JP3716709B2 - Engine room structure of a four-wheel drive vehicle - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an engine room structure of a four-wheel drive vehicle.
[0002]
[Prior art]
Conventionally, when four-wheel drive (4WD) is established by arranging the engine unit horizontally in the engine room, the front axle is taken out from the transaxle that integrates the transmission and axle (drive shaft), and the transaxle The output shaft is projected rearward from the combined transfer as an auxiliary transmission, and the driving force is transmitted from the output shaft to the rear axle via the propeller shaft (as a similar technique, the actual utility model 3) -126773).
[0003]
Such an engine unit is elastically supported by four mounting members arranged in the front, rear, left and right in the engine room. That is, the front end of the engine unit is supported by the center member by the front mount, the left and right sides are respectively supported by the front side member by the side mount, and the rear end is supported by the rear cross member by the rear mount. In this way, by securely arranging the four mounting members, a reliable support structure for the engine unit can be obtained. Since each mount member is supported by only four mount members, each mount member is large and has a high support strength.
[0004]
Of the four mount members, the rear cross member to which the rear mount is connected is particularly positioned below the output shaft of the transfer because the steering rack is attached to the upper surface. In other words, the lower position of the steering rack is advantageous in terms of high-speed straight running stability and turning performance, and therefore, the steering rack is positioned below the output shaft.
[0005]
Therefore, the rear mount is positioned above the steering rack in order to avoid interference with the steering rack, and is connected to the rear cross member via a connecting member extending in the vertical direction. Also, as this rear mount, in order to support the engine unit in a well-balanced manner, it is desired to be as close as possible to the center position in the vehicle width direction, but since the output shaft exists at the center position, the rear mount can not be helped. It is provided at a position offset to either the left or right side.
[0006]
The rear mount and the propeller shaft connected to the output shaft and extending rearward are housed in a floor tunnel portion formed upward from the floor panel. That is, in order to extend the dash panel sufficiently to the front side position in order to expand the vehicle interior space, the rear mount disposed rearward from the rear portion of the engine unit is also accommodated in the floor tunnel portion.
[0007]
[Problems to be solved by the invention]
However, in such a conventional technique, the large rear mount is provided at a position higher than the steering rack and offset to either the left or right side of the output shaft. The floor tunnel will become larger, which will put pressure on the interior space.
[0008]
In addition, since the rear mount is provided on either the left or right side of the output shaft, if the engine unit moves backward during a vehicle collision, the engine unit tilts and displaces, increasing the number of damaged parts of the engine unit and making repairs troublesome. Become.
[0009]
The present invention has been made by paying attention to such a conventional technique, and can reduce the floor tunnel portion and suppress the engine unit from being inclined and displaced at the time of a collision. Provide structure.
[0012]
[Means for Solving the Problems]
The invention described in claim 1 includes an engine body, a transaxle for rotating the front axle, and a transfer provided with a rearward output shaft for transmitting driving force for rotating the rear axle. The four-wheel drive engine unit is placed in the engine room in a sideways state, a rear cross member along the vehicle width direction is arranged below the output shaft, a steering rack is mounted on the rear cross member, and a transformer is mounted. A pair of rear mounts located above the steering rack and in the vicinity of the left and right sides of the output shaft are rearwardly arranged from the axle and transfer, and the rear mount and the rear cross member are connected by a connecting member extending in the vertical direction. Connected to the rear mount and output shaft The propeller shaft, and housed in the floor tunnel.
[0013]
According to the first aspect of the invention , since the steering rack is located below the output shaft, it is advantageous in terms of high-speed straight running stability and turning performance. Further, there is no obstruction above the output shaft, and the pair of rear mounts can be provided in a state sufficiently close to the output shaft.
[0014]
According to the second aspect of the present invention, the lower portion of the connecting member is connected to the front position of the rear cross member relative to the steering rack.
[0015]
According to the second aspect of the present invention, when the engine unit moves backward during a frontal collision, the rear mount and the connecting member also move backward. Since the lower part of the connecting member is located in front of the steering rack, the connecting member hits the steering rack and pushes the steering rack backward and downward. When the steering rack is pushed rearward and downward, the steering wheel connected to the steering rack is pulled downward to prevent the steering wheel from being pushed up.
[0016]
In the invention according to claim 3 , the exhaust pipe is passed directly under the propeller shaft connected to the output shaft and extending rearward.
