにより、上側セグメント１の基材１ａの方が下側セグメント２の基材２ａよりも耐摩耗性が高いことが解った。 In the reciprocating friction test, the lower test piece was slid against the upper test piece by stroking the lower test piece with a movable block. Lubricating oil was supplied to the sliding interface between the upper test piece and the lower test piece using a tubing pump or an air dispenser. The test conditions at this time are shown below.
<Test conditions>
・Stroke: 50mm
・Load: 50N
・Speed: 200 cycles/min
・Lubricating oil: 0W-20
A pin representing the base material 1a of the upper segment 1 was designated as an upper test piece A, and a pin representing the base material 2a of the lower segment 2 was designated as an upper test piece B. A reciprocating friction test was performed on each, and the amount of wear was compared. . The same SWRH72A as the base material 1a was used as the material of the upper test piece A, and the same SUS440B as the base material 2a was used as the material of the upper test piece B. FIG. 3 is a graph showing the results of the reciprocating friction test, showing the wear amount ratio. As a result of the measurement, the wear amount ratio between the upper test piece A and the upper test piece B was, as shown in FIG. 3, upper test piece A:upper test piece B=0.2:1.0. From this, it was found that the base material 1a of the upper segment 1 has higher wear resistance than the base material 2a of the lower segment 2. FIG.
　［作用・効果］
　以上のように、本実施形態に係るオイルリング４０は、上側セグメント１の基材１ａの耐摩耗性が下側セグメント２の基材２ａの耐摩耗性よりも高くなるように、一対のセグメント１，２の基材の材料を互いに異ならせている。具体的には、基材１ａの材料を基材２ａの材料であるＳＵＳ系材料よりも硬度の高いＳＷＲＨ系材料としている。基材１ａの耐摩耗性を基材２ａの耐摩耗性よりも高くすることで、上側セグメント１の摩耗を低減することができ、オイルシール機能の低下を防ぐことができる。このような特性により、実施形態に係るオイルリング４０は、ガソリンエンジンや、セグメントとリング溝の内壁との直接接触の機会が多い低粘度オイルを用いたエンジンに対して好適に用いることができる。但し、本発明に係るオイルリングが適用される内燃機関はこれらに限定されない。ここで、本実施形態に係るオイルリング４０は、上側セグメント１の基材１ａの材料と下側セグメント２の基材２ａの材料を異ならせて基材１ａの硬度を基材２ａの硬度よりも高くすることで、基材１ａの耐摩耗性を基材２ａの耐摩耗性よりも高くしている。基材１ａと基材２ａの硬度差は特に限定されないが、本実施形態に係るオイルリング４０のように、上側セグメント１の基材１ａの硬度を下側セグメント２の基材２ａの硬度よりも３０Ｈｖ以上高くすることが好ましい。また、本実施形態に係るオイルリング４０では、一対のセグメント１，２の基材の材料を異ならせることで、一対のセグメント１，２の表面色を互いに異ならせている。これにより、一対のセグメント１，２の識別性を高めることができる。 [Action/Effect]
As described above, the oil ring 40 according to the present embodiment is configured such that the wear resistance of the base material 1a of the upper segment 1 is higher than the wear resistance of the base material 2a of the lower segment 2. , 2 are made of different materials. Specifically, the material of the base material 1a is a SWRH material having higher hardness than the SUS material that is the material of the base material 2a. By making the wear resistance of the base material 1a higher than the wear resistance of the base material 2a, the wear of the upper segment 1 can be reduced, and the deterioration of the oil seal function can be prevented. Due to such characteristics, the oil ring 40 according to the embodiment can be suitably used for gasoline engines and engines using low-viscosity oil in which there are many chances of direct contact between the segments and the inner wall of the ring groove. However, the internal combustion engine to which the oil ring according to the present invention is applied is not limited to these. Here, in the oil ring 40 according to the present embodiment, the material of the base material 1a of the upper segment 1 and the material of the base material 2a of the lower segment 2 are made different so that the hardness of the base material 1a is higher than that of the base material 2a. By making it higher, the wear resistance of the base material 1a is made higher than the wear resistance of the base material 2a. The difference in hardness between the base material 1a and the base material 2a is not particularly limited. It is preferable to make it higher than 30Hv. In addition, in the oil ring 40 according to the present embodiment, the pair of segments 1 and 2 are made different in surface color by making the base materials of the pair of segments 1 and 2 different. Thereby, the identifiability of the pair of segments 1 and 2 can be improved.
　［変形例］
　以下、実施形態の変形例について説明する。以下の説明では、上述のオイルリングとの相違点を中心に説明し、同様の構成については詳細な説明は割愛する。 [Modification]
Modifications of the embodiment will be described below. In the following description, differences from the above-described oil ring will be mainly described, and detailed descriptions of similar configurations will be omitted.
