VEHICLE HEAT EXCHANGER ASSEMBLY

Abstract

A vehicle heat exchanger assembly includes first and second heat exchangers including first and second heat exchange units, respectively, a blower and a fan shroud. The blower causes air to flow from the first heat exchanger to the second heat exchanger, and is arranged in an air passage formed in a space between the first and second heat exchange units. The fan shroud has an enclosing wall part disposed on an external periphery of the blower to substantially enclose the air passage formed between the first heat exchanger and the second heat exchanger, a support part supporting the blower, and a plurality of support stays extending from the support par toward the enclosing wall part to connect the support part and the enclosing wall part.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to Japanese Patent Application No. 2010-136468 filed on Jun. 15, 2010. The entire disclosure of Japanese Patent Application No. 2010-136468 is hereby incorporated herein by reference.

BACKGROUND

1. Technical Field

The present invention relates to a vehicle heat exchanger assembly provided with a plurality of heat exchangers that cool a cooling medium that flows through the heat exchangers using air blown by a cooling fan.

2. Related Art

The vehicle heat exchanger assembly is composed of a single heat exchanger (e.g., only a radiator for cooling an engine) or a plurality of heat exchangers (e.g., a radiator and air conditioner) mounted in a vehicle. In this case, the manner in which required cooling ability is assured is important in order to efficiently cool the heat exchangers in a wide range of engine operation such as engine idling and high-speed travel. For this reason, the following conventional placements, mountings, and other arrangements of the heat exchangers and cooling fans have been made.

In a conventional vehicle heat exchanger assembly, two different heat exchangers, i.e., a radiator and a cooler condenser are arranged in the vehicle front and rear, respectively, and the external peripheral portions of the heat exchangers are connected together by a cylindrical cooling-air guide plate. A shroud is provided to the cooling-air guide plate in the lateral directions or in the left or right direction of the vehicle body, and an opening is provided in the shroud in which a cooling fan is disposed so as to draw air into the shroud via the heat exchangers. The airflow is discharged from the aperture toward width direction of the vehicle body to directly cause air inside the engine compartment to flow while neither of the heat exchangers use air that has flowed through the other heat exchanger (e.g., see Japanese Laid-Open Utility Model Application Publication No. 63-190517).

Another conventional vehicle heat exchanger assembly is a multi-pass heat exchanger that uses a two-path cross-flow system in which a shared engine coolant or the like flows in a parallel flow or a U-turn flow between a first heat exchanger (rearward placement) and a second heat exchanger (forward placement) in which the air flow surfaces are arranged substantially in parallel fashion; and an air fan unit is disposed in an air gap between the first heat exchanger and the second heat exchanger (e.g., see Japanese Laid-Open Patent Application Publication No. 2005-76560). The air fan unit is composed of a rectangular parallelepiped shroud case, circular apertures that match the circular shape of the cooling fans are provided in the front and rear surfaces where cooling fans are arranged facing each other, and air is made to flow in a uniform fashion to the heat exchangers.

In yet another conventional vehicle heat exchanger assembly, two different heat exchangers such as a radiator, an oil cooler, or the like are housed in a cooling package main body. The cooling package main body is composed of a quadrangular frame that covers the external peripheral side of the heat exchangers, large quadrangular apertures are provided in the front and rear surfaces, and long members are made to extend from the frame corners toward the motor support member in the aperture center position. A cooling fan drive motor is mounted on the motor support member on the external surface of the cooling package main body, a rotating shaft of the motor protrudes in the opposite direction aperture plane, and a cooling fan is mounted on the distal end of the rotating shaft, whereby the cooling fan is set at a distance from the cooling package main body to improve the suction ability of the cooling fan. A shroud is provided surrounding the cooling fan from the aperture plane, and a fan guard is disposed on the outside thereof (e.g., see Japanese Laid-Open Patent Application Publication No. 2008-190513).

Yet another conventional vehicle heat exchanger assembly is one in which a radiator is used, and a fan shroud is mounted directly on the two end parts of upper and lower tanks of the radiator using four mounting stays integrally formed with the fan shroud (e.g., see Japanese Laid-Open Utility Model Application Publication No. 03-37234).

A cylindrical shell is integrally formed with a fan shroud together with a cooling fan, the upper portion of the fan shroud covers the heat exchanger part of the radiator, and the lower portion of the fan shroud is formed with an opening. Holes for travel-induced airflow are formed in the mounting stays of the lower portion so that air is allowed to flow.

SUMMARY

However, the conventional heat exchangers for a vehicle described above have the following problems.

