JP5917364B2

JP5917364B2 - Adjustment weight fixing structure of internal combustion engine

Info

Publication number: JP5917364B2
Application number: JP2012238171A
Authority: JP
Inventors: 広之杉浦; 穂高向原
Original assignee: Honda Motor Co Ltd
Current assignee: Honda Motor Co Ltd
Priority date: 2012-10-29
Filing date: 2012-10-29
Publication date: 2016-05-11
Anticipated expiration: 2032-10-29
Also published as: JP2014088892A

Description

本発明は、往復動型内燃機関の調整ウエイト固定構造に関するものである。 The present invention relates to an adjustment weight fixing structure for a reciprocating internal combustion engine.

往復動型内燃機関において、シリンダ孔内を往復するピストンの往復動による起振力を打消すために、クランクウェブにバランス錘部が設けられている。 In a reciprocating internal combustion engine, a balance weight portion is provided on the crank web in order to cancel the vibration generated by the reciprocating motion of a piston that reciprocates in a cylinder hole.

しかも、バランス錘部の微妙な重量差や重量分布の差やピストン等の往復動部分の重量差による起振力を解消するために、クランクウェブに比重の異なる調整用ウエイトを着脱可能に取り付けていた。 In addition, adjustment weights with different specific gravities are detachably attached to the crank web in order to eliminate vibrations caused by subtle weight differences and weight distribution of the balance weight and reciprocating parts such as pistons. It was.

この調整用ウエイトをクランクウェブに強固に固定するために、従来では、調整用ウエイトをクランクウェブの凹部に軽圧入した後に、篏合部をカシメ等で塑性変形させていたが、この場合には、前記調整用ウエイトの交換が不可能であった。 In order to firmly fix the adjustment weight to the crank web, conventionally, after the adjustment weight is lightly press-fitted into the recess of the crank web, the joint portion is plastically deformed by caulking or the like. The adjustment weight could not be exchanged.

そこで、従来、調整ウエイトをクランクウェブの穴に嵌装した後に、締結部材でもって、前記調整用ウエイトを前記クランクウェブに固定していた。（特開平１１−１５３１９６号公報参照）。 Therefore, conventionally, after the adjustment weight is fitted into the hole of the crank web, the adjustment weight is fixed to the crank web with a fastening member. (See JP-A-11-153196).

特許文献１記載のものでは、前記締結部材が緩む可能性があるため、緩み止めを施す必要があり、緩み止め剤を塗布しなければならず、また緩み剤を剥して分解すると、これまた、再使用が不可能であった。 In the thing of patent document 1, since the said fastening member may loosen, it is necessary to give a locking agent, it is necessary to apply a locking agent. Reusable was impossible.

特開平１１−１５３１９６号公報Japanese Patent Laid-Open No. 11-153196

本発明は、前記特許文献１に記載のものの難点を克服した内燃機関の調整ウエイト固定構造の発明に係り、その目的とする処は、調整ウエイトをクランクウェブに取り付けて強固に固定できるとともに、固定後であっても、前記調整ウエイトを容易に取り外しでき、しかも、前記調整ウエイトを交換して前記クランクウェブに他の調整ウエイトを取り付けで強固に固定し、また、前記調整ウエイトに重量調整を施した後、再び前記クランクウェブを取り付け固定できる内燃機関の調整ウエイト固定構造を提供することにある。 The present invention relates to an invention of an adjustment weight fixing structure for an internal combustion engine that has overcome the difficulties of the one described in Patent Document 1, and its object is to attach the adjustment weight to a crank web and fix it firmly. Even after, the adjustment weight can be easily removed, and the adjustment weight can be replaced and another adjustment weight can be firmly fixed to the crank web by attaching it, and the adjustment weight can be adjusted in weight. Then, it is providing the adjustment weight fixing structure of the internal combustion engine which can attach and fix the said crank web again.

請求項１記載の発明は、
内燃機関本体（11，12）に回転自在に支持されるクランクシャフト（17）を有する内燃機関（10）で、
前記クランクシャフト（17）の回転により発生する振動を相殺する錘部（32，52）が設けられたバランス調整部（31，51）には、周方向に複数形成された同じ半径(R)の円状のウエイト挿入孔（33，53）が、前記クランクシャフト（17）の回転中心からの距離を一定とせずに配置され、
前記バランス調整部（31，51）と異なる比重の円柱状部材で構成され、前記バランス調整部（31，51）のウエイト挿入孔（33，53）に挿入されて一体化される調整用ウエイト（40，60）と、
前記ウエイト挿入孔（33，53）の内周面に形成された係止溝（34，54）に、係合する係止部材(45)と、を具備し、
前記ウエイト挿入孔（33，53）に挿入され前記調整用ウエイト（40，60）が、前記係止溝（34，54）に係合された前記係止部材(45)に当接して軸方向の移動が規制されることを特徴とする内燃機関の調整ウエイト固定構造である。 The invention described in claim 1
An internal combustion engine (10) having a crankshaft (17) rotatably supported by an internal combustion engine body (11, 12);
The balance adjusting portion (31, 51) provided with the weight portion (32, 52) that cancels the vibration generated by the rotation of the crankshaft (17) has a plurality of the same radius (R) formed in the circumferential direction. Circular weight insertion holes (33, 53) are arranged without a constant distance from the rotation center of the crankshaft (17),
An adjustment weight (consisting of a cylindrical member having a specific gravity different from that of the balance adjusting portion (31, 51) and being integrated by being inserted into the weight insertion hole (33, 53) of the balance adjusting portion (31, 51). 40, 60)
A locking member (45) that engages with a locking groove (34, 54) formed in the inner peripheral surface of the weight insertion hole (33, 53),
The adjustment weights (40, 60) inserted into the weight insertion holes (33, 53) abut on the locking members (45) engaged with the locking grooves (34, 54) in the axial direction. The adjustment weight fixing structure of the internal combustion engine is characterized in that the movement of the internal combustion engine is restricted .

