JPH0446825A - Power train construction for vehicle - Google Patents

Abstract

PURPOSE:To obtain an enough reduction gear ratio by positioning a differential gear and a drive shaft coaxially with the output shaft of a transmission for reducing the speed thereof, and providing a reduction gear for power transmission to the differential gear a a shaft other than the output shaft. CONSTITUTION:A transmission is of multi-shaft construction having, for example, an output shaft 12 and an input shaft 11 parallel to each other. Also, a front differential gear 21, a drive shaft 22 and a center differential gear 24 are arranged coaxially with the output shaft 12. Furthermore, a reduction gear 26 for transferring the rotation of the output shaft 12 to the differential gear 21 is provided at one end of a center differential gear input shaft 25 laid in parallel to the output and front drive shaft 12 and 22 at a suitable distance. The other end of the aforesaid center differential input shaft 25 is fitted with a gear 28 engaged with the gear 27 of the output shaft 12. According to the aforesaid construction, the power train of a vehicle can be made compact in both lengthwise and vertical directions.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a power train structure for a vehicle in which a transmission is placed horizontally with respect to the vehicle.

[Conventional technology]

2. Description of the Related Art Conventionally, in front-wheel drive vehicles or four-wheel drive vehicles, a structure in which an engine and a transmission are mounted horizontally in an engine room at the front of the vehicle is generally known.

In this type of structure, the transmission is usually placed in series with the engine, that is, on an extension of the engine output shaft, and the engine and transmission are placed forward of the front drive shaft. In order to reduce the weight bias toward the front wheels and improve steering stability, braking performance, etc., the engine and transmission are placed behind the front drive shaft, as shown in Japanese Utility Model Publication No. 63-23219, for example. is also known. In addition, as shown in Japanese Patent Application Laid-open No. 56-31824, a transmission that interlocks with the engine via a gear movement device is disposed in front of the engine and above the front differential and the front drive shaft,
There is also known a structure in which rotation is transmitted from the output shaft of the transmission to the input gear of the front differential via a transmission gear.

Transmissions with various structures are known. For example, in the above-mentioned Japanese Patent Laid-Open No. 56-31824, an input shaft and an output shaft are arranged parallel to each other, and a gear train for shifting is arranged between them. JP-A No. 56-31824 discloses an automatic transmission in which a V-belt type continuously variable transmission mechanism is provided between an input shaft and an output shaft arranged in parallel. has been done.

[Problem to be solved by the invention]

By the way, in this type of conventional structure, the shift shafts such as the input shaft and output shaft on which the transmission speed change mechanism is disposed, and the shafts of the differential (front differential) and drive shaft are aligned with each other in the longitudinal direction of the vehicle or Although they have been arranged offset in the vertical direction, such a structure requires a large installation space in the longitudinal and vertical directions of the vehicle, resulting in problems such as an increase in the longitudinal length of the engine compartment and the height of the bonnet. For this reason, there is a demand for a more compact structure including the transmission, differential, and drive shaft. In addition, in this type of powertrain structure, the rotation of the output shaft of the transmission is controlled by the differential side (
(front differential or center differential in 4-wheel drive, etc.)
A speed reduction mechanism such as a speed reduction gear is required to transmit data to the engine, and it is required to maintain the above speed reduction ratio even when downsizing.

In view of these circumstances, the present invention provides a power train including a transmission, differential, and drive shaft with a compact structure in the longitudinal and vertical directions of the vehicle.
Another object of the present invention is to provide a powertrain structure for a vehicle that can obtain a sufficient reduction ratio between the transmission and the differential side.

(Means for Solving the Problem) In order to achieve the above-mentioned object, the configuration according to claim 1 of the present invention is such that the transmission consisting of a mechanism for changing the speed of rotation transmitted from the engine is transverse to the vehicle. A powertrain structure of a vehicle arranged in a vehicle, in which a differential and a drive shaft are arranged coaxially with the output shaft of the transmission, and the rotation of the output shaft of the transmission is decelerated and transmitted to the differential side. A reduction gear is provided on a separate shaft from the output shaft.

