CN202651616U - Quick firing heterotype ground electrode spark plug - Google Patents

Abstract

The utility model relates to a quick firing heterotype ground electrode spark plug, comprising an insulator, a shell, a central electrode and a ground electrode. The quick firing heterotype ground electrode spark plug is characterized in that the ground electrode is a heterotype electrode, the middle part of the ground electrode is equipped with a through hole, and the through hole comprises at least two corners; each corner is a centripetal spur, the end face of the central electrode is slightly lower than the lower plane of the ground electrode, and spark gaps are formed between the central electrode and the spurs of the ground electrode. Compared with the prior art, the utility model has the following beneficial effects: 1, the ground electrode is side-mounted type, does not restrict the spark expansion due to covering the central electrode; 2, the ground electrode is equipped with a plurality of spurs which are equivalent to many independent ground electrodes, so that the service life of the spark plug can be prolonged; 3, the end face of the central electrode is lower than the ground electrode plane, so that a sparking line is not perpendicular to the axis direction of a combustion chamber like the multipolar spark plug, but is same with the flame propagation direction, and accordingly, the flame propagation speed is conducive to improve, the spontaneous combustion phenomenon before reaching normal flame of a final fuel mixture in the combustion chamber is avoided, and the work roughness of an engine is reduced.

Description

Quick firing special-shaped earth electrode spark plug

Technical field

The utility model relates to engine spark plug, particularly a kind of spark plug for controlled-ignition engine.

Background technology

The spark plug (Fig. 1, Fig. 2) of at present extensive use comprises insulator (1), wiring screw rod (3), central electrode (4), housing (2), the ground electrode (5) that is welded into one with housing.One arcing gap is arranged between the central electrode of spark plug and the ground electrode, and this gap forms ionization channels under the high voltage pulse effect, produces spark, the gaseous mixture in the ignition engine combustion chamber.

This traditional spark is plugged with the ground electrode (5) in a rectangle cross section, and an end is welded in the end face of housing (2) screw thread, and other end bending also covers central electrode (4) end face.The shortcoming of this spark plug is that ground electrode has covered electric spark, the contact-making surface of restriction electric spark and combustion mixture, and absorb the spark heat, spark is weakened.Ground electrode this " flame arrest effect " has reduced ignition energy, makes mixture combustion incomplete, increases the oil consumption of engine and the content of the middle CO that scavenges.

For overcoming this shortcoming of conventional ignition plug, multi-gap spark plug (Fig. 3, Fig. 4) has appearred on the market.Being that a plurality of independent ground electrodes (7) are other places around central electrode (6), ground electrode crooked, punching after welding with housing, and a plurality of cambered surfaces in hole and the face of cylinder of central electrode consist of horizontal spark gap.Multi-gap spark plug has solved the problem that the conventional ignition plug ground electrode covers central electrode, affects the spark expansion.Although it has a plurality of arcing points, simultaneously arcing, the just useful life of extending plug.And because the ionization channels of arcing is from the central electrode circumference to ground electrode, this " transverse discharge " just and flame along the perpendicular direction of combustion chamber axis propagation, flame transmission speed is descended to some extent.If the propagation velocity that the flame of engine chamber is pushed ahead is too low, the part that then is in the final combustion position eventually the combustion gaseous mixture when normal flame not yet arrives because of the temperature nature that raises, i.e. generation " pinking " phenomenon makes the be under pressure impact of ripple of cylinder.

