JP2020148190A - Swing arm support structure of internal combustion engine and internal combustion engine - Google Patents

Swing arm support structure of internal combustion engine and internal combustion engine Download PDF

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JP2020148190A
JP2020148190A JP2019049065A JP2019049065A JP2020148190A JP 2020148190 A JP2020148190 A JP 2020148190A JP 2019049065 A JP2019049065 A JP 2019049065A JP 2019049065 A JP2019049065 A JP 2019049065A JP 2020148190 A JP2020148190 A JP 2020148190A
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swing arm
side swing
shaft
intake
exhaust
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JP7304176B2 (en
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宏昌 田中
Hiromasa Tanaka
宏昌 田中
達也 北嶋
Tatsuya Kitajima
達也 北嶋
忠 山▲崎▼
Tadashi Yamazaki
忠 山▲崎▼
石井　基紀
Motoki Ishii
基紀 石井
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IHI Power Systems Co Ltd
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IHI Power Systems Co Ltd
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Abstract

To prevent partial wear of an intake side swing arm and an exhaust side swing arm, and make the swing arms compact.SOLUTION: A swing arm support structure provided in a swing arm support part 1 of an internal combustion engine comprises an intake side swing arm 3 that reciprocates an intake valve, and an exhaust side swing arm 4 that reciprocates an exhaust valve. An intake side swing arm shaft 6 that swingably supports the intake side swing arm 3 is arranged perpendicularly to the swing surface of the intake side swing arm 3. An exhaust side swing arm shaft 7 that swingably supports the exhaust side swing arm 4 is arranged perpendicularly to the swing surface of the intake side swing arm 3. The intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 are respectively supported by inside shaft supports 16, 17 and outside shaft supports 20, 21 at both ends in a longitudinal direction. The outside shaft supports 20, 21 are formed as through holes in a lateral side case 2, and the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 can be removed/inserted from the outside of the outside shaft supports 20, 21.SELECTED DRAWING: Figure 2

Description

本発明は、内燃機関の動弁装置に関するものであって吸気バルブ及び排気バルブを開閉弁作動する内燃機関の揺腕支持構造及び揺腕支持構造を備えた内燃機関に関する。 The present invention relates to a valve gear of an internal combustion engine, and relates to an internal combustion engine having a swing arm support structure and a swing arm support structure for operating an intake valve and an exhaust valve.

従来の内燃機関における代表的な２弁式機関のロッカーアーム周辺部品の構成として例えば図６及び図７に示すものが提案されている。従来の内燃機関では、シリンダヘッド１００に取り付けたフルクラムスタッド１０１、１０１に吸気側揺腕１０２と排気側揺腕１０３を揺動可能に備えた揺腕軸１０４が組み付けられている。内燃機関のクランク軸より伝達された回転運動は図示しない吸排気カム及びローラガイドによってプッシュロッドの上下動に変換される。プッシュロッドの上下動を吸気側揺腕１０２及び排気側揺腕１０３の揺動に変換して吸気バルブ１０５及び排気バルブ１０６に伝達し、吸気バルブ１０５及び排気バルブ１０６を動作させて燃焼室を開閉弁させている。 As configurations of rocker arm peripheral parts of a typical two-valve engine in a conventional internal combustion engine, for example, those shown in FIGS. 6 and 7 have been proposed. In a conventional internal combustion engine, a swaying arm shaft 104 having an intake side swaying arm 102 and an exhaust side swaying arm 103 so as to be swingable is assembled to the fulcrum studs 101 and 101 attached to the cylinder head 100. The rotational movement transmitted from the crankshaft of the internal combustion engine is converted into vertical movement of the push rod by an intake / exhaust cam and a roller guide (not shown). The vertical movement of the push rod is converted into the swing of the intake side swing arm 102 and the exhaust side swing arm 103 and transmitted to the intake valve 105 and the exhaust valve 106, and the intake valve 105 and the exhaust valve 106 are operated to open and close the combustion chamber. I'm letting you speak.

２弁式機関では、機関性能を向上させるため吸気バルブ１０５及び排気バルブ１０６の弁径を大径として燃焼室への流路面積を大きく取っている。吸気バルブ１０５及び排気バルブ１０６の弁径を大径にする場合、図８に示す様に吸気バルブ１０５及び排気バルブ１０６間距離が広くなるため吸気側揺腕１０２及び排気側揺腕１０３を「ハ」の字形状に配設する。すると、吸気側揺腕１０２及び排気側揺腕１０３の動作面が揺腕軸１０４の軸芯に直交しない。
この場合、揺腕軸１０４の軸芯方向とその軸直角方向に分解してモーメントを考えると、吸気側揺腕１０２と排気側揺腕１０３を軸直角まわりに回転させるモーメントが働くため、揺腕軸１０４の両端における吸気側揺腕１０２及び排気側揺腕１０３の内側に設けた揺腕ブッシュ１０４ａ、１０４ｂの偏摩耗を招くおそれがある。 In the two-valve engine, in order to improve the engine performance, the valve diameters of the intake valve 105 and the exhaust valve 106 are set to be large, and the flow path area to the combustion chamber is large. When the valve diameters of the intake valve 105 and the exhaust valve 106 are increased, as shown in FIG. 8, the distance between the intake valve 105 and the exhaust valve 106 becomes wide, so that the intake side swing arm 102 and the exhaust side swing arm 103 are set to "c". It is arranged in the shape of "". Then, the operating surfaces of the intake side swing arm 102 and the exhaust side swing arm 103 are not orthogonal to the axis of the swing arm shaft 104.
In this case, when the moment is considered by disassembling the swing arm shaft 104 in the axial center direction and the direction perpendicular to the axis, the moment for rotating the intake side swing arm 102 and the exhaust side swing arm 103 around the axis perpendicular direction acts, so that the swing arm Uneven wear of the swing arm bushes 104a and 104b provided inside the intake side swing arm 102 and the exhaust side swing arm 103 at both ends of the shaft 104 may occur.

ところで、揺腕ブッシュ１０４ａ、１０４ｂの偏摩耗を回避する方法の一つとして、吸気側揺腕１０２と排気側揺腕１０３の力点側をシリンダ中心から外側に移動させることが考えられる。しかしながら、このような構成を採用すると揺腕支持構造が大型化するため、プッシュロッドや吸気側揺腕１０２及び排気側揺腕１０３廻りを覆うカバーを取り付けることが困難になる。 By the way, as one of the methods for avoiding uneven wear of the swing arm bushes 104a and 104b, it is conceivable to move the force point side of the intake side swing arm 102 and the exhaust side swing arm 103 from the center of the cylinder to the outside. However, if such a configuration is adopted, the swing arm support structure becomes large, and it becomes difficult to attach a cover that covers the push rod, the intake side swing arm 102, and the exhaust side swing arm 103.

この場合、揺腕ブッシュ１０４ａ、１０４ｂへの注油は潤滑油の飛散防止の観点から、強制注油方式ではなく間欠的に注油穴へ滴下する間欠注油方式を採用することになる。しかしながら、間欠注油では油圧が立たないため油膜形成が難しく、揺腕ブッシュ１０４ａ、１０４ｂは厳しい環境下で使用される。一方、揺腕ブッシュ１０４ａ、１０４ｂに強制注油を行うには、潤滑油が飛散しないようにプッシュロッドや吸気側揺腕１０２及び排気側揺腕１０３廻りの部品を覆うカバーを取り付ける必要がある。
しかし、上述した理由により、カバーの取り付け構成と揺腕ブッシュ１０４ａ、１０４ｂの偏摩耗を抑制する構成とは両立し得ないため、トレードオフの関係にある。 In this case, the lubrication to the swing arm bushes 104a and 104b adopts an intermittent lubrication method in which the lubricating oil is intermittently dropped into the lubrication hole instead of the forced lubrication method from the viewpoint of preventing the lubricating oil from scattering. However, in intermittent lubrication, it is difficult to form an oil film because the hydraulic pressure does not rise, and the swing arm bushes 104a and 104b are used in a harsh environment. On the other hand, in order to forcibly lubricate the swing arm bushes 104a and 104b, it is necessary to attach a cover that covers the push rod and the parts around the intake side swing arm 102 and the exhaust side swing arm 103 so that the lubricating oil does not scatter.
However, for the reasons described above, the cover mounting configuration and the configuration for suppressing uneven wear of the swing arm bushes 104a and 104b are incompatible with each other, and thus there is a trade-off relationship.

