JP2011102068A - Cooling air introducing structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a cooling air introducing structure in which a heat exchanger can demonstrates the necessary cooling performance when a vehicle runs at the high speed and at the low speed, respectively. <P>SOLUTION: The cooling air introducing structure 10 includes: a cooling unit 22 that contains the air-cooled heat exchanger installed in a front of a floor tunnel 20; a first ventilation passage 42 formed backward in the floor tunnel 20 with respective to the cooling unit 22 so that a running air that has passed the cooling unit 22 is led thereinto; a second ventilation passage 44 formed backward in the floor tunnel 20 with respective to the cooling unit 22 independently of the first ventilation passage 42; and a cross flow fan 50 installed in the second ventilation passage 44. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a cooling air introduction structure for guiding cooling air to an air-cooled heat exchanger.

  There is known a cooling module in which an axial fan is disposed behind a radiator and a condenser, and a flow path is formed between the fan and the radiator and condenser by a shroud (see, for example, Patent Documents 1 and 2). In addition, in a configuration in which a plurality of radiators are provided, an air guide structure is known in which an air guide path behind the radiator is vertically divided (see, for example, Patent Document 3).

JP 2007-056717 A JP 2008-019741 A JP 2007-099194 A

  However, in the above-described technology, the fan becomes a ventilation resistance when the vehicle is traveling at a high speed, so there is a concern that the amount of ventilation of the radiator is small with respect to the engine load and the cooling efficiency is lowered.

  It is an object of the present invention to obtain a cooling air introduction structure that allows a heat exchanger to exhibit a required cooling performance each time a vehicle travels at a high speed and a low speed.

  The cooling wind introduction structure according to the first aspect of the present invention includes an air-cooled heat exchanger provided in a front portion of a floor tunnel in a vehicle front-rear direction, and a rearward direction of the vehicle in the front-rear direction with respect to the heat exchanger in the floor tunnel. In addition, the first ventilation path formed to guide the traveling wind that has passed through the heat exchanger, and the rear of the heat exchanger in the front-rear direction of the vehicle in the floor tunnel are independent of the first ventilation path. And a crossflow fan provided in the second ventilation path so that the axial direction coincides with the vehicle width direction.

  In the cooling air introduction structure according to claim 1, for example, when the vehicle travels at a high speed, the flow rate of the traveling air is large. Therefore, the traveling air exhausted from the first ventilation passage through the air-cooled heat exchanger has sufficient refrigerant. To be cooled. On the other hand, for example, when the vehicle is stopped or running at a low speed, an air flow (cooling air) that passes through the heat exchanger and is discharged from the second ventilation path is generated by operating the cross flow fan. The refrigerant is sufficiently cooled.

  And since the crossflow fan arrange | positioned so that an axial direction may substantially correspond to a vehicle width direction can suppress the dimension of a vehicle up-down direction, it becomes difficult to become resistance at the time of driving | running | working wind passing through the above-mentioned 1st ventilation path. It can be arranged. As a result, the traveling wind passes smoothly through the heat exchanger when the vehicle is traveling at high speed, and the cooling efficiency is improved as compared with the configuration using the axial fan. For this reason, in this cooling wind introduction structure, required cooling performance can be obtained when the vehicle travels at a high speed. On the other hand, when the vehicle is traveling at a low speed, the required cooling performance can be obtained by operating the cross flow fan.

  Thus, with the cooling air introduction structure according to the first aspect, the heat exchanger can exhibit the required cooling performance when the vehicle is traveling at a high speed and when the vehicle is traveling at a low speed.

  The cooling air introduction structure according to a second aspect of the invention is the cooling air introduction structure according to the first aspect, wherein the heat exchanger is positioned such that the upper part in the vehicle vertical direction is located on the front side in the vehicle longitudinal direction with respect to the lower part. It is inclined and the second ventilation path is arranged on the rear side in the vehicle longitudinal direction with respect to the lower part of the heat exchanger in the vehicle vertical direction.

  In the cooling air introduction structure according to claim 2, the cooling air passes through the heat exchanger along a direction substantially orthogonal to the inclination direction of the heat exchanger (in a diagonally upward and rearward direction). For this reason, the rear side with respect to the lower part of the heat exchanger is at a position deviated from at least a part of the path (range) of the air flow passing through the heat exchanger, and the second ventilation path (cross flow) provided at this position. The fan is less likely to resist ventilation against the running wind. Thereby, in this cooling wind introduction structure, the ventilation resistance at the time of high-speed driving | running | working of a vehicle further falls.

