JP2011144728A - Fuel injection valve and direct injection type internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel injection valve and a direct injection type internal combustion engine, performing proper fuel injection in all operation ranges of the direct injection type internal combustion engine. <P>SOLUTION: An injector 20 includes first fuel injection holes 201 provided in multiple directions on the same circumference of the tip portion of a nozzle body 203 and arranged for injecting fuel in directions dividing almost equally the outer periphery of a cavity 12, and second fuel injection holes 202 arranged for injecting fuel in directions dividing almost equally the outer periphery of a piston 11, can inject fuel almost uniformly in the cavity from the first fuel injection holes 201 and can inject fuel almost uniformly in the whole bore from the second fuel injection holes 202. Therefore, proper fuel injection can be performed in all operation ranges of the direct injection type internal combustion engine. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a fuel injection valve and a direct injection internal combustion engine.

  In recent years, for the purpose of improving fuel efficiency and reducing exhaust emission, fuel injection valves capable of executing fuel injection stepwise in accordance with the operating region of a direct injection internal combustion engine are known.

  Such a fuel injection valve includes a body in which first and second injection holes are formed, a first needle that is slidably received in the body and opens and closes the first injection hole, and a first needle. A variable injection hole nozzle type fuel injection valve capable of opening the first and second injection holes stepwise by including a second needle that is slidably received and opens and closes the second injection hole. It is disclosed in Patent Document 1.

  Further, Patent Documents 2 and 3 disclose other technologies that are considered to be related to the present invention.

JP 2005-320904 A JP 2003-214297 A Japanese Utility Model Publication No. 01-152025

  In a direct injection internal combustion engine represented by a diesel engine, a concave combustion chamber (cavity) is provided at the center of the piston top surface, and the tip of the fuel injection valve is located at the center axis of the cavity, that is, the piston (or bore). A configuration that is installed so as to coincide with the central axis is widely adopted. On the other hand, in a small diesel engine having a small diameter bore, it may be difficult in terms of layout to install the tip portion of the fuel injection valve so as to coincide with the central axis of the piston. Therefore, for example, in a small direct injection internal combustion engine, in order to improve layout, the installation position of the tip portion of the fuel injection valve is offset with respect to the central axis of the piston, and the central axis of the cavity is further fueled. In many cases, a configuration that matches the installation position of the tip portion of the injection valve is employed.

  In the direct injection type internal combustion engine having such a layout, since the tip portion of the fuel injection valve is installed so as to coincide with the central axis of the cavity, fuel can be injected substantially uniformly into the cavity. Good combustibility can be obtained in a low-speed / medium-load operation region where the indoor combustion ratio is high. On the other hand, since the installation position of the tip portion of the fuel injection valve is offset with respect to the central axis of the piston, it is difficult to inject fuel substantially uniformly into the entire bore. In the high speed / high load operation region where the combustion ratio is high, the combustibility is deteriorated.

  However, in the technique of Patent Document 1, when the installation position of the tip portion of the fuel injection valve and the central axis of the cavity are offset with respect to the central axis of the piston, the fuel is substantially uniformly distributed over the entire bore of the direct injection internal combustion engine. Can not be injected. Thus, there is a problem that it is difficult to perform appropriate fuel injection in the entire operation region of the direct injection internal combustion engine.

  The present invention has been made in view of such a point, and an object of the present invention is to provide a fuel injection valve and a direct injection internal combustion engine capable of executing appropriate fuel injection in the entire operation region of the direct injection internal combustion engine. And

In order to achieve the above object, a fuel injection valve according to the present invention is a direct injection internal combustion engine having a combustion chamber in which a central axis of a cavity formed in a concave shape on the top surface of a piston is offset with respect to the central axis of the piston. A fuel injection valve provided in a cylinder of an engine by projecting a tip portion, and provided in a plurality of directions on the same circumference of the tip portion, and injecting fuel in a direction substantially equally dividing the outer periphery of the cavity A first fuel injection hole arranged in a possible manner and a plurality of directions on the same circumference of the tip portion different from the first fuel injection hole, and fuel in a direction substantially equally dividing the outer periphery of the piston And a second fuel injection hole arranged to be injectable.
With the above configuration, in the direct injection internal combustion engine in which the installation position of the tip portion of the fuel injection valve and the central axis of the cavity are offset with respect to the central axis of the piston, the fuel is substantially uniformly introduced into the cavity from the first fuel injection hole. And the fuel can be injected substantially uniformly from the second fuel injection hole to the entire bore. Therefore, appropriate fuel injection can be executed in the entire operation region of the direct injection internal combustion engine.

