Process for controlling secondary gas fuel to normally liquid fueled I.C. engine

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Process for controlling secondary gas

the throttle is moved to increase engine speed the cable is actuated, and a control arm imparts rotational move

FUELTO NORMALLY LIQUID FUELED I.C. ment to a shaft member which carries a yoke in contact ENGINE with the valve. Upon rotation of the shaft, the yoke 5 member moves away from a top dead-center arrange

This application is a division of application Ser. No. ment which normally keeps the valve in a closed posi 397,168, filed July 12, 1982, now U.S. Pat. No. tion and the degree of rotation determines the degree of 4,440,137. opening of the valve which is acted upon by the gas fuel TECHNICAL FIELD OF THE INVENTION pressure and the inlet manifold pressure. Therefore, the O amount of gas which is allowed to be injected into the

The invention is a process for controlling the supply engine will initially be controlled by throttle position, of gaseous supplemental fuels to an internal combustion and thereafter by th air flow responsive member. As in engine normally supplied with liquid fuel. the first embodiment, an adjusting means is provided for SUMMARY OF THE INVENTION determining the amount of movement of the crank arm 15 and control shaft. This would again require a predeter

This invention relates to a propane or other supple mined engine speed to be reached before gas injection is mental gas fuel injection valve system for use in combi initiated.

nation with a diesel powered internal combustion en gine. The device allows the use of lower cost propane BRIEF DESCRIPTION OF THE DRAWINGS or other gas fuel in combination with the use of diesel 20 FIG. 1 is a schematic representation of the dual fuel fuel. It has been found that propane increases the effi system according to the present invention; ciency of a diesel engine, thereby allowing a prospec FIG. 2 is a top view of the gas injection meterinng tive diesel engine manufacturer to provide a smaller valve of the present invention;

engine to do substantially the same work as a larger FIG. 3 is a side view, in cross-section, of the metering engine counterpart running on diesel fuel alone. Also, 25 valve;

the addition of propane causes a more complete com FIG. 4 is a partial, side view, in cross-section, of an bustion of diesel fuel entering the engine. This has been alternative embodiment of the present invention; and, noted by a marked drop in the exhaust temperature in a FIG. 5 is a schematic representation of a control diesel engine after propane has been injected and the system for the embodiment shown in FIG. 4. throttle has been reduced to the same torque as it was 30 with a straight diesel. Due to the more complete com DETAILED DESCRIPTION OF THE bustion of the diesel fuel, pollution is greatly reduced by PREFERRED EMBODIMENT reducing the amount of the unburned diesel fuel previ Reference numeral 10 indicates a schematic represen ously passed through the exhaust system. This is also an tation of the dual fuel system as contemplated by the important ecological consideration. The valve unit, of 35 present invention. Internal combustion engine 12 has an the present invention, is designed to inject gas fuel into intake manifold 14 and an exhaust manifold 16. Con the intake air of a diesel. The unit is designed to meter nected between the manifolds 14-16, is a turbocharger the gas in proportion to the air demanded by the engine. 18 with an intake side 18 and a compression discharge In one embodiment, the air demanded by the engine side 18'. A supply tank 20 containing liquid fuel creates a pressure differential across an inlet air flow supplies the fuel to a fuel injection system (not shown) responsive element of the gas injection valve so as to for injection to the conbustion chambers (not shown) control the opening and closing of the valve so as to via a conduit 22, and a pump 24. An air cleaner 26 is control the amount of gas injected into the internal mounted on the engine in any well-known manner and combustion engine. The element which is responsive to is adapted to deliver air so as to ensure the proper air/fthe incoming air is disposed at one end of a cylindrical 45 uel ratio for combustion to engine 12 via conduit 19 to chamber within which is located a biasing means. The the metering or control valve 32 of the present inven incoming air to the internal combustion engine causes a tion. A gas fuel supply (e.g., propane) is indicated at 28 pressure drop in the chamber and, as the pressure falls in and is connected by conduit 30 to a vaporizer regulator the chamber, the atmospheric pressure creates a force 29, for vaporizing the gas, and the gas fuel metering or which compresses the spring and allows the air flow 50 control valve, of the present invention, indicated gener responsive element to open until the tension of the bias ally at 32. The metering or control valve 32 is attached ing means equals the forces acting on the air reactor so as to receive air demaned by the engine and, when member due to incoming air flow. Due to the intercon actuated, to transmit the air/gas vapor mixture to the nection of the valve, the air flow responsive element turbocharger 18 via conduit 33. The turbocharger 18 is controls the position of a gas valve which acts to meter 55 driven by exhaust gas from the exhaust manifold 16 via the incoming gas supply to the internal combustion conduit 17 or, in the alternative, by any well-known engine. The higher the air flow, the more the gas valve manner. The compression side 18" supplies the mixture is moved to an open position thereby allowing more gas to the intake manifold 14 via conduit 35. The unit 32 is to enter the engine. The element responsive to the air designed to meter the gas fuel in proportion to the air flow may be adjustably positioned by means of a demanded in accordance with engine speed as will be threaded engagement with a valve stem connected to explaind in further detail below.

