CA1062166A - Forced air control valve for exhaust pipe of internal combustion engine - Google Patents
Forced air control valve for exhaust pipe of internal combustion engineInfo
- Publication number
- CA1062166A CA1062166A CA252,148A CA252148A CA1062166A CA 1062166 A CA1062166 A CA 1062166A CA 252148 A CA252148 A CA 252148A CA 1062166 A CA1062166 A CA 1062166A
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- valve
- air
- main
- vacuum
- auxiliary
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Abstract
Abstract of the Disclosure A forced air control valve to control the flow of air to the exhaust pipe of an internal combustion engine immediately upstream of an oxidizing catalytic converter. The control valve when opened at a predetermined vacuum normally directs air to the exhaust pipe and when in a closed position at a low vacuum vents the forced air to atmosphere. Upon rapid deceleration when the main valve is open, a high vacuum is exerted and a separated diaphragm actuated auxiliary vent valve is actuated to vent the main diaphragm chamber to atmos-phere for a limited period of time thereby to close the main valve which is desirable upon rapid deceleration. An air bleed passage is provided in the diaphragm for the auxiliary vent valve diaphragm which permits the auxiliary vent valve to return to a closed position so that a vacuum can again be exerted against the main valve diaphragm. The air bleed passage pr?vides a delay in the equalization of the pressure on opposite sides of the vent valve diaphragm which delays the closing of the auxiliary vent valve thereby delaying the return of the main valve to an open position.
Description
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Background of the Invention Reference is made to United States Patent 3,964,259 which issued June 22, 1976, entitled Multi Condition Relief ~alve, which discloses a by-pass control valve for controlling the flow of forced air to the exhaust pipe of an internal combustion engine immediately upstream of an oxidizing catalytic converter. An oxidizing catalytic converter needs oxygen to function properly and additional oxygen can be provided by an engine driven air pump which forces air into an exhaust pipe of the engine upstream of the oxidizing catalytic converter. The control valve illustrated in United States Patent 3,964,259 is positioned in the air passage from the air pump to the exhaust pipe and is provided to shut off the air flow during periods of high acceleration ;- 15 and high deceleration as well as reducing the air flow during periods of sustained high speeds. During rapid deceleration of the vehicle, injected or forced air which may be injected in the oxidizing catalytic converter may create a violent type of burning in the exhaust system which may, in some instances, result in audible afte:r fires. This is objectionable noise and may create pressures that could be harmful to an exhaust system.
- Thus, during rapid deceleration it is desirable to close the main valve so that air may be by-passed into the ~ 25 atmosphere and not be provided to the secondary catalytic - converter. In the aforementioned United States Patent 3,964,259 the pressures on opposite sides of the main diaphragm were equalized through a separate vacuum control diaphragm system thereby resulting in the main valve being moved to a closed position in which position air was shut off to the ^ secondary oxidizing converter. The main valve and the by-., .. ... . , - . . . , , . . . -. , . - : , - ~ .
. . . , :-- , - - . , pass valve were both mounted on a common stem which was controlled by and connected to a main diaphragm which was not immediately responsive to rapid deceleration.
B ef Descr ption of the Invention_ _ _ _ The control valve of the present invention for controll-ing the flow of air through the forced air passage to the exhaust pipe of an internal combustion engine has a main valve seat positioned between inlet and outlet ports of the valve body and when in a seated position blocks the flow of air to the exhaust pipe. A separate by-pass valve is in an open position when the main valve member is seat~d and air is vented to the atmosphere from the forced air pump when the main valve member is seated across the passageway between the inlet and outlet ports. The main valve member and the by-pass valve member are mounted on a common stem which is controlled by a diaphragm. A separate auxiliary vent valve is positioned in the main vacuum chamber and has a separate stem connected thereto adjacent one end with an auxiliary diaphragm connected adjacent the other end of the stem.
The vent valve diaphragrn has a vacuurn chamber on one side thereof and a closed air chamber on the other side thereof with an air bleed passage through the auxiliary diaphragm between the enclosed air chamber and the auxiliary vacuum chamber. Upon rapid deceleration, a high vacuum is applied within the main vacuum chamber and the auxiliary vacuum chamber to open the vent valve immediately thereby to vent the main vacuum chamber to permit movement of the main valve to a closed position in which position the by-pass valve is ~ ~ -opened to allow the forced air to be discharged to atmosphere.
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106Z~6 The air bleed passage in the auxiliary diaphragm con-trols the return of the vent valve to a closed position in whi~h position the main valve chamber is again responsive to the intake manifold vacuum. The delay which is controlled by the size of the air bleed passage is provided by the auxiliary diaphragm thereby delaying any reopening of the main valve as the main valve chamber remains exposed to atmosphere while the vent valve is in open position. Upon closing of the vent valve, the vacuum, if between around three (3) inches and eighteen (18) inches of mercury obtained during normal engine operation, will aga~n open the main valve.
