JPH11301557A - Scooter type motorcycle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a scooter type motorcycle, excellent in the gait, with enough capacity in the air cleaner, and with an excellent suction performance. SOLUTION: A caburetor 33 is provided at a cylinder head 17D of a cylinder at the front of the vehicle, and the caburetor 33 is connected to the cylinder head 17D via a suction tube 32. The rear portion of an air cleaner with L shaped in a plan view is provided above the cylinder. At the side of the caburetor 33, a side portion 38 is provided which projects to the front of the cylinder head 17D.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scooter type motorcycle having a unit swing type engine in which an engine and a power transmission mechanism are housed in an integrated crankcase and transmission case.

[0002]

2. Description of the Related Art Generally, a scooter type motorcycle is provided with a unit swing type engine. The unit swing type engine can swing by a support shaft and a cushion unit provided at a front end thereof. It is supported and swings with the rear wheel. Above the cylinder of the unit swing type engine, an air cleaner case, a carburetor, and the like are sequentially held in series, and these are held so as to swing together with the unit swing type engine.

[0003]

By the way, in the above-mentioned conventional unit swing type engine, a trunk room or a seat for storing a helmet or the like exists above the unit swing engine, and the unit swings when the unit swings. It is necessary to avoid interference with the swing engine. For this reason, when the air cleaner case and the carburetor are held in series above the unit swing engine as in the above-described prior art, the air cleaner case is flattened in the vertical direction, or the air cleaner case is placed in a trunk room or the like. It is necessary to set the bottom position upward. However, when the air cleaner case is flattened, a sufficient capacity cannot be obtained in the air cleaner case, which may cause a decrease in intake performance.
When the height of the bottom of the luggage compartment is moved upward, the height of the seats provided above the luggage compartment also increases, resulting in a problem that the rideability and running stability decrease.

[0004] The present invention has been made to solve the above-mentioned problems of the prior art.
An object of the present invention is to provide a scooter-type motorcycle that can provide a sufficient capacity for an air cleaner and has excellent intake performance.

[0005]

According to the present invention, there is provided a transmission case which houses a power transmission mechanism for transmitting the rotational force of the crankshaft to a rear wheel, behind a crankcase which houses a crankshaft and the like. A scooter-type vehicle of a unit swing type engine having a cylinder extending and protruding substantially horizontally toward the front at the front end of the crankcase, wherein a cylinder head of the cylinder is provided with a carburetor in front of the vehicle. While connecting and connecting the carburetor and the cylinder head via an intake pipe, the rear part of the air cleaner having an L-shape in plan view is disposed above the cylinder, and the cylinder is disposed beside the carburetor. A side portion protruding forward from the head is provided, and the side portion of the air cleaner and the carburetor are air-cleaned through an outlet tube protruding in the vehicle width direction. Be coupled to the side portion of the Na, it is obtained by forming in plan view circular intake passage leading to the engine through the air cleaner case and an outlet from the inlet tube of the air cleaner.

In the present invention having the above-described structure, the side portions and the carburetor, which constitute a part of the air cleaner, are disposed by utilizing the space in front of the cylinder head. The space can be sufficiently secured without increasing the height of the sheet. For this reason, the capacity of the air cleaner can be sufficiently ensured, so that good air intake performance can be obtained, and good foot landing performance can be maintained.

If the air cleaner is held in a floating state with respect to the cylinder, it is possible to prevent engine vibrations and the like from being directly transmitted to the air cleaner, and to generate noise in the air cleaner. Can be reduced, and riding comfort can be improved.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an external side view showing an overall configuration of a scooter type motorcycle according to an embodiment of the present invention, FIG. 2 is an explanatory side view showing an internal configuration of the motorcycle shown in FIG. 1, and FIG. 3 is a view shown in FIG. FIG. 4 is a side view showing the unit swing engine and its peripheral configuration, FIG. 4 is a plan view of the one shown in FIG. 3, FIG. 5 is a front view of the one shown in FIG.
FIG. 7 is a partial vertical sectional side view of the one shown in FIG. 4, and FIG. 7 is a partial bottom view of the one shown in FIG.

As shown in FIG. 1, a motorcycle 1 in this embodiment is a large two-seater scooter equipped with a four-cycle DOHC engine, and has a vehicle body having a leg shield 2 and a screen 3 projecting left and right. The front portion 4 holds the handle 6 by a frame 20 described later, and the front wheel 8 is rotatably held by a front fork 7 connected below the handle 6. A double seat 10 having a backrest 9 and the like is held behind the front part 4 of the vehicle body. Between the front part 4 of the vehicle body and the seat 10, an occupant on the seat 10 places both feet. A pair of left and right footrests 11 and 12 with respect to the traveling direction of the vehicle, and a convex portion 13 rising upward between the footrests 11 and 12.
Thus, the floor portion 14 is formed.

