JP3161463B2 - Scooter type vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[Object of the invention]

[0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scooter-type vehicle of a unit swing type engine having a V-belt continuously variable transmission mechanism having ventilation holes and exhaust holes for air cooling.

[0003]

2. Description of the Related Art Most scooter-type motorcycles include:
A unit swing type engine is adopted.

As is well known, a unit swing type engine supports a rear wheel at a rear end of a swing case connected to a crankcase of an engine portion and extending rearward. It is organized as one unit.

A unit swing type engine is generally
The pivot part below the engine part is pivotally supported at the center lower part of the body frame of the motorcycle, and the entire unit swing type engine swings up and down freely around the horizontal support shaft of the pivot part, and serves as a suspension arm for the rear wheel. Accomplish.

Most unit swing type engines are equipped with a simple and inexpensive V-belt continuously variable transmission mechanism in the swing case as a means for transmitting the power of the engine section to the rear wheels. The V-belt continuously variable transmission mechanism changes the effective ratio of the drive V-pulley and the driven V-pulley on which the V-belt is suspended depending on the number of revolutions, thereby changing the speed ratio.

In this method, the tension of the V-belt is increased and the V-pulley is strongly pressed to prevent the occurrence of power loss due to slippage between the V-belt and each V-pulley. Therefore, the frictional heat during operation is high and the V-belt is deteriorated by the heat if left unattended. In many unit swing type engines, the ventilation holes and exhaust holes are opened in the case cover attached to the outside of the swing case. The V-belt continuously variable transmission mechanism is air-cooled by forcibly introducing outside air into the swing case by a fan provided on the side of the drive V pulley.

[0008]

However, the case cover of the swing case described above is screwed to the case body of the swing case and integrally forms the swing case to secure rigidity. In such a swing case, the above-mentioned ventilation port and exhaust port have caused a reduction in rigidity.

In particular, the air outlet needs to be provided at the rearmost portion of the case cover. This position is close to the fixed portion of the rear shock absorber that absorbs the swinging shock of the rear wheel, and is a portion where a strong load is constantly transmitted. For this reason, the reduction in rigidity of the rear part of the swing case due to the presence of the air outlet has been compensated for by providing a large reinforcing rib near the rear shock absorber mounting portion of the case body.

[0010] By the way, at the time of casting the case body, the reinforcing ribs are located farther from the gate, so that the running of the molten metal is poor, which is a major cause of the occurrence of defects. Also,
There were adverse effects such as an increase in the weight of the swing case and a reduction in the appearance due to the reinforcing ribs.

Further, the exhaust port conventionally provided in the case cover has a simple structure and is not shaped to promote efficient exhaust.

The present invention has been made in view of such a problem. By using the exhaust port of the case cover as a reinforcing member of the swing case, the reinforcing ribs of the case body can be reduced in size, and the castability of the swing case and the castability of the swing case can be improved. It is an object of the present invention to provide a scooter-type vehicle equipped with a unit swing type engine with a V-belt cooling device capable of contributing to an improved appearance and efficiently discharging air.

[Configuration of the Invention]

[0014]

In order to achieve the above object, a scooter type vehicle according to a first aspect of the present invention comprises a crankshaft driving a drive V pulley of a V-belt continuously variable transmission mechanism and a crankshaft substantially horizontally disposed. An engine part, comprising a case main body and a case cover, a swing case for accommodating the crankshaft and the starting clutch at a required interval in the vehicle front-rear direction, and a bending part capable of vertical swing and having one end. A suction pipe fixed to the vehicle body side for sending outside air into the swing case, and a fan disposed on the drive V pulley and sucking outside air from the suction pipe from a central portion in a side view of the vehicle and blowing it in a centrifugal direction. An air cleaner for removing dust from outside air sucked into the swing case; and a starting clutch opposite to a rear axle shaft with respect to a V-belt. A scooter-type vehicle equipped with a unit swing type engine equipped with a V-belt cooling device, which is provided with an exhaust port disposed on the rear side of the vehicle, wherein a wall surface of the case cover between the crankshaft and the starting clutch is disposed in front of the case cover. The stepped portion is formed by projecting outward in the vehicle width direction as compared with the wall surface of the portion, and the ridgeline of the stepped portion intersects the outer peripheral profile of the fan in a side view of the vehicle, and the vehicle rear side in a plan view of the vehicle. The height of the wall of the front part of the case cover is made lower than the height of the rear part of the case cover, and the step part is provided with a wind guide port connected to the ridge line of the step part, and is connected to the wind guide port. The suction pipe and the horizontal support shaft that allows the unit swing type engine to swing up and down are mounted on the unit swing type at the front side of the case cover in a vehicle side view. The air outlet is disposed on both sides with respect to the center of the engine portion of the engine, and the outside air drawn into the swing case via the suction pipe is cooled rearward in the V-belt speed change mechanism, and then the exhaust port From the outside.