請求項２記載の発明は、
前記バランス調整部（31）に前記ウエイト挿入孔（33）が貫通孔にて形成されて、
前記ウエイト挿入孔（33）の挿入側内周面（33ａ）に前記係止溝（34）が形成され、
前記ウエイト挿入孔（33）の出口側の内周面から軸中心に環状突出片（36）が突出して形成され、
前記ウエイト挿入孔（33）の入口側から挿入された前記調整用ウエイト（40）は、挿入先端部(41)が前記環状突出片（36）に当接し、挿入後端部(42)が前記係止溝（34）に係合された前記係止部材(45)に当接して軸方向の移動が規制されることを特徴とする請求項１記載の内燃機関の調整ウエイト固定構造である。 The invention according to claim 2
The wait insertion hole (33) is formed by a through hole in said balance adjustment unit (31),
The locking groove (34) is formed on the insertion side inner peripheral surface (33a) of the weight insertion hole (33),
An annular projecting piece (36) projects from the inner peripheral surface on the outlet side of the weight insertion hole (33) to the center of the shaft,
The adjustment weight (40) inserted from the inlet side of the weight insertion hole (33) has an insertion tip (41) abutting the annular projecting piece (36) and an insertion rear end (42). 2. The adjustment weight fixing structure for an internal combustion engine according to claim 1 , wherein movement in the axial direction is restricted by contacting the locking member (45) engaged with the locking groove (34) .

請求項３記載の発明は、
前記調整用ウエイト（40）の挿入先端部（41）が前記環状突出片（36）を貫通して前記ウエイト挿入孔（33）から突出することを特徴とする請求項２記載の内燃機関の調整ウエイト固定構造である。 The invention described in claim 3
The internal combustion engine adjustment according to claim 2, characterized in that the insertion tip (41) of the adjustment weight (40) penetrates the annular projecting piece (36) and projects from the weight insertion hole (33). Weight fixing structure.

請求項４記載の発明は、
前記係止部材(45)は環状リングを一部欠損した形状としたことを特徴とする請求項１乃至請求項３の何れか１項記載の内燃機関の調整ウエイト固定構造である。 The invention according to claim 4
The adjustment weight fixing structure for an internal combustion engine according to any one of claims 1 to 3, wherein the locking member (45) has a shape in which an annular ring is partially missing .

請求項５記載の発明は、
前記錘部（32）に前記係止部材（45）を取り外す際の工具差し込む用切欠き凹部（35）が設けられたことを特徴とする請求項４記載の内燃機関の調整ウエイト固定構造である。 The invention according to claim 5
The adjustment weight fixing structure for an internal combustion engine according to claim 4, wherein the weight portion (32) is provided with a notch recess (35) for inserting a tool when removing the locking member (45). .

請求項６記載の発明は、
前記ウエイト挿入孔（53）は、前記バランス調整部（51）に閉塞孔として形成され、
前記ウエイト挿入孔（53）の入口側の内周面に前記係止溝（54）が形成され、
前記ウエイト挿入孔（53）内の前記調整用ウエイト（60）は、挿入先端部(61)が前記閉塞孔の閉塞壁(56)に当接し、挿入後端部(62)が前記係止溝（54）に係合された前記係止部材(45)に当接して軸方向の移動が規制されることを特徴とする請求項１記載の内燃機関の調整ウエイト固定構造である。 The invention described in claim 6
The weight insertion hole (53) is formed as a blocking hole in the balance adjustment part (51),
The locking groove (54) is formed on the inner peripheral surface on the inlet side of the weight insertion hole (53),
The adjustment weight (60) in the weight insertion hole (53) has an insertion tip end (61) abutting against the blocking wall (56) of the blocking hole, and an insertion rear end portion (62) at the locking groove. 2. The adjustment weight fixing structure for an internal combustion engine according to claim 1, wherein movement in the axial direction is restricted by abutting on the locking member (45) engaged with (54). 3.

請求項７記載の発明は、
前記クランクシャフト（17）が前記内燃機関本体（11，12）の最外側ジャーナル部（11ａ，12ａ）にて回転自在に支持され、前記調整用ウエイト（40，60）は前記最外側ジャーナル部（11ａ，12ａ）に隣接する側から挿入着脱可能な状態に固定されることを特徴とする請求項１乃至請求項６の何れか１項記載の内燃機関の調整ウエイト固定構造である。 The invention described in claim 7
The crankshaft (17) is rotatably supported by outermost journal portions (11a, 12a) of the internal combustion engine body (11, 12), and the adjustment weights (40, 60) are supported by the outermost journal portion ( 11. The adjustment weight fixing structure for an internal combustion engine according to claim 1, wherein the adjustment weight fixing structure is fixed in a state where it can be inserted and removed from a side adjacent to 11 a, 12 a) .

