Vehicle cooling package

A vehicle cooling package has a fan shroud mounted to a heat exchanger assembly. A diverter plate is mounted adjacent to the shroud and spaced therefrom with a fan interposed therebetween. A diverting surface of the shroud and the diverter plate are angled from the axis of the fan when the shroud and plate are assembled to the vehicle. A vehicle hood has upper and side surfaces each having air discharge apertures corresponding with the space between the diverting surface and the diverter plate when the hood is closed. The diverting surface and the diverter plate both extend fully to the hood assembly when the hood is closed. The angles of the diverting surface and the diverter plate closely match a natural discharge angle of the fan, so that air is discharged from the fan at a high velocity from under the hood through the air discharge apertures.

FIELD OF THE INVENTION

The present invention relates generally to automotive vehicles such as work vehicles like agricultural tractors. More particularly, the present invention relates to such vehicles having internal combustion engines. Specifically, the present invention relates to cooling packages for such vehicles.

BACKGROUND OF THE INVENTION

Agricultural tractors in production today typically direct a significant portion of the cooling system fan exhaust under the hood enclosure and over the engine. A large amount of fan exhaust, both under the hood and outside the hood imparts heat to the operator station (cab). This happens due to the direction of the air being discharged from the cooling system and the fact that such air naturally tunnels through the hood enclosure toward the cab. This results in high heat loads on the cab, high under hood temperatures, significant backpressure on the fan and recirculation of heated air to the cooling system. Recirculation of heated air to the cooling system occurs due to the fact that heated air is discharged from the cooling system and is carried back to the intake of the cooling system via low air pressures at the cooling system intake and prevailing ambient air currents where it enters the system again and elevates the ambient temperature of the air the system ingests.

SUMMARY OF THE INVENTION

In view of the foregoing, it is an object of the invention to provide an improved cooling package for a work vehicle.

Another object of the invention is the provision of an improved cooling package which significantly reduces under hood temperatures as well as the heat load on the operator's station.

A further object of the invention is to provide an improved cooling package which is effective to expel a large quantity of the heated fan exhaust away from the vehicle and does not stir up excess dust and debris near the vehicle.

A still further object of the invention is to provide an improved cooling package which is quieter and more efficient than previously known systems.

An additional object of the invention is the provision of an improved cooling package which is compatible with existing vehicle and manufacturing technology.

The foregoing and other objects of the invention together with the advantages thereof over the known art which will become apparent from the detailed specification which follows are attained by a vehicle cooling package comprising: a heat exchanger assembly; a fan shroud mounted to the heat exchanger assembly, the fan shroud having a diverting surface; a diverter plate mounted adjacent to the fan shroud and spaced therefrom; a fan interposed between the fan shroud and the diverter plate; and, a vehicle hood enclosing the heat exchanger assembly, the fan shroud, the diverter plate, and the fan, the hood having at least one surface having air discharge apertures corresponding with the space between the diverting surface and the diverter plate when the hood is closed; wherein the diverting surface of the fan shroud and the diverter plate are each angled from the axis of the fan when the fan shroud and diverter plate are assembled to the vehicle, so as to closely match a natural discharge angle of the fan, and the diverting surface and the diverter plate both extend toward the hood assembly when the hood is closed so that air is discharged from the fan at a high velocity from under the hood through the air discharge apertures.

Other objects of the invention are attained by a fan shroud for a vehicle cooling fan comprising: a main body portion with a fan aperture therein, the fan aperture being defined by a circumferential wall extending outwardly from the main body portion of the fan shroud; a diverting surface extending from the circumferential wall opposite the main body portion at an angle to the axis of a fan when the fan is disposed in the fan aperture, the angle of the diverting surface corresponding to a natural discharge angle of the fan.

Still other objects of the invention are attained by a diverter plate for a vehicle cooling fan comprising: a main body portion angled from the axis of a fan disposed adjacent thereto at an angle corresponding to a natural discharge angle of the fan.

Further objects of the invention are attained by a vehicle hood assembly for enclosing the engine compartment and cooling package of a vehicle comprising: at least one surface having one or more air discharge apertures; wherein the air discharge apertures are located so as to correspond in location with a fan and one or more air diverting structures which extend to the hood surface(s) when the hood assembly is closed.

