Exhaust gas cooling valve

A valve having a housing including an inlet, an outlet, an internal passage connecting the inlet and the outlet, a pressure responsive member movably supported by the housing for opening and closing the internal passage, and a spring located between the member and the inlet for biasing the member away from the inlet.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to internal combustion engines, and particularly to 
arrangements for introducing cooling water into the exhaust gases of 
internal combustion engines. This invention also relates to valves, and 
more particularly, to pressure relief valves. 
2. Description of the Prior Art 
It is known to provide an engine with a restricted passage through the wall 
separating an exhaust passage and a water jacket in order to inject 
cooling water into the exhaust passage. 
Relief valves which provide relief to a fluid system in response to a 
predetermined pressure generally tend to employ a valve body, a valve 
seat, and a spring biasing the valve body against the valve seat. The 
pressure setting at which the valve body unseats is commonly determined by 
compressing the biasing spring for the valve to a desired degree. 
Attention is directed to the following United States Patents: 
______________________________________ 
U.S. Pat. No. 
Inventor Issued 
______________________________________ 
3,052,086 Kiekhaefer et al. 
September 21, 1982 
3,385,052 Holtermann et al. 
May 28, 1968 
4,350,010 Yukishima September 21, 1982 
______________________________________ 
SUMMARY OF THE INVENTION 
The invention provides an internal combustion engine comprising a cylinder 
block defining a cylinder bore, and an exhaust passageway communicating 
with the cylinder bore, and means for injecting cooling fluid into the 
exhaust passageway only at low engine speeds. 
The invention also provides a valve assembly adapted to be positioned 
between a coolant passageway and an exhaust passageway in an internal 
combustion engine, the assembly comprising a housing including an inlet 
adapted to communicate with the coolant passageway, an outlet adapted to 
communicate with the exhaust passageway, an internal passage connecting 
the inlet and the outlet, and means for opening and closing the internal 
passage. 
The invention also provides a valve comprising a housing having an inlet, 
an outlet, and an internal passage connecting the inlet and the outlet, a 
pressure responsive member movably supported by the housing for opening 
and closing the internal passage and spring means located between the 
member and the inlet for biasing the member away from the inlet. 
The invention also provides an internal combustion engine comprising a 
cylinder block defining a cylinder bore, an exhaust passageway 
communicating with the cylinder bore, a coolant passageway and a valve 
assembly including a housing including an inlet communicating with the 
coolant passageway, an outlet communicating with the exhaust passageway, 
an internal passage communicating between the inlet and the outlet, and 
means for opening and closing the internal passage. 
A principal feature of the invention is a pressure or speed responsive 
valve located between the coolant supply and the exhaust passage of an 
internal combustion engine to automatically control the flow of coolant to 
the exhaust passage. 
Another principal feature of the invention is a pressure or speed 
responsive valve located between the coolant supply and the exhaust 
passageway of an internal combustion engine, which valve will allow 
coolant into the exhaust passageway at low pressures or speeds and will 
cut off the supply of coolant to the exhaust passageway at high pressures 
or speeds.

Before one embodiment of the invention is explained in detail, it is to be 
understood that the invention is not limited in its application to the 
details of construction and the arrangement of components set forth in the 
following description or illustrated in the drawings. The invention is 
capable of other embodiments and of being practiced or carried out in 
various ways. Also, it should be understood that the phraseology and 
terminology used herein is for the purpose of description and should not 
be regarded as limiting. 
DESCRIPTION OF THE PREFERRED EMBODIMENT 
A marine propulsion device 4 embodying the invention is illustrated in the 
drawings. 
The marine propulsion device 4 includes (see FIG. 1) a lower unit 5 
including a propeller shaft 6 that supports a propeller 7. The lower unit 
5 also includes an upper end 8 and has therethrough an exhaust passageway 
12 communicating between the upper end 8 of the lower unit 5 and an 
exhaust outlet 16 in the propeller 7. Such an exhaust arrangement is known 
in the art and will not be described in greater detail. 
