JP4675171B2 - Belt type continuously variable transmission - Google Patents

Description

  The present invention relates to a belt-type continuously variable transmission mounted on a motorcycle, a three-wheeled vehicle, and the like, and more particularly, to a structure of an exhaust passage that releases heat in a transmission case and cools a belt.

As an exhaust passage provided in a transmission case in this type of belt-type continuously variable transmission, there is an example (Patent Document 1) which has been patented in a prior application related to the same applicant.
Japanese Patent No. 3212625

The exhaust passage of the belt-type continuously variable transmission described in Patent Document 1 includes a cap that extends in the vertical direction in the transmission case, communicates with the lower portion of the transmission case, and opens downward. The part is provided in a louver shape and covers the opening.
Therefore, the cooling air that cools the belt in the transmission case passes through the exhaust passage and is discharged to the outside through the cap opening at the lower part of the transmission case.

  A plate-like part is provided in the cap opening at the bottom of the transmission case in the shape of a louver, so the water splashed by the front wheel during traveling strikes the lower surface of the transmission case and strikes the exhaust passage, and further It is possible to prevent the belt slip from occurring in the case.

  However, if the vehicle travels in a puddle and the transmission case is immersed in the puddle, water may enter the exhaust passage from the cap opening and may enter the transmission case.

  The present invention has been made in view of the above points, and the object of the present invention is that water enters the transmission case from the exhaust passage even if the vehicle travels in a puddle and the transmission case is continuously immersed in water. This is in providing a belt-type continuously variable transmission that can prevent this.

In order to achieve the above object, according to the first aspect of the present invention, the power of the internal combustion engine can be shifted by changing the winding diameter of the belt covered with the transmission case and spanned between the driving pulley and the driven pulley. In the belt-type continuously variable transmission that transmits to the transmission case, a cylindrical exhaust passage that is elongated in the transmission case and that is substantially vertically oriented opens the upper end in the transmission case and the lower end to the outside. A belt type in which a first water preventing plate is provided at a lower end portion of the exhaust passage, and a second water preventing plate is provided above an intermediate portion in the vertical direction of the exhaust passage. A continuously variable transmission was adopted.

  According to a second aspect of the present invention, in the belt-type continuously variable transmission according to the first aspect, a float valve is provided above the exhaust passage.

According to a fourth aspect of the present invention, in the belt type continuously variable transmission according to the first aspect, a flap valve is provided at an upper end portion of the exhaust passage.

According to a fifth aspect of the present invention, the driven pulley shaft of the driven pulley is disposed above a plane including the crankshaft of the internal combustion engine and the rear axle of the rear wheel, and the upper end thereof is oriented substantially vertically. The belt-type continuously variable transmission according to claim 1 , wherein an exhaust passage having an opening in the transmission case and having a lower end opened to the outside is provided in the vicinity of the driven pulley of the transmission case.

According to a sixth aspect of the present invention, in the belt-type continuously variable transmission according to the fourth aspect, the upper end opening of the exhaust passage is located above the upper end of the drive pulley.

According to the belt-type continuously variable transmission according to claim 1, the cylindrical air exhaust passage that is long in the transmission case and is substantially vertically oriented has a first water prevention plate at the lower end. And a second water-prevention plate is provided above the middle part in the vertical direction, so even if the vehicle travels in a deep pool and the transmission case is temporarily immersed in the pool, It is possible to delay the progress of the water that attempts to pass through the passage, and consequently to prevent entry into the transmission case.

  According to the belt type continuously variable transmission according to claim 2, since the float valve is provided in the upper part of the exhaust air passage, when the water enters the exhaust air passage, the float valve is operated and the upper part of the exhaust air passage is Since it is closed, water can be reliably prevented from entering the transmission case.

According to the belt type continuously variable transmission according to claim 4 , since the flap valve is provided at the upper end portion of the exhaust passage, when the water enters the exhaust passage to the upper part, the flap valve is operated and the exhaust passage. Since the upper end part of this is closed, it is possible to reliably prevent water from entering the transmission case.

