JP4466301B2

JP4466301B2 - Motorcycle body structure

Info

Publication number: JP4466301B2
Application number: JP2004285266A
Authority: JP
Inventors: 浩長田
Original assignee: Suzuki Motor Co Ltd
Current assignee: Suzuki Motor Co Ltd
Priority date: 2004-09-29
Filing date: 2004-09-29
Publication date: 2010-05-26
Anticipated expiration: 2024-09-29
Also published as: JP2006096203A

Description

本発明は、自動二輪車の車体構造に関する。 The present invention relates to a vehicle body structure of a motorcycle.

車体フレームの後部にヘルメット等を収納可能な収納ボックスを設け、その下方にユニットスイング型エンジンを配置して車体フレームの中央下部にスイング自在に枢着したスクータ型の自動二輪車がある。このような自動二輪車は、一般にユニットスイング型エンジンをリヤクッションユニットにより車体フレームに弾性的に支持している。また、収納ボックスとユニットスイング型エンジンとの間のスペースに吸気装置を配置している。そして、収納ボックスの後方に燃料タンクを配置したものもある。（例えば特許文献１参照）。 There is a scooter type motorcycle in which a storage box capable of storing a helmet or the like is provided at the rear part of the body frame, a unit swing type engine is disposed below the box, and is pivotally attached to the lower center of the body frame so as to be swingable. In such a motorcycle, a unit swing type engine is generally elastically supported on a body frame by a rear cushion unit. In addition, an air intake device is arranged in a space between the storage box and the unit swing type engine. There is also a fuel tank disposed behind the storage box. (For example, refer to Patent Document 1).

一方、スクータ型自動二輪車の車体前下部にはライダが両足を乗せる低床のステップボードが備えられており、このステップボードを下方から支持する左右一対のフレーム部材が設けられている。（例えば特許文献２参照）。
特開平６−４８３４２号公報特開平６−４８３５０号公報 On the other hand, a scooter type motorcycle is provided with a low-floor step board on which the rider puts both feet at the front lower part of the vehicle body, and a pair of left and right frame members for supporting the step board from below are provided. (For example, refer to Patent Document 2).
JP-A-6-48342 JP-A-6-48350

しかしながら、車体フレーム後部の収納ボックスや燃料タンクのレイアウトに応じて車体フレームを曲げるとその剛性が低下するため、車体フレーム間に複数のブリッジ部材を設けて剛性を確保しなくてはならず、車体が大型化し、重量も増加してしまう。 However, if the vehicle body frame is bent according to the layout of the storage box or fuel tank at the rear of the vehicle body frame, the rigidity of the vehicle body frame decreases. Therefore, it is necessary to provide multiple bridge members between the vehicle body frames to ensure rigidity. Increases in size and weight.

また、燃料タンクの容量を確保しようとすると、周囲の機器のレイアウトに制限ができ、例えばリヤクッションユニットが短くなったり、極端に前傾斜させたりなど、乗り心地を低下させる虞がある。 Further, if it is attempted to secure the capacity of the fuel tank, the layout of surrounding devices can be limited, and there is a risk that the ride comfort will be reduced, for example, the rear cushion unit may be shortened or extremely forward inclined.

さらに、収納ボックスとユニットスイング型エンジンとの間のスペースに吸気装置を配置した場合、車体フレームとの干渉によってそのレイアウトが制限され、収納ボックス上方に配置される運転シートの座面が高くなったり、あるいは運転シート下方の車幅が広くなったりなど、ライダの足付き性を損なう虞がある。 Furthermore, when the intake device is disposed in the space between the storage box and the unit swing type engine, the layout is limited due to interference with the vehicle body frame, and the seat surface of the driving seat disposed above the storage box becomes high. Or, there is a possibility that the rider's legging property may be impaired, such as the vehicle width under the driving seat becomes wide.

一方、ステップボードを下方から支持する左右一対のフレーム部材の長さが同一であると固有の共振周波数が同等になると共に、車体フレームへの接続位置が振動源から等距離になると伝達される振動も同調するといった問題が生じ、ライダに不快感を与える。 On the other hand, if the lengths of the pair of left and right frame members that support the step board from the bottom are the same, the inherent resonance frequency is equal, and vibration is transmitted when the connection position to the body frame is equidistant from the vibration source. Causes problems such as synchronism, giving riders discomfort.

本発明は上述した事情を考慮してなされたもので、車体フレーム後部のコンパクト化を図ると共にその剛性を高める一方、乗り心地の向上を図った自動二輪車の車体構造を提供することを目的とする。 The present invention has been made in consideration of the above-described circumstances, and an object of the present invention is to provide a vehicle body structure for a motorcycle in which the rear portion of the vehicle body frame is made compact and the rigidity thereof is enhanced while the ride comfort is improved. .

本発明に係る自動二輪車の車体構造は、上述した課題を解決するために、請求項１に記載したように、略水平に前傾し、且つその中心が車両の進行方向に沿って配置されたシリンダアッセンブリを有するエンジン本体とこのエンジン本体の一側から後方に延びて後端に後輪を軸支するベルトケースとを一体的に備えると共に、車体フレームの中央下部にスイング自在に枢着され、且つリヤクッションユニットにより上記車体フレームに弾性的に支持されるユニットスイング型エンジンと、上記シリンダアッセンブリの吸気ポートに接続されて形成される吸気通路に燃料噴射手段とスロットルボディとエアクリーナとを備えて構成された燃料噴射式の吸気装置と、上記ユニットスイング型エンジンの上方に配置された収納ボックスとを備えたスクータ型の自動二輪車において、上記車体フレームの後部を、左右一対のサイドチューブと第一のブリッジ部材とによって平面視乃至前面視で環状に形成し、上記左右のサイドチューブを互いの後端部を対向するように接近させて結合しつつ前側部と後側部とが中間部より幅細い中膨らみ形状に形成する一方、上記収納ボックスをその一部が上記サイドチューブ内に没するように設け、上記収納ボックスの収納部の後部を上記左右のサイドチューブの中膨らみ部分に配置しつつ上記左右のサイドチューブ間の左右幅方向に渡って設け、さらに上記収納部の後部と上記左右のサイドチューブの後端結合部との間に形成される幅方向に長い扁平な湾曲空間にその前後幅に渡って燃料タンクを配置すると共に、上記収納ボックスは収納部と上部開口の後部から後方の燃料タンクの上部後方に向かって延出される後フランジ部とを備え、上記収納ボックスの固定部を、収納部の底面前部に設けた前固定部と、収納部の後部に設けた中間支持部と、上記収納部後側の上記後フランジ部に設けた後固定部とから構成し、且つ、上記収納部後部の中間支持部と上記後フランジ部の後固定部とを上記燃料タンクを前後から挟むように配置したものである。 In order to solve the above-described problems, the motorcycle body structure according to the present invention is inclined forward substantially horizontally and the center thereof is arranged along the traveling direction of the vehicle. An engine body having a cylinder assembly and a belt case extending rearward from one side of the engine body and pivotally supporting a rear wheel at the rear end are pivotally attached to a lower center portion of the vehicle body frame. A unit swing type engine that is elastically supported by the vehicle body frame by a rear cushion unit, and an intake passage formed by being connected to an intake port of the cylinder assembly includes a fuel injection means, a throttle body, and an air cleaner. A fuel injection type intake device and a storage box disposed above the unit swing type engine. In the motor type motorcycle, the rear portion of the body frame is formed in a ring shape in a plan view or a front view by a pair of left and right side tubes and a first bridge member, and the left and right side tubes are rear end portions of each other. The front side and the rear side are formed in a middle bulge shape that is narrower than the middle part while being coupled so as to face each other, while the storage box is provided so that a part of the storage box is submerged in the side tube. The rear portion of the storage box is provided in the left-right width direction between the left and right side tubes while the rear portion of the storage box is disposed in the middle bulge portion of the left and right side tubes. with arranging the fuel tank over its longitudinal width in a long flat curved space in a width direction is formed between the rear end coupling portion of the storage box housing portion and an upper opening And a flange portion after extending from the rear toward the upper rear of the rear of the fuel tank, the fixed portion of the storage box, and a hold portion provided on the bottom front of the housing portion, provided in the rear of the housing part An intermediate support portion and a rear fixing portion provided at the rear flange portion on the rear side of the storage portion, and the intermediate support portion at the rear portion of the storage portion and the rear fixing portion of the rear flange portion are connected to the fuel. The tank is arranged so as to be sandwiched from the front and back .

また、上述した課題を解決するために、請求項２に記載したように、略水平に前傾し、且つその中心が車両の進行方向に沿って配置されたシリンダアッセンブリを有するエンジン本体とこのエンジン本体の一側から後方に延びて後端に後輪を軸支するベルトケースとを一体的に備えると共に、車体フレームの中央下部にスイング自在に枢着され、且つリヤクッションユニットにより上記車体フレームに弾性的に支持されるユニットスイング型エンジンと、上記シリンダアッセンブリの吸気ポートに接続されて形成される吸気通路に燃料噴射手段とスロットルボディとエアクリーナとを備えて構成された燃料噴射式の吸気装置と、上記ユニットスイング型エンジンの上方に配置された収納ボックスとを備えたスクータ型の自動二輪車において、車体フレームの後部を、左右一対のサイドチューブと第一のブリッジ部材とで環状の第一の閉ループに形成すると共に、上記第一のブリッジ部材と、上記左右のサイドチューブと、これらの左右のサイドチューブを跨ぐように架設される第二ブリッジ部材とによって第二の閉ループを形成する一方、上記車体フレームの後部を側面視で上記第一の閉ループ前端が最下部に、後端が最上部になるように傾斜した略単純平面状に形成すると共に、この第一の閉ループの平面から上記第二の閉ループを上方に立ち上がるように屈曲させて形成し、上記収納ボックスを上記第一の閉ループの最上部と上記第二の閉ループの最上部とに連結した上で、上記収納ボックスの収納部の底部を上記第二の閉ループの最上部から水平に延出させて側面視で上記第一の閉ループの平面から後方に突出させて設け、上記収納部の後部と上記第一の閉ループの最上部との間に燃料タンクを配置し、この燃料タンクの前部と上記収納部の後部を車両側面視で前後にオーバーラップした状態で上記第一の閉ループの平面を上下に縦断させて設ける一方、上記左右のサイドチューブに車体艤装部材を吊り下げ支持し、この車体艤装部材で上記燃料タンクを保持したものである。 In order to solve the above-mentioned problem, as described in claim 2, an engine main body having a cylinder assembly tilted forward substantially horizontally and centered along the traveling direction of the vehicle, and the engine A belt case that extends rearward from one side of the main body and pivotally supports the rear wheel at the rear end is pivotally attached to a lower center portion of the vehicle body frame, and is swingably attached to the vehicle body frame by a rear cushion unit. A unit swing type engine that is elastically supported, and a fuel injection type intake device that includes a fuel injection means, a throttle body, and an air cleaner in an intake passage formed by being connected to an intake port of the cylinder assembly; In a scooter type motorcycle having a storage box disposed above the unit swing type engine, The rear part of the body frame is formed into an annular first closed loop with a pair of left and right side tubes and a first bridge member, and the first bridge member, the left and right side tubes, and the left and right sides thereof A second closed loop is formed by the second bridge member laid across the tube, while the front end of the first closed loop is at the bottom and the rear end is at the top in the rear view of the body frame. In this way, the storage box is formed at the top of the first closed loop, and is formed by bending the second closed loop so as to rise upward from the plane of the first closed loop. And the bottom of the storage portion of the storage box is horizontally extended from the top of the second closed loop and connected to the top of the second closed loop. Provided from the plane of the closed loop is projected rearwardly, and a fuel tank is disposed between the top of the rear and the first loop of the storage portion, the vehicle rear of the front and the housing part of the fuel tank While the plane of the first closed loop is vertically cut in a state of overlapping in front and rear in a side view, a vehicle body fitting member is suspended and supported on the left and right side tubes, and the fuel tank is supported by the vehicle body fitting member. It is held.

