JP2000328997A - Control system for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To operate an internal combustion engine even when pressure of supplied gaseous fuel is low. SOLUTION: This control system is provided with an injector for injecting gaseous fuel directly to a combustion chamber. Also, in addition to a pressure sensor for sensing pressure of the gaseous fuel supplied to an engine, combustion pressure judgement means S12 is provided for judging whether or not the pressure detected by the pressure sensor is lower than the reference pressure. Further, the control system has closing valve setting means S16 and injection control means S18. When the pressure of the gaseous fluid is judged to be lower than the reference pressure by the combustion pressure judgement means, the closing valve setting means S16 sets closing valve timing of an intake valve near an intake bottom dead center and the injection control means S18 activates the injector in an intake stroke.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine control device for an internal combustion engine that directly injects gaseous fuel into a combustion chamber.

[0002]

2. Description of the Related Art Conventionally, as for an internal combustion engine driven by gaseous fuel, a direct injection type in which gaseous fuel is directly injected into a combustion chamber, as described in JP-A-7-63076, is known. . This internal combustion engine uses compressed natural gas (CNG) as a gaseous fuel. Since natural gas cannot be stored in a liquid state at normal temperature like LPG (liquefied petroleum gas), it is compressed in a gaseous state and the fuel is compressed. Filled in tank.

[0003]

However, in the above-mentioned internal combustion engine, when the remaining amount of gaseous fuel in the fuel tank decreases, fuel injection becomes difficult, and the cruising distance that can be traveled by one refueling is reduced. There is a problem. That is, in order to perform fuel injection in the compression stroke in the direct injection type internal combustion engine, a higher injection pressure is required than in the port injection type. However, when the remaining amount of the gaseous fuel in the fuel tank decreases, the fuel pressure in the fuel tank decreases, so that it becomes difficult to supply high-pressure gaseous fuel to the internal combustion engine.
As a result, the cruising distance that a vehicle or the like can travel with one refueling operation is shortened.

Accordingly, the present invention has been made to solve such a problem, and provides an internal combustion engine control device capable of driving an internal combustion engine even when supplied gas fuel is at a low pressure. The purpose is to do.

[0005]

That is, an internal combustion engine control apparatus according to the present invention is a control apparatus for an internal combustion engine having an injector for directly injecting gaseous fuel into a combustion chamber.
Fuel pressure detecting means for detecting the pressure of the gaseous fuel supplied to the internal combustion engine; fuel pressure determining means for determining whether the pressure detected by the fuel pressure detecting means is smaller than a reference pressure; When it is determined that the pressure of the gaseous fuel is lower than the reference pressure, and when the fuel pressure determination means determines that the pressure of the gaseous fuel is lower than the reference pressure. And an injection control means for performing the injection of the injector during the intake stroke.

According to the present invention, when the pressure of the gaseous fuel supplied to the internal combustion engine is lower than the reference pressure, the injection of the gaseous fuel by the injector is performed in the intake stroke. Squirted into the combustion chamber. Therefore, even when the remaining amount of gaseous fuel in the fuel tank decreases and the pressure in the fuel tank decreases, gaseous fuel can be injected, and the cruising distance of a vehicle or the like can be increased. In addition, when the pressure of the gaseous fuel is smaller than the reference pressure, the closing time of the intake valve is set near the bottom dead center of the intake air, so that the closing time of the intake valve is advanced, and the gaseous fuel injected from the injector is discharged. Backflow to the pipe side can be prevented.

Further, according to the present invention, there is provided a control apparatus for an internal combustion engine having an injector for directly injecting gaseous fuel into a combustion chamber, wherein the fuel pressure detecting means detects the pressure of gaseous fuel supplied to the internal combustion engine. And a fuel pressure determining means for determining whether the pressure detected by the fuel pressure detecting means is smaller than a reference pressure; and closing the intake valve when the fuel pressure determining means determines that the pressure of the gaseous fuel is smaller than the reference pressure. Valve closing setting means for setting the timing near the intake bottom dead center;
Injection control means for injecting the injector immediately after intake bottom dead center when the fuel pressure determining means determines that the pressure of the gaseous fuel is lower than the reference pressure.

