JPS63110031A - Four-wheel drive vehicle with viscous coupling - Google Patents

Abstract

PURPOSE:To extend exibition of the performance of a four-wheel drive and improve its acceleration and steering stability by keeping a viscous coupling in a locked condition at the start and the acceleration of a vehicle, thus setting the vehicle in the state of four-wheel drive. CONSTITUTION:A damper case 31 is fixed in one body to a final gear 10 with a plural number of engaging protrusion 33 protruded around the outside circumference of the differential case 32 of a differential mechanism 11 inside the damper case 31 and the engaging protrusion 33 engages with a recess 34 of a wider width than that of the engaging protrusion 33 on the internal circumference of the damper case 31. Further, a damper rubber 35 and a damper rubber 36 are provided on both sides of the engaging protrusion 33 to rotate the damper case 31 through the damper rubber 35 and the damper rubber 36 relatively to the differential case 32 when the transmission torque makes a sudden increase.

Description

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

The present invention relates to a four-wheel drive vehicle with a viscous coupling in which a viscous coupling is provided at the 892271 portion, and more particularly to a mechanism that causes the viscous coupling to act in a locking state during starting and acceleration.

[Conventional technology]

Conventionally, regarding four-wheel drive vehicles with viscous couplings,
For example, there is a prior art disclosed in Japanese Utility Model Application Publication No. 59-188731. Here, a viscous coupling is installed in the middle of the drive system for the front and rear wheels, and when slip occurs between the rear wheels, the input and output sides of the viscous coupling are locked due to the rotation difference, resulting in four-wheel drive. It has been shown that

[Problems to be solved by the invention]

By the way, in the above-mentioned conventional vehicle, the four-wheel drive due to the locked state between the input side and the output side of the viscous coupling depends only on the slips of the front and rear wheels. Therefore, rain
The viscous coupling only works when driving on snow, mud, sand, or other slip-prone surfaces, and its performance is not demonstrated on dry roads. On the other hand, it is generally desirable for a vehicle to generate a large driving force through four-wheel drive when starting or accelerating, and it is desired that the viscous coupling be locked even during starting or accelerating. The present invention has been made in view of these points, and is therefore a 4-wheel drive vehicle with a viscous coupling that improves the performance of 4-wheel drive by locking the viscous coupling in the transfer portion even during start-up and acceleration. The purpose is to provide a chariot.

[Means to solve the problem]

In order to achieve the above object, the present invention has a drive system that is directly coupled to one of the front and rear wheels, and has another drive system that branches from there and connects to the other of the front and rear wheels via a viscous coupling. A torsion damper is attached after the branching point of the system to delay power transmission during start-up or acceleration, and the input side and output side of the viscous coupling are configured to be temporarily locked due to the power transmission delay caused by the torsional damper. has been done.

[For production]

Based on the above configuration, for example, in the case of a front engine/front drive (FF) base, the power transmission of the front wheel drive system is delayed by the torsional damper when starting or accelerating, and at this time a rotation difference occurs between the input side and output side of the viscous coupling. By locking it, power is transmitted to the rear wheels as well.
This results in occasional four-wheel drive driving. In this way, in the present invention, the four-wheel drive by the viscous coupling is exerted not only when a slip occurs, but also when starting and accelerating on a dry road, making it possible to improve the performance.

[Actual example]

