JPS62258114A - Exhaust device for vehicle - Google Patents

Abstract

PURPOSE:To improve maintainability for a carburetor, ignition plugs and the like in a vehicle equiped with a saddle type driver's seat by providing a plurality of exhaust pipes passing through both sides of a cylinder while extending afterward whereby providing at least one out of them removably. CONSTITUTION:A four wheel vehicle for running on ungraded roads has an engine, for example, a two cycle two cylinder engine 60 mounted on near the center of a vehicle body wherein each exhaust port of cylinders is opened directing obliquely forward down out of a right and a left down-tube 34 in front of the cylinders. A pair of a right and a left exhaust expansion pipe 68 is connected with the engine 60 at its each exhaust port of the cylinders wherein each expansion pipe 68 is connected with an exhaust pipe 70 of an approximately equal diameter passing through the upper outboard side of the engine. Each exhaust pipe 70 is oomposed of three pipes 70a through 70c wherein the center pipe 70c is provided removably against the other pipes 70a and 70b. Namely, both ends of the pipe 70b are connected with each pipe 70a and 70c by way of rubber pipes 70d and 70e wherein the rubber pipes 70a and 70e are fastened with a fastener.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is characterized in that an engine having a plurality of cylinders arranged in parallel in the width direction of the vehicle body is mounted near the center of the vehicle body, and a steering handlebar is mounted on the upper part of the vehicle body and a steering handlebar is mounted behind the steering handlebar. This invention relates to an exhaust system for a vehicle equipped with a straddle-type driver's seat.

(Background of the Invention) There is a vehicle for traveling on rough terrain that has an engine mounted near the center of the vehicle body, a steering handlebar at the top of the vehicle body, and a straddle-type driver's seat behind the steering handlebar. Up until now, single-cylinder engines have been common in this type of vehicle, but this time the engine has cylinders of several meters arranged in parallel in the width direction of the vehicle, and each cylinder has an independent exhaust pipe. The idea was to route these exhaust pipes to the rear through both outside sides of the engine's cylinders.In such a case, the spark plug and carburetor would be located between the left and right exhaust pipes, and these spark plugs A possible problem is that the exhaust pipe becomes an obstacle when servicing a carburetor or a carburetor, making it difficult to maintain.

(Object of the Invention) The present invention was made in view of the above circumstances, and when an exhaust pipe is passed on both sides of the cylinder of an engine,
The exhaust pipe does not become an obstacle when servicing spark plugs and carburetors.
It is an object of the present invention to provide a vehicle exhaust system that can improve maintainability.

(Structure of the Invention) According to the present invention, this purpose is to provide a carrot having a plurality of cylinders mounted near the center of the vehicle body and arranged in parallel in the width direction of the vehicle body;
A vehicle including a steering handlebar disposed on a vehicle body and a straddle-type driver seat behind the steering handlebar, the vehicle including a plurality of exhaust pipes extending rearward through both outside sides of the cylinder of the engine, and at least One exhaust pipe is achieved by a vehicle exhaust system characterized in that a portion including a portion passing outside the cylinder is removable.

(Example) Fig. 1 is a side view of a four-wheeled vehicle for traveling on rough terrain which is an embodiment of the present invention, Fig. 2 is a plan view of its main parts, and Fig. 3 is a partially cross-sectional view of an exhaust expansion pipe. The side view shown in Figure 4 is the IT-rV.
Figure 5 is a cross-sectional view of the left exhaust system, Figure 6 is a side view of the same, Figure 7 is a cross-sectional view of the front VI connection part of the exhaust pipe attachment/detachment part, Figure 8 2 is a sectional view of the rear connecting portion.

In these figures, numeral 10 is the vehicle body frame, and the left and right sides...
A pair of lower tubes 12.12, a pair of left and right E tubes 14.14 connected to the front and rear ends of the lower tube 12 and bent upwardly to convex, and a pair of left and right E tubes 14.14, and one tube from the rear to the rear. A pair of left and right seat rails 16.16 extending to
Pack tube 18 (only one shown), cross tubes 2o, 22.24 that connect rain tube 12.12, and cross tube 26 that connects both L tubes 14.14.
．． 28.30.32 and E down loss tube 22.28
A pair of left and right down tubes 34 (only one shown) connecting the cross tube 26 and a lower tube 12 are provided, and a pair of left and right front tubes 36 (only one shown) connecting the cross tube 26 and the lower tube 12.

