JPH10252571A - Water injection amount control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely prevent misfire so as to obtain a stable operating condition even when a condition of the atmosphere is changed, relating to a water injection amount control device suited for use in a Diesel engine of water injection type. SOLUTION: In a water injection amount control device for an engine of water injection type injecting fuel and water, the device has an atmospheric pressure detection means 95, atmospheric temperature detection means 93, and a control means 90 setting an injection amount of fuel and water. The control means 90 is constituted so as to provide a correction means 90c correcting an injection amount of water injected in a combustion chamber based on a pressure and temperature of the atmosphere detected by the atmospheric pressure/temperature detection means 95, 93.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water injection amount control device suitable for use in a water injection type diesel engine for injecting fuel and water into a combustion chamber.

[0002]

2. Description of the Related Art In a diesel engine, the combustion is performed by so-called in-cylinder air compression ignition, so that the generation mechanism of each component contained in the exhaust gas is different from that of gasoline premixed combustion. That is, in a diesel engine, combustion is generally performed in a state of excess air, and the emission concentration of HC (hydrocarbon) and CO (carbon monoxide) is relatively low, whereas the combustion temperature is high. Therefore, a relatively large amount of NOx (nitrogen oxide) is generated.

Further, after the fuel injection is performed, fuel vapor or an extremely over-concentrated air-fuel mixture is locally exposed to a high-temperature atmosphere, so that fuel molecules are thermally decomposed and carbon particles are easily formed. Therefore, the exhaust gas contains a large amount of soot. In particular, when the load is high, the combustion temperature becomes high, and N
Since the generation of Ox is promoted and the fuel density is higher than at the time of low load, the chance of the carbon particles coming into contact with air again decreases, and more soot is discharged.

Therefore, a so-called water-injection diesel engine has been proposed in which fuel and water are mixed and injected into a combustion chamber to perform combustion. In this water-injection diesel engine, water is injected into the combustion chamber together with fuel at the time of fuel injection, thereby reducing the combustion temperature and suppressing the generation of NOx. In addition, a small explosion due to vaporization of water, that is, a divergence phenomenon of water, generates a vortex in the combustion chamber, thereby improving the combustion efficiency and suppressing the generation of soot. Furthermore, fuel efficiency is improved by the improvement of the combustion efficiency.

FIG. 6 is a diagram for explaining the combustion state of such a water-injection diesel engine.
(A) is a graph showing the heat release rate dQ / dθ with respect to the crankshaft rotation angle θ (that is, a graph showing the combustion state), and (b) is a characteristic of the fuel and water injection amounts dq / dθ with respect to the crankshaft rotation angle θ. FIG.

As shown in FIG. 6B, the fuel is injected in the order of fuel, water, and fuel for each fuel injection from the fuel injection nozzle. Here, the setting of the water injection amount is set by a controller (ECU) attached to the engine. The controller stores in advance a table (map) of the optimum amount of water injection under standard atmospheric conditions (temperature of 25 ° C. and dry atmospheric pressure) obtained in a test. From the amount setting map, the water injection amount is set based on the engine speed and the engine load. Then, at the time of actual engine operation, the water injection amount corresponding to the engine operation state is read from this map each time, and the water injection amount is set.

FIG. 6A is a view showing a combustion state under standard atmospheric conditions. As shown in FIG.
When the fuel is injected from the fuel injection nozzle, combustion starts with a delay of a predetermined time τ ₀ from the fuel injection start timing. Such a predetermined time τ ₀ is also called an ignition delay time, and is greatly affected by atmospheric conditions, particularly, atmospheric pressure and atmospheric temperature. Further, as shown in FIG. 6A, when the fuel injected first ignites, the combustion is temporarily suppressed by the water injected next, and the combustion temperature decreases. Then, the fuel injected thereafter burns, and large heat energy is generated.

[0008]

However, in such a conventional technique, the value of the water injection amount setting map stored in the controller in advance is an optimum water injection amount setting value under standard atmospheric conditions. In the event that atmospheric conditions change, such as when used at high altitudes, misfire may occur if water is injected based on the injection amount set in such a map.

