JP2012126297A - Automobile cooling unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automobile cooling unit, capable of efficiently fluidizing cooling air flowing into an engine room during running, decreasing an air resistance coefficient of the vehicle, and moreover, increasing an engine cooling effect.SOLUTION: Cooling air Fa flows into an inflow ports 19, 21 for cooling air formed on a front wall f of a vehicle 2, wherein a heat exchanger 16 is provided on a rear side of the inflow ports. Then, an automobile cooling unit makes the cooling air Fa, which has passed through the heat exchanger 16, flow downward as a downward cooling air Fd along a front wall 152 of an engine body 151 and then flow into a rear side of an engine room 4. The automobile cooling unit includes a duct 26 having: a front opening end 261 connected to a front lower intake port 24 that is separately formed below the inflow ports 19, 21; and a rear opening end 262 formed to eject a backward flow Fb, toward a position in a space E between the heat exchanger 16 and the engine body and the position below a lower end of the engine body.

Description

  The present invention relates to an engine mounted in an engine room of an automobile and a cooling device for an automobile that cools a heat exchanger in front of the engine with cooling air flowing into the engine room.

  In a vehicle body, if there are protrusions, indentations, etc., air will not flow smoothly on the surface of the vehicle during travel, air vortices will be generated, and air resistance will increase. When the air resistance increases in this way, running stability is impaired and fuel consumption increases. Therefore, it is desirable to reduce the air resistance as much as possible. For this reason, in consideration of aerodynamic performance, a vehicle body with as little air resistance as possible is designed.

For example, when a car travels, the traveling wind directed toward the underside of the vehicle body collides with the engine body etc. exposed to the lower part of the engine room at the front part of the vehicle body, and the air flow is disturbed. Increases air resistance. Therefore, in order to reduce the air resistance at the lower part of the vehicle body, in general, the lower surface of the engine room is covered with a plate-like undercover so that the engine body is not exposed at the lower part of the vehicle body, the lower part of the vehicle body is flattened, and the air resistance is reduced. Processing for reducing the coefficient [CD] is performed.
By the way, a cooling air intake is provided in the front of the body of an automobile, and the outside air that has flowed into the vehicle is taken into the engine room as cooling air, thereby cooling the engine heat exchanger and the engine body behind it. ing.

  For example, Patent Document 1 (Japanese Patent Application Laid-Open No. 2010-111277) discloses a first outside air introduction unit that introduces outside air to both the upper and lower radiators that form part of each cooling system of the engine and the motor during traveling. And a second outside air introduction section for introducing outside air into the engine body during traveling, and by adjusting the amount of outside air introduced in each of the first and second outside air introduction sections with a shutter plate provided respectively, Cooling with cooling water by two radiators and cooling of the engine body are appropriately performed. Furthermore, after the cooling air passes through the upper and lower radiators by adjusting the opening and closing of the shutter plate, it collides with the forward wall of the engine body and changes the flow direction downward and to the left and right, and then escapes to the rear of the engine room. The flow rate is adjusted and the cooling air in the engine room is adjusted.

  On the other hand, when the lower surface of the engine room is covered with an under cover in order to reduce the flow resistance in the lower part of the engine room, the under cover is not removed when cooling air flows through the engine room and is discharged to the rear of the engine room. It is necessary to consider not to increase the flow resistance. Therefore, in attaching the under cover, avoid covering the entire lower surface of the engine room 41. For example, as in the under cover disclosed in Patent Document 2 (Japanese Patent No. 4076099), the front edge of the front wall of the vehicle has a front edge. Combined, the rear edge extends to the vicinity of a position immediately below the front end of the engine body, and the rear thereof is opened to facilitate the discharge of cooling air to the lower rear of the engine room. Here, a structure is shown in which the air behind the cooling fan is restrained from flowing again to the front negative pressure side.