Reference numeral 38 designates a pair of left and right front shock absorbers (only one is shown), the upper end of which is supported by the upper tube 14, and the lower end of which holds the swinging end of the lower arm 40 which is vertically swingable. A pair of left and right front wheels 42, 42 are attached to the lower end of each shock absorber 38 so as to be steerable, forming a strut type front wheel independent suspension system. 44 is a steering shaft, and 46 is a steering handlebar.

48 is a rear arm, the front end of which is connected to the vehicle body frame 10.
A rear wheel 52 (only one of which is shown) is fixed to the left and right ends of a rear wheel shaft 50, which is rotatably held at the rear end of the rear wheel shaft 50. This rear arm 48 is prevented from returning downward by a rear shock absorber 58 via links 54 and 56. These front wheels 42 and rear wheels 52
is equipped with wide, ultra-low-pressure tires (so-called balloon tires).

60 is a water-cooled 2-cycle 2 mounted near the center of the car body.
It is a cylinder engine. This engine 60 includes two cylinders arranged in parallel in the width direction of the vehicle body, and the cylinder 6 including each cylinder
2 stands diagonally L forward from the crankcase 64. There are two carburetors 66 and 66 on the rear surface of this cylinder 62.
are arranged in parallel in the width direction of the vehicle body.

68. 68 is a pair of left and right exhaust expansion pipes. The exhaust port of each cylinder of the engine 60 is located at the front surface of the cylinder, and opens from between the left and right down tubes 34 toward the front obliquely downward. 111! The tension pipes 68, 68 are connected to these exhaust ports, extend diagonally downward and forward from between the left and right down tubes 34, and enter between the front wheels 42, 42. Each of these expansion pipes 68 rises in the L direction between the engine 60 and the steering shaft 44, and draws a spiral toward the side of the heavy body while making one revolution almost along the vertical plane in the longitudinal direction of the vehicle body. are made by connecting three members 68a, 68b, and 68c, respectively. That is, these three members 68a, 68b, 6
8G (7) Two (7) connecting parts 68d and 68e are parallel circular shapes, and by changing only the connecting angles around the mutually parallel central axes a and b at these connecting parts 68d and 68e, the right side And each exhaust expansion pipe 68, 68 on the left side can be made. This makes it possible to share parts on the left and right sides. Note that each of these members 68a and 68b.

The 0 member 68a, which is made into a tubular shape by welding press-formed half-pieces to each other, is connected to the engine 60 by a spring 68f fixed to the flange portion, as shown in FIG.

Each expansion pipe 68 is connected to an approximately average diameter exhaust pipe 70.70 passing outside the upper part of the engine 60.
0 extends rearward through one tube 14.14. The downstream side of this exhaust pipe 70.70 is connected to a muffler 72.72.

Each of these exhaust pipes 70 has three pipes 70a.

The pipe 70a is connected to the member 68c of the exhaust expansion pipe 68, and the pipe 70c and the muffler 72 are integrated and fixed to the frame 10. Also, the middle pipe 70b is the other pipe 70a.

It can be attached to and detached from 70c. That is, its front end is connected to a rubber tube 70d as shown in FIG. 7, and its rear end is connected to a rubber tube 70e as shown in FIG. 8.

The tube 70b is attached or detached by loosening the fastener 70e and moving the rubber tubes 70d and 70e through the exhaust tube 70L. Note that the front part is fitted to the outer peripheral surface of the pipe 70a and the stopper 70
f, a tube 70b, and a rubber tube 70d.

The exhaust expansion pipe 68 is attached to the upper tube 14 via a hanger bracket 100, as shown in FIG. That is, the member 68b of the exhaust expansion pipe 68 and the pipe 70a of the exhaust pipe 70
are connected to each other by a bracket 102, while a bracket 104 is provided upright on the upper tube 14, and a rubber damper 106 is placed between these brackets 102 and 104.
A hanger bracket (100) having a Therefore, the exhaust expansion pipe 68 can be held in the vehicle body frame 10 in a well-balanced manner.

In FIG. 1.2, 74.74 is a spark plug attached to the upper surface of the cylinder 62, and in FIG. 1, 76 is a radiator disposed in front of the steering shaft 44.
0 cooling liquid. Coolant is sent to the upper part of the radiator 76 from near the center of the upper part of the cylinder 62 by a hose 78, and from the lower part of the radiator 76 the cooled coolant is led to the right side of the engine 60 by a hose 80. These hoses 78,80 are passed between the two inflation tubes 68,68. For this reason, the hose 78.8
0 means that you are less likely to be hurt by obstacles on the road. An engine cooling air passage A (FIG. 2) is formed below the radiator 76, passing between the expansion pipes 68, 68 and opening toward the front of the cylinder 62.

