JP4042368B2 - Auxiliary structure of 4-cycle engine for snow vehicles - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
  The present inventionFor snow vehiclesThe present invention relates to an auxiliary equipment arrangement structure of a 4-cycle engine.
[0002]
[Prior art]
Conventionally, an engine mounted on a small snow vehicle such as a snowmobile has a relatively simple structure, a lightweight, compact and powerful two-cycle. Recently, however, the 4-cycle engine has been promoted with the aim of improving exhaust gas regulations and fuel efficiency. Compared to the high-power and compact 2-cycle engine, the 4-cycle engine that requires camshaft and oil lubrication is It tends to be large.
[0003]
Therefore, in order to make the body and engine hood shape of a snow vehicle equipped with a 4-cycle engine the same size as when a 2-cycle engine is installed, the layout of the oil pan shape, intake, exhaust and related accessories is devised. Is indispensable.
[0004]
[Problems to be solved by the invention]
By the way, a flywheel magneto or alternator is required as a power generator to supply electricity to the ignition device or engine auxiliary machine. Since the flywheel magneto is provided at the end of the crankshaft, the width of the engine in the axial direction is increased. Or, there is a problem in that the acceleration performance is lowered because the inertia of the crankshaft is increased.
[0005]
The alternator is driven by transmitting the driving force of the crankshaft with a belt, but the front-rear width in the direction perpendicular to the crankshaft of the engine is enlarged, so it is necessary to arrange it at an appropriate position. It is necessary to optimize the positional relationship with the water pump to be reduced and to take into account the reduction of the front and rear width of the engine. When the engine is disposed in front of the steering shaft, there is a problem that the steering shaft interferes with auxiliary equipment such as an alternator.
[0006]
In addition, the engine mounted on a snow vehicle is covered with an engine hood, but it is common to incorporate the driving wind into the engine room in the hood to cool the engine while driving. In some cases, snow is blown in along with the traveling wind, and this snow may cause trouble for the alternator, which is an electrical component.
[0007]
  The present invention has been made paying attention to the problems of the prior art described above, and is mounted on a snow vehicle.4 cyclesDevise the arrangement of auxiliary equipment such as an alternator4 cyclesReduces the overall width of the engine so that it does not interfere with the steering post, etc.4 cyclesOn the snow, the engine can be set closer to the center of the vehicle body and the center of gravity can be set near the center of the vehicle body to improve maneuverability, and at the same time, snow blowing into the engine room can prevent troubles in the accessories. For cars4 cyclesIt is an object of the present invention to provide an engine accessory arrangement structure.
[0008]
[Means for Solving the Problems]
  The present invention achieves the object by the following configuration.
  That is, the present invention is for a snow vehicle that is housed in an engine hood located in front of the seat at the front of the vehicle body.4 cyclesIt is an arrangement structure of auxiliary machines such as engine alternators,
  A bulge protruding upward is formed at the top of the engine hood, and the four cyclesMake sure that the crankshaft is along the width of the vehicle.In addition, the cylinder center axis is disposed in a state of being inclined backward with respect to the vehicle body vertical direction, and the throttle body constituting the intake system is disposed so that the upper portion wraps around the bulging portion in a side view,
  AlternatorBelow the intake manifold connected from the throttle body to the intake port at the rear of the cylinder head,Located between the engine and the heat exchanger,
  4 cyclesA snow vehicle characterized in that a timing belt is wound between a pulley provided on the crankshaft end opposite to the side where the engine clutch device is installed and an alternator driving pulley, and the alternator is driven by rotation of the crankshaft. for4 cyclesIt is an engine auxiliary equipment arrangement structure.
  According to the invention, the alternator is4 cyclesBecause it is arranged between the engine and the heat exchanger, snow and rain do not hit the alternator with the traveling wind even if the traveling wind is introduced into the engine hood (in the engine room) during traveling. It is possible to prevent the possibility of troubles due to the moisture caused by spilling on the alternator.
  Further, the alternator can be driven by the timing belt in the same manner as the water pump, and the number of parts can be reduced.
[0009]
  In addition,The air cleaner box is wrapped on the cylinder head so that it wraps around the bulge in side view and wraps around the engine in plan view.It is suitable to arrange.
