JP2735343B2 - Internal combustion engine piston structure - Google Patents
Internal combustion engine piston structureInfo
- Publication number
- JP2735343B2 JP2735343B2 JP2043249A JP4324990A JP2735343B2 JP 2735343 B2 JP2735343 B2 JP 2735343B2 JP 2043249 A JP2043249 A JP 2043249A JP 4324990 A JP4324990 A JP 4324990A JP 2735343 B2 JP2735343 B2 JP 2735343B2
- Authority
- JP
- Japan
- Prior art keywords
- piston
- surface roughness
- pin hole
- pin
- piston structure
- Prior art date
- Legal status (The legal status 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 status listed.)
- Expired - Lifetime
Links
Classifications
-
- 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
- F02F3/00—Pistons
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F05—INDEXING SCHEMES RELATING TO ENGINES OR PUMPS IN VARIOUS SUBCLASSES OF CLASSES F01-F04
- F05C—INDEXING SCHEME RELATING TO MATERIALS, MATERIAL PROPERTIES OR MATERIAL CHARACTERISTICS FOR MACHINES, ENGINES OR PUMPS OTHER THAN NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES
- F05C2201/00—Metals
- F05C2201/02—Light metals
- F05C2201/021—Aluminium
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Pistons, Piston Rings, And Cylinders (AREA)
Description
【発明の詳細な説明】 産業上の利用分野 本発明は、内燃機関のピストン構造とりわけピストン
ピンが挿通支持されるピン孔の表面粗度を変化させたピ
ストン構造に関する。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a piston structure of an internal combustion engine, and more particularly to a piston structure in which the surface roughness of a pin hole through which a piston pin is inserted and supported is changed.
従来の技術 従来における内燃機関のピストン構造としては、例え
ば本出願人が先に提案した実開昭63−99064号公報に記
載されたものが知られている。2. Description of the Related Art As a conventional piston structure of an internal combustion engine, for example, a piston structure disclosed in Japanese Utility Model Laid-Open Publication No. 63-99064 proposed by the present applicant is known.
これは、アルミ合金材からなるピストンのピンボス部
に形成されたピン孔と該ピン孔に回転自在に支持される
ピストンピンとの滑動接触部の表面粗度を、長手方向に
変化させたものである。即ち、ピン孔は、ピストンピン
との滑動接触部の外方側の表面粗度を大きく形成する一
方、滑動接触部の長手方向内方側の表面粗度を小さく形
成している。これによって、表面粗度の大きな個所に潤
滑油を十分に収容保持することが可能となり、滑動接触
部の油膜切れが防止されて、ピン孔とピストンピン間の
焼き付きが防止される。一方、表面粗度の小さな個所で
は、耐摩耗性や耐荷重性が向上する。したがって、ピン
孔とピストンピンとの間に高価な低摩擦材を使用するこ
となく、極めて簡単な構造で前記のような効果を得るこ
とができるようになっている。This is a variation in the longitudinal direction of a surface roughness of a sliding contact portion between a pin hole formed in a pin boss portion of a piston made of an aluminum alloy material and a piston pin rotatably supported by the pin hole. . That is, the pin hole has a large surface roughness on the outer side of the sliding contact portion with the piston pin, and has a small surface roughness on the inner side in the longitudinal direction of the sliding contact portion. This makes it possible to sufficiently store and hold the lubricating oil in a portion having a large surface roughness, to prevent the oil film from being broken at the sliding contact portion, and to prevent seizure between the pin hole and the piston pin. On the other hand, at places where the surface roughness is small, wear resistance and load resistance are improved. Therefore, the above-mentioned effect can be obtained with an extremely simple structure without using an expensive low friction material between the pin hole and the piston pin.