A rear cover 15 is provided behind the floor portion 14 to cover a rear portion of the vehicle body, and a rear wheel 16 is provided below the rear cover 16 with a unit swing type engine 17.
It is supported swingably up and down. In this embodiment, the unit swing type engine has a four-cycle engine. The seat 10 is detachably held by a frame 20 described below, and a trunk room R for storing a helmet and the like is formed below the seat 10.

The motorcycle shown in FIG. 1 is provided with a so-called underbone type frame 20 as shown in FIG. That is, at the front end of the frame 20,
A head pipe 21 for rotatably supporting the steering stem 6a fixed to the handle 6 is provided. The head pipe 21 has an upper down tube 22 extending obliquely downward toward the rear, and a lower down tube 22. Tube 23
Are provided symmetrically with respect to the traveling direction. Further, each of the down tubes 22 and 23 has a pair of left and right upper frames 24 supporting the floor portion 14 and the seat 10.
And a lower frame 25 that supports the footrests 11 and 12 from below and raises a rear portion upward and is connected to a rear end of the upper frame.
A seat rail 26 bent in a U-shape for supporting the trunk room is provided at the rear end of the lower frame 25.
Has been fixed. The upper frame and the lower frame are connected to each other by a plurality of bridges 27 so that necessary and sufficient strength can be obtained.

A front end of the unit swing type engine 17, which rotatably supports a rear wheel 28, is rotatably connected to the lower frame 25 via a pivot 17a. 25 link mechanism 29
The rear wheel 28 is connected to a cushion unit connected through
And is swingably supported. The unit swing type engine 17 includes a crankcase 17A that houses a crankshaft (not shown) and a transmission case 17 that is integrally formed to extend behind the crankcase 17A.
B, a cylinder 17C and a cylinder head 17D projecting from the front end of the crankcase 17A form an outer shell. A power transmission mechanism for transmitting the torque of the crankshaft to the rear wheel 28 is provided inside the transmission case 17B.

A carburetor 3 is connected to a front end of the cylinder head 17D through a carburetor inlet tube 32.
3, and the carburetor 33 projects into a space in front of the cylinder head 17D. Further, the vaporizer 33 is disposed at a position deviated rightward between the pair of left and right upper frames 25 in a plan view. An air cleaner 35 is connected to an intake port formed in front of the vaporizer 33 via an outlet tube 34. The outer shell of the air cleaner 35 is constituted by an air cleaner case 36,
The air cleaner case 36 includes a rear portion 37 having a rectangular shape in a plan view and wide in the vehicle left-right direction (width direction), and a side portion 38 communicating with the rear portion 37. A cleaner element 39 is fitted and fixed inside the opening formed in the portion. The rear portion 3 of the air cleaner case 36
Numeral 7 is fixed to the upper surface of the cylinder 17C, and the side portion 38 is located on the side of the carburetor 33 and projects forward of the cylinder head 17D.

The rear portion 37 of the air cleaner case 36 is fixed on the cylinder 17C as follows. That is, as shown in FIGS. 3, 6, and 7, a plurality of (here, two) bosses 36A project from the bottom surface of the air cleaner case 36.
6A is pressed into a rubber cushion fixed to the upper surface of the cylinder 17C. Further, a rubber cushion member 41 is fixed to the bottom surface of the air cleaner case 36, and this is screwed to the cylinder head 17C.
It is fixed at. Therefore, the air cleaner case 36 in this embodiment holds the air cleaner 35 in a floating state by the cushion material 41 and the rubber cushion into which the boss 36 is press-fitted.

An outlet tube 34 is connected to a side portion 38 of the air cleaner case 36. The outlet tube 34 is connected to the side portion 38.
After protruding rightward from the right side surface, it is bent in a substantially L shape so as to protrude rearward. The rear end of the outlet tube 34 is connected to an opening 33 a formed at the front end of the vaporizer 33. And furthermore,
A cap 36B is detachably attached to an edge of an opening 36a formed at a rear portion of the cleaner case 36.
3 is closed. However, the cap 3
6B, the air cleaner inlet tube 3
6B1 is connected thereto, from which external air can be introduced into the air cleaner 35. The carburetor 33 is connected to a fuel tank (not shown).

[0016] In the intake device for a motorcycle according to this embodiment configured as described above, fresh air introduced from the inlet tube 36B1 passes through a spirally curved intake path in plan view as shown in FIG. The unit swing engine 17 is reached. That is, fresh air flows into the air cleaner 36 from the air cleaner inlet tube 36B1 opening forward, and the dust contained in the fresh air is removed by the cleaner element 39. The air supplied to the downstream side of 36 and further supplied to the downstream side is sent to a carburetor 33 through an outlet tube 34, where it is mixed with fuel such as gasoline supplied from a fuel tank (not shown). The mixture is supplied to the engine, and the engine is driven.

