JP4529642B2 - Scooter type motorcycle - Google Patents

Description

  The present invention relates to a scooter type motorcycle in which an article storage box is installed below a seating seat.

  Many of the scooter type motorcycles as described above have a power unit in which the engine and the transmission unit are integrated, and the rear wheel is directly supported on the rear part of the transmission unit, while the swing provided near the crankcase of the engine. The pivot part is pivotally connected to the body frame, the entire power unit is supported to swing up and down, and a shock absorber is connected between the rear part of the transmission unit and the rear part of the body frame, and the power unit itself is the rear arm of the swing arm of the rear wheel. Have a role.

  An article storage box that is opened and closed by a seating seat is installed above the power unit, so that the engine cylinder assembly is moved forward from the front of the crankcase to reduce the overall height of the engine and avoid interference with the article storage box. The engine layout extends horizontally.

  By the way, with the recent trend toward low pollution of vehicle exhaust gas, a scooter type motorcycle that combines a four-cycle engine and a fuel injection means (injector, etc.) instead of the two-cycle engine and carburetor that have been the mainstream until now. Has become widespread. Examples of such a scooter type motorcycle are described in Patent Document 1 and Patent Document 2, for example.

In each of these scooter type motorcycles, an intake port is formed in an upper surface of a cylinder assembly (cylinder head) extending substantially horizontally from the front of the crankcase to the front, and an intake pipe, a throttle body, and fuel injection means are formed in the intake port. And an air cleaner are connected to each other, and the entire intake device is disposed between the power unit and the article storage box.
JP 2001-213373 A JP 2004-144100 A

  However, as described above, since an intake port is conventionally formed in the upper surface of the cylinder head, intake device components such as an intake pipe, a throttle body, and a fuel injection means connected to the intake port are used as the cylinder head (cylinder assembly). There is a concern that the intake device may interfere with the bottom surface of the article storage box when the upper end position of the intake device is increased and the power unit swings upward.

  In order to prevent such interference between the air intake device and the bottom of the article storage box, the height of the bottom of the article storage box is increased to sacrifice the capacity of the article storage box, or the height of the bottom of the article storage box is increased and seated at the same time. The seat height was raised to secure the capacity of the article storage box, and the footing performance had to be sacrificed.

  In particular, when a fuel injection unit called a discharge pump in which a fuel pump and a fuel injector are integrated is used, the total height of the discharge pump is greater than that of a conventional injector type fuel injection unit. The problem gets worse.

  Further, the discharge pump needs to be provided with a fuel supply pipe and a return pipe for returning the fuel vapor (bubbles) generated when the pump is operated to the fuel tank side, and one end of each of these pipes swings up and down. Since it is connected to the power unit (discharge pump) side and the other end is connected to a fuel tank fixed to the vehicle body side, it is difficult to apply deformation stress to the fuel supply pipe and the return pipe as the power unit swings. It was. Note that the return pipe needs to have a piping layout that rises from the discharge pump toward the fuel tank in order to prevent vapor backflow.

  The present invention has been made in order to solve the above-described problems. The intake device is made compact in the height direction to prevent interference with the article storage box, and the capacity of the article storage box is increased and the legging property is improved. In addition to improving engine output, the power unit swing prevents deformation stress from being applied to the fuel supply pipe and return pipe to improve the durability of each pipe, and the return pipe vapor return performance is also improved. An object of the present invention is to provide a scooter type motorcycle that can be used.

