US2345256A - Internal combustion engine of the solid injection type - Google Patents

Description

March 28, 194 F. s. H. HEDLUND INTERNAL COMBUSTION ENGINE OF THE SOLID INJECTION TYPE Filed July 2. 1941 A W//////////////////////////// 1A v Patented Mar. 28, 1944 INTERNAL COMBUSTION ENGINE OF THE SOLID INJECTION TYPE Folke Gustaf Hjalmar Hedlund, Stockholm, Sweden, assignor, by mesne assignments, to Jarvis 0. Marble, Riverside, Conn., Chester A.

Adee, Port Washington, N. Y., and George Carlson, New York, N. Y., as trustees Application July 2, 1941, Serial'No. 400,746 In Sweden July 18, 1940 3 Claims.

The present invention relates to internal combustion engines in which liquid'fuel is sprayed into a rotating air charge in the combustion chamber towards the end of the compression stroke and in which the fuel is ignited by means of at least one special timed ignition device, such as an electric spark plug. In such engines it is important to fully utilize the air charge. An-

. other requirement is that the minute fuel quantities injected when the engine is running idle, should be ignited regularly.

In practice it has been proved to be difiicult to attain both of said desiderata simultaneously. Particularly when heavier fuels are used difliculties have been experienced to obtain both a satisfactory power output and an unobjectionable operation at no load.

The present invention relates more particularly to the type of engines in which at least one fuel jet which may be called the concurrent jet is injected nearly in the direction of rotation of the air in the combustion chamber and at least one jet which may be called the counter-current jet in a direction generally facing the rotation of the air. An engine of this type is described, inter alia, in the U. S. Patent No. 2,125,293 to Hesselman.

The present invention has for its object to attain a reliable ignition at no load, also when fuels are used which are difficult to ignite, and at the same time to utilize to a high degree the air of the combustion chamber to attain a satisfactory maximum power output.

One outstanding feature of the invention resides therein that the ignition device is disposed so much closer to the counter-current jet than to the concurrent jet that said device or its projection on a plane perpendicular to the axis of the cylinder falls within the range of the corresponding projection of the counter-current jet when the air charge is at rest or at least moving so slowly that said counter-current jet is practically undeviated.

According to an embodiment of the invention the ignition device is positioned so far laterally of a diametrical plane of the combustion chamber passing through the injection devic that, counted in the direction of air rotation, it is angularly displaced more than 180 degrees from the injection device. Such a displacement may be preferred in conjunction with the fact that the two or more jets are formed on both sides of and symmetrically in relation to said diametrical plane of the combustion chamber through the appertaining injection device.

The jets may also be injected under different angles of divergence to said diametrical plane as mentioned in the U. S. Patent No. 2,125,293. According to this patent the jets may have different factors of penetration.

The concurrent jet is accelerated by the rotating air and is slightly deviated. The countercurrent jet is retarded and its outline deformed. The influence of the air current on the fuel jets is different at different engine loads. At higher numbers of revolutions the air has a greater deviating power than at lower numbers of revolutions. The position of the fuel at the instant of ignition in relation to the spark plug will therefore be entirely different at different numbers of revolutions and engine loads.

To render ignition possibl there must exist, at the moment of ignition, an air-fuel-mixture at the electrode of the spark plug. On the other hand, the spark plug must not receive direct sprays. At least, the jets must not be directed towards the spark plug.

In order to assure a reliable operation at no load this spark plug is placed considerably closer to the center line of the counter-current jet than to that of the concurrent jet. In this way the ignition will take place directly in the countercurrent jet at no load, small loads, and low engine speeds. At high engine speeds and heavy loads the counter-current jet is deviated from the spark plug and instead the concurrent jet will be brought forward by the action of the rotating air and ignited. By this disposition a reliable ignition is obtained at all loads while at the same tim the risk of the spark plug being fouled by oil is reduced to a minimum.

The accompanying drawing illustrates by way of example different embodiments of the invention. On the drawing Fig. 1 is a longitudinal section through an internal combustion engine of the solid injection tand timed ignition type according to the invenion.

Figs. 2 and 3 are horizontal sections on the line II-lI in Fig. 1.

