JP2003278589A - In-cylinder direct injection internal combustion engine - Google Patents

Abstract

(57) [Summary] [PROBLEMS] NOx which becomes a problem when performing compression stroke injection
And at the same time improve the torque that is important for the intake stroke injection. SOLUTION: In a direct injection type internal combustion engine, at high load, fuel is injected during an intake stroke, and at medium load,
Fuel injection is performed during the compression stroke. A variable valve mechanism for continuously variably controlling the opening / closing timing of the intake valve is provided. In the compression stroke injection, the intake valve opening timing IVO is advanced and the closing timing IVC is delayed. As a result, a large amount of exhaust remains in the cylinder, and NOx is reduced. In the intake stroke injection, the intake valve opening timing IVO is delayed and the closing timing IVC is advanced. As a result, the discharge of the air-fuel mixture is reduced, the filling efficiency is increased, and the torque is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a 4-cycle spark ignition type internal combustion engine represented by a gasoline engine, and more particularly to a direct injection type internal combustion engine for directly injecting fuel into a cylinder.

[0002]

2. Description of the Related Art In recent years, some gasoline engines include a direct injection type cylinder in which an electromagnetic fuel injection valve is arranged toward the inside of the cylinder so that fuel is directly injected into the cylinder. It has been put to practical use.

Then, the fuel injection timing has been variably controlled according to the engine operating conditions. Specifically, in the high-load and high-speed range including full-open operation, fuel is injected during the intake stroke to achieve uniform mixing, and intake cooling is performed by vaporizing the fuel to improve knock resistance and improve the efficiency of intake. I am trying to realize. That is, this makes it possible to improve the torque. Further, in the other middle and low load regions, fuel is injected during the compression stroke to realize stratified mixing. With this layered mixing,
Ultra lean combustion with an air-fuel ratio of about 30 to 40 is possible and fuel consumption can be reduced (Mitsubishi Motors Corporation 19).
(See "In-cylinder injection gasoline engine" issued in May 1995).

[0004]

However, in the conventional in-cylinder direct injection type internal combustion engine, even if the fuel injection timing is variably controlled as described above, the variably controlled valve timing is not performed. Therefore, there is still room for improvement in reducing NOx and improving torque.

That is, when the fuel is injected during the compression stroke to form the stratified mixture, the air-fuel ratio in the combustion chamber varies. Here, in the portion where the air-fuel ratio is close to the theoretical air-fuel ratio, even if NOx is generated by combustion, it can be easily reduced by the three-way catalyst provided in the exhaust system. Further, the air-fuel ratio is 30 to
The NOx emission amount itself is small in the thin region of about 40.

However, in the middle layer having an air-fuel ratio of about 16 to 17, although the NOx emission amount is large,
Since the three-way catalyst does not work sufficiently, NOx is directly emitted to the outside of the engine. In other words, when the injection is performed during the compression stroke to perform lean combustion, the entire internal combustion engine,
NOx cannot be reduced sufficiently.

Further, in the intake stroke injection for injecting the fuel during the intake stroke, since it is a homogeneous mixture, there is no problem of NOx as described above, and it is important how the torque can be increased. With the fixed setting, the charging efficiency may be reduced due to the discharge back of the air-fuel mixture through the intake valve, and the torque cannot always be sufficiently increased.

[0008]

Therefore, according to the present invention, in a cylinder direct injection internal combustion engine in which the fuel injection timing is variably controlled according to the engine operating condition, the valve timing changes according to the fuel injection timing. It is configured as follows.

More specifically, the in-cylinder direct injection internal combustion engine of the present invention has a variable valve mechanism for variably controlling the opening / closing timing of the intake valve, and when the fuel injection start timing is in the intake stroke, intake air is taken. It is characterized by advancing the valve closing timing and advancing the intake valve opening timing when the fuel injection start timing is in the compression stroke.

More preferably, when the fuel injection start timing is in the intake stroke, the intake valve open timing is delayed and the intake valve close timing is advanced, and the fuel injection start timing is in the compression stroke. At times, it is advisable to advance the intake valve opening timing and delay the intake valve closing timing.