In order to achieve the above object, a scooter type motorcycle according to the present invention includes an engine provided with a cylinder assembly inclined forward in a substantially horizontal direction toward the front on a front surface of a crankcase including a crankshaft extending in the vehicle width direction. An intake passage that extends rearward from one side of the crankcase and is integrated with a transmission unit that supports a rear wheel at the rear and is connected to the body frame in a swingable manner, and is connected to the intake port of the cylinder assembly. In addition, a fuel injection type intake device comprising a throttle body, fuel injection means and an air cleaner is connected, an article storage box is disposed at the upper front of the power unit, and a fuel tank is disposed at the rear of the article storage box , The intake port has an upstream opening away from the center axis of the cylinder assembly. So that the formed by bending outwardly in the vehicle width direction, the fuel injection means, together with the fuel injection direction is disposed to be inclined outwardly in the vehicle width direction so that the intake port, the vehicle width of the fuel tank One end of the fuel supply pipe is connected to a connecting portion provided at the lower part on the outer side in the direction, and the other end of the fuel supply pipe is crossed in the vehicle body width direction in the space below the storage box in the vehicle body width direction. It is bent so that a section along the traveling direction can be formed and connected to the lower part of the fuel injection means on the outer side in the vehicle width direction opposite to the connecting part of the fuel tank, and provided on the upper part on the outer side in the vehicle width direction of the fuel tank. One end of the air pipe is connected to the connected part, the other end of the air pipe is extended downward along the fuel tank and connected to the fuel supply pipe, and a T-shaped union is interposed in the vertical middle part of the air pipe. One end of the return pipe is connected, and the other end of the return pipe is piped so as to cross the vehicle width direction while surrounding the rear of the article storage box so as to be lower than the T-shaped union connection portion. It is connected to the upper part of the fuel injection means on the outer side in the vehicle width direction on the side opposite to the pipe installation portion .
In the scooter type motorcycle according to the present invention , a curved portion that rises upward from near the center axis of the cylinder assembly to one side in the vehicle width direction is formed at the bottom of the article storage box. Thus, at least the fuel injection means of the intake device is disposed in the intake device accommodation space formed below or on the side of the article storage box, while the intake passage is spaced from the central axis of the cylinder assembly to one side in the vehicle width direction. Therefore, it extended and arranged substantially horizontally in the front-rear direction so as to follow the outer surface of the vehicle.

  Further, the scooter type motorcycle according to the present invention is configured such that a direction in which the intake port is curved outward in the vehicle width direction is opposite to a cam chain chamber provided on one side of the cylinder assembly with the cylinder assembly central axis interposed therebetween. did.

  The scooter type motorcycle according to the present invention has a layout in which the intake pipe, throttle body, fuel injection means, and the like constituting the intake device are arranged outside the cylinder assembly in the vehicle width direction outside. It can be made compact in the height direction, and at the same time, the space around the engine and the article storage box can be used effectively, preventing interference between the intake device and the article storage box, increasing the capacity of the article storage box and improving the legging performance. In addition to the improvement, it is possible to increase the radius of curvature of the intake passage including the intake port to promote the atomization of fuel injected from the fuel injection means and improve the intake efficiency, thereby improving the engine output.

  Moreover, the fuel supply pipe and the fuel return pipe connecting the fuel tank and the fuel injection means are prevented from being subjected to deformation stress due to the swing of the power unit to improve the durability of each pipe, and the return pipe hangs down. Can be prevented and the vapor return performance can be improved.

  The following is an embodiment of the present invention.

  FIG. 1 is a left side perspective view showing a scooter type motorcycle according to the present invention.

  The body frame 2 of the scooter type motorcycle 1 is made of steel pipe, and a down pipe 4 extends rearward and downward from a head pipe 3 located at the frontal region, and a pair of left and right rear pipes 5 extends rearward and obliquely upward from the vicinity of the rear end. A step frame 6 is formed in a portion where the down pipe 4 enters the lower part, and an engine bracket 7 is provided in the vicinity of the joint between the down pipe 4 and the rear pipe 5.

  A front fork 10 that supports a front wheel 9 is pivotally supported on the head pipe 3 together with a handle bar 11, a headlamp 12, a front fender 13, and the like, while being pivotally supported by the engine bracket 7 via a link 15. The rear wheel 17 is supported on the rear part of the power unit 16, and the shock absorber 18 is connected between the rear part of the power unit 16 and the rear part of the rear pipe 5.

  The power unit 16 is provided with a pair of left and right arm-like swing pivot portions 19 extending forward, and the swing pivot portion 19 is connected to both ends of a swing pivot shaft 20 installed on the rear end of the link 15. The entire power unit 16 swings up and down around the swing pivot shaft 20 together with the rear wheel 17 to serve as a swing arm for the rear wheel 17. The swing of the power unit 16 and the rear wheel 17 is buffered and restored by a shock absorber 18. A fuel injection type intake device 21 is installed at the front upper part of the power unit 16.

  Above the power unit 16, a bottomed box-shaped container-like article storage box 24 opened upward is installed while being supported by the rear pipe 5, and a seating seat 25 is placed so as to close the opening. The seating seat 25 can be opened and closed by lifting the rear end about the hinge portion 26 at the front end, so that articles can be taken in and out of the article storage box 24.