[0015]

A step is formed at the front of the case cover to narrow the gap between the fan and the fan, and a ventilation port is provided at the step, so that the amount of outside air sucked into the ventilation port can be increased. The amount of ventilation in the case cover can be increased. For this reason, the cooling efficiency of the V-belt continuously variable transmission mechanism including the V-belt cooled by the ventilation in the case cover can be improved.

Further, the width of the case cover in the vehicle width direction in a plan view of the vehicle is set such that the driven V pulley, the V belt, the starting clutch, etc. of the V-belt continuously variable transmission mechanism are behind the ridgeline of the stepped portion in the front-rear direction of the vehicle. The width of the rear part to be accommodated is formed to be wider than the width of the front part (step part) in front of the step part ridge line.

That is, even if the width of the front end of the swing case in a plan view of the vehicle is small, the rear side of the swing case receiving the load of the rear shock absorber has a wide structure, and the rear end has an exhaust port. The cooling air that is introduced from the suction pipe into the swing case and flows through the inside of the swing case from the front to the rear to cool the V-belt continuously variable transmission mechanism can easily flow smoothly from the exhaust port to the outside air. Efficiency is improved. For this reason, the ventilation efficiency in the swing case is improved, so that the cooling efficiency of the V-belt continuously variable transmission mechanism is improved.

Further, the ridgeline shape of the step portion at the front of the case cover is an arc shape expanding toward the vehicle rear side,
Since the shape intersects with the profile of the fan, the arc-shaped steps allow the cooling air blown from the fan to be guided from the front part to the rear part in the swing case so that the cooling air can be blown smoothly and efficiently. Therefore, the cooling air in the swing case is efficiently blown to the V-belt, the driven V-pulley, and the starting clutch, so that the cooling performance thereof can be further improved.

At the rear of the swing case, the required rigidity can be easily secured because the width in the vehicle plan view is large. On the other hand, by narrowing the width of the front end of the swing case where the load on the rear shock absorber is less likely to act, not only can the air blowing efficiency by the fan be increased, but also the width is reduced to reduce the load on the swing case itself. The so-called unsprung weight of the shock absorber can be reduced. For this reason, the magnitude of the reaction force to the swing case when an impact load is applied to the rear shock absorber can be made smaller than that of the swing case that is wide over substantially the entire length in the front-rear direction of the swing case. For this reason, from the viewpoint of the rigidity and strength of the swing case, the reinforcing ribs conventionally formed on the case body are not required, which is advantageous from the viewpoint of the rigidity and strength of the swing case.

Further, since the positions of the horizontal support shaft and the suction pipe of the unit swing type engine are distributed to both sides with respect to the center of the engine section, in the case of a small scooter type vehicle, the suction pipe is liable to be a problem in the vehicle configuration. It is possible to avoid interference between the piping and the vehicle body frame related to the engine suspension. That is, the suction pipe can be piped at an effective position while sufficiently securing the stroke of the rear shock absorber.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 shows a scooter type motorcycle equipped with a unit swing type engine equipped with a cooling device.

In the motorcycle 1, a suspension bracket 4 is provided on a pivot portion 3 at a lower center portion of the body frame 2.
, A unit swing type engine 5 is pivotally supported about its horizontal support shaft 6 so as to be vertically swingable. A rear wheel 7 is rotatably supported at the rear of the unit swing type engine 5.
Acts as a suspension arm. Here, the rear shock absorber mounting bracket 8 at the rear upper end of the unit swing type engine 5 and the vehicle body frame 2 are connected by a rear shock absorber 9, and the swinging shock of the rear wheel 7 is caused by the expansion and contraction of the rear shock absorber 9. Buffered.

FIG. 3 shows the unit swing type engine 5 described above.
FIG. 4 is a left side view showing the component configuration of FIG.

