JP4148773B2 - Homogeneous charge compression ignition barrel engine - Google Patents

Description

[0001]
(Field of the Invention)
The present invention relates generally to internal combustion engines, and more particularly to homogeneous charge compression ignition engines and barrel engines.
[0002]
BACKGROUND OF THE INVENTION
Internal combustion engine structure
Internal combustion engines (hereinafter sometimes simply referred to as “engines”) are widely used in both mobile power generation applications and stationary power generation applications. The most popular type of internal combustion engine is a crank-driven reciprocating piston engine. This type of engine has a cylinder that houses a piston whose position changes, and forms a combustion chamber between the closed end of the cylinder and the piston. A rod interconnects the piston and an offset journal attached to a rotatable crankshaft, and the piston reciprocates up and down in the cylinder by the rotation of the crankshaft. Conventional crank drive engines are the most prevalent, but many other engine structures have been proposed and used. An example is a Wankel rotary engine in which a lobe-shaped rotor rotates within the engine to cause expansion and contraction of the combustion chamber.
[0003]
Another internal combustion engine structure is shown in FIG. This engine structure is referred to by various names, including, among others, barrel engines, axial engines, axial piston or cylinder engines, cam engines, swash rings or swashplate engines, crank plate engines, cams or Examples include wave cam engines, rotary swash plate engines, and radial or rotary engines. In this specification, for convenience, these types of engines are referred to as barrel engines. However, the term “barrel engine” as used herein is not limited to the particular structure shown, but is to be understood to include similar engines.
[0004]
The engine 10 of FIG. 1 is merely a representative example of the overall structure of the engine, referred to herein as a barrel engine. The engine has a crankshaft or power shaft 12, and a plurality of cylinders are arranged around the power shaft 12. However, it is possible to adopt a single cylinder as a modification. The central axis of each cylinder 14 is preferably parallel to the power shaft 12 as a whole. As a modification, the axis of the cylinder 14 may be inclined outward or inward with respect to the power shaft 12. A cam plate or track 16 is preferably connected to the power shaft 12 so that the two rotate together. The track 16 extends outward from the power shaft 12 so as to surround the power shaft 12, and has a cam surface 18 that undulates in a wave shape. When the power shaft 12 is rotated about its longitudinal axis, the cam surface 18 of the track 16 oscillates toward and away from the cylinder 14. The piston 20 is movably provided in the cylinder 14 and constitutes a combustion chamber 22 between each piston and the upper end portion of the cylinder 14 corresponding to the piston. The piston 20 is interconnected to the track 16 so that when the track rotates, the piston reciprocates within the cylinder 14. In the illustrated example, a connecting rod (hereinafter sometimes simply referred to as a “rod”) 24 has an upper end interconnected with the piston 20 and a lower end with a roller 26, and these rollers 26 are connected to the track 16. It is on the cam surface. As a variant, the piston of such an engine may be directly interconnected with the track, for example a roller or a slider may be directly connected to the piston.
[0005]
As will be apparent to those skilled in the art, various strokes of the combustion cycle can be defined as the power shaft 12 rotates and the pistons 20 reciprocate within the corresponding cylinders. Typically, the cam surface 18 of the track 16 has a generally sinusoidal shape, thereby corresponding to the typical reciprocating motion of the crank drive piston. Further, the track as a whole is provided in a plane perpendicular to the power shaft, and the cam surface is provided as a whole at a certain distance from the axis of the power shaft.
[0006]
The barrel engine may be of single-ended design or double-ended design. In a single-ended design, the cylinder and piston are provided in the end of the engine on one side of the track, for example above the track as shown in FIG. In a double-ended design, cylinders and pistons are provided on both ends of the engine (both above and below the track when arranged as shown in FIG. 1). Another structure has a track provided at both ends of the engine and opposed pistons extending from the two tracks toward each other. The trajectory typically rotates in unison so that the two pistons reciprocate so that they move toward and away from each other in a common cylinder.
[0007]
Earlier applications of this application (which are referred to in the description part of the related application and which are hereby incorporated by reference as forming part of this specification) are generally referred to as reverse peristaltic engines. Various engine designs are described. In this application, the barrel engine is considered a variation that belongs to all grades of reverse peristaltic engines as disclosed in these applications. Other variations on the reverse peristaltic engine share certain functional attributes regarding the barrel engine as disclosed herein. It should be noted that some features of the present invention can be utilized in engine configurations rather than in the specific configurations shown or described.
[0008]
Another design engine that has some functional and / or structural similarity to the barrel engine as described above is a type of engine often referred to as a swashplate engine. . FIG. 2A is a schematic diagram of a portion of the rotary swashplate engine 30. In the barrel engine 10, the track 16 is shown as having two low points and two high points corresponding to four strokes (four cycles) that make up a complete set of compression engines. In the rotary swashplate engine, the plate 32 is interconnected to the longitudinal power shaft 34. The plate 32 is generally flat, but is inclined with respect to the power shaft 34 and thus has a high portion and a low portion. That is, the plate 32 is not perpendicular to the power shaft 34 but is somewhat inclined. Pistons 36 and 38 are mechanically connected to plate 32 in a manner similar to FIG. However, since the plate 32 is not a complicated shape like the track 16 but is generally flat, for example, only two strokes can be determined by one rotation of the plate 32. That is, when the shaft 34 is rotated once, the pistons 36 and 38 each experience the top dead center and the bottom dead center only once. On the other hand, in the barrel engine of FIG. 1, each revolution of the track 16 causes the piston 20 to advance twice to the top dead center and twice to the bottom dead center, respectively. A design similar to engine 30 is used in rotary swash plate compressors. In these compressors, the compression ratio of the compressor can be adjusted by adjusting the angle of the rotary swash plate. Typically, such compressors have spherical rollers that interconnect the piston and rotating swashplate. The engine can be configured similarly to this. Variations such as the design and compressor of FIG. 2A are considered barrel engines according to the definitions herein.
[0009]
Referring now to FIG. 2B, another variation of the engine 40 is shown. In this engine 40, a short longitudinal power shaft 42 is connected to an inclined cam 44, which has a generally triangular cross section. The power shaft 42 and the inclined cam 44 rotate at the same time. The rotary swash plate or piston support plate 46 is placed on the upper surface of the inclined cam 44, but does not rotate therewith. Therefore, when the tilt cam 44 rotates, the piston support plate 46 tilts back and forth. The piston is connected to the piston support plate 46, and the movement of the plate 46 causes the piston to reciprocate. This is again considered to be a type of barrel engine according to the definition herein. This design differs from the two previously described designs in that the piston support plate 46 is replaced by a roller to coordinate the relative movement of the cam 44 and the piston.
[0010]
According to the definition herein, another variation of a barrel engine is one type of engine called a nutating engine. Examples of these are shown in U.S. Pat. Nos. 5,992,357 and 6,019,073, the entire contents of both of which are incorporated herein by reference. Is quoted here as forming. Another design of a barrel engine, sometimes referred to as a slanted axis engine, is shown in US Pat. No. 1,293,733 to Duby, the entire description of which is also described in this document. Cited herein as forming part of the specification.
[0011]
Combustion method of internal combustion engine
Various combustion schemes have been proposed and / or tested for internal combustion engines. The most common scheme, referred to herein as spark ignition (SI), is shown in FIG. Air and fuel are mixed together prior to suction into the combustion chamber. The mixture is compressed in the combustion chamber, and then sparks are generated to ignite the compressed mixture. This process is used in most gasoline fueled internal combustion engines. Spark ignition internal combustion engines include a two-cycle reciprocating piston design and a four-cycle reciprocating piston design, as well as a number of lesser known variations. Air and fuel are typically mixed upstream of the cylinder using a carburetor or fuel injector. A multi-cylinder air / fuel mixture can be obtained at one location, for example using typical carburetor and outlet fuselage fuel injectors, or fuel and air can be mixed separately for each cylinder, eg Occurs in port fuel injection. A less popular approach is to inject fuel directly into the cylinder before or during the compression stroke. Regardless of the deformation, the spark ignition engine has the feature that combustion is initiated by bringing a spark to the compressed air / fuel mixture. Spark ignition engines have the advantage that the timing of combustion (which is sometimes referred to as combustion phasing) is easily controlled. Since combustion is initiated by creating a spark, the timing of combustion can be controlled by controlling the timing of the spark. Spark ignition engines also tend to be relatively compact and cheaper than some other types of engines. A disadvantage of spark ignition engines is that they have a lower combustion efficiency than some other types of engines.
[0012]
Another known combustion method is the method used in the diesel engine shown in FIG. In diesel, air without fuel is drawn into the combustion chamber and compressed. Once the air is partially or fully compressed, fuel, typically diesel fuel, is injected into the compressed air. By introducing fuel into the compressed air under appropriate conditions, the fuel / air mixture is combusted. Diesel variants include the introduction of fuel at two or more stages in a so-called layered charge diesel engine. In a stratified charge diesel engine, the air / fuel mixture is intentionally manipulated to produce regions of high fuel concentration (high fuel) and low fuel concentration (thin fuel). This is often accomplished by initially compressing the lean mixture and then providing additional fuel to create a localized rich region and initiate combustion. A stratified charge or lean burn scheme is also utilized in spark ignition engines. Combustion phasing is also easy to control in a diesel engine. This is because the timing of fuel injection determines the timing of combustion. Diesel engines provide superior fuel efficiency compared to spark ignition engines and provide the ability to burn inexpensive types of fuel. However, diesel engines are heavier, more expensive and more noisy than spark ignition engines. Diesel also has high levels of nitrogen oxides (NO_X  ) And particle emissions.
[0013]
Another combustion scheme (referred to herein as homogeneous charge compression ignition (HCCI)) is shown in FIG. In HCCI, a mixture of air and fuel is drawn into the combustion cylinder. Next, the air-fuel mixture is compressed so that the air-fuel mixture eventually self-ignites without introducing sparks. Variations on HCCI include direct injection of fuel into the cylinder at some point during the compression stroke to facilitate substantially premixed charge. The HCCI combustion system is known by various names, and includes such as controlled auto-ignition combustion (Ford), premixed charge compression ignition (Toyota and VW), active radical combustion (Honda), fluid dynamics Controlled combustion (French Petroleum Association) and active thermocombustion (Japanese engine).
[0014]
HCCI has several advantages over spark ignition and diesel systems. First, HCCI offers the potential for significantly improved fuel efficiency. Second, the exhaust gas component from HCCI is easier to manage than in other systems. HCCI combustion is significantly cooler than conventional combustion systems, so NO_X  Emissions are extremely low. HCCI also has less particulate emissions than diesel engines. In addition, conventional diesel engines do not have locally dense areas and therefore have less or no particle emissions and smoke. Advantages and disadvantages associated with HCCI and HCCI control schemes are extensively described in SAE article number 1999-01-3682, the entire contents of which are hereby incorporated by reference as if forming part of this specification. .
[0015]
The disadvantage of HCCI is that it is very difficult to control combustion phasing. Whether a compressed air / fuel mixture is self-igniting depends on many factors, including the exact refueling, the temperature of the mixture, the temperature of the cylinder, and any other components present in the combustion chamber. Replenishment and reactivity, combustion chamber geometry, engine operating speed, engine operating load and many other factors. Traditionally, there has been no practical way to effectively control HCCI combustion in engines that are subject to normal load and RPM transients. Unlike diesel and spark-ignited engines, where combustion phasing can be controlled by timing when fuel is injected or when sparks are introduced, HCCI engines have no direct way to control when combustion begins .
[0016]
Another challenge with HCCI concerns the burning rate. Combustion in HCCI engines occurs at many ignition points in the combustion chamber, and unlike diesel engines where the combustion rate is controlled by the mixing rate of the fuel jet and oxidant, the pressure increase in HCCI is very lean fuel If an air-fuel mixture is not used, it can occur very rapidly and destructively at high rates. The lean air-fuel mixture requirement limits the maximum power output of an HCCI engine to 50-75% of that of a uniform diesel and Otto cycle engine, imposing a limit on the market where HCCI engines can be used.
[0017]
HCCI control method
Many schemes for controlling combustion phasing in HCCI engines have been proposed. One way to control the HCCI engine combustion phasing is to adjust the compression ratio of the engine. When the air / fuel mixture is fully compressed, it will self-ignite. However, the amount of compression required to initiate combustion depends on many factors. By changing the compression ratio, the combustion phasing can be controlled. A higher compression ratio results in faster combustion, and a lower compression ratio results in slower combustion or no combustion. Several variable compression ratio engine designs have been proposed and possibly manufactured. These engines have the disadvantages of mechanical complexity and increased cost. In addition, depending on the method used to change the compression ratio of the engine, it cannot be changed quickly enough to adequately control the combustion phasing in the HCCI engine. Some designs also limit the location of the valve or create a gap region in the combustion chamber, thereby reducing efficiency and increasing emissions. Such a design is disclosed in SAE article 1999-01-3679, the contents of which are cited herein as forming part of this specification.
[0018]
Another way to control combustion phasing in HCCI engines is to control the temperature of the intake air. As the intake air temperature increases, combustion will occur early with all other conditions held constant. If the temperature of the intake air is decreased, combustion is delayed. Therefore, the combustion phasing can be controlled to some extent by controlling the intake air temperature. Disadvantages of this scheme include reduced volumetric efficiency with increasing intake air temperature and the complexity associated with providing superheated intake air. Accurate control of the intake air temperature in the combustion chamber is also difficult and the range of adjustments that can be made in this manner is very limited.
[0019]
Fuel blending is another way to control HCCI combustion phasing. Different types of fuel self-ignite under different conditions. Therefore, combustion phasing can be adjusted by blending two or more fuels having different properties that self-ignite. This scheme is typically limited to stationary applications. The obvious drawback is that there is a need for an infrastructure that differs in complexity and nature inherently with redundant fuel systems and that maintains a special fuel distribution.
[0020]
SAE paper 2000-01-0251, which is hereby incorporated by reference, forms part of this specification, describes the use of residual exhaust gas as a method of controlling HCCI combustion phasing. When the amount of exhaust gas introduced into the combustion chamber is increased, combustion occurs quickly. The disadvantages of this scheme are that the control range is limited, the power and efficiency at high residue levels is low, and the requirements for high residue levels under certain conditions are severe.
[0021]
US Pat. Nos. 5,832,880 and 5,875,743 issued to Dicky propose the use of water injection to control combustion phasing. Water is introduced into the intake manifold or directly into the combustion chamber. The start of combustion is delayed by the introduction of water into the combustible mixture. In this method, it is necessary to provide a water injection system that is very easy to control, and there is a concern that the degree of engine wear may increase due to the injection of water into the combustible mixture. Also, this scheme does not provide adequate control according to researchers in the art.
