JP2764991B2 - Automotive power transmission - Google Patents

Description

Description: BACKGROUND OF THE INVENTION The present invention relates to a power transmission device for a motor vehicle, and more particularly to a power transmission device, which can increase the degree of freedom in setting the gear ratio of each mechanism constituting the power transmission device, and is advantageous in terms of production technology. An advantageous vehicle power transmission.

[Conventional technology]

Recently, vehicles that transmit the power of the internal combustion engine to the front wheels and the rear wheels in order to improve the running performance and safety in all running conditions such as running on rough roads and running on rough roads as well as on ordinary roads have been introduced. Various types have appeared. Such a vehicle power transmission device includes a main power transmission system that transmits the power of the internal combustion engine to one of the front wheels and the rear wheels, and is taken out of the main power transmission system via a propulsion shaft. Some include an auxiliary power transmission system for transmitting the power of the internal combustion engine to the other wheel.

For example, Japanese Patent Application Laid-Open No. 58-209625 discloses an automobile in which a front wheel drive vehicle is provided with a rear wheel power transmission system for driving a rear wheel, and a front wheel such as a corner or on a snowy road slips to some extent. At the time, the vehicle is automatically switched to the four-wheel drive running state to remove the adverse factor based on the slip, and the front wheel drive running and the above-described automatic four-wheel drive running are performed by the driver's will. Selective switching is possible, and when front-wheel drive travel is selected, the propeller shaft, which is a large member that forms part of the power transmission system to the rear wheels, is not rotated to reduce noise. Also disclosed is a power transmission device for an automobile that achieves fuel saving.

[Problems to be solved by the invention]

By the way, in the case of a car as shown in Figs.
Power is transmitted as follows. In the figure, 2 is a car,
4 is an internal combustion engine, 6 is a front wheel, 8 is a rear wheel, 10 is a main power transmission system, 12 is a sub power transmission system, and 14 is a propulsion shaft. The power of the internal combustion engine 4 is transmitted to the front wheels 6 via the clutch 16, the transmission 18, the front final reduction mechanism 20, and the front differential mechanism 22 that constitute the main power transmission system 10. In addition, the propulsion shaft is
The motive power of the internal combustion engine 2 taken out through 14 is a viscous coupling 24 (viscus coupling) constituting the sub power transmission system 12,
The power is transmitted to the rear wheels 8 via the rear final reduction mechanism 26 and the rear differential mechanism 28.

That is, the power of the internal combustion engine 4 is input from the crankshaft 30 to the input shaft 32 of the transmission 18 via the clutch 16 and the transmission gear train
Output to the output shaft 36 via 34. The output shaft 36 is provided with an output gear 38 that is a front reduction gear of the front final reduction mechanism 18. The output of the transmission 18 is transmitted from the output gear 38 via a front reduction gear 40 to a front differential gear case 42 of the front differential mechanism 22, and is transmitted via a front differential gear train 44. Wheel 6
Is transmitted to The power of the propulsion shaft 14 is supplied by a rear reduction pinion 48 of the rear final reduction mechanism 26 provided on the output shaft 46 of the viscous coupling 24.
Is transmitted to a rear differential gear case 52 of a rear differential mechanism 28 via a rear reduction gear 50 and transmitted to a rear wheel 8 via a rear differential gear train 54.

In such a power transmission device, the vehicle 2 shown in FIG.
In the power transmission device of the first embodiment, the turning mechanism 60 includes a turning large gear 56 provided on the front differential gear case 42 of the front differential mechanism 22 and a turning small gear 58 provided on the propulsion shaft 14. 90 direction
The rear reduction pinion 48 has the same number of teeth as the diverting gear 56 and the diverting pinion 58 from the propulsion shaft 14 after being turned.
-It is transmitted to the rear wheel 8 via the rear reduction gear 50. Further, in the power transmission device of the automobile 2 shown in FIG. 5, the front reduction gear 40 is a distribution large gear, and the front reduction gear 40 serving as the distribution large gear and the distribution small gear 64 provided on the distribution shaft 62 are The power of the internal combustion engine 2 is distributed by a distribution mechanism 66 composed of a diverting large gear 56 provided on the distribution shaft 62 and a diverting small gear 58 provided on the propulsion shaft 14. After being turned by 90 degrees, it is taken out to the propulsion shaft 14 and transmitted to the rear wheels 8 via the rear reduction gear 48 and the rear reduction gear 50. In this case, the ratio of the number of teeth between the front reduction gear 40, which is the distribution gear, and the distribution pinion 64, the ratio of the number of the turning large gear 56, and the number of the conversion small gear 58, the number of the rear reduction pinion 48, and the rear reduction It is necessary to provide a fixed relationship between the gear ratios of the large gear 50 and the gear ratio so that the rotational speeds of the front wheel 6 and the rear wheel 8 become equal.

