JPH0462893B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a transfer structure for a four-wheel drive vehicle.

(Prior Art) As a transfer structure for a four-wheel drive vehicle, for example, as disclosed in Japanese Patent Application Laid-Open No. 59-57032, an engine and a clutch are arranged so that the crankshaft extends in the lateral direction of the vehicle body. A gear ratio changing means is provided between an input shaft driven by a crankshaft via means and an output shaft having a drive gear, and the transmission is arranged such that the input and output shafts extend in the lateral direction of the vehicle body. an inter-axle differential device in which the input member is driven by a drive gear; the input member is driven by one output member of the inter-axle differential device; The left and right front wheels are driven by a front wheel differential device that drives the left and right front wheels, and the other output member of the axle differential device, via a transfer gear mechanism, a bevel gear mechanism, and a propeller shaft. BACKGROUND ART A device having an inter-axle differential device for rear wheels that drives the rear wheels is known.

In such four-wheel drive vehicles, an inter-axle differential device is used as described above in order to absorb the difference in rotational speed between the front wheels and rear wheels when the vehicle turns. , When the front wheels enter sandy ground, it is necessary to release the differential mechanism of this inter-axle differential device and rotate the front and rear wheels equally. A limiting differential is provided.

As this differential limiting device, for example,
A deflock mechanism is known that includes a sleeve gear that slides in the longitudinal direction, as disclosed in Japanese Patent No. 57032. However, since this deflock mechanism operates by sliding a sleeve gear, it takes time to respond and it is difficult to automate its control.

Therefore, for example, British Patent No. 1252753,
In Japanese Patent Publication No. 47-20123 and Japanese Patent Publication No. 49-23168, in order to improve the responsiveness of the control of the deflock mechanism and to automate it, a plurality of discs are arranged facing each other and capable of transmitting torque between them. The idea of using disc-shaped plates is presented.

However, when using a disc-shaped plate as described above as a differential limiting device,
A certain diameter is required for torque transmission,
Due to the large diameter, it is difficult to apply this differential limiting device to the transfer structure of a four-wheel drive vehicle as disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 59-57032 for the following reasons. be. That is, in the transfer structure disclosed in JP-A-59-57032, the differential limiting device is provided in the engine-side portion of the clutch housing that accommodates the clutch. This portion cannot take up a large space in the radial direction, and therefore it is not possible to provide a differential limiting device using a disc-shaped plate in this portion.

The above-mentioned Japanese Patent Publication Nos. 47-20123 and 49-23168 and the above-mentioned British patent specifications disclose that a disc-shaped differential limiting device and a plate are placed between an inter-axle differential and a bevel gear corresponding to a transfer gear. According to this idea, in the transfer structure disclosed in JP-A-59-57032, a differential limiting device is provided between the transfer gear and the inter-axle differential device. can be placed.

(Problems to be Solved by the Invention) However, with the above arrangement, a large dead space is created in the transfer gear mechanism, particularly in the housing portion that accommodates the transfer gear, and there is a problem that the entire device becomes larger. In addition, in the event that this differential limiting device breaks down, it is located between two devices, so in order to repair it, the case must be disassembled and the transfer gear mechanism must be removed.
A problem arises in that repair work becomes complicated.

Therefore, the present invention provides a four-wheel drive system in which an inter-axle differential device, an inter-axle differential device for front wheels, a multi-plate differential limiting device, etc. can be arranged compactly and without wasting space. The purpose is to provide a transfer structure for vehicles.

(Means for Solving the Problems) The present invention provides an engine having a crankshaft extending in the lateral direction of the vehicle body, an input shaft driven by the crankshaft via a clutch means, and an output having a drive gear. It is composed of a planetary gear mechanism having a gear ratio changing means between the shaft and the transmission means arranged so that the input and output shafts extend in the lateral direction of the vehicle body, one input member and two output means. an inter-axle differential whose input member is driven by a drive gear, and which is coaxially arranged with the inter-axle differential which is driven by one output member of the inter-axle differential to drive left and right front wheels. A front wheel differential device for the front wheels and the other output member of the axle differential device drive the rear wheel through a transfer gear mechanism, a bevel gear mechanism, and a propeller shaft to drive the left and right rear wheels. In a transfer structure of a four-wheel drive vehicle having an inter-axle differential, a plurality of disc-shaped first
plate and a second plate, in order to limit the differential of the inter-axle differential device, torque transmission is possible between the first plate and the second plate, and the first plate is connected to the transfer gear mechanism. The second plate includes a differential limiting device connected to the front wheel differential device, and the differential limiting device is connected to the inter-axle differential device and the front wheel differential device. It is characterized in that it is disposed coaxially and on the side opposite to the inter-axle differential with respect to the transfer gear mechanism.