請求項８記載の発明は、
前記調整用ウエイト（40，60）の挿入側と反対の挿入後端部（42，62）が錘部（32，52）の挿入側端面（32ａ，52ａ）から突出しない位置に固定されたことを特徴とする請求項７記載の内燃機関の調整ウエイト固定構造。 The invention described in claim 8
The insertion rear end (42, 62) opposite to the insertion side of the adjustment weight (40, 60) is fixed at a position that does not protrude from the insertion side end surface (32a, 52a) of the weight (32, 52). 8. The adjustment weight fixing structure for an internal combustion engine according to claim 7.

請求項１記載の内燃機関（10）の調整ウエイト固定構造（30，50）によれば、調整用ウエイト（40，60）をウエイト挿入孔（33，53）に挿入して、挿入孔（33，53）の内周に円環状に弾発拡張する係止部材（45）をはめ込み固定する係止溝（34，54）を形成したので、係止部材（45）を再使用可能で取り外しができるようにして、調整用ウエイト（40，60）を着脱自在に取り付けることができる。 According to the adjustment weight fixing structure (30, 50) of the internal combustion engine (10) according to claim 1, the adjustment weight (40, 60) is inserted into the weight insertion hole (33, 53), and the insertion hole (33 53) The locking groove (34, 54) is formed on the inner periphery of the locking member (45) that elastically expands and expands in an annular shape, so that the locking member (45) can be reused and removed. In this way, the adjustment weights (40, 60) can be detachably attached.

請求項３記載の内燃機関（10）の調整ウエイト固定構造（30，50）によれば、ウエイト調整量を最大限に対応可能にできる。 According to the adjustment weight fixing structure (30, 50) of the internal combustion engine (10) according to claim 3, the weight adjustment amount can be maximized.

請求項２記載の内燃機関の調整ウエイト固定構造によれば、貫通した挿入孔（33，53）に対する調整ウエイト（40，60）の抜け止めと位置決めを行なうことが、簡単な構造にて可能となる。 According to the adjustment weight fixing structure of the internal combustion engine according to claim 2 , it is possible to prevent and position the adjustment weight (40, 60) with respect to the insertion hole (33, 53) penetrating with a simple structure. Become.

請求項４記載の内燃機関の調整ウエイト固定構造によれば、係止部材（45）を環状リングを一部欠損した形状とすることで、係止溝（34，54）に対する相対回転位置で位置決めが不要となり組付け作業の低下を抑制できる。 According to the adjustment weight fixing structure for an internal combustion engine according to claim 4 , the locking member (45) is formed in a shape in which a part of the annular ring is missing, so that it is positioned at a relative rotational position with respect to the locking groove (34, 54). Becomes unnecessary, and the reduction of assembly work can be suppressed.

請求項５記載の内燃機関の調整ウエイト固定構造によれば、前記係止部材（45）を取り外す際の工具用切欠き凹部（35，55）を錘部（32，52）に設けたので、調整用ウエイト（40，60）側に工具用切欠き凹部（35，55）を設けた場合には調整用ウエイト（40，60）の取り付け角度によりバランス量が変わるおそれがあるのを、調整用ウエイト（40，60）の切欠きをなくして取り付け角度の指定が不要になるので、組み付け作業が向上する。 According to the adjustment weight fixing structure of the internal combustion engine according to claim 5 , since the notch recess (35, 55) for tool when removing the locking member (45) is provided in the weight portion (32, 52), If the notch for tool (35, 55) is provided on the adjustment weight (40, 60) side, the balance may vary depending on the mounting angle of the adjustment weight (40, 60). Since the weight (40, 60) notch is eliminated and the specification of the mounting angle becomes unnecessary, the assembly work is improved.

請求項７記載の内燃機関（10）の調整ウエイト固定構造（30，50）によれば、錘部（32，52）のジャーナル部（11ａ，12ａ）側から調整用ウエイト（40，60）を挿入することで、反対側に較べて他方の錘部（32，52）による干渉が無いため取り付け作業が容易となり、また内燃機関（10）の運転中であっても、調整用ウエイト（40，60）の挿入後端部（42，62）はジャーナル部（11ａ，12ａ）に常に隣接しているため、挿入後端部（42，62）はウエイト挿入孔（33，53）から脱落する惧れがない。 According to the adjustment weight fixing structure (30, 50) of the internal combustion engine (10) according to claim 7, the adjustment weight (40, 60) is provided from the journal portion (11a, 12a) side of the weight portion (32, 52). By inserting, there is no interference by the other weight part (32, 52) compared to the opposite side, so that the mounting work becomes easy, and even when the internal combustion engine (10) is in operation, the adjustment weight (40, Since the rear end portion (42, 62) of 60) is always adjacent to the journal portion (11a, 12a), the rear end portion (42, 62) may be dropped from the weight insertion hole (33, 53). There is no.

請求項８記載の内燃機関（10）の調整ウエイト固定構造（30，50）によれば、調整用ウエイト（40，60）がジャーナル部（11ａ）と干渉することを抑制しながら、錘部（32，52）とジャーナル部（11ａ）を近接することができてクランク軸長を短縮してエンジン幅の小型化を図ることができる。 According to the adjustment weight fixing structure (30, 50) of the internal combustion engine (10) according to claim 8, the weight portion (40, 60) is suppressed while preventing the adjustment weight (40, 60) from interfering with the journal portion (11a). 32, 52) and the journal portion (11a) can be brought close to each other, and the crankshaft length can be shortened to reduce the engine width.

