JPH06107005A - Driving device for vehicle - Google Patents

Abstract

PURPOSE:To correct weight distribution in the front and rear direction of a vehicle body of a four-wheel drive vehicle. CONSTITUTION:In a driving device, which is provided with an engine 15 in the front part of a vehicle body and a differential gear 16 between right and left front wheels while provided with a transmission 18, a center differential gear 19, and a differential gear 21 for rear wheels in the rear part of the vehicle body, engine output is distributed between left and right rear wheels by the differential gear for the rear wheels after being transmitted by the transmission via the first propeller shaft 34 extending in the front and rear direction of the vehicle body and the like. Transmission output is inputted to the differential gear for the front wheels via the center differential gear and the second propeller shaft 45 extending in the front and rear direction of the vehicle body, and distributed between the left and right front wheels via the differential gear for the front wheels. The first propeller shaft is made of a solid shaft while the second propeller shaft is made of a hollow tube body, and the solid first propeller shaft is housed inside the hollow second propeller shaft.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle drive device, and more particularly to a four-wheel drive vehicle (4WD vehicle) in which both front wheels and rear wheels are driven.

[0002]

2. Description of the Related Art Among vehicles, a four-wheel drive vehicle is known in which both front wheels and rear wheels are driven. In this type of vehicle, as disclosed in Japanese Patent Laid-Open No. 64-103541, it is usual to arrange an engine and a transmission in the front part of the vehicle body, and the output from this transmission is a front wheel drive mechanism. And is transmitted to the rear wheel drive mechanism via a propeller shaft extending in the vehicle front-rear direction.

[0003]

[Problems for Solving the Problems] However, in the conventional four-wheel drive vehicle, the engine, the transmission, and the front wheel drive mechanism, which are heavy objects, are mounted in the front portion of the vehicle body, and therefore the vehicle front is inevitable. The part tends to be heavier than the rear part. Also, in the case where the engine is arranged in the front part of the vehicle body, that is, in the engine room, it is common to let a part of the transmission enter the tunnel part (formed on the floor panel). The front end of the section becomes large, which tends to narrow the foot space of the front seat occupant.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a vehicle drive device that solves the problems that a four-wheel drive vehicle has conventionally, that is, at least the problem of optimizing the weight distribution before and after the vehicle body. .

[0005]

In order to achieve the above technical problems, the present invention adopts the following constitution. That is, the front wheel drive mechanism connected to the left and right front wheels, the rear wheel drive mechanism connected to the left and right rear wheels, and the rear wheel drive mechanism arranged in a region sandwiched by the left and right rear wheels. A transmission coupled to the transmission, an engine disposed in front of the transmission, a first propeller shaft extending in the vehicle front-rear direction and transmitting the output of the engine to the transmission, and extending in the vehicle front-rear direction,
And a second propeller shaft that transmits the output of the transmission to the front wheel drive mechanism.

[0006]

According to the present invention, since the transmission is arranged between the left and right rear wheels separately from the engine, the weight distribution before and after the vehicle body can be made appropriate.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings. First Embodiment (FIGS. 1 and 2) FIGS. 1 and 2 show the first embodiment. In FIG. 2, reference numeral 1 represents an automobile, and in this embodiment, the automobile 1 has an engine room 2 formed in a front portion of a vehicle body,
It is a sedan type having a luggage compartment 3 formed in the rear part of the vehicle body and a passenger compartment 4 sandwiched between the engine compartment 2 and the luggage compartment 3, and the passenger compartment 4 has front seats 5 and rear seats. And 6 are provided. A fuel tank 7 is disposed in the rear of the passenger compartment 4 adjacent to the passenger compartment 4, and a recess 9 that opens upward is formed in the floor 8 of the luggage compartment 3. The spare tire 10 is arranged in a horizontal state.

The automobile 1 is a four-wheel drive vehicle that drives both front wheels 12 and rear wheels 13. Explaining the drive system of the automobile 1, the engine room 2 is equipped with an engine 15 with its output shaft oriented in the front-rear direction of the vehicle body and a front wheel differential gear 16, and the engine 15 has a torque converter 17 at its rear end. It is connected. On the other hand, as shown in FIG. 1, a drive unit 20 including a transmission 18 and a center differential gear 19, and a rear wheel differential gear 21 are disposed between the rear portion of the vehicle body, that is, between the left and right rear wheels 13. . That is, the drive system of the automobile 1 is a so-called transaxle system.

