JP2793285B2 - Gear noise reduction device for motorcycles - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a noise prevention device for a gear type transmission included in a motorcycle, which prevents gears from rattling with each other.

(Prior Art) Conventionally, there is a motorcycle disclosed in, for example, Japanese Utility Model Publication No. 58-4787. According to this, the engine, the transmission, and the rear wheel are integrated into a drive unit, and this drive unit is pivotally supported on the body frame so as to be vertically swingable.

In the above-described configuration, there is a transmission having a gear type. In this case, the driven side gear that normally rotates together with the rear wheel, meshes with the gear, and inputs the power from the engine to drive the driven side. A driving gear that transmits this power is provided to the side gear. In this case, when the gears mesh with each other, a backlash is set between the gears in order to prevent the inconvenience of the back surfaces of the respective teeth being pressed against each other to increase the rotational resistance. Have been.

(Problems to be Solved by the Invention) By the way, in the motorcycle having the above configuration, when the rear wheel is grounded when the engine is idling,
The front side of the drive unit swings up and down about the axle of the rear wheel due to the vibration of the engine. In this case, since the rear wheels are in contact with the ground, they do not rotate and remain stationary. Accordingly, the driven gear that rotates integrally with the rear wheel axle also remains stationary. On the other hand, the drive-side gear rotates relatively forward and reverse with a slight amplitude with respect to the driven-side gear with the vertical swing of the drive unit. Thus, there is a problem that the teeth of the drive side gear repeatedly collide with the teeth of the driven side gear, so that a so-called tooth hitting sound is generated.

(Object of the Invention) The present invention has been made in view of the above-described circumstances. Even when the rear wheel is in contact with the ground at the time of idling of the engine, it is possible to reduce the gear rattle in the gear transmission. It is another object of the present invention to prevent the inconvenience of noise from occurring.

(Structure of the Invention) A feature of the present invention for achieving the above object is that a driven gear that rotates integrally with the axle of the rear wheel, and a gear that meshes with the gear and applies power from the engine side to the gear. The backlash removing means for removing the backlash between the driving gear and the driving gear is provided.

(Operation) The operation of the above configuration is as follows.

When the rear wheel 6 is grounded when the engine 4 is idling, the front side of the drive unit 3 swings up and down about the axle 44 of the rear wheel 6 due to the vibration of the engine 4. In this case, since the rear wheel 6 is in contact with the ground 12, it does not rotate and remains stationary. Therefore, the second reduction large gear (driven side gear) 51 that is integrally rotated with the axle 44 of the rear wheel 6 also remains stationary. On the other hand, the second reduction small gear (drive-side gear) 50 is driven by the vertical swing of the drive unit 3, and the second reduction large gear (driven-side gear) is driven.
Although it has a slight amplitude with respect to 51, it rotates relatively in the forward and reverse directions. In this case, the second reduction small gear (drive-side gear) 50 and the second reduction large gear ( Due to the backlash between the driven gear 51 and the second reduction pinion (drive gear) 50, the teeth of the second reduction pinion (drive gear) 50 collide with the teeth of the second reduction gear (driven gear) 51. A striking sound is about to occur.

However, in the present invention, since the backlash removing means 53 for removing the backlash is provided, the occurrence of the rattle is reliably prevented.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

In FIGS. 2 and 3, 1 is a scooter type, and
This is a so-called swing unit type motorcycle. The motorcycle 1 has a body frame 2 formed by bending a circular pipe. Reference numeral 3 denotes a drive unit. The drive unit 3 includes an engine 4, a transmission 5, and a rear wheel 6.
Are integrated.

The drive unit 3 is pivotally supported on a bracket 8 attached to the vehicle body frame 2 by pivot means 9 so as to be vertically swingable. Further, the rear end of the transmission 5 which swings up and down around the pivot means 9 is supported at the rear of the vehicle body frame 2 by the shock absorber 10, and thus the drive unit 3 is attached to the vehicle body frame 2. Suspended.
In addition, 11 is a sheet and 12 is the ground.

2 to 5, the pivot means 9 has left and right pivot arms 14, 15 pivotally supported by a first pivot shaft 13 on the bracket 8, and these pivot arms 14, 15 are provided. These are firmly connected to each other by a connection bar 16. A pair of left and right brackets 19 protruding from a crankcase 18 of the engine 4 are respectively supported by second pivot shafts 20 at rear pivot ends of the pivot arms 14 and 15.

An elastic front stopper 21 made of rubber or the like protrudes from a front turning end of the left turning arm 14, and a protruding end of the front stopper 21 is in contact with a stopper piece 22 attached to the bracket 8. . That is, by this, the left and right rotating arms 14 and 15 are moved by the weight of the drive unit 3 to the first pivot shaft 13.
Attempts to pivot around are prevented. In this case, the drive unit 3 is vertically swingable about the second pivot 20.

