JPH0584368B2 - - Google Patents

Description

Claim 1: A piston having a working end for use in an internal combustion engine, wherein the internal combustion engine closes at one end and connects the piston in a close-fitting and reciprocating relationship with the working end of the piston. and an axial hole for defining and accommodating a variable volume working chamber for combustion of air-containing fuel between the end and the combustion chamber.
The piston also includes a lower guide portion axially spaced apart from the working end and having a major diameter D, a peripheral seal ring fitted in a groove in the lower guide portion, and a peripheral seal ring that is connected to the lower guide portion and the working end portion. an intermediate reduced periphery between the working end and the working end having a reduced cross-sectional area compared to the lower guide, the main diameter D and the reduced cross-sectional area of the working end of the piston A gap is formed in half of the difference between the diameter and the diameter, and this gap has a gap equal to the nominal width g, circumference length, horizontal cross-sectional area S, axial length L, and S×L. Volume Vg, gap volume Vg, and volume V _B including the remaining volume located between the intermediate decreasing periphery and the virtual cylindrical surface superimposed on the intermediate decreasing periphery.
, the virtual cylindrical surface is concentric with the piston and substantially equal to the main diameter D, and the volume V _B is expressed as D, g, S, and L by the following equations. V _B = SC ² / (L + Kg) (2πF _B ) ² cm ³ where (in the formula, metric units are used) C is the temperature at approximately the autoignition temperature of the compressed charge in the working chamber in cooperation with the piston. V _B is the sound velocity (cm/sec), K is the Helmholtz correction factor between 0.6 and 0.85 determined based on the geometry of the axial end limits of the gap, and F _B is the following equation: is the Helmholtz frequency in a given air chamber B, F _B = (K/D) Hz, where K is a constant with a value between 43000 and 51000, and L is the frequency at which fire propagation occurs through the gap. between the working chamber and the air chamber and is at least equal to the minimum length of the gap, the maximum linear extent defining the volumes VB and Vg being during combustion or expansion. is less than one-fourth of the wavelength of FB at the air chamber temperature of A piston characterized in that g=0.01072D+0.1143. 2 The relationship between L, V _B , g and S above satisfies the following formula

The piston according to claim 1, characterized in that: 3. Piston according to claim 1 or 2, characterized in that the gap is uniform and concentric with the main piston body. 4. A piston according to claim 3, wherein the gap extends around the entire circumference of the piston. 5. The portion of said volume V _B that does not include the gap volume Vg is defined at least in part by a generally laterally extending surface, a radially convergent focusing surface and laterally spaced surfaces, and 3. A piston according to claim 2, wherein the focusing surface closest to intersects said gap along a sharp edge. 6 said piston includes a working surface at the end of a working end of said piston adjacent to a working chamber, said working surface intersecting said gap along a sloped end, said sloped end forming said intermediate reduction; 6. Piston according to claim 5, characterized in that it is inclined towards the periphery. 7. The piston of claim 6, wherein the focusing surface closest to the gap includes a plurality of axially and radially projecting fins. FIELD OF THE INVENTION The present invention relates to internal combustion engines, particularly piston shapes for internal combustion piston engines. CROSS REFERENCES TO RELATED APPLICATIONS The subject matter disclosed in this application is incorporated herein by reference to the following patent applications filed on the same date by the applicant:
The title of the invention in U.S. Application No. 535336 is "Internal combustion piston engine using an air chamber in a piston driven in resonance with a combustion wave frequency," and the title of the invention in U.S. Application No. Combustion Process for Internal Combustion Engines Using Resonant Air Chambers to Induce Closed Sound Tube Resonance in the Combustion Chamber'', Title of Invention ``Dynamically Variable Compression Ratio Internal Combustion Engine'' of U.S. Application No. 535339, and U.S. Application No. 535340 It is related to the title of the invention: "Method for increasing combustion efficiency of an internal combustion engine." BACKGROUND OF THE INVENTION Description of the Prior Art The combustion process on which the present invention is based involves the generation of combustion wave energy that causes the air chamber of an internal combustion piston engine to resonate during combustion or expansion within the engine's operating cycle. It involves literally dynamically filling the combustion chamber completely passively with the air previously stored in the air chamber using a combustion engine. This filling effect occurs independently of the total average pressure difference between the air chamber and the combustion chamber. This process is generally
Thermal Balance Engine (Naval) by the Naval Academy
Academy Heat Balanced Engine
(NAHBE)) has already been described in published literature. For example, United States Naval Academy Trident Scholar Report No. 112
Trident Scholar Report No.USNA−TSPR
No. 112) (1981), "Optimizing the NAHBE Piston Cap Design Utilizing Screen Photography Methods and Applications of the Helmholtz Theory" Cap Design
Utilizing Schlieren Photography Methods
and Applications of the Helmholtz Theory)”
(William H. Johnson)
Johnson) (June 2, 1981), United
States Naval Academy Progress
Report No. EW-13-80 (United States
Naval Academy Progress Report No.EW−13
-80) “Time Dependent Analytical and Optical Studies of Heat Balance Internal Combustion Engine Flow Field”
Studies OF Heat Balanced Internal
Combustion Engine Flow Field” by Pouring and Rankin (1980)
(November)), and United States Naval
Academy Progress Report No. EW-10-
No. 78 (United States Naval Academy
Progress Report No. EW-10-78) Investigation of the Non-
Steady Combustion and Flow Process of the
Naval Academy Heat Balanced Engine
(NAHBE)” (June 1978). While the NAHBE project exemplifies the controlled charging of air into the combustion chamber of an internal combustion engine using combustion wave energy, the piston, combustion chamber, and filling in the conventional NAHBE engine described in the above-mentioned documents are Control systems are created experimentally by iteratively redesigning them until a model that operates according to, or at least approximates, theoretical possibilities is achieved. Often single-cylinder engines are used, which are experimental engines used in laboratories such as Combustion Fuel Research (CFR) engines, but more rarely multi-cylinder engines for commercial production are used, and various Experiments were conducted under variables. How to determine the optimal dimensions of the geometrical variables associated with engine pistons and cylinders, as well as the appropriate ratio of air to fuel, is a tedious, time-consuming, expensive, and inaccurate trial and error process. It is unclear whether a decision can be made without doing so. Even more troublesome,