課題を解決するための手段 然し乍ら、前記従来のピストン構造にあっては、ピン
孔の表面粗度を単に滑動接触部の長手方向にのみ変化さ
せるようにしており、即ち斯かる表面粗度を形成するた
めには、第3図に示すようにピストン1のピン孔2に対
する加工工具の軸心を、第1次加工と第2次加工の両方
とも同心上で行なっている。このため、表面粗度の長手
方向への変化は可能になるものの円周方向へ変化させる
ことが困難であり、該表面粗度がピン孔2の軸心Zを中
心とした上下左右部位が一様な粗度となってしまう。こ
の結果、機関の燃焼圧力によってピストンピン3との相
対関係で発生するピン孔2内周面への局部的に高面圧部
位に応じて表面粗度を変化させることができない。つま
り、第4図に示すように機関の爆発行程時における燃焼
圧力がピストン1の冠面1aに加わると、ピン孔2の内周
面には、コンロッド4を中心とした両側部に下方向への
応力が作用して、ピストンピン3との相対関係でピン孔
2の中心側上端縁5a,5bと両側下端縁6a,6bに高い面圧が
作用し、他の部位は比較的低い面圧が作用する。したが
って、高面圧部位と低面圧部位では、表面粗度を適宜変
化させることが望ましいが、前記従来の構造では任意に
変化させることが困難である。However, in the conventional piston structure, the surface roughness of the pin hole is changed only in the longitudinal direction of the sliding contact portion, that is, such a surface roughness is formed. In order to do this, as shown in FIG. 3, the axis of the machining tool with respect to the pin hole 2 of the piston 1 is performed concentrically for both the primary machining and the secondary machining. For this reason, it is possible to change the surface roughness in the longitudinal direction, but it is difficult to change the surface roughness in the circumferential direction. The roughness will be similar. As a result, the surface roughness cannot be changed locally in accordance with the high surface pressure portion on the inner peripheral surface of the pin hole 2 generated in a relative relationship with the piston pin 3 due to the combustion pressure of the engine. That is, as shown in FIG. 4, when the combustion pressure at the time of the explosion stroke of the engine is applied to the crown surface 1a of the piston 1, the inner peripheral surface of the pin hole 2 is moved downward on both sides around the connecting rod 4. , A high surface pressure acts on the center upper end edges 5a, 5b and both lower ends 6a, 6b of the pin hole 2 in relation to the piston pin 3, and the other parts have a relatively low surface pressure. Works. Therefore, it is desirable to appropriately change the surface roughness between the high surface pressure part and the low surface pressure part, but it is difficult to arbitrarily change the surface roughness in the conventional structure.
課題を解決するための手段 本発明は、前記従来の実情に鑑みて案出されたもの
で、ピストンピンを支持するピストンピン孔の内周面の
表面粗度を、ピストンピン孔加工用の工具の1次加工軸
心と2次加工軸心とを偏倚させることによりピン孔の長
手方向及び円周方向に変化させるようにしたことを特徴
としている。Means for Solving the Problems The present invention has been devised in view of the above-described conventional circumstances, and has a surface roughness of an inner peripheral surface of a piston pin hole for supporting a piston pin, which is a tool for machining a piston pin hole. By deviating the primary processing axis and the secondary processing axis, the pin hole is changed in the longitudinal direction and the circumferential direction of the pin hole.
作用 前記構成の本発明によれば、ピン孔内周面に形成され
る表面粗度を、長手方向ばかりか円周方向にも変化させ
るようにしたため、ピン孔の高面圧部位や低面圧部位に
所望の大きさの表面粗度を形成することが可能になり、
低面圧部位での潤滑油の保持能力を向上させることがで
きると共に、高面圧部位の耐摩耗性を向上させることが
できる。According to the present invention having the above-described configuration, the surface roughness formed on the inner peripheral surface of the pin hole is changed not only in the longitudinal direction but also in the circumferential direction. It is possible to form a desired surface roughness on the site,
The ability to hold the lubricating oil at the low surface pressure part can be improved, and the wear resistance at the high surface pressure part can be improved.
実施例 以下、本発明の実施例を図面に基づいて詳述する。Examples Hereinafter, examples of the present invention will be described in detail with reference to the drawings.
第1図は本発明に係るピストン構造の第1実施例を示
し、アルミ合金材からなるピストン11のピンボス部12
に、該ピストン11と図外のコンロッドとを連結するピス
トンピン13を回転自在に支持するピン孔14が形成されて
いる。このピン孔14は、ピストンピン13との滑動接触部
(内周面)15の下端部位16の表面粗度が周方向に沿って
大きく形成されている一方、滑動接触部15の上端部位17
の表面粗度が周方向に沿って小さく形成されている。即
ち、斯かる表面粗度は、燃焼圧力によるピン孔14面圧の
低い下端部位16の最下縁側が最大に形成され、周方向の
両側上方に至るにしたがって漸次小さくなり、面圧の高
い上端部位17の最上縁側が最小に形成されている。FIG. 1 shows a first embodiment of a piston structure according to the present invention, in which a pin boss portion 12 of a piston 11 made of an aluminum alloy material is shown.
Further, a pin hole 14 for rotatably supporting a piston pin 13 connecting the piston 11 and a connecting rod (not shown) is formed. The pin hole 14 is formed such that the surface roughness of the lower end portion 16 of the sliding contact portion (inner peripheral surface) 15 with the piston pin 13 increases along the circumferential direction, while the upper end portion 17 of the sliding contact portion 15
Has a small surface roughness along the circumferential direction. That is, such a surface roughness is maximized at the lowermost edge side of the lower end portion 16 where the surface pressure of the pin hole 14 is low due to the combustion pressure, and gradually decreases toward the upper side on both sides in the circumferential direction. The top edge of the portion 17 is formed to be minimum.
