JPH0311477Y2 - - Google Patents

Description

[Detailed explanation of the invention] [Industrial application field] This invention is applicable to scooters and motorized four-wheeled vehicles (vehicles equipped with an engine with a displacement of about 50 c.c.)
The present invention relates to power transmission devices used in light vehicles such as cars, and particularly relates to improvements in power transmission devices using V-belt continuously variable transmissions.

[Prior art]

Since the V-belt type continuously variable transmission has a structure in which power is transmitted by the frictional force acting between the V-belt and the pulley, power transmission loss is likely to occur due to slippage between the V-belt and the pulley. This tendency is particularly noticeable when the circumferential speed of the V-belt is high and the diameter of the V-belt wound around the pulley is small, that is, in a high-speed rotation range where the reduction ratio is small. For this reason, conventional power transmission devices using this transmission have been unable to efficiently transmit the engine output to the driving vehicle, and have been unable to increase the power and fuel efficiency of the vehicle.

[Purpose of invention]

In view of the above-mentioned problems, this idea reduces the power transmission loss of the power transmission device using a V-belt transmission as much as possible, transmits the engine output efficiently, and improves vehicle power and fuel efficiency. This is what we are trying to achieve.

[Structure of the idea]

In order to achieve the above-mentioned purpose, this invention uses V
In a power transmission device configured to transmit engine power via a belt type transmission, between the crankshaft of the engine and a driven shaft supporting a driven pulley of the V-belt type continuously variable transmission,
A bypass power transmission means for directly transmitting the power of the crankshaft to the driven shaft in a predetermined engine speed range is interposed between the crankshaft and the primary shaft supporting the drive pulley of the V-belt transmission. A clutch is interposed to cut off the engine power in a predetermined engine speed range,
When the engine reaches a predetermined engine speed or higher, the power of the crankshaft is transmitted to the driven shaft only through the bypass power transmission means.

〔Example〕

Hereinafter, one embodiment of the power transmission device according to the present invention will be described in detail.

FIG. 1 is a skeleton diagram showing an embodiment of the power transmission device according to the present invention, particularly when applied to a motorized four-wheeled vehicle.

In this power transmission device, a flywheel magneto 14 is attached to one end of the crankshaft 12 of the engine 10.
A rotor 14a is fixed to the rotor 14a. On the other hand, a drive gear 16 of bypass power transmission means and a primary drive gear 18, which will be described later, are each fixed to the other end of the crankshaft 12. Further, the primary shaft 22 to which the primary driven gear 20 is fixed has the primary driven gear 20 attached thereto.
A clutch 24 is disposed adjacent to the primary shaft 22 to cut off the power transmitted to the primary shaft 22 in a predetermined rotational speed range (here, a high rotational speed range) of the engine 10. Further, a drive pulley 28 of a V-belt type transmission 26 is rotatably supported at the other end of the primary shaft 22, and between the drive pulley 28 and the primary shaft 22, the engine 10 rotates from a low speed range to a high speed range. A centrifugal clutch 30 for starting is interposed, which is connected throughout the rotational range.

On the other hand, a driven pulley 32 of the V-belt type transmission 26 is fixed to one end of a driven shaft 35 located at the rear, and a V-belt 34 is wound around each of the driven pulley 32 and the drive pulley 28. is being done. Further, a reduction gear 38 is disposed on the driven shaft 35 via a one-way clutch 36, and this reduction gear 38 meshes with a driven gear 42 of a gear reduction mechanism 40, which will be described later. The one-way clutch 36 transmits only the driving force transmitted to the driven shaft 35 to the gear reduction mechanism 40 via the reduction gear 38. Further, a centrifugal clutch 52, which is one of the main components of the bypass power transmission means 50, is disposed at the other end of the driven shaft 35. The centrifugal clutch 52 engages when the driven shaft 35 reaches a predetermined high rotational speed range.The clutch 54 is fixed to the driven shaft 35, and the clutch housing 56 is rotatably supported by the driven shaft 35. ing. Further, a one-way clutch 58 is attached to the boss portion of the clutch housing 56.
is supported on the one-way clutch 58, and the drive gear 1 supported on the crankshaft 12 is supported on the one-way clutch 58.
A driven gear 60 meshing with 6 is supported. The one-way clutch 58 cuts off the power transmitted from the driven shaft 35 via the centrifugal clutch 52, and vice versa, that is, the one-way clutch 58 cuts the power transmitted from the driven shaft 35 through the centrifugal clutch 52.
Only the power transmitted through the drive shaft 35 is transmitted to the driven shaft 35.

