JP2007064452A

JP2007064452A - Connection pin

Info

Publication number: JP2007064452A
Application number: JP2005254348A
Authority: JP
Inventors: Makoto Kobayashi; 誠小林; Kenji Ushijima; 研史牛嶋; Katsuya Mogi; 克也茂木; Naoki Takahashi; 直樹高橋
Original assignee: Nissan Motor Co Ltd
Current assignee: Nissan Motor Co Ltd
Priority date: 2005-09-02
Filing date: 2005-09-02
Publication date: 2007-03-15
Anticipated expiration: 2025-09-02
Also published as: JP5070689B2

Abstract

<P>PROBLEM TO BE SOLVED: To shorten axial dimensions of a first connection pin and a bearing hole by surely forming an oil film of a bearing surface and preventing seizure of the first connection pin and excess abrasion. <P>SOLUTION: A lower link 13 and an upper link 11 constituting a double link type piston-crank mechanism are oscillatably connected by the first connection pin 12. The first connection pin 12 has a simple cylindrical face, and rotatably fitted to a pin bearing hole 27 of the upper link 11 and a pair of pin bearing holes 24 of the lower link 13. The first connection pin 12 has axial eccentric holes 28 on both end parts, and its center of gravity is eccentric from the center. Accordingly, when a position of the first connection pin 12 itself is moved along an oval movement locus, angular moment is generated, the first connection pin 12 rotates in the bearing holes, and the oil film is formed by wedge effect. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

この発明は、ピストン−クランク機構のようなリンク機構に好適なフルフロート形式の連結ピンに関する。 The present invention relates to a full float type connecting pin suitable for a link mechanism such as a piston-crank mechanism.

特許文献１は、本出願人が先に提案したものであって、内燃機関の複リンク式ピストン−クランク機構において、各リンクを連結するためのフルフロート形式の連結ピンを開示している。この連結ピンは、単純な円筒状をなし、長手方向の中央部に嵌合する一方の部材の軸受と、長手方向の両端部にそれぞれ嵌合する他方の部材の二股状の軸受とを、互いに回転自在に連結している。
特開２００３−３２２０５６号公報 Patent Document 1 has been previously proposed by the present applicant, and discloses a full float type connecting pin for connecting each link in a multi-link type piston-crank mechanism of an internal combustion engine. This connecting pin has a simple cylindrical shape, and a bearing of one member that fits in the central portion in the longitudinal direction and a bifurcated bearing of the other member that fits in both ends in the longitudinal direction are mutually connected. It is connected freely.
JP 2003-322056 A

このようなフルフロート形式の連結ピンにおいては、連結ピンの全長を短くして対応する軸受の小型化を達成するためには、連結ピン・軸受間の負荷容量を増大する必要がある。しかし、連結ピン・軸受間の負荷を増大すると、連結ピンと軸受との間で焼き付きや過大な摩耗が生じやすくなる。従って、大きな負荷の下でも良好な流体潤滑状態を保ち、金属接触を抑制することが要求されている。 In such a full float type connecting pin, it is necessary to increase the load capacity between the connecting pin and the bearing in order to reduce the total length of the connecting pin and achieve the corresponding downsizing of the bearing. However, if the load between the connecting pin and the bearing is increased, seizure or excessive wear tends to occur between the connecting pin and the bearing. Therefore, it is required to maintain a good fluid lubrication state even under a large load and suppress metal contact.

この発明は、２つの部材の軸受にフルフロート形式に支持されて両部材を互いに揺動可能に連結するとともに、軸受の位置自体が２次元的に運動する連結ピンにおいて、この連結ピンの重心が、該連結ピンの中心から偏心した位置にあることを特徴としている。 In this connection pin, the two pins are supported in a full float manner on the bearing of the two members so that the two members can be slidably connected to each other, and the position of the bearing itself moves two-dimensionally. , The center of the connecting pin is in an eccentric position.