また、例えば特許文献１，２に記載されたものでは、ハの字に配置した吸気側揺腕及び排気側揺腕を支持する揺腕軸を二分割して吸気側揺腕と排気側揺腕にそれぞれ直交するようにハの字に配設する内燃機関が提案されている。
しかしながら、これらの構造は半球型やペントルーフ型燃焼室を有する比較的小型のガソリンエンジン向けであり、燃料の供給は吸気ポートから行われるが，ディーゼルエンジンでは燃料を直接燃焼室に噴射する為の燃料噴射弁及びこれに燃料を供給する為の燃料噴射ポンプを配設する必要があり、設計的な制約を受ける。これに加え、過給機により高圧過給を行うエンジンにおいては排気弁開弁時の筒内ガス残圧が自然吸気エンジンに比べて高く、排気弁開弁時に揺腕構造体に加わる荷重も増加することから、より高い強度が必要となる。その為，この構成においても内燃機関の揺腕支持構造が大型化し、カバーの取り付けが困難になる。 Further, for example, in those described in Patent Documents 1 and 2, the intake side swing arm and the exhaust side swing arm are divided into two parts to support the intake side swing arm and the exhaust side swing arm arranged in a C shape. An internal combustion engine that is arranged in a V shape so as to be orthogonal to each other has been proposed.
However, these structures are for relatively small gasoline engines with hemispherical or pentroof combustion chambers, and fuel is supplied from the intake port, whereas diesel engines use fuel to inject fuel directly into the combustion chamber. It is necessary to dispose an injection valve and a fuel injection pump for supplying fuel to the injection valve, which is subject to design restrictions. In addition to this, in an engine that performs high-pressure supercharging with a turbocharger, the residual gas pressure in the cylinder when the exhaust valve is opened is higher than that of a naturally aspirated engine, and the load applied to the swing arm structure when the exhaust valve is opened also increases. Therefore, higher strength is required. Therefore, even in this configuration, the swing arm support structure of the internal combustion engine becomes large, and it becomes difficult to attach the cover.

特許第２８４８５４８号公報Japanese Patent No. 2848548 特許第３８３５８９３号公報Japanese Patent No. 3835893

本発明は、上述した課題に鑑みてなされたものであり、高圧過給を行うエンジンにおける大きな荷重に対応し、吸気側揺腕及び排気側揺腕の偏摩耗を防ぐと共に揺腕支持構造をコンパクトにすることができる内燃機関の揺腕支持構造及び内燃機関を提供することを目的とする。 The present invention has been made in view of the above-mentioned problems, and corresponds to a large load in an engine performing high-pressure supercharging, prevents uneven wear of the intake side swing arm and the exhaust side swing arm, and makes the swing arm support structure compact. It is an object of the present invention to provide a swing arm support structure for an internal combustion engine and an internal combustion engine.

本発明による内燃機関の揺腕支持構造は、吸気バルブを往復作動させる吸気側揺腕と、排気バルブを往復作動させる排気側揺腕と、吸気側揺腕を揺動可能に支持していてその揺動面に垂直に配置された吸気側揺腕軸と、排気側揺腕を揺動可能に支持していてその揺動面に垂直に配置された排気側揺腕軸と、吸気側揺腕軸及び排気側揺腕軸をそれぞれ長手方向両端で支持する内側軸支え及び外側軸支えと、を備え、吸気側揺腕軸及び排気側揺腕軸はそれぞれ外側軸支えを通して外側から挿脱可能とされていることを特徴とする。
本発明によれば、吸気側揺腕及び排気側揺腕の揺動面を吸気側揺腕軸及び排気側揺腕軸に対して垂直に配置したため、揺動時の偏摩耗の発生を防止できる。しかも、吸気側揺腕軸及び排気側揺腕軸の長手方向両端を内側軸支え及び外側軸支えで支持したため、揺腕軸のたわみを抑えて支持でき、大型の内燃機関に適した耐久性を発揮できる。更に、吸気側揺腕軸及び排気側揺腕軸はそれぞれ外側軸支えを通して外側から挿脱可能としたため限られた狭いスペースで挿脱可能であり、コンパクト化できる。 The swing arm support structure of the internal combustion engine according to the present invention supports the intake side swing arm that reciprocates the intake valve, the exhaust side swing arm that reciprocates the exhaust valve, and the intake side swing arm so as to be swingable. The intake side swing arm shaft arranged perpendicular to the swing surface, the exhaust side swing arm shaft that supports the exhaust side swing arm in a swingable manner and is arranged perpendicular to the swing surface, and the intake side swing arm. It is equipped with an inner shaft support and an outer shaft support that support the shaft and the exhaust side swing arm shaft at both ends in the longitudinal direction, respectively, and the intake side swing arm shaft and the exhaust side swing arm shaft can be inserted and removed from the outside through the outer shaft support, respectively. It is characterized by being done.
According to the present invention, since the swing surfaces of the intake side swing arm and the exhaust side swing arm are arranged perpendicular to the intake side swing arm shaft and the exhaust side swing arm shaft, it is possible to prevent the occurrence of uneven wear during swing. .. Moreover, since both ends of the intake side swing arm shaft and the exhaust side swing arm shaft in the longitudinal direction are supported by the inner shaft support and the outer shaft support, it is possible to suppress the deflection of the swing arm shaft and support it, providing durability suitable for a large internal combustion engine. Can be demonstrated. Further, since the intake side swing arm shaft and the exhaust side swing arm shaft can be inserted and removed from the outside through the outer shaft support, they can be inserted and removed in a limited narrow space and can be made compact.

また、吸気側揺腕及び排気側揺腕は、それぞれその一端がプッシュロッドにより駆動され他端が前記吸気バルブまたは前記排気バルブを開閉弁作動させ、プッシュロッド側の端部の間隔よりも吸気バルブ及び排気バルブ側の端部の間隔の方が広く設置されていることが好ましい。
これにより、機関性能を向上させるために吸気バルブ及び排気バルブを大型化しても互いに干渉することなく広いスペースに設置できると共に、吸気側揺腕軸及び排気側揺腕軸のプッシュロッド側端部を狭いスペースに互いに近接して配置できる。これにより吸気側揺腕及び排気側揺腕を有する揺腕支持構造を密閉する構造を実現することが容易になるため、これらの潤滑に有利である。 Further, one end of each of the intake side swing arm and the exhaust side swing arm is driven by a push rod, and the other end operates the intake valve or the exhaust valve as an on-off valve, and the intake valve is closer than the distance between the ends on the push rod side. It is preferable that the distance between the ends on the exhaust valve side is wider.
As a result, even if the intake valve and the exhaust valve are enlarged in order to improve the engine performance, they can be installed in a wide space without interfering with each other, and the push rod side ends of the intake side swing arm shaft and the exhaust side swing arm shaft can be installed. Can be placed close to each other in a small space. This facilitates the realization of a structure for sealing the swing arm support structure having the intake side swing arm and the exhaust side swing arm, which is advantageous for lubrication of these.

