JPS634849Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to power transmission devices for motorcycles, etc., and in particular relates to improvements in the mounting condition between the engine transmission case and the case cover that surrounds the power transmission mechanism. be.

(Prior art and its problems) As a conventional power transmission device of this type, one described in, for example, Japanese Utility Model Application Publication No. 70293/1983 is known.

According to this, the engine transmission case (engine 1
1) The power transmission mechanism (crankshaft sprocket 15, camshaft sprocket 1) is attached to the side end of the
6. Attach the case cover (cog belt cover 12) that surrounds the cog belt 17) via the tightening means (mounting bolts 24), and between this tightening means, the case cover (cog belt cover 12), and the transmission case (engine 11). A vibration isolating member (rubber bushings 27, 28) is interposed therein.

However, according to such a conventional configuration, what is surrounded by the case cover (cog belt cover 12) and pivotally supported by the transmission case is at most the drive shaft (crankshaft sprocket 15) for transmitting the output of the engine and the Driven shaft driven by the drive shaft (camshaft sprocket 1)
6). For example, in a motorcycle where an engine starting kick mechanism is attached in addition to the power transmission mechanism (belt transmission mechanism), such as a motorcycle, the vibration isolating member is simply installed. The load applied to the transmission case and case cover cannot be sufficiently supported by just interposing it, and the vibration and noise accompanying the load, especially the component in the direction perpendicular to the tightening direction (i.e., the axial direction of the bolt), cannot be sufficiently supported. There was a problem that it could not be sufficiently alleviated.

(Means for Solving the Problems) This invention was made to solve the problems of the prior art. A power transmission mechanism for pivotally supporting a driven shaft and transmitting power from the drive shaft to the driven shaft is accommodated, and a circuit for driving a heavy load operation mechanism associated with the power transmission mechanism. Both ends of the driving shaft are rotatably supported by the transmission case and a case cover surrounding the power transmission mechanism and the heavy load operation mechanism, respectively, and the case cover is bolted to the transmission case via a packing. In the power transmission device formed by tightening, a knock pin is provided, one end of which is inserted and fixed into the transmission case, and the other end of which is inserted into the case cover, and the knock pin is formed to penetrate the case cover, and is formed to penetrate the case cover. A vibration isolating member having a tapered portion that matches the tapered surface is attached to a bolt insertion hole whose opening end has a tapered surface that gradually widens toward the outer surface, and the vibration isolating member is penetrated. The bolt is tightened so that the tapered part of the vibration isolating member and the tapered surface of the opening are brought into pressure contact with each other, and when a heavy load operation mechanism such as a kick mechanism is added, Can withstand heavy loads,
Another object of the present invention is to provide a power transmission device that can reduce vibration and noise.

(Function) Even when the heavy load operation mechanism operates, the load is shared by the dowel pins interposed between the transmission case and the case cover, while the vibration isolating member is tightened by the bolts that pass through the vibration isolating member. The contact surface of the bolt comes into pressure contact with the tapered surface of the opening, and can absorb vibration components not only in the axial direction of the bolt but also in the direction perpendicular to the axial direction.

(Example) An example of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 shows a side view of a small motorcycle, such as a scooter type motorcycle, to which the present invention is applied.
A front fork 4 has a handle 2 fixed to its upper end and a front wheel 3 pivoted to its lower end at the front of the vehicle body 1.
is rotatably supported on a shaft, and a power transmission device 5 called a swing type power unit is connected to a link 6 at the rear.
It is swingably suspended on a frame 8 of the vehicle body 1 via a shock absorber 7. The crankcase 10 of the power transmission device 5 also serves as a transmission case, and has an engine 11 at the front, a rear wheel 12 at the rear, and a kick arm 13 of a crank mechanism 30 for starting the engine as a heavy-load operation mechanism at the side. are respectively attached, and an air cleaner case 14 is disposed above.

The engine 11 is integrally attached and fixed to the front part of the crankcase 10 as shown in FIGS.
A belt transmission mechanism is installed inside the crankcase 10 to change the speed and transmit the rotation of the engine to the rear wheel 12 serving as a driving wheel. is sealed.