On the other hand, the another one key factor that affects the plug ignition performance is " spark gap ".Generally speaking, spark gap determines the sparking voltage of spark plug, and the gap is larger, and required voltage is higher.From the mechanism of sparkover, for improving the ignition performance of spark plug, always wish to increase as far as possible spark gap.This is because sparkover is comprised of capacitor discharge and inductive discharge two parts.Capacitor discharge punctures the insulation in gap, the time compole short; Inductance partly causes heat, forms fire nuclear, and this part duration is longer, and ignition performance is better.Spark gap strengthens the time that is conducive to increase inductive discharge.But spark gap strengthens the restriction be subject to supply voltage, and along with the increase of voltage, and capacitor discharge increases and inductive discharge will reduce, and reduces on the contrary the ignition quality of spark plug.No matter be conventional ignition plug or many earth electrode spark plugs, between general 0.6 to 0.8 millimeter of the spark gap.Therefore, seeking a kind ofly not improve ignition voltage, and can strengthen the spark plug of spark gap, is favourable to the technique of improving engine.

Summary of the invention

The purpose of this utility model provides a kind of spark plug of new ignition end structure, has both kept the advantage of conventional ignition plug and multi-gap spark plug, evades both defect points, and obtains good ignition performance.

In order to solve the problems of the technologies described above, the utility model by the following technical solutions:

A kind of quick firing special-shaped earth electrode spark plug, comprise insulator, housing, central electrode and ground electrode, it is characterized in that: described ground electrode is shaped electrode, the ground electrode middle part is provided with through hole, through hole has at least two angles, each angle is centripetal spur, and the central electrode end face consists of spark gap a little less than the lower plane of ground electrode between the spur of central electrode and ground electrode.

Described ground electrode is formed by the punching out of nichrome sheet material.

Described ground electrode has at least two metal legs and housing to be welded into one.

The through hole of described ground electrode middle part is square hole, polygonal hole or circular hole.

Described spark gap is 0.9～1.1 millimeter.

The utility model compared with prior art has following beneficial effect:

1, ground electrode is side putting type, does not limit the spark expansion because covering central electrode.

2, ground electrode has a plurality of spurs, is equivalent to a plurality of independent ground electrodes, but the useful life of extending plug.

3, because the central electrode end face is lower than the ground electrode plane; the arcing route and unlike multi-gap spark plug perpendicular to the combustion chamber axis direction; but identical with the flame propagation direction; be conducive to improve rate of flame propagation; make eventually combustion gaseous mixture in the combustion chamber avoid dieseling before normal flame arrives, the rough running of minimizing engine.

4, because ground electrode is spur shape, make electric field distortion, internal field's density increases, and discharge is easy, and ignition voltage reduces.In the constant situation of engine igniting system supply voltage, can strengthen spark gap, increase to 0.9～1.1 millimeter by common 0.7～0.8 millimeter, thereby increase the duration of inductive discharge, circumference gaseous mixture, formation fire have been examined good action, and make mixture combustion complete, help to improve dynamic property, economy and the behavior in service of engine.

5, improve speed of ignition.Because the speed that the point discharge of electrode and burning interior flame are pushed ahead is better than traditional one pole and multi-gap spark plug, its speed of ignition, particularly cold-start performance are obviously because common spark plug.

6, this kind got angry and held spark plug to be specially adapted to the natural gas engine of large compression ratio.Natural gas, because has high octane number and has the high capability of antidetonance, so engine can adopt large compression ratio.Compression ratio increases the corresponding dielectric strength of the elaterometer that makes the spark gap place and increases, and punctures the higher ignition voltage of insulation needs at this place, produces thus the series of negative effect, and the ignition performance of spark plug is descended.Secondly, heating value of natural gas is very high, and the heat that burning produces is got angry spark plug and held has high temperature, and electrode is very easily ablated and shortened working life.The utility model is because the point discharge effect, need not higher voltage and the insulation of the high density gas of disruptive spark gap location, and a plurality of spur shapes and central electrode formation discharge channel arranged, the useful life of greatly improving spark plug.

Description of drawings

Fig. 1, Fig. 2 are traditional single earth electrode spark plug;

Fig. 3, Fig. 4 are many earth electrode spark plugs;

Fig. 5, Fig. 6 are the special-shaped earth electrode spark plug of the utility model;

Fig. 7 is special-shaped ground electrode stamping-out schematic diagram;

Fig. 8 is the crooked schematic diagram of special-shaped ground electrode.

