JP2004210282A - Snowmobile vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a snowmobile capable of mounting a four-cycle engine on the snowmobile without causing an interference with an engine hood by lowering its position of the center of gravity and improving traveling performance by bringing the center of gravity of the engine close to the center of gravity of a vehicle body and lowering the position of the center of gravity. <P>SOLUTION: In this snowmobile having the engine hood 14 positioned ahead a seat 12 and storing the four-cycle engine 16 in an engine room 46 covered with the engine hood 14, the four-cycle engine 16 is mounted on the vehicle body 10 in such a way that its crank shaft 22 is along the direction of a vehicle body width and a central axial line 24c of a cylinder 24 is backward tilted relative to a line 10c of vehicle body vertical direction. An oil pan 16a of the four-cycle engine 16 is arranged adjacent to the vicinity of the most bottom of the engine room 46 and an oil strainer 16b is stored in the oil pan 16a. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to a snowmobile equipped with a four-cycle engine.

  2. Description of the Related Art Conventionally, engines mounted on small snowmobiles such as snowmobiles have a relatively simple structure, are lightweight, compact, and have two power cycles.

  However, recently, four-stroke engines have been developed with the aim of improving exhaust gas regulations and fuel efficiency. However, four-stroke engines that require camshafts and oil lubrication are more compact than high-output, compact two-stroke engines. They tend to be large.

  Therefore, in order to make the shape of the body and engine hood of a snowmobile equipped with a 4-cycle engine almost the same as that of a 2-cycle engine, the layout of the oil pan, intake, exhaust, and related accessories were devised. Is essential.

  By the way, to lower the center of gravity when the engine is installed to lower the center of gravity of the snowmobile, the engine position should be lowered to the same level as the steering tie rod, and to set the center of gravity at the center of the vehicle, move the engine to the steering post. Is desirable.

  However, when the engine of a snowmobile is replaced with a two-cycle engine replaced with a four-cycle engine, the case where the crank center of the four-cycle engine is placed at the same position as the crank center of the two-cycle engine before replacement is considered. There is an oil pan at the bottom of the cycle engine, and the overall height of the engine is higher than that of a two-cycle engine. Therefore, when arranging the engine so that the cylinder faces upright, the engine may interfere with the steering rod, and the cylinder head and throttle body May interfere with the engine hood.

  Also, snowmobile two-stroke engines require a large-capacity expansion chamber to improve performance, and this chamber is normally routed to the side opposite to the drive clutch and connected to the muffler. The exhaust system is arranged in this way because of the necessity of space for handling and the balance between left and right weights. A flywheel magnet, chamber and muffler are arranged on the opposite side of the heavy clutch. I do.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art. A four-stroke engine can be mounted on a snowmobile without interference with an engine hood and at a low center of gravity. An object of the present invention is to provide a snowmobile capable of improving running performance by approaching and lowering the position of the center of gravity.

The present invention relates to a snowmobile.
The present invention relates to a snowmobile equipped with an engine hood positioned forward of a seat and having a four-cycle engine accommodated and mounted in an engine room covered by the engine hood. Along the direction, and mounted on the vehicle body in a state where the center axis of the cylinder is inclined backward with respect to the vehicle body vertical direction, and the oil pan of the four-stroke engine is disposed adjacent to the bottom of the engine room. A snowmobile having an oil strainer housed in an oil pan.

  In the present invention, the four-cycle engine can be a double overhead cam type.

According to the present invention, the four-stroke engine is tilted backward, so that the overall height of the engine can be far reduced as compared with the upright engine, and interference with the engine hood can be avoided.
Also, by tilting the four-cycle engine backward in the engine hood at the front of the vehicle body, the center of gravity of the engine can be brought closer to the center of the vehicle body. It can improve the running performance of snowmobiles.
In addition, the front of the engine is widened by tilting the engine backward, so that the engine can be arranged with a degree of freedom such as an exhaust pipe, and the height of the engine hood can be further reduced.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is an enlarged front side view explanatory view of a snowmobile equipped with a four-cycle engine applied to an embodiment of the present invention, FIG. 2 is an overall side view explanatory view of the snowmobile, and FIG. 4 is an enlarged detailed explanatory view of FIG. 3, FIG. 5 is a frontal explanatory view of a snowmobile, FIG. 6 is an explanatory view of disposing a battery in a cross section taken along line VI-VI of FIG. 4, FIG. (A) and (b) are an external side view and a front view of the four-cycle engine, and FIG. 8 is a plan view of the four-cycle engine.