More specifically, as shown in FIGS. 7 (a) and 7 (b), the ignition delay time may be increased if the same water injection amount is set as in the standard atmospheric condition. In this case, the fuel injected after water injection does not ignite and misfire occurs. Further, FIG. 8 shows the relationship between the ignition delay time τ and water injection amount q _w. As shown in FIG. 8, the optimal water injection amount q ₀ under the standard atmospheric condition is set with a predetermined margin with respect to the misfire region.
For example, if the ignition delay time becomes longer than τ ₀ and becomes a predetermined value τ ′ or more due to a change in atmospheric conditions, such a margin is exhausted and the engine enters a misfire area, thereby causing misfire in the engine. It is. Then, when the misfire occurs in the engine in this manner, there is a problem that the output of the engine is reduced and vibrations due to torque fluctuations are generated.

Japanese Patent Application Laid-Open No. Hei 5-164003 discloses a technique relating to control of the water injection amount of such a water injection type diesel engine. However, this technique is a technique for improving the startability at the time of low temperature of the engine and suppressing the emission of white smoke after the start, and does not solve the above-mentioned problem. The present invention has been made in view of such a problem, and provides a water injection amount control device capable of reliably preventing a misfire even when atmospheric conditions change to obtain a stable operation state. Aim.

[0011]

According to a first aspect of the present invention, there is provided a water injection amount control device for a water injection type engine for injecting fuel and water into a combustion chamber of the engine. Atmospheric pressure detecting means for detecting atmospheric pressure;
An atmospheric temperature detecting means for detecting the atmospheric temperature, and a control means for setting the injection amount of the fuel and the water, the control means, the atmospheric pressure detecting means and the atmospheric pressure detected by the atmospheric temperature detection and It is characterized in that a correction means is provided for correcting the amount of water injected into the combustion chamber based on the atmospheric temperature.

According to a second aspect of the present invention, there is provided a water injection amount control device according to the first aspect of the present invention, wherein the correction means is configured to operate in a standard atmospheric state based on the atmospheric pressure and the atmospheric temperature. Ignition delay coefficient calculating means for calculating the ignition delay degree with respect to the ignition delay, and a water injection amount correction coefficient calculating means for calculating a water injection amount correction coefficient based on the ignition delay coefficient calculated by the ignition delay coefficient calculating means, A water injection amount calculating means for correcting a water injection amount in a standard atmospheric condition set in advance using the water injection amount correction coefficient is provided.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a water injection amount control device as one embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram showing the overall configuration, and FIG. 2 is a schematic block diagram showing the configuration of the main part. In the figure, reference numeral 1 is 4
This is a fuel injection nozzle of a cycle water injection type diesel engine, and is attached to a cylinder head (not shown) for each cylinder. And this fuel injection nozzle 1
As a result, fuel and water are mixed and injected into the combustion chamber.

The nozzle holder 2 of the fuel injection nozzle 1 includes:
The spring housing chamber 3 and the rod hole 4 having a smaller diameter than the spring housing chamber 3 are formed continuously vertically. Also,
The upper part of the spring accommodating chamber 3 is open on the upper surface of the nozzle holder 2, and the upper part of the rod hole 4 is open on the lower surface of the nozzle holder 2. A push rod 6 formed in a columnar shape and having a flange-shaped spring seat 5 at an upper portion is slidably fitted into the rod hole 4 from the spring housing chamber 3 side. An adjusting screw 8 is screwed into the opening end of the spring housing chamber 3, and the adjusting screw 8 closes the opening end of the spring housing chamber 3.

A push spring 7 for urging the push rod 6 downward in the drawing is interposed between the spring seat 5 and the adjusting screw 8. The biasing force of the spring 7 is adjusted. At the upper part of the nozzle holder 2, connection ends 9, 10 are formed so as to protrude, respectively. A water pipe (water supply path) 30 is connected to one connection end 9, and the other connection end 10.
Is connected to a fuel pipe (fuel supply path) 31.