本発明の一実施の形態に係る調整ウエイト固定構造を具備した往復動型内燃機関を搭載した自動二輪車の全体左側面図である。1 is an overall left side view of a motorcycle equipped with a reciprocating internal combustion engine having an adjustment weight fixing structure according to an embodiment of the present invention. 図１に図示された自動二輪車に搭載されている前後Ｖ型４気筒４ストローク内燃機関の左側面図である。FIG. 2 is a left side view of a front / rear V-type four-cylinder four-stroke internal combustion engine mounted on the motorcycle shown in FIG. 1. 図２に図示の内燃機関の右側面図である。FIG. 3 is a right side view of the internal combustion engine shown in FIG. 2. 図２に図示の内燃機関の平面図である。FIG. 3 is a plan view of the internal combustion engine illustrated in FIG. 2. 図２のV−V断面図である。FIG. 5 is a VV cross-sectional view of FIG. 2. 図５のVI−VI断面図であって、クランクシャフトの中心線に対し直交した面に沿って切断したクランクケースとシリンダブロックの要部縦断斜視図である。FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG. 5, and is a vertical perspective view of a main part of a crankcase and a cylinder block cut along a plane orthogonal to the center line of the crankshaft. クランクシャフトと、調整用ウエイトと係止部材の傾斜図である。FIG. 5 is an inclined view of a crankshaft, adjustment weights, and locking members. 図６のVIII−VIII断面図である。It is VIII-VIII sectional drawing of FIG. 他の実施形態における図８と同じ部分の断面図である。It is sectional drawing of the same part as FIG. 8 in other embodiment.

以下、本発明に係る一実施の形態について図１ないし図９に基づいて説明する。 Hereinafter, an embodiment according to the present invention will be described with reference to FIGS.

本発明に係るロッカー軸配置構造を具備した前後Ｖ型４気筒ＤＯＨＣ型４ストローク内燃機関（以下内燃機関と称する）10は、図１に図示される自動二輪車０に搭載される。 A front / rear V-type four-cylinder DOHC type four-stroke internal combustion engine (hereinafter referred to as an internal combustion engine) 10 having a rocker shaft arrangement structure according to the present invention is mounted on a motorcycle 0 shown in FIG.

本実施形態では、上下、前後は、自動二輪車０の上下、前後を意味し、左右は自動二輪車０の前方に向いた方向を基準とした左右を意味している。 In the present embodiment, up and down, front and back mean up and down, front and back of the motorcycle 0, and left and right mean left and right with reference to a direction facing the front of the motorcycle 0.

自動二輪車０のメインフレーム１の前端にフロントフォーク２が左右に旋回可能に設けられ、該フロントフォーク２の上端に操舵ハンドル３が一体に取り付けられるとともに、フロントフォーク２の下部に前輪４が回転可能に枢支され、メインフレーム１の後部に上下へ揺動可能に設けられたリヤフォーク５の後端に後輪６が回転可能に枢支され、後輪６は内燃機関10からの動力によりチェーン伝動系７を介して回転駆動され、メインフレーム１の前部上方に燃料タンク８が載置されるとともに燃料タンク８の後方にシート９が設けられている。 A front fork 2 is provided at the front end of the main frame 1 of the motorcycle 0 so as to be able to turn left and right. A steering handle 3 is integrally attached to the upper end of the front fork 2 and the front wheel 4 is rotatable at the lower part of the front fork 2. The rear wheel 6 is pivotally supported at the rear end of a rear fork 5 that is pivotally supported by the rear portion of the main frame 1 so as to swing up and down. The rear wheel 6 is chained by power from the internal combustion engine 10. The fuel tank 8 is driven to rotate through a transmission system 7, and a fuel tank 8 is placed above the front portion of the main frame 1, and a seat 9 is provided behind the fuel tank 8.

図２および図３に図示されるように、内燃機関10では、クランクケース11の上にシリンダブロック12，シリンダヘッド13およびヘッドカバー14が順次重ねられ、これが相互に一体に結合されるとともに、クランクケース11の下にオイルパン15が一体に取り付けられている。 As shown in FIGS. 2 and 3, in the internal combustion engine 10, a cylinder block 12, a cylinder head 13, and a head cover 14 are sequentially stacked on the crankcase 11, and these are integrally coupled to each other. An oil pan 15 is integrally attached under 11.

図５に図示されるように、シリンダブロック12とその下方のクランクケース11との接合部には、左右方向に指向したクランクシャフト17が軸受部16を介して回転可能に枢支されるとともに、シリンダブロック12のシリンダ孔18にピストン19が摺動可能に嵌装され、クランクシャフト17にコンロッド20の大径端部20ａが回転可能に結合されるとともに、ピストン19に嵌装されたピストンピン21にコンロッド20の小径端部20ｂが回転可能に結合されており、ピストン19の上下往復運動によりクランクシャフト17は回転駆動されるようになっている。 As shown in FIG. 5, a crankshaft 17 oriented in the left-right direction is pivotally supported via a bearing portion 16 at a joint portion between the cylinder block 12 and the crankcase 11 below the cylinder block 12, The piston 19 is slidably fitted in the cylinder hole 18 of the cylinder block 12, and the large-diameter end 20 a of the connecting rod 20 is rotatably coupled to the crankshaft 17, and the piston pin 21 fitted to the piston 19 Further, a small-diameter end portion 20b of the connecting rod 20 is rotatably coupled, and the crankshaft 17 is driven to rotate by the reciprocating motion of the piston 19.

