JP4107099B2 - High compression ratio supercharging lean burn engine operation mode controller - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a high compression ratio supercharged lean burn engine, and more particularly to an operation mode control device for a high compression ratio supercharged lean burn engine.
[0002]
[Prior art]
As one of the engines of vehicles such as automobiles, for example, as described in the following Patent Document 1 filed by the applicant of the present application, a port injection valve that injects fuel into an air supply port and a fuel that is injected directly into a combustion chamber In-cylinder injection valve that uses only port injection in the light load range, expands the auto-ignition range by valve overlap, and reduces the in-cylinder fuel injection amount in the high load range 2. Description of the Related Art Conventionally, a compression ignition engine configured to expand a combustion zone is known.
[Patent Document 1]
JP-A-10-252512
[Patent Document 2]
Japanese Patent Laid-Open No. 2002-130006
[0003]
[Problems to be solved by the invention]
In general, in a high compression ratio supercharging lean burn engine in which the compression ratio is set high and the air supply is supercharged to achieve high efficiency and low fuel consumption by performing lean burn even at high loads, In the high load range, the compression ratio is high and the amount of air is large due to supercharging to obtain a high torque. These problems are likely to occur, and these problems cannot be solved simply by performing direct in-cylinder injection to lower the mixture temperature.
[0004]
In the conventional spark ignition type engine, the ignition timing is retarded to prevent knocking and self-ignition in a high load range, but the engine output torque is delayed by the retarded ignition timing. However, there is a problem that the fuel consumption is inevitably lowered or the fuel consumption is deteriorated.
[0005]
The present invention has been made in view of the above-mentioned problems in conventional high compression ratio supercharged lean burn engines and spark ignition engines. The main problem of the present invention is diffusion combustion (due to compression ignition). Focusing on the fact that the air-fuel ratio can be made leaner than in the case of premixed spark ignition, and that knock-free can be achieved by diffusing combustion in the high load range. Accordingly, by properly using combustion by spark ignition and diffusion combustion, knocking and self-ignition in a high load range can be prevented and fuel consumption can be improved without causing a decrease in output torque and deterioration in fuel consumption.
[0006]
[Means for Solving the Problems]
  According to the present invention, the main problem described above is the operation mode control device of the configuration of claim 1, that is, the high compression ratio supercharging lean burn engine,A plurality of predetermined values are set based on a plurality of parameters indicating the ease of combustion of fuel in the engine,Engine loadAnyWhen the engine load is below the predetermined value, the engine is operated in a spark ignition mode in which fuel is burned by spark ignition, and the engine load is reduced.All ofThis is achieved by an operation mode control device for a high compression ratio supercharged lean burn engine, characterized in that when higher than a predetermined value, the engine is operated in a diffusion combustion mode in which fuel is diffusively burned.
[0007]
  According to the present invention, in order to effectively achieve the main problems described above, the operation mode control device according to the configuration of claim 1 is provided.Is indicated by each parameterThe predetermined value is variably set according to the ease of combustion so that the predetermined value becomes lower as the ease of combustion becomes higher (structure of claim 2).
[0010]
  According to the present invention, in order to effectively achieve the main problems described above,1 or 2In the configuration, the operation mode control device is in the fuel type, engine warm-up state, fuel property, engine actual compression ratio, engine operating environment condition, fuel combustion state, and spark ignition operation mode. A plurality of predetermined values are configured to be set based on at least two parameters indicating whether knock has occurred or not.3Configuration).
[0011]
[Action and effect of the invention]
  According to the configuration of claim 1 above,A plurality of predetermined values are set based on a plurality of parameters indicating the ease of combustion of fuel in the engine,Engine loadAnyWhen the engine load is below the predetermined value, the engine is operated in a spark ignition mode in which fuel is burned by spark ignition, and the engine load is reduced.All ofWhen the engine is higher than the predetermined value, the engine is operated in the diffusion combustion mode in which the fuel is diffusively burned. Therefore, in the high load region of the engine, the air-fuel ratio can be made lean and the knock-free can be achieved. It is possible to improve the fuel consumption in the high load range without causing a decrease in output torque or deterioration in fuel consumption due to the retard of the ignition timing.The engine can be operated in a diffusion combustion mode, especially in situations where the fuel is easily combustible in the engine, which ensures that the engine operating conditions such as misfires become unstable. Can preventThe
[0012]
  According to the configuration of claim 2 above,The fuel indicated by each parameterThe predetermined value is variably set according to the ease of combustion so that the higher the burnability is, the lower the predetermined value is. Therefore, between the spark ignition mode and the diffusion combustion mode according to the ease of combustion of fuel in the engine. It is possible to switch the engine operation mode appropriately, and the more easily the fuel is combusted in the engine, the more the fuel consumption can be improved. This can be further improved.