According to a second aspect of the present invention, in the configuration of the first aspect, the engine is disposed horizontally with respect to the vehicle, and the transmission is disposed in parallel with the engine.

According to a third aspect of the present invention, in the configuration of claim 1, the transmission has a multi-shaft structure in which the transmission has a plurality of shift shafts arranged in parallel, and one of the shift shafts is an output shaft. In addition, a reduction gear is disposed at a position with respect to the output shaft that is substantially in the same direction as other speed change shafts when viewed from the side.

The configuration according to claim 4 is a four-wheel drive structure in which the power passing through the reduction gear is transmitted to the differential and drive shaft coaxially with the output shaft of the transmission and also to the propeller shaft in the configuration according to claim 1. In addition, power is transmitted to the propeller shaft via an idler, and the idler is arranged coaxially with the reduction gear.

Further, the configuration according to claim 5 is a power train structure for a vehicle in which a transmission consisting of a mechanism for changing the speed of rotation transmitted from an engine is placed horizontally with respect to the vehicle, and the power is transmitted to the front wheels and the rear wheels. The vehicle has a four-wheel drive structure including a center differential that distributes between the wheels, a reduction gear that reduces the rotation of the output shaft of the transmission, the center differential, and a left-right differential that differentially operates the left and right wheels. The left and right differential is provided coaxially with the output shaft of the transmission, and the left and right differential is located between the reduction gear and the center differential, and is arranged radially inward of a connecting portion that connects the reduction gear and the center differential. It is something that

[Effect]

According to the configuration of claim 1, the output shaft of the transmission, the differential, and the drive shaft are located coaxially, resulting in a compact arrangement in the longitudinal and vertical directions of the vehicle, and the reduction gear provided on a separate shaft from these. Sufficient deceleration is provided by the gears.

In this configuration, if the transmission is further arranged in parallel with the engine, the structure becomes more compact in the vehicle width direction as well. Further, if the reduction gear is arranged at a position with respect to the output shaft of the transmission in substantially the same direction as other shift shafts, the reduction gear will be rationally arranged with respect to the transmission. When power is transmitted to a propeller shaft via an idler in a four-wheel drive system, the idler and reduction gear can be arranged in a compact manner by arranging them above any number of wheels.

Further, according to the configuration of claim 4, the reduction gear, the center differential, and the left and right differentials are all located on the same axis with respect to the output shaft of the transmission, resulting in a compact arrangement,
In addition, the left and right differential is located closer to the center in the vehicle width direction than the center differential.

〔Example〕

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

1 and 2 schematically show the structure of a first embodiment of the present invention, and the figures show the structure applied to a four-wheel drive vehicle. Note that the left side in FIG. 1 and the lower side in FIG. 2 are the front side of the vehicle.

In these figures, an engine 2 is disposed horizontally in an engine room 1 at the front of the vehicle at a position near the rear of the engine room 1, and a mechanism for changing the speed of the rotation transmitted from the engine 2 is placed in front of the engine room 1. Transmission 1
0 is placed horizontally in parallel with the engine 2.

The power transmission system from the engine 2 to the transmission 10 includes a clutch 4 connected to one end side of an engine output shaft 3 extending in the vehicle width direction, and a clutch pulley 5 provided on the output side of the clutch 4 to the transmission 10. Power is transmitted to an input pulley 6 provided on the input side of the motor via a belt 7 (or chain).

The transmission 1o has a multi-shaft structure having a plurality of gear shifting shafts arranged in parallel, and in the figure, an input shaft 1 which is a gear shifting shaft on the input side and an output shaft which is a gear shifting shaft on the output side. 12 are arranged parallel to each other and shifted vertically so that the input shaft 11 is at the top and the output shaft 12 is at the bottom. One end of the input shaft 11 (second
An entry-cabinet 6 is provided (on the right side of the figure).

A plurality of transmission gear trains 13 are arranged on the input shaft 11 and the output shaft 12. Regarding this transmission gear train 13, only a part (two sets) are shown in FIG. A number of sets of gear trains 13 corresponding to the number of stages are arranged.

Then, a synchronizer (not shown) selectively connects the input shaft 11 and the output shaft 12 via a set of transmission gear trains except when in neutral, and the rotation transmitted to the input shaft 11 is changed in speed. The signal is transmitted to the output shaft 12.