[0022]
Yet another method of controlling HCCI combustion phasing is proposed in US Pat. No. 6,260,520 to Van Reesford (the contents of such US patent specification are described herein). Is quoted here as forming part of). This US patent proposes to provide an auxiliary compression device designed to provide additional compression of the air-fuel mixture within the combustion chamber. In this US patent, an auxiliary boost piston is provided in the cylinder head, and the volume of the combustion chamber is increased or decreased by movement of the piston. To explain the operation, first, the air / fuel mixture is compressed by the main piston. Next, the auxiliary piston is moved to further increase the degree of compression in the combustion chamber until the air-fuel mixture self-ignites. The timing of the movement of the auxiliary piston controls the start of combustion, thereby allowing control of combustion phasing. This design is mechanically complex and increases the clearance volume in the combustion chamber.
[0023]
A variable valve timing system has also been proposed as a method for controlling combustion phasing. By controlling the valve timing of the engine, the effective compression ratio can be changed somewhat.
Despite considerable efforts by many skilled artisans, there is no control scheme that has been found to be particularly effective in adjusting HCCI combustion phasing. This is especially true when the HCCI engine undergoes rapid changes in speed and load.
[0024]
[Summary of the Invention]
The present invention improves upon the prior art with a number of features applicable to barrel engines and / or homogeneous charge compression ignition engines and features relating to wide availability. In one embodiment of the present invention, a homogeneous charge compression ignition barrel engine has an engine housing with a first end and a second end. An elongate power shaft is provided longitudinally within the engine housing and defines a longitudinal axis of the engine. A plurality of cylinders surround the longitudinal axis, each having a closed end and an open end. Each cylinder has a central axis. Each open end of the cylinder is generally directed to the first end of the housing. An intake system is operable to introduce a combustible mixture of air and fuel into each of the cylinders. A track is provided so as to be positioned between the first end of the housing and the open end of the cylinder such that a portion is disposed in general alignment with each central axis of the cylinder. The track has a cam surface that undulates in the longitudinal direction relative to the open end of the cylinder. A part of the cam surface is arranged in a state aligned with the central axis of each cylinder as a whole. The track and the cylinder are rotatable with respect to each other so that a cam surface that is waved up and down moves relative to the open end of the cylinder. A piston is movably provided in each of the cylinders so as to form a combustion chamber with the closed end of the cylinder. Each piston is in mechanical linkage with the cam surface of the track so that as the cylinder and track move relative to each other, the piston reciprocates within the cylinder. Each cylinder is operable to compress the combustible mixture until the combustible mixture self-ignites without introducing sparks.
[0025]
The homogeneous charge compression ignition engine may further include a variable compression ratio device operable to adjust the longitudinal position of the track relative to the open end of the cylinder to adjust the compression ratio of the engine. In some embodiments, the central axis of each of the cylinders is parallel to the longitudinal axis of the engine. The track is generally provided in a plane perpendicular to the longitudinal axis of the engine, and the cam surface is provided at a substantially constant distance from the longitudinal axis of the engine.
[0026]
In one form of engine, the track is in mechanical linkage with the power shaft so that the shaft and track rotate together with respect to the cylinder. In another form, the track is in mechanical linkage with the engine housing so that the track and the engine housing do not rotate relative to each other. In this embodiment, the cylinder and power shaft are in mechanical linkage such that the cylinder and power shaft rotate simultaneously with respect to the engine housing.
[0027]
In some embodiments of the present invention, the wavy cam surface is generally sinusoidal. In other embodiments, the wavy cam surface has a non-sinusoidal shape. In the form of a non-sinusoidal cam surface, the cam surface may define at least one top dead center portion, which is greater than when the cam surface has a sinusoidal shape. It is short to see in a straight line. As a variant, the non-sinusoidal cam surface defines at least one compression stroke and at least one expansion stroke, and the compression stroke is slower but expands than if the cam surface has a sinusoidal shape. The process is fast.
[0028]
In some embodiments of the present invention, the intake system includes an intake valve and an exhaust valve, and further allows the valve opening timing and / or closing timing and / or lift to be adjustable. It has a valve timing (valve adjustment) system.
[0029]
In the double-ended configuration of the present invention, a second set of cylinders is provided between the track and the first end of the engine. Movable pistons are provided in the second set of cylinders, which are also mechanically connected to the track so that these pistons reciprocate in the second set of cylinders. The second set of cylinders can be used as combustion cylinders or as part of a supercharger that compresses air for the intake system of other cylinders.
[0030]
The invention also relates to a method for converting fuel and air into rotational energy. According to this method, a homogeneous charge compression ignition type barrel engine as described above is prepared, and one of the pistons is positioned at the upper position by rotating the track. Next, the track is continuously rotated to move one piston between an upper position and a lower position, and a combustible mixture of air and fuel is introduced into the combustion chamber. Next, the orbit is rotated to move the piston upward to compress the air-fuel mixture. The combustible air-fuel mixture is compressed until it is self-ignited without introducing sparks so that the air-fuel mixture burns. Combustion causes the piston to move downward, thereby causing the orbit to rotate.
[0031]
As described above, the homogeneous charge compression ignition type barrel engine of the present invention may have a variable compression ratio device. In these embodiments, the present invention provides a method of adjusting the compression ratio to establish and / or maintain autoignition. A method of adjusting the compression ratio to avoid pre-ignition is also provided.
[0032]
According to another feature of the present invention, the use of a corona discharge device can introduce radicals and ions into the combustion chamber of the engine to change the reactivity of the combustible mixture in the combustion chamber. This changes the combustion phasing of the engine. The corona discharge device is preferably provided in the engine intake system, but may alternatively be provided in the combustion chamber. The present invention provides a method for adjusting the reactivity of an air-fuel mixture using a corona discharge device. The corona discharge device can be used in a homogeneous charge compression ignition barrel engine as described above. Corona discharge devices can also be used as part of a method for controlling a homogeneous charge compression ignition engine by adjusting the air-fuel reactivity and adjusting the combustion phasing.
[0033]
Another feature of the present invention is that after the piston at least partially compresses the mixture, the level of compression in one of the combustion chambers is rapidly increased so that the combustible mixture self-ignites without the introduction of sparks. There is provided a homogeneous charge compression ignition barrel engine as described above, further comprising a quick compression device that can be adapted.
[0034]
The invention also relates to various novel quick compression devices. In one embodiment, the rapid compression device is designed to introduce hot gas into the combustion chamber and the internal combustion engine. The rapid compression apparatus has a body in which a chamber having an opening in communication with the chamber is configured. The ignition device can ignite the combustible mixture in the auxiliary chamber, and a gas permeable spark arrester is provided in the opening of the chamber, and the ignited combustible mixture in the chamber passes through the arrester. When pushed in, it disappears. In some embodiments, the igniter is not required indoors, instead the indoor combustible mixture is ignited by self-ignition by compression. The rapid compression device just described can be used in homogeneous charge compression ignition engines or have other uses. The present invention provides a method for providing rapid compression in an internal combustion engine using the rapid compression apparatus described above.
[0035]
An alternative embodiment of the rapid compression method has the steps of providing an internal combustion engine with a combustion chamber and introducing an air / fuel mixture into the combustion chamber. The mixture is then compressed and burned, thereby producing a pressurized gaseous combustion product. Next, a portion of the pressurized gaseous combustion product is captured and substantially all of the remainder of the gaseous combustion product is exhausted from the combustion chamber. Next, a fresh mixture of air and fuel is introduced into the combustion chamber and compressed. Next, the compressed gas combustion product holding portion is released into the combustion chamber to quickly increase the compression level.
[0036]
The present invention further provides a method of equalizing combustion phasing variations from cylinder to cylinder in an HCCI engine. On the other hand, the first corona discharge device is selectively operable to introduce ions and free radicals into the combustible mixture in the first cylinder, and the second corona discharge device is It is selectively operable to introduce free radicals into the combustible mixture of the second cylinder. A controller controls the first and second corona discharge devices to selectively adjust the relative combustion phasing of the first and second cylinders. As a modified example, first and second water injectors may be provided to selectively introduce water into the first and second cylinders, respectively. Again, the controller controls the first and second water injectors to selectively adjust the relative combustion phasing. As another variant, the temperature of the individual cylinders can be controlled separately to adjust the relative combustion phasing. The same can be done by individually adjusting the air-fuel ratio or intake air temperature or exhaust gas recirculation amount for each cylinder to adjust the relative combustion phasing.
[0037]
Detailed Description of Preferred Embodiments
HCCI barrel engine
The present invention relates to improvements in the grade of internal combustion engines, referred to herein as barrel engines, and improvements in homogeneous charge compression ignition (HCCI) engines, which are used in combination or separately. In addition, various features of the present invention can be applied to engine structures other than barrel engines and compression schemes other than HCCI. As described in the Background of the Invention, a barrel engine is a type of internal combustion engine that does not include a conventional crankshaft that reciprocates a piston within a cylinder. In contrast, in a barrel engine, one or more pistons are typically mechanically associated with a track or plate with a cam surface that waves towards and away from the cylinder as the engine rotates. Due to the mechanical linkage of the piston and cam surface, the piston reciprocates within the cylinder as the track or plate rotates relative to the cylinder.
[0038]
Referring again to FIG. 1, the general structure of a barrel engine is indicated generally at 10. A generally vertical power shaft 12 is surrounded by a number of cylinders 22. However, a single cylinder configuration can be used. A track 16 is attached to the power shaft 12 and has a sinusoidal cam surface 18 as a whole. The piston 20 is mechanically linked to the cam surface 18 by a connecting rod, and the connecting rod is preferably integral with the piston 20. The terminology used in this specification, for example, the terms vertical, horizontal, upward, downward and side, is for convenience and does not limit the actual arrangement or orientation of the various components. It should be noted.
[0039]
According to the first aspect of the present invention, the improved HCCI engine can be constructed using a barrel engine structure. As will be further understood with reference to the remainder of this specification, barrel engine design provides significant advantages, particularly when used with the HCCI combustion scheme. In an HCCI barrel engine, a combustible mixture of air and fuel is preferably obtained by mixing in the intake system of the engine. As a variant, the fuel may be injected directly into the combustion chamber, preferably early in the compression stroke. An intake valve or other means of controlling communication with the combustion chamber opens during the intake stroke for a particular cylinder. During the intake stroke, the piston 20 moves downward in the cylinder 14, thereby expanding the combustion chamber 22 and drawing in air or a mixture of air and fuel. In order to move the piston downward, the track 16 rotates to wave so that the cam surface 18 of the track moves downward and away from the upper end of the cylinder 14. Next, the intake valve is closed and the compression stroke begins. During the compression stroke, the piston 20 is pressed upward in the cylinder 14 as the track 16 continues to rotate and the cam surface 18 undulates toward the cylinder 14. In the case of HCCI, the combustible mixture is compressed until it self-ignites. During self-ignition, the combustible mixture expands dramatically and exerts a large downward force on the piston 20. When combustion is correctly phased, the cam surface 18 of the track 16 is at top dead center (TDC), i.e., the cam surface 18 is closest to the cylinder and the piston is at its highest point in its stroke. At or near the point. Next, the piston is pressed downward so that the track rotates, thereby driving the power shaft 12. This continues until the piston reaches bottom dead center (BDC), that is, the piston 20 is located furthest from the top of the cylinder 14 and the cam surface 18 is at its furthest point from the cylinder 14 for its stroke. . The exhaust valve or other device that controls the release of combustion products from the combustion chamber 22 is then opened and combustion products begin to exit the combustion chamber 22. At the same time, the piston 20 begins to move upward when the track 16 continues to rotate and the cam surface 18 is undulating toward the cylinder 14. The exhaust valve remains open for a period of time during which the piston can push combustion products out of the combustion chamber 22. When the piston 20 reaches top dead center again, the exhaust valve is closed, the intake valve is opened, and the piston 20 begins its downward movement again, bringing fresh flammable mixture of air and fuel into the combustion chamber 22. You can pull in. This process is repeated during engine operation. As is known to those skilled in the art, valve opening and closing events may not occur exactly at top and bottom dead centers, but are phased prior to or after this event, , May overlap each other. The timing of the valve operation as described above is simplified for easy understanding.
[0040]
In FIG. 1 it can be seen that two cylinders 14 are arranged on opposite sides of the power shaft 12. The shape of the track 16 is such that the piston 20 and the cylinder 14 move together. That is, the trajectory 16 has a sinusoidal shape as a whole with two top dead centers and two bottom dead centers per revolution. Additional cylinders may be provided at other locations around the power shaft, and these cylinders may be out of phase with the two illustrated cylinders. The track 16 may have a shape other than the shape shown in FIG. 1 in the illustrated rotary swash plate engine in which the plate has only one top dead center and one bottom dead center per revolution, for example. Good. In certain designs, especially for engines with these large numbers of cylinders, the trajectory may have three or more top and bottom dead centers. These other designs are considered barrel engines for purposes of the present invention, and the rotating swash plate or other device is considered a track with a cam surface that moves the piston. The cam surface 18 may be an upper surface, a lower surface, or another structure capable of pressing the piston up and down. For example, the track 16 may have a circumferential groove that mates with the connecting rod and the piston. This is also considered a cam surface.
[0041]
Variations on the barrel engine include, for example, the double-ended design and the counter-piston design described herein. In accordance with the present invention, any of these variations of the barrel engine can be used with the HCCI combustion scheme. For example, an additional set of cylinders may be provided at the other end of the engine as viewed from the location where the illustrated set of cylinders is provided. A second set of pistons may be movably provided in these cylinders in mechanical linkage with the track.
[0042]
In accordance with the present invention, a generator may be incorporated into the barrel engine as described in the priority document incorporated by reference in this application. The “rotor” is formed in the rotatable part of the barrel engine and the “stator” is formed in the stationary part. Thereby, a compact package is obtained.
[0043]
Barrel engine with variable compression ratio device
Referring now to FIG. 6, an improved barrel engine of the present invention is indicated generally at 50. The barrel engine 50 has a variable compression ratio device that is operable to change the distance between the track 56 and the cylinder 54. The barrel engine 50 has a longitudinal power shaft 52 arranged vertically in the illustrated example. A pair of cylinders 54 are disposed on opposite sides of the power shaft 52. However, a single cylinder and a wide range of multi-cylinder engines can be constructed in accordance with the present invention. As shown, the cylinders 54 are generally parallel to one another and to the longitudinal power shaft 52. As a modification, the cylinder 54 may be inclined inward or outward with respect to the shaft 52. A track 56 is provided around the power shaft 52 and has a cam surface 58 that waves in the longitudinal direction relative to the cylinder 54. As used herein, the term “cylinder” means a shape other than a geometric cylindrical shape. For example, a combustion “cylinder” as used herein may have a shape that is not a pure geometric cylinder. The term combustion cylinder also applies generally to internal combustion engines, including non-conventional designs used, for example, in rotary engines. In these cases, the term piston is likewise broadly defined as being a compression device used with the “cylinder” that forms the combustion chamber.