例えば内燃機関のピストンピンは、単純な上下直線運動つまり１次元的な直線往復運動を行うに過ぎないが、例えば複リンク式ピストン−クランク機構における２つのリンクを連結する連結ピンは、それ自体が２次元的な軌跡に沿って運動する。そのため、連結ピンの重心が該連結ピンの中心から偏心していると、２次元的な運動の慣性力によるモーメントが連結ピンに作用し、軸受内で連結ピンが回転つまり自転しようとする。従って、この連結ピンの自転により、いわゆる潤滑油のくさび効果が生じ、油膜圧力が発生しやすくなる。そのため、金属接触が緩和され、耐摩耗性、耐焼き付き性といった軸受耐久性能が向上する。 For example, a piston pin of an internal combustion engine only performs a simple vertical linear motion, that is, a one-dimensional linear reciprocating motion. However, for example, a connecting pin that connects two links in a multi-link piston-crank mechanism is itself. It moves along a two-dimensional trajectory. For this reason, if the center of gravity of the connecting pin is eccentric from the center of the connecting pin, a moment due to a two-dimensional motion inertia force acts on the connecting pin, and the connecting pin tends to rotate, that is, rotate within the bearing. Accordingly, the rotation of the connecting pin causes a so-called wedge effect of the lubricating oil, and the oil film pressure is easily generated. Therefore, metal contact is relaxed, and bearing durability performance such as wear resistance and seizure resistance is improved.

この発明によれば、連結ピン自体の２次元的な運動に伴い該連結ピンが軸受内で回転しようとし、潤滑油のくさび効果により金属接触が抑制されて、耐摩耗性や耐焼き付き性が向上する。 According to this invention, the connection pin tries to rotate in the bearing with the two-dimensional movement of the connection pin itself, the metal contact is suppressed by the wedge effect of the lubricating oil, and the wear resistance and seizure resistance are improved. To do.

以下、この発明の好ましい実施の形態を図面に基づいて詳細に説明する。 Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

図１は、本発明に係る連結ピンが適用されるピストン−クランク機構の一例として、複リンク式のピストン−クランク機構を利用した内燃機関の可変圧縮比機構を示している。 FIG. 1 shows a variable compression ratio mechanism of an internal combustion engine using a multi-link type piston-crank mechanism as an example of a piston-crank mechanism to which a connecting pin according to the present invention is applied.

これは前述した特許文献１の実施例と同様のものであって、図示するように、シリンダブロック５に形成されたシリンダ６内に、ピストン１が摺動可能に配設されており、このピストン１に、アッパリンク１１の一端がピストンピン２を介して揺動可能に連結されている。このアッパリンク１１の他端は、第１連結ピン１２を介してロアリンク１３の一端部に回転可能に連結されている。このロアリンク１３は、その中央部においてクランクシャフト３のクランクピン４に揺動可能に取り付けられている。なお、ピストン１は、その上方に画成される燃焼室から燃焼圧力を受ける。また、クランクシャフト３は、クランク軸受ブラケット７によってシリンダブロック５に回転可能に支持されている。 This is the same as the embodiment of Patent Document 1 described above, and as shown in the drawing, a piston 1 is slidably disposed in a cylinder 6 formed in a cylinder block 5. 1, one end of the upper link 11 is connected through a piston pin 2 so as to be swingable. The other end of the upper link 11 is rotatably connected to one end portion of the lower link 13 via a first connecting pin 12. The lower link 13 is swingably attached to the crankpin 4 of the crankshaft 3 at the center thereof. The piston 1 receives combustion pressure from a combustion chamber defined above. The crankshaft 3 is rotatably supported on the cylinder block 5 by a crank bearing bracket 7.