By delaying the closing of the vent valve to atmosphere, adequate time is provided to permit the pollutants in the exhaust pipe to be exhausted before additional air is provided by the forced air passage to the exhaust pipe upon subsequent reopening of the main valve. ~he spring holding the main diaphragm and main valve in a closed position is overcome by the application of manifold vacuum to the vacuum chamber. The amount of vacuum required will be selected in accordance with the requirements of the engine. However, it is common to select a spring that will allow the diaphragm to begin movement at a manifold vacuum in the order of three (3) to six (6) inches of mercury thereby creating a main valve open condition through the normal driving range of manifold vacuums which lie outside the wide open throttle and the deceleration range. In other words, when manifold vacuum is between the lower limit of three (3) to six (6) inches of mercury and a normal cruising vacuum of sixteen (16) to eighteen (18) inches of mercury, the main valve will be partially or fully open and will, thus,-pass air to the exhaust system as previously described. ~ -~
~, ' 4 Brief Descr ption of the Drawing _ _ The foregoing and other objec-ts, features and advantages of the invention will be apparent from the following more particular description of the preferred embodiments of the invention, as illustrated in the accompanying drawings in which reference characters refer to the same parts throughout the different views.
Figure 1 is schematic view of an internal combustion engine showing the control valve comprising the present invention positioned in an air passage from an air pump to the exhaust pipe to control the flow of air from the air pump to the exhaust pipe;
Figure 2 is an enlarged side elevation of the air control valve shown in figure 1 removed from the internal combustion engine of figure 1' Figure 3 is an enlarged section taken generally along line 3-3 of figure Z and showing the main valve member in a closed position with the flow of air being exhausted to atmosphere with the by-pass valve member being in an open position;
Figure 4 is a sectional view similar to figure 3 showing the main valve member in open position with air being supplied to the exhaust pipe and the by-pass valve member being in a closed position to block the flow of air to ~ -atmosphere;
Figure 5 is a bottom plan view of the control valve assmebly shown in figures 2-4;
Figure 6 is an enlarged fragment of figure 3 showing the air bleed passage in the auxiliary diaphragm to delay the closing of the vent valve after opening; and -.
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1~6Z~6~i Figure 7 is a longitudinal section of another embodi-ment of the present invention illustrating a primarily sheet metal construction for the body of the auxiliary diaphragm and the vent valve controlled thereby.
Referring now to figure 1, an internal combustion engine 11 has an intake manifold 13 thereon, an exhaust mani-fold 15 and an exhaust pipe 17 leading from exhaust manifold 15. First and second catalytic converter beds 19 and 21 are connected in series along exhaust pipe 17. The first cata-lytic converter bed 19 is a reducing converter and is intended to break down nitrogen - oxygen compounds into nitrogen gas and oxygen gas. The second catalytic converter bed 21 is an oxidi-zing type and is intended to convert hydrocarbons and carbon monoxide (CO) into carbon dioxide (C02) and water vapor. The ~ -second catalytic converter bed 21 requires additional oxygen in order to function properly.
To furnish air for injecting into exhaust pipe 17 is an air pump 25 driven by the crankshaft of the internal combustion engine 11 by a suitable pulley belt (not shown) and an air control valve assembly 27 comprising the present inventicn to control the flow of air from air pump 25 to ex-haust pipe 17. Air pump 25 injects air through air passage ~ -29 to control valve assembly 27 and from control valve assembly 27 through air passage 31 to exhaust pipe 17. A vacuum line 33 extends from air valve assembly 27 to intake manifold 13 and the magnitude of the vacuum in vacuum line 33 controls the flow of air through air control valve assmebly 27 from air pump 25 to exhaust pipe 17.
Referring particularly to figure 3, control valve assembly 27 has a main body 35 defining an inlet port 37, an outlet port 39, a main valve seat 41, and a by-pass valve '~
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106Zl~;6 seat 43. A main valve member 45 controls air flow -through central passage 47 and seat 41 through outlet 39. A by-pass valve member 49 controls the flow of air through seat 43 to atmosphere through muffler or filter 51 and retainer cup member 53 having suitable openings 54 therein to atmosphere.
A valve stem 55 has main valve member 45 and by-pass valve member 49 mounted thereon. A spring 57 extends between main valve member 45 and by-pass member 49. Mounted on one end of stem 55 is a spring retainer member 59 having an inner spring 61 seated thereon between retainer member 59 and by-pass valve member 49 to urge by-pass valve member 49 downwardly toward seat 43. A second outer coil spring 63 is seated between retainer 59 and valve body 35 to urge continu-ously stem 55 toward the seated position of main valve member 45. By-pass valve member 49 is mounted for sliding movement along the reduced end portion of valve stem 55 and when air ^ pressure within passage 47 reaches a sufficiently high magnitude, by-pass valve member 49 will unseat against the bias of spring 61 which is!overcome by the increased air pressure and thereby permit a flow of air to atmosphere until the pressure is re-duced to a predetermined amount of which time by-pass valve member 49 will reseat on seat 43. The end of stem 55 opposite spring retainer member 59 is secured to a diaphragm 65 attached about a peripheral portion to main body 35 of control air valve assembly 27. A guide 67 is mounted within a central air chamber 69 and stem 55 is adapted to move axially relative to guide 67.
An air tight seal is not provided between central air chamber 69 and a secondary air ~hamber 71 beneath guide 67 and a small leadkage of air occurs between chamber 71 and air chamber 69 about guide 67 to equalize the air pressure therebetween.
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1~6Z~66 A main vacuum chamber 73 is disposed on the side of diaphragm 65 opposite chamber 71 and a vacuum is exerted from line 33 through nipple 75 in bore 76 and small diameter passage 77 connecting vacuum chamber 73 to bore 76.
