RU2576691C1 - Igniter - Google Patents

Abstract

FIELD: engines.

SUBSTANCE: invention relates to antechamber type of internal combustion engines (ICE). This invention consists in implementing of igniter in form of antechamber equipped with laser spark-plug. Antechamber is separated from the laser spark-plug by washer with central hole, which can be made as narrowing to the output, and antechamber bottom with holes is made in form of partial sphere. Inside antechamber a target of spherical form is mounted on holder, and focus of laser spark-plug coincides with target surface. Output holes can be of radial, cylindric, or cone shape with their extensions toward outlet.

EFFECT: technical results are reduced dimension and higher efficiency of igniter in order to reduce fuel consumption and emission of harmful substances, as well as improving ignition reliability.

16 cl, 15 dwg

Description

The invention relates to igniters (spark plugs, in particular laser with a built-in prechamber, which can significantly improve the efficiency of the spread of the ignition flame and the efficiency of combustion of the air-fuel mixture - fuel assemblies when used in an internal combustion engine - internal combustion engine, carburetor, injector, and diesel, as well 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 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 “minicamera” 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 "minicamera" 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 due to corrosion, cracks may appear at the end of the axial central electrode, which leads to the occurrence of 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 Н01Т 13/20, publ. August 27, 2009. This spark plug contains a central electrode and a side electrode of a 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.

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 the housing, according to A.S. in the USSR No. 1802382, IPC Н01Т 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 "miniformer" 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 is optimal for an 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-camera” 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 start-up method with fuel assembly enrichment leads to excessive fuel consumption, wear of the internal combustion engine piston system and deposits of soot 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: prechamber housing, ignition cavity and fuel supply holes in the prechamber and 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 reducing 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 prototype.

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. 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 when filling the fuel assembly chamber and reducing 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 small-sized igniter that provides more reliable ignition when starting the engine especially at low temperatures, more complete combustion of the fuel assemblies and reliability.

The solution of these problems was achieved in an igniter containing a laser spark plug and a pre-chamber, separated from the laser spark plug by a washer with a central hole and containing a body and a bottom with outlet openings in it, characterized in that the bottom is made as part of a sphere, inside the pre-chamber on the holder is installed the target is in the shape of a sphere, and the focus of the laser spark plug matches the surface of the target. The Central hole may be made tapering to the exit.

The geometric centers of the spheres forming the prechamber and the target can coincide. The holder can be made in the form of a cone attached to the bottom of the prechamber. The holder can be made in the form of a cylinder attached to the bottom of the prechamber. The holder can be made in the form of a plate with holes. The target can be made of heat resistant metal. The target on the incident side of the laser beam may have a flat surface that is not perpendicular to the longitudinal axis of the igniter.

Outlets can be made radial. 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 ... 15, where

- in FIG. 1 shows an igniter assembly,

- in FIG. 2 shows a hemisphere-shaped prechamber, first embodiment,

- in FIG. 3 shows a hemispherical prechamber, a second embodiment,

- in FIG. 4 shows a hemispherical prechamber, the third option,

- in FIG. 5 shows a hemisphere-shaped prechamber with a target, the fourth embodiment,

- in FIG. 6 shows the prechamber,

- in FIG. 7 shows a diagram of the movement of combustion products in the prechamber and in cylindrical outlet openings,

- in FIG. 8 is a diagram of the movement of combustion products in the prechamber and in conical, expanding outlet openings

- in FIG. 9 shows view A,

- in FIG. 10 shows view B,

- in FIG. 9 shows the installation diagram of the fairing,

- in FIG. 10 shows a focusing scheme of a laser beam,

- in FIG. 11 shows a prechamber with chamfered outlets,

- in FIG. 12 shows the outlet with bevels,

- in FIG. 13 shows a view of C, the first option,

- in FIG. 14 shows view C, a second embodiment,

- in FIG. 15 shows view C, the third option.

The igniter (Fig. 1 ... 15) contains a laser spark plug 1, which in turn contains a housing 2 with a cavity 3, in which an optical window 4 made of quartz glass, a channel 4, in which a voltage converter 6 is connected, connected by a wire 7 to a solid-state laser, is installed 8, which is connected by an optical fiber 9 to the focusing lens 10. The laser spark plug 1 is screwed into the cylinder head 11. Under the laser candle 1, a prechamber 12 is made, which contains a bottom 13 with outlet holes 14. In the prechamber 12 on the holder 15 are installed Shen 16.

The prechamber 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 optical window 4 from the direct effects of combustion products in the prechamber 12. The central hole 18 is designed to pass the laser beam 20 from the focusing lens 10.

The holder 15 can be made in the form of a cone 20 mounted on the bottom 13 (Fig. 2), or a cylinder 21, also installed along the axis of the igniter on the bottom 13 of the pre-chamber 12 (Fig. 3), or in the form of a plate 22 mounted perpendicular to the axis of the ignitor , with through holes 24 for the passage of combustion products (Fig. 4).

The voltage matching unit 6 is electrically connected to the terminal lug 25, which is connected by a high voltage wire 26 to a pulse distributor 27, which is connected to a power source 29 by low voltage wires 28. One low voltage wire 29 is connected to ground 30 (grounded).

The prechamber 12 can be made as part of a ball having a volume of half the geometric volume of the ball. The outlet openings 14 may be made radial. The outlet openings 14 may be cylindrical in shape. The outlet openings 14 may be conical in shape with expansion towards the outlet. The outlet openings 14 may be overlapped. The geometric center of the target 16 O1 can be made coinciding with the geometric center O2 of the prechamber 12, made in the form of a hemisphere. This contributes to the radial exit of combustion products from the outlet openings 14 with minimal pressure loss (Fig. 5).