図５および図８に図示されるように、クランクシャフト17においてシリンダ孔18内を往復するピストンの起振力を消去するバランスウェイトと称せられる４個のバランス調整部の内、最外側のバランス調整部31には、クランクシャフト17の中心線に対し平行に指向した４個の半径Ｒの円筒形のウエイト挿入孔33が、クランクシャフト17の回転方向に沿い等間隔に形成され、このウエイト挿入孔33の挿入側内周面33ａには、横断形状が半円状の半径ｒの係止溝34が挿入側内周面33ａの全周に亘り形成されている。 As shown in FIGS. 5 and 8, the outermost balance adjustment among the four balance adjustment portions called balance weights that eliminate the vibration force of the piston reciprocating in the cylinder hole 18 in the crankshaft 17. In the portion 31, four cylindrical weight insertion holes 33 having a radius R and oriented parallel to the center line of the crankshaft 17 are formed at equal intervals along the rotation direction of the crankshaft 17. On the insertion side inner peripheral surface 33a of 33, a locking groove 34 having a radius r having a semicircular transverse shape is formed over the entire circumference of the insertion side inner peripheral surface 33a.

図８に図示されるように、バランス調整部31のウエイト挿入孔33の奥側内周面33ｂに環状突出片36が、接着剤また溶接等で一体に嵌着され、該環状突出片36の内周面には円錐状傾斜面36ａが形成されている。 As shown in FIG. 8, an annular protruding piece 36 is integrally fitted to the inner peripheral surface 33 b of the weight insertion hole 33 of the balance adjusting portion 31 by an adhesive or welding, and the annular protruding piece 36 is A conical inclined surface 36a is formed on the inner peripheral surface.

錘部32および環状突出片36よりも比重が大きな材質の半径Ｒ以下の調整用ウエイト40の挿入先端部41には、前記ウエイト挿入孔33の奥側内周面33ｂに一体に嵌着された環状突出片36の円錐状傾斜面36ａに抜き差し可能に嵌合できる円錐面41ａが形成されるとともに、円錐面41ａの先端側の円筒面41ｂは、環状突出片36の円筒面36ｂに密接できる円筒面41ｂが形成されている。 An insertion tip portion 41 of an adjustment weight 40 having a specific gravity greater than that of the weight portion 32 and the annular projecting piece 36 and having a specific gravity smaller than that of the weight portion 32 and the annular protruding piece 36 is integrally fitted to the inner peripheral surface 33b on the back side of the weight insertion hole 33. A conical surface 41 a that can be removably fitted to the conical inclined surface 36 a of the annular projecting piece 36 is formed, and a cylindrical surface 41 b on the tip side of the conical surface 41 a is a cylinder that can be in close contact with the cylindrical surface 36 b of the annular projecting piece 36. A surface 41b is formed.

前記係止溝34の半径ｒよりも僅かに細い線径でかつ最も縮めたときの線長が２π（Ｒ−ｒ）以下で、高い弾性率を有する鋼製針金を曲率半径（Ｒ−ｒ）以上の曲率半径を有する切欠環状に弯曲して、係止部材45が形成されている。 A steel wire having a slightly smaller wire diameter than the radius r of the locking groove 34 and a wire length of 2π (R−r) or less when it is most contracted and having a high elastic modulus is a radius of curvature (R−r). A locking member 45 is formed by bending into a notch ring having the above radius of curvature.

調整用ウエイト40の挿入後端部42には、係止部材45の直径２ｒよりも大きな幅Ｄでかつ挿入後端部42の後端面42ａから奥側に向って係止溝34の奥側縁34ｂに達する挿入後端外周切欠き部43が調整用ウエイト40の全周に亘って形成されている。 The rear end portion 42 of the adjustment weight 40 has a width D larger than the diameter 2r of the locking member 45 and a rear edge of the locking groove 34 from the rear end surface 42a of the insertion rear end portion 42 to the rear side. An insertion rear end outer peripheral notch 43 reaching 34b is formed over the entire circumference of the adjustment weight 40.

図６〜８に図示されるように、錘部32における各ウエイト挿入孔33の挿入側内周面33ａには、それぞれ工具差し込み用切欠き凹部35が１個所づつ形成されている。 6-8, the insertion side inner peripheral surface 33a of each weight insertion hole 33 in the weight portion 32 is formed with one notch recess 35 for tool insertion.

図１ないし図８に図示の実施形態では、軸受部17と一体の最外側のバランス調整部31の錘部32に形成された最外側の２個の錘部32におけるウエイト挿入孔33に調整用ウエイト40を挿入する場合には、軸受部17を枢支する最外側ジャーナル部11ａに隣接する側から錘部32のウエイト挿入孔33に調整用ウエイト40を挿入するようになっているので、中央の２個の錘部32におけるウエイト挿入孔33に調整用ウエイト40を挿入する場合と違って、隣接するバランス調整部31に邪魔されずに、この挿入作業を円滑に短時間内に遂行できる。 In the embodiment shown in FIGS. 1 to 8, the weight insertion holes 33 in the two outermost weight portions 32 formed in the weight portion 32 of the outermost balance adjustment portion 31 integral with the bearing portion 17 are used for adjustment. When inserting the weight 40, the adjustment weight 40 is inserted into the weight insertion hole 33 of the weight portion 32 from the side adjacent to the outermost journal portion 11a that pivotally supports the bearing portion 17. Unlike the case where the adjustment weights 40 are inserted into the weight insertion holes 33 in the two weight portions 32, the insertion operation can be smoothly performed in a short time without being disturbed by the adjacent balance adjustment portions 31.

