JPH03217385A - Motorcycle - Google Patents

Abstract

PURPOSE:To increase the total capacity of an air cleaner box as well as to improve the degree of freedom of a body design by installing each air cleaner box in the upper part of a transmission case and at the opposite side of this transmission case with a rear wheel in between after being divided into plurality. CONSTITUTION:In this motorcycle, a power unit 30 consisting of an engine 32 and a transmission case 34 extending to the rear from this engine is supported on a body frame 10 so as to be vertically shakable. In a rear part of this power unit 30, there is provided with a unit-swing type rear-wheel suspension system holding a rear wheel 36. In the above constitution, each of air cleaner boxes 50a, 50b is installed in the upper part of the transmission case 34 and at the opposite side of this case 34 with the rear wheel 36 in between, after being divided into plurality. With this constitution, the total capacity of each of these air cleaner boxes 50a, 50b is increased while individual air cleaner boxes 50a, 50b are contracted, thereby improving the degree of freedom of a body design.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a motorcycle having a unit swing type rear wheel suspension.

(Background of the Invention) A motorcycle is known that has a unit swing type rear wheel suspension system in which a power unit that integrates an engine and a transmission case is pivoted on a body frame so as to be vertically swingable. In such vehicles, an air cleaner box is usually provided above the transmission case. In this case, since the air cleaner box swings together with the transmission case, the capacity of the air cleaner box cannot be increased to avoid interference between the air cleaner box and the vehicle body, and the degree of freedom in design of the vehicle body is restricted. There was a problem.

(Object of the invention) This invention was made in view of the above circumstances,
To provide a motorcycle having a unit swing type rear transport suspension device and capable of increasing the capacity of an air cleaner box when the air cleaner box is installed in a transmission case of a power unit.

(Structure of the Invention) According to the present invention, the object is to pivot a power unit that integrates an engine and a transmission case extending rearward from the engine to the vehicle body frame so as to be able to swing vertically, and to attach the rear wheels to the rear of the power unit. In the motorcycle having a unit swing type rear wheel suspension system, an air cleaner box is provided above the transmission case and on the opposite side of the transmission case with the rear wheel in between. Achieved by motorcycles.

(Example) Fig. 1 is a side view of one embodiment of the present invention, Fig. 2 is a plan view mainly showing the frame structure, Fig. 3 is a plan view mainly showing the power unit, and Fig. 4 is the arrangement of the footrest. A sectional view taken along the line IV--IV in Figure 1 to show the
It is a sectional view taken along the V line.

In these figures, reference numeral 10 denotes a vehicle body frame, which includes a steering shaft cylinder 12, a lower frame 14, an upper frame 16, and a seat rail 18. The lower frame 14 includes one descending tube 14a that descends obliquely downward and rearward from the steering shaft cylinder 12.
It has a cross tube 14b fixed to the rear end of the descending tube 14a, and a pair of left and right lower tubes 14c and 14d fixed to the middle of the descending tube 14a and the cross tube 14b and extending rearward. .

The upper frame 16 extends rearward almost horizontally from the steering shaft cylinder 12 and then descends, and its rear ends are connected to left and right lower tubes 14c,
1 fixed to the cross tube 14e connecting 14d.
It is formed from a book tube. As a result, lower frame 1
4 and the upper frame 16, a large space open to the left and right sides is formed, in which a luggage box 68, which will be described later, is accommodated.

The seat rail 18 is formed by a pair of left and right tubes 18a, 18b extending rearward from the descending portion of the rear part of the upper frame 16, and the middle portion of the tubes 18a, 18b is connected to the lower tube via a stay 20 (20a, 20b). 14c
, 14d.

Reference numeral 22 denotes a front steering wheel, which is held on the steering shaft cylinder 12 by a front fork 24 so as to be rotatable left and right. 26 is a steering handle.

30 is a power unit. This power unit 30 has four
The engine 32 integrates a cycle overhead camshaft single-cylinder engine 32 and a transmission case 34 extending rearward from a crankcase 32a of the engine 32.
A driving rear wheel 36 is held on the right side of the rear end. The engine 32 has a crankshaft 32b that extends in the vehicle width direction, and the rotation of the crankshaft 32b is controlled by a VV housed in a transmission case 34.
The signal is transmitted to the rear wheels 36 via a continuously variable belt transmission (not shown). Further, a sill 32c of the engine 32 projects forward from the crankcase 32a. This cylinder 3
As shown in FIG. 3, the cylinder 2c has a width smaller than that of the crankcase 32a, and a cooling air duct 32d is attached to surround the cylinder 32c. A fan 32e is disposed on the right side of the cylinder 32c, and the fan 32e is rotated by a crankshaft 32a via a belt 32f to send cooling air into the exhaust 32d. Further, a radiator 32g is attached to the side surface of the fan 32e (FIG. 3). This engine 32 has a liquid-cooled cylinder head, and the radiator 32g cools this coolant.

The front end of an arm 38 that holds the right end of the axle of the rear wheel 36 is also fixed to the crankcase 32a of the power unit 30. The rear end of this arm 38 and the rear end of the transmission case 34 are connected by a U-shaped arm 40 that detours above the rear wheel 36, and the front end of this U-shaped arm 40 is attached to the upper surface of the crankcase 32a by an arm 42. combined. As a result, the transmission case 34 or the arm 38 and the arm 40
and 42 form a substantially triangular shape in side view.

This power unit 30 is pivotably supported on the vehicle body frame 10 so as to be vertically swingable. That is, the lower tubes 14c, 14d
Brackets 44, 44 are fixed to the rear ends of the
The upper surface of the crankcase 32a is pivoted to the rear end of a link 46 held between these brackets 44, 44. A joint between the arms 40 and 42 of the power unit 30 is supported by the upper frame 16 via one cushion unit 48.

