JP2003227390A - In-cylinder injection type internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an in-cylinder injection type internal combustion engine capable of effectively inhibiting a deviation of an air/fuel ratio caused by a pulsation. <P>SOLUTION: In the in-cylinder injection type internal combustion engine, a variable valve timing mechanism 9a for varying an opening/closing timing of a suction valve 9 is used and a delivery period of a high pressure fuel pump 14 is synchronized to a fuel timing of an injector varied corresponding to the operation state of the engine. Thereby, the fuel is actually injected from the injector 21 at an injection amount of high accuracy approximate to a target injection amount and the pulsation becomes small every time when the fuel is injected. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an in-cylinder injection type internal combustion engine which injects fuel pumped by a reciprocating fuel pump from a fuel injection valve into a cylinder.

[0002]

2. Description of the Related Art An in-cylinder injection type engine (internal combustion engine) that directly injects fuel into a cylinder has the advantage that the fuel injection timing and injection period can be set freely, so that the cylinder can be set according to the operating state of the engine. Various injection timings and injection periods of the injectors are changed according to the operating state of the engine so that optimum combustion is performed therein.

By the way, this cylinder injection type engine is
Depending on the selected injection timing, fuel may be injected into the cylinder during the stroke where high pressure is applied such as the compression stroke.
The fuel injected from the injector must be injected at a pressure higher than the pressure inside the cylinder.

Therefore, most of the cylinder injection type engines are
For example, a plunger type (reciprocating type) high-pressure fuel pump (fuel pump) is used.

This high-pressure fuel pump has a large load (requires a large driving force) in order to increase the pressure of the fuel to a predetermined high pressure value, and is normally driven by the driving force emitted from the engine to supply the fuel of high fuel pressure to the injector. It is being supplied.

[0006]

In the high-pressure fuel pump, in order to supply the fuel to the injector by repeating the suction operation and the discharge operation, the pressure in the pipe is increased in the passage up to the injector by the discharge operation and the suction operation. Pulsations that repeat rising and falling changes occur.

However, while the pulsation of the fuel pressure has a constant cycle, the injection timing of the injector changes over a wide range according to the operating state of the engine, so that the injector is injected in the low fuel pressure region and the high fuel pressure region of the pulsation. Fuel is often injected into the cylinder from. Moreover, even at the same injection timing, the fuel injection period changes according to the operating state, so that the fuel is highly likely to be injected in the pulsating low fuel pressure region and high fuel pressure region.

Therefore, the fuel amount actually injected from the injector is different from the target injection amount calculated by calculation. In particular, the target injection amount is an amount calculated by calculation processing using the average value of fuel pressure pulsation as a reference value,
Even in the same injection period, it is considerably different from the injection amount actually injected in the low fuel pressure region and the high fuel pressure region of pulsation.

Therefore, in the in-cylinder injection type engine, a fuel amount that largely deviates from the calculated value is easily injected into the cylinder, and the air-fuel ratio that is set according to the target engine operating state is likely to deviate.

As a countermeasure against this, the injection period of the injector is shortened when the injection timing of the injector is located in the upslope region of the pulsation, and conversely, the injection period of the injection injector is extended when it is located in the downslope region of the pulsation. It has been proposed to correct the target injection amount and the actual fuel injection amount (for example, Japanese Patent Laid-Open No. 2000-213397).

However, in this technique, although the fuel injection amount actually injected is corrected, on the other hand, the correction of the injection period shortens the injection period in the region where the pulsation pressure rises and further increases the fuel pressure. In the region where the pulsation pressure rises and the pulsation pressure falls, the injection period becomes longer and the fuel pressure tends to fall further, which increases the amplitude of the pulsation, which promotes an error in the injection amount, and is a fundamental improvement. I can't reach it.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a cylinder injection type internal combustion engine capable of effectively suppressing the deviation of the air-fuel ratio due to pulsation.

[0013]

In order to achieve the above object, the invention as set forth in claim 1 is a means for varying the discharge period of a fuel pump for supplying fuel to a fuel injection valve by driving an internal combustion engine, and a pump discharge timing varying means. Is used to shift the fuel injection valve so that it coincides with the injection period of the fuel injection valve.

As a result, the fuel actually injected from the fuel injection valve comes to be injected at a pressure close to the average pressure value of the pulsation, and the injection amount is close to the target injection amount. Moreover, since the amplitude of the pulsation is reduced each time fuel is injected from the discharge period of the fuel pump, the deviation of the air-fuel ratio can be effectively suppressed.