さらにまた、上述した課題を解決するために、請求項３に記載したように、上記収納ボックスの前下にこの収納ボックスの前下部を支持する水平部を備えた正面視台形状に形成された第二ブリッジ部材を上記左右のサイドチューブを繋ぐように設け、これらの左右のサイドチューブを、正面視で逆「ハ」の字状に車両の幅方向に拡開するように延設すると共に、これらの第一および第二ブリッジ部材と上記左右のサイドチューブとで正面視略六角形状の第二の閉ループを形成し、正面視この第二の閉ループで上記シリンダアッセンブリの全周を囲う一方、上記第二ブリッジ部材の脚部と上記サイドチューブとが狭角の略「Ｖ」字状を成すことにより形成される略三角形の空間に上記吸気装置の配管を収容すると共に、上記吸気装置の配管に設けられる上記燃料噴射手段を上記サイドチューブの延出方向に沿うように傾斜して配置し、その上端が上記第二ブリッジ部材の水平部を含む面より上方に突出するように設けたものである。 Furthermore, in order to solve the above-described problem, as described in claim 3 , the storage box is formed in a front view trapezoidal shape including a horizontal portion that supports a front lower portion of the storage box at the lower front. The second bridge member is provided so as to connect the left and right side tubes, and the left and right side tubes are extended so as to expand in the width direction of the vehicle in a reverse “C” shape in front view, These first and second bridge members and the left and right side tubes form a second hexagonal closed loop when viewed from the front, and the second closed loop when viewed from the front surrounds the entire circumference of the cylinder assembly. The pipe of the intake device is accommodated in a substantially triangular space formed by the leg portion of the second bridge member and the side tube forming a substantially “V” shape with a narrow angle, and the pipe of the intake device is Setting Is the fuel injection means is disposed inclined along the extending direction of the side tube, the upper end in which is provided so as to protrude upward from the plane including the horizontal portion of the second bridge member.

そして、上述した課題を解決するために、請求項４に記載したように、上記第二ブリッジ部材の水平部の両端部に脚部を設け、少なくとも一方の脚部の上記サイドチューブとの接続部近傍に枠部材を別体に設けてこの部分に側方乃至前方に向けて枠状の開口を形成し、この開口に臨むように上記シリンダアッセンブリを構成するシリンダヘッドを配設すると共に、このシリンダヘッドの開口に臨む部位に着脱可能なエンジン補器類を配設したものである。 And in order to solve the subject mentioned above, as described in Claim 4 , a leg part is provided in the both ends of the horizontal part of the said 2nd bridge member, and the connection part with the said side tube of at least one leg part A frame member is separately provided in the vicinity, and a frame-shaped opening is formed in this portion from the side to the front. A cylinder head constituting the cylinder assembly is disposed so as to face the opening, and the cylinder is disposed. Removable engine accessories are arranged at the part facing the opening of the head.

また、上述した課題を解決するために、請求項５に記載したように、上記車体フレームは車両の前部から斜め後下方に向かって延び、途中で略水平になるように湾曲して後方に向かって延びて上記第一のブリッジ部材に接続されるボディチューブと、このボディチューブの両側方に設けられた、ライダが両足を乗せる低床のステップボードを下方から支持する左右一対のフットレストチューブとを備える一方、上記ボディチューブに接続される上記左右のフットレストチューブの各先端を、互いに異なる高さで上記ボディチューブの相反する側面に接続したものである。 In order to solve the above-mentioned problem, as described in claim 5 , the vehicle body frame extends obliquely rearward and downward from the front portion of the vehicle, and is bent so as to be substantially horizontal in the middle. A body tube that extends toward the first bridge member and a pair of left and right footrest tubes that are provided on both sides of the body tube and support a low-floor step board on which the rider places both feet from below. On the other hand, the distal ends of the left and right footrest tubes connected to the body tube are connected to opposite side surfaces of the body tube at different heights.

さらに、上述した課題を解決するために、請求項６に記載したように、上記左右のフットレストチューブを同一の断面形状、且つ同一断面積の金属パイプから構成し、それぞれ互いに異なる長さに設定したものである。 Furthermore, in order to solve the above-described problem, as described in claim 6 , the left and right footrest tubes are composed of metal pipes having the same cross-sectional shape and the same cross-sectional area, and are set to different lengths. Is.

本発明に係る自動二輪車の車体構造によれば、車体フレームの後部が環状となってその剛性が高まると共に、収納ボックスを車体フレームの構成部材として利用できて車体フレーム後部の剛性が高まり、従来必要であった左右のサイドチューブの中間部を連結するブリッジ部材が不要となって車体フレームがコンパクト化する。また、吸気装置周りの車体のコンパクト化を図ることができる。 According to the vehicle body structure of the motorcycle according to the present invention, the rigidity of the rear portion of the vehicle body frame can be increased by using the storage box as a component of the vehicle body frame. This eliminates the need for the bridge member that connects the middle portions of the left and right side tubes, thereby reducing the size of the vehicle body frame. In addition, the vehicle body around the intake device can be made compact.

さらにまた、スペースを有効利用してコンパクト化を図りながら燃料タンクの容量も増やすことができる。さらに、懸架ブラケット周辺がコンパクトにまとまり、車両の乗り心地も向上すると共に、ユニットスイング型エンジン下部の保護を図ることもできる。 Furthermore, the capacity of the fuel tank can be increased while the space is effectively utilized and the size is reduced. Furthermore, the suspension bracket and its surroundings can be compactly compacted, improving the ride comfort of the vehicle and protecting the lower part of the unit swing type engine.

そして、ライダの足付き性が向上すると共に前輪からの衝撃伝達が緩和され、さらに左右のフットレストチューブが同時に共振することが抑止されてライダの乗り心地が向上する。 In addition, the rider's footability is improved, the impact transmission from the front wheels is reduced, and the left and right footrest tubes are prevented from resonating at the same time, thereby improving the rider's riding comfort.

以下、本発明の実施形態を図面に基づいて説明する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

図１は、この発明を適用した自動二輪車の実施形態例を示す左側面図である。また、図２はこの自動二輪車の平面図である。図１および図２に示すように、この自動二輪車１は例えばスクータ型の車両であり、車体フレーム２を有する。車体フレーム２は、主に車両の前部から斜め後下方に向かって延び、途中で略水平になるように湾曲して後方に向かって延びるボディチューブ３と、このボディチューブ３の後端側から後斜め上方に延びる左右一対のサイドチューブ４Ｌ，４Ｒと、ボディチューブ３の後端部とサイドチューブ４Ｌ，４Ｒの先端部とを繋ぐ第一のブリッジ部材であるブリッジチューブ５と、ボディチューブ３の前寄り中間部とサイドチューブ４Ｌ，４Ｒの前寄り中間部とを繋ぐ左右一対のフットレストチューブ６Ｌ，６Ｒとから構成される。 FIG. 1 is a left side view showing an embodiment of a motorcycle to which the present invention is applied. FIG. 2 is a plan view of the motorcycle. As shown in FIGS. 1 and 2, the motorcycle 1 is a scooter type vehicle, for example, and has a body frame 2. The body frame 2 mainly extends from the front portion of the vehicle obliquely rearward and downward, is curved so as to be substantially horizontal in the middle and extends rearward, and the rear end side of the body tube 3. A pair of left and right side tubes 4L, 4R extending diagonally upward, a bridge tube 5 as a first bridge member connecting the rear end of the body tube 3 and the tip of the side tubes 4L, 4R; It is composed of a pair of left and right footrest tubes 6L, 6R that connect the front intermediate portion and the front intermediate portions of the side tubes 4L, 4R.

ボディチューブ３の前端上部にはヘッドパイプ７が設けられ、このヘッドパイプ７によって、その下端で前輪８を回動自在に支持するフロントフォーク９や、前輪８を左右に操舵するハンドルバー１０等が支持される。 A head pipe 7 is provided at the upper part of the front end of the body tube 3, and the head pipe 7 has a front fork 9 that rotatably supports the front wheel 8 at its lower end, a handlebar 10 that steers the front wheel 8 left and right, and the like. Supported.

一方、サイドチューブ４Ｌ，４Ｒの上方にはヘルメット１１等を収納可能な収納ボックス１２が、その一部をサイドチューブ４Ｌ，４Ｒ内に没するように設けられる。また、収納ボックス１２の上方にはこの収納ボックス１２の蓋を兼ねた運転シート１３が、その前端部に設けられた回動ヒンジ１４を介して開閉自在に設置される。 On the other hand, a storage box 12 capable of storing the helmet 11 and the like is provided above the side tubes 4L and 4R so that a part thereof is submerged in the side tubes 4L and 4R. An operation seat 13 that also serves as a lid of the storage box 12 is installed above the storage box 12 so as to be openable and closable via a rotating hinge 14 provided at the front end thereof.