According to the belt type continuously variable transmission according to claim 5, the upper end of the belt type continuously variable transmission is directed substantially vertically in the vicinity of the driven pulley having the driven pulley shaft disposed above the plane including the crankshaft and the rear axle. Is provided in the transmission case and the lower end is opened to the outside, so the upper end opening of the exhaust passage is at a high position in the transmission case, the vehicle runs in a deep water pool, and the transmission case Even if it is temporarily immersed in water and water enters the exhaust passage, it is possible to make it difficult for water to enter the transmission case.

According to the belt-type continuously variable transmission according to claim 6, since the upper end opening of the exhaust passage is located above the upper end of the drive pulley, water can enter the transmission case even when traveling in a deeper water pool. Can be difficult.

Hereinafter, an embodiment according to the present invention will be described with reference to FIGS.
FIG. 1 is a side view of a scooter type motorcycle 1 according to an embodiment to which the present invention is applied.
The vehicle body front portion 2 and the vehicle body rear portion 3 are connected via a low floor portion 4, and the vehicle body frame forming the skeleton of the vehicle body is generally composed of a down tube 6 and a main pipe 7.

  That is, the down tube 6 extends downward from the head pipe 5 at the vehicle body front portion 2, the down tube 6 is bent horizontally at the lower end and extends rearward below the floor portion 4, and a pair of left and right main pipes 7 at the rear end. The main pipe 7 rises diagonally rearward from the connecting portion, bends horizontally at a predetermined height, and extends rearward.

A fuel tank and a storage box are supported by the main pipe 7, and a seat 8 is disposed above the fuel tank and the storage box.
On the other hand, in the front part 2 of the vehicle body, a handle 11 is provided above and supported by the head pipe 5, and a front fork 12 extends downward and a front wheel 13 is supported at the lower end thereof.

  A bracket 15 projects from the lower end of the rising portion of the main pipe 7, and a swing unit 17 is swingably connected to the bracket 15 via a link member 16.

  The swing unit 17 is mounted with a single-cylinder four-stroke cycle internal combustion engine 30 at the front of the swing unit 17 in a posture in which the cylinder block 32 is largely inclined to a substantially horizontal state. An end portion of a hanger bracket 18 projecting forward from the lower end of the corresponding portion is connected to the link member 16 via a pivot shaft 19.

The belt-type continuously variable transmission 35 is configured from the internal combustion engine 30 to the rear, and the rear wheel 21 is pivotally supported by a speed reduction mechanism 38 provided at a rear portion thereof.
A rear cushion 22 is interposed between the upper end of the speed reduction mechanism 38 and the upper bent portion of the main pipe 7.

An upper part of the swing unit 17 is provided with a carburetor 24 connected to an intake pipe 23 extending from an upper part of a cylinder head 33 of the internal combustion engine 30 and an air cleaner 25 connected to the carburetor 24.
On the other hand, a main stand 26 is pivotally attached to the hanger bracket 18 projecting from the lower part of the unit swing case 31, and a kick arm 28 is attached to a kick shaft 27 protruding from the transmission case cover 36 of the belt type continuously variable transmission 35. The kick pedal 29 is provided at the tip of the kick arm 28.

The front part 2 of the vehicle body is covered from the front and rear by the front cover 9a and the rear cover 9b from the left and right sides by the front lower cover 9c, and the center part of the handle 11 is covered by the handle cover 9d.
The floor portion 4 is covered with a side cover 9e, and the vehicle body rear portion 3 is covered with a body cover 10a and a tail side cover 10b from the left and right sides.

FIG. 2 is a cross-sectional view of the swing unit 17 which is cut and developed along the line II-II in FIG.
The unit swing case 31 is configured by combining a left unit case 31L and a right unit case 31R which are divided into left and right parts. The right unit case 31R forms a half of a crankcase part, and the left unit case 31L is It consists of a front and rear crankcase portion 31a, a central transmission case portion 31b, and a rear reduction gear case portion 31c.

