JPS5830835A - Four-wheel drive device with oil-hydraulically controlled speed changer - Google Patents

Abstract

PURPOSE:To enhance maneuverability, start acceleration and durability by furnishing an oil-hydraulic clutch, which is operated by the line pressure for the speed changer, in a transfer clutch of the four-wheel drive device equipped with an automatic speed changer etc. and thereby making it possible to change over from FF to 4WD and vice versa. CONSTITUTION:A transfer mechanism 6 for four-wheel drive is coupled with an extension case 30 at its rear and is provided with a rear drive shaft 31 rotatably inside the case 30. The shaft 31 is fitted with a transfer clutch 35 in oil-hydraulic clutch type in the same manner as the automatic speed changer 3, and a drum 35a is coupled with the shaft 31 in a solid body for its hub 35b to transmit the power to the transfer drive shaft 33. When, in the case of high load run, the line pressure is fed to the clutch 35 from the oil-hydraulic control device 5 to put the drum 35a in engagement with the hub 35b, the transfer gear 34 is directly coupled with the drive shaft 31 to transmit the power from the shaft 31 to the rear wheels through the propeller shaft 37. Thus the four-wheel drive condition is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a four-wheel drive device that is equipped in a transmission system of a vehicle such as an automobile and includes a hydraulically controlled transmission and a front and rear wheel drive mechanism. This invention relates to a combination of a transaxle type hydraulically controlled worting machine driving one side and a four-wheel drive transfer mechanism.

As a drive system for a car, for example, an engine is mounted in the front of the car body to drive the front wheels. So-called front engine
The front drive (hereinafter referred to as FF) eliminates the need for a propeller shaft and enables stable running by driving and steering with the front wheels.

It has been widely used for reasons such as improving performance. And this F
Even in the F driving system, a hydraulically controlled transmission is used in the transmission system to automatically change gears according to the driving condition of the vehicle. In the case where a transmission is provided, the torque converter, automatic transmission, and front wheel final reduction gear are integrally arranged in close proximity to each other.

By the way, in general, with two-wheel drive, the drive wheels tend to lose their grip ability during sudden starts, rough roads, hill driving, etc., especially during low-speed and high-load movements, and the vehicle performance may not be fully demonstrated.
This point should be improved by adding a transfer mechanism for rear wheel drive to the conventional front wheel drive system equipped with a manual transmission, allowing both front wheel drive driving and front and rear 4 wheel drive driving by manual operation. This has already been proposed by the applicant. However, conventionally, transfer clutches for four-wheel drives, including transfer clutches that are combined with automatic transmissions, have used a mechanical coupling method using a normal dog clutch, which inevitably requires manual operation. Not only was this accompanied by a sense of misalignment, but it could only be operated when stopped or when driving straight ahead with no difference in rotation between the front and rear wheels. Moreover, in the case of an automatic transmission, unlike a manual transmission, the clutch cannot be operated, so power from the engine is only cut off in the N (neutral) or P (park) positions, and when the transfer lever is operated. It is common practice to once set the main lever to the N or P position and then operate the transfer lever, making the operation even more complicated.

For this reason, when combining a four-wheel drive transfer mechanism with an automatic transmission unit that is controlled by hydraulic IJ, for example, a hydraulic clutch is installed in the transfer,
If the line pressure of the automatic transmission is used as the operating pressure of the clutch, FF (front wheel drive) and 4W can be used regardless of the driving conditions.
Not only is it possible to mutually switch between D (4-wheel drive), but by setting the operating conditions of the line pressure circuit switching pulp for the clutch in advance, it is also possible to automatically obtain 4WD (4-wheel drive) driving. , which is very advantageous in terms of vehicle performance and operability.

The present invention has been made in view of the above circumstances, and a transfer mechanism having a hydraulic clutch type transfer clutch is attached to one of the front and rear wheel drive devices equipped with a hydraulically controlled transmission. , connected to the other rear wheel,
By operating both the transmission and transfer clutch using the line pressure of the hydraulic control device, 2-wheel drive driving such as FF and 4-wheel drive are possible.
The present invention provides a four-wheel drive system having a hydraulically controlled transmission that can automatically switch to wheel drive driving depending on the driving condition of the vehicle, particularly during low speed and high load operation.

Hereinafter, one embodiment of the present invention will be specifically described with reference to the drawings.

In FIGS. 1 and 2, reference numeral 1 denotes a front wheel drive device with an automatic transmission, which is roughly divided into a torque converter 2, an automatic transmission 3, a front final reduction gear 4, and a hydraulic control device w5. A four-wheel drive transfer mechanism 6 is attached to the rear of the automatic transmission 3 of such a front wheel drive device 11 with an automatic transmission.

