US 1983351 A
Abstract available in
Claims available in
Description (OCR text may contain errors)
Dec. 4, 1934. c EDWARDS 1,983,351
INTERNAL COMBUST I ON ENGINE Filed Aug. 10, 1952 gwuc/fvto'b 173555???" E EDA/HERE.
Patented Dec, 4, 193
1,983,351 INTERNAL-COMBUSTION ENGINE Herbert 0. Edwards, Detroit, Mich assignor to Packard Motor Car Company, Detroit, Mich a corporation of Michigan Application August 10, 1932, Serial No. 628,216 12 Claims. (Cl. 123-32) This invention relates. to engines and more particularly to internal combustion engines.
The main object of the present invention resides in the association with an internal com- 9 bustion engine of means for stabilizing its speed of operation during idling.
Another object of the invention is to provide an engine in which negative work is introduced into the cycle in order to stabilize idling speed. A further object of the invention is to provide an internal combustion engine with means for relieving the explosion chamber during the working stroke in order to introduce negative work and thereby stabilize the engine when idling.
Other objects of the invention will appear from wthe following description taken-in connection with ithe'drawing', which forms a part of this specifi= cation, and in which:
lig. 1 is a vertical sectional view of an engine having stabilizing mechanism, forming the subject of this invention, associated therewith;
Fig. 2 is a fragmentary sectional view of the engine with the stabilizing mechanism in a po- 25 sition to permit pressure relief;
Referring now to the drawing by characters of reference, 10 represents the crank case of an internal combustion engine having one or more cylinders as indicated at 11 associated therewith. The usual crank shaft 12 is carried within the crank case and connected thereto is a rod 13 which is also connected to the piston 14 arranged to reciprocate within the cylinder. The engine illustrated is of the two-cycle type and has provision for separate introduction of air and atomired liquid fuel which unite to form fuel charges which ignite by means of heat developed by compression in the cylinder. It will be understood, however, that this invention can be applied to four or other cycle engines.
Suitable sets of ports, as indicated at 1.5, are provided through the cylinder walls in diametrically opposite relation and one set of such ports act as air inlets and the other set of ports act as exhaust outlets in the conventional two-cycle manner. The piston is also provided with a flanged head portion 16 which is associated to cooperate with the set of air inlet ports in a manner to direct air upwardly in the cylinder when first admitted therein.
Suitable mechanism is associated with the engine for injecting variable charges of liquid fuel into the cylinder. In this instance, there is a nozzle 1'7 anda pump 18 which are secured together to form a unitary structure. A portion 86 of the nozzle extends through the cylinder wall and associated with the outlet end thereof is a valve 19 which is normally substantially closed. Associated with the pump unit is a plunger 9 which is reciprccated by articulated push rod 69 members 20 and 21. The plunger controls passages, as indicated at 22, to trap liquid fuel and, after closing such passages, the plunger creates a pressure against the trapped fuel sumcient to open the valve 19 whereupon the fuel charge 65 is sprayed into compressed air in the cylinder.
A cam 23, driven from the crank shaft, is arranged within the crank case and associated therewith is a rock lever 24' which is mounted on a shaft 25. This rock lever has a curved face iii 26 upon which the push rod element 21 can be adjusted in a direction to change the eifective stroke of the plunger. An arm 27 is fixed to the shaft 28 upon which is also fixed a hand lever 29 and cbnnecting the arm with the link 21 is iii another link 30. By rocking the shaft 22, through means of the lever 29, the arm 27 and link 30 can be moved to adjust the rod element 21 along the curved face 26 of the rock lever and thus the quantity in the fuel charges delivered so from the injection device can be varied. When the rod 21 has been adjusted to the position shown in dotted lines in Fig. i, then the plunger will no longer cover the ports 22 during its reciprocation and consequently no fuel will be delivered into the 35 cylinder. The position of the rod 21' on the curved face 26 will determine the distance the plunger moves past the ports 22 and will thus regulate the quantity of liquid in the fuel charges delivered from the injection device. This fuel an injection device does not form a part of this invention and for a betterunderstanding thereof reference can be had to application Serial No. 358,899 filed by Lionel M; Woolson, April 29, 1929 and issued February 7, 1933 as Patent No. ,95
With the engine described, air is admitted into the cylinder and is trapped therein by the piston and compressed, and during the compression stroke, the fuel injection mechanism is timed to ma project charges of atomized. liquid fuei into the air charges in the cylinder whereupon the mixture of air and fuel will be ignited through the heat of compression. The explosion of the mixture moves the piston away from top center of the cylinder until it uncovers the set of outlet ports whereupon another charge of air rushes into the cylinder, through the set of inlet ports, displacing the exhaust gases and filling the cylinder with air. I have found with engines of the compression-ignition type that the adjustment of the injection device to regulate the fuel volume is very unstable when set for idling of the engine due to the high pressure and minute volume dispensed, and consequently if continued ignition is to be maintained, then the injection device must be set to deliver a greater volume of fuel than is required and, as a consequence, the engine speed is maintained higher than is desirable for some purposes and for economy. When an engine of this type is utilized as the power plant of an aeroplane, it is essential that there be no stalling during idling because the engine must be idling when landing, but with the fuel volume adjustment regulated to insure that there will be no stalling during gliding of the aeroplane, the speed developed is too high for safe landing.
