JPH0139397B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a seat-type motorcycle.

A sitting type automatic vehicle, generally referred to as a scooter, has a seat for sitting on at the rear of a vehicle body on which front and rear wheels are suspended, and a floor plate formed on the body between the front and rear wheels with a step for resting the feet of a passenger seated on the seat. In a two-wheeled vehicle, the step has a wide area and is provided at a desired height without being obstructed by the engine or the transmission mechanism that links the engine and the rear wheel, so that the rider can sit in a comfortable posture. There is a need to improve ride comfort, but
In conventional motorcycles of this kind, the arrangement of the floor plate forming the step is limited by the engine and transmission mechanism provided below, and the above requirements cannot be fully satisfied.

Therefore, the main object of the present invention is to provide a power transmission device for a seated motorcycle that satisfies the above-mentioned requirements. A horizontally opposed engine having a front cylinder block located at the front and a rear cylinder block located at the rear is suspended such that its crankshaft faces perpendicular to the longitudinal direction of the vehicle body, and the engine includes: An output shaft that interlocks with the crankshaft is suspended below the crankshaft in parallel thereto, and a rear fork that supports a rear wheel that interlocks with the output shaft is pivotally supported on the output shaft so as to be able to swing up and down. It is characterized by

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In Fig. 1, the front part of a body 1 of a seated motorcycle, generally designated by the symbol S, has a steerable front wheel Wf, and the rear part thereof is rotated by an engine E, which will be described in detail later. The driven rear wheels Wr are suspended. A sitting seat 2 is mounted on the rear part of the vehicle body 1. Further, between the front and rear wheels Wf and Wr, left and right steps 4f and 4r for the footrest of a passenger seated on the seat 2 are formed on the left and right sides of the floor plate 3 which is detachably attached to the vehicle body 1,
Further, a raised part 5 having a convex cross section extending in the front-rear direction of the main body 1 is integrally formed in the left and right center portions of the floor plate 3, and below this raised part 5 is a part of the engine E and an air cleaner, which will be described later. 7. Carburetor 8
A tunnel 6 extending in the front-rear direction is formed for accommodating auxiliary equipment such as.

An engine E for driving the rear wheels Wr is suspended below the vehicle body 1 between the front and rear wheels Wf and Wr, and this is a horizontally opposed four-stroke multi-cylinder engine.
It is arranged horizontally with respect to the vehicle body 1, that is, with its crankshaft 9 perpendicular to the longitudinal direction of the vehicle body 1. The front cylinder block 10 of the engine E is
It extends substantially horizontally toward the front of the vehicle body 1, and its rear cylinder block 11 extends substantially horizontally toward the rear of the vehicle body 1.

Pistons 14 and 15 are slidably fitted into cylinder bores 12 and 13 in the front and rear cylinder blocks 10 and 11, respectively, and these pistons 14 and 15 are connected to the crankshaft 9 via connecting rods 16 and 17. be done.

Inside the crankcase 18 of the engine E,
The crankshaft 9 is parallel and the crankshaft 9
The output shaft 19 located at the lower rear of the ball bearing 2
It is rotatably supported via 0.

A drive gear 21 is fixed to one end of the crankshaft 9, and the drive gear 21 is fixed to one end of the crankshaft 9.
A driven gear 22, which is always meshed with, is spline-coupled.

Camshafts 25 and 26 are rotatably supported by the output shaft 19 and cylinder heads 23 and 24 on the front and rear cylinder blocks 10 and 11, respectively.
are connected by timing transmissions T ₁ and T ₂ , respectively, so that the rotation of the output shaft 19 is transmitted to the camshafts 25 and 26 via these timing transmissions T ₁ and T ₂ . It's getting old. Each timing transmission T ₁ ,
T ₂ is a drive chain wheel 27 ₁ , 27 ₂ fixed to the output shaft 19,
Driven chain wheels 28 ₁ , 28 ₂ fixed to camshafts 25 , 26
and their chain wheels 27 ₁ , 28 ₁ , 27 ₂ , 28 ₂
It is composed of timing chains 29 ₁ and 29 ₂ that connect the two, respectively.

As shown in FIGS. 1 and 3, above the center of the horizontally opposed engine E in the longitudinal direction, there is a
An air cleaner 7 and a carburetor 8 are provided, and the upper portions of these and the engine E are housed in the tunnel 6 formed in the left and right center portions of the floor plate 3, and are protected by the floor plate 3.

The output shaft 19 extends to one side relative to the crankshaft 9 and projects outwardly from the crankcase 18, and a belt type continuously variable transmission M, which will be described later, is connected to the projecting portion 19a.

