RU2574189C1 - Laser igniter - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: task of the invention is reducing the size of the igniter and improving the efficiency of the spark discharge. A laser igniter, comprising an optical system and a pre-ignition chamber separated from the optical system by a washer with a centre hole, and a bottom with an exit hole therein, is configured to simultaneously generate corona discharge and a laser beam.

EFFECT: reduced fuel consumption and emission of harmful substances, and high reliability of ignition.

24 cl, 24 dwg

Description

The invention relates to igniters (spark plugs, in particular laser ones with an integrated prechamber, which can significantly improve the efficiency of spreading the ignition flame and the efficiency of burning the air-fuel mixture due to the simultaneous use of a laser beam and corona discharge for igniting. The invention can be used when used in an internal combustion engine - ICE as carburetor, and injection and diesel, as well as in rotary engines, gas piston and other types of engines her and in power plants.

State of the art

Usually the lateral grounded electrode of the spark plug is bent and L-shaped, being perpendicular to the direction of the axial central electrode so that the cross section of the discharge part, the so-called “mini-chamber”, facing the axial central electrode, is rectangular.

When a spark discharge occurs, the spark appears between the axial central electrode and the end discharge part of the grounded electrode located below the axial central electrode. The gas mixture in the spark gap formed by these electrodes is ignited by the spark so that the compressed gas mixture is ignited first in the “mini-chamber” between the electrodes, and then the horizontally expiring torch ignites the rest of the fuel assembly. In conventional designs, the high gas pressure caused by ignition can be blocked by the end discharge part so that the effect of the propagation of combustion on the air-fuel gas mixture in the combustion chamber is not good enough. And starting the engine at low temperatures generally causes difficulty due to the cooling of the flaming flame from the cold metal parts of the cylinder head.

When the residual carbon (the product of incomplete combustion of the fuel-air mixture - FA) remains in the spark gap between the electrodes, carbon can accumulate and change from the phase of the particles to the phase of the connection on the surfaces of the electrodes so that a short circuit can occur between the electrodes. In this state, even when voltage is applied, a spark may not occur, which leads to serious problems up to stopping the engine or releasing the air-fuel mixture through the exhaust pipe without combustion. When an unburned gas mixture is discharged into the exhaust pipe, a reverse flash effect is often manifested, with an emergency effect and a reduced combustion efficiency. Failure of one of several cylinders can remain unattended for a long time, which will lead to engine failure due to imbalance of rotor parts.

During the operation of the internal combustion engine, a crack may appear at the end of the axial central electrode due to corrosion, which leads to critical damage. Spark plug life may be reduced due to such a defect.

Known spark plug according to the patent of the Russian Federation for the invention No. 2366053, IPC H01T 13/20, publ. August 27, 2009. This spark plug contains a central electrode and a side electrode of cylindrical shape, between them a “mini-chamber” is formed. Spark discharge is carried out on a cylindrical wall, and the output of combustion products is carried out in an annular gap.

The disadvantages of this candle are possible clogging of the annular gap due to the deposition of solid particles of combustion products on both electrodes, especially when working on an enriched mixture.

Known spark plug according to the patent of the Russian Federation for invention No. 2366052, IPC H01T 13/00, publ. August 27, 2009. This candle contains a central electrode and a L-shaped side electrode, the plane of which is twisted along the length to create a vortex motion of the combustion products.

The disadvantage is poor engine starting at low temperatures.

Known spark plug according to the patent of the Russian Federation for the invention No. 2360342, IPC H01T 13/54, publ. 06/27/2009

This candle contains a central and side electrodes and two prechambers mounted in series.

Disadvantages: constructive complexity of the candle, its large axial dimensions and high cost.

It is known that for the trouble-free operation of the spark plug, the lower part of the insulator (thermal cone) should have a temperature of about 500-600 ° C. At a temperature lower than indicated on the candle, a layer of soot forms and it begins to work intermittently. The insufficient heating temperature of the insulator and the spark plug electrodes is especially pronounced when the cold engine starts at negative temperatures, when the fuel vapor partially condenses and the ignition reliability of the mixture is due not only to its ionization, but also to the heating of the gas volume adjacent to the electrodes. To increase the reliability of the ignition system in conditions of negative temperatures, candles with forced electric heating are used.