また、収納ボックス１２の下方にはユニットスイング型エンジン１５が配置され、懸架ブラケット１６を介して車体フレーム２の中央下部にスイング自在に枢着される。このユニットスイング型エンジン１５はエンジン本体１７と、このエンジン本体１７の一側から後方に延びるベルトケース１８とを一体的に備える。ベルトケース１８はスイングアームを兼ねており、リヤクッションユニット１９により車体フレーム２に弾性的に支持される。そして、運転シート１３の下方に位置するベルトケース１８の後端に駆動輪である後輪２０が軸支される。 A unit swing type engine 15 is disposed below the storage box 12 and is pivotally attached to the lower center portion of the vehicle body frame 2 via a suspension bracket 16 so as to be swingable. This unit swing type engine 15 is integrally provided with an engine body 17 and a belt case 18 extending rearward from one side of the engine body 17. The belt case 18 also serves as a swing arm, and is elastically supported by the vehicle body frame 2 by the rear cushion unit 19. A rear wheel 20 as a driving wheel is pivotally supported at the rear end of the belt case 18 positioned below the driving seat 13.

さらに、この自動二輪車１は、その車体全体が例えば合成樹脂製の車体カバー２１で覆われて外観が整えられる。車体カバー２１は、複数個のカバーエレメントを組み立てることにより構成される。カバーエレメントは、具体的にはフロントレッグシールド２２、リヤレッグシールド２３、フレームカバー２４、センターフロントカバー２５およびハンドルカバー２６等から構成される。また、前輪８の上方にはフロントフェンダ２７が、後輪２０の上方にはリヤフェンダ２８がそれぞれ配置される。 Further, the entire motorcycle 1 is covered with a vehicle body cover 21 made of synthetic resin, for example, so that the appearance of the motorcycle 1 is adjusted. The vehicle body cover 21 is configured by assembling a plurality of cover elements. Specifically, the cover element includes a front leg shield 22, a rear leg shield 23, a frame cover 24, a center front cover 25, a handle cover 26, and the like. A front fender 27 is disposed above the front wheel 8, and a rear fender 28 is disposed above the rear wheel 20.

運転シート１３とハンドルバー１０との間は下方に向かって大きくＵ字状に湾入し、その底部にライダが両足を乗せる低床のステップボード２９を備えたリヤレッグシールド２３が配置される。リヤレッグシールド２３は、ボディチューブ３の水平部３８分を上方から覆うように配置され、ボディチューブ３に固定される。また、ステップボード２９はフットレストチューブ６Ｌ，６Ｒの上面に固定される。さらに、リヤレッグシールド２３の前部からはライダの脚部を前方から覆うフロントレッグシールド２２が上方に向かって立ち上がるように配置され、ボディチューブ３の前部立ち上がり部分に固定される。 A rear leg shield 23 having a low-floor step board 29 on which a rider puts both feet is disposed between the driver's seat 13 and the handlebar 10 in a large U shape downward. The rear leg shield 23 is disposed so as to cover the horizontal portion 38 of the body tube 3 from above, and is fixed to the body tube 3. The step board 29 is fixed to the upper surfaces of the footrest tubes 6L and 6R. Further, a front leg shield 22 that covers the rider's legs from the front is arranged to rise upward from the front part of the rear leg shield 23, and is fixed to the front part rising part of the body tube 3.

一方、サイドチューブ４Ｌ，４Ｒおよび収納ボックス１２の周囲には、例えば左右別体に形成されたフレームカバー２４がサイドチューブ４Ｌ，４Ｒおよび収納ボックス１２の左右を囲むように設けられる。さらに、ハンドルバー１０の周囲はハンドルカバー２６によって覆われる。なお、これらのカバーエレメントはプラスティック樹脂素材、例えばＰＰ樹脂やＡＢＳ樹脂等で成型される。そして、運転シート１３直後方のフレームカバー２４上にはリヤキャリア３０が設けられる。さらに、この車両の例えばハンドルカバー２６にはヘッドライト３１が設けられ、フレームカバー２４の後部、リヤキャリア３０の下方にはリヤコンビネーションランプ３２が設けられる。 On the other hand, around the side tubes 4L and 4R and the storage box 12, for example, a frame cover 24 formed separately on the left and right sides is provided so as to surround the left and right sides of the side tubes 4L and 4R and the storage box 12. Further, the handle bar 10 is covered with a handle cover 26. These cover elements are molded from a plastic resin material such as PP resin or ABS resin. A rear carrier 30 is provided on the frame cover 24 immediately after the operation seat 13. Further, for example, a headlight 31 is provided on the handle cover 26 of the vehicle, and a rear combination lamp 32 is provided at a rear portion of the frame cover 24 and below the rear carrier 30.

図３は車体フレーム２単体の左側面図である。また、図４は車体フレーム２単体の平面図である。さらに、図５は図３のＶ矢視図、図６は図３のＶＩ矢視図、そして図７は図３のＶＩＩ矢視図である。図３〜図５に示すように、左右のフットレストチューブ６Ｌ，６Ｒは同一の断面形状、且つ同一断面積の金属パイプから構成される。そして、左右のフットレストチューブ６Ｌ，６Ｒの先端が矩形の断面を有するボディチューブ３の湾曲部の上方に接続され、平面視で車両の幅方向に向かって拡がった後、後方に向かって湾曲し、ステップボード２９の幅よりやや狭い幅でボディチューブ３に沿うよう車両の進行方向中心線３３と略平行に後方に向かって延設され、後端がサイドチューブ４Ｌ，４Ｒの立ち上がり首元に沿うように屈曲して接続される。 FIG. 3 is a left side view of the vehicle body frame 2 alone. FIG. 4 is a plan view of the body frame 2 alone. 5 is a view taken along the arrow V in FIG. 3, FIG. 6 is a view taken along the arrow VI in FIG. 3, and FIG. 7 is a view taken along the arrow VII in FIG. As shown in FIGS. 3 to 5, the left and right footrest tubes 6 L and 6 R are composed of metal pipes having the same cross-sectional shape and the same cross-sectional area. And the front-end | tip of right-and-left footrest tube 6L, 6R is connected above the curved part of the body tube 3 which has a rectangular cross section, and after it expands in the width direction of a vehicle by planar view, it curves toward the back, Extending rearward substantially parallel to the vehicle traveling direction center line 33 so as to be along the body tube 3 with a width slightly narrower than the width of the step board 29, so that the rear end is along the rising neck of the side tubes 4L and 4R. Bent and connected.

また、フットレストチューブ６Ｌ，６Ｒは側面視でステップボード２９の下面に沿ってやや後上がりに延設される。そして、図５に詳細に示すように、左右のフットレストチューブ６Ｌ，６Ｒは互いに異なる長さに設定されると共に、ボディチューブ３の湾曲部の上方に接続される左右のフットレストチューブ６Ｌ，６Ｒの各先端は、互いに異なる高さでボディチューブ３の相反する側面に接続される。 Further, the footrest tubes 6L and 6R extend slightly rearward along the lower surface of the step board 29 in a side view. As shown in detail in FIG. 5, the left and right footrest tubes 6L and 6R are set to different lengths, and each of the left and right footrest tubes 6L and 6R connected above the curved portion of the body tube 3 is set. The distal ends are connected to opposite side surfaces of the body tube 3 at different heights.

ところで、ボディチューブ３の最下端位置とステップボード２９の下面との間、およびボディチューブ３の側面とフットレストチューブ６Ｌ，６Ｒの内側面との間に囲まれた空間は物品の収納スペースとして利用可能であり、本実施形態においてはボディチューブ３と長さが短い左側のフットレストチューブ６Ｌとの間の空間を制御装置等の電装品３４Ｌや配線等の艤装部品の収納空間として用い、また、長さが長い右側のフットレストチューブ６Ｒとの間の比較的大きい空間をバッテリ３４Ｒの収納空間として用いる（図１および図２参照）。さらに、ボディチューブ３とブリッジチューブ５との接続部で電装品３４Ｌが搭載される側には補強部材３５が架設され、例えばこの補強部材３５の前部上方にバッテリ３４Ｒや電装品３４Ｌ等の艤装部品を収納したケース（図示せず）が載置される。 By the way, the space enclosed between the lowermost position of the body tube 3 and the lower surface of the step board 29 and between the side surface of the body tube 3 and the inner side surfaces of the footrest tubes 6L and 6R can be used as a storage space for articles. In the present embodiment, the space between the body tube 3 and the short left footrest tube 6L is used as a storage space for electrical equipment 34L such as a control device and equipment parts such as wiring. A relatively large space between the footrest tube 6R on the right side having a long length is used as a storage space for the battery 34R (see FIGS. 1 and 2). Further, a reinforcing member 35 is installed on the side where the electrical component 34L is mounted at the connection portion between the body tube 3 and the bridge tube 5, and for example, a battery 34R, an electrical component 34L, and the like are installed above the front portion of the reinforcing member 35. A case (not shown) in which components are stored is placed.

車体フレーム２の後部を構成する左右のサイドチューブ４Ｌ，４Ｒは、いずれもその前下半部が側面視でほぼ一直線上に形成される。また、左側サイドチューブ４Ｌの後上半部はそのまま一直線に延出する一方、右側サイドチューブ４Ｒの後上半部は上方に向かって略「く」の字状に立ち上がるように、あるいはなだらかなクランク状に屈曲され、さらに水平方向寄りに左側サイドチューブ４Ｌと重なるように折曲される。 The left and right side tubes 4L and 4R constituting the rear portion of the vehicle body frame 2 are formed so that their front lower half portions are substantially straight in a side view. Further, the rear upper half of the left side tube 4L extends straight as it is, while the rear upper half of the right side tube 4R rises upward in a substantially “<” shape or a gentle crank. And is bent so as to overlap the left side tube 4L toward the horizontal direction.

また、左右のサイドチューブ４Ｌ，４Ｒは、平面視乃至前面視でブリッジチューブ５の両端から逆「ハ」の字状に車両の幅方向に拡開しながら斜め後上方に向かって延設された後、車両の進行方向中心線３３と略平行に斜め後上方に向かって延設され、さらに、互いの後端部が車両の進行方向中心線３３に向かって対向するように折曲されて左右のサイドチューブ４Ｌ，４Ｒの後端部が接近して結合され、前側部と後側部とが中間部より幅細い中膨らみ形状、且つブリッジチューブ５を含めてほぼ左右対称な奇数角形、本実施形態においては七角形に近い環状の流線型に構成されて第一の閉ループ３６を形成する。すなわち、左右のサイドチューブ４Ｌ，４Ｒは、側面視で第一の閉ループ３６前端が最下部に、後端が最上部になるように傾斜した略単純平面状に形成される。 Further, the left and right side tubes 4L and 4R are extended obliquely rearward and upward from the both ends of the bridge tube 5 in a plan view or a front view while expanding in a reverse “C” shape in the width direction of the vehicle. Thereafter, the vehicle is extended obliquely rearward and upward substantially parallel to the vehicle traveling direction center line 33, and is further bent so that the rear end portions thereof face each other toward the vehicle traveling direction center line 33. The rear end portions of the side tubes 4L and 4R are connected to each other, the front side portion and the rear side portion are narrower than the middle portion, and the middle square shape is symmetric. In the form, the first closed loop 36 is formed by forming an annular streamline shape close to a heptagon. That is, the left and right side tubes 4L and 4R are formed in a substantially simple flat shape that is inclined so that the front end of the first closed loop 36 is at the bottom and the rear end is at the top in the side view.