In addition to the above object, a second aspect of the present invention has a fuel pump in which one of an intake valve and an exhaust valve can control the opening / closing timing by a variable valve timing mechanism and is driven through the variable valve timing mechanism. In order to effectively reduce pulsation and suppress deviation of the air-fuel ratio by using the internal combustion engine as it is, the pump discharge timing varying means is the control unit, and the operation of the internal combustion engine susceptible to the pulsation of the fuel pump is performed. In the region, the discharge period of the fuel pump is shifted by the phase control of the variable valve timing mechanism so as to coincide with the injection period of the fuel injection valve, and in the other operating regions, the engine is controlled by the phase control of the first variable valve timing mechanism. The structure is such that the amount of overlap is controlled according to the operating state of.

According to a third aspect of the invention, in addition to the above object, the internal combustion engine is provided with a second variable valve timing mechanism for the remaining valves so that the overlap amount is compensated even when the discharge period of the fuel pump is shifted. The control unit controls the phase of the first variable valve timing mechanism in the operating region of the internal combustion engine that is easily affected by the pulsation of the fuel pump.
The discharge period of the fuel pump is shifted so as to match the injection period of the fuel injection valve, while the phase control of the second variable valve timing mechanism follows the shifted valve and shifts the remaining valve according to the required overlap amount. I did it.

According to a fourth aspect of the present invention, the internal combustion engine is an operating region that is easily affected by the pulsation of the fuel pump so that the control for matching the discharge period with the injection period can be performed concurrently with the overlap control. It was set to the range of medium and low load and high rotation speed.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on the first embodiment shown in FIGS.

FIG. 1 shows a water-cooled engine body of a cylinder injection type internal combustion engine, for example, a direct injection spark type reciprocating gasoline engine (hereinafter, simply referred to as an engine).

The engine body 1 includes a cylinder block 2 having a cylinder 2a and a water jacket 2b, a cylinder head 3 mounted on the upper end of the block 2, and an oil pan 4 mounted on the lower end of the cylinder block 2. Is configured.

In the cylinder 2a, a bowl-shaped bowl curved surface 5a having a bowl shape is provided on the top surface.
The piston 5 having the above is reciprocally housed. In addition,
The piston 5 is connected to a crankshaft (not shown) via a connecting rod 5b, and the reciprocal displacement of the piston 5 is output as a rotational displacement.

A combustion chamber 6 facing the cylinder 2a is formed on the lower surface of the cylinder head 3. A spark plug 3a is incorporated in the center of the combustion chamber 6. An upright intake port 8 extending from the combustion chamber 6 to the upper end of the cylinder block 2 is formed on one side of the combustion chamber 6 sandwiching the ignition plug 3a, and the width of the combustion block 6 to the cylinder block 2 is formed on the other side. An exhaust port 7 extending in the direction is formed. These intake / exhaust ports 7 and 8 are connected to the combustion chamber 6 of each port 7 and 8.
An intake valve 9 and an exhaust valve 10 for opening and closing the ends are incorporated.
These intake / exhaust ports 9 and 10 are connected to the rocker arm 11
camshaft 12 for each intake and exhaust via a and 11b
a and 12b (both are engine parts driven by the driving force (engine) output from the crankshaft). Further, a variable valve timing mechanism 9a (VVT) is attached to one end of the camshaft 12a on the intake side of the camshafts 12a and 12b. The variable valve timing mechanism 9a has a structure in which the intake cam 12c is displaced around the axial center of the camshaft 12a when a hydraulic pressure is applied to the hydraulic chamber partitioned by the vane by a signal given from the outside, for example. The structure is such that the intake cam 12c is advanced or retarded according to an external signal.