As shown in FIG. 3, in the unit swing type engine 5, a swing case 12 is connected to a crankcase 11 of an engine section 10 and extends rearward.

The swing case 12 includes a case body 13 integrated with the crankcase 11 and a case cover 14.
Are fixed by a plurality of fastening bosses 15, a case main body 13 has a V-belt continuously variable transmission mechanism 19 including a drive V pulley 16, a driven V pulley 17, and a V-belt 18, a starting clutch 20, The transmission mechanism 21 is mounted on a shaft. The deceleration transmission mechanism 21 is mounted in a transmission chamber 24 including a transmission case 22 formed on the rear wheel 7 side of the rearmost part of the case body 13 and a transmission cover 23 that is mounted on the transmission case 22 in a liquid-tight manner. , Is always immersed in oil. On the other hand, the case cover 14 mounted on the case body 13 isolates the mechanisms mounted on the case body 13 from the outside air.

In the unit swing type engine 5, a piston 26 reciprocating in a cylinder 25 of the engine section 10 is provided.
Movement of the crankshaft 2 via the connecting rod 27
8 and converted into a rotational motion. The rotation of the crankshaft 28, one end of which protrudes into the inside of the swing case 12, is transmitted to the driven shaft 29 via the V-belt continuously variable transmission mechanism 19 and the starting clutch 20, and is decelerated by the reduction transmission mechanism 21 to rotate the rear axle shaft 30. The rear wheel 7 inserted into the free end of the rear axle shaft 30 is driven.

As shown in FIGS. 3 and 4, the case cover 14 extends the wall surface 14a between the starting clutch 20 and the crankshaft 28 outside the front wall surface 14b in front of the crankshaft 28 in the vehicle width direction. As a result, a stepped portion 14c is formed on the front wall surface 14b, and a ventilation passage gap with a part of the fan 33 inside the stepped portion 14c is formed narrow. Therefore, the width of the swing case 12 along the vehicle width direction in the vehicle plan view shown in FIG. 3 is wider on the rear side in the vehicle front-rear direction than on the ridgeline of the step portion 14 than in the step portion 14. It is formed as follows. Further, as shown in the vehicle side view of FIGS. 2 and 4, the ridge line at the boundary of the step portion 14 intersects with the center of the outer peripheral profile of the fan 33, and the ridge line of the step portion 14 faces the rear portion of the swing case 12. Because of the expanding arc shape, the air from the fan 33 is
The air can be efficiently blown to the rear along the arcuate curved surface of the ridgeline c.

The case cover 14 has an air introduction port 31 and an exhaust port 32. Vent 31 is drive V
It is located right beside the fan 33 that rotates integrally with the pulley 16,
As shown in FIG. 4, a suction pipe 34 and an air cleaner 35 fixed to the vehicle body frame 2 are sequentially inserted into the air guide port 31 and fixed by a fixing band 36. Inside the air cleaner 35, a cleaner element 37 is contained.
In other words, the arrangement positions of the suction pipe 34 and the horizontal support shaft 6 are distributed upward and downward with respect to the center of the engine unit 10 in the vehicle height direction. Therefore, interference between the suction pipe 34 and the vehicle body frame 2 can be prevented. The exhaust port 32 is located substantially below the rear of the case cover 14 and extends substantially in line with the rear shock absorber 9.
It is, for example, a square sleeve shape extending downward from the inside and going out to the outside. As shown in FIGS. 4 and 1, the upper end of the air outlet 32 and the outer peripheral wall surface of the case cover 14 are connected by a rib-like reinforcing wall 38. A portion where the reinforcing wall 38 is connected to the case cover 14 is a knock pin 39 for accurately positioning the case body 13 and the case cover 14.
Is buried. The knock pins 39 are half-fitted into the case body 13 and the case cover 14, respectively, and are usually arranged at one place before and after the swing case.

Meanwhile, the swing case 12 needs to have a sealed structure for preventing intrusion of water and dust in order to protect the mechanisms housed inside. For this reason, the case body 13
A thin gasket 40 is sandwiched between the cover 13 and the case cover 13. This gasket 40 is cut in the same shape as the contact surface between the case body 13 and the case cover 14 as shown by a two-dot chain line in FIG. 4, but only at the upper part of the exhaust port 32 at the rearmost part of the case cover 14. , Gradually projecting from the top toward the upper end of the air outlet 32 into the inside of the swing case 12, and this portion serves as a rectifying plate 41.