  Further, it is preferable to have a steering device in which a steering post having a handle at the upper end is disposed through the engine room, and an alternator is disposed on the side of the steering post in a front view of the vehicle body. In this way, the engine post can be positioned in the engine hood so that the steering post and the alternator do not interfere with each other as much as possible. It can be close to the center of gravity of the car body.
  Further, it is preferable that the water pump is disposed forward and the alternator is disposed substantially symmetrically with respect to each other about the engine cylinder axis.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
[0011]
FIG. 1 is a front side view enlarged explanatory view of a snow vehicle 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 snow vehicle, and FIG. FIG. 4 is an enlarged detailed explanatory view of FIG. 3, FIG. 5 is a front explanatory view of a snow vehicle, FIG. 6 is an explanatory view of battery arrangement taken along line VI-VI in FIG. FIGS. 8A and 8B are an external side view and a front view of the 4-cycle engine, and FIG. 8 is a plan view of the 4-cycle engine.
[0012]
As shown in FIGS. 1 to 4, the snow vehicle according to the embodiment includes a three-cylinder (an example of a multi-cylinder) four-cycle engine 16 in an engine hood 14 positioned in front of the seat seat 12 at the front portion 10 f of the vehicle body 10. Is a snow vehicle that houses A headlamp 20 is provided in front of the uppermost portion of the engine hood 14 (in the embodiment, the bulging portion 18 bulging upward). The four-cycle engine 16 is a rear-tilt engine in which the crankshaft 22 is along the vehicle body width direction and the center axis 24c of the cylinder 24 is inclined rearward by an angle α with respect to the vehicle body vertical direction line 10c.
[0013]
Further, the four-cycle engine 16 is provided with an alternator 66 as a generator, and the vehicle body of the snow vehicle has a heat exchanger 17 that cools the engine 16 cooling water by exchanging heat with outside air or snow. The alternator 66 is provided between the four-cycle engine 16 and the front heat exchanger 17a and is provided at the front part (17a) of the crawler house part 52 and the upper part (17b) of the rear crawler house 92. The engine 16 is installed via a bracket or the like.
[0014]
In the four-cycle engine 16, the timing belt 68 is wound around the pulley 22a provided at the end of the crankshaft 22 opposite to the side where the clutch device 82 is installed of the engine 16 and the driven pulley 66a for driving the alternator. The alternator 66 is driven by this rotation.
[0015]
Further, the air cleaner box 30 connected to the intake port 28 at the rear portion of the cylinder head 26 of the engine 16 and the throttle body 32 including the air cleaner box 30 front portion 30a and the upper portion of the throttle body 32 of the intake system 34 of the engine 16 are the engine hood 14. It is housed behind the headlamp 20 in the uppermost bulging portion 18 space. Then, exhaust is led to the front of the cylinder 24 by an exhaust system 38 connected to an exhaust port 36 in front of the cylinder head 26.
[0016]
Here, the structure of the snow vehicle will be described in more detail.
As shown in FIGS. 2 and 3, the snow vehicle according to the embodiment is rotated so that a pair of left and right steering sleds (skis) 40 are directed in the left-right direction below the front portion 10f of the vehicle body 10 extending in the front-rear direction. On the other hand, a crawler 44 that circulates the track belt 42 is disposed below the rear part 10r of the vehicle body on which the seat 12 is placed. The crawler 44 includes a drive wheel 44a disposed at the front end of the vehicle body rear portion 10r, a driven wheel 44b disposed at the rear end, a plurality of intermediate wheels 44c, a suspension mechanism 44d that suspends and cushions them, and each wheel. And a track belt 42 that wraps around and circulates.
[0017]
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 shape that is gradually squeezed toward the front in plan view and has an upper portion. It has a general ship bottom shape that is open, and the upper hood 10f1 is covered with an engine hood 14 to close the interior of the engine room 46. The peripheral edge of the upper opening 10f1 has a slightly gently wavy shape.
[0018]
Further, in the vehicle body front portion 10f, as mainly shown in FIG. 2, the inner bottom surface of the engine room 46 is formed at the center portion in the vehicle width direction and the center portion 48 in the front-rear direction (referred to as main portion). The four-cycle engine 16 is fixed and mounted by floating via a bracket 16c at the lower front portion thereof, positioned on the main portion 48 so that the engine oil pan 16a is adjacent to the bottom of the portion 48.