However, in the power transmission device of the automobile 2 shown in FIG. 4, the rotation speeds of the front wheel 6 and the rear wheel 8 are the same, but are caused by the air pressure of the tires, the load shared by the axles of the front and rear wheels 6.8, and the like. There is a problem that the rotational speed difference due to the rotational radius difference of the tire cannot be absorbed. In addition, in the power transmission device of the automobile 2 shown in FIG. 5, the power transmission device shown in FIG. In particular, since each of the gears 56 and 58 of the deflecting mechanism 60 is a bevel gear, each of the gears 56 and 58 of the deflecting mechanism 60 has two or more teeth in terms of production technology. It is necessary to make the ratio be a numerical ratio, and furthermore, there is an inconvenience that the realization is difficult due to the limitation of the gear ratio of each of the gears 48 and 50 of the rear final reduction mechanism 26.

[Object of the invention]

Accordingly, an object of the present invention is to provide a main power transmission system for transmitting power of an internal combustion engine to one of a front wheel and a rear wheel, and the power of the internal combustion engine taken out from the main power transmission system via a propulsion shaft. Power transmission device for a vehicle having a sub power transmission system for transmitting the gear ratio to the other wheel, it is possible to increase the degree of freedom in setting the gear ratio of each mechanism constituting the power transmission device, and to achieve a vehicle technology which is advantageous in terms of production technology. A power transmission device is to be realized.

[Means for solving the problem]

In order to achieve this object, the present invention includes a main power transmission system for transmitting the power of the internal combustion engine to one of the front wheels and the rear wheels, and from the main power transmission system via a propulsion shaft. In a power transmission device for a vehicle having a sub power transmission system for transmitting the power of the taken-out internal combustion engine to the other wheel, a viscous joint is connected to a final reduction mechanism of either the main power transmission system or the sub power transmission system. And a gear ratio adjusting means comprising a pair of gears having a gear ratio for increasing or decreasing the power of the internal combustion engine between the propulsion shaft and the viscous coupling. The ratio adjusting means is characterized in that one adjusting gear provided on the propulsion shaft is provided below the other adjusting gear provided on the viscous joint.

[Action]

According to the configuration of the present invention, the power transmission device includes a viscous coupling connected to a propulsion shaft that connects the main power transmission system and the sub power transmission system and a final reduction mechanism of one of the main power transmission system and the sub power transmission system. And a gear ratio adjusting means comprising a pair of gears having a gear ratio for transmitting power by increasing or decreasing power, thereby providing a power transmission device.
The degree of freedom in setting the gear ratio of each gear mechanism such as the rear final reduction mechanism can be increased. In addition, the gear ratio adjusting means sets the gear ratio of the pair of adjusting gears to the gear ratio at which the viscous joint increases in speed with respect to the propulsion shaft, thereby reducing the rotation speed of the propulsion shaft. In addition, the capacity of the viscous joint can be reduced. Further, the gear ratio adjusting means is provided by disposing one adjusting gear provided on the propulsion shaft below the other adjusting gear provided on the viscous coupling.
The propulsion axis can be lowered.

〔Example〕

Next, an embodiment of the present invention will be described in detail with reference to the drawings.

