JP4664328B2 - Scooter type motorcycle - Google Patents

Description

  The present invention relates to a scooter type motorcycle equipped with a large displacement engine.

  Conventionally, as a scooter type motorcycle having a low footrest between a steering handle and a seat, a power unit composed of a unit swing type single cylinder engine is provided below the seat, and the power unit and the seat Some have a storage box in between. In this type of scooter type motorcycle, a storage box with a deep and large capacity can be provided without increasing the seating position of the seat by, for example, arranging the cylinder of the engine substantially horizontally so that the axis is directed in the longitudinal direction of the vehicle body. It can be accommodated.

  As described above, the power unit in which the cylinder is arranged substantially horizontally is provided with a transmission case extending rearward at the left end portion of the crankcase in the vehicle body, and the rear wheel axle is cantilevered at the rear end portion of the transmission case. A structure is employed in which power is transmitted from the crankshaft via a V-belt type automatic transmission or a centrifugal clutch in the transmission case. This power unit has an intake system connected to the upper surface of the cylinder and an exhaust system connected to the lower surface.

  The intake system carburetor is disposed above the crankcase, and the air cleaner is disposed above the transmission case. In the exhaust system, a rear portion of the exhaust pipe extends to the right side of the vehicle body, and a silencer is provided at a rear end portion that is a side of the rear wheel.

In recent years, scooter type motorcycles are required to be equipped with a multi-cylinder engine to increase the amount of displacement as in large motorcycles.
However, when such a large engine is mounted on a conventional scooter type motorcycle, there is a problem that only a storage box having a small capacity can be used. This is because the space between the engine and the seat is narrowed by mounting a large engine.

  The present invention has been made to solve such problems, and an object of the present invention is to provide a large scooter type motorcycle equipped with a large capacity storage box.

In order to achieve this object, a scooter type motorcycle according to the present invention includes a head pipe, a pair of left and right main pipes extending rearward and downward from the head pipe, and a pair of left and right down tubes connected to the head pipe. A vehicle body frame, a footrest provided between the steering handle and the seat, a rear arm that is swingably connected to the vehicle body frame via a pivot shaft and supports a rear wheel, An engine disposed below and having a cylinder positioned in front of the pivot shaft and the crankshaft , fixed to the body frame, and a V-belt transmission that is connected to a shaft end of the crankshaft of the engine and extends rearward And a scooter type motorcycle having a storage box disposed under the seat and above the engine and fixed to the vehicle body frame. An intake pipe extending rearward from the cylinder is connected to an upper surface of the cylinder, and an intake system component provided in the intake pipe is in front of the storage box, below the seat, and It is arranged above the crankshaft of the engine.

  According to the present invention, in the above invention, a recessed portion is formed on the lower side of the seat, and the intake system component is disposed so as to face the recessed portion, and a part thereof overlaps the seat in a side view. Are arranged in such a way.

  According to the present invention, in the above invention, the engine is a parallel multi-cylinder type, and the footrest includes a projecting portion projecting upward in a center portion in a vehicle width direction, and legs formed on both sides of the projecting portion. The cylinder is a space surrounded by the head pipe and the down tube, and is disposed on the protruding portion of the footrest.

  In the present invention according to the present invention, the seat is swingably supported by the vehicle body about a fulcrum on the front side of the vehicle body, and the intake system component is disposed in the vicinity of the fulcrum.

  According to the present invention, in the above invention, the cylinder is attached to the crankcase in a state where the cylinder is tilted forward so that the axial direction is directed in the longitudinal direction of the vehicle body, and the engine is a multi-cylinder engine. These are arranged in parallel to the vehicle width direction.

According to the present invention, an engine having a V-belt transmission that extends rearward from the crankshaft is disposed under the seat, and an intake system component provided in an intake pipe that extends rearward from the upper surface of the cylinder is disposed above the crankshaft. Therefore, the intake system parts are arranged on the front side of the engine that is long in the vehicle front-rear direction. Since the storage box is located behind the intake system parts, under the seat and above the engine, the capacity of the storage box is increased despite the fact that the intake system is positioned backward from the engine. Can be secured.
Therefore, it is possible to provide a scooter type motorcycle equipped with a large capacity storage box.

  According to the invention in which the intake system component is exposed to the recessed portion on the lower side of the seat, a space necessary for arranging the intake system component can be widely formed in the vertical direction. For this reason, since the intake system component can be configured using a wide space in the vertical direction, the length of the intake system component in the vehicle front-rear direction can be shortened. Therefore, according to the present invention, the storage box positioned behind the intake system component can be formed long in the front-rear direction, so that a storage box with a larger capacity can be mounted.