JP 2010-111277 A Japanese Patent No. 4076099

  By the way, the cooling air that has flowed into the engine room through the cooling air intake at the front of the car body collides with the forward facing wall of the engine body, and further changes the flow direction downward and to the left and right of the engine, and then escapes to the rear of the engine room. Go. At that time, the downward cooling air collides with the cooling air flowing in from the cooling air intake at the lower part of the front of the car body, vortex is generated at the interference part where both air currents collide, and the flow resistance increases, resulting in this The cooling air volume is reduced and the cooling efficiency is lowered. Moreover, due to the increase in flow resistance, the air resistance coefficient increases, which causes a reduction in fuel consumption.

Furthermore, in the vicinity of the lower front side of the engine body, the downward cooling air and the cooling air from the cooling air intake at the lower front face collide with each other, and then the combined cooling air flows further to the rear, There is also a problem that it further collides with the under cover lower side cooling air that has flowed on the lower surface side, resulting in further increase in flow resistance and increase in air resistance coefficient.
In Cited Document 1, the amount of outside air introduced from the cooling air intake can be adjusted by the shutter plate during traveling, but the flow resistance of the cooling air flowing into the engine room is suppressed, and the cooling air flows from the engine room. The function of discharging without increasing the resistance is not disclosed. In the cited document 2, the flow resistance of the cooling air in the engine room cannot be suppressed only by suppressing the flow of the cooling air flowing again into the negative pressure side of the cooling fan.

  A main object of the present invention is to provide a cooling device for an automobile that can efficiently flow cooling air that has flowed into an engine room during traveling, lower the air resistance coefficient of the vehicle, and enhance the engine cooling effect. is there.

  In order to achieve the above object, an invention according to claim 1 is directed to a heat exchanger that flows into an inlet of cooling air formed on a front wall of a vehicle and is provided behind the inlet, and a rear of the heat exchanger. A cooling device for an automobile provided with an engine body, wherein a front opening end is connected to a front lower intake separately formed below the inlet, and a rear opening end is connected to the heat exchanger and the engine body. And a duct formed to eject a backward flow toward a position below the lower end of the engine body.

  According to a second aspect of the present invention, there is provided a cooling apparatus for an automobile according to the first aspect, further comprising an under cover that is coupled to a lower end of a front wall of the vehicle and covers a front lower portion of the engine room, and a rear end of the under cover. Is formed so as to be located behind the rear opening end.

  The invention according to claim 3 is the automobile cooling device according to claim 1 or 2, wherein the width of the duct in the vehicle width direction is set to be equal to the width of the heat exchanger in the vehicle width direction. And

  According to a fourth aspect of the present invention, in the automobile cooling apparatus according to the first, second, or third aspect, the duct is formed as a plurality of divided ducts arranged in parallel in the vehicle width direction.

  According to the invention of claim 1, by causing the cooling air to be ejected as a backward flow from the rear opening end of the duct, the flow velocity of the ejected cooling air is higher than its surroundings and negative pressure is generated. The downward cooling air that flows down along the front wall of the engine body through the heat exchanger toward the engine body is drawn in and merged to reduce the resistance. Since it can be made to flow smoothly, the cooling air flow rate can be increased to increase the cooling efficiency of the heat exchanger and the engine body. In addition, since the flow resistance when the backward flow draws the cooling air flowing downward and merges is relatively small, the air resistance coefficient of the vehicle can be reduced and fuel consumption can be reduced.

  According to the second aspect of the present invention, the downward cooling air flowing down along the front wall of the engine body is drawn into and merged with the backward flow ejected from the rear opening end portion of the duct, and after passing through the merge position The cooling air is guided to the rear of the vehicle body along the upper surface of the rear end of the under cover, and the cooling air that has flowed along the upper surface of the rear end of the under cover is directed rearward in the longitudinal direction of the vehicle substantially parallel to the lower surface of the under cover. The flow resistance can be relatively small and merged behind the rear end of the airflow and the undercover, and the air resistance coefficient of the vehicle can be further reduced in this respect.

