KR102581717B1 - Valve-controlled ignition prechamber - Google Patents

Abstract

The valve-controlled ignition pre-chamber (1) is intended for an internal combustion engine (2) with a combustion chamber (5) in which a main charge (30) less diluted with neutral gas is ignited, the pre-chamber (1) The means (11) is open and comprises a stack cavity (6) into which the stack injector (8) can inject a pressurized, easily-ignited pilot charge (9), the stack valve (13) being positioned, in particular in the combustion chamber ( Under the effect of the pressure of the gas obtained in 11), it is possible to completely or partially block the laminated duct 7.

Description

Valve-controlled ignition prechamber

The subject of the invention is a valve ignition prechamber which allows ignition of the main load introduced into the combustion chamber of an internal combustion engine by a pilot load ignited by a spark, said prechamber The chamber is designed to optimize the efficiency of the pilot load to ignite the main load.

The maximum and average efficiencies of reciprocating internal combustion engines according to the latest technology are relatively low. In automobiles, maximum efficiency is approximately 35 percent for Otto-cycle spark ignition engines and approximately 40 percent for diesel cycle engines. Regarding average efficiencies in current use of automotive engines, less than 20 percent for spark ignition engines and 25 percent for diesel engines are most common.

In the engine, the part of the energy released by the combustion of fuel and not converted into useful work is dissipated mainly in the form of heat in the cooling system and exhaust gases of the engine.

In addition to poor efficiency, reciprocating internal combustion engines used in automobiles produce polluting gases and particles that are harmful to the environment and health.

Despite these disadvantageous characteristics, and for the lack of other solutions that offer better energy, environmental, functional, and economic compromises, the Otto-cycle or diesel internal combustion engine is installed in almost all automobiles currently in use in the world.

This situation explains the significant research and development efforts made by engine manufacturers to ensure that the energy and environmental balance of internal combustion engines is improved. These efforts are specifically intended to perfect the technologies that make up the engines and to add to them new features that allow the implementation of new strategies.

Among these strategies is dilution of the air and fuel loads of reciprocating internal combustion engines with neutral gases or with oxygen-enriched fresh air.

The present invention relates to such dilution and is particularly intended for reciprocating internal combustion engines with spark ignition, which most commonly consume gasoline or natural gas.

Diluting the load of a spark ignition engine with fresh air or with previously cooled exhaust gases allows to increase the average and/or maximum thermodynamic efficiency of the engine. This results in reduced fuel consumption for the same useful work produced.

When a spark ignition engine operates at partial torque, introducing a diluted load into its (their) cylinder(s) produces less pumping losses than introducing an undiluted load. The reduction in losses is due to the fact that the diluted load is larger with the same energy content. Therefore, in order to introduce the same amount of energy to the cylinder(s), the throttling of the engine's air supply, usually achieved by a throttle valve, is less significant and the pressure of the gases developing at the intake is higher. Additionally, with the same energy introduced to the cylinder(s) of a spark ignition engine, diluting the load increases the mass and total heat capacity of the latter. Therefore, all else being equal, combustion of the rod is carried out at a lower temperature. In addition to reducing the amount of nitrogen oxides produced by combustion, the lower temperature reduces heat loss in the wall(s) of the cylinder resulting from transfer of a portion of the heat to the wall(s) by the rod.

Finally, the load is less susceptible to uncontrolled self-ignition of the air-fuel mixture, especially if the load is oxygen-poor or even diluted with oxygen-free neutral gas. The self-ignition is responsible for the rattling, undesirable phenomenon characterized by explosive combustion that degrades the performance of spark ignition engines and damages the mechanical components that make up them. The desensitization to rattle provided by dilution of the load allows the engine to operate at higher compression ratios, or with ignition triggered at the most advantageous time possible for performance, or both.

In this specific context of diluted air and fuel loads, spark ignition engines operating using stoichiometry are completely different from those operating in excess air, also called “lean-burn”.

Engines that operate using stoichiometry are only compatible with three-way catalysts, which are known devices for post-processing pollutants resulting from combustion. The catalyst is responsible for burning unburned hydrocarbons in the combustion chamber of the thermal engine. The products of this combustion are water vapor and carbon dioxide already present in the atmosphere. The three-way catalyst also completes the oxidation of the well-known polluted carbon monoxide to convert it to carbon dioxide, which makes up approximately 78 percent of the Earth's atmosphere, and reduces nitrogen oxides to convert them to pristine atmospheric dinitrogen. .

The reduction of nitrogen oxides by three-way catalysis requires that the load introduced into the engine is stoichiometric, that is, it contains the exact amount of oxygen required for combustion of the hydrocarbons contained in the load.

An excess of oxygen makes it impossible for the three-way catalyst to reduce nitrogen oxides. Therefore, it is impossible to after-treat the nitrogen oxides contained in the exhaust gas of an engine operating with excess air by a three-way catalyst.

This means that - to meet much more stringent environmental regulations - engines that used to operate with excess air now have devices specifically designed to reduce nitrogen oxides, such as nitrogen oxide traps, or devices for selective catalytic reduction of nitrogen oxides with urea. Explain why you accept it. The device is usually located at the outlet of the binary oxidation catalyst, which has previously combusted the unburned hydrocarbons and completed the oxidation of the carbon monoxide, and, more often, the particulate filter.

Considering that diesel engines naturally operate with an excess of air, since the entry into force of the Euro VI standard in Europe, almost all European diesel cars have been equipped with devices to post-process nitrogen oxides to convert them into dinitrogen.

The problem with these devices is that they are expensive, complex, and their size and maintenance requirements are so high that they are, in practice, almost exclusively used on diesel engines, which can run with only excess air.

As far as spark ignition engines are concerned, engine manufacturers necessarily struggle to make them work with stoichiometries so that they remain compatible with simple and inexpensive three-way catalysts, for that matter.

In order to benefit from the reduction in fuel consumption induced by the dilution of the load in spark ignition engines without having to suffer the specific economic disadvantages of nitrogen oxide traps or devices for the selective catalytic reduction of nitrogen oxides with urea, oxygen is therefore It is necessary to dilute the load of the engine with oxygen-free neutral gas, rather than rich air.

These neutral gases are usually obtained by recirculating the engine's own exhaust gases, which no longer contain oxygen and are available and abundant. This strategy is known under the name “exhaust gas recirculation” or the acronym “EGR”.

The gases escape at high temperatures at the exhaust of spark ignition engines, and to prevent them from overheating the loads introduced into the engine, it is necessary to reduce their temperature before mixing them with fresh gases. This strategy is known as “cooled EGR,” which specifies that the recirculated exhaust gases are cooled prior to mixing with fresh gases received by the engine. French engine manufacturers use the "English with French" term "EGR refroidi", which is easily understandable and easy to use.

Pre-cooling of the EGR gases is required for at least two purposes.

Firstly, it is necessary for the temperature of the EGR gas/fresh gas mixture received by the spark ignition engine to remain low so that the volumetric efficiency of the engine remains high when operating at full torque. In practice, for a given intake pressure, the mass of the mixture introduced into the cylinder(s) of the engine becomes increasingly important that the mixture be cold. Pre-cooling of the EGR gases becomes even more essential if the engine is supercharged by a turbocharger or any other means.

Second, the hotter the EGR gas/fresh gas mixture, the more likely it is to generate rattles that are detrimental to the performance of the engine.

The problem is that the load diluted with cooled EGR is oxygen sensitive. This is paradoxical since the goal pursued is specifically for the rod to remain stoichiometric and resistant to rattling. The consequence of this oxygen deficiency is that initiation of combustion is more difficult to achieve and its development is slower than when the load is not diluted with cooled EGR.

In spark-ignition engines, initiation of combustion occurs by creating a high-temperature electric arc between two electrodes separated from each other by a few tenths of a millimeter.

When the air-fuel load is very diluted with cooled EGR, the electric arc passes through a globally vulnerable mixture of oxygen and fuel. The risk of misfire is, in fact, a few tenths of a percent between the cathode and anode of the spark plug, as heterogeneities are inevitably created in the three-dimensional space of the combustion chamber, with pockets richer in oxygen and/or fuel than others. This increases if the millimeter of space does not contain enough combustible EGR gas/fresh gas mixture.