Further, elastic rear stoppers 24 made of rubber or the like are protruded from rear pivoting ends of the left and right pivoting arms 14 and 15, respectively, and the projecting ends of the rear stoppers 24 are slightly separated from the lower surface of the vehicle body frame 2. Face to face. That is, when the drive unit 3 attempts to rise to a predetermined size or more with respect to the vehicle body frame 2 due to vibration during running of the motorcycle 1 or the like, the rear stopper 24 contacts the lower surface of the vehicle body frame 2 and further exceeds the drive unit 3. Is prevented from rising. Each of the stoppers 21 and 24 absorbs vibration transmitted from the engine 4 to the vehicle body frame 2.

1, 2, and 6, the engine 4 is a crankshaft supported in the crankcase 18.
28 and a connecting rod 29.

The transmission 5 has a transmission case 30 integrally formed with the crankcase 18, and the transmission case 30 extends rearward. A left end portion of the crankshaft 28 is housed in a front portion of the transmission case 30, and a drive pulley 31 is attached to this. On the other hand, an intermediate shaft 32 is supported at a rear portion of the transmission case 30, and a driven pulley 33 is relatively rotatably supported by the intermediate shaft 32.
A V-belt 34 is wound around 31 and a driven pulley 33.

The drive pulley 31 has a fixed face 31a fixed to the crankshaft 28, and a movable face 31b facing the fixed face 31a and slidably supported on the crankshaft 28 only in the axial direction. I have. Also, this movable face 3
On the back side of 1b, a backup plate 37 is attached to the crankshaft 28.
Are attached by splines, these movable faces
A spherical weight 38 is inserted between 31b and the backup plate 37 together with lubricating oil.

When the speed of the crankshaft 28 increases, the weight 38 causes the movable face 31b and the backup plate 37 to move due to centrifugal force.
, The movable face 31b is pushed toward the fixed face 31a, and the diameter of engagement with the V-belt 34 is increased.

In FIGS. 1 and 2, the driven pulley 33 is also fixed to the intermediate shaft 32 and fixed to the intermediate shaft 32. The driven pulley 33 is slidably supported only on the intermediate shaft 32 in the axial direction, facing the fixed face 33a. Movable face 33b. Further, a spring 39 for biasing the movable face 33b toward the fixed face 33a is provided, and by biasing the spring 39,
The diameter of engagement with the V-belt 34 is increased.

Accordingly, when the crankshaft 28 is rotating at a low speed, the V-belt 34 engages with the drive pulley 31 with a small engagement diameter as shown by a solid line in FIGS. 1, 2, and 6. On the other hand, the driven pulley 33 engages with a large engagement diameter, that is, the reduction ratio increases.

When the speed of the crankshaft 28 increases, the engagement diameter of the V-belt 34 with respect to the drive pulley 31 is increased by the action of the weight 38, as indicated by the phantom line in FIGS. Accordingly, the engagement diameter of the driven pulley 33 is reduced against the spring 39. That is, at this time, the speed reduction ratio is reduced and the speed of the driven pulley 33 side is increased.

A centrifugal clutch 41 is provided between the driven pulley 33 and the intermediate shaft 32. Further, an inner cover 42 is attached so as to partition a partial space in the rear part of the transmission case 30, and the axle 44 of the rear wheel 6 is supported by the transmission case 30 and the inner cover 42. .

Gear reduction means 45 for transmitting the power of the intermediate shaft 32 to the axle 44
The gear reduction unit 45 is provided in a space defined by the internal cover 42. This gear reduction means 45
Has a reduction shaft 46, a first reduction gear 48 formed on the intermediate shaft 32, and a first reduction gear that is fitted around the reduction shaft 46 and crimped.
49 are in mesh. Further, a second reduction gear 50 formed on the reduction shaft 46 is engaged with a second reduction gear 51 which is fitted on the axle 44 and crimped.

Therefore, the power of the crankshaft 28 is first supplied to the drive pulley
It is transmitted to the centrifugal clutch 41 via the V-belt 34, the driven belt 33 and the driven pulley 33. When the centrifugal clutch 41 reaches a predetermined rotation speed, the connection operation is performed. This power is transmitted to the axle 44 via the intermediate shaft 32 and the gear reduction means 45, and the rear wheel 6 is driven to rotate.

The number of teeth of the first reduction gear 48 is 15, and the number of first reduction gears 49 is 40. These are helical gears. The second reduction pinion 50 has 13 teeth, and the second reduction pinion 51
Are 40, these are spur gears.