First, with the vehicle heat exchanger assembly described in Japanese Laid-Open Utility Model Application Publication No. 63-190517, air that has passed through one heat exchanger does not pass by the other heat exchanger to provide cooling. The air inside the engine room can be made to flow directly to and pass by both heat exchangers, and there is a correspondingly improved cooling effect. However, since the vanes of the cooling fan are arranged so as to extend in the front-rear direction of the vehicle, the radiator and condenser cannot be set at a considerable distance from each other in the front-rear direction of the vehicle, and the heat exchange system overall is increased in size, which imposes considerable restrictions on the onboard layout. The cooler condenser on the engine side draws in the high-temperature air in the engine compartment as well as high-temperature air on the engine side because ram pressure is not generated during engine idling while the vehicle is stopped or traveling at very low speed. There is a problem in this case in that high cooling capacity cannot be obtained in the cooler condenser when the air conditioner is operating.

Air passes through the second heat exchange unit on the upstream side in the vehicle heat exchanger assembly described in Japanese Laid-Open Patent Application Publication No. 2005-76560, and the flow of air in the first heat exchange unit on the downstream side is made uniform. Therefore, the front and rear surfaces of the shroud case have a circular opening that conforms to the cooling fan, and other portions have a shape that covers the heat exchanger. For this reason, there is a problem in that travel-induced airflow cannot be sufficiently utilized when the vehicle is traveling, and the front and rear surfaces of the shroud case interferes with and creates resistance to the flow of air to the heat exchange unit in areas other than the opening. Also, since the first heat exchanger and the second heat exchanger are the same type of heat exchanger (a radiator or the like) having the same purpose, either the first heat exchanger or the second heat exchanger is present between the condenser and the cooling fan in the case that a heat exchanger having a different purposed such as a condenser for an air conditioner must be added. Therefore, the cooling capacity of the condenser is considerably reduced during engine idling while the vehicle is stopped or when traveling at very low speed.

In the vehicle heat exchanger assembly described in Japanese Laid-Open Patent Application Publication No. 2008-190513, the cooling fan must be set at a certain distance in the forward direction away from the heat exchange unit in order to increase the air-suction force of the cooling fan, and there is a problem in that the size of the system overall is increased in the front-rear direction. Also, the oil cooler is affected by heat released from the radiator because the radiator, oil cooler, and other heat exchangers are arranged adjacent to each other. As a result, the cooling capacity of the oil cooler is considerably reduced due to heat from the radiator in the case that a shovel or the like is used during engine idling while the vehicle is stopped or traveling at very low speed.

In the vehicle heat exchanger assembly described in Japanese Laid-Open Utility Model Application Publication No. 03-37234, a fan shroud is directly mounted on the radiator tanks and cooling fans are made to face each other near the heat exchanger, the length in the front-rear direction of the vehicle can be reduced, and travel-induced airflow is more readily used due to the setting of the aperture in the lower part and the travel-induced airflow through-holes of the mounting stays. However, there are gaps in the front-rear direction of the vehicle between the heat exchangers and the cylindrical shell that houses the cooling fans. Therefore, a problem is presented in that, during engine idling when the vehicle is stopped, a portion of the air does not pass through the heat exchange unit and is taken in by the cooling fan from the external peripheral side, or passes through the cooling fan and is then blown back and taken into the cooling fan by way of the gaps from the external peripheral side of the cooling fan; and the cooling capacity of the heat exchangers is reduced by a commensurate amount.

The present invention was devised in view of the above, it being an object thereof to provide a vehicle heat exchanger assembly provided with a first heat exchanger and a second heat exchanger, wherein the airflow resistance produced between the heat exchangers can be reduced, and the effect of heat from one heat exchanger on the other heat exchanger can be suppressed.

A vehicle heat exchanger assembly according to one aspect of the present invention includes a first heat exchanger, a second heat exchanger, a blower and a fan shroud. The first heat exchanger has a first heat exchange unit that allows air to pass therethrough. The second heat exchanger is arranged on a downstream side of the first heat exchanger with respect to an air flow direction. The second heat exchanger has a second heat exchange unit arranged parallel to the first heat exchange unit to allow air to pass therethrough. The blower is configured and arranged to cause air to flow from the first heat exchanger to the second heat exchanger, the blower arranged in an air passage formed in a space between the first heat exchange unit and the second heat exchange unit. The fan shroud has an enclosing wall part, a support part and a plurality of support stays. The enclosing wall part is disposed on an external periphery of the blower to substantially enclose the air passage formed between the first heat exchanger and the second heat exchanger. The support part supports the blower. The support stays extend from the support par toward the enclosing wall part to connect the support part and the enclosing wall part.

In the vehicle heat exchanger assembly of the present invention, it is possible to suppress a reduction in cooling capacity of the two heat exchangers by reducing airflow resistance produced by a shroud or the like between the heat exchangers when ram pressure is generated by, e.g., travel, and by making use of travel-induced airflow. Even during engine idling when the vehicle is stopped or traveling at very low speed, it is possible to reduce the effect that the heat produced by an air conditioner or another heat exchanger has on the radiator or another heat exchanger.