[0015]
  And the above claims3According to the configuration, the operation mode control device is a knock type in the fuel type, engine warm-up state, fuel property, engine actual compression ratio, engine operating environment condition, fuel combustion state, and spark ignition operation mode. Since a plurality of predetermined values are set based on at least two parameters indicating whether or not there is occurrence, it is possible to reliably determine whether or not the fuel is easily combusted in the engine.
[0016]
[Preferred embodiment of the problem solving means]
  According to one preferred embodiment of the present invention, the above claims 1 toAny one of 3In the above configuration, the operation mode control device is configured to inject fuel into the air supply port of the engine in the spark ignition mode (preferred embodiment 1).
[0017]
  According to another preferred embodiment of the present invention, the above claims 1 toAny one of 3In this configuration, the operation mode control device is configured to inject fuel into the combustion chamber of the engine in the diffusion combustion mode (preferred aspect 2).
[0020]
    According to another preferred embodiment of the present invention, the aboveClaim 2In this configuration, the operation mode control device is configured to variably set a predetermined value corresponding to the engine speed and each parameter (preferred embodiment).3).
[0021]
  According to another preferred embodiment of the present invention, the above claims 1 toAny one of 3If the throttle opening is not fully open even when the engine operation mode is switched from the spark ignition mode to the diffusion combustion mode as the engine load increases, the operation mode control device Immediately after the spark ignition mode is switched from the spark ignition mode to the diffusion combustion mode, the throttle opening is rapidly increased to the fully open state while gradually increasing the throttle opening increase rate (preferred embodiment).4).
[0022]
  According to another preferred embodiment of the present invention, the above claims 1 toAny one of 3The predetermined value when the engine operation mode is switched from the diffusion combustion mode to the spark ignition mode is lower than the predetermined value when the engine operation mode is switched from the spark ignition mode to the diffusion combustion mode. (Preferred embodiment5).
[0023]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be described in detail with reference to the accompanying drawings with respect to several preferred embodiments (hereinafter simply referred to as embodiments).
[0024]
  First reference example
  Figure 1 applies to a high compression ratio supercharged lean burn gasoline engine.BurningFirst of the firing mode control deviceReference exampleIt is a schematic block diagram which shows.
[0025]
In FIG. 1, reference numeral 10 denotes a high compression ratio supercharged lean burn gasoline engine. The engine 10 includes a plurality of pistons 12 provided in each cylinder, and a cylinder block 14 that supports the pistons 12 so as to reciprocate. And a cylinder head 18 for defining the combustion chamber 16 in cooperation with the piston 12 and the cylinder block 14 for each cylinder. The compression ratio of the engine 10 is set to a high compression ratio of about 15 to 20, for example.
[0026]
The cylinder head 18 is provided with an air supply port 20 and an exhaust port 22 communicating with the combustion chamber 16, and the air supply port 20 and the exhaust port 22 are opened and closed by an air supply valve 24 and an exhaust valve 26, respectively. The cylinder head 18 is provided with a spark plug 28 that performs spark ignition and an in-cylinder injection valve 30 that injects fuel into the combustion chamber 16, and a port injection that injects fuel into the air supply port 20. A valve 32 is provided.
[0027]
Each supply port 20 is connected to a branch of an intake manifold hold 34, and a collecting pipe portion of the supply manifold hold 34 is connected to an air flow meter 38 and an air cleaner 40 by an intake pipe 36. The intake pipe 36 is provided with a throttle valve 42, and the opening degree of the throttle valve 42 is controlled by an actuator 44.