[0017]
According to the third aspect of the invention, since the propeller shaft and the exhaust pipe overlap each other, the width of the floor tunnel portion can be reduced correspondingly, and the space in the vehicle interior can be increased. If the exhaust pipe is shifted laterally from the propeller shaft, it is necessary to widen the lower portion of the floor tunnel portion to ensure a vertical distance in order to avoid heating by the exhaust pipe.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
A preferred embodiment of the present invention will be described below with reference to FIGS. In FIG. 1, symbol E is an engine room and is formed in front of the vehicle. In front of the engine room E, the first cross member 1 is arranged along the vehicle width direction. The left and right ends of the first cross member 1 are connected to the front ends of the front side member 2 along the front-rear direction.
[0019]
Between the rear portions of the front side member 2, a rear cross member 5 is installed along the vehicle width direction. A steering rack 6 is attached to the upper surface of the rear cross member 5 by a bracket (not shown). A steering gear 7 (FIG. 1) is engaged with the steering rack 6 and can be steered by the steering wheel 8. A center member 9 is attached from the lower side between the center portion of the rear cross member 5 and the center portion of the first cross member 1.
[0020]
The engine unit U is mounted sideways in the center of the engine room E having such a structure. The engine unit U includes an engine body C, a transaxle S, and a transfer T. The engine main body C is V-shaped, and the exhaust pipe 10 extending from the front surface of the engine main body C extends below the engine unit U and then extends substantially linearly toward the rear at the center position in the vehicle width direction. The exhaust pipe 10 also passes below the rear cross member 5 and includes a catalyst 11 at a position close to the rear cross member 5 after passing through the rear cross member 5.
[0021]
A front axle 16 extends from the transaxle S assembled on the left side of the engine body C to the left and right sides, and a tire 17 is attached to the tip of the axle 16. The tire 17 is connected to both ends of the steering rack 6, and the angle can be changed by operating the steering rack 6.
[0022]
A transfer T is further assembled to the transaxle S, and an output shaft F protrudes rearward from the transfer T. The transaxle S and the transfer T are connected via a transfer ring gear or a transfer pinion gear (not shown), and the direction of the driving force is converted and transmitted to the output shaft F. The steering rack 6 is positioned below the output shaft F in order to improve high-speed straight running stability and turning performance.
[0023]
A propeller shaft P is connected to the output shaft F to transmit a driving force to a rear axle (not shown) on the rear side. Since the propeller shaft P is at the center position in the vehicle width direction, the exhaust pipe 10 is positioned directly below the propeller shaft P, and both overlap in the vertical direction.
[0024]
The front end of the engine unit U is supported by the front mount 12 with respect to the center member 9, the left and right sides are supported by the front side member 2 by the side mounts 13 and 13, and the rear ends are rear mounts 14 and 15. And supported by the lower surface of the rear cross member 5.
[0025]
Of the four engine mounts, the rear mounts 14 and 15 are divided into two and are arranged on the left and right sides of the output shaft F. Both are located above the output shaft F. The left rear mount 14 projects a pair of brackets 14a rearward from the rear surface of the transaxle S, and an elastic member 14b sandwiched between the outer cylinder and the inner cylinder is provided at the rear end of the bracket 14a with a bolt 14c. It is attached with.
[0026]
The outer cylinder of the elastic member 14b and the rear cross member 5 are connected by a connecting member 19 along the vertical direction. The connecting member 19 includes a front leg portion 19 a and a rear leg portion 19 b that straddle the steering rack 6, and each is connected to the rear cross member 5. In particular, the front leg portion 19a overlaps the steering rack 6 in the front-rear direction with the upper side inclined rearward.
[0027]
The right rear mount 15 has the same structure and includes a bracket 15a, an elastic member 15b, and a bolt 15c. In the case of the right rear mount 15, it is attached to the transfer T, and since the attachment site is narrow, the front end portions of the pair of brackets 15 a are attached to the transfer T in a state of being bent together.
[0028]
Since these two rear mounts 14 and 15 support the rear end of the engine unit U, the individual rear mounts 14 and 15 may be smaller than those supported by the conventional one. The rear mounts 14 and 15 are provided as close as possible to the output shaft F.
[0029]
Such rear mounts 14 and 15 and the output shaft F are located above the floor panel 4, and the dash panel 3 itself is sufficiently extended to the front side in order to expand the vehicle interior space R. Therefore, the rear mounts 14 and 15 and the propeller shaft P are accommodated in the floor tunnel portion 18.
