JP4352887B2 - Underbody floor structure - Google Patents

Description

  The present invention relates to a vehicle body underfloor structure in which a passing air under the floor is effectively used for air cooling of a final reduction gear disposed behind a tunnel portion when the vehicle is traveling.

  Under the floor where the tunnel portion is provided on the vehicle body floor, the propeller shaft and exhaust pipe are arranged in the tunnel portion of the FR vehicle, and a final reduction device is arranged at the rear end of the propeller shaft. The device is preferably actively cooled.

For this reason, a cross member is provided in the vehicle width direction in front of the vehicle body of the final reduction gear, and a guide plate for guiding the passing air under the floor to the final reduction gear is attached to this to cool the final reduction gear. Is known (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 11-11360 (page 3, FIG. 1)

  However, in such a conventional underbody structure of the vehicle body, as described above, a guide plate is provided to cool the final reduction gear, and this is attached to the cross member. The number of man-hours increases and the cost is increased.

  Therefore, the present invention provides a vehicle body underfloor structure capable of introducing underfloor passing air to the final reduction gear without increasing the number of parts.

In the present invention, the vehicle body floor is provided with a tunnel portion extending in the front-rear direction, the propeller shaft and the exhaust pipe are disposed on the lower inner side of the tunnel portion, and the final reduction gear is provided at the rear end portion of the propeller shaft. And a vehicle body underfloor structure in which a reinforcing member is arranged in the vehicle width direction across the lower end both sides of the tunnel portion on the vehicle body front side of the final reduction gear. A first air guide portion is formed that takes the passing air into the tunnel portion and guides it to the final reduction gear, and the first air guide portion includes a front inclined portion that is inclined downward toward the front of the vehicle body, and the front inclined portion. The portion is formed in an arc shape in which the central portion in the vehicle width direction is curved toward the rear of the vehicle body in plan view .

  According to the present invention, the first air guide portion is formed in the reinforcing member disposed across the lower end portion of the tunnel portion, and the passing air under the floor during traveling is taken into the tunnel portion by the first air guide portion. This intake air is supplied to the final reduction gear through the inside of the tunnel portion, and this final reduction gear can be actively cooled.

  Therefore, in the present invention, since the first air guide portion can be formed on the existing reinforcing member and the passing air under the floor can be taken into the tunnel portion, an increase in the number of parts can be avoided and the number of assembling steps can be avoided. Can be prevented, and as a result, an increase in the cost of the vehicle can be suppressed.

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

  1 to 7 show an embodiment of the present invention, FIG. 1 is a bottom view of a vehicle body, FIG. 2 is a side view showing a cross section of a main part of the vehicle body, and FIG. 3 is an enlarged view of a portion A in FIG. 4 is an enlarged perspective view of the tunnel stay, FIG. 5 is an enlarged plan view of the tunnel stay, FIG. 6 is an enlarged perspective view of the connecting plate of the left and right exhaust pipes as seen from obliquely above, and FIG. 7 is a connection of the left and right exhaust pipes. It is the expansion perspective view which looked at the board from diagonally downward.

  As shown in FIGS. 1 and 2, the vehicle body underfloor structure of the present embodiment includes a tunnel portion 3 that extends in the front-rear direction on the vehicle body floor 2 of the vehicle 1. 4 and an exhaust pipe 5 are disposed, and a rear differential gear 6 as a final reduction gear is provided at the rear end portion of the propeller shaft 4.

  The exhaust pipe 5 constitutes a dual exhaust pipe system as shown in FIG. 1, and the left and right exhaust manifolds 5a and 5b connected to the engine E (see FIG. 2) arranged on the left side in the figure The left and right exhaust pipes 5d and 5e are branched to the left and right exhaust pipes 5d and 5e on the vehicle body front side of the rear differential gear 6, and the left and right exhaust pipes 5d and 5e are connected to the vehicle body of the rear differential gear 6. The vehicle is connected to the left and right center mufflers 7a and 7b in the vicinity of the front, and the rear end of each vehicle body is connected to the left and right main mufflers 8a and 8b. In FIG. 2, Wf is a front wheel and Wr is a rear wheel.

  As shown in FIG. 2, the exhaust pipe 5 is generally piped along the lower side of the propeller shaft 4, and the left and right exhaust pipes 5d and 5e together with the left and right center mufflers 8a and 8b are rear differential gears 6. Are arranged separately in the vehicle width direction so as to sandwich them.

  Of course, the left and right center mufflers 7a and 7b and the left and right main mufflers 8a and 8b constitute part of the left and right exhaust pipes 5d and 5e.

  The tunnel portion 3 is on the vehicle body front side of the rear differential gear 6, and in this embodiment, on the vehicle body front side of the left and right center mufflers 7 a and 7 b, on both sides of the lower end of the tunnel portion 3. A tunnel stay 10 as a reinforcing member is joined and disposed across the vehicle width direction, and the rigidity of the tunnel portion 3 in the opening / closing direction is secured by the tunnel stay 10.

  Here, in the present embodiment, the tunnel stay 10 is formed with a first air guide portion 11 that takes the passing air W under the floor generated when the vehicle 1 travels into the tunnel portion 3 and guides it to the rear differential gear 6. .

  As shown in FIGS. 4 and 5, the tunnel stay 10 is formed by pressing a plate material having a predetermined thickness into a strip shape having a long side in the vehicle width direction. Has a recessed portion 10a extending in the vehicle width direction to enhance bending rigidity.

