JPS62143729A - 4-wheel drive device - Google Patents

Abstract

PURPOSE:To improve driving performance, by a method wherein a transfer shaft and a viscous coupling are transmitted to either front and rear wheels through an engaging clutch in three positions for direct coupling, and one control system is combined with two sets of clutches to provide 4-wheel drive or 2-wheel drive of front wheel direct coupling with viscous coupling and rear front wheel direct coupling. CONSTITUTION:When a rail 48 is controlled to an R direct coupling 4WD position, an engaging clutch 40 is shifted to the viscous coupling side, an engaging clutch 45 to the direct coupling side to form 4-wheel drive through rear wheel direct coupling front wheel viscous coupling. When to an F direct coupling 4WD, the engaging clutch 40 is shifted to the direct coupling side, and the engaging clutch 45 to the viscous coupling side to form drive through front wheel direct coupling rear wheel viscous coupling. When to an FR position, the engaging clutch 45 is brought into a free state to form 2-wheel drive of F and F. This constitution improves drivability.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a four-wheel drive device for a vehicle such as an automobile, and more particularly, to a transverse transaxle type device that selectively provides various driving modes such as four-wheel drive using a viscous coupling.

[Background of the invention]

A four-wheel drive VI system that does not have a center differential generally has a configuration in which power is constantly transmitted to one of the front wheels or rear wheels, and the power is transmitted to the other wheel via a transfer device. It has been proposed to use clutches, hydraulic clutches, and electromagnetic clutches. Here, dog clutches cannot absorb any rotational differences during turning, and hydraulic clutches have advantages and disadvantages, such as requiring control of clutch oil pressure. On the other hand, in recent years, a clutch called a viscous coupling (viscous clutch) has appeared, which has a sealed structure of wet multi-plates filled with a viscous medium, and has the characteristic of increasing the transmitted torque as the rotational difference between input and output increases. Therefore, such a viscous coupling can be used as a differential lock, and when used in a transfer device of a four-wheel drive device, it automatically adjusts the performance of the four-wheel drive according to the rotational difference such as the slip state of the front and rear wheels. It can be strengthened. Furthermore, as long as the rotational difference does not become extremely large during turning, internal circulation torque can be absorbed by the slip of the viscous coupling, and this point is attracting attention.

[Prior art 1] Conventionally, regarding four-wheel drive using the above-mentioned viscous coupling, there is a prior art, for example, in Japanese Utility Model Application Publication No. 59-188731. It has been shown that power is transmitted to [Problems to be Solved by the Invention] By the way, in the configuration of the prior art described above, only one type of driving mode can be obtained in which the relationship TF>TR is satisfied between the bamboo wheel torque TF and the rear wheel torque TR. Therefore, there are problems such as not being able to drive with emphasis on maneuverability, and not being able to maximize drive performance such as starting depending on the loaded state. The present invention has been made in view of these points, and therefore provides a four-wheel drive system that can freely select multiple types of driving modes such as four-wheel drive using a viscous coupling and fully exhibit various performances. is intended to provide.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a transfer device disposed before and after a transverse transaxle type differential device, in which a transfer shaft is connected to the output side of the transmission, and a viscous coupling is attached to the transfer shaft. , and the transformer 71 axis and the output element of the viscous coupling are v,
Transmission is configured to one of the front and rear wheels via a dog clutch with 3 positions for c-direct connection, and at the same time, the other V, c-3 for direct connection-free use.
The transmission is configured to the other of the front and rear wheels via a dog clutch at the position, and one operating system is connected to the two sets of dog clutches. It is configured to obtain a driving mode of wheel drive or FF two-wheel drive.

[For production]

Based on the above configuration, the two navy blue dog clutches are simultaneously switched by a single operating system, and each driving mode is selected: front wheel direct connection via rear wheel viscous coupling, rear wheel direct connection via front wheel viscous coupling, or FF driving mode. It becomes like this. In this way, according to the present invention, it is possible to select the optimum four-wheel drive that fully utilizes the viscous coupling or the two-wheel front-wheel drive (FF) mode depending on the driving conditions, I-wheel conditions, and the like.