As shown in FIGS. 1 to 4, the snowmobile according to the embodiment has a three-cylinder (one example of a multi-cylinder) four-cycle engine 16 in an engine hood 14 located forward of a seat 12 at a front portion 10 f of a vehicle body 10. Is mounted and mounted.
A headlamp 20 is provided on the front side of the uppermost portion of the engine hood 14 (the bulging portion 18 bulging upward in the embodiment).

The four-stroke engine 16 is a rearward leaning engine in which the crankshaft 22 extends along the vehicle width direction and the center axis 24c of the cylinder 24 is inclined backward by an angle α with respect to the vehicle vertical line 10c. At least a part of the intake system 34 of the engine 16 including the air cleaner box 30 and the throttle body 32 connected to the rear intake port 28 (in the embodiment, the front part 30a of the air cleaner box 30 and the upper part of the throttle body 32) is the uppermost part of the engine hood 14. It is accommodated behind the headlamp 20 in the space of the upper bulging portion 18.
The exhaust gas is led out to the front of the cylinder 24 by an exhaust system 38 connected to an exhaust port 36 at the front of the cylinder head 26.

  Here, the structure of the snowmobile will be described in more detail.

As shown in FIGS. 2 and 3, the snowmobile according to the embodiment turns a pair of left and right steering sleds (skis) 40 in the lower part of a front part 10 f of the vehicle body 10 extending in the front-rear direction so as to face in the left-right direction. A crawler 44 for circulating the track belt 42 is disposed at a lower portion of the vehicle body rear portion 10r on which the seat 12 is mounted, and is disposed movably.
The crawler 44 includes a driving wheel 44a disposed at a front end of the vehicle body rear portion 10r, a driven wheel 44b disposed at a rear end, a plurality of intermediate wheels 44c, a suspension mechanism 44d for suspending and cushioning the wheels, and And a track belt 42 wrapped around and circulating.

  The vehicle body 10 has a monocoque frame structure, and a vehicle body front portion (engine mount frame) 10f on which the four-cycle engine 16 is mounted has a gradually narrowed shape as it goes forward in plan view, and Has an open bottom, and the upper opening 10f1 is covered with the engine hood 14 and closed to form an engine room 46. The periphery of the upper opening 10f1 has a slightly undulating shape.

  In the front part 10f of the vehicle body, as shown mainly in FIG. 2, the inner bottom surface of the engine room 46 is formed so that the center part in the vehicle width direction and the center part (referred to as main part) 48 in the front-rear direction are the lowest. The four-stroke engine 16 is fixed and mounted on the main part 48 by floating via the bracket 16c at the lower front part of the main part 48 so that the engine oil pan 16a is adjacent to the bottom of the part 48 so as to be adjacent thereto.

A central portion in the vehicle width direction of the inner bottom surface of the engine room 46 is a slope that rises gently at a front portion 48a of the main portion 48.
From the left and right sides of the main part 48 to the front part, it protrudes upward in the engine room 46 so that the sled 40 does not hit the vehicle body even in the swinging and cushion stroke of the steering sled 40 (the lower part in the front part 10f of the vehicle body). (Recessed toward).
The front part 50a of the sled house 50 is recessed and higher than the vicinity of the main part 48, and accommodates the suspension mechanism and the steering mechanism 40a of the sled 40 therein (see FIG. 4). .
Further, on the bottom side, a rear side of the main portion 48 is a crawler house portion 52 for accommodating a front portion of the crawler 44 (near the drive wheel 44a) protruding upward from the main portion 48.