BRIEF DESCRIPTION OF THE DRAWINGS

Referring now to the attached drawings which form a part of this original disclosure:

FIG. 1 is a top plan view showing a vehicle heat exchanger assembly of a first embodiment of the present invention;

FIG. 2 is a side view of a partial cross section of the first embodiment of the present invention;

FIG. 3 is an exploded perspective view as seen from the rear of a vehicle and shows the vehicle heat exchanger assembly of the first embodiment of the present invention;

FIG. 4 is a front view of the fan shroud part of the vehicle heat exchanger assembly of a second embodiment of the present invention;

FIG. 5 is front view showing the fan shroud part of the vehicle heat exchanger assembly of a third embodiment of the present invention;

FIG. 6 is an enlarged cross-sectional view along the line 6-6 of FIG. 5; and

FIG. 7 is an enlarged perspective view as seen from the rear of a vehicle and shows a structure of the non-return valve of the third embodiment of the present invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Embodiments of the present invention are described in detail below with reference to the examples shown in the drawings.

First Embodiment

First, the overall configuration of the first embodiment will be described.

The heat exchanger of the first embodiment is mainly composed of a condenser 1 as a first heat exchanger, a radiator 2 as a second heat exchanger, a motor fan 3 as a blower, and a fan shroud 4 for supporting the motor fan, as shown in FIGS. 1 and 2. The above are integrally mounted in the front-rear direction of the vehicle in the sequence of the condenser 1, the fan shroud 4 that supports the motor fan 3, and the radiator 2 from the front side of the vehicle, and the assembly is supported by the vehicle body by a radiator-core support (not shown).

The condenser 1 as the first heat exchanger is used as an air conditioner, and is provided with a first heat exchange unit (condenser core) 11 through which air can flow in the front-rear direction of a vehicle, a left-side tank 12 and right-side tank 13 mounted on the left- and right-side ends, respectively, and a liquid tank (not shown) mounted on the side surface in the forward area of the left-side tank 12, as shown in FIG. 3.

The first heat exchange unit 11 has a plurality of tubes 11a through which a cooling medium flows between the tanks 12, 13 and of which the two end parts are connected to the left-side tank 12 and the right-side tank 13, respectively; and corrugated fins 11b mounted between the adjacent tubes 11a, 11a. The upper and lower ends of the left and right tanks 12, 13 are connected to each other by a reinforcement 14. A cooling medium intake port P1 is provided to the upper-side part in the upper area of the right-side tank 13, and an outlet port Q2 is provided to a lower area.

The radiator 2 as the second heat exchanger is used for cooling the engine, and is disposed parallel to the first heat exchange unit 11 of the condenser 1 in the rear of the vehicle, which is the downstream side of the condenser 1. The radiator 2 is provided with a second heat exchanger (radiator core) 21 through which air can flow in the front-rear direction of the vehicle, and a left-side tank 22 and right-side tank 23 mounted on the left- and right-side ends, respectively.

The second heat exchanger 21 has a plurality of tubes 21a through which a cooling medium flows between the tanks 22, 23, the two end parts of the tubes 21a being connected to the left-side tank 22 and the right-side tank 23, respectively; and corrugated fins 21b mounted between the adjacent tubes 21a, 21a. The upper and lower ends of the left and right tanks 22, 23 are connected to each other by a reinforcement 15. A cooling medium intake port Q1 that protrudes rearward is provided to the upper portion of the right-side tank 23, and an outlet port PQ that protrudes rearward is provided to a lower portion of the left-side tank 22.

In this embodiment, the first heat exchange unit 11 of the condenser 1 is configured and arranged to receive a cooling medium having a temperature lower than a temperature of a cooling medium that flows in the second heat exchange unit 21 of the radiator 2.

The motor fan 3 as a blower causes a cooling fan to rotate using an electric motor 31 so as to cause air to flow from the condenser 1 toward the radiator 2, and is configured such that a fan 32 having four vanes is mounted on a fan axis FA (the rotating shaft) of the electric motor 31. The fan 32 has the distal ends of each vane connected to a ring 33, which forms the external peripheral portion of the fan 32.

The motor fan 3 configured in the manner described above is disposed in an air passage 5 (described further below) formed in the interior space of the fan shroud 4, which is arranged between the condenser 1 and the radiator 2.

The fan shroud 4 links the areas between the condenser 1 and the radiator 2, and the motor fan 3 is accommodated in and covered by the fan shroud 4.

The fan shroud 4 is made of resin and has a enclosing wall part 41 for covering the external periphery of the motor fan 3, a support part 42 for supporting the electric motor 31 of the motor fan 3, and four support stays 43 that extend outward in the radial direction from the support part 42 to the enclosing wall part 41 and connect the support part 42 and the enclosing wall part 41. It is preferred that the support stays 43 have to the extent possible a reduced width on the side with which the airflow makes contact and that the length in the depth direction (corresponding to the axial direction of the electric motor 31) be increased by a commensurate amount in order to assure sufficient strength while reducing airflow resistance.

