JP2016137824A - undercover - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an undercover capable of efficiently cooling a heating source during traveling of a vehicle.SOLUTION: An undercover 10 is disposed on a lower side of a vehicle 100 and covers a lower part of a heating source, for example, an engine or the like. The undercover 10 comprises: a body part 11 which extends in a longitudinal direction of the vehicle 100 and covers an underfloor region where the engine is disposed; and side support parts 12 provided on both left and right sides of the body part 11. The body part 11 has a shape curved downward over the entire in the longitudinal direction in a side view, its undersurface is formed in a substantially circular shape, and the entire body part is a curved part. A plurality of through holes 13 penetrating from the top surface to the undersurface are formed at a curved portion of the body part 11.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an under cover that is disposed on the lower side of a vehicle and covers a lower portion of a heat generation source. In particular, the present invention relates to an undercover capable of efficiently cooling a heat generation source during traveling of a vehicle.

  Under the automobile (vehicle), an under cover that covers the lower part of the engine or the like is disposed in order to protect devices such as the engine, transmission, and exhaust pipe from the flying stones and water splashes during traveling. Generally, the under cover is formed in a rectangular box shape with a flat bottom surface (see Patent Document 1).

  Since the engine generates heat and becomes hot during running, it needs to be cooled. If the engine gets too hot, it can cause performance degradation and failure. On the other hand, if it is covered with the under cover, it is difficult for heat to escape, so that heat tends to be trapped inside (upper side) of the under cover. Therefore, the driving wind taken from the front of the vehicle and the cooling air from the radiator fan are blown into the engine room formed on the upper side of the under cover, and the heat in the engine room is discharged from the rear end of the under cover. To cool down.

  Patent Document 1 proposes to provide a diffuser structure for promoting discharge of cooling air from the fan at the rear end of the engine undercover.

JP 2006-44337 A

  In a vehicle in which an under cover is disposed on the lower side of the vehicle, it is desired to efficiently cool a heat source such as an engine covered with the under cover. For this purpose, it is necessary to increase the cooling efficiency in the under cover (in the engine room), and as one of them, it is required to promote the discharge of heat in the under cover.

  As a means for promoting exhaust heat in the under cover, for example, it is conceivable to secure a sufficient amount of air to be discharged from the under cover to the outside. Specifically, it is possible to increase the air volume of the traveling wind taken into the under cover or the air volume of the radiator fan to promote exhaust heat in the under cover. However, in order to increase the air volume of the traveling wind to be taken in, it is conceivable to increase the intake opening (such as a grill or a bumper opening) that takes in the traveling wind, but the size of the intake opening is also limited. In particular, in the case of a small vehicle (for example, a light vehicle) or a cab-over type vehicle (for example, a truck or a one-box car) in which a passenger cabin (cab) is disposed above the engine, the running wind is taken in. It is difficult to ensure a sufficient mouth size. Also, in a cab-over type vehicle such as a full cab vehicle or a semi-cab vehicle, a device such as an engine may be mounted near the center of the vehicle, and it is difficult to obtain a sufficient cooling effect due to running wind. is there. On the other hand, if the fan volume is increased or added in order to increase the air volume of the radiator fan, there is a problem that it is necessary to secure a corresponding space, increase the weight, or increase the cost. In particular, in a cab-over type small vehicle, it is difficult to promote exhaust heat due to an increase in the air volume because there are large restrictions on the size and layout of the intake port for the traveling wind and the radiator fan.

  When the rear end of the under cover has a diffuser structure as in Patent Document 1, the shape is complicated, which may increase the cost and reduce the productivity.

  In addition to the engine, examples of the heat source that becomes high temperature during traveling include a transmission and an exhaust pipe. If these devices become too high in temperature, they may cause performance degradation, malfunction, or failure. Therefore, it is desired to develop an undercover capable of improving the cooling efficiency in the undercover while having a simple configuration and capable of efficiently cooling the heat generation source.

  Accordingly, one of the objects of the present invention is to provide an undercover capable of efficiently cooling a heat generation source while a vehicle is traveling.

  (1) An under cover according to an aspect of the present invention is an under cover that is disposed on the lower side of a vehicle and covers a lower portion of a heat source, and when viewed from the side of the vehicle, at least halfway in the front-rear direction of the vehicle Has a curved portion protruding downward from the vehicle, and at least one through hole is formed in the curved portion.

  Since the under cover has a curved portion that protrudes downward, the wind flowing through the lower surface of the cover (curved portion) has a higher flow velocity than the wind flowing through the upper side (inside) of the cover while the vehicle is running. It becomes. Therefore, a pressure difference is effectively generated between the lower side and the upper side of the under cover, and the air pressure is lower (that is, negative pressure) relative to the upper side of the lower side of the cover. As a result, negative pressure acts on the underside of the undercover, so that the air on the upper side (inside) of the cover is sucked out to the lower side (outside) through the through hole, and the heat in the cover is effectively discharged. Can do. That is, exhaust heat in the undercover is promoted. Therefore, the cooling efficiency in the under cover can be enhanced, and the heat source disposed on the upper side (inside) of the cover can be efficiently cooled. Examples of the heat source include an engine, a transmission, and an exhaust pipe.