The drive unit 20 will be described. In the drive unit 20, the transmission 18 is placed horizontally, that is, the transmission shaft 18a is oriented in the vehicle width direction, and the transmission shaft 18a and the transmission shaft 18a are provided at the output shaft end of the transmission shaft 18a. A center differential gear 19 arranged coaxially is connected. Further, the drive unit 20 includes the first intermediate shaft 2 in parallel with the mission shaft 18a.
4 and a second intermediate shaft 25 are arranged. The first intermediate shaft 24 is connected to the input shaft end of the transmission shaft 18a via the first gear train 27, and the first gear train 27 is
It comprises a first gear 30 attached to the outer end of the first intermediate shaft 24 and a second gear 31 attached to the input shaft end of the mission shaft 18a. First intermediate shaft 2
The inner end of No. 4 is connected to the first hypoid gear 33 via the first hypoid gear 33.
It is connected to the propeller shaft 34. On the other hand, the second intermediate shaft 25 has an outer end with respect to one output shaft 19a of the center differential gear 19 and the second gear train 3a.
It is connected through 8. The second gear train 38 includes a first gear 40 attached to the center differential output shaft 19a and a second gear train
It is composed of a second gear 41 attached to the intermediate shaft 25, and an intermediate gear, that is, a counter gear 42, interposed between the first and second gears 40 and 41. Second
The inner end of the intermediate shaft 25 has a second hypoid gear 43.
Is connected to the second propeller shaft 45 via. A gear 44 that meshes with the gear 21a of the rear wheel differential gear 21 is attached to the other output shaft 19b of the center differential gear 19.

Both the first propeller shaft 34 and the second propeller shaft 45 extend in the longitudinal direction of the vehicle body. In this embodiment, the first propeller shaft 34 is a solid shaft, while the second propeller shaft 45 is hollow. The first propeller shaft 34 is formed of a tubular body, and the first propeller shaft 34 is housed in the hollow second propeller shaft 45.
A plurality of bearings 47 are disposed between the first propeller shaft 34 and the first propeller shaft 34.

The tip of the first propeller shaft 34 is connected to the output shaft 17a of the torque converter 17. On the other hand, the tip of the second propeller shaft 45 has the relay shaft 5 connected to the front wheel differential gear 16.
It is connected to 0 through a gear train 51. The gear train 51 includes a first gear 52 attached to the second propeller shaft 45, a second gear 53 attached to the rear end of the relay shaft 50, and the first and second gears 52 and 53. The counter gear 54 is interposed therebetween.

The operation of the above drive system will be described below.
The engine output is input from the torque converter 17 to the transmission 18 through the first propeller shaft 34 and the first intermediate shaft 24, and after being subjected to a desired gear shift by the transmission 18, the center differential gear 19 distributes the engine output to the rear wheels. It is transmitted to the differential gear 21 for vehicles (left and right rear wheels 13) and the second intermediate shaft 25. The engine output transmitted to the second intermediate shaft 25 passes through the second hypoid gear 43, the second propeller shaft 45, and the relay shaft 50, and is transmitted to the front differential gear 16 (left and right front wheels 12). Here, the counter gear 42 of the second gear train 38 is set so that the first propeller shaft 34 and the second propeller shaft 45 rotate in the same direction. Thereby, the relative rotation difference between the first propeller shaft 34 and the second propeller shaft 45 can be reduced, and the wear of the bearing 47 can be reduced.

The front and rear shaft ends of the second propeller shaft 45 are integrated with the front sleeve 56 of the casing of the torque converter 17, respectively, and the drive unit 2.
It is surrounded by a rear sleeve 57 which is integrated with the casing of No. 0, and a second bearing 58 is interposed between each of these sleeves 56 and 57 and the outer peripheral surface of the second propeller shaft 45. Therefore, the front and rear sleeves 56 and 57 prevent the second propeller shaft 45 from swinging and function as a rigid body that connects the torque converter 17 and the drive unit 20. Therefore, it is not necessary to intentionally provide a rigid casing that connects the torque converter 17 and the drive unit 20, and therefore,
The size of the tunnel portion (not shown) that houses the second propeller shafts 34 and 45 can be minimized.

According to the first embodiment, the engine 15 and the front wheel differential gear 16 are arranged in the engine room 2.
Mounted on the other hand, on the other hand, the transmission 1 at the rear of the vehicle body
8. Since the center differential gear 19 and the rear wheel differential gear 21 are mounted, the weight distribution in the front-rear direction of the vehicle body can be made appropriate without uneven distribution of weight in the front portion of the vehicle body as in the conventional case. . Similarly, the size of the front end of the tunnel portion can be made smaller than in the conventional case, and the foot space of the front seat occupant can be enlarged.

