JPH10318016A - Fuel injection device for engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To secure good combustion in a full running area from a low load zone to a high load zone by providing an injection direction varying means for changing the direction of the injection port of a fuel injection valve and calculating a fuel injection direction from the fuel injection valve based on a detected load so as to control the injection direction varying means. SOLUTION: During the running of a direct injection type diesel engine, an engine load detected by a load detector 1 is sent to a fuel injection amount operation device 7 and, here, a fuel injection amount and an injection timing are calculated. The corresponding operation amount of a fuel injection pump 2 is outputted to the pump 2, a load detecting signal is inputted to an injection port angle operation device 4 at this time, the rotational amount of an injection port 11 is calculated so as to change an injection direction to the outer periphery of a combustion chamber 10 as a load is reduced or to the center of the combustion chamber 10 as a load is increased, and the injection port 11 is rotated to be set as required by a fuel injection valve rotating device 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection device for an internal combustion engine, and more particularly to an injection direction of an injection hole of a fuel injection valve in a direct injection type diesel engine in which fuel is directly injected from a nozzle hole of the fuel injection valve into a combustion chamber. To a device for controlling

[0002]

2. Description of the Related Art FIG. 5 is a system diagram of a fuel injection device in a normal direct injection type diesel engine. In FIG. 5, reference numeral 3 denotes a fuel injection valve for injecting fuel into a combustion chamber 10 (see FIGS. 3 and 4) of the engine, and reference numeral 2 denotes a predetermined injection by pressurizing fuel supplied by a fuel supply pump (not shown) to a high pressure. This is a fuel injection pump which feeds the fuel to the fuel injection valve 3 at a timing.

In such a fuel injection device, a load detector 1 detects a load on an engine and sends a detection signal to a fuel injection amount calculation device 7. The fuel injection amount calculating device 7 calculates a fuel injection amount and an injection timing corresponding to the detected load, and calculates an operation amount (rack position or the like) of the fuel injection pump 2 corresponding to the injection amount. Output to Thus, the fuel injection valve 3 outputs the combustion chamber 1 with an injection amount and an injection timing corresponding to the load of the engine.
Fuel is injected within zero.

[0004]

FIGS. 3 and 4 are plan views schematically showing patterns of fuel spray from a fuel injection valve 3 to a combustion chamber 10 in the direct injection type diesel engine. A case where two fuel injection valves 3 are provided on the outer peripheral portion of the cylinder (that is, the outer peripheral portion of the combustion chamber 10) and symmetrically provided at the center 10a of the combustion chamber is shown.

[0005] In the case of FIG.
Pattern 2 is set so that the best combustion can be obtained during low load operation of the engine. At low load, the fuel spray 12 is relatively small as shown in FIG. Is formed toward a portion near the outer periphery where the amount of air is large.

However, when the load is high, as shown in FIG. 3B, the distance of the spray 12 is extended and the spray largely develops. However, the direction of the injection port 11 of the injection valve 3 is the same as that at the time of low load. The cylinder inner wall surface 6 is exposed to the flame 13 from the spray 12 near the outer periphery of the combustion chamber 10. For this reason, at the time of such a high load, the lubrication state on the sliding surface between the piston ring and the cylinder liner (both not shown) is deteriorated, and seizure and wear of the piston ring are observed.

On the other hand, in the case of FIG. 4, the pattern of the spray 12 from the fuel injection valve 3 is set so that the best combustion can be obtained at the time of high load operation of the engine. As shown in FIG. 3B, the developed spray 12 having a longer reaching distance is formed closer to the center 10a of the combustion chamber 10 than in the case of FIG. 3B, and a flame 13 as shown in FIG. Does not collide with the cylinder inner wall surface 6.

However, in this case, FIG.
As shown in FIG. 3A, a relatively small spray 12 is formed closer to the center 10a of the combustion chamber 10 than in the case of FIG. The spray 12 applied to the portion having a large amount is small, so that the air in the combustion chamber 10 cannot be effectively used, and the combustion deteriorates.

As described above, in the conventional fuel injection device, since the direction of the fuel spray is determined by the mounting and setting of the fuel injection valve, the best combustion is obtained in both the high load region and the low load region of the engine. It was difficult. Further, in the related art, even if the same amount of fuel is injected from the fuel injection valve 3, spraying (flame) depends on the property (viscosity and the like) of the fuel.
Therefore, it was difficult to determine the optimal specifications of the fuel injection valve for various properties of the fuel oil.