  The cooling air introduction structure according to a third aspect of the invention is the cooling air introduction structure according to the second aspect, wherein the heat exchanger is a heat exchanger for air with a refrigerant for cooling a drive source of the vehicle. And the first ventilation path is disposed above the second ventilation path in the vehicle vertical direction, and an opening / closing mechanism that opens and closes the first ventilation path, and the vehicle traveling speed exceeds a predetermined speed, or When the temperature of the refrigerant is lower than a predetermined temperature, the opening / closing mechanism and the cross flow fan are controlled so that the first flow path is opened and the cross flow fan is inactivated, and the traveling speed of the vehicle is When the speed is equal to or lower than the speed and the temperature of the refrigerant is equal to or higher than a predetermined temperature, the opening / closing mechanism and the cross flow fan are controlled so as to close the first ventilation path and operate the cross flow fan. And means, further comprising a.

  In the cooling air introduction structure according to the third aspect, when the vehicle travels at a high speed, the first ventilation path is opened by the opening / closing mechanism, and the traveling wind that has passed through the heat exchanger is guided to the first ventilation path. Since the 1st ventilation path is arrange | positioned above the 2nd ventilation path in a tunnel, the driving | running | working wind which passed the heat exchanger diagonally upwards and backwards as a cooling wind smoothly on the 1st ventilation path where the fan is not arrange | positioned. To pass through. On the other hand, when the temperature of the refrigerant is equal to or higher than a predetermined temperature when the vehicle is stopped or running at a low speed, the air flow generated by the cross flow fan that operates with the first ventilation path closed by the opening / closing mechanism is The heat exchanger passes through the second flow path. As a result, the refrigerant can be sufficiently cooled, for example, during low-speed running where running wind tends to be insufficient with respect to the refrigerant cooling request. When the vehicle is traveling at a low speed and the temperature of the refrigerant is lower than the predetermined temperature, the first ventilation path is opened by the opening / closing mechanism and the cross flow fan is deactivated. Thereby, when heat exchange with the refrigerant | coolant by driving | running | working wind is enough, a crossflow fan can be made into non-operation and energy consumption can be suppressed. That is, it is possible to achieve both cooling performance and energy saving.

  The cooling air introduction structure according to the invention of claim 4 is the cooling air introduction structure of claim 3, wherein the heat exchanger in the vehicle front-rear direction and the first ventilation path and the second ventilation path are A common ventilation path communicating with each of the first ventilation path and the second ventilation path is formed.

  In the cooling air introduction structure according to claim 4, since the common ventilation path is provided, when the vehicle travels at a relatively high speed, the first ventilation path when almost the entire air flow that has passed through the heat exchanger travels. In addition, when the cross flow fan is operated, it is guided to the second ventilation path. As a result, the required cooling performance can be ensured without depending on the size of the heat exchanger during both high speed running and low speed running.

  The cooling air introduction structure according to a fifth aspect of the invention is the cooling air introduction structure according to any one of the first to fourth aspects, wherein the heat exchanger, the cross flow fan, and the first ventilation are provided. The road and the ventilation path forming member forming the second ventilation path are modularized so that they can be attached to and detached from the vehicle body.

  In the cooling air introduction structure according to claim 5, since the heat exchanger, the cross flow fan, and the ventilation path forming member are modularized, it is compared with a structure in which each component is assembled independently to the vehicle body (floor tunnel). As a result, the assemblability is improved.

  The cooling air introduction structure according to the invention of claim 6 is the cooling air introduction structure according to any one of claims 1 to 5, wherein the heat exchanger cools a refrigerant for cooling the power unit. And at least one of a condenser constituting a refrigeration cycle of the air conditioner.

  In the cooling air introduction structure according to the sixth aspect, the required cooling air can be guided to the heat exchanger to at least one of the radiator and the condenser during both high speed running and low speed running.

  As described above, the cooling air introduction structure according to the present invention has an excellent effect that the heat exchanger can exhibit the required cooling performance when the vehicle is traveling at a high speed and when the vehicle is traveling at a low speed.

It is the partially cutaway side view which shows the principal part of the cooling wind introduction structure which concerns on embodiment of this invention. 1 is a side sectional view showing a front portion of an automobile to which a cooling wind introduction structure according to an embodiment of the present invention is applied. It is a sectional side view which shows the flow of the cooling air at the time of low speed driving | running | working of the cooling air introduction structure which concerns on embodiment of this invention. It is a sectional side view which shows the flow of the cooling air at the time of high speed driving | running | working of the cooling wind introduction structure which concerns on embodiment of this invention. It is a perspective view which shows the cooling module which comprises the cooling wind introduction structure which concerns on embodiment of this invention. It is the perspective view seen from the direction different from FIG. 5 which shows the cooling module which comprises the cooling wind introduction structure which concerns on embodiment of this invention. It is a flowchart which shows the control flow by cooling ECU which comprises the cooling wind introduction structure which concerns on embodiment of this invention.