A vent valve 79 is seated on seat 81 about a vent opening 83 communicating with bore 84 which leads to atmos-phere through a filter 85. A stem 87 secured to vent valve member 79 adjacent one end is mounted adjacent its other end to an auxiliary diaphragm 89 which is gripped about its peripheral edge portion between a lower body portion 90 and an outer enclosed generally cylindrically housing 91. A peripheral flange 93 about housing 91 engages diaphragm 89 in gripping re lation to lower body portion 90. Vacuum chamber 97 for diaphragm 89 is connected by relatively large vacuum passage 99 to bore 76 and line 33 to intake manifold 13.
Referring to figure 6, an enlarged fragment of diaphragm 89 is shown in which a lower support plate 101 is mounted on one side of diaphragm 89 and an upper support plate 103 is mounted on the other side thereof for clamping diaphragm 89 therebetween. Stem 86 has a lower end portion extending through plates 101 and 103 to hold plates 101 and 103 into clamping contact with diaphragm 89. A spring 105 extends be~
tween plate 103 and lower body portion 90 to urge continuously .
diaphragm 89 and vent valve member 79 to a seated closed posi-tion on seat 81 to block flow of air into vacuum chamber 73 through vent passage 83 and bore 84 from atmosphere. End .
housing 91 provides an enclosed air chamber 107 and communica-tion is provided between the closed air chamber 107 and auxiliary vacuum chamber 97 through an ~ -.
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106Z~6 opening 109 in lower plate 101, an opening 111 in diaphragm 89, and a small bleed port or passage 113 provided in rib 115 on upper plate 103. Rib 115 acts as a retainer for adjacent spring 105 in addition to s-tiffening upper plate 103. Bleed passage 113 controls the flow of air between chamber 107 and vacuum chamber 97.
In operation, pressurized air is supplied to inlet port 37 by line 29 from air pump 25. Under normal engine operation, for example, when a vehicle is bein~ driven at a moderate steady speed, a vacuum applied to manifold vacuum chamber 71 by vacuum line 33 is between around three (3) inches and eighteen (18) inches of mercury. Under these conditions, the vacuum difference between vacuum chamber 73 and chamber 71 is sufficient to overcome the bias of spring 63 and move valve stem 55 downwardly to unseat main valve member 45 and to seat by-pass valve member 49 onto seat 43. In this position, as shown in figure 4, air travels through inlet :
port 37, air passage 47, air chamber 69, and outlet port 39 to be injected into exhaust pipe 17 through line 31.
However, assuming that a driver of a vehicle suddenly accelerates rapidly, the vacuum in manifold vacuum chamber 73 and in the auxiliary vacuum chamber 97 drops to a relatively low vacuum, for example, less than three (3) ~ -inches of mercury, which is insufficient to overcome spring .
-- 63. Spring 63 then moves stem 55 and main valve member 45 to a seated position and opens by-pass valve member 49 :
thereby to permit a flow fo air from inlet 37 through seat 43 and to atmosphere through muffler 51.
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.:' ' J . ' ' ~ , ' ' il~6Zl~i6 Assuming the vehicle is driven at a fast, relatively steady speed, a normal vacuum of twelve (12) to fifteen (15) inches of mercury is provided in manifold vacuum chamber 73 and auxiliary vacuum chamber 97 to hold valve stem 55 downwardly and main valve member 45 in an open position with by-pass valve member 49 in a closed position. However, as engine speed is increased, the speed at which combustion engine 11 drives air pump 25 is increased so that air pump 25 increases the air pressure at inlet port 37 and the air pressure acting against by-pass valve member 49. Eventually, the pressure reaches a relatively large amount so that by-pass valve member 49 is unseated against the bias of spring 61. As engine speed is reduced, the by-pass valve member 49 will reseat thereby to limit the actual amount of air at a fast`
steady speed as too great an amount of air in oxidizing cataly-tic converter bed 21 might cause damage to the converter bed resulting from relatively high temperatures being reached by the increased amount of oxygen.
One of the main advantages in the present design is obtained during deceleration of combustion engine 11. Assuming that a driver of a vehicle suddenly takes his foot from an accelerator pedal and thereby decelerates combustion engine 11, vacuum in manifold vacuum chamber 73 and in auxiliary vacuum chamber 97 increases rapidly to twenty-two (22) to twenty-five (25) inches of mercury, for example. It is noted that vacuum port 99 is of greater diameter than vacuum port 77 and, thus, the vacuum in chamber 97 responds slightly faster than the vacuum in vacuum chamber 73. Diaphragm 89 overcomes spring 105 to open vent valve 79 ~, .
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which open main vacuum chamber 73 to atmosphere through vent passage 83 and bore 84. Venting of vacuum chamberi73 to atmosphere results in an increase in pressure in vacuum chamber 73 to move valve stem 55 to a position in whilch main valve member 45 is reseated and by-pass valve member 49 is unseated thereby to permit the air to flow from inlet 37 through the by-pass opening to atmosphere. Vent valve 79 reseats itself when the pressure is generally equalized between auxiliary vacuum chamber 97 and air chamber 107 through bleed opening 113. Thus, the speed at which vent valve 79 is reseated is controlled by bleed opening 113 and bleed opening 113 thus provides a delay in any reopening of main valve member 45. This provides a time delay to permit the pollutants to be emitted from exhaust pipe 17 before air is again supplied to exhaust pipe 17 through line 31. The time delay may be controlled and is dependent on the vacuum.
