JPH03139437A - Power distribution control device for four-wheel drive car - Google Patents

Abstract

PURPOSE:To shorten a drive system and to improve assembly workability by a method wherein a center differential device and a differential limit device are coaxially combined together on a front drive shaft, a transmission output shaft, and a transfer shaft. CONSTITUTION:A front drive shaft 20 is extended rearwardly, and an output element coupled to the front drive shaft 20 and a transfer shaft 22 are intercoupled on the front drive shaft 20 through thrust bearings 41b and 41c by means of a transmission output shaft 19 and a center differential device 50. The output element and the transfer shaft are integrally fastened thereagainst by means of a lock nut 45 at the terminal end of the front drive shaft 20, and the center differential device 50 and a viscous coupling 60 are coaxially combined together on the front drive shaft 20, a transmission output shaft 19, and the transfer shaft 22. In this constitution, torque is distributed to front and rear wheels by means of the center differential device 50, and distribution of torque is controlled according to a slip by means of the viscous coupling 60.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a power distribution control device for a four-wheel drive vehicle equipped with a complex planetary gear type center differential device, and more particularly, the present invention relates to a power distribution control device for a four-wheel drive vehicle equipped with a complex planetary gear type center differential device. transmission output side.

The present invention relates to an assembly structure of a front and rear wheel drive system, a center differential device, and a differential limiting device.

[Conventional technology]

Conventionally, regarding a four-wheel drive vehicle with a center differential device based on a vertical transaxle type with a manual transmission, there is a prior art, for example, British Patent No. 1,114.756. Here, a bevel gear type center differential device is placed coaxially within the transfer behind the output shaft of the transmission, and power is transmitted from one side gear to the drive shaft inside the transmission output shaft and to the front wheels via a pair of gears. However, a transmission 11 is provided from the other side gear to the rear wheel. The center differential then distributes torque equally between the front and rear wheels.

Further, for example, the prior art of US Pat. No. 3,748,928 shows that a simple planetary gear type center differential device is used to distribute torque unequally to the front and rear wheels, and a differential limiting device is provided between the front and rear output elements. has been done.

[Problem to be Solved by the Invention] By the way, the former of the above-mentioned prior art uses a bevel gear type equal torque distribution, which maximizes running performance on rough roads, but on low μ roads etc. slips easily occur.

Adding a differential limiting function to the center differential device to prevent this slip improves driving force, but
Maneuverability is not particularly improved, and since the conditions for the occurrence of slip on the four wheels are the same, during high-speed turns, the vehicle may slip between the four wheels and become difficult to maneuver.

Further, in the latter prior art, steering stability is ensured even in a slip state due to unequal torque distribution with a large torque distribution to the rear wheels. However, when combined in a transaxle type, there are carrier manpower, sun gear front export force, and ring gear rear export force, and since the manpower element is placed on the same axis and outside of the front export force element, it is not easy to combine it. I can't.

Furthermore, when the drive pinion of the front drive shaft directly meshes with the final gear of the hypoid as in the present invention, a large thrust load is generated.

For this reason, the front drive shaft inside the transmission output shaft and the parts connected thereto need to be reliably supported so as to receive thrust loads in the longitudinal direction. In this respect, in the former prior art, the front drive shaft and drive pinion have a two-piece structure, so bearing is easy, but the front drive transmission system is complicated. configuration is required.

For this reason, the overall structure becomes complicated, leading to deterioration in ease of assembly, rigidity, etc., and problems such as an increase in length due to the bearing structure.

The present invention has been made in view of the above, and its object is to provide a vertical transaxle type equipped with a manual transmission with a transmission output shaft, a front drive shaft therein, a center differential device, and a differential transmission. When the motion limiting devices are arranged on the same axis, they can be integrally fastened to each other to receive thrust loads, thereby shortening the drive system and improving assembly workability, etc.4.
An object of the present invention is to provide a power distribution control device for a wheel drive vehicle.

[Means to solve the problem]

In order to achieve the above object, the power distribution control device for a four-wheel drive vehicle of the present invention connects the front drive shaft disposed inside the output shaft of the manual transmission directly to the front differential device, and In a four-wheel drive vehicle in which a center differential device is disposed between a front drive shaft, a front drive shaft, and a transfer shaft to rear wheels, the front drive shaft extends rearward, and the transmission output shaft is disposed on the front drive shaft. An output element and a transfer shaft connected to the front drive shaft in the center differential device are connected via a thrust bearing, and are integrally fastened by a lock nut at the end of the front drive shaft, and the front drive shaft, the transmission output shaft and The center differential device and the differential limiting device are coaxially combined on the transfer shaft.

[For production]

Based on the above configuration, the front drive shaft, which is directly connected to the front differential device, the transmission output shaft, and the center differential device.