The marine propulsion device 4 also includes an engine 20 supported by the 
upper end of the lower unit 5 and drivingly connected to the propeller 
shaft 6 by a drive train 28. While the engine 20 could be either a 
two-cycle engine or a four-cycle engine, the engine 20 is preferably a 
two-cycle engine. The engine 20 comprises (see FIG. 2) a cylinder block 32 
having a lower end having therein (see FIG. 5) a pair of exhaust outlets 
34 (one is shown in FIG. 5) communicating with the exhaust passageway 12 
in the lower unit 5. The cylinder block 32 defines (see FIG. 4) a pair of 
cylinder bores 44 and 46 including respective exhaust ports 47 and 48, a 
first exhaust passageway 49 communicating between the first or upper 
exhaust port 47 and the exhaust outlet 34 in the lower end of the block 
32, and a second exhaust passageway 50 communicating between the second or 
lower exhaust port 48 and the other exhaust outlet in the lower end of the 
block 32 . The cylinder block 32 partially defines (see FIG. 2) a first 
crankcase 52 communicating with the first cylinder bore 44 via a plurality 
of first intake passageways 62, and a second crankcase 64 communicating 
with the second cylinder bore 46 via a plurality of second intake 
passageways 66. The block 32 includes (see FIGS. 3 and 5) a wall 72 
partially defining a cooling jacket 74 located adjacent the exhaust 
passageways 49 and 50. As shown in FIG. 5, the cylinder block 32 includes 
a wall 78 partially defining both the first exhaust passageway 49 and the 
cooling jacket 74. The wall 78 has therethrough a threaded bore 82, the 
reason for which is explained below. In the illustrated construction, 
cooling water is supplied to the cooling jacket by a water pump (not 
shown) located in the lower unit 5, as is known in the art. 
The engine further comprises (see FIG. 2) a crankcase cover 86 which is 
mounted on the cylinder block 32, which further defines the crankcases 52 
and 64, and which includes first and second intake passageways 68 and 70 
respectively communicating with the first and second crankcases. The 
engine 20 further comprises means for supplying combustion air to the 
intake passages 68 and 70. While various suitable means can be employed, 
in the preferred embodiment, such means includes (see FIG. 2) an intake 
manifold 88 mounted on the crankcase cover 86, and first and second 
carburetors 90 and 92 which are mounted on the intake manifold 88 and 
which communicate with the first and second intake passages 66 and 70, 
respectively. 
The engine 20 further comprises (see FIG. 5) a cooling jacket cover 102 
which is mounted on the wall 72 of the cylinder block 32 and which further 
defines the cooling jacket 74, and a cylinder head 106 (FIG. 2) which is 
mounted on the cylinder block 32 and which closes the cylinder bores 44 
and 46. The cylinder head 106 supports a pair of spark plugs 110 and 114. 
The engine further comprises (see FIG. 2) a crankshaft 118 which is 
rotatably supported by the cylinder block 32 and the crankcase cover 86, 
which extends through the crankcases 52 and 64, and which is drivingly 
connected to the drive train 28. The engine further comprises first and 
second pistons 122 and 126 which are slideably housed in the first and 
second cylinder bores 44 and 46, respectively, and which are drivingly 
connected to the crankshaft 118 by connecting rods 130. 
In operation, the pistons 122 and 126 move down (to the left in FIG. 2) in 
the cylinder bores 44 and 46 and uncover the corresponding exhaust ports 
47 and 48. The exhaust gases then pass outwardly through the exhaust 
passageways 49 and 50. The discharge of the exhaust gases into the exhaust 
passageways 49 and 50 creates pressure waves which travel along the 
exhaust passageways 12, 49 and 50 and which return to the exhaust ports 47 
and 48. 
The timing of the return of these pressure waves can be controlled by 
injecting a cooling liquid into the gases. The cooling liquid lowers the 
temperature of the exhaust gases to thereby slow the rate of travel of the 
pressure waves. 
The volume of water introduced into the exhaust passageway gases should be 
inversely proportional to the speed of the engine 20, so that at low 
speeds a larger amount of water is injected into the exhaust passageway 
gases and at high speeds a lesser amount of water is introduced into the 
exhaust passageway gases. It is desirable to have less or no water 
introduced into the exhaust passageway gases at high engine speeds because 
the introduction of water at such speeds may hinder the engine 
performance. 