上記ロアリンク１３の他端部には、コントロールリンク１５の一端が第２連結ピン１４を介して回転可能に連結されている。このコントロールリンク１５の他端は、内燃機関本体の一部に揺動可能に支持されており、かつ、圧縮比の変更のために、その揺動支点１６が、支持位置可変手段により内燃機関本体に対して変位可能となっている。具体的には、支持位置可変手段として、クランクシャフト３と平行に延びた制御軸１８と、この制御軸１８に偏心して設けられた円形の偏心カム１９と、を有しており、この偏心カム１９の外周面に上記コントロールリンク１５の他端が回転可能に嵌合している。上記制御軸１８は、上記のクランク軸受ブラケット７と制御軸受ブラケット８との間に回転可能に支持されている。 One end of a control link 15 is rotatably connected to the other end of the lower link 13 via a second connecting pin 14. The other end of the control link 15 is supported by a part of the internal combustion engine body so as to be swingable. In order to change the compression ratio, the swing support point 16 is supported by the support position variable means. Is displaceable. Specifically, as the support position varying means, a control shaft 18 extending in parallel with the crankshaft 3 and a circular eccentric cam 19 provided eccentrically to the control shaft 18 are provided. The other end of the control link 15 is rotatably fitted to the outer peripheral surface 19. The control shaft 18 is rotatably supported between the crank bearing bracket 7 and the control bearing bracket 8.

従って、圧縮比の変更のために、図外のアクチュエータにより制御軸１８を回転駆動すると、コントロールリンク１５の揺動支点１６となる偏心カム１９の中心位置が機関本体に対して移動する。これにより、コントロールリンク１５によるロアリンク１３の運動拘束条件が変化して、クランク角に対するピストン１の行程位置が変化し、ひいては機関圧縮比が変更されることになる。 Therefore, when the control shaft 18 is rotationally driven by an actuator (not shown) to change the compression ratio, the center position of the eccentric cam 19 serving as the swing fulcrum 16 of the control link 15 moves relative to the engine body. As a result, the motion restraint condition of the lower link 13 by the control link 15 changes, the stroke position of the piston 1 with respect to the crank angle changes, and consequently the engine compression ratio changes.

図２は、上記の第１連結ピン１２によるロアリンク１３とアッパリンク１１とのピン連結構造を示している。ロアリンク１３は、クランクシャフト３のカウンタウエイト１７等との干渉を避けるために、そのクランクシャフト３軸方向の寸法が比較的小さく制限されている。 FIG. 2 shows a pin connection structure between the lower link 13 and the upper link 11 by the first connection pin 12. In order to avoid interference with the counterweight 17 of the crankshaft 3 or the like, the lower link 13 is limited to a relatively small dimension in the axial direction of the crankshaft 3.

ロアリンク１３の一端部には、中央部にアッパリンク嵌合溝２１が生じるように、一対のピンボス部２２が二股状に対向して形成されており、これらのピンボス部２２には、円筒面をなすピン軸受孔２４がそれぞれ貫通形成されている。この２つのピン軸受孔２４は、同軸上に位置し、かつ、互いに同じ径に形成されている。 A pair of pin bosses 22 are formed on one end of the lower link 13 so as to face each other in a bifurcated manner so that an upper link fitting groove 21 is formed at the center. Each of the pin bearing holes 24 is formed through. The two pin bearing holes 24 are located on the same axis and have the same diameter.

一方、アッパリンク１１の端部は、上記アッパリンク嵌合溝２１内にごく僅かな隙間をもって嵌合可能な軸方向寸法を有するピンボス部２６として構成されており、このピンボス部２６に、円筒面をなすピン軸受孔２７が貫通形成されている。このピン軸受孔２７の径は、ロアリンク１３側のピン軸受孔２４の径と等しい。 On the other hand, the end portion of the upper link 11 is configured as a pin boss portion 26 having an axial dimension that can be fitted in the upper link fitting groove 21 with a very small gap. The pin boss portion 26 has a cylindrical surface. A pin bearing hole 27 is formed so as to penetrate therethrough. The diameter of the pin bearing hole 27 is equal to the diameter of the pin bearing hole 24 on the lower link 13 side.