[Embodiment 1] Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings. In the drawings, a four-wheel drive system to which the present invention is applied and a transmission system based on a transverse transaxle type FF vehicle will be explained. An engine 1. A clutch 2 and a transmission 3 are arranged horizontally in the left-right direction, and a front differential device 4 is located behind the transmission 3. Transfer devices 5 are sequentially arranged. And transmission 3. The front differential device 4 and the transfer device 5 include a clutch housing 6, a transmission case 7, and an extension case 8.
It is installed inside the engine and forms a transaxle type. The speed change n3 is of a constant mesh type, and is connected to the input shaft 10 from the clutch 2 and the output shaft 11 arranged parallel to it, for example, five sets of speed changes that mesh with each other, from 1st speed to 5th speed (overdrive). Gears 12 to 16 are provided, including a synchronizing mechanism 17 between gears 12 and 13 and a synchronizing mechanism 18 between gears 14 and 15. Alternatively, by selectively operating the synchronizing mechanism 19 adjacent to the gear 16, each of the forward gears from the first gear to the fifth gear is shifted by one. Further, the gear 20 for the reverse gear integrated with the input shaft 10 is meshed with the gear 1721 on the sleeve side of the synchronizer mechanism 17 via an idler gear (not shown) to obtain the reverse gear. In the front differential device 4, a drive gear A722 (described later) meshes with a final gear 23, and this final gear V23
It is connected to the left and right front wheels via a differential gear 24 attached to the vehicle @25. In the transfer device 5, a transfer gear 27 is integrally connected to a transfer shaft 26 installed in the left-right direction of the vehicle body.
This transfer gear 27 and the output shaft 11 of the transmission 3
and the output gear 28 are always in mesh with each other via an intermediate gear 29. A viscous coupling 30 is coaxially provided on the transfer shaft 26 and connects a hub 31 thereto. This viscous coupling 30 is an integral play between the hub 31 and the housing 32)-3
3 and 34 are arranged alternately and a highly viscous liquid is sealed therein, and has a characteristic of increasing the transmitted torque in accordance with the difference in rotation between the hub 31 and the housing 32. Here, the hub 31 connected to the transformer 71 shaft 26 is inserted.
The housing 32 of the force element and output element is taken out coaxially with the transfer shaft 26 . The transfer shaft 26 and the housing 32 are connected to the V.V. It is connected to the drive gear 22 of the front differential device 4 via a C-direct connection 3-position dog clutch 40 for transmission to the front wheels. At the same time, the transfer shaft 26 and the housing 32 are
, C-directly connected to the bevel gear drive 35 via the free 3-position dog clutch 45, and connected to the bevel gear drive 35 from the bevel gear drive 36 to the rear drive shaft 37. It is configured to be connected to the rear wheels via the propeller shaft 38 and the like. One dog clutch 40 has a sleeve 42 constantly meshing with a hub 41 of the drive gear 22, and teeth 4 of the sleeve 42.
2a is the spline 26a of the transfer shaft 26 in the 2nd position.
@42b selectively meshes with the solenoid 32a of the housing 32 in the 1 position. The other dog clutch 45
The sleeve 47 is attached to the hub 46 of the bevel gear drive 35.
The teeth 47a and 47b of the sleeve 47 selectively mesh with the splines 26a and 32a at one position, respectively, and do not mesh at the remaining position. In the operation system, one rail 4 from the select lever
8 is: lll dog clutch 40.45 sleeve 4
2.47, and R on the left side of rail 48.
It has three positions in a straight line: direct 4WD, F direct 4WD in the middle, and FF on the right side. Next, the operation of the four-wheel drive device configured as described above will be explained. First, when the vehicle is running, the synchronizer @17 is activated in the transmission 3.
．． By synchronizing with 18, 19, etc., gears A712 to 16, 20, 21, etc. move the output shaft 11 forward in 5 stages. Outputs gear shifting power for 1 reverse gear. The power of the output shaft 11 is once transmitted to the transfer shaft 26 of the transfer device 5 via the gears 28, 29, 27, and then input to the viscous coupling 30. Therefore, when the rail 48 is operated to the left R direct connection 4WD position, the dog clutch 40 is moved to the sleeve 4 as shown in the figure.
