RU2504059C1 - Spark-plug - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: central and side ground strap have flat ends to make sharp edges while side strap ledge surface facing the central electrode cylindrical surface has a recess inclined at sharp angle to central electrode axis. Said central and side ground strap have flat ends to make sharp edges located in one plane crossing the central electrode flat end, perpendicular to its axis. Surface of central electrode flat end ledge has recess facing its cylindrical surface and formed by cone surface, its axis being aligned with central electrode axis. This results in that plug cross-section has spark gap profile shape confined by two concentric circles.

EFFECT: higher reliability and completeness of fuel combustion, longer life, decreased amount of emissions.

4 cl, 5 dwg

Description

Technical field

The invention relates to a technique for igniting fuel mixtures in internal combustion engines, namely, to spark plugs.

State of the art

Known spark plugs containing a housing, an insulator, a central electrode and a curved side electrode forming a spark gap with the end surface of the central electrode (see Bannikov S.P. Electrical equipment of automobiles. M; Transport, 1977, p.23, see also Engines internal combustion. Edited by A.S. Orlik, M.G. Kruglov. M .; Engineering, 1990. p.161)

The main disadvantage of candles of this design is that the spark arising in the spark gap is closed from the main volume of the working mixture by the side electrode and, as a result, the mixture ignites insufficiently quickly, efficiently and reliably.

A known spark plug containing a housing, an insulator fixed to it with a central electrode and two, three or four side electrodes mounted on the housing (see Auto Review magazine, 2004, No. 23 Multi-electrode spark plugs.) On two, With three or four electrode candles, only one spark is formed (and not two, three or four), that is, a high voltage will “break through” the gap that will have the least resistance. Meanwhile, other side electrodes actually impede the normal propagation of the combustion front, and, in addition, worsen the cooling of the insulator thermal cone and increase the carbon formation on the side electrodes.

The closest in technical essence and the achieved result is a spark plug according to the patent of Russian Federation No. 2260889 (published on September 20, 2005) containing a body with an external thread, a central electrode located in the insulator, and a side mass electrode fixed to the body, while the working part of the central the electrode forms pointed protrusions separated by a profile recess, and the mass electrode, inclined laterally to the central electrode, forms pointed protrusions in the working part, separated by a profile recess, m claws and profile of the central recess and the mass of the electrodes are opposed to each other and form a profile structure of the spark gap. This design is taken as a prototype. On these candles, screening braking by the side electrode of the exit of the combustion front to the volume of the combustion chamber is eliminated, since the ignition of the working mixture occurs not only bypassing the side electrode, but also in the gap between the electrodes. All this leads to a more rapid spread of the combustion process of the air-fuel mixture.

However, the pointed and thin protrusions of the electrodes become more heated, the rate of thermal and electrical erosion increases, which reduces the life of the spark plug.

The objective of the invention is to increase the reliability and completeness of combustion of the working mixture, reduce harmful emissions into the atmosphere and extend the life of the spark plug.

The problem is achieved by the fact that the proposed spark plug containing a body with an external thread, an insulator located in the housing, a central cylindrical electrode located in the axial hole of the insulator and a side mass electrode mounted on the housing having a protrusion facing the Central electrode and forming with profile profile of the spark gap. In this case, the central and side electrodes are made with flat ends forming sharp edges, the surface of the protrusion of the side electrode facing the cylindrical surface of the central electrode has a recess, the generatrix of which is inclined at an acute angle to the axis of the central electrode.

In the second embodiment, the stated task is achieved in that the central and side electrodes are made with flat ends forming sharp edges located in one plane passing through the flat end of the central electrode perpendicular to its axis, and the surface of the protrusion of the side electrode facing the cylindrical surface of the central electrode, has a recess formed by the surface of the cone, the axis of which coincides with the axis of the central electrode, as a result of which a profile shape is formed in the cross section of the candle spark gap shape bounded by two concentric circles.

It is possible to perform the proposed candle in such a way that the horizontal portion of the protrusion of the side electrode in the cross section of the candle has a greater thickness than the vertical portion of the electrode.

It is possible to perform the proposed candle so that the horizontal portion of the protrusion of the side electrode in the cross section of the candle is made in the form of two flat surfaces diverging from the vertical portion of the side electrode at an angle to each other.

It is possible to perform the proposed candle in such a way that the end surface of the protrusion of the side electrode is made obliquely to the axis of the central electrode at an acute angle or is located in the same plane as the end of the central electrode.

The proposed candle works as follows.

A spark occurs between the points of the electrodes, the distance and resistance between which are the smallest, namely, between the sharp edges of the electrodes.

A spark discharge emanates from the sharp edge of the protrusion of the side electrode to the sharp edge of the end of the central electrode, forming a sector of the spark discharge, which is located directly in the volume of the working air-fuel mixture, and in our case, due to the “open” spark gap, the speed of propagation of the combustion front into the volume of the combustion chamber occurs more intensively and, as a result, more complete combustion of fuel, increase in engine power and reduction of harmful emissions into the atmosphere.