When combustion initiates as expected, the fuel energy contained in the load begins to be released as heat and flame begin to form. To achieve this process, the flame transfers its heat to the surrounding EGR gas/fresh gas mixture in successive steps, combustible layer after combustible layer. Each layer is brought to its ignition temperature by the previous layer, burns, and releases heat that passes to the next layer. According to the principle of chain reaction, the flame propagates in the three-dimensional space of the combustion chamber of a spark ignition engine.

The main problem of cooled EGR is that it makes the initiation of combustion difficult, and then the latter due to the overall decrease in temperature and the varying degrees of abundance of combustion agents and/or fuel found within the volume of the combustion chamber and therefore on the path of the flame. This means that development will be significantly delayed.

Furthermore, it is experimentally observed that the higher the load content in the cooled EGR, the more unstable the engine becomes. From a certain given content, misfire occurs and efficiency - which by then tends to increase with the cooled EGR content of the load - decreases. Beyond a certain content of EGR, the spark ignition engine stalls and combustion cannot be initiated.

It is also observed that the unburned hydrocarbon and carbon monoxide content of the exhaust gases increases simultaneously with the cooled EGR content of the load. This is due to both the thickening of the boundary layer flame jam near the cold inner walls of the engine's combustion chamber and pockets of the mixture that are too fragile to burn properly encountered by the flame in its path.

Continuing experimentally, it is also observed that the higher the ignition power, the more possible it is to increase the cooled EGR content of the rod without significantly altering the stability of the engine.

As such, many laboratories - such as the South West Research Institute in the United States - have been developing increasingly powerful electric ignition devices to resist the accessible limitations of the cooled EGR content of the rod. The purpose of this strategy is, of course, to improve the efficiency of spark ignition engines.

The problem with increasing the power of electric ignitions is that their performance quickly decreases with power. More and more electrical power is therefore required to obtain less and less additional ignition power.

Additionally, high electrical power only occurs when the electrodes of a spark plug are moved away from each other to give the spark more opportunity to cross the combustible pocket, or the duration of the spark is increased, or the spark is repeated. Interested. This results in increasingly higher voltage and electrical power, which makes the realization of electrical insulation of the spark plug more complicated, while drastically reducing the life of the spark plug.

The difficulty in igniting the load is also due to the fact that both cooled EGR is more of a concern to turbocharged spark ignition engines when the goal is necessarily to reduce their sensitivity to rattle. However, the higher the boost pressure, the higher the density of the EGR gas/fresh gas mixture between the electrodes of the spark plug at the moment of activation of the spark, and the more voltage is required to cause a spark. Based on this, a cooled EGR does not go in the right direction because, with the same energy introduced into the cylinders of the engine, the mass of the gases between the electrodes increases as well as the resistance of these gases to ignition.

It is noted that the applicant's own patent number FR 2 986 564 is a powerful response to these problems. The spark ignition and high pressure lamination device for internal combustion engines referenced in the above patent is, at the center of the spark plug and immediately before the spark is triggered, is highly flammable because it has not been diluted with cooled EGR, and is potentially slightly fuel rich, approx. It is proposed to inject a stoichiometric pilot load under high pressure.

Once injected by the device, as soon as an electric arc is formed between the electrodes, the rod pilot clears the electrodes of the spark plug, and the rod immediately ignites, releasing the energy it contains. Accordingly, the rod itself is the means of ignition itself, the power of which is hundreds to thousands of times greater than that of the electric arc allowed to ignite. It is practically impossible to obtain such ignition power by electrical means alone.

In fact, experience has shown that approximately 50 percent cooler EGR gates are possible with these devices compared to approximately only 30 percent with simply the most powerful electric ignition devices.

It will be noted that the approach adopted in Patent No. FR 2 986 564 is found in related form in US Pat. No. 4,319,552 to inventors Fred N. Sauer and J. Brian Barry or in Patent No. DE 41 40 962 A1, owned by the Bosch Company. .

In any case, Orbital Company's patent number US6564770 states that the purpose of this patent is to ensure the configuration of the main rod as uniformly as possible at relatively low pressures and not to form a pilot rod for the purpose of ignition of the main rod, which is highly diluted with EGR. It doesn't fall into any of these categories.

The problem of the device described by patent number FR 2 986 564 and in the related patents as they have just been mentioned lies not in the initiation of a very efficient combustion, but in the development of said combustion. In particular, when the burned portion of the fuel contained in the main load reaches approximately 50 percent, combustion will occur until the total time required to combust all of the main load undiluted with cooled EGR increases. Try to proceed beyond the required time.

As a result, part of the potential energy gain of cooled EGR is lost due to combustion developing too slowly.

However, the maximum benefit of cooled EGR is, on the one hand, using a main load with a cooled EGR content of approximately 50 percent, and on the other hand, compared to those found for the same in the engine when the engine is burning an undiluted load. It will be discovered if it is possible to operate a spark ignition engine simultaneously, with the stability and total duration of combustion possible.

A solution may come from the use of a prechamber into which the pilot rod is introduced, which will receive the electrodes of the spark plug and may even form an integral part of the spark plug, as proposed in US Pat. No. 4,319,552. You can.

The first advantage of such a prechamber is to keep the pilot rod as close as possible to the electrodes of the spark plug, potentially limiting the dispersion of the rod in the main combustion chamber of a spark ignition engine prior to ignition of the rod.

A second advantage of the prechamber is that, once ignited, a pilot rod pressurizes the prechamber sending the hot gas torch at high speed through a hole contained in the prechamber to the main combustion chamber of the spark ignition engine.

Ignition of the main rod by the torch means that instead of starting at the center of the combustion chamber, as is often the case with conventional spark plug ignitions, the flame is initiated at multiple locations in the combustion chamber, radiating from the periphery of the chamber toward the center of the chamber. And it is very effective because it develops in a tangential direction between each torch.

The energy of the fuel is thus released in a very short period of time, which not only makes the triggering more productive for useful work, but also makes the engine operate with a significantly higher volume ratio, with minimal sensitivity to rattle resulting from this rapid combustion. It is advantageous for the thermodynamic engine of a spark ignition engine because it allows

In any case, the solution proposed in US Pat. No. 4,319,552, or Applicant's own patent FR 2,986,564, or in the previously mentioned related patents, is not a mixture of air and fuel, but rather a fuel injected into the prechamber with or without fuel alone. It cannot be compared to the numerous patents that entail it.

Among these patents, for example, an ignition system called "turbulent flow ignition", based on principles developed by the German circuit <<Mahle>> for Formula 1 engines, numbered from <<Fluid Research Limited>> GB 2 311 327 A, US Patent 4,864,989 from <<Tice Technology Corp>>, US Patent 4,124,000 from General Motors, US Patent 4,239,023 from <<Ford Motor Company>>, from inventor Dieter Kuhnert Reference will be made to those known under US Patent No. 4,892,070, US Patent Publication No. 2001/0050069 A1 from inventors Radu Oprea and Edward Rakosi, or US Patent Publication No. 2012/0103302 A1 from inventor William Attard.

The solution presented in these patents relates to "lean burn" spark ignition engines and its sole purpose is to enrich the fuel load around the ignition point on the basis that the load as a whole is low in fuel but rich in oxygen; On the basis of low fuel and oxygen, patents FR 2 986 564 and There are indeed fundamental differences between the solutions presented in the relevant patents.

At this stage, as proposed in patent number FR 2 986 564, a highly combustible pilot rod consisting of air and fuel is injected into the rod to envelop the electrodes of the spark plug, thereby forming a strongly diluted main rod with the EGR rod. It has been shown to allow for effective ignition.

It is also shown that once the main rod is ignited, combustion proceeds rapidly until approximately 50 percent of the total amount of fuel contained in the rod is burned. Beyond the 50 percent, combustion develops more slowly and therefore, from a specific EGR content of the main load, the thermodynamic efficiency of the spark ignition engine decreases instead of increasing as expected.

It is assumed that the spark plug's problem of combustion development exceeding 50 percent would be completely or partially solved if the pilot load were injected into the prechamber where the electrodes of the spark plug are housed - as suggested in US Pat. No. 4,319,552.

In practice, the prechamber initiates combustion over a large radial length around the point of ignition, but it also holds the torch in its hole, with hot gases activated at high velocities that will wrinkle the flame surface, which will promote the development of the flame perpendicular to the torch. It will be ejected through.

However, this last solution may prove unsatisfactory for many reasons, especially in the context of spark ignition engines, some of which lead to the abandonment of ignition devices based on prechambers.