As described above, when the fuel is injected during the compression stroke to form the stratified mixture, the air-fuel ratio in the combustion chamber varies. Here, in the portion where the air-fuel ratio is close to the theoretical air-fuel ratio, even if NOx is generated by combustion, it can be easily reduced by the three-way catalyst provided in the exhaust system. Further, in the lean region where the air-fuel ratio is about 30 to 40, the NOx emission amount itself is small. On the other hand, in the intermediate layer having an air-fuel ratio of about 16 to 17, there is a problem that the three-way catalyst does not work sufficiently despite the large amount of NOx emission.

However, according to the present invention, during this compression stroke injection, by advancing the intake valve opening timing, a large amount of exhaust gas as so-called internal EGR can be introduced into the combustion chamber, and the combustion temperature decreases. . As a result, NOx
Emissions are reduced.

If the intake valve closing timing is further delayed,
Since the actual compression ratio decreases and the combustion temperature further decreases, N
Ox emissions will be further reduced.

On the other hand, when the fuel is injected during the intake stroke, since it is a homogeneous mixture, NO such as in the compression stroke injection is used.
There is no problem of x, and how to increase the torque becomes a problem. In the present invention, by advancing the intake valve closing timing during the intake stroke injection, the discharge back of the air-fuel mixture to the intake port is reduced, and the charging efficiency is improved. Therefore, the torque is improved.

If the intake valve opening timing is delayed at the same time,
Since the valve overlap is reduced and the residual gas in the cylinder is reduced, the charging efficiency is further improved and the torque can be further increased.

Since the amount of mixture discharged back decreases as the engine speed increases, the intake valve closing timing may be gradually delayed as the engine speed increases. Also,
Since the intake efficiency decreases as the rotation speed increases, the intake valve opening timing may be gradually advanced as the rotation speed increases so that the intake valve opening angle increases.

Further, according to the present invention, preferably, as in claim 4, the injection start timing in the compression stroke is delayed at the same time as or slightly behind the intake valve closing timing.

That is, at the start of fuel injection, the intake valve is closed. As a result, it is possible to reliably prevent the gas flow accompanied by the fuel spray from leaking to the intake port side and secure a strong gas flow. In addition, it is possible to secure the time required for atomization before ignition, improve atomization, and realize good combustion.

Further, in the present invention, preferably, a time difference is provided between the fuel injection timing switching and the valve timing switching, as in the fifth aspect. Then, desirably, the switching of the fuel injection timing is executed before the switching of the valve timing with respect to the change of the engine operating condition.

Thus, by giving a time difference,
The torque change due to the switching of the injection timing and the torque change due to the switching of the valve timing do not occur at the same time, and the torque shock is suppressed. Since the injection timing can be switched more quickly, the injection timing can be switched ahead of the valve timing, so that the driver's accelerator operation can be favorably responded to and the response can be improved.

Further, according to the seventh aspect of the invention, the valve timing is switched after the switching of the fuel injection timing of all the cylinders is completed with respect to the change of the engine operating condition.

That is, by waiting for the completion of the switching of the fuel injection timings of all the cylinders, the valve timing is changed after the variation of the air-fuel ratio among the cylinders is reduced, and the occurrence of transient emission can be prevented. It is also advantageous in reducing torque shock.

Further, in the present invention, it is desirable that the valve timing be fixed at a predetermined timing at a low load including idle, regardless of the variable control of the fuel injection timing.

The idle has poor combustion stability, and it is important to prevent the engine from stopping due to a stall (so-called engine stall). However, switching the valve timing may cause the engine to stop. In particular, when trying to switch the valve timing when the engine is in a low temperature state, the response variation of the variable valve actuation mechanism may occur, which causes transient deterioration of combustion and further prone to stall. . Therefore, in the present invention, so-called engine stall can be prevented by fixing the valve timing to a predetermined timing regardless of the variable control of the fuel injection timing during low load including idle. Incidentally, in general, the valve timing for intake stroke injection is fixed.