Left open face of the left unit case 31L is covered by the transmission case cover 36 which is a part of the transmission case, the inside belt type continuously variable transmission 35 is accommodated in the right opening side of the rear of the reducer casing section 31c Is covered with a speed reducer case 37, and a speed reduction mechanism 38 is accommodated therein.

  In the so-called crankcase of the crankcase portion 31a and the right unit case 31R, the crankshaft 40 is rotatably supported by the left and right main bearings 41, 41, and the right extension of the extension portions extending in the left-right horizontal direction is provided. An AC generator 60 is provided in the part, and a cam chain drive sprocket 55 and a belt drive pulley 76 of the belt type continuously variable transmission 35 are provided in the left extension part.

In the internal combustion engine 30, a connecting rod 43 connects a piston 42 that reciprocates in a cylinder liner 44 of a cylinder block 32 and a crank pin 40 a of a crankshaft 40.
The four-cycle internal combustion engine 30 employs an SOHC type valve system. A valve mechanism 50 is provided in the cylinder head cover 34, and a cam chain 51 that transmits drive to the valve mechanism 50 includes a camshaft 53. The cam chain chamber 52 is provided in communication with the crankcase portion 31a, the cylinder block 32, and the cylinder head 33.

That is, the cam chain 51 passes through the cam chain chamber 52 between the driven sprocket 54 fitted to the left end of the camshaft 53 oriented in the horizontal direction and the drive sprocket 55 fitted to the crankshaft 40. It is being transported.
In the cylinder head 33, a spark plug 45 is fitted from the opposite side (right side) of the cam chain chamber 52 toward the combustion chamber.

  As shown in FIG. 3, the valve mechanism 50 in the cylinder head cover 34 is largely inclined forward to a state in which the cylinder is almost horizontal, so that an intake valve 56 and an exhaust valve 57 are disposed above and below the camshaft 53. Rocker arms 59, 59 are pivotally attached to the upper and lower rocker shafts 58, 58, respectively, and the rocker arms 59, 59 are swung by the rotation of the cam of the camshaft 53. The exhaust valve 57 is opened and closed.

The AC generator 60 provided on the right side surface of the right unit case 31R has a bowl-shaped outer rotor 62 fixed to the end of the crankshaft 40 protruding from the central cylindrical portion 31d of the right unit case 31R via an ACG boss 61. A stator 64 around which a stator coil 65 is wound is fixed to the central cylindrical portion 31d inside a magnet 63 disposed on the inner peripheral surface in the circumferential direction.
A forced air cooling fan 66 is attached to the right side surface of the outer rotor 62, and a fan cover covers the side thereof.

  On the other hand, the cam chain chamber 52 is formed in the crankcase portion 31a of the unit swing case 31 so as to be separated from the crank chamber by the main bearing 41, and the left side wall of the cam chain chamber 52 is further provided with a belt type non-left side. A partition wall 71 that partitions the step transmission chamber 70 and the cam chain chamber 52. A circular through hole 71a having a large-diameter flat cylindrical shape through which the crankshaft 40 penetrates is formed in the partition wall 71, and the through hole 71a An annular seal member 72 is press-fitted into the annular seal member 72, and the crankshaft 40 passes through the hollow portion of the annular seal member 72.

The drive sprocket 55 is fitted on the crankshaft 40 between the seal member 72 and the main bearing 41, and the cam chain 51 is wound around the drive sprocket 55.
This seal member 72 partitions the belt-type continuously variable transmission chamber 70 from the cam chain chamber 52 in a watertight manner to prevent oil from leaking into the belt-type continuously variable transmission chamber 70.
A belt drive pulley 76 is rotatably provided on the crankshaft 40 extending through the seal member 72.

  The belt drive pulley 76 includes a fixed pulley half 77 and a movable pulley half 78. The fixed pulley half 77 is fixed to the left end of the crankshaft 40 via a boss 79 and is movable to the right side thereof. The side pulley half 78 is slidably fitted to the crankshaft 40. The movable pulley half 78 rotates with the crankshaft 40 and slides in the axial direction to approach the fixed pulley half 77. The V belt 75 is sandwiched between the pulley halves 77 and 78 and can be wound.

