RU2043683C1 - Spark plug for internal combustion engine - Google Patents

Abstract

FIELD: engine engineering. SUBSTANCE: spark plug has central electrode 3 consisting of core 4 and tip 5 secured to the core from the side of the combustion chamber of the engine. The tip has radial projections which define spark spaces 7 together with the face surface of housing 1. Tip 5 is made of a conducting material having high resistence. This allows sparks to be obtained simultaneously at several spaces. Facet 8, which contributes to coming gases to the surface of insulator 2, is provided in the inner side of the housing. EFFECT: enhanced reliability. 3 cl, 3 dwg

Description

 The invention relates to engine building, and in particular to devices for igniting a mixture in gasoline internal combustion engines.

 A spark plug is known from the prior art, comprising a housing with a side electrode, an insulator fixed in the housing, and a central electrode located in the bore of the insulator and forming a spark gap with the side electrode [1] When using a spark plug due to erosion of the electrode surfaces, the spark gap changes, which leads to to the need for periodic adjustment.

 Also known is a spark plug adopted as a prototype, comprising a hollow body with an insulator fixed in it and a central electrode consisting of a rod located in the hole of the insulator and attached to the latter with radial protrusions forming spark gaps with the inner side surface of the body [2] several spark gaps allowed long-term operation of the candle without adjusting the gaps between the electrodes. However, when applying a high voltage to the candle, a spark will occur only between one of the protrusions of the tip and the inner surface of the housing. This is explained by the fact that after the breakdown of one of the spark gaps, its resistance drops sharply and the remaining spark gaps short-circuit, i.e. the voltage on them does not reach the value necessary for the spark to appear. The disadvantages of the candle also include the fact that the tip prevents the flow of gases into the space between the insulator and the candle body, as a result, the formation of carbon deposits in this place is accelerated.

 The invention provides the ability to receive sparks simultaneously in several intervals, and also allows to improve the "purge" of the space inside the candle body. The specified technical result improves the reliability of the candle and its durability and is achieved by the fact that the tip of the central electrode is made of electrically conductive material with high electrical resistance, and the protrusions are bent at the end, located outside the housing and form spark gaps with the end surface of the latter. The tip can be made cross-shaped, with the formation of four spark gaps. A chamfer can be made on the inner surface of the housing, the width of the end surface of the edge of the housing being equal to the width of the edges of the protrusions. The execution of the tip from a material with high electrical resistance eliminates the phenomenon of shunting of all spark gaps during the occurrence of a spark in one of them, and installing the tip outside the housing and chamfering makes it easier to access gases to the surface of the insulator. Moreover, from the point of view of ensuring the erosion resistance of the contact surfaces of the electrodes, it is advisable to choose the size of the chamfer based on the condition of equality of the width of the end edge of the housing to the width of the end edges of the protrusions of the tip.

 In FIG. 1 presents the proposed candle; in FIG. 2, section AA in FIG. 1; in FIG. 3 electrical equivalent circuit candles.

 The candle contains a housing 1, an insulator 2, a central electrode 3, consisting of a rod 4, a tip 5 with radial protrusions 6, forming spark gaps 7 with the end surface of the housing 1. A chamfer is made on the inner surface of the housing 1. The tip 5 is made of an electrically conductive material with high electrical resistance, for example, from a heat-resistant alloy (characteristics of alloys with high electrical resistance are given, for example, in the book by N.V. Nikulin, "A Handbook of a Young Electrician on Electrotechnical Materials and Publications Eliyam ", M. Higher School, 1982, S. 146-148). The tip can be attached to the rod, for example, by resistance welding.

 In FIG. 3, the position 9 denotes the equivalent resistance of the tip sections located between the rod 4 and the spark gaps 7.

 The candle works as follows.

 High voltage is supplied to the electrodes 3 and in the spark gaps 7 between the protrusions 6 and the end surface of the housing 1 there are electric discharges that ignite the fuel-air mixture in the combustion chamber of the engine. Hot gases heat the surface of the insulator and the carbon deposits formed on it. In the valve shut-off phase, carbon deposits are burned as a result of interaction with the flow of the fuel-air mixture, which, thanks to the presence of the chamfer 8, more efficiently blows the insulator 2.

Claims (3)

 1. IGNITION CANDLE FOR THE INTERNAL COMBUSTION ENGINE, comprising a hollow body with an insulator fixed therein and a central electrode consisting of a rod located in the hole of the insulator and attached to the latter on the side of the combustion chamber of the engine with radial protrusions that form spark gaps with the surface of the body, characterized by the fact that the tip is made of an electrically conductive material with high electrical resistance, and the protrusions are bent at the end, located outside the housing and form spark flowers with the end surface of the latter.  2. The spark plug according to claim 1, characterized in that the tip is made crosswise.  3. The spark plug according to paragraphs. 1 and 2, characterized in that a chamfer is made on the inner surface of the housing, wherein the width of the end edge of the housing is equal to the width of the end edges of the protrusions.

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