JPS5973649A - Transmission of four-wheel-drive car - Google Patents

Abstract

PURPOSE:To enable to realize the transmission of a four-wheel-drive car, in which two-wheel drive or either front-wheel drive or rear-wheel drive is possible and also two-wheel drive can be changed-over to four-wheel drive, by a structure wherein clutches are added to the power transmission system of a part-time type four-wheel-drive car. CONSTITUTION:When an output shaft 5 is coupled to a front wheel final drive gear 18 side by engaging a front wheel drive-rear wheel drive change-over clutch 20 and disconnected from a rear wheel side by disengaging two wheel drive-four wheel drive change-over clutch 24, the power of the output shaft 5 is transmitted only to front wheels in order to drive a car on two front wheels. On the contrary, when the front wheel drive-rear wheel drive change-over clutch 20 is disengaged in order to disconnect the front wheel side and the output shaft 5 is coupled to the rear wheel side by engaging the two wheel drive-four wheel drive change-over clutch 24, the car is driven on two rear wheels. Furthermore, the car is driven on four wheels by engaging the two wheel drive-four wheel drive change-over clutch 24 during the driving on two-front wheels and also by engaging the front wheel drive-rear wheel drive change-over clutch 20 during the driving on two-rear wheels.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a transmission for a part-time four-wheel drive vehicle.
In particular, it relates to two-wheel drive for either the front or rear wheels, and to a device that allows switching from two-wheel drive to four-wheel drive.

Regarding the transmission and speed change operation device for this type of four-wheel drive vehicle, the present applicant has disclosed, for example, Japanese Patent Laid-Open No. 55-4292, which allows switching between two-wheel drive and four-wheel drive using the front wheels by operating a lever. There have also been proposals to make it possible to switch between 2-wheel drive and 4-wheel drive using the rear wheels with the same lever operation, but these are FF or R
It is based on the R, and has two-wheel drive only on either the front or rear wheels.

Incidentally, in recent years, four-wheel drive vehicles have attracted attention for their excellent ability to travel on rough roads, steep climbs, slippery roads, and maneuverability, and four-wheel drive vehicles have become popular, especially in mountainous areas. In mountainous areas, the road conditions change significantly, with many slopes (and few paved roads), but in many cases it is possible to drive with two-wheel drive without the need for strong four-wheel drive.On the other hand, as a two-wheel drive is either the front wheel or the rear wheel, and front wheel drive has excellent straight-line stability and stability when cornering, and rear wheel drive is preferable for climbing and driving on roads that place a load on the rear, and each has its advantages and disadvantages. However, the traditional part-time system4
In the case of wheel drive vehicles, there is only one type of two-wheel drive as mentioned above, so there is room for improvement in the driving performance of two-wheel drive, especially in mountainous areas where four-wheel drive vehicles are popular. there were.

In view of these circumstances, the present invention aims to provide a transmission for a four-wheel drive vehicle that is capable of two-wheel drive on either the front or rear wheels and can then be switched to four-wheel drive. do.

For this purpose, the transmission of the present invention focuses on the fact that in a four-wheel drive vehicle, the transmission output side is configured to transmit power to the front wheels and rear wheels. The power transmission unit is equipped with a synchronized front and rear wheel switching clutch that selectively switches between the front and rear wheels. It is characterized by the ability to perform two-wheel drive using either one of the rear wheels and four-wheel drive from that.

Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings. In FIG. 1, a transmission system of a four-wheel drive vehicle including a transmission according to the present invention will be explained. Reference numeral 1 indicates an engine;
2 is a clutch, 3 is an input shaft, and 4 is a transmission. The transmission 4 is of a constant mesh type, with an output shaft 5 disposed parallel to the input shaft 3, and five pairs of gears meshing with each other at the first to fifth speeds on both shafts 3 and 5. Shift gears 6 to 10 are provided, a synchronization mechanism 11 between gears 6 and 7, and a synchronization mechanism 11 between gears 8 and 9.
a synchronizing mechanism 12 between and a synchronizing mechanism 13 on one side of the gear 10
By selectively operating the , each gear stage from the first gear to the overdrive fifth gear is obtained. Also,
A synchronizing mechanism 11 is attached to the reverse gear 14 provided on the input shaft 3.
A reverse gear is obtained by meshing the gear 15 on the sleeve side through an idler gear V (not shown).