Even if we find the optimum dimensions and optimum mixture proportions for one engine or group of engines, there are no geometrical dimensions or variables that will allow us to obtain the same effect in the next engine or group of engines as we did in the first engine. It turns out that it is not possible to estimate. The present invention provides improvements in engines consisting of piston and combustion chamber geometries and charge management and control systems used in pistons and combustion chambers, as well as in operation with various other engines and groups of engines. The purpose is to minimize the number of repeated experiments due to errors. The idea of using wave interaction to improve the combustion chamber in a NAHBE engine is only experimental, so engine designs to date have not focused on managing the fuel-air mixture. Ta. Furthermore, the formation of a layer in the combustion chamber before compression begins (making the gas mixture very thin near the piston, where the air chamber is located, and making the gas mixture rich near the opposite side of the combustion chamber) is not done. Furthermore, no attempt is made to operate the engine as economically as possible (eg, to make the gas mixture as lean as possible) while still delivering the full power output. Although theoretical studies show that the efficiency and power of NAHBE engines are superior to Otto engines and diesel engines, the best way to improve commercial engines in this way does not yet exist. This is because a practical method for automatically managing the filling has not yet been revealed. In the experimental NAHBE engine, charging is managed by operating valves to keep the engine running permanently. BRIEF DESCRIPTION OF THE INVENTION The present invention relates to the shape of a piston for an internal combustion engine, in which the interaction of combustion waves occurs and during combustion, from the air chamber to the working chamber through the coupled resonance effect between the combustion chamber and the air chamber. A controlled supply of air is obtained. More particularly, the present invention relates to a piston having an actuating end for use in an internal combustion engine, the engine closing at one end and closing the piston in a close fit and reciprocating relationship. It has an axial bore for defining and receiving a variable volume working chamber for combustion of air-containing fuel between the working end and the closed end. The piston also includes a lower guide portion axially spaced apart from the working end and having a major diameter D, a peripheral seal ring fitted in a groove in the lower guide portion, and a peripheral seal ring that is connected to the lower guide portion and the working end portion. and an intermediate reduced periphery between the working end and the lower guide, the working end having a reduced cross-sectional area compared to the lower guide. 2 of the difference between the main diameter D and the diameter size of the reduced cross-sectional area of the working end of the piston
A gap is formed in one half of the
Axial length L and gap volume equal to S x L
It has Vg. A volume V _B is located between said intermediate reduced periphery and an imaginary cylindrical surface, which imaginary cylindrical surface is superimposed on the volume V _B and is concentric with the piston and substantially equal to the main diameter D. . The above volume V _B is expressed by D, g, S and L according to the following formula. V _B = SC ² / (L + Kg) (2πF _B ) ² cm ³ where (in the formula, metric units are used)
C is the sound velocity (cm/sec) of V _B at approximately the autoignition temperature of the compressed charge in the working chamber in cooperation with the piston, and K is determined based on the geometry of the axial end limits of the gap. is the Helmholtz correction factor between 0.6 and 0.85, and F _B is the Helmholtz frequency in air chamber B given by: F _B = K/DHz where K is a value between 43000 and 51000. L is a constant having a length that is sufficient to prevent flame propagation through the gap between the working chamber and the air chamber and is at least equal to the minimum length of the gap, and L is a volume The maximum linear magnitude defining V _B and Vg is less than one quarter of the wavelength of F _B at the temperature of the air chamber during combustion or expansion, and S has an error of +0.050 cm to -0.025 cm. The range is calculated by assuming the nominal gap width g using the following formula. g=0.01072D+0.1143 Furthermore, the relationship between L, V _B , g and S satisfies the following equation.

Other details of the invention will become apparent from the detailed description below. DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a piston for an internal combustion engine incorporating the present invention; FIG. 2 is a front view of the piston of FIG. 1 disposed within a cylindrical bore of the engine; 3 is a schematic diagram of a fuel-intake internal combustion engine incorporating the piston of FIG. 1 and having an air-fuel ratio control system, and FIG. 4 shows a direct injection of substances into the working chamber of the engine using a fuel injector; 5 is a schematic diagram of an internal combustion engine similar to FIG. 3, and FIG. 5 is a plan view showing an embodiment of a piston gap constructed according to the present invention, in which the air chamber in the piston and the engine working chamber are This gap between the air chamber and the working chamber is uniform around the top of the piston, and FIG. 6 is a plan view showing another embodiment of the gap;・It is formed by the gap being arranged concentrically within the cylinder bore, and the seventh
The figure shows yet another embodiment of the gap formed according to the present invention, in which the gap is non-uniform and divided and arranged around the piston. 2 shows a detailed cross-section of the piston of FIG. 1 having an alternative shape,
FIG. 9 is a front view of the cross section of the piston in FIG. 1 showing another structure of the piston cap, and FIG. 10 is a front view of a cross section of the piston shown in FIG. 1, showing another structure of the piston cap, and FIG. FIG. 11 is a schematic diagram showing the similarity to the chamber; FIG. 11 is a diagram schematically showing the closed sound tube resonance induced in the working chamber by a resonant piston chamber; FIG. 12 (a-b) 13 is a diagram depicting the operating cycle of an engine incorporating the present invention, and FIG. 13 is for illustrating the horsepower of an engine constructed according to the present invention.
A series of graphs of the air-to-fuel ratio of the injectate delivered to the working chamber of the same engine, including specific fuel consumption, unburned exhaust hydrocarbons, exhaust carbon monoxide (volume percent), and the engine's "run" ratio. Figure 14 shows the pressure and temperature of the combustion chamber, the spontaneous ignition region of the injected material in the combustion chamber, and the rapidly increased spontaneous ignition region of the injected material in the combustion chamber. FIG. DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION With reference to the drawings, and in particular to FIGS. 1-3, the present invention has a cylinder 12 and a piston 14 reciprocating within the cylinder 12, and has a suction filling stroke, a compression stroke, and a combustion stroke. / It is intended to improve an internal combustion engine 10 operated with an operating cycle consisting of an explosion stroke and an exhaust stroke. In internal combustion engines, naturally aspirated, supercharged (intake air is pressurized), mixed, and fuel-injected, or a combination of these, it is usually appropriate to All of these are well known in the field of internal combustion engines. Although the particular preferred embodiment illustrated is a reciprocating piston type internal combustion engine, the inventive concepts disclosed and claimed herein are equally readily applicable to rotary piston type internal combustion engines. considered to be applicable. As shown in FIGS. 1 and 2, a piston 14 constructed in accordance with the present invention is disposed within cylinder 12. As shown in FIGS. As piston 14 reciprocates, piston 14 defines a variable volume working chamber 16 (designated as a "combustion chamber") between the top of piston 14 and the closed end of cylinder 12. The piston 14 has a conventional guide or skirt 20, a seal ring groove 22 for a seal ring 24, and a piston pin bearing 26 at the connection point between the piston 14 and a connecting rod 28. A connecting rod 28 connects the piston 14 to an output crankshaft 30 of the internal combustion engine 10. Piston 14 is cylinder 1
2 with a clearance CL (Fig. 2), the piston 14 is fitted with a clearance CL (Fig.
and top dead center (TDC). A piston 14 constructed according to the invention has a working end which is connected to a crown or cap 3.
It has 2. The cap 32 has a diameter dimension, the diameter of the cap 32 being smaller than the diameter of the skirt portion 20. The cap 32 usually has a symmetrical body, the diameter d of which is equal to the skirt portion 2.