  Moreover, since the air in the under cover is sucked out by the action of the negative pressure, heat is effectively discharged without increasing the size of the through hole. Therefore, it is not necessary to enlarge the through hole, and the device such as the engine can be sufficiently protected from the stepping stone and the water splash by the under cover.

It is the schematic perspective view which looked at the vehicle by which the under cover concerning Example 1 was arrange | positioned from the lower side. FIG. 3 is a schematic perspective view illustrating an under cover according to the first embodiment. It is a schematic side sectional view of the undercover of Example 1, and schematically shows the flow of wind in the undercover.

  Hereinafter, a specific example of an undercover according to an embodiment of the present invention will be described with reference to the drawings. The same reference numerals in the figure indicate the same names. In the following description, “front”, “rear”, “left”, “right”, “upper”, and “lower” mean the front of the vehicle as “front” and the direction based on this. In the figure, FR is the front in the vehicle front-rear direction, RR is the rear, LH is the left in the vehicle left-right direction (vehicle width direction), RH is the right, UP is the vehicle up-down direction, and LWR is the bottom.

[Example 1]
(vehicle)
A vehicle 100 shown in FIG. 1 includes a frame (chassis portion) 110 and a vehicle body (body portion) 120 having a cabin 121 and a loading platform 122, and the vehicle body 120 is supported by the frame 110. In the vehicle 100, devices such as an engine 130 (see FIG. 3), a transmission, and an exhaust pipe are disposed under the floor of the vehicle body 120 (under the floor panel 125). In this example, the vehicle 100 is a cab-over type (full cab type) automobile (truck), and the engine is located near the center of the vehicle 100 in the front-rear direction, specifically between the passenger compartment 121 and the loading platform 122 (so-called midship). ). The frame 110 has a pair of left and right side members 111 extending in the front-rear direction of the vehicle 100 and a cross member 112 that connects the side members 111 to each other. The engine 130 shown in FIG. 3 is supported on a cross member (not shown) that is placed between the left and right side members 111 below the floor panel. An under cover 10 (engine under cover) is disposed below the vehicle 100 so as to cover the lower part of the engine.

(undercover)
As shown in FIGS. 1 to 3, the under cover 10 extends in the front-rear direction of the vehicle 100 and covers a body portion 11 that covers an underfloor region where the engine 130 is disposed, and sides provided on both left and right sides of the body portion 11. Side support portion 12. The main body part 11 and the side support part 12 of the under cover 10 are formed of a thin plate material such as resin or metal, and are integrally formed in this example.

  The main body 11 is a portion that covers the lower part of the engine, and has a curved portion that protrudes downward at least halfway in the front-rear direction when viewed from the side. In this example, the main body portion 11 has a shape that is curved downward over the entire front-rear direction, the lower surface is formed in a substantially arc shape, and the whole is a curved portion. The main body 11 has a rectangular shape having an area covering the entire area of the lower surface of the engine when viewed from below.

  The main body (curved portion) 11 is formed with at least one through hole 13 penetrating from the upper surface to the lower surface. In this example, a plurality of through holes 13 are formed side by side in the front-rear direction of the main body 11. The magnitude | size of the through-hole 13 is a magnitude | size which can suppress intrusion of a stepping stone or a water splash. The shape of the through-hole 13 is a long hole that is long in the width direction, but is not limited thereto, and may be, for example, a round hole or a square hole. The number and position of the through holes 13 can be set as appropriate. For example, the through holes 13 may be arranged in parallel in the width direction of the main body 11.

  The side support portion 12 is a portion that stands upward from the left and right sides of the main body portion 11, and the main body portion 11 is a lower portion of the vehicle 100 (a virtual surface parallel to the lower surface of the side member 111 (see FIG. 3)). This surface is called “the lower surface of the vehicle”) and is supported with a certain space. A flange portion 14 is formed at the upper end portion of the side support portion 12 by bending outward in the width direction into an L shape. The under cover 10 is attached to the lower side of the vehicle 100 by fastening the flange portions 14 of the left and right side support portions 12 to the lower surfaces of the left and right side members 111 of the frame 110 with bolts or the like.

  The front end portion and the rear end portion of the under cover 10 are formed with an intake port 21 for taking in the traveling wind and a discharge port 22 for discharging the taken traveling wind while the vehicle 100 travels in the forward direction. In this example, gaps are formed between the front side and the rear side of the under cover 10 and the lower surface of the vehicle, and each gap is an opening, and the gap between the front side of the cover 10 and the lower surface of the vehicle is an intake port. 21, a gap between the rear side of the cover 10 and the lower surface of the vehicle is a discharge port 22.