The present invention has been made in view of the above-mentioned conventional problems, and makes it possible to change the direction of spraying from a fuel injection valve in accordance with the load of an engine, thereby achieving good combustion in all operating ranges from a low load range to a high load range. It is an object of the present invention to provide a fuel injection device for a direct injection type internal combustion engine.

[0011]

According to a first aspect of the present invention, a fuel injected from a fuel injection pump with an injection amount corresponding to an engine load is supplied to a fuel injection valve. An engine fuel injection device configured to inject fuel from an injection port into a combustion chamber of the engine; a load detection unit configured to detect a load of the engine; an injection direction variable unit configured to change a direction of the injection port of the fuel injection valve; A fuel injection device for an engine, comprising: a control means for calculating an injection direction of fuel from the fuel injection valve based on the detected load, and inputting the calculation result to the injection direction variable means.

Further, the second invention specifically defines the function of the control means. When the load detected by the load detection means is high, the control means changes the injection direction from the nozzle. When the load is low toward the center of the combustion chamber, the injection direction from the injection port is directed toward the outer periphery of the combustion chamber.

According to this invention, the engine load detected by the load detecting means is input to the control means, and the control means sets the relationship between the engine load and the injection direction suitable for the internal setting means in the internal setting means. When the detected value of the engine load is input, the detected engine load is matched with the setting means, the injection direction suitable for the detected value of the load is obtained from the setting means, and output to the injection direction changing means. In the injection direction changing means, the direction of the injection port of the fuel injection valve is adjusted so as to be the injection direction inputted from the control means. Here, in the setting means in the control means, as the engine load becomes lower, the injection direction (the direction of the injection port) becomes closer to the outer periphery of the combustion chamber and the engine load becomes higher. Accordingly, the injection direction is set so as to be toward the center of the combustion chamber.

Therefore, according to the present invention, the direction of the injection port of the fuel injection valve is changed in accordance with the engine load, and the injection port is directed to a portion near the outer periphery of the combustion chamber having a large amount of air when the engine is under a low load. When the load is high and the amount of air distributed to the entire combustion chamber is maximized, the injection port is directed toward the center of the combustion chamber to prevent the cylinder inner wall from being exposed to the spray flame. This prevents deterioration of the lubrication condition of the piston ring sliding surface due to the high temperature of the inner wall surface of the cylinder, thereby obtaining a good lubrication state.

Further, even when the properties such as the viscosity of the fuel change, the direction of the injection port is changed in accordance with the change in the reach of the spray due to the change in the properties, so that the use of fuel having the same injection amount and a long reach is possible. In some cases, the nozzle is directed toward the center of the combustion chamber, and when fuel with a short reach is used, the nozzle is directed toward the outer periphery of the combustion chamber.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will now be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, and are merely illustrative examples. Only.

FIG. 1 is a system diagram of a fuel injection device for a direct injection diesel engine according to an embodiment of the present invention, and FIG. 2 is a control block diagram. In FIG. 1, reference numeral 3 denotes a fuel injection valve for injecting fuel into a combustion chamber 10 of the engine (see FIGS. 3 and 4);
Reference numeral denotes a fuel injection pump which pressurizes fuel supplied by a fuel supply pump (not shown) to a high pressure and feeds the fuel to the fuel injection valve 3 at a predetermined injection timing.

1 is a load detector for detecting an engine load;
Reference numeral 7 denotes a fuel injection amount calculation device similar to the conventional one. Reference numeral 4 denotes a nozzle angle calculation device according to the present invention, to which an engine load detection signal is input from the load detector 1. 5
Is a fuel injection valve rotating device that changes the direction of the injection port 11 of the fuel injection valve 3 in response to the output signal of the injection port angle from the injection port angle calculation device 4.

In such a fuel injection device, the load detector 1 detects the load of the engine and sends a detection signal to the fuel injection amount calculation device 7. The fuel injection amount calculating device 7 calculates a fuel injection amount and an injection timing corresponding to the detected load, and calculates an operation amount (rack position or the like) of the fuel injection pump 2 corresponding to the injection amount. Output to Thus, the fuel injection valve 3 outputs the combustion chamber 1 with an injection amount and an injection timing corresponding to the load of the engine.
Fuel is injected within zero.