また、吸気側揺腕及び排気側揺腕は側部を側部ケースによって囲われており、外側軸支えは側部ケースに設けられていることが好ましい。
吸気側揺腕軸及び排気側揺腕軸を支持する外側軸支えを側部ケースに設けることで、構造をシンプルにできるとともに、側部ケースの外側から吸気側揺腕軸及び排気側揺腕軸を挿脱できるため、組み立てや保守や交換が容易になる。
また，外側軸支えと内側軸支えは前記側部ケースと一体に成形されていることが好ましい。
一体に成形することで外側軸支え及び内側軸支えへの揺腕軸の取付けが容易になると共に軸支えのシリンダヘッドへの脱着が容易となる。 Further, it is preferable that the intake side swing arm and the exhaust side swing arm are surrounded by a side case, and the outer shaft support is provided in the side case.
By providing the side case with an outer shaft support that supports the intake side swing arm shaft and the exhaust side swing arm shaft, the structure can be simplified, and the intake side swing arm shaft and the exhaust side swing arm shaft can be simplified from the outside of the side case. Can be inserted and removed, making assembly, maintenance and replacement easy.
Further, it is preferable that the outer shaft support and the inner shaft support are integrally molded with the side case.
By integrally molding, the swing arm shaft can be easily attached to the outer shaft support and the inner shaft support, and the shaft support can be easily attached to and detached from the cylinder head.

また、側部ケースは、外側軸支えが設けられた領域の幅が吸気バルブ及び排気バルブが設けられた領域の幅よりも小さく形成されていてもよい。
船舶推進等に用いられる大型の内燃機関では、複数のシリンダがクランク軸方向に並んで配置されており、特に側部ケースの外側軸支えが設けられた領域の幅が狭く形成されているため、吸気側揺腕軸及び排気側揺腕軸を挿脱する場合に隣接するシリンダに対して挿脱のスペースを確保できて挿脱が容易になる。 Further, the side case may be formed so that the width of the region where the outer shaft support is provided is smaller than the width of the region where the intake valve and the exhaust valve are provided.
In a large internal combustion engine used for ship propulsion, a plurality of cylinders are arranged side by side in the crankshaft direction, and the width of the area where the outer shaft support of the side case is provided is particularly narrow. When the intake side swing arm shaft and the exhaust side swing arm shaft are inserted and removed, a space for insertion and removal can be secured for the adjacent cylinders, and the insertion and removal becomes easy.

また、側部ケースの上部には側部ケースの内部を密閉する上部カバーが取り付けられ、吸気側揺腕軸及び排気側揺腕軸またはそれぞれの外側軸支えには、側部ケースの外部に油が漏れることを防止するシール部材が取り付けられていてもよい。
側部の側部ケースと上部の上部カバーによって揺腕支持構造を外周から囲うことができ、しかも、吸気側揺腕軸及び排気側揺腕軸またはそれぞれの外側軸支えにシール部材を設けて潤滑油の漏洩を防止できる。また、揺腕支持構造を強制潤滑した場合においても側部ケースと上部カバーによって密閉できるため、潤滑油の外部への漏出を阻止できる。 In addition, an upper cover that seals the inside of the side case is attached to the upper part of the side case, and oil is applied to the outside of the side case for the intake side swing arm shaft and the exhaust side swing arm shaft or their respective outer shaft supports. A sealing member may be attached to prevent leakage.
The swing arm support structure can be surrounded from the outer circumference by the side case on the side and the upper cover on the upper part, and a seal member is provided on the intake side swing arm shaft and the exhaust side swing arm shaft or their respective outer shaft supports for lubrication. Oil leakage can be prevented. Further, even when the swing arm support structure is forcibly lubricated, it can be sealed by the side case and the upper cover, so that the lubricating oil can be prevented from leaking to the outside.

また、吸気側揺腕軸及び排気側揺腕軸はそれぞれ内側軸支えに挿入される端部に凹部を備え、内部軸支えには凹部に係合する締結部材が挿通されることが好ましい。
凹部に係合する締結部材により、吸気側揺腕軸及び排気側揺腕軸が回転することが阻止される。さらに締結部材により内部軸支えに圧縮応力を加えることで、吸気側揺腕軸及び排気側揺腕軸から働く荷重を相殺する。 Further, it is preferable that the intake side swing arm shaft and the exhaust side swing arm shaft each have a recess at the end to be inserted into the inner shaft support, and a fastening member engaged with the recess is inserted into the inner shaft support.
The fastening member that engages with the recess prevents the intake side swing arm shaft and the exhaust side swing arm shaft from rotating. Further, by applying a compressive stress to the internal shaft support by the fastening member, the load acting from the intake side swing arm shaft and the exhaust side swing arm shaft is offset.

また、本発明による内燃機関は、上述したいずれかに記載された揺腕支持構造を備えたことを特徴とする。 Further, the internal combustion engine according to the present invention is characterized by having the swing arm support structure described in any of the above.

本発明による内燃機関の揺腕支持構造及び内燃機関によれば、吸気側揺腕及び排気側揺腕をそれぞれ直交する方向に支持する吸気側揺腕軸及び排気側揺腕軸を両端の内側軸支え及び外側軸支えで堅固に支持すると共に着脱操作を容易にでき、揺腕支持構造をコンパクト化できる。 According to the swing arm support structure of the internal combustion engine and the internal combustion engine according to the present invention, the intake side swing arm shaft and the exhaust side swing arm shaft that support the intake side swing arm and the exhaust side swing arm in orthogonal directions are the inner shafts at both ends. It can be firmly supported by the support and the outer shaft support, and can be easily attached and detached, and the swing arm support structure can be made compact.

本発明の実施形態によるエンジンの揺腕支持構造の要部構成を示す斜視図である。It is a perspective view which shows the main part structure of the swing arm support structure of the engine by embodiment of this invention. 図１に示す揺腕支持構造の分解斜視図である。It is an exploded perspective view of the swing arm support structure shown in FIG. 揺腕支持構造の揺腕と揺腕軸との関係を示す要部水平断面図である。It is a horizontal sectional view of the main part which shows the relationship between the swing arm and the swing arm axis of the swing arm support structure. 図１に示す揺腕支持構造に上部カバーを被せた斜視図である。It is a perspective view which covered the upper cover with the swing arm support structure shown in FIG. 軸支えの内側軸支えにおける、吸排気側揺腕の揚程動作で引張応力が増大する部分を示す図である。It is a figure which shows the part where the tensile stress increases by the lifting operation of the intake / exhaust side swing arm in the inner shaft support of a shaft support. 従来のエンジンにおける揺腕支持構造の要部斜視図である。It is a main part perspective view of the swing arm support structure in a conventional engine. 図６において揺腕軸と吸気側揺腕及び排気側揺腕を示す分解斜視図である。FIG. 6 is an exploded perspective view showing a swing arm shaft, an intake side swing arm, and an exhaust side swing arm. 揺腕軸に対する吸気側揺腕及び排気側揺腕の配置と分力によるモーメントの関係を示す説明図である。It is explanatory drawing which shows the relationship between the arrangement of the intake side swing arm and the exhaust side swing arm with respect to a swing arm shaft, and the moment by a component force.

以下、本発明の実施形態によるエンジンの揺腕支持構造について図１乃至図５により説明する。
本実施形態によるエンジンは、船舶推進等に用いられる大型の内燃機関に適したものである。しかも、舶用内燃機関として用いる２弁式のディーゼルエンジンにおけるシリンダヘッドの上部に設置される揺腕支持部１の周辺構造に関するものである。図１及び図２に示す揺腕支持部１の周囲には側部ケース２が設けられている。シリンダヘッド５の上部には揺腕支持部１を取り付けるための取り付け部２ａが固定されている。側部ケース２の内部には吸気側揺腕３と排気側揺腕４とが平面視で略ハの字型に配設されている。
しかも、上述した従来技術では、吸気側揺腕３と排気側揺腕４の間に燃焼室に燃料を噴射するための不図示の燃料噴射ポンプを配設していたが、本実施形態では後述するように側部ケース２の幅狭側面２８の外部に設置している。 Hereinafter, the swing arm support structure of the engine according to the embodiment of the present invention will be described with reference to FIGS. 1 to 5.
The engine according to this embodiment is suitable for a large internal combustion engine used for ship propulsion or the like. Moreover, it relates to the peripheral structure of the swing arm support portion 1 installed on the upper part of the cylinder head in the two-valve type diesel engine used as a marine internal combustion engine. A side case 2 is provided around the swing arm support portion 1 shown in FIGS. 1 and 2. An attachment portion 2a for attaching the swing arm support portion 1 is fixed to the upper portion of the cylinder head 5. Inside the side case 2, the intake side swing arm 3 and the exhaust side swing arm 4 are arranged in a substantially C shape in a plan view.
Moreover, in the above-mentioned conventional technique, a fuel injection pump (not shown) for injecting fuel into the combustion chamber is arranged between the intake side swing arm 3 and the exhaust side swing arm 4, but this embodiment will be described later. It is installed outside the narrow side surface 28 of the side case 2 so as to do so.