1 to 3 show an embodiment of the present invention. In the figure, 2 is an automobile, 4 is an internal combustion engine, 6 is a front wheel, 8
Is a rear wheel, 10 is a main power transmission system, 12 is a sub power transmission system, and 14 is a propulsion shaft. The power of the internal combustion engine 4 is transmitted to the front wheels 6 via the clutch 16, the transmission 18, the front final reduction mechanism 20, and the front differential mechanism 22 that constitute the main power transmission system 10. The power of the internal combustion engine 2 taken out of the main power transmission system 10 via the propulsion shaft 14 is supplied to a viscous coupling 24 (a viscous coupling) constituting the sub power transmission system 12, a rear final reduction mechanism 26, and a rear differential. The power is transmitted to the rear wheels 8 via the mechanism 28.

That is, the power of the internal combustion engine 4 is input from the crankshaft 30 to the input shaft 32 of the transmission 18 via the clutch 16 and the transmission gear train
Output to the output shaft 36 via 34. The output shaft 36 is provided with an output gear 38 that is a front reduction gear of the front final reduction mechanism 18. The output of the transmission 18 is transmitted from the output gear 38 via a front reduction gear 40 to a front differential gear case 42 of the front differential mechanism 22, and is transmitted via a front differential gear train 44. Wheel 6
Is transmitted to The power of the propulsion shaft 14 is supplied by a rear reduction pinion 48 of the rear final reduction mechanism 26 provided on the output shaft 46 of the viscous coupling 24.
Is transmitted to a rear differential gear case 52 of a rear differential mechanism 28 via a rear reduction gear 50 and transmitted to a rear wheel 8 via a rear differential gear train 54.

In such a power transmission device, the vehicle 2 shown in FIG.
In the power transmission device of the first embodiment, the turning mechanism 60 includes a turning large gear 56 provided on the front differential gear case 42 of the front differential mechanism 22 and a turning small gear 58 provided on the propulsion shaft 14. 90 direction
The rear reduction pinion 48 has the same number of teeth as the diverting gear 56 and the diverting pinion 58 from the propulsion shaft 14 after being turned.
-It is transmitted to the rear wheel 8 via the rear reduction gear 50. Further, in the power transmission device of the automobile 2 shown in FIG. 5, the front reduction gear 40 is a distribution large gear, and the front reduction gear 40 serving as the distribution large gear and the distribution small gear 64 provided on the distribution shaft 62 are The power of the internal combustion engine 2 is distributed by a distribution mechanism 66 composed of a diverting large gear 56 provided on the distribution shaft 62 and a diverting small gear 58 provided on the propulsion shaft 14. After being turned by 90 degrees, it is taken out to the propulsion shaft 14 and transmitted to the rear wheels 8 via the rear reduction gear 48 and the rear reduction gear 50. In this case, the ratio of the number of teeth between the front reduction gear 40, which is the distribution gear, and the distribution pinion 64, the ratio of the number of the turning large gear 56, and the number of the conversion small gear 58, the number of the rear reduction pinion 48, and the rear reduction It is necessary to provide a certain relationship between the gear ratios with the large gear 50 so that the rotational speeds of the front wheel 6 and the rear wheel 8 become equal.

By the way, in the conventional power transmission device of the automobile 2 shown in FIG. 5, the power of the internal combustion engine 4 is shifted by the transmission 18 and transmitted to the front wheels 6 via the front differential mechanism 22.
Also, they are distributed and taken out by the distribution mechanism 66, and are turned by the deflection mechanism 60.
Is turned by 90 degrees, is taken out to the propulsion shaft 14, and is
Is transmitted to The torque generated by the rotational speed difference in the viscous joint 24 is transmitted from the output shaft 46 to the rear final reduction mechanism 26, and transmitted to the rear wheels 8 via the rear differential mechanism 28.
On the other hand, the front wheel 6 and the rear wheel 8 are connected via the ground.

Here, the peripheral speeds of the front wheel 6 and the rear wheel 8 are V _F and V _R , respectively, the rotation speed of the propulsion shaft 14 is N _F , and the output shaft 46 of the viscous coupling 24 generated by the torque transmitted from the rear wheel 8 side. _Let N _{R be} the rotation speed of Where, R _F : average radius of left and right front wheels 6, i _TF : distribution mechanism 6
6, tooth ratio of each gear _40/64 (i _TF = Z ₆₄ ÷ Z ₄ o), ic: tooth ratio of each gear 56/58 of deflecting mechanism 60 (ic = Z ₅₈ ÷ Z ₅₆ ), R _R :
The average radius of the left and right rear wheels 8, i _R: is a gear ratio of each gear 48, 50 of the rear final reduction mechanism _{26 (i R = Z 5 o} ÷ Z 48).

