JPH011626A - 4-wheel drive with center differential - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

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

The present invention relates to a full-time four-wheel drive device equipped with a center differential device, and more particularly to a differential lock m structure for both devices in a gear train in which a center differential device is disposed coaxially with a differential device of one of the front and rear wheels.

[Conventional technology]

Generally, a full-time four-wheel drive device is equipped with a center differential, and is configured to distribute torque from a transmission to front and rear wheels using the center differential device and transmit it. Here, various proposals have been made regarding the arrangement of the center differential device and the routing of power, but there is a tendency to place the center differential device close to the differential device on the transmission side in order to downsize and reduce the vehicle height. Conventionally, regarding the arrangement of the differential device and the center differential device in the 4#la drive device with a center differential, there is a prior art, for example, in Japanese Patent Application Laid-Open No. 143131/1983. Here, it is shown that the differential device and the center differential device are disposed close to each other on the same axis, the center differential device is configured using a double binion type planetary gear, and a lock-up mechanism is provided.

[Problems to be solved by the invention]

Incidentally, in the prior art described above, the differential device itself is actually provided with a differential lock m mechanism, so that the differential device and the center differential device each have a separate differential lock mechanism. Each differential lock aata has a different structure, which makes the overall structure including the differential lock mechanism complicated. Furthermore, there are other problems, such as the increased number of parts, which increases the weight and requires more space. The present invention has been made in view of these points, and includes an overall structure including a differential device, a center differential device, and differential lock mechanisms for both devices. It is an object of the present invention to provide a 4M drive device with a center differential in which the structure of the differential lock mechanism itself is simplified.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a center differential device on the output side of a transmission, and connects one output element of the center differential device to one differential device of the front and rear wheels, and connects the other output element to the other of the front and rear wheels. A viscous coupling that differentially locks at a predetermined rotational difference is interposed between one and the other output element of the center differential device and the output element of the differential device in the drive system configured to transmit power to the center differential device. is configured to do so.

[For production]

Based on the above configuration, power from the transmission is distributed by the center differential device and immediately transmitted to one of the front and rear wheels and the other through the differential device, resulting in full-time four-wheel drive. At this time, if the rotational difference between the front and rear wheels and the output elements of the center differential device, or the rotational difference between the left and right wheels and the output elements of the differential device exceeds a set value, the differential is locked by engagement of the viscous coupling. In this way, in the present invention, it is possible to simplify the structure of the differential lock between the center differential device and the differential device by using a type 1 sticky coupling.