In particular, the fuel injection valve of the present invention may be configured such that the second fuel injection hole is provided at the tip portion closer to the cylinder head of the direct injection internal combustion engine than the first fuel injection hole.
With the above configuration, fuel can be injected substantially uniformly into the cavity from the first fuel injection hole provided at a position closer to the cavity, and the first fuel injection hole provided at a position further away from the cavity (closer to the cylinder head). Fuel can be injected substantially uniformly from the two fuel injection holes to the entire bore. Therefore, appropriate fuel injection can be executed in the entire operation region of the direct injection internal combustion engine.

In the fuel injection valve of the present invention, the second fuel injection hole may be arranged in a direction different from the arrangement direction of the first fuel injection hole with respect to a surface orthogonal to the sliding direction of the piston. it can.
With the above configuration, it is possible to suppress the fuel injected from the first fuel injection hole and the fuel injected from the second fuel injection hole from overlapping each other in the cylinder. Therefore, appropriate fuel injection can be executed in the entire operation region of the direct injection internal combustion engine.

The fuel injection valve according to the present invention includes a first adjusting means for arbitrarily adjusting a fuel injection amount from the first fuel injection hole, and a second for arbitrarily adjusting a fuel injection amount from the second fuel injection hole. Adjustment means.
With the above configuration, the fuel injection amount from the first fuel injection hole and the second fuel injection hole can be arbitrarily adjusted. Therefore, appropriate fuel injection can be executed in the entire operation region of the direct injection internal combustion engine.

Furthermore, the present invention is a direct injection internal combustion engine comprising the fuel injection valve, wherein the fuel injection is controlled by controlling the first adjustment means and the second adjustment means based on the output of the direct injection internal combustion engine. Control means is provided.
With the above configuration, the fuel injection amount from the first fuel injection hole and the second fuel injection hole can be appropriately controlled based on the output of the direct injection internal combustion engine. Therefore, appropriate fuel injection can be executed in the entire operation region of the direct injection internal combustion engine.

In the direct injection internal combustion engine of the present invention, the fuel injection control means injects fuel from the first fuel injection hole when the output of the direct injection internal combustion engine is lower, and the direct injection internal combustion engine When the output of is higher, fuel can be injected from the second fuel injection hole.
With the above configuration, in the low power operation region where the combustion ratio in the combustion chamber is high, fuel can be injected into the cavity from the first fuel injection hole substantially uniformly, and the high combustion ratio outside the combustion chamber is high. In the operating region, fuel can be injected substantially uniformly from the second fuel injection hole to the entire bore. Therefore, appropriate fuel injection can be executed in the entire operation region of the direct injection internal combustion engine.

  According to the fuel injection valve and the direct injection internal combustion engine of the present invention, in the direct injection internal combustion engine in which the installation position of the tip portion of the fuel injection valve and the central axis of the cavity are offset with respect to the central axis of the piston, The fuel can be injected substantially uniformly into the cavity from the fuel injection hole, and the fuel can be injected substantially uniformly from the second fuel injection hole to the entire bore. Therefore, appropriate fuel injection can be executed in the entire operation region of the direct injection internal combustion engine.

It is the figure which showed one structural example of the engine system of an Example. 1 shows a schematic configuration of an injector. An example of the fuel spray axis of the injector is shown. An example of a combustion state in a low speed operation region of the engine is shown. An example of a combustion state in a high-speed operation region of the engine is shown.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings.

  Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a diagram showing a configuration example of an engine system 1 equipped with a fuel injection valve of the present invention. FIG. 1 shows only a part of the configuration of the engine.