In practice, effectively, the prechamber is exposed by the dome and penetrates sufficiently into the combustion chamber of the engine so that the hole through which the hot gases are discharged to form the torch is positioned sufficiently within the chamber to prevent the torch from spilling over the cold internal walls of the engine. It must have an incoming protruding dome.

However, as soon as combustion is initiated in the prechamber, the gas contained in the prechamber rapidly rises in pressure and is discharged at high speed through the hole. When doing so, the gas heats the dome.

Once combustion of the main rod has been initiated, the pressure prevailing in the combustion chamber of the engine quickly exceeds the pressure prevailing in the prechamber, causing hot gases to pass through the hole in the dome in the opposite direction, thereby heating the dome again.

During expansion of gases by the piston of a spark ignition engine, the pressure prevailing in the prechamber becomes greater than that prevailing in the engine's combustion chamber. As a result, the hot gas contained in the prechamber passes a third time through the hole, further superheating the dome.

However, from a certain temperature, the protruding dome behaves like a "hot ball", like the ignition system of an internal combustion engine invented by Stuart Herbert-Akroyd and described in patent CHD4226 of December 4, 1891. These hot spots then potentially cause unintended, non-spark-controlled ignition of the main load. The resulting rattle has the potential to damage or even destroy the spark ignition engine.

A solution may be to extensively cool the dome to prevent it from becoming a hot spot. However, the resulting heat loss occurs at the expense of, on the one hand, the efficiency of the hot gas torch, whose temperature and speed are reduced during passage from the dome through the hole, and, on the other hand, the thermodynamic efficiency of the spark ignition engine.

The prechamber therefore cannot behave like a “hot-ball” ignition device, as previously mentioned, or at least ensures that initiation of combustion of the main load is reliably triggered at selected times and does not occur at uncontrolled times. It is absolutely necessary.

This involves cooling the hot part of the prechamber, which can trigger self-ignition, but this increases the efficiency of the prechamber to distribute the hot gas torch in the three-dimensional space of the engine's combustion chamber, including the main rod. It must be done without significant weakening.

Additionally, it is noted that the configuration of the high-pressure air-fuel pilot rod is not energy free. It is necessary to first compress the air, which requires a compressor driven by the spark ignition engine itself, and then to inject fuel into that air. Another strategy may lie in directly compressing the previously formulated air-fuel mixture.

Therefore, because of non-negligible energy costs, with the same ignition efficiency, the smaller the mass and pressure of the pilot rod compared to that of the main rod, the better the final energy balance of the spark ignition engine when operating under high EGR rates. Therefore, in order to ignite a rod, it is necessary, by all means, to provide the pilot rod with the highest possible specific efficiency relative to its mass and pressure.

In other words, with the same ignition efficiency, the pilot load must contain the smallest possible amount of air-fuel mixture, previously placed under the lowest possible pressure.

As such, it is best to avoid as much as possible the pilot rod dispersion into the main rod prior to ignition, as this dispersion reduces the specific efficiency of the pilot rod to ignite the main load and can be counteracted simply by increasing the mass of the pilot rod. This is done at the cost of losing the fuel efficiency of the spark ignition engine.

The dispersion results in particular from the time required by the injector to introduce the pilot rod into the prechamber to carry out injection of the pilot rod under necessarily greater pressure than that of the main rod.

It should also be noted that while the injection pressure of the pilot rod remains approximately constant, the pressure of the main rod increases under its compression effect following the rise of the piston of the spark ignition engine towards its Top Dead Center. The beginning of injection of the pilot rod therefore occurs under a greater differential pressure than the end of said injection. As a result, the discharge rate of the constituent gas of the pilot rod by the injector is greater at the beginning of injection than at the end of injection.

Before injection of the pilot rod, the pressure in the prechamber is lower than that prevailing in the compression chamber of the engine. A portion of the main rod therefore enters the prechamber first as the rod is compressed.

The injector then injects a pilot rod into the prechamber which has a high EGR content and mixes with the portion of the main rod previously introduced into the prechamber.

The excess gas mass due to this part is then discharged from a portion of the pilot rod and out of the prechamber, where it mixes with the high EGR content gas in and out of the prechamber.

The flammability of the mixture thus composed of air, fuel and EGR is therefore necessarily uniform in the volume of the prechamber and outside the prechamber. The effectiveness of the pilot rod to ignite as quickly as possible is thus reduced, as is the effectiveness of the hot gas torch to ignite the main rod.

This reduction in efficiency can only be offset by an increase in the air and fuel mass of the pilot load, which comes at the expense of the overall energy efficiency of the spark ignition engine.

Ideally, it should therefore be avoided at all costs to divert the pilot rod from the main rod prior to ignition of said pilot rod.

This does not in any way question the fact that it would be very advantageous to improve the device described by patent number FR 2 986 564. In practice, the device was effective in initiating combustion at very high levels of cooled EGR and allowing the combustion to develop until approximately 50 percent of the fuel contained in the main load was burned.

The goal would be to provide the device with the ability to develop the combustion very rapidly until at least 90 or 100 percent of the fuel is burned.

As previously mentioned, this is achieved by a prechamber, as suggested by US Pat. No. 4,319,552, but provided that it is possible to avoid the notorious, and possibly seriously damaging, defects of the prechamber. It can be. To this end, it maintains the same ignition efficiency while avoiding behaving like a "hot ball", preventing the pilot rod from dissipating in the main chamber, and limiting the amount of energy required to compress the pilot rod. There is a need to significantly improve the effectiveness of the prechamber, including:

All of these goals are addressed by the valve ignition prechamber according to the invention which - according to a particular embodiment - allows:

돌출 돔이 과도한 온도가 되고 메인 로드의 의도하지 않은 자기-점화를 야기할 가능성이 있는 핫스팟이 되는 것을 방지하기 위해, 상기 돔에서의 홀을 통해 그리고 상기 가스가 토출되는 고온 가스의 통로의 수를 대략 3으로 나눔으로써 달성된, 프리챔버에 의해 노출된 상기 돔이 겪는 열적 로드를 크게 감소시키는 것;

To prevent the protruding dome from becoming a hotspot where temperatures can become excessive and potentially cause unintentional self-ignition of the main rod, the number of passages for hot gas through which the gas is discharged and through the hole in the dome is increased. Significantly reducing the thermal load experienced by the dome exposed by the prechamber, achieved by dividing by approximately 3;

minimizing the mass and pressure of the pilot rod required not only for initiation of combustion of the main rod, which is strongly diluted with EGR, but also for rapid development of the combustion until all of the main rod is burned;

To achieve this last goal, avoiding dispersion of the pilot rod of the main rod during injection of the pilot rod in the prechamber.

To achieve all of these goals, the valve ignition prechamber according to the present invention,

keeping the prechamber closed when the pressure prevailing therein is lower than that prevailing in the combustion chamber to avoid unwanted coming and going of hot gases through holes provided in the protruding dome and with which said prechamber communicates with said chamber;

keeping the prechamber closed for most of the injection time of the pilot rod so that the injection occurs in a closed space where the gas of the pilot rod cannot mix with the gas of the main rod;

It allows lowering the mass and injection pressure of the pilot rod while maintaining high pressure and discharge velocity of hot gas through the hole in the protruding dome.

Valve ignition prechambers are designed to be inexpensive to mass produce in order to remain compatible with the economic constraints of most applications for which they are intended, including automotive.

The valve ignition prechamber according to the invention may be of any type, whatever the fuel consumed is gaseous, liquid or solid, and the main load may be cooled EGR, any natural neutral gas, or oxygen or any other combustion. It is understood that it can be applied to any spark ignition rotary or linear internal combustion engine, whether diluted with rich gas or not.

It is also understood that the pilot rod received by the valve ignition prechamber according to the invention may comprise a different fuel and/or combustion agent than the fuel and/or combustion agent that constitutes the main rod of the spark ignition engine.

Other features of the invention have been described in the description and in dependent claims, which are directly or indirectly dependent from the main claim.