Still further objects of the invention are attained by a vehicle cooling package comprising: a heat exchanger assembly in fluid communication with an engine of a vehicle; a fan; a fan shroud mounted to the heat exchanger assembly, the fan shroud having a main body portion with a fan aperture therein, the fan aperture being defined by a circumferential wall extending outwardly from the main body portion of the fan shroud, a diverting surface extending from the circumferential wall opposite the main body portion at an angle to the axis of the fan when the fan is disposed in the fan aperture; a diverter plate mounted adjacent to the fan shroud and spaced from the fan shroud such that the fan can be interposed generally between the fan shroud and the diverter plate, the diverter plate further having a main body angled from the axis of the fan when the cooling package is assembled to the vehicle, diffuser screens interposed between the main body of the diverter plate and the diverting surface of the fan shroud when the fan shroud and diverter plate are assembled to the vehicle; and, a vehicle hood assembly having at least one surface having one or more air discharge apertures, the air discharge apertures being located so as to correspond in location with the space between the diverting surface of the fan shroud and the diverter plate when the hood assembly is mounted to the vehicle and closed; wherein the diverting surface of the fan shroud and the diverter plate both extend toward the hood assembly when the hood assembly is mounted to the vehicle and the hood is closed, and the angles of the diverting surface of the fan shroud and the diverter plate closely match a natural discharge angle of the fan so that air being discharged from the fan is discharged at a high velocity from under the hood through the air discharge apertures and discharge openings of the hood assembly.

In general, a vehicle cooling package has a fan shroud mounted to a heat exchanger assembly. A diverter plate is mounted adjacent to the shroud and spaced therefrom with a fan interposed therebetween. A diverting surface of the shroud and the diverter plate are angled from the axis of the fan when the shroud and plate are assembled to the vehicle. A vehicle hood has upper and side surfaces each having air discharge apertures corresponding with the space between the diverting surface and the diverter plate when the hood is closed. The diverting surface and the diverter plate both extend fully to the hood assembly when the hood is closed. The angles of the diverting surface and the diverter plate closely match a natural discharge angle of the fan, so that air is discharged from the fan at a high velocity from under the hood through the air discharge apertures.

To acquaint persons skilled in the art most closely related to the present invention, one preferred embodiment of the invention that illustrates the best mode now contemplated for putting the invention into practice is described herein by and with reference to, the annexed drawings that form a part of the specification. The exemplary embodiment is described in detail without attempting to show all of the various forms and modifications in which the invention might be embodied. As such, the embodiment shown and described herein is illustrative, and as will become apparent to those skilled in the art, can be modified in numerous ways within the spirit and scope of the invention—the invention being measured by the appended claims and not by the details of the specification.

DESCRIPTION OF THE PREFERRED EMBODIMENT

With reference now to the drawings, and particularly toFIGS. 1 and 2, it can be seen that a vehicle cooling package according to the invention is designated generally by the numeral10. As shown the cooling package10is comprised generally of a heat exchanger assembly12, a fan14, a fan shroud16and a diverter plate18. The heat exchanger assembly12typically comprises one or more heat exchangers20in the form of charge air coolers, oil coolers, radiators, fuel coolers, air conditioning condensers or the like, mounted to a frame22. The fan shroud16is preferably mounted to the frame22and thus provides a generally enclosed air passage between the heat exchanger(s)20and the fan14, which is partially disposed within the shroud16. The diverter plate18is mounted to the fan shroud16, or other vehicle attachment points, but is sufficiently spaced from the shroud16such that the fan14is interposed generally between the shroud16and the diverter plate18.

Referring now toFIGS. 3,4and5it can be seen that the fan shroud16is a unitary member preferably molded from an appropriate thermoset or thermoplastic material. The shroud16is defined generally by a main body portion24and preferably includes one or more mounting flanges26adapted to mateably engage the radiator frame22. The shroud16further includes a fan aperture28in the main body portion24. The fan aperture28is defined by a circumferential wall30extending outwardly, as shown, from the main body portion24of the shroud16. For reasons which will become apparent as the description continues, a diverting surface32extends from the circumferential wall30opposite the main body portion24at an approximate 70 degree angle to the axis of the fan14when the fan14is disposed in the fan aperture28. The diverting surface32and main body portion24may include stiffening ribs34to impart some degree of rigidity to the shroud16. Plumbing recesses36may also be provided to facilitate routing of heat exchanger plumbing under the hood.