According to the present invention, when the pressure of the gaseous fuel supplied to the internal combustion engine is lower than the reference pressure, the injection of the gaseous fuel by the injector is performed mainly in the first half of the compression stroke. For this reason, since the pressure of the combustion chamber is small in the first half of the compression stroke, it is possible to reliably inject the gas fuel even at a low pressure. Therefore, even when the remaining amount of gaseous fuel in the fuel tank decreases and the pressure in the fuel tank decreases, gaseous fuel can be injected, and the cruising distance of a vehicle or the like can be increased. In addition, when the pressure of the gaseous fuel is smaller than the reference pressure, the closing time of the intake valve is set near the bottom dead center of the intake air, so that the closing time of the intake valve is advanced, and the gaseous fuel injected from the injector is discharged. Backflow to the pipe side can be prevented.

Further, the internal combustion engine control device according to the present invention includes a main passage which supplies a gaseous fuel to the internal combustion engine and which has a regulator for adjusting a fuel pressure in the middle thereof.
A bypass passage that branches from the main passage at an upstream portion of the regulator and joins at a downstream portion of the regulator; and a main passage that is provided at a branch position between the main passage and the bypass passage and that supplies a gas fuel supply path downstream of the branch position by switching a valve. A supply path switching means capable of switching to a bypass passage; and a supply for switching the gas fuel supply path to the bypass passage by the supply path switching means when the fuel pressure determining means determines that the pressure of the gaseous fuel is smaller than the reference pressure. Path switching control means.

According to the present invention, when the pressure of the gaseous fuel is lower than the reference pressure, the gaseous fuel can be supplied to the injector through the bypass passage without passing through the regulator. Therefore, a decrease in the flow rate of the gaseous fuel accompanying the passage through the regulator can be avoided, and more gaseous fuel can be supplied to the injector.

[0011]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In the description of the drawings, the same elements will be denoted by the same reference symbols, without redundant description. (First Embodiment) FIG. 1 is an explanatory diagram of an internal combustion engine control device according to the present embodiment.

As shown in FIG. 1, an internal combustion engine control device 10
Is applied to an internal combustion engine of a vehicle running on gaseous fuel, and gaseous fuel contained in a fuel tank 12 is supplied to an engine 20 which is an internal combustion engine. The engine 20 to be controlled is of a direct injection type, and includes an injector 22 for directly injecting gaseous fuel into the combustion chamber 21. The injector 22 is a fuel injection unit that supplies pressurized gaseous fuel to the combustion chamber 21.
It is installed for each cylinder 23 provided.

The combustion chamber 21 is formed above a piston 24 arranged in a cylinder 23. An intake port 25 and an exhaust port 26 are open above the combustion chamber 21. An intake valve 27 is arranged in the intake port 25, and an exhaust valve 28 is arranged in the exhaust port 26. The intake port 25 is an intake pipe for supplying air to the combustion chamber 21 and is opened and closed by an intake valve 27. The exhaust port 26 is an exhaust pipe for exhausting air from the fuel chamber 21 and is an exhaust valve 2.
8 is opened and closed.

The engine 20 is provided with a variable valve timing mechanism 30. The variable valve timing mechanism 30 is disposed above the intake valve 27, and changes the opening / closing timing of the intake valve 27.

On the other hand, the fuel tank 12 is constituted by a pressure-resistant container, and stores gaseous fuel in a high pressure state. A main passage 13 for pumping gaseous fuel into the fuel tank 12 is provided.
Is connected, and the gaseous fuel is pumped through the main passage 13 to the delivery pipe 17. The main passage 13 is constituted by a pipe or the like, and a pressure sensor 14, a bypass valve 15, and a regulator 16 are sequentially disposed in the middle of the main passage 13.