  According to the invention of claim 3, the flow width in the vehicle width direction of the downward cooling air after passing through the heat exchanger and the backward flow from the duct are made substantially equal. It can function to almost surely draw and join, and the flow resistance can be reduced in the entire vehicle width direction, and the air resistance coefficient of the vehicle can be reliably reduced in this respect.

  According to invention of Claim 4, the rigidity of each division | segmentation duct increases by using a some division | segmentation duct, and shape retention property and durability can be ensured.

It is a principal part notched side view of the front part of the vehicle equipped with the cooling device of the motor vehicle of 1st Embodiment of this invention. It is a schematic notch top view of the front part of the vehicle of FIG. It is a front view of the front surface of the vehicle of FIG. The duct used with the cooling device of the car of Drawing 1 is shown, (a) is an enlarged plan view and (b) is an enlarged front view. The duct used by other embodiment of this invention is shown, (a) is an enlarged plan view, (b) is an enlarged front view. It is a front notch bottom view of the vehicle of FIG. It is a diagram explaining the characteristic of the air resistance coefficient "CD" of the cooling device of the motor vehicle of FIG.

1 and 2 show a front vehicle body of a vehicle 2 to which an automobile cooling device 1 according to a first embodiment of the present invention is applied.
In the front body of the vehicle 2 shown in FIGS. 1 and 2, an engine room 4 is formed behind the front surface f of the vehicle, and a vehicle compartment 6 is formed behind the engine room 4 via a dash panel 5. . The engine room 4 is covered with a hood 7 at the top, left and right sides with left and right front fenders 8 (see FIG. 3), and a front face f with a front mask 9 and a bumper 11. Further, the lower front side of the engine room 4 is covered with an under cover 3 connected to the lower end of the bumper 11. As shown in FIGS. 1 and 2, the left and right side members 12, the front end cross member 13, and the front cross member 14 that extend in the front-rear direction are disposed in the lower portion of the engine room 4. Thus, the rigidity of the engine room 4 is ensured.

  The bumper 11 includes a resin bumper facing 111 extending in the width direction of the vehicle body (perpendicular to the plane of FIG. 1), a reinforcement 112 extending in the vehicle width direction, and a reinforcement 112 at the distal ends of the left and right side members 12 and 12. A bumper bracket (not shown) to be connected is provided.

As shown in FIGS. 1 and 2, various traveling operation devices such as an engine 15 and a rotational force transmission system are provided in the engine room 4, and are not shown in front of the engine 15, particularly immediately after the front surface f. A condenser 17 connected to the cooling device and a radiator 18 through which the cooling water of the engine 15 circulates are arranged in parallel in the front-rear direction with their longitudinal directions directed in the vehicle width direction Y (perpendicular to the plane of FIG. 1). .
A pair of forward-facing upstream inlets 19 are formed on the front mask 9 disposed at the upper part of the front surface f of the vehicle 2 on the left and right sides, and the bumper 11 disposed on the lower side has front downstream inlets 21 in the entire lower central part. It is formed. A plurality of rectifying grills 191 and 211 are arranged in parallel in the vertical direction immediately after the forward upstream inlet 19 and the front downstream inlet 21, respectively, thereby ensuring aesthetics and air permeability. The rectifying grills 191 and 211 can be opened and closed by an actuator (not shown), and the opening and closing rates of the forward upstream inlet 19 and the front downstream inlet 21 can be adjusted.