For example, the torque converter 2 is symmetrical 3! ! It is a single-stage, two-phase type with a pump impeller 2 inside the converter housing 7.
It comprises an a1 turbine 2b and a stator 2C. The pump impeller 2a is connected to the engine crankshaft 8 via a drive plate 9, and a turbine shaft 10 from the turbine 2b extends to the side of the automatic transmission lll3 behind the torque converter. Then, by driving the pump impeller 2a with the engine power of the crankshaft 8 and rotating the turbine 2b while changing the oil flow with the stator 2C, the torque transmitted to the turbine shaft 10 together with the turbine 2b is increased in accordance with the load. It is designed to output power while doing so. Further, the converter cover 11 integrated with the drive plate 9 has an oil pump drive shaft 12-5.
= is coupled, and this shaft 12 passes through the turbine shaft 10 and is connected to an oil pump 13 disposed at the rear of the automatic transmission 3 to drive it.

The automatic transmission 3 has a Lavigneau type planetary gear 15 provided at the front inside the transmission case 14, and a low and reverse brake 16 and a forward clutch 17 at the rear.
, reverse clutch 18, etc. are arranged in sequence. The turbine shaft 10 from the torque converter 2 is connected to a forward sun gear 15a of a planetary gear 15 via a forward clutch 17, and at the same time, a reverse clutch 1
8 and connecting shell 19 to reverse sun gear 15b, and by hydraulically operating these clutches 17 and 18, the power of turbine shaft 10 is transferred to sun gear 1
5a and 15b. Also, the drum 18 is integral with the connecting shell 19 of the reverse clutch 18.
A brake band 20 is attached to a, and this band 20
By tightening hydraulically, the reverse sun gear 15b is locked.

In the planetary gear 15, each sun gear 15 on the input side
a, short pinion 150106 meshing with 15b
The low and reverse brake 16 is provided on the carrier 15e that supports the one-ring pinion 15d, and the one-way clutch 2 is provided between it and the center support 21.
2 are provided, and the carrier 15c is locked by operation of these brakes 16 or one-way clutches 22. And long pinion 15d of planetary gear 15
A ring gear 15f meshing with the turbine shaft 10 is coupled to an output shaft 23 coaxially disposed around the turbine shaft 10. In addition, the code|symbol 24 is a parking gear.

The front wheel final reduction gear 4 is disposed below the shaft 10.12 between the torque converter 2 and the automatic transmission 3, and a case 25 is mounted between the housing 7 and the case 14. An output shaft 23 from the planetary gear 15 is rotatably supported inside. Further, a drive pinion 26 is supported by a bearing at the bottom of the output shaft 23 and is arranged in parallel.The output shaft 23 and the drive pinion 26 are connected to transmit power by a reduction gear 27, and the drive pinion 26 is coaxially arranged. It meshes with the crown gear 29 of the differential mechanism 28, which is arranged below and orthogonally to the shaft 10, 72.23.

The four-wheel drive transfer mechanism 6 is connected to the transmission case 14.
An extension case 3o is connected to the rear of the case 30, and a rear drive shaft 31 is rotatably provided inside the case 30. On the other hand, a transfer drive shaft 33 is rotatably disposed on the extension line of the drive pinion of the front wheel terminal reduction gear 4 in the inner lower part of these cases 14° 30, and the drive pinion 26 and shaft 33 can be attached and detached by a spline joint 32. It is now connected to. The rear drive shaft 31 is provided with a hydraulic clutch type transfer clutch 35 similar to the clutches 17 and 18 of the automatic transmission 3, and the drum 35
a is integrally connected to the rear drive shaft 31, a hub 35b is connected to the transfer drive shaft 33 via a transfer gear 34 to transmit power, and a propeller is connected to the rear end of the rear drive shaft 31 via a universal joint 36. A shaft 37 is connected.

Further, the hydraulic control device 5 has various pulp and oil passages inside a pulp pod 38 which is divided into upper and lower halves. It is installed horizontally inside an oil pan 39 installed under the transmission case 14, and regulates the hydraulic pressure generated by the oil pump 13 to control the torque converter 2, the brake 16, clutch 17, 18, and brake band of the automatic transmission 3. 20
The lubricant is supplied to the servo means of the transfer mechanism 6, the transfer clutch 35 of the transfer mechanism 6, and further to each lubricating section.

Since the present invention is configured in this manner, engine power is constantly transmitted to the turbine shaft 10 via the torque converter 2 during engine operation. In a low-speed operating state, the forward clutch 17 is operated by the hydraulic control device 5, and the power of the turbine shaft 10 is input to the forward sun gear 15a of the planetary gear 15. At the same time, the carrier 15e is locked by the one-way clutch 22, and the ring gear 15f is The rotational power with the largest gear ratio is taken out to the output shaft 23, and this is transferred to the reduction gear 2.
7 to the drive pinion 26 and then to the crown gear 29 of the differential mechanism 28.

9- On the other hand, the power of the drive pinion 26 is further transmitted to the transfer foot mechanism 6 side via the spline joint 32 and the transfer drive shaft 33.