The outlet openings 14 may be made radially (FIGS. 6 and 7). The outlet openings 14 may be cylindrical in shape (FIG. 7). The outlet openings 14 may be conical in shape with expansion towards the outlet (FIG. 8).

The outlet openings 14 can be overlapped (FIGS. 9 and 10) to increase the permeability of the bottom 13 (degree of perforation).

In FIG. 11 is a diagram of focusing a laser beam; FIG. 12 is a view C, a first variant with a chamfer 31 at the entrance to the outlet openings 14, FIG. 13 is a view C, a second embodiment with chamfers 32 at the outlet of the outlet openings 14, FIG. 14 shows a view C, a third variant with radial fillets 33 at the entrance to the outlet openings 14, in FIG. Fig. 15 shows view C, the fourth variant with radial fillets 34 at the outlet of the outlet openings 14. Chamfers 31 and 32 and radial fillets 33 and 34 at the inlet and outlet of the outlet openings 14 reduce the hydraulic losses of the ignition flames upon exiting the prechamber 12, which were observed upon sudden narrowing and sudden expansion of the flow.

Device operation

During operation of the igniter, for example, as part of the internal combustion engine (Fig. 1 ... 15), which includes the igniter, 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 a voltage conversion unit 6 and then to a solid-state laser 8, which generates a laser beam 20. The laser beam 20 heats the target 16 almost instantly due to its small size. A fuel assembly that is in contact with the target surface is ignited and the flame front in the form of a ball radially goes to the outlet openings 14 and leaves them. In the upper part of the prechamber 12, due to the presence of a flat surface 15 on the target 16, the flame front goes as indicated by arrow 26 and does not fall into the central hole 18 of the washer 17, does not clog the hole with incomplete combustion products and protects the optics.

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. Moreover, due to the fact that the total area of the outlet openings 12 is larger than the cross-sectional area of the prechamber 12, the outlet openings 14 do not throttle the fuel assembly flow when it enters the prechamber 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 spherical shape of the bottom (in the form of a hemisphere) 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 the spherical surface, the outlets 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 pre-chamber 12 and the target 16 must coincide, then the movement of the flame front inside the pre-chamber 12 will be strictly radial. The use of chamfers 31 and 32 or radial fillets 33 and 34 will significantly (by an order of magnitude) reduce the pressure loss of the ignition flames leaving their outlet openings (due to the absence of sudden expansion and contraction).

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 igniter;

2) to simplify the design of the ignition system by reducing the number of parts when combining the spark plug and the prechamber;

3) increase the power of the igniter by reducing aerodynamic losses in the outlet due to:

- execution of the prechamber and the target spherical and combining their geometric axes,

- run outlets radial,

- execution of chamfers or radius fillets at the outlet

- performing on the target from the side of the incident laser beam a flat surface made not perpendicular to the longitudinal axis of the igniter;

4) to improve ignition when starting an unheated engine, especially at low temperatures, due to ignition of fuel assemblies in a small volume of the prechamber;

5) to 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 pre-chamber torch;

6) reduce the emission of harmful substances due to more complete combustion of fuel;

7) increase the life of the candle by preventing soot deposits on its optics. This is achieved by performing on the target a flat inclined surface non-perpendicular to the longitudinal axis of the igniter.

Claims (16)

1. An igniter containing a laser spark plug and a pre-chamber, separated from the laser spark plug by a washer with a central hole and containing a body and a bottom with outlet openings in it, characterized in that the bottom is made as part of a sphere, a target in the form of a sphere is installed inside the pre-chamber, mounted on the holder, and the focus of the laser spark plug coincides with the surface of the target. 2. The ignitor according to claim 1, characterized in that the central hole is made tapering to the exit. 3. The ignitor according to claim 1 or 2, characterized in that the geometric centers of the spheres forming the prechamber and the target coincide. 4. The ignitor according to claim 1 or 2, characterized in that the holder is made in the form of a cone attached to the bottom of the prechamber. 5. The ignitor according to claim 1 or 2, characterized in that the holder is made in the form of a cylinder attached to the bottom of the prechamber. 6. The ignitor according to claim 1 or 2, characterized in that the holder is made in the form of a plate with holes. 7. The ignitor according to claim 1 or 2, characterized in that the target is made of heat-resistant metal. 8. The igniter according to claim 1 or 2, characterized in that the target from the side of the incident laser beam has a flat surface that is not perpendicular to the longitudinal axis of the igniter. 9. The ignitor according to claim 1 or 2, characterized in that the outlet openings are made radial. 10. The ignitor according to claim 1 or 2, characterized in that the outlet openings are cylindrical in shape. 11. The ignitor according to claim 1 or 2, characterized in that the outlet openings are conical in shape and extend towards the outlet. 12. The ignitor according to claim 1 or 2, characterized in that the outlet openings are overlapped. 13. The igniter according to claim 1 or 2, characterized in that bevels are made at the entrance to the outlet openings. 14. The igniter according to claim 1 or 2, characterized in that the chamfers are made at the outlet of the outlet openings. 15. The ignitor according to claim 1 or 2, characterized in that at the entrance to the outlet openings, radius fillets are made. 16. The igniter according to claim 1 or 2, characterized in that at the exit of their outlet openings radius fillets are made.

Images