JP6951390B2 - Transmission mechanism - Google Patents

Description

The present invention relates to a transmission mechanism.

Conventionally, a continuously variable transmission, a transmission case for accommodating the continuously variable transmission, a case cover for closing the transmission case, a centrifugal fan provided on the surface of the drive pulley on the case cover side, and a case cover are provided. A transmission mechanism including a ventilation port for introducing cooling air into the transmission case is known (see, for example, Patent Document 1). In Patent Document 1, the sound due to the cooling air is reduced by attaching a cover that covers the air guide port from the outside to the case cover.

International Publication No. 2017/033615

However, in the above-mentioned conventional transmission mechanism, since the cover covering the air guide is separately attached to the case cover, sound may be generated due to the resonance of the cooling air due to the gap between the cover and the case cover and the rigidity of the cover. In addition, the sound inside the transmission case leaks to the outside, which leads to noise.
The present invention has been made in view of the above circumstances, and an object of the present invention is to make it possible to reduce the noise caused by the cooling air in the transmission mechanism that introduces the cooling air into the transmission case.

The transmission mechanism includes a continuously variable transmission (46) including a drive pulley (50), a driven pulley (51), and a belt (52) connecting the drive pulley (50) and the driven pulley (51). A transmission case (40) for accommodating the continuously variable transmission (46), a case cover (41) for covering the continuously variable transmission (46) by closing the transmission case (40), and the drive pulley (50). ), A centrifugal fan (48) provided on the surface of the case cover (41), and an air guide (62) provided on the case cover (41) to introduce cooling air into the transmission case (40). In the transmission mechanism including, the case cover (41) includes an adjacent wall portion (60) that covers the centrifugal fan (48) from the axial direction (A) of the centrifugal fan (48), and the air guide port (62). ) Is provided on the axis (48b) of the centrifugal fan (48) at the adjacent wall portion (60) and opens in the axis direction (A) to cover the air guide (62). ) Is provided integrally with the case cover (41), and the air guide cover (65) is located in the axial direction from the peripheral edge of the air guide (62) that divides the outer diameter of the air guide (62). A side wall (66) that is erected in A) and surrounds the air guide (62), and a side wall that is connected to the outer end of the peripheral wall (66) and overlaps the air outlet (62) in the axial direction (A). (67) and provided with, characterized Rukoto opening (68) is provided in a part of the peripheral wall (66).

Further, in the above configuration, the case cover (41) includes a connection surface (41c) connected to the transmission case (40), and the case cover (41) is the transmission case (40). The air guide cover (65) has a protruding portion (61) that protrudes in the direction opposite to the side, and the air guide cover (65) is larger than the apex (61a) of the protruding portion (61) in the protruding direction of the protruding portion (61). It may be provided at a position close to the connection surface (41c).
Further, in the above configuration, the transmission mechanism is mounted on a saddle-riding vehicle (1) on which an occupant rides, and the air guide cover (65) is a portion of the air guide (62) located on the occupant side. You may cover it.

Further, in the above configuration, the air outlet (62) may be circular in coaxial with the axis (48b) of the centrifugal fan (48).
Further, in the above configuration, a protective cover (55) is provided to cover the air guide (62) and the air guide cover (65) from the outside in the vehicle width direction, and the protective cover (55) is the air guide (62). The outside air introduction port (74) is provided so as to be offset in the radial direction of the air guide port (62). ) The part located on the side may be covered.

Further, in the above configuration, between the protective cover (55) and the case cover (41), a chamber portion (73) that covers the air guide cover (65) from the periphery of the air guide (62) is provided. The air guide port (62) may be provided so as to be offset upward with respect to the lower end portion (73a) of the chamber portion (73).
Further, in the above configuration, the air outlet cover (65) may intersect the axis (48b) of the centrifugal fan (48).

Further, in the above configuration, the air outlet cover (65) may cover more than half of the surface area of the air vent (62) in the axial direction (A).
Further, in the above configuration, the peripheral wall (66) may be inclined so that the outer diameter and the inner diameter of the peripheral wall (66) become smaller toward the side wall (67) side .

The transmission mechanism includes a continuously variable transmission equipped with a drive pulley, a driven pulley, and a belt connecting the drive pulley and the driven pulley, a continuously variable transmission case for accommodating the continuously variable transmission, and a continuously variable transmission by closing the transmission case. It is equipped with a case cover that covers the machine, a centrifugal fan provided on the surface of the drive pulley on the case cover side, and a vent that is provided on the case cover and introduces cooling air into the transmission case. The case cover is a centrifugal fan. Is provided with an adjacent wall portion that covers the centrifugal fan from the axial direction, and the air guide is provided on the axial line of the centrifugal fan at the adjacent wall and opens in the axial direction. It is provided in.
According to this configuration, since the air guide cover is integrally provided with the case cover, the rigidity of the air guide cover can be improved, the resonance due to the cooling air can be reduced, and the noise can be reduced. Further, since the connection portion between the air outlet cover and the case cover is integrated, the sound generated in the gap between the air outlet cover and the case cover can be reduced, and the sound due to the cooling air can be reduced.