  A cooling air introduction structure 10 according to an embodiment of the present invention will be described with reference to FIGS. First, the configuration of the vehicle body 11 of the automobile A to which the cooling air introduction structure 10 is applied will be described, and then the specific configuration of the cooling air introduction structure 10 will be described. Note that an arrow FR appropriately shown in the drawing indicates a forward direction in the vehicle longitudinal direction, an arrow UP indicates an upward direction in the vehicle vertical direction, and an arrow W indicates a vehicle width direction.

(Schematic structure of the car body)
FIG. 2 is a schematic sectional side view of the front portion of the automobile A to which the cooling air introduction structure 10 is applied. As shown in this figure, a power unit chamber 14 in which a power unit 12 is disposed is disposed on the front end side of the vehicle A in the vehicle longitudinal direction. The power unit 12 in this embodiment includes an engine that is an internal combustion engine and an electric motor as drive sources for driving the front wheel Wf. Therefore, the automobile A is a hybrid automobile having two drive sources.

  Specifically, the power unit includes a horizontal engine having a crankshaft along the vehicle width direction and a transaxle connected to the engine so as to be able to transmit power. The transaxle includes an electric motor, a generator (not shown), a power split mechanism, a transmission such as a continuously variable transmission, and the like. In this embodiment, the transaxle includes, for example, an electric motor, a generator, and an inverter electrically connected to a battery. Therefore, the power unit according to this embodiment can also be regarded as a power plant.

  As described above, the power unit chamber 14 in which the power unit 12 including the engine that is an internal combustion engine is disposed can be regarded as a so-called engine room. A rear end portion of the power unit chamber 14 in the vehicle front-rear direction is defined by a dash panel 16 that separates from the vehicle compartment C. The dash panel 16 is joined to the front end of the floor panel 18 in the vehicle longitudinal direction. At the center of the floor panel 18 in the vehicle width direction, a floor tunnel 20 having a “U” shape that is elongated in the vehicle longitudinal direction and opens downward in the vehicle vertical direction in a cross-sectional view perpendicular to the longitudinal direction. Is formed.

  In the automobile A to which the cooling air introduction structure 10 is applied, the cooling unit 22 is provided so as to close the front opening end 20A of the floor tunnel 20 in the vehicle front-rear direction. Therefore, in this embodiment, the cooling unit 22 is disposed on the rear side in the vehicle front-rear direction with respect to the power unit 12. The cooling unit 22 is a radiator that is an air-cooled heat exchanger that circulates cooling water between the power unit 12 (engine and electric motor thereof) and cools the power unit 12, and an air conditioner (not shown). It is comprised including at least one (both in this embodiment) of the condenser (condenser) which is an air-cooled heat exchanger that constitutes.

  Hereinafter, the cooling air introduction structure 10 for guiding the cooling air that performs heat exchange with the refrigerant (cooling water circulating through the radiator, air conditioner refrigerant) to the cooling unit 22 will be described in detail.

(Configuration of cooling air introduction structure)
As shown in FIG. 2, the cooling air introduction structure 10 includes an under cover 24 that covers the power unit chamber 14 from below in the vehicle vertical direction. The under cover 24 is formed with a duct 26 for guiding the traveling wind flowing between the road surface R to the cooling unit 22 (in the floor tunnel 20). Further, the duct 26 is configured to function as a suction port for sucking air from under the floor of the automobile A when a cross flow fan 50 described later is operated.

  As shown in FIG. 1, the duct 26 has an inlet 26 </ b> A as an opening opened downward in the vehicle vertical direction in front of the vehicle in the vehicle longitudinal direction with respect to the floor tunnel 20, and immediately in the vehicle longitudinal direction with respect to the floor tunnel 20. And a lead-out port 26B opened rearward in the vehicle longitudinal direction. In the duct 26, the space between the inlet 26A and the outlet 26B is surrounded by a pair of left and right side walls 28 that face each other in the vehicle width direction, and a top wall 30 that connects the upper edges of the pair of side walls 28 in the vehicle vertical direction. The flow path is 26C.

  The cooling unit 22 (a cooling module 68 described later) is interposed between the front opening end 20A of the floor tunnel 20 and the outlet 26B of the duct 26 in a sealed state. That is, the duct 26 (between the automobile A and the road surface R) and the floor tunnel 20 are communicated with each other via the cooling unit 22 (the air-side flow path). The cooling unit 22 may be partly or entirely disposed at the front part in the floor tunnel 20, or may be partly or entirely disposed at the rear part in the duct 26. In other words, the cooling unit 22 only needs to be disposed in the middle of the space (air flow path) formed by the duct 26 and the floor tunnel 20.

