RU2634301C2 - Laser ignition system and laser ignition plug - Google Patents

Abstract

FIELD: electricity.

SUBSTANCE: laser ignition system contains a power source connected by low voltage wires through a switch with a high voltage unit that is connected by a high voltage wire to a distributor whose output is connected by an isolated high voltage wire to a laser ignition plug containing a laser source. The system contains a low-voltage distributor, the distributor and the low-voltage distributor are connected by a synchronization device, the laser ignition plug contains a preignition chamber with a cavity formed by an end bottom, a side wall and a conical wall in the form of a frustum of a cone in which outlets are made, the internal electrode is connected to the outlet of the distributor, and a microchip laser is connected to the power source via the low-voltage distributor. The laser ignition plug comprises a laser source and a focusing lens protected by an optical glass, characterized in that at the input of the preignition chamber an internal electrode is set, comprising at least one hole for the laser beam passing. The internal electrode can be connected by a high-voltage wire with a distributor.

EFFECT: reducing the size of the igniter and increasing the efficiency of the spark discharge and the reliability of the ignition.

17 cl, 15 dwg

Description

The group of inventions relates to igniters, spark plugs, in particular laser with an integrated prechamber, which can significantly improve the efficiency of the spread of the ignition flame and the efficiency of burning the air-fuel mixture due to the simultaneous use of a powerful electric field for fuel assembly to ignite the laser beam and to heat and activate the fuel-air mixture. The invention can find application when used in an internal combustion engine - internal combustion engine, both carbureted and injection and diesel, as well as in rotary engines, gas piston and other types of engines and in power plants.

State of the art

Usually, the lateral grounded electrode of the electric spark plug is bent and L-shaped, 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 electric spark plug according to the patent of the Russian Federation for the invention No. 2366053, IPC Н01Т 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 disadvantage of this candle is the 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 the invention No. 2366052, IPC Н01Т 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 Н01Т 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.

A known laser ignition system and a laser spark plug according to the patent of the Russian Federation for utility model No. 152420, IPC F02P 23/04, publ. 05/27/2015, the prototype of the ignition system and laser spark plugs.

These laser ignition systems and the candle contain an electric source connected by low-voltage wires through a switch to a high-voltage unit, which is connected by a high-voltage wire to a distributor, the output of which is connected by an insulated high-voltage wire to a laser spark plug, containing a laser radiation source.

Disadvantages:

- the large required laser power with limited dimensions of the laser spark plug, which it is advisable to produce the dimensions as an exact copy of standard electric spark plugs,

- relatively low completeness of combustion of fuel in the engine cylinder due to its ignition at one point,

- soot deposition on the optics of a laser candle.

The objective of the invention, corresponding to the achieved technical result, is to create a simple laser candle of small dimensions and low power, 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 reduction in the required laser power due to the use of a laser beam to pre-ignite the fuel assemblies and preprocess the fuel assemblies into prechambers with a very strong electric field.

The solution of these problems was achieved in a laser ignition system containing an electric source connected by low-voltage wires through a switch to a high-voltage unit, which is connected by a high-voltage wire to a distributor, the output of which is connected by an insulated high-voltage wire to a laser spark plug, containing a laser radiation, so that the system contains a low-voltage distributor, a distributor and a low-voltage distributor are connected by a synchronization device, a laser candle Ignition comprises a prechamber, the prechamber comprises a cavity formed by the socket bottom, side wall and the conical wall of the truncated cone, wherein outlet openings are made, the inner electrode connected to the output of the distributor, and the microchip laser is connected to a power source through a low voltage distributor.

The synchronization device can be made mechanical, for example, in the form of a shaft. The synchronization device can be made electronic, for example, in the form of a processor.

