JP3996251B2 - Scooter type motorcycle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a scooter type motorcycle equipped with a large displacement engine.
[0002]
[Prior art]
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.
[0003]
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.
[0004]
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.
[0005]
[Problems to be solved by the invention]
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, the conventional scooter type motorcycle configured as described above cannot increase the displacement by increasing the number of cylinders of the power unit.
[0006]
One reason for this is that as the number of cylinders increases and the size of each cylinder increases, the space between the power unit and the seat becomes narrow, and only a storage box with a small capacity can be used. It is. The second reason is that since the plurality of exhaust pipes extend to one side of the vehicle body (right side of the vehicle body), the diameter of each exhaust pipe is restricted, and the exhaust pipes are formed so as to reduce the exhaust resistance. It is not possible. Although the exhaust pipe diameter restriction on the exhaust pipe is extended by extending the exhaust pipe on both sides in the vehicle width direction, the minimum ground clearance of the vehicle body may be lowered by the large exhaust pipe. The bank angle must not be narrowed.
[0007]
The present invention has been made to solve such problems, and a first object of the present invention is to make it possible to use a large storage box for increasing the number of cylinders and the displacement of a power unit. It is a second object of the present invention to make it possible to form the exhaust pipe with a large diameter while satisfying conditions such as minimum ground clearance and bank angle.
[0008]
[Means for Solving the Problems]
The scooter type motorcycle according to the present invention includes a head pipe, a body frame having 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, and the head A scooter-type motorcycle including a footrest provided between a pipe and a seat, a parallel multi-cylinder engine including a crankcase and a cylinder, and an automatic transmission provided on a side of the crankcase. The footrest has a projecting portion formed by projecting a center portion in the vehicle width direction above the footrest portions on both sides, and the crankshaft of the engine is disposed below the seat, cylinders, wherein a space surrounded by the main pipe and the down tube are disposed below the footrest of the protrusion Than it is.
[0009]
According to the present invention, since the cylinder can be accommodated inside the footrest, a large space can be formed between the seat and the crankcase even if a multi-cylinder type large displacement engine is mounted. .
[0010]
A scooter type motorcycle according to another invention is the scooter type motorcycle according to the invention described above, comprising a storage box below the seat and above the crankcase, and a part of the storage box is a part of the storage box in a side view. It overlaps with the crankcase.
A scooter type motorcycle according to another invention is the scooter type motorcycle according to the above-described invention, wherein the engine is a parallel two-cylinder type, and the exhaust pipe of each cylinder overlaps with the oil pan in a side view from below the cylinder. Along the side of the pan, it extends to the rear of the car.
[0011]
According to the present invention, the exhaust pipe does not protrude downward from the lowermost oil pan of the engine, and does not protrude greatly to the side of the oil pan.
[0012]
A scooter type motorcycle according to another invention is the scooter type motorcycle according to the above-described invention, wherein an air cleaner is disposed between the front end of the vehicle body of the seat and the crankcase, and below the protruding portion of the footrest. The intake system between the air cleaner and the cylinder is accommodated in the space.
[0013]
According to the present invention, since the intake system parts can also be accommodated inside the footrest, the space below the seat is further widened.
[0014]
A scooter type motorcycle according to another invention is the scooter type motorcycle according to the invention described above, wherein an air cleaner is disposed in the vicinity of the head pipe of the vehicle body frame, and an air cleaner and a cylinder are provided in a space below the protruding portion of the footrest. It houses the intake system between.
[0015]
According to the present invention, the entire space between the seat and the crankcase can be used as a storage space.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
First Embodiment 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.
[0017]
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.
[0018]
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.
[0019]
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 composed of 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.
[0020]
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.
[0021]
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.
[0022]
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.
[0023]
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.
[0024]
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.
[0025]
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.
[0026]
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.
[0027]
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.
[0028]
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.
[0029]
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.
[0030]
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.
[0031]
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.
[0032]
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.
[0033]
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.
[0034]
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.
[0035]
The scooter 1 configured as described above has a crankcase 13 below the seat 16 and is below the projecting portion 30b formed by projecting the center portion in the vehicle width direction of the footrest 30 upward. Since the cylinder faces the space 31 sandwiched between the footrests 30a, the cylinder 12 can be accommodated inside the footrest 30, and the seat 16 and the seat 16 can be mounted even if a two-cylinder large displacement engine is mounted. A space used for luggage storage or the like can be formed widely between the crankcase 13 and the like.
