Abstract:
The invention disclosed herein provides an automotive fan shroud and method of making. The invention fan shroud includes an integral liquid reservoir at its left and right upper corners. The fan shroud has separate upper and lower halves formed by injection molding. The upper and lower halves have interengaging flanges for being assembled to each other to form a full fan shroud, thus simplifying assembly and subsequent servicing. The liquid reservoirs are initially formed with open tops that are closed by the insertion of a fixedly attached reservoir cover, each cover having a filler neck and a cap.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to an automotive fan shroud, and more particularly to an automotive fan shroud that is integrally formed with automotive liquid reservoirs. 
     2. Background of the Invention 
     Automotive engines continually generate heat as they operate due to the combustion of fuel in the cylinders. A liquid coolant is circulated through the engine block by a pump in order to absorb and remove a portion of the heat from the engine block and maintain the engine temperature within a safe operating range. The radiator has a plurality of tubes configured to receive and circulate the heated liquid. A flow of ambient air is drawn through the radiator by a fan so that the ambient air contacts the exterior surface of the liquid coolant-carrying tubes to remove some of the heat from the liquid coolant. The radiator tubes are spaced apart so that ambient air can flow through the spaces and across the tubes to cool the tubes. The liquid coolant is returned to the engine block as a partly cooled liquid. The fan is typically positioned in an automobile engine compartment adjacent the rear side of the automotive radiator, or heat exchanger. The effectiveness of the automotive fan to cause the air flow to pass over the radiator tubes is enhanced by use of a fan shroud, or housing, to draw the air flow through the radiator. 
     The vertical front and back surfaces of an automotive radiator are typically rectangular in shape, while the fan is round. The known fan shrouds for automotive fans accommodate this change in opening shape with a fan opening that is round so as to circumferentially surround the fan and a radiator opening that is rectangular to match the shape of the radiator. There are four corner segments situated radially beyond the periphery of the fan and within the rectangular shape of the radiator that are substantially triangular in shape. In the known fan shroud configurations, these triangular corner segments are essentially space that is empty, but could hold another component of the engine compartment. 
     Modem automotive engine compartments are getting more crowded as the car&#39;s or truck&#39;s transmission and drive components are placed in close proximity to the front wheels and as more luxury features and air pollution control equipment are added. As used herein, the term automotive encompasses passenger cars, trucks, and buses. Space within the engine compartment is at a premium. Thus, the unused space of the triangular corner segments of the known fan shrouds is wasted space. 
     Contemporary automotive fan shrouds are typically formed of plastics resin. Other engine compartment components that are also typically formed of plastics resin are liquid reservoirs, for example reservoirs used to contain engine coolant and windshield washer liquid. Known engine coolant reservoirs, also known as degassing chambers, have been formed with internal baffles to subdivide the reservoir into small cells to minimize liquid agitation and foaming. Assembly of the fan shroud into the engine compartment involves labor. Assembly of the liquid reservoirs into the engine compartment involves additional labor. 
     The present invention recognizes that combining the liquid reservoirs with the fan shroud would conserve both engine compartment space and assembly labor. 
     The concept of combining a fan shroud with liquid reservoirs is known. The prior known fan shroud and liquid reservoir combination unit is formed by a process known in the trade as blow molding. A known blow molded fan shroud and liquid reservoir combination is supplied by the McCord Winn Division of Textron Automotive Company of Madison Heights, Mich. Inherent limitations in blow molding make the process of producing a fan shroud having integral liquid reservoirs labor intensive, therefore comparatively expensive. In addition, the finished automotive fan shroud lacks the internal baffles in the engine coolant reservoir, also due to process limitations. 
     When the automobile is assembled, the fan shroud surrounds the fan and substantially fills the space between the engine block and the radiator. If a problem should arise in the fan, the radiator, the water pump, or other engine components in the area of the fan shroud, access by a mechanic is impeded by the fan shroud. However, removal of the fan shroud is a tedious process, frequently requiring the removal of other components in the vicinity of the fan shroud. It is thus recognized that provision of a fan shroud formed as a split ring would simplify servicing of the assembled engine. 
     Therefore, it is an object of the present invention to provide a fan shroud combined with a liquid reservoir that includes internal baffles. 
     It is a further object of the present invention to provide a fan shroud combined with plural liquid reservoirs, at least one of which includes internal baffles. 
     It is an additional object of the present invention to provide a fan shroud combined with plural liquid reservoirs by a manufacturing process which minimizes labor and cost. 
     It is a still further object of the present invention to provide a fan shroud formed of multiple parts so as to be installed and removed segmentally. 
     These and additional objects of the present invention will become more fully understood from the following description and claims. 
