JPS60143131A - Four-wheel drive car - Google Patents

Abstract

PURPOSE:To make distribution of the driving torque produced in both front and rear wheels so pertinent, by using a double-pinion type planetary gear, while freely selecting a ratio between a variation portion for a front wheel side output speed of rotation and that for a rear wheel side output speed of rotation in relation to an input speed of rotation. CONSTITUTION:A casing 9 is fitted with a final reduction gear 6 and rotatably supported on a transmission case 3 and that a differential gear set serving as a central differential gear 10 is built in. The differential gear 10 consists of a ring gear 11, a first planetary gear 12 engaging this ring gear, a second planetary gear 12' engaging this gear 12, a double-pinion type planetary gear mechanism having a sun gear 13 and a carrier 14 rotating on the same shaft around this sun gear 13. The number of teeth in the sun gear 13 of the central differential gear 10 and that of the ring gear 11 are selected into various sizes in type whereby driving torque is well distributable in response to a variety of load distribution between both fron and rear wheels of various vehicles.

Description

DETAILED DESCRIPTION OF THE INVENTION (Technical Field) The present invention relates to a four-wheel drive vehicle, and more particularly to a four-wheel drive vehicle equipped with a central differential in a transverse engine vehicle.

(Prior art) Conventionally, as a four-wheel drive vehicle equipped with a central differential in a transverse engine type vehicle, L.
There is something related to No. 5. This four-wheel drive vehicle uses a central differential to absorb the difference in rotation between the front and rear wheels when turning, etc., making it possible to run in four-wheel drive at all times, increasing the utility of the four-wheel drive vehicle.

By the way, due to reasons such as the layout of the vehicle, the load applied to the front wheels and the load applied to the rear wheels are not necessarily the same, and the load distribution may vary depending on braking or the presence or absence of cargo. There is also. On the other hand, it is important to distribute the drive torque generated between the front and rear wheels in accordance with the load distribution between the front and rear wheels in order to effectively utilize the engine output torque and improve fuel efficiency and driving performance. preferred.

However, the central differential in the conventional four-wheel drive vehicle uses a bevel gear of the same type as the differential gear mechanism conventionally used to absorb the rotation difference between the left and right wheels. A differential gear mechanism is used.

In such a differential gear mechanism, the input rotation speed NI,
The following relationship exists between the front wheel output rotation speed NF and the rear wheel output rotation speed NR.

2N1 = NF'+NR Collinear chart for such a differential gear mechanism
(Please refer to the explanation in No. 94053) as shown in Fig. 1. In the figure, the vertical axis showing the manual rotation speed N1 in the ring gear is the R axis, the vertical axis showing the front wheel output rotation speed NF in one side gear is the A axis, and the vertical axis showing the rear wheel output rotation speed NR in the other side gear. Let the axis be the B' axis. As is clear from the figure, the change in NR with respect to N1 (N12 - Nl) and the change in NF (CNx - NF )
is always equal. Therefore, the ratio between the respective changes on the front and rear wheel sides (Ng - N') / (Nl
-NF) cannot be changed freely. That is, it is not possible to vary the rotation ratio between the front wheels and the rear wheels by largely changing only the rotation speed of the other wheel without changing the rotation speed of one of the wheels. By the way, engine output P
Assuming that is constant, the drive torques TF and 1'R generated at the front and rear wheels as described above are inversely proportional to the rotational speeds NF and NR of the front and rear wheels, as shown below.

'rI:'/T# = Ntz /NF ', ' P, L: TF NF = 'Tf NR Therefore, in the differential gear mechanism using such bevel gears, one of the front and rear wheels By largely changing only the rotation speed of the other without changing the rotation speed too much, we can respond to various load distributions between the front wheels and rear wheels of various vehicles.
Drive generated in each of the front and rear wheels!・Luc TF and T
There is a disadvantage that the distribution between the two and I2 cannot be set to various appropriate values.