Further, since the transmission 18 is mounted horizontally, the length of the drive unit 20 including the transmission 18 in the longitudinal direction of the vehicle body can be shortened, and the volume of the rear portion of the vehicle compartment 4 or the luggage compartment 3 can be reduced. It can be applied to family cars that can be expanded. By the way, in the case of a transaxle type output in which the transmission is separated from the conventional engine and arranged at the rear of the vehicle body, it is customary to mount the transmission vertically, that is, to mount the transmission with the mission axis facing forward and backward. Was a sports car.

3 and subsequent drawings show another embodiment of the present invention. In the description of these embodiments, the same elements as those in the first embodiment will be designated by the same reference numerals and the description thereof will be omitted, and the characteristic portions of these embodiments will be described below. Second Embodiment (FIGS. 3 to 5) The drive system in this embodiment is substantially the same as the drive system in the first embodiment, but differs in the following points in detail.

First, the second propeller shaft 45
Like the propeller shaft 34, the propeller shaft 34 is formed of a solid shaft, and the second propeller shaft 45 and the first propeller shaft 34 are arranged in parallel. In addition, the first gear train 2 that connects the first intermediate shaft 24 and the mission shaft 18a
7, a counter gear 59 is interposed between the first gear 30 and the second gear 31. In addition, the gear train 51 that connects the second propeller shaft 45 and the front wheel differential gear 16 (relay shaft 50) includes a first gear 52 and a second gear 52.
The gear 53 is directly meshed with the gear train 53. An auxiliary gear 60 is meshed with the gear train 51. The auxiliary gear 60 is attached to the first propeller shaft 34. More specifically, the auxiliary gear 61 meshes with the first gear 52 of the second propeller shaft 45, and via the auxiliary gear 60, the input end of the first propeller shaft 34, the output end of the second propeller shaft, and the The front wheel differential gear 16 is connected.

Here, in the drive system of this embodiment, the first to fourth dog clutches 62 to 6 are provided at the following locations.
5, the power transmission path is changed by these dog clutches 62 to 65. The locations where the dog clutches 62 to 65 are provided will be described below. First, the first dog clutch 62 is interposed between the front end portion of the first propeller shaft 34, more specifically, between the first propeller shaft 34 and the auxiliary gear 60. The second dog clutch 63 is provided at the rear end of the first propeller shaft 34. Needless to say, at the location where the second dog clutch 63 is provided, the first propeller shaft 34 is divided into the front and the rear, and the second dog clutch 63 is interposed between them. Similarly, the third dog clutch 64 includes one output shaft 19a of the center differential gear 19 (an output shaft that transmits power to the front wheels 12) and another output shaft 19b (the rear wheels 1).
3 and an output shaft for transmitting power to 3).
That is, the center differential gear 19 is in a locked state (differential lock) by turning on the third dog clutch 64, and is in an operating state by turning it off. Further, the fourth dog clutch 65 is
It is interposed at the rear end of the second propeller shaft 45.

