JP6127248B2 - undercover - Google Patents

Description

  The present invention relates to an undercover that covers a lower portion of a vehicle. In particular, the present invention relates to an undercover capable of taking in traveling wind flowing under an undercover and blowing the traveling wind taken toward a cooling object such as an engine installed under a vehicle floor.

  In a so-called cab-over type vehicle such as a one-box car or a truck, the engine is arranged below the floor of the cabin. In this case, it becomes difficult for the driving wind to hit the engine, and the engine cannot be cooled by the driving wind. Further, it is not preferable in that heat generated from the engine tends to be trapped under the floor.

  In Patent Document 1, in a cab-over type vehicle, a hollow suspension frame is extended from the front of the vehicle to the front of an engine disposed under the floor, and the front and rear ends of the suspension frame are opened. Thus, the traveling wind taken from the front end of the vehicle is blown to the engine under the floor through the suspension frame.

  By the way, an under cover is installed in the lower part of the automobile for the purpose of improving aerodynamic characteristics and protecting equipment installed in the lower part of the automobile. The under cover disclosed in Patent Document 2 has a ventilation hole for introducing traveling air from below, and traveling air flowing under the under cover is introduced to the upper side of the under cover through the ventilation hole, so that the engine and transmission The heat generating part such as the exhaust pipe is cooled.

JP-A-5-330457 JP 2011-189770 A

  However, in the technique disclosed in Patent Document 1, in order to extend the suspension frame from the front of the vehicle to the front of the underfloor engine and to supply a sufficient air volume, a large passage cross section of the hollow portion is secured. This is likely to increase the size of the suspension frame or increase the weight of the vehicle.

  Further, the under cover disclosed in Patent Document 2 is merely intended to cool the heat generating portion installed above the under cover by introducing the traveling air from below to above through the ventilation holes. In other words, the undercover of the same document is not capable of blowing the introduced traveling wind while aiming at a specific place, so it is difficult to efficiently cool the heat generating portion.

  The present invention was devised in view of such a problem, and a traveling wind introduced from a traveling wind introduction section with a specific target at a cooling target such as a heat generating section installed in a lower part of a vehicle. It aims at providing the undercover which can cool a cooling target object efficiently by ventilating.

The under cover of the present invention covers a lower portion of a vehicle having an object to be cooled under the floor, and introduces traveling wind flowing backward along the lower surface of the under cover to the upper surface side of the under cover during traveling. Three traveling wind introduction portions disposed at the center and both sides in the vehicle body width direction, and the traveling wind introduced on the upper surface side from the central ventilation hole of the traveling wind introduction portion ascend. A guide slope having a shape that rises obliquely upward toward the rear at the lower rear part of the central ventilation hole, and the traveling wind that has been separated from the guide slope is climbed up the upper surface of the guide slope. to strike the object to be cooled, the set guide slope of the slope shape, the upper surface of the running wind introduction portion of the center, the wind from the front of the vehicle lower flowing an upper surface of the undercover Hands to form a gradually lower ridges in the vehicle width direction on both sides to branch, it is characterized in.

  According to the under cover having such a configuration, during traveling, traveling wind that flows backward along the lower surface of the under cover is introduced from the traveling wind introduction portion to the upper surface side of the under cover, and climbs the guide slope. During the climbing, the traveling wind is pressed against the guide slope due to inertia, and thus spreads in the vehicle width direction rather than the vertical direction. Thereby, even if the cooling target is large in the vehicle width direction, the entire cooling target can be cooled. Moreover, since it does not diffuse much in the up-down direction, the traveling wind can be blown aiming at a specific height position of the cooling object.

  According to the under cover of the present invention, it is possible to blow the traveling wind introduced to a specific place with a target to the object to be cooled installed at the lower part of the vehicle. As a result, the object to be cooled can be efficiently cooled. can do

It is a perspective view which shows the undercover which concerns on embodiment of this invention. It is AA sectional drawing of FIG. It is the figure which added the schematic structure of the vehicle lower part to the BB sectional view of Drawing 1, and added with the dashed-two dotted line. It is a perspective view which shows the undercover which concerns on embodiment of this invention. It is the figure which added the schematic structure of the vehicle lower part to the BB sectional view of Drawing 1, and added with the dashed-two dotted line. It is the simulation result which visualized and expressed the running wind with the streamline using CFD. It is the simulation result which visualized and expressed the driving | running | working wind in a vehicle center cross section with a streamline using CFD.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The under cover according to the embodiment of the present invention is installed so as to cover the lower part of the vehicle. As shown in FIGS. 1 to 3, the main body 2, the front support 3, and the intermediate support 4 and rear support portion 5. Each part 2-5 of the under cover 1 illustrated in the figure is formed of a thin plate material made of resin, metal or the like.