The diameter is reduced compared to the main diameter D of 0 (see FIG. 1). If only the radius is considered, cap 3
2 is shown as having a reduced radius r compared to the major radius R of the skirt portion 20 (FIG. 1). As shown in FIG.
is placed in the cylinder 12, it is clear that the width of the gap g is indicated by the difference between R+CL and r. For example, as shown in FIG. 1, when the piston 14 is viewed independently from the cylinder 12, the gap g is the width between the imaginary cylindrical surface 34 and r that spans between the skirt portion 20 and the cap 32. It can be defined by the directional dimension. The imaginary cylindrical surface 34 has a diameter substantially equal to the bore B of the cylinder 12 (or the diameter D of the skirt 20 of the piston 16 if the clearance CL can be ignored). The imaginary cylindrical surface 34 can be viewed as the locus of the bore of the cylinder 12 that receives the piston 14, or, if the above-mentioned clearance can be ignored, as the locus of the curved surface defining the upper part of the skirt portion 20. In the following description and claims, the clearance CL between the piston 14 and the bore will be referred to in the calculation of various mathematical relationships and geometries in order to avoid complicating the description of the invention. are largely ignored. If the clearance CL cannot be ignored, taking into account the dimensions of the clearance CL will be easily understood by those skilled in the art in making such calculations. As shown in FIGS. 5, 6 and 7,
Cap 32 can be configured in different shapes. For example, the cap 32 shown in FIG. 5 is a protrusion extending concentrically from the piston 14, and there is a uniform gap around the entire circumference of the cap 32. The cap 32 shown in FIG. 6 is an eccentric but symmetrical projection, and the gap g around the cap 32 varies uniformly. Further, as another shape that satisfies the geometrical requirements of the present invention, there is, for example, the shape shown in FIG. The cap 32 in FIG. 7 is shaped to divide the gap into two regions, and the gap has a width that varies circumferentially around the piston 14 or bore. Various shapes of the gap and cap result from the application of the invention to various types of internal combustion engines and are necessary to match the desired operating cycle. However, as will be apparent from an understanding of the concept of the invention described below, the piston (including the cap) and combustion chamber embodying this invention all depend on the various parameters of the internal combustion engine to which this invention is applied. and related by certain mathematical relationships involving dimensions. The piston 14 having the above-mentioned NAHBE type piston characteristics is provided with a reduced diameter portion 36 below the cap 32 and above the skirt portion 20, that is, the seal ring groove 22. This reduced diameter portion 36 forms an air chamber 38 below the cap 32 and above the seal ring 24.
communicates with the working chamber 16 only via the gap g. In other words, the air chamber 38 has a reduced diameter portion 36 which is the innermost portion in the radial direction, and a bore or imaginary cylindrical surface 34 of the cylinder 12 which is the outermost portion in the radial direction. upper and lower surfaces 40, 42 that converge;
It is completely defined by the gap length L and the length of the upper gap (LR) of the top seal ring.
In the preferred embodiment, the piston 1
4 intersects the periphery of the cap 32 of the piston 14 along a sharp edge 44 (FIG. 2). The peripheral region of the cap 32 includes an axial surface 46 having an axial length L. This axial length L defines the length of the gap. In this preferred embodiment, the axial surface 46 intersects the working surface of the piston along an inclined surface 48. According to the invention, the axial length L of the gap g is an important dimension along with the width g of the gap, the volume V _B of the air chamber 38 and the geometric dimensions of the upper and lower surfaces 40, 42. The volume V _B is calculated correctly, and this volume V _B is the volume V _g of the gap g
Contains. This volume V _g is obtained by multiplying the area of the gap (obtained by integrating the circumferential length of the gap around the piston (see Figures 5 to 7) by the width of the gap) and the axial length L of the gap. The axial length L is measured along the circumference of the axial face 46 of the cap. Such length and volume determinations are made by formal mathematical principles and require no effort. Further, as shown in FIG. 1, the volume V _B of the air chamber 38 is located between the piston 14 and the bore 12 (imaginary cylindrical surface 34), along the gap surface 50 and at the upper peripheral edge of the top seal ring groove 22. It is calculated including the gap volume V _C that reaches up to However, regarding the gap volume V _C ,
It will be largely ignored for purposes of explanation and description of this invention, except in specific cases where its significance is particularly important. In FIG. 2, the upper and lower surfaces 40, 42 of the air chamber 38 are shown to be smooth, but in the modification of FIG. 8, at least the upper surface 40 has radially and axially projecting fins. It is shown. These fins assist in heat exchange between the air circulating within air chamber 38 and the underside of cap 32 during operation of the internal combustion engine, as will be explained in more detail below. Furthermore, the structure of the piston 14 in another embodiment is illustrated in FIG.
Reference numeral 2 designates a separation member 54 that is assembled to the main body of the piston via a suitable fixing member 56 or via other suitable fixing mechanisms including brazing or welding. The upper and lower surfaces 40, 42 are also coated with a suitable catalytic material 58 to promote radicals in the air chamber 38 or to assist in controlling the force of chemical reactions occurring within the air chamber 38. You can also. Conventionally, for example, in an internal combustion engine 10 that uses a piston similar to piston 14, the determination of its compression ratio is determined by the ratio of the total volumes of the working chamber and air chambers 16 and 38, respectively, when the piston is at BDC and This can be easily done by comparing the volumes of the working chamber and air chamber at TDC. The volume of the working chamber when the piston is at TDC is conventionally designated as the "free" volume of the working chamber. For convenience,
The volume of the air chamber is often simply designated as "V _B ", and the ratio of V _A to V _B is conventionally designated as the "equilibrium ratio" from the early theoretical "thermal equilibrium cycle" terminology. In this theoretical "thermal equilibrium cycle" terminology, heat is considered to be added to the theoretical air cycle at "equilibrium". If additional information is desired regarding the theoretical thermal equilibrium cycle that provides the background for this invention, reference may be readily made to the various publications containing the term theoretical "thermal equilibrium cycle" mentioned above. A typical internal combustion engine system employing the present invention is shown in FIGS. 3 and 4. FIG. 3 schematically shows a typical fuel-breathing internal combustion engine, and FIG. 4 shows a typical fuel-injection internal combustion engine. Each internal combustion engine includes a piston 14 of the shape shown in FIGS. 1 and 2, and a suitable functional mechanism for connecting the piston 14 to an output shaft 30 to which a flywheel 60 is attached. In FIG. 3, the intake type internal combustion engine has an intake manifold 62 through which a mixture of combustible air and fuel is supplied to an intake port 64 of the internal combustion engine under the main control of a throttle 66. Ru. In a preferred embodiment of the invention, fuel is added to the first air stream 68 that is supplied to the intake manifold, and the second air stream 70 is provided with its own separate control system. This control system will be described below in connection with the description of FIG. The schematic implementation of FIG. 3 shows the first and second air streams connected to a common manifold. The first supply to the working chamber of the internal combustion engine
Separate manifolds are utilized, along with other equipment, to separately provide and control the and second air streams. In all cases, the first and second air flows (along with the necessary fuel) are suitably regulated or controlled, so that only air or a very small proportion of fuel fills the working chamber during each intake stroke. Air containing air (which is insufficient for fuel continuation) is first drawn into the working chamber and, after a delay, a rich mixture of fuel from the main side of the charging source. Therefore, when combustion begins, virtually only air is in the vicinity of the piston, and all of the fuel in the total charge (including all air and fuel in the working chamber when the intake port is closed) is It is included on the end side of the working chamber opposite to the piston. As the compression of the charge proceeds, the air containing very little fuel is transferred via the gap g to the air chamber 38 below the piston cap 32, where it is compressed together with the rest of the charge in the working chamber. and heated. The geometry of the air chamber 38, in particular the upper and lower sides 4
Due to the geometry of the air chamber 38, the air moved into the air chamber 38 swirls rapidly in an annular swirl pattern on the underside of the cap 32, which causes this air to flow into the upper and lower sides 40, 42. It is circulated through direct heat exchange between the The heat exchange that takes place between the displaced air and the piston cap (particularly the upper side 40) is very important. This is believed to be the basis for improving the efficiency of the working cycle in the present invention compared to engine and diesel cycles with conventional piston geometries. Essentially, the heat exchange that takes place during the subsequent compression stroke between the cap heated by the previous compression/explosion stroke and the air moved below this cap creates a regenerative effect, and this The regenerative effect reduces the total waste heat during each cycle for a given amount of fuel compared to conventional engine or diesel cycles. Therefore, if necessary, the eighth
The use of fins and catalyst surfaces as illustrated in FIGS. It can be done. Normally, a small amount of fuel is carried into the air chamber 38 with the air, so that some hydrocarbon radical generation occurs in the air chamber 38 as well as in the working chamber 16. Radical-generating reactions of hydrocarbon fuels under high pressure and high temperature conditions are described, for example, in U.S. Pat.