On the other hand, the detection signal of the engine load detected by the load detector 1 is input to the injection direction calculation unit 41 of the nozzle angle calculation device 4 as control means, as shown in FIG. In FIG. 2, reference numeral 43 denotes a load / injection direction setting unit. The setting unit 43 includes an engine load and a fuel injection valve 3.
Is set, and the relationship with the direction of the injection port 11 is set, and as the engine load becomes lower, FIG.
As shown in FIG. 4B, the direction of injection from the fuel injection valve 3 is closer to the outer periphery of the combustion chamber 10 (toward the inner wall surface 6 of the cylinder), and as the engine load increases. The injection direction is set so as to be in the direction of the center 10 a of the combustion chamber 10.

In the injection direction calculating section 41, the detected value of the load from the load detector 1 is compared with the load / injection direction setting section 43, and the injection direction suitable for the detected load value is obtained. Output to the unit 42. In the injection port operation amount calculation unit 42, the direction of the injection hole corresponding to the input injection direction is obtained, and the rotation amount (operation amount) of the injection port 11 of the fuel injection valve 3 is calculated based on this, and the fuel injection valve rotation is calculated. Output to the device 5. The fuel injection valve rotating device 5 rotates the nozzle 11 based on the operation amount input from the nozzle operation amount calculator 42 and sets the nozzle 11 in a desired direction.

By the above operation, the injection port 1 of the fuel injection valve 3
1 is always adjusted so as to be in a direction (angle) suitable for the engine load, and when the load is low, the combustion chamber 10 having a large air amount is used.
The fuel is injected near the outer periphery of the cylinder, and at high load, the fuel is injected near the center 10a of the combustion chamber 10 to prevent the cylinder inner wall surface 6 from being exposed to the spray flame.

Further, even when the properties such as the viscosity of the fuel change, the direction of the injection port 11 is changed in accordance with the change in the reach of the spray due to the change in the properties, so that the fuel with the same injection amount and the long reach can be obtained. In use, the injection port 11 is directed toward the center 10a of the combustion chamber 10 by the fuel injection valve rotating device 5, and when fuel with a short reach is used, the injection port 11 is directed toward the outer periphery of the combustion chamber.

[0024]

As described above, according to the present invention, the direction of the injection port of the fuel injection valve is changed according to the engine load.
When the engine is under a low load, the injection port can be directed to a portion near the outer periphery of the combustion chamber having a large amount of air to maximize the use of air and achieve good combustion. In addition, at high load when a sufficient amount of air is distributed in the entire combustion chamber, the injection port is directed toward the center of the combustion chamber to prevent the cylinder inner wall surface from being exposed to the flame due to spraying, so that the inside of the cylinder is prevented. It is possible to prevent deterioration of the lubrication conditions of the piston ring sliding surface due to the high temperature of the wall surface, and to obtain a good lubrication state.

Therefore, according to the present invention, good combustion can be achieved in the entire operating range from the low load range to the high load range of the engine, and overheating due to the combustion flame and the piston ring sliding due to the combustion can be achieved. It is possible to prevent a decrease in lubrication performance of the part.

[Brief description of the drawings]

FIG. 1 is a system diagram of a fuel injection device for a direct injection diesel engine according to an embodiment of the present invention.

FIG. 2 is a control block diagram in the embodiment.

FIG. 3 is a schematic plan view showing a situation (first example) of fuel spray in a direct injection diesel engine.

FIG. 4 is a schematic plan view showing a second example corresponding to FIG.

FIG. 5 is a system diagram of a conventional fuel injection device for a direct injection diesel engine.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Load detector 2 Fuel injection pump 3 Fuel injection valve 4 Injection angle calculation device 5 Fuel injection valve rotation device 6 Cylinder inner wall surface 7 Fuel injection amount calculation device 10 Combustion chamber 11 Injection port

Claims (2)

[Claims] A fuel injection device for an engine configured to inject fuel supplied from a fuel injection pump at an injection amount corresponding to an engine load from an injection hole of a fuel injection valve into a fuel chamber of the engine. , Load detection means for detecting an engine load, injection direction variable means for changing the direction of the injection port of the fuel injection valve, calculating the fuel injection direction from the fuel injection valve based on the detected load, Control means for inputting to the injection direction changing means. 2. The control means, when a load detected by the load detection means is high, directs an injection direction from the nozzle toward the center of the fuel chamber, and when the load is low, the injection direction from the nozzle is 2. The fuel injection device for an engine according to claim 1, wherein the injection direction is directed toward the outer periphery of the combustion chamber.