Referring to FIG. 4, a cam plate 80 is provided at a fixed position near the annular seal member 72 on the right side of the movable pulley half 78, and a slide piece 80a provided at the outer peripheral end thereof is connected to the movable pulley. The half plate 78 is slidably engaged with a cam plate sliding boss portion 78a formed in the axial direction at the outer peripheral end of the half body 78.
The side surface of the movable pulley half 78 on the cam plate 80 side is tapered toward the cam plate 80 side, and a dry weight roller 81 is accommodated between the cam plate 80 inside the tapered surface.

  Accordingly, when the rotational speed of the crankshaft 40 increases, the dry weight roller 81 that rotates between the movable pulley half 78 and the cam plate 80 moves in the centrifugal direction due to centrifugal force, and the movable pulley half 78 moves in the same direction. It is pressed by the weight roller 81 and moves to the left to approach the stationary pulley half 77 and moves the V belt 75 sandwiched between the pulley halves 77 and 78 in the centrifugal direction to increase the winding diameter. It is configured as follows.

The rear belt driven pulley 86 corresponding to the belt driving pulley 76 has a stationary pulley half 87 fitted to an inner sleeve 89 that is supported so as to be rotatable relative to the speed reducer input shaft 92 of the speed reduction mechanism 38. A movable pulley half 88 is fitted to an outer sleeve 90 that is slidably supported in the axial direction on the inner sleeve 89 on the left side of the fixed pulley half 87. ing.
The V belt 75 is sandwiched between the pulley halves 87 and 88.

A centrifugal clutch 91 is provided on the left side of the speed reducer input shaft 92 and the inner sleeve 89. When the rotational speed of the power transmitted to the inner sleeve 89 via the V belt 75 increases, the centrifugal clutch 91 is joined. Is transmitted to the reduction gear input shaft 92.
The speed reduction mechanism 38 transmits the power transmitted to the speed reducer input shaft 92 to the output shaft 94 through the intermediate shaft 93 while reducing the speed by meshing the gears, and the output shaft 94 is the rear wheel 21 axle. This is the rear axle that rotates 21.
A drum brake 95 is provided on the hub portion of the rear wheel 21.

  A transmission case cover 36 covering the belt type continuously variable transmission chamber 70 from the left side covers the belt drive pulley 76 on the front side and the centrifugal clutch 91 on the rear side, and the kick shaft 27 is rotatable slightly forward from the center. A drive helical gear 100 is fitted to the inner end of the kick shaft 27 and is urged by a return spring 101.

Referring to FIG. 4, a sliding shaft 102 is supported on the inner surface of the front portion of the transmission case cover 36 coaxially with the crankshaft 40 so as to be rotatable and slidable in the axial direction. A driven helical gear 103 is formed and meshed with the drive helical gear 100, and a ratchet wheel 104 is fixed to the right end, and the whole is biased to the left by a friction spring 105.
On the other hand, a ratchet 79 a is formed on the boss 79 on the crankshaft 40 side so as to face the ratchet wheel 104 , and both can be brought into contact with and separated from each other by sliding of the slide shaft 102.

  Therefore, when the kick pedal 29 is depressed and the kick shaft 27 rotates against the return spring 101 via the kick arm 28, the driving helical gear 100 rotates together with the kick shaft 27, and the driven helical gear 103 meshing with the driven helical gear 103 is While rotating integrally with the sliding shaft 102, it slides to the right against the friction spring 105, and the ratchet wheel 104 meshes with the ratchet 79 a of the boss 79 to forcibly rotate the crankshaft 40 to cause the internal combustion engine 30 to rotate. Can be started.

  On the other hand, in this internal combustion engine, a starter motor 110 is disposed above the crankcase portion 31a of the left unit case 31L. As shown in FIG. 4, the starter motor 110 is surrounded by a magnet 111 of the outer stator. A pinion 113 wound with the coil 112 of the inner rotor protrudes to the left, and a gear 113a is formed at the end of the pinion 113.