In addition, by modifying the differential gear mechanism using such bevel gears, it is possible to greatly change the rotation speed of the front and rear wheels without changing the rotation speed of one of the other wheels. , the equipment becomes larger, resulting in increased weight, increased cost of parts, and deterioration of fuel efficiency.

(Purpose of the Invention) Therefore, the present invention uses a double pinion type planetary gear instead of a bevel gear to reduce the difference between the change in the front wheel output rotation speed and the change in the rear wheel output rotation speed with respect to the input rotation speed. By freely selecting the ratio, the distribution of drive torque generated between the front and rear wheels can be set to suit various load distributions between the front and rear wheels of various types of vehicles. At the same time, the present applicant filed a patent application No. 56-13048.
The purpose is to enable the 4-wheel drive vehicle proposed in No. 0 to be used as the 4-wheel drive vehicle of the present application with almost no changes, thereby reducing weight, number of parts, and cost, as well as improving fuel efficiency and driving performance. do.

(Structure of the Invention) A four-wheel drive vehicle according to the present invention includes an engine whose crankshaft is arranged so as to extend in the lateral direction of the vehicle body, an input shaft and an output shaft which are arranged within a transmission case so as to extend in the lateral direction of the vehicle body. A final reduction gear is arranged approximately coaxially with either the front axle or the rear axle within the transmission case and is rotationally driven by the output shaft of the transmission mechanism. a central differential device provided inside a casing that rotates integrally with the final reduction gear; and a central differential device disposed approximately coaxially with the one axle within an additional housing connected to the transmission case and drive-coupled to the central differential device. a differential gear mechanism on one side of the front wheels or rear wheels, and a differential gear mechanism on the other side of the front wheels or rear wheels driven by the central differential device and converting the rotational direction of the driving force at right angles. A four-wheel drive vehicle is provided with a direction changing gear set for transmitting transmission to a mechanism, and the central differential device is configured using a double-binion type planetary gear mechanism having two types of pinion gears that mesh with each other.

(Example) Hereinafter, an example of the present invention will be described based on the drawings. Second
The figure is a diagram showing a four-wheel drive vehicle according to an embodiment of the present invention.

First, the configuration will be explained. 1 is a crankshaft 1a at the front of the vehicle.
This is a so-called transverse engine, which is arranged so that it extends in the lateral direction of the vehicle body. The second one is a manual transmission. The manual transmission system 2 includes a clutch 4 in a transmission case 3, a transmission mechanism 5 disposed in series with the engine 1, and a final reduction gear 6. The transmission mechanism 5 includes an input shaft 5a connected in series to the crankshaft 1a of the engine 1 via a clutch 4 and disposed in the lateral direction of the vehicle body;
It has an output shaft 5b disposed parallel to the input shaft 5a in the lateral direction of the vehicle body, and between the input shaft 5a and the output shaft 5b is a transmission gear set as a transmission mechanism 5. Speed gear set 5c, second gear set 5d, third gear set 5e, fourth gear set
A continuous gear set 5f and a reverse gear set 5g are interposed. A drive gear 7 is provided at one end of the output shaft 5b, and a final reduction gear 6 is meshed with this drive gear 7.

Final IT speed ti car 6 has transmission case 3
It is rotatably supported within the vehicle with an axis extending in the lateral direction of the vehicle body serving as a rotation axis, and is disposed coaxially with the front axle leg. 9 is a casing, to which the final reduction gear 6 is attached, is rotatably supported by the transmission case 3, and rotates integrally with the final reduction gear 6. A differential gear set as a central differential' device 10 is incorporated within the casing 9.

Zunawaji, the central differential gear 10, as shown in FIG.
Ring gear I provided integrally inside the casing 9
I, a first planetary gear 12 (the pinion gear is called a planetary gear 1) that meshes with this ring gear 11, a second planetary gear 12' that meshes with this first planetary gear I2, and a gear that meshes with this second planetary gear 12'. The carrier 14 rotatably supports the first planetary gear 12 and the second planetary gear 12' and rotates coaxially around the sun gear 13. The sun gear 13 is provided integrally with the first hollow shaft 15 through which the front axle 25 is inserted, and is further provided in the differential case 1 of the front wheel differential gear mechanism 16.
7 is integrally connected. The carrier 14 is provided integrally with the second hollow shaft 18 into which the first hollow shaft 15 is inserted, and is also integrally connected to the differential case 17 and a first transmission gear 39 provided separately.