The diverter plate18is illustrated inFIGS. 6 and 7. In a preferred embodiment the diverter plate18has a main section38and may also include a removable section40. The removable section40is provided to facilitate servicing of the fan components and/or cleaning of the heat exchanger(s). Accordingly the main section38and removable section40are each provided with mating flanges43to facilitate attachment of the sections38and40to one another by way of appropriate fasteners (not shown). It is contemplated that the diverter plate18could be a unitary member and as such in the description that follows the diverter plate18will be referred to in its assembled state as though it were a unitary member. The diverter plate18may include a central aperture42surrounded by a generally flat peripheral area44which, when the diverter plate18is assembled to the vehicle, is generally perpendicular to the axis of the fan14. The main body46of the diverter plate18extends angularly from the peripheral area44. In the preferred embodiment he angle of the main body46is approximately 70 degrees from the axis of the fan14when the cooling package10is assembled to the vehicle. The diverter plate18further includes a pair of side flanges48(FIG. 2) extending perpendicularly from the peripheral area44outward from the main body46. The side flanges48serve as a mounting surface for appropriate screens (not shown) fitted over the gap between the fan shroud16and the diverter plate18to prevent foreign objects from being introduced into the fan area even when the hood is opened. Diffuser screens50extend from the lower portion of the main body46as shown. The diffuser screens50are designed to abut the diverting surface32of the fan shroud16when the shroud16and diverter plate18are assembled to the vehicle. It is contemplated that the diffuser screens50can be molded integral with the diverter plate18or they could be separate parts or integral with the vehicle support or fan shroud. The diverter plate18may also include plumbing recesses and/or apertures52to facilitate routing of heat exchanger fluid lines under the hood. Depending upon the material selected for the diverter plate18it may further be desirable to include stiffening ribs53to increase the rigidity of the plate18. The diverter plate18preferably includes means for mounting the plate18to the vehicle structure. In a preferred embodiment this is accomplished by a first mounting boss54located directly above the central aperture42. The first mounting boss54is adapted to matingly fasten to a thermostat housing (not shown) bolted to the engine block. One or more additional mounting bosses56provide additional attachment points for affixing the diverter plate18to the front support of the vehicle (not shown).

A vehicle hood assembly58is illustrated inFIG. 8. While the preferred embodiment describes a pivoting hood assembly which may be lifted to provide access to the under hood area, it is to be understood that the invention is applicable to other hood configurations including, but not limited to, fixed or removable hood assemblies. A portion of the hood assembly58is also shown in phantom inFIG. 1. As can be seen the hood assembly58generally includes an upper surface60, a pair of opposed side surfaces62and a front radiator screen64. For reasons which will become apparent as the description continues the upper surface60has one or more air discharge apertures66. The air discharge apertures66are preferably fitted with screens or grids68. Likewise the side surfaces62of the hood assembly58have one or more air discharge openings70. The air discharge apertures66and air discharge openings70are located so as to correspond in location with the space between the diverting surface32of the fan shroud16and the diverter plate18when the hood assembly58is mounted to the vehicle and closed, as would be the case during normal operation of the vehicle. A vehicle front support72and wheel well louver73are also illustrated inFIG. 8. The front support72and wheel well louver73may each include one or more air discharge vents74which are also aligned generally with the space between the diverting surface32of the fan shroud16and the diverter plate18. However the inclusion of air discharge vents74in the front support72or wheel well louver73is optional and should be based upon the particular need to maximize air discharge while minimizing ground debris disturbance.

As is perhaps best illustrated inFIG. 1, the diverting surface32of the fan shroud16and the diverter plate18both extend fully to the hood assembly58when the hood assembly58is mounted to the vehicle and the hood is closed. Accordingly, air being discharged from the fan16is predominately discharged from under the hood58through the air discharge apertures66and discharge openings70of the hood assembly58as well as through the air discharge vents74of the front support72and wheel well louver73. A certain amount of air is allowed to circulate over the engine via the central aperture42of the diverter plate18. It has been found that pulling some air through the center of fan from the engine compartment helps to cool the under hood area. It is contemplated that within the scope of the invention the diverter plate18could be made without the central aperture42. A novel aspect of the present invention is that the air being discharged from the fan is expelled at a high velocity. This is possible due to the fact that the fan has a naturally radial discharge component of about 60 to 80 degrees. By matching the angles of the diverting surface32of the fan shroud16and the diverter plate18to the natural discharge angle of the fan14, so as not to force a change in direction of the air leaving the fan, the air velocity is optimized. The high velocity of air exiting the vehicle ensures that air is jettisoned away from the vehicle as far as possible. Getting the air away from the vehicle reduces the recirculation affects of various head, tail and cross winds the vehicle may be operated in. Reducing the amount of air tunneling through the under hood area and generally being vectored toward the cab prevents additional cab heat loads which tend to burden both the vehicle cooling and air conditioning systems of the vehicle. Traditional thinking to date has been that fan exhaust airflow under the hood is beneficial for keeping under hood temperatures down, however use of the present invention proves the opposite to be true. Under hood temperatures are significantly reduced when the present invention is employed. It has also been found that noise levels of the vehicle are decreased when the present invention is used. This is attributed in part to the fact that backpressure on the fan is reduced by allowing air to be discharged at the natural fan discharge angle. The reduced backpressure on the fan also allows the fan to work more efficiently. While it is generally desirable to maximize the air velocity leaving the fan, it is desired to reduce the velocity of air being discharged from the lower side of the vehicle to prevent the stirring up of dust and debris from the ground which otherwise reduces visibility and fouls vehicle components. This reduced velocity is attained primarily by the increased resistance to air flow provided by the diffuser screens50extending between the diverter plate18and the diverting surface32of the fan shroud16at the lower edges thereof.

