JP2000355221A - Layout of engine and intake / exhaust mechanism for snowmobile - Google Patents

Abstract

(57) [Summary] [Problem] To reduce the wind pressure resistance of a vehicle by lowering the vehicle height to enhance the kinetic performance of the vehicle, and to bring the position of the center of gravity near the engine closer to the position of the center of gravity of the entire vehicle, and Improves the handling and kinetic performance of the vehicle, smoothes the flow of air inside the shroud, improves the cooling of the engine without stagnation of hot air near the engine, and further scavenges air from the intake port of the mixture in the engine. To provide a layout of the engine and the intake / exhaust mechanism so that the flow to the engine goes smoothly. In a snowmobile (10), an engine (19) is mounted in an engine room (12) in a shroud (11), and an intake / exhaust mechanism associated with the engine (19) is arranged around the engine (19) to serve as a central mechanism source for traveling. Engine 1
The nine cylinder portions 1 are arranged near the traveling rudder 14 inclining rearward in the traveling direction of the vehicle 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a layout of an engine and its intake / exhaust mechanism in a snowmobile running on snow having an engine and its intake / exhaust mechanism in a shroud.

[0002]

2. Description of the Related Art Generally, in a vehicle such as a snowmobile, the layout of a power source (engine unit) in a vehicle such as an intake and exhaust mechanism centered on the engine is determined by setting the center of gravity of the engine at the center. Many of them were placed. For this reason, the intake system mechanism and the exhaust system mechanism are often arranged separately from front to back or left and right of the engine.

FIGS. 4 and 5 show a side view and a plan view of a typical example of a conventional snowmobile. As shown in FIG. 4 and FIG.
An engine room 12 surrounded by a shroud 11 is formed in the front half of the vehicle, and a pair of left and right steering skis 13 is disposed below the engine room 12. The steering ski 13 is provided so as to be steerable by a steering wheel 14. A seat 15 is provided in the rear half of the snowmobile 10, and a truck 16 is provided below the seat 15. The handle 14 is used for the seat 1
5 is arranged in front. The track 16 has an endless belt shape, and is supported by a sprocket 17 and a number of guide rollers 18. The truck 16 moves by the rotation of the sprocket 17 based on the driving force of the engine 19, and causes the snowmobile 10 to travel. The arrangement of the air cleaner box 3 and the carburetor (carburetor) 2 for sending the mixture to the engine 19 in the engine room 12 is such that the carburetor 2 is located behind the engine 19 and the air cleaner is located behind the carburetor 2. The exhaust pipe 4, which is the outlet of the exhaust port 4, is disposed on the front side of the engine 19.

In this case, as shown in FIG. 4, the center of gravity M of the engine unit, which is the main mechanical source of the vehicle, is located near the engine 19, and is located away from the center of gravity Mo of the entire vehicle. Due to the center of gravity, the mobility during steering and the handling of the vehicle were impaired. Also, as shown in the figure, the flow N of air entering through the front opening 11a of the shroud 11 and flowing inside the engine room 12 is
Put away stuck in 9 near N _0, air near the engine 19 which is heated by the engine had become a cause to lower the engine performance with basket inside shroud 11. Further, since the engine 19 has the cylinder 1 standing upright, the shroud 11 is high, and the vehicle height is correspondingly high, so that the engine 19 is susceptible to wind pressure resistance and adversely affects running performance.

[0005]

Therefore, conventionally, various techniques have been devised to solve the above three problems. First, technical development in terms of layout of an engine or the like is described in Japanese Patent Application Laid-Open Nos. 6-48370 and 9-324649.
No., published in Japanese Unexamined Patent Publication No. However, the former technique is for narrowing the vehicle width, and the latter technique has not yet changed the center of gravity of the engine.

In order to reduce the height of the vehicle height, which is the third problem, and to bring the center of gravity M of the engine closer to the center of gravity Mo of the engine, as shown in FIG. We considered a technology to attach it at an angle of θ toward the rear. In this case, the air flow N in the shroud 11
Becomes smooth. However, in this case, as shown in FIG. 7, the flow N ″ of the air-fuel mixture guided from the intake port 5 of the engine 19 to the crankcase 19a and the direction of the scavenging port 4 are sharpened, and the flow of the air-fuel mixture is reduced. The result was that the problem of not being achieved smoothly was left.

On the other hand, in order to improve the flow N '"of the air-fuel mixture from the intake port 5 to the scavenging port 4, and to solve the problem of the vehicle height, the engine cylinder 1 is moved forward as shown in FIGS. When the mixer is tilted by θ, the flow of the mixer is improved, but the center of gravity M in the vicinity of the engine 19 moves forward rather, and ends up moving away from the center of gravity of the entire vehicle with Mo. In addition, as shown in FIGS. 8 and 9, the air flow N in the shroud 11 is delayed by N ₀ ′ near the engine, and the Insufficient cooling resulted in reduced engine performance.