For the transmission 10, a front wheel side differential (front differential) 21 is provided coaxially with the output shaft 12.
and drive shaft (front drive shaft)
Furthermore, a center differential 24 that distributes power between the front wheels and the rear wheels is also arranged coaxially with the output shaft 12. That is, the front differential 21 is arranged on the extension line of the output shaft 12 on the side of the transmission 10, and the center differential 24 is arranged in line with the front differential 21 and closer to the output shaft 12 than the front differential 21. One of the left and right front drive shafts 22 connected to the differential 21 is connected to the center differential 2.
4 and the output shaft 12 and extends outward thereof. Left and right front wheels 23 are connected to the left and right front drive shafts 22 via joints or the like.

The center differential 24 is composed of a planetary gear unit similar to that shown in the specific structure of the second embodiment described later, and has an output section 24a to the front wheels and an output section 24b to the rear wheels concentrically. The differential case of the front differential 21 is connected to the output section 24a to the front wheel side.

The rotation of the output shaft 12 of the transmission 10 is transmitted to the differential side via the reduction gear 26. This reduction gear 26 is provided on a shaft different from the output shaft 12. That is, a center differential input shaft 25 is provided parallel to the output shaft 12 and the front drive shaft 22 at a position with an appropriate distance between the shafts, and an end of the output shaft 12 and the center differential input shaft 25 are provided.
5 are provided with gears 27 and 28 that mesh with each other, and the reduction gear 26 is provided on the other end side of the center differential input shaft 25. This reduction gear 26 is an outer gear 24C formed on the outer periphery of the center differential 24.
The outer gear meshes with the outer gear 24G to perform deceleration according to the gear ratio.

Center differential manual shaft 2 equipped with the above-mentioned reduction gear 26
5 is disposed above the output shaft 12 and on the side of the input shaft 11 so as to be located in substantially the same direction as the input shaft 11 with respect to the output shaft 12 of the transmission 10 when viewed from the side. Therefore, in the side view shown in FIG. 1, the input shaft 11 equipped with the transmission gear train 13 and the center differential input shaft 25 equipped with the reduction gear 26 are arranged so as to overlap.

Further, a propeller shaft 30 is connected to the output portion 24b of the center differential 24 to the rear wheel side via bevel gears 31 and 32 for direction change.

In this embodiment, the bevel gear 31 is provided directly on the output portion 24b of the center differential 24, and therefore, the bevel gear 31 is also disposed coaxially with the output shaft 12 of the transmission 10. The propeller shaft 30 extends toward the rear of the vehicle, and the propeller shaft 30 extends toward the rear of the vehicle.
The rear wheels are connected to the 0 via a rear differential (not shown).

3 and 4 schematically show the structure of a second embodiment of the invention. In this embodiment as well, a transmission 10 is arranged in parallel in front of the engine, and this transmission 10 includes an input shaft 11 having an input convertible 6 and an output shaft 12 arranged in parallel below the input shaft 11. In the first embodiment, the front differential 21, the front drive shaft 22, and the center differential 24 are arranged coaxially, and the reduction gear 26 is provided on the center differential input shaft 25, which is arranged separately from the output shaft 12. Similar to the example. However, in this embodiment, the output section 24b of the center differential 24 to the idler 3
An idler 34 and a bevel gear 31 are provided on an output shaft 33 separate from the output section 24b so that power is transmitted to the propeller shaft 30 via the output section 24b and the bevel gears 31 and 32.
Since the center differential input shaft 25 passes through the center differential input shaft 25, the reduction gear 26 and the idler 34 are coaxially provided.

In addition, in this embodiment, the center differential input shaft 2
5 and the output shaft 33 are connected to the transmission 10
It is arranged at the rear lower part of the output shaft 12 of.