Further, when the variable control of the fuel injection timing does not operate normally, the combustion becomes unstable and the engine is likely to stop. Therefore, in the present invention, as in claim 9, it is desirable that the valve timing be fixed to a predetermined timing when the variable control of the fuel injection timing is abnormal. As a result, engine stall accompanying switching of valve timing can be avoided. In addition, if the valve timing at this time is set to a characteristic for intake stroke injection, it is advantageous in ensuring startability.

In the present invention, as in claim 10,
It is desirable to use a variable valve mechanism that can continuously control the valve timing.

As a result, there is no shock as in the case where the valve timing is changed stepwise.

[0028]

As described above, according to the present invention, the NOx emission amount can be reduced and the torque can be increased by advancing the intake valve opening timing when the compression stroke injection is performed to perform lean combustion. Therefore, when the intake stroke injection is performed, advancing the intake valve closing timing can improve the charging efficiency and thus the torque.

According to the third aspect, the NOx emission amount can be further reduced and the torque can be further increased.

According to the fourth aspect, the atomization can be improved and the good combustion can be realized by the strong gas flow.

According to claims 5 and 6,
It is possible to prevent the occurrence of a large torque shock due to the change of the injection timing and the like and to prevent the deterioration of the response with respect to the change of the engine operating condition.

Further, according to the invention of claim 7, it is possible to prevent the occurrence of transient emission due to the variation of the air-fuel ratio between the cylinders, which is also advantageous in reducing the torque shock.

Further, according to claims 8 and 9,
It is possible to reliably prevent the engine from stopping due to the stall.

If a variable valve mechanism capable of continuously controlling the valve timing is used as in the tenth aspect, the valve timing can be maintained more appropriately and a large shock can be prevented.

[0035]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows an embodiment of a direct injection type internal combustion engine according to the present invention, in which a plurality of cylinders 2 are arranged in series in a cylinder block 1 and each cylinder 2 is directly connected to each other. An electromagnetic fuel injection valve 3 is arranged above each cylinder 2 so as to inject fuel. Fuel having a relatively high pressure is supplied to the fuel injection valve 3 so that fuel can be injected during the compression stroke. An intake port 6 opened / closed by an intake valve 5 and an exhaust port 8 opened / closed by an exhaust valve 7 are formed in a cylinder head 4 covering the top of the cylinder 2, and an ignition plug 9 is attached.

The exhaust valve 7 is opened and closed by the exhaust camshaft 10 at fixed valve timing. On the other hand, the intake valve 5 has a configuration in which the opening / closing timing of the intake valve 5 can be variably controlled by the variable valve mechanism 11.

Reference numeral 12 is a control unit consisting of a microcomputer system for controlling the injection timing of the fuel injection valve 3 and the valve timing of the intake valve 5 according to the engine operating conditions. A rotation speed signal indicating a condition, a load signal (for example, an intake air amount signal), and the like are input, and based on these detection signals, a control signal is sent to each fuel injection valve 3 and the hydraulic control valve 13 of the variable valve mechanism 11. Is being output.

The variable valve mechanism 11 is disclosed in JP-A-6-18.
As disclosed in Japanese Patent No. 5321, US Pat. No. 5,365,896, etc., the cylinder camshaft 22 of each cylinder is rotated at a non-constant speed by applying the principle of a non-constant-speed shaft coupling. The valve lift characteristic can be continuously and variably controlled.

Since this mechanism itself is publicly known, it will be briefly described with reference to FIGS. 1 and 2. In FIG.
Is from the engine crankshaft (not shown) to the timing chain 14
A drive shaft 22 through which a rotational force is transmitted (see FIG. 2)
Is a hollow cylindrical camshaft rotatably fitted to the outer periphery of the drive shaft 21. The cam shaft 22 is divided for each cylinder.

The cam shaft 22 is rotatably supported by a cam bearing at the upper end of the cylinder head 4, and a pair of cams 26 for opening the intake valves 5 of each cylinder are formed on the outer periphery of the cam shaft 22. . Also, the camshaft 22
Is divided into a plurality of pieces as described above, and the first flange portion 27 is provided at one of the divided ends. Further, a sleeve 28 and an annular disk 29 are arranged between the ends of the camshaft 22 divided into a plurality of parts. The first flange portion 27 is formed with an elongated engaging groove 30 along the radial direction.