The belt transmission mechanism is constructed as shown in FIG.
Further, a driven shaft 22 that transmits rotation to the rear wheel 12 is provided with a driven pulley 23 having a variable pitch structure and a centrifugal clutch 24, respectively, and a V-belt 25 formed mainly of rubber is provided between the pulleys 21 and 23. is rotated, and the rotation of the engine 11 is transmitted to the end of the final shaft 28 through the reduction gears 26 and 27 provided at the end of the driven shaft 22 and the gear 29 provided at the end of the final shaft 28. The signal is transmitted to the fixed rear wheel 12.

Furthermore, an engine drive kick device 30 is installed in the crankcase 10 in association with the belt transmission mechanism, and one end of the rotation shaft 32 is inserted through a hole 15p drilled in the case cover 15. It protrudes laterally, and a kick arm 13 is fixed to the end thereof as shown in FIG. One end of each shaft 31, 32 of this kick mechanism 30 is rotatably supported by the crankcase 10, and the other end by a case cover 15, respectively.

FIG. 4 shows an assembled perspective view of the main parts of the power transmission device 5, in which bosses provided at predetermined locations on the open end surface 10a of the crankcase 10 have bolt holes 10b to 1.
0h and knock pin holes 10m and 10n are drilled, respectively, and each boss portion provided in a predetermined position of the open end 15a of the case cover 15 corresponding to each of the boss portions of the crankcase 10 has the bolt holes. Bolt insertion holes 15b~corresponding to 10b~10h
15h and knock pin holes 15m and 15n are bored. Further, holes 35b to 35h, 38m, and 35n are provided at the peripheral edge of the gasket 35 interposed between the crankcase 10 and the case cover 15 at positions corresponding to the holes 10b to 10h, 10m, and 10n.
(holes 35g, 35h, 35m, 35n are not shown)
is drilled. Furthermore, bolt holes 10 are provided in the transmission cover 36 and the packing 37, which are interposed between the crankcase 10 and the case cover 15.
Bolt insertion holes 36 at positions corresponding to e and 10f
Holes e, 36f and 37e, 37f (hole 37f not shown) are bored.

As shown in FIG. 5, the bolt insertion hole 15b is formed with a tapered surface 15b' at the opening end expanding outward at a predetermined angle, for example, 45 degrees. Similar to the bolt insertion hole 15b, the other bolt insertion holes 15c and 15h have tapered surfaces at their opening ends. As shown in FIG.
0c is formed. The other bolts 41 to 46 are also provided with flanges in the same way as the bolt 40.

The bolts 40 to 42, 45, and 46 are formed in the same shape, and the bolt 43 is partitioned by a flange 43c as shown in FIG. It is formed longer than the other. The bolt 43 has a long shaft portion 43d in order to pass through the bolt insertion hole 36e of the transmission cover 36 and screw the case cover 15 onto the crankcase 10, and the bolt 44 is also formed in the same manner as the bolt 43. ing.

As shown in FIG. 6, the knock pin 47 has a threaded portion 47a having a slightly smaller diameter than the central shaft portion 47b at one end thereof, and a shaft portion 47c having a slightly smaller diameter than the shaft portion 47b at the other end. It is formed. Knock pin 48 is also formed similarly to knock pin 47.
These knock pins 47, 48 are of a solid type and are longer than conventional ones.

As shown in FIG. 5, the washer 51 is approximately bowl-shaped, and a bolt insertion hole 50a larger than the outer diameter of the flange of each bolt is bored in the center thereof. The washer 50 having such a shape is made of a strong metal member such as iron.

As shown in FIG. 5, the vibration isolating member 51 has a substantially cylindrical shape with an outer diameter larger than the diameter of each bolt insertion hole 15b to 15h of the case cover 15, and has one end 51a.
is fitted into the washer 50, and the other end 51b is inserted into each bolt insertion hole 15b to 15h of the case cover 15.
It is formed in a tapered shape so as to come into contact with the tapered surface of the opening end of the bolt insertion hole 51c in the axial direction.
is drilled. The vibration isolating member 51 is made of elastic rubber, for example.