[0044]
Unlike the barrel engine of FIG. 1, the track 56 is not rigidly connected to the shaft 52. Instead, the track 56 of the engine 50 can move longitudinally relative to the shaft 52. However, the shaft 52 and the track 58 are engaged with each other so that they rotate together. In the illustrated embodiment, the power shaft 52 is provided with longitudinal splines 60 that correspond to the corresponding longitudinal teeth or splines provided in the inner sleeve portion where the track 56 intersects the shaft 52. 62 is engaged. Other ways of rotatably interconnecting the power shaft 52 and the track 56 will be apparent to those skilled in the art. Due to the interlocking splines 60, 62, the track 56 moves longitudinally with respect to the shaft 52 and can accommodate a variable compression ratio while the track 56 and shaft 52 are still rotating in unison. The thrust bearing 64 supports the track 56 in the longitudinal direction in a state where the track 56 rotates with respect to the lower portion of the thrust bearing 64.
[0045]
Pistons 66 are provided in the cylinders 54 corresponding to these, respectively, and these pistons constitute a combustion chamber 68 between the upper surface of the piston 66 and the closed upper end of the cylinder 54. When the track 56 rotates mechanically in cooperation with the cam surface 58 of the track 56, the piston 66 reciprocates in the cylinders 54 corresponding to these. In the illustrated embodiment, the piston 66 has connecting rods 70 (hereinafter sometimes referred to as “rods”) extending downward, and these connecting rods have rollers 72 mounted on the upper and lower surfaces of the plate 56. ing. As a variant, the piston 66 may be dimensioned so that the roller forms part of the piston. As another variation, roller 72 may be replaced with a slider or other design that allows the piston and track to move relative to each other. The lower foil of each pair of foils is sized differently than the upper foil, and the lower foil may be retracted or not placed directly below the upper foil. One or both foils are also fitted in the groove, for example as shown at 73. These variations may help prevent the piston from rotating and increase the thickness of the track 56 as needed. As will be apparent to those skilled in the art, piston 66 and rod 70 preferably move axially within cylinder 54 without tilting side to side or back and forth. In the illustrated embodiment, a rod guide 74 is shown that helps to hold the rod 70 in its correct orientation.
[0046]
In order to prepare the barrel engine 50 with a variable compression ratio function, a thrust bearing 64 can move longitudinally relative to the cylinder 54. This can be achieved in various ways. In the illustrated embodiment, the thrust bearing 64 has a threaded inner periphery 76, which is the thread of the hub 80 formed as part of the bottom plate 82 of the engine 50. The outer peripheral portion 78 is engaged. The plate 82 is rigidly connected to an engine cylinder and a head by an engine case 84. By rotating the thrust bearing 64 relative to the hub 80, the contact surface between the thrust bearing 64 and the track 56 moves in the longitudinal direction. This directly changes the compression ratio of the engine. This also serves as a continuously variable compression ratio unit. This is because the compression ratio can be continuously changed by rotating the thrust bearing 64. Thrust bearing 64 can be rotated relative to plate 82 using any of a variety of methods, as will be apparent to those skilled in the art. Means are also provided for maintaining the track 56 in contact with the thrust bearing 64. This is because, under certain conditions, the inertia of the engine may try to lift the track 56 away from contact with the bearing 64. A stop plate 86 may be provided above the track 56 in an interconnected manner with the power shaft 52. A bushing 88 may be provided between the stop plate 86 and the track 56. Together, the stop plate 86 and the bushing 88 exert a downward force on the track 56 to maintain its contact with the bearing 64. Alternatively, a second variable compression ratio device may be provided above the track and held down. Next, the two variable compression ratio devices can be adjusted simultaneously to adjust and fix the track in place.
[0047]
Since the compression ratio can be continuously changed, a significant advantage is obtained in an internal combustion engine. In addition, the design of the present invention is very simple and effective. The use of the continuously variable compression ratio device in an internal combustion engine will be described in detail below.
[0048]
It is necessary to control the flow rate of gas entering and exiting the combustion chamber 68 during operation of the engine 50. This can be accomplished using any of a variety of known valve devices conventionally known for barrel engines or modified from other types of internal combustion engines. A port design may also be used. In the embodiment shown in FIG. 6, a valve 90 is provided in the head 92 so that intake gas and exhaust gas can flow into and out of the combustion chamber 68. According to the present invention, the upper end of the power shaft 52 may extend into the head 92, and a valve actuation plate 94 is connected to the upper end. The valve actuation plate 94 extends radially outward from the shaft 52 to a position above the upper end of the valve 90. By contouring the valve actuation plate 94, this plate can selectively cause the valve 90 to open and close. Plate 94 is shown as generally flat with a downwardly extending ridge 96 that pushes one of the valves 90 open.
[0049]
Many modifications of the barrel engine 50 shown in FIG. 6 may be made without departing from the scope or teaching of the present invention. As a first example, the track 56 may be rigidly connected to the shaft 52. In this case, a variable compression ratio device, for example, a movable thrust bearing 64, may press both the power shaft 52 and the plate 56 toward the cylinder 54 to adjust the compression ratio. Obviously, in this case, some modification of the power shaft 52 is required. For example, when using the valve actuation plate 94, compensation for changes in the position of the power shaft 52 must be made. As an example, the upper power shaft is connected to the lower power shaft by the splined interconnection portion so that the upper shaft does not change its longitudinal position, but the upper shaft and the lower shaft can rotate simultaneously.
[0050]
As another variation on the design of FIG. 6, a double-ended barrel engine may be provided. In the double-ended design, a cylinder is also provided at the other end of the engine. In the orientation shown in FIG. 6, the bottom plate 82 of the engine 50 is replaced with a cylinder and head similar to the cylinder 54 and head 92. In this case, it is preferable that the piston 66 has a lower cylinder and a downwardly extending portion constituting the piston in the upper cylinder. That is, the piston may be provided in both the upper cylinder and the lower cylinder, and the pistons are connected to each other directly or via a connecting rod. An example is shown in US Pat. No. 5,749,337 to Palatov, the contents of which are hereby incorporated by reference as if forming part of this specification. The advantage of the double-ended design is that the pistons cooperate to avoid non-axial movement.
[0051]
Referring to FIG. 7, another variable compression ratio device is shown. In this embodiment, an adjustable thickness collar 100 is disposed between the track 102 and a flange 104 provided on the power shaft 106. By changing the thickness of the collar 100, the position of the track 102 relative to a cylinder (not shown) can be adjusted, thereby adjusting the compression ratio of the engine. The collar 100 having an adjustable thickness may be adjusted by the action of hydraulic pressure in the same manner as the hydraulic pressure raising device, and adjusted by the hydraulic pressure sent through the power shaft 106. As a variant, a mechanical design may be used, for example an interacting inclined plate or wedge. Again, some type of retainer or second adjustable device may be provided to keep track 102 in contact with collar 100 and flange 104. Alternatively, the adjustable thickness collar 100 may extend between the engine bottom plate 108 and the track 102, similar to the design of FIG. As another alternative, an adjustable thickness collar is provided between the flange on the power shaft 106 and the engine bottom plate 108 or other portion with the track 102 rigidly connected to the shaft 106. Also good. By changing the thickness of the collar, part of the shaft and the track move together. In some of these embodiments, the adjustable thickness collar may further comprise a thrust bearing.
[0052]
Referring now to FIG. 8, another way of maintaining the track 110 in contact with the thrust bearing 112 is shown. A holding collar 114 engages with a flange 116 provided at the lower end of the track 110 to maintain the track 110 in contact with the thrust bearing 112. A similar scheme can be used with the adjustable thickness collar shown in FIG. 7, as with all the variations described above. It should be noted that the various features of this embodiment of the barrel engine and other above-described embodiments can be utilized in different combinations than those shown. As is known to those skilled in the art, variable displacement compressors of various designs have been proposed in the prior art. Some of these designs can be modified to work as the variable compression engine used in the present invention.
[0053]
Referring now to FIG. 9, a modified embodiment of the barrel engine of the present invention is indicated generally at 120. This barrel engine 120 differs from that of the previous embodiment in several respects. Again, a longitudinal power shaft 122 is provided, but this power shaft does not rotate relative to the cylinder 124. In contrast, the power shaft 122 is interconnected with the cylinder 124 to form a rotatable cylinder assembly. An engine housing 126 surrounds the power shaft 122 and the cylinder 124. A track 128 extends inward from the case 126 and forms a cam surface 130 that waves in the longitudinal direction relative to the cylinder 124. The track 128 is preferably movable longitudinally relative to the case 126, but is interconnected with the case so that both the case 126 and the track 128 remain stationary. Splines, teeth or other means that allow longitudinal movement without causing relative rotational movement can be used. A variable compression ratio device 134 is provided between the bottom plate 136 and the track 128 of the case 126 so that the device 134 can change the distance between the track 128 and the bottom plate 136. . As a result, the compression ratio of the engine 120 can be changed by changing the distance between the track 128 and the cylinder 124.
[0054]
In operation, the track 128 and the case 126 remain stationary and the cylinder assembly rotates. The head 138 of the engine 120 may be interconnected to the case 126 so that it also remains stationary. This barrel engine is also of a port design that avoids the use of the pocket valve shown in the previous embodiment. A generally spherical recess 140 provided in the head 138 mates with a corresponding spherical surface 142 formed at the top of the cylinder assembly. As the cylinder rotates relative to the head 138, the openings in the surface 142 and the recess 140 are aligned with each other to allow intake into and out of the cylinder 124. The engine is shown in a position where the opening 144 in the recess 140 of the head 138 is aligned with the opening 146 in the main surface 142 to allow gas communication between the combustion chamber 148 and the intake or exhaust runner 150. Yes. As will be apparent to those skilled in the art, the head 138 and cylinder assembly should be designed so that the ports open and close to provide correctly phased intake and exhaust as the engine rotates. This spherical interface of the recess 140 and the surface 142 also provides a certain sealing advantage. Basically, the seal supported in the opening 146 in the surface 142 is held in place by a spherical interface. In various construction engines, a spark plug, fuel injector and / or glow plug 152 may be provided in the upper end of the cylinder 124.
[0055]
The variable compression ratio device 134 shown in the engine 120 may be of any design described herein, such as adjusting the position of the hydraulic collar, mechanical collar, or track 128. Any other device that allows it to be mentioned. One alternative is to provide a number of independent hydraulic boosters that push upward relative to the track 128 at various locations around the engine.
[0056]
As an alternative to the operation just described for engine 120, case 126 and track 128 may be rotatable, and the cylinder assembly comprises cylinder 124 and power shaft 122, stationary with respect to the case and track. Good. A common feature of the barrel engine embodiments of the present invention is that the cam surface and cylinder rotate relative to each other. The track may be kept stationary when the cylinder is rotating, or the cylinder may be kept stationary when the track is rotating. Each variation provides its own set of advantages and disadvantages that may be selected based on the requirements of a particular application.
[0057]
Referring now to FIG. 10, another variant embodiment of the barrel engine of the present invention is indicated generally at 160. This design example can also be configured as a rotatable cylinder engine in which the cylinder 162 and the power shaft 164 rotate simultaneously. In this variation, a generally flat plate head 166 is interconnected with the case 168 so that the cylinder 162 rotates relative to the head 166. A port opening 170 is shown in the head 166 that allows gas communication between the combustion chamber and the intake or exhaust runner. A modified mechanical variable compression ratio device is shown generally at 172. The variable compression ratio device 172 has a plurality of power screws 174 that engage the lower side of the track 176 and move the track 176 closer to or away from the cylinder 162. In some embodiments, the track 176 may rotate relative to the bottom plate 178 of the case. In this case, a thrust bearing or thrust collar 180 is provided above the power screw 174. The power screws 174 may be individually powered, or the power screws may be chain driven by a chain 182 that is driven by a motor (not shown). The motor may be any type of hydraulic, electrical or mechanical. Also shown is an engine cooling fan 184 that is provided in an opening 186 provided in the case 168 and that directs cooling air against the cylinder 162. This is one alternative that provides cooling to the engine, particularly when the cylinder 162 rotates relative to the case, thereby allowing its own air to be agitated around the cylinder. Liquid cooling systems can also be provided, as will be apparent to those skilled in the art.
[0058]
Various designs of the variable compression barrel engine described herein can be modified in various ways as will be apparent to those skilled in the art. For example, various valve or port designs can be used to provide intake and exhaust effects to the cylinder. The barrel engine design of the present invention can utilize virtually any port or conventional valve design, moving or actuating the valve or port in any of a variety of ways, such as by reference. Examples include the methods described in the incorporated prior art literature. Further, the design of the barrel engine can be changed by changing the angle of the cylinder with respect to the power shaft. Various prior applications of the present applicant describe so-called reverse peristaltic engines and the contents of these prior application specifications are hereby incorporated by reference as forming part of this specification. Various features of these engines can be incorporated into the barrel engine. Also, a barrel engine as defined herein includes other design examples of Applicants for reverse-swing engines as long as the cam surface moves relative to the cylinder and the piston reciprocates within the cylinder. Should be considered. An additional engine design that can be used to provide a variable compression ratio is sometimes referred to as a turning engine. Examples of swivel engines are shown in US Pat. No. 6,019,073 to Sanderson and US Pat. No. 5,992,357 to Tashi. Some swivel engine designs accommodate variable compression ratios and can be used in accordance with various aspects of the present invention.
