JP2003314671A - Cooling structure for belt type transmission - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling structure for a belt type transmission capable of improving a cooling efficiency of a driving-side variable pulley and a transmission belt by a simple structure, and ensuring the durability of a transfer belt. <P>SOLUTION: In the belt type transmission device 60 mounted on a vehicle, a fan for sending air is integrally provided on a follower-side variable pulley 63a. A lower-side wall portion 61e of a transmission case 61 is formed to be close to the driving-side variable pulley 62a and the follower-side variable pulley 63a, and an upper-side wall portion 61f is formed to separate from the driving- side variable pulley 62a and the follower-side variable pulley 63a. An inner wall portion 61g is extended toward the driving-side variable pulley 62a between the upper-side wall portion 61f and the follower-side variable pulley 63a. An opening portion 61m is formed at a position opposite to the fan 63f of an outer wall portion. The transfer belt 67 makes a part in the upper-side wall portion 61f side travel from the driving-side variable pulley 62a side to the follower-side variable pulley 63a side. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a transmission for a vehicle, and more particularly to a cooling structure for a belt type transmission.

[0002]

2. Description of the Related Art In recent years, there has been adopted a so-called CVT using a V-belt as a transmission for automobiles and motorcycles. In the CVT, a V-belt for transmitting drive generates heat, so that the V-belt is configured to be cooled by blowing air.

The structure of a conventional CVT is shown in FIG.
As shown in FIG. 12, the drive side variable pulley 162a is attached to the transmission case 161 which is integrally formed with the crankcase 133.
And the driven side variable pulley 163a are arranged in parallel, and the transmission belt 167 is wound between the drive side variable pulley 162a and the driven side variable pulley 163a. The drive side variable pulley 162a and the driven side variable pulley 163a are fixed facings 162b and 163b and a movable facing 1 respectively.
62c and 163c. Reference numeral 161a is an inner speed change case, and 161b is an outer speed change case. Fixed facing 1 outside the drive side variable pulley 162a
A cooling fan 162f is provided at 62b to air-cool the drive-side variable pulley 162a, the driven-side variable pulley 163a, and the transmission belt 167. Code 109
Is the crankshaft.

The outside air taken in by the cooling fan 162f is introduced into the shift case 161 through the opening 161m provided in the outer shift case 161b as shown by the arrow in FIGS. Pulley 162a
Is sent along the direction of rotation (counterclockwise in the figure),
Air is fed from below the drive side variable pulley 162a to above the driven side variable pulley 163a through a space between the drive side variable pulley 162a and the driven side variable pulley 163a, and the rear side of the driven side variable pulley 163a is fed. The air is exhausted to the outside through the exhaust port 161p on the lower rear side of the driven variable pulley 163a.

[0005]

However, in the structure of the conventional transmission described above, the crankcase 133 is integrally formed, and the oil chambers 110 and 111 and the pulley chamber 112 are formed.
Since the and are separated by the partition walls 133a and 133b, the pulley is affected by the heat of the engine and the durability of the transmission belt 167 deteriorates. Further, since the cooling fan 162f and the intake port 161m are mounted on the left side of the vehicle, the drive side variable pulley 162a on the right side of the vehicle.
Has a problem that it easily generates heat.

The present invention has been made in view of the above problems of the prior art, and is a belt type gear shift that can improve the cooling efficiency of the drive side variable pulley and the transmission belt with a simple structure and ensure the durability of the transmission belt. An object is to provide a cooling structure for an apparatus.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a cooling structure for a belt type transmission, which is a transmission mounted on a vehicle and includes a drive side variable pulley and a driven side variable pulley in a transmission case. Also, in the cooling structure of the belt type transmission including the transmission belt wound between the drive side variable pulley and the driven side variable pulley, the driven side variable pulley is located at a position facing the transmission case in the axial direction. Is integrally provided with a fan for introducing outside air into the shift case, and the shift case has a side wall portion formed from the drive side variable pulley of the outer wall portion to the driven side variable pulley and the drive side variable pulley. And the other side wall portion that is formed close to the driven side variable pulley and that opposes the one side wall portion with the drive side variable pulley and the driven side variable pulley of the outer wall portion interposed therebetween. Formed separately from the driving side variable pulley, and extending the inner wall portion between the other side wall portion and the driven side variable pulley along the outer circumference in the circumferential direction of the driven side variable pulley and toward the driving side variable pulley, An exhaust passage is formed between the inner wall portion and the other side wall portion, and an opening portion for introducing outside air is formed at a position of the outer wall portion that faces in the axial direction of the fan. On the other hand, the portion located on the side wall portion side travels from the drive side variable pulley side toward the driven side variable pulley side.