【Example】

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. In the drawings, as a four-wheel drive system with a center differential to which the present invention is applied, for example, a transmission system based on a transverse transaxle type front engine/front drive (FF) vehicle will be described. ．． A clutch 2 and a transmission 3 are arranged horizontally in the left-right direction, and a center differential device 9 is located behind the transmission 3 and the vehicle body. Front differential device 4. Transfer device 5
are arranged sequentially. And transmission 3. Center differential device9. The front differential device 4 and the transfer device Wt5 are installed inside each of the clutch housing 6, the transmission case 7, and the side cover 8 to form a transaxle type. The transmission 3 is of a constant mesh type, and has five sets of gears meshing with each other, for example, 1st speed to 5th speed (overdrive), on an input shaft 10 from the clutch 2 and an output shaft 11 arranged parallel to the input shaft 10. A synchronizing mechanism 17 between gears 12 and 13, a synchronizing mechanism tR18, t between gears 14 and 15, or a synchronizing mechanism 19 adjacent to gear 16 are selectively operated. In this way, each forward gear stage from the first speed to the fifth speed is obtained. Further, the reverse gear is obtained by meshing a reverse gear 20 integral with the input shaft 10 with a gear 21 on the sleeve side of the synchronizer M17 via an idler gear (not shown). The center differential device 9 consists of a single-binion planetary gear, including a sun gear 30. It has a ring gear 31, a pinion 32, and a carrier 33 that supports the pinion 32. Then, the carrier 3 of the input element is connected to the large diameter final gear 23 that meshes with the drive gear 22 of the transmission output shaft 11.
3 are integrally connected, and the ring gear 31 of one output element is connected to the front differential device 4 side. The sun gear 30 of the other output element is connected to a sun gear shaft 34 . Pair of glue reduction gears 35° Transfer shaft 36 of transfer device 5. Bevel gear for direction conversion 37. Transmission is configured to the rear wheel side via the rear drive shaft 38. The front differential device 4 includes a differential case 40
A pinion shaft 41 is attached to the pinion shaft 41, left and right side gears 43 mesh with the pinion 42 of the pinion shaft 41, and a front wheel 44 is taken out from the side gears 43. Therefore, the center differential device 9 and the front differential device 4 are arranged coaxially and adjacently, and a viscous coupling 50 for differential locking is interposed between them. This viscous coupling 50 has inner plates 52a, 52b and an outer plate 5 inside a housing 51.
The inner blades 52a and 52b and the outer blades 1 and 3 are arranged alternately and filled with highly viscous oil.
When the difference in rotation with 53 becomes large, it engages with oil,
Inner plates 52a, 52b and outer plate 53
It has the characteristic of increasing the transmission torque between the Therefore, the viscous coupling 50 performs a differential lock between the center differential device 1 and the front differential device 4, and the center differential device 9. The arrangement is such that the front differential device 4 is configured to perform both differential lock operations at the same time. That is, the ring gears 31 of the center differential device 9 are connected to each other.
and the differential case 40 of the front differential device 4
A housing 51 having an outer plate 53 is coupled therebetween, and inner plates 52a and 52b are attached to the sun gear shaft 34 and the axle 44. and between the sun gear 30 and ring gear 31 on the center differential 9 side, and between the differential case 40 and the axle 4 on the front differential W4 side.
4, both have a transmission configuration in which a viscous coupling 50 is interposed. Next, the operation of the four-wheel drive device configured as described above will be described. First, the power of the engine 1 is input to the input shaft 10 of the transmission 3 via the clutch 2, and is transmitted through the gears 12 to 16, 20, 21, etc. by operating the synchronizing mechanisms 17 to 19, etc. in the transmission 3. Output shaft 11 has 5 forward speeds and 1 reverse speed.
The gear shifting power is output. This shifting power is transmitted to the drive gear 22. Center differential device 9 by final gear 23
The transmission is transmitted to the carrier 33 of the sun gear 30 and the ring gear 3.
Torque is distributed between 1 and 1. The power of the ring gear 31 is input to the differential case 40 of the front differential device 4, and the torque is further distributed and transmitted to the front wheels via the axle 44. On the other hand, the power of the sun gear 30 is transmitted from the sun gear shaft 34 to the rear wheels via the 1-transfer device 5, etc. In this way, the power is constantly transmitted to the front and rear wheels, making it possible to drive in full-time four-wheel drive. become. When turning, the differential operation of the front differential device 4 absorbs the rotational difference between the left and right wheels, and the differential operation of the center differential device 9 absorbs the rotational difference between the front and rear wheels, allowing the vehicle to turn smoothly. Therefore, when the vehicle travels through power transmission, the power of the ring gear 31 is input to the outer plate 53 of the viscous coupling 50, and the power of the sun gear 30 is input to the inner plate 52a. Further, the outer plate 53 is connected to the ring gear 31, and the inner plates 52a and 52b are connected to the sun gear 30. It rotates together with the axle 40, and the ring gear 31 and sun gear 30. Differential case 40 and axle 4
4 is small, therefore, the viscous coupling 50
outer plate 53 and inner plate) 52a, 52
The difference in rotation with b is also small, and they are simply released and rotated together. On the other hand, when one of the left and right wheels comes off, the difference in rotation between the differential case 40 and the axle 44 becomes significantly large due to the differential operation, and as a result, the outer plate 5 of the viscous coupling 50
3 and the inner plate 52b engage based on this rotational difference, thereby performing a differential locking action. Then, depending on the torque capacity of the viscous coupling 50, power is transmitted from the differential case 40 to the axle 44 in a bypass manner, thereby making it possible to escape from the derailed state. Furthermore, when one of the front and rear wheels comes off, a large rotational difference occurs between the sun gear 30 and the ring gear 31, and the outer plate 53 and inner plate 52a of the viscous coupling 50 similarly engage, resulting in a differential lock effect. . Then, power is transmitted from one of the sun gear 30 and ring gear 31 to the other by bypass, and the vehicle is released from the off-wheel state. In this way, when the viscous coupling 50 escapes and returns to the original rotational difference, the viscous coupling 50 is released again and can pivot. Although one embodiment of the present invention has been described above, it can also be applied to vertical transaxle types other than FF paces. Further, the viscous coupling may be divided into two or more sets.

【Effect of the invention】

As described above, according to the present invention, since the differential lock between the center differential device and the differential device is performed by one type of viscous coupling, the structure is simplified and both devices are connected by one viscous coupling. A method that locks the differential at the same time is more advantageous in terms of structure, space, and cost. Since it is sufficient to connect the inner plate and outer plate sides of the viscous coupling to the differential lock side of each device, the degree of freedom in design increases. Depending on the characteristics of the viscous coupling, it is possible to arbitrarily determine and optimize the differential lock rotation difference, transmission torque, etc.

[Brief explanation of drawings]

The drawing is a skeleton diagram showing an embodiment of a 41m drive device with a center differential according to the present invention. 3... Transmission, 4... Front differential device, 9... Center differential device, 30... Sun gear, 31... Ring gear, 40... Differential case, 44
... Axle, 50 ... Viscous coupling patent applicant Fuji Heavy Industries Co., Ltd. agent Patent attorney Makoto Kobashi Slag amount Patent attorney Susumu Murai

Claims (2)

[Claims] (1) In a drive system in which a center differential device is provided on the output side of the transmission, power is transmitted from one output element of the center differential device to one differential device of the front and rear wheels, and from the other output element to the other of the front and rear wheels. A center differential, characterized in that a viscous coupling is interposed between one and the other output element of the center differential device and the input and output elements of the differential device to lock the differential at a predetermined rotational difference. Comes with 4 wheel drive. (2) The center differential device and the differential device are coaxially arranged adjacent to each other, a viscous coupling is provided between the two devices, and the outer plate of the viscous coupling is connected to one output element of the center differential device. 4 with a center differential according to claim 1, wherein an inner plate is attached to the input element side of the differential device, and an inner plate is attached to the other output element of the center differential device and the output element side of the differential device. Wheel drive.