The enclosing wall part 41 of the fan shroud 4 is arranged so as to connect the areas between the external periphery of the first heat exchange unit 11 of the condenser 1 and the external periphery of the second heat exchanger 21 of the radiator 2. The space inside the enclosing wall part 41 forms an air passage 5 for directing air that has passed through the condenser 1 to the radiator 2.

In the present example, the air passage 5 has a ventilation cross-sectional area that is substantially equal in size to the cross-sectional area in the ventilation direction of the space (the space enclosed by the dash-dot line S in FIG. 3) formed by the connection between the external periphery of the first heat exchange unit 11 and the external periphery of the second heat exchanger 21, and does not narrow inward (the ventilation cross-sectional area is not greatly reduced) at an intermediate point.

The enclosing wall part 41 of the fan shroud 4 has left and right sidewalls 41a, 41b that extend in the horizontal direction, and an upper wall 41c and lower wall 41d that extend in the vertical direction and connect the upper and low ends of the left and right sidewalls 41a, 41b together to form a tubular member defining an opening 46, as shown in FIG. 3. In this embodiment, the tubular member formed by the left and right sidewalls 41a, 41b and the upper and lower walls 41c, 41d has a center axis that substantially coincides the fan axis FA of the fan 32. As mentioned above, the air passage 5 enclosed by the tubular member does not narrow inward. In other words, the tubular member has a rectangular cross-sectional shape taken along a plane perpendicular to the fan axis FA of the fan 32 which is substantially constant along the fan axis FA as shown in FIGS. 1-3. The rectangular cross-sectional shape defined by the left and right sidewalls 41a, 41b and the upper and lower walls 41c, 41d has an area (ventilation cross-sectional area) substantially equal to a cross-sectional area of the first heat exchange unit 11 of the condenser 1 taken along a plane perpendicular to the fan axis FA, and a cross-sectional area of the second heat exchange unit 21 of the radiator 2 taken along a plane perpendicular to the fan axis FA.

The enclosing wall part 41 has extension parts 44a, 44b that extend from the front edge part of the left and right sidewalls 41a, 41b in the outward width direction of the vehicle and then in forward direction of the vehicle, and that align with the vehicle-rear-facing external surface of the left-side tank 12 and the right-side tank 13 of the condenser 1.

The enclosing wall part 41 also has extension parts 45a, 45b that extend from the rear edge part of the left and right sidewalls 41a, 41b in the outward width direction of the vehicle and then in rearward direction of the vehicle, and that align with the vehicle-front-facing external surface of the left-side tank 22 and the right-side tank 23 of the radiator 2.

The enclosing wall part 41 has pawl parts 44c, 44d that extend from the front edge part of the upper wall 41c and the lower wall 41d to the forward direction of the vehicle, and that retain the upper and lower surfaces of the reinforcement 14 disposed in the upper and lower edges of the first heat exchange unit 11 of the condenser 1. Thus, the upper wall 41c (one example of the first wall portion) covers an upper side (one example of the first side) of the first heat exchange unit 11 and an upper side of the second heat exchange unit 21, and the lower wall 41d (one example of the second wall portion) covers a lower side (one example of the second side) of the first heat exchange unit 11 and a lower side of the second heat exchange unit 21.

The enclosing wall part 41 has pawl parts 45c, 45d that extend from the rear edge part of the upper wall 41c and the lower wall 41d to the rearward direction of the vehicle, and that retain the upper and lower surfaces of the reinforcement 15 disposed in the upper and lower edges of the second heat exchanger 21 of the radiator 2.

The vehicle heat exchanger assembly configured in the manner described above is integrally assembled in a state in which the condenser 1, the fan shroud 4 for supporting the motor fan 3, and the radiator 2 are superimposed in sequence from the front side FR of the vehicle in the front-rear direction of the vehicle. In their assembled state, the left and right tanks 12, 13 of the condenser 1 and the extension parts 44a, 44b that align with a part of the external surfaces thereof are in close contact, or even if a gap formed therebetween, the gap is formed to be as narrow as possible so that air that flows from an external space of the enclosing wall part 41 into the internal space (air passage 5) of the enclosing wall part 41 is reduced. Similarly, in their assembled state, the pawl parts 44c, 44d and the reinforcement 14 above and below the condenser 1 are in close contact, or even if a gap is formed therebetween, the gap is formed to be as narrow as possible so that air that flows from an external space of the enclosing wall part 41 into the internal space (air passage 5) of the enclosing wall part 41 is reduced.

Similarly, the left and right tanks 22, 23 of the radiator 2 and the extension parts 45a, 45b of the enclosing wall part 41 that cover a part of the external surfaces thereof are in close contact, or even if a gap is formed therebetween, the gap is formed to be as narrow as possible so that air that flows from an external space of the enclosing wall part 41 into the internal space (air passage 5) of the enclosing wall part 41 is reduced. Similarly, in their assembled state, the pawl parts 45c, 45d and the reinforcement 15 above and below the radiator 2 are in close contact, or even if a gap is formed therebetween, the gap is formed to be as narrow as possible so that air that flows from an external space of the enclosing wall part 41 into the internal space (air passage 5) of the enclosing wall part 41 is reduced.