Known, for example, a spark plug containing a metal housing, an insulator and a heating element placed in an annular groove made on the side wall of the insulator, in its part, closed by a housing according to Auth. USSR No. 1802382, IPC H01T 13/00, publ. 1993 year

The disadvantage of this design is that the heating element can be integrated into the candle only during its manufacture. However, the urgent task is the modernization of already made candles.

Known spark plug containing "mini-prechamber" according to the patent of the Russian Federation for invention No. 2356145, IPC H01T 13/20, publ. 05/20/2009

This spark plug contains an axial central electrode for a spark discharge and a side grounded electrode opposite the axial central electrode relative to the spark gap, with a circular portion in plan having a central circular hole formed at the discharge end of the lateral rounded electrode. In this case, the spark plug includes a plurality of spiral projections that protrude from the inner side of the circular part in the direction of the central circular opening so as to form a turbulent flow in the gas mixture when gas compressed during the compression stroke is supplied into the spark gap through the central circular opening.

The technical result is to improve the efficiency of spark propagation by providing better mixing in the spark gap between the electrodes, providing a function of generating a turbulent flow, and also increasing the ignition force.

The disadvantages of this device: low efficiency of the spark discharge, due to the mismatch of the shape, size and relative position of the electrodes, optimal for electric discharge in the gas gap. The disadvantage is that the area of the Central hole is made smaller than the cross-sectional area of the Central electrode. This gives several negative results: the twisting device is ineffective and does not perform its function for two reasons:

- spinning means have a very small height (due to the small diameter of the hole) and, being located within the boundary layer of the stream, do not affect the nature of the movement of the bulk of the stream flowing from the hole,

- the spin is carried out in a horizontal plane, which does not contribute to the introduction of the torch into a significant volume of the combustion chamber of the internal combustion engine cylinder, which is usually located below the candle.

In addition, this technical solution has several more disadvantages:

- a small diameter hole is more easily clogged by products of incomplete combustion of fuel assemblies,

- the hole acts as the output nozzle of the “mini-prechamber” and with a small area of the hole the torch power is insignificant and cannot ensure the start of the internal combustion engine at low temperatures. The role of the second nozzle is played by the lateral gaps between the central and side electrodes, but the combustion products flowing out along the head of the unheated cylinder are sharply cooled and cannot ignite the entire volume of the combustion chamber of the cylinder. The traditionally used method of starting with fuel assembly enrichment leads to excessive fuel consumption, wear of the internal combustion engine piston system and to soot deposition on the electrodes.

Known igniter according to the patent of the Russian Federation for the invention No. 2169885, IPC F23Q 9/00, publ. 06/27/2001

Signs common with the proposed technical solution are the prechamber housing, the ignition cavity and the fuel supply inlet to the prechamber and the torch discharge.

Disadvantages: large dimensions. Weight and structural complexity due to the presence of a large number of parts. At the same time, with a decrease in the size of the prechamber, it will not fulfill its main function; reliably ignite the vehicle (air-fuel mixture). The second disadvantage is the use of an electric spark plug.

Known pre-chamber ICE according to the patent of the Russian Federation for utility model No. 16, IPC F02B 19/16, publ. 06/25/1994

A remote prechamber for an internal combustion engine with a moving fuel flow in an air mixture, comprising a housing, a cavity with a spark plug and a transition channel, characterized in that a swirl plate is placed in the transition channel nozzle, twisted by an angle of rotation (1/2) · pi - (2/3) · pi rad (90-120 °).

The disadvantage is the complexity of the design.

Known pre-chamber ICE for St. RF for utility model No. 60635, IPC F02D 19/10, publ. 01/27/2007

The vortex prechamber of an internal combustion engine according to this patent comprises a cylindrical body with external and internal threads, an internal cavity, a lower hole and side flare channels, while the side flare channels have three deflection angles in the chamber chamber. The lower and side openings are located on a conical bottom.

The disadvantage is the low efficiency of the prechamber due to the fact that the total area of the holes is less than the cross-sectional area of the ignition chamber. This leads to throttling when filling the fuel assembly chamber and a decrease in its dose and the power of the ignition torches. The increase in the area of the holes is not technically feasible due to the fact that this will lead to the protrusion of the conical bottom inside the cylinder of the internal combustion engine.

