JPH0478620A - Structure of driving force distribution system for four wheel drive - Google Patents

Abstract

PURPOSE:To make it easy to change setting of parts of a center differential and a differential limiting device, etc. as well as extensively improving assembility by constituting an input part, the center differential, the differential limiting device and an output part respectively as independent members in one unit structure. CONSTITUTION:A driving force distribution system for four wheel drive is constituted of an input part to input a driving force of an engine through an automatic transmission, a center differential 12, a differential limiting device 28 and an output part to the front wheel side and the rear wheel side. At this time, the input part is constituted of an input gear wheel 113 and an input case 124. Additionally, the center differential 12 is constituted of a sun gear 121, a plural number of planetary gears 122, a ring gear 123 and a planet carrier 125. Furthermore, the differential limiting device 28 is constituted by reciprocally providing in parallel a plural number of input side disc blades 28b and front wheel output side disc blades 28a. And the output part is constituted of a front wheel output shaft 27 and a rear wheel output shaft 29, etc.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a four-wheel driving force distribution mechanism suitable for use in a so-called full-time four-wheel active vehicle, and in particular, its constituent parts can have a unit structure. The present invention relates to the structure of a four-wheel decommissioning drive force distribution mechanism.

[Prior art] In so-called full-time four-wheel drive vehicles, 41%
The dynamic driving force distribution mechanism generally includes a center differential (hereinafter abbreviated as center differential) in order to appropriately distribute the driving force from the engine between the front wheels and the rear wheels.
A differential limiting mechanism is provided to limit the differential movement at this center differential.

As such a four-wheel drive rolling force distribution mechanism, for example, a fourth
What is shown in the figure is disclosed.

In FIG. 4, 4' is a torque converter, 6' is an automatic transmission, and 8' is an output shaft of the automatic transmission.

12' is a center differential, 28' is a differential limiting mechanism for the center differential, 14' is a front wheel differential gear device (differential), 15' is a bevel gear mechanism, and 20' is a propeller shaft.

The driving output of the engine is transmitted from the torque converter 4' to the automatic transmission 6', and from the output shaft 8' to the gear mechanism 111'.
, 10a' to the intermediate shaft 10A', and is transmitted to the four-wheel drive driving force distribution mechanism through the gear mechanisms 10b' and 113'.

The four-wheel drive driving force distribution mechanism includes an input section from the automatic transmission 6', a center differential 12', a differential limiting mechanism 28',
It has an output section for the front wheels and the rear wheels.

The input section includes an input gear 113 that meshes with the intermediate shaft 10A' side.
', and hollow shafts 211 and 212 that connect this input gear 113' and the pinion support portion 206 of the center differential 12'.

The center differential 12' is of a type that combines bevel gears, and is composed of a pinion 201 provided on a pinion support 206, a rear wheel drive bevel gear 202 and a front wheel parking bevel gear 203 that mesh with the pinion 201. .

The rear wheel drive bevel gear 202 is connected to a bevel gear mechanism 15' which is an output section to the rear wheels.

That is, the bevel gear 202 is configured to rotate integrally with the carrier 206, and the bevel gear mechanism 15' is constituted by the king gear formed on the carrier 206 and the bevel gear 209 attached to the propeller shaft 20'.

Further, the front wheel drive bevel gear 203 is connected to a front wheel differential 14' which is an output section to the front wheels. In other words,
The front wheel differential 14' is composed of an input pinion 213, and a left wheel bevel gear 214 and a right wheel bevel gear 215 that mesh with the input pinion 213. (omitted).

Therefore, the engine output entering the center differential 12' is distributed from the pinion 201 to the rear wheel drive bevel gear 202 and the front wheel drive bevel gear 203, and from the rear wheel drive bevel gear 202, the engine output is distributed from the carrier 206 to the bevel gear mechanism 15' and the rear wheel drive bevel gear 202. It is transmitted to the rear wheel differential (not shown) via the propeller shaft 20', and from the front 1m drive bevel gear 203, it is transmitted via the hollow shaft 205 to the front wheel differential 14', and further to the left and right axles 17L, 17R. communicated.

In addition, a differential limiting mechanism 2 is installed in such a center differential portion.
8' is provided. This differential limiting mechanism 28' is interposed between the hollow shaft 205 or other drive force transmitting part to the front wheels and the input part from the automatic transmission 6 side, and is turned on and off by the drive mechanism 140'. Thus, the differential in the center differential 12 can be regulated as appropriate.