[0059]
Providing the barrel engine with a variable compression ratio device as defined herein provides many advantages. The compression ratio can be adjusted according to various factors, such as engine speed, engine load, fuel quality and type, and other factors. The variable compression ratio barrel engine can be used with an air cooling system, a liquid cooling system, a 4-cycle system, a 2-cycle system, a spark ignition system, and / or a diesel system, and a system not described herein. The variable compression ratio barrel engine of the present invention is particularly applicable to the combined use with HCCI. Variable compression ratio schemes other than those described herein can also be used with the HCCI combustion scheme. For example, it is possible to provide a variable compression ratio device having a certain type of plunger provided in the engine head or cylinder, wherein the compression ratio of the engine is changed by the movement of the plunger. SAE article 1999-01-3679, the contents of which are incorporated herein as part of this specification, describes such a variable compression ratio apparatus. According to the present invention, such a plunger may be provided in the barrel engine for use with HCCI. Another variable compression ratio design is described in the following patent documents and publications: US Pat. No. 5,329,893 to Dranger et al., US Pat. No. 5,443,043 to Nilsson et al. It is described in the specification and pamphlet of International Publication No. WO92 / 09798 (inventor: Dranger etc.), and the entire description of these technical documents is cited here as forming a part of this specification. This variable compression ratio design for an internal combustion engine can be used in conjunction with the HCCI of the present invention as described in Applicant's US Provisional Patent Application No. 60 / 267,598. The barrel engine may also be modified to use a variable compression ratio scheme similar to the scheme proposed in the cited patent documents and publications. According to the general knowledge of the present applicant, the combined use of the variable compression ratio design and the HCCI combustion method disclosed in the cited technical document is a novel combination.
[0060]
Use of variable compression ratio devices for control of HCCI engines
In particular, the variable compression ratio apparatus disclosed and / or claimed herein provides a particularly good HCCI control method. As the compression ratio increases, self-ignition of the combustible mixture of air and fuel occurs earlier. Conversely, when the compression ratio decreases, self-ignition occurs late or does not occur at all. In a variable compression ratio device, the engine compression ratio should first be set somewhat lower. At start-up, the air / fuel mixture is drawn into the cylinder and compressed by the engine. The compression ratio is slowly increased until autoignition occurs at some or all of the cylinders at or near top dead center. Preferably, the initial compression ratio is set to allow rapid start-up and avoid the release of excess exhaust gas components. The engine should then be run and the compression ratio should continue to increase until combustion phasing is optimized. If combustion begins to occur too early, the compression ratio should be lowered until this condition is improved. In applications where the engine is operated at a constant load and a constant RPM, the compression ratio may be adjusted until optimum conditions are reached and then remain at this setting until the load, speed or other factors are changed. Adjustments may also be made for fuel type or other changes. Engines that produce variations in speed or load, such as automotive engines, require more complex and sophisticated control. In this situation, the engine controller needs to control the compression ratio accurately and quickly to maintain combustion and optimize combustion phasing. Over time, the engine controller can “learn” which setpoint is appropriate under a particular combination of various conditions. By repeating this combination of conditions, the engine controller can return the variable compression ratio to this set value that worked well for these conditions previously.
[0061]
In order for the engine controller to be able to optimize combustion phasing, it is necessary to somehow determine when combustion has occurred in all or some of the cylinders. The novel method disclosed in the present invention uses a knock sensor, for example, a knock sensor found in many engine applications to monitor combustion. Standard methods for monitoring HCCI combustion include various types of pressure transducers that can be placed in cylinders, head bolts, spark plugs or other locations that allow monitoring of pressure conditions in the engine, such as strain gauges and piezoelectric devices, etc. Is used.
[0062]
As with any compression ignition engine, HCCI may make a knocking sound (similar to the knocking sound produced by conventional diesel engines). This knocking sound should be an effective way to monitor combustion. This knocking sound can be detected using a knock sensor or other type of vibration or sound detection device and data can be relayed to the engine control unit.
[0063]
More standard methods of monitoring HCCI combustion are various types of pressure transducers, such as strain gauges, which can be placed in cylinders, head bolts, spark plugs or other locations that allow monitoring of pressure conditions in the cylinders. A piezoelectric device or the like is used. Also, various types of light or electromagnetic radiation sensors may be used.
[0064]
Regardless of whether the engine uses a knock sensor, a pressure transducer, or another device, the feedback from the detection device is sent to the control unit and compared with the mechanical position of the piston at that time . If combustion occurs too early, the control unit sends a signal to the variable compression ratio device to lower the compression ratio of the engine. By reducing the compression ratio, the pressure / temperature necessary to ignite the air / fuel mixture is reached when the piston is located near top dead center. In order to allow the engine to accept a large amount of fuel and to ensure that combustion always occurs at the optimal time, the control unit is instructed until the combustion sensor indicates that combustion is taking place too early. Stably increase the compression ratio. In order to increase the speed at which the engine can navigate the changing load and RPM range, the control unit learns to map what the ideal compression ratio is under various normal circumstances. be able to. Such a map may be somewhat generic. This is because the map needs to be continuously updated and overwritten by variables from any given period. In addition to the conventional necessary elements, the engine system may have a sensor at the fuel tank that indicates to the control unit that the fuel tank can be opened to accommodate different fuels. Other schemes for determining fuel type and quality may also be used, such as manual input, use of various fuel sensors and other schemes. In this case, as a precautionary measure, the control unit starts the engine at a low compression ratio so that combustion does not occur prematurely (if it occurs prematurely, engine damage may occur) In addition, the compression ratio is slowly increased until ideal combustion is reached. Additional precautionary measures of this kind can be taken by manipulating the undulating trajectory gradient so that it has a slow compression stroke near the TDC and a steep power stroke near the TDC. it can. Such a structure minimizes the mechanical advantage that the piston will receive if combustion occurs too early.
[0065]
An additional option for using a knock sensor in line with the policy of which knock sensor to use in non-HCCI applications is to detect knock using the knock sensor. This system provides feedback from sensors that measure crank angle, engine speed, engine load, engine temperature, and other parameters, and indicates exact variable compression ratios or other phasing adjustment values for various engine operating parameters. Compare with a comprehensive control map. While following the reference map, if the knock exceeds a certain tolerance limit, the engine control unit directly reduces the compression ratio and then updates the reference map or is usually used for another fuel. Switch to another control map, or update the current control map and follow new instructions that probably recommend a reduced compression ratio. In order to keep the control map updated and maintain optimum efficiency and power, the control unit will gradually increase the compression ratio of the engine from time to time until the engine begins to knock. When this self-induced knock begins to occur, the control unit gradually reduces the compression ratio or gradually suppresses any other phasing device until the knock is over. A record of when this knock begins to occur or when it stops and the operating conditions of the engine at this point are recorded and used to keep the control map continuously updated.
[0066]
FIG. 39 shows a control system comprising a plurality of sensors and a control device in communication with the engine control device. Appropriate engine control can be performed using various combinations of the illustrated elements.
[0067]
Combustion phasing control
In HCCI engines, it is very important to control combustion phasing. Premature self-ignition not only reduces engine efficiency, but can also have a destructive effect on the engine. If combustion occurs too late, engine efficiency decreases. If the conditions are far from optimal, combustion may not occur at all. At high loads, phasing of combustion in HCCI engines becomes increasingly difficult and must be very accurate to prevent detonation (explosive combustion) or pre-ignition (pre-ignition). Currently, high load HCCI is very difficult or impossible to achieve at normal piston speed without problems with detonation and / or pre-ignition prior to TDC.
[0068]
In the past, high load HCCI combustion systems could only be achieved at very high piston speeds. This is because the duration of HCCI combustion is determined by time, not crank angle, regardless of engine RPM. Thus, at high piston speed, if ignition occurs before TDC, the mixture will still not have time to burn completely until the piston passes TDC. Unfortunately, high piston speed is unacceptable for reliable operation, and therefore HCCI combustion is limited to low loads that can better control the process.
[0069]
At normal piston speed, it is difficult to stabilize the air / fuel mixture long enough to pass TDC without causing premature ignition. If the engine compression ratio is reduced or other means are used to delay the crank angle or crank angle equivalent that reaches autoignition until the mixture is near TDC, fuel may not ignite during some cycles There is. There is a delicate balance between early ignition on one side and failure of ignition on the other.
[0070]
In light of the above, it is important to provide a method for controlling combustion phasing, particularly in engines that are subjected to various speeds and loads. As described above, the combustion phasing can be controlled by the variable compression ratio. However, other schemes for controlling combustion phasing can also be utilized alone or in combination with one or more other methods. Some of these methods of controlling combustion phasing are applicable to combustion schemes that are not HCCI.
[0071]
Corona discharge device
One method of controlling combustion phasing is to use ozone (O) using a corona discharge device in the intake system._Three) Is introduced into the air-fuel mixture to change the reactivity of the mixture. Corona discharge devices (CDD) (also commonly referred to as plasma generators or non-thermal plasma generators) can utilize alternating current or direct current, and such corona discharge devices can be placed in the intake manifold of the engine. Place ozone (O_Three), Ions and radicals may be introduced or generated in the intake air or mixture. Corona discharge devices may be placed before or after the fuel injector depending on what produces the most favorable results or what best fits the location of the fuel injector.
[0072]
For purposes of definition, a corona discharge device is a device that uses a high voltage to ionize a gas in its vicinity. Atmospheric oxygen (O₂) Is ionized, the atoms recombine and O_Three(Ozone) can be generated. O_ThreeIs a powerful low-temperature oxidant that is often manufactured commercially to be used to remove odors from automobiles and homes. The corona discharge device can be of several designs and can generate a thermal or non-thermal plasma. One design example used in an automobile exhaust system to generate ions is described in SAE article number 2000-01-3088, and the contents of such SAE article form part of this specification. Cite here as what to do. The design examples described in such cited papers can be used as part of the present invention or can be modified for use as part of the present invention. Other designs will be apparent to those skilled in the art. For the purposes of the present invention, a corona discharge device can be defined as any instrument that ionizes gas or generates radicals. The reactivity of the air-fuel mixture can be changed by introducing radicals into the intake air. By changing the reactivity of the mixture, the phasing or initiation of combustion can be controlled within certain limits. The reactivity of the air-fuel mixture can be changed by increasing radicals in the air-fuel mixture or generating radicals in the air-fuel mixture. It is considered that combustion phasing in the HCCI engine proceeds by increasing the amount of radicals, and combustion is delayed by decreasing the amount of radicals. The amount of radicals generated and thus the reactivity of the mixture can be varied by changing the voltage or duty cycle of the corona discharge device. In some cases, the current can be adjusted. The amount of radicals generated can also be varied by employing a corona discharge device with multiple elements (corona wires, dielectrics or similar components) or by using multiple corona discharge devices. In a corona discharge device having a large number of elements, the amount of radicals generated is controlled by bringing various numbers of elements into an operating state or a non-operating state. When a large number of corona discharge devices are used, the amount of radicals generated is controlled by putting various numbers of corona discharge devices into operating states at different times. Regardless of what type of corona discharge device is used, it is preferred that the engine control unit be in communication with and control the corona discharge device to optimize combustion phasing.
[0073]
Using a corona discharge device for adjustment of combustion phasing can be performed alone or in combination with any other feature of the present invention. Further, the corona discharge device may have a use other than the HCCI engine. Introducing radicals into compression ignition engines, such as HCCI, diesel, compression ignition natural gas engines and other types of engines, may help improve combustion and achieve compression ignition. To reduce the compression ratio required. There are also applications for improving the degree of combustion in spark ignition engines.
[0074]
In one combination example, one or more corona discharge devices are used in combination with a continuously variable compression ratio device to improve control of the HCCI engine. Corona discharge devices should be a quick and effective means of changing the reactivity of the air-fuel mixture and combustion phasing, thereby reducing the demands placed on the continuously variable compression ratio device. In certain applications, it is possible to eliminate the need for a continuously variable compression ratio device and to control the phasing of combustion by a corona discharge device. However, in most cases, corona discharge devices are used in conjunction with continuously variable compression ratio devices and / or other phasing devices or techniques. The purpose is to further enhance engine performance in response to changes in load and speed and different fuels.
[0075]
FIG. 11 is a schematic diagram of a combustion cylinder 190 that houses a piston 192. A combustion chamber 194 is formed between the piston 192 and the closed upper end of the cylinder 190. An intake runner 196 is shown in communication with the combustion chamber 194. The intake valve selectively closes the intake runner 196 from the combustion chamber 194. An exhaust runner and valve (not shown) are also provided in the working engine. It should be noted that the combustion chamber is configured in a cylinder containing a reciprocating piston in many of the illustrated examples, but the present invention is not limited to this configuration and can be used in other configurations. Also, a port design example or another valve design example can be utilized in place of the illustrated conventional valve without departing from the scope of the present invention.
[0076]
In FIG. 11, the corona discharge device 200 is shown in a state of being provided in the closed upper end portion of the cylinder 190. A second corona discharge device 202 is shown provided in the intake runner 196. It is presently preferred to position the corona discharge device in the intake system before or after the addition of fuel. However, as an additional example or modification, a corona discharge device arranged to introduce radicals directly into the combustion chamber may be provided. In one embodiment, corona discharge devices are provided in the main intake system to bring radicals to multiple cylinders. Further, since an additional cylinder-specific corona discharge device is used when averaging the variation among the cylinders as will be described below, it is preferable that the cylinder-specific corona discharge device is provided in each intake portion of each cylinder of the engine.
[0077]
In order to minimize unburned hydrocarbon (HC) exhaust gas components, it may be advantageous to provide one or more corona discharge devices, such as corona discharge device 200, in the head region or wall of each cylinder. Its purpose is to ionize the air or air / fuel mixture near the inner surface of the cylinder. It is possible to use cylinders and / or heads and / or pistons as actual elements of the corona discharge device. Such a configuration provides for complete ionization of the air or air / fuel mixture located near and / or in contact with these regions. Perhaps the best way to do this is to use a ceramic coated cylinder or cylinder liner as the dielectric. Ionization is most concentrated in the gap area between the piston crown and the cylinder and in the area where the head is adjacent to the cylinder. It is in these areas that most hydrocarbon emissions occur and the greatest improvement can be achieved.
[0078]
Another way to improve combustion efficiency is to place the microwave generator in a cylinder. The microwaves ionize the air / fuel mixture near the surface on which they strike. Microwaves may also increase the efficiency of preventing quenching by using water to accelerate the evaporation rate of wet surfaces. Gamma or X-ray, infrared or other electromagnetic devices placed in the cylinder can also provide similar effects. However, these effects on water are not the same. It is also possible to use a cathode to generate electrons in the cylinder to aid ionization.