  An engine system 1 shown in FIG. 1 includes an engine 100 that is a power source, and includes an engine ECU (Electronic Control Unit) 10 that comprehensively controls the operation of the engine 100. The engine system 1 also includes an injector 20 that directly injects fuel into the cylinders of the engine 100.

  The engine 100 is a multi-cylinder diesel engine mounted on a vehicle, and each cylinder includes a piston 11 that constitutes a combustion chamber. The piston 11 of each cylinder is slidably fitted to a cylinder of the engine 100 and is connected to a crankshaft (not shown) as an output shaft member via a connecting rod.

The engine ECU 10 determines the fuel injection amount and the injection timing based on information such as the intake air amount from the air flow meter 32 and the position of the piston 11 from the crank angle sensor 31, and sends a signal to the injector 20. The injector 20 injects fuel into the cylinder at an instructed fuel injection amount and injection timing in accordance with a signal from the engine ECU 10. The fuel injected from the injector 20 atomizes in the cylinder and forms an air-fuel mixture with the intake air that flows into the cylinder as the intake valve opens. The air-fuel mixture is compressed in the cylinder by the upward movement of the piston 11 and ignited to burn, expand in the cylinder and lower the piston 11. The descending motion is changed to the shaft rotation of the crankshaft through the connecting rod, whereby the engine 100 obtains power. In this case, the engine 100 is not limited to a diesel engine using light oil as fuel, but may be another internal combustion engine.
Engine 100 is an example of a configuration of the direct injection internal combustion engine of the present invention.

  A crank angle sensor 31 is provided in the vicinity of the crankshaft axis. The crank angle sensor 31 is configured to detect the rotation angle of the crankshaft shaft, and transmits the detection result to the engine ECU 10. Thereby, engine ECU 10 acquires information related to the crank angle, such as the rotational speed of engine 100.

An air flow meter 32, a throttle valve, and a throttle position sensor are installed in the intake passage of the engine 100. The air flow meter 32 and the throttle position sensor detect the amount of intake air passing through the intake passage and the opening of the throttle valve, respectively, and transmit the detection results to the engine ECU 10. The engine ECU 10 recognizes the intake air amount introduced into the intake port and the combustion chamber based on the transmitted detection result, and adjusts the opening degree of the throttle valve to execute the governor control of the engine 100 while taking in the intake noise. Reduce.
The throttle valve preferably employs a throttle-by-wire system using a step motor. For example, the throttle valve opening is changed in conjunction with an accelerator pedal (not shown) via a wire or the like instead of the step motor. Such a mechanical throttle mechanism can also be applied.

  The accelerator opening sensor 33 detects the driver's accelerator operation amount, and transmits the detection result to the engine ECU 10. The engine ECU 10 recognizes the accelerator opening based on the transmitted detection result. As the accelerator opening sensor 33, a general sensor employing a hall element or an operating transformer system can be applied.

  The piston 11 has a cavity 12 formed in a concave shape on the top surface. The cavity 12 has an annular shape, and its central axis is offset with respect to the central axis of the piston 11, and a portion of the injector 20 protruding from the cylinder head 15 into the cylinder (the tip portion of the nozzle body 203). It matches (or almost matches) the installation position. The piston 11 has a protrusion 13 formed at the center of the bottom surface of the cavity 12, and the wall surface of the cavity 12 is formed by a gentle curved surface continuous from the protrusion 13. The periphery of the protrusion 13 is an annular space in which the swirl flow swirls. The wall surface of the cavity 12 is narrowed toward the inner diameter side as it approaches the opening of the cavity 12, and a lip 14 protruding toward the inner diameter side is formed in the vicinity of the opening. Thus, the piston 11 constitutes a reentrant combustion chamber. In this case, the piston 11 is not limited to the reentrant combustion chamber, and can adopt any combustion chamber shape according to the specifications of the engine 100.

