JPH0633060B2 - Vehicle intake device - Google Patents

Description

TECHNICAL FIELD The present invention relates to an intake device applied to a vehicle including a power unit in which an engine, a transmission case, and rear wheels are integrated.

(Prior Art) There are vehicles such as two- and three-wheel vehicles in which a front end of a power unit in which an engine, a transmission case, and a rear wheel are integrated is connected to a body frame so as to be vertically swingable. In this type of vehicle, when an intake air purifier is installed in the transmission case at the rear of the engine, warm air is taken in by the heat of the engine depending on the position where the intake air intake is installed, and the engine charging efficiency is increased. It is not preferable because it decreases. In particular, when the power unit is covered above and sideways with a vehicle body cover such as a scooter, depending on the position of the intake port, warm air trapped in the vehicle body cover tends to be sucked.

Therefore, it is conceivable to install the intake air intake at a position where air that is not affected by the heat of the engine, such as traveling air, is taken in. However, in this case, the air flow of the traveling wind changes the flow of intake air in the intake air purifier, which affects the fuel supply system such as the carburetor and changes the intake air mixture ratio. As a result, inconveniences occur, such as unstable engine operation and poor fuel economy. Further, in the case where the V-belt type transmission is housed in the transmission case, outside air may be introduced into the transmission case to be cooled, and in this case, the outside air introduction port may be opened in the transmission case. It is necessary to prevent rainwater and dust from entering this outside air inlet,
If the front wheel is opened to the front or to the bottom, dust collected by the front wheels can easily enter, and if it is opened upward, rainwater can easily enter.

(Object of the Invention) The present invention has been made in view of such circumstances, and in spite of the fact that an intake air purifier is attached to a transmission case at the rear of the engine, cold air that is not affected by the heat of the engine is sucked in. In addition to improving the charging efficiency, it is possible to suppress fluctuations in the mixing ratio without being affected by the running wind to achieve stable engine operation and improve fuel efficiency, and to introduce outside air that guides outside air for cooling into the transmission case. It is an object of the present invention to provide an air intake device for a vehicle that makes it difficult for dust and rainwater to enter the mouth.

According to the present invention, an object of the present invention is to provide an engine, a transmission case that extends rearward from one side of the engine and accommodates a V-belt type transmission, and a rear wheel held at a rear portion of the transmission case. In a vehicle equipped with an integrated power unit, the front portion of the power unit being swingably connected to the vehicle body frame, and having an intake cleaner installed above the transmission case, the intake cleaner is opposite to the engine. An air intake port having a horizontal opening edge is provided on one side surface, and an outside air introduction port for guiding cooling air into the transmission case is provided in the transmission case so as to be directed rearward and forward from the intake port. On the other hand, a horizontal windbreak wall facing the intake air inlet and a vertical windbreak wall located in front of the windshield wall and the intake air inlet and above the outside air inlet are the intake cleaners. Integrated with the vessel It is achieved by the intake system of a vehicle characterized by being worn.

(Example) Hereinafter, the present invention will be described in detail based on an illumination surface.

FIG. 1 is a side view of a two-wheel scooter which is an embodiment of the present invention, and FIG. 2 is a partially sectional plan view of a developed power unit,
FIG. 3 is a side view of the same, partly in section. In FIG. 1, reference numeral 10 is a vehicle body frame, which includes a steering head tube 12, a down tube 14, and a back tube 16.
And so on. Steering shaft 1 held by head tube 12
8 has a front fork 20, a front wheel 22, and a steering handle 24.
Is installed.

A power unit 30 includes a forced air-cooled four-cycle single-cylinder engine 32, a transmission case 34 extending rearward from the left side surface of the engine 32, a V-belt continuously variable transmission 36 accommodated in the transmission case 34. , Transmission case 34
And a rear wheel 38 attached to the rear of the vehicle, which are integrated. The power unit 30 is vertically swingably connected by a bracket 40 (FIG. 1) pivot shaft 42, the front end of which is secured to the back tube 16. The rear of the transmission case 34 has a shock absorbing unit 44.
A unit swing suspension known in the art is formed by being elastically supported by the back tube 16 via.