The general object of the present invention is to minimize the amount of hot air being circulated over the under hood components of the vehicle. This is the case because air being circulated under the hood provides little benefit unless it has a temperature substantially lower than the components over which it is being circulated. With this in mind those having skill in the art will recognize that circulating fan discharge air over certain high temperature components under the hood can provide some cooling benefits. Examples of such high temperature components are turbochargers or engine exhaust manifolds wherein even the heated air being discharged from the fan is substantially lower in temperature than the component temperature. Accordingly, an alternative embodiment of a diverter plate18A is illustrated inFIGS. 9 and 10. As can be seen the diverter plate18A is very similar to the diverter plate18illustrated inFIGS. 6 and 7with the primary difference being that the diverter plate18A includes a port76in the removable section40A. The port76may be of any variety shapes depending on the application, but in the preferred embodiment includes an aperture78and a semi-cylindrical surface80which extends at angle from one side of the diverter plate18A. The purpose of the port in the preferred embodiment is to direct a discrete flow of fan discharge air to a high temperature component, for example a turbocharger. Targeted cooling of the high temperature component can thus be achieved by direct plumbing from the port76to the component or by passive channeling of air to the component sometimes referred to in the relevant art as ‘virtual ducting’. By utilizing such means it is possible to direct a portion of the fan discharge air to the high temperature component where it is most beneficial without generally circulating all of the fan discharge air over all of the under hood components. It should also be noted thatFIGS. 9 and 10illustrate the concept that the diffuser50need not be integrated with the diverter plate18as previously described. InFIGS. 9 and 10only the bottom diffuser screen50A is present while the side diffuser screens50B and50C are absent. It should be recognized that the diffuser screens50might also be entirely absent from the diverter plate18if it is desired to incorporate them in another component or to manufacture them as separate units. It should also be noted that the drawings ofFIGS. 9 and 10are used to illustrate one possible combination of diffuser screens50and the port76and those skilled in the art will recognize that different combinations are possible.

While the embodiment described herein utilizes a fan having a radial discharge component of 60-80 degrees and the diverting surface of the fan shroud and the diverter plate accordingly have angles of approximately 70 degrees these specific angles are described for purposes of illustration only. It is to be understood that different fans may have different discharge angles and that it is an object of the present invention to orient the diverting surface and diverter plate at as close to the natural discharge angle of the fan as possible without limitation to a specific angle or range of angles. The angle of the diverting surface and diverter plate is dependent upon the natural discharge angle of the particular fan selected for the particular application so that air flow direction is not changed unnecessarily, thereby allowing air to move more efficiently and at a higher velocity. Those having skill in the art will be able to determine the appropriate angles for the particular fan selected.

The heat exchanger(s) of the present invention are contained in a very tight configuration without much space between them. They are arranged such that air can pass through them in paths with as few obstructions as possible. Air passing through the heat exchanger(s) towards the fan experiences a high pressure drop due to friction with cooling fins of the heat exchanger(s). Thus there is negative pressure (vacuum) behind the heat exchanger(s) created by the fan's pumping action. This tends to draw air through the vehicle. It starts at standard pressure somewhere outside the vehicle and drops pressure due to friction in passing through the heat exchanger(s) until it reaches the fan. The high pressure drop at the fan works through the fans operating characteristics to produce the high velocity discharge at the natural fan discharge angle. Conventional cooling package arrangements have the fan located higher and further aft of the heat exchanger assembly than that of the present invention. The present invention's low and forward position of the fan relative to the heat exchanger assembly provides a path for the cooling air that is more direct or straight through the vehicle. The less need to change direction of air flow, the less power it takes to move it and the lower the noise will be. Having the cooling package low and forward allows the discharge air to better clear the front tires and other obstacles of the vehicle resulting in lower back pressure on the fan.

An alternative embodiment of the invention is contemplated wherein the diverter plate18does not extend fully to the hood58or there is a horizontal gap between the intersection of the hood58and the diverting surface32which is generally located at a rearward portion of the opening66. By leaving such a gap a venturi effect created by air exiting the under hood area at the air discharge apertures65and air discharge openings70tends to draw some additional air from the under hood area to provide additional under hood cooling, while the diverter plate still serves to substantially prevent fan exhaust from circulating over the engine.

Thus it can be seen that the objects of the invention have been satisfied by the structure presented above. While in accordance with the patent statutes, only the best mode and preferred embodiment of the invention has been presented and described in detail, it is not intended to be exhaustive or to limit the invention to the precise form disclosed. Obvious modifications or variations are possible in light of the above teachings. The embodiment was chosen and described to provide the best illustration of the principles of the invention and its practical application to thereby enable one of ordinary skill in the art to utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the invention as determined by the appended claims when interpreted in accordance with the breadth to which they are fairly and legally entitled.