収納ボックス１２の前下部、ブリッジチューブ５の後方には左右のサイドチューブ４Ｌ，４Ｒを跨ぐように第二のブリッジ部材３７が架設される。図６に示すように、この第二ブリッジ部材３７は収納ボックス１２の前下部を支持する水平部３８を備えた正面視台形状に形成される。 A second bridge member 37 is installed on the front lower part of the storage box 12 and behind the bridge tube 5 so as to straddle the left and right side tubes 4L, 4R. As shown in FIG. 6, the second bridge member 37 is formed in a trapezoidal shape including a horizontal portion 38 that supports the front lower portion of the storage box 12.

収納ボックス１２は、容器としての収納部３９と、この収納部３９の上部開口の周囲に形成された鍔状のフランジ部４０とから構成される。収納部３９の上部開口後部のフランジ部４０は後方に向かって延設されて後フランジ部４１を形成し、この後フランジ部４１に後固定部４２が設けられると共に、収納部３９の底面前部に前固定部４３が設けられる。そして、左右のサイドチューブ４Ｌ，４Ｒの後端結合部に架設された後支持部４４に後フランジ部４１の後固定部４２が、前記第二ブリッジ部材３７の水平部３８に収納部３９の前固定部４３がそれぞれ取り付けられて収納ボックス１２が車体フレーム２に固定される。さらに、左側サイドチューブ４Ｌには収納部３９の後部側方寄りに中間支持部４５が形成され、収納部３９を支持する。このとき、後フランジ部４１は左右のサイドチューブ４Ｌ，４Ｒの中膨らみ部分に配置されつつ左右のサイドチューブ４Ｌ，４Ｒ間の左右幅方向に渡って設けられる。 The storage box 12 includes a storage portion 39 as a container and a bowl-shaped flange portion 40 formed around the upper opening of the storage portion 39. A flange portion 40 at the rear of the upper opening of the storage portion 39 extends rearward to form a rear flange portion 41, a rear fixing portion 42 is provided on the rear flange portion 41, and a bottom front portion of the storage portion 39 is provided. A front fixing portion 43 is provided on the front side. Then, the rear fixing portion 42 is provided on the rear support portion 44 installed on the rear end coupling portion of the left and right side tubes 4L, 4R, and the horizontal portion 38 of the second bridge member 37 is provided in front of the storage portion 39. The fixing portions 43 are respectively attached, and the storage box 12 is fixed to the vehicle body frame 2. Further, an intermediate support portion 45 is formed on the left side tube 4 L toward the rear side of the storage portion 39 to support the storage portion 39. At this time, the rear flange portion 41 is provided in the left-right width direction between the left and right side tubes 4L, 4R while being disposed at the middle bulge portions of the left and right side tubes 4L, 4R.

上述した構造で収納ボックス１２が車体フレーム２に固定されることにより収納ボックス１２はその全長に渡ってシートフレームとして機能する。すなわち、運転シート１３上方からの荷重（主にライダの体重）や収納ボックス１２を含めた上方からの荷重（荷物を含めた重量）は収納ボックス１２の蓋を兼ねる運転シート１３の底面から収納ボックス１２の、収納部３９の上部開口の上端が受け、収納ボックス１２の剛性により車体フレーム２に伝える構造である。 When the storage box 12 is fixed to the vehicle body frame 2 with the structure described above, the storage box 12 functions as a seat frame over its entire length. That is, the load from the upper side of the operation seat 13 (mainly the weight of the rider) and the load from the upper side including the storage box 12 (weight including the luggage) are stored from the bottom of the operation seat 13 that also serves as a lid of the storage box 12. 12, the upper end of the upper opening of the storage portion 39 is received and transmitted to the vehicle body frame 2 by the rigidity of the storage box 12.

収納ボックス１２を構成する収納部３９は、平面視で略卵形状に類似する外形を有し、車両の中心付近に位置する前端付近の曲率半径が全体の中でもっとも小さいものに設定されたいわゆる先細り形状である。そして、この収納部３９にヘルメット１１が、ほぼ面対称形状であるヘルメット１１の中心面がほぼ水平となるように、且つヘルメット１１の顎部から後頭部を結ぶ長手方向が車両の進行方向中心線３３にほぼ沿って収納可能なように、収納部３９の縦断面形状は前側面および後側面が上下方向垂直に、底面が水平に、そして底面の後半部から後側面の下部にかけては球面に近い湾曲面形状に形成される。 The storage portion 39 constituting the storage box 12 has an outer shape similar to a substantially egg shape in plan view, and the so-called curvature radius in the vicinity of the front end located near the center of the vehicle is set to be the smallest in the whole. Tapered shape. The longitudinal direction connecting the chin portion of the helmet 11 to the back of the head is such that the helmet 11 has a substantially plane-symmetric shape in the storage portion 39 and the center surface of the helmet 11 is substantially horizontal. The vertical cross-sectional shape of the storage portion 39 is curved so that the front side surface and the rear side surface are vertically vertical, the bottom surface is horizontal, and the bottom surface of the bottom surface is close to a spherical surface from the rear half of the bottom surface to the lower part of the rear side surface. It is formed in a surface shape.

左側サイドチューブ４Ｌの上部且つ車体中心寄りの後端近傍にはこの左側サイドチューブ４Ｌの延出方向に対して略垂直に交差するように後下方に延びる前側ブラケット４６が設けられ、この前側ブラケット４６には前記リヤクッションユニット１９の上端部を支持するユニット支持部４７が設けられる。また、左右のサイドチューブ４Ｌ，４Ｒの後端部には左右一対の後側ブラケット４８が設けられ、これらの後側ブラケット４８には車体艤装部材である前記リヤフェンダ２８の前上部が吊り下げられるように支持される。 A front bracket 46 extending rearward and downward is provided in the upper part of the left side tube 4L and in the vicinity of the rear end near the center of the vehicle body so as to intersect substantially perpendicularly to the extending direction of the left side tube 4L. A unit support portion 47 that supports the upper end portion of the rear cushion unit 19 is provided. Also, a pair of left and right rear brackets 48 are provided at the rear ends of the left and right side tubes 4L and 4R, and the front upper part of the rear fender 28, which is a vehicle body fitting member, is suspended from these rear brackets 48. Supported by

収納ボックス１２の、収納部３９の後部と左右のサイドチューブ４Ｌ，４Ｒの後端結合部との間、且つ後フランジ部４１下方に形成される幅方向に長い扁平な湾曲空間にはその前後幅に渡って燃料タンク４９が配置される。そして、収納ボックス１２の後部を左右のサイドチューブ４Ｌ，４Ｒの後端結合部に固定する後フランジ部４１の後固定部４２は燃料タンク４９を挟んで収納部３９の後側に設けられる。 The flat curved space long in the width direction formed between the rear portion of the storage portion 39 and the rear end coupling portions of the left and right side tubes 4L, 4R and below the rear flange portion 41 of the storage box 12 has its front-rear width. The fuel tank 49 is arranged over the range. A rear fixing portion 42 for fixing the rear portion of the storage box 12 to the rear end coupling portions of the left and right side tubes 4L and 4R is provided on the rear side of the storage portion 39 with the fuel tank 49 interposed therebetween.

収納部３９の後部縦壁５０は車両の側部に向かうに従って前方に回りこむ形状を有し、この形状に沿って燃料タンク４９の前部形状も車両の側部に向かうに従って前方に回りこむ形状とされると共に、下方にも突出する形状を有する。 The rear vertical wall 50 of the storage part 39 has a shape that turns forward as it goes toward the side of the vehicle, and the shape of the front part of the fuel tank 49 also turns forward as it goes toward the side of the vehicle along this shape. And has a shape protruding downward.

また、燃料タンク４９はリヤフェンダ２８の上面に載置されると共に、燃料タンク４９の底部とその後方はリヤフェンダ２８内に入り込むように支持され、燃料タンク４９の水平方向、特に後方と左右方向への動きおよび下方への動きの位置決めをされつつ固定される。そして、側面視で収納部３９の後部と燃料タンク４９の前部とが重なる位置乃至その前方近傍の範囲に位置する左右のサイドチューブ４Ｌ，４Ｒの部位は平面視で左右のサイドチューブ４Ｌ，４Ｒの最大幅部となるように構成される。 The fuel tank 49 is mounted on the upper surface of the rear fender 28, and the bottom of the fuel tank 49 and the rear thereof are supported so as to enter the rear fender 28. The fuel tank 49 extends in the horizontal direction, particularly in the rear and left / right directions. Fixed while being positioned for movement and downward movement. The left and right side tubes 4L and 4R located in the position where the rear portion of the storage portion 39 and the front portion of the fuel tank 49 overlap in the side view or in the vicinity of the front thereof are the left and right side tubes 4L and 4R in the plan view. It is comprised so that it may become the largest width part.

さらに、燃料タンク４９の上部には燃料の給油管部５１が設けられ、この給油管部５１を収納ボックス１２の後フランジ部４１に形成された開口から上方へ突出するように勘合させることにより、燃料タンク４９はその水平方向および上下方への動きの位置決めをされつつ固定される。また、燃料注油口５２が収納部３９の後部縦壁５０と左右のサイドチューブ４Ｌ，４Ｒの後端結合部に架設された後支持部４４との間に配置される。 Furthermore, an upper portion of the fuel tank 49 is provided with a fuel supply pipe portion 51. By fitting the fuel supply pipe portion 51 so as to protrude upward from an opening formed in the rear flange portion 41 of the storage box 12, The fuel tank 49 is fixed while positioning its movement in the horizontal direction and in the upward and downward directions. Further, the fuel injection port 52 is disposed between the rear vertical wall 50 of the storage portion 39 and the rear support portion 44 installed on the rear end coupling portion of the left and right side tubes 4L and 4R.