[0019]
Further, the central portion in the vehicle width direction of the inner bottom surface of the engine room 46 is a slope that gently rises at the front portion 48 a of the main portion 48. From the left and right side positions of the main portion 48 to the front portion, the sled 40 protrudes upward in the engine room 46 so that the sled 40 does not hit the vehicle body even when the steering sled 40 swings and cushions (lower in the front portion 10f of the vehicle body). The sled house part 50 is recessed. The front portion 50a of the sled house portion 50 is recessed and higher than the vicinity of the main portion 48, and accommodates the suspension mechanism and steering mechanism 40a of the sled 40 therein (see FIG. 4). Further, the rear side of the main portion 48 on the bottom surface is a crawler house portion 52 that accommodates the front portion of the crawler 44 (near the driving wheel 44a) protruding upward from the main portion 48. The crawler house portion 52 accommodates the periphery of the drive wheel 44a of the crawler 44. The rear portion of the crawler house portion 52 includes the crawler 44, the driven wheel 44b, the intermediate wheel 44c, and the suspension mechanism 44d in the rear portion 10r of the vehicle body. It is connected to the rear crawler house 92 which accommodates it. A heat exchanger front portion 17a is provided on the front slope portion of the crawler house portion 52, and a heat exchanger rear portion 17b extends in the front and rear direction to the vicinity of the rear end portion of the crawler 44 on the upper surface portion of the rear crawler house 92. (See FIG. 2).
[0020]
A steering shaft (also referred to as a steering post) 54 is tilted slightly rearward at the rear portion of the engine hood 14 and immediately before the seat 12, and is installed so as to be rotatable through the hood. A bar-like steering handle 56 for steering is provided at the upper end of the shaft 54. 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 connected to the lower end portion of the steering mechanism 40a that swings and steers the sled 40 left and right. The steering force is transmitted with.
[0021]
As shown in FIGS. 1 to 8, the rearwardly tilted four-cycle engine 16 mounted in the engine room 46 in the engine hood 14 has an oil pan 16a at the bottom of the lower crankcase 58. In the oil pan 16a, an oil strainer 16b is accommodated in an oil suction port. The movement of the piston 24a that reciprocates in the cylinder 24 above the engine crankcase 58 is converted into the rotational movement of the crankshaft 22 through the connecting rod 58a. The cylinder head 26 provided on the upper part of the cylinder 24 includes an intake valve 60a and an exhaust valve 62b for opening and closing the intake port 28 and the exhaust port 36 connected to the combustion chamber in the cylinder 24, and its valve operating mechanism 60b. 62b is disposed. Thus, the engine of the embodiment is a double overhead cam type four-cycle engine.
[0022]
Above the crankcase 58, a water pump 64 is disposed at the front of the engine cylinder 24, and an alternator 66 is disposed at the rear of the engine cylinder 24. Driven pulleys 64a and 66a are respectively provided. A timing belt 68 is wound around these and a drive pulley 22a provided on the crankshaft 22 outside the crankcase 58, and is driven by rotation of the crankshaft.
[0023]
  The positional relationship among the water pump 64, the alternator 66, and the crankshaft 22 has an approximately inverted triangular shape in side view, and the engine cylinder24 centersA water pump 64 is disposed in the front and an alternator 66 in the rear is disposed substantially symmetrically with respect to the axis 24c. The upper path of the timing belt 68 is substantially parallel to the mating surface of the cylinder head 26 and the cylinder 24.
[0024]
The alternator 66 is disposed between the cylinder 24 of the four-cycle engine 16 and the oil pan 16a and above the oil pan 16a as described above. The alternator 66 is positioned below an intake pipe (intake manifold) 32a connected from the throttle body 32 of the intake system to the intake port 28. Further, the alternator 66 is disposed on the side of the steering shaft 54 in a front view of the vehicle body (see FIGS. 4 and 5).
[0025]
A substantially cylindrical oil filter 70 is erected on the front portion of the crankcase 58 so that its central axis is inclined obliquely forward and upward, and the upper end position of the oil filter 70 is below the water pump 64 in a side view. It almost coincides with the edge position.