Further, according to the present invention, in the transmission case, an air supply guide rib may be formed on an extension of the inner wall portion at a position approximately midway between the drive side variable pulley and the driven side variable pulley on the other side wall portion side. preferable. Further, in the present invention, in the shift case, it is preferable that the air supply guide wall portion is formed so as to project along the outer circumference in the circumferential direction of the driven side variable pulley inside the one side wall portion and along the track of the transmission belt. Further, in the present invention, it is preferable that a space portion is formed near the drive side variable pulley on the side of the exhaust passage.

Further, according to the present invention, the shift case is formed separately from the crankcase of a power unit mounted on a vehicle, and can be mounted integrally with the crankcase. A bearing boss portion for holding a shaft member connected with the shift case attached to the crankcase and a bolt boss portion for connecting the crankcase and the shift case to each other on the outer wall portion of the crankcase. It is preferable that a ventilated gap be formed between the outer wall portion of the crankcase and the outer wall portion of the transmission case when mounted on the outer wall portion of the case.

Further, according to the present invention, a gap formed between the outer wall portion of the crankcase and the outer wall portion of the transmission case is
It is preferable that the drive side variable pulley side is formed wider than the driven side variable pulley side. Further, in the present invention, it is preferable that, in the shift case, the drive side variable pulley side is formed to bulge outward along an axial direction.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. 1 to 9 are examples of embodiments of the invention, and FIG. 1 is a side view showing an overall configuration of a motorcycle equipped with an engine in which a cooling structure of a belt type transmission according to the present invention is adopted, 2 is a left side view of the vehicle showing the configuration of the engine, FIG. 3 is a right side view of the vehicle showing the configuration of the engine, FIG. 4 is a side view showing the configuration of a power train of the engine, and FIG. 5 is a power view of the engine. FIG. 6 is a right side view of the vehicle showing the configuration of the engine and the transmission, FIG. 7 is a sectional view taken along the line XX of FIG. 6, and FIG. 8 shows the configuration of the transmission. 9 is a right side sectional view of the vehicle showing the structure of the transmission, and FIG. 10 is a sectional view taken along the line YY of FIG.

The present embodiment is a motorcycle 1 equipped with an engine in which a cooling structure of a belt type transmission according to the present invention is adopted, and as shown in FIG. 1, a vehicle body extending in the longitudinal direction of the vehicle body. An engine unit 3 is suspended at a substantially central portion of the frame 2, and a front wheel 4 is provided on a forehead so as to be rotatable left and right by a handle bar (not shown), and a pivot shaft is provided behind the engine unit 3. A rear wheel suspension device (not shown) that extends rearward and pivotally supports a rear wheel 8 is supported via 7 in a vertically swingable manner.

The body frame 2 is constructed as follows. As shown in FIGS. 1 and 2, on the front side of the vehicle, a head pipe 21 for rotatably supporting a front fork (not shown) for rotatably supporting a front wheel 4 so as to be rotatable left and right, and the head pipe 21. A pair of left and right heads from the upper part of the head pipe, and a head upper tube 22 formed to hang down to a height approximately the same as the upper end of the front wheel, and a pair of left and right parts from the lower part of the head pipe 21 to the rear. On the other hand, a down tube 23 is formed to be substantially parallel to the head upper tube 22 and to face the head upper tube 22 so as to be shorter than the head upper tube 22.

A side upper tube 24 is provided between the head upper tube 22 and the down tube 23 to connect a substantially central portion of the head upper tube 22 and an end portion of the down tube 23.

A pair of left and right lower down tubes 25 are provided at the rear end of the down tube 23 so as to hang downward. The lower down tube 25
Is formed so as to hang downward behind the front wheel 4, and is formed to incline rearward from the lower side of the cylinder 32 that is inclined forward, and extends upward near the crankcase 33. It is provided and connected to the middle of the upper tube 26 described later.

At the center of the vehicle, an upper tube 26, which constitutes the main part of the vehicle body frame 2, extends from the lower rear of the head pipe 21 to above the rear wheel 8. The upper tube 26 is the lower down tube 25.
Is connected to the vicinity of the front end of the rear wheel 8 and extends rearward from the connecting part with a slight inclination, and is formed to incline upward from the front side of the rear wheel 8. The lower down tube 25
The engine unit 3 is suspended below the substantially central portion of the.