上記ロアリンク１３と上記アッパリンク１１とを連結する第１連結ピン１２は、外周面が単純な円筒面をなす円柱状をなし、かつその両端部に、それぞれ軸方向に沿った偏心穴２８が形成されている。この第１連結ピン１２の径は、ピン軸受孔２４，２７の径に実質的に等しく、第１連結ピン１２は、これらのピン軸受孔２４，２７に対し回転可能に嵌合する。つまり、双方の部材に対し回転自在なフルフロート形式となっている。これらの軸受面は、適宜な潤滑油供給方式によって潤滑されている。なお、第１連結ピン１２の軸方向の移動は、図示せぬスナップリング等によって拘束される。 The first connecting pin 12 that connects the lower link 13 and the upper link 11 has a cylindrical shape whose outer peripheral surface forms a simple cylindrical surface, and eccentric holes 28 along the axial direction are provided at both ends thereof. Is formed. The diameter of the first connecting pin 12 is substantially equal to the diameter of the pin bearing holes 24 and 27, and the first connecting pin 12 is rotatably fitted to the pin bearing holes 24 and 27. That is, the full float type is rotatable with respect to both members. These bearing surfaces are lubricated by an appropriate lubricating oil supply system. The movement of the first connecting pin 12 in the axial direction is restricted by a snap ring (not shown).

図３は、上記第１連結ピン１２の端部付近での断面図であり、図示するように、上記偏心穴２８は断面真円形をなし、第１連結ピン１２の断面において偏心した位置に形成されている。従って、この第１連結ピン１２の重心Ｇは、該連結ピン１２の中心Ｏから偏心穴２８と反対側に偏心している。また、この偏心穴２８は、図２に示したように、連結ピン１２の全長を貫通しておらず、アッパリンク１１を支持する中央部を中実状態に残すようにして、長手方向の両端部にのみ設けられている。 FIG. 3 is a cross-sectional view of the first connecting pin 12 in the vicinity of the end thereof. As shown in the drawing, the eccentric hole 28 has a true circular cross section and is formed at an eccentric position in the cross section of the first connecting pin 12. Has been. Therefore, the center of gravity G of the first connecting pin 12 is eccentric from the center O of the connecting pin 12 to the side opposite to the eccentric hole 28. Further, as shown in FIG. 2, the eccentric hole 28 does not penetrate the entire length of the connecting pin 12 and leaves the center portion supporting the upper link 11 in a solid state, so that both ends in the longitudinal direction are It is provided only in the department.

上記のような複リンク式ピストン−クランク機構においては、図４に示すように、クランクピン４の回転に伴ってロアリンク１３は上下に揺動するので、第１連結ピン１２は、符号３０で示すような楕円形に近い形状の２次元的な移動軌跡に沿って空間内を運動する。従って、重心Ｇが偏心した位置にある第１連結ピン１２は、その重心Ｇを通る方向に慣性力Ｆが発生する結果、移動軌跡３０上の移動に伴って第１連結ピン１２を自転させようとする回転モーメントＭが発生する。例えば、図４の（ａ）のような姿勢に第１連結ピン１２があったとすると、慣性力Ｆによって反時計回り方向の回転モーメントＭが発生し、図（ｂ）に示す姿勢になろうとする。重心Ｇの位置が中心から離れているほど回転モーメントＭは大きくなり、第１連結ピン１２の自転速度が、移動軌跡３０に沿った第１連結ピン１２の公転速度に近づく。 In the multi-link piston-crank mechanism as described above, the lower link 13 swings up and down as the crank pin 4 rotates as shown in FIG. It moves in the space along a two-dimensional movement locus having a shape close to an ellipse as shown. Therefore, the first connecting pin 12 at the position where the center of gravity G is eccentric will cause the first connecting pin 12 to rotate as the inertial force F is generated in the direction passing through the center of gravity G, as a result of movement on the movement locus 30. Rotational moment M is generated. For example, if the first connecting pin 12 is in the posture as shown in FIG. 4A, the inertial force F generates a rotational moment M in the counterclockwise direction, and the posture shown in FIG. . As the position of the center of gravity G is farther from the center, the rotational moment M increases, and the rotation speed of the first connection pin 12 approaches the revolution speed of the first connection pin 12 along the movement locus 30.

