JPS62137228A - Four-wheel drive device - Google Patents

Abstract

PURPOSE:To improve drive performance by providing a direct claw clutch between the input element of a viscous coupling and a transfer shaft to obtain in total two types of traveling modes of one type with the viscous coupling and direct coupling of front and rear wheels. CONSTITUTION:When a rail 43 is operated to the F direct 4WD position, a claw clutch 40 is changed over to the viscous coupling 35 side and connected directly to a transfer shaft 26 to transmit power to rear wheels. Then, when the rail is operated to the FR direct 4WD position, the claw clutch 40 is changed over to the direct side by the engagement of a sleeve 42 with a housing 37. Thus, a transfer gear 30 is connected directly to the transfer shaft 26 through the housing 37 to transmit power also to rear wheels directly. Thus, since total two types of four-wheel drive of direct coupling of front wheel and front and rear wheels are selectively obtained, the drive performance such as maneuverability and starting property can be sufficiently displayed.

Description

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

The present invention relates to a four-wheel drive system for 131 vehicles such as self-driving cars, and more particularly to one that selectively provides various four-wheel drive driving modes using a transverse transaxle type and a viscous coupling.

[Background of the invention]

A four-wheel drive vehicle without a center differential generally transmits power to one of the front or rear wheels at all times, and to the other through a transfer device. It has been proposed to use dog clutches, hydraulic clutches, and electromagnetic clutches. Here, dog clutches cannot absorb rotational differences during turning at all, 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 system, it automatically enhances the performance of the four-wheel drive according to the rotational difference such as the slip state of the front and rear wheels. It is possible. Also,
As long as the difference in rotation during turning does not become extremely large, the slip of the viscous coupling can absorb one herk of internal circulation, and this point is attracting attention.

[Prior art 1] Therefore, conventionally, regarding the four-wheel drive using the above-mentioned viscous coupling, for example, the actual f7fl
There is a prior art in Japanese Patent Publication No. 2003-11102, which shows that power is transmitted to the rear wheels via a viscous coupling as an FF base. Problems to be Solved by the Invention 1 By the way, in the configuration of the prior art described above, only one type of driving mode is available in which the relationship TF>TR exists between the front 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 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 for Solving the Problems] In order to achieve the above object, the present invention provides a transfer device disposed in front of a transverse transaxle type differential device that meshes with the final gear of the differential device. A transfer shaft is connected to transfer gear A7 via a viscous coupling, and a V, C-coupling dog clutch is provided between the input element of the viscous coupling and the transfer shaft, and the transfer shaft 1 is connected to one of the front and rear wheels. It is configured to provide two types of four-wheel drive driving modes: one with a viscous coupling and one with direct connection to the front and rear wheels.

[For production]

Based on the above configuration, by switching the dog clutch to the V, C, or direct coupling side, it is possible to select, for example, a driving mode in which the front wheels are directly connected via a rear wheel viscous coupling, or the front and rear wheels are directly connected. Thus, according to the present invention, it is possible to select the optimum four-wheel drive mode depending on the driving condition, loading condition, etc., depending on the presence or absence of a viscous coupling.