[0028]
A branch portion of an exhaust manifold hold 46 is connected to each exhaust port 22, and a collecting pipe portion of the exhaust manifold hold 46 is connected to an exhaust gas purification device and a muffler not shown in FIG. 1 by an exhaust pipe 48. . The exhaust pipe 48 and the intake pipe 36 are provided with a turbine 52 and a compressor 54 of the turbocharger 50, respectively, so that, for example, intake air is supercharged at a supercharging pressure ratio of 1.1 or more.
[0029]
The spark plug 28 is controlled by an electronic control unit 56 via a distributor not shown in FIG. 1, the in-cylinder injection valve 30 and the port injection valve 32 are also controlled by the electronic control unit 56, and the throttle valve 42 also has an actuator 44. Through the electronic control unit 56.
[0030]
As shown in FIG. 1, the electronic control unit 56 has a signal indicating the intake air amount Ain from the air flow meter 38 and a signal indicating the accelerator opening (accelerator pedal depression amount) θ from the accelerator opening sensor 58. A signal indicating the engine speed Ne is input from the engine speed sensor 60, and a signal indicating other engine operating parameters such as the engine coolant temperature is input although not shown in FIG.
[0031]
Although not shown in detail in FIG. 1, the electronic control unit 56 has a CPU, a ROM, a RAM, and an input / output port unit, which are connected to each other by a bidirectional common bus. It may consist of a microcomputer and a drive circuit.
[0032]
  The electronic control unit 56 controls the combustion mode of the engine 10 according to the flowchart shown in FIG. Especially the firstReference exampleIn this case, the electronic control unit 56 calculates the reference value Aino from the map corresponding to the graph shown in FIG. 2 based on the engine speed Ne, and the intake air amount Ain as the engine load is less than the reference value Aino. At times, the engine 10 is operated in a spark ignition mode in which fuel is injected into the combustion chamber 16 through the air supply port 20 by the port injection valve 32 and the air-fuel mixture is ignited by the spark plug 28.
[0033]
In contrast, when the intake air amount Ain exceeds the reference value Aino, the electronic control unit 56 directly injects fuel into the combustion chamber 16 by the in-cylinder injection valve 30 and does not perform ignition by the spark plug 28. The engine 10 is operated in a diffusion combustion mode in which the air-fuel mixture is ignited by compression ignition and diffused combustion is performed.
[0034]
The control of the fuel injection amount and throttle opening in the above two operation modes and the control of the ignition timing in the spark ignition mode are performed in a manner known in the art. The description of these controls is omitted because it does not form the gist of the invention, but in any of the operation modes, the fuel injection amount is a predetermined lean air-fuel ratio corresponding to the operating state of the engine 10. It is controlled to become.
[0035]
Further, as shown in FIG. 5, when the engine opening mode is switched from the spark ignition mode to the diffusion combustion mode as the engine load increases, the throttle opening is already fully opened. Is maintained as it is even in the diffusion combustion mode.
[0036]
On the other hand, as shown in FIG. 6, when the throttle opening is not fully open when the engine operation mode is switched from the spark ignition mode to the diffusion combustion mode as the engine load increases, the diffusion combustion mode is set. In order to reduce the pump loss at the time, if the throttle opening is controlled to be fully open simultaneously with the switching of the operation mode as shown by the phantom line in FIG. Steps in the torque are likely to occur and knocking and self-ignition are likely to occur.
[0037]
  Accordingly, as shown by the solid line in FIG. 6, the throttle opening is quickly increased by gradually increasing the increase rate with the increase in engine load immediately after the operation mode is switched from the spark ignition mode to the diffusion combustion mode. To be brought to a fully open state. In addition, this throttle opening control is the otherReference examples andThe same applies to the embodiments.
[0038]
  Next, referring to the flowchart shown in FIG.Reference exampleA combustion mode control routine will be described. The control according to the flowchart shown in FIG. 3 is started by closing an ignition switch (not shown), and is repeatedly executed at predetermined time intervals.
[0039]
First, in step 50, a signal indicating the intake air amount Ain detected by the air flow meter 38 is read, and in step 100, it corresponds to the graph shown in FIG. 2 based on the engine speed Ne. The reference value Aino is calculated from the map.