Hereinafter, an actual travel example of the present invention will be explained based on the drawings. Referring to FIG. 1, a case will be described in which the present invention is applied to a transverse transaxle type, FF-based vehicle. Engine 1. Clutch 2 and shifting! ! ! 3 are directly connected to each other in the left and right direction of the vehicle body. The transmission 3 has a plurality of sets of transmission gears 6 and a synchronizer mechanism 1 between a parallel input shaft 4 and an output shaft 5, and is configured to change speed in a plurality of stages. It meshes with the final gear 10 of the differential gear e9. A differential mechanism 11 of this front differential device 9 is connected to front wheels 13 via an axle 12 so as to constantly transmit power thereto. Further, the gear 15 of the transfer yVi'7314 meshes with the final gear 10 of the front drive system, and the rear drive system is branched, and the transfer shaft 16, which is integral with the gear 15, is connected to a pair of bevel gears 17. It is connected to the hub 20a of the viscous coupling 20 via the rear drive shaft 18. From the drum 20b of the viscous coupling 20 to the propeller shaft 21. Rear differential device 122.121@2
3's, transmission is configured to the rear wheel 24. Therefore, a torsion damper 30 is provided after the branching part of the front drive system, for example, between the final gear 10 and the differential mechanism 11. In FIG. 2 (2), @, to describe the torsional damper 30 part, the damper case 31 is connected to the final gear 10.
The differential case 32 of the differential mechanism 11 is rotatably installed inside the damper case 31. A plurality of engagement protrusions 33 protrude from the outer periphery of the differential case 32, and the engagement protrusions 33 fit into four parts 34 wider than the inner circumference of the old damper case. Further, damper rubbers 35 and 36 are installed on both sides of the protrusion engaging protrusion 33, so that the damper case 31 rotates relative to the differential case 32 via the damper rubbers 35 and 36 when the transmitted torque increases rapidly. Next, the operation of the four-wheel drive vehicle configured as described above will be explained. First, power from the transmission 3 is transmitted to the differential vJn mechanism 11 via the final gear 10 and the torsional damper 30, and further transmitted to the front wheels 13 via the axle 12. Therefore, during steady running, since the torque change is small, the projection 33 of the torsion damper 30 is positioned approximately in the middle of the recess 34 of the damper case 31 by the damper rubber 35.3G, and the differential case 32 is rotated integrally. Therefore, the shifting power is immediately transmitted to the front wheels 13 for running, and on a dry road, the rotational speeds of the front and rear wheels 13 and 24 are the same, and the rotational difference between the hub 20a and drum 20b of the viscous coupling 20 is approximately zero. Become. Therefore, viscous coupling 2
0 is released and power is no longer transmitted to the rear wheels, resulting in front-wheel drive two-wheel drive. Under such dry road driving conditions, when the torque increases rapidly during starting or acceleration, the torque is transferred to the final gear 10.
Viscous coupling 2 via transfer device 14
The information is immediately transmitted to the hub 20a of No. 0. - On the other hand, at this time, in the torsional damper 30, only the damper case 31 rotates together with the final gear 10 against one of the damper rubbers 36, and then the damper action is performed so that the differential case 32 is rotated by the engagement of the recess 34 and the protrusion 33. do. Therefore, the power transmission to the front wheels 13 is delayed, and accordingly, the rotation of the drum 2Ob side of the viscous coupling 20 as well as the 11th wheel 13.24 remains low. Therefore, a difference in rotation occurs between the hub 20a of the viscous coupling 20 and the drum 20b, and the viscosity of the liquid in the coupling changes.By locking the coupling, power is also applied to the rear wheel 24 after the viscous coupling 20. In this way, four-wheel drive is temporarily established at the initial stage of starting the vehicle, etc. After the two cases 31 and 32 of the torsional damper 30 are integrated again, normal power is transmitted to the front wheel 13, and the difference in rotation of the viscous coupling 20 disappears and the viscous coupling 20 is released.
Back to wheel drive. Furthermore, if the front wheels 13 slip on a snowy road or the like during FF two-wheel drive driving, a rotational difference will inevitably occur in the viscous coupling 20, locking the viscous coupling 20, resulting in four-wheel drive. Above, the FF base was described as an example of the present invention, but it is a front engine/rear drive. It can also be applied to rear engine/rear drive bases. Further, it can also be applied to a vertical transaxle type, and the mounting location of the torsion damper is not limited to the embodiment, and a spring may be used instead of rubber.

【Effect of the invention】

As described above, according to the present invention, the viscous coupling is locked even when starting and accelerating to achieve four-wheel drive, so the performance of four-wheel drive is expanded, and acceleration and acceleration are improved.
Improves handling stability. Simply adding a torsion damper in the middle of the drive system
The structure is simple, and the locking state of the viscous coupling can be freely set for starting, etc., depending on the damper performance. Since the damper is applied at the initial stage when the torque suddenly changes, such as when starting, the vehicle becomes four-wheel drive, so its performance can be effectively demonstrated.

[Brief explanation of the drawing]

FIG. 1 is a skeleton diagram showing an embodiment of the four-wheel drive vehicle of the present invention, FIG. 9...Front differential device, 13...Front wheel, 20...
・Viscous coupling, 24...rear wheel, 30...
Torsional damper. Patent applicant Fuji Heavy Industries Co., Ltd. Agent Patent attorney Jundo Kobashi Patent attorney Susumu Murai 2nd

Claims (1)

[Claims] In contrast to a direct-coupled drive system that directly transmits power to one of the front and rear wheels via a differential between the left and right wheels, another drive system that branches off from there and connects to the other of the front and rear wheels via a viscous coupling. A torsion damper is installed after the branch of the direct drive system to delay power transmission during start-up or acceleration, and the delay in power transmission caused by the torsion damper temporarily creates a rotational difference in the viscous coupling to increase the driving force. A four-wheel drive vehicle with a viscous coupling.