An ignition prechamber valve according to the present invention is provided for an internal combustion engine comprising a cylinder head covering a cylinder to form a combustion chamber in which the main rod can burn, the prechamber comprising:

A lamination injector arranged on the one hand in the cylinder head and connected to the combustion chamber by a lamination duct and on the other hand capable of directly or indirectly injecting a pilot rod previously pressurized by compression means into the lamination cavity. at least one stacked cavity receiving a , wherein the rod is made of a combustible/AF fuel mixture that is easily ignited by a spark;

Ignition means open toward the lamination cavity and capable of igniting the pilot rod;

A lamination valve that can close all or part of the lamination duct and expose, on the one hand, the cavity side experiencing the pressure of the gases prevailing in the lamination cavity, and, on the other hand, the chamber side experiencing the pressure of the gases prevailing in the combustion chamber. With respect to the duct under the effect of gas pressure, towards the stack cavity when the pressure prevailing in the stack cavity is lower than the pressure prevailing in the combustion chamber, or when the pressure in the chamber is lower than the pressure in the stack cavity. When the stacking valve can be turned towards the chamber;

at least one cavity side valve stop that determines the position of the stack valve closest to the stack cavity;

and at least one chamber side valve stop that determines the position of the stack valve closest to the combustion chamber.

The valve ignition prechamber according to the invention comprises a lamination valve that closes all or part of the lamination duct when closest to the lamination cavity while opening said duct on a wider section when disposed closest to the combustion chamber.

The valve ignition prechamber according to the invention comprises a cavity side valve stop consisting of a valve closing seat arranged in the laminated duct or at one end of the duct, the seat being located in the periphery and/or in the laminated valve. It cooperates with the cavity side valve bearing surface located at the end.

The valve ignition prechamber according to the invention comprises a valve closure seat and a cavity side valve seat which when they come into contact with each other create a seal wherein the pressure prevailing in the combustion chamber is greater than the pressure prevailing in the laminated cavity. When large, it prevents any gas from passing through upon contact.

A valve ignition prechamber according to the invention comprises a chamber side valve stop consisting of a valve opening seat arranged in a stacked duct or at one end of said duct, said seat being located at the periphery and/or at an end of said stacked valve. cooperates with the valve bearing surface on the chamber side.

A valve ignition prechamber according to the present invention includes a valve opening seat and a chamber side valve seat that create a seal when they contact each other to prevent any gases from passing upon said contact.

The valve ignition prechamber according to the invention comprises guiding means for maintaining the valve approximately centered in the stacked duct and in approximately the same longitudinal orientation as the duct, whatever the axial position of the valve with respect to the duct. and a laminated valve comprising its periphery.

The valve ignition prechamber according to the present invention is such that when the valve opening seat and the chamber side valve bearing surface are in contact with each other, the laminated valve is connected, on the one hand, to the laminated cavity and, on the other hand, to the combustion chamber through at least one gas discharge hole. and simultaneously forming a communicating torch ignition prechamber with the laminated duct.

The valve ignition prechamber according to the invention comprises an inner peripheral wall of the torch ignition prechamber that is cylindrical, while a stacked valve has a circular perimeter and is received at a low radial clearance in the prechamber.

The valve ignition prechamber according to the present invention accommodates the torch ignition prechamber and includes a laminated duct that protrudes and opens into the combustion chamber in the form of a protruding discharge dome through which a gas discharge hole is opened.

The valve ignition prechamber according to the invention includes a valve opening seat arranged on a protruding discharge dome.

The valve ignition prechamber according to the invention is such that when the stack valve is arranged close to the combustion chamber, that is to say near or even in contact with the cooperating chamber side valve stop, said valve discharges at least one gas connecting the combustion chamber and the stack cavity. Provides for exposing the hole.

The valve ignition prechamber according to the invention traverses all or part of the internal volume of the laminated cavity and its body is radially transversely formed by at least one radial slot connecting said internal volume with the inside of a perforated connecting tube. consisting of an ignition spark plug that closes the first end of the tube, while the second end of the tube receives a laminated duct and a laminated valve, and the center and ground electrodes of the spark plug are received in a perforated connecting tube. Contains means of ignition.

The valve ignition prechamber according to the invention includes a cavity side exposing an aerodynamic dome.

The valve ignition prechamber according to the invention includes a cavity side forming a ground electrode facing a central electrode contained in an ignition spark plug, the ignition spark plug constituting an ignition means.

The valve ignition prechamber according to the invention comprises a stacked valve that is axially thicker at its periphery than at its center, receiving cavity side valve bearing surfaces and chamber side valve bearing surfaces.

The following description, taken in conjunction with the accompanying drawings, which are given by way of non-limiting example, will help you better understand the invention and the features and benefits it is likely to offer:
Figure 1 is a schematic cross-sectional view of a valve ignition prechamber according to the invention as it may be installed in a cylinder head of an internal combustion engine.
Figure 2 is a schematic cross-sectional view of a valve ignition prechamber according to the present invention, the laminated valve being capable of completely closing the laminated duct when the cavity side valve bearing surface included in the laminated valve contacts the valve closing seat with which it cooperates; On the other hand, the stacked valve forms a torch ignition prechamber that is received in the protruding discharge dome when the valve rests on its chamber side valve stop.
3 to 8 are partial close-up views in a schematic section of a valve ignition prechamber according to the invention and according to the specific configuration shown in FIG. 2, the close-up views showing the operation of the prechamber. Various phases are illustrated.
Figure 9 is a schematic cross-sectional view of a valve ignition prechamber according to the invention incorporating the main features shown in Figure 2 with the addition of a radially perforated connecting tube transversely traversed by radial slots, said tube being located in the laminated cavity; While passing through the internal volume and being integral with the ignition spark plug, the cavity side of the laminated valve forms a ground electrode directed towards the center electrode contained in the spark plug.
Figure 10 is a three-dimensional view of a valve ignition prechamber according to the invention and according to the embodiment shown in Figure 9;
Figure 11 is a three-dimensional view in an exploded longitudinal section of a valve ignition prechamber according to the invention and according to the variant embodiment shown in Figure 9;
Figure 12 is an enlarged three-dimensional view of a valve ignition prechamber according to the present invention and an alternative embodiment shown in Figure 9;

1 to 12 show the valve ignition prechamber 1, various details of its components, modifications thereof, and accessories thereof.

In Figure 1, the valve ignition prechamber 1 is an internal combustion engine comprising a cylinder head 3 that covers the cylinder 4 to form with a piston 31 a combustion chamber 5 in which the main rod 30 can combust. It is shown that it is designed specifically for the organ 2.

The valve ignition prechamber (1) according to the invention is, on the one hand, arranged in the cylinder head (3) and connected to the combustion chamber (5) by a laminated duct (7) and, on the other hand, previously compressed by compression means (10). 1 to 12 that it includes at least one stack cavity 6 which accommodates a stack injector 8 capable of directly or indirectly injecting a pilot rod 9 into the stack cavity 6. It will be.

According to the invention, the pilot rod 9 consists of a combustion agent-AF fuel mixture that is easily ignited by a spark.

1, 2 and 9 are shown in the valve ignition prechamber 1 according to the invention, wherein the pilot rod 9 is injected directly or indirectly into the lamination cavity 6 via the injector outlet duct 28. A stacked injector (8) capable of doing this is shown.

The stacking injector 8 can be of any type without limitation, allowing the combustion agent-AF fuel mixture contained in said rod 9 to be converted, possibly with the aid of another injector of gas or liquid, or with the aid of a carburetor known as such. , can be made of any device capable of introducing the pilot rod 9 into the stack cavity 6 by any operating procedure, regardless of whether it is formed above or below the stack injector 8. there is.

Furthermore, the laminated cavity 6 and the laminated duct 7 can advantageously be coated with, or made of, a refractory material known per se. Alternatively, in order to limit heat exchange between the components 6 , 7 and the cylinder head 3 , an air gap is formed on the one hand by at least a part of the lamination cavity 6 and/or by the lamination duct 7 and, on the other hand, can be left between the cylinder head 3 which houses these components 6, 7.

The valve ignition prechamber (1) according to the invention opens towards the lamination cavity (6) and comprises ignition means (11) capable of igniting the pilot rod (9), which means (11) may be It can also be seen from Figures 1 to 12 that it consists of an ignition spark plug 12, known per se.

The valve ignition prechamber (1) according to the invention can close all or part of the stacked duct (7) and, on the other hand, has a cavity side (14) that experiences the pressure of the gas flowing in the stacked cavity (6); and on the other hand a stacked valve 13 which exposes the chamber side 15 which experiences the pressure of the gases prevailing in the combustion chamber 11 .

The stack valve (13) is directed, with respect to the stack duct (7), under the effect of the pressure of the gas, towards the stack cavity (6) when the pressure in the stack cavity is lower than the pressure prevailing in the combustion chamber (5). Alternatively, it should be noted that the pressure prevailing in the chamber can be turned towards the combustion chamber (5) when it is lower than the pressure prevailing in the stack cavity (6).