Next, the effect of the first embodiment will be described.

Since the speed is zero or very low during engine idling when the vehicle is parked, traveling at very low speed, or the like, the condenser 1 and the radiator 2 are not expected to be cooled by travel-induced airflow from the forward direction of the vehicle. Therefore, in such a state, the electric motor 31 is energized and the fan 32 is caused to rotate to forcibly take in external air from the forward area of the condenser 1. The external air is passed through the heat exchanger 11 of the condenser 1, whereby the cooling medium that flows through the tubes 11a is cooled by heat exchange via the fins 11b or in part by direct air contact with tubes 11a.

Air that passes through the condenser 1 passes by the fan 32 and flows to the second heat exchanger 21 of the radiator 2.

The air that passes through the condenser 1 is directed with slightly reduced speed to the air passage 5 formed inside the enclosing wall part 41 of the fan shroud 4 and moves toward the radiator 2 with good efficiency.

When the air passes through the second heat exchanger 21 of the radiator 2, the cooling medium that flows through tubes 21a is cooled by heat exchange via the fins 21b or in part by direct air contact with tubes 1a.

In the case that the condenser 1 and the radiator 2 are cooled, the engine speed is kept low during idling while the vehicle is parked, during very low speed travel, or at other times. Therefore, the amount of heat is not as great in comparison with ordinary travel, but the air conditioner is often used during such times, so the required cooling capacity of the condenser 1 is increased.

In the vehicle heat exchanger assembly of the first embodiment, the condenser 1 is cooled to a greater extent than when using air that has once passed through the radiator 2 because the condenser 1 is in front of the radiator 2, and as a result, air is initially sent to the condenser 1 by the motor fan 3. Therefore, the condenser 1 can be sufficiently cooled even when the air conditioner is operated during idling or very low speed travel. On the other hand, although the air that passes through the radiator 2 has been warmed once by the condenser 1 and has less cooling capacity, the cooling medium that flows through the engine during idling in which heat output is low does not have a temperature as high as during ordinary travel, and the radiator 2 is therefore sufficiently cooled.

A portion of the air that passes through the second heat exchanger 21 makes contact with the engine and is discharged from below the vehicle. A portion of the air that has made contact with and rebounded from the engine is blown back to the radiator 2 side, and the left and right tanks 22, 23 of the radiator 2, the reinforcement 15, and the extension parts 45a, 45b and pawl parts 45c, 45d formed in the enclosing wall part 41 of the fan shroud 4 are arranged in close contact or with a slight gap. Therefore, the air blown back through the area is returned from the exterior of the enclosing wall part 41 to the front surface of the radiator 2 and the cooling capacity of the radiator 2 is not reduced. Similarly, the left and right tanks 12, 13 of the condenser 1, the reinforcement 14, and the extension parts 44a, 44b and pawl parts 44c, 44d are arranged in close contact or with a slight gap. Therefore, the air blown back through the area is returned from the exterior of the enclosing wall part 41 to the front surface of the radiator 2 or motor fan 3, and the cooling capacity of the radiator 2 is not reduced.

On the other hand, the amount of airflow that passes through the condenser 1 and the radiator 2 is considerably increased because ram pressure is generated in the front portion of the vehicle during ordinary vehicle travel. At this point, the engine generates high heat because the engine is operating at higher speed than during idling. However, even when air warmed by cooling the cooling medium in the condenser 1 is sent to the radiator 2, the amount of air that flows through the second heat exchanger 21 of the radiator 2 increases dramatically and cooling capacity is therefore considerably increased. Therefore, the condenser 1, as well as the radiator 2, is sufficiently cooled during ordinary high-speed vehicle travel. At this point, the inside of the enclosing wall part 41 of the fan shroud 4 forms an air passage 5 in the space (the space surrounded by the dash-dot line S) that connects the external peripheral surfaces of the condenser 1 and the radiator 2 together, and since only the four support stays 43 of the motor fan 3 and fan shroud 4 are present in the air passage 5, the air that moves from the condenser 1 to the radiator 2 undergoes little resistance from the fan shroud 4 and cooling of the radiator 2 during travel is further enhanced. The motor fan 3 may be caused to rotate as required during travel, i.e., only in the case that cooling by ram pressure is insufficient.

As described above, the following effects can be obtained in the vehicle heat exchanger assembly of the first embodiment.