The sleeve 28 is fixed to the drive shaft 21, and the sleeve 28 is formed with a second flange portion 32 facing the first flange portion 27. The second flange portion 32 also has an elongated engagement groove formed in the radial direction.

The annular disc 29 located between the flange portions 27 and 32 has a substantially donut plate shape and has an annular gap between the outer peripheral surface of the drive shaft 21 and the inner periphery of the disc housing 34. It is rotatably held on the surface. Further, a pair of pins 36 and 37 projecting to opposite sides are provided at opposing positions on diameter lines different from each other by 180 °, and the pins 36 and 37 are engaged with the engagement grooves.

The disc housing 34 has a substantially triangular shape. An annular disc 29 is held in the circular opening of the disc housing 34, and the first cam fitting hole 38 and the second cam are respectively provided at the two positions which are the tops of the triangles. The fitting hole 39 is formed so as to penetrate therethrough.

The circular cam portions 41a and 43a of the first eccentric cam 41 and the second eccentric cam 43 are rotatably fitted in the first cam fitting hole 38 and the second cam fitting hole 39, respectively. I am fit.

As shown in FIG. 1, the second eccentric cam 43 is composed of a cylindrical shaft portion 43b and a circular cam portion 43a which are eccentric to each other by a predetermined amount, and both are rotatably fitted and integrated. Has been done. The circular cam portion 43a is prevented from coming off by the snap ring 30. The shaft 4
As shown in FIG. 1, 3b is press-fitted and fixed to the partition wall of the frame 33.

The first eccentric cam 41 has a control cam shaft 42 which is continuous over a plurality of cylinders in the longitudinal direction of the engine.
And a plurality of circular cam portions 41a fixed to the cam shaft 42 corresponding to each cylinder, and both are eccentric by a predetermined amount. The circular cam portion 41a of each cylinder is eccentric at a predetermined angular position of the cam shaft 42. The control cam shaft 42 is rotatably held by the frame 33 via a cam bracket 35. A rotary hydraulic actuator 46 is attached as a drive mechanism to one end of the control cam shaft 42 located at one end of the internal combustion engine. Further, a rotary potentiometer 47 for detecting the rotational position of the control cam shaft 42, that is, the phase of the circular cam portion 41a is attached to the other end of the control cam shaft 42 located in the front part of the internal combustion engine.

In the variable valve mechanism 11 described above, the first
By variably controlling the eccentric position of the annular disc 29 via the eccentric cam 41, the cam shaft 22 rotates at a non-constant speed, and a phase difference corresponding to the amount of eccentricity is generated between the cam shaft 22 and the drive shaft 21. For example, the center of the annular disc 29 and the drive shaft 21
In the state where the center of the drive shaft coincides with the center of the drive shaft, the camshaft 22 rotates synchronously with the drive shaft 21 at a constant speed, so that the valve lift characteristic shown by the solid line in FIG. On the other hand, when the center of the annular disc 29 is eccentric to one side, a phase difference corresponding to the amount of eccentricity occurs as shown by the chain line in FIG. 3 (B). A valve lift characteristic as shown by a chain line is obtained. That is, by controlling the amount of eccentricity, both the opening timing and the closing timing of the intake valve 5 can be continuously variably controlled.

FIG. 4 is a time chart showing the relationship between the fuel injection timing and the valve timing according to the present invention. As shown in the figure, the fuel injection timing can be switched between two types according to engine operating conditions. That is, the compression stroke injection, which is injected while the piston is in the compression stroke, and the intake stroke injection, which is injected while the piston is in the intake stroke, are appropriately switched. In the figure, GO is the injection start timing and GC is the injection end timing. Regardless of the magnitude of the injection amount, the injection start timing GO is during the compression stroke during the compression stroke injection, and during the intake stroke injection. Are controlled so as to be included in the intake stroke.