The solution of these problems was achieved in a laser spark plug containing a laser source and a focusing lens protected by optical glass, in that an internal electrode was installed at the inlet of the prechamber, containing at least one hole for the passage of the laser beam. The inner electrode may be connected by a high voltage wire to the distributor. The laser candle may contain additional optical glass with a protective cavity between them. The laser radiation source can be made in the form of a microchip laser with a vacuum tube. The source of laser radiation can be made in the form of a solid-state laser. The laser spark plug can be configured to split the laser beam. The inner electrode can be made with a pointed protrusion at the end facing the prechamber. The inner electrode can be made with an annular pointed protrusion at the end facing the prechamber. Several holes can be made on the inner electrode at an angle to the axis of the prechamber. At least one target may be installed inside the prechamber. The target can be made in the form of a metal ball mounted on a conical holder having a shank mounted in the end wall. Several targets can be mounted on the conical wall according to the number of outlet openings. Targets mounted on a cylindrical wall can be made in the form of a metal ball mounted on a conical holder. Targets can be set so that the axes of the outlet openings pass through the centers of the metal balls.

The invention is illustrated in the drawings of FIG. 1 ... 15, where

- in FIG. 1 shows an assembly ignition system,

- in FIG. 2 shows a laser spark plug, the first option,

- in FIG. 3 shows a laser spark plug, the second option,

- in FIG. 4 shows the prechamber, the first option,

- in FIG. 5 shows the prechamber, the second option,

- in FIG. 6 shows the prechamber, the third option,

- in FIG. 7 shows the prechamber, the fourth option,

- in FIG. 8 shows an internal electrode with a pointed protrusion,

- in FIG. 9 shows an internal electrode with an annular pointed protrusion,

- in FIG. 10 shows a washer with several holes made at an angle,

- in FIG. 11 shows a first embodiment of a target installation,

- in FIG. 12 shows a second option for setting targets,

- in FIG. 13 shows the target

- in FIG. 14 shows diagrams of the supply of laser pulses and voltage at the internal electrode when using a high-voltage DC unit,

- in FIG. Figure 15 shows the diagrams of the supply of laser pulses and the voltage at the internal electrode when using a high-voltage AC unit.

The laser ignition system (Fig. 1) contains a power source 1 connected by low-voltage wires 2 through a switch 3 to a high-voltage unit 4, which is connected by a high-voltage wire 5 to a distributor 6. The second high-voltage wire 7 is connected to ground 8. Each output of the distributor 6 is connected isolated high-voltage wire 9 with a laser spark plug 10, more precisely with a terminal lug 11. One low-voltage wire 2 is grounded to ground 8.

To provide power to the laser spark plug 10 and timely turn on the power of the laser spark plug 10 with a low voltage, a low-voltage distributor 12 is connected to the low-voltage wire 2, the output of which is connected by a wire 13 to the laser spark plug 10, more precisely, to terminal 14.

The laser ignition system 10 contains a control unit 15 (electronic), which is connected by electrical connections 16 to the distributors 6 and 12. The laser ignition system contains a speed sensor for the crankshaft 17 connected by electrical connection 16 to the control unit 15.

The operation of the valves 7 and 12 is synchronized by the synchronization mechanism 18, for example, a shaft or an electronic system (Fig. 1).

The laser spark plug 9 (FIGS. 1 and 2) contains a housing 19 (metal), an insulator 20, an internal high-voltage wire 21 connected to an internal electrode 22 made in the form of a washer with a hole 23 (holes) mounted on an insulating sleeve 24.

In the cavity 25 inside the insulator 20, a microchip laser 27 is mounted on the shock absorber 26, to which the vacuum tube 28 is connected. The vacuum tube 28 is a metal and ceramic tube inside which a vacuum is created. A focusing lens 29 is fixed at the opposite end of the vacuum tube 28.

An optical glass 30 and an additional optical glass 31 with a protective cavity 32 between them are mounted under the focusing lens 29.

Under the central electrode 22, a prechamber 33 with a cavity 34 is made, having an end face 35, a truncated conical wall 37 and a cylindrical wall 38. Outlets 39 are made in the conical wall 37 (Figs. 1 and 2).