For example, a time delay of around 2.4 seconds is desirable if the vacuum exerted is around twenty-two (22) inches of mercury; around 1.5 to 2.85 seconds for sixteen (16) inches . ~ .
of mercury; and from 0.5 to 1.6 seconds for eight (8) inches of mercury. Upon thè reseating of vent valve 79, the vacuum in vacuum chamber 73 is again exerted and if between around .~
three (3) inches and eighteen (18) inches of mercury, main valve member 45 will reopen to again supply air to exhaust pipe 17 through outlet 39 and line 31.
. Thus, the control valve assembly described herein while cutting off the flow of air injected into an exhaust pipe under a condition of high deceleration, aids the rapid closing of the main valve member by the immediate opening of a vent valve to atmosphere which permits the main vacuum .', .
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chamber for the main valve to communicate with atmosphere rapidly. In addition, means are provided to delay the closing of the vent valve for a predetermined time in order to permit the pollutants to be emitted from the secondary or oxidizing catalytic converter before àdditional air is supplied thereto.
The delay may be determined by the size of a bleed passage as a vacuum will not be exerted in the main vacuum chamber until the vent valve is closed.
In the event vacuum line 33 is severed or otherwise damaged, there will be no vacuum applied to fitting 75 and under such conditions, space 73 will be exposed to atmospheric pressure. In such event, spring 63 will bias valve plate 45 to a closed condition and valve plate 49 will be moved away froms its seat 43 so that all air from pump 25 is vented to atmosphere.
Referring to figure 7, a separate embodiment of the invention is illustrated in which a sheet metal body is provided by vent valve member 79A and auxiliary diaphragm 89A. --, , An enclosed air chamber 107A is provlded on one side of diaphragm 89A and a vacuum chamber 97A is provided on the opposite side of diaphragm 89A. A bleed passage 113A is provided in a rib 115A in a manner similar to that shown in figure 6 for the embodiment of figures 1-6. A vacuum is exerted from the intake manifold through vacuum nipples 75A.
During deceleration, a momentary pressure differential between chamber 107A and vacuum chamber 97A opens vent valve 79A to vent main vacuum chamber 73A to atmosphere through a vent opening lZ0. The pressure between chamber 107A and chamber 97A
is equalized by bleed passage 113A to permit closing of vent valve 79A after a controlled time delay. The functioning of , the embodiment of figure 7 is generally identical to the ? functioning of the embodiment of figures 1-6.
:, ' ' ' ;: -12-.
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Background of the Invention Reference is made to United States Patent 3,964,259 which issued June 22, 1976, entitled Multi Condition Relief ~alve, which discloses a by-pass control valve for controlling the flow of forced air to the exhaust pipe of an internal combustion engine immediately upstream of an oxidizing catalytic converter. An oxidizing catalytic converter needs oxygen to function properly and additional oxygen can be provided by an engine driven air pump which forces air into an exhaust pipe of the engine upstream of the oxidizing catalytic converter. The control valve illustrated in United States Patent 3,964,259 is positioned in the air passage from the air pump to the exhaust pipe and is provided to shut off the air flow during periods of high acceleration ;- 15 and high deceleration as well as reducing the air flow during periods of sustained high speeds. During rapid deceleration of the vehicle, injected or forced air which may be injected in the oxidizing catalytic converter may create a violent type of burning in the exhaust system which may, in some instances, result in audible afte:r fires. This is objectionable noise and may create pressures that could be harmful to an exhaust system.
- Thus, during rapid deceleration it is desirable to close the main valve so that air may be by-passed into the ~ 25 atmosphere and not be provided to the secondary catalytic - converter. In the aforementioned United States Patent 3,964,259 the pressures on opposite sides of the main diaphragm were equalized through a separate vacuum control diaphragm system thereby resulting in the main valve being moved to a closed position in which position air was shut off to the ^ secondary oxidizing converter. The main valve and the by-., .. ... . , - . . . , , . . . -. , . - : , - ~ .
. . . , :-- , - - . , pass valve were both mounted on a common stem which was controlled by and connected to a main diaphragm which was not immediately responsive to rapid deceleration.
B ef Descr ption of the Invention_ _ _ _ The control valve of the present invention for controll-ing the flow of air through the forced air passage to the exhaust pipe of an internal combustion engine has a main valve seat positioned between inlet and outlet ports of the valve body and when in a seated position blocks the flow of air to the exhaust pipe. A separate by-pass valve is in an open position when the main valve member is seat~d and air is vented to the atmosphere from the forced air pump when the main valve member is seated across the passageway between the inlet and outlet ports. The main valve member and the by-pass valve member are mounted on a common stem which is controlled by a diaphragm. A separate auxiliary vent valve is positioned in the main vacuum chamber and has a separate stem connected thereto adjacent one end with an auxiliary diaphragm connected adjacent the other end of the stem.
The vent valve diaphragrn has a vacuurn chamber on one side thereof and a closed air chamber on the other side thereof with an air bleed passage through the auxiliary diaphragm between the enclosed air chamber and the auxiliary vacuum chamber. Upon rapid deceleration, a high vacuum is applied within the main vacuum chamber and the auxiliary vacuum chamber to open the vent valve immediately thereby to vent the main vacuum chamber to permit movement of the main valve to a closed position in which position the by-pass valve is ~ ~ -opened to allow the forced air to be discharged to atmosphere.