そして、燃料タンク４９はその後端が後輪２０の車軸５３のほぼ鉛直方向上方に配置されると共に、燃料タンク４９の後端と後輪２０の車軸５３との間にこれらを繋ぐように前記リヤクッションユニット１９がほぼ直立に近い状態で前傾配置される。そしてまた、後輪２０の車軸５３の後方にはリヤフェンダ２８の後半部と前記リヤコンビネーションランプ３２が配置される。 The rear end of the fuel tank 49 is disposed substantially vertically above the axle 53 of the rear wheel 20, and the rear end of the fuel tank 49 is connected between the rear end of the fuel tank 49 and the axle 53 of the rear wheel 20. The cushion unit 19 is tilted forward in a state of being almost upright. Further, the rear half of the rear fender 28 and the rear combination lamp 32 are disposed behind the axle 53 of the rear wheel 20.

前述したように、収納ボックス１２の下方に配置されたユニットスイング型エンジン１５は例えば４サイクル空冷単気筒のエンジン本体１７と、このエンジン本体１７の一側、本実施形態においては左側から後方に延びるベルトケース１８とを一体的に備える。図８は、このユニットスイング型エンジン１５の拡大左側面図であり、図９はユニットスイング型エンジン１５の平面図である。また、図１０は図８のＸ−Ｘ線に沿う断面図である。 As described above, the unit swing type engine 15 arranged below the storage box 12 extends, for example, from a four-cycle air-cooled single cylinder engine body 17 and one side of the engine body 17, in this embodiment, from the left side to the rear. A belt case 18 is integrally provided. FIG. 8 is an enlarged left side view of the unit swing type engine 15, and FIG. 9 is a plan view of the unit swing type engine 15. FIG. 10 is a sectional view taken along line XX in FIG.

図８〜図１０に示すように、エンジン本体１７は主に、略水平に前傾し、且つその中心が車両の進行方向に沿って配置されたシリンダブロック５４、シリンダヘッド５５およびシリンダヘッドカバー５６から構成されるシリンダアッセンブリ５７とクランクケース５８とから構成され、シリンダブロック５４に形成されたシリンダ５９内のピストン６０の往復運動がコンロッド６１を介してクランクケース５８内を車幅方向に延びるクランクシャフト６２を回転運動させる。また、エンジン本体１７の一側から後方に延びるベルトケース１８はその内部にベルト室６３を形成し、このベルト室６３にＶベルト式自動変速装置６４が配置され、クランクシャフト６２の回転が伝達される。さらに、クランクケース５８、シリンダブロック５４およびシリンダヘッド５５の各上面は略平坦に形成される。 As shown in FIGS. 8 to 10, the engine body 17 mainly includes a cylinder block 54, a cylinder head 55, and a cylinder head cover 56 that are inclined forward in a substantially horizontal direction and whose center is disposed along the traveling direction of the vehicle. A crankshaft 62, which is composed of a cylinder assembly 57 and a crankcase 58, is configured so that the reciprocating motion of the piston 60 in the cylinder 59 formed in the cylinder block 54 extends in the vehicle width direction through the connecting rod 61 in the crankcase 58. Rotate. The belt case 18 extending rearward from one side of the engine body 17 forms a belt chamber 63 therein. A V-belt type automatic transmission 64 is disposed in the belt chamber 63, and the rotation of the crankshaft 62 is transmitted. The Further, the upper surfaces of the crankcase 58, the cylinder block 54, and the cylinder head 55 are formed substantially flat.

シリンダヘッド５５にはシリンダ５９に整合する燃焼室６５が形成され、外方から、本実施形態においてはシリンダヘッド５５の左側部前方から点火プラグ６６が、この点火プラグ６６にプラグコード６７がそれぞれ装着される。また、シリンダヘッド５５内には図示しない吸・排気バルブを開閉させる動弁装置６８が配置され、シリンダヘッドカバー５６によって覆われる。さらに、シリンダヘッドカバー５６には排気浄化用の補器類が設けられる。具体的には、シリンダヘッドカバー５６の内側に金属板６９を取り付けてブリーザ室７０を区画形成すると共に、シリンダヘッドカバー５６の外側端面には二次エア供給用リードバルブ７１が一体的に形成され、収納ボックス１２下方の車体カバー２１に沿うように対向配置される。 The cylinder head 55 is formed with a combustion chamber 65 aligned with the cylinder 59. From the outside, in the present embodiment, a spark plug 66 is attached from the front of the left side of the cylinder head 55, and a plug cord 67 is attached to the spark plug 66. Is done. Further, a valve operating device 68 for opening and closing an intake / exhaust valve (not shown) is disposed in the cylinder head 55 and is covered with a cylinder head cover 56. Further, the cylinder head cover 56 is provided with auxiliary devices for exhaust purification. Specifically, a breather chamber 70 is defined by attaching a metal plate 69 to the inside of the cylinder head cover 56, and a secondary air supply reed valve 71 is integrally formed on the outer end surface of the cylinder head cover 56 for storage. Oppositely arranged along the body cover 21 below the box 12.

図１、図８および図９に示すように、エンジン本体１７の上方には吸気装置７２が配置される。吸気装置７２は、シリンダヘッド５５内の図示しない吸気ポートを介して燃焼室６５に接続されて形成される吸気通路にインレットパイプ７３と、このインレットパイプ７３の途中に接続される燃料噴射手段７４と、インレットパイプ７３の上流側に接続されるスロットルボディ７５と、このスロットルボディ７５の上流側にアウトレットパイプ７６を介して接続されるエアクリーナ７７とを備えて構成された燃料噴射式の吸気装置７２である。なお、詳細には図示しないが、上記ブリーザ室７０からはブリーザホース７８がスロットルボディ７５に繋がる。 As shown in FIGS. 1, 8, and 9, an intake device 72 is disposed above the engine body 17. The intake device 72 includes an inlet pipe 73 in an intake passage formed by being connected to the combustion chamber 65 via an intake port (not shown) in the cylinder head 55, and fuel injection means 74 connected in the middle of the inlet pipe 73. A fuel injection type intake device 72 comprising a throttle body 75 connected to the upstream side of the inlet pipe 73 and an air cleaner 77 connected to the upstream side of the throttle body 75 via an outlet pipe 76. is there. Although not shown in detail, a breather hose 78 is connected to the throttle body 75 from the breather chamber 70.

一方、図１および図２に示すように、シリンダヘッド５５の下面には燃焼室６５に繋がるエキゾーストパイプ７９の上流端が接続される。エキゾーストパイプ７９はエンジン本体１７の下部を回って車両の右側に導かれてさらに後方に向かって延設され、後輪２０の右側部に配置されたマフラ８０にエキゾーストパイプ７９の下流端が接続されて排気装置８１を構成する。 On the other hand, as shown in FIGS. 1 and 2, the upstream end of the exhaust pipe 79 connected to the combustion chamber 65 is connected to the lower surface of the cylinder head 55. The exhaust pipe 79 goes around the lower part of the engine body 17 and is led to the right side of the vehicle and extends rearward. The downstream end of the exhaust pipe 79 is connected to a muffler 80 disposed on the right side of the rear wheel 20. Thus, the exhaust device 81 is configured.

車体フレーム２の中央下部、より具体的には車体フレーム２を構成するサイドチューブ４Ｌ，４Ｒの先端部とブリッジチューブ５との接続部の後方下部には左右一対の補強部材８２が架設される。これらの補強部材８２はユニットスイング型エンジン１５を軸支する車体懸架部を兼ね、前述したように、ユニットスイング型エンジン１５はこれらの補強部材８２に懸架ブラケット１６を介してスイング自在に枢着される。 A pair of left and right reinforcing members 82 is installed at the center lower portion of the body frame 2, more specifically, at the rear lower portion of the connection portion between the distal ends of the side tubes 4 L and 4 R constituting the body frame 2 and the bridge tube 5. These reinforcing members 82 also serve as vehicle body suspensions that pivotally support the unit swing type engine 15. As described above, the unit swing type engine 15 is pivotally attached to these reinforcing members 82 via the suspension bracket 16 so as to be swingable. The

図１１は、懸架ブラケット１６およびその周辺の拡大左側面図である。図１１に示すように、懸架ブラケット１６はその前部に車体懸架部である補強部材８２に枢着する車体側回動軸８３と、その後部にエンジン本体１７を構成するクランクケース５８の下面に一体に設けられて前方に向かって延びるエンジン懸架部である懸架アーム８４に枢着するエンジン側回動軸８５とを有する側面視円弧形状を有するものであり、剛性だけではなく強さを有する鉄系の金属素材から成形される。 FIG. 11 is an enlarged left side view of the suspension bracket 16 and its surroundings. As shown in FIG. 11, the suspension bracket 16 has a vehicle body side rotation shaft 83 pivotally attached to a reinforcing member 82 which is a vehicle body suspension portion at a front portion thereof, and a lower surface of a crankcase 58 constituting the engine body 17 at a rear portion thereof. It has an arc shape in a side view and has an engine-side rotation shaft 85 pivotally attached to a suspension arm 84 that is an integral engine suspension portion that extends forward, and has not only rigidity but also strength. Molded from metallic materials.

車両の下面を形成する懸架ブラケット１６の円弧面８８の曲率半径８６は、側面視で両回動軸間距離８７より大きく一定に設定され、例えばこの自動二輪車１に装備される前輪８や後輪２０のタイヤ８ｔ，２０ｔやホイール８ｗ，２０ｗの外径の曲率半径と同程度に設定される。ここで、タイヤ８ｔ，２０ｔの外径は、車両走行時に必要な走破性を有する程度に設定されているので、物理的な慣性に、異物や路面との接触状態で乗り越え性を有するものである。 The radius of curvature 86 of the arcuate surface 88 of the suspension bracket 16 that forms the lower surface of the vehicle is set to be constant and larger than the distance 87 between both rotation shafts in a side view, for example, the front wheel 8 and the rear wheel that are mounted on the motorcycle 1. The radius of curvature of the outer diameters of the 20 tires 8t and 20t and the wheels 8w and 20w is set to be approximately the same. Here, the tire 8t, the outer diameter of the 20t, because it is set so that with a running property required during vehicle running, the physical inertia, those having overcome resistance in contact with foreign matter or the road surface .

クランクケース５８の下面から延びる懸架アーム８４は、その懸架ブラケット１６への枢着部がエンジン本体１７のシリンダブロック５４とシリンダヘッド５５との合わせ面の、シリンダ５９の軸に沿うシリンダ５９の中間位置の上下方向に位置するように形成される。また、懸架アーム８４の後部内側からはオイルパン８９が後方に向かって形成される。一方、シリンダブロック５４とシリンダヘッド５５との合わせ面の鉛直上方付近には上記燃料噴射手段７４が、その上端が後方に位置するよう傾斜した状態で配置される。 The suspension arm 84 extending from the lower surface of the crankcase 58 is located at the intermediate position of the cylinder 59 along the axis of the cylinder 59 at the joint surface of the cylinder block 54 and the cylinder head 55 of the engine body 17. It is formed so as to be positioned in the vertical direction. An oil pan 89 is formed rearward from the rear inner side of the suspension arm 84. On the other hand, the fuel injection means 74 is disposed in the vicinity of the vertically upper portion of the mating surface of the cylinder block 54 and the cylinder head 55 so that the upper end thereof is inclined rearward.