An example of control of these dog clutches 62 to 65 will be described below. First example First mesh clutch 61 and third mesh clutch 6
When both 3 are disengaged (OFF) and the second and fourth dog clutches 62 and 64 are both engaged (ON),
The connection between the input end of the first propeller shaft 34 and the output end of the second propeller shaft 45 is cut off. Therefore, the engine output is the same as that of the first embodiment from the torque converter 17 to the first propeller shaft 34, 1 is input to the transmission 18 through the intermediate shaft 24,
After a desired speed change is made by the transmission 18, it is distributed by the center differential gear 19,
It is transmitted to the rear wheel differential gear 21 (the left and right rear wheels 13) and the second intermediate shaft 25. The engine output transmitted to the second intermediate shaft 25 passes through the second hypoid gear 43, the second propeller shaft 45, and the relay shaft 50, and is transmitted to the front differential gear 16 (left and right front wheels 12). Second example First, third, and fourth dog clutches 61, 63, 64
Are connected together (ON) and the second dog clutch 62 is disconnected (OFF), the first propeller shaft 34
The rear end portion of the first propeller shaft 34 is cut off.
Power transmission from the vehicle to the transmission 18 is prohibited. On the other hand, since the third dog clutch 63 is connected (ON), the center differential gear 19 is in the differential lock state. In addition, the first dog clutch 61
Is connected (ON), the output of the torque converter 17 is transmitted from the auxiliary gear 60 to the output end of the second propeller shaft 45 and the front wheel differential gear 16 (front wheel 12). Here, the engine output transmitted to the output end of the second propeller shaft 45 flows backward toward the input end of the second propeller shaft 45, and passes from the second intermediate shaft 25 through the second gear train 38 to the rear wheels. It is transmitted to the differential gear 21 (rear wheel 13). Therefore, both engine outputs are transmitted to the front wheels 12 and the rear wheels 13 without passing through the transmission 18. For example, when the speed ratio of the transmission 18 is set to "1", that is, in the case of so-called overdrive,
When the aspect of the second example is set, the power transmission loss can be reduced as compared with the case where four wheels are driven via the transmission 18 or the hypoid gear 33. Third Example First and second dog clutches 61 and 62 are both connected (O
N) and disengage the fourth dog clutch 64 (OFF)
In addition, the third dog clutch 63 is properly connected (O
N) or when disconnected (OFF), the engine output is transmitted to the transmission 18 through the first propeller shaft 34 and then the center differential gear 19 because the first propeller shaft 34 and the transmission 18 are in a connected state. And is transmitted to the rear wheel differential gear 21 (rear wheel 13). On the other hand, the first dog clutch 61 is engaged (O
N), the engine output is the auxiliary gear 6
It is directly transmitted to the front differential gear 16 (front wheel) through 0 (gear train 51). Therefore, for example, the combination of the gear train 51 including the auxiliary gear 60 is
When the so-called overdrive (speed ratio = 1) is set, the power transmission to the front wheels 12 is transmitted via the transmission 18 arranged at the rear part of the vehicle body by forming this mode during overdrive. It is possible to directly carry out the operation without increasing the power transmission efficiency. Of course, in the case of the first speed, the second speed, etc., the mode of the first example may be adopted.

The control example of the drive system of the present embodiment has been described above. For example, the first, third, and fourth control are always performed.
Disengage the dog clutches 61, 63, 64 (OFF)
Then, the second clutch 62 is engaged (ON), and the rear wheel drive (FR) that drives only the rear wheel 13 is set.
The first dog clutch 61 may be connected (ON) when the stack exits or when the vehicle rapidly starts. In this case, the combination of the gear train 51 including the auxiliary gear 60 is 1
By setting the speed to high speed, it becomes easy to escape the stack under four-wheel drive. The modes of the dog clutches 61 to 64 in the first to third examples are listed in FIG. Third Embodiment (FIG. 6) In the drive system of the present embodiment, as compared with the drive system of the second embodiment, basically, the second propeller shaft 45 does not exist. That is, the output of the torque converter 17 is input to the transmission 18 through the first propeller shaft 34, the hypoid gear 33, and the first gear train 27, and after the gear shift is performed by the transmission 18, the differential gear 21 for the rear wheels is used. It is transmitted to the left and right rear wheels 13. On the other hand, the auxiliary gear 60 is attached to the front end portion of the first propeller shaft 34, and the output of the torque converter 17 passes through the auxiliary gear 60, the counter gear 68, the gear train 69 including the second gear 53, and the relay shaft 50. It is distributed by the front wheel differential gear 16 and transmitted to the left and right front wheels 12. Here, the gear train 69
The combination of the respective gears in is set to be so-called overdrive (speed ratio = 1). In addition, the first propeller shaft 34 and the auxiliary gear 60 are provided with a first
A dog clutch 62 is interposed, and the power transmission to the front wheels 12 is controlled by the first dog clutch 62.

Based on the above, in the present embodiment, the first dog clutch 62 is normally disengaged (OF).
Then, the rear-wheel drive type in which only the rear wheels 13 are driven is set. On the other hand, the transmission 18 displays “speed ratio =
When the overdrive is set to "1", the first dog clutch 62 is connected (ON), and the front wheels 12 are driven together with the rear wheels 13 (four-wheel drive type).

According to this embodiment, the transmission 1
A part time 4WD can be constructed while taking advantage of the transaxle in which 8 is separated from the engine 15 and arranged laterally between the left and right rear wheels 13. Further, since the power transmission to the front wheels 12 is directly performed from the torque converter 17 without passing through the transmission 18, the power transmission efficiency to the front wheels 12 can be improved. Of course, since it becomes 4WD at the time of overdrive, it is possible to improve the stability of high-speed traveling. Fourth Embodiment (FIG. 7) In the drive system of the present embodiment, in the gear train 69 of the third embodiment, the combination of the gears in the gear train 69 is set to be the so-called first speed. ing.