3a is a part of the transmission case 3 on the transmission mechanism 5 side, and 3b is a part of the four clutches of the transmission case 3, and both are connected near the plane containing the final reduction gear 6. Transmission case 3
An additional housing 8 is attached to the portion 3b of the four clutches, and houses a first hollow shaft 15 and a second hollow shaft 18 that protrude from the transmission case 3. The additional housing 8 is divided into two parts near the front wheel differential gear mechanism 16.
6 is rotatably supported by an additional housing 8. Differential case 17 of front wheel differential gear mechanism 16
Inside, a pair of first bevel gears 2I and 22 are rotatably supported on an axis 2o orthogonal to the axis extending in the transverse direction of the vehicle body, and a pair of first bevel gears 21 and 22 are engaged with each other with their axes orthogonal to each other. A differential gear set consisting of a pair of second bevel gears 23 and 24 is housed. The second bevel gears 23 and 24 are respectively connected to the front axle 2.
5.26 and is splined to the front axle 25.2
6 are constant velocity joints 27 and 28, and drive axle 29, respectively.
．． 30. Constant velocity joint 31: (Connected to the left and right front wheels 33, 34 via 2. 36 is a lock amplifier mechanism, and the lock-up mechanism 36 is provided at the end of the second hollow shaft 18. A compression sleeve (7) which is slidable on the spline is provided on the differential case 17 of the front wheel differential gear mechanism 16 and is capable of meshing with a coupling leaf 37 to form latch teeth 38. I9 is an intermediate shaft, which is disposed within the additional housing sink 8 in the lateral direction of the vehicle body, and is rotatably supported by the additional housing 8.

A second transmission gear 40 that meshes with the first transmission gear 39 is rotatably provided on the intermediate shaft 19, and a third bevel gear 41 is provided by spline connection so as to rotate integrally with the intermediate shaft 19. It is being 42 is a two-wheel/four-wheel drive switching mechanism, which includes a coupling sleeve 59 that can slide on a spline provided on the intermediate shaft 19 and a second transmission gear 40.
It has latch teeth 43 which are disposed on and capable of engaging with the compression sleeve 59. 44 is a fourth bevel gear, which meshes with the third bevel gear 41 and is provided on a shaft 45 extending in the longitudinal direction of the vehicle body. These third and fourth bevel gears 4I and 44 constitute a direction conversion gear set. The shaft 45 projects outward from the housing 8 and has a universal joint 46.
The propeller shaft 47 is connected to a rear wheel final reduction gear 49 via a universal joint 4B. The rear wheel final reduction gear 49 has a rear wheel differential gear mechanism 50 therein. The rear wheel differential gear mechanism 50 includes a constant velocity joint 51.
52, left and right rear axles 53.54, constant velocity joint 55.
It is connected to left and right rear wheels 57 and 58 via 56.

Next, the effect will be explained.

The driving force output from the engine 1 is inputted to the human power shaft 5a of the transmission mechanism 5 via the clutch 4, the speed is changed by the transmission gear set, and outputted from the output shaft 5b. 60 rotations of the final reduction gear are transmitted to the gear teeth 9 and then to the central differential gear 10.If the lock-up mechanism 36 is now released, the coupling sleeve 37 is connected to the clutch teeth 3.
8 and 11+1, and the first hollow shaft 15 and the second hollow shaft 18, that is, the sun gear 13 and the carrier 14, can freely rotate with respect to each other. In the double pinion type planetary gear mechanism, the input rotation speed N in the ring gear II
I, the front wheel output rotation speed NF delivered to the Zangito 13, and the rear wheel output rotation speed NR delivered to the carrier 14 have the following relationship.