[0026]
  A bulging portion 18 protruding upward is formed at the uppermost portion of the engine hood 14, and a single headlamp 20 is provided at the front portion of the bulging portion 18, while the vehicle is provided at the rear portion of the bulging portion 18. An instrument panel 72 for displaying the state is provided, and at least a part of the intake system 34 is sandwiched between the headlamp 20 of the bulging portion 18 and the instrument panel 72.spaceIt is housed inside. Further, a fairing 19 for avoiding the wind of the driver is formed on the engine hood 14 so as to be wider rearward than the steering handle 56 so as to cover the bulging portion 18.
[0027]
In the intake system 34 of the embodiment, the air cleaner box 30 is divided into two front and rear (a front box 30a and a rear box 30b) at a position sandwiching the throttle body 32, and the front box 30a and the upper part of the throttle body 32 are viewed from the side. It wraps around the bulging portion 18. The front box 30a is positioned on the cylinder head 26 (on the cylinder head cover 26a) and is wrapped on the engine 16 in plan view, and the rear box 30b is positioned in a space on 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.
[0028]
1 and FIGS. 4 to 5, the exhaust system 38 is located in front of the engine 16 and connected to the exhaust port 36 in the front part of the cylinder head 26, and via an exhaust pipe 76. The exhaust muffler 78 connected to the outlet side of the exhaust manifold 74 is disposed in the engine room 46 covered with the engine hood 14, and the muffler 78 is placed on the main portion front portion 48a in the embodiment. ing. An exhaust outlet pipe 80 of the muffler 78 penetrates the lower part of the vehicle body 10 and an opening 80a is provided at a vehicle width direction central portion (indicated by the symbol SC) of the lower surface of the vehicle body 10 to exhaust the engine 16 from the opening 80a. It is designed to discharge downward toward the outside of the vehicle body.
[0029]
  From the engine cylinder 24exhaustMuffler 78Is located below, and an exhaust pipe 76 connected to the exhaust manifold 74 isexhaustIt extends forward and downward toward the muffler 78. There are a plurality of exhaust manifolds 74 corresponding to the plurality of exhaust ports 36 of the four-cycle engine 16 (three cylinders in the embodiment), and the outlet side connected to the exhaust pipe 76 is collectively. And this collective part is a forward drop.
[0030]
  Also, the aboveexhaustThe muffler 78 is a substantially cylindrical body, and the cylindrical body shaft 78a extends along the vehicle width direction, and the exhaust pipe 76 is bent in a substantially C shape on one side in the vehicle width direction (the left side of the vehicle body in the embodiment). The four-stroke engine 1 is connected through the exhaust pipe 76.6Exhaust from the saidexhaustThe muffler 78 is introduced. SaidexhaustThe muffler 78 is biased and installed on the other side in the vehicle width direction (right side of the vehicle body in the embodiment), thereby ensuring a space for arranging the exhaust pipe 76 with a space from the inner wall of the engine room 46. ing.
[0031]
  Further, in the engine hood 14, the four-cycle engine 16 is disposed such that the center position 16C in the crankshaft 22 direction is biased to one side with respect to the center position SC in the vehicle body width direction (see FIG. 4). The engine hood 14 has a four-cycle engine 16A clutch device 82 is disposed on one side in the vehicle width direction (in the embodiment, on the left side of the vehicle body), and a battery 86 is disposed on the other side in the vehicle width direction. The clutch device 82 includes a drive clutch pulley 82a installed at the output end of the engine crankshaft, a driven clutch pulley 82b installed at the opposite end of the sprocket 84a in the crawler drive sprocket shaft 84, and a V-belt 84c having a V-shaped cross section. The V-belt transmission composed of 4 cycle engine of drive clutch pulley 82a of clutch device 8216On the side, a ring gear 85 that meshes with a starter motor (not shown) and transmits the driving force to the crankshaft 22 is disposed.
[0032]
In addition, it is preferable to install an electrical component 90 such as an ECU CDI unit in the battery holder portion 88 that houses and places the battery 86 so as not to rattle. As shown in FIGS. 4 and 6, the battery holder 88 is formed of a metal fitting having an L-shaped cross section, and 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.
[0033]
As described above, according to the present embodiment, since the alternator 66 is disposed between the engine and the heat exchanger (the front portion 17a), the vehicle travels in the engine hood 14 (in the engine room 64) during traveling. Even if wind is introduced, snow and rain do not hit the alternator along with the traveling wind, and it is possible to prevent the possibility of troubles due to moisture from the snow and rain on the alternator 66.