  Further, in this embodiment, the cooling unit 22 is disposed so as to be inclined (forwardly inclined) so that the upper end side of the vehicle is positioned on the front side of the vehicle with respect to the lower end side. The position of the rear end in the vehicle front-rear direction at the inlet 26A and the position of the lower end in the vehicle up-down direction at the outlet 26B substantially coincide with the position of the lower end in the vehicle vertical direction of the cooling unit 22. With this arrangement, the cooling air passes through the cooling unit 22 (air-side flow path) along a direction substantially orthogonal to the front surface (inclination direction) of the cooling unit 22 (see arrow FA shown in FIG. 2). Has been.

  Further, in this embodiment, a venturi wall 32 as an inclined wall is formed on the vehicle front side of the duct 26 in the under cover 24. The venturi wall 32 is such that the front side portion in the vehicle front-rear direction with respect to the front edge portion 26D of the duct 26 (introduction port 26A) in the under cover 24 is closer to the road surface R on the rear end side than the front end side in the vehicle front-rear direction. It is formed by inclining. The venturi wall 32 may be formed at least on the front side in the vehicle front-rear direction of the installation range of the duct 26 in the vehicle width direction. In this embodiment, the front portion of the under cover 24 has a substantially full width in the vehicle width direction. The venturi wall 32 is an inclined wall.

  The venturi wall 32 is configured such that the space formed between the road surface R and the road surface R has a venturi shape with a narrower vertical width (a channel cross-section is narrowed) toward the vehicle rear end side. In this embodiment, the portion immediately below the front edge 26D of the duct 26 in the space formed between the venturi wall 32 and the road surface R in the vertical direction of the vehicle is the throat where the flow path cross section is most narrowed. ing. In the cooling wind introduction structure 10 provided with the venturi wall 32, the traveling wind toward the rear of the vehicle is guided upward of the vehicle by the venturi effect of the venturi wall 32 generated in front of the vehicle with respect to the inlet 26A, and follows the direction of the arrow FA described above. Therefore, the traveling wind is likely to flow into the duct 26 at an angle close to the direction of the arrow FA with respect to the road surface R before reaching the cooling unit 22.

  In the cooling air introduction structure 10, a first ventilation path 42 and a second ventilation path 44 are formed in the floor tunnel 20 for allowing the airflow that has passed through the cooling unit 22 to flow out of the floor tunnel 20.

  As shown in FIG. 1, the rear surface (rear surface) 22 </ b> A side in the vehicle front-rear direction of the cooling unit 22 is covered with a first shroud 38 provided in the floor tunnel 20 over the entire surface. The first shroud 38 has a substantially rectangular opening corresponding to the cooling unit 22 in a front view and a substantially “U” cross section that also opens downward in the vehicle. Specifically, the first shroud 38 includes a pair of left and right side walls 38A facing each other in the vehicle width direction, and a top wall 38B that connects the upper edges of the pair of side walls 38A in the vehicle vertical direction. The top wall 38 </ b> B (the vehicle upper edge of the side wall 38 </ b> A) has a substantially arc shape that protrudes upward and rearward in a side view and reaches the opening end (lower end) of the floor tunnel 20. As shown in FIGS. 5 and 6, the width of the first shroud 38 along the vehicle width direction (the distance between the pair of side walls 38 </ b> A) is substantially equal to the width of the cooling unit 22 along the vehicle width direction. Yes.

  A second shroud 40 is disposed in the first shroud 38. The second shroud 40 is formed in a substantially arc shape such that the top wall 38B of the first shroud 38 is shrunk in the up-down direction and the front-rear direction, and both ends in the vehicle width direction are respectively joined to both side walls 38A of the first shroud 38. Yes. An end 40A on the front side of the vehicle in the second shroud 40 (a boundary portion between a first ventilation path 42 and a second ventilation path 44 described later) is disposed on the vehicle rear side with respect to the rear surface 22A of the cooling unit 22. .

  Thereby, in the 1st shroud 38, it is the space below the vehicle up-down direction with respect to the 1st ventilation path 42 which is the space between this 1st shroud 38 and the 2nd shroud 40, and the 2nd shroud 40. A second ventilation path 44 and a common ventilation path 46 that is a space between the first ventilation path 42 and the second ventilation path 44 and the rear surface 22A of the cooling unit 22 are formed. Therefore, in this embodiment, the 1st shroud 38 and the 2nd shroud 40 are equivalent to the ventilation path formation member in this invention.

  The first air passage 42 has an air outlet 42B (FIG. 6) in which an air flow that flows in from an inflow port 42A that opens toward the common air passage 46 (cooling unit 22) opens downward along the vehicle body floor lower surface 48. (See also). In the second ventilation path 44, the air flow that flows in from the inlet 44 </ b> A that opens toward the common ventilation path 46 below the inflow port 42 </ b> A toward the common ventilation path 46 faces down the vehicle along the vehicle body floor lower surface 48 in front of the outflow port 42 </ b> B. It flows out from the outflow port 44B (see also FIG. 6) that opens to the top.