  A fuel tank 27 made of, for example, resin is installed behind the article storage box 24, and a fuel filler port 28 faces upward through a tray portion 29 extending rearward from the upper edge of the article storage box 24. The fuel tank 27 has a shape that wraps around right after the article storage box 24.

  The front and rear portions of the vehicle body frame 2 are covered with a synthetic resin front frame cover 31 and a rear frame cover 32, respectively, to adjust the vehicle body appearance, and a tail lamp 33 is provided at the rear end of the rear frame cover 32. A rear fender 34 is provided above the rear wheel 17. The fuel tank 27 is placed on the rear fender 34.

  A synthetic resin step board 35 is formed on the top of the step frame 6. The front frame cover 31, the rear frame cover 32, and the step board 35 are continuously connected. Further, a bicycle parking center stand 36 is provided below the power unit 16 so as to be rotatable between a traveling position 36a and a parking position 36b.

  2 is a left side view of the power unit 16, the intake device 21, and the fuel tank 27, FIG. 3 is a plan view thereof, FIG. 4 is a cross-sectional view of the power unit 16 taken along line IV-IV in FIG. FIG. 6 is a perspective view taken along arrow VI in FIG. 5, and FIG. 7 is a view taken along arrow VII-VII in FIG.

  The power unit 16 has a general layout for a scooter type motorcycle in which a four-cycle engine 37 and a transmission unit 38 are integrated.

  The engine 37 is a forced air-cooling type, and a single-cylinder cylinder assembly 42 is installed on the front surface of the crankcase 41 so as to be tilted forward to substantially horizontal. As shown in FIG. 4, the crankcase 41 is a left-right split type in which a left case half 43 and a right case half 44 are combined, and a shift case body 45 extending rearward is integrally connected to the left case half 43. A left side opening of the transmission case body 45 is closed by a transmission case cover 46 to form a transmission case 47, and the transmission unit 38 is configured by the transmission case 47, a belt-type transmission 48 accommodated therein, and a deceleration transmission mechanism 49. Is configured.

  A crankshaft 52 extending in the vehicle width direction is pivotally supported inside the crankcase 41, and both ends of the crankshaft 41 protrude to the left and right of the crankcase 41, and the left end of the crankshaft 52 extends into the transmission case 47. On the other hand, a driven shaft 56, an intermediate shaft 57, and a rear wheel shaft 58 are supported in order from the front at the rear portion of the transmission case 47, and the rear wheel shaft 58 protrudes from the right side surface of the transmission case 47 so that the rear wheel 17 rotates integrally therewith. It is attached.

  Inside the speed change case 47, a drive pulley 61 is mounted on the crankshaft 52, and a driven pulley 62 is mounted on the driven shaft 56, and a V-belt 63 is stretched between the pulleys 61 and 62, and on the left side of the driven pulley 62. A centrifugal clutch 64 is provided. The pulleys 61 and 62, the V belt 63, and the centrifugal clutch 64 constitute a belt type transmission 48.

  A primary drive gear 66 is provided near the right end of the driven shaft 56, a primary driven gear 67 and a secondary drive gear 68 are provided on the intermediate shaft, and a secondary driven gear 69 is provided on the rear wheel shaft 58. .. -69 are separated in a liquid-tight manner by a mission cover 70 mounted on the rear portion of the transmission case main body 45 and immersed in oil to constitute a deceleration transmission mechanism 49.

  The rotation of the crankshaft 52 is transmitted to the driven shaft 56 through the drive pulley 61, the V belt 63, the driven pulley 62, and the centrifugal clutch 64, and the rotation of the driven shaft 56 is decelerated in two stages by the speed reduction mission mechanism 49. And transmitted to the rear wheel 17. The effective diameter of the drive pulley 61 is increased by the action of the internal weight roller 71 as the centrifugal force increases. On the contrary, the effective diameter of the driven pulley 62 is reduced, so that the rotation of the crankshaft 52 is automatically changed steplessly ( And is transmitted to the driven shaft 56.

  A kick starter shaft 73 is installed between the crank shaft 52 and the driven shaft 56, a kick starter lever 74 is provided at the outer end thereof, and a kick starter mechanism 75 is provided at an intermediate portion of the kick starter shaft 73. Yes. A member 76 shown in FIG. 3 is a starter motor.