Further, in the above configuration, the case cover includes a connecting surface connected to the transmission case, the case cover has a protruding portion protruding in the direction opposite to the side of the transmission case, and the air guide cover is In the protruding direction of the protruding portion, it may be provided at a position closer to the connecting surface than the apex of the protruding portion.
According to this configuration, the air outlet cover is provided at a position closer to the connection surface than the apex of the projecting portion in the projecting direction of the projecting portion. The case cover can be easily formed without the need to increase the size.
Further, in the above configuration, the transmission mechanism may be mounted on a saddle-riding vehicle on which an occupant rides, and the air guide cover may cover a portion of the air guide located on the occupant side.
According to this configuration, the sound reaching the occupant from the air guide can be reduced by the air guide cover.

Further, in the above configuration, the air outlet may be circular in coaxial with the axis of the centrifugal fan.
According to this configuration, the cooling air can be smoothly flowed from the air guide port to the centrifugal fan, and the air conduction efficiency is good.
Further, in the above configuration, a protective cover is provided to cover the air guide and the air guide cover from the outside in the vehicle width direction, and the protective cover is an outside air introduction port arranged so as to be offset in the radial direction of the air guide with respect to the air guide. The air guide cover may cover a portion of the air guide located on the outside air introduction port side.
According to this configuration, the air passage of the cooling air from the outside air introduction port to the air guide port can be lengthened, and water, dust, etc. are less likely to enter the air guide port. In addition, the sound transmitted from the air guide port to the outside through the outside air introduction port can be reduced.

Further, in the above configuration, a chamber portion is provided between the protective cover and the case cover to cover the vent cover from the periphery of the vent, and the vent is offset upward with respect to the lower end of the chamber portion. It may be arranged.
According to this configuration, the chamber portion can suppress the entry of water, dust, etc. into the air guide port. In addition, it is possible to prevent water, dust, etc. that have entered the inside of the chamber portion from entering the air guide port.
Further, in the above configuration, the air outlet cover may intersect the axis of the centrifugal fan.
According to this configuration, the sound emitted from the air outlet can be effectively reduced by the portion of the air outlet cover that intersects the axis of the centrifugal fan.

Further, in the above configuration, the air outlet cover may cover more than half of the surface area of the air vent in the axial direction.
According to this configuration, the rigidity of the air outlet cover can be effectively improved, and the sound can be efficiently reduced.
Further, in the above configuration, the air guide cover has a peripheral wall that is erected in the axial direction from the peripheral edge of the air guide and surrounds the air guide, and a side wall that is connected to the outer end of the peripheral wall and overlaps the air vent in the axial direction. An opening may be provided in a part of the peripheral wall.
According to this configuration, the sound of the air guide can be efficiently reduced by the peripheral wall and the side wall. Further, the air guide cover can be made three-dimensional by the peripheral wall and the side wall, the rigidity of the air guide cover can be increased, and the air can be efficiently guided from the opening of the peripheral wall.

It is a left side view of the motorcycle which concerns on embodiment of this invention. It is a left side view of a unit swing engine. FIG. 2 is a sectional view taken along line III-III of FIG. It is a left side view of the unit swing engine with the protective cover removed. It is a left side view which looked at the case cover from the outside in the vehicle width direction. It is the figure which looked at the case cover from the bottom. FIG. 5 is a cross-sectional view taken along the line VII-VII of FIG. FIG. 2 is a cross-sectional view taken along the line VIII-VIII of FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the explanation, the directions such as front / rear / left / right and up / down are the same as the directions with respect to the vehicle body unless otherwise specified. Further, the reference numeral FR shown in each figure indicates the front of the vehicle body, the reference numeral UP indicates the upper part of the vehicle body, and the reference numeral LH indicates the left side of the vehicle body.

FIG. 1 is a left side view of a motorcycle according to an embodiment of the present invention.
The motorcycle 1 is a scooter-type saddle-riding vehicle having a low-floor step floor 11 on which an occupant seated on the seat 10 rests his / her feet. The motorcycle 1 has a front wheel 2 in front of a vehicle body frame (not shown), and a rear wheel 3 which is a driving wheel is pivotally supported by a unit swing engine 13 arranged at the rear of the vehicle.

The motorcycle 1 includes a front fork 14 that is pivotally supported at the front end of the vehicle body frame, and the front wheel 2 is pivotally supported at the lower end of the front fork 14. The steering wheel 15 steered by the occupant is attached to the upper end of the front fork 14 above the front of the seat 10.
The motorcycle 1 includes a vehicle body cover 16 that covers the vehicle body such as the vehicle body frame.