  The inflow port 42A of the first ventilation path 42 has a lower edge in the vehicle vertical direction so that air that has passed through the air flow path on the lower end side of the cooling unit 22 in the direction of the arrow FA (see arrow FA in FIG. 1). The position of the front front end 40A of the second shroud 40 is determined. In other words, in the cooling air introduction structure 10, the second ventilation path 44 is formed in the lower part of the cooling unit 22 so that the air flow that has passed through the cooling unit 22 in the direction of the arrow FA is hardly introduced into the second ventilation path 44. It is arranged behind the vehicle.

  The cooling air introduction structure 10 includes a cross flow fan 50 provided in the second ventilation path 44. The cross flow fan 50 has a substantially cylindrical shape whose longitudinal direction coincides with the axial direction, and is configured to blow out air sucked from the outer peripheral side from the outer peripheral side. The cross flow fan 50 is arranged so as to seal the inlet 44A of the second ventilation path 44 so that the axial direction coincides with the vehicle width direction, and is sucked in from the common ventilation path 46 side by being operated. The air is blown out to the outlet 44B side. The cross flow fan 50 arranged in this way is configured to have a significantly smaller vertical dimension in the vehicle as compared with an axial fan having equivalent performance.

  In this embodiment, the third shroud 52 is bridged between the left and right side walls 38A of the first shroud 38 between the lower end on the rear surface 22A side of the cooling unit 22 and the cross flow fan 50 (lower edge of the suction portion). A fourth shroud 54 is provided between the front edge of the outlet 44B and the cross flow fan 50 (the lower edge of the blowout portion), spanning the left and right side walls 38A of the first shroud 38. Yes. The front edge at the outlet 44 </ b> B of the second ventilation path 44 and the rear edge at the inlet 26 </ b> A of the duct 26 are closed by a bottom plate 56 that bridges the left and right side walls 38 </ b> A of the first shroud 38.

  Further, the cooling air introduction structure 10 includes a movable flap mechanism 58 as an opening / closing means for opening and closing the first ventilation path 42. In this embodiment, the movable flap mechanism 58 is provided along the opening surface of the inflow port 42A, and switches between a closed state and an open state of the inflow port 42A.

  Specifically, the movable flap mechanism 58 rotates around the support shaft 60A whose axial direction coincides with the vehicle width direction, thereby indicating the closed position of the inlet 42A shown by a solid line in FIG. A movable flap 60 that can take an open position of the inflow port 42A is provided. In this embodiment, a plurality (two) of movable flaps 60 are provided above and below. The movable flap mechanism 58 includes an actuator 62 that drives each movable flap 60 between a closed position and an open position.

  The cooling air introduction structure 10 includes a cooling ECU 64 as control means for controlling the operation of the crossflow fan 50 and the actuator 62. The cooling ECU 64 circulates between the power unit 12 and the cooling unit 22, and the vehicle speed sensor 66 that outputs a signal corresponding to the traveling speed of the automobile A to which the cooling air introduction structure 10 is applied. Each of the water temperature sensors 72 that output a signal corresponding to the temperature of the cooling water is electrically connected.

  Based on the signal from the vehicle speed sensor 66, the cooling ECU 64 has the vehicle speed V of the automobile A lower than the predetermined vehicle speed V1 (or less than V1), and the cooling water temperature T based on the signal load from the water temperature sensor 72. Is determined to be equal to or higher than a predetermined temperature T1 (or exceeds T1), the actuator 62 is controlled so that the movable flap 60 is positioned at the closed position, and the crossflow fan 50 is operated. . In this embodiment, when the water temperature T is equal to or higher than the predetermined temperature T1 even when the vehicle is stopped (the vehicle speed V is 0) while the power unit 12 is operating, the cooling ECU 64 is positioned at the closed position. In addition to controlling the actuator 62, the cross flow fan 50 is operated.

  On the other hand, the cooling ECU 64 determines that the vehicle speed V of the automobile A is equal to or higher than the predetermined vehicle speed V1 (or exceeds V1) based on the signal from the vehicle speed sensor 66, or based on the signal load from the water temperature sensor 72. When it is determined that the coolant temperature T is lower than the predetermined temperature T1 (or lower than T1), the actuator 62 is controlled so that the movable flap 60 is located at the open position, and the cross flow fan 50 is stopped. It is like that. In this embodiment, after the cooling ECU 64 determines that the vehicle speed V of the automobile A is equal to or higher than the predetermined vehicle speed V1, the cooling ECU 64 separately determines that the vehicle speed of the automobile A is equal to or lower than the predetermined vehicle speed V2 (V2 <V1). The movable flap 60 is located in the open position and the cross flow fan 50 is maintained in a stopped state. In this embodiment, the cooling ECU 64 is movable until it is determined that the cooling water temperature T is equal to or higher than the predetermined temperature T2 (T2> T1) after the cooling water temperature T is determined to be lower than the predetermined temperature T1. The flap 60 is positioned at the open position, and the state where the cross flow fan 50 is stopped is maintained. By these, it is set as the structure by which the sensitive operation (fluctuation etc.) etc. with respect to the speed of the actuator 62 and the crossflow fan 50 are suppressed.