[0040]
In step 150, it is determined whether or not the intake air amount Ain exceeds the reference value Aino. If a negative determination is made, that is, if the engine load is equal to or less than the reference value, in step 200. When the operation mode of the engine 10 is set to the spark ignition mode and an affirmative determination is made, that is, when the engine load exceeds the reference value, the operation mode of the engine 10 is set to the diffusion combustion mode in step 250. .
[0041]
In step 300, when the set operation mode is the spark ignition mode, fuel is injected into the combustion chamber 16 through the air supply port 20 by the port injection valve 32, and the air-fuel mixture is ignited by the ignition plug 28. When the operation of the engine 10 is controlled in the spark ignition mode, and the set operation mode is the diffusion combustion mode, fuel is directly injected into the combustion chamber 16 by the in-cylinder injection valve 30, and ignition by the spark plug 28 is performed. The engine 10 is operated and controlled in the diffusion combustion mode in which the air-fuel mixture is ignited by compression ignition and the diffusive combustion is performed.
[0042]
  Thus the first shownReference exampleWhen the intake air amount Ain is less than the reference value Aino and the engine load is less than the reference value, a negative determination is made at step 150, and the operation mode of the engine 10 at step 200 is the spark ignition mode. However, when the intake air amount Ain exceeds the reference value Aino and the engine load is greater than or equal to the reference value, an affirmative determination is made at step 150, and the operation mode of the engine 10 is determined at step 250. The diffusion combustion mode is set.
[0043]
Therefore, as shown in FIG. 4, when the engine load is high, the engine is operated in the diffusion combustion mode, the air-fuel ratio is made lean by diffusion combustion, and knocking can be effectively prevented. The fuel consumption in the high load region can be improved without causing a reduction in output torque or deterioration in fuel consumption due to the retard of the ignition timing.
[0044]
  Especially illustratedReference exampleAccording to the above, when the throttle opening is not fully opened when the engine operation mode is switched from the spark ignition mode to the diffusion combustion mode as the engine load increases, the operation mode is changed from the spark ignition mode to the diffusion combustion mode. As the engine load increases immediately after switching to the throttle opening, the throttle opening is controlled to be brought into the fully open state quickly by gradually increasing the increase rate, so the throttle opening is controlled to be fully opened at the same time as the operation mode is switched. Can effectively prevent the stepped increase in output torque and the occurrence of knocking and self-ignition (this effect is another effect described later).Reference examples andThe same applies to the embodiment).
[0045]
  Second reference example
  Figure 7 applies to a high compression ratio supercharged lean burn engine that can use many types of fuel.BurningSecond of the firing mode control deviceReference example5 is a flowchart showing a combustion mode control routine in FIG. In FIG. 6, the same steps as those shown in FIG. 3 are assigned the same step numbers as those shown in FIG. 3 (this will be described later).The fruitThe same applies to the embodiment).
[0046]
  This secondReference exampleAlthough not shown in the figure, the engine 10 can be operated with various types of fuel such as light oil, regular gasoline, high-octane gasoline, ethanol, and the electronic control unit 56 is operated by the driver. A signal indicating the fuel used by the switch is input.
[0047]
  This secondReference exampleIn step 55, which is executed after step 50, it is determined whether or not the fuel used is light oil. If an affirmative determination is made, the process proceeds to step 250 as it is and negative. When the determination is made, a map for calculating the reference value Aino is selected in step 60 in accordance with the type of fuel used (ignitability) as shown in FIG.
[0048]
The ignitability of the fuel is determined based on a signal indicating the fuel input from a switch operated by the driver. Generally, it is determined that the higher the octane number of the fuel, the lower the ignitability of the fuel. It is determined that the higher the value, the higher the ignitability of the fuel.
[0049]
  In step 100, the reference value Aino is calculated based on the engine speed Ne from the map selected in step 60 (FIG. 8).Reference exampleSteps 150 to 300 are executed in the same manner as in the above case.
[0050]
  Thus this secondReference exampleAccording to the engine, the engine can be operated with various fuels including light oil, and the operation mode of the engine is changed to the spark ignition mode and the diffusion combustion mode according to the type of fuel used (ignitability) and the engine load. In this way, even when various fuels are used, the output torque is reduced and the fuel consumption is not deteriorated due to the retarded ignition timing. Fuel consumption can be improved.