Accordingly, the engine includes valve means communicating between the 
cooling jacket 74 and the exhaust passageway 49 for injecting cooling 
water into the exhaust passageway 49 only at low engine speeds. While 
various suitable valve means can be employed, in the preferred embodiment, 
such means includes (see FIGS. 5-7) a valve assembly 138. 
The valve assembly 138 comprises (see FIG. 6) a housing 142 including an 
inlet 146 communicating with the cooling jacket 74, an outlet 150 
communicating with the exhaust passageway 49, and an internal passage 154 
connecting the inlet 146 and the outlet 150. The housing 142 further 
includes a valve seat 158 surrounding the inlet 146. In the illustrated 
construction, the housing 142 includes a main portion 159 having an open 
lower end and partially defining the passage 154. The housing 142 also 
includes an outlet portion 160 which is threaded into the bore 82, which 
extends integrally from the main portion 159 and which defines the outlet 
150. The housing 142 further includes a base portion 161 that closes the 
lower end of the main portion 159. 
The valve assembly 138 also comprises means for opening and closing the 
internal passage 154. The opening and closing means preferably includes 
(see FIG. 6) a valve member 162 which is located in the housing portion 
159, which is movable into and out of engagement with the valve seat 158, 
and which divides the main portion 159 into an upper chamber 164 and a 
lower chamber 165. The inlet 146 and the outlet 150 communicate with the 
upper chamber 164, and the internal passage 154 includes the upper chamber 
164. 
The valve member 162 comprises a stem portion 178 which cooperates with and 
extends into the inlet 146. The size of the stem portion is such that the 
area of the portion of the inlet 146 not occupied by the stem portion 178 
is substantially equal to the area of the outlet 150. The stem portion 178 
preferably has therein an orifice 182 which is calibrated to a 
predetermined speed or pressure and which communicates between the inlet 
146 and the lower chamber 165. The stem portion 178 has thereon a shoulder 
186 movable into and out of engagement with the valve seat 158 for opening 
and closing the inlet 146. The valve member 162 further comprises a main 
or piston portion 190 that is connected to the stem portion 178 and that 
is slideably housed by the main portion 159. The valve member 162 is 
movable relative to the housing 142 along an axis 192 coaxial with the 
inlet 146. The valve member 162 is movable between a closed position (see 
FIG. 7) wherein the valve member 162 minimizes the volume of the upper 
chamber 164 and closes the inlet 146 so that water cannot flow through the 
passage 154, and an open position (see FIG. 6) wherein the valve member 
162 maximizes the volume of the upper chamber 164 and opens the inlet 146 
so that water can flow through the passage 154. 
The opening and closing means preferably also includes spring means 200 
located in the upper chamber 164 between the housing 142 and the valve 
member 162 for biasing the valve member 162 downwardly or away from the 
valve seat 158. The spring means 200 thus biases the valve member 162 in 
the direction maximizing the volume of the upper chamber 164. 
During operation, the spring 200 holds the valve member 162 in its open 
position when the engine is turned off. After the engine is turned on, 
water will flow through inlet 146, through internal passage 154, and 
through outlet 150 and into the exhaust passageway 49. The orifice 182 is 
calibrated such that at the above-mentioned predetermined engine speed, 
the pressure in chamber 165 will overcome the force of the spring means 
200 and cause the valve member 162 to move upwardly and close the inlet 
146, thereby preventing water flow into the exhaust passageway 49. Thus, 
the valve member 162 is pressure responsive in that when the pressure in 
the lower chamber 165 reaches a predetermined level due to the water 
flowing through the orifice 182 and into the lower chamber 165, the 
pressure will force the valve member 162 upward, thereby causing shoulder 
186 to contact valve seat 158 and close the inlet 146. The valve member 
162 is responsive to engine speed in that the pressure of the water 
increases as the speed of the engine 20 increases. 
Various features of the invention are set forth in the following claims.