  The movable flap mechanism 58 keeps the movable flap 60 at the closed position by a biasing force such as a spring and a stopper and the vehicle speed V becomes a predetermined speed V1 or the cooling water temperature T is a predetermined temperature T1. It is good also as a structure which act | operates the actuator 62 when it falls below.

  In 10 described above, as shown in FIGS. 5 and 6, the cooling unit 22, the first shroud 38 (first air passage 42), the second shroud 40 (second air passage 44), The three shroud 52, the fourth shroud 54, the bottom plate 56, and the movable flap mechanism 58 constitute a cooling module 68 that is integrated (modulated) before being assembled to the vehicle body. The cooling module 68 has both openings of the floor tunnel 20 facing the vehicle tunnel downward at the flange portion 70 projecting outward from the lower edge of the first shroud 38 in the vehicle vertical direction along the vehicle longitudinal direction. It is designed to be joined to the edge.

  The flange portion 70 functions as a tunnel brace that reinforces both side portions of the floor tunnel 20 in the floor panel 18. Furthermore, the bottom plates 56 (third shroud 52 and fourth shroud 54) that bridge the left and right side walls 38A, that is, the opening ends (between the lower ends) of both side walls facing the vehicle width direction of the floor tunnel 20 reinforce the floor tunnel 20. It functions as a reinforcing member.

  Next, the operation of this embodiment will be described with reference to the flowchart shown in FIG.

  In the automobile A to which the cooling air introduction structure 10 having the above configuration is applied, the cooling water circulates between the power unit 12 and the cooling unit 22 when traveling. The cooling water is cooled by heat exchange with air in the cooling unit 22. Further, when the air conditioner is operated, the refrigerant circulates in the order of the cooling unit 22, the expansion valve, the evaporator, and the compressor to form a refrigeration cycle. The cooling unit 22 functions as a condenser that cools and condenses the refrigerant by heat exchange with air.

  The heat exchange of the cooling unit 22 is performed by the running air of the automobile A or the air flow (cooling air) generated by the operation of the cross flow fan 50 flowing through the air side flow path of the cooling unit 22. This will be specifically described below.

  In step S10, the cooling ECU 64 determines whether or not the vehicle speed V of the automobile A is equal to or higher than a predetermined vehicle speed V1 based on a signal from the vehicle speed sensor 66. When the cooling ECU 64 determines that the vehicle speed V is equal to or higher than the predetermined vehicle speed V1, the cooling ECU 64 proceeds to step S12, controls the actuator 62 to move the movable flap 60 to the open position, and deactivates the crossflow fan 50 ( Stop). Then, as shown in FIG. 4, the traveling wind Fh of the automobile A flows into the duct 26 with a vector component upward of the vehicle, and passes through the cooling unit 22 in the direction of the arrow FA. The traveling wind Fh passes through the first ventilation path 42 via the common ventilation path 46.

  On the other hand, when the cooling ECU 64 determines in step S10 that the vehicle speed V is equal to or higher than the predetermined vehicle speed V1, the cooling ECU 64 proceeds to step S14 and determines whether or not the cooling water temperature T is equal to or higher than the predetermined temperature T1. When it is determined that the cooling water temperature T is equal to or higher than the predetermined temperature T1, the cooling ECU 64 proceeds to step S16, controls the actuator 62 to close the inlet 42A with the movable flap 60, and operates the cross flow fan 50. Let Then, as shown in FIG. 3, cooling air Fl that is an air flow passing through the duct 26, the cooling unit 22, the common air passage 46, and the second air passage 44 is generated. Thereby, in the cooling unit 22, heat exchange between the cooling air Fl, the cooling water, and the refrigerant is performed.

  Further, when the cooling ECU 64 determines in step S14 that the cooling water temperature T is lower than the predetermined temperature T1, the cooling ECU 64 proceeds to step S18 to control the actuator 62 to move the movable flap 60 to the open position, and to cross-flow fan 50. Is deactivated (stopped). In this case, in the cooling unit 22, the cooling water can be sufficiently cooled by heat exchange between the cooling water and a small amount of traveling wind that flows into the duct 26 as the vehicle travels.