The differential limiting device may include a friction clutch including a hydraulic piston that presses the first and second plates into contact with each other to transmit torque between the plates.

(Operations and Effects of the Invention) In the transfer structure for a four-wheel drive vehicle of the present invention, a plurality of disc-shaped first
a differential limiting device having a plate and a second plate coaxially with the interaxle differential and the front wheel interaxle differential and on a side opposite to the interaxle differential with respect to the transfer gear mechanism; Since the differential limiting device is located on the outside, the differential limiting device can be easily repaired, resulting in a compact and space-saving arrangement.

(Embodiment) Hereinafter, a transfer structure for a four-wheel drive vehicle according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a power transmission system of a four-wheel drive vehicle according to an embodiment of the present invention, in which an engine 1 is arranged so that its crankshaft 2 extends in the lateral direction of the vehicle body, and a transmission 8 is also connected to its input. The shaft 4 and the output shaft 6 are arranged horizontally with the shaft 4 facing the lateral direction of the vehicle body, the input shaft 4 is connected to the crankshaft 2 via the clutch 3, and a drive gear 5 is connected to the end of the output shaft 6. It is provided. In addition, the input shaft 4 and the output shaft 6
Over time, the transmission mechanism 7, which is a transmission ratio changing means,
is provided.

The drive gear 5 is meshed with an input gear 11 formed on the outer periphery of a ring gear 10 of a center differential gear 9, which is an inter-axle differential comprised of a planetary gear mechanism.

As shown in FIG. 2, the center differential gear 9 includes the ring gear 10, a sun gear 12 concentric with the ring gear 10, a plurality of pinions 13 meshing with the ring gear 10 and the sun gear 12, and the plurality of pinions. 13 via a pin 14, and a pinion carrier 15, which is configured by a planetary gear mechanism.

Here, as shown in FIG. 3, the ring gear 10 and sun gear 12 of the center differential gear 9
The plurality of pinions 13 between the two pinions 13a and 13a each mesh with the ring gear 10, and a pinion 13a that meshes with this pinion 13a and the sun gear 12.
It is composed of a double pinion consisting of b.

As shown in FIG. 2, a front wheel inter-axle differential device (hereinafter referred to as front wheel differential gear) 20 is disposed on one side of the center differential gear 9, and this front wheel differential gear 20 is
It is composed of a differential case 16, a radial pin 17 supported by the case 16, a pair of pinions 18 rotatably fitted to the pin 17, and a pair of left and right bevel gears 19 meshing with both pinions 18. ing.

A left front wheel drive shaft 21 and a right front wheel drive shaft 22 are respectively coupled to the left and right bevel gears 19 of the front wheel differential gear 20.
1 passes through the center of the center differential gear 9 and is connected to the left front wheel 23, and the right front wheel drive shaft 22 is connected to the right front wheel 24 (see FIG. 1).

The pinion carrier 15 of the center differential gear 9 and the differential case 16 of the front wheel differential gear 20 located to the side thereof are integrally arranged.

Further, the ring gear 10 of the center differential gear 9 has its support portion 10a connected to the differential case 16.
It extends to and is rotatably supported by this.

On the other hand, an intermediate shaft 29 is disposed parallel to the axes of the center differential gear 9 and the front wheel differential gear 20 at a constant distance from each other, and a gear 30 integrally formed with the intermediate shaft 29 is arranged in parallel to It is disposed on the opposite side of the front wheel differential gear 20 with respect to the sun gear 12 of the differential gear 9, and meshes with a transfer gear 31 integrally formed with the sun gear 12.

The intermediate shaft 29 is further provided with an output gear 36 consisting of a crown gear, and a bevel gear 38 integral with a propeller shaft 37 extending in the longitudinal direction of the vehicle body is meshed with the output gear 36. As shown in FIG. 1, this propeller shaft 37 reaches a rear wheel interaxle differential device (hereinafter referred to as a rear wheel differential gear) 39, and extends left and right from this rear wheel differential gear 39. The left and right rear wheels 42 and 4 are connected to each other via the left rear wheel drive shaft 40 and the right rear wheel drive shaft 41.
It is designed to drive 3.