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' . : . ,- . . .- :- : , - -. .
106Z~6 The air bleed passage in the auxiliary diaphragm con-trols the return of the vent valve to a closed position in whi~h position the main valve chamber is again responsive to the intake manifold vacuum. The delay which is controlled by the size of the air bleed passage is provided by the auxiliary diaphragm thereby delaying any reopening of the main valve as the main valve chamber remains exposed to atmosphere while the vent valve is in open position. Upon closing of the vent valve, the vacuum, if between around three (3) inches and eighteen (18) inches of mercury obtained during normal engine operation, will aga~n open the main valve.
By delaying the closing of the vent valve to atmosphere, adequate time is provided to permit the pollutants in the exhaust pipe to be exhausted before additional air is provided by the forced air passage to the exhaust pipe upon subsequent reopening of the main valve. ~he spring holding the main diaphragm and main valve in a closed position is overcome by the application of manifold vacuum to the vacuum chamber. The amount of vacuum required will be selected in accordance with the requirements of the engine. However, it is common to select a spring that will allow the diaphragm to begin movement at a manifold vacuum in the order of three (3) to six (6) inches of mercury thereby creating a main valve open condition through the normal driving range of manifold vacuums which lie outside the wide open throttle and the deceleration range. In other words, when manifold vacuum is between the lower limit of three (3) to six (6) inches of mercury and a normal cruising vacuum of sixteen (16) to eighteen (18) inches of mercury, the main valve will be partially or fully open and will, thus,-pass air to the exhaust system as previously described. ~ -~
~, ' 4 Brief Descr ption of the Drawing _ _ The foregoing and other objec-ts, features and advantages of the invention will be apparent from the following more particular description of the preferred embodiments of the invention, as illustrated in the accompanying drawings in which reference characters refer to the same parts throughout the different views.
Figure 1 is schematic view of an internal combustion engine showing the control valve comprising the present invention positioned in an air passage from an air pump to the exhaust pipe to control the flow of air from the air pump to the exhaust pipe;
Figure 2 is an enlarged side elevation of the air control valve shown in figure 1 removed from the internal combustion engine of figure 1' Figure 3 is an enlarged section taken generally along line 3-3 of figure Z and showing the main valve member in a closed position with the flow of air being exhausted to atmosphere with the by-pass valve member being in an open position;
Figure 4 is a sectional view similar to figure 3 showing the main valve member in open position with air being supplied to the exhaust pipe and the by-pass valve member being in a closed position to block the flow of air to ~ -atmosphere;
Figure 5 is a bottom plan view of the control valve assmebly shown in figures 2-4;
Figure 6 is an enlarged fragment of figure 3 showing the air bleed passage in the auxiliary diaphragm to delay the closing of the vent valve after opening; and -.
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1~6Z~6~i Figure 7 is a longitudinal section of another embodi-ment of the present invention illustrating a primarily sheet metal construction for the body of the auxiliary diaphragm and the vent valve controlled thereby.
Referring now to figure 1, an internal combustion engine 11 has an intake manifold 13 thereon, an exhaust mani-fold 15 and an exhaust pipe 17 leading from exhaust manifold 15. First and second catalytic converter beds 19 and 21 are connected in series along exhaust pipe 17. The first cata-lytic converter bed 19 is a reducing converter and is intended to break down nitrogen - oxygen compounds into nitrogen gas and oxygen gas. The second catalytic converter bed 21 is an oxidi-zing type and is intended to convert hydrocarbons and carbon monoxide (CO) into carbon dioxide (C02) and water vapor. The ~ -second catalytic converter bed 21 requires additional oxygen in order to function properly.
To furnish air for injecting into exhaust pipe 17 is an air pump 25 driven by the crankshaft of the internal combustion engine 11 by a suitable pulley belt (not shown) and an air control valve assembly 27 comprising the present inventicn to control the flow of air from air pump 25 to ex-haust pipe 17. Air pump 25 injects air through air passage ~ -29 to control valve assembly 27 and from control valve assembly 27 through air passage 31 to exhaust pipe 17. A vacuum line 33 extends from air valve assembly 27 to intake manifold 13 and the magnitude of the vacuum in vacuum line 33 controls the flow of air through air control valve assmebly 27 from air pump 25 to exhaust pipe 17.
Referring particularly to figure 3, control valve assembly 27 has a main body 35 defining an inlet port 37, an outlet port 39, a main valve seat 41, and a by-pass valve '~
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106Zl~;6 seat 43. A main valve member 45 controls air flow -through central passage 47 and seat 41 through outlet 39. A by-pass valve member 49 controls the flow of air through seat 43 to atmosphere through muffler or filter 51 and retainer cup member 53 having suitable openings 54 therein to atmosphere.