Next, the operation of the power transmission device described above will be explained, and the configuration will also be explained in more detail.

When the engine 10 starts and its rotational speed is in the idling rotational speed range, the power of the crankshaft 12 is transmitted to the primary shaft 22 via the primary drive gear 18 and the primary driven gear 20; Since the centrifugal clutch 30, which is a starting clutch, is not engaged in the idling speed range, the generated power is not transmitted to the V-belt type transmission 26, and the vehicle remains stopped. On the other hand, the power transmitted from the crankshaft 12 to the drive gear 16 of the bypass power transmission means 50 is transferred to the driven gear 60.
and is transmitted to the clutch housing 56 of the centrifugal clutch 52 via the one-way clutch 58,
Since the driven shaft 35 is not rotating, the centrifugal clutch 52 does not engage, and therefore no power is transmitted to the driven shaft 35.

On the other hand, when the engine 10 reaches from low to medium rotation, the centrifugal clutch 30, which is a starting clutch, engages, and the power from the clutch shaft 12 is transferred to the drive pulley 28 of the V-belt transmission 26 and the V-belt type transmission 26.
The speed is transmitted to the driven pulley 32 while being sequentially changed via the belt 34, and the driven pulley 3
The power transmitted to the drive shaft 2 is transmitted to the reduction gear 38 via the driven shaft 35 and the one-way clutch 36. Note that the power transmitted to the reduction gear 38 is transmitted to the main shaft 60 of the gear reduction mechanism 40 and the counter shaft 62.
and the drive wheel 4 via the rear drive shaft 64.
4,46. In addition, the power transmitted via the drive gear 16 of the bypass power transmission means 50 does not reach the predetermined high rotational speed range in which the rotational speed of the driven shaft 35 brings the centrifugal clutch 52 into the engaged state. is not transmitted.

Next, the rotation speed of the engine 10 reaches a high rotation range, and the driven shaft 35 is moved by the V-belt transmission 26.
When the rotation speed reaches a predetermined rotational speed, the centrifugal clutch 52 of the bypass power transmission means 50 engages. However, while power is being transmitted to the driven shaft 35 by the V-belt transmission 26, the one-way clutch 58 of the bypass power transmission means 50 operates, and the power is transmitted to the driven shaft 35 via the bypass power transmission means 50. It never happens. On the other hand, engine 10
When the rotation speed reaches a higher rotation speed range, the clutch 24 disposed on the primary shaft 22 is activated, and the power transmitted to the primary shaft 22 is no longer transmitted to the driven shaft 35 via the V-belt transmission 26. . Thus, when power is no longer transmitted to the driven shaft 35 via the V-belt transmission 26, the one-way clutch 58 of the bypass power transmission means 50 is actuated, and the power of the crankshaft 12 is transferred to the drive gear 1.
6. Driven gear 60 and one-way clutch 58
It is transmitted to the centrifugal clutch 52 via the centrifugal clutch 52, and further transmitted to the driven shaft 35 via the centrifugal clutch 52. The power transmitted to the driven shaft 35 is transmitted to the reduction gear 3 via the one-way clutch 36.
8, and the power further transmitted to this reduction gear 38 is transmitted to the driving vehicle 4 via a gear reduction mechanism 40.
4,46.