[0051]
  First embodiment
  FIG. 9 shows a first embodiment of the combustion mode control device according to the present invention applied to a high compression ratio supercharging lean burn gasoline engine.oneIt is a flowchart which shows the combustion mode control routine in this embodiment.
[0052]
  This firstoneIn this embodiment, in step 70 executed after step 50, the engine is warmed up, the fuel property (ignitability), the actual compression ratio of the engine, the operating environment condition of the engine, Index values K1 to K6 of the ease of combustion of the fuel in the engine 10 are calculated in accordance with the combustion state and the presence or absence of knocking in the spark ignition operation mode.
[0053]
In this case, the index value K1 of the ease of combustion based on the warm-up state of the engine 10 is calculated so as to increase as the engine coolant temperature Trw decreases, in other words, as the engine warm-up state decreases, and the ignition of fuel is performed. An easy-to-burn index value K2 based on the properties of the fuel is calculated so as to decrease as the performance increases, and based on the actual compression ratio of the engine so as to decrease as the actual compression ratio of the engine 10 that varies by control of the variable valve timing increases. An index value K3 of the ease of combustion is calculated.
[0054]
Also, an index value K4 of the ease of combustion based on the engine operating environment conditions is calculated so that the intake air temperature is low and the intake pressure is low and the humidity is high, and the in-cylinder combustion state is detected by detecting the in-cylinder pressure or measuring an ion ammeter. The combustion ease index value K5 based on the combustion state of the fuel is calculated such that the longer the combustion time is, the larger the axial torque of the engine 10 is, and the larger the torque fluctuation is, the larger the torque fluctuation is. When the occurrence of knocking is detected in the spark ignition operation mode, the index value K6 of the ease of combustion based on the presence or absence of the occurrence of knocking is calculated.
[0055]
  In step 75, the sum of the index values K1 to K6 of the ease of combustion is calculated as the index value K of the ease of combustion, and a reference is made according to the index value K of the ease of combustion as shown in FIG. A map for calculating the value Aino is selected, and in step 100, the reference value Aino is calculated based on the engine speed Ne from the map selected in step 75 (FIG. 10). OneReference exampleSteps 150 to 300 are executed in the same manner as in the above case.
[0056]
  Thus this firstoneAccording to the embodiment, the engine warm-up state based on the engine coolant temperature Trw, the ignitability of the fuel, the actual compression ratio of the engine, the operating environment conditions of the engine based on the intake air temperature, intake air pressure and humidity, the combustion state of the fuel, An index value K for the ease of combustion is calculated based on the presence or absence of knocking in the spark ignition operation mode, and a reference value Aino is calculated based on the index value K for the ease of combustion and the engine speed Ne.
[0057]
  Therefore, according to this embodiment, the engine operation mode can be optimally switched between the spark ignition mode and the diffusion combustion mode according to the ease of combustion in the engine 10 and the engine load. And secondReference exampleThe operation mode of the engine can be switched and set more appropriately than in the case of.
[0058]
  Second embodiment
  FIG. 11 shows a first embodiment of the combustion mode control device according to the present invention applied to a high compression ratio supercharging lean burn gasoline engine.twoIt is a flowchart which shows the combustion mode control routine in this embodiment.
[0059]
  This firsttwoIn this embodiment, the map corresponding to the graph shown in FIG. 12 variably set in accordance with the engine coolant temperature Trw indicating the engine warm-up state in step 80 executed after step 50. Based on the engine speed Ne, a reference value Aino1 for determination based on the warm-up state of the engine is calculated. In step 85, it is determined whether or not the intake air amount Ain exceeds the reference value Aino1, and a negative determination is made. When the determination is made, the process proceeds to step 200 as it is, and when the determination is affirmative, the process proceeds to step 90.
[0060]
In step 90, a reference value Aino2 for determination based on the fuel property is calculated based on the engine speed Ne from the map corresponding to the graph shown in FIG. 13 variably set in accordance with the ignitability of the fuel. In 95, it is determined whether or not the intake air amount Ain exceeds the reference value Aino2, and if a negative determination is made, the process proceeds to step 200, and if an affirmative determination is made, the process proceeds to step 100.