Divide the above formula by 2 formulas Get.

Here, in the case of N _F / N _R ≠ 1, a slip has occurred in the viscous joint 24. Further, when the viscous joint 24 is not provided, a slip has occurred between the front and rear wheels 6 and 8 or one of the front and rear wheels 6.8 and the ground, and a part of the power is converted into heat. It's strange.

V _F / V _R is V _F / V _R = 1 when traveling straight, and V _F / V _R > 1 when turning. R _R / R _F is determined by the weight distribution of the front and rear wheels 6.8, the tire pressure, and the variation of the tire products. If the tire pressure, the product variation, and the like are equal, the front and rear wheels 6.8 are determined. R _R / R _F > 1 based on the spring constant and the shared load of the tire.

In the conventional power transmission system of the automobile 2 shown in FIG. 4, the above equation (3) indicates that i _TF = 1, and Becomes

Generally, it is advantageous to use a hypoid gear having a gear specification common to 1 / ic = i _R in terms of production. In this case, since R _R / R _F > 1, as described above, N _F / N _R > 1.

Similarly, in the conventional vehicle power transmission device shown in FIG. Becomes

Generally, i _TF is set in the speed increasing state, and i _TF <1
It has become. On the other hand, ic and i _R need to be 2.8 or more in terms of the number of teeth in order to manufacture a gear that is quiet in terms of production technology using a bevel gear.

However, i _R is to reduce the suppressed low by vibration and noise of the rotational speed of the propeller shaft 14 using conventional hypoid gear is required to be a i _R = 3-3.5. On the other hand, in the practical of one arrangement obtained by i _TF in normal parallel shaft gear, i _TF = 1 /
3.7 to 1 / 4.2, where R _R / R _F ≒ 1 and N _F / N _R = 1
Is Which is far from the required gear ratio.

 For this reason, there are disadvantages as described above.

In the present invention, as shown in FIGS. 1 to 3, any one of the final reduction mechanism of the main power transmission system 10 and the sub power transmission system 12,
In this embodiment, a viscous joint 24 is connected to a rear final reduction mechanism 24 constituting the auxiliary power transmission system 12 to increase or decrease the power of the internal combustion engine 4 between the propulsion shaft 14 and the viscous joint 24. The inconvenience is eliminated by providing a gear ratio adjusting mechanism 68 which is a gear ratio adjusting means including a pair of gears 70 and 72 having a gear ratio transmitted to the gears. The gear ratio adjusting mechanism 68 is provided between the power transmission end portion 14e of the propulsion shaft 14 and the power transmission start portion 12b of the auxiliary power transmission system 12.
The gear ratio adjusting mechanism 68 includes a first adjusting gear 70 provided at a power transmission end portion 14e on the output side of the propulsion shaft 14 and a power transmission on the input side of the viscous joint 24 constituting the auxiliary power transmission system 12. An adjustment second gear 72 provided at the start end portion 12b. The number-of-tooth ratio adjusting mechanism 68 is provided with these adjusting first and second gears 70.
With the gear ratio of 72, the power of the internal combustion engine 4 can be transmitted at an increased or reduced speed.

Therefore, assuming that ico _M p = Z ₇₂ ÷ Z ₇ o, in the power transmission device of the automobile 2 shown in FIG. Next Get.

Usually, the difference in the number of teeth between the gears 70 and 72 of the gear ratio adjusting mechanism 68 is
Since the ratio is obtained as 1, N _F / N _R = 1.