A valve stem 55 has main valve member 45 and by-pass valve member 49 mounted thereon. A spring 57 extends between main valve member 45 and by-pass member 49. Mounted on one end of stem 55 is a spring retainer member 59 having an inner spring 61 seated thereon between retainer member 59 and by-pass valve member 49 to urge by-pass valve member 49 downwardly toward seat 43. A second outer coil spring 63 is seated between retainer 59 and valve body 35 to urge continu-ously stem 55 toward the seated position of main valve member 45. By-pass valve member 49 is mounted for sliding movement along the reduced end portion of valve stem 55 and when air ^ pressure within passage 47 reaches a sufficiently high magnitude, by-pass valve member 49 will unseat against the bias of spring 61 which is!overcome by the increased air pressure and thereby permit a flow of air to atmosphere until the pressure is re-duced to a predetermined amount of which time by-pass valve member 49 will reseat on seat 43. The end of stem 55 opposite spring retainer member 59 is secured to a diaphragm 65 attached about a peripheral portion to main body 35 of control air valve assembly 27. A guide 67 is mounted within a central air chamber 69 and stem 55 is adapted to move axially relative to guide 67.
An air tight seal is not provided between central air chamber 69 and a secondary air ~hamber 71 beneath guide 67 and a small leadkage of air occurs between chamber 71 and air chamber 69 about guide 67 to equalize the air pressure therebetween.
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1~6Z~66 A main vacuum chamber 73 is disposed on the side of diaphragm 65 opposite chamber 71 and a vacuum is exerted from line 33 through nipple 75 in bore 76 and small diameter passage 77 connecting vacuum chamber 73 to bore 76.
A vent valve 79 is seated on seat 81 about a vent opening 83 communicating with bore 84 which leads to atmos-phere through a filter 85. A stem 87 secured to vent valve member 79 adjacent one end is mounted adjacent its other end to an auxiliary diaphragm 89 which is gripped about its peripheral edge portion between a lower body portion 90 and an outer enclosed generally cylindrically housing 91. A peripheral flange 93 about housing 91 engages diaphragm 89 in gripping re lation to lower body portion 90. Vacuum chamber 97 for diaphragm 89 is connected by relatively large vacuum passage 99 to bore 76 and line 33 to intake manifold 13.
Referring to figure 6, an enlarged fragment of diaphragm 89 is shown in which a lower support plate 101 is mounted on one side of diaphragm 89 and an upper support plate 103 is mounted on the other side thereof for clamping diaphragm 89 therebetween. Stem 86 has a lower end portion extending through plates 101 and 103 to hold plates 101 and 103 into clamping contact with diaphragm 89. A spring 105 extends be~
tween plate 103 and lower body portion 90 to urge continuously .
diaphragm 89 and vent valve member 79 to a seated closed posi-tion on seat 81 to block flow of air into vacuum chamber 73 through vent passage 83 and bore 84 from atmosphere. End .
housing 91 provides an enclosed air chamber 107 and communica-tion is provided between the closed air chamber 107 and auxiliary vacuum chamber 97 through an ~ -.
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106Z~6 opening 109 in lower plate 101, an opening 111 in diaphragm 89, and a small bleed port or passage 113 provided in rib 115 on upper plate 103. Rib 115 acts as a retainer for adjacent spring 105 in addition to s-tiffening upper plate 103. Bleed passage 113 controls the flow of air between chamber 107 and vacuum chamber 97.
In operation, pressurized air is supplied to inlet port 37 by line 29 from air pump 25. Under normal engine operation, for example, when a vehicle is bein~ driven at a moderate steady speed, a vacuum applied to manifold vacuum chamber 71 by vacuum line 33 is between around three (3) inches and eighteen (18) inches of mercury. Under these conditions, the vacuum difference between vacuum chamber 73 and chamber 71 is sufficient to overcome the bias of spring 63 and move valve stem 55 downwardly to unseat main valve member 45 and to seat by-pass valve member 49 onto seat 43. In this position, as shown in figure 4, air travels through inlet :
port 37, air passage 47, air chamber 69, and outlet port 39 to be injected into exhaust pipe 17 through line 31.
However, assuming that a driver of a vehicle suddenly accelerates rapidly, the vacuum in manifold vacuum chamber 73 and in the auxiliary vacuum chamber 97 drops to a relatively low vacuum, for example, less than three (3) ~ -inches of mercury, which is insufficient to overcome spring .
-- 63. Spring 63 then moves stem 55 and main valve member 45 to a seated position and opens by-pass valve member 49 :
thereby to permit a flow fo air from inlet 37 through seat 43 and to atmosphere through muffler 51.
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.:' ' J . ' ' ~ , ' ' il~6Zl~i6 Assuming the vehicle is driven at a fast, relatively steady speed, a normal vacuum of twelve (12) to fifteen (15) inches of mercury is provided in manifold vacuum chamber 73 and auxiliary vacuum chamber 97 to hold valve stem 55 downwardly and main valve member 45 in an open position with by-pass valve member 49 in a closed position. However, as engine speed is increased, the speed at which combustion engine 11 drives air pump 25 is increased so that air pump 25 increases the air pressure at inlet port 37 and the air pressure acting against by-pass valve member 49. Eventually, the pressure reaches a relatively large amount so that by-pass valve member 49 is unseated against the bias of spring 61. As engine speed is reduced, the by-pass valve member 49 will reseat thereby to limit the actual amount of air at a fast`
steady speed as too great an amount of air in oxidizing cataly-tic converter bed 21 might cause damage to the converter bed resulting from relatively high temperatures being reached by the increased amount of oxygen.