懸架ブラケット１６の前半部上方の、車両正面視で逆「ハ」の字状に車両の幅方向に拡開する左右のサイドチューブ４Ｌ，４Ｒ間にはシリンダヘッドカバー５６が配置される。すなわち、ブリッジチューブ５と、左右のサイドチューブ４Ｌ，４Ｒと、これらの左右のサイドチューブ４Ｌ，４Ｒを跨ぐように架設される第二ブリッジ部材３７とによって形成され、略単純平面状に形成された第一の閉ループ３６から上方に立ち上がるように屈曲させて形成された正面視略六角形状の第二の閉ループ９０内にシリンダアッセンブリ５７の全周が正面視で囲まれるように構成される。また、この部位に左右のフットレストチューブ６Ｌ，６Ｒの後端が接続される。 A cylinder head cover 56 is disposed between the left and right side tubes 4L and 4R that expand in the width direction of the vehicle in a reverse “C” shape when viewed from the front of the vehicle, above the front half of the suspension bracket 16. That is, it is formed by the bridge tube 5, the left and right side tubes 4L and 4R, and the second bridge member 37 that is laid across the left and right side tubes 4L and 4R, and is formed in a substantially simple planar shape. The cylinder assembly 57 is configured so that the entire circumference of the cylinder assembly 57 is surrounded in a front view in a second closed loop 90 having a substantially hexagonal shape in a front view formed by bending so as to rise upward from the first closed loop 36. Also, the rear ends of the left and right footrest tubes 6L, 6R are connected to this part.

第二ブリッジ部材３７は、図２、図３および図６に示すように、収納ボックス１２の前下部を支持する水平部３８を備えた正面視台形状に形成されており、その水平部３８の両端部に脚部９１Ｌ、９１Ｒを有する。そして、少なくとも一方の脚部、本実施形態においては左側の脚部９１Ｌの左側サイドチューブ４Ｌとの接続部近傍には別体に設けられた枠部材９２が用いられてこの部分に側方乃至前方に向けて枠状の開口９３（閉空間）が形成され、この開口９３に臨むようにシリンダヘッド５５が配設されると共に、このシリンダヘッド５５の開口９３に臨む部位に着脱可能なエンジン補器類、例えば前記点火プラグ６６およびプラグコード６７が配設される。 As shown in FIGS. 2, 3, and 6, the second bridge member 37 is formed in a trapezoidal shape including a horizontal portion 38 that supports the front lower portion of the storage box 12. Legs 91L and 91R are provided at both ends. A frame member 92 provided separately is used near at least one leg, in the present embodiment, in the vicinity of the connecting portion of the left leg 91L to the left side tube 4L. A frame-shaped opening 93 (closed space) is formed to face the cylinder head 55 so that the cylinder head 55 faces the opening 93, and the engine accessory that can be attached to and detached from the part facing the opening 93 of the cylinder head 55 For example, the spark plug 66 and the plug cord 67 are provided.

さらに、車両正面視で別体に設けられた枠部材９２を含む第二ブリッジ部材３７の左側脚部９１Ｌと左側サイドチューブ４Ｌとが狭角の略「Ｖ」字状を成すことにより形成される略三角形の空間９４に前記吸気装置７２の配管が収められる。 Furthermore, the left leg 91L and the left side tube 4L of the second bridge member 37 including the frame member 92 provided separately from the front of the vehicle form a substantially “V” shape with a narrow angle. The piping of the intake device 72 is accommodated in a substantially triangular space 94.

一方、図１に示すように、吸気装置７２を構成する燃料噴射手段７４は左側サイドチューブ４Ｌの延出方向に沿うように傾斜して配置されると共に、その上端が第二ブリッジ部材３７の水平部３８を含む面より上方に突出するように設けられる。また、燃料噴射手段７４は側面視で収納ボックス１２と重なるように配置される。このとき、収納ボックス１２底部の前後長の中央位置に対し、燃料噴射手段７４はこの中央位置より前方に配置されると共に、燃料噴射手段７４が接続されるインレットパイプ７３の上流側に接続されるスロットルボディ７５は中央位置より後方に配置される。 On the other hand, as shown in FIG. 1, the fuel injection means 74 constituting the intake device 72 is disposed so as to be inclined along the extending direction of the left side tube 4 L, and the upper end thereof is horizontal to the second bridge member 37. It is provided so as to protrude upward from the surface including the portion 38. Further, the fuel injection means 74 is disposed so as to overlap the storage box 12 in a side view. At this time, the fuel injection means 74 is arranged in front of the center position of the front and rear length of the bottom of the storage box 12 and is connected to the upstream side of the inlet pipe 73 to which the fuel injection means 74 is connected. The throttle body 75 is arranged behind the center position.

さらに、左側サイドチューブ４Ｌは燃料噴射手段７４とスロットルボディ７５との間、すなわち収納ボックス１２底部の前後長の中央位置付近を通るように配設される。さらにまた、収納部３９底面の最下部は大半が水平な平面状に形成され、その前後方向の中心はスロットルボディ７５より前方に配置される。 Further, the left side tube 4L is disposed so as to pass between the fuel injection means 74 and the throttle body 75, that is, near the center position of the front and rear length of the bottom of the storage box 12. Furthermore, the lowermost part of the bottom surface of the storage part 39 is mostly formed in a horizontal flat surface, and the center in the front-rear direction is arranged in front of the throttle body 75.

ところで、上述した実施形態においては右側サイドチューブ４Ｒの後上半部を上方に向かって略「く」の字状に立ち上がるように、あるいはなだらかなクランク状に屈曲させた例を示したが、左側サイドチューブ４Ｌと同様に一直線状に形成することは支持剛性の観点からも充分可能である。また、上述した実施形態においてはユニットスイング型エンジン１５を車体フレーム２に懸架させる懸架アーム８４をクランクケース５８の下面に一体に設けた例を示したが、懸架アーム８４をクランクケース５８とは別体に設けてもよい。 By the way, in the above-described embodiment, an example in which the rear upper half of the right side tube 4 R rises upward in a substantially “<” shape or is bent in a gentle crank shape is shown. Similarly to the side tube 4L, it is sufficiently possible to form it in a straight line from the viewpoint of support rigidity. In the above-described embodiment, the example in which the suspension arm 84 for suspending the unit swing type engine 15 on the vehicle body frame 2 is integrally provided on the lower surface of the crankcase 58 has been described, but the suspension arm 84 is separated from the crankcase 58. It may be provided on the body.

次に、本実施形態の作用について説明する。 Next, the operation of this embodiment will be described.

車体フレーム２の後部を、左右一対のサイドチューブ４Ｌ，４Ｒとブリッジチューブ５とで平面視（または前面視）環状の第一の閉ループ３６に形成し、左右のサイドチューブ４Ｌ，４Ｒを互いの後端部を対向するように接近させて結合しつつ前側部と後側部とが中間部より幅細い中膨らみ形状にしたことにより、車体フレーム２後部の剛性が高まる。 The rear portion of the vehicle body frame 2 is formed in a first closed loop 36 having a pair of left and right side tubes 4L, 4R and a bridge tube 5 in an annular shape in plan view (or front view), and the left and right side tubes 4L, 4R are rearward of each other. The rigidity of the rear part of the vehicle body frame 2 is increased by making the front side part and the rear side part narrower than the middle part while making the ends approach each other so as to face each other.

また、ブリッジチューブ５と、左右のサイドチューブ４Ｌ，４Ｒと、これらの左右のサイドチューブ４Ｌ，４Ｒを跨ぐように架設される第二ブリッジ部材３７とによって第二の閉ループ９０を形成し、車体フレーム２の後部を側面視で第一の閉ループ３６前端が最下部に、後端が最上部になるように傾斜した略単純平面状に形成すると共に、この第一の閉ループ３６の平面から第二の閉ループ９０を上方に立ち上がるように屈曲させて形成し、収納ボックス１２をその一部がサイドチューブ４Ｌ，４Ｒ内に没するよう、第一の閉ループ３６の最上部と第二の閉ループ９０の最上部とに連結し、さらに収納ボックス１２の収納部３９の後部を左右のサイドチューブ４Ｌ，４Ｒの中膨らみ部分に配置されつつ左右のサイドチューブ４Ｌ，４Ｒ間の左右幅方向に渡って設けた上で、収納部３９の底部を第二の閉ループ９０の最上部、すなわち第二ブリッジ部材３７の水平部３８から水平に延出させて側面視で第一の閉ループ３６の平面から後方に突出させて設けたことにより、収納ボックス１２を車体フレーム２の構成部材として利用できて車体フレーム２後部の剛性が高まると共に、従来必要であった左右のサイドチューブ４Ｌ，４Ｒの中間部を連結するブリッジ部材が不要となり、車体フレーム２のコンパクト化、重量の低減が図れる。 Further, a second closed loop 90 is formed by the bridge tube 5, the left and right side tubes 4L and 4R, and the second bridge member 37 laid so as to straddle these left and right side tubes 4L and 4R. The rear portion of the first closed loop 36 is formed in a substantially simple plane shape that is inclined so that the front end of the first closed loop 36 is at the lowermost portion and the rear end is at the uppermost portion in a side view. The closed loop 90 is bent so as to rise upward, and the storage box 12 is soaked in the side tubes 4L and 4R so that the uppermost portion of the first closed loop 36 and the uppermost portion of the second closed loop 90 are formed. Further, the rear portion of the storage portion 39 of the storage box 12 is disposed between the left and right side tubes 4L, 4R while being arranged in the middle swelling portions of the left and right side tubes 4L, 4R. In the right width direction, the bottom of the storage portion 39 extends horizontally from the uppermost portion of the second closed loop 90, that is, the horizontal portion 38 of the second bridge member 37, and the first closed loop in side view. Since the storage box 12 can be used as a structural member of the vehicle body frame 2 and the rigidity of the rear portion of the vehicle body frame 2 is increased, the left and right side tubes 4L and 4R that are conventionally required are provided. The bridge member for connecting the intermediate portions of the body frame 2 is not necessary, and the body frame 2 can be made compact and the weight can be reduced.