In FIGS. 1 and 7, the second reduction gear 51 is
It rotates with the rear wheel 6 via the axle 44, that is, it corresponds to a driven gear when viewed from the engine 4. Further, the second reduction small gear 50 meshing with the second reduction large gear 51 corresponds to a driving gear.

A backlash removing means 53 for removing backlash between the gears 50 and 51 is provided. The backlash removing means 53 has a friction gear 54 provided facing the side surface of the second reduction large gear 51. The wear gear 54 is supported on the axle 44 so as to freely rotate, and the second reduction small gear 50 mesh. In order to frictionally connect the friction gear 54 to the side surface of the second reduction gear 51, a disc spring 55 is provided which is pressed against the side surface.

In the above case, the tooth profile and size of the friction gear 54
Although the same as the reduction gear 50 and the second reduction gear 51, the number of teeth thereof is 39, which is one less than the second reduction gear 51. The teeth of the friction gear 54 are the second reduction gear 50
The backlash between the second reduction small gear 50 and the second reduction large gear 51 is eliminated as a result.

Note that the friction gear 54 may have the same number of teeth as the second reduction gear 51 as a scissors gear.

The drive unit 3 is provided with a starting device.
That is, a kick starter 57 is provided in FIG. A self-starter type starter is also provided.
This has a rotating plate 58 attached to the crankshaft 28 by a spline on the outer surface side of the backup plate 37, as shown in FIG. 1 and FIG. The rotating plate 58 is connected via a one-way clutch 59 to an input gear 60 that receives the power of a starter motor.

When the input gear 60 is rotated by the above cell motor, this power is supplied to the input gear 60 by the one-way clutch 59.
The crankshaft 28 is transmitted only from the rotation plate 60 to the rotating plate 58, whereby the crankshaft 28 is cranked.

An annular sheet metal cover plate 61 is screwed to the outer peripheral portion of the movable face 31b of the drive pulley 31 with bolts 62. The cover plate 61 is formed so that its inner peripheral edge is close to the outer peripheral surface of the one-way clutch 59, and
The inner diameter is slightly larger than the outer diameter of the one-way clutch 59.

In other words, the gap between the outer peripheral surface of the one-way clutch 59 and the inner peripheral edge of the cover plate 61 is kept small during any sliding of the movable face 31b. The space is closed. Therefore, the lubricating oil inserted between the movable face 31b and the backup plate 37 is prevented from scattering outside.

And since it did in this way, conventionally, in order to prevent the said lubricating oil from scattering, the outer peripheral part of the movable face 31b and the crankshaft 28 were connected, and it was provided so that the back side of the movable face 31b might be covered. Rubber boots are no longer needed,
Therefore, there is an advantage that the configuration in the axial direction of the crankshaft 28 is correspondingly reduced.

(Effect of the Invention) According to the present invention, the back gear between the driven gear that rotates integrally with the axle of the rear wheel and the drive gear that meshes with the gear and transmits power from the engine to the gear. The provision of the backlash removing means for removing the lash has the following effects.

That is, when the rear wheels are grounded during idling of the engine, a driving gear that repeats forward and reverse rotations as the drive unit swings up and down around the rear wheel axle, and meshes with this. Due to the backlash between the driven gear and the driven gear, the teeth of the driving gear collide with the teeth of the driven gear, so that a so-called tooth striking sound is generated.

However, according to the above-described invention, since the backlash removing means for removing the backlash is provided,
The occurrence of the above-mentioned rattle noise is prevented.

That is, even when the rear wheel is in contact with the ground at the time of idling of the engine, it is possible to prevent the occurrence of the inconvenience that noise is generated based on the rattle of the gears in the gear transmission.

[Brief description of the drawings]

1 shows an embodiment of the present invention. FIG. 1 is a plan sectional view of a drive unit, FIG. 2 is a rear side view of a motorcycle, FIG. 3 is a plan view of the same, and FIG. 4 is a partially enlarged view of FIG. FIG. 5 is a partially enlarged view of FIG. 3, and FIGS. 6 and 7 are partially enlarged views of FIG. 1 ... motorcycle, 2 ... body frame, 3 ... drive unit, 4 ... engine, 5 ... transmission, 6 ... rear wheel, 12 ... ground, 44 ... axle, 50 ... second Reduction small gear (drive side gear), 51... Second reduction large gear (driven side gear), 53.

Continuation of the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B62M 7/00-11/18 A62M 17/00 B62M 15/00

Claims (1)

(57) [Claims] An engine, a gear transmission for inputting the power of the engine to the rear wheels, and a drive unit integrating the rear wheels are provided. The drive unit is vertically swingable on a vehicle body frame. A driven gear in which the transmission is rotated integrally with the axle of the rear wheel; and a driven gear engaged with the driven gear, the driven gear and the driven gear A gear noise prevention device for a motorcycle provided with backlash removing means for removing backlash between the gear.