吸気側揺腕３は吸気側揺腕軸６に回転可能に支持され、吸気側揺腕軸６を挟むその一端側には弁押し金具１０を介して燃焼室を開閉する不図示の吸気バルブが取り付けられ、他端側には不図示のプッシュロッドに連結されたアジャストボルト８が設けられている。排気側揺腕４は排気側揺腕軸７に回転可能に支持され、排気側揺腕軸７を挟むその一端側の弁押し金具１１を介して燃焼室を開閉する不図示の排気バルブが取り付けられ、他端側にはプッシュロッドに連結されたアジャストボルト９が設けられている。吸気バルブと排気バルブは吸気側揺腕３と排気側揺腕４の揺動によって往復作動して開閉弁作動する。 The intake side swing arm 3 is rotatably supported by the intake side swing arm shaft 6, and an intake valve (not shown) that opens and closes the combustion chamber via a valve push metal fitting 10 is provided on one end side of the intake side swing arm shaft 6. An adjust bolt 8 that is attached and connected to a push rod (not shown) is provided on the other end side. The exhaust side swing arm 4 is rotatably supported by the exhaust side swing arm shaft 7, and an exhaust valve (not shown) that opens and closes the combustion chamber is attached via a valve push metal fitting 11 on one end side of the exhaust side swing arm shaft 7. An adjust bolt 9 connected to the push rod is provided on the other end side. The intake valve and the exhaust valve reciprocate by swinging the intake side swing arm 3 and the exhaust side swing arm 4, and the on-off valve operates.

ここで、図３にも示すように、吸気バルブと排気バルブのバルブ外径が大きく設定されているため、吸気側揺腕３と排気側揺腕４は平面視ハの字型に配設されている。吸気側揺腕３と排気側揺腕４はプッシュロッド側のアジャストボルト８、９の間で幅が狭く設定され、吸気バルブ及び排気バルブ側で幅が広く設定されている。そのため、吸気バルブと排気バルブの径を拡大して，吸排気流路断面積を拡大することが出来ることから，吸排気効率を改善して機関性能を向上できる。
吸気側揺腕３と吸気側揺腕軸６とは略直交する方向に配設され、排気側揺腕４と排気側揺腕軸７とは略直交する方向に配設されている。吸気側揺腕軸６と排気側揺腕軸７は分割され、両者の間には軸支え部１５が設置されている。軸支え部１５は、側部ケース２と共に鋳造により一体に成形されている。軸支え部１５の両端部には吸気側揺腕軸６の内側端部を受け入れて支持する筒状の内側軸支え１６と、排気側揺腕軸７の内側端部を受け入れて支持する筒状の内側軸支え１７とがそれぞれ形成されている。 Here, as shown in FIG. 3, since the valve outer diameters of the intake valve and the exhaust valve are set large, the intake side swing arm 3 and the exhaust side swing arm 4 are arranged in a C shape in a plan view. ing. The intake side swing arm 3 and the exhaust side swing arm 4 are set to have a narrow width between the adjustment bolts 8 and 9 on the push rod side, and a wide width is set on the intake valve and the exhaust valve side. Therefore, the diameters of the intake valve and the exhaust valve can be increased to increase the cross section of the intake / exhaust flow path, so that the intake / exhaust efficiency can be improved and the engine performance can be improved.
The intake side swing arm 3 and the intake side swing arm shaft 6 are arranged in a direction substantially orthogonal to each other, and the exhaust side swing arm 4 and the exhaust side swing arm shaft 7 are arranged in a direction substantially orthogonal to each other. The intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 are divided, and a shaft support portion 15 is installed between the two. The shaft support portion 15 is integrally formed by casting together with the side case 2. At both ends of the shaft support portion 15, a tubular inner shaft support 16 that receives and supports the inner end portion of the intake side swing arm shaft 6 and a tubular shape that receives and supports the inner end portion of the exhaust side swing arm shaft 7. The inner shaft support 17 is formed.

しかも、軸支え部１５の両端に設けた内側軸支え１６、１７には、吸気側揺腕軸６及び排気側揺腕軸７の内側端部を係止させるためのボルト穴１６ａ、１７ａが形成されている。このボルト穴１６ａ、１７ａにシリンダヘッド５に取付けられたスタッドボルト１９を締結部材として挿通させ，ボルト穴１６a、１７a上部に露出したねじ部に不図示のナットを締め付けることで，軸支え部１５がシリンダヘッド５に固定される。また、吸気側揺腕軸６及び排気側揺腕軸７の内側端部には、ボルト穴１６ａ、１７ａと同軸同径をなす略半円状の凹部６ａ、７ａが上下方向に切り欠かれて形成されている。凹部６ａ，７ａはスタッドボルト１９の逃げ加工部であり、吸気側揺腕軸６及び排気側揺腕軸７に回転作用が生じた際に凹部６ａ，７ａがスタッドボルト１９に接触することで吸気側揺腕軸６及び排気側揺腕軸７の回転を制止している。スタッドボルト１９に対して不図示のナットを締め付けることで、内側軸支え１６，１７に対して圧縮応力が加わり、吸気側揺腕軸６及び排気側揺腕軸７から受ける上方向の応力が相殺される。 Moreover, the inner shaft supports 16 and 17 provided at both ends of the shaft support portion 15 are formed with bolt holes 16a and 17a for locking the inner ends of the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7. Has been done. A stud bolt 19 attached to the cylinder head 5 is inserted into the bolt holes 16a and 17a as a fastening member, and a nut (not shown) is tightened to a screw portion exposed above the bolt holes 16a and 17a to form a shaft support portion 15. It is fixed to the cylinder head 5. Further, substantially semicircular recesses 6a and 7a having the same diameter as the bolt holes 16a and 17a are cut out in the vertical direction at the inner ends of the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7. It is formed. The recesses 6a and 7a are relief processing portions of the stud bolt 19, and when the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 are rotated, the recesses 6a and 7a come into contact with the stud bolt 19 to take in air. The rotation of the side swing arm shaft 6 and the exhaust side swing arm shaft 7 is stopped. By tightening a nut (not shown) to the stud bolt 19, compressive stress is applied to the inner shaft supports 16 and 17, and the upward stress received from the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 cancels each other out. Will be done.

また、側部ケース２において、軸支え部１５の両端の内側軸支え１６、１７に対向する位置に孔部形状をなす外側軸支え２０、２１が一体に成形されている。この外側軸支え２０、２１を通して吸気側揺腕軸６及び排気側揺腕軸７が内側軸支え１６、１７に挿入可能とされている。吸気側揺腕軸６及び排気側揺腕軸７の外周面と吸気側揺腕３及び排気側揺腕４の内周面３ａ、４ａとの間には筒状の揺腕ブッシュ２３、２３が嵌挿されている。この揺腕ブッシュ２３，２３には外部から潤滑油が充填されていて吸気側揺腕３及び排気側揺腕４の揺動をスムーズにしている。 Further, in the side case 2, the outer shaft supports 20 and 21 having a hole shape are integrally formed at positions facing the inner shaft supports 16 and 17 at both ends of the shaft support portion 15. The intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 can be inserted into the inner shaft supports 16 and 17 through the outer shaft supports 20 and 21. Cylindrical swing arm bushes 23 and 23 are provided between the outer peripheral surfaces of the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 and the inner peripheral surfaces 3a and 4a of the intake side swing arm 3 and the exhaust side swing arm 4. It is inserted. The swing arm bushes 23, 23 are filled with lubricating oil from the outside to smooth the swing of the intake side swing arm 3 and the exhaust side swing arm 4.