50 (50a, 50b) are a pair of left and right air cleaner boxes having almost the same shape, while 50a is a transmission case 34.
The other 50b is fixed to the arms 38 and 40 so as to be located above the arm 38. Both air cleaner boxes 50a and 50b are communicated with each other by rubber tubes 52, and an outside air intake port 50C (second
The intake air entering from the tube 52 enters the air cleaner box 50a on the left side, and is further led to the carburetor 56 by the duct 54. This carburetor 56 is connected to the crank case 32
It is located above the cylinder 32c and directs the air-fuel mixture to the cylinder 32c. Of course, a filter is housed in at least one of these air cleaner boxes 50a and 50b.

58 is an exhaust muffler, which is an arm 38 on the right side of the rear wheel 36.
installed on. The exhaust from the engine 32 is carried out by the muffler 5 through an exhaust pipe 60 passing under the crankcase 32a.
Guided by 8.

62 is a straddle type driver's seat, and the seat rail 18
installed on. This driving seat 62 is the engine 3
Located above 2.

64 (64a, 64b) are a pair of left and right footrests.

These footrests 64 are connected to the lower tubes 14c and 14d.
The bracket 6 descends from the left and right sides of the cylinder 32c.
6 (66a, 66b).

68 is a luggage box made of hard resin. The luggage box 68 is housed in the space between the lower frame 14 and the upper frame 16, that is, the space surrounded by the steering shaft cylinder 12, the engine 32, and the driving seat 62, as described above, and its rear part is cushioned. A rear extension portion 68c extends rearward through the left side of the unit 48. A cylindrical portion 68d extends from the rear extension portion 68c and passes under the driver seat 62 to the rear.
is installed protrudingly. The tennis racket A can be stored as shown in the imaginary line in Figure 1, and fishing rods can be stored in the cylindrical part 68d.
The lid at the rear end can be opened to allow insertion into the luggage box 68 from the rear.

As shown in FIG. 5, this luggage box 68 has a box main body 68a with a large opening on the left side, and a lid plate 68b that closes this opening. The lower surface of the box body 68a is fixed to an appropriate number of bracket plates 70 fixed to the frames 14b and 14c, and the upper surface of the box body 68a is fixed to a bracket plate 70 fixed to the upper frame 16.
, 72. Further, the right side surface of the box body 68a is smoothly bulged outward so as to substantially follow the inner surface of a cowling 80, which will be described later. Lid plate 68 on the left side of the box body 68a
b also bulges outward. By inflating the left and right side surfaces in this way, the rigidity of these wide-area surfaces increases and vibrations thereof are suppressed.

The lower part of the lid plate 68b is attached to the lower part of the box body 68a by two sets of hinges 74, 74.
It can be opened and closed to the left using 4 as a fulcrum. A rubber seal 76 is attached to the opening edge of the box body 68a, and when the lid plate 68b is closed, the lid plate 68b is pressed against the seal 76 to seal the box 68 liquid-tightly.

Reference numeral 78 denotes a fuel tank, which is attached so as to straddle the upper frame 16. 80 is a cowling, and this fuel tank 78 and luggage box 6 are connected from the front of the steering shaft cylinder 12.
8 and smoothly continues to the driving seat 62. A part of the cowling 80, that is, a portion 80a facing the lid plate 68b of the luggage box 68 is fixed to the lid plate 68b side and can be opened and closed integrally with the lid plate 68b. Below the left and right sides of the cowling 80 are long resin moldings 8 from front to back.
2 and 82 are fixed, and the molding 82 on the left side is attached to the hinge 7.
4, covering 74. Further, 84 is a battery, which is disposed below the lower tubes 14c and 14d. A main stand 86 is attached to the lower surface of the power unit 30.

Therefore, when the lid plate 68b of the luggage box 68 is opened to the side as shown in FIG. 5, the opening of the box body 68a is exposed on the side. When storing a long item such as a tennis racket A through this opening, insert the grip side of the racket A into the rear extension 68c of the storage box 68, as shown by the temporary line in FIG. It can be placed in the storage box 68.

In the above embodiment, each air cleaner box 50a, 5
0b are communicated with each other through a duct 52, so that they essentially function as one air cleaner box. However, if the engine has two cylinders, these two air cleaners may be operated independently. Also air cleaner box 5
Since the heights of 0a and 50b can be made small, a large space can be secured between them and the driving seat 62 above them.

Therefore, it is also possible to accommodate large capacity luggage boxes in this space.

(Effects of the Invention) As described above, this invention has two air cleaner boxes disposed above the transmission case and on the opposite side of the transmission case across the rear wheel. The total capacity of the box can be increased. Furthermore, since each air cleaner box can be made smaller, there is an effect of increasing the degree of freedom in designing the vehicle body.

4.

[Brief explanation of drawings]

Fig. 1 is a side view of one embodiment of the present invention, Fig. 2 is a plan view showing its frame structure, Fig. 3 is a plan view showing the power unit, and Fig. 4 is a plan view showing the arrangement of the footrest. 1 is a sectional view taken along the line IV--IV, and FIG. 5 is a sectional view taken along the line V-V. DESCRIPTION OF SYMBOLS 10... Vehicle body frame, 30... Power unit, 34... Transmission case, 36... Rear wheel, 50a, 50b... Air cleaner box.

Claims (1)

[Scope of Claims] A unit swing type rear wheel in which a power unit that integrates an engine and a transmission case extending rearward from the engine is pivotally supported on the vehicle body frame so as to be able to swing vertically, and the rear wheels are held at the rear of the power unit. A motorcycle having a suspension system, characterized in that air cleaner boxes are provided above the transmission case and on the opposite side of the transmission case with the rear wheel in between.