そして、前記表面粗度を形成するには、ピン孔14の表
面粗度の加工時における加工工具の第1次加工軸心X
と、第2次加工軸心Yとを所定のオフセット量αで偏心
させて加工作業を行なうようになっている。In order to form the surface roughness, the primary machining axis X of the machining tool at the time of machining the surface roughness of the pin hole 14 is used.
And the secondary machining axis Y are eccentric by a predetermined offset amount α to perform the machining operation.
したがって、この実施例によれば、ピストン11の往復
運動時に、図外のクランク軸の回転により跳ね掛けられ
た潤滑油が滑動接触部15に供給される。この供給された
潤滑油の多くは表面粗度の大きな下端部位16に収容保持
され、ここから表面粗度の小さな上端部位17に漸次供給
される。したがって、滑動接触部15全体の油膜切れが防
止されてピストン11とピストンピン13との焼き付きが防
止される。Therefore, according to this embodiment, the lubricating oil splashed by the rotation of the crankshaft (not shown) is supplied to the sliding contact portion 15 when the piston 11 reciprocates. Most of the supplied lubricating oil is stored and held in a lower end portion 16 having a large surface roughness, and is gradually supplied to an upper end portion 17 having a small surface roughness. Therefore, oil film breakage of the entire sliding contact portion 15 is prevented, and seizure between the piston 11 and the piston pin 13 is prevented.
また、上端部位17は、表面粗度が小さいため、ピン孔
14内周面の耐摩耗性及び耐荷重性が向上し、たとえ高い
面圧が作用しても摩耗等の発生を十分に防止できる。In addition, since the upper end portion 17 has a small surface roughness,
(14) The abrasion resistance and load resistance of the inner peripheral surface are improved, and even if a high surface pressure acts, the occurrence of abrasion or the like can be sufficiently prevented.
第2図は本発明の第2実施例を示し、この実施例では
ピン孔14の上端部位17の表面粗度が、中心側つまりコン
ロッド大径部側からピストン11の外周側に亘って漸次大
きく形成され、下端部位16の表面粗度が、逆に中心側か
らピストン11外周側に亘って漸次小さく形成されてい
る。即ち、斯かる表面粗度は、ピン孔14の面圧の比較的
低い上端部位17の外端側17a付近と下端部位16の内端側1
6a付近が最大に形成され、面圧の高い長手方向の上端部
位17内端側17b付近と下端部位16の外端側16b付近に最小
に形成されている。FIG. 2 shows a second embodiment of the present invention. In this embodiment, the surface roughness of the upper end portion 17 of the pin hole 14 gradually increases from the center side, that is, the connecting rod large diameter portion side to the outer peripheral side of the piston 11. On the contrary, the surface roughness of the lower end portion 16 is gradually reduced from the center side to the outer peripheral side of the piston 11. That is, such surface roughness is near the outer end side 17a of the upper end portion 17 and the inner end side 1 of the lower end portion 16 where the surface pressure of the pin hole 14 is relatively low.
The vicinity of 6a is formed to the maximum, and the minimum is formed near the inner end 17b of the upper end portion 17 and the outer end 16b of the lower end portion 16 in the longitudinal direction where the surface pressure is high.
これは、表面粗度形成時における1次加工軸心Xと2
次加工軸心Yとを所定の角度βをもって傾斜させて加工
作業を行なったものである。This is because the primary processing axes X and 2 at the time of forming the surface roughness are
The machining operation is performed by inclining the next machining axis Y at a predetermined angle β.
したがって、この場合は表面粗度の大きな上端部位17
の外端側17aと下端部位16の内端側16aに潤滑油が収容保
持される一方、高面圧が作用する表面粗度の小さな上端
部位17の内端側17bと下端部位16の外端側16bの耐摩耗性
等が向上し、摩耗等の発生を十分に防止できる。Therefore, in this case, the upper end portion 17 having a large surface roughness is used.
The lubricating oil is stored and held on the outer end side 17a and the inner end side 16a of the lower end part 16 while the inner end side 17b of the upper end part 17 and the outer end of the lower end part 16 having a small surface roughness on which high surface pressure acts The wear resistance and the like of the side 16b are improved, and the occurrence of wear and the like can be sufficiently prevented.
尚、本発明は前記実施例に限定されず、第1次加工軸
心Xと第2次加工軸心Yのオフセット量αが傾斜角度β
は機関やピストンの大きさや長さ等に応じて任意に変更
することが可能である。Note that the present invention is not limited to the above embodiment, and the offset amount α between the primary machining axis X and the secondary machining axis Y becomes the inclination angle β
Can be arbitrarily changed according to the size and length of the engine and the piston.
