JP4792774B2 - Drive mechanism arrangement structure for all-wheel drive vehicles - Google Patents

Description

  The present invention relates to a drive mechanism arrangement structure for an all-wheel drive vehicle that drives all wheels, and in particular, based on a front engine / rear drive type drive mechanism in which an engine is mounted on the front of the vehicle to drive a rear wheel. The present invention relates to a drive mechanism arrangement structure.

  Conventionally, as an all-wheel drive vehicle for driving all the wheels, one based on a front-wheel drive vehicle and one based on a rear-wheel drive vehicle are known.

  Among these, as an all-wheel drive vehicle based on a rear wheel drive vehicle, one having the following drive mechanism arrangement structure is known.

That is, a drive unit having an engine and a transmission is arranged at the front of the vehicle, and the transmission and a rear differential device that drives the rear wheels are connected by a rear propeller shaft so that drive transmission is possible. Further, in the drive unit, a transfer for extracting the rotational driving force is provided at the output portion of the transmission, and this transfer and a front differential device for driving the front wheels are coupled to each other so as to be able to transmit the drive by the front propeller shaft (for example, patent Reference 1).
Japanese Utility Model Publication No. 5-82638

  However, in the conventional technology, the engine, the transmission, and the transfer are integrally assembled as one drive unit in the front part of the vehicle, so that the entire length of the drive unit is increased, and the bending strength and rigidity of the drive unit are ensured. If the strength and rigidity are insufficient, the sound vibration performance deteriorates and it is difficult to increase the guaranteed rotational speed.

  Therefore, the present invention can distribute the weight of the drive unit in a well-balanced manner and ensure the bending strength and rigidity of the drive unit system to improve the sound vibration performance and the guaranteed rotational speed. An object of the present invention is to provide a drive mechanism arrangement structure for a wheel drive vehicle.

  The present invention has been made in view of the above circumstances, and includes a front drive unit in which a vehicle drive mechanism has an engine and is disposed at the front of the vehicle, and a rear drive unit that has a transmission and is disposed at the rear of the vehicle. The main feature is that the front drive unit and the rear drive unit are connected to each other so that power can be transmitted by the rear propeller shaft, and the transmission and the front differential device are connected to be able to transmit power by the front propeller shaft. A drive mechanism arrangement structure for an all-wheel drive vehicle is adopted.

  According to the present invention, the drive mechanism of the vehicle is divided into a front drive unit having an engine and a rear drive unit having a transmission, which are arranged separately in the vehicle front part and the vehicle rear part. The weight of the unit can be distributed in a well-balanced manner.

  Also, compared to a drive unit in which the engine and transmission are integrated, the overall length of each of the front drive unit and the rear drive unit can be shortened, so that it is possible to ensure bending strength and rigidity in each of the front and rear drive units. This is easy and advantageous in terms of sound vibration performance, and it is easy to secure a guaranteed rotational speed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  In the drive mechanism arrangement structure of the all-wheel drive vehicle of this embodiment, the drive mechanism of the vehicle drives the front drive unit 1 having the engine 11 and disposed at the front of the vehicle, the transmission 21, and the rear wheel RW. A rear differential unit 22 and a rear drive unit 2 disposed at the rear of the vehicle. The front drive unit 1 and the rear drive unit 2 are connected by a rear propeller shaft 3 so that power can be transmitted, and the rear drive The transmission 21 of the unit 2 and the front differential device 6 that drives the front wheels FW are connected by a front propeller shaft 5 so that power can be transmitted.

  The first embodiment, which is the best mode of the drive mechanism arrangement structure for an all-wheel drive vehicle of the present invention, corresponding to the inventions of claims 1 to 4 will be described below.