  A jumping gear mechanism 115 sandwiched between the crankcase portion 31a and the transmission case cover 36 is provided between the starter motor 110 and the belt driving pulley 76 with the shaft oriented in the horizontal direction. When the input gear 116 on the right side of the gear mechanism 115 is engaged with the pinion gear 113a of the starter motor 110, and the left jumping gear 117 on the left side jumps out to the left, the startering gear 77a formed on the outer peripheral edge of the stationary pulley half 77. Engage with.

Therefore, when the starter motor 110 is driven, the rotation of the pinion 113 is transmitted to the input gear 116 of the jumping gear mechanism 115, and the jumping gear 117 jumps to the left and engages with the startering gear 77a of the fixed pulley half 77, thereby fixing the fixed pulley. The internal combustion engine 30 can be started by rotating the half body 77 together with the crankshaft 40.
When the starter motor 110 is stopped, the dive gear 117 is disengaged from the retraction starter gear 77a.

  The fixed pulley half 77 having the startering gear 77a that receives the engagement of the jumping gear 117 has a rubber cooling fan 118 attached to the side surface (left side surface) opposite to the side surface sandwiching the V-belt 75 by rubber baking. The belt type continuously variable transmission 35 is cooled by the rotation of the cooling fan 118.

  As shown in the inner view of the transmission case cover 36 in FIG. 5 (also refer to FIGS. 2 and 6), the transmission case cover 36 constituting the belt type continuously variable transmission chamber 70 is substantially in the front-rear direction. A rectangular cylindrical air discharge passage 121 is formed between the belt driving pulley 76 and the belt driven pulley 86 at the center and slightly inclined toward the belt inner surface of the side wall near the belt driven pulley 86 so as to be slightly inclined in the vertical direction. ing.

The exhaust passage 121 has an upper end opening 121t opened in a belt-type continuously variable transmission chamber 70 covered with a transmission case , and a lower end opening 121b opened to the outside, and is generated by the rotation of the cooling fan 118. The cooling air cools the belt-type continuously variable transmission 35 and removes heat, and then is discharged to the outside through the exhaust air passage 121.

This exhaust passage 121 extends obliquely rearward downward from the upper end opened in the belt type continuously variable transmission chamber 70 and has a lower end opening 121b on the lower wall of the transmission case cover 36 and is open to the outside. .
The inclined exhaust passage 121 is formed in a rectangular cylindrical shape by the front, rear, left and right wall surfaces, and a lower end opening 121b is provided with a first water prevention plate 122 projecting substantially horizontally from the front wall surface to the rear. The front side of 121b is covered about half and the rear side is opened to serve as an outlet for cooling air.

The substantially horizontal lower surface of the first water-preventing plate 122 can prevent the water splashed by the front wheel 13 during traveling from entering the exhaust passage 121.

Further, the exhaust passage 121 is provided with a pair of upper and lower second water entry preventing plates 123 and 124 that are located above the middle portion in the vertical direction.
The lower second water prevention plate 123 is sandwiched between the left and right walls and protrudes obliquely downward from the rear wall surface, leaving a required gap between the front wall surface and the upper second water prevention plate 124. Is sandwiched between the left and right walls and protrudes obliquely downward from the front wall surface, leaving a required gap between the rear wall surface and the lower second water-preventing plate 123.

Accordingly, in the exhaust passage 121, the second water preventing plates 123 and 124 and the first water preventing plate 122 protrude into the passage, but the upper end opening 121t and the lower end opening 121b communicate with each other, and the belt type The cooling air in the continuously variable transmission chamber 70 can be discharged to the outside.
The first water preventing plate 122 and the second water preventing plates 123 and 124 can be fixed by welding or screwing in the exhaust passage 121 that has been punched out by a mold.