     SUMMARY OF THE INVENTION 
     The present invention provides an automotive fan shroud that is comprised of upper and lower halves, which when combined serves to draw air flow generated by the fan through the radiator. The two halves are formed with mating edge portions adapted to engage one another. The upper half of the fan shroud incorporates two liquid reservoirs that are located outside the periphery of the fan. The liquid reservoirs are for containing engine coolant liquid and windshield washer liquid. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In order that the invention will become more clearly understood it is disclosed below in greater detail with reference to the accompanying drawings wherein similar parts are similarly numbered, and in which: 
     FIG. 1 is a side elevation schematic view showing an automotive engine, a radiator, a cooling fan with a prior art fan shroud, and a pair of conventional liquid reservoirs. 
     FIG. 2 is a side elevation schematic view of an automotive engine, a radiator, a cooling fan, and the fan shroud of the present invention incorporating a pair of integral liquid reservoirs. 
     FIG. 3 is an enlarged rear elevation section view of the cooling fan, the fan shroud and integral liquid reservoirs of the invention, and the radiator, with the section taken in the direction of line  3 — 3  of FIG.  2  through the cooling fan shaft. 
     FIG. 4 is an exploded perspective view of the fan shroud and integral liquid reservoirs according to the present invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Pursuant to the brief description above, FIG. 1 portrays a typical automotive fan shroud of the prior art in side elevation. Automotive engine  10  is shown schematically positioned adjacent radiator  18  which has a filler cap  16  mounted on its upper surface. A pair of hoses (not shown) are connected between engine  10  and radiator  18  for circulation of a coolant liquid. Cooling fan  12  is mounted between engine  10  and radiator  18  and oriented with its shaft  14  substantially horizontal. Fan shroud  20  is mounted to the rear face  23  of radiator  18  in a position to concentrically surround cooling fan  12  so that as cooling fan  12  rotates, ambient air is caused to be drawn through radiator  18  in the direction shown by arrows A so as to also flow over engine  10  to provide further cooling. It is common for fan  12  to be smaller in diameter than radiator  18  is wide; thus discharge side  22  is shown smaller than rectangular side  23 , and fan shroud  20  is appropriately tapered. The body of the automobile, in which engine  10  and other described components are mounted, is not shown for reasons of clarity. 
     A degas chamber  24 , or coolant reservoir, is a separate container that is mounted within the engine compartment in close proximity to radiator  18  and is connected in fluid communication thereto by hose  26 . Degas chamber  24  permits excess volume of liquid, caused by the heating of the coolant liquid in engine  10 , to escape from radiator  18  and not be wasted. Degas chamber  24  is generally provided with a set of internally mounted antifoaming baffles (not shown). 
     Referring still to FIG. 1, a further component in the engine compartment of modern automobiles is windshield washer liquid reservoir  28 . Windshield washer liquid reservoir  28  is a simple bottle that is connected by means of hose  30  to a set of windshield spray nozzles (not shown). Liquid stored within windshield washer liquid reservoir  28  is pumped to the nozzles and onto the automobile&#39;s windshield by a pump (not shown) that may be mounted internally or externally of liquid reservoir  28 . 
     Referring now to FIG. 2, engine  10  is mounted proximate to radiator  18 . Filler cap  16  is positioned at the upper portion of radiator  18  to add coolant liquid thereto. Cooling fan  12  is positioned between engine  10  and radiator  18  so as to draw ambient air through radiator  18  in a direction indicated by arrows A. Fan shroud  34  of the present invention is mounted to radiator  18  so as to circumferentially surround fan  12 . In side elevation view, fan shroud  34  of the present invention has a horizontal upper surface  34   t . Reservoir cover  70  is assembled to horizontal top  34   t  with a vertically extending filler cap  74  mounted thereto. As seen in side elevation, the lower portion  34   b  of fan shroud  34  is formed in a curve to provide a gradual transition from round opening  42  (see FIG. 3) to the rectangular portion  43  where fan shroud  34  connects to radiator  18 . 
     Referring now to FIG.  3  and FIG. 4, fan  12  is rotatably mounted about horizontal axis X—X and centrally positioned within round opening  42 . Whereas cooling fan  12  is portrayed as having  4  blades, other numbers of blades, such as  3  or  5 , are common. It is to be noted that fan shroud  34 , mounted to radiator  18  and surrounding cooling fan  12 , has a generally rectangular periphery  43  and has a substantially round opening  42  formed therein. Fan shroud  34  of the present invention is the combination of upper segment  38  and lower segment  40 , each segment surrounding a respective upper and lower portion of fan  12 . Upper segment  38  is formed with a downwardly extending lip  58  that engages and overlaps the upwardly extending edge  41  of lower segment  40 . According to the illustrated embodiment of fan shroud  34 , horizontal axis X—X of fan  12  is above horizontal mid-line Z—Z of radiator  18 . It is recognized that an alternate configuration in which horizontal axis X—X coincides with or is lower than horizontal mid-line Z—Z is possible within the scope of the present invention, changing the transitional curvature from that of round opening  42  to the rectangular periphery  43  of fan shroud  34 . Since the distance from round entry opening  42  to rectangular portion  43  differs from the center to the corners of lower segment  40 , the degree of curvature also will vary. As seen best in FIG. 2, the curvature of lower portion  34   b  assists in drawing the air flow from the lowest parts of radiator  18  past fan  12 . 