FIG. 5 shows the specific structure of the second embodiment. In this figure, an input shaft 11 and an output shaft 12 of the transmission 10 are rotatably supported by a transmission case 15, respectively. An input pulley 6 is integrally provided at one end of the input shaft 11, and this pulley 6
A belt 7 is wound around the clutch pulley 5 provided on the output shaft 4a of the clutch 4. Further, a plurality of sets of gear trains 13 for speed change are arranged on the two wheels 11 and 12, and in each gear train 13, a gear 13a on the input shaft side and a gear 13b on the output shaft side mesh with each other ( In the reverse gear train, these gears mesh with the intermediate gear. Furthermore, a synchronizer 14 is disposed on the shaft 11.12, which allows the shaft 11.12 to be selectively coupled to the gears 13a, 13b. This synchronizer 14 is operated by a control rond, a shift rond, etc. (not shown) in response to the operation of a change lever. When one gear train 13 is connected to the shaft 11.12 by this synchronizer 14, the rotation of the input shaft 11 is transmitted to the output shaft 12 at the gear ratio of the gear train 13. It has become.

The output shaft 12 is a hollow shaft through which the front drive shaft 22 passes, and a gear 27 is attached to the end of the output shaft 12 on the side closer to the center differential 24.
is provided. A center differential input shaft 25, which is provided with a gear 28 meshing with the gear 27 and a reduction gear 26, is rotatably supported by the casing 16 at the lower rear of the output shaft 12.

In addition, the center differential 24 is connected to the front drive shaft 2
A ring gear 24d is disposed concentrically with the shaft 22 around the shaft 22, and integrally has an outer gear 24c that meshes with the reduction gear 26, a double pinion gear 1724f held on a carrier 24e, and a sun gear 24.
Q, and the power transmitted to the ring gear 24d is distributed between the carrier 24e side and the sun gear 24a side.

The carrier 24e is connected to a cylindrical output portion 24a extending toward the front wheels, and a differential case 21a of the front differential 21 is connected to the output portion 24a. The front differential 21 includes a pinion gear, side gears, etc. within a differential case 21a, and left and right front drive shafts 22 are connected to both side gears.

Further, the sun gear 24o is connected to an output section 24b which is a hollow shaft and which is connected to the rear wheel side, and a gear 35 is provided at the end of this output section 24b, and an idler 34 meshes with this gear 35. There is. The output shaft 33, on which the idler 34 and hevel gear 31 are provided, is a hollow shaft so that the center differential input shaft 25 passes through the inside thereof. A longitudinal shaft 30a having a bevel gear 32 at its front end is arranged behind the output shaft 18, and a propeller shaft 30 is connected to the rear end of this shaft 30a.

According to the structure of the first embodiment or the second embodiment described above, since the transmission 10 is arranged in parallel to the horizontally mounted engine 2, the dimension in the vehicle width direction is made compact, and The engine 2 itself is located rearward from the front drive shaft 13 and is midshipped, so that a rational layout such as improved weight distribution can be obtained. .

In particular, since the front differential 21, front drive shaft 22, and center differential 24 are arranged coaxially with the output shaft 12 of the transmission 10, the transmission 10, front differential 21, etc. are laid out sufficiently compactly in the vertical and longitudinal directions. be done.

Further, a reduction gear 26 that reduces the rotation of the output shaft 12 of the transmission 10 and transmits it to the differential side,
Center differential input shaft 25 separate from the output shaft 12
Because it is provided in It can be set so that the ratio is obtained.

Since the reduction gear 26 is not bulky compared to the front differential 21 and the like, the output shaft 12 of the transmission 10
On the other hand, if the front differential 21 and the like are arranged on the same axis, even if the reduction gear 25 is arranged on a separate shaft, there is no major problem in making the vehicle compact. In particular, as in the first embodiment, the shaft 25 equipped with the reduction gear 26 is located in substantially the same direction as the input shaft 11 with respect to the output shaft 12 of the transmission 10, and is arranged such that it overlaps the input shaft 11 in a side view. , the reduction gear 26 is the transmission 1
It fits into the space on the side of the 0 and does not take up any extra space above or below or in the front and back, making it advantageous for compactness.