[0061]
In step 100, a reference value Aino3 for determination based on the actual compression ratio of the engine is calculated based on the engine speed Ne from the map corresponding to the graph shown in FIG. 14 variably set in accordance with the actual compression ratio of the engine. In step 105, it is determined whether or not the intake air amount Ain exceeds the reference value Aino3. If a negative determination is made, the process proceeds directly to step 200. If an affirmative determination is made, step 110 is performed. Proceed to
[0062]
In step 110, a reference value Aino4 for determination based on the engine operating environment condition is calculated based on the engine speed Ne from the map corresponding to the graph shown in FIG. 15 which is variably set according to the engine operating environment condition. In step 115, it is determined whether or not the intake air amount Ain exceeds the reference value Aino4. If a negative determination is made, the process proceeds directly to step 200. If an affirmative determination is made, step 120 is performed. Proceed to
[0063]
In step 120, a reference value Aino5 for determination based on the combustion state of the fuel is calculated based on the engine speed Ne from a map corresponding to the graph shown in FIG. 16 variably set according to the combustion state of the fuel. In step 125, it is determined whether or not the intake air amount Ain exceeds the reference value Aino5. If a negative determination is made, the process proceeds directly to step 200. If an affirmative determination is made, the process proceeds to step 130. .
[0064]
  In step 130, the determination based on the presence or absence of the occurrence of knock based on the engine speed Ne from the map corresponding to the graph shown in FIG. 17 which is variably set according to the presence or absence of the occurrence of knock in the spark ignition operation mode. The reference value Aino6 is calculated. In step 135, it is determined whether or not the intake air amount Ain exceeds the reference value Aino6. If a negative determination is made, the process proceeds to step 200, where an affirmative determination is made. If YES, go to step 250. In this embodiment, steps 200 to 300 are the same as those in the first step.Reference exampleIt is executed in the same way as in
[0065]
  Thus this firsttwoAccording to the embodiment, the engine warm-up state, the fuel property (ignitability), the actual compression ratio of the engine, the engine operating environment condition, the fuel combustion state, the presence or absence of knock occurrence in the spark ignition operation mode Reference values Aino1 to Aino6 for determining the engine operation mode for each parameter are calculated, and when the intake air amount Ain exceeds the reference value for all parameters, the operation mode of the engine 10 is set to the diffusion combustion mode. The
[0066]
Therefore, according to this embodiment, the engine can be operated in the diffusion combustion mode in a situation in which the fuel is easily combusted in the engine 10, thereby preventing the operating state of the engine such as misfire. It is possible to reliably prevent the engine from becoming stable, and to reliably improve the fuel efficiency in the high load range while avoiding the decrease in output torque and the deterioration in fuel efficiency caused by the retard of the ignition timing as much as possible. .
[0067]
Although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to the above-described embodiments, and various other embodiments are possible within the scope of the present invention. It will be apparent to those skilled in the art.
[0068]
  For example, each of the aboveReference examples andIn the embodiment, when the throttle opening is not fully opened when the engine operation mode is switched from the spark ignition mode to the diffusion combustion mode as the engine load increases, a solid line in FIG. As shown in the figure, as the engine load increases immediately after the operation mode is switched from the spark ignition mode to the diffusion combustion mode, the throttle opening is quickly brought into the fully open state by gradually increasing the increase rate. However, when the throttle opening is close to the fully open state when the engine operation mode is switched from the spark ignition mode to the diffusion combustion mode, it may be immediately controlled to fully open.
[0069]
  Also the second mentioned aboveReference exampleIn this case, light oil can be used as fuel. When light oil is used, the engine operation mode is set to the diffusion combustion mode regardless of the engine load, but light oil is not used. It may be modified as follows.
[0070]
  Also the above mentionedoneIn the embodiment, the sum of the index values K1 to K6 of the ease of combustion is calculated as the index value K of the ease of combustion. May be calculated as a sum of values obtained by multiplying each of the index values K1 to K6 by a weighting factor, or may be calculated as a product of the index values K1 to K6. May be calculated as a product of values obtained by multiplying by a weight coefficient.
[0071]
  Furthermore, the first and the above mentionedIn the second embodiment, engine warm-up conditions, fuel properties (ignitability), engine actual compression ratio, engine operating environment conditions, fuel combustion status, spark ignition as parameters for determining the engine load. Although parameters regarding whether or not knocking occurs in the operation mode are considered, any of these parameters may be omitted.