吸気側揺腕軸６及び排気側揺腕軸７の外側端部近傍にはリング状の溝部６ｂ、７ｂが形成されている。この溝部６ｂ、７ｂにゴム等の弾性部材からなるＯリング２４、２４が嵌合されて外側軸支え２０、２１との間を液密に封止し、揺腕ブッシュ２３，２３に供給される潤滑油の外部漏洩を阻止している。吸気側揺腕軸６及び排気側揺腕軸７において、溝部６ｂ、７ｂの外側で外側軸支え２０、２１の内面にはリング状の溝部２０ａ、２１ａが形成されている。この溝部２０ａ、２１ａに嵌合されたＣ型トメワ２６、２６によって吸気側揺腕軸６及び排気側揺腕軸７が外側軸支え２０、２１から脱落しないように係止されている。
そのため、吸気側揺腕軸６及び排気側揺腕軸７は、内側の凹部６ａ、７ａ及び内側軸支え１６、１７のボルト穴１６ａ，１７ａに挿通されたスタッドボルト１９，１９と、外側軸支え２０、２１に嵌合されたＣ型トメワ２６、２６とによって両端を固定されている。 Ring-shaped grooves 6b and 7b are formed in the vicinity of the outer ends of the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7. O-rings 24 and 24 made of elastic members such as rubber are fitted into the grooves 6b and 7b to tightly seal between the outer shaft supports 20 and 21 and supplied to the swing arm bushes 23 and 23. It prevents the lubricating oil from leaking to the outside. In the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7, ring-shaped groove portions 20a and 21a are formed on the inner surfaces of the outer shaft supports 20 and 21 outside the groove portions 6b and 7b. The intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 are locked by the C-shaped tomewas 26 and 26 fitted in the groove portions 20a and 21a so as not to fall off from the outer shaft supports 20 and 21.
Therefore, the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 are the stud bolts 19 and 19 inserted into the inner recesses 6a and 7a and the bolt holes 16a and 17a of the inner shaft supports 16 and 17, and the outer shaft support. Both ends are fixed by C-shaped tomewas 26 and 26 fitted to the 20 and 21.

図１及び図４に示す揺腕支持部１の側面を囲うように形成した側部ケース２において、吸気側揺腕３及び排気側揺腕４のプッシュロッド側の領域と外側軸支え２０、２１の領域では最大幅Ａとなる幅狭側面２８を有しており、吸気バルブ及び排気バルブ側の領域では最大幅Ｂ（>Ａ）となる幅広側面２９を有している。側部ケース２において、幅狭側面２８と幅広側面２９との境界は屈曲または湾曲して形成されている。しかも、側部ケース２の両側の幅狭側面２８に孔部形状をなす外側軸支え２０、２１を設けたため、外側軸支え２０、２１を通して吸気側揺腕軸６及び排気側揺腕軸７の挿入と離脱が容易に行える。また、幅狭側面２８の内部には吸気側揺腕３及び排気側揺腕４が設置され、その外側に燃料噴射ポンプが設置される。 In the side case 2 formed so as to surround the side surface of the swing arm support portion 1 shown in FIGS. 1 and 4, the region of the intake side swing arm 3 and the exhaust side swing arm 4 on the push rod side and the outer shaft supports 20, 21. The region has a narrow side surface 28 having a maximum width A, and the region on the intake valve and exhaust valve sides has a wide side surface 29 having a maximum width B (> A). In the side case 2, the boundary between the narrow side surface 28 and the wide side surface 29 is formed to be bent or curved. Moreover, since the outer shaft supports 20 and 21 having a hole shape are provided on the narrow side surfaces 28 on both sides of the side case 2, the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 pass through the outer shaft supports 20 and 21. Easy to insert and remove. Further, an intake side swing arm 3 and an exhaust side swing arm 4 are installed inside the narrow side surface 28, and a fuel injection pump is installed outside the intake side swing arm 3.

また、図４に示すように、側部ケース２の上面を上蓋としてのボンネット３０で覆っている。そのため、吸気側揺腕軸６及び排気側揺腕軸７の揺腕ブッシュ２３，２３に強制注油を行っても、潤滑油が側部ケース２及びボンネット３０の外部に漏洩しない。
吸気側揺腕軸６及び排気側揺腕軸７の揺腕ブッシュ２３、２３に強制注油を行う潤滑油は不図示の各プッシュロッド内を通してアジャストボルト８，９へ流れ，吸気側揺腕３及び排気側揺腕４においてプッシュロッド側から吸排気バルブ側に向かって穿孔された不図示のキリ穴を介して揺腕ブッシュ２３、２３及び弁押し金具１０、１１に注油している。 Further, as shown in FIG. 4, the upper surface of the side case 2 is covered with a bonnet 30 as an upper lid. Therefore, even if the swing arm bushes 23 and 23 of the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 are forcibly lubricated, the lubricating oil does not leak to the outside of the side case 2 and the bonnet 30.
Lubricating oil forcibly lubricating the swing arm bushes 23 and 23 of the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 flows through the push rods (not shown) to the adjust bolts 8 and 9, and the intake side swing arm 3 and In the exhaust side swing arm 4, the swing arm bushes 23 and 23 and the valve push metal fittings 10 and 11 are lubricated through holes (not shown) drilled from the push rod side toward the intake / exhaust valve side.

揺腕ブッシュ２３に供給された潤滑油は吸気側揺腕軸６及び排気側揺腕軸７の外周面を油圧で強制潤滑し、潤滑不良による揺腕ブッシュ２３の摩耗を抑制する。
吸気側揺腕軸６及び排気側揺腕軸７に供給される潤滑油はＯリング２４によって外側軸支え２０、２１から外部に漏出することを阻止される。この潤滑油は外側軸支え２０、２１及び内側軸支え１６、１７の側面と吸気側揺腕３及び排気側揺腕４の側面との隙間３４から漏出する（図３参照）。隙間３４は、側部ケース２及びボンネット３０によって囲われているため、潤滑油は外部に漏出せずに隙間３４から流出してエンジン内に戻される。 The lubricating oil supplied to the swing arm bush 23 forcibly lubricates the outer peripheral surfaces of the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 by hydraulic pressure, and suppresses wear of the swing arm bush 23 due to poor lubrication.
The lubricating oil supplied to the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 is prevented from leaking to the outside from the outer shaft supports 20 and 21 by the O-ring 24. This lubricating oil leaks from the gap 34 between the side surfaces of the outer shaft supports 20 and 21 and the inner shaft supports 16 and 17 and the side surfaces of the intake side swing arm 3 and the exhaust side swing arm 4 (see FIG. 3). Since the gap 34 is surrounded by the side case 2 and the bonnet 30, the lubricating oil flows out of the gap 34 and is returned to the engine without leaking to the outside.

本実施形態によるエンジンにおける揺腕支持部１の揺腕支持構造は上述の構成を備えており、次にその作用効果について説明する。
先ず、揺腕支持部１における揺腕支持構造の組み立て方法について説明する。シリンダヘッド５には１対のスタッドボルト１９、１９が取り付けられており、その上に、一体に成形された軸支え部１５と側部ケース２が載置される。スタッドボルト１９，１９は、ボルト穴１６ａ、１７ａに挿通される。次に、吸気側揺腕３及び排気側揺腕４が、それぞれ内側軸支え１６、１７と外側軸支え２０、２１との間に配置される。この状態で、側部ケース２の外側軸支え２０、２１の開口から吸気側揺腕軸６及び排気側揺腕軸７をそれぞれ挿入し、先端を軸支え部１５の内側軸支え１６、１７に挿入する。
そして、吸気側揺腕軸６及び排気側揺腕軸７の内側の凹部６ａ、７ａをスタッドボルト１９，１９に当接させる。次いでスタッドボルト１９，１９に不図示のナットを螺合させて締め付けを行う。 The swing arm support structure of the swing arm support portion 1 in the engine according to the present embodiment has the above-described configuration, and the effects thereof will be described next.
First, a method of assembling the swing arm support structure in the swing arm support portion 1 will be described. A pair of stud bolts 19 and 19 are attached to the cylinder head 5, and an integrally molded shaft support portion 15 and a side case 2 are placed on the pair of stud bolts 19 and 19. The stud bolts 19 and 19 are inserted into the bolt holes 16a and 17a. Next, the intake side swing arm 3 and the exhaust side swing arm 4 are arranged between the inner shaft supports 16 and 17, respectively, and the outer shaft supports 20 and 21, respectively. In this state, the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 are inserted from the openings of the outer shaft supports 20 and 21 of the side case 2, respectively, and the tip is inserted into the inner shaft supports 16 and 17 of the shaft support portion 15. insert.
Then, the recesses 6a and 7a inside the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 are brought into contact with the stud bolts 19 and 19. Next, nuts (not shown) are screwed into the stud bolts 19 and 19 to tighten them.