When the motorcycle 1 is running, the fan 33 rotates integrally with the drive V pulley 16, so that the space around the fan 33 in the swing case 12 becomes a negative pressure, and the outside air is sucked into the suction port of the suction pipe 34. From the suction pipe 3, and after the dust is removed by the air cleaner 35.
4, enters the swing case 12 from the air guide port 31, and moves rearward as shown by the arrow in FIG. 4. The drive V pulley 16, the driven V pulley 17, and the V belt 18, which are heated by the friction during operation, After air-cooling, the air is discharged from the air outlet 32 to the outside. At this time, as described above, when the cooling air is blown from the front part to the rear part in the swing case 12, the width of the swing case 12 along the vehicle width direction is changed to the front part where the step part 14c of the swing case 12 is provided. Since it is wider at the rear, the air blowing efficiency from the front to the rear is improved. A rectifying plate 41 of the swing case 12 in which the above-described reinforcing plate 38 and gasket 40 protrude.
Accordingly, the air is smoothly guided to the exhaust port 32. Therefore, the cooling efficiency in the swing case 12 is improved, and the durability of the V-belt continuously variable transmission mechanism 19 is increased.

Further, since the stepped portion 14c of the case cover 14 narrows the ventilation gap with a part of the fan 33,
To that extent, the negative pressure in the ventilation gap can be increased,
The suction efficiency of sucking outside air into the swing case 12 through the suction pipe 34 can be improved. For this,
Since the amount of air that is sucked into the swing case 12 and ventilated can be increased, the belt continuously variable transmission mechanism 19
The ventilation cooling efficiency can be improved.

The swing case 12 having such a structure
During the operation of the motorcycle 1, the rear wheel 7 swings and the reaction force F of the rear shock absorber 9 is reduced as shown in FIG.
When the force F is transmitted to the case body 13 through the shock absorber mounting bracket 8, the force F is applied to the knock pin 39 around the outer peripheral wall surface of the case body 13. Knock pin 39 is the reaction force F because it is inserted so as to be sandwiched in the case body 13 and Kesukaba 14 dispersed in both the case body 13 and Kesukaba 14 becomes F ₁ and F _2. Force F ₂ applied to Kesukaba 14 side is transmitted to the air discharge port 32 through the reinforcing wall 38, the exhaust outlet 32 has a sleeve-shaped penetrating the Kesukaba 14 up and down, and on approximately the extension of the rear shock absorber 9 because it is arranged, the received force F ₂ is uniformly dispersed into the sides and bottom of Kesukaba 14, to reduce the force F ₁ applied to the case body 13.

For this reason, the case body 13 in which the reaction force F of the rear shock absorber 9 has been applied to the prior art
Has been reinforced by large reinforcing ribs A and B. However, the practice of the present invention has reduced the size of the reinforcing ribs so that the reinforcing ribs need only be shaped like 42 in FIG. As a result, the castability of the case main body is greatly improved, the cost is reduced, and the swing case 12 looks small, which is advantageous in appearance.

[0035]

As described above, according to the present invention, a step is formed at the front portion of the case cover to reduce the gap between the fan and the fan, and a ventilation port is provided at the step. By increasing the amount of outside air to be sucked, the amount of air flow inside the case cover can be increased. For this reason, the cooling efficiency of the V-belt continuously variable transmission mechanism including the V-belt cooled by the ventilation in the case cover can be improved.

The width of the case cover in the vehicle width direction in a plan view of the vehicle is set such that the driven V pulley, the V belt, the starting clutch, etc. of the V-belt continuously variable transmission mechanism are behind the ridgeline of the stepped portion in the front-rear direction of the vehicle. The width of the rear part to be accommodated is formed to be wider than the width of the front part (step part) in front of the step part ridge line.

That is, even if the width of the front end of the swing case in a plan view of the vehicle is small, the width of the rear side of the swing case receiving the load of the rear shock absorber is wide, and the rear end has an exhaust port. The cooling air that is introduced from the suction pipe into the swing case and flows through the inside of the swing case from the front to the rear to cool the V-belt continuously variable transmission mechanism can easily flow smoothly from the exhaust port to the outside air. Efficiency is improved. For this reason, the ventilation efficiency in the swing case is improved, so that the cooling efficiency of the V-belt continuously variable transmission mechanism is improved.