At the right end of the horizontal crankshaft 46, the magneto generator 4 is installed.
8 is attached, and a fan 50 is fixed to a flywheel that holds the magnet of the generator 48. The fan 50 has an outside air intake 54 provided in the engine cover 52.
The outside air is sucked into the cover 52 to forcibly cool the engine 32. The cooling air for this engine is duct 56
Thus, it passes through the front of the pivot shaft 42 and is discharged below the pivot shaft 42. In FIG. 2, 58 is a piston, 60
Is an overhead camshaft, and 62 is a timing chain.

At the left end of the crankshaft 46, the V belt transmission 36
The drive side pulley 64 is attached. This pulley 6
4 is a movable pulley half 64a that slides on the crankshaft 46.
And a fixed pulley half 64b that is fixed to the end of the crankshaft 46 and faces the pulley half 64a. The movable pulley half body 64a slides on the crankshaft 46 in accordance with the rotation speed, so that the winding radius of the V-belt 66 wound between the half bodies 64a and 64b increases as the rotation speed increases. It has become. The rotation of the drive pulley 64 is transmitted to the rear wheel shaft 74 via the V belt 66, the driven pulley 68, the centrifugal clutch 70, and the reduction gear 72. The distance between the opposing pulley halves of the driven pulley 68 changes according to the change in the radius of the drive pulley 64 wound around the V belt 66.

Reference numeral 76 denotes an intake air purifier, which is attached to the upper surface of the transmission case 34. The intake air purifier 76 takes in outside air from an intake air intake port 78 having a horizontal opening edge that is directed downward from a left side surface thereof, that is, one side surface opposite to the engine 32, and introduces the outside air into the engine 32 via a carburetor 80. Guide the intake.
The exhaust pipe 82 of the engine 32 extends below the engine 32 through the side of the duct 56 and is connected to an exhaust silencer 84 located on the right side of the rear wheel 38 (FIG. 1).

A fan 86 is integrally formed on the outer side surface of the fixed pulley half 64b of the drive side pulley 64. An opening 88 is formed in the transmission case 34 at a position facing the fan 86.
Are formed. In FIGS. 2 and 3, 90 is an element support plate, 92 is an air purification element made of urethane foam or the like, and 94 is a cover material as an outside air introduction duct. The element support plate 90 prevents the element 92 from falling into the opening 88, and a large number of openings 90a are provided in a portion facing the opening 88. The peripheral edges of the support plate 90 and the element 92 are the outer surface of the transmission case 34 and the lid member 9
It is sandwiched between 4 and held. That is, a large number of elongated holes 90b are provided on the inner side of the peripheral edge of the support plate 90, the ribs 96 that engage with the elongated holes 90b are formed on the transmission case 34, and the ribs 98 facing the ribs 96 are formed on the lid member 94. It is provided. The outer peripheral edge of the element 92 is formed by these ribs 9.
Held between 6,98. In order to facilitate the mounting of the element 92, a plurality of pin-shaped protrusions for penetrating and holding the element 92 should be provided on the lid member 94, and the lid member 94 should be fixed by holding the element 92 in advance on this pin. The element 92 may be attached by. The lid member 94 has an outside air introduction port 100 that opens obliquely upward and rearward.
Are formed. An umbrella 102 is integrally formed on the left side surface of the case of the intake air purifier 76, and the outside air inlet 100
Is facing this umbrella 102. At the rear of the transmission case 34, an outlet 104 for the cooling air of the transmission device 36 is provided.

4 and 5 are a partial sectional side view and a plan sectional view of the intake cleaner 76, and FIGS. 6 and 7 are a sectional view taken along the line VI and VII-VII in FIG. As shown in FIGS. 4 and 5, this intake air purifier 76 is divided into left and right case halves 106, 1
08, and the element 110 is sandwiched between these mating surfaces. A duct 112 on the right case half 108
Is connected to which the vaporizer 80 is connected. Reference numeral 114 is a blow-by gas recirculation pipe.

The intake inlet 78 opens downward in the left case half 106, and the outside air sucked from the inlet 78 extends obliquely rearward and upward and makes an U-turn to the element 110. Be led to. Case half 10
At the lower part of 6, there is a rivet plate 120 which extends to the left side and faces downward so as to face the intake port 78.
It is fixed by 120. Also, this intake air intake 78
The rear wall 102a of the umbrella 102 is located in front of the.
The baffle plate 118 and the rear wall 102a act as a windbreak wall that prevents running wind from directly flowing into the intake intake 78. That is, the baffle plate 118 serves as a horizontal windshield that faces below the intake port 78. Further, the umbrella 102 is located in front of the baffle plate 118 and the intake port 78 and serves as a vertical windbreak wall for preventing traveling wind from entering the intake port 78.