FIG. 2 is a left side view of the unit swing engine 13.
With reference to FIGS. 1 and 2, the unit swing engine 13 is a unit swing type engine in which an engine body 20 as a drive source and an arm portion 21 supporting the rear wheels 3 are integrated. The unit swing engine 13 is located directly below the seat 10 when viewed from the side of the vehicle.
The rear wheel 3 is pivotally supported by a rear wheel axle 3a provided at the rear end of the arm portion 21.

The engine body 20 includes a crankcase 22 and a cylinder portion 23 extending forward from the crankcase 22.
The cylinder portion 23 includes a cylinder 23a, a cylinder head 23b, and a head cover 23c in this order from the crankcase 22 side.
The engine body 20 is a horizontal engine in which the cylinder axis 23d of the cylinder portion 23 extends substantially horizontally in the vehicle front-rear direction. Specifically, the cylinder portion 23 extends substantially horizontally toward the front of the vehicle in a slightly upward direction when viewed from the side of the vehicle.

The intake device of the unit swing engine 13 includes an air cleaner box 24 and a throttle body 25.
The air cleaner box 24 is attached to the upper part of the arm portion 21. The throttle body 25 is connected to an intake port on the upper surface of the cylinder portion 23.
The exhaust pipe 26 extends rearward from the exhaust port on the lower surface of the cylinder portion 23.

The unit swing engine 13 includes a link connecting portion 27 on the upper portion of the front portion of the crankcase 22. The unit swing engine 13 is connected to the rear portion of the vehicle body frame via a link mechanism (not shown) connected to the link connecting portion 27.
The unit swing engine 13 can swing up and down around the link mechanism.
A rear cushion 29 is hung between the cushion connecting portion 28 provided at the rear end of the arm portion 21 and the vehicle body frame.

FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 2, which passes through the axis lines of the camshaft, the crankpin, the crankshaft 30, and the reduction gear of the valve gear.
The crankcase 22 includes a crank chamber 31 that accommodates a crankshaft 30 that extends in the vehicle width direction (left-right direction). The crank chamber 31 includes a pair of left and right support walls 31a and 31b orthogonal to the crankshaft 30. The crankshaft 30 is supported by the support walls 31a and 31b via bearings.
The piston 32 that reciprocates in the cylinder 23a is connected to the crankshaft 30 in the crank chamber 31 via the connecting rod 33.

The crankcase 22 is provided with a generator chamber 35 on one left and right side (right side) of the crank chamber 31.
At one end of the crankshaft 30 extending into the generator room 35, a generator 36 that generates electricity by the rotation of the crankshaft 30 is provided. A blower fan 37 is provided on the outer surface of the generator 36.
A radiator 38 through which the cooling water of the engine body 20 passes is provided on the outer side of the blower fan 37. The radiator 38 is fixed to the outer surface of the generator chamber 35 and receives the air blown by the blower fan 37.

The crankcase 22 integrally includes a transmission case portion 40 (transmission case) extending rearward from a side surface portion on the side opposite to the generator chamber 35 side. The transmission case portion 40 extends from the side portion of the crank chamber 31 to the left side of the rear wheel 3.
The transmission case portion 40 is formed in a case shape in which the outer surface in the vehicle width direction is open.
Specifically, the transmission case portion 40 includes a case side wall portion 40a extending forward and backward along the outer surface of the rear wheel 3, and a case peripheral wall portion 40b extending outward in the vehicle width direction from the peripheral edge portion of the case side wall portion 40a. And. One support wall 31a constitutes a front end portion of the case side wall portion 40a.
The open portion 40c partitioned in the transmission case portion 40 by the case peripheral wall portion 40b is closed by the case cover 41 fixed to the case peripheral wall portion 40b.

The arm portion 21 of the unit swing engine 13 is composed of a transmission case portion 40 and a case cover 41. The arm portion 21 is hollow. The arm portion 21 extends longer in the front-rear direction than in the up-down direction when viewed from the side of the vehicle.
The arm portion 21 is provided with a transmission mechanism 43 that shifts the rotation of the crankshaft 30 and transmits it to the rear wheel 3 side, a centrifugal clutch mechanism 44, and a reduction mechanism 45 composed of a plurality of gears.
The driving force of the crankshaft 30 is transmitted to the rear wheels 3 via the transmission mechanism 43, the clutch mechanism 44, and the reduction mechanism 45.

At the other end of the crankshaft 30, a pulley support shaft portion 30a projecting from the crank chamber 31 side into the transmission case portion 40 is provided.
An output shaft 47 arranged in parallel with the pulley support shaft portion 30a is provided at the rear portion of the transmission case portion 40. The output shaft 47 is rotatably supported by the case side wall portion 40a via a bearing.

The transmission mechanism 43 includes a belt-type continuously variable transmission 46, the transmission case portion 40 for accommodating the continuously variable transmission 46, the case cover 41, and a centrifugal fan 48.
The continuously variable transmission 46 includes a drive pulley 50 supported by the pulley support shaft portion 30a, a driven pulley 51 supported by the output shaft 47, and a V-belt 52 (belt) connecting the drive pulley 50 and the driven pulley 51. To be equipped.

