US1506166A - Regulation of the combustible mixture in internal-combustion engines - Google Patents

Description

A. M. U'RRANT EGULATUN OF THE COMBUSTIBLE MXTUR NTERNAL CO'vBUSTlON ENGINES Filed Jam Villr Patented Aug. 26, 1924.

UNITED STATES PATENT OFFICE.

ALBERT ARTHUR MOLTENO DURRANT, F LONDON, ENGLAND, ASSIGNOR TO THE LONDON GENERAL OMNIBUS COMPANY LIMITED, OF LONDON, ENGLAND, A.

BRITISH COMPANY.

REGULATION OF THE COMBUSTIBLE MIXTURE IN INTERNAL-COMBUSTION ENGINES.

Application led January 2, 1923. Serial No. 610,394.

To all whom t may concern:

Be it known that I, ALBERT ARTHUR MoLTnNo DURRANT, a subject of the King of England, residing at Dulwich, London,

England, have invented certain new and useful Improvements in the Regulation of the Combustible Mixture in Internal-Combustion Engines, of which the following is a specification.

This invention is for improvements in or relating to apparatus for regulating the combustible mixture in internal-combustion engines. The type of apparatus to which the invention relates is' that wherein -a conduit for the supply of an anti-detonating agent t0 the enginecylinder is controlled by a valve which is operated by a movable member, such as a piston, the movement. of which is controlled by the suction action produced by the partial vacuum in the main fuel and air passage of the engine.

It is well known that in some types of internal-combustion engines, particularly with certain fuels, faulty or incomplete combustion of the fuel regularly occurs, with resulting loss in power and efficiency, whenever certain conditions of compression or engine speed exist. This unsatisfactory combustion has been described in certain theories as being due to detonation, and to overcome it, anti-detonating agents have been proposed to be introduced into the combustible mixture. For example it has been proposed to add inert gases, such as exhaust gases, to the combustible mixture for this purpose, this being done either by incom plete scavenging or by adding the exhaust gases to the stream of incoming combustible mixture. When the compression in the engine cylinder is increased beyond a certain figure, which figure will vary depending upon the type of engine, and type of fuel used, and upon other circumstances, th looses due to unsatisfactory combustion are much greater than at lower degrees of compression, but, of course, a high compression is normally sought after because a higher efficiency is theoretically obtainable thereat than at low compressions.

This invention has for its main object to provide an improved construction of apparatus of the type referred to such that the anti-detonating agent will be supplied to the combustible mixture even at high degrecs of compression in the engine cylinder.

A. specific obj ect of the invention is to supply a gaseous anti-detonating agent to the air intake of the engine carburetor.

In apparatus of the type referred to proposed heretofore, the movable member in the form of a piston has been loaded by a spring that tended to keep the valve seated so that the supply of the anti-detonating agent was normally cut off. In such an arrangement, if the suction action in the main passage was so weak, owing to the throttle being fully open, that the load of the spring on the piston could not be overcome by it, the passage for the supply of the antidetonating agent would be closed when the` compression in the cylinder was high.

AccordingA to this invention, apparat-us of the type described for regulating the combustible mixture in internal-combustion engines is characterized by the fact that the spring or its equivalent acts on the movable member in such a manner that the latter tends to open the valve against the action of the said suction effect which controls the movement of the movable member. In this construction, therefore, the supply of antidetonating agent to the combustible mixture is controlled by means which are only operative when the engine compression exceeds a predetermined amount.. For effecting this automatic control, the compression in the cylinder may be estimated or measured by the degree of opening of the main throttle or the degree of partial vacuum in the engine induction pipe on the cylinder side of the main throttle, since the engine compression will normally be at its greatest when the throttle is fully opened and similarly in such a state of affairs there will be the least amount of partial vacuum in the engine induction pipe.

Where the engine compression is estimated by the degree of partial vacuum in the engine induction pipe on the cylinder side of the main throttle, and the suction action is operative directly on one face of the movable member aforesaid, according to another feature of the present invention the said movable member is in the form of a flexible diaphragm to which the stem of said valve is attached. As this diaphragml and the valve controlled by it is spring loaded the valve will only be opened when there is but little partial vacuum in the engine induction p1pe.

In the -foregoing there has been described means for regulating the supply of antidetonating'agent in accordance with varlations in the engine compression. 'As the compression increases, supplies of anti-det nating agent are introduced into the combustible mixture and thus, although the latter is with certain anti-detonating agents renderedy less eiHcie-nt so far as its power factor is concerned, yet this loss is more than counterbalanced by the increased efficiency obtained owing to the prevention of deto nation. v

. For a. more complete understanding of the invention there will now be described, by wayvof example'only and with 'reference to the accompanying drawings, certain constructional Vforms of mechanism according to the present invention.V It is to be understood, however, that the invention is not limited to the precise constructional details set forth.

vIn these drawings :--y

Figure 1 is an outside View, partly in section, of certainarts of an internal-combustio'n engine wit one form of mechanism according to the present invention applied thereto;

Figure 2 is a cross-section through' apart of the mechanism shown in Figure l;

"Fi as v Figure 3 is a section on the line 3-3 of re 2, and I igure4 is a detail sectional view on a scale larger than that of the precedingigures showing a portion of the mechanism. Like reference numerals indicate like parts throughout the drawings.