The engine 100 includes a common rail fuel injection system including an injector 20, a common rail (not shown), a low pressure fuel pump, a high pressure fuel pump, and the like.
The fuel sucked from the fuel tank by the low-pressure fuel pump is discharged and stored in the common rail at a high pressure by the high-pressure fuel pump. The common rail is a container that accumulates high-pressure fuel supplied to the injector 20. The fuel pumped from the high-pressure fuel pump is accumulated in the common rail to a pressure required for injection, and is supplied to the injectors 20 of the respective combustion chambers through the high-pressure piping. The common rail is provided with a rail pressure sensor and a pressure reducing valve. The engine ECU 10 instructs to open the pressure reducing valve when the fuel pressure inside the common rail output from the rail pressure sensor exceeds a specified value. Then, by discharging the fuel from the pressure reducing valve, the common rail pressure is always adjusted to be equal to or lower than a specified value. The fuel discharged from the pressure reducing valve is returned to the fuel tank through the relief pipe.

Each cylinder of engine 100 is provided with an injector 20. The injector 20 has a configuration in which the tip portion of the nozzle body 203 protrudes from the cylinder head 15 into the cylinder, and the installation position of the tip portion is offset with respect to the center axis of the piston 11. Match (or nearly match).
The fuel supplied from the common rail through the high-pressure pipe is injected and supplied into the cylinder by the injector 20 in accordance with an instruction from the engine ECU 10. The engine ECU 10 determines the fuel injection amount and the injection timing based on the intake air amount from the air flow meter 32 and the piston position information from the crank angle sensor 31 and sends a signal to the injector 20. The injector 20 injects fuel into the cylinder at a high pressure at the instructed fuel injection amount / injection timing according to a signal from the engine ECU 10. The leaked fuel from the injector 20 is returned to the fuel tank through the relief pipe. In this case, the injector 20 can be mounted at any position in the cylinder according to the specifications of the engine 100 and layout requirements.
The injector 20 is a configuration example of the fuel injection valve of the present invention.

FIG. 2 shows a schematic configuration of the injector 20. FIG. 2 shows only a part of the configuration of the injector (near the tip portion of the nozzle body 203).
The injector 20 includes a nozzle body 203 in which a first fuel injection hole 201 and a second fuel injection hole 202 are formed, and a cylindrical outer member that is slidably accommodated in the nozzle body 203 and opens and closes the second fuel injection hole 202. A needle 204, an inner needle 205 that is slidably inserted into the outer needle 204, opens and closes the first fuel injection hole 201, and an outer needle set that biases the outer needle 204 in a direction to close the second fuel injection hole 202 A spring 206 and an inner needle set spring 207 that urges the inner needle 205 in a direction to close the first fuel injection hole 201 are configured.

  The injector 20 has a first back pressure chamber 208 and a second back pressure chamber 209, and a fuel flow path communicating with the two back pressure chambers is freely controlled by a back pressure control valve 210 realized by an electromagnetic valve. Can be switched to. When the back pressure control valve 210 causes the first back pressure chamber 208 and the second back pressure chamber 209 to communicate with the supply-side channel 212, high-pressure fuel is introduced into the first back pressure chamber 208 and the second back pressure chamber 209. As a result, the outer needle 204 and the inner needle 205 are urged in the closing direction by the back pressure. On the other hand, when the back pressure control valve 210 causes the first back pressure chamber 208 and the second back pressure chamber 209 to communicate with the discharge side passage 211, the high pressure fuel from the first back pressure chamber 208 and the second back pressure chamber 209 is obtained. Discharge begins. As a result, the back pressure applied to the outer needle 204 and the inner needle 205 is reduced, and the urging force based on the back pressure is also reduced. Further, when the sum of this biasing force and the elastic force (biasing force) of the inner needle set spring 207 becomes smaller than the biasing force based on the fuel pressure of the fuel supplied for injection, the inner needle 205 opens the first fuel injection hole 201. The movement starts in the opening direction, and fuel injection from the first fuel injection hole 201 starts. Similarly, when the sum of the biasing force based on the back pressure and the elastic force (biasing force) of the outer needle set spring 206 becomes smaller than the biasing force based on the fuel pressure of the fuel supplied for injection, the outer needle 204 opens. The fuel injection from the second fuel injection hole 202 starts.

