JPH05294158A - Four wheel drive power transmission - Google Patents

Abstract

PURPOSE:To provide a power transmission wherein a power train can be designed very freely and the interference between a friction clutch and a steering device is avoided for a four-wheeled car wherein an engine is placed transversely, a transmission is connected serially by a clutch on one side of the width direction of the engine, and power is transmitted to the rear wheel side via a transfer shaft and the friction clutch. CONSTITUTION:A four wheel drive power transmission comprises a first ring gear 13 engaged with an output gear 10 in a transmission 5 to transmit drive power to a front wheel differential device 11, a second ring gear 25 disposed more internally in the car body than the first ring gear 13, a transfer shaft 26 which includes an input gear 28 engaged with the second ring gear 25 and is disposed in the width direction, and a transmission means which transmits power to the rear wheel side via an input gear 33 engaged with an output gear 31 on the transfer shaft 26. A friction clutch 30 is provided on the transfer shaft 26 or the transmission means for the rear wheel side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power transmission device for a four-wheel drive vehicle.

[0002]

2. Description of the Related Art In a four-wheel drive vehicle based on a front-wheel drive vehicle, in which an engine is laterally mounted on a front portion of a vehicle body and a transmission is arranged in series through a clutch on one side in the vehicle width direction For example, as disclosed in Japanese Patent Laid-Open No. 62-50235, a transfer shaft arranged in parallel with a front wheel axle in order to transmit the driving force of an engine transmitted through a transmission to a rear wheel axle at any time. It is known that a friction clutch composed of a hydraulic clutch is provided.

[0003]

By the way, in the configuration of the four-wheel drive vehicle described in the above publication, a ring gear is fixed to a differential case of a front wheel differential device provided on a front wheel axle, and the output of the transmission is transmitted to this ring gear. The gears mesh with each other so that the output of the transmission is transmitted to the front wheel axle, and the input gear provided on the transfer shaft meshes with the ring gear,
The output of the transmission is transmitted to the transfer shaft.

However, since the ring gear provided in the differential case of the front wheel differential gear is formed to have a relatively large diameter due to the relationship of the final reduction ratio, when the ring gear is engaged with the input gear on the transfer shaft, the front wheel is engaged. Not only is the distance between the output shaft and the transfer shaft increased, but the rotation ratio between the output shaft of the transmission and the transfer shaft is restricted, and the degree of freedom in designing the transfer shaft is poor.

When determining the layout of the power train of a vehicle, a domestic right-hand drive vehicle having a driver's seat on the right side of the vehicle body and a left-hand drive vehicle for overseas export having a driver's seat on the left side of the vehicle body Although it is necessary to consider that it can be applied to both vehicles,
In the configuration of a wheel drive vehicle, since the friction clutch is attached to the end of the transfer shaft opposite to the engine side, when the steering device is provided on the same side as the friction clutch, friction is reduced. There was a risk that the automatic clutch would interfere with the steering system.

In view of the above problems, the present invention provides a power transmission device for a four-wheel drive vehicle which has a high degree of freedom in designing a power train and which can avoid interference between a friction clutch and a steering device. The purpose is to

[0007]

A power transmission device for a four-wheel drive vehicle according to the present invention is provided on a second inner side of a vehicle body than a ring gear which meshes with an output gear of a transmission and transmits a driving force to a front wheel differential device. Are arranged in parallel, and the input gear of the transfer shaft is meshed with the second ring gear.

In addition to the above structure, a friction clutch for controlling the amount of power transmitted to the rear wheel side is provided. This friction clutch is used for transmitting power to the end portion of the transfer shaft or the rear wheel side. Provided on the means.

[0009]

In the power transmission device for a four-wheel drive vehicle according to the present invention, the second ring gear is arranged in parallel on the inner side of the vehicle body with respect to the first ring gear meshing with the output gear of the transmission. Since the input gear of the transfer shaft is in mesh, it is possible to freely set the gear ratio between the second ring gear and the input gear of the transfer shaft without being restricted by the final reduction ratio on the front wheel side. In addition, the axial distance between the front wheel axle and the transfer shaft can be shortened.

Further, since the position of the input gear of the transfer shaft is closer to the inner side (engine side) than the case where the second ring gear is not provided, the friction clutch is provided at the outer end of the transfer shaft. Even when it is provided,
The position of the friction clutch can be moved inward, and interference with the steering device can be avoided.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a skeleton diagram showing a first embodiment of the present invention. Reference numeral 1 denotes an engine horizontally mounted on the front part of a vehicle body, a crankshaft 2 of which extends in the vehicle width direction and is led out to the side of the engine 1. It is arranged to be done.