  Thus, since the pair of upper and lower second water entry prevention plates 123 and 124 are provided so as to protrude above the intermediate portion in the vertical direction of the exhaust passage 121 so as to form a labyrinth structure, the scooter type motorcycle 1 Travels in a deep water pool, even if the unit swing case 31 is temporarily immersed in the water pool, the progress of the water passing through the exhaust passage 121 is delayed, and as a result, the belt type continuously variable transmission chamber 70 is The intrusion can be prevented, and the occurrence of belt slip due to the ingress of water can be avoided.

Next, another embodiment will be described with reference to FIG.
FIG. 7 is an inner surface view of the transmission case cover 130, which basically has the same structure as the transmission case cover 36, and includes an exhaust passage 131, a first water prevention plate 132, and a second water prevention plate. 133 and 134 have the same shape as the exhaust passage 121, the first water preventing plate 122, and the second water preventing plates 123 and 124.

The upper end opening 131t of the exhaust passage 131 is narrowed by the projecting portion 135 toward the center to form a circular opening. The projecting portion 135 of the exhaust passage 131 and the upper second water preventing plate 134 are A ball-like float valve 136 is loosely fitted between them.
The diameter of the float valve 136 is larger than the diameter of the circular upper end opening 131t formed by the protruding portion 135.

  Therefore, even if the unit swing case is temporarily immersed in the water pool and the exhaust passage 131 water enters, the float valve 136 rises and closes the upper end opening 131t, so that the water into the belt type continuously variable transmission chamber 70 is blocked. Intrusion can be reliably prevented.

  In the case of the present embodiment, the elastic material 137 is coated on the upper surface of the upper second water prevention plate 134 and the inner surface of the wind passage 131 above the second water prevention plate 134, Even if the float valve 136 jumps in the exhaust passage 131 due to vibration, noise can be prevented.

Further, as shown in FIG. 8, a flap valve 146 may be provided in the upper end opening 131t instead of the float valve 136.
The flap valve 146 is pivotally supported by a support shaft 147 at the upper end of the front wall of the exhaust passage 131 so that it can swing freely. When entering, it floats on the water surface and swings upward to close the upper end opening 131t, so that it is possible to prevent water from entering the belt type continuously variable transmission chamber 70.

Next, another embodiment will be described with reference to FIGS.
The unit swing case 150 according to the present embodiment differs from the unit swing case 31 of the above embodiment in the shape of the rear part, and is otherwise exactly the same.

That is, the driven pulley shaft (reduction gear input shaft) 152 of the belt driven pulley is disposed above the plane h including the crankshaft 151 and the rear axle (output shaft) 154 that pivotally supports the rear wheel.
Therefore, the rear part of the unit swing case 150 has a shape that slightly bulges upward.
The intermediate shaft 153 of the speed reducer is substantially on the plane h.

  The transmission case cover 160 covering the left open surface of the unit swing case 150 is also shaped to slightly bulge upward, and is above the plane h passing through the shaft hole 161 facing the crankshaft 151 as shown in FIG. A circular hole 162 is formed opposite the driven pulley shaft 152.

In the transmission case cover 160, a wind passage 165 is inclined slightly obliquely in the vertical direction along the inner wall of the side wall in the vicinity of the driven pulley 172 (indicated by a one-dot chain line in FIG. 10) at the approximate center in the front-rear direction. The bulge is formed.

The air exhaust passage 165 extends upward to the bulging portion above the transmission case cover 160, and the upper end of the front wall 165f is curved in the backward direction and smoothly contacts the upper wall of the transmission case cover 160 so that the upper end opening 165t is high. The belt type continuously variable transmission is open in the room.
Therefore, the upper end opening 165t of the exhaust passage 165 is located above the upper end of the drive pulley 171 (shown by a one-dot chain line in FIG. 10).

  The air exhaust passage 165 extends obliquely rearward downward from the upper end opened in the belt type continuously variable transmission chamber, and the lower end opening 165b is formed in the lower wall of the transmission case cover 160 in the same manner as in the above embodiment. Open to the outside.

  Thus, since the upper end opening 165t of the exhaust passage 165 is at a higher position above the upper end of the drive pulley 171, the vehicle travels in a deep water pool, and the unit swing case is temporarily immersed in the water pool and discharged. Even if water enters the wind passage 165, the possibility of reaching the upper end opening 165t is small and entry into the belt type continuously variable transmission chamber is prevented.