A camshaft member 13 dedicated to the pump is connected to the other end of the intake side camshaft 12a. The cam shaft member 13 is provided with a pump drive cam formed on the cam shaft member 13, for example, a four-mount type pump-dedicated cam 13a. This cam 1
A fuel pump, for example, a single-plunger high-pressure fuel pump 14 (corresponding to the fuel pump of the present application) is driven by 3a. The high-pressure fuel pump 14 has, for example, a pump structure in which a plunger 15 that reciprocates with four cams 13a and a pump chamber 16 having a suction valve 16a and a discharge valve 16b are combined. That is, the plunger 15 is reciprocally driven for each cam lobe, so that the suction operation and the discharge operation are repeatedly performed. The intake valve 16 a of the high-pressure fuel pump 14 is connected to the fuel tank 20 via the damper 17, the filter 18, and the low-pressure pump 19.
Connected to the pump and sucked up by the low pressure pump 19 (low pressure)
I inhale. The discharge valve 16b of the high-pressure fuel pump 14 is, for example, an electronically controlled injector 21 incorporated in a cylinder head portion near the intake port 8.
High pressure fuel connected to (INJ: fuel injection valve) and increased in pressure to a predetermined pressure value is directly injected into the cylinder 2a (specifically, the bowl curved surface 5a direction) by the valve opening operation of the injector 21. I am doing it. Incidentally, 22 is a low pressure regulator for maintaining the fuel pressure discharged from the low pressure pump 19 at a predetermined low pressure value, and 23 is the high pressure fuel pump 14.
A high pressure regulator for keeping the fuel discharged from the fuel cell at a predetermined high pressure value, and a fuel pressure sensor 24 for detecting the fuel pressure (fuel pressure) applied to the passage from the high pressure fuel pump 14 to the injector 21.

A predetermined combustion cycle (for example, intake, compression, combustion, exhaust) is performed in the cylinder 2a by the ignition operation of the spark plug 3a, the intake operation of the intake valve 9, the exhaust operation of the exhaust valve 10 and the injection operation of the injector 21. The cycle is repeated.

Further, control devices for various parts of the engine (spark plug 3a, variable valve timing mechanism 9a, injector 2)
1, a fuel pressure sensor 24, a rotation speed sensor (not shown) that detects the rotation speed of the engine, a throttle opening sensor (not shown) that detects the throttle opening of the engine, etc.)
Is, for example, the ECU 2 configured by a microcomputer.
6 is connected. The ECU 26 has a function of setting an optimum injection timing according to the operating state of the engine detected from, for example, the engine speed and the throttle opening, for example, an injection period () based on a target injection amount calculated according to the operating state of the engine. A function of setting the valve opening period) and a function of opening and closing the injector 21 according to the set injection timing and injection period are set so that the fuel is injected at the injection timing and injection period according to the operating state of the engine. ing. The target injection amount is calculated using the average value of the pulsation output from the fuel pressure sensor 24.

Further, the ECU 26 has a function of controlling the phase of the variable valve timing mechanism 9a in accordance with the overlap amount (including zero) of the intake / exhaust valves 9 and 10 set in advance according to the operating state of the engine. It is set.

Further, the ECU 26 is set to control to synchronize the discharge timing of the high-pressure fuel pump 14 with the changing injection timing of the injector 21.

For this, a structure for controlling the variable valve timing mechanism 9a for shifting the opening / closing timing of the intake valve 9 in the advance direction or the retard direction is used.

Since the high-pressure fuel pump 14 is a device driven by the engine output through the variable valve timing mechanism 9, displacement control of the high-pressure fuel pump 14a is
It is required to be compatible with the control of the overlap amount that makes the opening / closing timing of the intake valve 9 phase.

Therefore, one variable timing mechanism 9a
Is selectively used for the shift control of the pump discharge period and the overlap amount control of the intake valve 9.

Specifically, looking at the operating state of the engine, the pulsation of the fuel pressure shows that the pulsation of the fuel pressure is in a high engine speed region (for example, 400 rpm).
Higher than 0 rpm). Also, engine load (average effective pressure P calculated from engine speed and throttle opening)
In a region where e) is high, there is a region where the injection period of the injector 21 is longer than the suction / discharge period (1 pulse width) of the high-pressure fuel pump 14, and in this case, the control of the injection amount is little affected.

Therefore, as shown in FIG. 2, the ECU 26
For example, in the engine operating range, the α region is defined as the region that is easily affected by pulsation, and the other β region is defined as the region that is less likely to be affected by pulsation. Without the high-pressure fuel pump 14 from the VVT phase angle
Is detected, and the variable valve timing mechanism 9a is operated according to the detected information to advance the discharge period of the high-pressure fuel pump 14 to the injection period of the injector 21 as shown in FIG. 3B. The control is performed so as to phase in the direction (or the retard angle direction).
That is, the variable valve timing control giving priority to the injection timing is performed. In the β range, on the contrary, the variable valve timing mechanism 9a is advanced or retarded in accordance with the set overlap amount to control the opening / closing timing of the intake valve 9 instead of controlling the phase of the pump discharge period. The shift control is performed. That is, the variable valve timing control with priority on the overlap amount is performed.