Known pre-chamber ICE according to the patent of the Russian Federation for utility model No. 30396, IPC F02B 19/00, publ. 06/27/2003

The prechamber of the internal combustion engine contains a cavity (ignition chamber), an axial flare channel and side flare channels made at an angle to the longitudinal axis, side flare channels in plan are made at an angle to the radii passing through the axis of the prechamber and are located on a conical bottom. The conical bottom has a large angle at the apex from 60 to 90 degrees, because at small angles, its length will be large and the piston may be grazed at top dead center. Since the length of the conical bottom is limited, both the number of holes and their area are limited. In addition, the installation angles of all side holes are the same, which limits the diameter of the total flammable flame. The twist effect is insufficient, since the volume of the prechamber is less than 1% of the volume of the engine cylinder and the entire volume of the fuel assembly in the cylinder cavity cannot be twisted.

The disadvantage of this technical solution is the low efficiency of the prechamber due to the fact that the total area of the holes is less than the cross-sectional area of the ignition chamber. This leads to throttling during filling of the fuel assembly chamber and a decrease in its dose and, as a consequence, the power of the ignition torches. The second disadvantage is the use of an electric spark plug.

The objective of the invention, corresponding to the achieved technical result, is to create a simple laser candle of small dimensions, providing more reliable ignition when starting the engine especially at low temperatures, more complete combustion of the fuel assemblies and reliability.

The technical result is a simultaneous increase in the power of the spark plug while reducing the laser power due to the use of a laser beam and corona discharge at the same time to ensure ignition of the fuel assemblies.

The solution of these problems was achieved in a laser spark plug containing optics and a prechamber separated from the optics by a washer with a central hole and a bottom with outlet holes in it, in that the laser spark plug is configured to simultaneously create a corona discharge and a laser beam.

The laser spark plug can be configured to rotate a corona discharge. The laser spark plug can be configured to create a corona discharge inside the prechamber. The laser spark plug can be configured to create a corona discharge outside the prechamber. The laser spark plug can be configured to simultaneously create a corona discharge inside and outside the prechamber. The laser spark plug can be configured to split the laser beam. The laser spark plug may include a terminal block, a high-voltage converter, and a solid-state laser connected in series by an internal high-voltage wire and internal wires, as well as optics, including a focusing lens and an optical window. The washer can act as an internal electrode and is made of an electrically conductive material and is connected to the internal high-voltage wire. The washer can be made with an annular pointed protrusion at the end facing the prechamber. The washer can be made with local pointed protrusions at the end facing the prechamber. Several holes can be made on the washer at an angle to the axis of the igniter, an outer ring electrode is made concentrically with the insulating sleeve. The outer ring electrode may be made in the form of a tapering nozzle. The outer ring electrode may be made in the form of an expanding nozzle. The outer ring electrode may be made in the form of a tapering-expanding nozzle. Inside the outer ring electrode, flow swirling means may be provided. Outlets can be made radial. Outlets may be tangential. The outlet openings may be cylindrical in shape. The outlet openings may be conical in shape with expansion towards the outlet. Outlets may be overlapped. Chamfers can be made at the entrance to the outlet openings. Chamfers can be made at the outlet of the outlet openings. At the entrance to the outlet openings, radius fillets can be made. At the exit of the outlet openings, radius fillets can be made.