  According to the invention in which the cylinder is arranged at the protruding portion of the footrest, a large space can be formed between the seat and the crankcase even when a multi-cylinder type large displacement engine is mounted. Therefore, it is possible to increase the number of cylinders and the engine displacement while using a large storage box.

  According to the invention in which the intake system component is disposed in the vicinity of the fulcrum on the front side of the vehicle body of the seat, the position of the intake system component can be relatively positioned on the front side, and the space below the seat is further widened. Therefore, according to the present invention, a storage box having a larger capacity can be mounted.

  According to the invention in which the multi-cylinder engine having the forwardly inclined cylinder is mounted, the crankcase is located below the cylinder, so that the space for arranging the intake system parts can be further widened in the vehicle vertical direction. For this reason, the space for the storage box can be formed wider in the vehicle front-rear direction behind the intake system parts, so that a storage box with a larger capacity can be mounted.

Hereinafter, a scooter type motorcycle according to the present invention will be described in detail with reference to FIGS.
1 is a side view of a scooter type motorcycle according to the present invention, FIG. 2 is a plan view of the same, FIG. 3 is a side view of a power unit, and FIG. 4 is a plan view of the power unit. 5 is a longitudinal sectional view of the oil pan portion of the power unit, FIG. 6 is a sectional view taken along the line VI-VI of FIG. 3, FIG. 7 is a longitudinal sectional view of the rear of the power unit, and FIG. 8 is a sectional view of the balancer. FIG. 9 is a perspective view showing the main part.

  In these drawings, reference numeral 1 denotes a scooter type motorcycle (hereinafter simply referred to as a scooter) according to this embodiment. Unlike a conventional scooter, the scooter 1 has a power unit 2 fixed to a vehicle body frame 3 by engine mount bolts 4 and a rear wheel 5 supported by a rear arm 6. Transmission of power from the power unit 2 to the rear wheel 5 is performed by a conventionally known shaft drive mechanism 6b built in the arm 6a on the left side of the vehicle body of the rear arm 6.

  A cushion unit 7 is interposed between the two arms 6 a and 6 a of the rear arm 6 and the rear portion of the vehicle body frame 2. The front wheel 8 is supported by a telescopic front fork 10 that is steerably attached to the head pipe 9 of the vehicle body frame 3. A steering handle 11 is attached to the upper end of the front fork 10.

  As shown in FIGS. 3 and 4, the power unit 2 includes a V-belt type automatic transmission 14 and a centrifugal clutch 15, which will be described later, in a four-cycle parallel two-cylinder engine including a cylinder 12 and a left and right split crankcase 13. It has a built-in structure. As shown in FIG. 1, the scooter 1 has a seat 16 and a storage box 17 disposed above the crankcase 13. The seat 16 is integrally provided with a driver seat and a passenger seat, and has a structure that can swing in the vertical direction with an end on the front side of the vehicle body as a fulcrum. The pivot serving as the fulcrum is indicated by reference numeral 16a.

  The storage box 17 has a box shape that opens upward, and is formed in a shape that allows the full-face helmet 18 and the jet helmet 19 to be stored side by side in the longitudinal direction of the vehicle body. 3 is supported. The opening of the storage box 17 is opened and closed by rotating the seat 16 like a conventional scooter.

  The cylinder 12 of the power unit 2 is attached to the crankcase 13 in a state in which the axial direction is inclined forward so that the axial direction is directed to the front-rear direction of the vehicle body, and as shown in FIG. 3, an intake pipe is provided above the cylinder head 12a. 20 and an exhaust pipe 21 are connected to the lower part. The intake pipe 20 and the exhaust pipe 21 are provided for each cylinder, and the intake pipe 20 extends from the cylinder head 12a to the rear side of the vehicle body and is connected to the carburetor 22 at the rear end. The air cleaner 23 connected to the carburetor 22 is located between the front portion of the seat 16 and the crankcase 13, in front of the vehicle body from the storage box 17, and with the upper portion facing the recessed portion 16 b below the seat 16. It is arranged with. Reference numeral 23a denotes an air suction duct of the air cleaner 23, and reference numeral 23b denotes an air cleaner element.