A substantially weight-shaped nozzle 11 is provided below the nozzle holder 2, and a water reservoir 12 and a fuel reservoir 13 are formed below the nozzle 11. Each of the water pool 12 and the fuel pool 13 is formed as a disc-shaped cavity, and has a two-layer structure in a vertical direction. A guide hole 14 is formed in the nozzle 11 so as to penetrate the water reservoir 12 from the upper surface thereof and open to the fuel reservoir 13. This guide hole 14 is formed to have a larger diameter than the rod hole 4 of the nozzle holder 2.
A nozzle needle 15 is slidably and liquid-tightly fitted into the guide hole 14 from above. The lower end of the nozzle needle 15 is formed in a weight shape, and a cylindrical protruding end 16 through which the rod hole 4 can be inserted is formed at the upper end.

At the lower end of the nozzle 11, a protruding portion 17 having a substantially hemispherical tip is provided so as to protrude therefrom.
A plurality of nozzles 18 for injecting fuel and water into the combustion chamber at a required angle are formed at the tip of the projection 17. Also,
Each injection port 18 communicates with a communication hole 19 formed in the projection 17, and the communication hole 19 opens to the fuel reservoir 13.

The nozzle 11 is fitted in a retaining nut 20, and the retaining nut 20 is screwed to the nozzle holder 2. Further, the nozzle 11 and the nozzle holder 2 are mounted in a liquid-tight manner, and the upper surface of the nozzle 11 and the lower surface of the nozzle holder 2 are mounted so as to be in close contact with each other. On the other hand, the protruding end 16 of the nozzle needle 15 is in contact with the push rod 6 and is constantly urged downward by the urging force of the push spring 7.
As a result, the weight-shaped portion 15a of the nozzle needle 15 comes into contact with the opening end 19a of the communication hole 19, and the fuel injection nozzle 1 is closed. The nozzle 18 of the nozzle 11 is
A hole 21 formed at the lower end of the retaining nut 20 is inserted and protrudes into the combustion chamber.

The fuel reservoir 13 is connected to the connection end 10 of the nozzle holder 2 through a feed hole 22 continuously formed in the nozzle 11 and the nozzle holder 2. In addition, the puddle 12 is provided with the nozzle 1 as described above.
It is connected to the connection end 9 of the nozzle holder 2 through a feed hole 23 continuously formed in the nozzle holder 1 and the nozzle holder 2. The feed hole 23 is provided with a check valve 24 that allows only the flow from the connection end 9 to the water pool 12 and prevents the back flow of water.

Further, a water pump 40 is connected to one connection end 9 of the fuel injection nozzle 1 via a water pipe 30, and a fuel pipe 3 is connected to the other connection end 10.
The fuel pump 70 is connected to the fuel pump 70 via the fuel pump 1. A rack actuator 80 is mounted on the water pump 40. The rack actuator 80 is electrically connected to a controller (control means) 90 described later, and its operation is controlled by a control signal from the controller 90 to control the rack position of the water pump 40. . In the water pump 40, the discharge amount of water can be continuously changed from 0 to the water injection amount at the time of the maximum engine load according to the rack position.

On the other hand, a rack actuator 81 is mounted on the fuel injection 70. Rack actuator 8
1 is also electrically connected to the controller 90, and its operation is controlled by a control signal from the controller 90. Then, similarly to the case of the rack actuator 80 of the water pump 40 described above, the fuel pump 7
It is configured such that the fuel discharge amount from 0 can be continuously changed from 0 to at least the total discharge amount of the fuel injection amount and the water injection amount at the time of the maximum engine load.

Next, the main parts of the present invention will be described.
The above controller (control means) 90 includes
As shown in the figure, an engine speed sensor 91 for detecting the engine speed, an engine load sensor 92 for detecting the load of the engine, an atmospheric temperature sensor (atmospheric temperature detecting means) 93 for detecting the ambient atmospheric temperature, an engine cooling water An engine cooling water temperature sensor 94 for detecting the temperature of the engine and an atmospheric pressure detecting sensor (atmospheric pressure detecting means) 95 for detecting the ambient atmospheric pressure are connected. The engine load sensor 92 detects an engine load by detecting, for example, the amount of depression of an accelerator pedal.