FIG. 4 shows a flowchart in which the overlap amount control and the phase control of the pump discharge period are selectively used.

The phase control during the pump discharge period will be described with reference to this flowchart.

The engine opens / closes the intake / exhaust valves 9 and 10 at predetermined timing, reciprocates the piston 5, injects fuel from the injector 21, and spark plug 3a.
By the ignition operation of, power is generated in a cycle in which an intake stroke, a compression stroke, a combustion stroke, and an exhaust stroke are repeated. The injector 21 is supplied with fuel whose pressure is increased by the low-pressure pump 19 and the high-pressure fuel pump 14 driven by the pump-dedicated cam 13a.

At this time, the ECU 26 monitors the operating state of the engine from the engine speed and the throttle opening (step S1), and according to the operating state of the engine, the optimum injection timing and injection period of the injector 21 (valve opening time). The period is set (step S2), or the optimum overlap amount (including zero) is set according to the operating state of the engine (step S3).

Next, the ECU 26 determines whether or not the current engine operating state is in an operating region that is easily affected by the pulsation of fuel pressure (step S4). This determination is made based on whether or not the current engine speed and engine load are in, for example, the α range in the map shown in FIG. 2 which is set in advance.

At this time, the current engine operating state is α
If it is outside the range, that is, in the β range, the variable valve timing control that gives priority to the overlap amount is selected (step S5).

Here, the β region is an operating region in which the pulsation of fuel pressure is less likely to affect the operation, such as being longer than the intake / exhaust period (1 pulse width) of the high-pressure fuel pump 14 with respect to the injection period of the injector 21. The variable valve timing mechanism 9a is selected to be used for controlling the overlap amount and not used for the phase control (deviation control) of the high pressure fuel pump 14.

As a result, the ECU 26 advances or retards the variable valve timing mechanism 9a so that the set overlap amount is secured (step S5).

On the other hand, if the engine operating state is in the α region, that is, in the operating region where the pulsation of fuel pressure affects the operation, the control in which the injection timing of the injector 21 is prioritized in order to avoid the influence of the pulsation on the operation. Is selected.

Then, the ECU 26 detects the cycle of the pump discharge period of the high-pressure fuel pump 14 shown in FIG. 3 from, for example, the VVT phase angle (step S6), and activates the variable valve timing mechanism 9a so that the variable valve timing mechanism 9a shown in FIG. As shown in b), during the injection period of the injector 21, the high pressure fuel pump 1
The pump discharge timing of No. 4 is synchronized (step S7). Specifically, the variable valve timing mechanism 9a is shifted in the advance direction or the retard direction until the pump discharge period of the high-pressure fuel pump 14 matches the injection period of the injector 21 (for example, intermediate match). As a result, the pump discharge period of the high-pressure fuel pump 14 is shifted so that the entire injection period of the injector 21 is included in the range as shown in FIG. 3 (b).

As a result, when the pump discharge periods of the high-pressure fuel pump 14 are in phase with each other, the injector 21
From the set injection timing to the predetermined injection period for the cylinder 2
Fuel is directly injected into a (step S8).

In this way, by controlling the pump phase so that the fuel injection from the injector 21 is performed during the pump discharge period of the high-pressure fuel pump 14, the fuel actually injected from the injector 21 is the average pressure of pulsation. Since the injection is performed at a pressure close to the value, the injection is performed with a highly accurate injection amount close to the target injection amount. In particular, as shown in FIG. 3B, if the pump discharge period and the injection period of the injector 21 are synchronized such that they coincide with each other, a higher precision injection amount is guaranteed. Moreover, the amplitude of the pulsation is reduced each time fuel is injected from the injector 21, so that the pulsation is leveled, and this also promises fuel injection with high accuracy.

Therefore, in the direct injection type engine, the deviation of the air-fuel ratio due to the pulsation is effectively suppressed, and the target air-fuel ratio can be obtained even with the changing injection timing and injection period, and the target air-fuel ratio is followed. You can promise burning.

In addition, for the phase control of the high-pressure fuel pump 14, an existing drive system, that is, a drive system for giving a driving force to the intake valve 9 and the high-pressure fuel pump 14 through the variable valve timing mechanism 9a for controlling the overlap amount is used. ,
Since the control is performed so that the pump discharge period coincides with the injection period of the injector 21 only in the operating region of the engine that is easily affected by pulsation, and the overlap amount control is performed in other operating regions, the equipment of the existing drive system is controlled. It is possible to improve the deviation of the air-fuel ratio due to the pulsation, while making it compatible with the control of the overlap amount. In particular, the control of the pump discharge period was performed in the medium and low load range and the high rotation speed range of the engine operating condition, thereby achieving good balance with the overlap amount control.