　［変形例１］
　変形例１のオイルリング４０は、上側セグメント１の基材１ａの材料と下側セグメント２の基材２ａの材料を同一としつつも、上側セグメント１の基材１ａの耐摩耗性が下側セグメント２の基材２ａの耐摩耗性よりも高くなるように、一対のセグメント１，２の基材の硬度を互いに異ならせている。変形例１の場合、例えば、熱処理の仕方を異ならせることで硬度を異ならせることができる。変形例１によっても、上側セグメント１の基材１ａの硬度を下側セグメント２の基材２ａの硬度よりも高くすることで、上側セグメント１の耐摩耗性を高め、オイルシール機能の低下を防ぐことができる。基材１ａと基材２ａの硬度差は特に限定されないが、上側セグメント１の基材１ａの硬度を下側セグメント２の基材２ａの硬度よりも３０Ｈｖ以上高くすることが好ましい。 [Modification 1]
In the oil ring 40 of Modification 1, while the material of the base material 1a of the upper segment 1 and the material of the base material 2a of the lower segment 2 are the same, the wear resistance of the base material 1a of the upper segment 1 is higher than that of the lower segment. The hardness of the base material of the pair of segments 1 and 2 is made different from each other so that the wear resistance of the base material 2a of the pair of segments 1 and 2 is higher than that of the base material 2a of the pair of segments. In the case of Modification 1, for example, the hardness can be varied by varying the manner of heat treatment. According to Modification 1 as well, by making the hardness of the base material 1a of the upper segment 1 higher than the hardness of the base material 2a of the lower segment 2, the wear resistance of the upper segment 1 is increased and deterioration of the oil seal function is prevented. be able to. The difference in hardness between the base material 1a and the base material 2a is not particularly limited, but the hardness of the base material 1a of the upper segment 1 is preferably higher than that of the base material 2a of the lower segment 2 by 30 Hv or more.
　［変形例２］
　変形例２のオイルリング４０は、上側セグメント１の基材１ａの耐摩耗性が下側セグメント２の基材２ａの耐摩耗性よりも高くなるように、一対のセグメント１，２の基材表面における炭化物占有面積率（炭化物析出率）を互いに異ならせている。炭化物占有面積率は、セグメントの表面に占める炭化物の面積の割合のことをいう。炭化物占有面積率は、例えば、マーブル試薬によるエッチング処理後に金属顕微鏡により基材表面の画像を取得し、取得した画像を２値化し、白色部分の面積率を算出することで得られる。但し、炭化物占有面積率の算出方法はこれに限定されない。 [Modification 2]
The oil ring 40 of Modified Example 2 is configured such that the base material surfaces of the pair of segments 1 and 2 are arranged such that the wear resistance of the base material 1a of the upper segment 1 is higher than the wear resistance of the base material 2a of the lower segment 2. The carbide occupied area ratio (carbide precipitation rate) in is different from each other. The carbide occupied area ratio refers to the ratio of the area of carbide occupying the surface of the segment. The carbide occupied area ratio can be obtained, for example, by acquiring an image of the substrate surface with a metallurgical microscope after etching treatment with a marble reagent, binarizing the acquired image, and calculating the area ratio of the white portion. However, the method for calculating the carbide occupied area ratio is not limited to this.
　変形例２では、上側セグメント１の基材１ａと下側セグメント２の基材２ａとで炭素含有量及びクロム含有量の異なるステンレス鋼が用いられている。より具体的には、上側セグメント１の基材１ａはクロムを多く含有するマルテンサイト系ステンレス鋼である１７クロムＳＵＳ材を材料とし、下側セグメント２の基材２ａはクロム含有量がやや少ないステンレス鋼である１３クロムＳＵＳ材を材料としている。但し、本発明に係るセグメントの材料はこれに限定されない。変形例２では、上側セグメント１の基材１ａの炭化物占有面積率が上述の算出方法で７．２％～１５．３％、下側セグメント２の基材２ａの炭化物占有面積率が０．２％～２．０％となっている。つまり、変形例２では、上側セグメント１の基材１ａの方が下側セグメント２の基材２ａよりも炭化物占有面積率が高く、その差が５．２％以上となっている。 In Modification 2, the base material 1a of the upper segment 1 and the base material 2a of the lower segment 2 are made of stainless steel with different carbon and chromium contents. More specifically, the base material 1a of the upper segment 1 is made of 17 chromium SUS material, which is martensitic stainless steel containing a large amount of chromium, and the base material 2a of the lower segment 2 is made of stainless steel with a slightly low chromium content. 13 chromium SUS material, which is steel, is used as the material. However, the material of the segment according to the present invention is not limited to this. In modification 2, the carbide occupied area ratio of the base material 1a of the upper segment 1 is 7.2% to 15.3% by the above calculation method, and the carbide occupied area ratio of the base material 2a of the lower segment 2 is 0.2. % to 2.0%. That is, in Modification 2, the substrate 1a of the upper segment 1 has a higher carbide occupied area ratio than the substrate 2a of the lower segment 2, and the difference is 5.2% or more.