Note that 210 is a center differential mechanical lock sleeve.

[Problems to be Solved by the Invention] However, in the structure of the conventional active force distribution mechanism 4111 described above, the input section from the automatic transmission 6', the output section to the front wheel side and the rear wheel side, and the center differential Since the differential limiting mechanism 12' and the differential limiting mechanism 28' have a structure in which they are related to each other, and the power transmission path is complicated, there is a problem in that assembly is difficult.

Furthermore, since it is not possible to take out only the center differential 12' or only the differential limiting mechanism 28', for example, when trying to change the distribution ratio of output torque to the front and rear wheels by the center differential, Limiting mechanism 2
When attempting to change the settings of 8', it is necessary to change the layout of the entire shaft system, which reduces the degree of freedom in configuration and is disadvantageous in terms of cost.

The present invention was devised in view of such problems, and
An object of the present invention is to provide a structure of a four-wheel drive driving force front division mechanism that has good assembly efficiency and allows easy changes in the settings of a center differential and a differential limiting mechanism.

[Means for Solving the Problems] For this reason, the structure of the four-wheel drive driving force front distribution mechanism of the present invention transmits the engine output of the automobile via the transmission and distributes it between the front wheels and the rear wheels. The front drive force distribution mechanism for four-wheel drive includes an input section that receives drive force from the transmission, and a center differential that distributes the drive force received at the input section between the front wheels and the rear wheels.
It is equipped with a differential limiting mechanism that regulates the differential in the center differential, and an output section that outputs the driving force distributed through the center differential and the differential limiting mechanism to the front wheels and the rear wheels. and the output section are provided coaxially with each other, and the center differential and the differential limiting mechanism are provided coaxially with the input section and the output section between the input section and the output section. It is characterized by

Preferably, the center differential is
It has a unit structure that can be assembled as a subassembly separately from the input section, differential limiting mechanism, and output section.

Furthermore, preferably, the differential limiting mechanism is configured separately from the input section, center differential, and output section,
It has a unit structure that can be assembled as subassemblies.

[Function] In the structure of the four-wheel drive driving force front distribution mechanism of the present invention described above,
Since the input section and the output section are provided coaxially with each other, and the center differential and the differential limiting mechanism are provided between the input section and the output section coaxially with the input section and the output section, The power transmission meridian becomes relatively simple, and the input section, center differential, differential limiting mechanism, and output section can be configured as independent members. Therefore, the center differential and the differential limiting mechanism can be constructed as independent units.

[Example] Hereinafter, the structure of a four-wheel drive driving force front distribution mechanism as an example of the present invention will be explained with reference to the drawings. FIG. 3 is a schematic diagram showing the overall configuration of a driving force transmission system of an automobile equipped with a driving force forward distribution mechanism, and FIG. 3 is a sectional view showing the main parts of the driving force transmission system.

The four-wheel drive driving force front dividing mechanism according to this embodiment has a second
It is installed in the drive power transmission system of an automobile as shown in the figure.

Referring to FIG. 2, reference numeral 2 denotes an engine, and the output of the engine 2 is transmitted to an output shaft 8 via a torque converter 4 and an automatic transmission 6. The output of the output shaft 8 is transmitted to the cantering bowl power distribution mechanism AM via an intermediate gear (transfer idler gear) 10.

On the one hand, the output of this four-wheel drive driving force front division mechanism AM is transmitted to the reduction gear mechanism 19 and the front wheel differential gear device 14.
from the axles 17L and 17R to the left and right front wheels 16.1 through
8 and, on the other hand, a bevel gear mechanism 15. The power is transmitted from the axles 25L and 25R to the left and right rear wheels 24, 26 via the propeller shaft 20° bevel gear mechanism 21 and the rear wheel differential gear device 22.

As shown in FIGS. 1 to 3, the four-wheel drive driving force distribution mechanism AM includes an input section into which the driving force of the engine is input through the automatic transmission 6, a center differential (center differential) 12, and a differential limiting mechanism. 28, and an output section to the front wheel side and the rear wheel side.