A condenser 17, which is a heat exchanger 16, a radiator 18, and a cooling fan 23 are arranged behind the forward upstream inlet 19 and the front downstream inlet 21 immediately below. The condenser 17 and the radiator 18 are supported by a front end cross member 13 which is a part of the front base frame of the engine room 4 via a rectangular frame-like support frame 22, and the cooling fan 23 is connected to the condenser 17 and the radiator. 18 is supported by the support frame 22 behind. Further, the engine 15 is disposed behind the cooling fan 23 through a space E having a predetermined width with its longitudinal direction directed in the vehicle width direction Y. (See Figure 2)
Here, the traveling wind Fo flows into the forward upstream inlet 19 and the front downstream inlet 21 when the vehicle travels and the cooling fan is driven, and the cooling wind Fa that has passed through the condenser 17 and the radiator 18 flows into the space E. Further, the cooling air abuts on the forward wall 152 of the main body 151 of the engine 15 and changes its direction downward, and flows downward as the cooling air Fd to the lower end side of the engine main body 151. Since the engine body 151 and the like are cooled by the downward cooling air Fd, the cooling efficiency of the engine increases as the flow rate of the downward cooling air Fd increases. Here, focusing on this point, means for further reducing the flow resistance of the downward cooling air Fd and increasing the flow rate will be described later.
As shown in FIGS. 1 and 6, the lower end of the bumper 11 is formed with a lower end edge 111 that is continuously curved in the vehicle width direction Y, and a front edge portion 301 of the under cover 3 in the entire vehicle width direction Y is overlapped therewith. The front edge portion 301 is screwed to a plurality of stop plates 112 extending from the lower end edge 111.

As shown in FIG. 6, the undercover 3 here is a press-formed product of a steel plate, and a plurality of beads b extending in the front-rear direction are formed to maintain shape retention. The under cover 3 may be resin-molded.
Here, the under cover 3 covers the entire lower part of the engine room 4, and the lower surface 303 is formed to be gently curved, whereby the running wind Fo smoothly flows backward through the lower area of the engine room. Functions as a guide plate. Further, the under cover 3 is formed such that a rear end edge 302 extends to a central position immediately below the oil pan 153 at the lower end of the engine body 151. As will be described later, the rear edge 302 is formed so as to be positioned behind the rear opening end 262 of the duct 26.

As shown in FIG. 1, a front lower intake port 24 that is positioned below the front downstream inlet 21 and is flat in the vehicle width direction Y is separately formed below the bumper facing 111.
As shown in FIG. 3, the front lower intake 24 is formed such that the lateral width Ly in the vehicle width direction Y is substantially equal to the lateral width of the condenser 17 and the radiator 18 as heat exchangers, and has a height h (FIGS. 4 and 5). Is formed relatively small.
As shown in FIG. 1, a duct 26 is provided between the under cover 3 and the support frame 22 and sucks the traveling wind Fo through the front lower intake 24 and blows it out to the lower end front position of the engine body 151.

As shown in FIG. 1, the duct 26 has a front opening end 261 (see FIG. 4) connected to the front lower intake 24, and a rear opening end 262 (see FIG. 4) is connected to a cooling fan (heat exchanger 16). ) And the engine body, and extends from the lower end of the engine body to the front side (see FIG. 1).
The duct 26 is resin-molded, and the whole is attached and supported to the support frame 22 via a bracket 27 (see FIG. 1). As shown in FIG. 4, the duct 26 is formed as divided ducts 26a, 26b, and 26c arranged in parallel by being divided into three in the width Ly direction, thereby facilitating molding, maintaining shape rigidity, and durability. Is secured.

Each rear opening end 262 of each of the divided ducts 26 a, 26 b, and 26 c is formed to extend to a position directly below the space E and below the lower end of the engine main body 151. Moreover, when the blowing air Fb that is a backward flow is blown out from the outlet 26ex of the rear opening end 262 of each of the divided ducts 26a, 26b, and 26c, as shown in FIG. 1, the center line Lc of the blowing air Fb Is formed so as to face directly below the lower end of the rear engine main body 151. In addition, the code | symbol gp in FIG. 4 shows the baffle plate, and the straightness of the blowing wind Fb from the jet nozzle 26ex is hold | maintained by these. For this reason, straightness can be imparted to the blown air Fb from the jet outlet 26ex, the wind speed can be made faster than the surrounding air flow, and negative pressure in the flow region of the blown air Fb can be promoted.
Instead of the duct 26, a duct 26d may be integrally formed as shown in FIG.