  Next, an image of the flow of the traveling wind that flows under the floor of the vehicle 100 during traveling of the vehicle 100 equipped with the under cover 10 will be described mainly with reference to FIG. A traveling wind (indicated by a thin line in the figure) flowing under the vehicle is divided by the under cover 10 into a wind W1 that passes under the under cover 10 and a wind W2 that passes over the under cover 10. The wind W1 passing through the lower side of the under cover 10 flows from the front to the rear along the lower surface (curved portion) of the under cover 10. On the other hand, the wind W <b> 2 passing through the upper side of the under cover 10 is taken in from the front intake port 21 of the under cover 10, flows linearly on the upper side (inside) of the under cover 10, and is discharged from the rear discharge port 22. Is done. Since the wind W1 flows along the arcuate curved portion, the flow velocity V1 of the wind W1 becomes larger than the flow velocity V2 of the wind W2 (V1> V2), and the pressure P1 below the under cover 10 is on the upper side. Becomes smaller than the atmospheric pressure P2 (P1 <P2). As a result, a negative pressure acts on the lower side of the under cover 10, thereby causing a flow of air flowing from the upper side (inner side) of the under cover 10 to the lower side (outer side) through the through hole 13 (indicated by a dotted line in the figure). ) Occurs, and the air in the undercover 10 is sucked out.

<Effect>
The under cover of Example 1 mentioned above can have the following effects.

  (1) Since the under cover 10 has a curved portion that protrudes downward, the velocity of the wind flowing through the lower surface of the curved portion of the cover 10 is higher than that flowing through the upper side (inside) of the cover 10 during traveling of the vehicle. Becomes large, a pressure difference of air occurs between the lower side and the upper side of the cover 10, and the lower side of the cover 10 becomes a negative pressure. As a result, the air inside the cover 10 can be effectively discharged by the air on the upper side (inside) of the cover 10 being sucked out to the lower side (outside) through the through-hole 13 by the action of the negative pressure. Therefore, exhaust heat in the under cover 10 is promoted, the cooling efficiency in the cover 10 can be increased, and a heat source such as the engine 130 disposed on the upper side (inside) of the cover 10 can be efficiently cooled. Therefore, when the under cover 10 is mounted on the vehicle 100, a sufficient cooling effect can be obtained without enlarging the grille, bumper opening, etc., or increasing the size of the radiator fan. This does not cause an increase in weight or cost. This is particularly effective when applied to a cab-over type small vehicle whose cooling performance is likely to deteriorate.

  Heat is effectively discharged from the through-hole 13 by sucking out the air in the undercover 10 by the action of the negative pressure. Although it is conceivable to enlarge the through-hole 13 so that the heat in the cover 10 can be easily released, in that case, there is a possibility that it cannot be sufficiently protected from a stepping stone or water splash during traveling. Since the negative pressure is used to suck out the heat in the under cover 10, a sufficient cooling effect can be obtained without increasing the size of the through hole 13. There will be no decline. Further, the through hole 13 also functions as a drain hole when water enters the under cover 10.

  In addition, when the vehicle 100 travels on a flooded road having a deeper water level (for example, 600 mm) than the lower surface of the under cover 10, water flows along the lower surface (curved surface) of the under cover 10. Resistance can be reduced.

  The conventional under cover has a rectangular box shape, and a side cross-sectional shape is a substantially square bracket shape. On the other hand, the under cover 10 has a substantially round bracket shape in which the side cross-sectional shape is curved downward in the entire front-rear direction, and therefore, compared to the conventional under cover, the under cover 10 is rearward from the front end along the front-rear direction. Since the cross-sectional length to the end is shortened, the weight can be reduced.

  In the first embodiment, as illustrated in FIG. 3, the side cross-sectional shape of the curved portion of the under cover 10 (main body portion 11) has been described as a substantially arc shape, but the embodiment is not limited thereto. The shape of the curved portion is such that, in the vehicle traveling state, the traveling wind flowing along the lower surface of the under cover 10 has a higher flow velocity than the traveling wind flowing on the upper side, and the lower side of the under cover 10 has a negative pressure with respect to the upper side. Any shape can be used. Examples of the shape other than the arc shape include a shape in which an airfoil (wing cross-sectional shape) is turned upside down, a semi-spindle shape, a semi-teardrop shape, and an elliptic arc shape.

  The present invention is not limited to these exemplifications, is shown by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

  The under cover of the present invention can be suitably used for a vehicle under cover that is disposed on the lower side of a vehicle and covers a lower portion of an engine or the like.

DESCRIPTION OF SYMBOLS 100 Vehicle 110 Frame 111 Side member 112 Cross member 120 Car body 121 Guest room 122 Loading platform 125 Floor panel 130 Engine 10 Under cover 11 Main body part 12 Side support part 13 Through hole 14 Flange part 21 Inlet 22 Outlet

Claims (1)

An under cover that is disposed under the vehicle and covers the lower part of the heat source,
When viewed from the side of the vehicle, it has a curved portion projecting downward of the vehicle at least halfway in the front-rear direction of the vehicle,
An under cover in which at least one through hole is formed in the curved portion.

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