  The first air guide portion 11 has a front inclined portion in which a front edge portion of the tunnel stay 10 which is in front of the vehicle body is recessed downward than the recessed portion 10a and is inclined downward toward the vehicle body front. The front inclined portion 11a is formed in an arc shape in which the central portion in the vehicle width direction is curved toward the rear of the vehicle body in plan view, and the arcuate flat portion 11b surrounded by the arc-shaped inclined portion 11a is formed. Is the guiding part of the passing wind.

  Further, the left and right center mufflers 7a and 7b positioned in front of the vehicle body relative to the rear differential gear 6 are connected in the vehicle width direction by a connecting plate 20, and in this embodiment, the passing air W under the floor is transmitted to the connecting plate 20. A second wind guide portion 21 is formed which guides in the direction of the rear differential gear gear 6 along with the passing wind W introduced and introduced by the first wind guide portion 11.

  As shown in FIGS. 6 and 7, the connecting plate 20 is composed of three first to third connecting plates 20 </ b> A, 20 </ b> B, and 20 </ b> C in the present embodiment. The first and second connecting plates 20A and 20B are spaced apart from each other at the same height above and behind, while the third connecting plate 20C is spaced above the second connecting plate 20B. The second air guide portion 21 is formed on the two connecting plates 20A and 20B, and the second air guide portion 21 has the rear edge portions of the first and second connecting plates 20A and 20B facing upward rearward. It is formed by the inclined rearward inclined portions 21Aa and 21Ba.

  With the above configuration, according to the vehicle body underfloor structure of the present embodiment, the passing wind W generated under the floor as the vehicle 1 travels is guided upward by the first air guide portion 11 formed in the tunnel stay 10 and tunneled. Since the air can be taken into the part 3, the air taken in can be guided to the rear differential gear 6 through the inside of the tunnel part 3, and the rear differential gear 6 can be actively cooled.

  Therefore, since the first differential guide 11 can be formed on the existing tunnel stay 10 to cool the rear differential gear 6, it is possible to avoid an increase in the number of parts and an increase in the number of assembling steps. This can prevent the increase in cost.

  In the present embodiment, in addition to the above-described effects, the second air guide portion 21 is formed on the connecting plate 20 of the left and right center mufflers 7a and 7b. A part of the taken passing air W is introduced above the connecting plate 20, and the introduced passing air W is guided upward by the second air guide portion 21 formed in the connecting plate 20, and the rear differential gear. 6 can be supplied.

  Therefore, in addition to the cooling effect of the rear differential gear 6 by the first air guide portion 11, the cooling effect by the second air guide portion 21 can be obtained, and the cooling efficiency of the rear differential gear 6 can be further increased.

  Moreover, even if it exists in the said 2nd air guide part 12, by forming in the existing connection board 20, the increase in the cost of the vehicle 1 can be suppressed avoiding the increase in a number of parts and the increase in an assembly man-hour.

  By the way, although the vehicle body underfloor structure of this invention was demonstrated taking the example of the said embodiment, it is not restricted to these embodiments, Various embodiments can be employ | adopted in the range which does not deviate from the summary of this invention.

It is a bottom view of the vehicle body which shows one Embodiment of this invention. It is a side view which shows the principal part of the vehicle body which shows one Embodiment of this invention as a cross section. It is an enlarged view of the A section in FIG. It is an expansion perspective view of the tunnel stay which shows one Embodiment of this invention. It is an enlarged plan view of a tunnel stay showing an embodiment of the present invention. It is the expansion perspective view which looked at the connection board of the left-right exhaust pipe which shows one Embodiment of this invention from diagonally upward. It is the expansion perspective view which looked at the connection board of the left-right exhaust pipe which shows one Embodiment of this invention from diagonally downward.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Car body floor 3 Tunnel part 4 Propeller shaft 5 Exhaust pipe 5d Left exhaust pipe 5e Right exhaust pipe 6 Rear differential gear (final reduction gear)
7a Left center muffler (left exhaust pipe)
7b Right center muffler (Right exhaust pipe)
10 Tunnel stay (reinforcing member)
11 1st air guide part 20 connecting plate 21 2nd air guide part W passing air

Claims (3)

A tunnel portion extending in the front-rear direction is provided on the vehicle body floor, and a propeller shaft and an exhaust pipe are disposed on the lower inner side of the tunnel portion, and a final reduction gear is provided at the rear end portion of the propeller shaft. In the vehicle body underfloor structure in which the reinforcing member is arranged in the vehicle width direction across the lower end both sides of the tunnel portion on the vehicle body front side of the speed reducer,
The reinforcing member is formed with a first air guide portion that takes the passing air under the floor generated when the vehicle travels into the tunnel portion and guides it to the final reduction gear ,
The first air guide portion includes a front inclined portion that is inclined downward toward the front of the vehicle body,
The vehicle body underfloor structure is characterized in that the front inclined portion is formed in an arc shape in which a central portion in the vehicle width direction is curved toward the rear of the vehicle body in plan view . The first air guide part is further provided with an arcuate flat part formed in a flat shape by being continuously provided in the forward inclined part and by denting the thickness of the reinforcing member downward. The vehicle body underfloor structure as described in 1. The exhaust pipe is provided below the final reduction gear and includes left and right exhaust pipes separated in the vehicle width direction so as to sandwich the final reduction gear, and the left and right exhaust pipes are arranged more than the final reduction gear. Connected in the vehicle width direction by a connecting plate in front of the vehicle body and at a position behind the reinforcing member with respect to the reinforcing member, along with the passing wind introduced by the first air guide section by taking the passing air under the floor into this connecting plate The vehicle body underfloor structure according to claim 1 or 2 , wherein a second air guide portion for guiding the final reduction gear is formed.

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