Air cooling of vehicle radiators

In combination with a vehicle hood and windshield, an engine compartment, an engine in the compartment, and a heat radiator located to pass cooling air flowing toward the engine, the radiator having an air inlet side, that combination comprising a cooling air receiving plenum chamber located at the air inlet side of the radiator; air inlet ducting having an entrance proximate the windshield to receive air flowing over the vehicle hood; and at least one passage communicating with the air inlet ducting and the plenum chamber to deliver cooling air to the plenum chamber for flow through the radiator. One plenum chamber acts to recover air pressure for efficient direct application to the radiator.

BACKGROUND OF THE INVENTION 
This invention relates generally to air cooling of vehicle engines; and 
more particularly concerns unusual advantages obtained by ducting of 
cooling air flow from near the vehicle windshield to a plenum chamber 
associated with the radiator. 
There is need for the unusual combinations of structures, modes of 
operation of such structures, and unusually beneficial results, as are 
disclosed herein. 
SUMMARY OF THE INVENTION 
It is a major object of the invention to provide highly beneficial and 
efficient vehicle engine air cooling, in association with a vehicle engine 
compartment, and a heat radiator that passes cooling air flowing toward 
the engine. Basically, the apparatus of the invention includes 
a) a cooling air receiving plenum chamber located at the air inlet side of 
the radiator, and 
b) air inlet ducting having an entrance proximate the windshield to receive 
air flowing over the vehicle hood, as may define the engine compartment, 
c) and at least one passage communicating with that air inlet ducting and 
the plenum chamber to deliver cooling air to the plenum chamber for 
efficient application to and flow through the radiator. 
As will be seen, the plenum chamber is typically located forwardly of the 
engine, in the direction of vehicle forward travel; also, the engine 
compartment may then be closed, forwardly of the plenum chamber. As a 
result, the closed forward panel structure that faces on-coming air flow 
may be contoured to offer minimum resistance of the vehicle to such 
on-coming air flow, enhancing engine fuel savings. 
The plenum chamber preferably has an effectively enlarged cross-sectional 
area, greater than the area of the flow passage to the plenum chamber, to 
receive air pressure, for efficiently distributed application over the 
inlet area of the radiator, for enhanced cooling efficiency. 
It is another object of the invention to provide a fan in the plenum 
chamber to displace and re-direct cooling air flow through the radiator 
and over the engine, such cooling air being supplied to the plenum chamber 
from the inlet ducting proximate the windshield. As will be seen, the 
vehicle engine compartment typically has a hood lid over which external 
cooling air is flowable toward the entrance to the air inlet ducting, the 
air passage extending toward said plenum located below the level of the 
lid. The air flow passage typically extends forwardly, in offset relation 
to the engine, and out of sideward communication with the engine. 
The air flow passage may extend above the engine, and adjacent the lid; and 
a panel may be provided below the lid and extending generally in the same 
direction as said lid, the flow passage formed between the lid and the 
panel. 
It is another object to provide the air flow passage to the plenum chamber 
to tilt with the lid, as the lid is raised and lowered. 
A further object is to provide the air flow passage extending forwardly to 
the plenum chamber to be located within one or more ducts located either 
within the engine compartment, or outside that compartment; or, the 
passage may extend within the vehicle wheel well. 
A yet further object is to provide the vehicle with contoured forward panel 
structure that faces externally forwardly, at the forwardmost extent of 
said engine compartment, that contoured panel structure blocking access of 
air to the engine compartment, via the front side of said panel structure. 
Accordingly, there is no need for a grille, and cost savings are obtained. 
These and other objects and advantages of the invention, as well as the 
details of an illustrative embodiment, will be more fully understood from 
the following specification and drawings, in which:

DETAILED DESCRIPTION 
In FIGS. 1 and 2, showing a preferred embodiment, or one preferred 
embodiment, a motor vehicle 10 has an engine compartment 11 containing an 
engine 12 that drives the vehicle. A heat radiator 13 is located forwardly 
of the engine, and extends upright. It receives liquid coolant from the 
engine and recirculates it to the engine. The radiator is perforated to 
pass cooling air in heat transfer relation to liquid coolant ducts in the 
radiator. Such cooling air flows rearwardly in the compartment 11. See 
arrows 14. A vehicle windshield is shown at 15. 
A cooling air receiving plenum chamber or box is shown at 16 at the front 
side 13a of the radiator. It has a front wall 16a, top wall 16b, bottom 
wall 16c, and side walls 16d. The chamber 16 may be generally co-extensive 
with i.e. span the radiator front side 13a, i.e. vertically and 
horizontally, as shown, whereby cooling air flow received in the plenum 
chamber circulates in the chamber interior toward the radiator front side 
and passes rearwardly substantially at the same rate through all portions 
of the radiator, for maximum heat transfer efficiency, i.e. cooling of the 
liquid flowing in the radiator. Also, the effective cross-sectional flow 
area A.sub.2 of the plenum chamber is substantially larger than the 
cross-sectional area or areas A.sub.1 of the air flow passage or passages 
25 to the plenum chamber, to recover pressure directly adjacent the 
radiator for effecting well distributed flow through the radiator. A fan 
or fans 18 may be located in the chamber interior 20, as seen in FIG. 2, 
and driven as at 21, or by drive from an engine driven sheave, to assist 
in displacing and re-directing cooling air flow through the radiator. 
Forward wall 16a of the plenum chamber 16 is preferably closed, and spaced 
rearwardly from the vehicle forward panel or panels 22 that face the 
exterior, frontwardly of the vehicle. Panel or panels 22 are also closed 
and contoured aerodynamically, i.e. forwardly convex, to deflect the 
on-coming air flow or streams 23, to minimize resistance to vehicle 
forward travel. This assists in fuel savings. 
Air inlet ducting is provided to have an entrance, or entrances, proximate 
the windshield, to receive cooling air flowing rearwardly at 24 over the 
vehicle engine compartment, as for example over a hood or lid 45 at the 
top of that compartment. FIG. 3 schematically shows such an entrance 26 
via which cooling air flow 24 enters air inlet ducting 27 at the foot of 
the windshield 15. The air then flows reversely at 24a and 24b, through an 
elongated passage extending forwardly to the plenum chamber or box 16, as 
referred to. 
In FIG. 1, the air inlet ducting includes two laterally spaced plenums 28 
extending below the hood or lid 24, near its pivot location 26. Air enters 
the plenum as at entrances 27a associated with rearwardmost extents of the 
lid or hood, and at the foot of the windshield. 
Two passages, as may be defined by ducting 30 and 31, extend from the 
respective plenums 28 to opposite sides of the receiving plenum 16, to 
conduct cooling air forwardly and discharge cooling air streams into that 
larger plenum. Ducts 30 and 31 may typically extend at opposite sides of 
the engine, within the engine compartment, so as not to interfere with 
normal servicing of the engine. The passages defined by ducting 30 and 31 
are below the level of the lid or hood, and offset from the engine, as by 
spacing at 32 and 33. 
FIG. 4 shows an alternative configuration with a cooling air passage 34 
located above the engine, and immediately below pivotable hood or lid 35. 
Panel 36 spaced below lid 35 cooperates with the lid to define passage 34, 
which extends forwardly from an entrance 37 at the foot of the windshield 
to the plenum chamber 16, as described above. Passage 34 tilts up and down 
with the lid, as about pivot 39, lower panel 36 being operatively attached 
to the lid. Forward terminals 34a of the passage 34 formed by the panel 
and lid extend close to an entrance 16e. at the top of the plenum, in lid 
closed position. 
FIG. 5 shows a duct 40 defining a cooling air passage 41 extending from an 
entrance 42 to chamber 16. Duct 40 is forwardly elongated, extends below 
the level of the lid, and also extends externally of the engine 
compartment, as through a vehicle wheel well 46. The vehicle hood is shown 
at 49.