In this case, the duct 26d is provided with a plurality of partition walls gp1, thereby giving straightness to the blown air Fb and ensuring shape retention. In this case, the configuration can be simplified.
Further, as shown in FIG. 1, the under cover 3 is provided immediately below the duct 26, and the blown air Fb from the outlet 26 ex is rearwardly between the position immediately below the lower end of the engine body 151 and the upper surface of the under cover 3. To flow.
Here, the rear end edge 302 of the under cover 3 is formed to extend to a central position immediately below the oil pan 153 of the engine body 151, so that the blown air Fb that has passed above the rear end edge 302 is generated at the rear end edge 302. The traveling wind Fo that has passed below can be merged at the merging portion C <b> 2, and can flow out directly behind the front cross member 14.

Next, the operation of the automobile cooling device 1 of FIG. 1 will be described. When the vehicle 2 moves forward, the traveling wind Fo flows into the front upstream inlet 19 and the front downstream inlet 21 formed in a part of the front mask 9 and the bumper 11, passes through the heat exchanger 16 as the cooling wind Fa, and the space E As a result, the heat dissipation of the capacitor 17 and the radiator 18 is promoted to keep the cooling efficiency high and the cooling process is performed.
Further, the cooling air Fa contacts the forward wall 152 of the main body 151 of the engine 15 and changes its direction downward, and flows downward as the cooling air Fd to the lower end side of the engine main body 151, thereby efficiently cooling the engine main body 151 and the like. To do.
On the other hand, the traveling wind Fo that has flowed into the duct 26 from the front lower intake 24 of the bumper facing 111 flows backward between the bottom of the engine body 151 and the upper surface of the under cover 3 in the direction of the center line Lc.

The jet wind Fb from the jet outlet 26ex of the duct 26 has a straight traveling property, the wind speed thereof is faster than the surrounding air flow, and the flow area of the jet wind Fb becomes negative pressure. For this reason, the downward cooling air Fd turning downward along the forward wall 152 of the engine main body 151 collides with the blowout air Fb from the jet outlet 26ex in a direction almost orthogonal.
At this time, the downward cooling air Fd can be drawn into and merged with the blown-down air Fb having a negative pressure, and the flow resistance at the confluence portion C1 of the blowing air Fb and the downward cooling air Fd can be greatly reduced. In this way, it is possible to increase the cooling air flow rate and contribute to improving the cooling efficiency of the heat exchanger 16 and the engine main body 151.

Further, the blown air Fb that has passed through the merging portion C <b> 1 flows rearward along the upper surface of the under cover 3. Here, the rear end edge 302 of the under cover 3 extends to the central position immediately below the oil pan 153 of the engine main body 151, that is, extends to be positioned behind the rear opening end 262 of the duct 26. Therefore, the blown air Fb that has passed over the rear end edge 302 merges with the traveling air Fo that has passed under the rear end edge 302 at the junction C2.
At this time, the jet air Fb on the upper side of the under cover 3 has a lower flow velocity than the running wind Fo on the lower side of the under cover 3, so that the negative pressure of the running wind Fo on the lower side of the upper jet wind Fb. Is progressing. For this reason, the upper jet wind Fb is attracted to and merges with the lower travel wind Fo, but since both flow directions are substantially the same, the merge portion C2 can smoothly merge and the flow resistance at the time of collision is low.

  Thus, in the automobile cooling device 1 of FIG. 1, the flow resistance at the junction C1 of the blown air Fb and the downward cooling air Fd can be greatly reduced, and further, the flow of the blown air Fb and the lower traveling wind Fo is reduced. Since the merging at the merging portion C2 can be merged in a smooth state with little flow resistance at the time of collision, the cooling air Fa1 that passes through the heat exchanger 16 and a forward wall 152 flows downward with a part of the traveling air Fo The cooling air flow rate of the downward cooling air Fd can be increased. Moreover, since the traveling wind Fo flowing into the duct 26 from the front lower intake 24 blows out the blown air Fb from the outlet 26ex in a straight traveling state, the cooling air flow rate can be increased from these points, and the heat exchanger 16 and the engine main body can be increased. This can contribute to increase the cooling efficiency of 151. Moreover, it can contribute to reducing the air resistance coefficient of the vehicle and reducing fuel consumption.