Further, as shown in FIG.
In 0, standard atmospheric conditions (temperature at 25 ° C and dry atmospheric pressure)
Is stored. In the water injection amount map 90a, the optimum water injection amount under standard atmospheric conditions is finely tabulated according to the engine speed and the engine load. The water injection amount _qW0 is set based on detection information from the engine load sensor 91 and the engine load sensor 92.

Further, a water injection prohibiting means 90b is provided in the controller 90, and when it is detected from the detection information from the engine coolant temperature sensor 94 that the engine coolant temperature is lower than a predetermined value, Water injection prohibition means 9
By 0b, the injection of water is prohibited.
This is because the engine may be misfired if water injection is performed immediately after starting or when the temperature of the engine cooling water is low, such as in a cold region. In such a case, water injection is prohibited to prevent misfire. You do it.

Now, as shown in FIG.
In 0, a correction means 90c for correcting the water injection amount _qW0 set in the water injection amount map 90a is provided. The correcting means 90c is operated when the operating state of the engine is different from the standard atmospheric conditions described above, for example, when the engine is operated at a high altitude (that is, operated at a place where the atmospheric pressure is low) or at a low temperature. If you are, by correcting the water injection amount q _W0 set in the water injection amount map 90a, thereby preventing the engine misfire.

For this reason, the correcting means 90c corrects the water injection amount based on the atmospheric pressure and the atmospheric temperature detected by the atmospheric pressure detecting sensor 95 and the atmospheric temperature sensor 93. The correcting means 90c
As shown in FIG. 2, the ignition delay coefficient calculation means 90d, the water injection amount correction coefficient calculation means 90e, and the water injection amount calculation means 90f
With Here, the ignition delay coefficient calculating means 90
d denotes an atmospheric pressure detection sensor 95 and an atmospheric temperature sensor 93.
The ignition delay degree (ignition delay coefficient) κ for the ignition delay τ ₀ in the standard atmospheric condition is calculated based on the atmospheric pressure P ₁ and the atmospheric temperature T ₁ detected in the step ( ₁ ). Calculates a water injection amount correction coefficient m for correcting the water injection amount based on the ignition delay coefficient κ calculated by the above-described ignition delay coefficient calculation unit 90d, and the water injection amount calculation unit 90f , water injection amount in normal atmospheric conditions that have been set in advance, i.e., the water injection amount q _W0 set by the water injection amount map 90a is corrected by using the water injection amount correction coefficient m.

Hereinafter, the correction of the water injection amount by the correction means 90c will be described in detail. Generally, the ignition delay time τ of the engine can be obtained by the following equation (1). ^{τ = a · P b · exp} (c / T) ······· (1) Incidentally, a, b, c respectively is a constant, P is the atmospheric pressure, T is a ambient temperature. Therefore, the ignition delay time τ ₀ of the engine under standard atmospheric conditions can be expressed by the following equation (2), where P ₀ and T ₀ are the pressure and temperature in standard atmospheric conditions, respectively.

Τ ₀ = a · P ₀ ^b · exp (c / T ₀ ) (2) First, the ignition delay coefficient calculating means 90 d detects the ignition delay coefficient by the atmospheric pressure detection sensor 95 and the atmospheric temperature sensor 93. Based on the measured atmospheric pressure P ₁ and atmospheric temperature T ₁ , the ignition delay time τ ₁ of the engine at this time is calculated, and thereafter, the ignition delay degree with respect to the ignition delay τ ₀ in the standard atmospheric state is calculated. ing.

That is, the ignition delay time τ ₁ of the engine in an arbitrary state can be obtained by the following equation (3) in the same manner as described above. ^{_{τ 1 = a · P b ·}} exp (c / T 1) ······ (3) Then, the ignition delay coefficient calculating means 90d, the ignition delay time of the engine under standard atmospheric conditions tau ₀ and the equation ( The ratio with the ignition delay time τ ₁ of the engine obtained in 3) is calculated as the ignition delay degree (ignition delay coefficient) κ by the following equation (4).

Κ = τ ₁ / τ ₀ (4) Here, by substituting the equations (2) and (3) into the equation (4), the following equation (5) is obtained. Become like In the following equation (5), ε is the compression ratio of the engine, and d is the specific heat ratio.