  A steering shaft (also referred to as a steering post) 54 projects rearwardly in front of the engine hood 14 and in front of the seat 12 with a slight inclination, and a bar-shaped steering handle for steering is provided at the upper end of the steering shaft 54. 56 are provided.

  A lower end portion of the steering shaft 54 is rotatably supported by the vehicle body adjacent to the crawler house portion 52. A link mechanism (not shown) is provided at the lower end portion of the steering mechanism 40a which swings the sled 40 right and left. Is used to transmit the steering force.

The rearwardly inclined four-cycle engine 16 mounted in an engine room 46 in the engine hood 14 has an oil pan 16a at the bottom of a lower crankcase 58 as shown in FIGS. In the oil pan 16a, an oil strainer 16b is accommodated in an oil suction port.
The movement of the piston 24a, which reciprocates up and down in the cylinder 24 above the engine crankcase 58, is converted into the rotation movement of the crankshaft 22 via the connecting rod 58a.
An intake valve 60a, an exhaust valve 62b for opening and closing an intake port 28 and an exhaust port 36 connected to a combustion chamber in the cylinder 24, and a valve mechanism 60b, 62b are provided on a cylinder head 26 provided above the cylinder 24. Have been.
As described above, the engine of the embodiment is a double overhead cam type four-cycle engine.

A water pump 64 is provided above the crankcase 58 and in front of the engine cylinder 24, and an alternator 66 is provided at the rear of the engine cylinder 24, and driven pulleys 64a and 66a are provided respectively. A timing belt 68 is wound around these and a drive pulley 22 a provided on the crankshaft 22 outside the crankcase 58, and is driven by the rotation of the crankshaft 22.
The positional relationship among the water pump 64, the alternator 66, and the crankshaft 22 has a substantially inverted triangular shape in a side view, and the upper path of the timing belt 68 is substantially parallel to the mating surface of the cylinder head 26 and the cylinder 24. .

  At the front of the crankcase 58, a substantially cylindrical oil filter 70 is provided upright so that the center axis thereof is inclined obliquely forward and upward. It almost coincides with the lower edge position.

A bulge 18 projecting upward is formed at the uppermost part of the engine hood 14. A single headlamp 20 is provided at the front of the bulge 18, while the vehicle is mounted at the rear of the bulge 18. An instrument panel 72 for displaying a state is provided, and at least a part of the intake system 34 is housed in a space 74 between the headlamp 20 of the bulging portion 18 and the instrument panel 72.
Further, a fairing 19 for protecting the driver from wind is formed wider than the steering handle 56 so as to cover the bulging portion 18 and is provided on the engine hood 14.

In the intake system 34 of the embodiment, the air cleaner box 30 is divided into two front and rear portions (a front box 30a and a rear box 30b) at positions sandwiching the throttle body 32, and the front box 30a and the upper portion of the throttle body 32 are viewed from the side. And wraps around the bulging portion 18.
The front box 30a is located on the cylinder head 26 (on the cylinder head cover 26a) and wraps around the engine 16 in plan view, and the rear box 30b is located in a space above the drive sprocket shaft 84.
In the intake system 34, the intake air flows from the rear box 30b to the front box 30a, and the air-fuel mixture flows obliquely downward and forward from the throttle body 32 to the intake pipe 32a and further to the intake port 28 of the engine 16.

As shown in FIGS. 1, 4 and 5, the exhaust system 38 is connected to an exhaust manifold 74 connected to the exhaust port 36 at the front of the cylinder head 26 and an exhaust pipe 76 located in front of the engine 16 and at the same time. The exhaust muffler 78 connected to the outlet side of the exhaust manifold 74 is disposed in the engine room 46 covered by the engine hood 14. In the embodiment, the muffler 78 is mounted on the main portion front portion 48a. ing.
An exhaust outlet pipe 80 of the muffler 78 penetrates the lower portion of the vehicle body 10 and an opening 80a is provided at a central portion (indicated by reference numeral SC) of the lower surface of the vehicle body 10 in the vehicle width direction. Is emitted downward toward the outside of the vehicle body.