[0079]
Quick compression device
Another way to control HCCI combustion phasing is to use a rapid compression device. For the purposes of the present invention, a quick compression device is an auxiliary device (ie, a main compression device, eg, a device other than the primary piston of a reciprocating piston engine) that quickly increases the compression level in the combustion chamber at a particular time. In HCCI engines, a quick compression device is used to initiate combustion. For example, the compression ratio of the HCCI engine may be set so that the combustible air-fuel mixture in the combustion chamber is not compressed to the extent that it causes self-ignition. In this case, the compression pressure in the combustion chamber can be increased sufficiently to start self-ignition using the quick compression device at approximately the top dead center. When using a quick compression device to assist ignition, the reactivity or time temperature history of the air / fuel mixture can be kept stable by reducing the compression ratio or any other means, and It is likely to be altered (continuously or permanently) so that detonation or pre-ignition does not occur until the crank angle or crank angle equivalent where ignition is desired to occur or beyond. When the engine reaches the correct mechanical position, combustion begins by quickly compressing the mixture until it self-ignites. Since this rapid compression is not easily done directly by the piston, it is possible to initiate a successful HCCI combustion by self-igniting the mixture at or after the TDC. Quick compression can be used to extend combustion load range, when it becomes difficult to properly phase combustion, and to reduce vibration and / or pressure rise in the engine. It is good to adopt when it can be used. Using a rapid compression device is likely to avoid HCCI pre-ignition, especially at high loads. By causing rapid compression at or near the TDC (the purpose is to reach high temperatures and pressures that are sufficient for self-ignition), piston speeds that exceed compression phasing are required It can be controlled without.
[0080]
Rapid compression can be achieved by a number of mechanical means, such as plungers, compressed gas injectors, hot gas injectors, etc., or by using indirect combustion chambers, stratified charge, pilot charge and other means. Also, similar effects can be achieved using light, sound waves, vibrations, various types of radiation, magnetic fields and other means. However, in order to maintain the lowest possible emissions and manufacturing costs, the use of a rapid compression apparatus and the method described below would be preferred.
[0081]
A mechanical quick compression apparatus is shown in FIG. 12, which is disclosed in U.S. Pat. No. 6,260,520 to Van Leatherford (note that such U.S. Pat. The description is hereby incorporated by reference as forming part of this specification). FIG. 12 is a schematic view of the combustion chamber 212 formed between the upper end of the piston 214 and the closed upper end of the cylinder 212. Other components required for the engine, such as the intake runner, exhaust runner and valves or ports, have been omitted for clarity of the drawing. A mechanical quick compression device is provided in the closed upper end of the cylinder. The device has a movable plunger 216 disposed in a chamber or passage 218. By moving the plunger 216 toward the combustion chamber 210, the compression level in the combustion chamber 210 can be quickly increased. For example, the plunger may be retracted somewhat relative to the closed top end of the cylinder 212 during the piston compression stroke. Next, at or near the top dead center, the plunger is quickly moved downward. The purpose is to help increase the compression level in the combustion chamber 210 quickly to facilitate self-ignition.
[0082]
Next, another method for preparing a quick compression apparatus will be described with reference to FIG. Again, a schematic view of the combustion chamber 220 is shown formed between the piston 222 and the closed top end of the cylinder 224. In this example, intake valves and passages are also shown. However, other valves as well as other port designs can be used. The auxiliary chamber 226 is shown in gas communication with the main combustion chamber 220. The spark plug 228 has an electrode that extends into the auxiliary chamber 226 to introduce sparks into the auxiliary chamber 226. A spark arrester or flame arrester 230 is disposed between the main combustion chamber 220 and the auxiliary chamber 226 such that gas passing between the two chambers passes through the arrester 230. During operation of an engine using a rapid compression device of this design, a combustible mixture of air and fuel is introduced into the main combustion chamber 220. Some percent of this mixture will naturally flow through the arrester 230 into the auxiliary chamber 226. When the piston 222 moves upward and compresses the air-fuel mixture, a combustible air-fuel mixture at a higher rate is pushed into the auxiliary chamber 226. At about the top dead center, a spark is introduced into the auxiliary chamber 226 by the spark plug 228. The spark burns a portion of the air-fuel mixture in the auxiliary chamber 226, thereby producing hot gaseous combustion products. Due to combustion, this combustion product expands very quickly and is pushed back through the arrester 230. As this passes through the arrester 230, the flame and sparks disappear, so that only the hot gas product enters the main combustion chamber 220 in the absence of a flame. Thereby, the compression level in the main combustion chamber 220 rises rapidly. Preferably, combustion in the auxiliary chamber 226 occurs near top dead center, and the rapidly leveling compression later caused in the main combustion chamber 220 causes self-ignition of the air-fuel mixture in the main combustion chamber 220. Enough. Although a conventional design of spark plug 228 is shown, other designs as well as other devices for igniting the air-fuel mixture in the auxiliary chamber can be used. The combustible air-fuel mixture can be introduced into the auxiliary chamber by a method other than the method described above. For example, a combustible mixture can be injected or drawn into the auxiliary chamber via an injector or some type of valve. Further, the air-fuel mixture in the auxiliary chamber may be different from the air-fuel mixture in the main combustion chamber. Additional fuel can be injected into the auxiliary chamber to produce a rich mixture. Other fuels can also be used.
[0083]
For the purposes of the present invention, a spark or flame arrestor is any device that allows the passage of gas but blocks or extinguishes all or most of the flame or spark in the gas. The flame arrestor may be composed of a number of different materials and can be configured in a wide variety of ways. It may be important to prevent the frame arrester from overheating. Possible problems with overheating are solved by composing the arrester from a material that can withstand high temperatures, such as ceramics or alloys of tungsten nickel and iron or other refractory materials, or by providing a method for cooling the arrester. it can. In order to cool the arrester, it may be necessary to simply retract the arrester side end of the rapid compression device into the engine head. Retracting the arrester into the head is sufficient to remove enough heat from the rapid compression device, whether the engine coolant is in direct contact with the rapid compression device or the metal near the rapid compression device. Cooling will be obtained by the engine, whether or not it remains cooled. A flame arrester is used to generate heat from a large number of perforated plates, a single perforated plate, a mesh matrix, a long tube, a series of long tubes arranged in parallel or in series with each other, a series of baffle plates or gases. It may consist of any other means that can extinguish the flame without taking too much. It is also possible to extinguish the flame with careful arrangement or stratification of EGR (recirculated exhaust gas), or with air in the quick compression device or engine main combustion chamber.
[0084]
The rapid compression device utilizing the spark ignition combustion system of the present invention has the side effect of introducing high temperature charge air into the main combustion chamber, and additionally serves to induce or facilitate self-ignition. Of free radicals or combustion by-products. As the pressure increases in the chamber of the rapid compressor, most of the charge air during combustion is pushed into the flame arrester and disappears prior to complete combustion. Therefore, in many cases, the partially burned fuel having a higher reactivity than the unburned fuel is injected into the main combustion chamber of the engine. This may increase the reactivity of the air / fuel mixture and help initiate autoignition.
[0085]
14 and 15, an additional embodiment of a rapid compression device utilizing combustion is indicated generally at 232. FIG. 15 shows the quick compression device 232 itself, and FIG. 14 shows the device 232 in the top of the engine in communication with the combustion chamber 234. In the embodiment of FIG. 13, the auxiliary chamber is provided in the engine, for example, in the head of the engine. Thus, it is necessary to form an auxiliary chamber in the head or block. The configuration of FIGS. 14 and 15 provides a spark plug-like device that is screwed into a screw hole provided in the engine head and extends into the combustion chamber 234.
[0086]
Device 232 has a body 236 in which chamber 238 is formed. The outer portion of the body 236 is threaded or otherwise configured to engage an opening provided in the engine to place the chamber 238 in gas communication with the combustion chamber 234 in the body 236. Has been. The chamber 238 has an opening filled with a gas permeable spark arrester 240 so that gas flowing between the chamber 238 and the combustion chamber 234 passes through the arrester 240. An electrode 242 extends into the chamber 238 of the body 236 to introduce a spark. The quick compression device 232 operates according to the same steps as described with reference to FIG. As shown, the electrode 242 is a portion of a spark plug 244 that is screwed into an upper opening into the chamber 238. However, the spark generating electrode may be formed as part of the entire device 232 rather than as part of the spark plug removable from the device 232. In addition, other types of spark generating devices and other methods for igniting the air-fuel mixture in the chamber 238 can be used. The device 232 has the advantage that the body 236 can be removed from the engine for replacement or cleaning. For example, it may be necessary to periodically replace the spark arrester 240 during engine operation. In the form of using a spark plug, the spark plug can also be replaced.
[0087]
FIGS. 16-25 show a modified embodiment of a quick compression device utilizing a spark ignition combustion scheme similar to that described above. The various features of each of these devices can be combined in different ways than shown. In the embodiment of FIG. 16, the apparatus 250 is provided near the bottom of the chamber and has a baffle plate 252 that facilitates the generation of turbulence and / or vortices in the combustion products exiting the chamber and the chamber. is doing. FIG. 17 shows another form of rapid compression device in which a turbine type blade 254 is provided in the chamber to facilitate the generation of vortex flow. In the form of FIG. 18, the body 256 extends downward beyond the arrester 258, which has an end cover 262 with a nozzle 260 on the side. This creates a convoluted path to and from the chamber 264 that facilitates the generation of vortices. Also, the nozzle 260 can be directed in various ways so that the hot gas flowing out of the quick compression device can be directed into the combustion chamber as desired. Further, the nozzle 260 may be inclined to facilitate the generation of vortex. The end plate 262 can also provide some protection for the flame arrester 258 so that pressure waves in the main combustion chamber do not hit the flame arrester 258 directly. Various designs of nozzles, as well as other features just described, can be utilized in the embodiment of FIG.
[0088]
FIG. 19 shows another alternative embodiment in which the body 270 is very compact and the frame arrester 272 is provided in the side of the body 270. The frame arrester 272 may be a circumferential ring or may be located within an individual window provided on the side of the body 270.
[0089]
20-23 are various views of a spark plug modified to operate as a quick compression device. FIG. 20 shows a conventional spark plug 274. In FIG. 21, the spark plug 274 has a modified ground electrode 276 that forms an arch on the center electrode 278. FIG. 22 is an end view showing the ground electrode crossed in the form of a cross on the center electrode. In FIG. 23, a frame arrester 280 is attached to or integral with the cross-shaped electrode 282. The spark arrester 280 surrounds a region around the center electrode so as to form a chamber into which a spark is introduced by the generation of electricity between the center electrode and the electrode 282 or the spark arrester 280. As a result, a combustion flame is generated inside the flame arrestor 280, and this combustion flame disappears when passing through the arrester 280.
[0090]
FIGS. 24 and 25 show a quick compression device that is shaped like a typical spark plug, but includes a molded spark arrester 284 instead of a ground electrode. The spark arrester forms a dome on the center electrode.
[0091]
FIG. 26 schematically illustrates the general concept obtained by some of the rapid compression devices described above. Basically, the large combustion chamber 290 is separated from the auxiliary chamber 292 by a flame arrester 294. An ignition source 296 (which can be any method of igniting the combustible mixture in the auxiliary chamber 292) is also provided.
[0092]
Next, another design example of the quick compression apparatus will be described with reference to FIG. As described in various embodiments of the quick compression device using the spark ignition combustion method, the compression level in the combustion chamber can be increased by injecting pressurized gas. The rapid compression apparatus of FIG. 27 has a gas injector 300 that communicates with the combustion chamber 302. The gas injector 300 is operable to send pressurized gas into the combustion chamber to quickly increase the compression level in the combustion chamber 302. In the illustrated embodiment, a pressurized gas source 304 is provided along with a controller 306 that controls the flow of gas to the gas injector.
[0093]
Other schemes that allow hot gas injection into the combustion chamber are available. For example, high temperature and high pressure exhaust gas from one chamber can be directed to the second combustion chamber when the second combustion chamber is near top dead center, resulting in a quick compression level effect by adding hot exhaust gas, Thereby, self-ignition may be triggered. FIG. 28 provides one form of using exhaust gas from combustion that is used later for rapid compression purposes. In FIG. 28, the combustion chamber 310 is formed between the piston 312 and the closed upper end of the cylinder 314. When the auxiliary chamber 316 is separated from the main combustion chamber 310 by the valve 318 and the valve 318 is opened, the auxiliary chamber 316 is in gas communication with the main combustion chamber 310 and when the valve 318 is closed, the two chambers are mutually connected. It comes to be separated. As shown in the figure, the auxiliary chamber 316 is configured to be directly separated from the main combustion chamber 310. However, the auxiliary chamber may be provided in other ways that allow gas communication between the two chambers. Moreover, you may use the valve of arbitrary designs which can connect and isolate | separate these chambers mutually selectively. For example, a rotary valve may be preferred depending on the application. As yet another approach, the auxiliary chamber 316 may also communicate with other parts of the engine, such as the intake runner 320 or the exhaust runner 322.
[0094]
In operation, combustion occurs in the main combustion chamber 301, thereby producing a pressurized gaseous combustion product. Next, a part of the product is captured in the auxiliary chamber 316 and held in the auxiliary chamber 316. As an example, valve 318 may be held partially open during a combustion event in main combustion chamber 310. Alternatively, the valve 318 may be opened at some point during the expansion or exhaust stroke, for example, after the initialization or start of combustion. The valve 318 is then closed so that a portion of the pressurized gaseous combustion product is retained in the auxiliary chamber 316. During the next combustion cycle, the air / fuel mixture is compressed in the combustion chamber 310. At or near top dead center, valve 318 is opened to release pressurized gaseous combustion products from auxiliary chamber 316 into main combustion chamber 310. This preferably increases the level of compression in the combustion chamber 310 quickly enough to initiate self-ignition. The process should then be repeated.
[0095]
Alternatively, gaseous combustion products may be captured from one chamber and used in another chamber to initiate rapid compression and autoignition. As an example just described, if the two combustion chambers are 90 ° apart in phase, a portion of the gaseous combustion product is advanced 90 ° after combustion at the top dead center, and the top dead center from the first combustion chamber is reached. At or near the second combustion chamber. This turning of the pressurized gaseous combustion product is sufficient to initiate self-ignition in the auxiliary combustion chamber. Other variations of this scheme will be apparent to those skilled in the art.
[0096]
With a rapid compression device as described herein, the combustion phasing of any design or form of HCCI engine can be controlled, such a rapid compression device alone or any other of the present invention. Can be used in combination with features. These quick compression devices may be located in the engine head or elsewhere as shown. Also, two or more quick compression devices can be used for each chamber, or two or more types may be provided in a single engine. The preferred embodiment uses a quick compression device in the barrel engine configuration, which may further include a variable compression ratio device, such as described above. In an HCCI engine that combines a variable compression ratio device and a rapid compression device, the compression ratio of the engine should be reduced when reaching or reaching the point where pre-ignition and / or detonation begins to occur. If the compression ratio after reduction is not sufficient to maintain HCCI combustion, a rapid compression device may be used to initiate combustion. The quick compression scheme may be applicable to other engine configurations. The rapid compression apparatus using the spark ignition combustion system described in this specification has a wide range of applications, and examples of such applications include applications other than internal combustion engines.