[0031]

(Equation 1)

When the ignition delay coefficient κ is calculated by the ignition delay coefficient calculating means 90d in this manner, the water injection amount correction coefficient calculating means 90e calculates the water injection amount correction coefficient m based on the ignition delay coefficient κ. (0 ≦ m ≦ 1.0) is set. Here, a map as shown in FIG. 3 is stored in the water injection amount correction coefficient calculating means 90e, and the water injection amount correction coefficient m is set from this map.

As shown in FIG. 3, in this embodiment, when the ignition delay coefficient κ is 1.0 or less, the water injection amount correction coefficient m is set to 1.0, and the ignition delay coefficient κ is 1 .0
To the predetermined value, the water injection amount correction coefficient m is linearly reduced according to the ignition delay coefficient κ, and when the ignition delay coefficient κ exceeds the predetermined value, the water injection amount correction coefficient m
Is set to 0.

When the water injection amount correction coefficient m is set in this manner, the water injection amount calculating means 90f corrects the water injection amount q _W0 set in the water injection amount map 90a by the water injection amount correction coefficient m _W0 . by correcting the water injection amount q _W0 by multiplying the coefficients m, is to set the amount q _w of water that is actually injected.
That is, when the water injection amount correction coefficient m is 1.0, the water injection amount q _W0 set in the water injection amount map 90a becomes the amount q _{w of} actually injected water, and the correction coefficient m becomes 0. case, so that the actual water injection amount q _w = 0 becomes water injection is not performed.

The characteristics of the map shown in FIG. 3 will be briefly described. The ignition delay coefficient κ indicates the degree of ignition delay when the ignition delay time τ ₀ under standard atmospheric conditions is set to 1, and κ = In the case of 1.0, the ignition delay time τ is the same as the standard atmospheric condition. Therefore, in such a case, it is not necessary to correct the water injection amount _qW0 set in the water injection amount map 90a, so the correction coefficient m is set to 1.0.

When κ <1.0, the ignition delay time τ is shorter than the ignition delay time τ _{0 under} standard atmospheric conditions, and the fuel is liable to burn in the combustion chamber. is there. In this case as well, there is no need to particularly correct the water injection amount _qW0 , so the correction coefficient m is set to 1.0 here. In this case, the correction factor m is set to 1.0 or more, the actual water injection amount q _w is the water injection amount map 90
The water injection amount _qW0 may be set to be _larger than the water injection amount _qW0 set in a.

On the other hand, when κ> 1.0, the ignition delay time τ is longer than the ignition delay time τ _{0 under the} standard atmospheric condition, and the fuel in the combustion chamber is hardly ignited. is there. Therefore, since this is the case is likely to misfire and performing water injection by water injection amount q _W0 set in the water injection amount map 90a, the correction coefficient m 1.0
This is set so that the actual water injection amount q _W is equal to or less than the water injection amount q _W0 set in the water injection amount map 90a.

In particular, in the present embodiment, the correction coefficient m is gradually decreased until κ reaches a predetermined value. However, when κ exceeds this predetermined value, the correction coefficient m becomes independent of the magnitude of κ. The coefficient m is set to 0, and the water injection is substantially prohibited. By executing such correction of the water injection amount, when the operation or the temperature of the atmospheric pressure at a low place, such as high altitude is low, the amount q _W water injection amount map of water actually injected This is smaller than the water injection amount _qW0 set at 90a, and misfire is reliably prevented.

[0039] FIG. 4 is a graph showing the relationship between the ignition delay time τ and the water injection amount q _W, shaded area shows the misfire region. The water injection amount q _W0 set by the water injection amount map 90a is set in anticipation of certain margin so as not reach the misfire region. However, as shown in this graph, when the ignition delay time τ is increased, the water injection amount q _W is constant, it is considered that lead to misfire region. For example, thereby leading to a misfire region is water injection amount q _W0 water injection amount when the ignition delay time tau ₁ in the figure is set by the water injection amount map 90a.