It will be noted that the stacked valve 13 may also move in the stacked duct 7 under the effects of gravity or acceleration, which cannot be interpreted as any advantageous or desired mode of motion.

It may be emphasized that the laminated valve 13 can be made of a temperature-resistant superalloy, remaining as light as possible, or it can be a ceramic material such as silicon carbide.

In addition to what has just been described, the valve ignition prechamber (1) according to the invention has at least one cavity-side valve stop (16) which determines the position of the stacked valve (13) closest to the stacked cavity (6). It will be noted that it includes This is especially visible in Figures 3 to 8.

Additionally, the valve ignition prechamber 1 according to the invention includes at least one chamber-side valve stop 17 that determines the position of the stacked valve 13 closest to the combustion chamber 5 .

In a variant of the valve ignition prechamber 1 according to the invention, the lamination valve 13, when placed closest to the combustion chamber 5, opens the duct 7 through a wider section while the lamination cavity 6 It will be noted that all or part of the stacked duct 7 can be closed when closest to ).

In particular in FIGS. 3 to 8 , the cavity side valve stop 16 may consist of a valve closing seat 18 provided in the laminated duct 7 or at either end of the duct 7, said seat ( It will be noted that the 18) cooperates with the cavity side valve bearing surface 19 located at the periphery and/or at the end of the stacked valve 13.

The valve closing seat 18 and the cavity side valve bearing surface 19 create a seal when they contact each other, which seal is formed when the pressure prevailing in the combustion chamber 5 is greater than the pressure prevailing in the stacked cavity 6. It should also be noted that this prevents any gas from passing through upon contact.

As another variant, the chamber side valve stop 17 may consist of a valve opening seat 20 provided in the laminated duct 7 or at either end of the duct 7, the seat 32 being located at the periphery. and/or cooperate with the chamber side valve bearing surface 21 located at the end of the stacked valve 13.

In this case, the valve opening seat 20 and the chamber side valve bearing surface 21 may create a seal when they contact each other to prevent any gases from passing upon said contact.

3 to 8 and FIG. 12 show that the stacked valve 13 is approximately centered in the stacked duct 7 and, regardless of the axial position of the valve 13 with respect to the duct 7, is positioned approximately in the duct. It is clearly shown that guide means 22 holding the valve 13 in the same longitudinal orientation as (7) can be included in its periphery.

2, 3, 6, 8 and 9, when the valve opening seat 20 and the chamber side valve bearing surface 21 are in contact with each other, the laminated valve 13 is on the one hand laminated cavity 6 ) and, on the other hand, a torch ignition prechamber 23 in simultaneous communication with the combustion chamber 5 through at least one gas discharge hole 24 can be formed together with the laminated duct 7.

In this specific context of the ignition prechamber valve 1 according to the invention, the inner peripheral wall of the torch ignition prechamber 23 may be cylindrical, while the laminated valve 13 has a circular perimeter and a small radial gap above. It is received with a low radial gap in the prechamber 23 such that it remains between the valve 13 and the wall regardless of the position of the valve 13 with respect to the prechamber 23, the small gap being laminated. Between the cavity (6) and the combustion chamber (5), a restricted passage is formed that slows down the passage of gases.

1 to 12 show that, according to a specific embodiment of the valve ignition prechamber 1 according to the invention, the laminated duct 7 is open and accommodates the torch ignition prechamber 23 and has a gas discharge hole 24. It is shown that it can protrude into the combustion chamber (5) in the form of an open, protruding discharge dome (25).

It is noted that the gas discharge hole 24 is oriented approximately towards the combustion chamber 5 and can exit approximately tangentially at the periphery of the protruding discharge dome 25 . Additionally, the geometry of the gas discharge hole 24 may vary depending on whether the jet of gas exiting the orifice 24 is designed to be slightly directional or slightly diffuse. By way of example, the gas discharge holes 24 may be cylindrical, conical, or form converging or diverging shapes.

Advantageously, and as shown in FIGS. 1 to 12 , the valve opening seat 20 may be arranged in a protruding discharge dome 25 , the discharge dome having an anti-friction and/or non-stick and/or It may be coated with, or made of, a refractory material known as such.

In general, when the stacked valve 13 is arranged in the combustion chamber 5, that is to say in the vicinity or even in contact with the cooperating chamber side valve stop 17, the valve 13 is stacked with the combustion chamber 5. It is understood that at least one gas discharge hole 24 connecting the cavity 6 may be exposed.

9 to 12, the ignition means 11 passes through all or part of the internal volume of the laminated cavity 6 and its body connects this internal volume with the interior of the tube 26. It may consist of a spark plug (12) closing the first end of a perforated connecting tube (26) radially transverse by at least one radial slot (27), while the second end of the tube (26) The end receives the laminated duct 7 and the laminated valve 13, and the center electrode 40 and the ground electrode 39 of the spark plug 12 are received in the perforated connecting tube 26.

It should be noted that the perforated connecting tube 26 in FIGS. 9 to 12 may be part of the spark plug 12 of which it extends. In this case, the spark plug 12 is screwed directly into the cylinder head 3 by means of threads formed on the outer cylindrical side of its seat and/or on the outer cylindrical side of the perforated connecting tube 26 from which it extends. do.

Alternatively, the spark plug 12 may be screwed onto the tube 26 while the tube is screwed onto the cylinder head 3. In all cases, the seal is formed, on the one hand, between the cylinder head 3 and the spark plug 12 and/or the perforated connecting tube 26, and on the other hand between the spark plug 12 and the laminated duct 7. ) in both, is created.

9 to 12 show that the cavity side 14 directs the flow of gas to the gas discharge hole(s) 24, inter alia, by providing the least possible resistance to the flow and creating the least possible disturbance in the flow. It is shown that the aerodynamic dome (29) can be exposed allowing for

1 to 12 show, according to a specific embodiment of the valve ignition prechamber 1 according to the invention, the cavity side 14 facing the ground electrode (40) included in the spark plug 12. 39), the spark plug constitutes the ignition means 11, and when a high-voltage current passes from the center electrode 40 to the ground electrode 39, the ground electrode 39 and the center electrode ( 40) shows that an electric arc can be formed between

1-12 add that the stacked valve 13 may be axially thicker at its periphery, which accommodates the cavity side valve bearing surface 19 and the chamber side valve bearing surface 21, than at its center. Example:

These properties ensure that the valve 13 is cooled as effectively as possible upon contact between the valve bearing surfaces 19, 21 and the seats 18, 20 with which the bearing surfaces 19, 21 cooperate. The valve 13 is provided with a radial thickness that gradually increases from the center of the valve 13 to its periphery so as to be the lightest and most impact resistant possible.

Mode of operation of the invention:

The operating mode of the valve ignition prechamber 1 according to the present invention is easily understood when looking at FIGS. 1 to 12.

According to a non-limiting example of the application of the valve ignition prechamber 1 according to the present invention shown in Figure 1, the prechamber 1 creates a combustion chamber 5 in which the main rod 30 can burn and a piston ( It can be seen that it is implemented in an internal combustion engine 2 comprising a cylinder head 3 covering the cylinder 4 to form together with 31).

The piston 31 is connected to the crankshaft 37 via a connecting rod 38, and the piston 31 makes a rotational movement when the piston 31 is driven by an alternating translational movement in the cylinder 4. It should be noted that it is provided on the crankshaft 37.

1 shows that the combustion chamber 5 is placed in communication with the intake duct 32 through the intake valve 34, while the combustion chamber 5 can be put in communication with the exhaust duct 33 by means of the exhaust valve 35. It also shows that it can be done.

Figures 1 to 8, which will be taken here as an example to illustrate the operating modes of the valve ignition prechamber 1 according to the invention, show that the prechamber 1 is integrated into the cylinder head 3. 1 to 8 also show that the ignition means 11 consists of a spark plug 12 , known per se, with its electrodes opening towards the laminated cavity 6 . A stacking injector 8 is also shown in FIGS. 1 and 2 , which is capable of injecting a pilot rod 9 in the stacking cavity 6 via the injector outlet duct 28 .

In Figure 1, prior to injection by the stack injector 8, a pilot rod 9 consisting of a flammable combustion agent-AF fuel mixture is pressurized by a stack compressor 36 forming the compression means 10. This will be noted. This is also a non-limiting example of an embodiment of the valve ignition prechamber 1 according to the invention, taken here as an example to illustrate the operating mode.