It is known from reference No. 4317432 and
The phenomenon is described here. The generation and treatment of radicals generated within the air chamber 38 and how they are used to contribute to the main reaction within the working chamber 16 is illustrated in FIGS. 12a to 12.
Discussed below in conjunction with the description of p-diagrams. In FIG. 4, an internal combustion engine 72 uses a similar piston 14. However, for the fuel intake system illustrated in FIG. 3, fuel is injected by using an injector 74.
Injectors 74, shown as supplying high-pressure fuel directly to the working chamber of the internal combustion engine, or alternative fuel injection devices are utilized, which provide axial stratification in the working chamber at the beginning of the compression stroke. Guarantee. Also, although indirect fuel injection in the area of the intake port gives rise to the necessary layer control, the invention is not limited to a method based on a given injector system.
Fuel in the figure is supplied via an injection controller 79 which is responsive to the position of throttle 79'. In both the internal combustion engine embodiments of FIGS. 3 and 4, an exhaust port 80 is connected to an exhaust manifold 82 for exhausting combustion products from the working chamber 16. Third
In the figure, a spark igniter 84 serves to initiate the combustion reaction within the working chamber 16 in the conventional manner and is supplied with a high energy electrical potential via a distributor 86. Thereby, sparks can be generated within the working chamber 16 at a timing related to the movement of the piston 14. In the embodiment of FIG. 4, ignition is either compression induced or spark driven. According to the invention, it is desirable to use shock wave energy for ignition of the combustion chamber charge in order to operate the air chamber as a Helmholtz resonator. Helmholtz resonators are generally well known and widely described in the literature. The classic discussion of the Helmholtz resonator in the combustion chamber environment of an internal combustion engine began in 1951.
A. on October 30th. G. U.S. Patent Granted to ADBodine, Jr.
It can be seen in No. 2573536. This patent relates to a process for weakening or eliminating detonation waves in combustion processes. In FIG. 10, the upper part of the figure shows a classical Helmholtz resonator comprising a chamber 90 containing gas at a predetermined temperature, the chamber 90 having a restricted aperture or neck 92.
have. This net 92 has a length Ln,
It has geometric orifices at both ends.
When the air in the network 92 is given an excitation frequency corresponding to the natural resonance frequency of the gas in the chamber 90, a resonance condition is generated in the chamber 90, and the gas in the chamber 90 is oscillated at the Helmholtz resonance frequency and , the transmitting state is maintained even with relatively small input energy. The diameter, cross-sectional area and length Ln of the net 92 and the volume of the chamber 90 are variable and determine the oscillation state of the chamber 90, but the Helmholtz resonator theory
It is quite general regarding the actual shape of 0 itself. Accordingly, the present invention provides a method for generating the pressure wave shown in FIG. 1 or FIG. It is based on the assumption that the air chamber 38 of the designed piston structure can react exactly like the Helmholtz resonant chamber 90. When the members constituting the Helmholtz resonance chamber have a suitable shape, the input pressure wave energy whose frequency coincides with the Helmholtz resonance frequency of the gas in the chamber 38 at the temperature of the chamber 38 is as shown in the upper part of FIG. A resonant condition is induced in the air chamber 38 in a manner similar to the system depicted in FIG. The similarity between the classical Helmholtz resonator configuration and the Helmholtz resonator obtained by the shape of the piston 14 is illustrated at the top and bottom of FIG.
In calculating the resonant frequency of the Helmholtz resonant chamber 90 or 38, the length Ln of the net is important, and the length Ln of the net is determined by an appropriate parameter depending on the geometry of the entrance and exit ends of the net. must be adjusted by dimensional constants. For example, a flanged inlet provides the neck with one effective length, while the angled inlet shown at the bottom of FIG. 10 provides the neck with a different effective length.
In practice, for the inclined inlet shown in the lower chamber configuration of FIG. 6 and. A Helmholtz correction factor between
It is given to adjust the actual neck length to obtain a valid neck length. If optimum efficiency and operation of the piston and combustion chamber is to be achieved, an important aspect of this invention is to provide periodic shock frequencies and frequencies that are transmitted at a velocity close to the speed of sound in the combustion chamber at its combustion temperature. To find a certain relationship that necessarily exists between the ignition of the charge and the expansion frequency of the explosion; the geometrical dimensions of the cylinder; the volume of the air chamber; the width of the gap; the length and cross-sectional area; and the combustion temperature. Furthermore, when applying the present invention to different types of internal combustion engines,
It is important to understand these relationships and to set the shapes and volumes of the piston, combustion chamber, gap, and air chamber. As mentioned above, this method uses an air chamber that responds to the interaction of combustion waves.
Although the NAHBE internal combustion engine is already in practical use,
Optimization of actual internal combustion engines to reach the theoretical efficiency limits suggested by the "thermal equilibrium" or "regeneration" theory is not yet readily available in practical applications. The invention is therefore based on a more recent discovery that it is possible to mathematically define the shape of the piston, the compression ratio and its movement in an internal combustion engine using a given fuel and having a given cylinder bore. , thereby ensuring a Helmholtz resonance condition and obtaining optimal internal combustion engine operation. In particular, assuming that the ignition of the charge in the working chamber 16 creates a periodic vibrational shock wave of frequency _A that is transmitted within the working chamber at a speed close to the speed of sound.