As shown in FIGS. 2 to 5, the engine unit 3 directs the crankshaft 9 in the vehicle width direction, and the cylinder head 3 for two cylinders is provided in front of the crankcase 33.
1 and a cylinder 32, which is a front transversely mounted engine mounted so that the center axis of the cylinder is inclined forward and upward, and a transmission 60 is integrally arranged in the front-rear direction behind the crankcase 33. It is a unit engine with two cylinders and four cycles.

The engine unit 3 has an intake system arranged above the cylinder center axis in a side view of the vehicle.
A radiator 15 and an exhaust system are arranged below the central axis of the cylinder. The radiator 15 has a rectangular shape,
It is provided in front of the engine unit 3 and below an air cleaner 14, which will be described later, so as to face the traveling direction of the vehicle.

The cylinder head 31 is shown in FIGS.
As shown in FIG. 3, the intake camshaft 16 is arranged above the cylinder central axis and the exhaust camshaft 17 is arranged below the cylinder central axis in a side view of the vehicle.

An intake manifold 31a is formed above the cylinder head 31. In the intake manifold 31a, an intake path communicating with an intake port (not shown), that is, an intake pipe 11, a throttle body 12, a carburetor inlet tube 13, and an air cleaner 14 are arranged in a substantially straight line inclining upward toward the front. It is set up. The air cleaner 14 is arranged in a space formed between the head upper tube 22, the down tube 23, and the side upper tube 24.

Below the air cleaner 14, the radiator 1
A secondary air valve unit 41, which constitutes the secondary air supply device 40, is arranged in the space above 5. One end of the secondary air valve unit 41 is connected to the secondary air supply hose 43, and the other end is connected to the reed valve 45.

The reed valve 45 is provided on the side wall of the breather chamber 50 formed in the cylinder head cover 35 on the intake path side so as to protrude between the intake manifolds 31a of the two cylinders in a plan view and substantially parallel to the center axis of the cylinder. The reed valve 45 is located on the vehicle front side with respect to the intake path, above the vehicle with respect to the intake camshaft 16, and on the vehicle rear side with respect to the radiator 15. The secondary air supply hose 43
Are extended substantially parallel to the intake path along the attachment side of the reed valve 45.

The breather chamber 50 is formed in a rectangular shape on the upper side of the intake head cam shaft 16 of the cylinder head cover 35 along the intake cam axis direction, and has an upper opening. A box-shaped breather cover 51 having an opening on the opposite surface side is provided so as to cover the opening.

Further, the intake camshaft 1 of the breather chamber 50
Bolts (not shown) for fastening the cylinder head cover 35 to the cylinder head 31 are provided at both ends in the longitudinal direction along the line 6.
Is installed. The mounting position of the fastening bolt is wider than the mounting position on the exhaust side because the breather chamber 50 is formed on the intake side.

On the other hand, as shown in FIGS. 1 and 2, the structure of the exhaust path is such that the exhaust pipe 18 extends from the cylinder head 31 toward the rear of the vehicle body. The exhaust pipe 18 extends rearward from the lower side of the cylinder head 31,
Further, an exhaust silencer (muffler) 19 which is extended to the rear of the vehicle body along a side portion of a crankcase 33 arranged below the cylinder 32 and is attached to the vehicle body frame 2 on the side of the rear wheel 8. It is connected to the.

An engine case 36, which constitutes a crankcase 33, is provided behind the cylinder 32. The engine case 36 is composed of two bodies, a vehicle right side engine case 36a and a vehicle left side engine case 36b, which are formed so as to be split in a direction substantially perpendicular to the axial center direction of a shaft member disposed inside. There is.

Inside the engine case 36, as shown in FIGS. 5 and 7, a crankshaft 9, an input shaft 37 for inputting the output from the crankshaft 9 to the transmission 60, and A clutch shaft 38 that transmits the output from the transmission 60 and an output shaft 39 that outputs the driving force transmitted to the clutch shaft 38 to the drive wheels are arranged in parallel. The output shaft 39 also serves as the pivot shaft 7 for supporting the rear wheel side.

On the left side engine case 36b of the vehicle,
A magnet cover 36c for covering the magnet 36m provided at one end of the crankshaft 9 is provided.
A clutch cover 36d is provided to cover the clutch portion 38a provided at one end of the No. 8 clutch.

In the vehicle right side engine case 36a,
Fitting portions 36j and 3j to which the transmission 60 is attached are provided at portions where the end portions of the input shaft 37 and the clutch shaft 38 are provided in a protruding manner.
6k is formed with an opening. An oil seal 3 is provided between the inner peripheral portion of the fitting portion 36j and the outer peripheral portion of the tip end portion of the input shaft 37.
6s is assembled and the airtightness inside the engine case 36 is maintained.