[Brief description of the drawings]
[Fig. 1] Applicable to high compression ratio supercharged lean burn gasoline engineBurningFirst of the firing mode control deviceReference exampleIt is a schematic block diagram which shows.
FIG. 2 is a graph showing a relationship between an engine speed Ne and a reference value Aino.
[Figure 3] FirstReference example5 is a flowchart showing a combustion mode control routine in FIG.
FIG. 4 is a graph showing a relationship between an engine speed Ne and an intake air amount Ain and an engine operation mode.
FIG. 5 is an explanatory diagram showing a case where the throttle opening is already fully open when the engine operation mode is switched from the spark ignition operation mode to the diffusion combustion mode with an increase in engine load.
FIG. 6 is an explanatory diagram showing control of the throttle opening when the throttle opening is not already fully open when the engine operation mode is switched from the spark ignition operation mode to the diffusion combustion mode with an increase in engine load. is there.
FIG. 7 is applied to a high compression ratio supercharged lean burn engine that can use various types of fuel.BurningSecond of the firing mode control deviceReference example5 is a flowchart showing a combustion mode control routine in FIG.
FIG. 8 is a graph showing a relationship between an engine speed Ne and a fuel type (ignitability) and a reference value Aino.
FIG. 9 shows a first embodiment of a combustion mode control device according to the present invention applied to a high compression ratio supercharged lean burn gasoline engine.oneIt is a flowchart which shows the combustion mode control routine in this embodiment.
FIG. 10 is a graph showing a relationship between an engine speed Ne and an index value K of the ease of combustion of fuel in the engine and a reference value Aino.
FIG. 11 is a schematic diagram of a combustion mode control device according to the present invention applied to a high compression ratio supercharged lean burn gasoline engine.twoIt is a flowchart which shows the combustion mode control routine in this embodiment.
FIG. 12 is a graph showing a relationship between an engine speed Ne, an engine coolant temperature Trw, and a reference value Aino1.
FIG. 13 is a graph showing a relationship between an engine speed Ne and fuel properties (ignitability) and a reference value Aino2.
FIG. 14 is a graph showing a relationship between an engine speed Ne, an actual compression ratio of the engine, and a reference value Aino3.
FIG. 15 is a graph showing a relationship between an engine speed Ne and an engine operating environment condition (intake air temperature, intake air pressure, humidity) and a reference value Aino4.
FIG. 16 is a graph showing a relationship between an engine speed Ne, a combustion state of fuel, and a reference value Aino5.
FIG. 17 is a graph showing the relationship between the engine speed Ne, the presence / absence of knocking, and a reference value Aino6.
[Explanation of symbols]
        10 ... Engine
        12 ... Piston
        14 ... Cylinder block
        18 ... Cylinder head
        20 ... Air supply port
        22 ... Exhaust port
        28 ... Spark plug
        30 ... In-cylinder injection valve
        32 ... Port injection valve
        38 ... Air flow meter
        50 ... Turbocharger
        56 ... Electronic control unit
        58 ... accelerator opening sensor
        60 ... Engine speed sensor

Claims (3)

A high compression ratio supercharging lean burn engine operation mode control device is used to set a plurality of predetermined values based on a plurality of parameters indicating the ease of combustion of fuel in the engine , and the engine load is any predetermined value The engine is operated in a spark ignition mode in which fuel is combusted by spark ignition when the engine is below, and the engine is operated in a diffusion combustion mode in which fuel is diffusely combusted when the engine load is higher than all predetermined values. High compression ratio supercharging lean burn engine operation mode control device. The said operation mode control apparatus variably sets the said predetermined value according to the said combustion ease so that the said predetermined value becomes low, so that the combustion ease shown by each parameter is high. Operation mode control device for compression ratio supercharged lean burn engine. The operation mode control device includes at least a fuel type, an engine warm-up state, a fuel property, an actual engine compression ratio, an engine operating environment condition, a fuel combustion state, and the presence or absence of knock occurrence in a spark ignition operation mode. The operation mode control apparatus for a high compression ratio supercharging lean burn engine according to claim 1 or 2 , wherein a plurality of predetermined values are set based on two parameters.

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