That is, in the power transmission device described above, the engine 1
0 is in the low/medium rotation range, power is transmitted only through the V-belt transmission 26, and when the engine 10 reaches a high rotation range, power is transmitted only through the gear-driven bypass power transmission means 50. It is designed to transmit power. Therefore, since the V-belt transmission is not used in the high-speed range of the engine, the power transmission loss that tends to occur in the V-belt transmission in the high-speed range is prevented.

A rotor 14a of a flywheel magneto is fixed to the end of the crankshaft 12 of the power transmission device shown in FIG. This results in an extremely large power transmission loss. In addition, the rotor 14
It is known that the driving energy of a varies depending on the magnitude of the load on the magneto, which will be described later. Therefore, it is desirable to reduce power transmission loss due to such factors as much as possible. Therefore, in the present invention, the V-belt transmission 26 is used. In other words, engine 10 with large power transmission loss
In the rotation speed range, the load on the magneto is reduced.

Hereinafter, the power generation circuit that operates as described above will be described as a second generation circuit.
This will be explained with reference to the figures.

The flywheel magneto 70 shown in the figure includes the flywheel rotor 14a shown in FIG.
and a first secondary coil 74 that supplies power to the ignition circuit 72 and second and third secondary coils 8 that supply power to a charging circuit 78 that includes a battery 76.
0.82. The coil 80 of this magneto is connected between the AC input terminals of a full-wave rectifier 90, and the coil 82 is connected to the coil 80 through switches 94 and 96, which will be described later, and which are connected in parallel with each other.
are connected in parallel.

In the figure, 84 is a CDI (capacitive discharge ignition device), 86 is an ignition coil, 88 is a spark plug, 92 is a load, and 98 is a main switch that short-circuits both ends of the coil 74.

The switch 94 maintains the contacts in an open state when the engine speed is below a predetermined speed (for example, 6000 rpm), and maintains the contacts in a closed state when the engine speed is above a predetermined speed. . Further, the switch 96 functions to maintain the closed state when the negative pressure in the intake manifold of the engine is higher than the set negative pressure, and to maintain the open state when it is lower than the set negative pressure.

Next, the operation of the power generation circuit described above will be explained, and the configuration will also be explained in more detail.

When the engine 10 shown in FIG. 1 is started and its rotational speed is below a predetermined rotational speed (for example, 6000 rpm or less) and the negative pressure in the intake manifold is smaller than the set negative pressure, the engine 10 shown in FIG. Both open/close switches 94 and 96 are in the open state. Therefore, in this state, the second
Only the output power of the secondary coil 80 is rectified by the rectifier 90 and charged into the battery 76. Note that the first and second secondary coils 80, 82
The output currents I and A for a given load change in the manner shown by curve A in FIG. 3 depending on the engine speed.

On the other hand, when the engine 10 shown in FIG. If the negative pressure in
The secondary coil 80 and the third secondary coil 82 are connected in parallel, and as a result, the output power of each coil is superimposed and the battery 76 is charged. Note that the combined output current of the coils 80 and 82 for a given load changes in the manner shown by curve B in FIG. 3 with respect to the engine speed.

The magneto 70 acts as a load on the engine, and the magnitude of this load changes depending on the magnitude of the output power of the magneto 70. That is, the magnitude of the load is different between when only the output power of the coil 80 is used and when the output power of both coils 80 and 82 is used, and the load is larger in the latter case than in the former case. Therefore, by adopting the circuit configuration shown in FIG. 2, the power transmission device shown in FIG. The charging circuit uses only the secondary coil 80 of the flywheel rotor 1.
By reducing the load on 4a, power transmission loss is further reduced. Further, in a rotation range (for example, 6000 rpm or more) in which the gear-driven bypass power transmission means 50 with relatively little transmission loss is used, the flywheel rotor 14a is placed in a normal load state to charge the battery 76 in large amounts. Also, whether the V-belt transmission 26 is in use or the bypass power transmission means 50 is in use, when the negative pressure of the intake manifold becomes higher than the set value, that is, when using the engine brake, the second and the third 2
Since the charging circuit uses the secondary coils 80 and 82, it is possible to charge the battery 76 in large quantities by setting the load on the magneto flywheel 14a to a normal load state. Note that the open/close switch 96 shown in FIG. 2 is opened and closed in accordance with the negative pressure in the intake manifold, but the present invention is of course not limited to the above embodiment, and the open/close switch 96 may be linked to the brake system of the vehicle. You may also let them do so. That is, when the brake is applied, the open/close switch 96 is kept in the connected state to achieve a large amount of charging, and when the brake is not applied, the switch 96 is kept in the open state to reduce power transmission loss.