When attaching the case cover 15 to the crankcase 10 in such a configuration, the crankcase 1
Threaded portion 47a of dowel pin 47 within 10 m of hole 0
Then, the shaft portion 47b is inserted, and the threaded portion 47a is screwed into the threaded portion 10m' of the hole 10m as shown in FIG. In this state, the shaft portion 4 of the knock pin 47
7b is fitted into the hole 10m so that the stepped portion between the shaft portions 47b and 47c is flush with the end surface 10a of the crankcase 10. Similarly, the threaded portion 48a and shaft portion 48b of the knock pin 48 are inserted into the hole 10n of the crankcase 10 and screwed. In this way, the knock pins 47 and 4 are attached to the end surface 10a of the crankcase 10.
Plant 8.

Next, the shaft portions 47c, 48c of the knock pins 47, 48 are inserted into the holes 35m, 35n of the gasket 35, and the gasket 35 is attached to the crankcase 10.
The respective shaft portions 47c, 4 of the knock pins 47, 48 are located within n.
8c and these two knock pins 47,
The case cover 15 is attached to the crankcase 10 via 48. The shaft portions 47c and 48c of the respective knock pins 47 and 48 have holes 15m and 1, respectively, at minute intervals.
5n. Further, a packing 37 and a transmission cover 36 are interposed behind the crankcase 10 and the case cover 15 and between the crankcase 10 and the packing 35.

Next, each of the bolts 40 to 46 is inserted into the hole 50a of each washer 50 as shown in FIG. 5, and then inserted into the hole 51c of each vibration isolating member 51. , 45, 46 into each hole 15b of the case cover 15 and packing 35, respectively.
~15d, 15g, 15h and 35b~35d,
35g and 35h (35g and 35h are not shown) and screwed into the corresponding bolt holes 10b to 10d, 10g and 10h of the crankcase 10. In addition, the bolts 43 and 44 are respectively connected to the case cover 15, the packing 35, the transmission cover 36, and the packing 3.
7 holes 15e, 15f, 35e, 35f, 36
e, 36f, 37e, 37f (35f, 37f are not shown) and screwed into the corresponding screw holes 10e, 10f of the crankcase 10. The case cover 15 and the transmission cover 3 are attached to the crankcase 10 by these bolts 40 to 46.
Attach and fix 6. Of course, the end of the rotating shaft 32 (FIG. 3) of the locking mechanism 30 protrudes outward from the case cover 15 from the hole 15p of the case cover 15, and the locking arm 13 (FIG. 1) is fixed to the end. Ru.

As shown in FIG. 5, the other end of the vibration isolating member 51, a tapered portion 51b, is press-fitted onto the tapered surface 15b' of the opening of the bolt insertion hole 15b of the case cover 15, and the end of the vibration isolating member 51 is The case cover 15 is held on the bolt 40 in cooperation with the washer 50 fitted onto the portion 51a. The same applies to the other bolts 41 to 46 as for the bolt 40. In this way, the case cover 15 is held floating from the crankcase 10. Further, as shown in FIGS. 5 and 7, each bolt 4 is attached to the end surface 10a of the crankcase 10 and the end surface 36a of the transmission cover 36.
The flanges 40c and 43c formed on the shaft portions 40b and 43b of 0 and 43 are brought into contact with each other, and the fitting positions of the bolts 40 and 43 are restricted by these flanges 40c and 43c to prevent compressive deformation of each vibration isolating member 51. do.

Furthermore, as shown in FIG.
By making the distance d between the opposing surface 15q and the end surface 50d of the case cover 15 extremely small compared to the conventional case, the kick arm 13
When the case cover 15 is lifted from the crankcase 10, the outer surface 15q of the case cover 15 is lifted from the crankcase 10.
is in contact with the end surface 50c of the washer 50, thereby minimizing lifting of the case cover 15 relative to the crankcase 10 so as to be able to withstand severe operating loads.

Thus, vibrations from the engine 11 are attenuated by the vibration isolating member 51 and transmitted to the case cover 15, thereby preventing vibrations of the case cover 15. Furthermore, by making the dowel pin solid, the rigidity is improved and its length is increased, and the tightening load of the bolt is received by the tapered surface of the vibration isolating member, thereby preventing the case cover from shifting or falling due to the sharp actuation load. can do.

Furthermore, since the distance d between the end surface 50c of the washer 50 and the outer surface 15q of the case cover 15 is extremely small, even if the elasticity of the vibration isolating member 51 decreases due to aging, the tightening force of the bolt will not decrease much. When the belt type transmission is housed inside the case 15, even if the vibration isolating member 51 deteriorates, there is no oil leakage within the crankcase, and the function of the power transmission device is always maintained in good condition. I can do it.