これにより、第１連結ピン１２とピン軸受孔２４，２７との間の摺動速度が高くなり、くさび効果による油膜が発生しやすくなる。この油膜の確実な形成により金属接触が抑制され、過度の摩耗や焼き付きが防止される。従って、第１連結ピン１２や軸受孔２４，２７の軸方向寸法の短縮ひいてはロアリンク１３の小型化が可能となる。 Thereby, the sliding speed between the 1st connection pin 12 and the pin bearing holes 24 and 27 becomes high, and it becomes easy to generate | occur | produce the oil film by a wedge effect. The reliable formation of the oil film suppresses metal contact and prevents excessive wear and seizure. Therefore, the axial dimension of the first connecting pin 12 and the bearing holes 24 and 27 can be shortened, and the lower link 13 can be downsized.

また、上記連結ピン１２にアッパリンク１１から燃焼圧による最大荷重Ｌが作用するときに、回転モーメントＭによって、第１連結ピン１２は図５に示すような姿勢となる。このとき、図６に示すように、第１連結ピン１２が撓み変形し、符号Ａで示す中央部の下側部分（アッパリンク１１からの荷重作用方向と反対側の部分）が大きな引張応力を受ける。従って、仮に、この中央部を偏心穴２８が貫通していると、外周面との間の薄肉部分に大きな引張応力が作用することになり、好ましくない。本実施例では、図２に示したように、大きな引張応力を受ける長手方向の中央部が中実状であるので、引張応力に確実に抗することができる。また、この中実となった中央部は両端部に比較して質量が大きくなり、ここに作用する上方への慣性力Ｆは両端部に作用する慣性力Ｆよりも相対的に大きくなるので、図６に示す撓み変形が緩和される、という作用も得られる。 Further, when the maximum load L due to the combustion pressure is applied from the upper link 11 to the connecting pin 12, the first connecting pin 12 assumes a posture as shown in FIG. At this time, as shown in FIG. 6, the first connecting pin 12 is bent and deformed, and the lower portion of the central portion indicated by the symbol A (the portion on the side opposite to the load acting direction from the upper link 11) exerts a large tensile stress. receive. Therefore, if the eccentric hole 28 passes through this central portion, a large tensile stress acts on the thin portion between the outer peripheral surface and this is not preferable. In the present embodiment, as shown in FIG. 2, the central portion in the longitudinal direction that receives a large tensile stress is solid, so that the tensile stress can be reliably resisted. Also, the solid central portion has a larger mass than both ends, and the upward inertial force F acting here is relatively greater than the inertial force F acting on both ends. The effect | action that the bending deformation shown in FIG. 6 is relieved is also acquired.

上記偏心穴２８としては、図７に示すように、短軸を偏心方向に一致させた楕円形状の穴としてもよい。このような楕円形状とすることで、外周面との間の肉厚の薄い部分が、真円形の穴の場合よりも広範囲に生じる。例えばロアリンク１３側の二股状のピンボス部２２は、図２に示すような荷重を受けたときに傾くように変形するが、このような軸受孔２４，２７の傾き・変形に対し、第１連結ピン１２の肉厚の薄い部分は容易に追従・変形し、軸受孔２４，２７のエッジが局所的に金属接触することを抑制する。これにより、耐久性が向上する。また、楕円形状とすることで、重心Ｇがより大きく偏心する利点もある。 As the eccentric hole 28, as shown in FIG. 7, an elliptical hole whose short axis is aligned with the eccentric direction may be used. By adopting such an elliptical shape, a thin portion between the outer peripheral surface is generated in a wider range than in the case of a perfect circular hole. For example, the bifurcated pin boss portion 22 on the side of the lower link 13 is deformed so as to be inclined when a load as shown in FIG. 2 is applied. The thin portion of the connecting pin 12 easily follows and deforms to suppress local contact of the edges of the bearing holes 24 and 27 with the metal. Thereby, durability improves. In addition, the elliptical shape has an advantage that the center of gravity G is more eccentric.