  On the other hand, the cylinder assembly 42 is assembled from a cylinder block 85, a cylinder head 86, and a head cover 87. A piston 89 inserted into a cylinder bore 88 inside the cylinder block 85 is connected to a crank pin 91 of the crankshaft 52 by a connecting rod 90. The reciprocating motion of the piston 89 in the cylinder bore 88 is converted into the rotational motion of the crankshaft 52 and becomes the output of the engine 37.

  As shown in FIGS. 4 and 5, the cylinder head 86 is formed with a combustion chamber 93 that is aligned with the cylinder bore 88, and an intake port 94 and an exhaust port 95 are formed. A cam shaft 98 is supported in the vehicle width direction inside the head 86, and a cam chain 101 is wound between a cam drive sprocket 99 provided on the crank shaft 52 and a cam driven sprocket 100 provided on the cam shaft 98. It is disguised.

  The rotation of the crankshaft 52 is reduced by half and transmitted to the camshaft 98, and the intake cam 103 and the exhaust cam 104 formed on the camshaft 98 are connected to an intake valve and an exhaust valve (not shown) via a rocker arm (not shown). ) At a predetermined timing, the intake valve opens and closes the intake port 94, and the exhaust valve opens and closes the exhaust port 95.

  The intake port 94 is connected to an intake device 21 that will be described in detail later, and the exhaust port 95 is connected to an exhaust muffler (not shown). The cam chain 101 is accommodated in a cam chain chamber 105 provided, for example, on the right side surface of the cylinder assembly 42 (85, 86, 87).

  As shown in FIG. 4, a gear cover member 106 is liquid-tightly mounted on the right side surface of the crankcase 41 (right case half body 44), and an auxiliary machine drive gear chamber 107 is defined between the gearcase member 106 and the crankcase 41. Yes. The auxiliary machine drive gear chamber 107 communicates with the cam chain chamber 105. The auxiliary machine drive gear chamber 107 has a cam drive sprocket 99 for the crankshaft 52 and an auxiliary machine drive adjacent to the axially outer side (right side). An auxiliary machine driven gear (not shown) that meshes with the gear 108 and the auxiliary machine drive gear 108 is accommodated. The accessory drive gear 108 and the accessory driven gear are gears that drive an oil pump (not shown) as an accessory.

  The gear cover member 106 is formed with a recess 132 that is recessed toward the accessory drive gear chamber 107, and a generator 133 is installed in the recess 132. The stator 134 of the generator 133 is fastened and fixed in the recess 132 with bolts, the right end portion of the crankshaft 52 passes through the center of the recess 132, and the rotor 137 of the generator 133 is rotatably integrated with the right end portion of the crankshaft 52. Yes. Then, the rotation of the crankshaft 52 causes the rotor 137 to go around the stator 134 to generate power.

  A cooling fan 138 is fixed to the rotor 137 of the generator 133, and the periphery of the cylinder assembly 42 and the right side surface of the crankcase 41 are covered with a cooling cowling 139 made of synthetic resin. The cooling cowling 139 is formed with a cooling air intake port 140 that opens to the right side of the cooling fan 138 and a cooling air discharge port that is opened below the cylinder assembly 42. When the cooling fan 138 rotates together with the rotation of the crankshaft 52, outside air is sucked into the cooling cowling 139 as cooling air from the cooling air intake port 140, and the cooling air forcibly cools the cylinder assembly 42 and then the cooling air discharge port. The engine 37 is forcibly air-cooled.

  As shown in FIGS. 5 and 7, the intake port 94 formed in the cylinder head 86 extends upward from the combustion chamber 93, and its upstream opening is the central axis C of the cylinder assembly 42 (here, the cylinder central axis). It is formed to be curved outward in the vehicle width direction so as to be separated from the vehicle. The bending direction of the intake port 94 is opposite to the cam chain chamber 105 provided on the right side surface of the cylinder assembly 42 with respect to the central axis C, that is, the left side. Accordingly, the upstream opening of the intake port 94 opens slightly upward at the upper left side of the cylinder head 86. An intake pipe mounting flange 94 a is formed in the upstream opening of the intake port 94.