The input section consists of an input gear 113 that meshes with the intermediate shaft 10A side, and an input case 124 to which this input gear 113 is coupled with serrations.
58 and the spacer member 115b, the bearings 114a, 11
It is rotatably mounted via 4b. In addition, the input case 124 has a shape whose diameter increases toward the front (toward the left in FIGS. 1 and 3), and includes an expanded diameter section that houses the planetary gear element and a first expanded diameter section behind this expanded diameter section. In the figure, a reduced diameter part is formed on the right side), and an opening is formed in front of the enlarged diameter part. It can be attached to the rear wheel output shaft 29 from behind (rightward in FIGS. 1 and 3), which will be described later. Further, a plurality of grooves 124d are formed on the outer periphery of the opening.

The center differential 12 is a planetary gear type center differential using a planetary gear mechanism, and includes a sun gear 121 and a sun gear 1.
21 includes a plurality of planetary pinions (planetary gears) 122 arranged outwardly to surround the sun gear 121, a ring gear 123 arranged around the planetary pinions 122, and a planetary carrier 125 supporting the planetary pinions 122. Each gear is composed of a straight tooth gear.

Of these, the sun gear 121 is integrally provided with a hollow shaft member 27a, and both the hollow shaft member 27a and the front wheel output shaft 27 are connected to a hollow shaft 145 through serrations. , hollow shaft member 27a
The front wheel output shaft 27 and the front wheel output shaft 27 can rotate together. Note that the hollow shaft 145 is formed with a piston accommodating portion 145a, which will be described later.

Further, the ring gear 123 is fixed to a connecting member 130, and the connecting member 130 is connected to the rear wheel output shaft 29 through serrations, so that the ring gear 123 is connected to the rear wheel output section. As a result, the output of the ring gear 123 is transmitted to the connecting member 130. Rear wheel output shaft 29. The signal is input to the propeller shaft 20 via the bevel gear mechanism 15.

The planet carrier 125 has protrusions 125i formed on its outer periphery that fit into the respective grooves 124d of the input case 124, and by these fittings, the input case 12
4 and are connected to rotate together. Further, the sun gear 121 is connected to the front wheel output section, and the ring gear 123
is connected to the rear wheel output section.

Further, a stopper 134 is provided to fix each pinion shaft 126.

A plurality of planetary pinions 122 are provided between the sun gear 121 and the ring gear 123, and each of these planetary pinions 122 is connected to the planet carrier 1 via a pinion shaft 126.
It is installed on 25.

The planet carrier 125 is coupled to the input case 1.24 so as to rotate together with the input case 1.24. A clutch disk support portion 125f shaped like the clutch disk support portion 125f is provided.

And each of these members 121, 122, 123.12
5 can be assembled individually as a planetary gear mechanism unit 12 in advance, and after being formed into a subassembly in this way, the planetary gear mechanism unit 12 can be installed in the transmission case 115.

Furthermore, after the input case 124 is installed into the case 115, it is installed so as to cover the planetary gear mechanism unit 12.

The differential limiting mechanism 28 is constituted by a hydraulic multi-plate clutch, and includes an input side disk plate 2 mounted on the clutch disk support portion 125f of the planet carrier 125.
8b, and a plurality of front export force side disc plates 28a attached to a clutch case 146 that rotates integrally with the sun gear 121 and the front wheel output shaft 27 via a hollow shaft 145 are arranged alternately in parallel. There is.

Among these, the front export force side disk plate 28a is the first
It is driven by a piston 141 and a second piston 142, and can be joined to the input side disk plate 28b.

Note that the first piston 141 and the second piston 142 are
Piston housing portion 145 formed on the outer periphery of hollow shaft 145
A partition plate 143 is interposed between these two pistons 141 and 142 so as to be movable in the axial direction. .

The first piston 141 and the piston accommodating portion 145a
A first oil chamber 144a is provided between the second piston 142 and the partition plate 143, and a second oil chamber 144a is provided between the second piston 142 and the partition plate 143.
44b is provided, and these oil chambers 144a, 14
4b, appropriate hydraulic pressure is supplied from a hydraulic pressure supply system (not shown) through an oil passage 117a bored in the support member 116 fixed to the transmission case 115 side and an oil passage 117b bored in the hollow shaft 145. It is now possible to do so.

Each of these members 28a, 28b, 141, 142.14
3,145,146 are also preliminarily equipped with the differential limiting mechanism unit 28.
After being made into a subassembly in this way, the differential limiting mechanism unit 28 can be mounted inside the transmission case 115.