When the back pressure control valve 210 causes the second back pressure chamber 209 and the supply side flow passage 212 to communicate with each other, the injector 20 causes the inner needle 205 to communicate with the first back pressure chamber 208 and the discharge side flow passage 211. Only the first fuel injection hole 201 is opened. On the other hand, when the back pressure control valve 210 communicates the second back pressure chamber 209 and the discharge side channel 211 with the first back pressure chamber 208 and the supply side channel 212 communicating, only the outer needle 204 is By lifting, only the second fuel injection hole 202 is opened. As described above, the injector 20 adjusts the fuel pressure inside the first back pressure chamber 208 and the second back pressure chamber 209 to open and close the first fuel injection hole 201 and the second fuel injection hole 202 independently. Can be made.
In this case, the back pressure control valve 210 is not limited to a solenoid valve (solenoid type), and other actuators such as a piezoelectric type using a piezoelectric element can also be applied. In this embodiment, two back pressure chambers are provided. However, a single back pressure chamber may be used as long as the outer needle 204 and the inner needle 205 can be lifted independently.
The inner needle 205, the first back pressure chamber 208, and the back pressure control valve 210 are a structural example of the first adjusting means of the present invention. Further, the outer needle 204, the second back pressure chamber 209, and the back pressure control valve 210 are a configuration example of the second adjusting means of the present invention.

  The first fuel injection hole 201 is a six-hole fuel injection hole provided in the circumferential direction of the tip portion of the nozzle body 203 protruding from the cylinder head 15 into the cylinder, and the piston is more piston than the second fuel injection hole 202. It is located closer to 11 (lower side). The first fuel injection holes 201 are arranged so as to be able to inject fuel in a direction substantially equally dividing the outer periphery of the cavity 12 provided in the piston 11 (provided at substantially equal intervals (for example, 60 ° intervals)), Fuel can be injected into the cavity 12 substantially uniformly.

  The second fuel injection holes 202 are six fuel injection holes provided in the circumferential direction of the tip portion of the nozzle body 203 protruding from the cylinder head 15 into the cylinder, and the cylinders are more cylinders than the first fuel injection holes 201. It is located near the head 15 (upper side). The second fuel injection holes 202 are arranged so as to be able to inject fuel (provided at unequal intervals) in a direction in which the outer periphery (or bore circumference) of the piston 11 is substantially equally divided, so that the second fuel injection hole 202 is substantially uniform over the entire bore. Allow fuel to be injected. The second fuel injection hole 202 is arranged in a direction different from the arrangement direction of the first fuel injection hole 201 with respect to the surface orthogonal to the sliding direction of the piston 11, and the fuel injected from the second fuel injection hole 202 is the first. The fuel injected from one fuel injection hole 201 and the cylinder are prevented from overlapping each other.

FIG. 3 shows an example of the fuel spray axis of the injector 20. The installation position of the tip portion of the nozzle body 203 protruding from the cylinder head 15 into the cylinder coincides with the center axis of the cavity 12, and the center axis of the cavity 12 (that is, the installation position of the tip portion of the injector 20) is the piston 11. It is offset with respect to the central axis.
The fuel injected from the first fuel injection hole 201 scatters in a direction that divides the outer periphery of the opening of the cavity 12 into approximately six equal parts. On the other hand, the fuel injected from the second fuel injection hole 202 is in a direction that divides the outer periphery (or bore circumference) of the piston 11 into approximately six equal parts and overlaps with the fuel injected from the first fuel injection hole 201. Splashes in the direction that is not. By providing the first fuel injection hole 201 and the second fuel injection hole 202 in this way, it is possible to inject fuel from the first fuel injection hole 201 into the cavity substantially uniformly and from the second fuel injection hole 202 to the bore. The fuel can be injected substantially uniformly throughout.
In this case, the first fuel injection holes 201 and the second fuel injection holes 202 are not limited to six fuel injection holes, and any number of holes can be applied according to the specifications of the engine 100.

  Returning to FIG. 1, the engine ECU 10 includes a CPU (Central Processing Unit) that performs arithmetic processing, a ROM (Read Only Memory) that stores programs, a RAM (Random Access Memory) that stores data, and an NVRAM (Non Volatile). RAM). The engine ECU 10 reads the detection results of a plurality of sensors such as a crank angle sensor 31, an air flow meter 32, and an accelerator opening sensor 33 provided in each part of the engine 100, and integrates the operation of the engine 100 based on the detection results. Control.