On one side of the crankcase 18 of engine E,
The front end of a transmission case 30 constituting a part of the rear fork F is pivotally supported via a ball bearing 31 concentrically with the output shaft 19, and this transmission case 30 swings up and down about the axis of the output shaft 19. can move. Also, on the other side of the crankcase 18,
A pivot shaft 32 is rotatably supported via a ball bearing 33 on the same axis as the output shaft 19, and the front end of an arm member 34 constituting another part of the rear fork F is attached to the connecting bolt 3.
It is fixed with 5. A cross member 36 is integrally formed in the middle of the transmission case 30 in the longitudinal direction toward the arm member 34, and this cross member 36
The free end of the arm member 34 is integrally connected with a connecting bolt 37 in the middle of the arm member 34, and the transmission case 30 and the arm member 34 are integrated, and the rear fork F
The output shaft 19 swings up and down around the axis of the output shaft 19. Since the rear fork F is pivotally supported by the output shaft 19 located below the crankshaft 9, the rear fork F is disposed at a low position under the vehicle body 1, and is compatible with the low position of the engine E itself. In addition, the center of gravity of the entire motorcycle S can be lowered, and the position of the floor plate 2 can also be lowered.

Further, the cross member 36 serves as a reinforcing member for the rear fork F itself. Further, the cross member 3
A boss 36a is integrally formed in the left and right center portions of the vehicle body 1, and a rear shock absorber D that is swingably suspended from the rear of the vehicle body 1 is connected to this boss 36a. The rear fork F can be swung up and down in a well-balanced manner to reduce twisting and distortion of the rear fork F.

Furthermore, the rigidity of the rear fork F is maintained high by the portions that constitute the transmission case 30.

The rear ends of the transmission case 30 and the arm member 34 are opposed to each other, and a rear axle 41 is rotatably horizontally suspended therebetween via ball bearings 38, 39, and 40. A transmission case 30 is attached to the rear wheel 41.
A rear wheel Wr located between the arm member 34 and the arm member 34 is connected.

An outside air inlet 42 is opened at the front end of the transmission case 30, and a fan 47b is integrally formed with the fixed pulley half 47, which will be described later.
2 into the transmission case 30,
The continuously variable transmission M, which will be described later, inside the case can be actively cooled.

The output shaft 1 is disposed at the rear of the transmission case 30.
A driven shaft 43 parallel to the output shaft 1 is rotatably supported via ball bearings 44 and 45.
9 and the driven shaft 43, the belt type continuously variable transmission M housed in the transmission case 30 is suspended. Since this continuously variable transmission M is conventionally known, its structure will be briefly described below. The output shaft 19 is provided with a driving side transmission pulley 46 consisting of a fixed pulley half 47 and a movable pulley half 48. The fixed pulley half 47 is fixed to the end of the output shaft 19,
Further, the movable pulley half 48 is fitted onto the output shaft 19 so as to be slidable in the axial direction. Opposed conical surfaces 4 of fixed and movable pulley halves 47, 48
A V-shaped annular groove 49 is formed between 7a and 48a, and an endless V-belt 50 is inserted into the annular groove 49 and held between the conical surfaces 47a and 48a. A ramp plate 51 is fixed to the output shaft 19 on the back surface of the movable pulley half 48, and a plurality of ramps are arranged in a radially tapered gap formed between the ramp plate 51 and the back surface of the movable pulley half 48. A weight roller 52 is housed in a floating state. When the output shaft 19 is rotated and its rotational speed increases, the weight roller 52 subjected to centrifugal force moves radially outward, moves the movable pulley half 48 in a direction approaching the fixed pulley half 47, and forms a conical shape. Surface 47
The contact radius of the endless V-belt 50 with respect to a and 48a can be increased.

On the other hand, the driven shaft 43 includes a driven pulley shaft 53.
A fixed pulley half 55 is fixed to one end of the pulley shaft 53, and a movable pulley half 56 is fitted to be slidable in the axial direction. , 56, the endless V-belt 50 is inserted into a V-shaped annular groove 57 formed between opposing conical surfaces 55a, 56a. The movable and fixed pulley halves 5
Reference numerals 5 and 56 constitute a driven transmission pulley 54 that is paired with the driving transmission pulley 46 . A drive plate 58 of a centrifugal clutch C, which will be described later, is fixed to the outer end of the driven pulley shaft 53, and a compression spring 5 is installed between the drive plate 58 and the movable pulley half 56.
9 is compressed, and the elastic force of the compression spring 59 biases the movable pulley half 56 toward the fixed pulley half 55.

The driven side transmission pulley 54 and the driven shaft 43 are connected via a conventionally known centrifugal clutch C. When the rotational speed of the transmission pulley 54 exceeds a predetermined value, the centrifugal clutch C becomes "contacted" and the transmission pulley 54 is connected. The rotation is transmitted to the driven shaft 43 via the centrifugal clutch C.

Since the centrifugal clutch C is conventionally known, its structure will be briefly explained. A clutch outer 60 having a U-shaped cross section is fixed to the outer end of the driven shaft 43.
Further, the aforementioned drive plate 58 is fixed to the outer end of the pulley shaft 53 that is integral with the fixed pulley half 55. Several clutch weights 53 are pivotally supported on the drive plate 58 via support pins 62 so as to be rotatable in the radial direction, and a clutch spring 64 is connected between each of the clutch weights 63. The spring force of the clutch weight 63 is fixed to the outer periphery of the clutch weight 63.
5 away from the inner circumferential surface of the clutch outer 60, that is, to disengage the centrifugal clutch C.