The opening / closing timing of the intake valve 5 differs depending on whether the fuel injection timing is the compression stroke injection or the intake stroke injection. Specifically, in the case of the compression stroke injection, the opening timing IVO of the intake valve 5 is relatively early as compared with the case of the intake stroke injection, and
The closing timing IVC is relatively late. Further, at the time of compression stroke injection, the fuel injection start timing GO is the intake valve closing timing I
Slightly slower than VC.

FIG. 5 and Table 1 collectively show the relationship between the engine operating conditions and the above-mentioned fuel injection timing and valve timing. In the region A on the high speed and high load side, as shown in Table 1, The stroke injection is performed, and correspondingly, the opening timing IVO of the intake valve 5 is delayed and the closing timing IVC is advanced. In the medium load region B, in order to perform lean combustion,
The compression stroke injection is performed, and correspondingly, the opening timing IVO of the intake valve 5 is early and the closing timing IVC is late.

Further, in the region C on the low speed and low load side including the idle, the fuel injection timing varies depending on the engine temperature condition. After the engine is warmed up, compression stroke injection is used to improve fuel efficiency. Also, at the time of cryogenic cooling,
In order to ensure startability, injection stroke injection is used to ensure a long atomization time. The valve timing is fixed to the characteristic for intake stroke injection, regardless of the switching of the injection timing. Therefore, for example, when the engine is left idle after a cold start at a very low temperature, the fuel injection timing is switched to the compression stroke injection when the engine temperature rises slightly, but the valve timing is not switched. It is possible to avoid the stall and the engine stop due to the switching of the engine.

Although illustration is omitted, if the fuel injection timing is not normally changed due to some abnormality, the valve timing is also fixed. In this case, if it is fixed to the characteristic of the intake stroke injection, it is still advantageous for ensuring the startability.

[0054]

[Table 1]

Next, FIG. 6 is a time chart for explaining the fuel injection timing and the valve timing switching timing in a multi-cylinder internal combustion engine, for example, a 4-cylinder internal combustion engine.
Specifically, it shows changes during acceleration. Here, the black circles indicate the compression stroke injection, and the white circles indicate the intake stroke injection. As shown in FIG.
When the throttle opening of the internal combustion engine increases and the operating condition changes from the region B to the region A, at the same time, the injection timing is switched, specifically, the compression stroke injection is switched to the intake stroke injection. To be done. However, since this switching is actually performed sequentially for the four cylinders according to the ignition order,
One cycle of the engine is required to complete the switching for all cylinders. Then, after the switching of the injection timing is completed for all the cylinders, the valve timings are simultaneously switched via the variable valve mechanism 11. Specifically, the control cam shaft 42 is rotationally driven to a predetermined position.

In this way, by giving a slight time difference between the switching of the fuel injection timing and the switching of the valve timing,
Torque shock can be suppressed. Also, since the fuel injection timing switching is executed immediately without any mechanical delay,
The acceleration response is excellent while suppressing the torque shock.

[Brief description of drawings]

FIG. 1 is a structural explanatory view showing an embodiment of a direct injection type internal combustion engine according to the present invention.

FIG. 2 is a perspective view of a main part showing the configuration of the variable valve mechanism.

FIG. 3 is a characteristic diagram showing a comparison between a rotational phase difference between a drive shaft and a cam shaft and a valve lift characteristic in this variable valve mechanism.

FIG. 4 is a time chart showing the relationship between fuel injection timing and valve timing.

FIG. 5 is a characteristic diagram showing an engine operating region.

FIG. 6 is a time chart showing a switching timing between fuel injection timing and valve timing in a multi-cylinder internal combustion engine.