  The exhaust pipe 21 extends downward from the cylinder body 12b along the front-rear direction of the vehicle body from the cylinder head 12a, and the oil pan 13a provided at the lowermost portion of the crankcase 13 is seen in a side view as shown in FIGS. While overlapping, as shown in FIG. 5, it passes through the lower side of the crankcase 13 in a state along the side surface of the oil pan 13a and extends rearward of the vehicle body. By passing the exhaust pipe 21 to the side of the oil pan 13a in this way, the exhaust pipe does not protrude downward from the lowermost oil pan 13a of the engine, and greatly protrudes to the side of the oil pan 13a. Nor. Therefore, the bank angle indicated by θ in FIG. 5 is not narrowed by the exhaust pipe 21, and the minimum ground height H can be ensured.

  As shown in FIGS. 1 and 2, the vehicle body frame 3 on which the power unit 2 is mounted includes the head pipe 9, main pipes 24, 24 extending rearward and downward from the head pipe 9 in a pair of left and right, and the head pipe. 9 includes a down tube 26 connected through three connecting pipes 25, a seat rail 27 connected to a rear portion of the main pipe 24, a backstay 28, and the like. The main pipe 24 extends above the power unit 2 to the rear of the power unit 2, and the rear arm 6 is swingably connected to a rear end portion via a pivot shaft 29. The upper portion of the crankcase 13 is fixed to the main pipe 24 with bolts, and the rear portion of the crankcase 13 is fixed to the bracket 24a provided at the rear end portion of the main pipe 24 with bolts.

  As shown in FIG. 2, the down tube 26 is formed in a horizontal U shape in a plan view as shown in FIG. 2, and passes from the front of the head pipe 9 to the side of the front fork 10 and to the lower side of the cylinder 12. It is extended to. The cylinder 12 is fixed to the rear end portion of the down tube 26 with a bolt.

  That is, the vehicle body frame 3 supports the power unit 2 in a state where the cylinder 12 is housed in a space surrounded by the main pipe 24 and the down tube 26. Since the vehicle body frame 3 takes such a form, the footrest 30 of the scooter 1 has a center portion in the vehicle width direction protruding upward from the footrest portions 30a on both sides as shown in FIG. Yes. This protrusion is indicated by reference numeral 30b. The cylinder 12 faces the space between the left and right footrests 30a below the protrusion 30b of the footrest 30. This space is indicated by reference numeral 31 in FIG. In addition to the cylinder 12, the space 31 also accommodates an intake system (the intake pipe 20 and the carburetor 22) between the cylinder 12 and the air cleaner 23. These parts constitute the intake system parts referred to in the present invention.

  The V-belt type automatic transmission 14 incorporated in the power unit 2 has a structure equivalent to that used in a conventional scooter, and as shown in FIG. The pulley 33 and a driven pulley 35 connected to the drive pulley 33 via a V-belt 34 are configured. As shown in FIG. 6, the driven pulley 35 has a connecting shaft 36 whose axial direction is parallel to the vehicle width direction coupled to the shaft center portion, and the input member 37 of the centrifugal clutch 15 on the left side of the vehicle body via the connecting shaft 36. It is linked to. The V-belt type automatic transmission 14 is accommodated in a space formed by a right side wall of the crankcase 13 and a transmission cover 2a attached to the outside of the side wall.

  The centrifugal clutch 15 is a wet multi-plate type in which a friction plate 39 is urged by a ball 38, and the rotation of the input member 37 is transmitted to the output member 40 via the friction plate 39 due to the rotation of the input member 37. It has a structure. The output member 40 is connected to a shaft drive mechanism 6b in the rear arm 6 through a power transmission mechanism denoted by reference numeral 41 in FIG. The power transmission mechanism 41 is formed in a cylindrical shape and covers a first rotating shaft 42 that covers the outside of the connecting shaft 36, a second rotating shaft 43 that is gear-coupled to the first rotating shaft 42, A universal joint 46 is connected to the second rotating shaft 43 via bevel gears 44 and 45.

  Thus, when the driven pulley 35 of the V-belt type automatic transmission 14 is disposed on the right side of the vehicle body and the centrifugal clutch 15 is disposed on the left side of the vehicle body, a space is formed around the connecting shaft 36 between these two members. . The power unit 2 uses the upper side of this space as a part of the luggage storage space and uses the lower side as a balancer storage space.

  That is, as shown in FIG. 7, a recessed portion 47 is formed in a portion between the driven pulley 35 and the centrifugal clutch 15 on the upper surface of the crankcase 13, and the bottom portion 17a of the storage box 17 is formed in the recessed portion 47 from above. I ’m here. By adopting this structure, the upper side of the space can be used as a part of the luggage storage space, and the capacity of the storage box 17 can be increased.