さらに、収納部３９の後部と左右のサイドチューブ４Ｌ，４Ｒの後端結合部との間、すなわち収納部３９の後部と第一の閉ループ３６の最上部との間に形成される幅方向に長い扁平な湾曲空間にその前後幅に渡って燃料タンク４９を配置し、燃料タンク４９の前部を側面視で収納部３９の後部に重ねた状態で第一の閉ループ３６の平面を上下に縦断させて設けたことにより、スペースを有効利用してコンパクト化を図りながら燃料タンク４９の容量も増やすことができる。 Furthermore, it is long in the width direction formed between the rear part of the storage part 39 and the rear end coupling parts of the left and right side tubes 4L, 4R, that is, between the rear part of the storage part 39 and the uppermost part of the first closed loop 36. A fuel tank 49 is arranged in a flat curved space across its front and rear width, and the plane of the first closed loop 36 is vertically cut in a state where the front part of the fuel tank 49 is overlapped with the rear part of the storage part 39 in a side view. Accordingly, the capacity of the fuel tank 49 can be increased while the space is effectively utilized and the size is reduced.

一方、車体フレーム２の中央下部にユニットスイング型エンジン１５を軸支する車体懸架部である補強部材８２を設けると共に、エンジン本体１７を構成するクランクケース５８の下面前部にエンジン懸架部である懸架アーム８４を設け、これらの両懸架部８２，８４により懸架ブラケット１６を介して車体フレーム２とユニットスイング型エンジン１５とをスイング自在に連結すると共に、懸架ブラケット１６に車体懸架部である補強部材８２に枢着する車体側回動軸８３とエンジン懸架部である懸架アーム８４に枢着するエンジン側回動軸８５とを設け、懸架ブラケット１６の側面視形状を曲率半径が一定の円弧形状とすることにより、懸架ブラケット１６周辺がコンパクトにまとまり、車両の乗り心地も向上すると共に、ユニットスイング型エンジン１５下部の保護を図ることもできる。 On the other hand, a reinforcing member 82 that is a vehicle body suspension portion that pivotally supports the unit swing type engine 15 is provided at the center lower portion of the vehicle body frame 2, and a suspension that is an engine suspension portion is provided at the front of the lower surface of the crankcase 58 that constitutes the engine body 17. An arm 84 is provided, and the vehicle body frame 2 and the unit swing type engine 15 are swingably connected to each other by the suspension portions 82 and 84 via the suspension bracket 16, and a reinforcing member 82 that is a vehicle body suspension portion is attached to the suspension bracket 16. A vehicle body side rotation shaft 83 pivotally attached to the vehicle and an engine side rotation shaft 85 pivotally attached to the suspension arm 84 as an engine suspension portion are provided, and the side view shape of the suspension bracket 16 is an arc shape with a constant curvature radius. it result, the peripheral suspension brackets 16 coherent compact and improved riding comfort of the vehicle, the unit Sui It is also possible to achieve grayed engine 15 under protection.

また、収納ボックス１２の前下にこの収納ボックス１２の前下部を支持する水平部３８を備えて正面視台形状に形成された第二ブリッジ部材３７を左右のサイドチューブ４Ｌ，４Ｒを繋ぐように設け、これらの左右のサイドチューブ４Ｌ，４Ｒを、平面視（または前面視）でブリッジチューブ５（第一ブリッジ部材）の両端から逆「ハ」の字状に車両の幅方向に拡開しながら斜め後上方に向かって延設すると共に、これらの第一および第二ブリッジ部材５，３７と左右のサイドチューブ４Ｌ，４Ｒとで正面視略六角形状の第二の閉ループ９０を形成し、この第二の閉ループ９０でシリンダアッセンブリ５７の全周を正面視で囲ったことにより、車体フレーム２の高剛性化が図れると共に、車体のコンパクト化を図ることができる。ユニットスイング型エンジン１５をその下部で車体フレーム２に懸架することから、この第二の閉ループ９０はシリンダアッセンブリ５７の揺動方向を前後に相通する位置であるため、コンパクトに形成しても互いに干渉することはない。 Further, a second bridge member 37 that is provided with a horizontal portion 38 that supports the front lower portion of the storage box 12 at the front lower side of the storage box 12 and is formed in a trapezoidal shape in front view is connected to the left and right side tubes 4L and 4R. The left and right side tubes 4L and 4R are expanded in the width direction of the vehicle in a reverse “C” shape from both ends of the bridge tube 5 (first bridge member) in plan view (or front view). The first and second bridge members 5 and 37 and the left and right side tubes 4L and 4R form a second closed loop 90 having a substantially hexagonal shape when viewed from the front. By surrounding the entire circumference of the cylinder assembly 57 with the second closed loop 90 in a front view, the vehicle body frame 2 can be made highly rigid and the vehicle body can be made compact. Since the unit swing type engine 15 is suspended from the lower part of the vehicle body frame 2, the second closed loop 90 is a position where the swing direction of the cylinder assembly 57 communicates back and forth, so that even if it is compact, it interferes with each other. Never do.

さらに、別体に設けられた枠部材９２を含む第二ブリッジ部材３７の左側脚部９１Ｌと左側サイドチューブ４Ｌとが狭角の略「Ｖ」字状を成すことにより形成される車両正面視略三角形の空間９４に吸気装置７２の配管を収容すると共に、吸気装置７２を構成する燃料噴射手段７４を左側サイドチューブ４Ｌの延出方向に沿うように傾斜して配置し、その上端が第二ブリッジ部材３７の水平部３８を含む面より上方に突出するように設けたことにより、吸気装置７２周りの車体のコンパクト化を図ることができる。 Further, the front view of the vehicle formed by the left-side leg portion 91L of the second bridge member 37 including the frame member 92 provided separately and the left-side side tube 4L forming a substantially narrow “V” shape. The piping of the intake device 72 is accommodated in the triangular space 94, and the fuel injection means 74 constituting the intake device 72 is disposed so as to be inclined along the extending direction of the left side tube 4L, and the upper end thereof is the second bridge. By providing the member 37 so as to protrude above the surface including the horizontal portion 38, the vehicle body around the intake device 72 can be made compact.

さらにまた、第二ブリッジ部材３７の水平部３８の両端部に脚部９１Ｌ、９１Ｒを設け、少なくとも一方の脚部９１Ｌのサイドチューブ４Ｌとの接続部近傍に枠部材９２を別体に設けてこの部分に側方乃至前方に向けて枠状の開口９３（閉空間）を形成し、この開口９３に臨むようにシリンダヘッド５５を配設すると共に、このシリンダヘッド５５の開口９３に臨む部位に着脱可能なエンジン補器類６６，６７を配設したことにより、比較的大きなシリンダヘッド５５を車体フレーム２に近接配置でき、その結果車体フレーム２の幅を狭くできるので、車体のコンパクト化が図れると共に、ライダの足付き性も向上する。 Furthermore, leg portions 91L and 91R are provided at both ends of the horizontal portion 38 of the second bridge member 37, and a frame member 92 is provided separately in the vicinity of the connection portion between at least one leg portion 91L and the side tube 4L. A frame-shaped opening 93 (closed space) is formed in the part from the side to the front, and the cylinder head 55 is disposed so as to face the opening 93, and is attached to and detached from the portion of the cylinder head 55 facing the opening 93. By disposing the possible engine accessories 66 and 67, a relatively large cylinder head 55 can be disposed close to the vehicle body frame 2 and, as a result, the width of the vehicle body frame 2 can be reduced, so that the vehicle body can be made compact. Also, rider's footing is improved.

また、枠状の開口はシリンダヘッド５５に着脱される点火プラグ６６やプラグコード６７のメンテナンス時に作業空間として利用できるので、エンジン補器類のメンテナンス性も向上する。さらに、この開口９３の枠構造により、比較的大きなシリンダヘッド５５に車体フレーム２を近接配置でき、フレーム幅を狭くすることが可能となってライダの足付き性が向上する。なお、クランクケース５８、シリンダブロック５４およびシリンダヘッド５５の各上面を略平坦に形成することもライダの足付き性の向上に繋がる。 Further, since the frame-shaped opening can be used as a work space during the maintenance of the spark plug 66 and the plug cord 67 that are attached to and detached from the cylinder head 55, the maintainability of the engine accessories is also improved. Further, the frame structure of the opening 93 allows the vehicle body frame 2 to be disposed close to a relatively large cylinder head 55, thereby reducing the frame width and improving the rider's legibility. Note that forming the upper surfaces of the crankcase 58, the cylinder block 54, and the cylinder head 55 substantially flat also leads to an improvement in the rider's legibility.

ところで、ボディチューブ３に接続される左右のフットレストチューブ６Ｌ，６Ｒの長さが同一であると固有の共振周波数が同等になると共に、接続位置が振動源から等距離になると伝達される振動も同調するといった問題が生じる。そこで、ボディチューブ３に接続される左右のフットレストチューブ６Ｌ，６Ｒの各先端を、互いに異なる高さでボディチューブ３の相反する側面に接続したことにより、左右のフットレストチューブ６Ｌ，６Ｒが同調して振動することが抑止されると共に、トータル的な前輪８からの衝撃伝達が緩和され、乗り心地が向上する。 By the way, if the lengths of the left and right footrest tubes 6L and 6R connected to the body tube 3 are the same, the specific resonance frequency is equal, and the transmitted vibration is also tuned when the connection position is equidistant from the vibration source. Problem arises. Therefore, the left and right footrest tubes 6L and 6R are synchronized with each other by connecting the tips of the left and right footrest tubes 6L and 6R connected to the body tube 3 to opposite sides of the body tube 3 at different heights. The vibration is suppressed, and the total shock transmission from the front wheels 8 is alleviated to improve the riding comfort.

また、左右のフットレストチューブ６Ｌ，６Ｒを同一の断面形状、且つ同一断面積の金属パイプから構成し、それぞれ互いに異なる長さに設定したことにより、対を成す部材の互いの共振周波数（固有周波数）が変わり、左右のフットレストチューブ６Ｌ，６Ｒが同時に共振することが抑止される。 In addition, the left and right footrest tubes 6L and 6R are made of metal pipes having the same cross-sectional shape and the same cross-sectional area, and are set to different lengths from each other, so that the mutual resonance frequency (natural frequency) of the paired members Changes and the left and right footrest tubes 6L and 6R are prevented from resonating simultaneously.