最外側の２個の錘部32に対しクランクケース11，シリンダブロック12の最外側ジャーナル部11ａ，12ａに隣接する側から調整用ウエイト40が挿入されるので、内燃機関10の運転中、調整用ウエイト40の挿入後端部42は常に最外側ジャーナル部11ａ，12ａに隣接し、また調整用ウエイト40の挿入先端部41は先細に形成されて、錘部32に一体的に固着された環状突出片36に当接している結果、調整用ウエイト40がウエイト挿入孔33から脱着する惧れがない。 Since adjustment weights 40 are inserted into the outermost two weight portions 32 from the side adjacent to the outermost journal portions 11a, 12a of the crankcase 11 and the cylinder block 12, the adjustment weight 40 is adjusted during operation of the internal combustion engine 10. The insertion rear end 42 of the weight 40 is always adjacent to the outermost journal portions 11a and 12a, and the insertion tip 41 of the adjustment weight 40 is formed in a tapered shape, and is an annular protrusion integrally fixed to the weight portion 32. As a result of the contact with the piece 36, there is no possibility that the adjustment weight 40 is detached from the weight insertion hole 33.

錘部32に形成されたウエイト挿入孔33の中心線33ｃは軸受部17の中心線17ａと平行であるので、内燃機関10の運転中に、錘部32のウエイト挿入孔33に挿入された調整用ウエイト40に遠心力が働いても、調整用ウエイト40がその遠心力でもって、ウエイト挿入孔33から抜ける方向の力を受けることがなく、調整用ウエイト40は安定してウエイト挿入孔33内に静止できる。 Since the center line 33 c of the weight insertion hole 33 formed in the weight portion 32 is parallel to the center line 17 a of the bearing portion 17, the adjustment inserted into the weight insertion hole 33 of the weight portion 32 during operation of the internal combustion engine 10. Even if a centrifugal force is applied to the weight 40 for adjustment, the adjustment weight 40 is not subjected to the force in the direction of coming out of the weight insertion hole 33 due to the centrifugal force, and the adjustment weight 40 is stably placed in the weight insertion hole 33. Can be stationary.

調整用ウエイト40を軸受部17における錘部32のウエイト挿入孔33に調整用ウエイト40を挿入した後、係止部材45のバランス調整部51における両端面を相互に当接するように係止部材45を変形した状態で、ウエイト挿入孔33の挿入側内周面33ａから係止部材45を押し込み、係止部材45をウエイト挿入孔33の係止溝34に係止部材45を係合すれば、挿入後端部42を錘部32のウエイト挿入孔33のから脱落不能に固定でき、また先端が尖った工具の先端を錘部32の工具差し込み用切欠き凹部35に差し込み、手前側に掻き出すように工具を傾斜すれば、係止部材45を係止溝34から取り出すことができ、錘部32のウエイト挿入孔33，係止溝34や係止部材45を損傷させずに、係止溝34に対する係止部材45の脱着を短時間内に実行することができる。 After the adjustment weight 40 is inserted into the weight insertion hole 33 of the weight portion 32 in the bearing portion 17, the locking member 45 is brought into contact with both end surfaces of the balance adjustment portion 51 of the locking member 45. If the locking member 45 is pushed from the insertion side inner peripheral surface 33a of the weight insertion hole 33 and the locking member 45 is engaged with the locking groove 34 of the weight insertion hole 33 in the deformed state, The rear end 42 can be fixed so that it cannot be removed from the weight insertion hole 33 of the weight 32, and the tip of a tool with a sharp tip is inserted into the notch recess 35 for inserting the tool of the weight 32 and scraped to the front side. If the tool is tilted, the locking member 45 can be removed from the locking groove 34, and the locking groove 34 can be removed without damaging the weight insertion hole 33, the locking groove 34 and the locking member 45 of the weight portion 32. Detachment of the locking member 45 with respect to can be performed within a short time.

調整用ウエイト40の挿入先端部41を錘部32の奥端部32ｂより外方へ突出させているので、その突出分だけ調整用ウエイト40のウエイト調整量を増大でできる。 Since the insertion tip 41 of the adjustment weight 40 protrudes outward from the back end 32b of the weight 32, the weight adjustment amount of the adjustment weight 40 can be increased by the protrusion.

調整用ウエイト40の挿入先端部41を先細に形成し、円錐状傾斜面36ａを形成した環状突出片36をウエイト挿入孔33の奥側内周面33ｂに一体に固着し、調整用ウエイト40の挿入先端部41に形成した円錐面41ａを環状突出片36の円錐状傾斜面36ａに当接させたため、貫通したウエイト挿入孔33に対する調整用ウエイト40の抜け止めと位置決めを簡単な構造で実現できる。 An insertion tip 41 of the adjustment weight 40 is tapered, and an annular protruding piece 36 having a conical inclined surface 36a is integrally fixed to the inner circumferential surface 33b of the weight insertion hole 33 so that the adjustment weight 40 Since the conical surface 41a formed on the insertion tip 41 is brought into contact with the conical inclined surface 36a of the annular projecting piece 36, the adjustment weight 40 can be prevented from coming off and positioned with respect to the penetrating weight insertion hole 33 with a simple structure. .