[0030]
Next, the advantages of this embodiment are listed.
[0031]
Expansion of vehicle interior space R:
Since the rear mounts 14 and 15 are divided into two parts and provided on the left and right sides of the output shaft F, the respective rear mounts 14 and 15 can be made small. Therefore, the floor tunnel portion 18 that accommodates the rear mounts 14 and 15 can be reduced in size, and the vehicle interior space R can be increased accordingly. That is, as shown in FIG. 4, conventionally, since one large rear mount M is provided in an offset state on either the left or right side of the output shaft F, the floor tunnel portion 18 ′ for housing it is also enlarged. In this embodiment, since the two rear mounts 14 and 15 are small, each of the rear mounts 14 and 15 can be inserted into the space between the output shaft F and the inner surface of the floor tunnel portion 18. The height H and width W of 18 can be reduced.
[0032]
Furthermore, since the propeller shaft P and the exhaust pipe 10 overlap each other, the width W of the floor tunnel portion 18 can be reduced correspondingly, and in this respect also, the vehicle interior space R can be expanded. . If the exhaust pipe 10 is shifted laterally from the propeller shaft P, it is necessary to widen the lower portion of the floor tunnel portion 18 to further secure the vertical distance in order to avoid heating by the exhaust pipe 10.
[0033]
Prevention of tilting of engine unit U at the time of collision:
Since the rear mounts 14 and 15 exist on the left and right sides of the output shaft F, respectively, the engine unit U is not displaced in a tilted state even when the engine unit U moves backward during a vehicle collision. Accordingly, the engine unit U is less damaged and can be repaired easily.
[0034]
Prevention of push-up of the steering wheel 8:
When the engine unit U moves backward during a frontal collision, the rear mounts 14 and 15 and the connecting member 19 move backward, and the front leg portion 19 a of the connecting member 19 hits the steering rack 6. When the front leg portion 19a hits, the steering rack 6 is pushed rearward and downward, so that the steering wheel 8 connected to the steering rack 6 is pulled downward and the steering wheel 8 is prevented from being pushed up.
[0035]
Improved exhaust performance:
Since the exhaust pipe 10 passes under the rear cross member 5 in a substantially linear state, the exhaust noise can be reduced. In addition, since the exhaust pipe 10 is passed through an unobstructed space below the rear cross member 5, the catalyst 11 installed in the exhaust pipe 10 can be positioned sufficiently forward and close to the engine body C. it can. Since the catalyst exhibits better performance as the path from the engine main body C is shorter, the performance can be improved even with the same amount of catalyst as in the past.
[Brief description of the drawings]
FIG. 1 is a plan view showing an engine room structure according to an embodiment of the present invention.
FIG. 2 is a side view showing an engine room structure according to the first embodiment.
FIG. 3 is an enlarged view showing a rear mount.
4 is a sectional view taken along the line SA-SA in FIG.
[Explanation of symbols]
2 Front side member 3 Dash panel 5 Rear cross member 6 Steering rack 10 Exhaust pipes 14 and 15 Rear mount 18 Floor tunnel portion 19 Connecting member E Engine room R Vehicle interior space U Engine unit C Engine body S Transaxle T Transfer F Output shaft P Propeller shaft H Floor tunnel height W Floor tunnel width

Claims (3)

An engine unit for four-wheel drive comprising an engine body, a transaxle that rotates the front axle, and a transfer that has a rear-facing output shaft that transmits driving force for rotating the rear axle. Placed in the engine room in landscape orientation,
A rear cross member is disposed below the output shaft along the vehicle width direction, and a steering rack is mounted on the rear cross member. A pair of rear mounts are arranged in a rearward direction, the rear mount and the rear cross member are connected by a connecting member extending in the vertical direction, and the propeller shaft connected to the rear mount and the output shaft is stored in the floor tunnel portion. The engine room structure of a four-wheel drive vehicle characterized by this. The engine room structure of a four-wheel drive vehicle according to claim 1 ,
An engine room structure for a four-wheel drive vehicle, characterized in that a lower part of the connecting member is connected to a position on the front side of the steering rack in the rear cross member. The engine room structure of the four-wheel drive vehicle according to claim 1 or 2,
An engine room structure for a four-wheel drive vehicle, characterized in that an exhaust pipe is passed directly under a propeller shaft connected to the output shaft and extending rearward.

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