JPH0331623B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a small vehicle equipped with a pair of left and right rear wheels, on which a driver sits astride a straddle-type seat.

(Background of the Invention) This vehicle is equipped with a main frame having a main pipe extending rearward and diagonally downward from the steering head pipe, and has a straddle-type seat behind the steering head pipe and an engine near the center of the vehicle body. Small vehicles with three or four wheels are known.

In order to extend the cleaning and replacement cycle of the air cleaner in this type of vehicle, it is desirable to increase the surface area of the element, increase the capacity of the air cleaner, and increase the size of the air cleaner. It is required to make it difficult for people to be sucked in.

On the other hand, this air cleaner is also connected to an intake pipe that introduces outside air and a connection pipe to the carburetor, but these need to be made difficult to interfere with surrounding components. For example, the driver's seat is usually placed above the air cleaner, the rear wheel suspension system is placed below it, and the engine exhaust pipe is placed on the side of the engine. is not adversely affected by the heat of the exhaust pipe, and is easy to maintain.
Moreover, it is desirable to lower the driver's seat sufficiently to improve seating comfort on the driver's seat.

(Purpose of the Invention) The present invention was made in view of the above circumstances, and it is possible to increase the size and capacity of the air cleaner, and to prevent water, sand, etc. from being sucked in during driving with a very simple configuration. In addition, it prevents mutual interference with the intake pipe, carburetor, and exhaust pipe connected to the air cleaner, prevents any adverse thermal effects on the carburetor, and especially reduces the vertical dimensions of these intake systems. To provide a small vehicle in which a driver's seat can be lowered and rationally arranged.

(Structure of the Invention) According to the present invention, the object is to provide a straddle type seat disposed behind a steering shaft support, a pair of left and right rear wheels, at least one front wheel, and both rear wheels. In a small vehicle equipped with an air cleaner disposed between the two, an engine mounted near the center of the vehicle body, and an exhaust pipe led out from the engine and extending toward the rear of the vehicle body through the side of the engine, a connecting pipe is provided in front of the air cleaner. and an intake duct whose rear end is connected to the front surface of the air cleaner and whose front end opens near the steering shaft support part, the rear end of the intake duct being connected to the connecting pipe when viewed from above. This is achieved by a small vehicle characterized by being located between the rear end and the exhaust pipe.

The present invention will be explained in detail below based on the illustrated embodiments.

(Example) Fig. 1 is a side view showing an embodiment of the present invention applied to a tricycle, Fig. 2 is a partially omitted plan view, Fig. 3 is a rear view, and Figs. 4 and 5 are main parts. FIG.

In FIGS. 1 and 2, the reference numeral 10 denotes a main frame, which includes a steering head pipe 12 as a steering shaft support, a main pipe 14 extending diagonally downward from the head pipe 12, and a left and right frame extending diagonally downward from the head pipe 12. A pair of down tubes 16, 16a, 16b, seat pillar tubes 18, 18a, 18b whose upper ends are welded to the main pipe 14, and seat rails 20, 20a, 20b whose front ends are welded to the seat pillar tube 18 and extend rearward. , the upper end is seat rail 2
Backstays 22, 22a, 22 welded to 0
b. The rear end of the down tube 16, the seat pillar tube 18 and the back stay 22
The lower ends are connected to each other by bearings 24, 24a, 24b. As a result, seat rail 20
is coupled to the main pipe 14 via the seat pillar tube 18, and the seat rail 20 extends rearward from the main pipe 14. Further, the rear end of the main pipe 14 opens rearward and forms part of an intake duct as described later.

26 is an engine, and the main pipe 1
4, that is, the main pipe 14, the down tube 16, and the seat pillar tube 18.
It is mounted in a space surrounded by In FIG. 1, 28 is a front fork, 30 is a front wheel having wide ultra-low pressure tires, and 32 is a handlebar.

34 is a rear arm, which is formed into a substantially rectangular shape as shown in FIG. This rear arm 34
The front side 34a of the front side 34a is pivotally attached between the pair of bearings 22a, 22b by a pivot shaft 36 (FIG. 1), and the rear side 34b has an axle 38 rotatably held therein. A pair of left and right rear wheels 40, 40a, 40b are fixed to both ends of this axle 38. This rear wheel 40 has, for example, a known wide ultra-low pressure tire. A left side 34c of the rear arm 34 is formed into a pipe shape, and a drive shaft is inserted through the left side 34c. A gear case 42 is attached to the joint between the left side 34c and the rear side 34b, and a bevel gear that transmits rotation of the drive shaft to the axle 38 is housed here. The rotation of the engine 26 is the left side 3
It is transmitted to the axle 38 and rear wheel 40 via a universal joint, a drive shaft and a bevel gear housed in the front part of 4c.

44 is a cushion unit, which is composed of a cylindrical hydraulic damper and a coil spring. One end of the cushion unit 44 is pivoted to the main pipe 14 via a bracket, and the other end is pivoted to the rear side 34b of the rear arm 34 via a bracket.