The invention is illustrated in the drawings of FIG. 1 ... 24, where

- in FIG. 1 shows the igniter assembly, the first option,

- in FIG. 2 shows the igniter assembly, the second option,

- in FIG. 3 shows the igniter assembly, the third option,

- in FIG. 4 presents the igniter assembly, the fourth option,

- in FIG. 5 shows a washer with an annular pointed protrusion,

- in FIG. 6 shows a washer with local pointed protrusions,

- in FIG. 7 shows a washer with several holes made at an angle,

- in FIG. 8 shows the prechamber,

- in FIG. 9 shows the prechamber, the second option,

- in FIG. 10 shows a section aa, the first option,

- in FIG. 11 shows a section aa, the second option,

- in FIG. 12 shows the lower part of the igniter, the first option,

- in FIG. 13 shows the lower part of the igniter, the second option,

- in FIG. 14 shows the lower part of the igniter, the third option,

- in FIG. 15 shows the lower part of the igniter, the fourth option,

- Fig.16 shows a view of the first option,

- in FIG. 17 shows view B, the second option,

- in FIG. 18 shows the view, the third option

- in FIG. 19 shows view B, fourth embodiment,

- in FIG. 20 shows view B, fifth embodiment,

- in FIG. 21 shows view B, sixth embodiment,

- in FIG. 22 shows the appearance of a laser spark plug, the first option,

- in FIG. 23 shows the appearance of a laser spark plug, the second option,

- in FIG. 24 shows the operation of a laser spark plug in an internal combustion engine.

The laser spark plug 1 (Fig. 1 ... 24) contains a housing 2 (metal), an insulator 3, a terminal lug 4, to which is connected an internal high-voltage wire 5 high-voltage Converter 6, designed to convert high voltage to voltage required to power a solid-state laser 7 connected by electrical wires 8 to this unit.

A solid-state laser 7 is connected by an optical fiber 9 to a focusing lens 10. A laser spark plug 1 is screwed into the cylinder head 11. A prechamber 12 is made under the laser candle 1, which contains a bottom 13 with exit holes 14. The bottom 13 is made in the form of a truncated cone and has side walls 15 and bottom wall 16.

The camera 12 is separated from the laser candle 1 by a washer 17 with a central hole 18, which communicates to the prechamber 12 with a protective cavity 19 designed to protect the optics from direct exposure to combustion products in the prechamber 12. The central hole 18 is designed to pass the beam of the laser 20 from the focusing lens 10. An optical window 21 is installed in the protective cavity 19 above the washer 17. The optical window 21 and the focusing lens 10 form the optics of the claimed device.

In this case, the laser spark plug 1 can be made in one of four options.

The laser spark plug 1 can be configured to create a corona discharge inside the pre-chamber 12 (Fig. 1)

Concentric to the washer 17 in this embodiment, an electrical insulator 22 is installed (Fig. 1)

A variant is possible when the laser candle is made with the possibility of creating a corona discharge outside the prechamber 12 (Fig. 2). In this case, an electric insulator 23 is mounted concentrically to the body 2 of the laser candle 1, and concentrically to it, an external annular nozzle 24.

A variant is possible when the laser candle is configured to create a corona discharge outside the prechamber 12 and inside the prechamber 12 (Fig. 3). In this embodiment, an electric insulator 22 is installed and an electric insulator 23 is mounted concentrically to the laser candle body 2, and an external annular nozzle 24 is concentric to it.

In the fourth embodiment (Fig. 4), a prism 25 is used to divide the beam of the laser 20 into several.

The voltage matching unit 6 (Fig. 1) is electrically connected by an internal high-voltage wire 5 to a terminal lug 4, which is connected by a high-voltage wire 26 to a pulse distributor 27, which is connected by a high-voltage wire 28 to a high-voltage block 29, which is connected by a low-voltage wire 30, containing a switch 31, to with an energy source 32. One low voltage wire 30 is connected to ground 33 (grounded).

There are three possible versions of the washer 17, which performs the function of a central electrode (Fig. 5 ... 7).

In FIG. 5 shows a washer with an annular pointed protrusion 34, in FIG. 6 shows the washer 17 with local pointed protrusions 35, in FIG. 7 shows a washer 17 with several holes 36 made at an angle to prevent contamination of the optics.

Outlets 12 can be made in several versions (Fig. 8 ... 11).

The outlet openings 14 may be made radial (FIGS. 8 and 10). The outlet holes 14 can be performed tangentially (Fig. 9 ... 11). Outlets 14 can be made only on the side wall 15 (Figs. 8 and 10). At least one outlet 14 may be provided on the bottom wall 16 (FIGS. 9 and 11).

There are different versions of the outer ring electrode 24 (Fig. 12 ... 15).

The outer annular nozzle 24 may be a tapering 37 (FIG. 12) expanding 38 (FIG. 13) or in the form of a tapering-expanding nozzle 39, i.e. in the form of Laval (Fig. 4). Inside the outer annular nozzle 24, flow swirling means 40 may be installed (FIG. 15).