A friction clutch-type center differential lock mechanism 50 is disposed between the pinion carrier 15 of the center differential gear 9 and the transfer gear 31, and serves as a differential limiting device for the center differential gear 9. There is. This center differential lock mechanism 50 includes an outer hub 51 that is provided to rotate integrally with the pinion carrier 15, and an inner hub 52 that is integrally molded with the transfer gear 31 and is opposed to the outer hub 51. have. The outer hub 51 and the inner hub 52 movably support a plurality of disc-shaped first and second plates 53 and 54, which are arranged opposite to each other. A stopper 55 is provided at one end of the center differential lock mechanism 50 to limit the above-mentioned sliding movements of the first and second plates 53 and 54, and a stopper 55 is provided at the other end which is operated by hydraulic pressure to limit the above-mentioned sliding movement of the first and second plates 53 and 54. A pinion 56 is provided that presses against the first and second plates 53 and 54 to variably transmit torque between these plates.

In the above configuration, the rotation of the crankshaft 2 of the engine 1 is input to the transmission 8 via the clutch 3, and the output shaft 6 is driven at a reduction ratio selected by the transmission 8. The signal is input from the drive gear 5 to the ring gear 10 of the center differential gear 9 via the input gear 11. When the center differential lock mechanism 50 is inactive, the power input to the ring gear 10 is divided at the center differential gear 9 and output from the pinion carrier 15 and sun gear 12, respectively. Output is from front differential gear 2
0, the left and right front wheel drive shafts 21 and 22, that is, the left and right front wheels 23 and 24 are driven. On the other hand, the output from the sun gear 12 is transmitted to gears 31, 30,
The propeller shaft 37 is driven through the intermediate shaft 29 and the output gear 36, and the left and right rear wheel drive shafts 40, 4 are driven through the rear wheel differential gear 39.
1, that is, the left and right rear wheels 42 and 43 are driven.

On the other hand, if hydraulic pressure is introduced into the differential lock mechanism 50 of the center differential gear 9, the piston 56 is moved toward the plates 53 and 54, and the clutch structure is tightened by pressing these, the ring gear 10 and pinion carrier 15, the differential function of the center differential gear 9 is eliminated, and as a result, the front wheels 23, 24 and the rear wheels 42, 43 are rotated by the rotation of the engine 1, regardless of the resistance acting on each. It will be rotated equally.

In order to disable the differential lock mechanism 50, it is sufficient to discharge the mechanism 50 in the opposite manner to the above, and this disable control can be performed in about 0.1 seconds, so it is possible to unlock the differential differential gear with a quick response. can be controlled.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing a power transmission system of a four-wheel drive vehicle according to an embodiment of the present invention, FIG. 2 is a horizontal sectional view of a structure surrounding a center differential gear,
FIG. 3 is a sectional view taken along line - in FIG. 2. 1...Engine, 8...Transmission,
9... Center differential gear, 15... Pinion carrier, 20... Front wheel differential gear, 31... Transfer gear, 50... Center differential lock mechanism.

Claims (1)

[Claims] 1. An engine arranged such that the crankshaft extends in the lateral direction of the vehicle body, and a transmission ratio between an input shaft driven by the crankshaft via a clutch means and an output shaft having a drive gear. A means of change is provided;
A transmission means arranged so that the input and output shafts extend in the lateral direction of the vehicle body, a planetary gear mechanism having one input member and two output means, and the input member is driven by a drive gear. a differential device, an inter-wheel differential device for front wheels arranged coaxially with the inter-axle differential device that is driven by one output member of the inter-axle differential device to drive the left and right front wheels, and the inter-axle differential device; The transfer gear of a four-wheel drive vehicle has an inter-axle differential for rear wheels that is driven by the other output member of the differential via a transfer gear mechanism, a bevel gear mechanism, and a propeller shaft, and drives the left and right rear wheels. The axle structure includes a plurality of disc-shaped first plates and second plates arranged opposite to each other, and in order to limit the differential movement of the inter-axle differential device, the first plate and the second plate a differential limiting device, in which the first plate is connected to the transfer gear mechanism and the second plate is connected to the front wheel differential device, the differential limiting device is arranged coaxially with the inter-axle differential device and the front wheel differential device, and on the opposite side of the transfer gear mechanism from the inter-axle differential device. Transfer structure for wheel drive vehicles. 2. The differential limiting device is a friction clutch including a hydraulic piston that brings the first and second plates into pressing contact with each other to transmit torque between the plates. A transfer structure for a four-wheel drive vehicle according to scope 1.