The drive pulley 50 includes a disk-shaped fixed pulley piece 50a fixed to the shaft end portion of the pulley support shaft portion 30a, and a movable pulley piece 50b movable in the axial direction on the pulley support shaft portion 30a. The movable pulley piece 50b moves in the axial direction by being pushed by a roller weight (not shown) that moves by centrifugal force due to the rotation of the crankshaft 30. As a result, the distance between the fixed pulley piece 50a and the movable pulley piece 50b changes. The V-belt 52 is sandwiched between the fixed pulley piece 50a and the movable pulley piece 50b.

The driven pulley 51 has a cylindrical outer shaft 51a that rotatably fits on the outer circumference of the output shaft 47, a fixed pulley piece 51b fixed on the outer shaft 51a, and axially movable on the outer shaft 51a. It is provided with a movable pulley piece 51c. The movable pulley piece 51c is urged to move toward the fixed pulley piece 51b by a spring (not shown). The V-belt 52 is sandwiched between the fixed pulley piece 51b and the movable pulley piece 51c.
In the continuously variable transmission 46, when the movable pulley piece 50b and the movable pulley piece 51c are displaced in the axial direction, the pulley diameter with respect to the V-belt 52 changes, and the gear ratio is changed steplessly.

The clutch mechanism 44 is fixed to a disk-shaped clutch plate 44a fixed to the outer end portion of the outer shaft 51a, a plurality of clutch shoes 44b supported by the clutch plate 44a, and an outer end portion of the output shaft 47. It is provided with a cup-shaped clutch outer 44c.
When the output of the crankshaft 30 is transmitted to the driven pulley 51 via the V-belt 52, the outer shaft 51a is rotated on the output shaft 47, and the centrifugal force of this rotation causes the clutch shoe 44b to move to the outer peripheral side. Then, when the clutch shoe 44b is frictionally engaged with the inner peripheral surface of the clutch outer 44c, the clutch mechanism 44 is in a connected state, and the clutch mechanism 44 rotates integrally with the outer shaft 51a.
The rotation of the output shaft 47 is transmitted to the rear wheel axle 3a via the reduction mechanism 45.

The centrifugal fan 48 is integrally provided on the outer surface of the fixed pulley piece 50a of the drive pulley 50 in the vehicle width direction. The centrifugal fan 48 is provided on the surface of the fixed pulley piece 50a on the side of the case cover 41.
The centrifugal fan 48 includes a plurality of blades 48a extending radially outward from the center of the disk-shaped fixed pulley piece 50a on the outer surface of the fixed pulley piece 50a.
The axis 48b of the centrifugal fan 48, which is the center of rotation of the centrifugal fan 48, coincides with the axis 30b of the crankshaft 30. The axial direction A of the axis 48b is the extending direction of the axis 48b and coincides with the vehicle width direction.

With reference to FIGS. 2 and 3, the transmission mechanism 43 includes a protective cover 55 that covers the case cover 41 from the outside in the vehicle width direction, and a rear protective cover 56 that covers the case cover 41 from the outside in the vehicle width direction behind the protective cover 55. To be equipped.
The protective cover 55 and the rear protective cover 56 are fixed to the case cover 41.

FIG. 4 is a left side view of the unit swing engine 13 with the protective cover 55 removed. FIG. 5 is a left side view of the case cover 41 as viewed from the outside in the vehicle width direction. FIG. 6 is a view of the case cover 41 as viewed from below.
With reference to FIGS. 3 to 6, the case cover 41 is a plate-shaped member that covers the entire open portion 40c of the transmission case portion 40, and extends long in the vehicle front-rear direction. The case cover 41 covers the continuously variable transmission 46, the centrifugal fan 48, and the clutch mechanism 44 from the outside in the vehicle width direction.

The case cover 41 is provided on the peripheral portion of the cover side wall portion 41a that covers the opening portion 40c from the outside in the vehicle width direction and the peripheral portion of the cover side wall portion 41a, and is fixed to the case peripheral wall portion 40b of the transmission case portion 40. And are provided together.
The inner end surface of the cover peripheral wall portion 41b in the vehicle width direction is a connecting surface 41c connected to the outer end surface of the case peripheral wall portion 40b in the vehicle width direction. The connecting surface 41c is a plane orthogonal to the axis 30b of the crankshaft 30.
The cover peripheral wall portion 41b is provided with a plurality of fixing hole portions 41d that penetrate the cover peripheral wall portion 41b in the vehicle width direction.
The case cover 41 is fastened to the case peripheral wall portion 40b by a fixture 57 inserted into each fixing hole portion 41d from the outside in the vehicle width direction.

The cover side wall portion 41a has an adjacent wall portion 60 that covers the centrifugal fan 48 from the outside in the axial direction A in the front portion of the cover side wall portion 41a.
Further, the cover side wall portion 41a has a protruding portion 61 protruding outward in the vehicle width direction from the adjacent wall portion 60 at the rear portion of the cover side wall portion 41a.