また、吸気側揺腕軸６及び排気側揺腕軸７の外側の溝部６ｂ、７ｂにＯリング２４を嵌合させて外側軸支え２０、２１との間を封止する。Ｏリング２４の外側で、外側軸支え２０、２１の内面の溝部２０ａ、２１ａにＣ型トメワ２６を嵌合させることで、吸気側揺腕軸６及び排気側揺腕軸７が離脱する方向へ移動した場合、Ｃ型トメワ２６が吸気側揺腕軸６及び排気側揺腕軸７の外側端面と接触することでその離脱を阻止する。これにより、吸気側揺腕軸６及び排気側揺腕軸７をその軸方向の内側と外側とで固定保持できる。 Further, the O-ring 24 is fitted into the outer grooves 6b and 7b of the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 to seal between the outer shaft supports 20 and 21. By fitting the C-shaped tomewa 26 into the grooves 20a and 21a on the inner surfaces of the outer shaft supports 20 and 21 on the outside of the O-ring 24, the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 are separated from each other. When it moves, the C-type tomewa 26 comes into contact with the outer end faces of the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 to prevent their detachment. As a result, the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 can be fixedly held inside and outside in the axial direction.

これにより、吸気側揺腕３及び排気側揺腕４はハの字型に配置され、吸気側揺腕軸６及び排気側揺腕軸７はそれぞれ吸気側揺腕３及び排気側揺腕４の揺動面に直交して配置される。次に、側部ケース２の上部にボンネット３０を装着して閉蓋し、ネジ止めする。しかも、燃焼室に燃料を噴射する燃料噴射ポンプは、吸気側揺腕３及び排気側揺腕４の間から外されて側部ケース２の幅狭側面２８の外側下側部のスペースに設置されている。 As a result, the intake side swing arm 3 and the exhaust side swing arm 4 are arranged in a V shape, and the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 are the intake side swing arm 3 and the exhaust side swing arm 4, respectively. It is arranged perpendicular to the rocking surface. Next, the bonnet 30 is attached to the upper part of the side case 2, the lid is closed, and the bonnet 30 is screwed. Moreover, the fuel injection pump that injects fuel into the combustion chamber is removed from between the intake side swing arm 3 and the exhaust side swing arm 4, and is installed in the space on the outer lower side of the narrow side surface 28 of the side case 2. ing.

このように構成された揺腕支持部１の作用について説明する。
不図示のクランク軸の回転を受けて連動するカムシャフトによりプッシュロッドを上下動させる。これに連動して、吸気側揺腕３及び排気側揺腕４が吸気側揺腕軸６及び排気側揺腕軸７を中心に揺動し、シリンダの燃焼室に対して吸気バルブ及び排気バルブを開閉作動させる。
その際、吸気側揺腕３及び排気側揺腕４はそれぞれの揺動面に垂直に吸気側揺腕軸６及び排気側揺腕軸７が配置されているため、吸気側揺腕３及び排気側揺腕４をこじる方向のモーメントが働かない。そのため、揺腕ブッシュ２３，２３の偏摩耗が防止される。しかも、吸気側揺腕３及び排気側揺腕４と吸気側揺腕軸６及び排気側揺腕軸７の間の揺腕ブッシュ２３、２３には強制潤滑により潤滑油が供給される。そのため、揺腕ブッシュ２３、２３との間の潤滑不良による摩耗が抑制される。 The action of the swing arm support portion 1 configured in this way will be described.
The push rod is moved up and down by a camshaft that is interlocked with the rotation of a crankshaft (not shown). In conjunction with this, the intake side swing arm 3 and the exhaust side swing arm 4 swing around the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7, and the intake valve and the exhaust valve with respect to the combustion chamber of the cylinder. To open and close.
At that time, since the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 are arranged perpendicular to the respective swing surfaces of the intake side swing arm 3 and the exhaust side swing arm 4, the intake side swing arm 3 and the exhaust The moment in the direction of prying the lateral swing arm 4 does not work. Therefore, uneven wear of the swing arm bushes 23 and 23 is prevented. Moreover, lubricating oil is supplied to the swing arm bushes 23 and 23 between the intake side swing arm 3 and the exhaust side swing arm 4 and the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 by forced lubrication. Therefore, wear due to poor lubrication between the swing arm bushes 23 and 23 is suppressed.

しかも、本実施形態による揺腕支持部１は、揺腕ブッシュ２３、２３に強制注油を行う際、潤滑油が吸気側揺腕軸６及び排気側揺腕軸７から外側軸支え２０、２１の外側に漏洩することをＯリング２４によって阻止する。
また、揺腕支持部１は、周囲を囲う側部ケース２と上部を覆うボンネット３０によって密閉された構成である。そのため、一部の潤滑油が外側軸支え２０、２１と吸気側揺腕３及び排気側揺腕４との間の隙間３４から漏出し得るが、揺腕支持部１の外部に漏出せず隙間３４から流出した潤滑油は不図示のシリンダヘッド上面からシリンダブロック内部に戻される。 Moreover, in the swing arm support portion 1 according to the present embodiment, when the swing arm bushes 23 and 23 are forcibly lubricated, the lubricating oil is supplied from the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 to the outer shaft supports 20 and 21. The O-ring 24 prevents leakage to the outside.
Further, the swing arm support portion 1 is configured to be sealed by a side case 2 surrounding the periphery and a bonnet 30 covering the upper portion. Therefore, some of the lubricating oil may leak from the gap 34 between the outer shaft supports 20 and 21 and the intake side swing arm 3 and the exhaust side swing arm 4, but the gap does not leak to the outside of the swing arm support portion 1. The lubricating oil flowing out from 34 is returned to the inside of the cylinder block from the upper surface of the cylinder head (not shown).

また、プッシュロッドの上下動に連動する吸気側揺腕３及び排気側揺腕４の揚程動作時に、吸気側揺腕軸６及び排気側揺腕軸７が上方に持ち上げられる動きになる。その際、図５に示すように、軸支え部１５の内側軸支え１６、１７におけるボルト穴１６ａ、１７ａの上端のエッジ部Ｈに引張応力が生じる。この場合、軸支え部１５のスタッドボルト１９のナットを締め付けることで平均応力を圧縮側に移動させることができ、疲労破壊のリスクを低減できる。 Further, when the intake side swing arm 3 and the exhaust side swing arm 4 are lifted in conjunction with the vertical movement of the push rod, the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 are lifted upward. At that time, as shown in FIG. 5, tensile stress is generated at the upper end edge portions H of the bolt holes 16a and 17a in the inner shaft supports 16 and 17 of the shaft support portion 15. In this case, the average stress can be moved to the compression side by tightening the nut of the stud bolt 19 of the shaft support portion 15, and the risk of fatigue failure can be reduced.