NI-αNp-(1-α)Ng=O1 α-ZS/ZR However, Zs is the number of teeth of the sun gear 13, and ZI2 is the number of teeth of the ring gear 11. A collinear chart for such a double pinion type planetary gear mechanism is shown in FIG. 4. In other words, in the same figure, if a straight line is drawn on the vertical axis R, which indicates the rotational speed of the ring gear 11, and passes through the point The number, that is, the front wheel output rotation speed NF, and the point where the straight line intersects with the vertical axis PC indicate the output rotation speed of the carrier 14, that is, the rear wheel output rotation speed NR. Since the sun gear 13 and carrier 14 can freely rotate with respect to each other as described above, no matter how inclined this straight line is, N and F
and NR are free to each other on their respective vertical axes S and P
The respective rotational speeds can be shown at the intersection with C. In this way, when the ring gear II is rotated at a certain input rotation speed and a rotation difference occurs between the front and rear wheels when the vehicle is turning, etc., this double pinion type planetary gear mechanism changes the rotation of the ring gear 11 to the sun gear. 13 and carrier 1
The central differential device 10 can perform the function of the central differential device 10 by distributing the differential to the central differential device 10 (absorbing the rotational difference). Rotation of the sun gear 13 is transmitted to the ζ differential case 17 via the first hollow shaft 15. The rotation transmitted to the differential case 17 is differentially distributed to the left and right front axles 25, 26 through the differential gear mechanism G of the first bevel gear 21, 22, the second bevel gear %, and 24, and is then distributed to the left and right front axles 25, 26. .2
8. Drive the front wheels 33.34 via the drive axle 29.30 and the constant velocity joint 31.32.

On the other hand, the rotation of the carrier 14 is transmitted to the second hollow shaft 18 and then to the second transmission gear 40 via the first transmission gear 39. If the two-wheel/four-wheel drive switching mechanism 42 is now switched to four-wheel drive, the force/knob ring sleeve 59 is engaged with the clutch teeth 43, and the rotation of the second transmission gear 40 is caused by the intermediate shaft 19. Reportedly.

The rotation direction of the intermediate shaft 19 is converted to a right angle by the meshing of the third bevel gear 41 and the fourth bevel gear 44, and is transmitted to a shaft 45 extending in the longitudinal direction of the vehicle body. The driving force transmitted to the shaft 45 is transmitted through the universal joints 1 to 46, the propeller shaft 47, and the universal joint 48 to the rear wheel final reducer 49, where the rear wheel final reducer 49 again changes the direction of rotation at right angles. It is converted to and decelerated, differentially distributed by the rear wheel differential gear mechanism 50, and drives the rear wheels 57.58 via the constant velocity joint 51.52, the rear axle 53.54, and the constant velocity joint 55.56. do. As a result, the front wheel is 33.3
This is a four-wheel drive system in which both the rear wheels 57 and 58 are driven by the engine output drive system.