図１乃至図８に図示の第１実施形態の調整ウエイト固定構造30では、調整用ウエイト40を挿入保持するウエイト挿入孔33は貫通孔であって、調整用ウエイト40の挿入先端部41はウエイト挿入孔33から外部へ突出していたが、図９に図示の第２実施形態の調整用ウエイト固定構造50では、調整ウエイト60を挿入保持するウエイト挿入孔53は閉塞孔に構成されており、両実施形態における符号１ないし21の部分と符号45，46の部分の構造は共通しているので、これらの部分の符号は共用しており、第１実施形態の調整ウエイト固定構造30の各構成部分に対し、第２実施形態の調整用ウエイト固定構造50の各構成部分が相違している点について説明する。 In the adjustment weight fixing structure 30 of the first embodiment shown in FIGS. 1 to 8, the weight insertion hole 33 for inserting and holding the adjustment weight 40 is a through hole, and the insertion tip 41 of the adjustment weight 40 is the weight. Although protruding from the insertion hole 33 to the outside, in the weight fixing structure 50 for adjustment of the second embodiment shown in FIG. 9, the weight insertion hole 53 for inserting and holding the adjustment weight 60 is configured as a blocking hole. Since the structure of the reference numerals 1 to 21 and the reference numerals 45 and 46 in the embodiment are common, the reference numerals of these parts are shared, and each component of the adjustment weight fixing structure 30 of the first embodiment. On the other hand, the difference between the components of the adjustment weight fixing structure 50 of the second embodiment will be described.

調整用ウエイト固定構造50のバランス調整部51の錘部52におけるウエイト挿入孔53の挿入側内周面53ａは円筒形状に形成され、その奥側には、先細の奥側テーパ面53ｂが形成され、奥側テーパ面53ｂの奥側は、錘部52と一体の閉塞壁56が形成されている。 The insertion side inner peripheral surface 53a of the weight insertion hole 53 in the weight portion 52 of the balance adjustment portion 51 of the adjustment weight fixing structure 50 is formed in a cylindrical shape, and a tapered back side tapered surface 53b is formed on the back side. A closed wall 56 integral with the weight portion 52 is formed on the back side of the back taper surface 53b.

調整ウエイト60の挿入テーパ先端部61は、バランス調整部51における錘部52のウエイト挿入孔53の挿入側内周面53ａに密接しうるとともに、挿入テーパ先端部61の先端円錐面61ａは錘部52における閉塞壁56の内壁面56ａに密接しうるように形成されている。 The insertion taper tip 61 of the adjustment weight 60 can be in close contact with the insertion side inner peripheral surface 53a of the weight insertion hole 53 of the weight portion 52 in the balance adjustment portion 51, and the tip conical surface 61a of the insertion taper tip 61 is a weight portion. It is formed so as to be in close contact with the inner wall surface 56a of the blocking wall 56 in 52.

図２の実施形態は前述されたように構成されているので、ウエイト挿入孔53はクランクケース11，シリンダブロック12の最外側ジャーナル部（11ａ，12ａ）に隣接する側の面からのみ挿入されるので、バランス調整部51のウエイト挿入孔53へ挿入する方向が限定されて、挿入方向を迷うことなく容易に挿入でき、しかも調整用ウエイト固定構造50の挿入側内周面53ａと調整ウエイト60の先端円錐面61ａとの間に隙間が存在していても、閉塞壁56と調整用ウエイト固定構造50とで確固と固定状態を保持できる。 Since the embodiment of FIG. 2 is configured as described above, the weight insertion hole 53 is inserted only from the surface of the crankcase 11 and the cylinder block 12 adjacent to the outermost journal portion (11a, 12a). Therefore, the direction in which the balance adjusting portion 51 is inserted into the weight insertion hole 53 is limited, the insertion can be easily performed without losing the insertion direction, and the insertion-side inner peripheral surface 53a of the adjustment weight fixing structure 50 and the adjustment weight 60 Even if there is a gap between the front end conical surface 61a, the closed wall 56 and the adjustment weight fixing structure 50 can firmly hold the fixed state.

本実施例では、Ｖ型４気筒ＤＯＨＣ４ストローク内燃機関について説明したが、気筒数に限らず、本発明の調整ウエイト固定構造を採用できる。また、実施例の自動二輪車に限らず車両に搭載される内燃機関から汎用の内燃機関であっても良い。 In the present embodiment, the V-type four-cylinder DOHC four-stroke internal combustion engine has been described, but the adjustment weight fixing structure of the present invention can be adopted without being limited to the number of cylinders. Further, the invention is not limited to the motorcycle according to the embodiment, and may be a general-purpose internal combustion engine to an internal combustion engine mounted on the vehicle.