The air chamber is configured to operate at Helmholtz resonance under its natural frequency F _B by frequency _A like a Helmholtz resonator during the combustion/explosion phase of the cycle. On the other hand, cylinder bore, air chamber 3
8. The geometric ratio of gap g, axial gap length and gap cross-sectional area is established by the following equation. V _B = SC ² / (L + H _g ) (2πF _B ) ² cm ³ where (all dimensions use metric units), V _B is the volume of the air chamber 38; S is the cross-sectional area of the gap g; C is the the sound velocity in the air chamber 38 at approximately the autoignition temperature of the compressed charge in the working chamber 16; L is the gap length; K is for adjusting the effective length of the gap based on the shape of the end regions of the gap; 6 and. a suitable _Helmholtz dimensionless correction factor between
A number between 43000 and 51000, B is the diameter of the bore (or piston diameter if clearance is ignored); and g is g=. 01072B+. represented by 1143,
The tolerance is +. From 050-. It is in the range of 025cm. If the gap g varies around the piston, a uniform gap with the above dimension g exhibits a cross-sectional area s. The actual gap area must satisfy the area value related to the gap shape. The maximum width of the non-symmetrical gap cannot exceed the dimension that occurs when a choke flow (critical pressure ratio) is obtained between the air chamber and the working chamber during at least some strokes of the working cycle of the internal combustion engine. Therefore, when the oscillation frequency _A is applied to the working chamber, the total gap area and volume must satisfy the requirements of a Helmholtz resonator. Furthermore, the gap length L is initially selected to always cut off any flame propagation between the working chamber and the air chamber. (Assuming there is a pocket or region of combustible mixture in the air chamber, i.e. assuming that the air chamber is filled with fuel before the flame front travels through the combustion chamber) Assuming that this L is related to the absolute temperature of combustion in the working chamber and the pressure in the working chamber, it is conventionally determined by the flame propagation cutoff theory of the following equation. L∝(K)(T _A ) ^1/2 /P _A where K is a constant; T _A is the combustion temperature of the fuel in the working chamber; P _A is the pressure in the working chamber; Also, in the above equation for V _B , the maximum linear dimension of the gap and air chamber in any direction is the resonant frequency within the air chamber 38 at the temperature of the air chamber 38 during the combustion/explosion stroke of the internal combustion engine's operating cycle. It is assumed to be smaller than 1/4 wavelength of _B. It is desired to obtain a reasonably wide frequency response between F _A in the air chamber and the resonant condition, or what is called the "Q" response, and the following equation is
Used to "adjust" dimensions to satisfy VB formulas.

[Chemical formula] When the dimensions of L, g, and S satisfy both the VB and Q equations, an appropriate dimensional relationship according to the present invention is established. Appropriate balance ratios, gap geometry, and air chamber volumes are provided for a given fuel, compression ratio, bore size, and stroke of the internal combustion engine. Another aspect of the invention is that, with appropriate "adjustment" of the variables mentioned above, combustion of the working chamber at the end of the expansion stroke of the working cycle is achieved by "sound tube" oscillation of the working chamber on the working surface of the piston. This is the discovery that intense mixing occurs in the region. The principle of sound tube resonance in a closed tube is well known, and its fundamental resonant frequency depends only on the length of the tube and the speed of sound at the gas temperature within the tube. In this invention, a frequency of approximately _B (which is somewhat different from _A , since the working chamber is cooled below the original combustion temperature) is used to actuate the working chamber in sound tube resonance for at least a small period of time. When the piston reaches BDC by using the resonant gas in the original air chamber (natural frequency), it induces a fundamental or harmonic tube resonance in the cylinder bore above the piston. However, theoretically, it should be possible to operate the working chamber at multiple points in the expansion stroke during sound tube resonance. The principle of sound tube resonance is illustrated in FIG. 11A, where the piston 14 has reached BDC and the air chamber 38 _is
It resonates at or near this frequency. This air chamber 38 causes the working chamber to oscillate at temperature T _A and has a length LW at its fundamental tube frequency, as shown schematically by dashed line 94 . It is important to emphasize the significance of the heat exchange that occurs between the cap 32 and the air in the chamber 38 during the latter part of the compression stroke of each operating cycle. The previous cycle's heat storage in the cap contributes significantly to the overall efficiency of the cycle, so the temperature of the cap is important. The temperature of the cap is controlled by selecting suitable materials for the cap and by coupling the cap to the main piston body to achieve and maintain the desired cap temperature during operation of the internal combustion engine. I can do it. To ensure that F _B matches F _A , the temperature of the air chamber 38 is controlled by the pressure at the time of fuel ignition to obtain the desired Helmholtz resonance, which is important for satisfying the operation of the system of this invention. It must be. Furthermore, in a spark ignition internal combustion engine,
It is important to maintain the temperature of the air chamber 38 at its pressure below the detonation or "knock" temperature of the fuel in the working chamber, thereby avoiding engine knock under all operating conditions of the internal combustion engine. Additionally, the temperature of the air chamber 38 must be controlled so that the generation of radicals within the chamber 38 and the The maintenance of introduced (or already included) radicals is important from the standpoint of promoting combustion of internal radicals.
This is ensured by maintaining the temperature of the chamber below such a temperature that it will not react with the required compound. In addition to obtaining suitable piston and combustion chamber geometries for a given internal combustion engine according to the above-described formulas, the present invention also provides a method for supplying the working chamber of an internal combustion engine using the piston and chamber of the present invention. The present invention seeks to obtain an internal combustion engine regulation system that is applied to control the air-fuel ratio of the charge.
If spark ignition is used to initiate combustion, the advance setting of the ignition timing is controlled in addition to the air/fuel ratio. As a starting point, the internal combustion engine 10 or 72 (FIG. 3 or 4) is completely "measured" on a suitable test stand (not shown) and the air/fuel ratio of the internal combustion engine; ignition timing; indicated horsepower; Fuel consumption; engine speed; load; fuel flow rate; emissions (especially non-combustible hydrocarbons and carbon monoxide) are determined. As shown in Figure 13, a set of curves is obtained from the engine's measurement procedure, which curves include monohydrocarbon (CO), uncombustible hydrocarbon (UHC), indicated fuel consumption (ISFC) and its total operating 1 shows indicated horsepower (IHP) for internal combustion engine air-fuel ratios over a range of air-fuel ratios. Empirical experiments in the laboratory have shown that when the piston and combustion chamber geometries obtained according to the equations described above are utilized, the air-fuel ratio at maximum power is uniformly approximately equal for all internal combustion engines. 16:1, and also indicates that the most economical case air/fuel ratio is approximately 20:1. Thus, a variable range of air-fuel ratios varying from 16:1 at maximum power to 20:1 in the most economical case is obtained, as well as an opening for internal combustion engines with pistons and combustion chambers according to the invention. A fuel and air distribution system is established. However, the problem of controlling the air-fuel ratio under other operating conditions of the internal combustion engine remains, in order to obtain the maximum efficiency allowed for the internal combustion engine. In order to achieve the maximum permissible efficiency, the invention provides that at various operating speeds of the internal combustion engine:
Recently developed characteristic curves for CO, UHC, ISFC and IHP for air-fuel ratio are used.