The assembly is completed by attaching the differential limiting device, transfer shaft, etc. and tightening with a lock nut. Then, a center differential device distributes torque between the front and rear wheels, and a differential limiting device controls torque distribution according to slippage, etc.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

Referring to FIG. 1, a vertical transaxle type drive system to which the present invention is applied will be described. An extension case 3 is joined to a transmission case 1 via a transfer case 2. Then, the crankshaft 11 on the engine side is connected to the clutch 13 via the flywheel 12.
The input shaft 18 from this clutch I3 is input to the manual transmission 30.

The output shaft 19 of the manual transmission 30 is arranged parallel to the input shaft 1B and is connected to a center differential device 50 inside the transfer case 2. A front drive shaft 20 is inserted into the transmission output shaft 19, and the center differential device 50 is connected to the front drive shaft 20.
The front differential device 21 is connected to the front differential device 21 via the front differential device 21.
Power is transmitted from the front wheels to the front wheels.

The front drive shaft 20 is installed to extend toward the extension case 3 side further rearward than the center differential device 50, and a transfer shaft 22. Viscous coupling 60 for differential limiting
are arranged coaxially, and a transfer drive gear 24 is spline-coupled to the transfer shaft 22, and is positioned and supported by a ball bearing 42d and attached to the extension case 3. On the other hand, a rear drive shaft 23 is arranged at a height above the input shaft te, and the front end of this rear drive shaft 23 fits into the bearing portion 2a of the transfer case 2 via a needle bearing 40a, and also has a thrust bearing 41a. supported in contact with
The middle portion is supported by a ball bearing 42a of a bearing portion 3a of the extension case 3. The driven gear 2 of the rear drive shaft 23 is connected to the transfer drive gear 24.
5 mesh with each other, and the transmission is configured to be transmitted to the rear wheels.

The manual transmission 30 is of a constant mesh type, and includes first to fifth speed change gears 31 to 35 and synchronizing mechanisms 36 to 38 between a parallel input shaft 1B and an output shaft 19. A selective mesh type reverse gear mechanism 39 is further provided on the outer periphery of the synchronizing mechanism 3B.

Then, the synchronizer mechanism 36 or 38 shifts the transmission gear 31.
By selecting any one of the speeds 35 to 35, the gear is shifted to the first to fifth speeds, and the reverse gear mechanism 39 provides a reverse gear.

In FIG. 2, the center differential device 5
0 and the viscous coupling 60 will be described.

The center differential device 50 includes a front drive shaft 20 and a transmission output shaft 19 disposed coaxially on the outside thereof. It is provided between the transfer shaft 22 and the transfer shaft 22 . That is, the first sun gear 51 is connected to the transmission output shaft 19 on the input side.
A second sun gear 53 is formed on the output side transfer shaft 22, and a second sun gear 53 is formed on the output side transfer shaft 22.
．． 54 is the first. It meshes with the second sun gear 51°53. The pinion member 5B is supported by the pinion shaft 57 of the carrier 55, which is also connected to the front drive shaft 20 on the output side, via the needle bearing 40b.
In this way, a composite planetary gear type is formed.

Here, the carrier 55 includes left and right flanges 55a.

The first. A second pinion 52,54 is installed. In addition, a spline 20a is provided in the middle of the front drive shaft 20.
is formed, and the first. A connecting member 55d is spline-coupled to the spline 20a between the second pinions 52 and 54,
The engaging portion 55c of the arm 55c of this connecting member 55d is connected to the front drive shaft 20 side by spline connection. Furthermore, one flange 55a is connected to the transfer case 2.
The other flange 55b is positioned and supported by the ball bearing 42b of the bearing part 2b of the transfer member 2b.
It is supported by two ball bearings 42c and is rotatably installed.

In this way, the power of the transmission output shaft 19 is transferred to the first sun gear 5.
1 by hand, 1st. Torque is transmitted to the carrier 55 and the second sun gear 53 via the second pinions 52, 54 at a predetermined distribution ratio. And when transmitting such torque,
1st. The difference in rotational speed between the carrier 55 and the second sun gear 53 is absorbed by the rotation and revolution of the second pinions 52 and 54.

Here, the torque distribution of the center differential device 50 will be described in detail using the schematic diagram of FIG.

The manual torque of the first sun gear 5I is T11, its meshing pitch radius is rsl, the front side torque of the carrier 55 is TP, and the first sun gear 5I has a manual torque of T11. The engagement pitch radius of the second pinion 52.54 is rp1+'! '2. If the rear side torque of the second sun gear 53 is TR and its meshing pitch radius is rs2, then Ti -TF +TR (1) rsl +rp1 -rs2 +r+)2
(2> holds true. Also, the tangential load P acting on the meshing point between the first sun gear 5■ and the first pinion 52
are the tangential load P1 acting on the carrier 55 and the second
is equal to the sum of the tangential load P2 acting on the meshing point between the sun gear 53 and the second pinion 54.