The adjacent wall portion 60 is arranged adjacent to the outer surface of the centrifugal fan 48 from the outside in the vehicle width direction, and covers the centrifugal fan 48 from the outside in the vehicle width direction.
The adjacent wall portion 60 is provided with an air guide 62 that penetrates the adjacent wall portion 60 in the vehicle width direction. The air guide 62 is provided on the axis 48b of the centrifugal fan 48 at the adjacent wall portion 60, and opens in the axis direction A. The outside air outside the transmission mechanism 43 is taken into the transmission case portion 40 from the air guide port 62 as cooling air for cooling the continuously variable transmission 46, the clutch mechanism 44, and the like.
As shown in FIG. 5, the air guide 62 is a circular opening arranged coaxially with the axis 48b of the centrifugal fan 48. The outer diameter of the air guide 62 is smaller than the outer diameter of the centrifugal fan 48.

FIG. 7 is a cross-sectional view taken along the line VII-VII of FIG. 5, and the cross section of VII-VII is vertical while passing through the axis 30b of the crankshaft 30.
With reference to FIGS. 3 to 7, the case cover 41 is provided with an air guide cover 65 that covers the air guide 62 from the outside in the vehicle width direction integrally with the case cover 41.
The air guide cover 65 is erected from the peripheral edge of the air guide 62 to the outside in the vehicle width direction in the axial direction A, and is connected to a peripheral wall 66 surrounding the air guide 62 from the surroundings and an outer end portion of the peripheral wall 66 on the outside in the vehicle width direction. In the axial direction A, the air guide 62 is provided with a side wall 67 that overlaps from the outside in the vehicle width direction.
Further, the air guide cover 65 includes an opening 68 provided in a part of the peripheral wall 66 so as to cut out the lower surface portion of the peripheral wall 66.
The peripheral wall 66 includes a front wall 66a located in front of the air guide 62, an upper wall 66b located above the air guide 62, and a rear wall 66c located behind the air guide 62.

As shown in FIG. 5, the side wall 67 of the air guide cover 65 covers the entire upper part of the air guide 62 and the upper part of the lower part of the air guide 62 in the axial direction (vehicle side view) of the axis 48b. The side wall 67 covers a range from the upper end of the air guide 62 to about 3/4 of the height of the air guide 62. That is, the air guide cover 65 covers more than half of the surface area of the air guide 62 in the axial direction of the axis 48b. The side wall 67 intersects the axis 48b of the centrifugal fan 48 and overlaps the centrifugal fan 48 from the outside in the vehicle width direction.
The lower end 62a of the air guide 62 is not covered from the outside in the vehicle width direction by the air guide cover 65, and when the case cover 41 is viewed alone, the lower end 62a is exposed to the outside.

On the outer surface of the adjacent wall portion 60, ribs 69 arranged in an annular shape so as to surround the air guide port 62 and the air guide cover 65 from the surroundings are provided. The rib 69 projects outward from the adjacent wall portion 60 in the vehicle width direction.
A groove 69a recessed inward in the vehicle width direction is provided on the end surface of the rib 69. The groove portion 69a is provided on the entire circumference of the rib 69.
A plurality of cover fixing portions 70 to which the protective cover 55 is fixed are provided on the outer side of the rib 69 in the adjacent wall portion 60.

The protruding portion 61 of the cover side wall portion 41a is a clutch mechanism accommodating portion for accommodating the clutch mechanism 44 inside the protruding portion 61. The air guide cover 65 is provided at a position closer to the connecting surface 41c than the apex 61a of the protruding portion 61 in the axial direction A corresponding to the protruding direction of the protruding portion 61.

The material of the case cover 41 is metal or resin. The case cover 41 is manufactured by casting a light alloy such as an aluminum alloy as an example.
With reference to FIGS. 3, 5 and 7, in the case cover 41, the cover side wall portion 41a including the air outlet cover 65 and the protruding portion 61 and the cover peripheral wall portion 41b are integrally molded by casting using a mold. NS.
The die-cutting direction for manufacturing the case cover 41 is the plate thickness direction of the case cover 41 and is the axial direction A. In the case cover 41, the air guide cover 65 is provided at a position closer to the connection surface 41c than the apex 61a of the protruding portion 61 in the die cutting direction, and the protruding amount of the air guide cover 65 is larger than the protruding amount of the protruding portion 61. Is also small. Therefore, it is not necessary to increase the size of the mold in the die cutting direction in order to provide the air guide cover 65, and the case cover 41 can be easily manufactured.

FIG. 8 is a cross-sectional view taken along the line VIII-VIII of FIG. 2, and the cross section of VIII-VIII is vertical while passing through the axis 30b of the crankshaft 30.
With reference to FIGS. 2, 3 and 8, the protective cover 55 covers the case cover 41 from the front end to the rear from the outside in the vehicle width direction.
A protective cover opening 55a that penetrates the protective cover 55 is provided at the rear portion of the protective cover 55. The protective cover 55 is made of resin. The rear portion of the protective cover 55 covers the rear protective cover 56 from the outside in the vehicle width direction. A part 56a of the rear protective cover 56 is exposed to the outside from the protective cover opening 55a.