Further, the output section includes a front wheel output section and a part of the rear wheel output section, and the front wheel output section includes a front wheel output shaft 27 formed of a hollow shaft, and a front wheel output shaft 27 that is attached to the front wheel output shaft 27. and an output gear 19a that meshes with an input gear 19b of a differential gear W (differential) 14 for the front wheels, and the output section for the rear wheels is provided so as to pass through the inside of the output shaft 27 for the front wheels. a rear wheel output shaft 29; a bevel gear shaft 15A coupled to the tip of the rear wheel output shaft 29;
A bevel gear 15a is attached to the propeller shaft 2'0 and meshes with a bevel gear 15b at the tip of the propeller shaft 2'0.

The output gear 19a is supported on the transmission case 115 side via bearings 114c and 114d, and the bevel gear shaft 15A and the bevel gear 15a are supported by the bearing 1
Transmission case 1 via 14e and 114f
It is supported on the 15 side. Further, the output gear 19a and the input gear 19b constitute a reduction gear mechanism 19, and the bevel gear 15a and the bevel gear 15b constitute the bevel gear mechanism 1.
5 are configured.

In FIG. 1, 131 and 132 are plates that support each shaft in the axial direction, and 133 is an O-ring.

In addition, in Fig. 3, 101 is a converter housing, 10
2 is the oil pump, 103 is the front clutch, 104
is the kickdown brake, 105 is the rear clutch, 10
6 is a low reverse brake, 107 is a planetary gear set, 108 is a transfer drive gear, 109 is a rear cover, and 112 is an end clutch.

The structure of the four-wheel drive power distribution mechanism as an embodiment of the present invention is constructed as described above.
, 143, 145, 146 to the differential limiting mechanism unit 2
8, the planetary gear mechanism unit 12 is assembled in advance from each member 121, 122, 123, and 125.

After attaching the protruding parts of the rear wheel output shaft 29 and the front wheel output shaft 27 to predetermined locations inside the case 115,
First, the differential limiting mechanism unit 28 is installed from the rear end side (the right end side in FIG. 1.3) of the rear wheel output shaft 29. - This allows the front wheel output shaft 27 to be connected to the differential #limiting mechanism unit 2.
8 hollow shafts 145 are connected through serrations.

Finally, the planetary gear mechanism unit 12 is attached to the rear wheel output shaft 29 from the rear end side. As a result, the hollow shaft member 27a provided with the sun gear 121 is coupled to the hollow shaft 145 of the differential limiting mechanism unit 28 through serrations. In addition, the input side disc plate 28b of the differential limiting mechanism unit 28 is connected to the clutch disc support portion 1 of the planet carrier 125.
Install it on 25f.

Next, from the rear end side of the rear wheel output shaft 29, enter the entrance portion 124.1.
Attach 13. At this time, each part 1 of the input case 124
24d are fitted with each convex portion 1251 of the planet carrier 125, and the planet carrier 125 is connected to the input case 124 so as to rotate together with the input case 124. Also, at this time, the bearings 114a and 114b are also installed.

Finally, the end cover 1158 is attached.

In this way, the input section, the center differential 12, and the differential limiting mechanism 2
8 and the output section are each constructed as independent members, making it easy to change the settings of each section.
For example, by replacing only the center differential 12, it becomes possible to change the torque distribution ratio between the front and rear wheels, making it possible to easily and at low cost make fine adjustments to suit the type of vehicle, purpose, etc.

Furthermore, since the center differential 12 and the differential limiting mechanism 28 are constructed as independent units, ease of assembly is greatly improved.

Furthermore, since the center differential 12 is constituted by a planetary gear mechanism using a straight tooth gear, no axial thrust force is generated inside the center differential 12, and
The radial load is also balanced inside the center differential 12.

Therefore, shim adjustment is not necessary, and the center differential 12 and the differential limiting mechanism 28 can be replaced extremely easily.

Further, the rigidity required for the center differential 12 is also smaller than that of the conventional one, and the support structure is simplified, and the center differential 12 itself can be made smaller and lighter.

In addition, instead of using a planetary gear mechanism as the center differential 12, a type that combines bevel gears (
(See the conventional center differential 12') is also conceivable. In this case, for example, the input case 124 is used as a carrier, and a pinion that revolves integrally with the carrier and a front wheel bevel gear and a rear wheel bevel gear that mesh with the pinion are provided inside the carrier.