To supply energy to the microchip laser 27, in addition to terminal 14, a metallized coating 40 is provided on the insulator 20 on the inside and an electrode 41 for transmitting voltage to the microchip laser 27.

The laser spark plug 10 is screwed into the cylinder head 42 by thread 43.

The central hole 18 is intended for the passage of the laser beam 44 from the focusing lens 29. In more detail, the design of the laser spark plug 10 is shown in FIG. 2.

In FIG. 3 shows a second embodiment of a laser spark plug 10, in which a solid-state laser 45 is installed instead of a microchip laser 27 with a vacuum tube 28. FIG. 4 ... 7 are options for the pre-chamber 33.

According to the first embodiment (Fig. 4), one hole 23 is made in the inner electrode 22 along the axis of symmetry of the laser spark plug 10.

In the second embodiment (Fig. 5), a prism 46 is used, mounted above the optical glass 30, to split the beam of the laser 44 into several beams (according to the number of exit openings 39).

According to the third embodiment (Fig. 6), it is proposed to install one target 46 in the cavity 34 inside the pre-chamber 33.

According to the fourth embodiment (Fig. 7), it is proposed to install several targets 47 in the chamber 33 in the cavity 34 and attach them to the cylindrical wall 37.

The laser candle may have a target 47 for the laser beam 44 in the cavity 34 of the pre-chamber 33 33 (Fig. 3 ... 6). In this case, the laser spark plug 10 can be made in one of four options, depending on the design of this target. 47 (Fig. 3 ... 6).

In FIG. 4 shows a prechamber 33 in which one internal electrode 22 with one hole 23 is mounted.

In FIG. 5 shows a prechamber 33 in which a prism 46 for splitting the laser beam 44 is mounted and several holes 23 are made in the inner electrode 22, the number of holes being equal to the number of laser beams.

In FIG. Figure 6 shows the prechamber 33 with target 47.

In FIG. 7 shows a laser spark plug with several targets 47.

The prechamber 33 can be made in several versions, depending on the design of the target 47 (Fig. 8 ... 10).

In FIG. Figure 8 shows the target 47 mounted along the axis OO of the laser spark plug inside the chamber 33 in the cavity 34.

This target 47 is made in the form of a metal ball 48 mounted on a conical holder 49 having a shank 50 mounted in the end face 35 (Fig. 9).

In the second embodiment, several targets 47 are mounted on the side wall 38.

There are three possible versions of the washer 22, which performs the function of the central electrode (Fig. 11 ... 13).

In FIG. 11 shows a washer 22 with an annular pointed protrusion 51, in FIG. 12 shows a washer 22 with an annular pointed protrusion 52, in FIG. 13 shows a washer 22 with several holes 23 made at an angle to release several laser beams and prevent contamination of the optics,

- in FIG. 14 shows diagrams of the supply of laser pulses 52 and voltage 53 at the internal electrode when using a high-voltage DC unit,

- in FIG. 15 shows diagrams of the supply of laser pulses 52 and voltage 54 at the internal electrode when using an AC high voltage unit.

Device operation

During operation of the igniter, for example, as part of an internal combustion engine - ICE (Fig. 1 ... 13), which includes an ignitor, the engine is started with a starter (not shown) and at the same time turn on the switch 31 (ignition switch). After injection of the fuel assembly (air-fuel mixture), part of it through the outlet openings 14 enters 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 33. The fuel assembly in contact ignites the flame front in the form of a ball, the flame front radially goes to the outlet openings 37 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 33 into 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 22, which acts as the central electrode, which significantly heats the air-fuel mixture inside the pre-chamber 33, 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 50 or 51 contributes to the occurrence of corona discharge.