Note that the electric circuit shown in Figure 2 may not be able to perform large amounts of charging when the power transmission device shown in Figure 1 is in neutral, and when accelerating from idling to full throttle, which requires efficient power transmission. Also, since charging is performed even when climbing steeply, it may not be possible to efficiently transmit power depending on the usage state of the engine.

Therefore, in order to solve the above-mentioned problems, it is also possible to configure the electric circuit shown in FIG. 4. Note that the same parts as in FIG. 2 are indicated by the same symbols.

In this circuit, the on/off switch 9 of the charging circuit 78
An open/close switch 100 is further arranged in parallel with the switches 4 and 96. This opening/closing switch 100 has a first
Only when the power transmission device shown in the figure is in a neutral state, the contacts are maintained in a connected state to charge a large amount of battery 76. Also, one end of the rectifier 90 and the first and second secondary coils 82,
An on/off switch 1 is connected to the conductive path connecting between
02 and 104 are arranged in parallel. Among these, the open/close switch 102 is a switch that opens and closes the contacts in accordance with the accelerator opening, and maintains the contacts in an open state only when the accelerator opening reaches 80% or more, for example. Similarly to the switch 94, the open/close switch 104 is a switch that opens and closes the contact points according to the engine speed, but the set speed is lower than that of the switch 94 (for example,
5000rpm), and the contacts are kept in contact only at or above this set rotational speed.
Therefore, when the throttle opening is almost fully open (over 80%) and the engine speed is low (5000 rpm
(below), when accelerating from the idling speed range with the accelerator fully open, or when climbing steeply with the accelerator fully open, the battery 76 is not charged at all, reducing power transmission loss and increasing engine speed. Power can be transmitted efficiently.

Note that FIG. 5 is an enlarged view of the main part of FIG. 1 showing the arrangement of the on-off switch 100.
The end 108a of the operating rod 108 that operates the shift hub 106 provided in the
00a and 100b are maintained in contact. FIG. 6 is a diagram showing the arrangement of the open/close switch 96, in which an operating rod 114 is supported on a diaphragm 112 that communicates with the intake manifold 110. Switch only in case 9
The contacts 96a and 96b of No. 6 are maintained in contact.
Further, FIG. 7 shows a case where the open/close switch 96 is operated by the brake pedal 120, and the open/close switch 96 is operated only when the brake is applied.
A and 96b are maintained in contact. Further, FIG. 8 shows the arrangement of the open/close switch 102. This open/close switch 102 has a contact 102a which is connected only when the accelerator opening is almost fully open by means of a protrusion 32 disposed at the tip of the accelerator pedal 130. ,1
02b is maintained in an open state.

[Effect of idea]

This invention is a power transmission device using a V-belt transmission, and a gear-driven bypass power transmission means is arranged in parallel with the V-belt transmission, and when the engine reaches a predetermined high speed range, this Since the engine power is transmitted only through the bypass power transmission means, it is possible to prevent as much as possible the power transmission loss that occurs in the V-belt transmission in the high rotation range, and this makes the engine output more efficient. Good transmission can improve the power and fuel efficiency of vehicles using V-belt transmissions. Furthermore, since the V-belt transmission is not used in the high-speed range of the engine, the life of the V-belt can be improved. In addition, in this invention, of the two secondary coils of the flywheel magneto that supplies power to the charging circuit, the power supply line of one of the secondary coils is turned OFF when the engine speed is below a predetermined rotation speed. A switch that is turned ON when the rotation speed is exceeded is connected in parallel with a switch that is turned ON when the negative pressure in the engine intake manifold is greater than a predetermined negative pressure, and turned OFF when it is less than the predetermined negative pressure. In the rotation range where a V-belt continuously variable transmission is used, where transmission loss is relatively likely to occur due to
Since power is supplied to the charging circuit by only one of the two secondary coils, the flywheel rotor is This reduces power transmission loss in light vehicles that use V-belt continuously variable transmissions.