　なお、変形例２では、上側セグメント１の基材１ａと下側セグメント２の基材２ａの材料が同一であってもよい。基材１ａと基材２ａの材料を同一とした場合、例えば、熱処理の仕方を異ならせることで炭化物の大きさを変化させ、炭化物占有面積率を異ならせることができる。また、上側セグメント１と下側セグメント２とで基材の材料を互いに異ならせることで炭化物占有面積率を互いに異ならせてもよい。 Note that in Modification 2, the material of the base material 1a of the upper segment 1 and the material of the base material 2a of the lower segment 2 may be the same. When the base material 1a and the base material 2a are made of the same material, the size of the carbides can be changed by, for example, different heat treatment methods, and the carbide occupied area ratios can be varied. In addition, the upper segment 1 and the lower segment 2 may be made of different base material materials so that the carbide occupied area ratios are different from each other.
　上述のように、変形例２では、上側セグメント１の基材１ａの炭化物占有面積率が下側セグメント２の基材２ａの炭化物占有面積率よりも高くなるように、一対のセグメント１，２の基材を互いに異ならせている。上側セグメント１の基材１ａの炭化物占有面積率を下側セグメント２の基材２ａの炭化物占有面積率よりも高くすることで、上側セグメント１の耐摩耗性を高め、オイルシール機能の低下を防ぐことができる。なお、基材１ａと基材２ａの炭化物占有面積率の差は特に限定されない。また、変形例２では、一対のセグメント１，２の基材表面における炭化物占有面積率を異ならせることで、一対のセグメント１，２の表面色を互いに異ならせている。これにより、一対のセグメント１，２の識別性を高めることができる。 As described above, in Modification 2, the pair of segments 1 and 2 are arranged such that the carbide occupied area ratio of the base material 1a of the upper segment 1 is higher than the carbide occupied area ratio of the base material 2a of the lower segment 2. The substrates are made different from each other. By making the carbide occupied area ratio of the base material 1a of the upper segment 1 higher than the carbide occupied area ratio of the base material 2a of the lower segment 2, the wear resistance of the upper segment 1 is improved and the deterioration of the oil seal function is prevented. be able to. In addition, the difference in the carbide occupied area ratio between the base material 1a and the base material 2a is not particularly limited. In Modification 2, the surface colors of the pair of segments 1 and 2 are made different from each other by making the carbide occupied area ratios of the base material surfaces of the pair of segments 1 and 2 different. Thereby, the identifiability of the pair of segments 1 and 2 can be improved.
　上述した往復動摩擦試験により、変形例２に係るセグメントの基材の耐摩耗性を評価した。上側セグメント１の基材１ａを見立てたピンを上試験片Ｃとし、下側セグメント２の基材２ａを見立てたピンを上試験片Ｄとして夫々について往復動摩擦試験を行い、摩耗量を比較した。上試験片Ｃの材料には基材１ａと同じ１７クロムＳＵＳ材を用い、上試験片Ｄの材料には基材２ａと同じ１３クロムＳＵＳ材を用いた。また、上試験片Ｃの炭化物占有面積率は上述の算出方法で７．２％～１５．３％とし、上試験片Ｄの炭化物占有面積率を０．２％～２．０％とし、炭化物占有面積率の差が５．２％以上となるようにした。図４は、往復動摩擦試験の結果を示すグラフであって、摩耗量比を示すグラフである。図４に示す通り、炭化物占有面積率の大きい上側セグメント１の上試験片Ｃの方が下側セグメント２の上試験片Ｄよりも耐摩耗性が高い結果を得た。 The abrasion resistance of the base material of the segment according to Modification 2 was evaluated by the reciprocating friction test described above. A reciprocating friction test was performed on each of the pins representing the base material 1a of the upper segment 1 as an upper test piece C and the pin representing the base material 2a of the lower segment 2 as an upper test piece D to compare the amount of wear. The material of the upper test piece C was the same 17 chromium SUS material as the base material 1a, and the material of the upper test piece D was the same 13 chromium SUS material as the base material 2a. In addition, the carbide occupied area ratio of the upper test piece C was set to 7.2% to 15.3% by the above calculation method, and the carbide occupied area ratio of the upper test piece D was set to 0.2% to 2.0%. The difference in occupied area ratio was set to 5.2% or more. FIG. 4 is a graph showing the results of the reciprocating friction test, showing the wear amount ratio. As shown in FIG. 4, the upper test piece C of the upper segment 1 having a larger carbide occupied area ratio had higher wear resistance than the upper test piece D of the lower segment 2 .