Further, the vehicle right side engine case 36a
Bolt boss portions 36e, to which the fastening bolts 64b are fastened, are provided at a plurality of locations on the mounting portion of the outer wall portion to which the transmission device 60 is attached.

As shown in FIGS. 6 and 7, the speed change device 60 includes a speed change case 61 formed separately from the engine case 36, and a drive shaft 62 and a driven shaft 63 are disposed therein. Then, it is configured as a separate unit that can be attached to the engine case 36.

The transmission case 61 has a drive shaft 62 inside.
Further, the driven shaft 63 is arranged in parallel, and is constituted by two bodies, an inner gear shift case 61a and an outer gear shift case 61b, which are formed so as to be split in a direction substantially perpendicular to the axial center direction thereof. One end of each of the drive shaft 62 and the driven shaft 63 is arranged so as to project to the outside of the transmission case 61.

As shown in FIG. 7, the inner transmission case 61a has a fitting portion 6 corresponding to the fitting portions 36j and 36k at a portion where an end portion of the drive shaft 62 and an end portion of the driven shaft 63 are disposed.
Projections 1j and 61k are formed. The fitting portion 61j,
The 61k is configured to be fitted and assembled with the fitting portions 36j and 36k. Also, the fitting portion 36j,
61j and 61k also serve as bearings.

The outer periphery of the fitting portion 61k and the fitting portion 3
An O-ring 61r is assembled between the inner periphery of 6k and an oil seal 61s is assembled between the inner periphery of the fitting portion 61k and the outer periphery of the components of the driven shaft 63. The inside of the engine case 36 and the inside of the transmission case 61 are kept airtight.

The bolt boss portion 3 projecting from the vehicle right engine case 36a is attached to the mounting portion of the inner transmission case 61a with the vehicle right engine case 36a.
A bolt boss 61d is provided so as to face 6e.

Engine case 36 of the transmission case 61
In order to mount it on the vehicle, the transmission case 61 is arranged outside the vehicle right side engine case 36a, and the plurality of fastening bolts 64b are attached.
Thus, the vehicle right side engine case 36a is sandwiched and fastened to the vehicle left side engine case 36b.

The fastening bolts 64b are, as shown in FIG. 8, on the outer peripheral edge of the transmission case 61, the front side of the drive shaft 62, the rear side of the driven shaft 63, the drive shaft 62 and the driven shaft 6.
3 and the drive shaft 62 and the driven shaft 63 are sandwiched in the vertical direction so that the transmission case 61 is fastened to the engine case 36.

Both ends of the drive shaft 62 are rotatably supported by bearings 71 and 72 incorporated in the inner transmission case 61a and the outer transmission case 61b, respectively. One end of the drive shaft 62 on the inner transmission case 61a side is provided so as to be connectable to one end of an input shaft 37 that is rotatably supported in the engine case 36 by a joint (input shaft side) 65. A drive-side variable pulley 62a is provided in a portion arranged inside the transmission case 61.

Both ends of the driven shaft 63 are rotatably supported by bearings 73 and 74 incorporated in the inner transmission case 61a and the outer transmission case 61b, respectively. The one end portion of the driven shaft 63 on the inner transmission case 61a side is rotatably supported in the engine case 36 by a joint (clutch shaft side) 66.
8, a driven variable pulley 63a is provided at a position facing the drive variable pulley 62a in the transmission case 61 so as to be connectable to one end thereof.

A transmission belt 67 is wound between the drive side variable pulley 62a and the driven side variable pulley 63a.

As shown in FIG. 7, the drive side variable pulley 62a comprises a fixed facing 62b formed integrally with the drive shaft 62 and a movable facing 62c movable in the axial direction. The movable facing 62c is integrally provided with a variable speed driven gear 62d coaxially via a bearing 75. The variable speed driven gear 62d is configured to mesh with an electric motor 68, which will be described later, by a gear, and is displaced along the axial direction of the drive shaft 62 by the rotation of the electric motor 68.

Thus, the drive side variable pulley 62a is
The movable facing 62c is displaced in accordance with the displacement of the shift driven gear 62d, so that the fixed facing 62
The width of the pulley groove between b and the movable facing 62c fluctuates to variably control the arc size of the transmission belt 67 wound around the drive side variable pulley 62a in an arc shape.

As shown in FIG. 7, the driven-side variable pulley 63a is composed of a fixed facing 63b formed integrally with the driven shaft 63 and a movable facing 63c coaxially movable in the axial direction. There is. A fan 63f is projectingly provided on an outer surface of the fixed facing 63b that faces the outer transmission case 61b. The movable facing 63c is rotatably and slidably arranged on the driven shaft 63. A pressure contact spring 69 is provided on the side opposite to the fixed facing 63b of the movable facing 63c so as to bias the movable facing 63c toward the fixed facing 63b.