The pressure sensor 14 is first fuel pressure detecting means for detecting the pressure of gaseous fuel in the main passage 13. The regulator 16 is pressure adjusting means for adjusting the pressure of the gaseous fuel contained in the fuel tank 11 to a low pressure. The delivery pipe 17 feeds the pumped gaseous fuel to each injector 22.
It is distributed to. The delivery pipe 17 is provided with a pressure sensor 31. Pressure sensor 31
Is a second fuel pressure detecting means for detecting the pressure of the gaseous fuel in the delivery pipe 17.

The delivery pipe 17 is provided with a fuel temperature sensor 32. The fuel temperature sensor 32 is a fuel temperature detecting unit that detects the temperature of the gaseous fuel in the delivery pipe 17.

The main passage 1 serves as a passage for pressure-feeding gaseous fuel.
A bypass passage 40 branching from 3 is provided. The bypass passage 40 is a passage that bypasses the regulator 16 on the main passage 13 and feeds the gaseous fuel to the delivery pipe 17 side.
3 and a main passage 1 at a position downstream of the regulator 16.
Merges with 3.

The bypass valve 15 is connected to the main passage 1 on the upstream side.
3 is connected to either the downstream side of the main passage 13 or the bypass passage 40 by switching the valve. For example, an electromagnetic three-way valve is used. This bypass valve 15
, The gaseous fuel pumped from the fuel tank 12 is fed to the delivery pipe 17 only through the main passage 13 or the bypass passage 40.

The internal combustion engine control device 10 is provided with an ECU 50. The ECU 50 controls the internal combustion engine control device 10
It controls the entire device, including a CPU, a ROM,
It is mainly composed of a computer including a RAM. Various control routines including an internal combustion engine control routine are stored in the ROM.

The ECU 50 is connected to the pressure sensor 14 and the pressure sensor 31, and receives a pressure detection signal of the gaseous fuel in the main passage 13 and a pressure detection signal of the gaseous fuel in the delivery pipe 17, respectively. The ECU 50
Is connected to the fuel temperature sensor 32, and receives a temperature detection signal of the gaseous fuel in the delivery pipe 17. The ECU 50 is connected to the variable valve timing mechanism 30, and receives a detection signal of the variable valve timing.

The ECU 50 is connected to the bypass valve 15 and outputs a switching control signal to the bypass valve 15 to control the switching of the bypass valve 15. The ECU 50
Is connected to the injector 22 and outputs an injection control signal to the injector 22 to perform gas fuel injection control. The ECU 50 also controls the variable valve timing mechanism 3
A valve timing control signal is output to 0 to control the closing timing of the intake valve 27.

Next, the operation of the internal combustion engine control device will be described.

FIG. 2 is a flowchart showing the operation of the internal combustion engine control device 10. First, step S1 in FIG.
At 0 (hereinafter simply referred to as “S10”; the same applies to other steps), the fuel pressure is read based on the pressure detection signal output from the pressure sensor 31 and output from the fuel temperature sensor 32. The fuel temperature is read based on the detected temperature signal. Next, the process proceeds to S12, and it is determined whether the read fuel pressure is lower than a reference pressure stored in the ECU 50 in advance. Here, as the reference pressure, for example, a pressure slightly higher than the adjustment pressure of the regulator 16 is set.

Specifically, when the adjustment pressure of the regulator 16 is 5 MPa, the reference pressure is set to 5.5 MPa. In S12, the fuel pressure detected by the pressure sensor 31 is compared with the reference pressure. However, a fuel pressure based on the pressure detected by the pressure sensor 14 may be used.

When it is determined in S12 that the fuel pressure is lower than the reference pressure stored in advance, the process proceeds to S14, where a switching control signal is output from the ECU 50 to the bypass valve 15, and the main passage is switched by switching the bypass valve 15. The bypass passage 40 communicates with the upstream side of the thirteen. As a result, gaseous fuel pumped from the fuel tank 12 to the bypass valve 15 through the upstream portion of the main passage 13 is supplied to the bypass passage 4.
The pressure is fed to the delivery pipe 17 side through 0.