一方、収納部３９の後部縦壁５０を車両の側部に向かうに従って前方に回りこむ形状とし、この形状に沿って燃料タンク４９の前部形状も車両の側部に向かうに従って前方に回りこむ形状、且つ下方にも突出する形状とする一方、左右のサイドチューブ４Ｌ，４Ｒの後下部に車体艤装部材であるリヤフェンダ２８の前上部を吊り下げ支持し、燃料タンク４９をリヤフェンダ２８の上面に載置すると共に、燃料タンク４９の底部とその後方をリヤフェンダ２８内に入り込むように支持したことにより、燃料タンク４９の保持が確実になると共に、車両の減速時など、燃料の重量による燃料タンク４９の前方向の荷重を収納ボックス１２および車体フレーム２で受けることが可能になる。 On the other hand, the rear vertical wall 50 of the storage part 39 is shaped to wrap forward as it goes to the side of the vehicle, and the shape of the front part of the fuel tank 49 also wraps forward toward the side of the vehicle along this shape. The front upper part of the rear fender 28, which is a vehicle body fitting member, is suspended and supported at the rear lower parts of the left and right side tubes 4L, 4R, and the fuel tank 49 is placed on the upper surface of the rear fender 28. In addition, since the bottom of the fuel tank 49 and the rear thereof are supported so as to enter the rear fender 28, the fuel tank 49 is securely held and the front of the fuel tank 49 due to the weight of the fuel, for example, when the vehicle is decelerated. The load in the direction can be received by the storage box 12 and the vehicle body frame 2.

さらに、右側サイドチューブ４Ｒの後上半部を上方に向かって略「く」の字状に立ち上がるように形成したことにより、この立ち上がった部分で燃料タンク４９の容量を確保することができる。なお、対応した左側サイドチューブ４Ｌの後上半部では燃料タンク４９ではなく、リヤクッションユニット１９の前方を収納空間として拡大して設けるので、収納ボックス１２の収納部３９の容量を充分に確保でき、収容したヘルメット１１等を取り出すための手掛かり空間としても利用可能である。 Furthermore, the rear upper half of the right side tube 4R is formed so as to rise upward in a substantially “<” shape, so that the capacity of the fuel tank 49 can be secured at this raised portion. The rear upper half of the corresponding left side tube 4L is provided with the front of the rear cushion unit 19 expanded as a storage space instead of the fuel tank 49, so that the capacity of the storage 39 of the storage box 12 can be sufficiently secured. It can also be used as a clue space for taking out the stored helmet 11 and the like.

本発明に係る自動二輪車の車体構造の一実施形態を示すスクータ型車両の左側面図。1 is a left side view of a scooter type vehicle showing an embodiment of a vehicle body structure of a motorcycle according to the present invention. 図１に示すスクータ型車両の平面図。The top view of the scooter type vehicle shown in FIG. 車体フレーム単体の左側面図。The left view of a vehicle body frame simple substance. 車体フレーム単体の平面図。The top view of a vehicle body frame single-piece | unit. 図３のＶ矢視図。FIG. 図３のＶＩ矢視図。FIG. 図３のＶＩＩ矢視図。VII arrow line view of FIG. ユニットスイング型エンジンの拡大左側面図。The enlarged left view of a unit swing type engine. ユニットスイング型エンジンの平面図。The top view of a unit swing type engine. 図８のＸ−Ｘ線に沿う断面図。Sectional drawing which follows the XX line of FIG. 懸架ブラケットおよびその周辺の拡大左側面図。The enlarged left side view of a suspension bracket and its periphery.

Explanation of symbols

１スクータ型自動二輪車
２車体フレーム
３ボディチューブ
４Ｌ，４Ｒサイドチューブ
５ブリッジチューブ（第一ブリッジ部材）
６Ｌ，６Ｒフットレストチューブ
１２収納ボックス
１５ユニットスイング型エンジン
１６懸架ブラケット
１７エンジン本体
１８ベルトケース
１９リヤクッションユニット
２０後輪
２８リヤフェンダ（車体艤装部材）
２９ステップボード
３６第一の閉ループ
３７第二ブリッジ部材
３８第二ブリッジ部材の水平部
３９収納部
４２後フランジ部の後固定部（収納ボックスの固定部）
４９燃料タンク
５７シリンダアッセンブリ
６６点火プラグ（エンジン補器類）
６７プラグコード（エンジン補器類）
７２吸気装置
７４燃料噴射手段
７５スロットルボディ
７７エアクリーナ
８２補強部材（車体懸架部）
８３車体側回動軸
８４懸架アーム（エンジン懸架部）
８５エンジン側回動軸
８８円弧面の最下点
９０第二の閉ループ
９１Ｌ、９１Ｒ第二ブリッジ部材の脚部
９２枠部材
９３枠状の開口
９４略三角形の空間 1 Scooter type motorcycle 2 Body frame 3 Body tube 4L, 4R Side tube 5 Bridge tube (first bridge member)
6L, 6R Footrest tube 12 Storage box 15 Unit swing type engine 16 Suspension bracket 17 Engine body 18 Belt case 19 Rear cushion unit 20 Rear wheel 28 Rear fender (vehicle body fitting member)
29 Step board 36 First closed loop 37 Second bridge member 38 Horizontal portion 39 of second bridge member Storage portion 42 Rear flange portion rear fixing portion (storage box fixing portion)
49 Fuel tank 57 Cylinder assembly 66 Spark plug (engine accessories)
67 Plug cord (engine accessories)
72 Intake Device 74 Fuel Injection Means 75 Throttle Body 77 Air Cleaner 82 Reinforcing Member (Car Body Suspension)
83 Car body side rotation shaft 84 Suspension arm (engine suspension part)
85 Engine-side rotation shaft 88 Lowermost point 90 of the arcuate surface Second closed loops 91L, 91R Legs 92 of the second bridge member Frame member 93 Frame-shaped opening 94 A substantially triangular space

Claims

An engine body having a cylinder assembly that is inclined forward in a substantially horizontal manner and whose center is arranged along the traveling direction of the vehicle, and a belt case that extends rearward from one side of the engine body and pivotally supports a rear wheel at the rear end. Connected to the intake port of the cylinder assembly and a unit swing type engine that is pivotally attached to the lower center of the body frame and is elastically supported by the body frame by a rear cushion unit. A scooter type equipped with a fuel injection type intake device comprising a fuel injection means, a throttle body, and an air cleaner in an intake passage formed in this way, and a storage box disposed above the unit swing type engine In this motorcycle, the rear part of the body frame is connected to the pair of left and right side tubes and the first bridge. The front and rear side portions are narrower than the middle portion while the left and right side tubes are joined close to each other so as to face each other. While forming the middle bulge shape, the storage box is provided so that a part of the storage box is submerged in the side tube, and the rear portion of the storage box is disposed in the middle bulge portion of the left and right side tubes. Provided in the width direction between the left and right side tubes, and further in the flat curved space long in the width direction formed between the rear part of the storage part and the rear end coupling part of the left and right side tubes. over and to thereby place the fuel tank, the storage box includes a flange portion after extending from the rear of the housing part and the upper opening towards the upper rear of the rear of the fuel tank, the storage box Configuration of the fixed part, from a front fixing portion which is provided on the bottom front of the housing portion, and an intermediate support portion which is provided in the rear of the housing part, and the fixing portion after providing to the rear flange of the housing part rear A vehicle body structure for a motorcycle, wherein an intermediate support portion at the rear portion of the storage portion and a rear fixing portion of the rear flange portion are arranged so as to sandwich the fuel tank from the front and rear .

An engine body having a cylinder assembly that is inclined forward in a substantially horizontal manner and whose center is arranged along the traveling direction of the vehicle, and a belt case that extends rearward from one side of the engine body and pivotally supports a rear wheel at the rear end. Connected to the intake port of the cylinder assembly and a unit swing type engine that is pivotally attached to the lower center of the body frame and is elastically supported by the body frame by a rear cushion unit. A scooter type equipped with a fuel injection type intake device comprising a fuel injection means, a throttle body, and an air cleaner in an intake passage formed in this way, and a storage box disposed above the unit swing type engine In the motorcycle, the rear part of the body frame is connected to the pair of left and right side tubes and the first bridge. The first bridge member, the first bridge member, the left and right side tubes, and the second bridge member constructed so as to straddle the left and right side tubes. In addition, the rear part of the vehicle body frame is formed in a substantially simple flat shape inclined so that the front end of the first closed loop is at the lowermost part and the rear end is at the uppermost part in a side view. The second closed loop is bent so as to rise upward from the plane of the closed loop, and the storage box is connected to the uppermost part of the first closed loop and the uppermost part of the second closed loop, A bottom portion of the storage portion of the storage box is horizontally extended from the uppermost portion of the second closed loop and protrudes rearward from the plane of the first closed loop in a side view; and a rear portion of the storage portion; Serial fuel tank is disposed between the top portion of the first closed loop, the first plane of the closed loop in a state in which the rear of the overlapping in the longitudinal side of the vehicle viewed from the front and the housing part of the fuel tank A motorcycle body structure characterized in that a vehicle body fitting member is suspended and supported on the left and right side tubes, and the fuel tank is held by the vehicle body fitting member, while being vertically provided vertically.

A second bridge member formed in a trapezoidal shape with a horizontal portion supporting the front lower portion of the storage box is provided below the front of the storage box so as to connect the left and right side tubes. The tube is extended so as to expand in the width direction of the vehicle in a reverse “C” shape when viewed from the front, and the first and second bridge members and the left and right side tubes are substantially hexagonal when viewed from the front. A second closed loop having a shape is formed, and when viewed from the front, the second closed loop surrounds the entire circumference of the cylinder assembly, while the leg portion of the second bridge member and the side tube are substantially narrow and substantially "V" -shaped. The pipe of the intake device is accommodated in a substantially triangular space formed by forming a shape, and the fuel injection means provided in the pipe of the intake device is inclined along the extending direction of the side tube. And arranged, body structure of a motorcycle according to claim 1, wherein the plane containing the horizontal portion is provided so as to protrude above the upper end the second bridge member.

Leg portions are provided at both ends of the horizontal portion of the second bridge member, and a frame member is provided separately in the vicinity of the connection portion of the at least one leg portion with the side tube, and this portion is directed laterally or forwardly. forming a frame-like opening, with disposing the cylinder head constituting the cylinder assembly so as to face the opening, the claims were provided with engine auxiliary components detachable from the site facing the opening of the cylinder head 3. A motorcycle body structure according to 3.

The body frame extends obliquely rearward and downward from the front of the vehicle, is curved so as to be substantially horizontal in the middle, extends rearward, and is connected to the first bridge member. A pair of left and right footrest tubes, which are provided on both sides of the tube and support a low-floor stepboard on which the rider puts both feet from below, while each tip of the left and right footrest tubes connected to the body tube is provided The motorcycle body structure according to any one of claims 1 to 4, wherein the body tubes are connected to opposite sides of the body tube at different heights.

The motorcycle body structure according to claim 5, wherein the left and right footrest tubes are made of metal pipes having the same cross-sectional shape and the same cross-sectional area, and are set to different lengths.