  The fuel injection type intake device 21 includes an intake pipe 145 that is an intake passage fastened and fixed to an intake pipe mounting flange 94a of an intake port 94 with a bolt, and a throttle body 146 that is sequentially connected to the upstream side of the intake pipe 145, A suction duct 147, an air cleaner 148, and a discharge pump 149 as fuel injection means attached to the throttle body 146 are configured. The air cleaner 148 is fixed to the upper part of the transmission unit 38.

  The intake pipe 145 extends from the central axis C of the cylinder assembly 42 to one side (left side) in the vehicle width direction and extends substantially horizontally in the front-rear direction so as to follow the outer surface of the vehicle. An upward angle is given, and a throttle body 146 and a suction duct 147 are connected to the intake pipe 145 and a coaxial extension line.

  The discharge pump 149 is a unit in which a fuel injector (injector) and a fuel pump are united. The discharge pump 149 is inclined outward in the vehicle width direction (here, on the left side) so that the fuel injection direction is in the intake port 94. Is arranged.

  Further, as shown in FIG. 7, a curved portion 24a is formed at the bottom of the article storage box 24 so as to rise upward from near the center axis C of the cylinder assembly 42 to one side (here, the left side) in the vehicle width direction. ing. An intake device accommodation space 151 is formed below or to the side of the article storage box 24 by the curve 24a, and a discharge pump 149 of the intake device 21 is arranged in the intake device accommodation space 151.

  Although the discharge pump 149 protrudes upward most among the components of the intake device 21, the swing pivot shaft 20 of the power unit 16 is disposed almost directly below the discharge pump 149. It does not rise only by moving in the front-rear direction in the intake device accommodation space 151, so there is no concern that the discharge pump 149 interferes with the article storage box 24.

  As shown in FIG. 6, the front upper portion of the rear fender 34 is formed in a tray shape, and the fuel tank 27 is placed thereon, but the fuel filter 154 and the intake pressure are located in front of the fuel tank 27 and on the right side. A sensor 155 is installed. These members 154 and 155 are also fixed on the rear fender 34.

  Then, one end of the fuel supply pipe 158 is connected to a union-like connection portion 157 provided at the lower part of the fuel tank 27, the other end is connected to the lower part of the discharge pump 149, and a fuel filter 154 is provided in the middle of the fuel supply pipe 158. Is connected.

  In addition, one end of an air pipe 162 is connected to a union-like connection part 161 provided on the upper part of the fuel tank 27, the other end is connected to a fuel filter 154, and a T-shaped union 163 is provided at an intermediate part of the air pipe 162. The other end of the return pipe 164 is connected to the upper part of the discharge pump 149. The return pipe 164 is piped so that the end on the discharge pump 149 side is lower than the end on the T-shaped union 163 side.

  The fuel supply pipe 158, the air pipe 162, and the return pipe 164 are formed of a flexible piping material such as a rubber hose. Since these pipe materials 158, 162, and 164 are not subjected to fuel pressure, it is not necessary to use pressure hoses. The intake pressure sensor 155 is connected to the intake pipe 145 by a negative pressure hose 166.

  The position of the connecting portion 157 where the fuel supply pipe 158 is connected to the fuel tank 27 is the position of the fuel tank 27 opposite to the inclination direction of the discharge pump 149 that is inclined outward in the vehicle width direction (left side in this case). It is provided on the outer side in the vehicle width direction (here, the right side).

  Further, as shown in FIG. 3, the fuel supply pipe 158 is disposed so as to cross the crankcase 41 of the engine 37 in the vehicle body width direction, and a section 158a along the vehicle traveling direction is formed at an intermediate portion thereof. It is bent in a crank shape.

  On the other hand, the connecting portion 161 where the return pipe 164 is connected to the fuel tank 27 is also provided on the outer side (right side) of the fuel tank 27 in the vehicle width direction so as to be opposite to the inclination direction of the discharge pump 149. Yes. The return pipe 164 is routed around the rear of the article storage box 24 and is disposed so as to cross the rear of the article storage box 24 in the vehicle width direction.

  The fuel in the fuel tank 27 passes through the fuel supply pipe 158 by gravity and is filtered by the fuel filter 154 before being supplied to the discharge pump 149. The discharge pump 149 increases the fuel pressure by a built-in pump and injects the fuel into the intake port 94 from the injector.