P-TI/rs1 Pl-TP/ (rs1+rp1)P2-T
R/rs 2 TI/rs 1-i (TF/(rs 1+ rp 1
)1+TR/rs2 (3)(1),
Substituting equation (2) into equation (3) and sorting it out, TP =
(1-rpl ・rs2 /rs1 ・rl12
) Tl TR-(rpl ・rs 2 /rs 1 °rp2
)TI becomes. From this, 1. 2nd sun gear 51°5
3 and 1st. Depending on the engagement pitch radius with the second pinion 52, 54, front torque TF and rear torque TI? It can be seen that the reference torque distribution of i can be freely set.

Here, rs 1-23.5non, rp 1-1
6.5mm.

rp 2-18.8mm, rs 2-21.2mm
Then, it becomes TF-20753・Tl TR-33153・T1. Therefore, the torque distribution between the front and rear wheels becomes TP+TR≠38:82, and the reference torque distribution can be set to sufficiently bias the rear wheels.

Next, the viscous coupling 60 will be described.
A cylindrical case 61 is rotatably installed on the transfer support 22 with a connecting portion 61a splined to the flange 55b of the carrier 55, and a hub 62 is connected to the transfer support 22.
integrally splined to. Inside case 61,
Case side outer plate 63 and hub side inner plate 6
4 are arranged alternately, the case 61 and the hub 62 are sealed with an oil seal 65, and oil such as silicone is sealed inside.

In this way, the viscous coupling 6 is connected between the carrier 55 on one output side and the second sun gear 53 on the other output side.
0 is provided as a bypass, and as the difference in rotation speed between the two increases, viscous torque, that is, differential limiting torque is generated, and the torque is bypassed from the high rotation side to the low rotation side.

Further, a transmission output shaft 19 .coaxially arranged. Front drive shaft 20. Center differential device 50
．． The assembly structure of the transfer shaft 22 and the like will be described.

First, a drive pinion 21a of a front differential device 21 is formed at the tip of the front drive shaft 20, and is configured to mesh with a hypoid final gear 21b. The front drive shaft 20 has needle bearings 40c and 40d at both ends of the transmission output shaft 19.
The transfer lever 22 is also fitted and supported via needle bearings 40e and 401' at both ends.

Therefore, at the tip step portion 20b of the front drive shaft 20,
The tip of the transmission output shaft 19 is abutted through the adjustment washer 43a, and the driven gears 31a to 35a of the transmission gears 31 to 35, the hub 36a of the synchronizing mechanism 36, and the bearing part of the transmission case 1 are abutted to the transmission output shaft 19 via the adjustment washer 43a. Double tapered roller bearings 44 of 1a are mounted in contact with each other. The above-mentioned gears and the like are fastened to the transmission output shaft 19 by screwing a lock nut 45a of the transmission output shaft 19 onto the terminal gear 35a through a washer 44a.

Further, the tapered roller bearing 44 is fixed to the bearing portion 1a by the bolt 4B, so that the transmission output shaft 19. The axial direction of the front drive shaft 20 is determined, and in this case, the meshing state between the drive pinion 21a and the final gear 21b is adjusted by interposing the shim 47 between the bearing 44 and the bearing portion la.

Furthermore, a connecting member 55d of the carrier 55 and a transfer shaft 22 are connected to the rear of the transmission output shaft 19 on the front drive shaft 20 via thrust bearings 41b and 41e.
are sequentially connected, and the center differential device 50. Viscous coupling 60. Transfer drive gear 24 is assembled. Then, an adjustment washer 43 is attached to the transfer shaft 22 at the end of the front drive shaft 20.
b. A lock nut 45b is screwed onto the front drive shaft 20 via a washer 44b, thereby attaching the transmission output shaft 19.b to the front drive shaft 20. Connecting member 55d.

The transfer shafts 22 are preloaded and integrally fastened in a mutually rotatable state.

Next, the operation of the four-wheel drive vehicle configured in this manner will be described.

First, the power of the engine 10 is supplied to the clutch 13. Input shaft 1B
input to the manual transmission 30 via the manual transmission 30
The shifting power that has been shifted is input from the transmission output shaft 19 to the first sun gear 51 of the center differential device 50. Here, the center differential device 50
Depending on the specifications of each gear element, for example, TP: TR Aya 3B
: 62, 38% of the shifting power is distributed to the carrier 55, and 62% of the torque is distributed to the second sun gear 53 and output.