As described above, in this embodiment,
Since the air cleaner case 36 is constituted by the rear portion 37 and the side portions 38, a sufficient capacity can be obtained in the air cleaner 35, and the cleaner element 39 is provided in the opening 37a of the wide air cleaner 35. Since they are arranged, a large filtration area can be obtained, and an extremely good air supply state can be obtained.

Further, since the air cleaner case 36 is disposed so as to effectively utilize a dead space in which a side portion which is a part thereof is located forward of the cylinder head 17C and below the seat 10, the air cleaner case 36 is provided. In addition, the position of the carburetor 33 can be set downward, so that even if a sufficient space is set between the seat 10 and the bottom portion R1 of the trunk room R, the position of the seat 10 does not need to be particularly increased. For this reason, even if the unit swing type engine 17 swings up and down, the carburetor 33 and the air cleaner 35 do not interfere with the seat 10 or the bottom R1 of the trunk room R. Also, the vehicle 1 is not damaged.

Further, since the air cleaner box 36 is held in a floating state with respect to the cylinder head 17C by the cushion member 41 as described above, the air cleaner box 36 is kept in a state where the vibration of the unit swing type engine 17 is reduced. 35 and the carburetor 33 are transmitted, and it is possible to prevent the air cleaner 35 and the carburetor 33 from generating unpleasant vibration noise, breakage, and the like, and to obtain good rideability. Further, since the cap 36B of the air cleaner box 35 in this embodiment is disposed below the detachable seat 10, when the cleaning operation of the cleaner element 39 is performed,
By removing the cap 36B, the cleaner element 39 can be easily attached and detached, and the cleaning operation can be easily performed.

Also, the inlet 36B of the air cleaner.
Is projected forward from the front surface of the air cleaner 35 and is open, so that dust and muddy water splashed up by the rear wheel 28 are blocked by the rear portion of the air cleaner 35 and the opening of the inlet tube 36B. Suction is prevented. Therefore, the contamination of the air cleaner element 39 can be suppressed.

In the above-described embodiment, the carburetor 33 is disposed so as to be biased to the right side of the vehicle in the space in front of the cylinder 17C, and the side portion 38 forming a part of the air cleaner case 36 is formed. Although the description has been made of the case where the carburetor 33 is disposed on the left side of the vehicle as an example, the carburetor 33 may be disposed on the left side of the vehicle and the side portion 38 of the air cleaner case 35 may be disposed on the right side.

[0022]

As described above, according to the present invention, the carburetor is disposed in front of the cylinder head of the cylinder, and the carburetor and the cylinder head are connected via the intake pipe. The rear part of the air cleaner is located above the cylinder, and the side part protruding forward from the cylinder head is provided on the side of the carburetor, so that the air cleaner does not need to increase the height of the seat or the trunk room. A large capacity can be obtained, and good intake performance and good footwear can be obtained. In addition, if the air cleaner is attached to the cylinder in a floating state, the vibration generated in the unit swing type engine can be mitigated from being directly transmitted to the air cleaner, and noise etc. is generated in the air cleaner etc. Can be prevented.

[Brief description of the drawings]

FIG. 1 is an external side view showing an overall configuration of a scooter type motorcycle according to an embodiment of the present invention.

FIG. 2 is an explanatory side view showing an internal configuration of the motorcycle shown in FIG.

FIG. 3 is a side view showing the unit swing engine shown in FIG. 1 and its peripheral configuration.

FIG. 4 is a plan view of what is shown in FIG.

FIG. 5 is a front view of what is shown in FIG.

FIG. 6 is a partial longitudinal side view of the one shown in FIG. 4;

FIG. 7 is a partial bottom view of the one shown in FIG. 6;

[Explanation of symbols]

 R Crankcase 1 Motorcycle 17B Transmission case 17C Cylinder 17D Cylinder head 17 Unit swing type engine 32 Inlet pipe 33 Vaporizer 34 Outlet tube 35 Air cleaner 37 Rear part 38 Side part 41 Cushion material

Claims (2)

[Claims] 1. A transmission case, which houses a power transmission mechanism for transmitting the rotational force of the crankshaft to a rear wheel, extends behind a crankcase, which houses a crankshaft and the like. A scooter type vehicle of a unit swing type engine provided with a cylinder projecting substantially horizontally forward at a front end of the scooter type vehicle, wherein a cylinder head of the cylinder is provided with a carburetor in front of the vehicle, and the carburetor and While connecting the cylinder head to the cylinder head via an intake pipe, the rear part of the air cleaner having an L shape in a plan view is arranged above the cylinder, and the side protruding forward of the cylinder head to the side of the carburetor. A side portion of the air cleaner and the carburetor are not connected to a side portion of the air cleaner via an outlet tube projecting in a vehicle width direction. A scooter-type motorcycle in which an intake path from an inlet tube of the air cleaner to the engine via the air cleaner case and the outlet is formed in a plan view annular shape. 2. The scooter-type motorcycle according to claim 1, wherein the air cleaner case is held in a floating state on the cylinder head via a cushion made of rubber or the like.