Further, in the power transmission device of the automobile 2 shown in FIG. And, in the same manner as the above equation (6), Becomes

To set ic = 2.8 Becomes

Here, i _R Since the relationship through the i _COMP to the rotation speed of the propeller shaft 14, from the propeller shaft 14 and i _COMP <1 that power is transmitted to the speed increase in the viscous coupling 24, propeller shaft The number of revolutions of 14 can be made sufficiently low. Also, this ico _M p
c> 1.5. Here, if i _R = 4, Can be realized.

Also, more precise, it is needless to say it is desirable to determine the ico _M p by considering the ratio of _R R / R _F.

The gear ratio adjusting mechanism 68 may be a chain, a planetary gear, or the like, in addition to the parallel shaft gear.

The power is increased and input to the viscous coupling 24 by the gear ratio adjusting mechanism 68 with i _COMP <1, and is transmitted to the rear wheels 8 after being decelerated by the rear final reduction mechanism 26. The capacity of 24 can be reduced, which is practically advantageous.

Further, as shown in FIG. 3, a rear reduction small gear 48 comprising a hypoid gear of the rear final reduction mechanism 26 and a rear reduction large gear
The offset with respect to 50 is set such that the rear reduction small gear 48 is higher than the rear reduction gear 50 by A, and the first adjustment gear 70 of the gear ratio adjusting mechanism 68 is set to be higher than the second adjustment gear 72. By setting it lower downward, the propulsion shaft 14 is
Can be lowered regardless of the ground clearance.

〔The invention's effect〕

As described above, the power transmission device of the present invention includes a propulsion shaft that connects the main power transmission system and the sub power transmission system, and a viscous joint that is connected to one of the final reduction mechanisms of the main power transmission system and the sub power transmission system. Between the front and rear final reduction mechanisms, etc., constituting a power transmission device by providing a gear ratio adjusting means comprising a pair of gears having a gear ratio for transmitting power by increasing or decreasing power. The degree of freedom in setting the gear ratio of each gear mechanism can be increased. For this reason, the power transmission system can be configured without being limited by the gear ratio of each gear mechanism such as the distribution mechanism and the deflection mechanism, which is advantageous in production technology. Further, the gear ratio adjusting means can reduce the rotational speed of the propulsion shaft by setting the gear ratio of the pair of adjustment gears to the gear ratio at which the viscous joint speeds up with respect to the propulsion shaft. As a result, vibration and noise can be reduced, and the capacity of the viscous joint can be reduced. Further, the tooth number ratio adjusting means can lower the propulsion shaft by providing one adjustment gear provided on the propulsion shaft below the other adjustment gear provided on the viscous coupling.

[Brief description of the drawings]

1 to 3 show an embodiment of the present invention. FIG. 1 is a schematic plan view of a power transmission device for transmitting power to a sub power transmission by a deflecting mechanism, and FIG. Schematic plan view of a power transmission device for transmitting power to the auxiliary power transmission system,
FIG. 3 is a schematic side view of the auxiliary power transmission system. 4 and 5 show a conventional example, FIG. 4 is a schematic plan view of a power transmission device for transmitting power to a sub power transmission unit by a deflection mechanism, and FIG. 5 is a sub power transmission by a distribution mechanism and a deflection mechanism. FIG. 2 is a schematic plan view of a power transmission device that transmits power to a system. In the figure, 2 is an automobile, 4 is an internal combustion engine, 6 is a front wheel,
8 is a rear wheel, 10 is a main power transmission system, 12 is a sub power transmission system, 14
Is a propulsion shaft, and 68 is a gear ratio adjusting mechanism.

Claims (1)

(57) [Claims] 1. A main power transmission system for transmitting power of an internal combustion engine to one of a front wheel and a rear wheel, and power of the internal combustion engine taken out from the main power transmission system via a propulsion shaft. A power transmission device having an auxiliary power transmission system for transmitting the force to the other wheel, a viscous joint connected to a final reduction mechanism of one of the main power transmission system and the auxiliary power transmission system, And a viscous coupling, a gear ratio adjusting means including a pair of gears having a gear ratio for increasing or decreasing the power of the internal combustion engine to be transmitted, and the gear ratio adjusting means is provided with the propulsion shaft. A power transmission device for an automobile, wherein one of the adjustment gears provided on the viscous joint is provided below the other adjustment gear provided on the viscous joint.