発明の効果 以上の説明で明らかなように、本発明に係るピストン
構造によれば、ピン孔の加工時における工具の第1次加
工軸心と第2次加工軸心とを適宜偏倚させて、表面粗度
をピン孔の長手方向及び円周方向に変化させるようにし
たため、ピン孔内周面の高面圧部位の表面粗度を小さく
し、低面圧部位の表面粗度を大きく形成することができ
る。したがって、ピストンピンとピン孔間の油膜切れが
十分に防止されることは勿論のこと、高面圧部位の耐摩
耗性が耐荷重性が向上し、ピストン作動中における摩耗
等の発生が十分に防止される。しかも、単に工具の第1
次加工軸心と第2次加工軸心を偏倚させるだけで表面粗
度を所望の位置及び大きさに形成できるので、製造作業
も簡単であり、コスト面でも有利である。Advantageous Effects of the Invention As is clear from the above description, according to the piston structure of the present invention, the primary machining axis and the secondary machining axis of the tool are appropriately deviated at the time of machining the pin hole, Since the surface roughness is changed in the longitudinal direction and the circumferential direction of the pin hole, the surface roughness of the high contact pressure portion on the inner peripheral surface of the pin hole is reduced, and the surface roughness of the low contact pressure portion is increased. be able to. Therefore, the oil film between the piston pin and the pin hole is not only sufficiently prevented, but also the wear resistance of the high surface pressure area is improved, the load resistance is improved, and the occurrence of wear during the operation of the piston is sufficiently prevented. Is done. Moreover, simply the first of the tools
Since the surface roughness can be formed at a desired position and size only by displacing the secondary processing axis and the secondary processing axis, the manufacturing operation is simple and the cost is advantageous.
第1図は本発明のピストン構造の第1実施例を示す要部
拡大断面図、第2図は本発明の第2実施例を示す要部拡
大断面図、第3図は従来のピストン構造を示す要部拡大
断面図、第4図は燃焼圧力によるピン孔の高面圧位置を
示す説明図である。 11……ピストン、13……ピストンピン、14……ピン孔、
15……滑動接触部(内周面)、16……下端部位、17……
上端部位、X……1次加工軸心、Y……2次加工軸心。FIG. 1 is an enlarged sectional view of a main part showing a first embodiment of a piston structure of the present invention, FIG. 2 is an enlarged sectional view of a main part showing a second embodiment of the present invention, and FIG. FIG. 4 is an enlarged sectional view of a main part, and FIG. 4 is an explanatory view showing a high surface pressure position of a pin hole by a combustion pressure. 11 ... piston, 13 ... piston pin, 14 ... pin hole,
15 ... sliding contact part (inner peripheral surface), 16 ... lower end part, 17 ...
Upper end portion, X: primary processing axis, Y: secondary processing axis.
Claims (1)
内周面の表面粗度を、ピストンピン孔加工用工具の1次
加工軸心と2次加工軸心とを偏倚させることによりピン
孔の長手方向及び円周方向に変化させるようにしたこと
を特徴とする内燃機関のピストン構造。The surface roughness of the inner peripheral surface of a piston pin hole for supporting a piston pin is adjusted by displacing a primary machining axis and a secondary machining axis of a piston pin hole machining tool. A piston structure for an internal combustion engine, wherein the piston structure is changed in a longitudinal direction and a circumferential direction.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2043249A JP2735343B2 (en) | 1990-02-23 | 1990-02-23 | Internal combustion engine piston structure |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2043249A JP2735343B2 (en) | 1990-02-23 | 1990-02-23 | Internal combustion engine piston structure |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH03246354A JPH03246354A (en) | 1991-11-01 |
JP2735343B2 true JP2735343B2 (en) | 1998-04-02 |
Family
ID=12658606
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP2043249A Expired - Lifetime JP2735343B2 (en) | 1990-02-23 | 1990-02-23 | Internal combustion engine piston structure |
Country Status (1)
Country | Link |
---|---|
JP (1) | JP2735343B2 (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE19956425A1 (en) | 1999-11-24 | 2001-05-31 | Mahle Gmbh | Piston for IC engines uses Laser beams to roughen bearings for gudgeon pin or crankshaft at points of max.load |
DE10340990A1 (en) * | 2003-09-05 | 2005-04-28 | Ks Kolbenschmidt Gmbh | Finished surface of the bolt holes of a piston |
-
1990
- 1990-02-23 JP JP2043249A patent/JP2735343B2/en not_active Expired - Lifetime
Also Published As
Publication number | Publication date |
---|---|
JPH03246354A (en) | 1991-11-01 |
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