  Here, in the cooling air introduction structure 10, when the automobile A is traveling at a low speed and the cooling requirement of the power unit 12 is relatively high, the cooling air Fl that is an air flow generated by the operation of the cross flow fan 50, The required cooling performance can be obtained. At this time, since the inlet 42A of the first ventilation path 42 is closed by the movable flap 60, the flow from the first ventilation path 42 to the second ventilation path 44 is not generated by the operation of the cross flow fan 50. .

  On the other hand, in the cooling air introduction structure 10, the cooling air Fl for heat exchange in the cooling unit 22 when traveling at a low speed or when the vehicle is stopped is generated by the crossflow fan 50 whose axial direction is substantially coincident with the vehicle width direction. Because of this configuration, when the crossflow fan 50 is stopped during high-speed traveling, the crossflow fan 50 is unlikely to become a draft resistance of the traveling wind Fh. Further, since the crossflow fan 50 is disposed in the second ventilation path 44 that is independent of the first ventilation path 42 through which the traveling wind Fh passes, the crossflow fan 50 is less likely to have a draft resistance of the traveling wind Fh.

  Moreover, in the cooling air introduction structure 10, the second air passage 44 is disposed at the rear of the vehicle with respect to the vehicle lower portion of the cooling unit 22 that is disposed forwardly, so that most of the cross flow fan 50 is in the direction of the arrow FA. Therefore, it is located outside the passage range of the traveling wind Fh flowing into the first ventilation path 42 (where there is no wind flow or very weak part), and the ventilation resistance of the traveling wind Fh is more unlikely. That is, the traveling wind Fh that has passed through the cooling unit 22 upward and rearward passes through the first ventilation path 42 in which the crossflow fan 50 that may cause ventilation resistance is not disposed.

  As described above, in the cooling air introduction structure 10, the axial fan does not become a large ventilation resistance when the automobile A is traveling at a high speed as in the comparative example in which the axial fan is stacked on the rear surface 22 </ b> A of the cooling unit 22. For this reason, in the cooling air introduction structure 10, the cooling efficiency of the cooling unit 22 when the automobile A is traveling at high speed is high, and the required cooling performance can be obtained.

  Thus, in the cooling air introduction structure 10, the first ventilation path 42 and the second ventilation path 44 are provided at the rear of the cooling unit 22. The required cooling performance can be exhibited. In addition, when the cooling water temperature T is lower than the predetermined temperature T1, that is, when the cooling request for the power unit 12 is relatively low, the cross flow fan 50 is deactivated to reduce energy consumption (power saving). it can.

  Moreover, in the cooling air introduction structure 10, since the cooling unit 22 is inclined forward as described above, the size of the installation space of the cooling unit 22 in the vertical direction of the vehicle can be kept low. Thereby, it becomes easy to suppress the height of the floor tunnel 20 and to secure the ground clearance at the lower end of the cooling unit 22.

  Further, in the cooling air introduction structure 10, since the common ventilation path 46 is formed between the cooling unit 22 and the first ventilation path 42 and the second ventilation path 44, almost the traveling wind Fh that has passed through the cooling unit 22. The entire amount can be caused to flow into the first ventilation path 42, and almost the entire amount of Fl that has passed through the cooling unit 22 can be caused to flow into the second ventilation path 44. For this reason, in the structure which divided the back flow path of the cooling unit 22 up and down, required cooling performance can be obtained at the time of high speed driving | running | working at low speed, without enlarging the cooling unit 22 up and down. That is, in the cooling air introduction structure 10, the cooling unit 22 can be reduced in size as compared with the configuration in which the common ventilation path 46 is not formed, the height of the floor tunnel 20 described above can be suppressed, and the ground at the lower end of the cooling unit 22 can be reduced. It contributes further to securing high.

  Furthermore, in the cooling air introduction structure 10, the cooling module 68 is composed mainly of the cooling unit 22, the first shroud 38, the second shroud 40, and the movable flap mechanism 58. Good properties. That is, a structure in which the first ventilation path 42 and the second ventilation path 44 that are divided into two at the rear of the cooling unit 22 are formed can be easily configured in the floor tunnel 20.

  In the above-described embodiment, the example in which the movable flap mechanism 58 is an active opening / closing means provided with the actuator 62 has been shown. However, the present invention is not limited to this, and for example, the opening / closing control of the movable flap 60 is performed. In a configuration in which the movable flap 60 is biased to the closed position by an urging force of a spring or the like when the vehicle is stopped or travels at a low speed, a passive opening / closing means that moves the movable flap 60 to the open position by the wind pressure of the traveling wind Fh may be used. . In this configuration, the vehicle speed at which the inlet 42A is opened can be set by the spring constant of the spring. The cooling ECU 64 controls the operation and stop of the cross flow fan 50 according to the vehicle speed and the cooling water temperature of the power unit 12.