　＜その他＞
　以上、本発明の好適な実施形態について説明したが、上述した種々の形態は、可能な限り組み合わせることができる。 <Others>
Although the preferred embodiments of the present invention have been described above, the various forms described above can be combined as much as possible.
１００：内燃機関
１０：シリンダ
２０：ピストン
３０：リング溝
４０：オイルリング
１：上側セグメント
２：下側セグメント
３：スペーサエキスパンダ
１ａ，２ａ：基材 100: Internal combustion engine 10: Cylinder 20: Piston 30: Ring groove 40: Oil ring 1: Upper segment 2: Lower segment 3: Spacer expander 1a, 2a: Base material

Claims (5)

  1. 　内燃機関におけるピストンに組み付けられるオイルリングであって、
    　環状の線材を基材として前記オイルリングの周長方向に沿うように形成され、互いに独立して前記オイルリングの軸方向に並んで設けられる一対のセグメントと、前記一対のセグメント同士の間に配置されるスペーサエキスパンダと、を備え、
    　前記一対のセグメントのうち前記内燃機関において燃焼室側に位置する上側セグメントの基材の方が、前記一対のセグメントのうち前記内燃機関においてクランク室側に位置する下側セグメントの基材よりも耐摩耗性が高い、
    　オイルリング。     An oil ring assembled to a piston in an internal combustion engine,
    A pair of segments formed along the circumferential direction of the oil ring using an annular wire rod as a base material and arranged independently of each other in the axial direction of the oil ring, and arranged between the pair of segments. and a spacer expander,
    Of the pair of segments, the base material of the upper segment located on the combustion chamber side in the internal combustion engine is more durable than the base material of the lower segment located on the crank chamber side of the internal combustion engine. highly abrasive,
    oil ring.
  2. 　前記上側セグメントの基材の方が前記下側セグメントの基材よりも硬度が高い、
    　請求項１に記載のオイルリング。     the base material of the upper segment is harder than the base material of the lower segment;
    The oil ring according to claim 1.
  3. 　前記上側セグメントの基材の方が前記下側セグメントの基材よりも硬度が３０Ｈｖ以上高い、
    　請求項１又は２に記載のオイルリング。     The base material of the upper segment has a hardness higher than that of the base material of the lower segment by 30 Hv or more,
    The oil ring according to claim 1 or 2.
  4. 　前記上側セグメントの基材の方が、前記下側セグメントの基材よりも表面における炭化物占有面積率が高い、
    　請求項１に記載のオイルリング。     The base material of the upper segment has a higher carbide occupied area ratio on the surface than the base material of the lower segment.
    The oil ring according to claim 1.
  5. 　前記上側セグメントの基材の材料と前記下側セグメントの基材の材料とが異なっている、
    　請求項１から４の何れか一項に記載のオイルリング。     the material of the base material of the upper segment and the material of the base material of the lower segment are different;
    The oil ring according to any one of claims 1 to 4.
PCT/JP2022/024541 2021-08-05 2022-06-20 Oil ring WO2023013264A1 (en)

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Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62294152A (en) * 1986-06-12 1987-12-21 Hitachi Metals Ltd Wear resistant member
JPH0464656U (en) * 1990-10-16 1992-06-03
JPH11101189A (en) * 1997-09-26 1999-04-13 Nippon Piston Ring Co Ltd Rotary compressor
JP2019124288A (en) * 2018-01-16 2019-07-25 Ｔｐｒ株式会社 Combined oil ring
JP2020026805A (en) * 2018-08-09 2020-02-20 Ｔｐｒ株式会社 Combined oil ring

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS62294152A (en) * 1986-06-12 1987-12-21 Hitachi Metals Ltd Wear resistant member
JPH0464656U (en) * 1990-10-16 1992-06-03
JPH11101189A (en) * 1997-09-26 1999-04-13 Nippon Piston Ring Co Ltd Rotary compressor
JP2019124288A (en) * 2018-01-16 2019-07-25 Ｔｐｒ株式会社 Combined oil ring
JP2020026805A (en) * 2018-08-09 2020-02-20 Ｔｐｒ株式会社 Combined oil ring

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