[0097]
Another method of preferred rapid compression is similar to the auxiliary chamber shown in FIG. 13 and uses an auxiliary chamber within which HCCI or auto-ignition allows for rapid compression of the main combustion chamber. In order to prevent quenching and to ensure that the temperature in the auxiliary chamber remains high enough to cause autoignition here first, some form of insulation, for example a type of ceramic coating, is placed in the auxiliary chamber. Probably necessary. Alternatively, an auxiliary chamber of ceramic composite material may be configured or a ceramic insert may be used.
[0098]
In an HCCI engine using an HCCI powered rapid compression system, the reactivity or time temperature history of the air / fuel mixture is determined by decommissioning the mixture in the main combustion chamber before top dead center by reducing the compression ratio or any other means. It is changed (continuously or permanently) so that it can remain so stable that it does not cause premature ignition. If a quick compression device is not provided, it may be necessary to adjust such reactivity to a sufficiently low level if the engine passes through top dead center without igniting the mixture. As the engine approaches top dead center, HCCI combustion occurs in the auxiliary chamber in front of the main combustion chamber due to the high temperature and radicals in the residual exhaust gas remaining in the narrow auxiliary chamber. The pressure and heat resulting from HCCI combustion in the auxiliary chamber pressurizes the main combustion chamber and facilitates HCCI combustion. Since conditions in the small auxiliary chamber were more advantageous for HCCI combustion than conditions in the main combustion chamber, the time when the auxiliary chamber provides enough pressure to start combustion in the main combustion chamber from the time combustion begins to occur in the auxiliary chamber There is a delay. This delay needs to be sufficient to allow the main charge to be located very close to or past top dead center before self-ignition.
[0099]
Since the auxiliary chamber uses the HCCI combustion method, if a flame arrester is necessary, it may not be necessary. If the auxiliary chamber does not require a flame arrestor and a spark plug is provided in this chamber, the flame from the spark plug can propagate from the auxiliary chamber into the main combustion chamber. Accordingly, the engine can function in both the spark ignition mode and the HCCI mode without providing an ignition plug outside the auxiliary chamber. This leaves more space in the engine head. This also allows the use of a compact integral screw in the apparatus that is similar in form to that shown in FIGS. 15, 16, 17, 18, and 19.
[0100]
The preferred embodiment of this device is very similar to the embodiment shown in FIG. 15, but does not have a frame arrester. As described above, it is important to thoroughly insulate the inside of the auxiliary chamber. Ideally, the engine starts in spark ignition mode and remains in spark ignition mode until the auxiliary chamber reaches a temperature that is so high that HCCI autoignition occurs in the auxiliary chamber before it occurs in the main combustion chamber. At this point, the engine returns to HCCI mode, and compression from HCCI combustion in the auxiliary chamber facilitates HCCI combustion in the main combustion chamber.
[0101]
It is advantageous if a type of corona discharge device is provided in the auxiliary chamber to produce a high mixture reactivity in this region, so that autoignition first occurs here. The spark plug can be modified to double as a corona discharge device. Moreover, it may be advantageous to provide a heating means.
If the combustion stability provided by this rapid compression device (or any of the above-mentioned rapid compression devices) is sufficiently high, a preset ignition point can be used and no adjustable phasing is required. Is possible. However, with this device, it would be possible to control phasing in the same way as any type of HCCI engine, partly because it uses HCCI only in a two-stage manner. It would be best to supplement this device with a phasing method to maintain fuel flexibility.
[0102]
As in the case of the spark ignition quick compression device described above, the air-fuel mixture in the auxiliary chamber may be different from the air-fuel mixture in the main combustion chamber. Additional fuel may be injected into the auxiliary chamber to produce a rich mixture. Different fuels can be used.
Again, there are applications for this arrangement in other types of compression ignition engines and lean burn engines, such as lean natural gas engines.
[0103]
Another way to provide a quick compression device is by providing an opposed piston design in a crank drive engine design or a barrel engine design. In the opposed piston design, two pistons reciprocate in the same cylinder, and a combustion chamber is formed between the pistons. In an HCCI opposed piston engine, a combustible mixture of air and fuel is introduced between the two pistons and then the piston is moved to compress the mixture until it self-ignites. The pistons should be completely in phase, i.e. they reach top dead center at the same time or somewhat out of phase. For example, if one piston is somewhat out of phase with the other piston, the first piston may have slightly passed through top dead center when the second piston reaches top dead center. The second piston then acts as a quick compression device and causes self-ignition. This can effectively shorten the time for the entire engine to pause at top dead center. In the barrel engine design, an opposed piston design can be provided by placing a central set of cylinders around the central power shaft. The cylinder has two open ends that are directed to opposite ends of the engine. A first set of pistons is provided in the first end of the cylinder, and a second set of pistons is provided in the second end of the cylinder. A track is provided at each end of the engine and this track is in mechanical communication with one of the piston sets. As the track rotates, the piston reciprocates within the cylinder, resulting in various strokes of the combustion cycle. Various designs can also be applied to the crank drive engine. In one example, the inverted “V” design has two rows of cylinders that meet in a “V” state at the normally closed end of the cylinder. In this case, two cranks are provided to operate the pistons on opposite sides of the “V”.
[0104]
In addition to the rapid compression method described above, another method of rapidly compressing the mixture near, at or after TDC is to quickly compress the remaining charge and facilitate HCCI combustion. To produce some kind of flame kernel (smaller is better). By igniting a small portion of the charge air using lean combustion, conventional combustion, or some type of pilot charge, the rapid heating of the local area increases the internal pressure of the entire combustion chamber and increases self- Start ignition.
[0105]
For purposes of definition, lean combustion is generally similar to a typical SI combustion cycle, but can be described as a cycle occurring at an ultra lean air / fuel ratio. In general, special methods must be implemented to obtain reliable and complete ignition under lean conditions. Lean combustion is similar in many respects to that of the SI cycle, but combustion is not always initiated by a spark. Lean burn can be initiated with conventional spark plugs, plugs specially designed for lean burn, corona injection, pilot charge and many other means, most of which are known in the art. It has been.
[0106]
Rapid when combustion phasing becomes difficult or impossible to control by other means, or when a suitable compromise between early ignition and unreliable incomplete combustion cannot be found Good compression should be used. In the case of a variable compression ratio engine, the compression ratio should be reduced to reduce or eliminate early ignition and detonation. At this point, the compression ratio is probably not high enough to provide reliable self-ignition. In order to self-ignite the mixture, it is preferable to generate small lean combustion flame nuclei, for example by means of spark plugs. The flame kernel causes a rapid heating of the local area, which causes the flame kernel to expand and quickly compress the remaining unburned charge. This additional compression (although this is not important) may be sufficient to facilitate reliable self-ignition. The spark timing is adjusted for when the flame kernel becomes so large that it will auto-ignite the mixture at a desired time. By creating a flame kernel at top dead center, premature ignition never occurs, but it may be desirable to advance or retard this ignition point under various conditions. When extending the range of HCCI with a lean flame kernel, if this range can be expanded too much, the flame kernel is no longer considered lean and is in fact the theoretical level.
[0107]
Another rapid compression method is to create an in-cylinder environment that does not lead to lean combustion and use a lean combustion igniter to create a flame kernel that cannot propagate beyond the immediate vicinity of the igniter. Such a method may include a high power spark igniter that can spread the spark over a large area. When a spark from this device passes through the mixture, only the mixture that is directly in the spark path or located very close to the spark is ignited and cannot propagate through the remaining mixture. However, rapid heating of this region may still be sufficient to initiate autoignition. It is also possible to use vortex chamber spark plugs, plasma injectors, some of the devices that do not use the flame arrestor proposed earlier in this application, pilot charge and other means of achieving a similar effect. . Yet another way to initiate self-ignition that can be used in the present invention is to use a plasma injector. For the reasons given in the previous specification section describing the hot gas injection and spark plug quick compression device, the present application is also layered enough to extinguish the flame kernel before it can propagate through the entire chamber. Proposing the use of in-cylinder hydrodynamics or a new injection scheme that is carefully organized for fuel and / or air and / or EGR (recirculated exhaust gas) to provide composting as an additional rapid compression method Yes. In a carefully organized stratification scheme, the combustion of the engine by conventional or non-conventional ignition means is sufficient to initiate self-ignition of the remaining mixture without causing the flame to propagate through the entire chamber. It is possible to create a flame kernel in a part of the chamber. This can be achieved by promoting good conditions for ignition in the area around the spark plug, pilot charge or other igniter and promoting good conditions for self-ignition of the remaining mixture. . Between these two prepared regions, an inert gas or rare gas barrier is provided. This barrier may consist of EGR, air or other gas, and this barrier is too dilute for the flame to propagate. However, this barrier allows the prepared mixture located beyond this to self-ignite by compression from the flame kernel.
[0108]
Dual mode engine
Depending on the application, it may be desirable to provide an engine that sometimes operates in HCCI mode and at other times as a spark ignition or diesel engine. Variable compression ratio devices are particularly useful for this application. In dual mode engines, it may be advantageous to employ partial time or full time lean combustion as an intermediate mode to help crossover between HCCI and spark ignition or diesel mode.
[0109]
As explained earlier in this application, an HCCI engine has a power output that is 50-75% of the power output of an equivalent diesel or SI engine. As a remedy for this problem, it is possible to adopt a dual mode system that works in HCCI mode when the engine is up to 75% load and then returns to SI or diesel mode if higher power is required.
[0110]
A dual mode design can also be utilized to facilitate starting the HCCI engine. As mentioned above, the compression ratio of the variable compression ratio HCCI engine needs to be adjusted to establish starting conditions. Thereby, an excessive exhaust gas component may occur at the time of starting. Alternatively, the engine may be started as a spark ignition engine and then switched to HCCI once it is running. This enables rapid catalyst warm-up operation and allows the engine to reach a stable operating temperature before returning to the HCCI mode.
[0111]
One method of mode switching is to gradually allow lean burn flame nuclei to propagate further into the combustion chamber before the remaining charge self-ignites. Eventually, the flame will propagate through the entire charge and the engine will operate in lean burn mode. As an example, the engine compression ratio is slowly decreased and / or the ignition timing is adjusted. When reducing the compression ratio, the flame kernel will propagate further into the combustion chamber before it can self-ignite the remaining charge (and must propagate before self-ignition occurs). Eventually, the flame will propagate through the entire charge and the engine will operate in lean burn mode. As the load increases, the air-fuel ratio becomes deeper and the engine enters the conventional theoretical spark ignition mode. This occurs in a fraction of a second depending on the operating conditions, but such a gradual crossover differs from the case where the engine changes directly from HCCI to spark ignition mode, where the compression ratio or the throttle position of the engine is abrupt. No change is required.
[0112]
Another method is to switch directly from HCCI mode to intermediate lean combustion mode. This can be used when trying to expand the range of the HCCI mode using lean burn nuclei. As an example, an engine quickly reduces its compression ratio to an acceptable compression ratio for reliable lean combustion. At the same time or shortly thereafter, the engine will operate in lean burn mode. Since the air-fuel ratio at the upper end of the HCCI mode and the lower end of the lean burn mode are not very different, the engine will probably still operate with the throttle wide open. It is certain that the power output during lean burn mode is controlled by adjusting the richness of the mixture as in the HCCI mode. Increasing the load will cause the mixture to become thicker.
[0113]
For both of the above methods, depending on the required air / fuel ratio, the NO during lean burn mode_x  Emissions may not be accepted if the engine remains in this mode for a period of time. In such cases, lean burn mode is used only to facilitate the conversion process, and the control unit slightly expands the range of HCCI mode, or the engine converts the load range of spark ignition mode over a long period of time. The engine is programmed to minimize the time it operates in this mode by decreasing it when it is operating at or near the threshold.
[0114]
Water jet
Another way to control combustion phasing in an HCCI engine is to use water injection. A schematic of the combustion chamber and water injection system is shown in FIG. The combustion chamber 350 is formed between the piston 352 and the closed upper end of the cylinder 354. A water injection nozzle 356 is shown in communication with the combustion chamber 350 so that a spray of water can be provided to the combustion chamber 350. A second water injector is shown in communication with the intake runner 360. Water injection means may be provided at one or both locations to introduce water or water vapor into the combustible mixture compressed in the combustion chamber 350. The introduction of water vapor tends to delay combustion due to self-ignition. Therefore, combustion phasing can be controlled somewhat by controlling the amount of water introduced into the combustible mixture. Although the system is shown as having water injectors on both the cylinder and the intake runner, only one injector may be required. This system is shown as further having a controller 362 and a water source 363.
[0115]
Another way to reduce the quenching or cooling of the mixture to the extent that the mixture does not burn completely in certain areas is to spray or apply water to the most sensitive inner surface or gap area of the combustion chamber. Wet with water. When water hits or wets such a surface, the water becomes water vapor and lifts the air / fuel mixture from the gap or quench region into the region of the cylinder where it burns more completely. For this purpose, a water injector may be provided that directs the spray to the gap area. Water vapor near the quench surface is also a type of thermal insulation. If the water injection means is used for the purpose of making the cylinder uniform or as an auxiliary or replacement means for the CVCR device, the spray is directed into an area susceptible to quenching so that the purpose is dual. It is advantageous. However, in order to use water so as not to prevent quenching, it is necessary to use water for controlling the reactivity of the air-fuel mixture. As a further alternative, water or other substances may be mixed with the fuel and these substances indirectly introduced into the combustible mixture. Water injection systems may also inject material other than water to affect combustion phasing or crevice volume.
In accordance with the present invention, the water injection scheme may be used on its own or in other combustion phasing control schemes, such as variable compression ratio devices and / or corona discharge devices and / or rapid compression devices for HCCI barrel engines. Good.
[0116]
HCCI barrel engine with non-sinusoidal orbit
As described above, a barrel engine typically has a sinusoidal trajectory as a whole, thereby imitating a sinusoidal piston motion as a whole of a crank drive engine. In conventional crank drive engines, the piston motion is necessarily sinusoidal. This is because a change from the sinusoidal shape is not possible due to the shape of the crank. However, with a barrel engine, the designer can select a shape other than a sine wave. In accordance with the present invention, it has been discovered that certain non-sinusoidal piston motion profiles provide advantages over conventional sinusoidal piston motion profiles. FIG. 30 shows a non-sinusoidal piston motion profile 364. This profile has a downward intake gradient 365 corresponding to the movement of the piston away from the closed end of the combustion cylinder and the expansion of the combustion chamber. The slope gradient ends at the transition through “intake bottom dead center” 366. This is followed by an upward compression gradient 367 that terminates at a transition through “compression top dead center” 368. Under proper conditions, combustion occurs at or near compression top dead center 368 and the piston moves downward as indicated by the combustion or expansion gradient 369. The piston then transitions through “expanded bottom dead center” 370 and begins upward motion as indicated by the exhaust gradient 371. The exhaust stroke ends at the transition through the “exhaust top dead center” 372 and the intake stroke 365 is repeated.