A muffler 78 is located below the engine cylinder 24, and an exhaust pipe 76 connected to the exhaust manifold 74 extends downward toward the muffler 78.
The exhaust manifold 74 has a plurality of inlet portions corresponding to the plurality of exhaust ports 36 (three cylinders and three cylinders in the embodiment) of the four-cycle engine 16, and an outlet portion connected to the exhaust pipe 76 collectively. And this collective part is lowered forward.

Further, the muffler 78 is a substantially cylindrical body, and the cylindrical body shaft 78a extends along the vehicle width direction, and the exhaust is bent in a substantially C-shape on one side (in the embodiment, the left side of the vehicle body) in the vehicle width direction. The outlet side of the pipe 76 is connected, and the exhaust from the four-cycle engine 14 is introduced into the muffler 78 via the exhaust pipe 76.
The muffler 78 is installed so as to be deviated to the other side in the vehicle width direction (in the embodiment, the right side of the vehicle body), so that a space is provided between the muffler 78 and the inner wall of the engine room 46 to secure a space for disposing the exhaust pipe 76. are doing.

Further, in the engine hood 14, the four-stroke engine 16 is arranged such that its center position 16C in the direction of the crankshaft 22 is deviated to one side with respect to the center position SC in the vehicle width direction (see FIG. 4).
In the engine hood 14, a clutch device 82 is disposed on one side in the vehicle width direction (the left side of the vehicle body in the embodiment) with the four-cycle engine 14 interposed therebetween, and a battery 86 is disposed on the other side in the vehicle width direction. ing.

  The clutch device 82 includes a drive clutch pulley 82a installed at an output end of an engine crankshaft, a driven clutch pulley 82b installed at an end of the crawler drive sprocket shaft 84 opposite to the sprocket 84a, and a V belt 84c having a V-shaped cross section. And a V-belt transmission comprising:

  Further, it is preferable to install an electrical component 90 such as an ECU or a CDI unit in the battery holder portion 88 in which the battery 86 is accommodated and mounted without play.

  As shown in FIGS. 4 and 6, the battery holder 88 is formed of a metal fitting having an L-shaped cross section. As shown in FIG. 6A, the electrical component 90 is installed back to back with the battery 86. (B), the electrical component 90 can be installed above the battery 86.

  As described above, according to the present embodiment, the four-stroke engine 16 is tilted rearward, and a part of the intake system above the engine 16 is provided behind the headlamp 20 at the uppermost portion (the bulging portion 18) in the engine hood 14. Since the housing is accommodated, the overall height of the engine can be significantly reduced as compared with the upright engine, and interference with the engine hood 14 and the headlamp 20 can be avoided.

  Further, by tilting the four-cycle engine 16 backward in the engine hood 14 at the front of the vehicle body, the center of gravity of the engine 16 can be brought closer to the center of the vehicle body, and the position of the center of gravity becomes lower even when the position of the cylinder head 26 is lowered. This improves the maneuverability and improves the running performance of snowmobiles.

  In addition, the front of the engine 16 becomes wider due to the backward inclination of the engine 16, and the engine hood 14 can be further reduced in height by being able to arrange the exhaust pipe with a degree of freedom. Further, even if the intake system 34 connected to the rear of the engine is installed above the engine 16, the intake system can be accommodated behind the headlamp 20 at the top of the engine hood 14, so that the space efficiency is improved and the overall height of the engine hood is increased. There is no need to make any major changes or modifications.

An upwardly bulging portion 18 is formed at the uppermost portion of the engine hood 14, a headlamp 20 is provided at a front portion of the bulging portion 18, and an instrument panel 72 for displaying a vehicle state is provided at a rear portion of the bulging portion 18. Each is provided, and at least a part of the intake system 34 can be housed in a space between the head lamp 20 of the bulging portion 18 and the instrument panel 72.
In this way, at the top of the engine hood 14 where the headlamp 20 and the instrument panel 72 are to be arranged, a part of the intake system is accommodated in the space behind the headlamp 20 which is a vacant space, so that the intake system can be space-efficiently. And the shape of the engine hood 14 can be reduced.