Inside the pre-chamber 12, an internal swirl means 41 can be installed (Fig. 16), it is possible to simultaneously use the swirl means of the flow 40 and the internal swirl means 41 (Fig. 17).

In FIG. 18 is a view C, the first embodiment with a chamfer 42 at the entrance to the outlet openings 14, in FIG. 19 is a view C, a second embodiment with chamfers 43 at the outlet of the outlet openings 14, FIG. 18 is a view C, a third embodiment with radial fillets 44 at the entrance to the outlet openings 14, FIG. Figure 19 shows view C, the fourth variant with radial fillets 45 at the outlet of their outlet openings 14. Chamfers 42 and 43 and radial fillets 44 and 45 at the inlet and outlet of the outlet openings 14 reduce the hydraulic losses of the ignition flames when leaving the chamber 12, which were observed upon sudden narrowing and sudden expansion of the flow.

In FIG. 22 and 23 show the appearance of two variants of a laser spark plug, and in FIG. 24 - her work as part of the internal combustion engine.

Device operation

When the ignitor is operating, for example, as part of an internal combustion engine (Fig. 1 ... 24), which includes an ignitor, the engine is started with a starter (not shown) and at the same time the switch 31 (ignition switch) is turned on. After injection of the fuel assembly (air-fuel mixture), part of it passes through the outlet 14 to the pre-chamber 12. At the time of ignition timing, the distributor 27 supplies the potential to the voltage conversion unit 6, where the voltage decreases to the working one, and then to the solid-state laser 7, which generates a laser beam 20 The laser beam 20 almost instantly ignites the fuel assemblies in the prechamber 12. The fuel assemblies that are in contact ignite the flame front in the form of a ball, the flame front radially goes to the outlet openings 14 and exits them into the combustion chamber of the cylinder wiggler.

In the “stroke” cycle, combustion products having a very high temperature are ejected from the chamber 12 to the cavity of the combustion engine cylinder with great speed and ignite the entire fuel assembly charge present in it.

Simultaneously, a corona discharge arises between the metal casing 2 and the washer 17 acting as the central electrode, which significantly heats the air-fuel mixture inside the pre-chamber 12, which facilitates the operation of the laser spark plug 1 and allows several times to reduce the energy of the solid-state laser 7. The presence of pointed protrusions 34 and 35 contributes to the occurrence of corona discharge.

In the case of the use of an external electrode 24 (Fig. 2), a corona discharge occurs outside the prechamber 12.

The use of a means of swirling the stream 40 and / or an internal swirling means 41 will allow the corona discharge to be twisted together with the flow.

Moreover, due to the fact that the total area of the outlet openings 14 is larger than the cross-sectional area of the pre-chamber 12, the outlet openings 14 do not throttle the fuel assembly flow when it enters the pre-chamber 12 and the ignition chamber. As a result, the charge of the fuel assembly in the prechamber 12 increases. In the cycle, the stroke due to the larger total area of the outlet openings 12 as compared with the prototype, the power of the flaming flame increases.

The conical shape of the bottom allows you to place on it the maximum number of holes with a minimum protrusion of the prechamber 12 inside the engine cylinder. In addition, on this surface, the outlet openings 14 can be positioned at any angle to the axis of the prechamber 12. Preferably, radially. In this case, the geometric centers of the spheres forming the prechamber 12 must coincide, then the movement of the flame front inside the prechamber 12 will be strictly radial. The use of chamfers 31 and 32 or radial fillets 33 and 34 will significantly (an order of magnitude) reduce the pressure loss of the ignition flames exiting the outlet openings (due to the absence of sudden expansion and contraction).

In the second embodiment (Fig. 2), a corona discharge occurs outside the prechamber 12, and in the third version (Fig. 3) both inside and outside the prechamber 12.

In the fourth embodiment (Fig. 4), several laser beams can be obtained by splitting the laser beam 20 on a prism 25.

Such an organization of the fuel assembly ignition process will provide 100% ignition even in the worst conditions at low temperature and high humidity at low power of the solid-state laser 6 (Fig. 1). Also, this approach can be applied on engines operating on cryogenic fuels: hydrogen and liquefied natural gas. To ignite a cryogenic fuel having a very low temperature, it is not necessary to significantly increase the power of the spark plug. This effect will be especially well manifested on high power engines and on engines running on natural gas.