Although an embodiment in which the crankcase 10 also serves as a transmission case has been described, the present invention is not limited to this, and the invention may be applied to a case in which the crankcase and the transmission case are separated.

(Effects of the invention) As described above, according to this invention, the transmission case that pivotally supports the drive shaft for transmitting the output of the engine has a driven shaft that is spaced apart from the drive shaft, and A power transmission mechanism that transmits power from the shaft to the driven shaft is housed, and both ends of a rotating shaft for driving a heavy load operating mechanism associated with the power transmission mechanism are connected to the transmission case and the power transmission case. In a power transmission device, the mechanism and a case cover surrounding the heavy-load operation mechanism are respectively rotatably supported, and the case cover is bolted to the transmission case via a packing. A dowel pin is inserted and fixed into the case and the other end thereof is inserted into the case cover, and the taper pin is formed to penetrate the case cover and gradually widens toward the outer surface of the case cover. A vibration isolating member having a tapered portion that matches the tapered surface is attached to a bolt insertion hole formed in the opening end, and a bolt passing through the vibration isolating member connects the tapered portion of the vibration isolating member with the vibration isolating member. Since the bolt is tightened so as to make pressure contact with the tapered surface of the opening, the load applied to the transmission case and case cover can be reduced even when a heavy load operation mechanism is attached in addition to the power transmission mechanism. Furthermore, by installing a vibration isolating member having a tapered portion, vibration and noise components can be reduced not only in the axial direction of the bolt, that is, in the direction perpendicular to the surface of the case cover, but also in the tangential direction to the surface. It is particularly useful when applied to motorcycles equipped with a locking mechanism.

[Brief explanation of the drawing]

Fig. 1 is a side view of a motorcycle to which the present invention is applied, Fig. 2 is an enlarged view of the power transmission device shown in Fig. 1, Fig. 3 is a horizontal sectional view of the main part of Fig. 2, and Fig. 4 is a cross-sectional view of the main part of Fig. 2. FIG. 2 is an assembled perspective view of the main parts of the crankcase of the power transmission device, and FIGS. 5 and 7 are main parts showing the attached state of the crankcase and case cover of FIG. 4 to which the power transmission device according to the present invention is applied. FIG. 6 is a cross-sectional view of essential parts showing a state in which the crankcase and case cover of FIG. 4 are attached via a knock pin. 10...Crank case (transmission case), 11
...Engine, 15...Case cover, 15b~
15h...Bolt insertion hole, 15b'...Tapered surface,
20...Crankshaft (drive shaft), 21...
Drive pulley (power transmission mechanism), 22... Driven shaft (driven shaft), 23... Driven pulley (power transmission mechanism), 25... V-belt (power transmission mechanism), 30... Kick mechanism (heavy load operation mechanism), 32...rotation shaft, 36...mission cover (transmission case), 40-46...bolt, 47,
48... Knock pin, 51... Vibration isolating member, 51b
...Tapered part.

Claims (1)

[Claims for Utility Model Registration] 1. A transmission case that pivotally supports a drive shaft for transmitting the output of the engine, and a driven shaft is pivotally supported at a distance from the drive shaft. A power transmission mechanism that transmits power to the power transmission case is housed, and both ends of a rotating shaft for driving a heavy load operation mechanism associated with the power transmission mechanism are connected to the transmission case, the power transmission mechanism, and the heavy load operation mechanism. In a power transmission device in which the mechanism is rotatably supported by a case cover surrounding the mechanism, and the case cover is bolted to the transmission case via a gasket, one end is inserted and fixed into the transmission case, and the other is fixed. A knock pin whose end is inserted through the case cover is provided, and a taper surface is formed at the open end so as to penetrate through the case cover and gradually widen toward the outer surface of the case cover. A vibration isolating member having a tapered portion that matches the tapered surface is attached to the bolt insertion hole, and a bolt passing through the vibration isolating member connects the tapered portion of the vibration isolating member with the tapered surface of the opening. A power transmission device characterized in that the bolts are tightened so as to bring them into pressure contact. 2. The power transmission device according to claim 1, wherein the heavy load operating mechanism is a starting kick mechanism for the engine.