  The front support part 3 extends in the vehicle width direction and is connected to the front end of the main body part 2. Reinforcing ribs 9 are provided between both ends in the vehicle width direction of the front support portion 3 and both ends in the vehicle width direction of the main body portion 2. The front support portion 3 is fastened to a cross member 6 (see FIG. 3) installed on left and right side members (not shown) extending in the front-rear direction of the vehicle.

  The intermediate part support part 4 is erected at the intermediate position in the front-rear direction of both side parts of the main body part 2, and a flange 7 that is fastened to the lower part of the vehicle with a bolt or the like is formed at the upper end thereof. The rear support part 5 is connected to the rear end positions of both side parts of the main body part 2, and a fastening surface 8 that is fastened with a bolt or the like is formed in the lower part of the vehicle. Each said support part 3,4,5 supports the main-body part 2 in the state which interposed the lower part and fixed space of the vehicle.

  The main body 2 is provided with a traveling wind introduction portion 19 and a guide slope 25. The traveling wind introduction unit 19 introduces traveling wind that flows backward along the lower surface of the main body 2 during traveling of the vehicle to the upper surface side of the main body 2, and the introduced traveling wind hits a rising surface 25 a of a guide slope 25 described later. It is formed as follows. Specifically, the traveling wind introduction section 19 is configured by a ventilation hole 19a that communicates with the upper and lower sides of the main body 2 and a traveling wind guide section 19b. The traveling wind guide portion 19b has an inclined surface inclined obliquely upward toward the rear, and the traveling wind that efficiently flows along the lower surface of the main body portion 2 is introduced to the upper surface side of the main body portion 2 by the inclined surface. .

  The guide slope 25 includes an ascending surface 25a that rises obliquely upward toward the rear, a top portion 25b that continues to the rear end of the ascending surface, and a descending surface 25b that descends obliquely downward continuously from the top portion 25b. It consists of The traveling wind introduced from the traveling wind introduction section 19 climbs along the rising surface 25a of the guide slope 25, and after detaching from the top section 25b, blows against the engine 24 (cooling target). That is, the slope shape of the rising surface 25 a of the guide slope 25 is set so that the traveling wind hits the engine 24. In the present embodiment, the slope shape of the rising surface 25a of the guide slope 25 is set so that the traveling wind that has left the guide slope 25 blows toward the top of the engine 24. The rising surface 25a of the guide slope 25 illustrated in the figure is neither inclined nor curved in the vehicle width direction, but may be slightly inclined or curved. Further, the rising surface 25a of the guide slope 25 illustrated in the drawing is curved obliquely downward toward the rear, but the rising surface 25a may be a flat inclined surface.

  Moreover, in this embodiment, the main-body part 2 is the wheel house 10 (refer FIG. 5) from the position which can receive the hot air (henceforth "hot air") which blows off diagonally back downward from the lower part of a vehicle front part. It is provided so as to cover the lower part of the vehicle until it reaches a predetermined position (negative pressure generation region S) described later. The hot air is, for example, high-temperature air that passes through a heat source such as a radiator 26 and a condenser 27 from the front grill while traveling and then blows obliquely rearward and downward from the lower part of the front portion of the vehicle.

In the main body portion 2 of the under cover 1, a raised portion 13 whose back surface functions as the traveling wind introduction portion 19 is formed in a portion that receives the hot air. As shown by the arrow 14 in FIG. 4, the raised portion 13 branches the hot air blown obliquely downward downward into two hands as shown by the arrows 15 and 16 so as to flow toward the negative pressure generation region S on both sides of the rear. Is formed. Specifically, as shown in FIG. 5, the raised portion 13 gradually increases in the rear direction in the portion 2 a that receives the hot air of the main body portion 2, and suddenly drops at a predetermined position at the rear end (position indicated by the arrow P). It is made into a shape. Further, as shown in FIG. 2, the vehicle width direction of the raised portion 13 is gradually lowered from the center position in the vehicle width direction toward both sides in the vehicle width direction. In the present embodiment, the vent holes 18, 19a, and 20 are formed in the sharply dropped portion at the rear end of the raised portion 13, so that ribs are provided in two places on the raised portion 13 in the front-rear direction for the purpose of reinforcing the main body portion 2. 21 is formed. As is well known, a negative pressure generation region always exists at a position behind the wheel house on the lower surface of a vehicle such as an automobile.

  As shown in FIG. 5, in the main body 2, a curved portion 22 that is curved obliquely forward and downward is formed on the front side of the raised portion 13 in order to facilitate the formation of an air flow toward the rear raised portion 13. .