Thus, the driven side variable pulley 63a is
Is moved by the transmission belt 67 according to the driving force transmitted from the drive side variable pulley 62a.
The width of the pulley groove between the fixed facing 63b and the movable facing 63c is changed by the displacement of c against the pressure contact spring 69, and the transmission belt 67 wound around the driven variable pulley 63a in an arc shape. The arc size of is controlled variably.

As shown in FIGS. 6 and 8, the electric motor 68 is integrally mounted on the side wall of the outer transmission case 61b of the transmission case 61 above the drive shaft 62, and in front of the drive shaft 62. Further, it is provided behind the front end of the transmission case 61. The electric motor 68 is fastened to the transmission case 61 at a position sandwiched by fastening bolts 64b in the front-rear direction.

Here, the structure of the transmission case 61 will be described in detail. As shown in FIGS. 7 to 10, the shift case 61 has an inner shift case 61a so as to cover outer peripheries of the drive side variable pulley 62a and the driven side variable pulley 63a.
An outer wall portion of the outer transmission case 61b is formed. The inner shift case 61a and the outer shift case 61b are integrally fastened together by fastening bolts 64a at substantially equal intervals along the outer circumference of each outer wall portion.

The outer wall portions of the inner transmission case 61a and the outer transmission case 61b are, as shown in FIGS. 7 and 8, from the drive side variable pulley 62a to the driven side variable pulley 63a.
Lower side wall portion 61e which is one side wall portion in the drawing formed over
Are formed close to the drive side variable pulley 62a and the driven side variable pulley 63a. On the other hand, the upper side wall portion 61f, which is the other side wall portion in the drawing formed from the drive side variable pulley 62a to the driven side variable pulley 63a, is formed apart from the drive side variable pulley 62a and the driven side variable pulley 63a. ing.

Between the upper side wall portion 61f and the driven-side variable pulley 63a, as shown in FIG. 9, along the outer circumference of the driven-side variable pulley 63a and on the drive-side variable pulley 62.
An inner wall portion 61g is extended toward a. At the end of the inner wall portion 61g on the drive side variable pulley 62a side, an air supply guide rib 61i is extended to a substantially intermediate position between the drive side variable pulley 62a and the driven side variable pulley 63a. The tip end of the air supply guide rib 61i has a transmission belt 67 wound around it.
It is curved so as to approach the side.

The inner wall portion 61g separates the driven side variable pulley 63a side from the upper side wall portion 61f side, and the inner wall portion 6g is separated.
An exhaust passage 61l is formed between 1g and the upper side wall portion 61f. An exhaust port 61p is formed at the end of the exhaust passage 61l at the rear of the upper side wall 61f.

As shown in FIGS. 9 and 10, the lower side wall portion 61e is in close proximity to the driven side variable pulley 63a along the outer circumference of the driven side variable pulley 63a, and along the transmission belt 67, the driven side variable pulley 63a. An air supply guide wall portion 61h is formed so as to gradually project inward from the drive side variable pulley 62a.

As shown in FIG. 9, the upper side wall portion 61f bulges outward in the vicinity of the drive side variable pulley 62a and is larger than the passage cross-sectional area of the air discharge passage 61l and the space portion 61n.
Are formed.

The outer transmission case 61b is shown in FIG.
As shown in 0, the outer wall portion on the drive side variable pulley 62a side is formed to bulge outward along the axial direction, and the vicinity of the axial center of the fan 63f provided on the driven side variable pulley of the outer wall portion. An opening 61m for introducing outside air is formed at a position facing each other. A blower duct 63g for covering the opening 61m and introducing outside air is provided outside the opening 61m. The blower duct 63g extends obliquely upward and forward from the side of the outer transmission case 61b, and is formed so as to open laterally in the vicinity of the upper tube 26.

The transmission belt 67 includes a drive side variable pulley 62a and a driven side variable pulley 6 as shown by an arrow in FIG.
It is configured to travel counterclockwise from the drive side variable pulley 62a side to the driven side variable pulley 63a side at a portion located on the upper side wall portion 61f side with respect to 3a.

As shown in FIGS. 4 and 5, the transmission of the output to the rear wheels 8 is performed by decelerating the rear wheels 8 via a transmission unit 80 arranged on the left side of the vehicle by an output shaft 39. ing. The rear wheel 8 has the transmission unit 8 on the left side of the vehicle.
0 is pivotally supported in the vertical direction, and the right side of the vehicle is pivotally supported in the vertical direction by a light rear arm 88.