Further, since the alternator 66 is driven by the timing belt 68 similarly to the water pump 64, the number of parts for driving can be reduced.
[0034]
Further, in the 4-cycle engine 16, the alternator 66 is provided below the intake manifold (corresponding to the intake pipe 32a connected to the throttle body 32), so the alternator 66 is disposed in the space below the intake manifold. In addition, interference with the intake system 34 can be prevented, and the intake system 34 and the intake pipe 32a act as an umbrella even if snow or rain that enters the engine room 46 from the upper side of the engine 16 wraps around from above the engine 16. Thus, it is possible to reliably prevent snow and the like from being applied to the alternator 66.
[0035]
In addition, since the steering shaft 54 having a steering wheel at the upper end is provided in the engine room 46 and the alternator is disposed on the side of the steering post as viewed from the front of the vehicle body, the four-cycle engine 16 is installed in the engine hood 14. Since the steering shaft 54 and the alternator 66 can be arranged at a position where they do not interfere with each other when trying to arrange them rearward as much as possible, the engine 16 can be positioned further rearward in the engine room 46 to bring the engine center of gravity closer to the vehicle body center of gravity. it can.
[0036]
Since the four-stroke engine 16 is tilted rearward and a part of the intake system above the engine 16 is accommodated behind the headlamp 20 at the uppermost part (the bulging part 18) in the engine hood 14, the engine is compared with an upright engine. The overall height can be greatly reduced 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 is lowered by a decrease in the position of the cylinder head 26. , The maneuverability is improved and the driving performance of snow vehicles can be improved. Further, when the engine 16 is tilted backward, the front of the engine becomes wider, and the engine hood 14 can be further reduced in height by being arranged with a degree of freedom such as an exhaust pipe. Further, even if the intake system 34 connected to the rear part 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 space efficiency is improved and the overall height of the engine hood is increased. There is no need to make any changes or modifications.
[0037]
Further, an upward bulging portion 18 is formed at the top of the engine hood 14, a headlamp 20 is provided at the front of the bulging portion 18, and an instrument panel 72 for displaying the vehicle state is provided at the rear of the bulging portion 18. Each is provided, and at least a part of the intake system 34 can be accommodated in a space sandwiched between the headlamp 20 of the bulging portion 18 and the instrument panel 72. In this way, at the uppermost part of the engine hood 14 where the headlamp 20 and the instrument panel 72 are to be disposed, a part of the intake system is accommodated in the space behind the headlamp 20 which is an empty space, and the intake system is efficiently space-efficient. The shape of the engine hood 14 can be lowered.
[0038]
  Further, an exhaust manifold that connects the exhaust system 38 to an exhaust port 36 in front of the cylinder head 26.74And an exhaust muffler 78 located in front of the engine and connected to the outlet side of the exhaust manifold 74 via the exhaust pipe 76 is disposed in the engine hood 14, and an opening 80 a of the exhaust outlet pipe 80 from the muffler 78. Is provided at the center position in the vehicle width direction on the bottom surface of the vehicle body so that the exhaust is discharged from the opening 80a toward the outside of the vehicle body. Since the sound is divided into both sides from the lower side of the vehicle body and at the front part of the vehicle body, the sound is far from the driver and the exhaust sound does not disturb the driver during driving. In addition, since it is at the center of the vehicle width, the exhaust noise during driving is the same on the left and right sides of the vehicle body, and by setting it downward, it is possible to expect a noise reduction effect due to snow splashed on the snow surface or steering sled.
[0039]
  Also engineShiFrom Linda 24exhaustAn exhaust pipe 76 connected to the exhaust manifold 74 is located below the muffler 78.exhaustSince it extends forward and downward toward the muffler 78, the exhaust pipe 76,exhaustIt is lowered forward over the muffler 78, and has a shape along the shape of the forwardly lowered engine hood 14 in order to improve aerodynamic performance.
[0040]
The muffler 78 is a substantially cylindrical body. When the cylindrical body axis is along the vehicle width direction and connected to one side in the vehicle width direction, exhaust from the engine 16 is introduced into the muffler 78 via the exhaust pipe 76. Thus, the muffler 78 can be accommodated in the engine hood 14 without taking the length in the front-rear direction.