なお、ロアリンク１３においては、上記の軸受孔２４のエッジへの過大な入力によって、これに隣接するクランクピン４の軸受孔が変形する、という問題があるが、本発明によれば、第１連結ピン１２からの入力がなだらかなものとなるので、このクランクピン軸受孔の変形が抑制される。 In the lower link 13, there is a problem that the bearing hole of the crank pin 4 adjacent to the edge of the bearing hole 24 is deformed due to excessive input to the edge of the bearing hole 24. Since the input from the connecting pin 12 becomes gentle, deformation of the crank pin bearing hole is suppressed.

図８は、第１連結ピン１２の異なる実施例を示す。この実施例では、上記の実施例とは逆に、アッパリンク１１側が二股状のピンボス部２６を有し、ロアリンク１３側の単一のピンボス部２２がその間に挟み込まれている。このような構成では、アッパリンク１１側から燃焼圧による最大荷重Ｌが作用したときに、引張応力は、重心Ｇ寄りつまり偏心穴２８と反対側の部分（図の上側の部分）に作用するので、偏心穴２８を第１連結ピン１２の全長に亘って貫通形成してある。 FIG. 8 shows a different embodiment of the first connecting pin 12. In this embodiment, contrary to the above embodiment, the upper link 11 side has a bifurcated pin boss portion 26, and a single pin boss portion 22 on the lower link 13 side is sandwiched therebetween. In such a configuration, when the maximum load L due to the combustion pressure is applied from the upper link 11 side, the tensile stress acts on the portion near the center of gravity G, that is, on the side opposite to the eccentric hole 28 (the upper portion in the figure). The eccentric hole 28 is formed through the entire length of the first connecting pin 12.

上記の各実施例における偏心穴２８に、第１連結ピン１２自体の材質よりも軽量な材質からなる棒状の部材を密に圧入し、第１連結ピン１２の剛性を高めるようにしてもよい。図９の実施例は、偏心穴２８に嵌合する棒状部３１ａとフランジ部３１ｂとが一体となった抜け止め部材３１を軽量な材質から構成し、上記棒状部３１ａを偏心穴２８に圧入して固定したものである。なお図（ａ）は、偏心穴２８が貫通していない例、図（ｂ）は、偏心穴２８が貫通している場合の例を示す。上記フランジ部３１ｂは、第１連結ピン１２の軸方向の移動を規制し、軸受孔２４，２７からの脱落を阻止する。ここで、上記抜け止め部材３１として、その重心が第１連結ピン１２の中心から偏心した構成としてもよく、これにより例えば、第１連結ピン１２と組み合わせた状態での重心Ｇの位置をより大きく偏心させることが可能である。また上記のような軽量な部材を圧入することで第１連結ピン１２自体の剛性が向上するので、その薄肉化が可能となり、重量分布の設定が容易となる。 A rod-shaped member made of a material that is lighter than the material of the first connecting pin 12 itself may be press-fitted into the eccentric hole 28 in each of the above embodiments so as to increase the rigidity of the first connecting pin 12. In the embodiment of FIG. 9, the retaining member 31 in which the rod-like portion 31 a and the flange portion 31 b that fit into the eccentric hole 28 are made of a lightweight material, and the rod-like portion 31 a is press-fitted into the eccentric hole 28. It is fixed. In addition, the figure (a) shows the example in which the eccentric hole 28 has not penetrated, and the figure (b) shows the example in the case where the eccentric hole 28 has penetrated. The flange portion 31b restricts the movement of the first connecting pin 12 in the axial direction and prevents the first connecting pin 12 from dropping out of the bearing holes 24 and 27. Here, the retaining member 31 may have a structure in which the center of gravity is decentered from the center of the first connecting pin 12, and for example, the position of the center of gravity G in a state where it is combined with the first connecting pin 12 is increased. It is possible to make it eccentric. Moreover, since the rigidity of the first connecting pin 12 itself is improved by press-fitting such a lightweight member, it is possible to reduce the thickness of the first connecting pin 12 and to easily set the weight distribution.