  The throttle body 146 opens the throttle valve in response to the rider's accelerator operation, and the air sucked by the intake negative pressure of the engine 37 is purified by the air cleaner 148 and passes through the suction duct 147, the throttle body 146, and the intake pipe 145. It is supplied to the intake port 94.

  Then, the fuel injected by the discharge pump 149 and the intake air are mixed in the intake port 94 to become an air-fuel mixture and sucked into the engine 37. The fuel vapor (bubbles) generated when the discharge pump 149 is operated is returned to the fuel tank 27 through the return pipe 164, and the bubbles that have entered the fuel supply pipe 158 from the fuel tank 27 also pass through the air pipe 162. Returned to 27.

  In the scooter type motorcycle 1 configured as described above, the intake port 94 of the engine 37 (cylinder head 86) is curved outward in the vehicle width direction so that its upstream opening is separated from the central axis C of the cylinder assembly 42. Since the discharge pump 149 is disposed so as to be inclined outward in the vehicle width direction so that the fuel injection direction is in the intake port 94, the intake pipe 145, the throttle body 146, and the discharge pump 149 constituting the intake device 21 are formed. And the like are arranged outside the cylinder assembly 42 (center axis C) in the vehicle width direction outside.

  For this reason, the intake device 21 is made compact in the height direction, and as a result, the height of the engine 37 is reduced to prevent interference with the article storage box 24 when the power unit 16 swings, and the bottom height of the article storage box 24 is reduced. The capacity of the article storage box 24 can be increased by lowering the height, or the height of the seating seat 25 can be decreased to improve the legging performance.

  In addition, the radius of curvature of the intake passage including the intake port 94 can be increased to promote atomization of the fuel injected from the discharge pump 149 and improve the intake efficiency, thereby improving the output of the engine 37.

  In addition, a curved portion 24a that rises upward is formed on one side of the bottom of the article storage box 24, and the curved portion 24a sucks air into an intake device accommodation space 151 that is formed below or on the side of the article storage box 24. The discharge pump 149 of the device 21 is arranged, and the intake pipe 145 is arranged to extend substantially horizontally in the front-rear direction so as to be along the outer surface of the vehicle, separated from the central axis C of the cylinder assembly 42 on one side in the vehicle width direction. Thus, the space around the engine 37 and the article storage box 24 can be effectively used to more effectively prevent interference with the article storage box 24 when the power unit 16 is swinging.

  Further, since the intake port 94 is curved outwardly in the vehicle width direction on the opposite side of the cylinder assembly central axis C with respect to the cam chain chamber 105 of the cylinder assembly 42, the intake port 94 and the cam chain chamber 105 are mutually connected. The position of the opening portion of the intake port 94 can be positioned so as not to protrude greatly upward from the upper end portion of the cylinder head 86 by avoiding interference, thereby lowering the position of the entire intake device 21 and reducing the intake device 21 ( In particular, it can greatly contribute to the prevention of interference between the discharge pump 149) and the article storage box 24.

  Further, the positions of the connecting portion 157 and the connecting portion 161 where the fuel supply pipe 158 and the return pipe 164 are connected to the fuel tank 27 are opposite to the inclination direction of the discharge pump 149 which is inclined outward (left side) in the vehicle width direction. Since the fuel tank 27 is provided on the outer side (right side) of the fuel tank 27 in the vehicle width direction, the intermediate portions of the fuel supply pipe 158 and the return pipe 164 cross over the power unit 16 in the vehicle width direction in the vehicle plan view. Has been.

  For this reason, the intermediate part of the fuel supply pipe 158 and the return pipe 164 connected between the fuel tank 27 fixed to the vehicle body side and the discharge pump 149 that moves as the power unit 16 swings is stressed by the swing of the power unit 16. This prevents deformation stress from being applied to the fuel supply pipe 158 and the return pipe 164 as a whole, thereby improving the durability of each pipe and preventing the pipes from being removed at both ends. , 164 can be minimized to prevent interference with the article storage box 24, rubbing, and the like.

  In particular, the fuel supply pipe 158 is crossed in the vehicle body width direction on the crankcase 41 and bent so that a section 158a along the vehicle traveling direction is formed in the middle portion thereof, so that the power unit 16 swings at both ends of the fuel supply pipe 158. Even if the relative position change occurs, the relative position change is completely absorbed by the back-and-forth movement of the section 158a, and it is possible to effectively prevent a load from being applied to the connecting portions at both ends of the fuel supply pipe 158.