In this embodiment, the transmission is an automatic transmission, but the present structure can of course also be applied to a manual transmission.

[Effects of the Invention] As described in detail above, according to the structure of the four-wheel drive ridge power distribution mechanism of the present invention, the input section, center differential, differential limiting mechanism, and output section are each formed into a unit as independent members. This greatly improves the ease of assembly, and makes it easy to change the settings of parts such as the center differential and differential limiting mechanism. For example, by replacing the center differential, you can change the torque distribution ratio between the front and rear wheels to suit the vehicle type and purpose, etc. By sharing a large number of parts and replacing only the minimum necessary parts, This makes it possible to make detailed adjustments to suit the vehicle model, etc., and to construct an appropriate four-wheel drive drive force distribution mechanism while greatly reducing the cost of each part and assembly.

[Brief explanation of the drawing]

1 to 3 show the structure of a four-wheel drive driving force distribution mechanism as an embodiment of the present invention. A schematic diagram showing the overall configuration of a driving force transmission system of an automobile equipped with a distribution mechanism, Fig. 3 is a cross-sectional view showing the main parts of the driving force transmission system, and Fig. 4 shows a conventional four-wheel drive driving force. FIG. 3 is a cross-sectional view schematically showing a part of the structure of the distribution mechanism. 2-engine, 4-torque converter, 6-automatic transmission, 8-output shaft, 10-intermediate gear (transfer idler gear), 12-center differential (center differential), 14-differential gear device for front wheels, 15--Bevel gear mechanism, 15A--Bevel gear shaft, 15a-Bevel gear, 16.18--Front wheel, 17L, 17R-Front wheel side axle, 19-Reduction gear mechanism 1.19a-Output gear, 2
0-Propeller shaft, 21-・Bevel gear mechanism, 22
-・Differential gear device for rear wheels, 24.26-Rear wheels, 25L
, 25R - rear wheel axle, 27 - front wheel output shaft, 27
a - hollow shaft member, 28 - differential limiting mechanism, 28a - front export force side disc plate, 28 b - input end disc plate, 29 - output shaft for rear wheel, 113 - human power gear,
114a 114f--bearing, l 15-transmission case, 115a--end cover 1
15b--Spacer member, 116-Support member, 117a
, 117b-oil passage, 121-sun gear, 122-planetary pinion (planetary gear). 123--Ring gear, 124--Manpower case, 12
5-Planet carrier, 125a-base plate portion, 125b-planetary pinion housing portion, 125f-
Clutch disc support part, 126-pinion shaft,
130-Connecting member, 141-First piston, 142-Second piston, 143-Partition plate, 144a-First
Oil chamber, 144 b--Second oil chamber, 145-Hollow shaft,
145a-Piston housing, A M-4 wheel drive power distribution mechanism.

Claims (4)

[Claims] (1) In a four-wheel drive drive force distribution mechanism that transmits the engine output of an automobile via a transmission and distributes it to the front wheels and rear wheels, there is an input section that receives the drive force from the transmission, and an input section that receives the drive force from the transmission. A center differential that distributes the received driving force between the front wheels and the rear wheels, a differential limiting mechanism that regulates the differential in this center differential, and a differential limiting mechanism that controls differential movement through these center differentials and differential limiting mechanisms. an output section that outputs the distributed driving force to the front wheels and the rear wheels, the input section and the output section are provided coaxially with each other, and the center differential and the differential limiting mechanism are provided. A structure of a four-wheel drive driving force distribution mechanism, characterized in that a is provided between the input section and the output section coaxially with the input section and the output section. (2) In the four-wheel drive drive force distribution mechanism, the center differential has a unit structure that can be assembled as a subassembly separately from the input section, differential limiting mechanism, and output section. A structure of a four-wheel drive driving force distribution mechanism according to claim 1. (3) In the above four-axis drive force distribution mechanism, the differential limiting mechanism has a unit structure that can be assembled as a subassembly separately from the input section, center differential, and output section. A structure of a driving force distribution mechanism for four-axis drive according to claim 1, characterized in that: (4) In the four-wheel drive driving force distribution mechanism, the center differential and differential limiting mechanism have a unit structure that can be assembled as a subassembly separately from the input section and output section. A structure of a four-wheel drive driving force distribution mechanism according to claim 1.