the gas valve. Accordingly, the gas fuel can be injected FIG. 2 is a top sectional view taken along the lines in response to varying engine speeds. II-II in FIG. 3. The housing casing is shown at 34 and A second aspect of the invention utilizes a direct supports a valve body 36 by a three-post mounting mechanical connection between the gas valve and the 65 arrangement, one of which is shown at 38. The gas fuel engine throttle control. In this concept, the gas valve is inlet conduit 30 is received within an opening 40 of the held in a closed position until the cable is actuated by valve body 36. As shown, the body member 36 has a gas the throttle control as the throttle is initially opened. As entrance passage 42 for receiving the gas fuel supply 6 from the conduit 30. The duct 42 is fluidly connected, in arrow 96, and passes the air flow responsive member 76 a manner to be explained later, with a central aperture in the direction of arrow 98 into the cylindrical cham 44 in the valve body 36. ber 100. A lower pressure is created in chamber 100 due The valve unit 32, shown in FIG. 3, is contained to the pressure drop across member 76 caused by the within a two-part casing 34, 46. The valve body assem force exerted by spring 78. This air is demanded by the bly 36 defines an L-shaped area, when viewed in cross engine, incoming flow causes a pressure drop in cham section, which is defined by a vertically extending wall ber 100 and chamber 102, respectively. As the pressure portion 50 and a horizontally extending ledge portion falls in chambers 100 and 102, the atmospheric pressure 52. The L-shaped area 48 positions a guide block 54. exerts a force in the direction of arrow 104 and com The guide block 54 is provided with converging side O presses spring 78 as member 76 is forced in the direction walls 56 which define a centrally located, circular aper of arrow 104. Air flow responsive element 76 will open ture. The guide block 54 also defines a plurality of gas until a balance between an engine air demand plus the passages, one of which is shown at 58, which allows the spring tension in spring 78 equals the incoming atmo gas fuel to communicate between gas entrance passage spheric pressure. The position of the member 76 con 42 and the central body aperture 44 of the valve body 15 trols the position of the gas valve element 88. Gas valve assembly 36. A valve cover assembly 60 is provided 88 seals off the gas passage completely by an O-ring 92. with a central aperture 62 and converging side walls 64. As the engine demands more air, the valve 88 is forced The side walls 64 and 56, of the cover and guide block, down the diverging walls 94 of the valve body 36 by respectively, are mounted in flush engagement with pressure differential forces. The further the valve 88 is each other. The valve cover 60 may be secured to the 20 forced down the diversing passage, the more gas is vertically extending wall portions 50 of the valve body allowed to pass from the gas entrance passage 27, 36, by any known manner which ensures a tight seal. through the gas passageways, 58, to the gas inlet area 44 For purposes of illustration, a bolt attachment is shown of the valve body 36. The gas vapors enter the conduit at 66. 33 through the orifices 70. After compression in the Secured to the base of the valve body assembly 36 is 25 turbocharger 18, the mixture is introduced into the a cone-shaped orifice housing 68. As with the cover intake manifold 14. As previously discussed, the relative assembly 60, the orifice housing 68 may be secured to positioning of the air flow responsive member 76 can be the body assembly 36 by a series of screws, not shown, changed on rod 72 by loosening the fastening means 82 arranged around the periphery of the housing 68. This so as to change the relative position of the member 76 arrangement would be similar to the attachment means 30 with respect to the casing section 46. Accordingly, this 66 for the cover assembly 60. As will be described later, changes the engine rpm when the gas injection is to orifices 70 are provided for directing the gas fuel from start entering the airstream. Accordingly, it is to be the central aperture 44 into the air stream of the internal understood that the system has two modes of operation, combustion engine 12. i.e., liquid fuel alone or a combination of liquid fuel and Slidably mounted within the cover assembly 60 is a 35 gaseous fuel.

rigid rod connector 72. As shown in FIG. 3, one end of FIG. 4 discloses an alternate embodiment of the gas the rod 72 is threadedly engaged at 74 with air flow inlet valve 32 disclosed in FIG. 3.

