JPS6334233A - Four wheel drive device - Google Patents

Abstract

PURPOSE:To aim at enhancing the maneuverability and traveling property of a vehicle, by changing over first and second change-over clutches to make it possible to select five drive conditions of front wheel drive, for wheel drive biased to the front wheel side, direct-coupled four wheel drive, four wheel drive biased to the rear wheel side and rear wheel drive. CONSTITUTION:When clutches 13, 14 are changed over by a lever 20, the rear wheel drive shaft 3 is free from an input torque split gear 10 at the position I so that a front wheel drive condition is set up, and the torque transmission path is changed over to increase the front torque at the position II so that a sour wheel drive condition biased to the front wheel side is set up. Further, the front and rear wheel drive shafts are coupled directly with each other through the intermediary of gears 9, 10 at the position III so that four wheel drive condition is set up, and the gears 9, 10 are changed over to increase the rear torque at the position IV so that a four wheel drive condition biased to the rear wheel side is set up. Further, the front wheel drive shaft is free from the gear 9 by means of the clutch 13 at the position V so that a rear wheel drive condition is set up. With this arrangement, it is possible to select an optimum condition in accordance with running condition of the vehicle.

Description

[Detailed description of the invention] [Industrial application field]

This invention is a full-time four-wheel drive vehicle equipped with a transversely mounted engine, etc. and equipped with a Sen-Imaichi differential, which improves maneuverability, stability, and driving performance by arbitrarily controlling the drive torque distribution between the front and rear wheels. This invention relates to a four-wheel drive system that can be changed according to purpose or preference.

[Conventional technology]

Conventionally, for four-wheel drive vehicles with a center differential, a differential gear 17 is used in the center differential device, and a dog locking the center differential device is used to limit the operation of the center differential device, as shown in Japanese Patent Laid-Open No. 55-72420, for example. Some are equipped with a clutch.

[Problems to be Solved by the Invention] By the way, in the configuration of the prior art described in L, the differential gear device serving as the center differential has two side gears having the same diameter due to the mechanism. ,
The drive torque distribution to the rear wheels is always approximately equal. Therefore, it was not possible to actively change the drive torque distribution of C1. Further, the dog clutch only has a differential lock function that integrally locks the differential gear device for emergency escape when one of the front and rear wheels is idling. In a four-wheel drive vehicle, changing the torque distribution of front wheel torque TF and rear wheel torque TR based on various driving conditions improves turning performance in addition to driving performance. It is known that stability also improves maneuverability and stability. Therefore, even in full-time four-wheel drive vehicles with center differential f=j, torque distribution is actively controlled to improve maneuverability and
It has been desired to improve stability and driving performance, but conventionally only an in-cylinder four-wheel drive system has been used to improve front wheel torque T.
F and rear wheel side torque TR are TF > TR and TF
<Currently, there is no 4-wheel drive system that can put both TR into practical use. This invention was made in view of these points, and it is possible to actively change the torque distribution between the front and rear wheels to change the maneuverability, stability, and driving performance according to the purpose or preference. The purpose is to provide a four-wheel drive device that can. [Means for Solving the Problems] In order to achieve the above first object, the present invention comprises a center differential comprising first and second planetary gear mechanisms for torque splitting, and the first planetary gear mechanism and the second planetary gear mechanism. The first switching clutch is connected between the front differential and the second switching clutch.
A second switching clutch and a bistunos coupling for slip prevention 1F are respectively disposed between the planetary gear mechanism and the rear wheel drive shaft, and the first and second switching clutches are switched into one. By interlocking with the lever and switching between five stages, it is possible to select five different drive states: front-wheel drive, front-side 4-wheel drive, direct-coupled 4-wheel drive, rear-side 4-wheel drive, and rear-wheel drive. , :, is a thing. 1 Effect] Based on the above configuration, the first and second
When the switching clutch is switched in five stages, in position ■, the rear wheel drive shaft is released from the connection with the second planetary gear mechanism for input torque splitting by the second switching clutch and becomes free, and the front wheel drive state is changed. Become. In addition, in the positive control mode (2), the torque transmission path is switched to the front torque increasing side, resulting in a four-wheel drive state closer to the front wheels. Further, in position (3), the front and rear drive shafts are directly coupled via the first and second planetary gear mechanisms, resulting in a direct four-wheel drive state. Furthermore, at position 1■, the torque transmission paths of the first and second planetary gear mechanisms are switched to the rear torque increasing side, resulting in a four-wheel drive state closer to the rear wheels. At position V, the front wheel drive shaft is disconnected from the first planetary gear mechanism by the first switching clutch and becomes free, resulting in a rear wheel drive state. In addition, in positions II and IV, the viscous coupling is in operation, and if one wheel side slips, it will not occur. The drive torque of the other wheel is increased by the rotation difference between the rear wheel drive shafts, thereby attempting to escape from the slip state. According to the present invention, it is possible to select the optimum driving state depending on various road surfaces, driving purpose, or preference.