[0117]
The power output and combustion stability of the HCCI engine can be improved by countering the rate of pressure increase due to the fast piston speed near top dead center. The compression top dead center 368 is shown as a faster transition than would occur with a sinusoidal profile. As a result of the HCCI combustion method, a very high pressure rise rate is obtained. Due to the contoured nature of the barrel engine trajectory, the piston speed near top dead center can be much faster than in a conventional crank drive engine. The increased descending speed depressurizes the mixture at a fast rate. This is indicated by the steep slope of the combustion stroke 369. If the combustion is timed so that combustion occurs at or immediately after TDC, the increased depressurization rate counters the rate of pressure increase. By reducing the rate of increase of the combustion pressure, the mechanical stress applied to the engine is reduced, so that a richer fuel / air mixture can be used, thus increasing the power output of the engine. Fast piston motion near top dead center on the compression side causes the engine to pass the self-ignition threshold at high speed, making pre-ignition and detonation less likely. This improved combustion stability as a result of non-sinusoidal motion is another reason why barrel engines are better suited for HCCI than conventional engines.
[0118]
In a crank drive engine, there is a pause period in the region near top dead center, during which the speed of the piston is quite slow compared to other times in the cycle. This low descent rate occurs when the ignited mixture is hottest and densest. The slow decompression at this point maximizes the heat exchange that occurs between the hot gas and the engine coolant, resulting in a significant loss of thermal efficiency. In a barrel engine using a non-sinusoidal piston motion profile, the rate of descent near top dead center is quicker in comparison, so that the thermal energy of the gas can be quickly converted into mechanical energy, thus The time that the gas remains in the hot and dense state is minimized. By minimizing the time that the gas remains in the hot and dense state, the thermal efficiency of the engine is significantly increased.
[0119]
Profile 364 also shows a slow transition between intake air 365 and compression 367. This is provided to maximize the intake charge and increase the effective valve closing speed. This also reduces the inertial force applied to the piston and roller. The compression stroke 367 is shown as occurring over a longer period than the combustion stroke 369.
In the profile 364, the combustion stroke 369 is shown as having a greater displacement than the compression stroke 367. This is another advantage for the barrel engine. A long expansion stroke may be provided to capture much of the combustion energy and lengthen the transition to exhaust as shown. In a crank drive engine, the various strokes are necessarily identical in displacement, thereby limiting efficiency.
[0120]
Variable valve timing (valve adjustment)
Another way to control combustion phasing in HCCI engines is to utilize variable valve timing. Variable valve timing includes valve phasing, valve lift and / or change of total valve opening time. In a typical internal combustion engine, the opening of the intake and exhaust valves is controlled by a cam with a lobe that mechanically activates the valves. The cam is in mechanical communication with a crankshaft or drive component in the engine so that the relationship between the cam and the other components of the engine remains in the set state. Recently, considerable research has been done on variable valve timing. In the simplest form of variable valve timing, the intake and / or exhaust cam has an adjustable relationship to the engine crankshaft or other main drive component. That is, the cam can be adjusted to open the valve early or later. However, in the simplest approach to variable valve timing, the total valve lift and the length of time that the valve is open remains the same despite relative phasing changes. A newer method of variable valve timing accommodates variable valve heads and variations in the total time that the valve is open. In the newest form, electromechanical actuators directly control the opening and closing of individual valves, allowing very accurate control of all aspects of valve timing and lift. Such a system is disclosed in SAE paper 2000-01-0251, the contents of which are cited herein as forming part of this specification.
[0121]
Any of the known or to-be-developed schemes for variable valve timing can be used in the HCCI engine of the present invention, independently or in combination with any other feature of the present invention. In a preferred embodiment, variable valve timing is used for HCCI barrel engines. Using new valve timing (which can accurately control the valve head) can be partially replaced by the use of a throttle that controls the amount of air / fuel mixture drawn into the combustion chamber. That is, with less valve opening, power is somewhat limited because the flow of intake air into the combustion chamber is reduced.
[0122]
If the variable valve timing is used to some extent, the combustion phasing of the HCCI engine of the present invention can be controlled. By delaying the opening of the intake valve or reducing the total head or opening time, the amount of air and fuel combustible mixture introduced into the combustion chamber of the engine is somewhat reduced. This has the same effect as reducing the compression ratio of the engine. That is, reducing the opening of the intake valve or delaying the opening of the intake valve delays or prevents self-ignition. Conversely, opening the valve early (within a certain limit) or increasing the head or lengthening the total opening time increases the amount of combustible mixture drawn into the combustion chamber, resulting in certain conditions. If is satisfied, self-ignition will occur early.
[0123]
Variable exhaust valve timing can also be utilized in some manner to affect combustion phasing. For example, if the exhaust valve remains open beyond top dead center, some exhaust components may be pulled back into the combustion chamber when the piston begins to return downward. This will have the same effect as exhaust gas recirculation (EGR) as will be explained below. As a modification, the exhaust valve may be closed early, or the head used may be reduced so that more exhaust gas remains in the cylinder.
[0124]
Fuel formulation
Combustion phasing can also be controlled by changing the mixture of two fuels that tend to self-ignite and differ from each other. For example, if you prepare a first fuel that self-ignites very easily and select a second fuel that resists self-ignition, the mixture of these two fuels will be combined with air to There will be different tendencies in self-igniting based on percentage. The fuel formulation is shown schematically in FIG. The first fuel supply source is indicated by reference numeral 374, the second fuel supply source is indicated by reference numeral 375, and the mixing control device is indicated by reference numeral 376. The mixing control device changes the ratio of the first fuel and the second fuel sent to the combustion injector 377. Other methods include individual fuel injectors and / or completely separate fuel systems for each fuel. The fuel formulation can itself be used as a control method for HCCI combustion phasing, or it can be combined with any of the other features of the present invention.
[0125]
EGR control
Referring to FIG. 32, the exhaust gas recirculation (EGR) usage is schematically illustrated. EGR recirculates exhaust gas from exhaust runner 380 to intake runner 382 to increase the amount of residual exhaust gas introduced into combustion chamber 384. As is known to those skilled in the art, some residual exhaust gas remains in the combustion chamber 384 after the exhaust stroke because it is incomplete to empty the combustion chamber 384. The amount of exhaust gas recirculated into the combustion chamber 384 can be increased using, for example, the illustrated EGR system. In the illustrated embodiment, an EGR pipe 386 extends between the exhaust runner and the intake runner. A control valve 388 controls the flow rate of exhaust gas into the intake runner 382. Although this is illustrated for a single cylinder, it can be configured to direct exhaust gas from the exhaust passages as a group of EGR to individual intake passages or a common intake plenum. As described above, effects similar to those described above can be achieved by controlling the exhaust valve opening / closing timing, the lift, and the opening interval to affect the amount of exhaust gas remaining in the combustion chamber or drawn back into the combustion chamber. Within certain limits, increasing the amount of exhaust gas recirculation leads to combustion phasing in the HCCI engine, and decreasing the amount of EGR delays combustion phasing in the HCCI engine. A control scheme using HCCI combustion phasing EGR can be used alone or in combination with any other feature of the present invention. EGR can also be used for combustion cycles other than HCCI.
[0126]
Intake air (intake) temperature
HCCI combustion phasing can be controlled somewhat by changing the temperature of the intake air, air / fuel mixture or fuel. 33 and 34 show a system for adjusting the temperature of the intake air supplied to the combustion chamber. In FIG. 33, a hot air source 390 and a cold air source 392 are mixed together using a mixing controller 394 that provides air to an intake system 396 of the engine. In FIG. 34, a temperature control device for changing the temperature of the air supplied to the intake system 396 is provided in the air inlet 399. The temperature control device 398 may be a heating device, a cooling device, or both. Generally, combustion phasing advances by raising the intake air temperature, and combustion phasing is delayed by lowering this temperature. The air temperature control device can be achieved in various ways, such as using an exhaust stream or exhaust manifold to mix with the intake air to increase its temperature. A cooling system utilizing a cooling device, for example an intercooler or a compressor, can be used for cooling the intake air. A similar method can be used to adjust the temperature of the combustible mixture as well as the temperature of the fuel. Control of HCCI combustion phasing using air temperature can be used alone or in combination with any other feature of the present invention. Further, the air temperature control device can be used to some extent for engines using other combustion methods.
[0127]
Supercharge
FIG. 35 schematically illustrates the use of another method of controlling supercharging, ie combustion phasing in an HCCI engine. A supercharger 400 produces pressurized intake air or a fuel / air mixture provided to the combustion chamber 404. Preferably, boost control device 402 controls the level of pressure delivered to the intake system. By increasing the pressure of the air provided to the intake system, combustion phasing can be advanced. Decreasing the pressure delays combustion. Various designs for controlling the boost level can be utilized, such designs include upstream or downstream controllers and exhaust relief valves. Various modifications include using a turbocharger instead of a supercharger and other methods of pressurizing the intake air. The supercharger or turbocharger may be of any design, such as an integrated supercharger as described in Applicant's PCT priority document, of such PCT priority document. The description is hereby incorporated by reference as forming part of this specification. A double-ended barrel engine may be configured. In the double-ended configuration, the trajectory in the barrel engine is in communication with pistons at opposite ends of the engine. For example, a single piston assembly may include a piston provided at one end of the engine, a portion intermediate in communication with the track, and another piston provided at the other end. Cylinder bores provided at opposite ends of the engine receive the two ends of the piston assembly. By using a piston and a cylinder provided at one end of the engine, an integrated supercharger can be provided to compress the air supplied to the combustion chamber at the other end of the engine. As a variant, the combustion chamber and the compression chamber may be mixed at each end of the engine.
[0128]
Supercharging can be used in combination with any other features of the present invention on its own or for other designs of HCCI and engines. Supercharging is particularly suitable for engines that operate in HCCI mode at one point and in spark ignition or diesel mode at another point. This is particularly advantageous when combined with a variable compression ratio. This allows for greater flexibility in the combustion scheme, fuel usage and other variables.
[0129]
Cylinder timing equalization
background
In multi-cylinder engines, there are generally slight variations from cylinder to cylinder in, for example, combustion ratio, combustion chamber shape, intake and exhaust efficiency, temperature, and other factors. These variations cause slight variations in combustion characteristics. While this is true for all types of internal combustion engines, variability from cylinder to cylinder is of particular interest for HCCI engines. Unlike spark ignited or diesel engines, where combustion events can be triggered by spark plugs or fuel injectors, HCCI engines utilize self-ignition of a compressed mixture of fuel and air. Therefore, slight variations among cylinders cause variations in combustion phasing. This is especially true when the engine ages and combustion residues accumulate in the individual cylinders. In the above-described method for controlling HCCI combustion phasing, combustion phasing of the entire engine is considered. That is, some control method is used to advance or retard the overall combustion phasing of the engine. When one cylinder fires slightly earlier or later than the other, the engine controller will select the optimal combustion phasing for the “weakest link”. In other words, if one cylinder fires earlier than the other cylinders with respect to each top dead center of each cylinder, the engine controller is generally forced to adjust the combustion phasing for all cylinders, and the previously fired cylinder Will not ignite prematurely, which will damage the engine. As a variant, the engine controller can “divide the difference” between the earlier firing cylinders and the later firing cylinders. Neither method is optimal. In accordance with the present invention, several methods are provided to smooth out cylinder-to-cylinder variations in combustion phasing. Although not required for the HCCI engine of the present invention, it is preferred to optimize the overall efficiency and performance of the engine using one or more of these methods as needed. Although particularly advantageous for HCCI, some or all of the following control methods can be used for other engine configurations and combustion regimes.
[0130]
Corona discharge device
FIG. 36 schematically shows a multi-cylinder engine in which combustion chambers 420 and 422 are formed between the piston and the closed upper end of the combustion cylinder. Although shown by design as a reciprocating piston, many features of the present invention can be used in other internal combustion engine configurations that do not have a reciprocating piston in the cylinder, such as rotary configurations and other configurations. Should be understood. A pair of intake runners 424, 426 are shown in a state of supplying a fuel mixture to the combustion cylinders 420, 422 in a corresponding relationship. Corona discharge devices 428 and 430 are provided in the intake runners 424 and 426, respectively. As described above, the corona discharge device can be used to adjust combustion phasing in an HCCI engine. By providing individual corona discharge devices for each cylinder of a multi-cylinder engine, the combustion phasing of the individual cylinders can be controlled. Preferably, corona discharge devices 428 and 430 are in communication with and under control of engine controller 432. As a modification or addition, a corona discharge device may be provided in the combustion chambers 420, 422 as indicated at 434, 436, respectively. One or both of the corona discharge devices may be provided for each cylinder, and each provided corona discharge device is preferably in communication with the engine controller 432. For cylinders that need to advance the combustion peak, increase the voltage, duty cycle, or number of components in the corona discharge device, whereas for cylinders that need to retard the combustion peak relative to the shaft angle. Reduce the voltage or the number of components or cut off completely. The opposite may be true under certain circumstances.
[0131]
The corona discharge device can be used in the engine alone or in combination with any other feature of the present invention. As an alternative, a main corona discharge device may be provided to add radicals to the intake air of all cylinders and additional corona discharge devices may be assigned to individual cylinders. The corona discharge device can be used for other types of engines.
[0132]
Water jet
Referring now to FIG. 37, the multi-cylinder engine is schematically shown again. A water injector 440 is shown for introducing water directly into the cylinder for each intake path or cylinder. As described above, combustion fading can be adjusted using water injection. By coordinating the water injectors of the individual cylinders by using the engine controller 442, combustion fading can be adjusted to optimize engine performance.