In the above case, the central differential device 10 differentially distributes the driving force between the front wheels 33, 34 side and the rear wheels 57, 58 side, and distributes the driving force between the front and rear wheels 33 when turning or when the front and rear wheels have different tire diameters. Absorbs the rotation difference between .34 and 57.58,
It is the same as a conventional central differential using bevel gears in that it allows four-wheel drive at all times, regardless of whether the vehicle is traveling on level ground or rough terrain. However, since the central differential device 10 of the present invention uses a double-binion type planetary gear mechanism, it is possible to change the rotation speed of one side without changing the rotation speed of the other to a large extent, thereby increasing the speed between the front wheels and the rear wheels. The rotation ratio can be varied in various ways. As described above based on FIG. 1, in the conventional central differential, the change in the rear wheel output rotation speed NR with respect to the input rotation speed NI (NR-
NI) and the change in front wheel output rotation speed NF (Nr-NF)
is always equal. On the other hand, in the central differential device 10 according to the present invention, as shown in FIG.
The ratio of the distance between C and the vertical axis S and R is α/(1-α)
Therefore, it is not []/1 as in the past. Therefore, the change (N
tz -Nr ) and the change in front wheel output rotation speed NF (N
I-NF) is also α/(1-α). (l
-α)>α, even if the rear wheel output rotation speed Np does not change much with respect to the input rotation speed J, the front wheel output rotation speed NF changes greatly with respect to the input rotation speed Nf. In FIG. 4, the rear wheel output rotation speed NP is slightly larger than the input rotation speed Nr, and the front wheel output rotation speed N is considerably smaller than the input rotation speed NI. This is done so that the rear wheels 57 and 58 do not shift too much and the front wheels 3
This means that the rotation speed of 3.34 is significantly lower. This situation occurs when the front wheels 33.34 have a larger load distribution than the rear wheels 57.58.
．． Minimize the slippage on the 58 side as much as possible (suppress the front axle 33
．． The drive torque TF of the 34 examples is the drive torque T of the rear wheel 57.58? It is very useful when you need to make it larger than the size. This is because, as described above, when the engine output is constant, the rotational speed and drive torque between the front wheels and the rear wheels are inversely proportional to each other.

By selecting α, that is, Zs (number of teeth of sun gear 3)/ZI2 (number of teeth of ring gear 11) to various sizes, the above-mentioned α/(1-α) can also be selected variously. α or α/(1-
α) can be freely selected. In this way,
By freely selecting the ratio between the change in the front wheel output rotation speed NF and the change in the rear wheel output rotation speed Ng with respect to the input rotation speed N1, various changes can be made between the front wheels and rear wheels of various vehicles. The distribution of the drive torque generated between the front and rear wheels can be appropriately set in accordance with the load distribution of the vehicle.

Therefore, the engine output torque can be effectively used in accordance with the load distribution between the front and rear wheels, thereby improving fuel efficiency and driving performance.

In addition, in order to use a double pinion type planetary gear mechanism instead of the conventional central differential using bevel gears, it is necessary to A double pinion type planetary gear mechanism is housed in place of the simple planetary gear mechanism that constitutes the gear mechanism, and the first transmission gear is separated from the front wheel differential gear mechanism, and other vehicle structures can be adapted by simply changing the connection relationship slightly. Since it can be used in its entirety, there is no need to significantly modify the vehicle structure. Therefore, it is possible to reduce the amount of M, the number of parts, and cost.

Next, the compression sleeve 3 of the lock-up mechanism 36
7 is engaged with the clutch teeth 38 connected to the differential case 17 of the front wheel differential gear mechanism 16, and when the second hollow shaft 18 and the differential case 17 are integrally connected and locked, the central differential device 10 operates as described above. The differential distribution is stopped, the first hollow shaft 15 and the second hollow shaft 18 are rotated together, and the front and rear wheels 33, 34, 57, 58 are rotated at a constant speed. Therefore, it is effective for escaping the vehicle when driving on rough terrain or slipping.

Next, the compression sleeve 3 of the lock-up mechanism 36
7 is engaged with the clutch teeth 38 of the differential case 17 of the front wheel differential gear mechanism 16, and the engagement between the compression sleeve 59 of the two-wheel/four-wheel drive switching mechanism 42 and the clutch teeth 43 of the second transmission gear 4o is disengaged. When switching to two-wheel drive, the second transmission gear 40 idles on the intermediate shaft 19, and the driving force from the engine 1 side is no longer transmitted to the intermediate shaft 19, and the driving force of the engine 1 is transmitted only to the front axle 26. It will be a two-wheel drive system.

In the above-described embodiments, a front engine type four-wheel drive vehicle with an engine mounted at the front of the vehicle body was described, but this invention is applicable to a rear engine type four-wheel drive vehicle with an engine mounted at the rear of the vehicle body, or a rear engine type four-wheel drive vehicle with an engine mounted at the rear of the vehicle body. Of course, it can also be applied to small four-wheel drive vehicles.