(1) In the device of the first embodiment, the condenser 1 and radiator 2 are arranged on the upstream side and the downstream side, respectively, a fan shroud 4 having an air passage 5 is provided therebetween, and a motor fan 3 arranged under support by the support stays 43 at an intermediate point in the air passage 5. The ventilation cross-sectional area of the air passage 5 formed inside the enclosing wall part 41 of the fan shroud 4, which is arranged so as to connect the areas between the external peripheries of the first heat exchange unit 11 and the second heat exchanger 21, is designed so as to remain substantially unchanged from the surface areas of the first heat exchange unit 11 and the second heat exchanger 21.

The airflow resistance in the condenser 1 can thereby be reduced and the condenser 1 as well as the downstream radiator 2 can be sufficiently cooled even when the engine produces high heat during travel when, e.g., ram pressure is produced during travel in a vehicle heat exchanger assembly provided with a condenser 1 and a radiator 2.

(2) In the case that ram pressure is not generated such as during engine idling or the like when the vehicle is parked or traveling in very low speed, the cooling medium of the condenser 1 can be sufficiently cooled by causing the motor fan 3 to rotate even when the air conditioner is being operated because the condenser 1 is upstream from the radiator 2. In this case, in comparison with the case in which the condenser is arranged behind the radiator, the condenser airflow amount is increased by an amount commensurate with the reduction in radiator airflow resistance because the condenser 1 is arranged in front of the radiator 2. Therefore, the condenser 1 can be readily cooled.

On the other hand, there is no concern for reduced cooling capacity in this case even if the radiator 2 is cooled by air warmed by the condenser 1 because the engine is producing a low amount of heat.

(3) Since the motor fan 3 is disposed between the condenser 1 and the radiator 2, the heat received by the condenser 1 from the radiator 2 can be reduced. It is therefore possible to prevent the cooling capacity of the condenser 1 from degrading.

(4) The enclosing wall part 41 of the fan shroud 4 has extension parts 44a, 44b that extend so as to align with the vehicle-rear-facing external surface of the left-side tank 12 and the right-side tank 13 of the condenser 1 from the front edge part of the left and right sidewalls 41a, 41b of the enclosing wall part 41, and has extension parts 44a, 44b that extend so as to align with the vehicle-front-facing external surface of the left-side tank 22 and the right-side tank 23 of the radiator 2 from the rear edge part of the left and right sidewalls 41a, 41b of the enclosing wall part 41.

The extension parts 44a, 44b, 45a, 45b can thereby prevent air blown backward from the engine side from returning to the front surface of the radiator 2 via gaps between the enclosing wall part 41 of the fan shroud 4 and the tanks 12, 13, 22, 23 and prevent a reduction in cooling efficiency of the radiator 2, and also improve air utilization efficiency.

(5) Pawls 44c, 44d extend from the front edge part of the upper and lower walls 41c, 41d of the enclosing wall part 41 of the fan shroud 4 so as to retain the upper and lower surfaces of the reinforcement 15 provided to the upper and lower edges of the first heat exchange unit 11 of the condenser 1; and pawls 45c, 45d extend from the rear edge part of the upper and lower walls 41c, 41d of the enclosing wall part 41 so as to retain the upper and lower surfaces of the reinforcement 16 provided to the upper and lower edges of the second heat exchanger 21 of the radiator 2.

The pawl parts 44c, 44d, 45c, 45d can thereby prevent air blown backward from the engine side from returning to the front surface of the radiator 2 via gaps between the enclosing wall part 41 of the fan shroud 4 and the reinforcements 15, 16 and prevent a reduction in cooling efficiency of the radiator 2, and also improve air utilization efficiency.

(6) The motor fan 3 is covered by the fan shroud around the external periphery between the condenser 1 and the radiator 2 and it is therefore possible to prevent human hands and tools from making contact with the motor fan 3 during maintenance and inspection, and safety can be assured.

(7) Since the tanks of the condenser 1 and the radiator 2 are crimped or otherwise fabricated in a conventional manner, the crimped portions are arranged so as to avoid contact with each other in the case that the radiator is arranged on the downstream side of the condenser and the motor fan is disposed on the downstream side of the radiator and the condenser. Therefore, the gap between the condenser and the radiator are unavoidably enlarged. However, in the first embodiment, the entire heat exchanger can be made more compact in terms of the length (depth) in the front-rear direction of the heat exchanger because the motor fan 3 is disposed between the condenser and the radiator and the condenser 1 and the radiator 2 are arranged so as to be connected by the fan shroud 4.

Other examples will be described next. Illustration or description of the same constituent elements having the same reference numerals as the first embodiment are omitted in the description of the other examples, and only points of difference will be described.

Second Embodiment

Referring now to FIG. 4, a vehicle heat exchanger assembly in accordance with a second embodiment will now be explained. In view of the similarity between the first and second embodiments, the parts of the second embodiment that are identical to the parts of the first embodiment will be given the same reference numerals as the parts of the first embodiment. Moreover, the descriptions of the parts of the second embodiment that are identical to the parts of the first embodiment may be omitted for the sake of brevity.