[0041]
In the engine hood 14, the four-cycle engine 16 is arranged such that the center position in the crankshaft direction is deviated to one side with respect to the center position in the vehicle body width direction, and the battery 86 is arranged on the other side to provide space utilization efficiency. Has improved.
[0042]
Further, in the engine hood 14, the clutch device 82 is disposed on one side in the vehicle width direction with the engine 16 in between, and the battery 86 is disposed on the other side in the vehicle width direction. Can be easily done.
[0043]
In addition, since the electrical components are installed in the battery holder portion 88 on which the battery 86 is placed, for example, an electrical component 90 such as an ECU or a CDI unit can be installed in the battery holder portion 88 to achieve a better weight balance, and the engine Since the electrical components can be disposed immediately beside the 16, lead wires to the engine 16 can be shortened, and wiring can be easily performed.
[0044]
【The invention's effect】
  As described above, according to the present invention, it is mounted on a snow vehicle.4 cyclesDevise the arrangement of auxiliary equipment such as an alternator4 cyclesReduces the overall width of the engine so that it does not interfere with the steering post, etc.4 cyclesThe engine can be moved closer to the center of the vehicle body so that the position of the center of gravity can be set near the center of the vehicle body, thereby improving the steering performance. At the same time, the snow blowing into the engine room can prevent troubles in the auxiliary equipment.
[Brief description of the drawings]
FIG. 1 is a front side enlarged explanatory view of a snow vehicle equipped with a four-cycle engine applied to an embodiment of the present invention.
FIG. 2 is an explanatory side view of the entire snow vehicle.
FIG. 3 is an explanatory plan view of the entire snow vehicle.
FIG. 4 is an enlarged detailed explanatory view of FIG. 3;
FIG. 5 is a front view explanatory view of a snow vehicle.
FIG. 6 is an explanatory diagram of battery arrangement as viewed in section VI-VI in FIG. 4;
7A and 7B are an external side view and a front view, respectively, of the four-cycle engine.
FIG. 8 is a plan view of a four-cycle engine.
[Explanation of symbols]
10 body
10c Body center axis
14 Engine hood
16 4-cycle engine
17 Heat exchanger
18 bulge
22 Crankshaft
24 cylinders
24c Cylinder center axis
26 Cylinder head
28 Intake port
30 Air cleaner box
30a, 30b Front and rear boxes of air cleaner box
32 Throttle body
32a Intake pipe
34 Intake system
36 Exhaust port
38 Exhaust system
44 Crawler
46 engine room
52 Crawler House Club
54 Steering shaft
66 Alternator
72 Instrument panel
74 Exhaust manifold
78 Exhaust muffler

Claims (4)

An arrangement structure of auxiliary equipment such as an alternator of a 4-cycle engine for a snow vehicle stored in an engine hood located in front of the seat at the front of the vehicle body,
A bulging portion that protrudes upward is formed at the top of the engine hood , and the center axis of the cylinder is directed rearward with respect to the vehicle body vertical direction so that the crankshaft direction is along the vehicle body width direction. Arranged in a tilted state, the throttle body constituting the intake system is arranged so that the upper part wraps around the bulging part in a side view,
An alternator is provided below the intake manifold that connects the throttle body to the intake port at the rear of the cylinder head, and is located between the 4-cycle engine and the heat exchanger,
A timing belt is wound between a pulley provided on the crankshaft end opposite to the clutch device installation side of the four-cycle engine and an alternator driving pulley, and the alternator is driven by rotation of the crankshaft. A four-cycle engine accessory arrangement structure for snow vehicles. 2. The four-cycle engine for a snow vehicle according to claim 1 , wherein an air cleaner box is disposed on the cylinder head so as to wrap on the bulging portion in a side view and on the engine in a plan view . Auxiliary equipment arrangement structure. 3. The snow top according to claim 1, further comprising a steering device having a steering post with a handle installed at an upper end thereof penetratingly disposed in the engine room, wherein the alternator is disposed on a side of the steering post in a front view of the vehicle body. Auxiliary equipment layout structure for a 4-cycle engine for cars. Snow according to the water pump forward around the engine cylinder axis, in any one of claims 1, 2 or 3, characterized in that arranged so as to be substantially symmetrical positions to each other the alternator to the rear Auxiliary equipment layout structure for a 4-cycle engine for cars.

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