According to the present invention, the vehicle height is reduced to reduce the wind pressure resistance of the vehicle to enhance the kinetic performance of the vehicle, and the position of the center of gravity in the vicinity of the engine is brought closer to the position of the center of gravity of the entire vehicle so that the vehicle can be steered during steering. It improves the handling performance and exercise performance, smoothes the air flow inside the shroud, and keeps the engine cool without stagnation near the engine.Furthermore, from the intake port of the mixture in the engine to the scavenging port The purpose of the present invention is to provide a layout of an engine and an intake / exhaust mechanism in which the flow to the engine goes smoothly.

[0009]

In order to achieve the above object, the present invention has the following arrangement. The present invention
In an engine unit of a snowmobile in which an engine and an intake / exhaust mechanism associated with the engine are arranged and housed around the engine in a shroud, a cylinder portion of the engine is tilted rearward in a traveling direction of the vehicle to drive a rudder. It is a layout of an engine and an intake / exhaust mechanism in a snowmobile characterized by being disposed close to the vehicle. By inclining the engine cylinder as described above, the height of the snowmobile can be kept low, the air resistance of the vehicle can be reduced, and the kinetic performance of the vehicle can be improved. At the same time, since the engine, which is the center of the center of gravity near the engine, is near the traveling rudder, the steering performance during steering and the kinetic performance of the vehicle are enhanced. Furthermore, the flow of air in the shroud does not stay near the engine, and the flow of air becomes smooth, so that the engine can be cooled efficiently and the engine performance can be improved.

[0010] In the present invention, a carburetor in the engine unit of the snowmobile can be arranged in front of the engine. As a result, the flow of the air-fuel mixture in the engine from the intake port to the scavenging port becomes smooth, and the engine performance is enhanced.

In the present invention, an air cleaner box in the engine unit of the snowmobile can be arranged in front of the carburetor. Thereby, the flow of air to the air cleaner box that supplies air to the carburetor can be made smooth.

In the present invention, the exhaust pipe in the engine unit of the snowmobile can be disposed on the front side with respect to the same engine as the carburetor and the air cleaner box. This achieves the overall possibility of positioning the engine, which is at the center of the center of gravity near the engine, near the lower part of the traveling rudder, and allows the mixture in the engine to flow from the intake port to the scavenging port. Can also go smoothly.

In the present invention, a part of the air cleaner box in the engine unit of the snowmobile protrudes from the front edge of the vehicle body, and the front part of the air cleaner box on the traveling direction side of the snowmobile moves in the same direction. An opening can be made for this. As a result, the traveling air can be taken into the air cleaner box during traveling and the air can be supercharged and supplied from the carburetor to the engine, so that the performance of the engine during traveling can be further improved.

[0014]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is a side view of a snow vehicle with a layout of an engine and an intake / exhaust mechanism in the snow vehicle according to the first embodiment of the present invention, and FIG. 2 is a detailed view of an engine portion of the snow vehicle.

As shown in FIG. 1, the snowmobile 10 has an engine room 12 surrounded by a shroud 11 in the front half of the vehicle, and a pair of left and right steering skis 13 for steering is disposed below the engine room. The steering ski 13 is provided so as to be steerable by a steering wheel 14. A seat 15 is provided in the rear half of the snowmobile 10, and a truck 16 is provided below the seat 15. The handle 14 is provided with a seat 15
Is placed in front of the The track 16 is a crawler belt having an endless belt shape, and is supported by a sprocket 17 and a number of guide rollers 18. The truck 16 circulates by rotation of the sprocket 17 based on the driving force of the engine 19 to obtain the driving force on the snow surface, and causes the snowmobile 10 to travel.

As shown in FIG. 1, the cylinder 1 of the engine 19 is tilted rearward in the engine room 12 by an angle θ with respect to the traveling direction of the snowmobile (the center of the cylinder head is located behind the crankshaft). Make sure)
Shall be. As a result, the height of the snow vehicle can be kept low, the air resistance during traveling of the vehicle can be reduced, and the kinetic performance of the vehicle can be improved.
Then, the position of the engine 19 including the cylinder 1 is retracted to a position near the lower part of the traveling rudder 14 and disposed. As a result, the position M of the center of gravity of the engine 19 becomes a distance L very close to the vicinity of the traveling rudder 14 and the sprocket 17 which is the position of the center of gravity Mo of the vehicle, and the kinetic performance and maneuverability of the vehicle are significantly improved. This is the center of gravity position M of the vehicle.
When the position M of the center of gravity of the engine 19 is away from the position o, the swinging force of the vehicle due to the action of the moment force is apt to be applied during that time, and the action force is increased, which adversely affects the above-mentioned handling performance when steering the rudder. According to the present invention, since the center of gravity Mo of the vehicle and the center of gravity M of the engine 19 can be brought close to each other, the moment force is reduced, and the acting force of swinging the vehicle is reduced. The handling performance of the rudder 14 is significantly improved.