The second embodiment shows another example of the fan shroud portion in the first embodiment, and FIG. 4 is a front view showing the fan shroud part of the vehicle heat exchanger assembly of the second example.

The vehicle heat exchanger assembly of the second embodiment is different from the first embodiment described above in that the portion around a circular ventilating aperture 47 for directing air blown by the motor fan is blocked by a panel member 48 inside the frame of the enclosing wall part 41 in the fan shroud 4. However, the interior of the enclosing wall part 41 of the fan shroud 4 has the same size and shape as the first embodiment on the upstream and downstream sides of the ventilating aperture 47.

Therefore, in the second embodiment, the airflow resistance in the fan shroud 4 is slightly increased in the effect (1) of the first embodiment, but the following effect can be obtained in addition to the same effect as the first embodiment.

(8) Since the portions other than the ventilating aperture 47 are blocked, it is possible to further prevent backflow of heat from the radiator 2 side to the condenser 1 side in comparison with the first embodiment. Reduction in the cooling efficiency of the condenser 1 can thereby be prevented.

Third Embodiment

Referring now to FIGS. 5 to 7, a vehicle heat exchanger assembly in accordance with a third embodiment will now be explained. In view of the similarity between the second and third embodiments, the parts of the third embodiment that are identical to the parts of the second embodiment will be given the same reference numerals as the parts of the second embodiment. Moreover, the descriptions of the parts of the third embodiment that are identical to the parts of the second embodiment may be omitted for the sake of brevity.

The third embodiment shows a modified example of the fan shroud portion in the second embodiment. FIG. 5 is a front view showing the fan shroud part of the vehicle heat exchanger assembly of the third embodiment. FIG. 6 is an enlarged cross-sectional view along the line 6-6 of FIG. 5. FIG. 7 is a perspective view as seen from the rear of a vehicle and shows the main part of the third embodiment.

Flow from the condenser 1 side to the radiator 2 side is allowed in the four corners in portions other the ventilating aperture 47 in the panel member 48 of the fan shroud 4, but the vehicle heat exchanger assembly of the third embodiment is different from the second embodiment in that a communication aperture 50 has a non-return valve 49 that prevents backflow from the radiator 2 side to the condenser 1 side.

In other words, the ventilating aperture 47 for directing air blown from the motor fan 3 is disposed substantially in the center of the panel member 48 that blocks the area within the frame of the enclosing wall part 41 in the fan shroud 4, and the communication aperture 50 is disposed in each of the four corners away from the ventilating aperture 47 in the panel member 48.

The non-return valve 49 blocking the communication aperture 50 from the radiator 2 side is provided to the upper-side aperture edge part of each communication aperture 50 and is capable of rotating about the center of a hinge part 51 formed in the upper-side aperture edge part.

The non-return valve 49 has a bottom plate part 49b that folds toward the communication apertures 50 in the lower edge part of the bottom plate part 49b which has a width sufficient to close off the communication aperture 50. Left and right sidewall parts 49c, 49c for blocking a triangular portion formed by a line connecting the upper end of a plate-shaped flap 49a and the distal ends of the bottom plate part 49b are formed in the left and right edge parts of the bottom plate part 49b and the plate-shaped flap 49a.

In the vehicle heat exchanger assembly of the third embodiment, the configuration described above produces a state in which the communication aperture 50 is blocked by the weight of the non-return valve 49, as shown by the solid line representation in FIG. 6, when the vehicle is stopped or idling, and the heated air of the radiator 2 side is prevented from flowing to the condenser 1 side. Reduction in the cooling efficiency of the condenser 1 can thereby be prevented.

The non-return valve 49 is opened to the radiator 2 side by the pressure of travel-induced airflow, as shown by the dashed line in FIG. 6, when the vehicle is traveling. Therefore, the travel-induced airflow passed through to the radiator 2 side with good efficiency. Cooling efficiency of the radiator 2 can thereby be improved.

The present invention was described above on the basis of examples, but the present invention is not limited to these examples; design modifications or the like can be performed within a range that does not depart from the spirit of the present invention.

The examples describe a case in which the first heat exchanger is a condenser and the second heat exchanger is a radiator, but the first heat exchanger may be a radiator and the second heat exchanger may be a condenser. The heat exchangers may both be radiators or another heat exchanger. In such instances it is sometimes the case that, when a second heat exchanger is disposed at least on the downstream side, in a hybrid automobile that is operated using an engine and an electric motor as power sources, the temperature of the cooling medium in the heat exchanger on the engine side is lower than in the heat exchanger for cooling the inverter on the electric motor side during engine idling while the vehicle is stopped or during travel at very low speed. In an electric automobile, there is no engine power source and therefore no radiator, but an inverter is used because the vehicle is operated by an electric motor as the power source. In such cases, for example, a heat exchanger for cooling the inverter, and a condenser for the air conditioner must be arranged.