【Example】

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. In FIG. 1, reference numeral 1 denotes an input shaft to which a driving torque T from the transmission is input. 2a
, 2b is a left and right front wheel drive shaft, 3 is a rear wheel drive shaft, 4 is a transfer shaft supported on the transmission case, 5 is a gear fixed to the input shaft 1, and 6 is rotatable on the front wheel drive shaft 2a. 7 is a gear fixed to the transfer shaft 4, and transmits the drive torque from the input shaft 1 to the transfer shaft 4 via the gear 5.6. 8 is a front differential, and 9 is a gear supported on the transfer shaft 4. The first planetary gear mechanism is composed of a plurality of planetary pinions 9a, a sun gear 9b, and a ring gear 90.The second planetary gear mechanism 10 is composed of a plurality of planetary pinions 10a, a sun gear 10b, and a ring gear 10c. 11 is a carrier fixed to the transfer shaft 4, which prevents both planetary vinyls A 9a and 10a from orbiting. 12 is a planetary gear housing integrated with both planetary gears \79C and 10c, and 13 is a first switching clutch. , a director sleeve 13a having internal teeth 13a1, 13a2, 13a, and a transfer shaft 4-L.
4-position engagement gear 13h rotatably supported on
1, a 2-position engageable gear 13b integrally coupled with the leaning gear 179b, and a 2-position engageable gear \y13t)3 integrally engaged with the housing 12. is the second switching clutch, with internal teeth 14a5
．． 14az, 14as / Kuta Sleeve 1
4a and a 1-position engageable gear fixed on the hollow shaft.
V 14b1, a 2-position engageable gear %t 14b2, a 3-position engageable gear A214b3 integrally engaged with the sun gear 10b, and a 3-position engageable gear fixed on the hollow shaft. 14b, a 1-position engagement gear j714b4, and a 4-position engagement gear 1714b fixed on the hollow shaft.
It consists of , and. Reference numeral 15 denotes a viscous coupling, which is rotatably supported on the trans-non-7 shaft 4, such as a housing 15a with a protruding hollow shaft for fixing the planetary gear N7 housing 12 on the negative side and the gears 14b1, 14b on the other side. The housing H+a and the hub 15b are erected so that a plurality of plates fit into each other, and a high viscosity fluid is sealed inside, and when a difference in rotation occurs between the two, the cup is rotated accordingly. 1 and 16, where ring torque is generated, are gears integrally connected to the gear 13b1, and gears 17L; 19 Hake left lever and its fork 19a. 191) engage with the selector sleeves 13a and 14a, respectively. Reference numeral 20 denotes a switching lever that allows selection of positions from position E to position V. Next, regarding the operation of the four-wheel drive system configured as described above, the first section shown in FIG. Second switching clutch 13.1
This will be explained with reference to the engagement state of No. 4 and the drive torque distribution table shown in FIG. First, when the switching lever 20 is set to position 2, as shown in FIG. , and the gear t713b2 disengages, so the front differential 8 is moved to the gear 17.1B, ? - Lancer shaft 1 to 4.1Y rectifier sleeve 13a, connected to ring gears 9c, 10c of first and second planetary gear mechanisms 9, 10 via housing 12;
1 On the other hand, the second switching clutch 14 is connected to the south 14a1.14
a. are engaged with the gears 14b1, 141)s, the viscous coupling 15 becomes inoperative because relative rotation between its housing 15a and the hub 151) is disabled, and the second propeller gear puller 7 mechanism 10 as well, its sun gear 10b and ring gear 10c are integrated to prevent planetary motion. And tooth 14a3 and gear A714b5
Since the rear wheel drive shaft 3 is disengaged from the second planetary gear mechanism 10, the rear wheel drive shaft 3 is released from the second planetary gear mechanism 10 and becomes free. Therefore, the driving torque T from the input shaft 1 is applied to the gears 5, 6,
7. Transfer shaft 4. Both the planetary bins A 9a, 10a are driven to revolve through the carrier 11, the ring gears 9c, 10c, and the housing 12. Engagement between gear 13b2 and tooth 13a1, l! Connect the front differential 8 to the front [F (TF L +
TF R) = T, and the front wheel drive state is established. In this driving state, stability during high-speed running 4j is improved. Next, when the switching lever 20 is switched to position H, the first and second switching clutches 13 and 14 are switched as shown in FIG. 2(b).
The second switching clutch 1 becomes engaged as shown in 1.
4 @ Since the engagement between 14a1 and gear 714b is disengaged, the viscous coupling 15 is removed from its housing 1!
1a and the hub 1511 are in an operating state in which they can rotate relative to each other. Then, the driving torque T input via the carrier 11
The planetary pinion 9a, the ring gear 4, 79c, Housing 12. Engagement between gear 13b and tooth 13a3. t=t The front torque TF is transmitted to the front differential 8 through the engagement of the nocta sleeve 13a, l@13a1 and gear pin 13b1. On the other hand, planetary binion 10
a. sun gear 101), hub 1 of viscous coupling 15
51) and is transmitted to the rear wheel side drive shaft 3 as V torque TR through the engagement between the gear 14b3 and the south 14a, and the engagement between the selector sleeve 14a, the teeth 14a3 and the gear 14b. However, due to the gear ratio of 17 between the ring gear 9C and the ring gear 10b, a four-wheel drive state with the front wheels closer to TF:'/TR is achieved. Here, the viscous coupling 151 is connected to the housing 1 when driving with normal one-wheel drive near the front wheel.
Since there is no difference in rotation between the housing 15a and the hub 15b, no cup link torque is generated. However, for example, if the front wheel with a large drive torque distribution slips, the housing 15a tries to rotate at high speed, so the rotation difference with the hub 15h increases. As a result, a coupling torque Tc is generated, and this torque Tc is added to the rear torque TR on the low speed side to increase the drive torque of the rear wheel drive shaft 3, so that it is possible to easily escape from the slip state. Furthermore, when the switching lever 20 is switched to the position E1, the first and second switching clutches 13 and 14 are switched to the position shown in FIG.
C), it becomes engaged as shown in 1, and the second switching 7 edges 14＠14al, 14a, , 14a3 and gear 1
4bt. 14b2.14b, the viscous coupling 15 and the second planetary gear mechanism 10 are integrated together and the first planetary gear ψg! The front differential 8 and the rear wheel drive shaft 3 are directly connected via the structure 9 and the first switching clutch 13, resulting in a direct four-wheel drive state. In such a direct four-wheel drive state, drivability on rough roads and stability on low 71 roads are improved. Furthermore, when the switching lever 20 is switched to position Iv, the first and second switching clutches 13,14 are switched to the second
The engaged state as shown in FIG. , to the front differential 8 side via the planetary pinion 9a and sun gear 9b, and
A planetary binion 10a and a ring gear 1 are connected to the rear wheel drive shaft 3.
0c, respectively, resulting in a rear-wheel-biased four-wheel drive state where TF <TR. Note that the viscous coupling 15 in this case functions to similarly increase the drive torque TF on the front wheel side when the rear wheel slips. Then, when the switching lever 20 is switched to the position ■, the first and second switching clutches 13 and 14 move as shown in FIG.
In e), the fully engaged state is reached, and the front differential 8 is separated from the first planetary gear mechanism 9 and becomes free. On the other hand, since all of the second switching clutches 14 are in the engaged state, the viscous coupling 15 and the second planetary gear A structure 10 are integrated, and the torque T input from the carrier 11 is directly converted into a torque TR. The transmission is transmitted to the rear wheel side drive shaft 3, and the rear wheels are driven, thereby improving the turning performance and starting performance. In the above embodiment, the first and second switching clutches 13, 14 are switched by manual operation of the switching lever 20, but they may be operated electrically or pneumatically.