One of the main advantages in the present design is obtained during deceleration of combustion engine 11. Assuming that a driver of a vehicle suddenly takes his foot from an accelerator pedal and thereby decelerates combustion engine 11, vacuum in manifold vacuum chamber 73 and in auxiliary vacuum chamber 97 increases rapidly to twenty-two (22) to twenty-five (25) inches of mercury, for example. It is noted that vacuum port 99 is of greater diameter than vacuum port 77 and, thus, the vacuum in chamber 97 responds slightly faster than the vacuum in vacuum chamber 73. Diaphragm 89 overcomes spring 105 to open vent valve 79 ~, .
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. . : . :. ~ . .. .... .
which open main vacuum chamber 73 to atmosphere through vent passage 83 and bore 84. Venting of vacuum chamberi73 to atmosphere results in an increase in pressure in vacuum chamber 73 to move valve stem 55 to a position in whilch main valve member 45 is reseated and by-pass valve member 49 is unseated thereby to permit the air to flow from inlet 37 through the by-pass opening to atmosphere. Vent valve 79 reseats itself when the pressure is generally equalized between auxiliary vacuum chamber 97 and air chamber 107 through bleed opening 113. Thus, the speed at which vent valve 79 is reseated is controlled by bleed opening 113 and bleed opening 113 thus provides a delay in any reopening of main valve member 45. This provides a time delay to permit the pollutants to be emitted from exhaust pipe 17 before air is again supplied to exhaust pipe 17 through line 31. The time delay may be controlled and is dependent on the vacuum.
For example, a time delay of around 2.4 seconds is desirable if the vacuum exerted is around twenty-two (22) inches of mercury; around 1.5 to 2.85 seconds for sixteen (16) inches . ~ .
of mercury; and from 0.5 to 1.6 seconds for eight (8) inches of mercury. Upon thè reseating of vent valve 79, the vacuum in vacuum chamber 73 is again exerted and if between around .~
three (3) inches and eighteen (18) inches of mercury, main valve member 45 will reopen to again supply air to exhaust pipe 17 through outlet 39 and line 31.
. Thus, the control valve assembly described herein while cutting off the flow of air injected into an exhaust pipe under a condition of high deceleration, aids the rapid closing of the main valve member by the immediate opening of a vent valve to atmosphere which permits the main vacuum .', .
'' -11- '; ' -: : :
: .. . , . :
. - : . . . , , . : : . , .
,, ....................... . ~. .. .
chamber for the main valve to communicate with atmosphere rapidly. In addition, means are provided to delay the closing of the vent valve for a predetermined time in order to permit the pollutants to be emitted from the secondary or oxidizing catalytic converter before àdditional air is supplied thereto.
The delay may be determined by the size of a bleed passage as a vacuum will not be exerted in the main vacuum chamber until the vent valve is closed.
In the event vacuum line 33 is severed or otherwise damaged, there will be no vacuum applied to fitting 75 and under such conditions, space 73 will be exposed to atmospheric pressure. In such event, spring 63 will bias valve plate 45 to a closed condition and valve plate 49 will be moved away froms its seat 43 so that all air from pump 25 is vented to atmosphere.
Referring to figure 7, a separate embodiment of the invention is illustrated in which a sheet metal body is provided by vent valve member 79A and auxiliary diaphragm 89A. --, , An enclosed air chamber 107A is provlded on one side of diaphragm 89A and a vacuum chamber 97A is provided on the opposite side of diaphragm 89A. A bleed passage 113A is provided in a rib 115A in a manner similar to that shown in figure 6 for the embodiment of figures 1-6. A vacuum is exerted from the intake manifold through vacuum nipples 75A.
During deceleration, a momentary pressure differential between chamber 107A and vacuum chamber 97A opens vent valve 79A to vent main vacuum chamber 73A to atmosphere through a vent opening lZ0. The pressure between chamber 107A and chamber 97A
is equalized by bleed passage 113A to permit closing of vent valve 79A after a controlled time delay. The functioning of , the embodiment of figure 7 is generally identical to the ? functioning of the embodiment of figures 1-6.
:, ' ' ' ;: -12-.
,: : . . . . . . . .
Claims (3)
1. In an internal combustion engine exhaust of the type wherein forced air is injected into an exhaust pipe through a forced-air passage, an improved automatically-actuated control valve in said forced-air passage for controlling the flow of air through said forced-air passage to the exhaust pipe wherein the improvement comprises:
a. a valve body having inlet, outlet and by-pass ports, said inlet port being in fluid communication with a forced-air source, said outlet port being in fluid communication with said exhaust pipe, and said by-pass port being in fluid communication with atmosphere;
b. a main valve seat positioned between said inlet and outlet ports; a by-pass valve seat positioned between said inlet and by-pass ports; a passage between said seats;
c. a valve stem positioned in said passage having affixed thereto a main valve member and a by-pass valve member adapted to seat on the respective seats;
d. a main diaphragm assembly secured to the valve body and connected to an end of said valve stem, a spring biasing means to urge said diaphragm assembly and said main valve member toward a seated position, said valve body having a main manifold vacuum chamber on one side of said main diaphragm assembly in fluid communication with an intake manifold of said internal combustion engine;
e. a vent valve seat in fluid communication with the main vacuum chamber, a vent valve for said seat, a stem connected adjacent one end to said vent valve, a vent passage to atmosphere in fluid communi-cation with the main vacuum chamber when the vent valve is open and being closed to the main vacuum chamber when the vent valve is closed, an auxiliary diaphragm assembly connected adjacent the other end of said vent valve stem, spring biasing means to urge said auxiliary diaphragm assembly and said vent valve toward a seated position, said valve body forming an auxiliary vacuum chamber on one side of said auxiliary diaphragm assembly in fluid communication with the intake manifold of said internal combustion engine; and forming an enclosed air chamber on the opposed side of said auxiliary diaphragm assembly;
f. an air bleed passage in said auxiliary diaphragm assembly between the enclosed air chamber and the auxiliary vacuum chamber, wherein a high deceleration of the combustion engine exerts a high vacuum within the auxiliary vacuum chamber to open the vent valve against the biase of its spring biasing means to vent the main vacuum chamber to atmosphere thereby to urge the main diaphragm and main valve member to a closed position, the pressure between the enclosed air chamber and the auxiliary vacuum chamber being equalized upon the flow of air through the air bleed passage in said auxiliary diaphragm assembly whereby the auxiliary diaphragm assembly returns to its normal position to close the vent valve and block the vent passage to atmosphere.