The protective cover 55 includes a peripheral wall portion 71 extending inward in the vehicle width direction from the inner surface of the front portion of the protective cover 55. The peripheral wall portion 71 is a rib arranged in an annular shape so as to surround the air guide port 62 and the air guide port cover 65 from the surroundings when viewed from the inside in the vehicle width direction.
The peripheral wall portion 71 is formed in an annular shape corresponding to the arrangement of the groove portion 69a of the rib 69 of the case cover 41, and the tip of the peripheral wall portion 71 engages with the groove portion 69a. An annular sealing member 72 that seals between the peripheral wall portion 71 and the groove portion 69a is interposed between the tip of the peripheral wall portion 71 and the groove portion 69a.

When the protective cover 55 is fixed to the case cover 41, a chamber portion 73 for accommodating the air outlet cover 65 is formed inside the protective cover 55.
The portion of the wall portion of the protective cover 55 that is surrounded by the peripheral wall portion 71 in a side view is the chamber outer wall portion 55b that forms the outer wall of the chamber portion 73.
The chamber portion 73 is a room surrounded by a peripheral wall portion 71, an adjacent wall portion 60, and a chamber outer wall portion 55b.

An outside air introduction port 74 penetrating the chamber outer wall portion 55b is provided above the chamber outer wall portion 55b of the protective cover 55. The chamber portion 73 communicates with the outside through the outside air introduction port 74, and the outside air is taken into the chamber portion 73 from the outside air introduction port 74. The outside air introduction port 74 is provided with a plurality of slit-shaped openings that are long in the front-rear direction.

The outside air introduction port 74 is arranged so as to be offset in the radial direction of the air guide port 62 with respect to the air guide port 62 and the air guide port cover 65. Specifically, the outside air introduction port 74 is arranged so as to be offset above the air guide port 62 with respect to the air guide port 62 and the air guide cover 65.
The protective cover 55 is fastened to the cover fixing portion 70 of the case cover 41 by a plurality of protective cover fixtures 75 inserted into the front portion of the protective cover 55 from the outside in the vehicle width direction. The protective cover fixture 75 is provided on the outside of the peripheral wall portion 71 in a side view.

Here, the flow of the cooling air will be described.
The outside air is taken into the chamber portion 73 from the outside air introduction port 74 as the cooling air W (FIG. 8). The uptake of the cooling air W is promoted by the air blown by the centrifugal fan 48.
The cooling air W flows into the upper part of the chamber portion 73 from the outside air introduction port 74, passes around the air guide cover 65, wraps around below the air guide cover 65, and enters the opening 68 and the air outlet 62 on the lower surface of the air guide cover 65. It flows into the transmission case portion 40 from the lower end portion 62a of the above. The cooling air W flowing into the transmission case portion 40 cools the continuously variable transmission 46, the clutch mechanism 44, and the like, and is discharged to the outside of the arm portion 21 from the discharge port (not shown).

The air guide cover 65 is formed integrally with the case cover 41 and is made of the same metal as the case cover 41. Therefore, the rigidity of the air guide cover 65 can be improved, and the resonance noise due to the cooling air W flowing around the air guide cover 65 and the air guide 62 can be reduced.
The air guide cover 65 includes a peripheral wall 66 and a side wall 67, covers the air guide 62 from the outside in the vehicle width direction with a shape that bulges in the vehicle width direction with respect to the air guide 62, and has an opening 68 on the lower surface of the peripheral wall 66. Be done. Therefore, the air guide cover 65 can prevent water, dust, and the like from entering the air guide 62.

The air guide cover 65 and the air guide 62 are housed in the chamber portion 73, and water and dust that have entered together with the cooling air W from the outside air introduction port 74 temporarily stay in the lower part of the chamber portion 73. As shown in FIG. 8, the air guide 62 is arranged so as to be offset upward with respect to the lower end 73a of the chamber portion 73, and the lower end 62a of the air guide 62 is above the lower end 73a of the chamber 73. Located in. Therefore, it is possible to prevent water, dust, etc. that have entered the chamber portion 73 from entering the air guide port 62.

The outside air introduction port 74 is located above the air guide cover 65, and the upper portion 65a of the air guide cover 65 covers a portion of the air guide 62 located on the outside air introduction port 74 side. Here, the upper portion 65a of the baffle cover 65 includes at least a part of the portion of the baffle cover 65 located above the center of the baffle 62. The upper portion 65a includes the upper portion of the peripheral wall 66 and the upper portion of the side wall 67. The center of the air guide 62 coincides with the axis 48b.
In this way, since the upper portion 65a of the air guide cover 65 covers the portion of the air guide 62 located on the outside air introduction port 74 side, water, dust, etc. that have entered from the outside air introduction port 74 directly enter the air guide 62. This can be suppressed by the air outlet cover 65.