In the first embodiment, an example of an engine having a variable valve timing mechanism on the intake side is given.
The same applies to the case where there is a variable valve timing mechanism on the exhaust side and the structure drives the high-pressure fuel pump.

5 and 6 show a second embodiment of the present invention.

In this embodiment, a variable bubble timing mechanism 10a is also provided on the exhaust side camshaft 12b with an exhaust cam 12d, and phase control is performed on both the intake side and exhaust side variable bubble timing mechanisms 9a, 10a. The present invention is applied to an engine whose overlap amount can be controlled.

That is, in the second embodiment, as shown in the flow chart of FIG. 6, step S9 and step S10 are added instead of step S7 of the first embodiment, and the discharge period of the high-pressure fuel pump 14 is changed. Even when they are shifted, the overlap amount is compensated.

More specifically, as shown in FIG. 6, the ECU 26 of the second embodiment determines in step S9 following step S6 that the pulsation of the high-pressure fuel pump 14 is apt to be affected by the α range (FIG. 2). By the phase control of the variable valve timing mechanism 9a (first variable timing mechanism) on the intake side,
As in the first embodiment, the discharge period of the high-pressure fuel pump 14 is shifted so as to match the injection period of the injector 21, and subsequently, in step S10, the variable valve timing mechanism 10a (second variable valve timing mechanism) on the exhaust side is shifted. By the phase control, the opening / closing timing of the remaining exhaust valve 10 is made to follow the intake valve 9 phased by the variable valve timing mechanism 9a, and is shifted by the required overlap amount.

According to this control, even if the discharge period of the high-pressure fuel pump 14 is shifted by the phase control of the variable bubble timing mechanism 9a on the intake side, the required overlap amount is obtained by the phase control of the variable valve timing mechanism 10a on the exhaust side. Is secured.

Therefore, even if the discharge period of the high-pressure fuel pump 14 is shifted, the overlap amount according to the operating state of the engine is compensated, and good combustion can be expected.

However, in FIGS. 5 and 6, the same parts as those in the first embodiment are designated by the same reference numerals and the description thereof is omitted.

Although the variable valve timing mechanism attached to the camshaft is used to shift the discharge period of the high-pressure fuel pump in the above-described embodiments, the discharge period of the high-pressure fuel pump is not limited to this. A variable drive unit may be provided, and the discharge period of the high-pressure fuel pump may be shifted by the control of the drive unit. Needless to say, the engine is limited to the number of cylinders. As a matter of course, the engine may be a stoichiometric operation, a stratified lean operation, or a direct injection in which the mode can be changed according to the operating state of the engine.

[0056]

As described above, according to the first aspect of the invention, the pump discharge timing varying means synchronizes the discharge period of the fuel pump with the fuel timing from the injector, so that the fuel injection is actually performed. The fuel injected from the valve is injected at a pressure close to the average pressure value of pulsation, and can be injected with a highly accurate injection amount that is close to the target injection amount. Moreover, the amplitude of the pulsation decreases every time the fuel is injected, so that accurate fuel injection can be performed.

Therefore, the deviation of the air-fuel ratio due to the pulsation is effectively suppressed, and even in the changing injection timing and injection period,
Combustion according to the target air-fuel ratio can be promised, and fuel efficiency and exhaust gas properties can be improved.

According to the second aspect of the present invention, in addition to the above effects, in order to utilize the structure of the internal combustion engine that drives the fuel pump through the variable valve timing mechanism that changes the opening / closing timing of the valve, the influence of pulsation is exerted. Only in the easy engine operating range, the pump discharge period is controlled to match the injection period of the fuel injection valve, and in other operating ranges, the overlap amount control is performed.Therefore, the existing drive system equipment can be used as it is. Thus, the phase control of the pump discharge period compatible with the overlap amount control can be performed.

According to the invention of claim 3, in addition to the above effect, the variable valve timing mechanism for varying the opening / closing timing of the remaining valve can be utilized to compensate the overlap amount when the discharge period of the fuel pump is shifted. , Good combustion can be expected.

According to the fourth aspect of the present invention, the phase control of the fuel pump discharge period described above can be most effectively performed in combination with the overlap amount control.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a structure of a cylinder injection type internal combustion engine according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a map for controlling a variable valve timing mechanism of the internal combustion engine.