Embodiment

Referring to Fig. 5, Fig. 6, the utility model is take following theoretical foundation as starting point: consider traditional single earth electrode spark plug, can be considered the flat capacitor device that is consisted of by central electrode transverse plane and ground electrode lower plane, and multi-gap spark plug can be considered the capacitor that is made of two faces of cylinder.Capacitor discharge is exactly that the electric charge that preserves in this kind capacitor was emitted by moment.If a very most advanced and sophisticated shape of this kind capacitor but not tabular then changes the distribution of electric field between electrode, the place large at electric field density very easily discharges electronics, and discharge voltage is reduced.

Do not change insulator 1, wiring screw rod 3, the housing 2 of conventional ignition plug, for reaching the reduction discharge voltage, strengthen the purpose of spark gap, the utility model adopts a kind of new special-shaped ground electrode (referring to Fig. 7, Fig. 8).Central electrode 8 point diameters are contracted to φ 1.5mm by original φ 2.7 or φ 2.5mm.Ground electrode 9 is by the nichrome sheet material punching out (see figure 7) of 1.2 millimeters thick, and the sheet material of ground electrode can be the Ni-Cr-Mn silicon alloy, also can be other alloy materials of anti-ablation.Ground electrode 9 middle parts are provided with through hole, and through hole has at least two angles, and each angle is centripetal spur 10, and the through hole of ground electrode 9 middle parts can be square hole, also can be polygonal hole or circular hole.Central electrode 8 end faces consist of spark gap a little less than the lower plane of ground electrode 9 between the spur 10 of central electrode 8 and ground electrode 9, and specifically, central electrode is relative with the spur of ground electrode, and the distance of spur and central electrode end face circumference is spark gap.Spark gap increases to 0.9～1.1 millimeter by common 0.7～0.8 millimeter, and other parts of spark plug are identical with conventional ignition plug.Ground electrode has at least two metal legs and housing 2 to be welded into one, 90-degree bent behind at least two metal leg stamping-outs of ground electrode, and the ignition location that the length of metal leg is pressed spark plug calculates, and gives the welding ablation amount (about 0.6 millimeter) of staying.During the welding of this electrode and housing with special-purpose anchor clamps location, clamp, guarantee that the housing mesopore is concentric with the ground electrode square hole, and the distance of guaranteeing to weld rear ground electrode lower plane and housing end face meets the requirement of product design.

During the spark plug general assembly, fill between central electrode and the ground electrode square hole with positioning sleeve.The positioning sleeve external diameter cooperates with the ground electrode square hole, and mesopore is identical with the central electrode diameter.After general assembly is finished, positioning sleeve is extracted, can obtain uniform spark gap.

Claims (5)

1. quick firing special-shaped earth electrode spark plug, comprise insulator (1), housing (2), central electrode (8) and ground electrode (9), it is characterized in that: described ground electrode (9) is shaped electrode, ground electrode (9) middle part is provided with through hole, through hole has at least two angles, each angle is centripetal spur (10), and central electrode (8) end face consists of spark gap a little less than the lower plane of ground electrode (9) between the spur (10) of central electrode (8) and ground electrode (9).

2. a kind of quick firing special-shaped earth electrode spark plug as claimed in claim 1, it is characterized in that: ground electrode (9) is formed by the punching out of nichrome sheet material.

3. a kind of quick firing special-shaped earth electrode spark plug as claimed in claim 1 or 2, it is characterized in that: ground electrode has at least two metal legs and housing (2) to be welded into one.

4. a kind of quick firing special-shaped earth electrode spark plug as claimed in claim 1 or 2, it is characterized in that: the through hole of ground electrode (9) middle part is square hole, polygonal hole or circular hole.

5. a kind of quick firing special-shaped earth electrode spark plug as claimed in claim 1 or 2, it is characterized in that: spark gap is 0.9～1.1 millimeter.

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