The high voltage applied to the sharp edges of the electrodes gives a greater electric field strength in the zone of the spark discharge and, therefore, a lower minimum required voltage is required for sparking of the spark plug. And this leads to an increase in the reliability of sparking and ignition of the air-fuel mixture, as well as the stable operation of the engine in all modes.

Another example of a side electrode is the implementation of its horizontal section with increased thickness in the cross section of the candle.

This gives a large length of the spark gap around the central electrode, which reduces the erosion of the electrodes and extends the life of the candle.

Another example of the implementation of the side electrode is the implementation of its horizontal part in the cross section of the candle in the form of two flat surfaces diverging from the vertical portion of the electrode at an angle to each other. This also gives a large length of the spark gap around the central electrode, which reduces the erosion of the electrodes and extends the life of the spark plug.

Another example of the execution of the side electrode is that the end surface of the protrusion of the side electrode is inclined to the axis of the central electrode at an acute angle or is located in the same plane as the end of the central electrode. This reduces the thermal tension of the side electrode, leads to uniform electroerosive wear of both electrodes and extends the life of the candle.

The proposed spark plug allows you to completely fill the spark gap between the central and side electrodes on the compression cycle with the air-fuel mixture.

The essence of the proposed technical solution is illustrated by drawings, where in Fig.1 and 2 shows a General view of the spark plug; figure 3 and 4 are embodiments of the side electrode and the spark gap between it and the Central electrode.

The spark plug contains a housing 1 (see figure 1), equipped with a thread 2 for screwing into the cylinder head of the engine, an insulator 3 fixed in the housing and a central electrode 4 located in the insulator.

The side electrode 5 is attached to the housing 1 and has a vertical part 5 and a horizontal protrusion 6. The surface of the protrusion 7 of the side electrode 5 has an acute angle to the axis of the central electrode 4 and is part of a conical surface. The end surface 8 of the protrusion of the side electrode 5 is made with an inclination to the axis of the Central electrode at an acute angle or is located in the same plane with the end face 9 of the Central electrode 4.

In Fig.2, the profile shape of the spark gap "a" between the central 4 and side 5 electrodes in the cross section of the candle is limited to two concentric circles.

3, the horizontal protrusion 6 of the side electrode in the cross section of the candle has a greater thickness than the vertical portion 5 of the side electrode.

In Fig.4, the horizontal section of the protrusion 6 of the side electrode 5 in the cross section of the candle is made in the form of two flat surfaces 10 and 11, diverging from the vertical section of the side electrode 5 at an angle to each other.

Figure 5 shows an isometric view of one of the embodiments of the spark plug.

The proposed spark plug works as follows: as a result of a high voltage pulse supplied to the contact head of the central electrode 4, an electric spark occurs between the sharp edge of the end face 9 of the central electrode 4 and the sharp edge of the protrusion 6 of the side electrode 5 (see Figs. 1-4).

After reaching the breakdown voltage, the spark gap "a" (Fig. 2) breaks through and a spark occurs, and a small volume of gas with a high temperature is formed, which ignites the combustible mixture near the electrodes, as a result, a flame front arises rapidly propagating in the combustion chamber of the engine and ignites the entire air-fuel mixture in the cylinder.

The test results of spark plugs of this design in the engine model ZM3-4062 OD on a car brand GAZ-31105 confirmed its expected characteristics and its advantages compared to analogues and prototype spark plugs.

Thus, the proposed options for the spark plug can ensure that all the tasks of the invention are fulfilled.

Claims (4)

1. A spark plug comprising a body with an external thread, an insulator located in the body, a central cylindrical electrode located in the axial bore of the insulator, and a side mass electrode mounted on the body, having a protrusion facing the central electrode, forming with it a profile spark shape a gap, characterized in that the central and lateral electrodes are made with flat ends forming sharp edges located in the same plane passing through the flat end of the central electrode of the perpendicular its axis, and the surface of the protrusion of the side electrode facing the cylindrical surface of the central electrode has a recess, the surface of which has a slope at an acute angle to the axis of the central electrode and formed by the surface of the cone, the axis of which coincides with the axis of the central electrode, resulting in a cross section candles, a profile shape of the spark gap is formed, limited by two concentric circles. 2. The spark plug according to claim 1, characterized in that the horizontal portion of the protrusion of the side electrode in the cross section of the plug has a greater thickness than the vertical portion of the electrode. 3. The spark plug according to claim 1, characterized in that the horizontal portion of the protrusion of the side electrode in the cross section of the plug is made in the form of two flat surfaces diverging from the vertical portion of the side electrode at an angle to each other. 4. The spark plug according to claim 1, characterized in that the end surface of the protrusion of the side electrode is made with an inclined angle to the axis of the central electrode or is located in the same plane as the end of the central electrode.

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