“Run Quality Index”
The curve called "Index)" or RQI is calculated mathematically using the following formula. RQI=(IHP)K/(ISFC)(UHC)(CO) The RQI curve is also illustrated as curve 106 with its ordinate on the right side of FIG. Therefore, in reality, a curve 106 with a sharp peak indicates the optimum air-fuel ratio for optimum running of the internal combustion engine.
To obtain the RQI curve, the RQI curve relates to what is supplied to the combustion chamber and exhausted to the exhaust stream. It is clear that at maximum RQI, the internal combustion engine actually operates at maximum efficiency at any speed and load condition. Of course, this efficiency need not be equal to the theoretical maximum efficiency under similar conditions. The maximum RQI curve is the target for achieving the charged air-fuel ratio as well as proper ignition timing during actual internal combustion engine operation. However, in all operating conditions of the internal combustion engine, the air-fuel ratio and ignition timing (assuming spark ignition) are controlled so that the composition of the charge can be adjusted in the direction of obtaining the maximum RQI of the internal combustion engine. It is necessary to obtain suitable control means that can do this. During the internal combustion engine measurements described above, the optimal air-fuel ratio and ignition timing that yields the optimal RQI in the RPM test for each internal combustion engine is determined and assumed.
Still further, in accordance with the present invention, the air-fuel ratio of the initial charge flow supplied to the intake manifold 62 of the fuel-breathing internal combustion engine shown in FIG. The secondary air is adjusted to approximately twice the economical air-fuel ratio, and the secondary air is adjusted to balance the overall air-fuel ratio. Secondary air (indicated by 70 in Figure 3)
is provided with a control mechanism which controls the air-fuel ratio supplied to the internal combustion engine intake manifold to provide an air-fuel ratio that operates the internal combustion engine at an optimum RQI under various internal combustion engine load and speed conditions. Next, constantly adjust the amount of air. According to the invention, the secondary air is provided by Irvin and Michael
By using a "lean limit control" system, such as that disclosed in U.S. Pat.
It is only controlled by modifying the system described above to seek a "lean limit" corresponding to the RQI. Of course, the patented system seeks a minimum misfire lean limit for the internal combustion engine regardless of RQI operation. However, by appropriately adjusting its measurements, the system determines the optimal air-fuel ratio for the internal combustion engine to operate at optimal RQI, thereby providing maximum
A "misfire" situation can be seen on either side of the RQI. The system responds by adjusting the air/fuel ratio toward maximum RQI. Thus, referring to FIG. 3, secondary airflow is controlled by a restrictor plate or valve 110 which is controlled by a servo motor 112. Referring to FIG. This servo motor 112 is
It is controlled by a central control unit of a lean limit control system similar to that described in No. 4,368,707. The lean limit control system described in the above patent instantaneously detects the output of the internal combustion engine by instantaneously magnetically detecting the angular velocity of the flywheel 60 using the pickup 116. The pick-up 116 instantaneously detects the passing speed of the teeth of the flywheel in the vicinity of the pick-up 116. After receiving the sensor signal via line 118, the speed signal is processed in central control unit 114 to generate an instantaneous acceleration (or deceleration) signal. The central control unit 114 ``interprets'' the instantaneous acceleration or deceleration signal as an instantaneous power reading of the internal combustion engine and directs the servo motor 112 to the ``lean side''.
Or command the "rich side", thereby valve 11
0 is operated open or closed to obtain a lean or rich condition. The predetermined air-fuel ratio determined by the control system 14 is determined by the curve 106 in FIG.
corresponds to the air-fuel ratio that produces the optimal RQI, as shown by . In this respect, it is recognized that the internal combustion engine operates with an optimal balance between the fuel supplied to it and the power required, and that the internal combustion engine operates at the maximum efficiency it can obtain. But it works. Of course. If a misfire is detected by sensor 116, this indicates to central control unit 14 that the air/fuel ratio is inappropriate and must be further adjusted to obtain the required power output of the internal combustion engine. Instruct. However, when the sensor 116 recognizes that the misfire limit has been reached and the central control unit 114 determines that the secondary air controller 112 is set to produce an air/fuel ratio that matches the optimum RQI. , it can be easily recognized that the internal combustion engine operates at maximum efficiency available. Preferably, an ignition timing controller 120 is provided which controls the advance/retard settings of the distributor at the request of the central control unit 114, so that the spark timing controller 120 controls the advance/retard settings of the distributor in accordance with the appropriate settings determined by the aforementioned internal combustion engine measurement tests. , each as recognized by the flywheel sensor 116.
For RPM, an optimal ignition setting with optimal RQI is established. Therefore, the central controller 114, in addition to the "lean limit control" system just discussed, includes a sensor that receives or derives the internal combustion engine RPM signal from the flywheel sensor 116, which sensor is connected via line 22 to the distributor. generates a signal responsive to the speed signal that controls the ignition advance mechanism 120 of the engine. In an internal combustion engine in which combustion is initiated by self-ignition, such as the internal combustion engine shown in Figure 4, which uses a compression ratio of 5 to 9:1, the optimum
To maintain RQI operation, a lean limit controller 114 is provided that controls a fuel injection control system 79 that adjusts the air-fuel ratio. The timing and amount of fuel delivered to each cylinder of a fuel-injected internal combustion engine is carefully controlled by control system 114 to obtain the precise air-fuel ratio necessary for optimal RQI operation of the internal combustion engine. Additionally, of course, the control system 114 ensures that no fuel is supplied into the working chamber 16 during the compression stroke, which would adversely affect the transfer of fuel-free air into the air chamber 38. In a preferred embodiment of the invention, at least in part of the high operating speed range of the internal combustion engine, during at least part of the compression stroke, the classical critical pressure ratio for producing a choke flow through the orifice is set to the air chamber volume V _B A gap g is formed between the working chamber volume V A and the working chamber volume V _A . By starting the ignition timing of the filling, the operation and air chambers 16,
Assuming that the pressures between 32 and 32 are not equal, the invention provides an internal combustion engine with a dynamically variable compression ratio that depends only on the speed of the internal combustion engine. As the speed of an internal combustion engine increases, its effective compression ratio also increases to increase power output. At low speeds, when no flow is induced, the piston of the internal combustion engine
The volume of the working chamber and the piston when it is at BDC are
According to the ratio between the volume of the working chamber when at TDC, it actually operates at a lower compression ratio in volumetric terms. Preferably, the gap g is selected such that choke flow is present over the upper 35% of the speed range of the internal combustion engine. However, the above-mentioned speed ranges may be varied to suit specific requirements. It can be seen that if the gap g is constant, the maximum width of the gap does not exceed the value necessary to obtain a choke flow between the air and the working chamber above the threshold speed, where the air flow through the gap g Due to the lack of pressure in the working chamber causing it to flow into chamber 32, the effective compression ratio begins to increase. Furthermore, it can be seen that when the pressure in the working chamber suddenly decreases, a choke flow between the air chamber and the working chamber is obtained at the moment the exhaust valve opens. When the exhaust valve is opened, expansion of the high pressure gas in the air chamber into the working chamber is momentarily delayed by appropriately selecting the gap width to create a critical pressure ratio across the gap. Thereby, the delivery of high-pressure, high-temperature air containing radicals from the air chamber to the exhaust system is maintained and controlled. Of course, the degree of heated air and radical retention will depend on the degree of throttling and other factors. For example, by providing a sharp edge 44 at the edge of the gap adjacent to the air chamber 33, the choke flow can be ensured at a practically normal gap width. 12a-12p, the operation of the present invention is schematically illustrated, where a Helmholtz resonance condition is shown which causes periodic pumping of air from the air chamber 38 into the working chamber 16. Uses; flow conditions between air and working chambers; sound tube resonance; coupled oscillators; and generation of radicals to improve and control the compression stroke of internal combustion engines.