The purpose of this invention is to associate with an engine of the type described, means whereby negative work is introduced in the cycle when idling to permit adjustment of the injection device sufficient to insure continued ignition and, at the same' time, reduce the engine speed over that which would normally result with such a fuel delivery.
In order to provide for such stabilizing of an engine of the character above set forth when idling, I propose to associate with the cylinder means for relieving it of some of the gaseous con- .having a neck 32 with a passage therein which opens into the interior of the cylinder. The passage communicates with the chamber 33 in the housing and from which extends an outlet neck 34 having a passage therein leading exteriorly of the cylinder. The housing is formed with another neck 85 which is formed hollow to provide a. bearing for valve 36 which co-operates with a seat 37 formed at the junction of the passage in the neck-32 with the chamber 33. 4
Suitable mechanism can be associated with the valve to control its relation with the seat and thereby regulate the escape of gas from the cylinde'r. Preferably I propose that such mechanism be associated with the fuel control lever so that the valve regulation will occur automatically and in a predetermined relation with the adjustment of the fuel charges so that the valve can open during idling operation of the engine and be positively closed when the engine is operating at a speed above idling. To this end, a regulating member 38 is mounted to reciprocate within the neck 35 of the housing and is provided with an open end into which the valve stem end extends so that in this respect the member also serves as a guide for the valve. Intermediate the regulating member 38 and the bearing portion 39 of the valve is a coil spring 8 which exerts sufficient pressure to normally close the valve, and contacting with the end of the control member is a cam lever 40 which is pivotally mounted upon a pin 41 carried by extended ear portions of the neck, as indicated at 42. This cam lever contacts with the regulating element 38 and carries a roller 43 which is engaged by a control member 44 which is pivoted as at 45 to an ear 46 projecting from the housing. Pivotally connected to the control member and the hand lever is a rod 4'7. The control member is provided with a curved face 48, the radius of which is taken'on the pivotal point of the member, and with a straight face 49 which extends substantially at right angles to the curved face. The faces 48 and 49 provide contact surfaces for engaging the roller 43 and controlling the position of the valve regulating member.
When the roller is in contact with thecurved face 48, the cam lever 40 will be maintained in a substantially uniform position pressing the control member 38 in a direction towards the valve head and thereby compressing the spring to such a degree that the valve will be held positively seated irrespective of the pressure developed in the cylinder tending to open the same. When the regulating member 44 is moved so that the face 49 engages the roller 43, the cam member can be rocked by the spring in a direction such that spring pressure is relieved and when the pressure in the cylinder overcomes such spring pressure, then there wiil be escape of gas from the cylinder through the chamber 33 and the outlet passage 34.
With the mechanism in the position illustrated in Fig. 1, the fuel injection device is adjusted-$0 a closed position against the seat 37. Asian as' the roller contacts with the curved face 48, the valve will be held in this position and this face is of such length that when the fuel adjustment is regulated so that the volume of the charges results in an engine speed above idling, the valve will be held closed. When the lever 29 is moved in the lower portion of its range to produce an idling condition of the engine by reducingthe volume of the fuel charges delivered, then the control member will be rocked to a position as" shown in Fig. 2 wherein the roller 43 will engage the face 49 and, under such circumstances, compression of the spring is relieved and the valve can be opened by the pressure of expanding gas in the cylinder and preferably during the begin 1 can be calibrated or designed to meet any re- 1 quired pressure conditions. Upon release of gas from the cylinder during the working stroke, negative work is introduced into the cycle. In other words, expansion pressure in the cylinder drops below atmospheric pressure causing the piston to do more work and thus 1 slowing down the speed of the engine so that the volume of the fuel charges can be maintained higher than if the relief valve were not employed. This greater fuel volume gives more assurance that the fuel charges will be of a uniform nature so that the engine will not stall when idling and, at the same time, maintains the engine speed constant. As a. result, idling speed of the engine is stabilized because the injection device is more;
eficient and also, the engine will be governed so that a uniform idling speed is maintained.