The transmission unit 80 is provided with a transmission case 81, a drive gear 82 provided at one end of the output shaft 39 is disposed in the transmission case 81, and idle gears 83, 84, 85 and the rear wheel shaft 8a. Final gears 86 provided in the above are arranged substantially in parallel.

The transmission case 81 is composed of an outer case 81a which can be divided in a direction substantially perpendicular to the drive axis direction and an inner case 81b which is arranged on the rear wheel side. The transmission unit 80 is assembled as a single unit. It is configured to be possible. Thus, the driving force from the output shaft 39 is the idle gear 83,
The rear wheels 8 are configured to be transmitted to the final gear 86 via 84 and 85.

Next, the operation of the cooling structure of the belt type transmission of this embodiment will be described with reference to the drawings. First, when assembling the transmission 60 to the engine unit 3, as shown in FIG. 5 or FIG. 7, an engine case 36 in which the components of the engine body are incorporated and a transmission case in which the components of the transmission 60 are incorporated. Assemble 61 separately. That is, it is possible to assemble the engine case 36 and the transmission case 61 simultaneously in separate steps.

Then, the engine case 36 and the transmission case 61, which are respectively assembled and unitized, are assembled. At this time, the input shaft 37 and the drive shaft 62 are connected, and the clutch shaft 38 and the driven shaft 63 are connected. Then, the fitting portions 36j and 36k on the engine case 36 side and the fitting portions 61j and 61k on the transmission case 61 side are fitted to each other to integrally assemble the engine case 36 and the transmission case 61.

Then, with the vehicle right side engine case 36a sandwiched between the vehicle left side engine case 36b and the transmission case 61 of the engine case 36, the fastening bolt 64 is inserted.
The shift case 61 can be integrally assembled with the engine case 36 by so-called co-fastening using b.

At this time, since the engine case 36 and the transmission case 61 are assembled through the bolt boss portions 36e and 61d provided on the outer wall portions of the engine case 36, the outer wall portion of the engine case 36 and the transmission case 61 are assembled. A gap 90 is formed between and. The gap 90 is formed so that the gap 90a on the drive side variable pulley 62a side is wider than the gap 90b on the driven side variable pulley 63a side. In this way, since the gap near the crankcase 33, which is largely affected by the heat of the engine unit 3, is formed wide, the transmission case 6
It is possible to suppress the thermal influence on the drive side variable pulley 62a in the No. 1 unit.

Further, as shown in FIG. 5, the transmission case 61 is mounted so as to protrude outward in the vehicle width direction from the outer side portion of the engine case 36 in a plan view. With such a configuration, traveling wind can be effectively applied to the shift case 61, so that the shift case 61 can be effectively cooled.

When the engine is operating, the fan 63f rotates as the driven variable pulley 63a rotates,
The outside air is introduced into the transmission case 61 through the air duct 63g from the opening 61m formed in the outer transmission case 61b.

As shown in FIG. 9, the air introduced into the transmission case 61 is sent along the lower side wall portion 61e from the driven side variable pulley 63a to the drive side variable pulley 62a in the direction shown by the arrow. It The driven variable pulley 63
It is sent to the upper side in the figure along the rotation direction of a and once the space 6
After being opened at 1n, the air supply guide rib 61i and the inner wall portion 61
The air is exhausted from an exhaust port 61p formed in the rear portion of the transmission case 61 through an exhaust passage 61l formed by g and the upper side wall portion 61f.

With the above-described structure, according to the structure of the present embodiment, the outside air introduced from the rear of the speed change case 61 has the driven side variable pulley 63a inside the speed change case 61.
From the drive side variable pulley 62a to the drive side variable pulley 62a, the transmission belt 67 is cooled by blowing air over substantially the entire circumference and exhausted from the upper rear portion of the transmission case 61. Therefore, the driven side variable pulley 63a, the drive side variable pulley 62a, and Transmission belt 67
Can be cooled effectively.

Further, according to this embodiment, the space 61n is formed by utilizing the installation space of the electric motor 68 and the reduction gear 68a arranged above the drive side variable pulley 62a, so that the space is saved and the efficiency is improved. Good exhaust can be done.

Further, according to the present embodiment, the transmission belt 67 around which the tip of the air feeding guide rib 61i on the air feeding upstream side is wound.
Since the opening area of the exhaust air passage 61l on the upstream side of the air supply of the exhaust air passage 61l is increased, the exhaust air is improved and the cooling air sent is again driven by the driven variable pulley 63a. Since returning to the side can be suppressed, a highly efficient air cooling effect can be realized.