Therefore, the second heat exchanger is preferably arranged on the downstream side as the heat exchanger having less cooling capacity than the first heat exchanger.

There has been described a case in which tanks have been provided to the left and right of the condenser and the radiator, but it is also possible to apply the present invention to cases in which the tanks are provided above and below.

Also, the extension parts and pawl parts formed in the enclosing wall part of the fan shroud may be provided so as to conform to a portion of the inlet pipe and outlet pipe of the heat exchangers as required.

GENERAL INTERPRETATION OF TERMS

In understanding the scope of the present invention, the term “comprising” and its derivatives, as used herein, are intended to be open ended terms that specify the presence of the stated features, elements, components, groups, integers, and/or steps, but do not exclude the presence of other unstated features, elements, components, groups, integers and/or steps. The foregoing also applies to words having similar meanings such as the terms, “including”, “having” and their derivatives. Also, the terms “part,” “section,” “portion,” “member” or “element” when used in the singular can have the dual meaning of a single part or a plurality of parts. Finally, terms of degree such as “substantially”, “about” and “approximately” as used herein mean a reasonable amount of deviation of the modified term such that the end result is not significantly changed. For example, these terms can be construed as including a deviation of at least ±5% of the modified term if this deviation would not negate the meaning of the word it modifies.

While only selected embodiments have been chosen to illustrate the present invention, it will be apparent to those skilled in the art from this disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined in the appended claims. Furthermore, the foregoing descriptions of the embodiments according to the present invention are provided for illustration only, and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.

Claims

1. A vehicle heat exchanger assembly comprising:

a first heat exchanger having a first heat exchange unit that allows air to pass therethrough;

a second heat exchanger arranged on a downstream side of the first heat exchanger with respect to an air flow direction, the second heat exchanger having a second heat exchange unit arranged parallel to the first heat exchange unit to allow air to pass therethrough;

a blower configured and arranged to cause air to flow from the first heat exchanger to the second heat exchanger, the blower arranged in an air passage formed in a space between the first heat exchange unit and the second heat exchange unit; and

a fan shroud having an enclosing wall part disposed on an external periphery of the blower to substantially enclose the air passage formed between the first heat exchanger and the second heat exchanger, a support part supporting the blower, and a plurality of support stays extending from the support part toward the enclosing wall part to connect the support part and the enclosing wall part.

2. The vehicle heat exchanger assembly according to claim 1, wherein

each of the first heat exchanger and the second heat exchanger has a plurality of tanks, and

the fan shroud has a plurality of extension parts arranged at positions corresponding to at least a part of the tanks to restrict air flow through a gap between the enclosing wall part and the tank.

3. The vehicle heat exchanger assembly according to claim 1, wherein

the first heat exchange unit of the first heat exchanger is configured and arranged to receive a cooling medium having a temperature lower than a temperature of a cooling medium that flows in the second heat exchange unit of the second heat exchanger.

4. The vehicle heat exchanger assembly according to claim 2, wherein

the first heat exchange unit of the first heat exchanger is configured and arranged to receive a cooling medium having a temperature lower than a temperature of a cooling medium that flows in the second heat exchange unit of the second heat exchanger.

5. The vehicle heat exchanger assembly according to claim 1, wherein

the blower includes a fan, and

the enclosing wall part of the fan shroud has a tubular member with a rectangular cross-sectional shape taken along a plane perpendicular to a fan axis of the blower.

6. The vehicle heat exchanger assembly according to claim 5, wherein

the rectangular cross-sectional shape of the tubular member is substantially constant along the fan axis, and has an area substantially equal to a cross-sectional area of the first heat exchange unit of the first heat exchanger taken along a plane perpendicular to the fan axis.

7. The vehicle heat exchanger assembly according to claim 6, wherein

the area of the rectangular cross-sectional shape of the tubular member is also substantially equal to a cross-sectional area of the second heat exchange unit of the second heat exchanger taken along a plane perpendicular to the fan axis.

8. The vehicle heat exchanger assembly according to claim 5, wherein

the tubular member of the enclosing wall part has first and second wall portions facing each other, the first wall portion covering a first side of the first heat exchange unit and a first side of the second heat exchange unit, and the second wall portion covering a second side of the first heat exchange unit and a second side of the second heat exchange unit.

9. The vehicle heat exchanger assembly according to claim 1, wherein

the blower includes a fan, and

the enclosing wall part includes a tubular member with a center axis extending in a direction parallel to a fan axis of the blower, and a panel member extending along a plane perpendicular to the fan axis of the blower, the panel member defining a circular ventilating aperture formed around the fan.

10. The vehicle heat exchanger assembly according to claim 9, wherein

the panel member includes at least one communication aperture and a non-return valve configured and arranged to allow air flow in a direction from the first heat exchanger to the second heat exchanger through the at least one communication aperture and to prevent air flow in a direction from the second heat exchanger to the first heat exchanger.