The seat 10 on which the occupant sits is located above the air guide cover 65, and the upper portion 65a of the air guide cover 65 covers a portion of the air guide 62 located on the occupant side (upper side).
In this way, since the upper portion 65a of the air guide cover 65 covers the portion of the air guide 62 located on the occupant side (seat 10 side), it is possible to suppress the sound emitted from the air guide 62 from reaching the upper occupant. Here, the sound emitted from the air guide port 62 includes the operating sound of the continuously variable transmission 46 and the clutch mechanism 44 in addition to the resonance sound of the cooling air W.

As described above, according to the embodiment to which the present invention is applied, the transmission mechanism 43 includes a drive pulley 50, a driven pulley 51, and a stepless V-belt 52 for connecting the drive pulley 50 and the driven pulley 51. The transmission 46, the transmission case 40 accommodating the continuously variable transmission 46, the case cover 41 that closes the transmission case 40 and covers the continuously variable transmission 46, and the surface of the drive pulley 50 on the case cover 41 side. The case cover 41 is provided with a centrifugal fan 48 provided in the case cover 41 and a baffle 62 provided in the case cover 41 for introducing cooling air W into the transmission case portion 40. An adjacent wall portion 60 covering from A is provided, and the air guide 62 is provided on the axis 48b of the centrifugal fan 48 in the adjacent wall 60 and opens in the axial direction A, and the air guide cover 65 covering the air guide 62 is a case. It is integrally provided on the cover 41.
According to this configuration, since the air guide cover 65 is integrally provided with the case cover 41, the rigidity of the air guide cover 65 can be improved, the resonance due to the cooling air W can be reduced, and the noise can be reduced. Further, since the connection portion between the air guide cover 65 and the case cover 41 is integrated, the sound generated in the gap between the air guide cover 65 and the case cover 41 can be reduced, and the sound due to the cooling air W can be reduced.

Further, the case cover 41 includes a connection surface 41c connected to the transmission case portion 40, and the case cover 41 has a protruding portion 61 projecting in the direction opposite to the side of the transmission case portion 40, and the air guide port. The cover 65 is provided at a position closer to the connecting surface 41c than the apex 61a of the protruding portion 61 in the protruding direction of the protruding portion 61.
According to this configuration, the air guide cover 65 is provided at a position closer to the connection surface 41c than the apex 61a of the protruding portion 61 in the protruding direction of the protruding portion 61, so that the mold for manufacturing the case cover 41 is guided. The case cover 41 can be easily formed without having to be large in order to form the air vent cover 65.
Further, the transmission mechanism 43 is mounted on the motorcycle 1 on which the occupant rides, and the air guide cover 65 covers a portion of the air guide 62 located on the occupant side.
According to this configuration, the sound reaching the occupant from the air guide 62 can be reduced by the air guide cover 65.

Further, the air guide 62 has a circular shape coaxial with the axis 48b of the centrifugal fan 48.
According to this configuration, the cooling air W can be smoothly flowed from the air guide port 62 to the centrifugal fan 48, and the air flow efficiency is good.
Further, a protective cover 55 is provided to cover the air guide 62 and the air guide cover 65 from the outside in the vehicle width direction, and the protective cover 55 is arranged so as to be offset in the radial direction of the air guide 62 with respect to the air guide 62. The air guide cover 65 includes 74, and covers a portion of the air guide 62 located on the outside air introduction port 74 side.
According to this configuration, the air passage of the cooling air W from the outside air introduction port 74 to the air guide port 62 can be lengthened, and water, dust, etc. are less likely to enter the air guide port 62. Further, the sound transmitted from the air guide port 62 to the outside through the outside air introduction port 74 can be reduced.

Further, between the protective cover 55 and the case cover 41, a chamber portion 73 that covers the air guide port cover 65 from the periphery of the air guide port 62 is provided, and the air guide port 62 is upward with respect to the lower end portion 73a of the chamber portion 73. Arranged at an offset.
According to this configuration, the chamber portion 73 can prevent water, dust, and the like from entering the air guide port 62. Further, it is possible to prevent water, dust, etc. that have entered the inside of the chamber portion 73 from entering the air guide port 62.
Further, the air guide cover 65 intersects the axis 48b of the centrifugal fan 48.
According to this configuration, the sound coming out of the air guide 62 can be effectively reduced by the portion of the air guide cover 65 that intersects the axis 48b of the centrifugal fan 48.