1 to 3 show the drive mechanism arrangement structure of the all-wheel drive vehicle of the first embodiment, and FIG. 1 is a plan view schematically showing the drive mechanism arrangement structure of the all-wheel drive vehicle of the first embodiment. FIG. 2 is an explanatory side view thereof, and FIG. 3 is a sectional view taken along line S3-S3 of FIG. In the figure, an arrow FR indicates the front of the vehicle. In the drawing, CL indicates a line in the center of the vehicle in the vehicle width direction, FL indicates a line on the axle of the front wheel FW, and RL indicates a line on the axle of the rear wheel RW.
As shown in FIG. 1, the drive mechanism arrangement structure of the all-wheel drive vehicle of the first embodiment has a front drive unit 1 mounted on the front portion of the vehicle and a rear drive unit 2 mounted on the rear portion of the vehicle. ing.

  First, the outline of each drive unit 1 and 2 is demonstrated.

  The front drive unit 1 has a vertically mounted engine 11 and a first clutch 12 assembled in a front-rear manner. The front drive unit 1 is disposed on the axle of the front wheel FW (on the line FL) in a front compartment 42 partitioned in front of the vehicle room 41 of the vehicle body 4 via a mount member (not shown). These are elastically supported by a subframe or a vehicle body front frame member (not shown).

  The first clutch 12 transmits or blocks the rotational driving force of the engine 11 to the rear propeller shaft 3 described later.

  The rear drive unit 2 has a transmission 21, a rear differential device 22 and a second clutch 23 assembled together. The rear drive unit 2 is elastically supported on the lower side of the rear floor panel 43 via a non-illustrated subframe or a vehicle body front skeleton member via a non-illustrated mount member.

  The rear differential device 22 is driven by transmitting the rotational driving force output from the transmission 21 to the left and right rear wheels RW. The second clutch 23 transmits or blocks the rotational driving force output from the transmission 21 to the front wheel FW side, which will be described later.

  Next, a drive transmission structure between the front drive unit 1 and the rear drive unit 2 will be described.

  The output of the engine 11 is transmitted to the input shaft (not shown) of the transmission 21. That is, on the center line CL in the vehicle width direction, the output shaft 12a of the first clutch 12 and the input shaft (not shown) of the transmission 21 are connected to the universal joints 31 and 32 by a single rear propeller shaft 3. To transmit power.

  As shown in FIG. 3, a floor tunnel 44a is formed in the vehicle width direction central portion of the front floor panel 44 so as to protrude upward from the vehicle by a separate panel. The floor tunnel 44a The rear propeller shaft 3 is disposed inside.

  The rear propeller shaft 3 is formed of a hollow metal pipe.

  Next, a drive transmission structure between the rear drive unit 2 and the front wheels FW will be described.

  An output portion (not shown) of the second clutch 23 of the rear drive unit 2 and the front differential device 6 that drives the front wheels FW perform power transmission via the front propeller shaft 5.

  The front propeller shaft 5 is divided into a front shaft 51 and a rear shaft 52 with a center universal joint 53 as a joint portion in the claims interposed therebetween, and a rear end portion of the rear shaft 52. Is connected to the output portion (not shown) of the second clutch 23 via a universal joint 54, and the front end portion of the front shaft 51 is connected to the front differential device 6 via a universal joint 55.

  The connection by the front propeller shaft 5 is performed in the vehicle width direction at a position shifted to the vehicle right side from the vehicle width direction center line CL as shown in FIG.

  The front propeller shaft 5 is disposed at a position slightly lower than the rear propeller shaft 3 in the vehicle vertical direction. That is, as shown in FIG. 3, the floor tunnel 44a has a bulging portion 44b slightly inflated toward the vehicle compartment 41 at a position slightly lower than the rear propeller shaft 3 on the lower right side of the vehicle. The front propeller shaft 5 is disposed on the bulging portion 44b. Accordingly, the front propeller shaft 5 is disposed at a position slightly lower than the rear propeller shaft 3 and at substantially the same height as the front floor panel 44.

  The front propeller shaft 5 is supported on the vehicle body 4 at the position of the center universal joint 53.