Therefore, the above-mentioned correction coefficient m is set so that the actual water injection amount q _W always has a certain margin with respect to the ignition delay time τ, ie, the actual water injection amount q
_W is set so as to be on a straight line a indicated by a dashed line in FIG. The thus determined correction coefficients m, by correcting the water injection amount q _W as m · q _W0, is the misfire of the engine is reliably prevented.

The water injection amount control device according to one embodiment of the present invention is configured as described above.
The correction of the water injection amount is performed according to the flowchart shown in FIG. First, in step S1, engine speed information and engine load information are fetched from the engine speed sensor 91 and the engine load sensor 92.
Then, the process proceeds to step S2, these engine speed and on the basis of the engine load, the water injection amount q _W0 standard atmospheric conditions is set from the water injection amount map 90a. And
Proceeding to step S3, the engine coolant temperature sensor 94
The engine cooling water temperature T _W is taken in from step S
In 4, it is determined whether the engine coolant temperature T _W is higher than a predetermined temperature T _W1 .

Here, if it is determined that the engine cooling water temperature T _W is lower than the predetermined temperature T _W1 , the process proceeds to step S5, and water injection is prohibited by the water injection prohibiting means 90b. This is because if water injection is performed at such a low temperature of the engine cooling water, the engine may be misfired, and water injection is prohibited to prevent such misfire.
Here, by setting the water injection amount q _W = 0, water injection is prohibited. If water injection is prohibited in step S5, the process proceeds to step S10.

On the other hand, if it is determined in step S4 that the engine coolant temperature T _W is higher than the predetermined temperature T _W1 , the process proceeds to step S6. At step S6, the atmospheric pressure and temperature are taken from the atmospheric pressure sensor 95 and the atmospheric temperature sensor 93, and at step S7, the ignition delay coefficient calculating means 90d calculates the ignition delay coefficient κ based on these atmospheric pressure and temperature. The ignition delay coefficient κ is a ratio of the ignition delay of the engine when the ignition delay under the standard atmospheric condition is set to 1, and the larger the ignition delay coefficient κ, the larger the ignition delay.

When the ignition delay coefficient κ is calculated in step S7, the process proceeds to step S8, where a correction coefficient m is set based on the ignition delay coefficient κ. The correction coefficient m is set according to a map set in the water injection amount correction coefficient calculation means 90e. When the correction coefficient m is set, the process proceeds to step S9, and the water injection amount is corrected by the water injection amount calculation means 90f. More specifically, the water injection amount q _W0 under standard atmospheric conditions set in step S2 described above, the actual water injection amount q _W by multiplying the correction coefficient m which is set in step S8 is set. That is, q _W = m · q _W0 .

Further, in step S9 or step S5, the water injection amount q _W is set, in step S10, the water injection amount control signal corresponding to q _W is output from the set controller 90. Then, step S11
Then, the rack position of the rack actuator 80 of the water pump 40 is controlled, and the process returns. In the water injection amount control device of the present invention, since the water injection amount is corrected as described above, the water injection amount is accurately controlled even if atmospheric conditions such as atmospheric pressure and temperature change, so that the engine There is an advantage that misfire can be reliably prevented. Further, by preventing the misfire of the engine, there is an advantage that a decrease in engine output, a torque fluctuation, and the like can be eliminated, and drivability is also improved. Further, the present device has the advantage that it does not need to provide new parts or the like and only needs to change the control logic, and thus does not cause an increase in cost and weight, compared to the conventional water injection engine. doing.

The water injection amount control device of the present invention is not limited to the above-described embodiment, but can be variously modified. For example, the fuel injection nozzle 1, the water pump 40,
The configurations of the fuel pump 70, the rack actuators 80, 81 and the like are not limited to those described above.
Changes may be made as appropriate without departing from the spirit of the present invention.
The present device may be applied to a two-cycle diesel engine.