Further, according to the present embodiment, the exhaust port 61p
Since the gearbox is formed at the rear of the gearbox 61, the gearbox 6
(1) The warmed air can be exhausted to the rear part of the engine without being blown to the engine body or the feet of the rider, so that efficient cooling can be performed without causing discomfort.

The cooling structure for the belt-type transmission of the present invention is not limited to the above-mentioned illustrated example, and various modifications can be made without departing from the scope of the present invention. . For example, although the present embodiment is applied to an engine mounted on a motorcycle, the present invention is not limited to the mounted vehicle.

Further, in the present embodiment, the transmission 60 is an electronically controlled type that employs the electric motor 68, but the present invention is not limited to this, and it may be controlled by hydraulic pressure. Good.

[0070]

As described above, the first aspect of the present invention is as described above.
According to the belt type transmission cooling structure described in any one of 1 to 7, it is possible to improve the cooling efficiency of the drive-side variable pulley and the transmission belt with a simple structure, and it is possible to enhance the durability of the transmission belt. obtain.

Specifically, according to the present invention, in the cooling structure of the belt type transmission, the fan for introducing the outside air into the transmission case is integrally formed with the driven side variable pulley,
The upstream side of the air supply passage of the speed change case is narrowed and the downstream side is widened to improve exhaust efficiency, and the circumference of the driven side variable pulley is provided between the side wall portion of the speed change case on the downstream side and the driven side variable pulley. Along the outer circumference in the direction and toward the drive side variable pulley, an inner wall portion is extended to form an exhaust passage between the inner wall portion and the side wall portion, and the outer wall portion is located at a position facing each other in the axial direction of the fan. By forming an opening for introducing outside air, and allowing the part of the transmission belt located on the exhaust passage downstream of the air passage to run from the drive side variable pulley side to the driven side variable pulley side, the driven side The variable pulley 63a, the drive-side variable pulley 62a, and the transmission belt 67 can be effectively cooled over the entire length. Therefore, the durability of the belt can be remarkably improved as compared with the conventional structure.

By providing the blower fan integrally with the driven variable pulley, it is possible to constantly blow air according to the operating condition of the engine, so that cooling can be performed with high efficiency even at high speed operation.

Further, according to the present invention, in the structure of the speed change case, the air supply guide rib is formed on the extension of the inner wall portion at a substantially intermediate position between the drive side variable pulley and the driven side variable pulley on the exhaust path side. By doing so, it is possible to improve the rectification effect by guiding the air flow on the downstream side of the ventilation passage. As a result, the retention of air can be reduced and the cooling effect in the transmission case can be improved.

Further, according to the present invention, the structure of the speed change case is configured so that air is supplied along the outer circumference of the driven side variable pulley in the inner side of the one side wall portion on the upstream side of the air passage and along the track of the transmission belt. By forming the guide wall portion so as to project, it is possible to guide the air flow on the upstream side of the blower passage near the driven variable pulley and improve the rectification effect. As a result, the drive-side variable pulley can be cooled effectively, so that the durability of the belt can be improved.

Further, according to the present invention, by forming the space portion in the vicinity of the drive side variable pulley on the side of the exhaust passage, the blown air can be decompressed in the space portion and exhausted easily. . As a result, the air is blown efficiently, so that the cooling effect in the transmission case can be improved.

Further, according to the present invention, the structure of the transmission case is formed separately from the crankcase of the power unit mounted on the vehicle, and can be mounted integrally with the crankcase. A bearing boss portion that holds a shaft member that is connected in a state where the shift case is mounted on a crankcase, and a bolt boss portion that connects the crankcase and the shift case are provided on each outer wall portion of the shift case. With the transmission case attached to the outer wall of the crankcase, a heat-permeable effect from the engine case is created by forming a ventilation gap between the outer wall of the crankcase and the outer wall of the transmission case. It can be reduced.

Further, according to the present invention, the gap formed between the outer wall portion of the crankcase and the outer wall portion of the transmission case is formed wider on the drive side variable pulley side than on the driven side variable pulley side, so that heat insulation is achieved. Since the effect can be enhanced, it is possible to effectively reduce the thermal influence on the drive side variable pulley side, which is greatly influenced by the engine case.

Further, according to the present invention, since the structure of the transmission case is formed such that the drive side variable pulley side is bulged outward along the pulley axial direction, it is easy to receive a running wind, The air-cooling effect of the running wind can effectively reduce the heat effect on the drive side. The excellent effects as described above are obtained.