The air cleaner box 3 for sending the air-fuel mixture to the engine 19 and the carburetor (carburetor) 2 are arranged so that the carburetor 2 is in front of the engine 19 and the air cleaner box 3 is in front of the carburetor 2. And the exhaust pipe 4 which is the outlet of the exhaust port 4
9 in front of it. As a result, the engine 19 can be arranged near the lower part of the traveling rudder 14, so that the center of gravity of the engine 1 can approach the center of gravity of the vehicle.
At the same time, as shown in FIG. 2, the flow of air from the air cleaner box 3 to the carburetor 2 and the flow of fresh air N ′ from the carburetor 2 to the exhaust port 4 through the intake port 5 are smooth. And engine performance is improved. Also, the air flow N from the opening 11a in front of the shroud 11 flows smoothly without stagnation in the vicinity of the engine 19, and the heat generated in the engine 19 is quickly cooled, thereby improving the engine efficiency during traveling. Is what you do.

Next, a second embodiment of FIG. 3 will be described.
In this embodiment, a part of the air cleaner box 3 disposed in front of the vehicle 10 is protruded from the vehicle body toward the traveling direction of the vehicle 10, and an opening 3 'is provided at the projecting portion in the traveling direction. As a result, the traveling wind is supplied in a supercharged manner into the air cleaner box 3 during traveling, and the inside of the air cleaner box 3 is pressurized,
The oxygen density in the air in the air cleaner box 3 is increased and supplied to the engine 19, so that the output of the engine 19 is improved.

[0019]

As described above, according to the present invention, as described above, the engine is mounted in the shroud and the intake / exhaust mechanism associated with the engine is disposed around the engine. In a snowmobile, the cylinder portion of the engine is arranged in the vicinity of the traveling rudder inclining rearward in the traveling direction of the vehicle, so that the vehicle height can be kept low and the air resistance of the vehicle can be reduced. In addition to improving the vehicle's kinetic performance, the engine, which is the center of the center of gravity near the engine, is close to the traveling rudder, so the steering performance and the vehicle's kinetic performance during steering are improved,
In addition, the flow of air in the shroud does not stay near the engine, and the flow of air becomes smooth, so that the engine is efficiently cooled and the engine performance is enhanced.

[Brief description of the drawings]

FIG. 1 is a side partial sectional view of a snowmobile used for a layout of an engine and an intake / exhaust mechanism in the snowmobile according to a first embodiment of the present invention.

FIG. 2 is a partial side sectional view of the engine unit according to the first embodiment.

FIG. 3 is a detailed view of a layout of an engine and an intake / exhaust mechanism in a snowmobile according to a second embodiment of the present invention.

FIG. 4 is a side view illustrating a layout example of an engine unit of a conventional snowmobile.

FIG. 5 is a plan view of the same.

FIG. 6 is a side view illustrating another example of the layout of an engine unit of a conventional snowmobile.

FIG. 7 is an explanatory diagram of the engine unit of FIG. 6;

FIG. 8 is a side view illustrating still another example of a layout of an engine unit of a conventional snowmobile.

FIG. 9 is an explanatory diagram of the engine unit of FIG. 8;

[Explanation of symbols]

 Reference Signs List 1 cylinder 2 carburetor (carburetor) 3 air cleaner box 3 'opening 4 exhaust pipe (exhaust port) 5 intake port 10 snow vehicle 11 shroud 12 internal space 13 steering ski 14 steering wheel (running rudder) 15 seat 16 truck 17 sprocket 18 Guide Roller 19 Engine θ Cylinder Inclination Angle N Running Wind Flow N 'Engine Air Flow M Engine Unit Center of Gravity Mo Center of Gravity L Distance between Centers of Gravity M and Mo

Claims (5)

[Claims] 1. An engine unit for a snowmobile in which an engine and an intake / exhaust mechanism accompanying the engine are arranged and housed in a shroud around the engine, wherein a cylinder portion of the engine is inclined rearward in a traveling direction of the vehicle. A layout of an engine and an intake / exhaust mechanism in a snowmobile, wherein the engine and the intake / exhaust mechanism are arranged near a traveling rudder. 2. The layout of an engine and an intake / exhaust mechanism in a snowmobile according to claim 1, wherein a carburetor in the engine unit of the snowmobile is disposed in front of the engine. 3. The layout of an engine and an intake / exhaust mechanism in a snowmobile according to claim 1, wherein an air cleaner box in the engine unit of the snowmobile is arranged in front of the carburetor. 4. The snow-covered vehicle according to claim 1, wherein an exhaust pipe of the engine unit of the snow-covered vehicle is disposed on the front side with respect to the same engine as the carburetor and the air cleaner box. Layout of engine and intake / exhaust mechanism in car. 5. A part of the air cleaner box in the engine unit of the snowmobile protrudes from a front edge of a vehicle body, and a front portion of the air cleaner box in a traveling direction of the snowmobile moves in the same direction. The layout of the engine and the intake / exhaust mechanism in the snowmobile according to any one of claims 1 to 4, wherein the engine and the intake / exhaust mechanism are open.