Reference numeral 82 denotes a straddle-type driver's seat that is long in the front-rear direction.
It is located above the rear of 4. Reference numerals 84 and 84 denote a pair of left and right footrests, which are fixed to the lower tubes 12 and 12 so as to be located on the sides of the engine 60. Further, 86 is a front fender that covers the front wheel 42, 88 is a rear fender that covers the rear wheel 52, and 90 is a tank cover that covers a fuel tank (not shown).

As shown in FIG. 1, the driver sits on the driver's seat 82 with both feet placed on the footrest 84.84.

The exhaust expansion pipe 68 is located in front of the engine 60 and is connected to both front wheels 42.4.
Since a part of the exhaust pipe 70 is disposed so as to fit between the two, it is sufficient to pass a small-diameter exhaust pipe 70 having a substantially uniform diameter to the upper side of the engine 60. Therefore, even though the capacity of the expansion tube 68 is increased, the driver's feet do not come into contact with the expansion tube 68.

The carburetor 66 and the spark plug 74! ! When performing a maintenance check, loosen the fasteners on the rubber pipes 70d and 70e and connect the exhaust pipe 70J.
: , move the tube 70b backwards, let its front end escape from the tube 70a, and remove it as shown by the imaginary line in Figure 5.6. By removing the tube 70b in this way, the side of the vehicle body can be removed. The carburetor 66 and the spark plug 74 can be easily maintained and inspected by hand or tools.

The intermediate tube 70b to be attached and detached is the tube 70a.

Of course, it may be made of the same material as 70c, such as a steel tube, but only the intermediate tube 70b may be made of another material, such as an aluminum alloy or a high-tensile steel tube, to reduce its weight.

In this embodiment, the middle tube 70b is a rubber tube 70cl, 7
However, if a rubber tube is used to connect at least one of the tubes 70b in this way, the transmission of engine vibration to the entire exhaust pipe 70 is effectively blocked, which is suitable for reducing vibrations, and the exhaust gas Manufacturing errors or assembly errors of the tube 70 can be absorbed by this rubber tube. When the intermediate y7ob is formed of metal in this way, it is desirable to fix the heat shield plate 70g to the tube 70b as shown in Figure 5.6. The plate 70g can also be attached and detached at the same time, improving work efficiency.

Furthermore, if the entire portion of the tube 70b is made of a flexible and heat insulating material such as a rubber tube, the rubber tubes 70d and 70e for connection
70g of heat shield plate becomes unnecessary.

In this embodiment, only the exhaust pipe 70 passes above the cylinder, so only the pipe 70b, which is a part of the exhaust pipe 70, is detachable. However, if a part of the exhaust expansion pipe is located above the cylinder, It is also possible to make the - section of the exhaust expansion pipe removable, and the present invention also includes such a configuration.

In this embodiment, the engine is a two-cylinder two-stroke engine, but the present invention also includes an engine with three or more cylinders or a four-stroke engine.

It also includes those applied to motorcycles.

(Effects of the Invention) As described above, the present invention is such that, when the exhaust pipe passes through both outside sides of the engine cylinder, at least a portion of one exhaust pipe including the part passing outside the cylinder is detachable. Therefore, by removing this part, it becomes possible to easily maintain the carburetor and spark plug located between the left and right exhaust pipes.

[Brief explanation of drawings]

Fig. 1 is a side view of a four-wheeled vehicle for traveling on rough terrain which is an embodiment of the present invention, Fig. 2 is a plan view of the main parts thereof, and Fig. 3 is a side view showing a partially sectional view of the exhaust expansion pipe. , Figure 4 shows the 1'V-I
Figure 5 is a plan view of the left exhaust system, Figure 6 is a side view, Figure 7 is a cross-sectional view of the front connection part of the exhaust pipe attachment/detachment part, Figure 8 is an exploded cross-sectional view at the V line position, It is a sectional view of a rear connection part similarly. 42... Steering front wheel, 46... Steering handlebar, 60... Engine, 62... Cylinder, 70... Exhaust pipe, 70b... Detachable pipe. 82...Driving seat.

Claims (1)

[Claims] An engine mounted near the center of the vehicle body and having a plurality of cylinders arranged in parallel in the width direction of the vehicle body, a steering handlebar disposed at the top of the vehicle body, and a straddle-type driver seat behind the steering handlebar. The vehicle is equipped with a plurality of exhaust pipes extending rearward passing through both outside sides of the cylinders of the engine, and at least one part of the exhaust pipe including the part passing outside the cylinders is detachable. Characteristic vehicle exhaust system.