The conical shape of the bottom allows you to place on it the maximum number of holes with a minimum protrusion of the pre-chamber 33 inside the engine cylinder. In addition, on this surface it is possible to position the outlet openings 39 at any angle to the axis of the prechamber 33.

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 45 (Fig. 3). 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.

In FIG. 14 shows diagrams of the supply of laser pulses 52 and voltage 53 at the internal electrode when using a high-voltage direct current unit, and voltage 53 may decrease as the stroke is completed.

In FIG. 15 shows diagrams of the supply of laser pulses 52 and voltage 54 at the internal electrode when using an AC high voltage unit.

The laser pulse frequency may be greater or less than the frequency of the alternating voltage at the output of the high voltage unit 4.

As a result, the use of a group of inventions will allow:

1. Reduce the overall dimensions of the laser spark plug to the dimensions of standard electric spark plugs.

2. To reduce the required laser power through the use of preheating of the fuel assembly and its activation inside the chamber with a powerful electric field.

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

4. Improve the ignition when starting an unheated engine, especially at low temperatures, due to the ignition of the fuel assemblies in a small volume of the prechamber with two sources of laser energy and electric field preheating.

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.

9. Prevent soot deposits on the focusing lens and reduce the harmful effects of high temperatures.

Claims (17)

1. A laser ignition system comprising an electric power source connected by low voltage wires through a switch to a high voltage unit, which is connected by a high voltage wire to a distributor, the output of which is connected by an insulated high voltage wire to a laser spark plug containing a laser radiation source, characterized in that the system comprises a low voltage the distributor, the distributor and the low-voltage distributor are connected by a synchronization device, the laser spark plug contains rkameru, pre-chamber comprises a cavity formed by the bottom of the socket, and a side wall konicheskory wall in the form of a truncated cone in which the outlet openings are made, the inner electrode connected to the output of the distributor, and the microchip laser is connected to a power source through a low voltage distributor. 2. The laser ignition system according to claim 1, characterized in that the synchronization device is made mechanical, for example, in the form of a shaft. 3. The laser ignition system according to claim 1, characterized in that the synchronization device is electronic, for example, in the form of a processor. 4. Laser spark plug containing a laser source and a focusing lens protected by optical glass, characterized in that at the entrance to the prechamber an internal electrode is installed, containing at least one hole for the passage of the laser beam. 5. The laser spark plug according to claim 4, characterized in that the internal electrode is connected by a high-voltage wire to the distributor. 6. The laser spark plug according to claim 4 or 5, characterized in that it contains an additional optical glass with a protective cavity between them. 7. The laser spark plug according to claim 4 or 5, characterized in that the laser radiation source is made in the form of a microchip laser with a vacuum tube. 8. The laser spark plug according to claim 4 or 5, characterized in that the laser radiation source is made in the form of a solid-state laser. 9. The laser spark plug according to claim 4 or 5, characterized in that it is made with the possibility of splitting the laser beam. 10. Laser spark plug according to claim 4 or 5, characterized in that the inner electrode is made with a pointed protrusion at the end facing the prechamber. 11. The laser spark plug according to claim 4 or 5, characterized in that the inner electrode is made with an annular pointed protrusion at the end facing the prechamber. 12. The laser spark plug according to claim 4 or 5, characterized in that several holes are made at an angle to the axis of the prechamber on the inner electrode. 13. The laser spark plug according to claim 4 or 5, characterized in that at least one target is mounted inside the prechamber. 14. The laser spark plug according to claim 13, characterized in that the target is made in the form of a metal ball mounted on a conical holder having a shank mounted in the end wall. 15. The laser spark plug according to claim 13, characterized in that several targets are installed on the conical wall according to the number of outlet openings. 16. The laser spark plug according to claim 15, characterized in that the targets mounted on the cylindrical wall are made in the form of a metal ball mounted on a conical holder. 17. The laser spark plug according to claim 16, characterized in that the targets are mounted so that the axes of the outlet openings pass through the centers of the metal balls.

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