Next, the program proceeds to S16, in which a valve timing control signal is output from the ECU 50 to the variable valve timing mechanism 30, and the closing timing of the intake valve 27 is set near the intake bottom dead center. That is, as shown in FIG. 3, the closing timing of the intake valve 27 is set near the intake bottom dead center of the crankshaft rotation angle. Here, the vicinity of the bottom dead center of the intake means that the closing of the intake valve 27 is near the bottom dead center of the intake, and the combustion chamber 21 is driven in the current engine 20 driving state.
Means the timing at which the air inside does not flow backward to the intake port 25 side. By setting the closing timing of the intake valve 27 near the intake bottom dead center in this way, the air in the combustion chamber 21 is prevented from flowing back to the intake port 25.

Then, the process shifts to S18 in FIG.
From 0, an injection control signal is output to the injector 22 and gaseous fuel is injected into the fuel chamber 21 during the intake stroke. That is, as shown in FIG. 3, the gaseous fuel is injected before the bottom dead center of the intake of the crankshaft. Thus, injection can be performed reliably even when the pressure of the gaseous fuel is low. In addition,
The injection time of the gaseous fuel is appropriately set according to the pressure, temperature, etc. of the gaseous fuel.

When it is determined in S12 that the fuel pressure is equal to or higher than the reference pressure stored in advance, the program proceeds to S12.
The process then proceeds to step 20, where a switching control signal is output from the ECU 50 to the bypass valve 15, and the switching of the bypass valve 15 causes the upstream side of the main passage 13 to communicate with the downstream side of the main passage 13. Thus, the gaseous fuel that has been pressure-fed from the fuel tank 12 to the bypass valve 15 through the upstream portion of the main passage 13 is pressure-fed to the delivery pipe 17 through the downstream portion of the main passage 13 without passing through the bypass passage 40.

Next, the flow shifts to S22, where a valve timing control signal is output from the ECU 50 to the variable valve timing mechanism 30, and normal VVT control is performed. For example,
As shown in FIG. 4, the closing of the intake valve 27 is performed during the compression stroke after the intake bottom dead center, and the valve closing timing is appropriately set according to the rotation state of the engine 20 and the like.

Then, the process shifts to S24 in FIG.
From 0, an injection control signal is output to the injector 22, and normal gaseous fuel injection is performed. That is, as shown in FIG. 4, the injection of the gaseous fuel is performed in the compression stroke after the bottom dead center of the intake of the crankshaft.

As described above, according to the internal combustion engine controller 10 of the present embodiment, when the pressure of the gaseous fuel supplied to the engine 20 is lower than the reference pressure set in the ECU 50 in advance, the fuel injection by the injector 22 is performed. Is performed in the intake stroke, so that the gaseous fuel is reliably injected into the combustion chamber 21 even in a low pressure state. Therefore, the fuel tank 12
Even when the remaining amount of gaseous fuel in the fuel tank 12 decreases and the pressure in the fuel tank 12 decreases, gaseous fuel can be injected and the cruising distance of a vehicle or the like can be increased.

When the pressure of the gaseous fuel is smaller than the reference pressure, the closing time of the intake valve 27 is set near the bottom dead center of the intake air, and the closing timing of the intake valve 27 is advanced. The gaseous fuel that has flowed back through the intake port 25 can be prevented.

Further, when the pressure of the gaseous fuel is lower than the reference pressure, the gaseous fuel can be pumped to the injector 22 through the bypass passage 40 without passing through the regulator 16. Therefore, a decrease in the flow rate of the gaseous fuel accompanying the passage through the regulator 16 can be avoided, and more gaseous fuel can be supplied to the injector 22. Therefore, the fuel tank 1
Even when the remaining amount of gaseous fuel in the fuel tank 12 decreases and the pressure in the fuel tank 12 decreases, gaseous fuel can be injected, and the cruising distance of a vehicle or the like can be increased. (Second Embodiment) Next, an internal combustion engine control device according to a second embodiment will be described.

The internal combustion engine control device 10a according to this embodiment
The internal combustion engine to be controlled has the same structure as the engine 20 of the first embodiment, and the supply path of the gaseous fuel has the main passage 13 and the bypass passage 40. They have the same structure. However, the internal combustion engine control device 10a according to the present embodiment
The internal combustion engine according to the first embodiment in which the fuel injection by the injector 22 is performed in the compression stroke even when the pressure of the gaseous fuel supplied to the engine 20 is smaller than the reference pressure, and the fuel injection is performed in the intake stroke in such a case. It is different from the control device 10.