In such a state, when the engine load is small, when the transfer clutch 35 is released by the pulp operation of the hydraulic control device 5, the transfer gear 34 and the rear drive shaft 31 are separated by the clutch 35, and the rear drive shaft 31 and the subsequent parts are separated. Power is no longer transmitted to the rear wheels, and the first front-wheel drive is driven by the differential mechanism 2B.
It will be running at high speed.

On the other hand, since it is relatively easy to lose the grip ability at this time, when the load operation is performed, line pressure is supplied from the hydraulic control device 5 to the transfer clutch 35, and the drum 35a and hub 3
5b is engaged, the transfer gear 34 is directly connected to the rear drive shaft 31 and the power is transferred to the rear drive shaft 31.
The power is also transmitted to the rear wheels via the propeller shaft 37, resulting in a four-wheel drive state in which the front and rear wheels are driven simultaneously.

Next, as the vehicle speed increases, the hydraulic control device 5 operates the brake band 20 to lock the reverse rotation gear 15b, and rotational power with a small gear ratio is extracted from the ring gear 15f of the planetary gear 15 to the output shaft 23. 2nd speed is automatically shifted, but at this time, the engine load decreases and the transfer clutch 3
5 is released again, power is no longer transmitted to the rear drive shaft 31 and beyond, and if the vehicle was traveling in four-wheel drive, the vehicle returns to the FF state. Furthermore, the vehicle speed increases and reverse clutch 1
8 also operates, and the planetary gear 15 is the two sun gears 15.
When power is simultaneously input from a and 15b and they are integrated, the engine power is extracted directly from the turbine shaft 10 and the output shaft 23, and the gear is automatically shifted to third speed.

Reverse speed is obtained by operating the reverse clutch 18 to input power to the reverse sun gear 15b of the planetary gear 15, and by operating the low and reverse brake 16 to lock the carrier 15e.

In addition, at the time of the above-mentioned first gear, the low and reverse brake 16 is operated instead of the one-way clutch 22, and the
When 5e is locked to prevent reverse rotation, engine braking becomes effective.

As explained above, according to the present invention, a hydraulic clutch operated by the line pressure of the transmission is used as a transfer clutch of a four-wheel drive device having a hydraulically controlled transmission such as an automatic transmission. F regardless of the conditions
It is now possible to switch between FWD and 4WD, making it extremely easy to operate, and it also automatically switches to 4WD during low-speed, high-load driving when the front wheels are relatively prone to losing grip in FF automatic transmission mode. As a result, starting acceleration performance and driving performance are improved, and the load on the drive system is dispersed, improving durability. For example, based on a front wheel drive system 1fl equipped with an existing transaxle-type transmission that is hydraulically controlled, not only in a longitudinal type but also in a horizontal position, a trans-77 mechanism 6 is attached to the rear part of the system, and a hydraulic clutch type transmission is added. Since the four-wheel drive device is configured to operate by the common hydraulic control device 5 using the transfer clutch 35, it is possible to obtain a four-wheel drive device that is compatible with those without a transfer mechanism and has high productivity.

In the embodiments described above, an automatic transmission was exemplified as a hydraulically controlled transmission, but this type of transmission also includes a belt-type continuously variable transmission. This continuously variable transmission is disclosed, for example, in Japanese Patent Laid-Open No. 51-33422,
Since the hydraulic control device is configured to continuously variable speed, the transformer 7 of the four-wheel drive device in which a transfer mechanism is added as in the present invention by the hydraulic control device in this case.
It is also possible to perform switching operations for 7 mechanisms.

The transfer gear 34 of the transformer 77 mechanism 6 is used to convert the rotation direction and adjust the front and rear wheel differential gear ratio in order to use the existing rear wheel drive differential structure.
and the rear drive shaft 31 directly to the transfer clutch 3.
5 may be connected.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a four-wheel drive system having a hydraulically controlled transmission according to the present invention, and FIG. 2 is a skeleton diagram schematically showing the same system. DESCRIPTION OF SYMBOLS 1...Front wheel drive system with automatic transmission, 2...Dorkco 13-inverter, 3...Automatic transmission, 4...Front wheel final reduction gear, 5...Hydraulic control device, 6...・4-wheel drive transfer mechanism, 35...transfer clutch. Patent applicant Fuji Heavy Industries Co., Ltd. Representative Patent Attorney Jundo Kobashi Patent Attorney Susumu Murai 14-

Claims (1)

[Claims] A transfer mechanism having a hydraulic clutch type transfer clutch is attached to a drive device for one of the front and rear wheels equipped with a hydraulically controlled transmission and connected to the other of the front and rear wheels, and the transmission is automatically shifted. A four-wheel drive system having a hydraulically controlled transmission that operates the transfer clutch using a hydraulically controlled equipment to automatically switch between two-wheel drive and four-wheel drive depending on the driving condition. @pupil.