上述したように、本実施形態によるエンジンの揺腕支持部１の揺腕支持構造によれば次の作用効果を奏する。
（１） 吸気側揺腕３及び排気側揺腕４はハの字型に配設され、しかも吸気側揺腕軸６及び排気側揺腕軸７に直交して配設されているため、揺腕ブッシュ２３、２３の偏摩耗を抑制できる。
（２） 吸気側揺腕軸６及び排気側揺腕軸７の揺腕ブッシュ２３、２３に潤滑油が強制潤滑で供給されているため一層摩耗を軽減できる。しかも、潤滑油が隙間３４から漏出しても側部ケース２及びボンネット３０で密閉されているため、外部に漏出することを阻止してエンジン内に戻すことができる。また、吸気側揺腕軸６及び排気側揺腕軸７上の潤滑油はＯリング２４によって外側軸支え２０，２１との隙間から外部に漏出することを阻止できる。 As described above, according to the swing arm support structure of the swing arm support portion 1 of the engine according to the present embodiment, the following actions and effects are obtained.
(1) Since the intake side swing arm 3 and the exhaust side swing arm 4 are arranged in a V shape and are arranged orthogonal to the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7, they swing. Uneven wear of the arm bushes 23 and 23 can be suppressed.
(2) Since the lubricating oil is supplied to the swing arm bushes 23 and 23 of the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 by forced lubrication, wear can be further reduced. Moreover, even if the lubricating oil leaks from the gap 34, it is sealed by the side case 2 and the bonnet 30, so that it can be prevented from leaking to the outside and returned to the inside of the engine. Further, the lubricating oil on the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 can be prevented from leaking to the outside through the gap between the outer shaft supports 20 and 21 by the O-ring 24.

（３） 吸気側揺腕軸６及び排気側揺腕軸７は内側軸支え１６、１７と外側軸支え２０、２１により両端を支持される構造であるため、吸気側揺腕軸６及び排気側揺腕軸７のたわみを抑制出来ることから、大型の内燃機関に適した耐久性が得られる。
（４） 吸気側揺腕軸６及び排気側揺腕軸７の内側端部には、略半円状の凹部６ａ、７ａが上下方向に切り欠かれて形成され、スタッドボルト１９、１９に当接することで吸気側揺腕軸６及び排気側揺腕軸７の回転が制止される。また、スタッドボルト１９に対してナットを締め付けることで、内部軸支え１６，１７に対して圧縮応力が加わり、吸気側揺腕軸６及び排気側揺腕軸７から受ける引張の応力が相殺される。 (3) Since both ends of the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 are supported by the inner shaft supports 16 and 17 and the outer shaft supports 20 and 21, the intake side swing arm shaft 6 and the exhaust side are supported. Since the deflection of the swing arm shaft 7 can be suppressed, durability suitable for a large internal combustion engine can be obtained.
(4) Approximately semicircular recesses 6a and 7a are formed by being cut out in the vertical direction at the inner ends of the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7, and hit the stud bolts 19 and 19. Upon contact, the rotation of the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 is stopped. Further, by tightening the nut to the stud bolt 19, compressive stress is applied to the internal shaft supports 16 and 17, and the tensile stress received from the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 is offset. ..

（５） 側部ケース２はその対向する幅狭側面２８の側面に外側軸支え２０、２１を貫通孔で設けることで、吸気側揺腕軸６及び排気側揺腕軸７を支持する部材を兼ねることができる。そのため、構造をシンプルにできるとともに、側部ケース２の外側から吸気側揺腕軸６及び排気側揺腕軸７を挿脱することができて組立や保守や交換が容易である。
また、外側軸支え２０、２１と内側軸支え１６、１７は側部ケース２と一体に成形されていることが好ましい。これにより外側軸支え２０、２１及び内側軸支え１６、１７への吸気側揺腕軸６及び排気側揺腕軸７の取付けが容易になると共に、軸支え部１５のシリンダヘッド５への脱着が容易となる。
（６） 吸気側揺腕３及び排気側揺腕４は、プッシュロッド側の端部の間隔よりも吸気バルブ及び排気バルブ側の間隔の方が広いハの字型に配置されている。これにより、大径化された吸気バルブ及び排気バルブによって機関性能を向上できる上に、双方のプッシュロッドを狭いスペースに近接配置できてコンパクトにできる。
（７） 一般に、船舶推進等に用いられる大型の内燃機関では、複数の揺腕支持部１がクランク軸方向に並んで配置されている。しかも、内燃機関の寸法を小さくするために、隣接する揺腕支持部１と揺腕支持部１の間隔はできるだけ狭く設定される。そのため、側部ケース２の外側から吸気側揺腕軸６及び排気側揺腕軸７を挿脱する場合、隣の揺腕支持部１が邪魔となって挿脱の操作ができなくなる。
これに対し、本実施形態では、側部ケース２とボンネット３０で覆われた揺腕支持部１において、外側軸支え２０、２１が設けられた幅狭側面２８、２８間の幅Ａが、吸気バルブ及び排気バルブに対応する幅広側面２９の幅Ｂよりも小さい幅にできる。これにより、幅狭側面２８の外側軸支え２０、２１が設けられた部分で隣り合う揺腕支持部１の間に吸気側揺腕軸６及び排気側揺腕軸７を挿脱する空間ができて、挿脱が可能となる。 (5) The side case 2 is provided with outer shaft supports 20 and 21 through holes on the side surfaces of the narrow side surfaces 28 facing each other, thereby providing a member for supporting the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7. Can also serve as. Therefore, the structure can be simplified, and the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 can be inserted and removed from the outside of the side case 2, and assembly, maintenance, and replacement are easy.
Further, it is preferable that the outer shaft supports 20 and 21 and the inner shaft supports 16 and 17 are integrally molded with the side case 2. As a result, the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 can be easily attached to the outer shaft supports 20 and 21 and the inner shaft supports 16 and 17, and the shaft support portion 15 can be attached to and detached from the cylinder head 5. It will be easy.
(6) The intake side swing arm 3 and the exhaust side swing arm 4 are arranged in a V shape in which the distance between the intake valve and the exhaust valve side is wider than the distance between the ends on the push rod side. As a result, the engine performance can be improved by the intake valve and the exhaust valve having a large diameter, and both push rods can be arranged close to each other in a narrow space to be compact.
(7) Generally, in a large internal combustion engine used for ship propulsion or the like, a plurality of swing arm support portions 1 are arranged side by side in the crankshaft direction. Moreover, in order to reduce the size of the internal combustion engine, the distance between the adjacent swing arm support portion 1 and the swing arm support portion 1 is set as narrow as possible. Therefore, when the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 are inserted and removed from the outside of the side case 2, the adjacent swing arm support portion 1 becomes an obstacle and the insertion / removal operation cannot be performed.
On the other hand, in the present embodiment, in the swing arm support portion 1 covered with the side case 2 and the bonnet 30, the width A between the narrow side surfaces 28 and 28 provided with the outer shaft supports 20 and 21 is intake air. The width can be smaller than the width B of the wide side surface 29 corresponding to the valve and the exhaust valve. As a result, a space for inserting and removing the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 is created between the adjacent swing arm support portions 1 at the portion of the narrow side surface 28 where the outer shaft supports 20 and 21 are provided. Therefore, it can be inserted and removed.

なお、本発明による内燃機関の揺腕支持部１の揺腕支持構造は、上述した実施形態による揺腕支持部１に限定されるものではなく、本発明の要旨を逸脱しない範囲で適宜の変更や置換等が可能である。以下に、本発明の変形例等について説明するが、上述した実施形態で説明した部品や部材等と同一または同様なものについては同一の符号を用いて説明を省略する。 The swing arm support structure of the swing arm support portion 1 of the internal combustion engine according to the present invention is not limited to the swing arm support portion 1 according to the above-described embodiment, and is appropriately modified without departing from the gist of the present invention. And replacement are possible. Hereinafter, modifications of the present invention and the like will be described, but the same or similar parts and members described in the above-described embodiment will be described by using the same reference numerals.