[Explanation of symbols]

2 ... Cylinder 3 ... Fuel injection valve 5 ... Intake valve 11 ... Variable valve mechanism

[Procedure amendment]

[Submission date] May 1, 2003 (2003.5.1)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0007

[Correction method] Change

[Correction content]

Further, in the intake stroke injection for injecting the fuel during the intake stroke, since it is a homogeneous mixture, there is no problem of NOx as described above, and it is important how the torque can be increased. With the fixed setting, the charging efficiency may be reduced due to the discharge back of the air-fuel mixture through the intake valve, and the torque cannot always be sufficiently increased. This invention responds to engine operating conditions.
Direct injection type internal combustion engine with variable fuel injection timing
The appropriate valve tie according to the fuel injection timing.
In particular, injection timing switching and valve
Torque shock due to timing switching can be suppressed.
And is intended.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

[0008]

Therefore, according to the present invention, in a cylinder direct injection internal combustion engine in which the fuel injection timing is variably controlled according to the engine operating condition, the valve timing changes according to the fuel injection timing. Is configured and
It takes time to switch the fuel injection timing and the valve timing.
It is characterized in that a difference is provided.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0009

[Correction method] Change

[Correction content]

Preferably, the direct injection type internal combustion engine of the present invention has a variable valve mechanism for variably controlling the opening / closing timing of the intake valve, and the intake valve closing timing when the fuel injection start timing is in the intake stroke. early, and Ru advancing the intake valve opening timing when the fuel injection start timing is in the compression stroke.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Correction target item name] 0010

[Correction method] Change

[Correction content]

[0010] More preferably, the intake valve opening timing when the advancing the intake valve closing timing with delaying the intake valve opening timing when the fuel injection start timing is in the intake stroke and fuel injection start timing is in the compression stroke It is advisable to delay the intake valve closing timing as soon as possible.

[Procedure correction 6]

[Document name to be amended] Statement

[Correction target item name] 0012

[Correction method] Change

[Correction content]

[0012] However, at the time of the compression stroke injection of this,
By advancing the intake valve opening timing, so-called internal EGR
As a result, a large amount of exhaust gas can be introduced into the combustion chamber, and the combustion temperature decreases. As a result, the NOx emission amount is reduced.

[Procedure Amendment 7]

[Document name to be amended] Statement

[Correction target item name] 0017

[Correction method] Change

[Correction content]

[0017] In the present invention, preferably, the injection start timing that is in compression stroke is delayed to simultaneously or slightly intake valve closing timing.

[Procedure Amendment 8]

[Document name to be amended] Statement

[Correction target item name] 0019

[Correction method] Change

[Correction content]

[0019] In the present invention, switching and two hours difference switching the valve timing of the fuel injection timing is provided.
Then, desirably, the switching of the fuel injection timing is executed before the switching of the valve timing with respect to the change of the engine operating condition.

[Procedure Amendment 9]

[Document name to be amended] Statement

[Correction target item name] 0021

[Correction method] Change

[Correction content]

Further, according to the third aspect of the invention, the valve timing switching is executed after the switching of the fuel injection timings of all the cylinders is completed in response to changes in the engine operating conditions.

[Procedure Amendment 10]

[Document name to be amended] Statement

[Name of item to be corrected] 0025

[Correction method] Change

[Correction content]

Further, when the variable control of the fuel injection timing does not operate normally, the combustion becomes unstable and the engine is likely to stop. Therefore, in the present invention, it is desirable that the valve timing be fixed at a predetermined timing when the variable control of the fuel injection timing is abnormal as in the fifth aspect . As a result, engine stall accompanying switching of valve timing can be avoided. In addition, if the valve timing at this time is set to a characteristic for intake stroke injection, it is advantageous in ensuring startability.

[Procedure Amendment 11]

[Document name to be amended] Statement

[Correction target item name] 0026

[Correction method] Change

[Correction content]

[0026] In the present invention, it is preferable to use a continuously controllable variable valve mechanism valves timing.