また、図１０は、第１連結ピン１２の両端に装着される抜け止め用のＣ字形クリップ４１の重心位置を偏心させたものであって、特に、この実施例では、合口４２を構成する一対のつまみ部４３を部分的に大きくし、部分的に重くしている。これにより、第１連結ピン１２に取り付けた状態において、全体の重心Ｇが偏心する。なお、上述した偏心穴２８を備えた第１連結ピン１２と組み合わせることもでき、あるいは、それ自体は重心が偏心していない第１連結ピン１２と組み合わせることもできる。また、この構成では、一対のつまみ部４３に半径方向外側へ慣性力Ｆが作用するので、Ｃ字形クリップ４１を締め付ける方向となり、第１連結ピン１２と一体に回転しやすくなる。なお、つまみ孔４４の位置が第１連結ピン１２の外周面から離れるため、脱着作業の作業性が向上する。 FIG. 10 shows the center of gravity of the retaining C-shaped clip 41 attached to both ends of the first connecting pin 12 in an eccentric manner. In particular, in this embodiment, a pair constituting the joint 42 is shown. The knob portion 43 is partially enlarged and partially heavy. Thereby, in the state attached to the 1st connection pin 12, the whole gravity center G decenters. In addition, it can also combine with the 1st connection pin 12 provided with the eccentric hole 28 mentioned above, or can also combine with the 1st connection pin 12 which itself is not eccentric. Further, in this configuration, the inertia force F acts on the pair of knob portions 43 outward in the radial direction, so that the C-shaped clip 41 is tightened, and the first connecting pin 12 is easily rotated. In addition, since the position of the knob hole 44 is separated from the outer peripheral surface of the first connecting pin 12, the workability of the detachment work is improved.

図１１の実施例は、合口４２と反対側（１８０°離れた側）の部分４５を局部的に大きくしたものである。この場合は、形状に自由度があるため、重心位置を大きく偏心させることが可能である。また、大きく張り出した部分４５をつまみながら脱着作業をできるので、その作業性が向上する。 In the embodiment of FIG. 11, the portion 45 on the side opposite to the abutment 42 (the side separated by 180 °) is locally enlarged. In this case, since the shape has a degree of freedom, the position of the center of gravity can be greatly decentered. Moreover, since the detachment work can be performed while pinching the projecting portion 45, the workability is improved.

この発明に係る連結ピンが用いられた複リンク式ピストン−クランク機構の全体構成を示す内燃機関要部の断面図。Sectional drawing of the principal part of an internal combustion engine which shows the whole structure of the multilink type piston-crank mechanism in which the connection pin which concerns on this invention was used. 軸受孔および第１連結ピンの断面図。Sectional drawing of a bearing hole and a 1st connection pin. 第１連結ピンの横断面図。The cross-sectional view of a 1st connection pin. 運動中の第１連結ピンの姿勢を示す説明図。Explanatory drawing which shows the attitude | position of the 1st connecting pin in motion. 燃焼圧による最大荷重を受けるときの第１連結ピンの姿勢を示す説明図。Explanatory drawing which shows the attitude | position of the 1st connecting pin when receiving the maximum load by combustion pressure. 最大荷重時の第１連結ピンの変形状態を示す説明図。Explanatory drawing which shows the deformation | transformation state of the 1st connecting pin at the time of the maximum load. 偏心穴を楕円形状とした実施例を示す断面図。Sectional drawing which shows the Example which made the eccentric hole elliptical shape. 偏心穴が貫通した第１連結ピンの異なる実施例を示す断面図。Sectional drawing which shows the Example from which the 1st connection pin which the eccentric hole penetrated differs. 軽量な抜け止め部材を偏心穴に圧入した実施例を示す説明図。Explanatory drawing which shows the Example which press-fitted the lightweight retaining member to the eccentric hole. Ｃ字形クリップの重心を偏心させた実施例を示す平面図。The top view which shows the Example which decentered the gravity center of a C-shaped clip. Ｃ字形クリップの異なる実施例を示す平面図。The top view which shows the Example from which a C-shaped clip differs.