  A reciprocating balancer 51 is disposed below the space as shown in FIG. As shown in FIG. 8, the balancer 51 is a round balancer connecting rod 52 connected to the crankshaft 32, and a round member connected to the tip of the connecting rod 52 via a connecting member including a cylindrical body 53 and a pivot pin 54. The balance weight 55 is reciprocally supported on the crankcase 13 by a ball type direct acting bearing 56 and a holder 57. Further, the balance weight 55 is positioned at a position where its axis coincides with an extension line of the cylinder axis in a side view shown in FIG.

The crankshaft 32 that connects the balancer 51 is formed so that the two pistons 58 and 58 (see FIG. 4) reciprocate with the same phase, and two crankshafts 32 that connect the large ends of the connecting rods 59 and 59 for the piston. A balancer crank pin 32b is provided between the crank pins 32a and 32a so that the phase is shifted by 180 °. The connecting rod 52 of the balancer 51 is connected to the crank pin 32b. Further, the crankshaft 32 is rotatably supported by the crankcase 13 only at both ends in the vehicle width direction.
In this embodiment, the rotation radius of the balancer crank pin 32b, that is, the arm length indicated by symbol r in FIG. 8 is set to be shorter than the arm length R of the crank pin 32a. Further, the weight of the balancer 51 is set to a weight that cancels out the inertial force generated in the crankshaft 32 when the pistons 58 for two cylinders reciprocate.

  If the balancer 51 is configured in this way, the primary vibration generated in the two cylinders by one balancer 51 can be canceled. Moreover, since the inertia weight of the balancer 51 acts between the two crank pins 32a in the crankshaft 32, the vibration in the bending direction caused by the couple is small. That is, although it is a two-cylinder engine, it has vibration characteristics equivalent to those of a four-cylinder engine.

  As shown in this embodiment, when the arm length r of the balancer crankpin 32b is shorter than the arm length R of the crankpin 32a, the amount of movement of the balance weight 55 is smaller than when both arm lengths are equal, Resistance when the balance weight 55 moves, that is, loss is reduced.

  Further, if the structure in which the V-belt type automatic transmission 14 and the centrifugal clutch 15 are arranged on one side and the other side in the vehicle width direction, the space between these two members can be effectively used as described above. In addition to this, the V-belt type automatic transmission 14 can be easily separated from the oil in the crankcase 13 by being disposed outside the crankcase 13. This means that a special partition wall is not provided for isolating the dry V-belt type automatic transmission 14 from the space for accommodating the crankshaft 32, the wet multi-plate clutch 15 and the like, that is, the space for accommodating the oil-applied member. Means good.

  In the scooter 1 configured as described above, an engine including the V-belt type automatic transmission 14 extending rearward from the crankshaft 32 is disposed under the seat 16 and provided in the intake pipe 20 extending rearward from the upper surface of the cylinder 12. Since the intake system component to be used is disposed above the crankshaft 32, the intake system component is disposed on the front side of the engine that is formed long in the vehicle longitudinal direction. Since the storage box 17 is disposed behind the intake system components and under the seat and above the engine, the capacity of the storage box 17 is not limited even though the intake system is disposed rearward from the engine. A lot can be secured.

  Further, in the scooter 1 according to this embodiment, since the intake system component faces the recessed portion 16b on the lower side of the seat 16, a space necessary for arranging the intake system component is formed wide in the vertical direction. can do. Since the intake system component is configured by using a space that is wide in the vertical direction, the length of the intake system component in the vehicle front-rear direction can be shortened. Therefore, according to this scooter 1, the storage box 17 located behind the intake system parts can be formed long in the front-rear direction, and the capacity of the storage box 17 can be increased.

  In the scooter 1 according to this embodiment, the cylinder 12 is disposed on the projecting portion 30b of the footrest 30. Therefore, even if a multi-cylinder type large displacement engine is mounted, the space between the seat 16 and the crankcase 13 is not limited. A wide space can be formed. Therefore, it is possible to increase the number of cylinders and the displacement of the engine while using the large storage box 17.

In the scooter 1 according to this embodiment, since the intake system parts are arranged in the vicinity of the fulcrum (pivot 16a) on the front side of the vehicle body of the seat 16, the position of the intake system parts can be relatively positioned on the front side. For this reason,
The space below the seat 16 is further increased, and the capacity of the storage box 17 can be further increased.