[Brief description of drawings]

FIG. 1 is a side view showing the overall configuration of a motorcycle equipped with an engine that employs a belt-type transmission cooling structure according to the present invention.

FIG. 2 is a left side view of a vehicle showing a configuration of the engine.

FIG. 3 is a right side view of a vehicle showing a configuration of the engine.

FIG. 4 is a side view showing a configuration of a power train of the engine.

FIG. 5 is a plan sectional view showing a configuration of a power train of the engine.

FIG. 6 is a right side view of the vehicle showing the configurations of the engine and the transmission.

7 is a cross-sectional view taken along the line XX of FIG.

FIG. 8 is a right side view of the vehicle showing the configuration of the transmission.

FIG. 9 is a right side sectional view of the vehicle showing the configuration of the transmission.

10 is a cross-sectional view taken along the line YY of FIG.

FIG. 11 is a side sectional view showing a configuration of a conventional transmission.

FIG. 12 is a plan sectional view showing a configuration of a conventional transmission.

[Explanation of symbols]

1 motorcycle 2 body frame 3 engine unit 9 crankshaft 33 crankcase 36 engine case 36a Vehicle right side engine case 36b Vehicle left engine case 36e Bolt boss 36j, 36k Fitting part 37 Input axis 38 Clutch shaft 39 Output shaft 60 transmission 61 gearbox case 61a Inner speed change case 61b Outer shift case 61d Bolt boss 61e Lower side wall 61f Upper wall part 61g inner wall 61h Air supply guide wall 61i Air supply guide rib 61j, 61k Fitting part 61l exhaust path 61m opening 61n space section 61p exhaust port 62 drive shaft 62a Drive side variable pulley 63 Driven shaft 63a Driven side variable pulley 63f fan 63g air duct 67 transmission belt 80 transmission unit 90, 90b, 90a gap

Claims (7)

[Claims] 1. A transmission mounted on a vehicle, comprising a drive side variable pulley and a driven side variable pulley in a shift case, and being wound between the drive side variable pulley and the driven side variable pulley. In a cooling structure of a belt type transmission including a transmission belt, the driven-side variable pulley integrally includes a fan for introducing outside air into the shift case at a position facing the shift case in an axial direction. In the transmission case, one side wall portion formed from the drive side variable pulley of the outer wall portion to the driven side variable pulley is formed in the vicinity of the drive side variable pulley and the driven side variable pulley,
The other side wall portion facing the one side wall portion with the drive side variable pulley and the driven side variable pulley of the outer wall portion interposed therebetween is formed apart from the drive side variable pulley and the driven side variable pulley,
Between the other side wall portion and the driven side variable pulley, an inner wall portion is provided along the outer circumference of the driven side variable pulley in the circumferential direction and toward the drive side variable pulley, and between the inner wall portion and the other side wall portion. An exhaust passage is formed, and an opening for introducing outside air is formed at a position of the outer wall portion that opposes in the axial direction of the fan, and the transmission belt has a portion located on the other side wall portion side on the drive side. A belt-type transmission cooling structure, characterized in that it travels from the variable pulley side to the driven side variable pulley side. 2. The air transmission guide rib is formed on the extension of the inner wall portion of the transmission case at a position approximately midway between the drive side variable pulley and the driven side variable pulley on the other side wall portion side. Item 2. A belt-type transmission cooling structure according to Item 1. 3. The air transmission guide wall portion is formed so as to project along the outer circumference of the driven side variable pulley in the circumferential direction and along the track of the transmission belt in the transmission case. The cooling structure for a belt type transmission according to claim 1. 4. The cooling structure for a belt type transmission according to claim 1, wherein a space is formed in the vicinity of the drive side variable pulley on the side of the exhaust passage. 5. The shift case is formed separately from a crankcase of a power unit mounted on a vehicle, and is configured to be attachable integrally with the crankcase, and the crankcase and the shift case have outer wall portions respectively. A bearing boss portion for holding a shaft member connected in a state where the shift case is mounted on the crankcase; and a bolt boss portion for connecting the crankcase and the shift case, the shift case being an outer wall portion of the crankcase. The belt according to any one of claims 1 to 4, characterized in that a ventilation gap is formed between the outer wall portion of the crankcase and the outer wall portion of the transmission case when mounted on the belt. Type transmission cooling structure. 6. The gap formed between the outer wall portion of the crankcase and the outer wall portion of the transmission case is wider on the drive side variable pulley side than on the driven side variable pulley side. 5. A belt-type transmission cooling structure according to item 5. 7. The cooling structure for a belt-type transmission according to claim 5, wherein the transmission case is formed by bulging the drive side variable pulley side outward along the axial direction. .