上述した実施形態では、側部ケース２の外側軸支え２０、２１から挿入される吸気側揺腕軸６及び排気側揺腕軸７をＣ型トメワ２６によって係止したが、本発明はそのような構成に限定されない。例えば、外側軸支え２０、２１に開閉可能な蓋を設けて吸気側揺腕軸６及び排気側揺腕軸７の側部ケース２内への挿脱と係止を行ってもよい。Ｃ型トメワ２６と蓋は係止部材に含まれる。
また、上述の実施形態では、吸気側揺腕軸６及び排気側揺腕軸７に側部ケース２から外部に潤滑油が漏れることを防止するシール部材としてＯリング２４を設けたが、これに代えて、外側軸支え２０，２１の内面に溝部を設けてＯリング２４を装着して吸気側揺腕軸６及び排気側揺腕軸７との間で液密にシールしてもよい。
なお、Ｏリング２４はシール部材に含まれる。ボンネット３０は上部カバーに含まれる。 In the above-described embodiment, the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 inserted from the outer shaft supports 20 and 21 of the side case 2 are locked by the C-type tomewa 26. The configuration is not limited to. For example, the outer shaft supports 20 and 21 may be provided with openable / closable lids to insert / remove and lock the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 into the side case 2. The C-shaped retaining ring 26 and the lid are included in the locking member.
Further, in the above-described embodiment, the O-ring 24 is provided on the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 as a sealing member for preventing the lubricating oil from leaking from the side case 2 to the outside. Alternatively, a groove may be provided on the inner surface of the outer shaft supports 20 and 21 and an O-ring 24 may be attached to seal the intake side swing arm shaft 6 and the exhaust side swing arm shaft 7 in a liquid-tight manner.
The O-ring 24 is included in the seal member. The bonnet 30 is included in the top cover.

１ 揺腕支持部
２ 側部ケース
３ 吸気側揺腕
４ 排気側揺腕
６ 吸気側揺腕軸
６ａ、７ａ 凹部
７ 排気側揺腕軸
１５ 軸支え部
１６、１７ 内側軸支え
１６ａ、１７ａ ボルト穴
１９ スタッドボルト
２０，２１ 外側軸支え
２３ 揺腕ブッシュ
２４ Ｏリング
２６ Ｃ型トメワ
２８ 幅狭側面
２９ 幅広側面
３０ ボンネット 1 Swing arm support 2 Side case 3 Intake side swing arm 4 Exhaust side swing arm 6 Intake side swing arm shaft 6a, 7a Recess 7 Exhaust side swing arm shaft 15 Shaft support 16, 17 Inner shaft support 16a, 17a Bolt hole 19 Stud bolts 20, 21 Outer shaft support 23 Swing arm bush 24 O-ring 26 C-type Tomewa 28 Narrow side 29 Wide side 30 Bonnet

Claims (8)

吸気バルブを往復作動させる吸気側揺腕と、
排気バルブを往復作動させる排気側揺腕と、
前記吸気側揺腕を揺動可能に支持していてその揺動面に垂直に配置された吸気側揺腕軸と、
前記排気側揺腕を揺動可能に支持していてその揺動面に垂直に配置された排気側揺腕軸と、
前記吸気側揺腕軸及び前記排気側揺腕軸をそれぞれ長手方向両端で支持する内側軸支え及び外側軸支えと、を備え、
前記吸気側揺腕軸及び前記排気側揺腕軸はそれぞれ前記外側軸支えを通して外側から挿脱可能とされていることを特徴とする内燃機関の揺腕支持構造。 The intake side swing arm that reciprocates the intake valve and
The exhaust side swing arm that reciprocates the exhaust valve and
The intake side swing arm shaft that supports the intake side swing arm so as to be swingable and is arranged perpendicular to the swing surface,
An exhaust side swing arm shaft that supports the exhaust side swing arm so as to be swingable and is arranged perpendicular to the swing surface,
It is provided with an inner shaft support and an outer shaft support that support the intake side swing arm shaft and the exhaust side swing arm shaft at both ends in the longitudinal direction, respectively.
A swing arm support structure for an internal combustion engine, wherein the intake side swing arm shaft and the exhaust side swing arm shaft are respectively removable from the outside through the outer shaft support. 前記吸気側揺腕及び前記排気側揺腕は、それぞれその一端がプッシュロッドにより駆動され他端が前記吸気バルブまたは前記排気バルブを開閉弁作動させ、
前記プッシュロッド側の端部の間隔よりも前記吸気バルブ及び排気バルブ側の端部の間隔の方が広く設置されている請求項１に記載された内燃機関の揺腕支持構造。 One end of each of the intake side swing arm and the exhaust side swing arm is driven by a push rod, and the other end operates the intake valve or the exhaust valve as an on-off valve.
The swing arm support structure for an internal combustion engine according to claim 1, wherein the distance between the ends on the intake valve and the exhaust valve side is wider than the distance between the ends on the push rod side. 前記吸気側揺腕及び排気側揺腕は側部を側部ケースによって囲われており、
前記外側軸支えは前記側部ケースに設けられている請求項１または２に記載された内燃機関の揺腕支持構造。 The side of the intake side swing arm and the exhaust side swing arm is surrounded by a side case.
The swing arm support structure for an internal combustion engine according to claim 1 or 2, wherein the outer shaft support is provided on the side case. 前記外側軸支えと内側軸支えは前記側部ケースと一体に成形された請求項３に記載された内燃機関の揺腕支持構造。 The swing arm support structure of an internal combustion engine according to claim 3, wherein the outer shaft support and the inner shaft support are integrally molded with the side case. 前記側部ケースは、前記外側軸支えが設けられた領域の幅が前記吸気バルブ及び前記排気バルブが設けられた領域の幅よりも小さく形成されている請求項３または４に記載された内燃機関の揺腕支持構造。 The internal combustion engine according to claim 3 or 4, wherein the side case is formed so that the width of the region where the outer shaft support is provided is smaller than the width of the region where the intake valve and the exhaust valve are provided. Shaking arm support structure. 前記側部ケースの上部には前記側部ケースの内部を密閉する上部カバーが取り付けられ、
前記吸気側揺腕軸及び排気側揺腕軸またはそれぞれの前記外側軸支えには、前記側部ケースの外部に油が漏れることを防止するシール部材が取り付けられる請求項３から５のいずれか1項に記載された内燃機関の揺腕支持構造。 An upper cover that seals the inside of the side case is attached to the upper part of the side case.
Any one of claims 3 to 5 to which a seal member for preventing oil from leaking to the outside of the side case is attached to the intake side swing arm shaft and the exhaust side swing arm shaft or each of the outer shaft supports. The swing arm support structure of the internal combustion engine described in the section. 前記吸気側揺腕軸及び排気側揺腕軸はそれぞれ前記内側軸支えに挿入される端部に凹部を備え、前記内側軸支えには前記凹部に係合する締結部材が挿通される請求項３から６のいずれか１項に記載された内燃機関の揺腕支持構造。 3. The intake side swing arm shaft and the exhaust side swing arm shaft each have a recess at an end inserted into the inner shaft support, and a fastening member engaged with the recess is inserted into the inner shaft support. The swing arm support structure of the internal combustion engine according to any one of 6 to 6. 請求項１から７のいずれか１項に記載された前記揺腕支持構造を備えたことを特徴とする内燃機関。 An internal combustion engine provided with the swing arm support structure according to any one of claims 1 to 7.
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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5825860B2 (en) * 1980-06-25 1983-05-30 三菱重工業株式会社 cylinder head of internal combustion engine
JPS61169214U (en) * 1985-04-10 1986-10-20
JPH08226310A (en) * 1995-02-20 1996-09-03 Nissan Diesel Motor Co Ltd Fitting structure for rocker shaft
JPH09250321A (en) * 1996-03-15 1997-09-22 Kubota Corp Valve system of engine

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5825860B2 (en) * 1980-06-25 1983-05-30 三菱重工業株式会社 cylinder head of internal combustion engine
JPS61169214U (en) * 1985-04-10 1986-10-20
JPH08226310A (en) * 1995-02-20 1996-09-03 Nissan Diesel Motor Co Ltd Fitting structure for rocker shaft
JPH09250321A (en) * 1996-03-15 1997-09-22 Kubota Corp Valve system of engine

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