To illustrate the mode of operation of the valve ignition prechamber 1 according to the invention, it can be assumed here that the volume ratio of the internal combustion engine 2 - excluding the volume of the valve ignition prechamber 1 - is 14 to 1. will be. To obtain this result, a volume of 500 cubic centimeters swept by the piston 31 is provided, while the volume of the combustion chamber 5 is 38.5 cubic centimeters.

Additionally, and as a non-limiting example, the volume of the ignition valve prechamber 1 - including the volume of the stack duct 7 and that of the injector outlet duct 28 - is here 1/2 cubic centimeter.

The representative embodiment shown in Figures 1 to 8 will be used here to explain in detail the operating mode of the valve ignition prechamber 1 according to the invention, in which the cavity side valve stop 16 is laminated. It is found that it consists of a valve closing seat (18) arranged in the duct (7), which seat (18) cooperates with a cavity side valve bearing surface (19) located at the periphery of the stacked valve (13).

The valve closing seat 18 and the cavity side valve bearing surface 19 form a seal when they contact each other, which seal is formed when the pressure prevailing in the combustion chamber 5 is greater than the pressure prevailing in the stacked cavity 6. The choice here has been made to prevent any gas from passing upon said contact.

To illustrate the operating mode of the valve ignition prechamber 1 according to the present invention, the chamber side valve stop 17 consists of a valve opening seat 20 arranged in a laminated duct 7, and the seat 32 ) will also be provided to cooperate with the chamber side valve bearing surface 21 located at the periphery of the stacked valve 13 . This particular configuration is clearly visible in Figures 3 to 8.

In this particular context, it will be provided that the valve opening seat 20 and the chamber side valve bearing surface 21 create a seal when they contact each other to prevent any gases from passing upon said contact.

In particular, in Figures 2, 3, 6 and 8, when the valve opening seat 20 and the chamber side valve bearing surface 21 are in contact with each other, the stacked valve 13 is connected to the toroidal shaped torch ignition prechamber ( 23) together with the stacked duct 7, and the prechamber 23 communicates simultaneously with the combustion chamber 5 through the stacked cavity 6 on the one hand and several gas discharge holes 24 on the other hand. It will also be noted that

The inner peripheral wall of the torch ignition prechamber 23 is cylindrical, but the laminated valve 13 has a small radial gap between the valve 13 and the valve 13, regardless of the position of the valve 13 with respect to the prechamber 23. It has a circular perimeter left between the walls and is received in the prechamber 23 at a low radial gap, the small gap between the stack cavity 6 and the combustion chamber 5 - through which - the gas It should also be noted that it forms a confined passageway that slows down any passage of .

1 to 8 the stacked duct 7 houses the torch ignition chamber 23 and, according to this example, has a protruding discharge dome 25 opening a gas discharge hole 24 oriented towards the combustion chamber 5 . It is also noted that it protrudes and opens into the combustion chamber 5 in the form of . It will be noted in passing that the valve opening seat 20 is arranged in a protruding discharge dome 25 .

Incidentally, in FIGS. 1 to 8 the cavity side 14 of the stacked valve 13 is particularly designed to provide the least possible resistance to the flow and to generate the least possible disturbance in the flow, thereby allowing the flow of gas into the gas discharge hole 24. It can be seen that it exposes the aerodynamic dome 29 which allows directing the flow.

It is also noted that the stacked valve 13 is axially thicker at its periphery than at its center. This feature allows the valve 13 to be the lightest possible and the most shock-resistant, while allowing the valve 13 to be the lightest possible and the most impact-resistant possible, while allowing the valve 13 to be the lightest possible and the most shock-resistant possible, while allowing the valve 13 to be the lightest possible and the most shock-resistant possible, while allowing the valve 13 to be the lightest possible and the most shock-resistant possible, while allowing the valve 13 to be the lightest possible and the most shock-resistant possible. ensures its cooling as effectively as possible upon contact. As a non-limiting example, the laminated valve 13 may be made of a superalloy that is mechanically and thermally very resistant.

According to the embodiment of the valve ignition prechamber 1 according to the invention shown in Figures 1 to 8 and taken here as an example of the operating mode of the prechamber 1, the diameter of the gas discharge hole 24 is stacked The maximum total stroke that the valve 13 can move between the valve closed seat 18 and the valve open seat 20 will be assumed to measure 12/100 millimeters while measuring 15/100 millimeters.

In order to understand the operating modes of the valve ignition prechamber 1 according to the invention, with reference to FIGS. 3 to 8 , it is useful here to decompose the operation into four stages of the internal combustion engine 2 .

It will be considered that the internal combustion engine 2 operates with an approximately stoichiometric air-gasoline main load 30 strongly diluted by cooled recirculated exhaust gases, known as “cooled EGR”. The rod 30 is therefore resistant to ignition and is in no way conducive to the rapid development of its combustion in the three-dimensional space of the combustion chamber 5 .

In this way, the pilot rod 9, which will be implemented by the valve ignition prechamber 1 according to the invention, not only initiates combustion of the main rod 30, but also develops this combustion in the shortest possible time. It is expected that it should have the highest possible efficiency. It is understood that these two goals are directly served by the valve ignition prechamber 1 according to the invention.

According to the invention, according to a non-limiting example of the valve ignition prechamber 1, taken here to illustrate the mode of operation, the pilot rod 9 delivers 1.6 percent of the fuel contained in the main rod 30. It will be assumed that the pilot rod 9 consists of a highly flammable combustion agent-AF fuel mixture by means of a spark.

The four-stroke cycle designed/conceived by Otto/Beau de Rochas will be broken down here according to the usual sequencing.

In the intake phase, the piston 31 of the internal combustion engine 2 moves down into the cylinder 4 with which it cooperates and draws the main load 30 from the intake duct 32 through the intake valve 34, which remains open. causes introduction into the cylinder.

During this phase, the pressure prevailing in the combustion chamber (5) is lower than the pressure prevailing in the stack cavity (6). As a result, and as shown in Figure 3, the lamination valve 13 remains pressed with the valve opening seat 20 with which it cooperates and the lamination cavity 6 is pushed through the torch ignition prechamber 23 to the gas discharge hole. It communicates with the combustion chamber (5) through (24).

When the piston 31 reaches its bottom dead center, the inlet valve 34 closes and the piston 31 begins its rise in the cylinder 4, back to its top dead center.

When doing so, the piston 31 compresses the main rod 30 and the pressure prevailing in the combustion chamber 5 becomes higher than that prevailing in the stack cavity 6.

The pressure difference between the combustion chamber 5 and the cavity 6 depends on the one hand on the small section of the gas discharge hole 24 and on the other hand on the position of the valve 13 relative to the prechamber 23. Regardless, both increase more rapidly as a small radial gap is left between the stacking valve 13 and the inner wall of the torch ignition prechamber 23.

To go from the combustion chamber 5 to the stack cavity 6, the constituent gases of the main rod 30 have virtually no passage other than the gas discharge hole 24.

Since the gas discharge hole leaves only a limited passage section for the gas, the difference between the pressure applied on the cavity side 14 and that applied on the chamber side 15 increases, causing the cooperating valve closing seat 18 ) has the effect of pressing the laminated valve (13). This situation is clearly illustrated in Figure 4.

The time required for the stacked valve 13 to break the contact it has formed with the cooperating valve opening seat 20 on the one hand and to make contact with the valve closing seat 18 on the other hand is a few degrees of rotation of the crankshaft 37. or even correspond to said rotation of only 1 or 2 degrees, and it will be noted that these values are provided for information only.

When doing so, the stack valve 13 closes the stack duct 7 and the combustion chamber 5 no longer communicates with the stack cavity 6. The pressure that continues to increase in the combustion chamber (5) due to the rise of the piston (31) in the cylinder (4) no longer has any effect on the pressure prevailing in the stack cavity (6), which remains stable.

A few degrees of the crankshaft after the stacking valve 13 closes the stacking duct 7, the stacking injector 8 starts injecting the pilot rod 9 into the stacking cavity 6. This situation is illustrated in Figure 5. The temperature of the constituent gas of the rod 9 is approximately 80 degrees according to this example.

A few crankshaft degrees after the stacking valve 13 closes the stacking duct 7, the stacking injector 8 starts injecting the pilot rod 9 into the stacking cavity 6. This situation is illustrated in Figure 5. The temperature of the constituent gas of the rod 9 is, according to this example, approximately 80 degrees.