Furthermore, although a manual transmission mechanism is used in the above-described embodiment, it goes without saying that an automatic transmission mechanism may be applied.

(Effects of the Invention) As explained above, according to the present invention, the ratio between the change in the front wheel output rotation speed and the change in the rear wheel output rotation speed with respect to the input rotation speed can be freely selected. In response to various load distributions between the front and rear wheels of various vehicles,
The distribution of drive torque generated between the front and rear wheels can be set to various appropriate values, improving fuel efficiency and driving performance.

In addition, since the four-wheel drive vehicle according to the present invention can be configured using almost any other type of conventional four-wheel drive vehicle,
There is no need to make major modifications to the conventional vehicle structure, and it is possible to reduce vehicle volume, number of parts, and costs.

[Brief explanation of drawings]

Fig. 1 is a collinear diagram of a differential gear mechanism using bevel gears that constitutes a central differential in a conventional four-wheel drive vehicle, and Fig. 2 shows a four-wheel drive vehicle according to an embodiment of the present invention. Skeleton diagram, Figure 3 is a schematic diagram of the double pinion type planetary gear mechanism that constitutes the central differential in Figure 2, viewed from the m-m arrow, and Figure 4 is a schematic view of the double pinion type planetary gear mechanism shown in Figure 3. This is a collinear chart of the differential gear mechanism. 1----111 engine, 1a---- crankshaft, 3・---- transmission case, 5----
1 transmission mechanism, 5 a -, --- single power shaft, 5 b --- one output shaft, 50 to 5 g --- 1 transmission mechanism, 6 --- final reduction gear, 8 --- --Additional housing, 9--Casing, 10-- Central differential, 11-- Ring gear, 12-- First planetary gear, 12'--
---Second planetary gear, 13-----Sun gear, 14-----Carrier, 16-----Differential gear mechanism for one front wheel, 17----- Tiffential case, 20- ---
--Single shaft, 2], 22----First bevel gear, 23.24--One--Second bevel gear, 25.26--One front axle, 33.34-- ---One front wheel, 36-----Rosoku arm mechanism, - 37,59--One coupling sleeve, 38.4
3-----Crack-7 teeth, 41---1 3rd bevel gear, 42--2-wheel/4-wheel drive switching mechanism, 44---1 4th bevel gear, 50-----1 Differential gear mechanism for rear wheels, 53.54---One rear axle, 57.5B---One rear wheel. Patent Applicant Nissan Motor Co., Ltd. Representative Patent Attorney Agagun Part

Claims (3)

[Claims] (1) An engine arranged so that the crankshaft extends in the lateral direction of the vehicle body, a transmission mechanism provided between an input shaft and an output shaft arranged in the transmission case so as to extend in the lateral direction of the vehicle body, and the transmission case. A final reduction gear is arranged approximately coaxially with either the front axle or the rear axle within the transmission case and is rotationally driven by the output shaft of the transmission mechanism, and a final reduction gear is provided inside the casing that rotates integrally with the final reduction gear within the transmission case. a central differential device connected to the transmission case; and a differential device on either one of the front wheels or the rear wheels, which is disposed substantially coaxially with the one axle in an additional housing connected to the transmission case and drive-coupled to the central differential device. A gear mechanism, and a direction changing gear set driven by the central differential device, which converts the rotational direction of the driving force at right angles and transmits it to the differential gear mechanism on the other side of the front wheels or the rear wheels. A four-wheel drive vehicle, characterized in that the central differential device is configured using a double-binion planetary gear mechanism having two types of pinion gears that mesh with each other. (2) The four-wheel drive vehicle according to claim 1, wherein the central differential device has a lock-up mechanism for restraining the differential mechanism. (3) The central differential device and the direction conversion gear set are connected via a two-wheel/four-wheel switching device that is capable of intermittent transmission of driving force between them.
Four-wheel drive vehicle as described in section.