【Effect of the invention】

As is clear from the above description, according to the four-wheel drive system of the present invention, the center differential is configured with two sets of planetary gear mechanisms and a viscous coupling, and the first and second differentials are configured to switch front and rear wheel drive torque distribution. The two switching clutches are linked by a switching lever and can be switched in five stages, allowing you to select five different drive states, so you can choose between front-wheel drive, front-side 4-wheel drive, or direct-coupled 4-wheel drive, depending on driving conditions or preference. , rear-wheel-biased 4-wheel drive, and rear-wheel drive can be selected arbitrarily, improving maneuverability, stability, and performance on rough roads.
This has the effect of improving road running performance.

[Brief explanation of the drawing]

1 to 3 are diagrams showing one embodiment of the present invention, and FIG. 1 is a skeleton diagram showing the configuration of a four-wheel drive device;
FIG. 2 is a diagram showing the engaged state of the first and second switching clutches, and FIG. 3 is a diagram showing the drive torque distribution. 1...Input shaft, 2a, 2b...Front wheel drive shaft, 3.
...Rear wheel side drive shaft, 4...Transfer shaft...
8... Front differential, 9... First planetary gear mi, io-... Second planetary gear mechanism, 13...
- First switching clutch, 14... Second switching clutch, 15... Viscous coupling, 20... Switching lever. Patent Applicant Tomiju Heavy Industries Co., Ltd. Agent Patent Attorney Jundo Nobu Kobashi Patent Attorney Susumu Murai-14=

Claims (1)

[Claims] The center differential is the first and second one for torque splitting.
a first switching clutch between the first planetary gear mechanism and the front differential, a second switching clutch between the second planetary gear mechanism and the rear wheel drive shaft, and a second switching clutch between the second planetary gear mechanism and the rear wheel drive shaft. A viscous coupling is provided for prevention, and the first and second switching clutches are linked by a single switching lever and switched in five stages, allowing for front-wheel drive, front-side 4-wheel drive, and direct-coupled 4-wheel drive. A four-wheel drive device characterized in that five different drive states can be selected: drive, rear-side four-wheel drive, and rear-wheel drive.