Further, the baffle cover 65 covers more than half of the surface area of the baffle 62 in the axial direction A.
According to this configuration, the rigidity of the air outlet cover 65 can be effectively improved, and the sound can be efficiently reduced.
Further, the air guide cover 65 is erected from the peripheral edge of the air guide 62 in the axial direction A and is connected to the peripheral wall 66 surrounding the air guide 62 and the outer end of the peripheral wall 66, and is connected to the air guide 62 in the axial direction A. It is provided with an overlapping side wall 67, and an opening 68 is provided in a part of the peripheral wall 66.
According to this configuration, the sound of the air guide 62 can be efficiently reduced by the peripheral wall 66 and the side wall 67. Further, the peripheral wall 66 and the side wall 67 make the air guide cover 65 three-dimensional, so that the rigidity of the air guide cover 65 can be increased, and air can be efficiently guided from the opening 68 of the peripheral wall 66.

It should be noted that the above embodiment shows one aspect to which the present invention is applied, and the present invention is not limited to the above embodiment.
In the above embodiment, the centrifugal fan 48 has been described as being integrally provided on the outer surface of the drive pulley 50, but the present invention is not limited to this, and the centrifugal fan 48 is provided separately from the drive pulley 50. Is also good.
Further, in the above embodiment, the transmission mechanism 43 has been described as being mounted on the motorcycle 1, but the present invention is not limited to this, and the present invention includes two front wheels or two rear wheels. It can be applied to the transmission mechanism of a three-wheeled vehicle and a saddle-riding type vehicle having four or more wheels.

1 Motorcycle (saddle-riding vehicle)
40 Transmission case (transmission case)
41 Case cover 41c Connection surface 43 Transmission mechanism 46 Continuously variable transmission 48 Centrifugal fan 48b Axis line 50 Drive pulley 51 Driven pulley 52 V belt (belt)
55 Protective cover 60 Adjacent wall part 61 Protruding part 61a Apex 62 Air vent 65 Air vent cover 66 Circumferential wall 67 Side wall 68 Opening 73 Chamber part 73a Lower end 74 Outside air inlet A Axial direction

Claims (9)

A continuously variable transmission (46) including a drive pulley (50), a driven pulley (51), and a belt (52) connecting the drive pulley (50) and the driven pulley (51), and the continuously variable transmission. A transmission case (40) accommodating (46), a case cover (41) that closes the transmission case (40) and covers the continuously variable transmission (46), and the case in the drive pulley (50). A speed change equipped with a centrifugal fan (48) provided on the surface on the cover (41) side and an air guide (62) provided on the case cover (41) to introduce cooling air into the transmission case (40). In the mechanism
The case cover (41) includes an adjacent wall portion (60) that covers the centrifugal fan (48) from the axial direction (A) of the centrifugal fan (48), and the air guide port (62) is the adjacent wall portion. In (60), the centrifugal fan (48) is provided on the axis (48b) and opens in the axis direction (A).
A vent cover (65) covering the vent (62) is integrally provided with the case cover (41).
The baffle cover (65) is erected in the axial direction (A) from the peripheral edge of the baffle (62) that divides the outer diameter of the baffle (62) and surrounds the baffle (62). A peripheral wall (66) and a side wall (67) connected to the outer end of the peripheral wall (66) and overlapping the air guide port (62) in the axial direction (A) are provided.
Transmission mechanism, characterized in Rukoto opening (68) is provided in a part of the peripheral wall (66). The case cover (41) includes a connection surface (41c) connected to the transmission case (40).
The case cover (41) has a protruding portion (61) that protrudes in a direction opposite to the side of the transmission case (40).
The air guide cover (65) is provided at a position closer to the connecting surface (41c) than the apex (61a) of the protruding portion (61) in the protruding direction of the protruding portion (61). The transmission mechanism according to claim 1. The transmission mechanism is mounted on a saddle-riding vehicle (1) on which an occupant rides.
The speed change mechanism according to claim 1 or 2, wherein the air guide cover (65) covers a portion of the air guide (62) located on the occupant side. The speed change mechanism according to any one of claims 1 to 3, wherein the air guide port (62) has a circular shape coaxial with the axis (48b) of the centrifugal fan (48). A protective cover (55) is provided to cover the air guide (62) and the air guide cover (65) from the outside in the vehicle width direction.
The protective cover (55) includes an outside air introduction port (74) arranged so as to be offset in the radial direction of the air guide port (62) with respect to the air guide port (62).
The speed change mechanism according to any one of claims 1 to 4, wherein the air guide cover (65) covers a portion of the air guide (62) located on the outside air introduction port (74) side. A chamber portion (73) is provided between the protective cover (55) and the case cover (41) to cover the air guide cover (65) from the periphery of the air guide (62).
The speed change mechanism according to claim 5, wherein the air guide port (62) is arranged so as to be offset upward with respect to the lower end portion (73a) of the chamber portion (73). The speed change mechanism according to any one of claims 1 to 6, wherein the air guide cover (65) intersects the axis (48b) of the centrifugal fan (48). The speed change mechanism according to any one of claims 1 to 7, wherein the air guide cover (65) covers more than half of the surface area of the air guide (62) in the axial direction (A). The speed change mechanism according to claim 1 to 8, wherein the peripheral wall (66) is inclined so that the outer diameter and the inner diameter of the peripheral wall (66) become smaller toward the side wall (67) side.

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