Although the invention has been described in connection with a specific embodiment, the principles involved are susceptible of numerous other applications which will readily occur to persons skilled inthe art. The invention is therefore to be limited only as indicated by the scope of the appended claims.
What I claim is:
1. The method of operating an engine comprising introducing air and liquid fuel into a combustion chamber, compressing the air and fuel mixture until combustion occurs, introducing negative work in the expansion portion of the cycle only when the engine is idling through the release of gas from the cylinder, and scavenging the exhaust gas from the cylinder.
2. The method of operating an engine comprising introducing unthrottled air charges and charges of liquid fuel into a cylinder, compressing the air and fuel mixture until combustion occurs, automatically introducing negative work. into the cycle in the work performing period thereof only when operating under engine idling conditions, and scavenging exhaust gases from the cylinder.
3. In an internal combustion engine, the combination with a working cylinder, of stabilizing means comprising a cylinder relief passage, a valve in said passage, spring means associated to normally seat the valve when the pressure thereof is greater than the pressure in the cylinder, means for securing said valve in closed position, and fuel control mechanism connected to regulate said means.
4. In an engine of the fuel injection type, the combination with a cylinder, of an adjustable pressure relief means, a fuel control mechanism, and connection means between the relief means and the fuel control mechanism, the adjustment of said mechanism adjusting said pressure relief means.
5. The method of operating anengine comprising introducing a combustible charge of fuel 'and air into a cylinder, compressing and igniting the charge, releasing some of the charge during the high pressure period of the cycle but only when the fuel charge volume introduced into the cylinder is below a predetermined amount, and scavenging exhaust gas from the cylinder during the low pressure period of the cycle.
6. In an internal combustion engine, a cylinder having a relief port,a valve-in the port opening away from the interior of the cylinder, pressure means normally urging the valve toward seated position in opposition to pressure in the cylinder, a fuel regulating mechanism, and a connection between the mechanism and the pressure means whereby the pressure means will be regulated in a definite relation with the fuel adjustment.
7. In an internal combustion engine, a cylinder having an outlet port, a valve in the port opening away from the interior of the cylinder, spring means normally urging the valve toward seated position in opposition to pressure in the cylinder, operated by the fuel regulating mechanism for varying the pressure exerted by the spring means against the valve.
8. In an internalcombustion engine, a cylinder having an outlet port, a valve in the port opening away from the interior of the cylinder, pressure means normally urging the valve toward seated position in opposition to pressure in the cylinder, a fuel regulating mechanism, and a connection between the mechanism and the pressure means operable to positively seat the valve when the fuel mechanism is set for maximum injection.
9. In an internal combustion engine, a cylinder having an outlet port, a valve in the port opening away from the interior of the cylinder, pressure means associated with the valve in a relation opposed to the pressure in the cylinder, a fuel regulating mechanism, and a connection between the pressure means and the mechanism including a cam actuator, said cam adjusting said pressure means during adjustment of said fuel regulating mechanism.
10. In an internal combustion engine, a cylina fuel regulating mechanism, and means der having an outlet port, a valve in the port opening away from the interior of the cylinder, a
'slidable regulating member, a spring between the valve and the regulating member, an actuator associated to engage the regulator and adjust the compression of the spring, a cam for operating the actuator, a fuel control lever, and a connection between the cam and the fuel control lever, the operation of the fuel control lever, to regulate the fuel, moving said cam to operate the actuator,
11. In a two cycle internal combustion engine, a cylinder, a piston in the cylinder, said cylinder having inlet and outlet ports therein adapted to be uncovered when the piston is at one end of its stroke and a relief port adjacent the other end of the piston stroke, a valve in the relief port, pressure means normally urging the valve toward seated position in opposition to pressure in the cylinder, mechanism for adjusting said pressure means whereby negative work can be introduced into the cylinder during idling of the engine, and fuel control means connected to regulate said mechanism.
12. The method of operating an engine comprising introducing unthrottled air charges and liquid fuel charges into a combustion chamber, compressing the air and fuel mixture until combustion occurs, releasing some of the combustion charge during the high pressure period of the cycle only when the fuel charge in the mixture is below a predetermined quantity, and scavenging exhaust gas from the cylinder.
, HERBERT C. EDWARDS.