a. a valve body having inlet, outlet and by-pass ports, said inlet port being in fluid communication with a forced-air source, said outlet port being in fluid communication with said exhaust pipe, and said by-pass port being in fluid communication with atmosphere;
b. a main valve seat positioned between said inlet and outlet ports; a by-pass valve seat positioned between said inlet and by-pass ports; a passage between said seats;
c. a valve stem positioned in said passage having affixed thereto a main valve member and a by-pass valve member adapted to seat on the respective seats;
d. a main diaphragm assembly secured to the valve body and connected to an end of said valve stem, a spring biasing means to urge said diaphragm assembly and said main valve member toward a seated position, said valve body having a main manifold vacuum chamber on one side of said main diaphragm assembly in fluid communication with an intake manifold of said internal combustion engine;
e. a vent valve seat in fluid communication with the main vacuum chamber, a vent valve for said seat, a stem connected adjacent one end to said vent valve, a vent passage to atmosphere in fluid communi-cation with the main vacuum chamber when the vent valve is open and being closed to the main vacuum chamber when the vent valve is closed, an auxiliary diaphragm assembly connected adjacent the other end of said vent valve stem, spring biasing means to urge said auxiliary diaphragm assembly and said vent valve toward a seated position, said valve body forming an auxiliary vacuum chamber on one side of said auxiliary diaphragm assembly in fluid communication with the intake manifold of said internal combustion engine; and forming an enclosed air chamber on the opposed side of said auxiliary diaphragm assembly;
f. an air bleed passage in said auxiliary diaphragm assembly between the enclosed air chamber and the auxiliary vacuum chamber, wherein a high deceleration of the combustion engine exerts a high vacuum within the auxiliary vacuum chamber to open the vent valve against the biase of its spring biasing means to vent the main vacuum chamber to atmosphere thereby to urge the main diaphragm and main valve member to a closed position, the pressure between the enclosed air chamber and the auxiliary vacuum chamber being equalized upon the flow of air through the air bleed passage in said auxiliary diaphragm assembly whereby the auxiliary diaphragm assembly returns to its normal position to close the vent valve and block the vent passage to atmosphere.
2. The improved automatically-actuated central valve set forth in claim 1 wherein a lower body portion has the main vacuum chamber on one side thereof and the auxiliary vacuum chamber on the other side thereof, and a bore in fluid communication with a vacuum source extends within said lower body portion and is in fluid communication with both said main and said auxiliary vacuum chambers.
3. The improved automatically-actuated control valve set forth in claim 1 wherein an outer body portion has said main vacuum chamber on one side thereof and said auxiliary vacuum chamber on the other side thereof, a vacuum passage in said outer body portion in fluid communication with a vacuum source, a relatively small-sized vacuum port from said vacuum passage to said main vacuum chamber and a relatively large-sized vacuum port from said vacuum passage to said auxiliary vacuum chamber so that the auxiliary diaphragm assembly responds faster to the vacuum source than does the main diaphragm assembly under rapid deceleration of the engine.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US62294375A | 1975-10-16 | 1975-10-16 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1062166A true CA1062166A (en) | 1979-09-11 |
Family
ID=24496139
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA252,148A Expired CA1062166A (en) | 1975-10-16 | 1976-05-10 | Forced air control valve for exhaust pipe of internal combustion engine |
Country Status (2)
| Country | Link |
|---|---|
| JP (1) | JPS5250415A (en) |
| CA (1) | CA1062166A (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS53113015U (en) * | 1977-02-17 | 1978-09-08 | ||
| JPS55125148U (en) * | 1979-02-28 | 1980-09-04 | ||
| JPS55147025A (en) * | 1979-05-04 | 1980-11-15 | Sanyo Seikou Kk | Switching and displaying unit for tuning audio level |
| JPS5662430A (en) * | 1979-10-26 | 1981-05-28 | Pioneer Electronic Corp | Receiver |
| JPS6123875Y2 (en) * | 1980-03-14 | 1986-07-17 | ||
| JPS6123876Y2 (en) * | 1980-03-14 | 1986-07-17 |
-
1976
- 1976-05-10 CA CA252,148A patent/CA1062166A/en not_active Expired
- 1976-10-15 JP JP12438376A patent/JPS5250415A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5250415A (en) | 1977-04-22 |
| JPS5310215B2 (en) | 1978-04-12 |
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