[0047]

As described above in detail, according to the water injection amount control device of the present invention, the water pressure is detected by the atmospheric pressure detection means and the atmospheric temperature detection by the correction means provided in the control means. Since the amount of water injected into the combustion chamber is corrected based on the atmospheric pressure and the atmospheric temperature, the optimal water injection amount can be controlled according to all atmospheric conditions.
Engine misfire can be reliably prevented. Also,
Since the misfire of the engine is reliably prevented, there is an advantage that a decrease in engine output, torque fluctuation, and the like can be eliminated, a stable operation state can be obtained, and drivability is improved. Further, the present device has the advantage that it does not need to provide new parts or the like and only needs to change the control logic, and thus does not cause an increase in cost and weight, compared to the conventional water injection engine. doing.

According to the water injection amount control device of the present invention, the ignition delay coefficient calculating means calculates the degree of ignition delay with respect to the ignition delay in standard atmospheric conditions.
Based on the ignition delay coefficient, the water injection amount correction coefficient is calculated by the water injection amount correction coefficient calculation means, and then, using this water injection amount correction coefficient, the water injection amount correction coefficient is calculated in the standard atmospheric state preset by the water injection amount calculation means. Since the water injection amount is corrected,
There is an advantage that the water injection amount can be accurately corrected and the engine misfire can be reliably prevented.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an overall configuration of a water injection amount control device as one embodiment of the present invention.

FIG. 2 is a schematic block diagram showing a main configuration of a water injection amount control device as one embodiment of the present invention.

FIG. 3 is a diagram showing characteristics of a water injection amount correction coefficient in the water injection amount control device as one embodiment of the present invention.

FIG. 4 is a diagram for explaining an operation of the water injection amount control device as one embodiment of the present invention.

FIG. 5 is a flowchart for explaining the operation of the water injection amount control device as one embodiment of the present invention.

FIG. 6 is a diagram for explaining combustion characteristics of an engine provided with a conventional water injection amount control device.

FIG. 7 is a diagram for explaining combustion characteristics of an engine including a conventional water injection amount control device.

FIG. 8 is a diagram showing a relationship between an ignition delay time and a water injection amount in a general water injection amount control device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fuel injection nozzle 2 Nozzle holder 3 Spring accommodating chamber 4 Rod hole 5 Spring seat 6 Push rod 7 Push spring 8 Adjust screw 9, 10 Connection end part 11 Nozzle 12 Water pool 13 Fuel pool 14 Guide hole 15 Nozzle needle 15a Weight part 16 Projecting end 17 Convex part 18 Injection port 19 Communication hole 19a Opening end 20 Retaining nut 21 Hole 22, 23 Feed hole 24 Check valve 30 Water pipe (water supply path) 31 Fuel pipe (fuel supply path) 40 Water pump 70 Fuel pump 80, 81 Rack actuator 90 Controller (control means) 90a Water injection amount map 90b Water injection inhibition means 90c Correction means 90d Ignition delay coefficient calculation means 90e Water injection amount correction coefficient calculation means 90f Water injection amount calculation means 91 engine Engine speed sensor 92 Engine load sensor 93 Atmospheric temperature sensor (atmospheric temperature detecting means) 94 Engine cooling water temperature sensor 95 Atmospheric pressure detecting sensor (atmospheric pressure detecting means)

Claims (2)

[Claims] 1. A water injection amount control device for a water injection engine for injecting fuel and water into a combustion chamber of an engine, comprising: an atmospheric pressure detecting means for detecting an atmospheric pressure; an atmospheric temperature detecting means for detecting an atmospheric temperature; Control means for setting the injection amount of the fuel and the water, wherein the control means injects the fuel into the combustion chamber based on the atmospheric pressure and the atmospheric temperature detected by the atmospheric pressure detecting means and the atmospheric temperature detection. A water injection amount control device, comprising: a correction means for correcting the water injection amount. 2. An ignition delay coefficient calculating means for calculating an ignition delay degree with respect to an ignition delay in a standard atmospheric condition based on the atmospheric pressure and the atmospheric temperature, and an ignition delay coefficient calculating means. A water injection amount correction coefficient calculating means for calculating a water injection amount correction coefficient based on the ignition delay coefficient, and a water injection amount for correcting a water injection amount in a standard atmospheric condition set in advance using the water injection amount correction coefficient. The water injection amount control device according to claim 1, further comprising a calculation unit.