  In the above-described embodiment, an example in which the venturi wall 32 is formed in front of the duct 26 in the vehicle is shown. However, the present invention is not limited to this. For example, the under cover 24 in front of the duct 26 is flat (road surface). (Substantially parallel to R). Furthermore, an aerodynamic structure that allows the traveling wind Fh to flow into the duct 26 may be provided together with or in place of the venturi wall 32. As such an aerodynamic structure, for example, an air guide member such as spats protruding from the lower end of the cooling unit 22 to the bottom of the floor can be provided. Further, the air guide member may be changed in shape or posture according to the vehicle speed, for example.

  Furthermore, in the above-described embodiment, the example in which the power unit 12 including the internal combustion engine is disposed in the power unit chamber 14 positioned in front of the vehicle interior C and drives the front wheel Wf is shown, but the present invention is not limited to this. For example, the power unit 12 may be configured to drive the rear wheel instead of the front wheel Wf or together with the front wheel Wf, and the power unit 12 does not include a motor (engines such as general FF vehicles, FR vehicles, and 4WD vehicles). The power unit 12 including the internal combustion engine may be arranged in a power unit chamber located behind the vehicle compartment C, or the power unit may not include the internal combustion engine. In these configurations, instead of the introduction port 26A that opens downward in the vehicle, for example, a bumper reinforcement or a duct that opens forward in the front grille can be used.

  In the above-described embodiment, the cooling unit 22, the first shroud 38, the second shroud 40, the cross flow fan 50, the movable flap mechanism 58, and the like are shown as examples of the cooling module 68. For example, a part or all of the components of the cooling module 68 may be individually assembled to the vehicle body. In this configuration, it is possible to eliminate the first shroud 38 and form the first ventilation path 42 between the floor tunnel 20 and the second shroud 40.

  In addition, the present invention is not limited to the configuration of the above-described embodiment, and it is needless to say that various modifications can be made without departing from the scope of the invention.

10 Cooling air introduction structure 12 Power unit 20 Floor tunnel 22 Cooling unit (heat exchanger)
38 1st shroud (ventilation path forming member)
40 Second shroud (ventilation path forming member)
42 1st ventilation path 44 2nd ventilation path 46 Common ventilation path 50 Cross flow fan 58 Movable flap mechanism (opening-closing means)
64 Cooling ECU (control means)

Claims (6)

An air-cooled heat exchanger provided at the front of the floor tunnel in the longitudinal direction of the vehicle,
A first ventilation path formed so that traveling wind that has passed through the heat exchanger is guided behind the heat exchanger in the floor tunnel in the vehicle front-rear direction;
A second ventilation path provided so as to form a flow path independent of the first ventilation path behind the heat exchanger in the floor tunnel in the vehicle longitudinal direction;
A cross flow fan provided in the second ventilation path such that the axial direction coincides with the vehicle width direction;
Cooling air introduction structure with The heat exchanger is inclined such that the upper part in the vehicle vertical direction is positioned on the front side in the vehicle front-rear direction with respect to the lower part,
The cooling air introduction structure according to claim 1, wherein the second ventilation path is disposed on a rear side in the vehicle front-rear direction with respect to a lower part of the heat exchanger in the vehicle vertical direction. The heat exchanger is a heat exchanger between air and a refrigerant for cooling a drive source of a vehicle,
The first ventilation path is disposed on the upper side in the vehicle vertical direction with respect to the second ventilation path,
An opening and closing mechanism for opening and closing the first ventilation path;
When the traveling speed of the vehicle exceeds a predetermined speed or when the temperature of the refrigerant is lower than the predetermined temperature, the opening / closing mechanism and the cross flow are configured to open the first ventilation path and to deactivate the cross flow fan. The fan is controlled so that the first air passage is closed and the cross-flow fan is operated when the running speed of the vehicle is equal to or lower than the predetermined speed and the temperature of the refrigerant is equal to or higher than the predetermined temperature. A control means for controlling the mechanism and the cross flow fan;
The cooling air introduction structure according to claim 2, further comprising:   A common ventilation path communicating with each of the first ventilation path and the second ventilation path is formed between the heat exchanger in the vehicle front-rear direction and the first ventilation path and the second ventilation path. 3. The cooling air introduction structure according to 3.   The said heat exchanger, the said crossflow fan, and the ventilation path formation member which forms the said 1st ventilation path and the 2nd ventilation path are modularized so that it can attach or detach with respect to a vehicle body integrally. The cooling air introduction structure according to claim 4.   The said heat exchanger is comprised including at least one of the radiator which cools the refrigerant | coolant for cooling a power unit, and the condenser which comprises the refrigerating cycle of an air conditioner. The cooling air introduction structure according to claim 1.

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