     As shown in FIGS. 3 and 4, upper segment  38  and lower segment  40  have matching mounting holes  56   a  and  56   b  that are formed in flanges  59   a  and  59   b  respectively so that fan shroud  34  becomes a complete ring when it is assembled in the automotive engine compartment. In the preferred embodiment, flanges  59   a  and  59   b  are configured as stepped dual flanges for maximizing the stability of the assembled upper segment  38  and lower segment  40  of fan shroud  34 . Additional assembly brackets  52  are also provided for connection to engine compartment braces (not shown). A pair of spring tabs  48  is provided at the lower border of lower half  40  for engagement with a complementary pair of sockets (not shown) for mounting purposes. 
     The present invention recognizes that it is preferable to utilize the substantially triangular space radially outward of the periphery of fan  12 , particularly those in upper segment  38 . A first liquid reservoir  44  and a second liquid reservoir  47  are advantageously formed respectively at the upper triangular corner portions to benefit from the available space. First liquid reservoir, for example degas chamber  44  for engine coolant liquid, is formed with a set of internal baffles  46  that are configured in a matrix pattern as is known in the trade. Baffles  46  extend from a height marginally below the uppermost wall height of degas chamber  44  to its curved bottom. A reservoir cover  60 , configured to be mounted in sealing engagement within the top periphery of liquid reservoir  44  has a downwardly extending peripheral lip  63  that contacts the upper ends of baffles  46  when assembled, leaving a gap between baffles  46  and the horizontal planar surface of cover  60 . This gap over baffles  46  and below cover  60  allows the cells formed by baffles  46  to transfer pressure and fluids from one to the other. Cover  60  is formed with a filler neck  62  that is threaded to receive a complementarily threaded cap  64 . Reservoir cover  60  is fixedly assembled into reservoir  44  by ultrasonic welding or other available means. An upper hose nipple  66  and a lower hose nipple  45  are provided for connecting hoses to allow excess coolant to flow to and from radiator  18 , as is known in the trade. 
     Referring further to FIG. 3, second liquid reservoir  47 , for example a windshield washer reservoir, is formed as an internally unrestricted bottle in a substantially triangular cross sectional shape to fully utilize the available corner space. Reservoir cover  70  is separately formed with filler neck  72  and a separate cap  74 . Upon assembly, cover  70  is affixed, for example by ultrasonic welding, into the upper opening of second liquid reservoir  47 . Hose nipple  49  is provided at the rear wall of second liquid reservoir  47  for drawing windshield washer fluid for use when required. 
     Whereas fan shroud  34  of the present invention is illustrated as being a ring that is split along a horizontal diameter, other configurations of two or more parts are possible within the scope of the invention. For example, a fan shroud divided into two substantially equal side-by-side segments along a vertical diameter is a feasible option. Also, the fan shroud of the present invention could be formed of two upper side-by-side quarter segments and a lower half segment that are assembled to form a ring as they are mounted into the automotive engine compartment. It is recognized that forming fan shroud  34  of the present invention in multiple parts simplifies the assembly of components in the engine compartment by permitting the fan and radiator to be installed before installing the fan shroud. Similarly, access to forward engine components, e.g. the water pump, is substantially simplified by the ability to remove upper segment  38  of fan shroud  34 . 
     The preferred process for making the fan shroud of the invention is by injection molding of plastics resin. A resin of choice is polypropylene, available from numerous sources. Other types of resin as are known may be substituted according to design specifications. To maintain upper segment  38  so it is able to transmit light, i.e., to be translucent for liquid level visibility, upper segment  38  is made of unfilled natural polypropylene resin. In the discretion of the designer, upper segment  38  could be made of a plastics resin that cools to be transparent. Since lower segment  40  is not intended to transmit light, lower segment  40  is made of a reinforced polypropylene resin, for example, polypropylene with approximately 40% talcum powder, to improve its strength and rigidity. Reservoir covers  60  and  70  and their respective caps  64  and  74  can be made either with filled or unfilled polypropylene resin. 
     The process of injection molding involves use of a mold that is divided along a selected parting line. A liquid material, such as a plastics resin, is introduced into the closed mold and caused to solidify. The mold for producing lower segment  40  of fan shroud  34  can be configured to divide either vertically or horizontally, as referring to the orientation shown in the figures. The mold for producing upper segment  38  is preferably configured to divide along a horizontal line at the top surface of fan shroud  34  with a perpendicularly acting cam provided to form hose nipples  45  and  49  as well as mounting holes  56   a . The fan shroud produced as described will be formed in completed condition with a minimum of manual labor. 
     While the invention has been described with reference to specific embodiments thereof, it will be appreciated that numerous variations, modifications, and enhancements are possible and are therefore regarded as being within the spirit and scope of the invention that is only limited by the claims to follow.