As a result, the application of the invention will allow:

1. Reduce the axial overall dimensions of the laser spark plug.

2. To reduce the required laser power due to the use of corona discharge both inside the chamber and outside it, also additionally due to the twist of the corona discharge.

3. Simplify the design of the ignition system by reducing the number of parts when combining a laser spark plug and a prechamber.

4. Replace commercially available spark plugs without changing the electrical part of the ignition system with laser spark plugs.

5. To increase the igniter power by reducing aerodynamic losses in the outlet due to:

- the implementation of the outlet radial or tangential,

- execution of chamfers or radius fillets at the outlet openings.

6. Improve ignition when starting an unheated engine, especially at low temperatures, due to ignition of fuel assemblies in a small volume of the prechamber by two laser and corona discharge energy sources.

7. Reduce fuel consumption due to its more complete combustion, provided more accurate ignition of the fuel assemblies in the combustion chamber of the internal combustion engine with a powerful prechamber torch.

8. Reduce the emission of harmful substances due to more complete combustion of the fuel.

Claims (24)

1. A laser spark plug containing optics and a prechamber separated from the optics by a washer with a central hole and a bottom with outlet openings in it, characterized in that the laser spark plug is configured to simultaneously create a corona discharge and a laser beam. 2. The laser spark plug according to claim 1, characterized in that it is configured to rotate the corona discharge. 3. The laser candle is made according to claim 1 or 2, characterized in that it is made with the possibility of creating a corona discharge inside the prechamber. 4. The laser spark plug according to claim 1 or 2, characterized in that it is configured to create a corona discharge outside the prechamber. 5. The laser spark plug according to claim 1 or 2, characterized in that it is configured to simultaneously create a corona discharge inside and outside the prechamber. 6. The laser spark plug according to claim 1 or 2, characterized in that it is made with the possibility of splitting the laser beam. 7. The laser spark plug according to claim 1 or 2, characterized in that it comprises serially mounted terminal lugs, a high-voltage converter and a solid-state laser connected by an internal high-voltage wire and internal wires, as well as optics, including a focusing lens and an optical window. 8. The laser spark plug according to claim 1 or 2, characterized in that the washer performs the function of an internal electrode and is made of an electrically conductive material and connected to an internal high-voltage wire. 9. The laser spark plug according to claim 1 or 2, characterized in that the washer is made with an annular pointed protrusion at the end facing the prechamber. 10. The laser spark plug according to claim 1 or 2, characterized in that the washer is made with local pointed protrusions at the end facing the prechamber. 11. Laser spark plug according to claim 1 or 2, characterized in that the washer is made at an angle to the axis of the igniter several holes. 12. Laser spark plug according to claim 1 or 2, characterized in that the concentric electrical insulating sleeve is made of an external ring electrode. 13. The laser spark plug according to claim 1 or 2, characterized in that the outer ring electrode is made in the form of a tapering nozzle. 14. The laser spark plug according to claim 1 or 2, characterized in that the outer ring electrode is made in the form of an expanding nozzle. 15. The laser spark plug according to claim 1 or 2, characterized in that the outer ring electrode is made in the form of a tapering-expanding nozzle. 16. The laser spark plug according to claim 1 or 2, characterized in that a flow swirl means is made inside the outer ring electrode. 17. The laser spark plug according to claim 1 or 2, characterized in that the outlet openings are made radial. 18. The laser spark plug according to claim 1 or 2, characterized in that the outlet openings are made tangential 19. The laser spark plug according to claim 1 or 2, characterized in that the outlet openings are cylindrical in shape. 20. The laser spark plug according to claim 1 or 2, characterized in that the outlet openings are conical in shape with expansion towards the exit. 21. The laser spark plug according to claim 1 or 2, characterized in that bevels are made at the entrance to the outlet openings. 22. The laser spark plug according to claim 1 or 2, characterized in that the chamfers are made at the outlet of the outlet openings. 23. The laser spark plug according to claim 1 or 2, characterized in that at the entrance to the outlet openings, radius fillets are made. 24. The laser spark plug according to claim 1 or 2, characterized in that at the outlet of the outlet openings radius fillets are made.

Images