[0133]
Cylinder temperature control
Referring now to FIG. 38, another method for adjusting combustion phasing for each cylinder is described. Two combustion chambers 450, 452 are shown schematically for a multi-cylinder engine. Coolant jackets 254, 256 are shown for cooling the combustion chambers 250, 252 respectively. As will be apparent to those skilled in the art, there are many methods that can be used to cool individual cylinders, including liquid cooling, oil cooling, air cooling, and other methods. In some applications, auxiliary cooling may not be necessary. However, the relative combustion phasing can be adjusted to some extent by adjusting the cylinder temperature for each cylinder. High temperature cylinders tend to burn some time earlier, and low temperature cylinders tend to burn some time later. Typically, engine cooling systems provide coolant to all parts of the engine without individually controlling the temperature of certain parts of the engine. As shown in FIG. 38, the cooling system is designed to control the temperature of the cylinder for each cylinder. A coolant source 258 provides coolant to the coolant jackets 254, 256. Individual outlet controllers 260, 262 control the flow rate of coolant through the individual cylinders, thereby controlling the cooling of the cylinders. Temperature sensors 264 and 266 may be provided for each cylinder for monitoring purposes. The outlet controller and temperature sensor are all in communication with and under control of the engine controller 268. Individual cylinder cooling can be accomplished in other ways, for example, by controlling the inlet of coolant to each cylinder or adjusting the temperature of the coolant provided to the individual cylinders. For example, an engine may have a source of hot coolant and cooler coolant, and two coolants can be mixed for temperature control. Also, individual temperature sensors may not be required under certain control schemes. The engine controller uses a variety of methods to monitor relative combustion phasing, and then adjusts cylinder-by-cylinder temperature or temperature related factors, such as coolant flow rate, to adjust cylinder combustion phasing. Can be uniform. On the other hand, a plurality of thermostats or coolant flow control devices are provided at a particular location, each providing coolant to an individual cylinder. This can serve as a manifold for dispensing the coolant. By arranging each of the flow control devices in the center, inspection and maintenance of the control device can be simplified.
Another method is to use oil cooling or air cooling, and an individual controller is provided for each cylinder.
[0134]
Change in air-fuel ratio
Another way to balance cylinder variability is to change the individual air / fuel ratio of each cylinder. A rich air / fuel mixture generally self-ignites at a lower pressure and at a lower temperature than a lean air / fuel mixture. Therefore, by changing the air-fuel ratio, a means for leveling cylinder variations can be obtained. In cylinders that are slightly hotter than others due to non-uniform cooling performance and cylinders that have slightly higher compression ratios due to poor tolerances used during carbon deposition or production, the air / fuel ratio is It is kept thinner than the air-fuel ratio of the cylinder. The purpose is to delay the start of combustion so that combustion occurs at an ideal shaft angle. For cylinders that are cooler than others and for cylinders that are lower in pressure due to wear, the shaft angle is ideal for combustion by making the air-fuel ratio darker than the air-fuel ratio of the other cylinders and starting combustion. To happen in. Alternatively, air may be injected into each of the cylinder intake pipes or into the cylinder itself to dilute the mixture.
[0135]
Air temperature control
Another way to equalize cylinder variations is to give each cylinder a mode that changes the temperature of its intake air. Changing the temperature of the intake air may be advantageous for air-fuel ratio adjustment for cost reasons. This is because the engine only needs to have one or more injectors in the main intake pipe. As an option, it is not necessary to provide a means for measuring the intake air temperature of each cylinder. Instead, the intake temperature is adjusted by feedback from the combustion sensors, and these combustion sensors shall provide all necessary information. As in the case of adjusting the air-fuel ratio, a large difference in intake air temperature causes a large variation in power output of different cylinders.
[0136]
EGR control
Another way to balance cylinder variability is to use different amounts of exhaust gas recirculation (EGR) for each of the cylinders. This method may reduce the reactivity of the air-fuel mixture if the exhaust gas is relatively cold, or can increase the reactivity of the air-fuel mixture by raising the temperature. The disadvantage of EGR is that its responsiveness to changes in operating conditions is generally slow due to gas inertia. However, this problem can be solved. As in the case of air fuel control and temperature control, if the amount of EGR is large, the power output may decrease.
[0137]
control method
In order to properly control the combustion phasing for the entire engine or for each cylinder, each cylinder may have its own corona discharge device or other control mechanism. In addition, the control unit requires some way of monitoring the start or peak of combustion in each cylinder so that the control unit can send a signal to the correct component to adjust the combustion phasing. It may be possible to connect a central sound or pressure detection device to the control unit and compare the signal to the engine's mechanical position to monitor the state of combustion. However, each cylinder probably requires its own sound, pressure, heat or light detection device, whose signal is sent to the engine control unit and compared against the mechanical position of the engine to compare the fuel injector or Allow CDD to be adjusted accordingly. As described above, all methods for leveling cylinder variations can be used alone or in combination. It should also be noted that the methods for leveling cylinder variability, when used alone or in combination, can complement the variable compression ratio device or in some cases replace it in some applications. is there.
[0138]
It will be apparent to those skilled in the art that the various features of the invention can be changed or combined in various ways other than those shown or described without departing from the scope or teachings of the invention. It should be understood that the illustrated embodiments are provided for illustrative purposes and that many variations are possible. Terms used herein should be construed in their broadest sense. In some cases, the Applicant has defined terms in a specific manner for ease of explanation. Moreover, item names used throughout the specification should not be construed to limit the present invention in any way.
[Brief description of the drawings]
FIG. 1 is a cross-sectional front view of a generalized embodiment of an internal combustion engine referred to herein as a barrel engine.
FIG. 2A is a schematic diagram of a generalized embodiment of an internal combustion engine referred to herein as a rotary swashplate engine.
FIG. 2B is a cross-sectional view of another form of engine defined herein as a barrel engine.
FIG. 3 is a block diagram illustrating the steps performed in a spark ignition engine.
FIG. 4 is a block diagram showing the steps performed in a diesel engine.
FIG. 5 is a block diagram illustrating the steps that occur in a homogeneous charge compression ignition (HCCI) engine.
FIG. 6 is a cross-sectional view of one embodiment of a variable compression ratio barrel engine of the present invention.
FIG. 7 is a cross-sectional view of a part of a barrel engine provided with a second embodiment of the variable compression ratio device according to the present invention.
FIG. 8 is a partial cross-sectional view of a barrel engine provided with a third embodiment of the variable compression device of the present invention.
FIG. 9 is a cross-sectional view of another embodiment of a barrel engine with a variable compression device.
FIG. 10 is a cross-sectional view of yet another embodiment of a barrel engine with a variable compression ratio device.
FIG. 11 is a schematic view of a cylinder and a piston provided with the corona discharge device of the present invention.
FIG. 12 is a schematic view of a cylinder and a piston in which a mechanical quick compression device is provided in the upper end of the cylinder.
FIG. 13 is a schematic view of a cylinder and a piston in a state where an auxiliary chamber is separated from a main combustion chamber by a spark arrester.
FIG. 14 is a schematic view of a cylinder and a piston in which a spark ignition quick compression device is provided in the upper end of the cylinder.
FIG. 15 is a cross-sectional view of a modified example of the spark ignition rapid compression apparatus of the present invention.
FIG. 16 is a cross-sectional view of another modified example of the spark ignition type quick compression device of the present invention.
FIG. 17 is a cross-sectional view of still another modified example of the spark ignition type quick compression device of the present invention.
FIG. 18 is a cross-sectional view of an additional embodiment of the spark ignition rapid compression apparatus of the present invention.
FIG. 19 is a cross-sectional view of yet another embodiment of the rapid compression apparatus of the present invention.
FIG. 20 is a front view of a spark plug.
FIG. 21 is a front view of a modified example of a spark plug in which a ground electrode extends above the center electrode.
FIG. 22 is an end view of another embodiment of a ground electrode used for a spark plug.
23 is an end view of the ground electrode of FIG. 22 modified to have a spark arrester.
FIG. 24 is a side view of a modified spark plug in which a spark arrester is used instead of the ground electrode, and the spark arrester is shown in cross section.
25 is a side view of the modified spark plug of FIG. 24. FIG.
FIG. 26 is a block diagram showing the overall structure of the spark ignition quick compression device of the present invention.
FIG. 27 is a schematic diagram of a system and piston with a gas injection system used in a rapid compression apparatus.
FIG. 28 is a schematic view of a cylinder and a piston in a state where the auxiliary chamber is separated from the main combustion chamber by the auxiliary valve.
FIG. 29 is a schematic illustration of a cylinder and piston with a water injection system shown schematically.
FIG. 30 is a graph of a non-sinusoidal motion profile of a piston used in the engine of the present invention.
FIG. 31 is a schematic diagram showing a fuel blending system used in the present invention.
FIG. 32 is a schematic illustration of a cylinder and piston with an exhaust gas recirculation (EGR) system.
FIG. 33 is a block diagram showing an intake air temperature control system used in the present invention.
FIG. 34 is a block diagram showing a modified embodiment of the intake air temperature control device used in the present invention.
FIG. 35 is a block diagram showing how to use supercharging of the engine of the present invention.
FIG. 36 is a schematic diagram of an engine control device that controls combustion phasing in two combustion chambers using two corona discharge devices.
FIG. 37 is a schematic diagram of an engine control apparatus that controls a number of water injectors to control combustion phasing in two combustion chambers.
FIG. 38 is a schematic diagram of an engine controller and a cylinder temperature controller that control combustion phasing in two combustion chambers.
FIG. 39 is a schematic diagram of an engine control device including a plurality of sensors and a control device in communication therewith.

Claims (7)

A homogeneous charge compression ignition type barrel engine,
Having an engine housing with a first end and a second end;
Having an elongated power shaft provided longitudinally within the engine housing and defining a longitudinal axis of the engine;
Surrounding said longitudinal axis, each having a plurality of cylinders with a closed end and an open end, each cylinder having a central axis, each of the open ends of the cylinders as a whole as a housing Is directed to the first end of the
An intake system operable to introduce a combustible mixture of air and fuel into each of the cylinders;
A track is provided between the first end of the housing and the open end of the cylinder such that a portion is disposed in general alignment with each central axis of the cylinder, the track being a cylinder A cam surface that undulates in the longitudinal direction with respect to the open end of the cylinder, and a part of the cam surface is arranged in a state aligned with the central axis of each cylinder, and the track and the cylinder are The cam surface, which is wavy and undulated, moves with respect to the open end of the cylinder,
A piston is movably provided in each of the cylinders to form a combustion chamber between the closed end of the cylinders, and each piston moves into the cylinder as the cylinder and track move relative to each other. The pistons are in mechanical linkage with the cam surface of the track so that they can reciprocate in the flammable mixture until each flammable mixture is self-ignited without any sparks or additional fuel. Can operate to compress
A second plurality of cylinders disposed between the track and the first end of the housing, each of the cylinders having a closed end and an open end; , Generally directed to the second end of the housing;
There is further provided a piston movably provided in each of the second plurality of cylinders so as to form a combustion chamber between the closed end of the cylinders, each piston moving the cylinder and the track relative to each other. And mechanically linked to the cam surface of the track so that the piston reciprocates in the cylinder,
The second plurality of cylinders and the pistons provided therein constitute a supercharger that compresses air and makes it usable for a combustible mixture.
engine. A homogeneous charge compression ignition type barrel engine,
Having an engine housing with a first end and a second end;
Having an elongated power shaft provided longitudinally within the engine housing and defining a longitudinal axis of the engine;
Surrounding said longitudinal axis, each having a plurality of cylinders with a closed end and an open end, each cylinder having a central axis, each of the open ends of the cylinders as a whole as a housing Is directed to the first end of the
An intake system operable to introduce a combustible mixture of air and fuel into each of the cylinders;
A track is provided between the first end of the housing and the open end of the cylinder such that a portion is disposed in general alignment with each central axis of the cylinder, the track being a cylinder A cam surface that undulates in the longitudinal direction with respect to the open end of the cylinder, and a part of the cam surface is arranged in a state aligned with the central axis of each cylinder, and the track and the cylinder are The cam surface, which is wavy and undulated, moves with respect to the open end of the cylinder,
A piston is movably provided in each of the cylinders to form a combustion chamber between the closed end of the cylinders, and each piston moves into the cylinder as the cylinder and track move relative to each other. In reciprocating motion with the cam surface of the track, and each piston can operate to compress the combustible mixture,
The compression level of one of the plurality of combustion chambers is rapidly increased after the piston has at least partially compressed the mixture so that a combustible mixture can be introduced with sparks or fuel can be added. Has a quick compression device that can operate without self-ignition,
The quick compression device has an auxiliary chamber formed therein, a main body having an opening communicating the auxiliary chamber and the combustion chamber, an ignition device operable to ignite a combustible air-fuel mixture in the auxiliary chamber, and a gas permeable property A spark arrester, and the spark arrester is provided in the opening so that the ignited combustible air-fuel mixture in the auxiliary chamber disappears when the air-fuel mixture is pushed into the arrester.
engine. The engine of claim 2 , wherein the quick compression device has a movable member operable to change the volume of the combustion chamber. The engine according to claim 3 , wherein the movable member is an auxiliary piston provided in a closed upper end portion of the cylinder. The engine according to claim 2 , wherein the ignition device is a spark plug. The engine of claim 2 , wherein the quick compression device has a system operable to inject hot gas into the combustion chamber. A homogeneous charge compression ignition type barrel engine,
Having an engine housing with a first end and a second end;
Having an elongated power shaft provided longitudinally within the engine housing and defining a longitudinal axis of the engine;
Surrounding said longitudinal axis, each having a plurality of cylinders with a closed end and an open end, each cylinder having a central axis, each of the open ends of the cylinders as a whole as a housing Is directed to the first end of the
An intake system operable to introduce a combustible mixture of air and fuel into each of the cylinders;
A track is provided between the first end of the housing and the open end of the cylinder such that a portion is disposed in general alignment with each central axis of the cylinder, the track being a cylinder A cam surface that undulates in the longitudinal direction with respect to the open end of the cylinder, and a part of the cam surface is arranged in a state aligned with the central axis of each cylinder, and the track and the cylinder are The cam surface, which is wavy and undulated, moves with respect to the open end of the cylinder,
A piston is movably provided in each of the cylinders to form a combustion chamber between the closed end of the cylinders, and each piston moves into the cylinder as the cylinder and track move relative to each other. In reciprocating motion with the cam surface of the track, and each piston can operate to compress the combustible mixture,
The compression level of one of the plurality of combustion chambers is rapidly increased after the piston has at least partially compressed the mixture so that a combustible mixture can be introduced with sparks or fuel can be added. Has a quick compression device that can operate without self-ignition,
The rapid compression device captures a portion of the combustion products resulting from the initial self-ignition of the combustible mixture and releases the captured portion into the next combustible combustible mixture to cause self-ignition A system operable to operate, the system comprising an auxiliary chamber and a valve for selectively communicating the auxiliary chamber and the combustion chamber;
engine.

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