In FIG. 7, the air resistance coefficient of the cooling air and the radiator 18 before the application of the automobile cooling device 1 of the present invention (□ in FIG. 7) and after application (■ in FIG. 7). It is a diagram which shows an example of the displacement of the passing wind speed [m / sec] of the cooling air Fa of the front part.
Here, before the automobile cooling device 1 is applied (indicated by □ in FIG. 7), the bumper facing 111 is not provided with the front lower intake 24 or the duct 26 as shown in FIGS. The cooling air ΔCD at that time was (0.012), and the passing air speed of the front cooling air Fa of the radiator 18 was {4.75 [m / sec]}. On the other hand, the cooling air ΔCD in a state in which the front lower intake 24 and the duct 26 are arranged on the bumper facing 111 after application (marked with ■ in FIG. 7) as shown in FIGS. (0.006), the passing air speed of the front cooling air Fa of the radiator 18 has reached the state of {4.8 [m / sec]}.

  As can be seen, in the state where the present invention in which the front lower intake port 24 and the duct 26 as shown in FIGS. 1 and 3 are applied to the bumper facing 111 is applied, the cooling air ΔCD is (0 .012) to (0.006), the value of the cooling air ΔCD was greatly reduced. From this point, it became clear that the cooling efficiency of the heat exchanger 16 and the engine main body 151 can be increased, and further, the air resistance coefficient of the vehicle can be lowered and the fuel consumption can be reduced.

As described above, the rear end edge 302 of the under cover 3 is formed to extend to the central position immediately below the oil pan 153 of the engine body 151. However, as shown by a two-dot chain line in FIG. 14 may be extended to a position immediately after the front cross member 14 with a predetermined amount of gap t1 held. In this case, the junction C2 ′ between the blowing wind Fb and the traveling wind Fo is positioned behind the front cross member 14, so that further increase in flow resistance due to the influence of the front cross member 14 can be surely eliminated. In addition, the air resistance coefficient of the vehicle can be reduced to reduce fuel consumption.
Although the embodiment of the present invention has been described above, the present invention is not limited to the embodiment, and various modifications can be made without departing from the spirit of the present invention.

DESCRIPTION OF SYMBOLS 1 Automobile cooling device 2 Vehicle 4 Engine room 9 Front mask 11 Bumper 15 Engine 151 Engine body 152 Front wall 19, 21 Inlet 16 Heat exchanger 17 Condenser 18 Radiator 23 Cooling fan 24 Front lower intake 26 Duct 261 Front opening End portion 262 Rear opening end portion 26ex Spout 26a, 26b, 26c Split duct f Front wall E Space between cooling fan and engine body Fa Cooling air Fb Blowing air (rearward flow)
Fd Downward cooling air Fo Traveling air Ly Horizontal width X Front-rear direction Y Vehicle width direction C1, C2 Junction

Claims (4)

In a cooling apparatus for an automobile, comprising: a heat exchanger that flows into a front inlet formed on a front wall of a vehicle and is provided behind the front inlet; and an engine main body that is provided behind the heat exchanger.
A front opening end is connected to a front lower intake separately formed below the front inlet, and a rear opening end is between the heat exchanger and the engine body and below the lower end of the engine body. A cooling apparatus for an automobile, comprising a duct formed to eject a backward flow toward the position.   A front end edge is coupled to a lower end of the front wall of the vehicle, and an under cover is provided to cover a front lower portion of the engine room, and a rear end of the under cover is formed to be located rearward of the rear opening end. The automobile cooling device according to claim 1, wherein   The vehicle cooling device according to claim 1 or 2, wherein the width of the duct in the vehicle width direction is set to be equal to the width of the heat exchanger in the vehicle width direction.   4. The automobile cooling apparatus according to claim 1, wherein the duct is formed as a plurality of divided ducts arranged in parallel in the vehicle width direction.

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