A mission chamber 66 is formed inside the rear end of the transmission case 30, and inside this mission chamber 66,
A reduction gear mechanism R that interlocks the driven shaft 43 and the rear axle 41 is housed therein. Mission room 6
6, between the driven shaft 43 and the rear axle 41,
An intermediate shaft 67 parallel to these is rotatably supported. A drive gear 68 fixed to the inner end of the driven shaft 43 in the mission chamber 66 is meshed with a first reduction gear 69 fixed to the intermediate shaft 67, and further
A small gear 70 integrated with the rear wheel 7 is meshed with a second reduction gear 71 fixed to the rear wheel 41.

The rotational force of the output shaft 19 is transmitted to the rear axle 41 via the belt type continuously variable transmission M, the centrifugal clutch C, and the reduction gear mechanism R, and can rotate the rear wheel Wr. It is designed to automatically change according to the load applied to Wr, and as the load applied to the rear wheel Wr increases, the reduction ratio of the continuously variable transmission M increases and the rear wheel Wr is rotated at a reduced speed.
Conversely, if the load applied to the rear wheels Wr decreases, the reduction ratio of the continuously variable transmission M decreases, and the rear wheels Wr rotate at an increased speed.

When driving the motorcycle configured as described above, the rider sits on the seat 2 and then puts his/her feet on the left and right steps 4f, 4r to drive the engine E. The rotation of the crankshaft 9 is transmitted to the rear axle 41 via the output shaft 19, the continuously variable transmission M, the centrifugal clutch C, and the reduction gear mechanism R, and can drive the rear wheels Wr. Also then the wheels
The rear fork F supporting Wr moves up and down around the axis of the output shaft 19, and the rear shock absorber D is activated. At this time, since the rear shock absorber D is connected to the left and right intermediate portions of the rear fork F, twisting and distortion when the rear fork F swings up and down can be reduced.

Therefore, between the front and rear wheels Wf and Wr, the vehicle body 1
The horizontally opposed engine E is suspended at the bottom of the vehicle, and its front and rear cylinder blocks 10 and 11 are connected to the vehicle body 1.
By arranging the engine E in the longitudinal direction,
In this case, the width of the vehicle body 1 in the left-right direction is reduced, and the engine E can be placed lower while maintaining a predetermined bank angle.

As described above, according to the present invention, a horizontally opposed engine is provided in the lower part of the vehicle body between the front and rear wheels, with the front cylinder block located at the front and the rear cylinder block located at the rear. The engine is suspended so as to face perpendicular to the engine direction, and an output shaft that interlocks with the crankshaft is suspended parallel to the engine below the crankshaft, and a rear wheel that interlocks with the shaft is supported on the output shaft. Since the rear fork is pivoted so that it can swing up and down, the left and right steps of the floorboard can be placed at a lower position on the vehicle body and can be made longer in the front and rear directions, allowing the occupants to take a comfortable seating position. This improves riding comfort and makes it easier to get on and off the vehicle.

In addition, the rear fork can secure a desired length of left and right shaft support spacing without being obstructed by the steps, making stable vertical swing possible.

Furthermore, by housing the transmission mechanism within the rear fork, the center of gravity of the vehicle can be lowered and the dynamic characteristics of the vehicle can be improved.

[Brief explanation of drawings]

The drawings show one embodiment of the motorcycle of the present invention, FIG. 1 is a side view thereof, and FIG. 2 is a side view thereof.
The enlarged line cross-sectional view, FIG. 3, is an enlarged line longitudinal cross-sectional view taken from FIG. 1. Wf, Wr...Front, rear wheels, E...Engine, F
... Rear fork, R ... Reduction gear mechanism as a transmission mechanism, 1 ... Vehicle body, 4f, 4r ... Left and right steps, 9 ... Crankshaft, 10, 11 ... Front,
Rear cylinder block, 19... Output shaft, 30...
...Transmission case.

Claims (1)

[Scope of Claims] 1. A seat-type motorcycle having left and right steps for resting the feet of an occupant on the lower part of the vehicle body between the front and rear wheels,
A horizontally opposed engine is installed in the lower part of the vehicle body between the front and rear wheels, with the front cylinder block located at the front and the rear cylinder block located at the rear, with its crankshaft facing in a direction perpendicular to the longitudinal direction of the vehicle body. A rear fork is mounted on the engine, and an output shaft that is connected to the crankshaft is mounted below the crankshaft in parallel with the output shaft, and a rear fork that supports a rear wheel that is connected to the output shaft is mounted on the output shaft. A seat-type motorcycle that is supported on a shaft so that it can swing up and down. 2. In the seat-type motorcycle according to claim 1, at least a part of the rear fork is formed in a transmission case, and a transmission mechanism for interlocking the output shaft and the rear wheel is housed in the transmission case. A seat-type motorcycle.