０…自動二輪車、１…メインフレーム、２…フロントフォーク、３…操舵ハンドル、４…前輪、５…リヤフォーク、６…後輪、７…チェーン伝動系、８…燃料タンク、９…シート、10…内燃機関、11…クランクケース、12…シリンダブロック、13…シリンダヘッド、14…ヘッドカバー、15…オイルパン、16…軸受部、17…クランクシャフト、18…シリンダ孔、19…ピストン、
20…コンロッド、21…ピストンピン、
30…調整ウエイト固定構造、31…バランス調整部、32…錘部、33…ウエイト挿入孔、34…係止溝、35…工具差し込み用切欠き凹部、36…環状突出片
40…調整用ウエイト、41…挿入先端部、42…挿入後端部、43…挿入後端外周切欠き部、45…係止部材、46…欠除部、
50…調整用ウエイト固定構造、51…バランス調整部、52…錘部、53…ウエイト挿入孔、54…係止溝、55…工具差し込み用切欠き凹部、56…閉塞壁、
60…調整ウエイト、61…挿入テーパ先端部、62…挿入後端部、63…挿入後端外周切欠き部。 DESCRIPTION OF SYMBOLS 0 ... Motorcycle, 1 ... Main frame, 2 ... Front fork, 3 ... Steering handle, 4 ... Front wheel, 5 ... Rear fork, 6 ... Rear wheel, 7 ... Chain transmission system, 8 ... Fuel tank, 9 ... Seat, 10 ... internal combustion engine, 11 ... crankcase, 12 ... cylinder block, 13 ... cylinder head, 14 ... head cover, 15 ... oil pan, 16 ... bearing part, 17 ... crankshaft, 18 ... cylinder hole, 19 ... piston,
20 ... connecting rod, 21 ... piston pin,
30 ... Adjustment weight fixing structure, 31 ... Balance adjustment part, 32 ... Weight part, 33 ... Weight insertion hole, 34 ... Locking groove, 35 ... Notch recess for tool insertion, 36 ... Annular protruding piece
40 ... adjusting weight, 41 ... insertion tip, 42 ... insertion rear end, 43 ... insertion rear end outer periphery notch, 45 ... locking member, 46 ... notch,
50 ... Weight fixing structure for adjustment, 51 ... Balance adjustment part, 52 ... Weight part, 53 ... Weight insertion hole, 54 ... Locking groove, 55 ... Notch recess for tool insertion, 56 ... Closure wall,
60: adjusting weight, 61: tip end of insertion taper, 62: rear end portion of insertion, 63: outer periphery notch portion of insertion rear end.

Claims

An internal combustion engine (10) having a crankshaft (17) rotatably supported by an internal combustion engine body (11, 12);
The balance adjusting portion (31, 51) provided with the weight portion (32, 52) that cancels the vibration generated by the rotation of the crankshaft (17) has a plurality of the same radius (R) formed in the circumferential direction. Circular weight insertion holes (33, 53) are arranged without a constant distance from the rotation center of the crankshaft (17),
An adjustment weight (consisting of a cylindrical member having a specific gravity different from that of the balance adjusting portion (31, 51) and being integrated by being inserted into the weight insertion hole (33, 53) of the balance adjusting portion (31, 51). 40, 60)
A locking member (45) that engages with a locking groove (34, 54) formed in the inner peripheral surface of the weight insertion hole (33, 53),
The adjustment weights (40, 60) inserted into the weight insertion holes (33, 53) abut on the locking members (45) engaged with the locking grooves (34, 54) in the axial direction. The adjustment weight fixing structure of the internal combustion engine, wherein the movement of the internal combustion engine is restricted .

The wait insertion hole (33) is formed by a through hole in said balance adjustment unit (31),
The locking groove (34) is formed on the insertion side inner peripheral surface (33a) of the weight insertion hole (33),
An annular projecting piece (36) projects from the inner peripheral surface on the outlet side of the weight insertion hole (33) to the center of the shaft,
The adjustment weight (40) inserted from the inlet side of the weight insertion hole (33) has an insertion tip (41) abutting the annular projecting piece (36) and an insertion rear end (42). 2. The adjustment weight fixing structure for an internal combustion engine according to claim 1 , wherein movement in the axial direction is restricted by contacting the locking member (45) engaged with the locking groove (34) .

The internal combustion engine adjustment according to claim 2, characterized in that the insertion tip (41) of the adjustment weight (40) penetrates the annular projecting piece (36) and projects from the weight insertion hole (33). Weight fixing structure.

Said locking member (45) is adjusted weights fixing structure according to any one of an internal combustion engine according to claim 1 to claim 3, characterized in that a part missing shape an annular ring.

The adjustment weight fixing structure for an internal combustion engine according to claim 4, wherein the weight portion (32) is provided with a notch recess (35) for inserting a tool when removing the locking member (45).

The weight insertion hole (53) is formed as a blocking hole in the balance adjustment part (51),
The locking groove (54) is formed on the inner peripheral surface on the inlet side of the weight insertion hole (53),
The adjustment weight (60) in the weight insertion hole (53) has an insertion tip end (61) abutting against the blocking wall (56) of the blocking hole, and an insertion rear end portion (62) at the locking groove. 2. The adjustment weight fixing structure for an internal combustion engine according to claim 1, wherein movement in the axial direction is restricted by coming into contact with the locking member (45) engaged with (54).

The crankshaft (17) is rotatably supported by outermost journal portions (11a, 12a) of the internal combustion engine body (11, 12), and the adjustment weights (40, 60) are supported by the outermost journal portion ( The adjusting weight fixing structure for an internal combustion engine according to any one of claims 1 to 6, wherein the adjusting weight fixing structure is fixed in a state where it can be inserted and removed from a side adjacent to 11a, 12a) .

The insertion rear end (42, 62) opposite to the insertion side of the adjustment weight (40, 60) is fixed at a position that does not protrude from the insertion side end surface (32a, 52a) of the weight (32, 52). 8. The adjustment weight fixing structure for an internal combustion engine according to claim 7.