  Further, in the main body 2, the hot air that is bifurcated by the raised portion 13 and flows toward the both sides on the rear side is discharged from between the main body 2 and the lower part of the vehicle by the negative pressure action of the negative pressure generation region S. The under cover 1 has a hot air outlet 23 opened to the negative pressure generation region S. In the present embodiment, the hot air discharge port 23 is formed in a portion surrounded by the rear end edge of the intermediate portion support portion 4, the side end edge of the main body portion 2, the front end edge of the rear portion support portion 5, and the vehicle lower portion. Is done.

  According to the vehicle in which the under cover 1 according to the present embodiment is installed, the traveling wind that flows backward along the lower surface of the under cover 1 is introduced from the traveling wind introduction portion 19 to the upper surface side of the under cover 1 during traveling. The ascending surface 25a of the guide slope 25 is climbed. At the time of climbing, the traveling wind is pressed against the rising surface 25a due to inertia, so that it is more likely to diffuse in the vehicle width direction than in the vertical direction. For this reason, even if the dimension in the vehicle width direction of the ventilation hole 19a is small, the traveling wind introduced from the ventilation hole 19a is largely diffused in the vehicle width direction before being separated from the top portion 25b of the guide slope 25, and the object to be cooled Even if this is large in the vehicle width direction, the object to be cooled can be cooled as a whole. Further, since the traveling wind does not diffuse much in the vertical direction when climbing the guide slope 25, it is possible to intensively cool the target wind at a specific height position of the object to be cooled. As shown in FIG. 3, in the present embodiment, traveling wind is applied aiming at the upper part of the engine 24. The low-temperature traveling wind that hits the upper part of the engine 24 hits the upper part of the engine 24, covers the entire engine, and cools the engine efficiently. FIG. 6 and FIG. 7 are simulation results showing the traveling wind visualized with streamlines using CFD (Computational Fluid Dynamics). As shown in FIGS. 6 and 7, the low-temperature traveling wind introduced from the traveling wind introduction section 19 detaches from the guide slope 25, then hits the upper portion of the engine 24 while diffusing in the vehicle width direction, and then the entire engine 24. It spreads to cover. Also, wind tunnel experiments gave similar results to this simulation.

Further, according to the under cover 1 according to the present embodiment, the hot air blown out from the lower front part of the vehicle as indicated by the arrow 14 in FIG. 4 hits the raised portion 13 of the under cover 1 and travels as indicated by the arrows 15 and 16. , Branching into two directions, flowing toward the hot air outlet 23 opened in the negative pressure generation region S on both sides of the rear, and the hot air flowing between the under cover 1 and the lower part of the vehicle by the negative pressure action is outside the under cover 1. To be discharged. As a result, discharge of hot air inside the compartment 28 (see FIG. 5) in which heat sources such as the radiator 26 and the condenser 27 are installed is promoted.

  Moreover, since the traveling wind introduction part 19 and the raised part 13 provided in the under cover are formed on the back and front of the same part, the cold traveling wind introduced from the traveling wind introduction part 19 and the raised part 13 The branching hot air forms separate flow paths so that two winds having a temperature difference do not mix. Therefore, according to the under cover 1 according to the present embodiment, the two different functions and effects described above can be obtained with one under cover 1.

<Modification of Embodiment>
In the under cover 1 according to the above-described embodiment, a cover in which the ventilation holes 18 and 20 other than the ventilation hole 19 are closed, or a rib 21 is omitted may be employed. It goes without saying that the above-described operational effects can be obtained even with such an undercover.

  The object to be cooled is not limited to the engine, and may be other devices and devices (for example, a transmission, an exhaust pipe, etc.) that are installed under the floor and generate heat.

  The present invention can be applied to, for example, an undercover that is installed so as to cover a lower portion of an automobile.

1 Undercover 24 Engine (cooling object)
19 Running wind introduction part 25 Guide slope

Claims (1)

An under cover for covering a lower portion of a vehicle having an object to be cooled under the floor,
Three running wind introduction portions disposed at the center and both sides in the vehicle body width direction, having ventilation holes for introducing running wind that flows backward along the lower surface of the under cover to the upper surface side of the under cover during traveling. When,
A guide slope having a shape that is provided so that the traveling wind introduced from the central ventilation hole of the traveling wind introduction part to the upper surface side climbs, and rises obliquely upward toward the rear at the lower rear part of the central ventilation hole; With
The slope shape of the guide slope is set so that the upper surface of the guide slope is climbed so that the traveling wind separated from the guide slope hits the object to be cooled.
The upper surface of the central traveling wind introduction part forms a bulge that gently falls on both sides in the vehicle width direction so as to bifurcate the wind from the lower front part of the vehicle flowing on the upper surface of the under cover.
Undercover characterized by that.