  In the scooter 1 according to this embodiment, since a multi-cylinder engine having a forwardly inclined cylinder 12 is mounted, the crankcase 13 is positioned below the cylinder 12 and a space for arranging intake system components. Can be made wider in the vehicle vertical direction. For this reason, the space for the storage box can be further widened in the vehicle front-rear direction behind the intake system components, so that the capacity of the storage box 17 can be further increased.

  In addition, the scooter 1 has a parallel two-cylinder engine, and the exhaust pipe 21 for each cylinder extends along the side surface of the oil pan 13a so as to overlap the oil pan 13a from below the cylinder 12 when viewed from the side. Therefore, the exhaust pipe 21 does not protrude downward from the lowermost oil pan 13a of the engine, and does not protrude greatly to the side of the oil pan 13a. Accordingly, the exhaust pipe 21 can be extended to both sides in the vehicle width direction so as to have a large diameter so as to reduce the exhaust resistance while satisfying conditions such as the minimum ground clearance of the vehicle body and the bank angle.

  Further, an air cleaner 23 is disposed between the front end of the vehicle body of the seat 16 and the crankcase 13, and an air intake system between the air cleaner 23 and the cylinder 12 is provided in a space below the protrusion 30 b of the footrest 30. Since it is accommodated, the intake system components can be accommodated inside the footrest 30, so that the space below the seat 16 is further increased. Therefore, a storage box having a larger capacity can be mounted.

1 is a side view of a scooter type motorcycle according to the present invention. 1 is a plan view of a scooter type motorcycle according to the present invention. It is a side view of a power unit. It is a top view of a power unit. It is a longitudinal cross-sectional view of the oil pan part of a power unit. FIG. 4 is a cross-sectional view taken along line VI-VI of the power transmission system in FIG. 3. It is a longitudinal cross-sectional view of the rear part of a power unit. It is sectional drawing of a balancer. It is a perspective view which shows the principal part.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Scooter type motorcycle, 2 ... Power unit, 3 ... Body frame, 12 ... Cylinder, 13 ... Crankcase, 13a ... Oil pan, 16 ... Seat, 21 ... Exhaust pipe, 22 ... Vaporizer, 23 ... Air cleaner, 30 ... a footrest, 30a ... a footrest, 30b ... a protrusion.

Claims (5)

A vehicle body frame having a head pipe, a pair of left and right main pipes extending rearwardly downward from the head pipe, and a pair of left and right down tubes connected to the head pipe;
A footrest provided between the steering handle and the seat;
A rear arm that is swingably connected to the vehicle body frame via a pivot shaft and supports a rear wheel;
An engine disposed below the seat, with a cylinder positioned in front of the pivot shaft and the crankshaft, and fixed to the body frame;
A V-belt transmission that is connected to an end of the crankshaft of the engine and extends rearward;
A scooter type motorcycle having a storage box disposed below the seat and above the engine and fixed to the vehicle body frame;
An intake pipe extending backward from the cylinder is connected to the upper surface of the cylinder,
The scooter type motorcycle according to claim 1, wherein an intake system component provided in the intake pipe is disposed in front of the storage box, below the seat and above the crankshaft of the engine. The scooter type motorcycle according to claim 1, wherein a recessed portion is formed on the lower side of the seat,
The scooter type motorcycle according to claim 1, wherein the intake system component is disposed so as to face the recessed portion, and a part thereof is overlapped with the seat in a side view. The scooter type motorcycle according to claim 1, wherein the engine is a parallel multi-cylinder type,
The footrest has a protrusion that protrudes upward in the center in the vehicle width direction, and a footrest formed on both sides of the protrusion,
The scooter type motorcycle according to claim 1, wherein the cylinder is a space surrounded by the head pipe and the down tube, and is disposed on a protruding portion of the footrest. The scooter type motorcycle according to claim 1, wherein the seat is swingably supported by the vehicle body around a fulcrum on the front side of the vehicle body,
The scooter type motorcycle, wherein the intake system component is disposed in the vicinity of the fulcrum. The scooter type motorcycle according to claim 1, wherein the cylinder is attached to the crankcase in a state where the cylinder is tilted forward so that the axial direction is directed in the longitudinal direction of the vehicle body.
The engine is a multi-cylinder engine;
A scooter type motorcycle, wherein each cylinder of the engine is arranged in parallel to the vehicle width direction.

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