  Further, the engine ECU 10 executes fuel injection control for arbitrarily controlling the fuel injection from the first fuel injection hole 201 and the fuel injection from the second fuel injection hole 202 based on the operation region (output) of the engine 100. To do. Hereinafter, fuel injection control executed by the engine ECU 10 will be described.

  The engine ECU 10 recognizes the output (rotation speed, torque, etc.) of the engine 100 based on the detection results of the crank angle sensor 31, the air flow meter 32, the accelerator opening sensor 33, and the like. The engine ECU 10 lifts the inner needle 205 of the injector 20 and opens only the first fuel injection hole 201 when the recognized output of the engine 100 is lower, for example, less than a predetermined first output. The injection supply is executed. Here, the first output is an output of the engine 100 (for example, a low speed / medium load operation region) that can be determined to have a high combustion rate in the cavity 12 (combustion chamber). The determined output can be applied.

  FIG. 4 shows an example of the combustion state of the engine 100 in the low speed operation region. Since the combustion rate in the combustion chamber (cavity) is high when the engine 100 is in the low speed operation region, if the fuel is injected almost uniformly from the second fuel injection hole 202 to the entire bore, the air utilization rate in the cylinder is poor. Combustion is biased and smoke emission increases (see FIG. 4B). On the other hand, when fuel is injected substantially uniformly into the cavity 12 from the first fuel injection hole 201, good combustibility can be obtained, and the smoke discharge amount can be suppressed (see FIG. 4A). As described above, when the output of the engine 100 is less than the predetermined first output, the fuel is supplied from the first fuel injection hole 201 of the injector 20 to improve the fuel consumption and the exhaust gas in the low speed operation region. Reduction of emissions can be achieved.

  On the other hand, when the recognized output is higher, for example, when the output is equal to or higher than a predetermined second output, the engine ECU 10 lifts the outer needle 204 of the injector 20 and opens only the second fuel injection hole 202 to inject and supply fuel. Let Here, the second output is an output of the engine 100 (for example, a high-speed / high-load operation region) that can be determined to have a high combustion rate outside the cavity 12 (combustion chamber). The determined output can be applied.

  FIG. 5 shows an example of the combustion state of the engine 100 in the high-speed operation region. When the engine 100 is in the high speed operation region, the combustion rate is high outside the combustion chamber (cavity), that is, in the entire bore. Therefore, when fuel is injected substantially uniformly into the cavity 12 from the first fuel injection hole 201, the air in the cylinder The utilization rate is poor and combustion is biased, resulting in an increase in smoke emission (see FIG. 5A). On the other hand, if fuel is injected substantially uniformly from the second fuel injection hole 202 to the entire bore, good combustibility can be obtained, and the smoke emission amount can be suppressed (see FIG. 5B). Therefore, when the output of the engine 100 is equal to or higher than the predetermined second output, the fuel is supplied from the second fuel injection hole 202 of the injector 20 to improve the fuel consumption and the exhaust emission in the high speed operation region. Reduction can be achieved.

Further, the engine ECU 10 recognizes that the output of the engine 100 is in a region where the use of air in the entire cylinder is required (for example, greater than or equal to the first output and less than the second output), the outer needle 204 of the injector 20. In addition, the fuel can be injected and supplied by lifting the inner needle 205 and opening the first fuel injection hole 201 and the second fuel injection hole 202. By executing this control, fuel can be injected substantially uniformly into the cavity 12 and the entire bore, so that good combustibility can be obtained.
The engine ECU 10 is a configuration example of the fuel injection control means of the present invention.

  As described above, the injector of the present embodiment is provided in a plurality of directions on the same circumference of the tip portion of the nozzle body, and is disposed so as to be able to inject fuel in a direction substantially equally dividing the outer periphery of the cavity. By providing one fuel injection hole and a second fuel injection hole disposed so as to be able to inject fuel in a direction substantially equally dividing the outer periphery of the piston, fuel is injected substantially uniformly from the first fuel injection hole into the cavity. The fuel can be injected substantially uniformly from the second fuel injection hole to the entire bore. Therefore, since appropriate fuel injection can be executed in the entire operation region of the direct injection internal combustion engine, improvement in fuel consumption and reduction in exhaust emission can be achieved.