responsive member 76. A spring member 78 biases the The embodiment of FIG. 4 relates eseential to the member 76 away from the valve cover element 60. The mechanism by which valve 8 is operated and con spring 78 is concentric to the rod 72 and one end is 40 trolled. Accordingly, like elements of FIG. 4 will be seated within member 76 within a shoulder 80. The denoted by the same reference numerals as set forth in other end of the spring 78 is seated against the valve the disclosure of FIG. 3. In this embodiment, the gas cover 60. An adjusting member 82 is threadedly en inlet valve element 88 is allowed to slide freely on the gaged with the rod 72 and contacts the member 76 at 84. rod 72 forming a lost motion, connection, in that rod 72 The adjusting means 82 allows the relative position of 45 can move one way (down) without moving valve ele the air flow responsive member 76 to be changed on rod ment 88, but will positively drive the valve element 72 by loosening the adjustment means 82 and threading towards a closed position when it moves the other way the member 76 up or down on rod 72. This changes the (up). A stop element 86 is provided on the end of the relative position of the member 76 with respect to the rod 72 to effect positive closing motion. A crank lever casing member 46. assembly, for controlling the opening and closing of the At the opposite end of the threaded section 74 of the aperture 44 by the valve element 88, is indicated gener rod 72 is a stop member 86. The stop member 86 sup ally at 106. The assembly 106 is rotationally attached to ports and fixedly positions valve element 88 comprising the shaft 108 which, in turn, is operatively connected to a rectilinearly movable plug in a tapered bore 94. The the engine throttle in a manner to be explained below. valve element 88 has a central aperture 90 to allow the 55 The crank assembly and shaft 106, 108, respectively, rod 72 to pass therethrough. Circumferentially sur are positioned within the cone-shaped orifice housing rounding the valve element 88 at its topmost portion of 68. The assembly 106 consists of a yoke member 110 largest radius is an O-ring 92. When the valve 88 is in its fixedly attached to the shaft 108 and a stop member 112. closed position, i.e., when it does not allow gas to pass The yoke assembly 110 is engaged, in cam and follower into the air stream of the engine, the O-ring 92 sealingly 60 relationship with the bottom surface area of the valve engages with the diverging side walls of the bore 94. element 88 so as to control its reciprocating movement In operation, the unit 32 is designed to inject gas that within the aperture 44 of the valve body element 36 as has been vaporized into the intake manifold of an inter defined by the diverging wall portions 94. The rota nal combuston engine, and in the case contemplated by tional movement of the shaft 108 is controlled by a cable the present invention, a diesel engine. The unit is de 65 114 connected to the engine throttle (not shown). An signed to meter the gas in proportion to the air de end 116, of the cable 114, is attached to the crank lever manded by the engine as determined by throttle position assembly 106 by an adjustment member 118. The adjust (engine speed). Air enters the unit 32 in the direction of ment member 118 is threadedly engaged with a control 7 arm 120. The control arm 120 has a slot 122 which invention be limited solely by that of the following allows the cable end 116 to be attached to the screw claims.

118. Further, the slot 122 determines the maximum and I claim minimum rotational movement of shaft 108 and hence, 1. A process for controlling the supply of gaseous the maximum and minimum reciprocating travel of the 5 secondary fuel to the intake air stream of an internal valve 88, which in turn determines the amount of gas combustion engine that normally is supplied with a entering into the airstream of the engine. A spring 124 liquid primary fuel under the control of an engine speed functions as the return spring for the crank assembly controller comprising:

106. This spring 124 holds the gas valve closed unless 10 (a)intake supplying gaseous secondary fuel to the engine air stream in accordance with a desired air to the throttle of the engine is depressed.

In operation, the valve element 88 is held in a closed secondary fuel ratio during normal engine opera position by the spring 124 until the cable 114 is actuated tion by using a moveable air flow responsive mem by the throttle, not shown. Because of the lost motion ber in the direct path of the engine air intake stream connection, movement of the rod 72 and the air reaction 5 to control the position of a moveable gas valve member 76 is unrestricted, and these elements can still element in a gas fuel supply system; and, move in response to air flow pressure. Once the cable (b) effecting positive closure of the gas valve element when the engine speed controller is at or ap 114 is actuated, the crank arm 120 rotates shaft 108 and proaches its idle or off position without effecting with it, yoke 110. The rotational movement of the yoke movement of the air flow responsive member, so 110 allows the valve element 88 to move to an open 20 the air flow responsive member is movable by re position and an amount of gas, determined by the ad sponse to intake air flow even when the gas valve justment of screw 118, enters the turbocharger 18 and is closed.

the engine 12, as previously discussed. 2. A process as claimed in claim 1, wherein the step of After the throttle has moved beyond a low throttle progressively closing the gas valve element comprises position near idle, of course, yoke 110 is moved by the 25 using a linkage between the speed controller and the throttle cable and valve element 88 moves in accor movable gas valve element, the linkage being displaced dance with the fluid pressures acting on it to seat against by the speed controller; and moving the linkage so that the stop 86, at which time the valve element follows the the movable gas element is moved towards a closed motion of rod 72 until or unless the yoke 110 moves the 30 position only when the speed controller approaches its valve element towards the closed position indepen idle or off position, while not affecting the position of the gas valve element at other speed controller posi dently of the air flow responsive member as the throttle tions.

moves towards its idle position. 3. A process as claimed in claim 1 or 2, wherein the While the invention has been described in terms of certain preferred embodiments, the skilled worker in 35 passingisalla diesel engine of the primary fuel injected engine, including engine intake air through the gas fuel the art will recognize that there are various changes, control valve housing and permitting the air flow re omissions, modifications, and substitutions that may be sponsive member to be deflected by said air stream made without departing from the spirit of the invention. during engine operation.

Accordingly, it is intended that the scope of the present k k ak s k