A pinion shaft 16 is rotatably mounted on the front end of the output shaft 5 , and the drive pinion 11 of the pinion shaft 16 meshes with the crown gear 19 of the front wheel final reduction device 18 . is provided with a synchronous front +Wt wheel switching clutch 20.

Further, a transfer device 21 is provided at the rear end of the output shaft 5, and in this device 21, a transfer drive gear 22 integrally coupled to the output shaft 5 and a driven gear 23 rotatably fitted to the input shaft 3 mesh with each other. This gear 23 is further
．． The transmission is configured to be transmitted to a rear drive shaft 25 via a four-wheel switching clutch 24, and the rear drive shaft 25 is connected to a rear wheel final reduction gear 27 via a propeller shaft 26. The shift pattern of the change lever that operates each synchronizing mechanism 11 to 13 etc. is as shown in Figure 2 (a), and the shift pattern of the select lever that operates the clutches 20, 24 is as shown in Figure 2 (b). It has become.

Because of this configuration, when the synchronizing mechanisms 11 to 13 etc. are operated in the transmission 4, the gears 6 to 10
14, 15, etc., the power of the first to fifth speeds and the reverse gear is output directly to the output shaft 5. Therefore, the front and rear wheel switching clutches 20 are engaged to connect the output shaft 5 to the front final reduction gear 18 side, and the 2.4-wheel switching clutch 24
When the rear wheel side is separated by releasing ., the power from the output shaft 5 is transferred to the pinion shaft 16. Drive pinion 17 of front wheel final reduction gear 18
, is transmitted only to the front wheels via the crown gear 19, resulting in two-wheel drive by the front wheels.

On the other hand, when the front and rear wheel switching clutches 20 are released to disconnect the front wheels, and the 2.4-wheel switching clutch 24 is engaged to connect the output shaft 5 to the rear wheels, the power of the output shaft 5 is transferred. device 21, rear drive shaft 25, propeller shaft 26,
Only 5- is transmitted to the rear wheels via the rear wheel final reduction gear 27, resulting in two-wheel drive by the rear wheels.

In the case of two-wheel drive using the front wheels, the released two- and four-wheel switching clutches 24 are engaged to transmit power to the rear wheels as well, and in the case of two-wheel drive using the rear wheels, the released two- and four-wheel switching clutches 24 are engaged. By engaging the rear wheel switching clutch 20 and transmitting power to the front wheels as well, four-wheel drive is achieved using both the front wheels and the rear wheels.

As is clear from the above description, according to the present invention, in a part-time 4-wheel drive vehicle that is normally 2-wheel drive but capable of 4-wheel drive if necessary, 2-wheel drive can be selected for either the front or rear wheels. This makes it possible to drive optimally by taking advantage of the characteristics of each system, further improving drivability especially in mountainous areas where four-wheel drive vehicles are valuable. Structurally, it is very simple because it only requires adding a clutch 2o to the power transmission system of a part-time four-wheel drive vehicle.

[Brief explanation of the drawing]

FIG. 1 is a skeleton diagram showing an embodiment of a transmission according to the present invention, and FIGS. 2(a) and (I) show a change lever,
It is a figure showing the shift pattern of a select lever. 6- 1...Engine, 2...Clutch, 3...Input shaft, 4...Transmission, 5...Output shaft, 6 to 10...
・Transmission gear, 11 to 13...Synchronization mechanism, 14.
15... Reverse gear, 16... Pinion shaft, 11
...Drive pinion, 18...Front wheel final reduction gear,
19... Crown gear, 20... Front and rear wheel switching clutch, 21... Transfer device, 22.23...
Transfer gear, 24...2.4 wheel switching ludge,
25...Rear drive shaft, 2G...Propeller shaft, 2
7...Rear wheel final reduction device. Patent applicant: Fuji Heavy Industries Co., Ltd. Agent: Patent attorney: Makoto Kobashi Ukiyo Patent attorney: Susumu Murai 7-

Claims (1)

[Claims] One of the output shafts, which is arranged parallel to the input shaft and outputs the power of each gear, is configured to transmit power to the front wheels via a front/rear wheel switching clutch, and the other output shaft is configured to transmit power to the front wheels through a front/rear wheel switching clutch.
．． A transmission for a four-wheel drive vehicle characterized by transmitting power to the rear wheels via a four-wheel switching clutch.