The flow rate of the injector is such that the pressure prevailing in the stack cavity 6 is such that the stack valve 13 never separates from the valve closing seat 18 with which it cooperates via the valve bearing surface 19 on its cavity side. ) was calculated to always remain lower than the prevailing one.

At a few degrees of the crankshaft 37 before top dead center of the piston 31, the pressure prevailing in the combustion chamber 5 and experienced by the main rod 30 is such that the pressure in the laminated cavity 6 is 20 bars. It reached almost 40 bars while reaching. The stack injector (8) stops injecting the pilot rod (9) into the stack cavity (6).

As shown in Figure 6, when the piston 31 reaches near its top dead center, a high-voltage current is applied to the terminal end of the spark plug 12. The spark plug ignites the pilot rod (9) held in the laminated cavity (6).

It will be noted that the pressure of only 20 bar prevailing in the cavity 6 allows for applying only the appropriate voltage to the terminal ends of the spark plug 12.

As shown in Figure 6, the pilot rod 9 is made of a readily flammable combustion agent-AF fuel mixture, and the flame initiated by the spark plug 12 is the pressure prevailing in the stack cavity 6. As shown, it propagates very quickly in the pilot rod 9 where the temperature increases rapidly.

When the pressure reaches, for example, 45 bar - i.e. 5 bar more than the pressure prevailing in the combustion chamber 5 - the lamination valve 13 has already moved 15 hundredths of a millimeter. In doing so, the valve (13) has separated from contact with the valve closing seat (18) and is dependent on the valve opening seat (20). This situation is also shown in Figure 6.

During this process, the stacking valve 13 gradually exposed the gas discharge hole 24 and hot gas - e.g., brought to a temperature of about 2000°C - passed through the torch ignition prechamber 23 and into the protruding At the discharge dome 25, discharge began to be discharged from the lamination cavity 6 in the form of a torch through the orifice 24. This effect provided by the valve ignition prechamber 1 according to the invention is shown in Figure 6.

As the pressure continues to rise in the stack cavity (6), the pressure in this cavity (6) is now 20 bar higher than that prevailing in the combustion chamber (5). As a result, the pressure of the hot gases drops by 20 bar during their passage through the gas discharge hole 24 so that their temperature drops to about 1300 degrees. As a result, the gases are created to travel at high speeds, allowing them to penetrate deep into the volume of the combustion chamber 5.

When doing so, the hot gas ignites the surrounding gas that makes up the main rod 30. In addition to releasing the fuel energy they contain as heat, the surrounding gases are made to move at high local velocities by the hot gases, and these velocities manifest themselves in the form of micro-disturbances. The folding of the flame surface resulting from these micro-disturbances accelerates the development of combustion, which quickly propagates into the entire main rod 30 and throughout the entire volume of the combustion chamber 5.

The efficiency of the valve ignition prechamber (1) according to the invention for developing the combustion is such that the hot gas torch formed throughout the protruding discharge dome (25) ignites the main rod (30) at a number of places in the combustion chamber (5). It will be noted that both are larger because they ignite.

In practice, with a rapid initialization from the center of the combustion chamber 5 to the periphery, the combustion of the rod 30 starts in a second phase radially from the periphery of the combustion chamber 5 towards the center of the combustion chamber 5 and the gas It is developed in a tangential direction between each high-temperature torch coming out of the discharge dome 25 protruding through the discharge hole 24.

Once the combustion agent-AF fuel mixture constituting the pilot rod 9 is completely burned and discharged mainly in the form of hot gas jets through the gas discharge hole 24, combustion develops in the combustion chamber 5 and the pressure prevailing in the combustion chamber quickly becomes larger than that prevailing in the stack cavity (6).

Additionally, as soon as this situation is reached, the chamber side 15 of the stacked valve 13 receives a pressure greater than that applied on the cavity side 14 of the valve 13. The lamination valve 13 moves rapidly over 15/100ths of a millimeter towards the lamination cavity 6 so that it is pressed firmly against the cooperating valve closing seat 18 . This situation is illustrated in Figure 7.

The combustion of the main rod 30 occurs very quickly despite the high content of "cooled EGR" in the rod 30 and the combustion occurs only a few degrees of the crankshaft 37 when the piston 31 reaches top dead center. It is completed later. The thermodynamic efficiency of the internal combustion engine 2 will thus be able to reach its maximum level since expansion barely begins while all of the energy contained in the constituent fuel of the main load 30 has already been released.

The stacking valve 13 remains closed, as shown in Figure 7, and the piston 31 then begins its expansion stroke and converts the high temperature of the main rod 30 and much of the heat of the burnt gases into useful work. Let's begin. This work is transmitted by the piston 31 via the connecting rod 38 to the crankshaft 37.

In doing so, the pressure and temperature prevailing in the combustion chamber 5 gradually decreases. When the pressure reaches, for example, 60 bar, the pressure remaining in the stack cavity 6 becomes greater than that prevailing in the combustion chamber 5 .

As a result of this situation, the chamber side valve seat 21 of the stacked valve 13 returns to contact with the valve opening seat 20, as illustrated in FIG. 8. The stacking valve 13 completely exposes the gas discharge hole 24 again, and the remaining hot gas in the pilot rod 9 is expanded by the piston 31 while the expansion of the main rod 30 continues. is discharged through.

Once the piston 31 has reached its bottom dead center, the exhaust valve 35 is opened and gases are forced out of the duct by the piston 31 as it rises in the cylinder 4 towards its top dead center. They terminate their expansion in the exhaust duct (33) before being actively pushed into (33).

During the entire exhaust stroke of the piston 31, the stacked cavity 6 can complete exhausting the remaining hot gas from the pilot rod 9 through the gas discharge port 24. This discharge may also continue during the current supply phase, marking the beginning of a new four-stroke cycle designed/conceived by Otto/Beau de Rochas according to the usual sequencing.

As can be seen throughout the description just given, unlike known devices according to the state of the art, the valve ignition prechamber 1 according to the invention allows limiting the injection pressure of the pilot rod 9 to approximately 20 bar. .

This relatively low pressure makes it possible not only to limit the energy consumption of the stack compressor 36, but also to limit its complexity in that a single compression stage is sufficient to reach this pressure.

Additionally, only 1.6 percent of the fuel contained in the main load 30 not only ensures powerful ignition of the load 30 - approximately 200 times more powerful than a conventional spark ignition - but also ensures that the ignition is not only ignited in the combustion chamber 5. It was sufficient to occur at multiple locations uniformly distributed in three-dimensional space.

On the one hand, the low compression pressure of the pilot rod (9), and on the other hand, the small amount of combustion agent-AF fuel mixture contained in the rod (9), both allow the stacked compressor to compress the pilot rod (9). (36) helped to minimize the energy consumed.

Therefore, this allowed the stack compressor 36 to minimize the amount of work applied directly or indirectly to the crankshaft 37 of the internal combustion engine 2, helping to maximize the final energy efficiency of the engine 2.

Additionally, the time allowed for the stack injector (8) to inject the pilot rod (9) into the stack cavity (6) is in accordance with the four-stroke cycle designed/conceived by Otto/Beau de Rochas for an internal combustion engine (2 It will be noted that the time allocated to the compression phase of ) was approximately the same. This allowed, on the one hand, to limit the power sought for the injector 8 and, on the other hand, to limit the supply pressure of the injector 8. This helps to reduce the cost and complexity of the injector 8 while providing inter alia better reliability and greater durability.

It will be noted that during the entire duration of injection of the pilot rod 9 into the stack cavity 6, the rod 9 is mixed with very little residual burned gas. The content of burnt gas in the rod 9 before spark ignition was only about 1 part per thousand, which is extremely low.

As a result, the pilot rod 9 will be applied to the terminal end of the spark plug 12 to achieve the ignition, combined with a pressure of only 20 bar when the spark plug 12 ignites the rod 9. The maximum flammability allowed was maintained by limiting the voltage. This results in lower power consumption to power the spark plug 12, and added durability of the spark plug.

During the sequence of operations illustrated in the successive steps of FIGS. 3 to 8 , the thermal load applied to the protruding discharge dome 25 is such that the gases raised to a high temperature are subjected to In comparison, it will be noted that this prechamber is reduced to a minimum in that it only passes through the gas discharge hole 24 once, and that this prechamber is devoid of the stacked valve 13.