including management. Starting from FIG. 12a, the piston 38 is
BDC, both valves (intake and exhaust) are closed,
Then, an axially layered filling is shown in the working chamber 16, with air and a very small amount of fuel on the side close to the piston, and a rich mixture near the closed end of the working chamber. It is represented. In all cases, at the beginning of the compression stroke, no or very little fuel-containing air is present in order to ensure that air is introduced into the air chamber 38 at least at the beginning of the compression stroke. Air must be present near the working end of the piston.
Such axial layers can be obtained using a variety of filling control devices, including, but not limited to, dual air supply intake manifolds containing air controls; Includes the intake valve mechanism, fuel injection control, intake manifold port mechanism, etc. The compression stroke begins and progresses as shown in Figures 12b and 12c, and is indicated by arrow 1 in Figure 12b.
Air enters the air chamber from the working chamber as indicated by 23. As the compression stroke progresses, a rolling vortex 124 is formed in the air chamber under the cap 32 due to the geometry of the gap g and the walls of the air chamber and the movement of the fluid within the chamber.
This roll vortex is important. This rolling vortex causes an intimate heat exchange between the air entering the air chamber and the underside of the cap 32, and after a few cycles the Helmholtz resonance frequency _B of the air chamber operates as described above. The cap will be heated to the desired temperature to match the natural frequency _A of the chamber. If the internal combustion engine is configured to have a dynamically variable compression ratio as described above, the operation and initiation of the flow between the air chambers 16, 32 will occur when the piston reaches its maximum speed. done at some point during the journey. Then, when the piston reaches TDC, the air in the air chamber 16 has been heated to such a point that its temperature matches the desired Helmholtz resonance frequency _B , and ignition of the charge occurs (Figure 12d). The generation of radicals in the air chamber 38 is already underway before the ignition point of the fuel, which is determined by the pressure and temperature conditions of the air chamber and the nature of the fuel combusted by the internal combustion engine. However, since the fuel in the air chamber is very small, as will be explained repeatedly, the content of radicals generated from the small amount of fuel contained in the air is the same as that in the air chamber generated in the working chamber during the previous cycle. can be easily recognized to be smaller than the amount of radicals. In Figure 12d, the ignition has started and the shock wave preceding the flame tip has not yet reached the gap between the actuation and air chambers, and the shock wave from the ignition has not yet reached the gap, as shown in Figure 12e. It passes through this gap and drives the heated gas in the air chamber resonantly at the Helmholtz resonant frequency of the air chamber. The interaction of compression and expansion waves between the working and air chambers now generates a periodic oscillatory movement of air from the air chamber to the working chamber to participate in the combustion reaction of the fuel.
Of course, all the air in the room is not introduced at once, as this would adversely affect the combustion process. Rather, the air is released in a controlled manner through the critical gap in order to react with the fuel for a certain period of time in a manner dependent on the proportions adapted to the combustion process itself. The transfer of air from the air chamber to the working chamber proceeds like a pumping action even when the pressure in the working chamber increases and the overall average pressure in the working chamber is higher than that average pressure in the air chamber. It should be noted that The essence of the wave interaction process is that the rebound of the shock wave from the gap region creates a temporary and localized pressure drop in the vicinity of the gap, which allows the expansion of the Helmholtz oscillation from the air chamber into the combustion zone. . Therefore, air movement continues throughout the combustion stroke and causes an appropriate reduction in working chamber pressure, so that after the piston has moved a sufficient distance from the closed end of the cylinder, air movement will stop expanding. It is therefore not simply dependent on the air capacity of the air chamber to be discharged into the working chamber. As shown in Figure 12f, the movement of air from the air chamber to the working chamber occurs when the working chamber expands due to the movement of the piston while the air chamber is still oscillating at the Helmholtz resonance frequency B. Proceed to. As hot air from chamber 38 enters the combustion zone along the outer cylinder wall and expands centrally into the upper region of the working chamber of the cylinder, a reaction between the air and the fuel is observed. be done. Therefore, from the moment ignition proceeds, air is constantly supplied to the combustion zone due to the Helmholtz resonance in the air chamber and the interaction of the shock/expansion waves in the vicinity of the gap. This improves the combustion stroke so that all of the charged fuel reacts, since the device of the invention allows a long combustion time for all of the fuel elements to react. As is well known, oxidation of fuel (combustion) is a chemical process that breaks the bonds between hydrocarbon components and produces intermediate compounds with different bond strengths. By providing additional time for combustion with additional highly activated oxygen in the combustion zone, unstable compounds that require additional time for reaction can react with available oxygen. can. Of course, the flame tip in the working chamber never actually penetrates the gap and enters the air chamber.