  Further, the middle part of the return pipe 164 formed of a flexible hose hangs down and prevents the vapor from the discharge pump 149 from staying in the middle part of the return pipe 164, improving the vapor return performance of the return pipe 164. Can be made.

1 is a left side perspective view showing a scooter type motorcycle according to the present invention. The left view of a power unit, an intake device, and a fuel tank. The top view of a power unit, an intake device, and a fuel tank. The cross-sectional view of the power unit along the IV-IV line of FIG. The VV arrow directional view of FIG. The perspective view by VI arrow of FIG. The figure which shows one Embodiment of this invention by the VII-VII arrow view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Scooter type motorcycle 2 Body frame 16 Power unit 17 Rear wheel 20 Swing pivot shaft 21 Intake device 24 Article storage box 24a Curved portion 27 Fuel tank 37 Engine 38 Transmission unit 41 Crankcase 42 Cylinder assembly 52 Crankshaft 94 Intake port 105 Cam chain Chamber 145 Intake pipe 146 as intake passage Throttle body 148 Air cleaner 149 Discharge pump 151 as fuel injection means Intake device accommodating space 154 Fuel filter 155 Intake pressure sensor 157 Connection portion 158 of fuel supply pipe to fuel tank Fuel supply pipe 158a Section 161 of the fuel supply pipe along the traveling direction of the vehicle 161 Connection portion of the return pipe to the fuel tank 162 Air pipe 163 T-shaped union 164 Return pipe C Cylinder up The center axis of the assembly

Claims (3)

An engine in which a cylinder assembly is tilted forward in a substantially horizontal direction toward the front in the front of the crankcase containing the crankshaft along the vehicle width direction, and a rear wheel extending rearward from one side of the crankcase A fuel unit comprising a power unit integrated with a transmission unit that pivotally supports the vehicle body frame so as to be swingable up and down, and having a throttle body, fuel injection means, and an air cleaner in an intake passage connected to an intake port of the cylinder assembly. An injection-type intake device is connected, an article storage box is arranged at the upper front of the power unit, and a fuel tank is arranged at the rear of the article storage box, and the intake port is connected to the upstream opening from the central axis of the cylinder assembly. The fuel injection means is formed by curving outward in the vehicle width direction so as to leave. Together with the fuel injection direction is disposed to be inclined outwardly in the vehicle width direction so that the intake port, to connect one end of the fuel supply pipe to the connecting portion provided at a lower portion of the vehicle transverse direction outer side of the fuel tank, The other end of the fuel supply pipe is bent across the crankcase in the space below the storage box in the vehicle body width direction so that a section along the vehicle traveling direction is formed in the middle thereof, and opposite to the connection portion of the fuel tank. Connected to the lower part of the fuel injection means on the outer side in the vehicle width direction on the side, and one end of the air pipe is connected to the connecting portion provided on the upper part on the outer side in the vehicle width direction of the fuel tank, and the other end of the air pipe is connected to the fuel tank Is connected to the fuel supply pipe, and one end of the return pipe is connected to the middle portion in the vertical direction of the air pipe via a T-shaped union, and the other end of the return pipe is connected to the T-shaped unit. A pipe is arranged so as to be lower than the on-connecting portion and traverse in the vehicle width direction around the rear of the article storage box, and above the fuel injection means on the outer side in the vehicle width direction opposite to the air pipe installation portion. A scooter type motorcycle characterized by being connected . A curved portion is formed at the bottom of the article storage box so as to rise upward from near the center axis of the cylinder assembly to one side in the vehicle width direction. At least fuel injection means of the intake device is disposed in the formed intake device accommodation space, while the intake passage is substantially spaced in the front-rear direction so as to be along the outer surface of the vehicle and separated from the central axis of the cylinder assembly on one side in the vehicle width direction. The scooter type motorcycle according to claim 1, which extends horizontally. The scooter-type automatic according to claim 1 or 2, wherein a direction in which the intake port is curved outward in the vehicle width direction is opposite to a cam chain chamber provided on one side of the cylinder assembly with the central axis of the cylinder assembly interposed therebetween. Motorcycle.

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