[Brief explanation of drawings]

Fig. 1 is a skeleton diagram showing the power transmission device of the present invention, Fig. 2 is an electric circuit diagram of a vehicle using the power transmission device of the present invention, Fig. 3 is a graph showing the output of the generator, and Fig. 4 is a diagram showing the power transmission device of the present invention. This figure is an electric circuit diagram showing another embodiment, and each of FIGS. 5 to 8 is a diagram showing the arrangement of on-off switches arranged in the electric circuit. 10...engine, 13...crankshaft, 16
...Drive gear, 22 ...Primary shaft, 2
4... Cut clutch, 26... V-belt type continuously variable transmission, 28... Drive pulley, 32... Driven pulley, 35... Driven shaft, 50... Bypass power transmission means, 52... Centrifugal clutch, 58
...One-way clutch, 60...Driven gear.

Claims (1)

[Claims for Utility Model Registration] (1) The power of the engine 10, in which the rotor 14a of the flywheel magneto 70 is fixed to one end of the crankshaft 12, is transmitted via the V-belt type continuously variable transmission 26, and the flywheel In a light vehicle power transmission device that supplies power to a charging circuit 78 through secondary coils 80 and 82 of a magneto 70 connected in parallel, the crankshaft 12 and the V-belt continuously variable transmission 26 A bypass power transmission means 50 for transmitting the power of the crankshaft 12 to the driven shaft 35 at a predetermined rotation speed of the engine 10 or more is interposed between the driven shaft 35 supporting the driven pulley 32 of the crankshaft 12. and the primary shaft 22 that supports the drive pulley 28 of the V-belt type continuously variable transmission 26, a clutch 24 is interposed that cuts off the power of the crankshaft 12 when the engine 10 has a predetermined rotation speed or more, and further, A power supply line between one of the secondary coils 80 and 82 connected in parallel to each other and the charging circuit 78 is turned OFF when the engine speed is below the predetermined rotation speed, and ON when the engine rotation speed is higher than the predetermined rotation speed. A switch 94 is connected in parallel with a switch 96 that is turned on when the negative pressure in the engine intake manifold is greater than a predetermined negative pressure and turned off when it is smaller than the predetermined negative pressure, so that the engine rotates at the predetermined speed. When the number of rotations exceeds the predetermined number of revolutions, the power of the crankshaft 12 is transmitted to the driven shaft 35 only via the bypass power transmission means 50, and when the engine reaches the predetermined number of revolutions or more, When the negative pressure becomes larger than the predetermined negative pressure, or when the engine speed exceeds the predetermined rotation speed and the negative pressure in the intake manifold becomes larger than the predetermined negative pressure, the two One or both of the switches 94 and 96 are turned on, and power is supplied to the charging circuit 78 via the one secondary coil 82 and the other secondary coil 80. Vehicle power transmission device. (2) The bypass power transmission means 50 includes a drive gear 16 fixed to the crankshaft 12;
a one-way clutch 58 rotatably supported on the driven shaft 35; a driven gear 60 supported on the one-way clutch 58 and meshing with the drive gear 16; Interposed between, engine 1
When the rotation speed exceeds a predetermined rotation speed of 0, the power transmitted from the one-way clutch 58 is transferred to the driven shaft 35.
Utility model registration claim No. (1) characterized in that the centrifugal clutch 52 is provided with a centrifugal clutch 52 for transmitting power to the
A power transmission device for a light vehicle as described in .