This is because the gap is constructed to prevent any flame front from reaching the air chamber. If the internal combustion engine operates in a self-ignition mode, the ignition timing is determined by the pressure and temperature in the working chamber, as is well known. However, according to the invention, the autoignition process is activated due to the presence of radicals pre-seeded by the filling as well as additional radicals supplied from the air chamber by the Helmholtz resonance effect. It is thought that this occurs at many points indoors. Ignition timing is controlled by constructing the cap of a material with a temperature coefficient that facilitates self-ignition at low compression ratios and optimizes the temperature of the cap for the fuel being combusted and the compression ratio of the internal combustion engine. It is possible. This will be discussed in more detail later when the process for controlling the timing of autoignition is described. In FIG. 12g, the piston approaches the BDC position and a sound tube resonance is generated within the working chamber as described above. The reaction of the remaining fuel near the cap continues and further heating of the cap occurs due to radiant heat. In FIG. 12h, the exhaust valve is opened and the combustion products immediately begin to be exhausted from the combustion chamber with the lowering of the working chamber. The oxygen and radicals left in the air chamber begin to expand across the gap (with a delay if the gap is configured to create a flow between the air chamber and the working chamber at this point); and combine with exhaust gas,
It is capable of reacting with hydrocarbon compounds within the working chamber to provide a thermal reactor that reacts with residual fuel or exhausts exhaust. During the exhaust stroke, degassing of non-combustible hydrocarbons and vaporized oil in the ring and clearance gaps occurs, and the presence of these compounds is likely to contribute significantly to the amount of non-combustible hydrocarbons in the exhaust gas in standard conventional internal combustion engines. Are known. In this invention, the degassing of hydrocarbons from the area of the gap and the ring is extended only into the air chamber adjacent to the gap. (As shown in FIG. 2, the length of the gap surface 50 between the bottom of the air chamber 38 and the top of the first ring seal is set as long as possible to minimize the volume of the gap area above the ring seal groove. On the other hand, the degassing of hydrocarbons and evaporated oil into the air chamber generates hydrocarbon radicals, which further contribute to the reaction between the oxygen obtained from the air chamber and the fuel in the working chamber. Some of the radicals generated by the venting of the interstitial region remain in the air chamber for later use. Therefore, the heated air chamber 38 on the underside of the cap 32
acts as a reactor area for the fuel molecules degassed from the piston clearance and ring gap, thereby reducing or eliminating the amount of UHC from the source in the exhaust stream. Incidentally, it should be noted that the bulk of the interstitial area is dimensionally too small to allow the generation of radicals within it, thereby reducing the volume of the larger and closer heated air chamber V _B. Availability provides significant benefits in reducing the emission UHC generated by the degassing process. As the exhaust stroke progresses, the reaction occurring in the air chamber further causes the gas within this chamber to expand and agitate, and as the exhaust stroke progresses (see Figures 12i and 12j), the cylinder 12
This causes an acceleration of the cylinder of gas towards the closed end of the cylinder over the gap region within the cylinder, and a subsequent rebound of the cylinder of gas towards the piston, thereby creating significant turbulence and mixing within the working chamber. arise. As shown in Figure 12k,
In the middle of the exhaust stroke, when the flow across the gap region is reversed, the acceleration of the piston causes an instantaneous inflow of combustion products into the air chamber. However, in FIG. 12l, as the end of the exhaust stroke approaches, the deceleration of the piston and the low pressure in the working chamber causes a final depressurization of the air chamber and complete venting of the interstitial region of the piston. The final reaction of the interstitial vapor in the air chamber then produces various hydrocarbon radicals, which are present in the exhaust stream produced during the combustion process and are characterized as "post-flame" radicals. It is then characterized as a "pre-flame" radical. Of course, the pre-flame radicals are clearly somewhat different in chemical composition from the post-flame radicals. This is because these radicals do not take part in the high-temperature and high-pressure combustion reactions of the charged fuel, but arise only from the cracks of the low-pressure and low-temperature fuel molecules present in the air chamber during the exhaust stroke. Therefore, along with the air in the chamber 38, the remainder of the post-flame radicals from the combustion products in the exhaust gas as well as the pre-flame radicals from the interstitial venting are present in the chamber as a highly reactive mixture. Upon completion of the exhaust stroke, the exhaust valve is closed and the intake valve is opened (possibly with appropriate overlap to suit the requirements of a given internal combustion engine). The piston begins to move away from the closed end of the cylinder bore to begin the next intake of air into the working chamber. As the piston accelerates downward, as shown in Figure 12m, venting of air and radicals from the air chamber to the working chamber occurs due to the rapid piston movement and the reduced pressure in the working chamber. This generates a species of inhaled air containing highly reactive radical mixtures in the air chamber. Since the air in the working chamber is much cooler than the air in the air chamber, the hot radicals are "cooled" and diluted. This further substantially retards the reaction of the radicals within the air chamber until they are reactivated during the next compression and combustion stroke. In Figure 12n, the piston is nearing the end of its intake stroke, but fuel has not yet been introduced into the working chamber. 12o and 12p, fuel is added to the intake port area of the working chamber (for a fuel-breathing internal combustion engine) and stratified in the desired axial direction before compression begins to begin the next cycle. Generate a filling that has formed. In order to avoid contaminating the air chamber with fuel except in very small quantities (sufficient for combustion), various procedures as described above are used to obtain an axially layered packing. can be used. When the next compression stroke begins (FIG. 12a) and ignition begins (FIG. 12d), the charge is a mixture of fresh fuel and radicals. This radical is generated during heating and compression of fresh fuel.
Post-flame radicals and pre-flame radicals are seeded from the previous compression cycle and the degassing of the fuel and air gap at the end of the previous cycle. Ignition is therefore sharply increased, whereby the autoignition pressure/temperature range is reduced according to known principles, as illustrated in FIG. 14. In FIG. 14, a typical compression ignition autoignition region 128 is shown in relation to the pressure and temperature within the working chamber 16. The region 130 is a self-ignition region where radicals increase, and the seeding effect of radicals is a self-ignition region and the Russian physicist N. N. It shows how this affects the phenomenon extensively investigated by NNSeminov. The shape of radical enrichment region 130 is sometimes referred to as a "Seminov Peninsula" in nature. Region 132 to the lower left of region 130 requires a spark or high temperature source to initiate combustion in a typical internal combustion engine. This is because ignition of the charge does not occur spontaneously. Therefore, the pressure within the working chamber is at least in the radical increase autoignition region 130.
The temperature of the charge is determined only by whether the ignition starts spontaneously or only by the induction of a spark, a high temperature source, as long as it is above the general horizontal leg of the area 130 and to the left of the vertical leg of this region 130. can recognize the 2
By controlling the temperature of the charge by adjusting the amount of sub-air, and by maintaining the temperature of the cap 32 below the detonation temperature, the combustion cycle of the present invention is independent of whether the ignition is self-ignition or spark ignition. Controlled to be selectively implemented. According to the invention, the temperature of the charge is close to the radical increase autoignition temperature with respect to the extreme pre-combustion temperature of the charge, which is varied by varying the air-fuel ratio through the control of the secondary air entering the working chamber. It is carried out at the temperature of the filling of the working chamber. In this way, a slight increase or phenomenon of the charge temperature within the self-ignition region (region 130 or region 132) and outside this region is achieved, and the combustion cycle is carried out selectively in spark-ignition or self-ignition mode. be done. Of course, in autoignition mode, the cycle is a low compression ratio (5-9:1) fuel intake cycle. Due to the controlled supply of Helmholtz resonant air from the air chamber to the combustion zone 16 throughout the combustion stroke and the long combustion time provided by the piston and combustion chamber geometry, violent detonations and knocks are avoided even with gasoline fuels. It is believed that the radical type (pre-flame) imparted to the working chamber enhances the entire process and allows close control of ignition on both sides of the radical build-up region. In the case of fuel injection, such as the compression ignition internal combustion engine shown in FIG.
Optimum ignition timing is believed to be ensured by selecting the cap 32 with the thermal coefficient and construction that produces the highest power for that cycle when implemented in the 1st cycle. That is, the material of the cap and the construction of the cap are such that, depending on the fuel and compression ratio used in the internal combustion engine, the cap temperature will be such that the timing of self-ignition will take full advantage of the maximum power output of the internal combustion engine. selected to have a thermal coefficient of Only preferred embodiments of the invention have been described herein, and those skilled in the art may make various modifications to the described structure or process without departing from the concept of the invention as defined in the claims that follow. It is clear that this can be done.