Explanation of symbols

１１…アッパリンク
１２…第１連結ピン
１３…ロアリンク
２２…ピンボス部
２４…ピン軸受孔
２６…ピンボス部
２７…ピン軸受孔
２８…偏心穴
４１…Ｃ字形クリップ
DESCRIPTION OF SYMBOLS 11 ... Upper link 12 ... 1st connection pin 13 ... Lower link 22 ... Pin boss part 24 ... Pin bearing hole 26 ... Pin boss part 27 ... Pin bearing hole 28 ... Eccentric hole 41 ... C-shaped clip

Claims

In a connecting pin that is supported in a full float form on a bearing of two members and connects both members so as to be able to swing with each other, and the position of the bearing itself moves two-dimensionally, the center of gravity of the connecting pin is the connecting pin A connecting pin characterized by being in an eccentric position from the center.

The connecting pin according to claim 1, wherein at least one hole is formed along the axial direction so that the center of gravity is eccentric.

The connecting pin according to claim 2, wherein the hole having a perfectly circular cross section is provided at a position eccentric from the center of the connecting pin.

The connecting pin according to claim 2, wherein the hole having an elliptical cross section is provided at a position eccentric from the center of the connecting pin.

The bearing of one member is fitted in the center part of the connecting pin, and the other member is provided with a pair of bifurcated bearings so as to support both ends of the connecting pin. The direction of the maximum load acting on the part is configured to be substantially opposite to the direction of the inertial force acting on the connection pin by the movement, and the hole is solid at the center of the connection pin. The connecting pin according to claim 2, wherein the connecting pin is formed only at both ends.

The bearing of one member is fitted in the center part of the connecting pin, and the other member is provided with a pair of bifurcated bearings so as to support both ends of the connecting pin. The direction of the maximum load acting on the part is configured to be substantially the same as the direction of the inertial force acting on the connecting pin by the motion, and the hole is formed through the entire length of the connecting pin. The connecting pin according to claim 2, wherein the connecting pin is provided.

A retaining member for retaining the connecting pin from the bearing is fitted in the hole, and the retaining member is formed of a material that is lighter than the material of the connecting pin itself. The connecting pin according to any one of claims 2 to 6.

The connecting pin according to claim 7, wherein the retaining member has a center of gravity at a position away from the center of the connecting pin in a state of being attached to the connecting pin.

3. A C-shaped clip for retaining the end of the connecting pin is attached, and the C-shaped clip has a large joint portion locally formed so that the center of gravity is decentered. The connecting pin as described.

A C-shaped clip for retaining is attached to the end of the connecting pin, and this C-shaped clip is characterized in that a portion on the side opposite to the joint is locally large so that the center of gravity is eccentric. The connecting pin according to claim 2.

An upper link having one end coupled to the piston via a piston pin, and a lower link coupled to the other end of the upper link via a first coupling pin and rotatably attached to the crank pin of the crankshaft; A multi-link type piston for an internal combustion engine, having one end connected to the lower link via a second connection pin and a control link supported at the other end so as to be swingable with respect to the main body of the internal combustion engine. In the crank mechanism,
The connection pin according to claim 1, wherein the connection pin is used as the first connection pin or the second connection pin.

The connection pin according to claim 11, wherein the connection pin is used as the first connection pin.