Further, an exhaust manifold 74 that connects the exhaust system 38 to the exhaust port 36 at the front of the cylinder head 26 and an exhaust muffler 78 that is located in front of the engine and that is connected to the exhaust manifold 74 outlet side via an exhaust pipe 76 14, an opening 80 a of an exhaust outlet pipe 80 from the muffler 78 is provided at a central position in the vehicle width direction on the lower surface of the vehicle body, and exhaust gas is discharged from the opening 80 a toward the outside of the vehicle body. The exhaust sound can be emitted from the center of the vehicle body underneath the vehicle body in the vehicle width direction, and the exhaust sound is divided from the lower side of the vehicle body on both sides and at the front of the vehicle body, so it is far from the driver and the exhaust sound is driving when driving It does not hurt the elderly.
In addition, since the vehicle is located at the center of the vehicle width, the exhaust sound during driving is the same on the left and right sides of the vehicle body, and the downward sound can be expected to have a noise-reducing effect due to the snow surface or the snow jumped up by the steering sled.

  Further, the muffler 78 is located below the engine cylinder 24, and the exhaust pipe 76 connected to the exhaust manifold 74 extends forward and downward toward the muffler 78. And the shape follows the shape of the engine hood 14 which is lowered forward to improve aerodynamic performance.

  Further, the muffler 78 is a substantially cylindrical body whose axis extends in the vehicle width direction, and when connected to one side in the vehicle width direction, exhaust gas from the engine 16 is introduced into the muffler 78 through an exhaust pipe 76. As a result, the muffler 78 can be accommodated in the engine hood 14 without taking the front-rear length.

  Further, in the engine hood 14, the four-stroke engine 16 is disposed such that the center position in the crankshaft direction is deviated to one side with respect to the center position in the vehicle width direction, and the battery 86 is disposed on the other side to achieve space utilization efficiency. Has been improved.

  In the engine hood 14, the clutch device 82 is disposed on one side in the vehicle width direction with the engine 16 interposed therebetween, and the battery 86 is disposed on the other side in the vehicle width direction. Can be done easily.

  In addition, since the electric components are installed in the battery holder portion 88 on which the battery 86 is mounted, for example, the electric components 90 such as an ECU and a CDI unit can be installed in the battery holder portion 88 to achieve more weight balance, and the engine can be used. Since the electrical components can be arranged immediately beside the 16, the lead wire between the electrical component and the engine 16 can be shortened, and the wiring can be easily arranged.

FIG. 1 is an enlarged front side view explanatory view of a snowmobile equipped with a four-cycle engine applied to an embodiment of the present invention. It is an explanatory view of the whole snowmobile as viewed from the side. FIG. 3 is an overall plan view of the snowmobile. FIG. 4 is an enlarged detailed explanatory diagram of FIG. 3. It is a front view explanatory drawing of a snowmobile. FIG. 5 is an explanatory view of the arrangement of the battery as viewed in section along line VI-VI in FIG. (A), (b) is an external side view and a front view of the four-cycle engine. FIG. 2 is a plan view of the four-cycle engine.

Explanation of reference numerals

Reference Signs List 10 vehicle body 10c vehicle body vertical line 14 engine hood 16 four-cycle engine 16a oil pan 16b oil strainer 18 bulging part 22 crankshaft 24 cylinder 24c cylinder center axis 28 intake port 30 air cleaner box 32 throttle body 34 intake system 36 exhaust port 38 exhaust System 78 muffler

Claims (2)

In a snowmobile with an engine hood located forward of the seat, and a 4-cycle engine housed and mounted in the engine room covered by the engine hood,
A four-cycle engine is mounted on the vehicle body with its crankshaft extending along the width of the vehicle body and the center axis of the cylinder inclined backward with respect to the vertical line of the vehicle body, and the oil pan of the four-cycle engine is mounted on the engine. A snowmobile characterized by being disposed adjacent to the bottom of the room and containing an oil strainer in the oil pan. The snowmobile according to claim 1, wherein the four-cycle engine is of a double overhead cam type.

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