46 is a box-shaped air cleaner. This air cleaner 46 is located between the pair of left and right rear wheels 40 behind the rear end of the main pipe 14, that is, between the seat rail 20
It is arranged so as to overlap both rear wheels 40 in a side view below between a and 20b, and a recess 48 is formed on the lower front surface of the cushion unit 44 so as to straddle the cushion unit 44 (FIG. 4). A cover plate 50 is removably attached to the rear surface of the air cleaner 46 with four bolts.
is defined. The element 52 is the lid plate 50
It is designed so that it can be pulled out backwards with it removed. The front side of the right air chamber 56 is connected to the rear end of the main pipe 14 through a connecting tube 58, and the left air chamber 54 is connected to the engine 26 through a connecting tube and a carburetor 60. Note that an air intake port 62 is opened at the lower surface of the front end of the main pipe 14 as shown in FIG.
Air flows from this air intake port 62 to the main pipe 14.
air chamber 56 through and through connecting tube 58
flows into. That is, the main pipe 14 and the connecting tube 58 form an intake duct that guides intake air to the air cleaner 46. The main pipe 14 is usually formed in a straight line or slightly curved shape, and the intake air enters the air cleaner from its rear end, so that the intake resistance is extremely small.

64 is a battery, 66 is an exhaust silencer, and battery 6
4 is between the left seat rail 20a and the rear wheel 40a, and the exhaust silencer 66 is between the right seat rail 20a and the rear wheel 40a.
0b and the rear wheel 40b. Exhaust gas from the engine 26 is guided to the exhaust muffler 66 by an exhaust pipe 68 that extends rearward from the front of the engine 26 through the right side of the engine 26 . As a result, on the front of the air cleaner 46,
The intake duct and the connection pipe of the carburetor 60 are arranged side by side on the left and right, and the exhaust pipe 68 is located on the opposite side of the carburetor 60 across the intake duct in a plan view.

In FIG. 1, reference numeral 70 denotes a rear fender, which is integrally formed so as to cover the front and upper sides of both the left and right wheels 40a, 40b, and is attached so as to cross over the seat rail 20. 72 is a fuel tank attached to the main pipe 14; 74 is a vertically long straddle-type seat attached above the seat rail 20, that is, on the top surface of the rear fender 70; the front end of this seat 74 is in contact with the fuel tank 72; ing.

In this embodiment configured as above,
During the operation of the engine 26, air (intake) flows from the air intake port 62 to the main pipe 14 and to the connecting tube 5.
8. Flows into the air chamber 56 on the right side, and the element 52
It passes through and enters the air chamber 54 on the left. Sand and dirt sucked in with the intake air are removed when passing through this element 52. The air in the air chamber 54 further passes through a carburetor 60, where it is mixed with fuel and then sucked into the engine 26.

When replacing, washing, or cleaning the element 52, remove the cover plate 50 by removing the four bolts, and then attach the element 52 to the rear wheel 4.
Pull it out from the 0 space to the rear. Element 5 like this
Since element 2 is attached and detached from the rear, there is no need to remove the seat 74 or the rear fender 70 when attaching or detaching the element 52, which improves work efficiency.

In the present invention, the front surface of the air cleaner does not need to be a vertical surface, but may be an inclined plane or a curved surface as in the embodiment.

(Effects of the Invention) As described above, the present invention provides an air cleaner between the left and right rear wheels, connects the intake duct and the carburetor connection pipe to the front of the air cleaner, and connects the exhaust pipe to the side of the engine. Since the connecting pipe and exhaust pipe are located on both sides of the intake duct in plan view, the space between the two rear wheels can be effectively used to increase the capacity and size of the air cleaner. becomes possible.

Furthermore, since the intake duct is sloped so that the front end is higher, the air intake port at the front end is located at a relatively high place. This makes it difficult for water and sand to be sucked into the air cleaner even when driving on rough terrain.

Furthermore, since the intake duct, the carburetor connection pipe, and the exhaust pipe are offset from left to right, the degree of freedom in their arrangement increases, and in particular, it is possible to change their arrangement not only vertically but also horizontally. This makes it possible to lower the position of the driver's seat while avoiding interference with the driver's seat and the rear wheel suspension system, making it possible to improve seating comfort in the driver's seat. Furthermore, since the carburetor is located on the opposite side of the exhaust pipe across the intake duct, it is not adversely affected by the heat of the exhaust pipe, and maintainability of the carburetor is also good.

[Brief explanation of the drawing]

Figure 1 is a side view showing one embodiment of the present invention, Figure 2 is a side view showing one embodiment of the present invention;
The figure is a partially omitted plan view, FIG. 3 is a rear view, and FIGS. 4 and 5 are a side view and a plan view of the main parts. 12...Steering as a steering shaft support part
Head pipe, 14... Main pipe as intake duct, 20... Seat rail, 26... Engine, 40... Rear wheel, 46... Air cleaner, 7
4...Driving seat.

Claims (1)

[Scope of Claims] 1. A straddle seat disposed behind the steering shaft support, a pair of left and right rear wheels, at least one front wheel, and an air cleaner disposed between the two rear wheels. In a small vehicle equipped with an engine mounted near the center of the vehicle body, and an exhaust pipe led out from the engine and extending to the rear of the vehicle body through the side of the engine, a carburetor connected to the front surface of the air cleaner via a connecting pipe. and an intake duct whose rear end is connected to the front surface of the air cleaner and whose front end opens near the steering shaft support, the rear end of the intake duct being between the rear end of the contact pipe and the exhaust pipe when viewed from above. A small vehicle characterized by being located at