This particularity, in particular, causes the dome to rise to excessively high temperatures and cause untimely and uncontrolled ignition of the main rods, creating hot spots that are likely to cause rattling and damage or even destruction of the internal combustion engine 2. allowed to prevent formation. Furthermore, this tendency of the protruding discharge dome 25 to remain at low temperatures allows providing a high compression ratio for the internal combustion engine 2 without the risk of rattling.

Therefore, the valve ignition prechamber 1 according to the invention is a spark ignition internal combustion engine that operates under high rates of cooled EGR, whatever the load and rotational speed of the engine 2, and without compromising this combustion stability. (2) is allowed to be created.

As a result of the high rate of EGR, the intake pressure of the engine 2 is higher at part load than that of an internal combustion engine 2 of the same design operating without naturally cooled EGR. This reduces pumping losses caused by adjustment of the rod by suction pressure, which is operated by means of a butterfly, for example.

Additionally, the internal combustion engine 2 housing the valve ignition prechamber 1 according to the present invention has reduced heat loss due to the amount of nitrogen oxides per kilowatt hour produced by the engine 2. This is due to the fact that the combustion of the main rod 30 operates at a lower average temperature thanks to the possibility provided by the valve ignition prechamber 1 according to the invention to introduce a high proportion of cooled EGR in the rod 30. It originates from

In this context, the compression ratio of the internal combustion engine 2, made possible by the valve ignition prechamber 1 according to the invention, will be higher than that of the same engine operating without cooled EGR and without the risk of rattling. can be expected. This is beneficial to the efficiency of the engine 2.

The reduction in pumping losses and heat losses caused by the valve ignition prechamber 1 according to the invention can be achieved by adding a boost, for example by means of a turbocharger, of the internal combustion engine 2 according to ISO torque and ISO power. It will be further noted that this reduces the need to significantly reduce displacement. In practice, the boost may be reduced or non-existent while high energy efficiency is maintained compared to state-of-the-art technologies.

The set of properties and advantages conferred by the valve ignition prechamber 1 according to the invention has an affordable cost price, low fuel consumption, low carbon dioxide emissions and is suitable for internal combustion in which after-treatment of pollutants is ensured by a simple three-way catalyst. Allows acquisition of organs (2).

It will be noted that it is possible for the valve ignition prechamber 1 according to the invention to be applied in domains other than just internal combustion engines. The prechamber 1 can be applied, for example, to a gas nailer, to a firearm, or to any device requiring firing of the main rod by means of a pilot rod with the highest possible efficiency. there is.

The possibilities of the valve ignition prechamber 1 according to the invention are not limited to the applications just described and the foregoing description is given by way of example only and may include any other equivalent embodiments used in place of those described therein. It should also be understood that there is no limitation on the scope of the invention.

Claims (16)

A valve ignition prechamber for an internal combustion engine (2) comprising a cylinder head (3) covering a cylinder (4) to form a combustion chamber (5) in which the main load (30) can combust. As a prechamber (1),
On the one hand, it is arranged in the cylinder head 3 and connected to the combustion chamber 5 by a lamination duct 7 and, on the other hand, is transferred by compression means 10 to the lamination cavity 6. At least one laminate cavity (6) housing a laminate injector (8) capable of directly or indirectly injecting a pressurized pilot rod (9) into the said at least one stacked cavity comprised of a first-AF fuel mixture;
Ignition means (11) open towards the laminated cavity (6) and capable of igniting the pilot rod (9);
It is possible to close the whole or part of the stack duct 7, with the cavity side 14 experiencing, on the one hand, the pressure of the gases prevailing in the stack cavity 6 and, on the other hand, the pressure of the gases prevailing in the combustion chamber 5. A stacking valve (13) exposing a chamber side (15) experiencing the pressure of the gas, which, under the effect of the pressure of the gas, is positioned in the stacking cavity with respect to the stacking duct (7). towards the stack cavity (6) when the pressure prevailing in the chamber is lower than the pressure prevailing in the combustion chamber (5), or towards the combustion chamber (5) when the pressure prevailing in the chamber is lower than the pressure prevailing in the stack cavity (6). the laminated valve, which can be turned towards;
at least one cavity side valve stop (16) that determines the position of the stack valve (13) closest to the stack cavity (6);
At least one chamber side valve stop (17) that determines the position of the stacked valve (13) closest to the combustion chamber (5),
The chamber side valve stop 17 consists of a valve opening seat 20 arranged in the stacked duct 7 or at one end of the stacked duct 7, wherein the valve opening seat 20 is cooperating with a chamber side valve bearing surface (21) located at the periphery or end of said stacked valve (13);
When the valve opening seat 20 and the chamber side valve bearing surface 21 contact each other, the stacked valve 13 discharges at least one gas with the stacked cavity 6 on the one hand and on the other hand. A valve ignition prechamber, characterized in that it forms together with the laminated duct (7) a torch ignition prechamber (23) that simultaneously communicates with the combustion chamber (5) through a hole (24). 2. The lamination valve (13) according to claim 1, wherein the lamination valve (13) is positioned closest to the lamination cavity (6) while opening the lamination duct (7) on a wider section than when disposed closest to the combustion chamber (5). A valve ignition prechamber, characterized in that all or part of the laminated duct (7) is closed. 2. The cavity-side valve stop (16) according to claim 1, wherein the cavity-side valve stop (16) consists of a valve closing seat (18) arranged in the laminated duct (7) or at either end of the laminated duct (7). A valve ignition prechamber, characterized in that the valve closing seat (18) cooperates with a cavity side valve seat (19) located at the periphery or end of the stacked valve (13). 4. The method of claim 3, wherein the valve closing seat (18) and the cavity side valve bearing surface (19) create a seal when in contact with each other, wherein the pressure prevailing in the combustion chamber (5) A valve ignition prechamber, characterized in that it prevents any gas from passing upon said contact when it is greater than the pressure prevailing in said laminated cavity (6). 2. The valve opening seat (20) and the chamber side valve bearing surface (21) of claim 1, wherein the valve opening seat (20) and the chamber side valve bearing surface (21) create a seal when they contact each other to prevent any gases from passing upon said contact. , valve ignition prechamber. 2. The method of claim 1, wherein the laminated valve (13) is centered in the laminated duct (7) and regardless of the axial position of the valve (13) with respect to the laminated duct (7). A valve ignition prechamber, characterized in that it comprises guiding means (22) on the periphery of the stacked valve, which maintains the valve (13) in the same longitudinal orientation as 7). 2. The method of claim 1, wherein the inner peripheral wall of the torch ignition prechamber (23) is cylindrical while the laminated valve (13) has a circular perimeter and is received at a low radial clearance in the torch ignition prechamber (23). Characterized by a valve ignition prechamber. The method of claim 1, wherein the laminated duct (7) accommodates the torch ignition prechamber (23) and flows into the combustion chamber (5) in the form of a protruding discharge dome (25) through which the gas discharge hole (24) is opened. A valve ignition prechamber, characterized in that it protrudes and opens. 9. Valve ignition prechamber according to claim 8, characterized in that the valve opening seat (20) is arranged in the protruding discharge dome (25). The method according to claim 1, wherein when the stacked valve (13) is disposed in contact with the chamber side valve stop (17), the valve (13) connects the stacked cavity (6) to the combustion chamber (5). A valve ignition prechamber, characterized in that exposing at least one gas discharge hole (24). 2. The ignition means (11) according to claim 1, wherein the ignition means (11) traverses all or part of the internal volume of the laminated cavity (6) and has a body extending at least one radius connecting the internal volume with the inside of the connecting tube (26). It consists of a spark plug (12) closing the first end of the connecting tube (26) perforated radially by a directional slot (27), while the second end of the connecting tube (26) is laminated. Characterized in that the duct (7) and the stacked valve (13) are accommodated, and the center electrode (40) and the ground electrode (39) of the spark plug (12) are accommodated in the perforated connecting tube (26). Valve ignition prechamber. 2. Valve ignition prechamber according to claim 1, characterized in that the cavity side (14) exposes an aerodynamic dome (29). 2. The method of claim 1, wherein the cavity side (14) forms a ground electrode (39) facing the central electrode (40) contained by a spark plug (12), which spark plug (12) ignites the ignition means (11). A valve ignition prechamber comprising: 4. The laminated valve (13) according to claim 1 or 3, wherein the laminated valve (13) receives the cavity side valve bearing surface (19) and the chamber side valve bearing surface (21) rather than the center of the laminated valve. A valve ignition prechamber, characterized in that it is axially thicker at the periphery of the valve. delete delete