[0036]
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. Thus, 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.
[0037]
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.
[0038]
The intake system component according to the second embodiment can be arranged on the front side of the power unit 2 as shown in FIG.
FIG. 10 is a side view showing a main part of a scooter according to another invention. In FIG. 10, the same or equivalent members as those described in FIGS. 1 to 9 are denoted by the same reference numerals and detailed description thereof is omitted. .
[0039]
The intake pipe 20 shown in FIG. 10 extends from the upper surface of the cylinder head 12a to the front upper side, and a carburetor 22 is connected to the front end. An air cleaner 23 is disposed in front of the vaporizer 22 and in the vicinity of the head pipe 9. These intake system components are housed in a space formed below the protrusion 30 b of the footrest 30 in the same manner as the cylinder 12.
[0040]
By disposing the intake system parts so as to extend forward from the engine in this way, the entire space between the seat 16 and the crankcase 13 can be used as a storage space. Further, compared to the case of the first embodiment described above, the intake passage including the intake port 61 in the cylinder head 12a is not greatly bent, so that the intake resistance is reduced and the engine performance is improved. Can do.
[0041]
【The invention's effect】
According to the present invention, since the cylinder can be accommodated inside the footrest, a large space can be formed between the seat and the crankcase even if a multi-cylinder type large displacement engine is mounted. . Therefore, it is possible to increase the number of cylinders and the displacement of the power unit while using a large storage box.
[0042]
According to another invention in which the exhaust pipe is arranged on the side of the oil pan, the exhaust pipe does not protrude downward from the lowermost oil pan of the engine, and further protrudes greatly to the side of the oil pan. Nor. Therefore, the exhaust pipe 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.
[0043]
According to another invention in which the air cleaner is disposed below the front end portion of the seat, since the intake system parts can be accommodated inside the footrest, the space below the seat is further increased. Therefore, a storage box having a larger capacity can be mounted.
[0044]
According to another invention in which an air cleaner is disposed on the head pipe side, the entire space between the seat and the crankcase can be used as a luggage storage space, so that interference with intake system components is avoided. A large-capacity storage box can be mounted below the seat.
[Brief description of the drawings]
FIG. 1 is a side view of a scooter type motorcycle according to the present invention.
FIG. 2 is a plan view of a scooter type motorcycle according to the present invention.
FIG. 3 is a side view of the power unit.
FIG. 4 is a plan view of a power unit.
FIG. 5 is a longitudinal sectional view of an oil pan portion of a power unit.
6 is a cross-sectional view of the power transmission system taken along the line VI-VI in FIG. 3;
FIG. 7 is a longitudinal sectional view of a rear portion of a power unit.
FIG. 8 is a cross-sectional view of a balancer.
FIG. 9 is a perspective view showing a main part.
FIG. 10 is a side view showing a main part of a scooter type motorcycle according to another invention.
[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 head pipe and the seat;
A parallel multi-cylinder engine having a crankcase and a cylinder ;
In a scooter type motorcycle equipped with an automatic transmission provided on the side of the crankcase,
The footrest has a projecting portion formed by projecting the center portion in the vehicle width direction above the footrest portions on both sides,
A crankshaft of the engine is disposed below the seat;
The scooter type motorcycle according to claim 1, wherein the cylinder of the engine is a space surrounded by the main pipe and the down tube, and is disposed below the protruding portion of the footrest . The scooter type motorcycle according to claim 1, further comprising a storage box below the seat and above the crankcase.
A scooter type motorcycle, wherein a part of the storage box overlaps with the crankcase in a side view.   2. The scooter type motorcycle according to claim 1, wherein the engine is a parallel two-cylinder type, and the exhaust pipe of each cylinder extends along the side of the oil pan in a side view from the bottom of the cylinder and extends rearward of the vehicle body. A scooter type motorcycle characterized by having been installed.   The scooter type motorcycle according to claim 1, wherein an air cleaner is disposed between a front end portion of the seat and a crankcase, and the air cleaner and the cylinder are disposed in a space formed below the protruding portion of the footrest. A scooter type motorcycle characterized by containing an intake system between the two.   The scooter type motorcycle according to claim 1, wherein an air cleaner is disposed in the vicinity of the head pipe of the vehicle body frame, and an air intake system between the air cleaner and the cylinder is formed in a space formed below the protruding portion of the footrest. A scooter type motorcycle characterized by being housed.

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