The 38% torque output to the carrier 55 is then directly transferred to the front drive shaft 20. It is transmitted to the front wheels via the front differential device 21. Further, 62% of the torque output to the second sun gear 23 is the same as that of the transfer shaft 22. Transfer drive gear 24°Transfer driven gear 25. The power is transmitted to the rear wheels after the rear drive shaft 23, resulting in four-wheel drive driving with a biased emphasis on the rear wheels. With this torque distribution, there is a slight understeer, ensuring good maneuverability.

Also, when turning, the center differential device 50
is the first depending on the difference in rotation speed between the front and rear wheels. Second pinion 52
．． 54 rotates and revolves to completely absorb the difference in rotational speed, making it possible to turn freely.

Next, when driving on a slippery road, the rear wheels always slip first due to torque distribution biased towards the rear wheels.

Then, the viscous coupling 60 connects the carrier 55 on the front wheel side. An outer plate 63 integrated with the case 61 and a transfer shaft 22 on the rear wheel side. A large rotational speed difference occurs between the hub 62 and the integral inca plate 64, generating differential limiting torque, and the torque is bypassed from the high-speed transfer shaft 22 to the low-speed carrier 55 by this differential limiting torque. do. Therefore, the torque distribution between the front and rear wheels is shifted toward the front wheels.
rlJ #, which prevents slipping and improves running performance.

Further, during the above-mentioned four-wheel drive, a thrust load is generated at the engagement point between the drive pinion 21a of the front differential device 21 and the final gear 22b, and this load acts in the axial direction of the front drive shaft 20. Therefore, this front drive shaft 20 has a transmission output shaft 19. The connecting member 55d and the transfer shaft 22 are connected to the lock nut 4.
5b etc. and are connected coaxially, the above-mentioned thrust load is reversed through the transmission output shaft 19 etc. and acts in the opposite direction on the front drive shaft 20, so that it is canceled out. .

Although the embodiments of the present invention have been described above, a hydraulic multi-disc clutch may be used instead of the viscous coupling. It is also possible to connect a rear drive shaft coaxially behind the transfer shaft.

〔Effect of the invention〕

As described above, according to the present invention, in a four-wheel drive vehicle of a vertical transaxle type equipped with a manual transmission and equipped with a center differential device and a differential limiting device, the transmission output shaft.

Since the center differential device and the differential limiting device are assembled adjacent to the front drive shaft, etc. that directly meshes with the front differential device, the entire drive system can be prevented from becoming elongated, and a comfortable interior of the vehicle can be ensured.

Furthermore, a center differential device uses the same manual transmission and distributes torque with an emphasis on the rear wheels.

Since the configuration is simply a combination of transfer units having a differential limiting device that controls torque distribution, it is advantageous in terms of production and cost.

Furthermore, since the front drive unit, center differential device, and differential limiting device are integrated into the assembly on the output shaft side of the transmission by tightening them with a lock nut at the end, assembly work efficiency is improved. . Further, the thrust load of the drive pinion, etc. can be reduced.

In addition, the center differential device is of a composite planetary gear type and the output is output at the center, so it is compact, and since both sides of the carrier are supported by ball bearings, positioning accuracy, durability, etc. are improved.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view showing an embodiment of the power distribution control device for a four-wheel drive vehicle of the present invention, Fig. 2 is an enlarged sectional view of a portion of the transfer unit including the center differential device, and Fig. 3 is a state of torque distribution. FIG. 19... Transmission output shaft, 20... Front drive shaft, 21... Front differential device, 22
... Transfer shaft, 23 ... Rear drive shaft, 3
0...Manual transmission, 41b, 41c...Thrust bearing, 45b...Lock nut, 50...
Center differential device, 55...Carrier, 55d...Connection member, 60...Viscous coupling

Claims (2)

[Claims] (1) The front drive shaft disposed inside the output shaft of the manual transmission is directly connected to the front differential device, and a center differential device is installed between the transmission output shaft, the front drive shaft, and the transfer shaft to the rear wheels. In a four-wheel drive vehicle, the front drive shaft is extended rearward, and the transmission output shaft is disposed on the front drive shaft.
The output element and transfer shaft connected to the front drive shaft in the center differential device are connected via a thrust bearing, and are integrally fastened with a lock nut at the end of the front drive shaft, and the front drive shaft and the transmission output shaft are connected together by a lock nut at the end of the front drive shaft. 4, characterized in that the center differential device and the differential limiting device are coaxially combined and configured on the transfer shaft.
Power distribution control device for wheel drive vehicles. (2) The center differential device is a composite planetary gear type consisting of a transmission output shaft, a sun gear formed on the transfer shaft, a pinion that is integrally formed and meshes with each sun gear, and a carrier that supports the pinion. Claim (1) characterized in that the differential limiting device is supported by a bearing and connected and assembled to the front drive shaft between two pinions, and the differential limiting device is installed in a bypass manner between the carrier and the transfer shaft.
The power distribution control device for the four-wheel drive vehicle described above.