【Example】

Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings. In the drawings, a four-wheel drive device to which the present invention is applied,
To explain the transmission system based on a transverse transaxle type FF vehicle, the engine 1 is located at the front of the vehicle. A clutch 2 and a transmission 3 are arranged horizontally in the left-right direction, and a front differential fffi4. t-
Lansif 1 devices 5 are arranged one after the other. And transmission 3.
The front differential device 4 and transfer'#ais are
Clutch housing 6. It is installed inside the transmission case 7 and the extension shaft 8, forming a transaxle type. The transmission 3 is of a constant mesh type, and has an input shaft 10 from the clutch 2 and an output shaft 11 arranged parallel thereto, for example, five sets of 1st gear to 5'a (overdrive) that mesh with each other. Shift gears 12 to 16 are provided, including a synchronizing mechanism 17° between gears 12 and 13, and gears 14 and 15.
Synchronization mechanism between 18. Alternatively, by selectively operating the synchronizing mechanism 19 adjacent to the gear 16, each of the forward gears from the first speed to the fifth speed is obtained. In addition, a reverse gear 20 integrated with the input shaft 10 is connected to an idler gear A7 (not shown).
By meshing with the gear 21 on the sleeve side of the synchronizing mechanism 17 via the synchronizing mechanism 17, a reverse gear is obtained. In the front differential device 4, a drive gear 22 of a transmission output shaft 11 meshes with a large-diameter final gear 23, and a differential device 24 attached to the final gear 23 is connected to left and right front wheels via an axle 25. Link. The transfer device @5 is rotatably supported by a transfer shaft 26 and installed in the left-right direction of the vehicle body, and a pair of bevel gears 27. Rear drive shaft 28
．． Transmission is configured to the rear wheels via the propeller shaft 29 and the like. Further, a transfer gear 30 that meshes with the final gear 723 is provided coaxially with the transfer shaft 2G, and the housing 37 of the viscous coupling 35 is connected to this transfer gear 1730. This viscous coupling 3
5 is comprised of integral plates 38 and 39 installed alternately on either side between the hub 36 and the housing 37, and filled with a highly viscous liquid, thereby reducing the rotational difference between the hub 3G and the housing 37. The housing 37 connected to the transfer gear 730 is an input element, and the output element hub 36 is connected to the transfer shaft 26.The input side of the viscous coupling 35 A dog clutch 40 for direct coupling between the housing 37 and the transformer 77 shaft 26 on the output side is provided.This dog clutch 40 has a sleeve 42 constantly meshing with the hub 41 of the transfer shaft 2G. The teeth 42a of the sleeve 42 engage or disengage the splines 37a of the housing 37.In the operating system, one rail 4 from the select lever
3 is connected to the sleeve 42, and on the left side of the rail 43 is a front and rear wheel FR directly connected 4WD, and on the right side is a front wheel F directly connected 4WD.
It has two positions. Next, a 4-wheel drive wJ configured like this! ! i'!
The effect of No. 1 will be explained. First, when the vehicle is running, the synchronizer mechanism 17 is activated in the transmission 3.
．． By operating 18, 19, etc., gears 12 to 16
．． 20, 21, etc., power for changing speeds for five forward speeds and one reverse speed is output to the output shaft 11. This power is always directly transmitted to the front wheels by the front differential device 4, and at the same time is input to the viscous coupling 35 of the transfer device 5 via the transfer gear 30. Therefore, when the rail 43 is operated to the F direct connection 4WD position on the right side, the dog clutch 40 is released and switched to the viscous coupling 35 side as shown in Figure 1, so that the transfer gear 30 passes through the viscous coupling 35 to the transformer. 77 shaft 26, and power is transmitted to the rear wheels via this path. In this way, the vehicle enters a four-wheel drive mode in which the front wheels are directly coupled via the rear wheels via a viscous coupling. In this driving mode, when the difference in rotation between the front and rear wheels is small, the torque transmitted by J3 to the viscous coupling 3ji is small, resulting in FF-like driving. On the other hand, when the front wheels slip and the rotation difference between the front and rear wheels increases, the transmission torque of the viscous coupling 35 increases rapidly, thereby enhancing the four-wheel drive performance. In addition, in this case, TF > T in front axle torque TF and rear axle torque TR
Since it is R, emphasis is placed on driving stability. Next, when the rail 43 is operated to the left FR direct connection 4WD position, the dog clutch 40 engages the teeth 42 of the sleeve 42.
a engages with the spline 37a of the housing 37 and switches to the direct connection side. Therefore, the transfer gear 30 is directly connected to the transfer shaft 26 through the housing 37 of the viscous coupling 35, and power is also directly transmitted to the rear wheels, resulting in a four-wheel drive system in which the front and rear wheels are directly connected. Therefore, in this driving mode, the vehicle is always in four-wheel drive to maximize performance when starting off or on rough roads. Although one embodiment of the present invention has been described above, it is also possible to apply it to an RR base to obtain R direct-coupled 4WD and FR-directly coupled 4WD. Further, the hub 3G of the viscous coupling 3;) and the position and output of the housing 37 may be reversed. Furthermore, the rail 43 can be operated either manually or with a button switch.

【Effect of the invention】

As described above, according to the present invention, two types of four-wheel drive with viscous coupling, for example, front wheel direct connection and front and rear wheel direct connection, can be arbitrarily selected, resulting in improved maneuverability and stability. You can start off or run according to your preference. Since one set of dog clutches is switched by one rail, operability is good and the structure is simplified.

[Brief explanation of drawings]

The drawing is a skeleton diagram showing an embodiment of the four-wheel drive device of the present invention. 4...Front differential device, 5...Transfer device, 23...Final gear, 26...Transformer 77
! Shaft, 30... Transfer gear, 35... Viscous coupling, 36... Hub, 37... Housing, 40..., C-direct connection dog clutch, 43...
・Operation rail.

Claims (1)

[Claims] In a transfer device disposed before and after a horizontal transaxle type differential device, a transfer shaft is connected to the transfer gear meshing with the final gear of the differential device via viscous couplings V and C. A dog clutch for direct connection between the input element of the viscous coupling and the transfer shaft is installed, and the transfer shaft is configured to transmit power to one of the front and rear wheels. A four-wheel drive system that provides a total of two types of four-wheel drive driving modes.