On the left side of the engine 1, a clutch housing 4 for accommodating the clutch 3 and a transmission case 6 for accommodating a manual transmission 5 arranged in series with the engine 1 are integrally connected.
The transmission 5 includes a primary shaft (input shaft) 7 connected to a crankshaft 2 of an engine 1 via a clutch 3, a secondary shaft (output shaft) 8 arranged in parallel with the shaft 7, and both shafts. It is constituted by the first to fifth speeds and the reverse speed change gear train 9 provided between Nos. 7 and 8. Then, the rotation of the crankshaft 2 of the engine 1 transmitted to the primary shut 7 via the clutch 3 is transmitted to the secondary shaft 8 by being selectively geared by the gears of the transmission gear train 9 being selectively meshed. The rotation of is output from a drive gear 10 fixed to the end of the shaft 8 on the engine 1 side. A first ring gear 13, which is a spur gear fixed to a differential case 12 of a front wheel differential device 11, is engaged with the drive gear 10.

The front wheel differential device 11 includes pinion gears 15 and 16 rotatably supported on a pinion shaft 14 provided in the differential case 12, and a pair of side gears 17 and 18 meshing with the pinion gears 15 and 16. A relatively short left front axle 19 is splined to one side gear 17, and a relatively long right front axle 20 is splined to the other side gear 18. And left front axle 19
Is connected to a left front wheel drive shaft 22 via a constant velocity joint 21, and to the right front axle 20 is connected to a right front wheel drive shaft 24 via a constant velocity joint 23.

The differential case 12 of the front wheel differential device 11 has a second
The ring gear 25 is connected to the inner side of the vehicle body (engine 1 side) with respect to the first ring gear 13. Also, the front axle 19,
A transfer shaft 26 is provided parallel to the transfer shaft 26, and a cylindrical shaft 27 is coaxially and relatively rotatably arranged with respect to the transfer shaft 26 on the outer periphery of the left portion of the transfer shaft 26. The second ring gear 25 is provided on the right end of the tubular shaft 27.
An input gear 28 that meshes with is coupled.

A friction clutch 30, which is a hydraulic clutch, is attached to the left end of the transfer shaft 26. The friction clutch 30 includes a plurality of friction plates 30a meshing with spline teeth formed on the outer peripheral surface of the cylindrical shaft 27 and an inner peripheral surface of a cup-shaped body 30b coaxially fixed to the transfer shaft 26. The friction plate 30 meshes with the formed spline teeth and
a and a plurality of friction plates 30c arranged alternately. When the friction clutch 30 is engaged by hydraulic pressure, the transfer shaft 26 and the tubular shaft 27 rotate integrally, and the transmission The driving force output from the output shaft 8 of No. 5 is transmitted to the transfer shaft 26, and the hydraulic pressure applied to the friction clutch 30 is controlled to transmit the amount of power to the rear wheels. Is controlled. The transfer shaft 26 and the friction clutch 30 are housed in a transfer case 29 integrated with the clutch housing 4 and the transmission case 6.

The transfer shaft 26 includes the transfer shaft 26.
An output gear 31 consisting of a bevel gear or a hypoid gear is attached in order to convert the power transmitted to the vehicle by 90 ° and transmit it to the rear wheel side.A power transmission shaft 32 extending rearward of the vehicle body is attached to the output gear 31. The pinion gear 33 that it has is in mesh. The pinion gear 33 serves as the input gear of the power transmission means to the rear wheel side. The power transmission shaft 32 is a rear wheel differential device via a constant velocity joint 34 and a propeller shaft 35.
It is connected to 36.

The rear wheel differential 36 has a structure in which a differential gear mechanism 37 similar to that of the front wheel differential 11 is driven through a drive pinion 38, and is an output shaft of the differential gear mechanism 37. Drive shafts 43 and 44 for the left and right rear wheels are connected to the left rear axle 39 and the right rear axle 40 via constant velocity joints 41 and 42, respectively.

Reference numeral 45 denotes an exhaust pipe led out from the engine 1 to the rear, and a catalytic converter 46 is arranged in the exhaust pipe 45. In addition, a rack and pinion type steering device 47 is provided at the left end of the transfer case 29.
The rack case 47a extends in the vehicle width direction below the transfer case 29.

The above is the configuration of the first embodiment of the present invention. According to the above configuration, the differential case 12 of the front wheel differential device 11 is provided.
The first gear meshing with the output gear 10 of the transmission 5
A second ring gear 25 different from the ring gear 13 is arranged in parallel, and an input gear 28 of the transfer shaft 26 meshes with the second ring gear 25. Therefore, the tooth ratio of the second ring gear 25 and the input gear 28 is Can be set freely, and the degree of freedom in designing the power train is correspondingly increased.

Moreover, in the present embodiment, the second ring gear 25 is located on the inner side of the vehicle body (engine 1
Since it is provided on the side), the position of the input gear 28 of the transfer shaft 26 can be moved closer to the inner side of the vehicle body.
Therefore, avoiding heat damage from the exhaust system, friction clutch
Even when the 30 is arranged at the end of the transfer shaft 26 opposite to the engine 1 side, the position of the friction clutch 30 can be moved closer to the inner side of the vehicle body than in the conventional case, as shown in FIG. Even in the configuration in which the steering device 47 is provided on the same side as the friction clutch 30, it is possible to avoid the possibility that the friction clutch 30 and the steering device 47 interfere with each other.

Next, a second embodiment of the present invention will be described with reference to FIG. 2 which is a skeleton diagram.