Referring to the drawing, the engine induction pipe is, indicated at 10, the main throttle at 11 and the carburetor at 12. Clamped between fianges 13 and 14 is alug 15 having a erforation 16 lto coincide with the borel of tlie induction pipe. The lug 15 projects from a valve casing 17 havin bosses 18 and 19 which arey bored to orm a f slthroughway 20. The boss 18 is intended to be coupled to a supply of the anti-detonating a nt .such as cylinder exhaust gases, and t e boss 19 is coupled to a conduit 21 leading to the air intake of the carburetor 12. The casin 17 has an aperture at its to which is clos/ef? by a cap 22, and below thls cap is situated a valve 23 which controls the passage 20. The valve 23 is o f conical formation and has circular seatings 24"and 25 in the casing. The passage 20, where it passes the valve 23, is increased in width (at 26 Figure 3) and is provided with ribs 27 which also form seatlngs forlthe valve. When the valve is down upon its seatin' the passage 20 will be closed but it.will seen that the formation and arran ement of the parts is such that only mslight 'ft of the the pressure of the spring 36.

guided in a boss 29 'and this stem is secured at its lower end to a flexible diaphragm 30 of leather, corrugated iiexible metal, or other suitable material. The outer edges of the diaphragm 30 are secured against a face 31 in the casing 17 by a clamping ring 32 and below the clamping ring there is screwed into the easing 17 a cap 33 with a detachable plug 34. The plug 34 is recessed at 35 to house a springv36 which at'one end bears against.` a. surface of the plug and at the other end bears against an abutment 37 on the stem 28.A The spring 36 tends to open the valve 23.

The diaphragm 30 divides the interior of the casing 17 into two separated chambers 38 39. The chamber 38 has a vent 138 to provide communication with the outside and the chamber 39 `is in communication with the interior of the engine induction pipe l0 on the cylinder side of the throttle 11. For this purpose the passage '40 which extends between the perforation 16 and the clamping ring 32'is provided. The clamping ring 32 also has fitted into it a. plug 41 having a bore 42 of smaller diameter than the bore 40. In this way communication is established between the interior of the induction pipe 10 and the chamber 39, the smallness of the bore 42 operating to damp the fluctuations in pressure and secure regularity in the movements 'of the diaphragm due to such iiuctuations in pressure. A securing pin v43 is provided which is passed through the casing 17 into the ring 32 and which operates to prevent the latter from slackening and to maintain it in appropriate alignment withthe bore 40.

In operation, it will be appreciated that when the engine compression is high, there will not be a very considerable vacuum established in the engine induction pipe, consequently the difference in pressures in the two chambers 38A and 39 will be such that the spring 36 will be able to open the valve 23. When, however, the compression in the cylindenfalls, the vacuum in the induction pipe will become greater \and vthis will operate to maintain thevalve 23 closed despite The spring 36 may be made adjustable to vary the amount of vacuum required to close lthe valve.

The anti-detonating agent employed may be exhaust gases from the engine which may be cooled if desired before they are returned to the engine cylinder; or steam generated -say in a coil surrounding the exhaust ipe may be employed; or some other inert 11uent may be employed, or instead of an inert gas a combustible gas mai be employed which has properties capab of correcting the detonating pro ensities of the main fuel, for example alco ol injected through a needle valve may be employed. It will also be understood that the supply of anti-detonating agent may reach the cylinder by a path other than that of the engine carburetor.

`l`urther,r the precise constructional details hereinbefore set forth may be modified in various ways without de arting from the scope of the invention as dpefined in the claims. For example, instead of employing the flexible diaphragm 30, the same result will be obtained by employing collapsible corrugated bellows, say of spun copper to operate the controlling valve.

I claim 1. The combination of an induction conduit for fuel and'air leading to the cylinder of an internal-combustion engine, a valve controlling said conduit, a carburetor supplying said conduit, a supply conduit for the supply of a gaseous anti-detonating agent to the air intake of the carburetor, a valve controlling said supply conduit, a chamber connected to said induction conduit at the cylinder side of the first said valve, a controlling member operatively connected lwith the latter valve and movable in said chamber under the suction action therein 'in a direction to close the latter valve, and

a spring operative on the second said valve tending to open the same against the suction action on said controlling member.

2. The combination of an induction conduit for fuel and air leading to the cylinder of an internal-combustion engine, a valve controlling said conduit, a carburetor supplying said conduit, a supply conduit for the supply of a gaseous anti-detonatin'g agent to the air intake of the carburetor, a valve controlling said supply conduit, a suction chamber whereof one wall is constituted by a flexible diaphragm so connected to the latter valve that suction in the chamber tends to flex the diaphragm so as to close the latter valve, a duct connecting said chamber to said induction conduit on the cylinder side of the first said valve, and a spring operative on the second said valve tending to open the same against the action of suction in said chamber.

. 3. The combination with a valve arranged to control a conduit for the rsupply of a gaseous anti-detonating agent to the air intake of the carburetor of an internal-combustion engine, of a suction chamber, a controlling member movablein said chamber and operatively connected to the valve and arranged to seat the valve under the .action of suction in the chamber, and a spring tending to open the valve, said chamber having a duct for connection to the induction pipe of an internal-combustion engine.

4. The combination with a valve arran ed to control a conduit for the supply o a gaseous anti-detonating agent to the air intake of the carburetor of an internal-combustion engine, of a suction chamber whereof one wall is in the form of a flexible diaphragm that is carried by the stem of the valve is arranged to seat the valve under the action of suction in the chamber, and a spring tending to open the valve, said chamber having a duct for connection to the` induction pipe of the internal-combustion engine.

5. The combination with a valve arran ed to control a conduit for the supply of engine exhaust gases to the air intake of the carburetor of an internal-combustion engine, of a suction chamber whereof one wall is in the form of a eXible diaphragm that is carried by the stem of the valve and is arranged toy seat the valve under .the action of suction in the chamber, and a spring in said chamber tending to open the valve, said chamber having a duct for connection to the induction pipe of the engine, which duct has a restricted end that opens into the said chamber, for the purpose described.

In testimony whereof I aliix my signature.

ALBERT ARTHUR MOLTENO DURRANT.

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