The V.2 tooth 42b meshes with the spline 32a and the V. Switch to C side. Therefore, the transfer shaft 2G is connected to the drive gear 22 of the front differential device 4 through the viscous coupling 30, and power is transmitted to the front wheels via this path. On the other hand, the dog clutch 45
The teeth 47a of No. 7 mesh with the spline 26a and switch to the direct connection side, and the transfer shaft 2G is connected to the bevel gear drive 35.
Directly connected to. Therefore, power is directly transmitted to the rear wheels, resulting in four-wheel drive via a front wheel viscous coupling that is directly connected to the rear wheels. Therefore, in this driving mode, when the difference in rotation between the front and rear wheels is small, the torque transmitted by the Bisnokos coupling 30 is small, resulting in FR-like driving. Meanwhile, the rear wheels slipped,
Or, if the rear wheel radius decreases due to an increase in rear load capacity and the rotation difference between the front and rear wheels increases, the viscous coupling 30
The transmission torque increases rapidly, increasing the driving force for the front wheels, thereby enhancing the performance of four-wheel drive. Further, in this case, since TF<TR holds between the front axle torque Tl1- and the rear axle torque TR, maneuverability is emphasized. On the other hand, when the rail 48 is operated to the intermediate F direct coupling 4WD position, the dog clutch 40 is switched to the direct coupling side by meshing the teeth 42a and the spline 26a, directly coupling the transfer shaft 2G to the drive gear 12. On the other hand, the dog clutch 45 has teeth 47b and splines 3.
V. by meshing with 2a. Switching to the C side, the transfer shaft 26 is connected to the bevel gear drive 35 through the viscous 7J coupling 30 to transmit power, resulting in four-wheel drive via the front wheel directly connected rear wheel viscous coupling. Therefore, in this driving mode, TF > TR and FF
Stability tax becomes heavy due to target driving. As described above, the four-wheel drive performance is enhanced according to the difference in rotation between the front and rear wheels. Furthermore, when the rail 48 is set to the FF position on the right side, the dog clutch 40 is in the F direct connection switching state, but the dog clutch 45 becomes free and the rear wheel side is disconnected. It becomes a drive. Therefore, in this driving mode, the vehicle runs in the same way as a normal front-wheel drive vehicle, with no tight corner braking phenomenon occurring at all. Although one embodiment of the present invention has been described above, it can also be applied to an RR (rear engine/rear drive) base. Also, the output elements of the viscous coupling 30 may be reversed. Furthermore, the rail 48 can be operated manually or by a button switch. Effects of the Invention As described above, according to the present invention, it is possible to arbitrarily select two types of driving modes: front wheel drive with a viscous coupling or rear wheel direct connection. can be fully utilized. Depending on driving conditions, loading conditions, etc., it is possible to drive with both stability and maneuverability. You can also select the FF two-wheel drive driving mode, so you can enjoy the difference in maneuverability and drive according to your preference. Since two sets of dog clutches are switched by one rail,
It has good operability and a simple structure. The three positions are arranged in a straight line, making it easy to operate.

[Brief explanation of drawings]

The drawing is a skeleton diagram and does not show an embodiment of the four-wheel drive device of the present invention. 3...Transmission, 4...-70 differential gear, 5...
Transfer device, 26... Transfer shaft, 21.
-・Transfer gear, 28.29...gear, 30・
...Viscous coupling, 31...Hub, 32...
・Housing, 40...V. C-3-position dog clutch for direct connection, 45...V, C-3-position dog clutch for direct connection-free, 48...operation rail.

Claims (1)

[Claims] In a transfer device disposed before and after a transverse transaxle type differential device, a transfer shaft is connected to the output side of the transmission, and a viscous coupling V. C, and transfer shaft and viscous coupling output element to V.
．． Power is transmitted to one of the front and rear wheels via a 3-position dog clutch for direct connection, and at the same time the other V. C-Direct connection - Transmission is configured to the other front and rear wheels via a 3-position dog clutch for free, and one operating system is connected to the above two sets of dog clutches, and the front wheel direct connection with viscous coupling and the rear wheel are connected. A four-wheel drive system that provides two types of driving modes: direct-coupled four-wheel drive or front-wheel drive two-wheel drive.