In this embodiment, the friction clutch 30 is provided at the end of the transfer shaft 26 on the inner side (engine 1 side) of the vehicle body, and the friction plate 30a of one set of the friction clutch 30 is the transfer shaft 26. Friction clutch
The other set of friction plates 30c of 30 are engaged with the inner peripheral surface of a cup-shaped body 30b mounted on a cylindrical shaft 27 'which is relatively rotatably fitted to the outer periphery of the transfer shaft 26. Also, the second
The input gear 28 that meshes with the ring gear 25 is the transfer shaft 26.
The output gear 31 is mounted on the cylindrical shaft 27 '. Since the other parts have the same configuration as in FIG. 1, the corresponding elements are designated by the same reference numerals, and the duplicated description will be omitted.

In this embodiment, in addition to the effect of providing the second ring gear 25 described above, the friction clutch 30 is provided at the end of the transfer shaft 26 on the engine 1 side.
Since it is not necessary to consider interference with the steering device and the heavy friction clutch 30 can be arranged near the center of the vehicle in the vehicle width direction, there is an advantage that weight distribution is good.

FIGS. 3 to 5 are skeleton diagrams showing the third to fifth embodiments of the present invention, respectively. In the third to fifth embodiments, the friction clutch 30 is provided not on the transfer shaft 26 but on the power transmission means for transmitting power from the transfer shaft 26 to the rear wheel side. Different from the embodiment.

That is, in the third embodiment shown in FIG. 3, the friction clutch 30 is provided at the rear end of the shaft 32 of the pinion gear 33 which is an input gear in the power transmission means to the rear wheel side. In this embodiment, since the friction clutch 30 is provided inside the transfer case 29, in addition to the effect of providing the second ring gear 25, the oil inside the transfer case 29 is used as the operating oil for the friction clutch 30. There is an advantage that can be.

In the fourth embodiment shown in FIG. 4, the friction clutch 30 is provided at the front end of the drive pinion 38 of the rear wheel differential device 36. In this embodiment, the second ring gear
In addition to the effect of providing 25, the friction clutch 30 is arranged at the rear part of the vehicle body, which has the advantage that the weight distribution of the entire vehicle is improved.

Further, in the fifth embodiment shown in FIG. 5, the friction clutch 30 is divided into propeller shafts 35a and 35b.
It is provided between. In this embodiment, a friction clutch
Since the 30 can be fixed to the vehicle body and the propeller shafts 35a and 35b are connected to the front and rear thereof, in addition to the effect of providing the second ring gear 25, the friction clutch 30 can be removed and replaced. Has the advantage of easy service and good serviceability.

[Brief description of drawings]

FIG. 1 is a skeleton diagram showing a configuration of a first embodiment of the present invention.

FIG. 2 is a skeleton diagram showing the configuration of the second embodiment of the present invention.

FIG. 3 is a skeleton diagram showing a configuration of a third embodiment of the present invention.

FIG. 4 is a skeleton diagram showing a configuration of a fourth embodiment of the present invention.

FIG. 5 is a skeleton diagram showing a configuration of a fifth embodiment of the present invention.

[Explanation of symbols]

 1 Engine 3 Clutch 4 Clutch Housing 5 Transmission 7 Primary Shaft 8 Secondary Shaft 11 Front Wheel Differential 12 Differential Case 13 1st Ring Gear 25 2nd Ring Gear 26 Transfer Shaft 28 Input Gear 30 Friction Clutch 36 Rear Wheel Differential

Claims (8)

[Claims] 1. A four-wheel drive vehicle in which an engine is laterally mounted and a transmission is connected in series to one side in the vehicle width direction of the engine, wherein a front wheel differential gear meshes with an output gear of the transmission. A first ring gear that transmits power to the vehicle, a second ring gear that is arranged inward of the first ring gear in the vehicle body, and an input gear that meshes with the second ring gear are arranged in the vehicle width direction. A transfer shaft, a power transmission unit that transmits power to the rear wheels via an input gear that meshes with an output gear provided on the transfer shaft, and a friction clutch that controls the amount of power transmitted to the rear wheels. A power transmission device for a four-wheel drive vehicle, comprising: 2. The power transmission device for a four-wheel drive vehicle according to claim 1, wherein the friction clutch is provided on the transfer shaft. 3. The power transmission device for a four-wheel drive vehicle according to claim 2, wherein the friction clutch is provided at an end of the transfer shaft on a transmission side. 4. The power transmission device for a four-wheel drive vehicle according to claim 2, wherein the friction clutch is provided at an end of the transfer shaft on the engine side. 5. The power transmission device for a four-wheel drive vehicle according to claim 1, wherein the friction clutch is provided on the power transmission means to the rear wheel side. 6. The power transmission apparatus for a four-wheel drive vehicle according to claim 5, wherein the friction clutch is provided at a rear end portion of an input gear shaft of the power transmission means. 7. The power transmission device for a four-wheel drive vehicle according to claim 5, wherein the friction clutch is provided at a front end portion of a drive pinion of a rear wheel differential device. 8. The power transmission device for a four-wheel drive vehicle according to claim 5, wherein the friction clutch is provided in the middle of a propeller shaft of the power transmission means.