1 is an overall side view of a scooter type motorcycle according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the internal combustion engine of the scooter type motorcycle cut along line II-II in FIG. 1. It is sectional drawing cut | disconnected along the III-III line | wire in FIG. It is sectional drawing cut | disconnected along the IV-IV line in FIG. It is an inner surface figure of a transmission case cover. It is sectional drawing cut | disconnected along the VI-VI line in FIG. It is an inner surface figure of the transmission case cover which concerns on another embodiment. Moreover, it is an inner surface figure of the transmission case cover which concerns on another embodiment. Furthermore, it is an inner surface figure of the unit swing case which concerns on another embodiment. It is an inner surface figure of the transmission case cover of the embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Scooter type motorcycle, 17 ... Swing unit, 18 ... Hanger bracket, 19 ... Pivot shaft, 21 ... Rear wheel, 27 ... Kick shaft, 28 ... Kick arm, 30 ... Internal combustion engine, 31 ... Unit swing case, 35 ... Belt type continuously variable transmission, 36 ... Transmission case cover, 37 ... Reduction gear case, 38 ... Reduction mechanism, 40 ... Crankshaft, 70 ... Belt type continuously variable transmission chamber, 75 ... V belt, 76 ... Belt drive pulley, 77 ... half of fixed pulley, 78 ... half of movable pulley, 86 ... belt driven pulley, 87 ... half of fixed pulley, 88 ... half of movable pulley, 91 ... centrifugal clutch, 92 ... speed reducer input shaft, 93 ... Intermediate shaft, 94 ... Output shaft, 110 ... Starter motor, 115 ... Dive gear mechanism, 118 ... Cooling fan,
121 ... Exhaust passage, 122 ... First water prevention plate, 123,124 ... Second water prevention plate,
130 ... Transmission case cover, 131 ... Exhaust passage, 132 ... First water prevention plate, 133, 134 ... Second water prevention plate, 135 ... Flange, 136 ... Float valve,
146 ... flap valve, 147 ... spindle,
150 ... unit swing case, 151 ... crankshaft, 152 ... driven pulley shaft, 153 ... intermediate shaft, 154 ... rear axle, 160 ... transmission case cover, 161 ... shaft hole, 162 ... round hole, 165 ... exhaust passage, 171 ... drive pulley, 172 ... driven pulley.

Claims (6)

In the belt-type continuously variable transmission that transmits the power of the internal combustion engine to the rear wheel side so as to be able to change speed by changing the winding diameter of the belt that is covered with the transmission case and spanned between the driving pulley and the driven pulley,
A cylindrical exhaust passage that is long and oriented in the transmission case in a substantially vertical direction has an upper end opened in the transmission case and a lower end opened to the outside.
A first water preventing plate is provided at the lower end of the exhaust passage;
A belt-type continuously variable transmission, wherein a second water-preventing plate is provided above an intermediate portion in the vertical direction of the exhaust passage.   The belt-type continuously variable transmission according to claim 1, wherein a float valve is provided in an upper portion of the exhaust passage. The float valve is loosely fitted between the opening at the upper end of the exhaust passage and the second water preventing plate,
  The belt-type continuously variable transmission according to claim 2, wherein an elastic material is coated on an upper surface of the second water preventing plate with which the float valve abuts.   The belt-type continuously variable transmission according to claim 1, wherein a flap valve is provided at an upper end portion of the exhaust passage. A driven pulley shaft of the driven pulley is disposed above a plane including a crankshaft of the internal combustion engine and a rear axle of the rear wheel;
2. A belt according to claim 1 , wherein an exhaust passage having a top end opened in the transmission case and a bottom end opened outside is provided in the vicinity of the driven pulley of the transmission case. Type continuously variable transmission. 6. The belt type continuously variable transmission according to claim 5 , wherein an upper end opening of the exhaust passage is located above an upper end of the drive pulley.

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