[Procedure Amendment 12]

[Document name to be amended] Statement

[Correction target item name] 0028

[Correction method] Change

[Correction content]

[0028]

As described above, according to the present invention, the engine operation
When switching the fuel injection timing according to the change of the rotation condition,
To obtain the appropriate valve timing according to the fuel injection timing.
It is possible to change the fuel injection timing and valve tie
Since there is a time difference between the switching of
For torque change and valve timing switching
Torque shock does not occur simultaneously with
Can be suppressed. Also, as in claim 2, fuel injection
Perform timing switching before switching valve timing.
By doing so, it is possible to prevent deterioration of response. further,
According to the third aspect of the present invention, the variation in the air-fuel ratio among the cylinders
It is possible to prevent the occurrence of transient emissions due to
It is also advantageous in reducing ku. Further claim 4 and claim
According to Item 5, surely prevent engine stop due to stall
it can. Further, as in claim 6, the valve timing is changed.
If a variable valve mechanism that can be continuously controlled is used,
You can maintain the iming more appropriately, and
Occurrence can be prevented. Further, according to claim 7, lean combustion
Intake valve opening timing when the compression stroke injection is performed to
NOx emissions can be reduced by speeding up
In addition, when the intake stroke injection is performed to increase the torque,
By advancing the valve closing time, the filling efficiency is improved and
It is possible to improve the quality.

[Procedure Amendment 13]

[Document name to be amended] Statement

[Name of item to be corrected] 0029

[Correction method] Change

[Correction content]

According to the eighth aspect , the NOx emission amount can be further reduced and the torque can be further increased.

[Procedure Amendment 14]

[Document name to be amended] Statement

[Name of item to be corrected] 0030

[Correction method] Change

[Correction content]

Further, according to the ninth aspect , the atomization can be improved and the good combustion can be realized by the strong gas flow.

[Procedure Amendment 15]

[Document name to be amended] Statement

[Correction target item name] 0031

[Correction method] Delete

[Procedure Amendment 16]

[Document name to be amended] Statement

[Name of item to be corrected] 0032

[Correction method] Delete

[Procedure Amendment 17]

[Document name to be amended] Statement

[Correction target item name] 0033

[Correction method] Delete

[Procedure 18]

[Document name to be amended] Statement

[Correction target item name] 0034

[Correction method] Delete

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Claims (10)

[Claims] 1. An in-cylinder direct injection internal combustion engine in which the fuel injection timing is variably controlled in accordance with engine operating conditions is characterized in that the valve timing is changed in accordance with the fuel injection timing. In-cylinder direct injection internal combustion engine. 2. A variable valve mechanism for variably controlling the opening / closing timing of an intake valve, advancing the intake valve closing timing when the fuel injection start timing is during the intake stroke, and the fuel injection start timing during the compression stroke. The direct injection type internal combustion engine according to claim 1, wherein the intake valve opening timing is advanced at a certain time. 3. A variable valve mechanism for variably controlling the opening / closing timing of an intake valve, delaying the intake valve opening timing and advancing the intake valve closing timing when the fuel injection start timing is in the intake stroke, and fuel injection 2. The in-cylinder direct injection internal combustion engine according to claim 1, wherein when the start timing is during the compression stroke, the intake valve opening timing is advanced and the intake valve closing timing is delayed. 4. The in-cylinder direct injection internal combustion engine according to claim 1, wherein the injection start timing in the compression stroke is delayed at the same time as or slightly behind the intake valve closing timing. . 5. The in-cylinder direct injection internal combustion engine according to claim 1, wherein a time difference is provided between the fuel injection timing switching and the valve timing switching. 6. The in-cylinder direct injection internal combustion engine according to claim 5, wherein the switching of the fuel injection timing is executed prior to the switching of the valve timing in response to changes in the engine operating conditions. 7. The in-cylinder direct injection internal combustion engine according to claim 6, wherein the valve timing switching is executed after the switching of the fuel injection timings of all the cylinders is completed in response to changes in the engine operating conditions. organ. 8. The in-cylinder according to claim 1, wherein the valve timing is fixed at a predetermined timing regardless of the variable control of the fuel injection timing at the time of low load including idle. Direct injection internal combustion engine. 9. When the variable control of the fuel injection timing is abnormal,
The in-cylinder direct injection internal combustion engine according to any one of claims 1 to 8, wherein the valve timing is fixed at a predetermined time. 10. A variable valve mechanism capable of continuously controlling valve timing is provided.
10. The in-cylinder direct injection internal combustion engine according to any one of 1 to 9.