  That is, as shown in FIG. 1, the tunnel stay 45 extends in the vehicle width direction in the vicinity of the position where the center universal joint 53 is disposed. This tunnel stay 45 is a substantially square hollow stay, and has an arcuate portion 45a bent upward in the vehicle at a position overlapping the floor tunnel 44a in the vehicle direction, as shown in FIG.

  The tunnel stay 45 is fixed to the left and right surfaces of the front floor panel 44 by welding or bolts across the floor tunnel 44a to prevent the floor tunnel 44a from opening.

  Further, a shaft mount portion 45b is provided on the upper surface on the vehicle right side of the arcuate portion 45a of the tunnel stay 45, and the shaft mount portion 45b supports the front end portion of the rear shaft 52 that is in the vicinity of the center universal joint 53. ing.

  Further, the tunnel stay 45 has an exhaust pipe mount portion that supports an exhaust pipe 11b that exhausts the engine 11 on the lower left side of the arcuate portion 45a that is opposite to the shaft mount portion 45b. 45c.

  Next, the operation of the drive mechanism arrangement structure for the all-wheel drive vehicle of the first embodiment will be described.

  In the first embodiment, the drive mechanism is divided into a front drive unit 1 having an engine 11 and a rear drive unit 2 having a transmission 21, and separated into a vehicle front part and a vehicle rear part, respectively, 2 has a structure in which the rear propeller shaft 3 is connected, so that the weight of the entire drive mechanism is larger than a structure in which a drive unit in which an engine and a transmission are integrated (hereinafter referred to as an integral drive unit) is mounted on the front of the vehicle. Can be distributed in a balanced manner. As a result, nose diving during vehicle braking can be suppressed as compared with the integral drive unit, and it is advantageous in terms of turning performance.

  Furthermore, since the front drive unit 1 and the rear drive unit 2 are separated as described above, the total length of each of the front drive unit 1 and the rear drive unit 2 can be shortened compared to the integrated drive unit. It is easy to ensure bending strength and rigidity in each of the front drive unit 1 and the rear drive unit 2, which is advantageous in sound vibration performance as compared with the integral drive unit, and it is easy to secure a guaranteed rotational speed.

  In particular, when the first clutch 12 between the engine 11 and the transmission 21 is connected or disconnected, the rear propeller shaft 3 absorbs the deflection of the power shaft generated around the first clutch 12. In addition, it is possible to suppress the occurrence of bending and vibration in each of the drive units 1 and 2, and it is possible to absorb vibration interference generated on the engine 11 side and the transmission 21 side with the rear propeller shaft 3. As a result, vibrations and deflections generated in the drive units 1 and 2 can be suppressed, which is advantageous in terms of sound vibration performance, and it is easy to ensure a guaranteed rotational speed.

  In the first embodiment, the front propeller shaft 5 that connects the rear drive unit 2 and the front differential device 6 that are separated from each other in the front-rear direction is divided into a front shaft 51 and a rear shaft 52. Were connected by a center universal joint 53.

  For this reason, compared with the structure in which the front propeller shaft 5 is integrated, the same strength and rigidity can be ensured even if the diameter is reduced, the cost and mass can be reduced, and the layout space can be reduced. Efficiency can be improved.

  Furthermore, in the first embodiment, since the front propeller shaft 5 is supported on the vehicle body 4 by the shaft mount 45b of the tunnel stay 45, the number of parts is reduced compared to the case where this support is performed by a dedicated member. Reduction, cost reduction and mass reduction.

  In addition, since the tunnel stay 45 is also used to support the exhaust pipe 11b, the number of parts can be reduced, and the cost and mass can be reduced compared to the structure dedicated to support the exhaust pipe 11b.

  Further, in the first embodiment, since the front propeller shaft 5 is disposed in the bulging portion 44b formed at the lower right end portion of the floor tunnel 44a, compared to the case where the front propeller shaft 5 is disposed so as to be overlapped below the rear propeller shaft 3, Compared with the arrangement below the front floor panel 44, the vertical space required for the layout can be reduced to save space.