On the other hand, according to the second embodiment, the output section 2 of the center differential 24
Since power is transmitted from 4b to the propeller shaft 30 via the idler 34, the degree of freedom in the layout of the propeller shaft 30 is increased by selecting the position of the output shaft 33 equipped with the idler 34. A preferred propeller shaft 30 arrangement can be set. In other words, as in the first embodiment, the center differential 24
If the power is transmitted directly from the output section 24b to the propeller shaft 30, there will be problems such as the propeller shaft 30 passing through a relatively high position and the tunnel section of the vehicle floor becoming large. In the case of the embodiment, if the F distribution output shaft 33 is arranged at the rear lower part of the output shaft 12 as shown in FIG. 3, the propeller shaft 30 will be offset downward and the position of the propeller shaft 30 will not be too high. can avoid. In this case, since the idler 34 and the reduction gear 26 are arranged coaxially, they can be assembled compactly.

FIG. 6 shows a third embodiment. In this embodiment, in addition to a front differential (left and right differential) 21 that differentially drives left and right front wheels, a front drive shaft 22, and a center differential 24, a reduction gear 41 is also provided on the output shaft 1 of the transmission 10.
2, and the front differential 21 is arranged between the reduction gear 41 and the center differential 24, so that the front differential 21 is located closer to the center in the vehicle width direction than the center differential 24. ing.

In this embodiment, the reduction gear 41 is composed of a planetary gear unit, and the sun gear 4 of this unit
1a is fixed to the end of the output shaft 12, a pinion gear 41b meshes with the sun gear 41a, and a connecting portion 41G to the center differential 24 is provided on the carrier holding the pinion gear 41b. The connecting portion 41C projects laterally. Then, with the front differential 21 positioned between the reduction gear 41 and the center differential 24 inward of the coupling portion 41c, the inner periphery of the side end of the coupling portion 41 and the outer periphery of the center differential 24 are coupled. , the output section 24a of the center differential 24 and the front differential 21
It is combined with a differential case. Furthermore, the left and right front drive shafts 2 connected to the front differential 21
One of the two front drive shafts passes through the reduction gear 41 and the output shaft 12 of the transmission 10, and the other front drive shaft 22 passes through the center differential 24. Note that power is transmitted from the output portion 24b of the center differential 24 to the rear wheel side to the propeller shaft 30 via a gear 42, an idler 43, an output shaft 44, and bevel gears 31 and 32.

According to this embodiment, in addition to the front differential 21 and the like, the reduction gear 41 is also disposed coaxially with the output shaft 12 of the transmission 10, which is even more advantageous in terms of compactness in the vertical and longitudinal directions. Furthermore, since the front differential 21 is disposed between the reduction gear 41 and the center differential 24, it is closer to the center in the vehicle width direction than if it were disposed on the outside of the center differential. It is advantageous for power transmission to the left and right front wheels to be closer to the center in the width direction.

Even with such a structure, the rotation of the output shaft 12 of the transmission 10 is reduced by the reduction gear 41 and transmitted to the differential side, etc., as described above. Second
This is similar to the example. However, the first embodiment is better than the third embodiment. The second embodiment has a greater degree of freedom in setting the reduction ratio using the reduction gear.

In each of the above embodiments, the transmission 10 is arranged in front of the engine 2 in parallel with the engine 2, but if there is sufficient space in the engine room in the vehicle width direction, the input shaft of the transmission 10 11
The present invention can also be applied to a structure in which the output shaft 12 is arranged in series with the engine output shaft 3 (arranged on an extension of the engine output shaft), and the output shaft 12 is arranged parallel thereto.

Further, the structure shown as the first embodiment except for the center differential 24 and the rear wheel drive system can also be applied to two-wheel drive vehicles such as FF vehicles, and in this case, the reduction gear 2
6 may be connected to the input side of the front differential 21.

〔Effect of the invention〕

As described above, according to the powertrain structure according to claim 1, since the differential and the drive shaft are arranged coaxially with the output shaft of the transmission arranged horizontally with respect to the vehicle, the transmission and the differential etc. can be made compact in the longitudinal and vertical directions of the vehicle, and the reduction gear that reduces the rotation of the output shaft and transmits it to the differential side is provided on a separate shaft from the output shaft. A sufficient reduction ratio can be ensured by the reduction gear.