Fig. 4 is a similar section as in Figs. 2 and 3 but relates to a modified embodiment of the invention. 1

In Fig. 1 the piston 2 is reciprocable in the cylinder l and is at its top provided with a peripheral flange 3. In the cylinder head ii an injection nozzle I3 and an electrical spark plug 5 are provided. During th suction stroke of the piston 2 air is sucked through a tangential air inlet channel 6 and an inlet valve 1 governed in the usual manner and into the cylinder I. The air charge is caused to rotate due to the tangential flow of air into the combustion chamber. This rotation has a direction indicated by the arrow 8 and will continue until the moment of ignition. The exhaust valve I1. is positioned as shown in Fig. 2. The tip I of the injection nozzle I3 is of the so-called multi-orifice type. In the embodiment her described there are two orifices provided through each of which a fuel jet is sprayed into the combustion chamber. The nozzle as illustrated is of the open type. Fuel is supplied from a fuel pump not shown on the drawing through the pressure line l2. nozzle ii there are provided pressure valves not shown on the drawing which permit flow of fuel towards the tip I but prevent a back flow of fuel or gas into the pressure line I 2.

Fig. 2 illustrates the appearance of the jets when the influence of the air rotation is insignificant.

If there is a considerable air rotation the jets will have the deformed outlines shown in Fig. 3.

Figs. 2 and 3 indicate a preferred embodiment in regard to the positions of the jets andthe spark plug. The jets enter the combustion chamber generally under the same angles of divergence in relation to a diametrical plane of the combustion chamber through the injection nozzle. The spark plug is laterally displaced in relation to this diametrical plane towards the counter-current jet. As shown in Fig. 2 the projection of the counter-current jet will cover the spark plug when theair in the combustion chamber is at rest or at least has such a slow rotation that the deviation of the counter-current jet is insignificant.

' Under other circumstances another disposition is also conceivable as shown in Fig. 4. Also in this embodiment the spark plug is closer to the counter-current jet and falls within the projection of the undevlated counter-current jet. This is here attained by injecting thejets unsymmetrically in relation to a diametrical plane of the combustion chamber through the nozzle so that they form difierent angles of divergence in relation to said plane.

However, the invention is not to be limited to the illustrated embodiments as other modifications are conceivable without departing from the spirit of the invention.

What is claimed is:

1. The method of operating an internal combustion engine of the injection type having a combustion chamber provided with a timed ignition device therein which includes introducing an air charge into said chamber to rotate therein at a rate varying with variations in engine speed, directing a first fuel jet transversely of the retating air charge toward said ignition device to be ignited thereby when said jet is substantially In the undeflected due to a relatively low rate of air rotation and directing a second fuel jet transversely of the rotating air charge toward a place in said chamber in advance of said ignition device with respect to the direction of air rotation so as to be carried to said ignition device and ignited thereby only when said second jet is laterally deflected by a relatively high rate of air rotation which simultaneously operates to deflect said first jet laterally away from said ignition device.

2. The method of operating an internal combustion engine of the injection type having 'a circular combustion chamber provided with a timed ignition device located adjacent to the periphery of said chamber, which includes introducing an air charge into said chamber to rotate therein at a rate varying with variations in engine speed, directing a first fuel jet transversely of the rotating air charge along a chord of said chamber and generally counter to the direction of rotation of the air toward said Qnition device to be ignited thereby when said. jet is substantially undeflected due to a relatively low rate of air rotation and directing a second fuel jet transversely of the rotating air charge along.

a second chord of said chamber and generally with the direction of air rotation toward a place in said chamber in advance of said ignition device with respect to the direction of air rotation so as to be carried to said ignition device and ignited thereby only when said second jet is laterally deflected by a relatively high rate of air rotation which simultaneously operates to deflect said first jet laterally away from said ignition device.

3. The method of operating aninternal combustion engine of the injection 'type having a circular combustion chamber provided with a timed ignition device located adjacent'to the periphery of said chamber, which includes introducing an air charge into said chamber to rotate therein at a rate varying with variations in engine speed, directing a first fuel jet transversely of the rotating air charge along substantially a diameter of said chamber toward said ignition device to be ignited thereby when said jet issubstantially undeilected due to a relatively low rate of air rotation and directing a second fuel jet transversely of the rotating air charge along a chord of said chamber and generally with the direction of air rotation toward a place in said chamber in advance of said ignition device with respect to the direction of air rotation so as to be carried to said ignition device and ignited thereby only when said second jet is laterally deflected by a relatively high rate of air rotation which simultaneously operates to deflect said first jet laterally away from said ignition device.

FOLKE GUSTAF HJALMAR. HEDLUND;

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