FIG. 3A is a diagram for explaining a state where the discharge timing of the fuel pump and the injection timing of the fuel injection valve are deviated.
(B) is a figure for demonstrating when the injection timing of a fuel injection valve is synchronized by the phase control of a variable valve timing mechanism so that the discharge period of a fuel pump may correspond.

FIG. 4 is a flowchart showing a control flow in which the overlap control and the control for shifting the discharge timing of the fuel pump are both performed by the phase control of the variable valve timing mechanism of the internal combustion engine.

FIG. 5 is a schematic diagram showing the structure of a cylinder injection type internal combustion engine according to a second embodiment of the present invention.

FIG. 6 is a flowchart showing a control flow for performing control for shifting the discharge timing of the fuel pump while compensating for the overlap amount by using the variable valve timing mechanism on the intake side and the variable valve timing mechanism on the exhaust side of the internal combustion engine. .

[Explanation of symbols]

2a ... Cylinder 9 ... Intake valve 9a ... Intake valve variable valve timing mechanism (first variable valve timing mechanism) 10 ... Exhaust valve 10a ... Exhaust valve variable valve timing mechanism (second variable valve timing mechanism) 14 ... High pressure fuel pump (Fuel pump) 21 ... Injector (fuel injection valve) 26 ... ECU (pump injection timing varying means, control unit).

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F02M 59/20 F02M 59/20 J (72) Inventor Koichiro Tsuzuki 5-3-8 Shiba, Minato-ku, Tokyo F term in Mitsubishi Motors Corporation (reference) 3G066 AA02 AB02 AD12 BA08 BA12 BA51 CA01S CC34 CD03 CE22 DA04 DA06 3G084 BA13 BA14 BA15 BA23 DA04 EB08 EC02 FA13 FA33 3G092 AA06 AA11 AB02 BA03 BB04 DA09 DA12 3G301 HA04 LC19 MA01 LB04 MA19 MA28 NC02 PA11Z PB05Z PB08Z

Claims (4)

[Claims] 1. A fuel injection valve for injecting fuel into a cylinder of an internal combustion engine at an injection timing according to an operating state of the internal combustion engine; a fuel pump for supplying fuel to the fuel injection valve by driving the internal combustion engine; An in-cylinder injection internal combustion engine, comprising: pump discharge timing varying means for shifting the discharge period of the fuel pump so as to match the injection period of the fuel injection valve. 2. The in-cylinder injection internal combustion engine according to claim 1, wherein the internal combustion engine has a first variable valve timing mechanism that varies the opening / closing timing of one of the intake valve and the exhaust valve,
The first variable valve timing mechanism is an engine capable of controlling the amount of overlap between the intake valve and the exhaust valve, and the fuel pump is driven together with the one valve via the first variable valve timing mechanism. In the pump discharge timing varying means, an operating region of the internal combustion engine that is easily influenced by the pulsation of the fuel pump is set, and when the operating region is easily affected by the pulsation of the fuel pump, The discharge period of the fuel pump is shifted by the phase control of the variable valve timing mechanism so as to match the injection period of the fuel injection valve, and in the other operating range, the operating state is controlled by the phase control of the first variable valve timing mechanism. An in-cylinder injection internal combustion engine having a control unit that controls the amount of overlap according to the above. 3. The in-cylinder injection internal combustion engine according to claim 2, wherein the internal combustion engine further has a second variable valve timing mechanism for varying the opening / closing timing of the other valve, and the first variable valve. The engine includes an engine capable of controlling the amount of overlap between the intake valve and the exhaust valve by the timing mechanism and the second variable valve timing mechanism, and the control unit operates the internal combustion engine that is easily affected by the pulsation of the fuel pump. In the region, by the phase control of the first variable valve timing mechanism, the discharge period of the fuel pump is shifted so as to match the injection period of the fuel injection valve, and by the phase control of the second variable valve timing mechanism, The opening and closing timings of the remaining valves are shifted according to the overlap amount by following the valve deviations caused by the first variable valve timing mechanism. Cylinder injection type internal combustion engine, wherein the door. 4. The in-cylinder injection type internal combustion engine according to claim 2 or 3, wherein the operating region that is easily affected by the pulsation of the fuel pump is:
An in-cylinder injection internal combustion engine, characterized in that the internal combustion engine is in a region of low load and high rotation speed.