In FIG. 1, reference numeral 122 is a vehicle body cover that covers the upper portion of the power unit 30, and 124 is a driving seat.

In this embodiment, since intake air is taken in from the side of the transmission case 34, warm air is not taken in by the engine 32 during traveling and when the vehicle is stopped, and the charging efficiency of the engine 32 is improved.
While the vehicle is traveling, the traveling wind passes laterally and downwardly of the transmission case 34, but the umbrella 102 and the binding plate 118 having a wind barrier function are located in front of and below the intake port 78. Does not enter the intake intake 78 directly. Further, when the power unit 30 swings up and down, a force is exerted on the intake intake 78 in the direction of pulling the intake air downward or pushing the intake air upward. The plate 118 suppresses the movement of the intake air. Therefore, the fluctuation of the intake air is not caused in the intake air purifier 76 due to the traveling wind or the movement of the air accompanying the vertical swing of the power unit 30, and the intake air flow passing through the carburetor 80 is stably changed. Is suppressed and, as a result, fuel consumption is improved. In this embodiment, the intake air that has entered through the intake air intake 78 is U-turned in the passage 116, so that the kinetic energy of the intake air is sufficiently absorbed and the effect of the present invention becomes more remarkable.

In the present embodiment, the umbrella 102 and the binding plate 118 are used as the windbreak wall, but the present invention is not limited to this, and the desired effect can be obtained even with only the baffle plate 118 facing the intake port 78.

(Effect of the Invention) As described above, according to the present invention, since the intake air intake of the intake air cleaner installed above the transmission case is provided on one side opposite to the engine, the heat of the engine located at the front of the transmission case can be prevented. Inspired air is not affected, and cold inhaled air can always be inhaled. Therefore, the filling efficiency of the engine is improved.

In addition, since the intake air intake is directed vertically, the wind does not directly enter, and there is a horizontal wind barrier facing the intake air intake and a vertical wind barrier in front of the wind intake wall and the intake air intake. Since the intake air cleaner is integrated with the intake air purifier, movement of air near the intake air intake due to running wind and vertical movement of the power unit does not change the air flow entering the intake air cleaner, and Since the distance between the inlet and the windbreak wall is always kept constant, the intake air flow through the fuel supply system such as the carburetor is stabilized. Therefore, the mixing ratio is stabilized, and the operation of the engine is stabilized. In addition, fuel efficiency can be improved at the same time.

Further, the outside air introduction port for guiding the cooling air into the transmission case is opened rearward in front of the intake port, and in the vertical direction,
Since the outside air intake is covered with the windbreak wall, there is an effect that rainwater and dust are less likely to enter the outside air inlet.

[Brief description of drawings]

FIG. 1 is a side view of an embodiment of the present invention, FIG. 2 is a developed plan view in which a part of a power unit is sectioned, FIG. 3 is a side view in which a part thereof is similarly sectioned, and FIGS. A partial sectional side view and a plan sectional view of the purifier, and FIGS. 6 and 7 are a sectional view taken along the arrow VI in FIG. 4 and a sectional view taken along the line VII-VII. 30 ... power unit, 32 ... engine, 34 ... transmission case, 38 ... rear wheel, 76 ... intake cleaner, 78 ... intake intake, 102a ... rear wall as windshield, 118 ... Jiyama board as a windbreak wall.

Claims (1)

[Claims] 1. A power unit comprising an engine, a transmission case extending rearward from one side of the engine and accommodating a V-belt type transmission, and a rear wheel held at a rear portion of the transmission case. In a vehicle in which a front portion of this power unit is swingably connected to a vehicle body frame and an intake air cleaner is mounted above the transmission case, the intake air cleaner has a horizontal opening on one side opposite to the engine. An intake inlet having an edge is provided, and an outside air introduction port for guiding cooling air into the transmission case is provided in the transmission case so as to be directed rearward and forward of the intake inlet,
A horizontal windbreak wall facing the intake air inlet and a vertical windbreak wall in front of the windshield wall and the intake air intake and above the outside air inlet are provided in the intake air purifier. An intake device for a vehicle, which is provided integrally.