  The engine system of the present embodiment also injects fuel from the first fuel injection hole of the injector when the engine output is lower, and injects fuel from the second fuel injection hole of the injector when the engine output is higher. As a result, in the low power operation region where the combustion ratio in the combustion chamber is high, the fuel can be injected substantially uniformly into the cavity from the first fuel injection hole, and the high power operation where the combustion ratio outside the combustion chamber is high. In the region, fuel can be injected substantially uniformly from the second fuel injection hole to the entire bore. Therefore, since appropriate fuel injection can be executed in the entire operation region of the direct injection internal combustion engine, improvement in fuel consumption and reduction in exhaust emission can be achieved.

  The above embodiments are merely examples for carrying out the present invention. Therefore, the present invention is not limited to these, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims.

  For example, the installation position of the tip portion of the injector 20 may coincide with the central axis of the piston 11 or may be offset with respect to the central axis of the piston 11 and the central axis of the cavity 12. Of course, also in this case, the first fuel injection hole 201 is disposed so as to be able to inject fuel in a direction substantially equally dividing the outer periphery of the cavity 12, and the second fuel injection hole 202 is approximately the outer periphery (or bore circumference) of the piston 11. It arrange | positions so that a fuel can be injected in the direction to divide equally.

  Further, the first fuel injection hole 201 is disposed so as to be able to inject fuel in a direction substantially equally dividing the outer periphery (or bore circumference) of the piston 11, and the second fuel injection hole 202 substantially equally divides the outer periphery of the cavity 12. The structure arrange | positioned so that fuel can be injected in a direction may be sufficient.

1 engine system 10 engine ECU (fuel injection control means)
DESCRIPTION OF SYMBOLS 11 Piston 12 Cavity 15 Cylinder head 20 Injector 100 Engine 201 1st fuel injection hole 202 2nd fuel injection hole 203 Nozzle body 204 Outer needle (2nd adjustment means)
205 Inner needle (first adjusting means)
208 first back pressure chamber (first adjusting means)
209 Second back pressure chamber (second adjusting means)
210 Back pressure control valve (first adjusting means, second adjusting means)

Claims (6)

A fuel injection valve provided with a tip portion protruding in a cylinder of a direct injection internal combustion engine having a combustion chamber in which a central axis of a cavity formed in a concave shape on the top surface of the piston is offset with respect to the central axis of the piston There,
A first fuel injection hole that is provided in a plurality of directions on the same circumference of the tip portion and is arranged so that fuel can be injected in a direction that substantially divides the outer periphery of the cavity;
A second fuel injection hole provided in a plurality of directions on the same circumference of the tip portion different from the first fuel injection hole, and arranged to be able to inject fuel in a direction substantially equally dividing the outer periphery of the piston; ,
A fuel injection valve comprising:   2. The fuel injection valve according to claim 1, wherein the second fuel injection hole is provided at the tip portion closer to the cylinder head of the direct injection internal combustion engine than the first fuel injection hole.   3. The fuel injection valve according to claim 1, wherein the second fuel injection hole is arranged in a direction different from an arrangement direction of the first fuel injection hole with respect to a surface orthogonal to a sliding direction of the piston. .   A first adjusting means for arbitrarily adjusting a fuel injection amount from the first fuel injection hole; and a second adjusting means for arbitrarily adjusting a fuel injection amount from the second fuel injection hole. The fuel injection valve according to any one of claims 1 to 3. A direct injection internal combustion engine comprising the fuel injection valve,
A direct injection internal combustion engine comprising fuel injection control means for controlling the first adjustment means and the second adjustment means based on the output of the direct injection internal combustion engine. The fuel injection control means injects fuel from the first fuel injection hole when the output of the direct injection internal combustion engine is lower, and the second fuel injection when the output of the direct injection internal combustion engine is higher. 6. The direct injection internal combustion engine according to claim 5, wherein fuel is injected from the hole.

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