Based on the above, in the present embodiment, as in the third embodiment, the first dog clutch 62 is normally disengaged (OFF) to drive only the rear wheel 13. Wheel drive format is set. On the other hand, when the transmission 18 is set to "first speed" or when the stack exits, the first dog clutch 62 is engaged (O
N), and the front wheels 12 are driven together with the rear wheels 13 (four-wheel drive type).

According to this embodiment, as in the third embodiment,
The transmission 18 is separated from the engine 15, and while taking advantage of the transaxle that is placed horizontally between the left and right rear wheels 13, a part-time 4WD that can be changed to a four-wheel drive type when the stack escapes is configured. be able to.

[0025]

As is apparent from the above description, according to the present invention, in a four-wheel drive vehicle that drives not only the front wheels but also the rear wheels,
Since the basic form of the driving method is a transaxle type, the weight distribution in the vehicle front-rear direction can be made appropriate. Further, in the case where the engine is arranged in the so-called engine room, the size of the front end portion of the tunnel portion formed on the passenger compartment floor can be made small.

[Brief description of drawings]

FIG. 1 is a plan view of a drive system of a vehicle according to a first embodiment as viewed from above.

FIG. 2 is a side view of a vehicle on which the drive system shown in FIG. 1 is mounted as seen from the side.

FIG. 3 is a plan view of a drive system of a vehicle according to a second embodiment as viewed from above.

FIG. 4 is a side view of a vehicle equipped with the drive system shown in FIG. 3 as viewed from the side.

FIG. 5 is a table showing a control example of a dog clutch provided in a drive system according to a second embodiment.

FIG. 6 is a diagram of a drive system of a vehicle according to a third embodiment as viewed from above.

FIG. 7 is a diagram of the drive system of the vehicle according to the embodiment in FIG. 4 viewed from above.

[Explanation of symbols]

2 engine room 3 luggage room 4 vehicle compartment 12 front wheels 13 rear wheels 15 engine 16 front wheel differential gear 17 torque converter 17a torque converter output shaft 18 transmission 18a mission shaft 19 center differential gear 20 drive unit 21 rear wheel differential gear 34 fourth 1 Propeller shaft 45 Second propeller shaft 51 Gear train 60 Auxiliary gear 62 First mesh clutch 63 interposed between first propeller shaft and auxiliary gear 63 Second mesh clutch 64 Third mesh clutch (ON of center differential gear) / For OFF control) 65 4th dog clutch

Claims (6)

[Claims] 1. A front wheel drive mechanism connected to the left and right front wheels, a rear wheel drive mechanism connected to the left and right rear wheels, and a rear wheel arranged in a region sandwiched by the left and right rear wheels. A transmission coupled to the vehicle drive mechanism, an engine disposed in front of the transmission, a first propeller shaft extending in the vehicle front-rear direction and transmitting the output of the engine to the transmission, and extending in the vehicle front-rear direction, A second propeller shaft that transmits the output of the transmission to the front-wheel drive mechanism, the drive device for a vehicle. 2. The vehicle according to claim 1, wherein either one of the first and second propeller shafts is a hollow shaft, and the other propeller shaft is arranged in the hollow shaft. Drive. 3. The first propeller shaft and the second propeller shaft
The drive system for a vehicle according to claim 1, wherein the propeller shaft of the vehicle extends in parallel. 4. The vehicle drive device according to claim 1, wherein the transmission is arranged with its transmission shaft oriented in the vehicle width direction. 5. A clutch for disconnecting power transmission from the first propeller shaft to the transmission when a speed ratio generated by the transmission is set to "1", and an output of the engine The drive device for a vehicle according to claim 3, further comprising a power transmission mechanism that directly transmits to the second propeller shaft without passing through a transmission. 6. A power transmission mechanism that transmits the output of the engine to the front wheel drive mechanism without passing through the transmission, and a speed ratio generated by the transmission that is interposed in the power transmission mechanism. A first clutch that is connected when set to "1" and allows power transmission to the front wheel drive mechanism; and a transmission that is generated when the speed ratio generated by the transmission is set to "1". The second
The vehicle drive device according to claim 3, further comprising a second clutch that disconnects power transmission to the propeller shaft.