  As mentioned above, although Embodiment and Example 1 of this invention were explained in full detail with reference to drawings, the concrete structure is not restricted to this Embodiment and Example 1, and does not deviate from the summary of this invention. A degree of design change is included in the present invention.

That is, in the drive mechanism arrangement structure of the all-wheel drive vehicle of the first embodiment, the first clutch 12 is provided in the front drive unit 1. With this arrangement, it preferred to be able to suppress and absorb the deflection at the time of disengaging at the rear propeller shaft 3. Also, the first clutch 12 may be one that transmits and blocking the rotational driving force between the engine and the rear propeller shaft, for example, can also be used other means such as a torque converter.

  Further, as the second clutch 23, a clutch that changes the distribution of the rotational driving force transmitted to the front propeller shaft 5 may be used.

  Further, the front and rear propeller shafts 5 and 3 may be made of solid metal, and the material thereof is a fiber reinforced synthetic resin material reinforced with fibers such as carbon fiber or glass fiber instead of metal. Can be used. In this case, the propeller shafts 3 and 5 are advantageous due to the bending between the front and rear drive units 1 and 2 and the absorption of vibration interference, which is advantageous in terms of sound vibration performance, and it is easy to ensure a guaranteed rotational speed.

  Further, in the first embodiment, an example in which the front propeller shaft 5 is divided into two in the front-and-rear direction is shown, but it may be divided into a plurality of three or more.

  In the first embodiment, a hollow tunnel stay 45 is used. However, the tunnel stay 45 may be a solid one, and the shape thereof is not limited to the one shown in the embodiment, such as a linear one.

  Moreover, in the drive mechanism arrangement structure of the all-wheel drive vehicle of the first embodiment, an example is shown in which the engine 11 is placed vertically, but it may be placed horizontally.

FIG. 3 is an explanatory plan view schematically showing a drive mechanism arrangement structure of the all-wheel drive vehicle of the first embodiment. It is side explanatory drawing which shows schematically the drive mechanism arrangement | positioning structure of the all-wheel drive vehicle of Example 1. FIG. It is sectional drawing which follows the S3-S3 line | wire of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Front drive unit 2 Rear drive unit 3 Rear propeller shaft 4 Car body 5 Front propeller shaft 6 Front differential device 11 Engine 11b Exhaust pipe 21 Transmission 22 Rear differential device 43 Rear floor panel 44 Front floor panel 45 Tunnel stay 45b Shaft mount 45c Exhaust Pipe mount 51 Front shaft 52 Rear shaft 53 Center universal joint (joint)
FW Front wheel RW Rear wheel

Claims (4)

The driving mechanism of the vehicle, separates the front drive unit disposed in the vehicle front having an engine, to a rear drive unit which drives the rear wheels arranged on the vehicle rear portion has a trans mission,
The rear drive unit and the forward drive unit, connected in a power transmission with the rear propeller shaft,
The transmission of the rear drive unit, connecting the front propeller shaft for transmitting the driving force to the front wheels,
A drive mechanism arrangement structure for an all-wheel drive vehicle , wherein the front drive unit is provided with a first clutch for connecting and disconnecting power transmission from the front drive unit to the rear propeller shaft . 2. The all-wheel drive vehicle drive according to claim 1 , wherein a second clutch that transmits or interrupts the rotational driving force output from the transmission to the front propeller shaft is provided in the rear drive unit. Mechanism arrangement structure. 3. The drive mechanism arrangement structure for an all-wheel drive vehicle according to claim 2, wherein the rear propeller shaft and the front propeller shaft are arranged side by side in a vehicle width direction in a floor tunnel formed on a floor panel of a vehicle body . At the lower end of the floor tunnel, a bulging portion bulging toward the passenger compartment is formed,
4. The drive mechanism arrangement structure for an all-wheel drive vehicle according to claim 3 , wherein the front propeller shaft is arranged at the bulging portion .

Images