Further, the ridge shape of the step portion at the front of the case cover is an arc shape expanding toward the vehicle rear side,
Since the shape intersects with the profile of the fan, the arc-shaped steps allow the cooling air blown from the fan to be guided from the front part to the rear part in the swing case so that the cooling air can be blown smoothly and efficiently. Therefore, the cooling air in the swing case is efficiently blown to the V-belt, the driven V-pulley, and the starting clutch, so that the cooling performance thereof can be further improved.

At the front portion of the swing case, the required rigidity is easily secured because the width in the vehicle plan view is large. On the other hand, by narrowing the width of the front end of the swing case where the load on the rear shock absorber is less likely to act, not only can the air blowing efficiency by the fan be increased, but also the width is reduced to reduce the load on the swing case itself. The so-called unsprung weight of the shock absorber can be reduced. Therefore, the magnitude of the reaction force to the swing case when an impact load is applied to the rear shock absorber can be made smaller than that of a swing case having a wide width. For this reason, from the viewpoint of the rigidity and strength of the swing case, the reinforcing ribs conventionally formed on the case body are not required, which is advantageous from the viewpoint of the rigidity and strength of the swing case.

Further, since the positions of the horizontal support shaft and the suction pipe of the unit swing type engine are distributed to both sides with respect to the center of the engine section, in the case of a small scooter type vehicle, the suction pipe is liable to be a problem in the vehicle configuration. It is possible to avoid interference between the piping and the vehicle body frame related to the engine suspension. That is, the suction pipe can be piped at an effective position while sufficiently securing the stroke of the rear shock absorber.

[Brief description of the drawings]

FIG. 1 is a perspective sectional view showing one embodiment of a swing case structure of a unit swing type engine according to the present invention.

FIG. 2 is a side view of a scooter type motorcycle equipped with a unit swing type engine.

FIG. 3 is a plan sectional view of a unit swing type engine employing the present invention.

FIG. 4 is a left side view of the unit swing type engine shown in FIG. 3;

[Explanation of symbols]

 Reference Signs List 5 unit swinging type engine 7 rear wheel 9 rear shock absorber 10 engine unit 11 crankcase 12 swing case 13 case body 14 case cover 19 V-belt continuously variable transmission mechanism 31 air guide port 32 exhaust port 38 reinforcing wall 40 gasket 41 rectifying plate

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) B62J 39/00 B62K 11/10 B62M 9/08 F16H 57/04

Claims (1)

(57) [Claims] 1. A crankshaft for driving a drive V-pulley of a V-belt continuously variable transmission mechanism, an engine part arranged substantially horizontally, a case body and a case cover, and the crankshaft and the starting clutch are connected in the vehicle longitudinal direction. A swing case for accommodating at a required interval, a suction pipe having a bent portion capable of swinging up and down and having one end fixed to the vehicle body side to send outside air into the swing case, and a drive V pulley. A fan for sucking outside air from the suction pipe from a central portion as viewed from the side of the vehicle and blowing it in a centrifugal direction; an air cleaner for removing outside air sucked into the swing case; and a rear axle shaft for the V belt And a discharge port disposed on the opposite side of the starting clutch and on the rear side of the vehicle with respect to the starting clutch. In a scooter-type vehicle equipped with a clutch type engine, a step portion is formed by projecting a wall surface of the swing case between the crankshaft and the starting clutch outward in a vehicle width direction as compared with a wall surface of a front portion of the case cover,
The ridgeline of this step portion intersects the outer peripheral profile of the fan when viewed from the side of the vehicle, and is formed to have a shape that expands toward the rear of the vehicle when viewed from the top of the vehicle. A horizontal support shaft which is disposed on the step portion and which is connected to a ridge line of the step portion, and which allows the unit swing type engine to vertically swing with the suction pipe connected to the air guide port. Are arranged on both sides at the front side of the case cover with respect to the center of the engine unit of the unit swing type engine when viewed from the side of the vehicle, and the outside air sucked into the swing case via the suction pipe. Scooter equipped with a unit swing type engine with a V-belt cooling device, which cools the V-belt continuously variable transmission mechanism toward the rear and discharges it to the outside through the exhaust port. Both.