Further, according to the structure according to claim 2, in addition to the effect of the structure according to claim 1, since the transmission is arranged in parallel with the engine, the entire power train can be made more compact in the vehicle width direction. can.

According to the structure according to claim 3, in addition to the effect of the structure according to claim 1, the reduction gear is arranged at a position with respect to the output shaft of the multi-shaft transmission at a position substantially in the same direction as other speed change shafts. Because of this, the reduction gear can also be placed in the multi-shaft transmission without taking up any extra space in the longitudinal or vertical directions.

According to the structure set forth in claim 4, in addition to the effects of the structure set forth in claim 1, in the case of a four-wheel drive structure, power is transmitted to the propeller shaft via the idler, thereby improving the layout of the propeller shaft. Since the idler is arranged coaxially with the reduction gear, the idler and the reduction gear can be arranged compactly.

Further, according to the structure according to claim 4, a reduction gear, a center differential, and a left-right differential are provided coaxially with the output shaft of the transmission disposed horizontally with respect to the vehicle, and the transmission is provided with a reduction gear, a center differential, and a left-right differential. Since the differential is located between the reduction gear and the center differential and radially inward of the connecting portion that connects the reduction gear and the center differential,
In the case of four-wheel drive, the transmission, reduction gear A7, center differential, and left and right differentials can be arranged compactly, and the position of the left and right differentials is moved closer to the center in the vehicle width direction, creating a layout that is advantageous for driving force transmission, etc. It is something that can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a schematic side view of the structure of the first embodiment of the present invention, and FIG.
The figure is a skeleton diagram of the same structure, Figure 3 is a schematic side view of the structure of the second embodiment of the present invention, Figure 4 is a skeleton diagram of the same structure, and Figure 5 specifically shows the structure of the second embodiment. The sectional view shown in FIG. 6 is a skeleton diagram of the structure of a third embodiment of the present invention. 2...Engine, 10...Transmission, 1
DESCRIPTION OF SYMBOLS 1... Input shaft, 12... Output shaft, 21... Front differential, 22... Front drive shaft, 24...
... Center differential, 25... Center differential input shaft,
26.41...Reduction gear, 34...Idler. Patent applicant Mazda Co., Ltd. Agent
People Patent Attorney Etsushi Kotani
Patent Attorney Chief 1) Masamukai Patent Attorney
Takao Ito

Claims (1)

[Claims] 1. A powertrain structure for a vehicle in which a transmission consisting of a mechanism for changing the speed of rotation transmitted from an engine is placed horizontally with respect to the vehicle, the transmission being coaxial with the output shaft of the transmission. A vehicle characterized in that a differential and a drive shaft are arranged, and a reduction gear that reduces the rotation of the output shaft of the transmission and transmits it to the differential is provided on a shaft separate from the output shaft. powertrain structure. 2. The power train structure for a vehicle according to claim 1, wherein the engine is disposed horizontally with respect to the vehicle, and the transmission is disposed in parallel with the engine. 3. The transmission has a multi-shaft structure with a plurality of speed change shafts arranged in parallel, one of these speed change shafts serving as an output shaft, and when viewed from the side, 2. The powertrain structure for a vehicle according to claim 1, wherein the reduction gear is disposed at a position substantially in the same direction as the other transmission shafts. 4. The power that passes through the reduction gear is transmitted to the differential and drive shaft coaxial with the output shaft of the transmission, and is also transmitted to the propeller shaft.
2. The vehicle powertrain according to claim 1, wherein the vehicle has a wheel drive structure, and power is transmitted to the propeller shaft via an idler, and the idler is disposed coaxially with the reduction gear. structure. 5. A vehicle powertrain structure in which a transmission consisting of a mechanism for changing the speed of the rotation transmitted from the engine is placed horizontally with respect to the vehicle, and is equipped with a center differential that distributes power between the front wheels and the rear wheels. It has a four-wheel drive structure, and a reduction gear that reduces the rotation of the output shaft of the transmission, the center differential, and a left and right differential that differentially operates the left and right wheels are coaxially arranged on the output shaft of the transmission. and the left-right differential is disposed between the reduction gear and the center differential, radially inward of a connecting portion that connects the reduction gear and the center differential. Powertrain structure.