FIG. 5 is a flowchart showing the operation of the internal combustion engine control device 10a.

At step S30 in FIG.
The fuel pressure is read based on the pressure detection signal output from the fuel cell 1, and the fuel temperature is read based on the temperature detection signal output from the fuel temperature sensor 32. Next, S32
Then, it is determined whether the read fuel pressure is lower than the reference pressure stored in the ECU 50 in advance. In S32, the pressure detected by the pressure sensor 14 may be used as the fuel pressure.

When it is determined in S32 that the fuel pressure is lower than the reference pressure stored in advance, the process proceeds to S34, where a switching control signal is output from the ECU 50 to the bypass valve 15, and the switching of the bypass valve 15 causes the main passage to be switched. The bypass passage 40 communicates with the upstream side of the thirteen. As a result, gaseous fuel pumped from the fuel tank 12 to the bypass valve 15 through the upstream portion of the main passage 13 is supplied to the bypass passage 4.
The pressure is fed to the delivery pipe 17 side through 0.

Next, the routine proceeds to S36, where a valve timing control signal is output from the ECU 50 to the variable valve timing mechanism 30, and the closing timing of the intake valve 27 is set near the intake bottom dead center. That is, as shown in FIG. 6, the closing timing of the intake valve 27 is set near the intake bottom dead center of the crankshaft rotation angle. By setting the closing timing of the intake valve 27 near the intake bottom dead center, the air in the combustion chamber 21 is prevented from flowing back to the intake port 25.

Then, the flow shifts to S38 in FIG. 5, where the required injection time and the available injection time are calculated. Here, the required injection time refers to the time required to inject a constant gaseous fuel amount in one fuel injection, and is determined according to the current fuel pressure. The required injection time is stored in the ECU 50 in advance corresponding to the fuel pressure, and the required required injection time is set longer as the fuel pressure decreases. Therefore, the calculation of the required injection time is performed based on the fuel pressure read in S30. The amount of gaseous fuel in one fuel injection is calculated based on a signal output from a throttle sensor (not shown).

The injection possible time is a time calculated from the bottom dead center of the intake of the crankshaft, and is a time until injection into the combustion chamber 21 becomes impossible at the current fuel pressure. The injectable time is stored in the ECU 50 in advance corresponding to the fuel pressure, and is stored, for example, as a map corresponding to the fuel pressure as shown in FIG. This map is set in consideration of the characteristic that the pressure in the combustion chamber 21 increases as the rotation angle of the crankshaft advances. Therefore, the calculation of the injection possible time is performed by a map process based on the fuel pressure read in S30.

Next, the flow shifts to S40 in FIG. 5, and it is determined whether or not the calculated required injection time is shorter than the available injection time. When it is determined that the required injection time is shorter than the available injection time, the process proceeds to S42, where an injection control signal is output from the ECU 50 to the injector 22, and the injection of gaseous fuel is performed. This gaseous fuel injection is performed immediately after the bottom dead center of the intake of the crankshaft, as shown in FIG. Thus, the gaseous fuel can be injected before the pressure in the combustion chamber 21 increases greatly with the rotation of the crankshaft, so that the injection can be performed even if the pressure of the gaseous fuel is small. The injection time of the gaseous fuel is appropriately set according to the pressure of the gaseous fuel and the like.

On the other hand, when it is determined in S40 that the required injection time is not shorter than the injectable time, the flow shifts to S44, where the injection control signal is not output from the ECU 50 to the injector 22, and the injection of gaseous fuel is performed. Absent. In this case, it is determined that there is no fuel, and a refueling warning is displayed.

If it is determined in S32 that the fuel pressure is equal to or higher than the reference pressure stored in advance, the program proceeds to S32.
The process proceeds to 46, where a switching control signal is output from the ECU 50 to the bypass valve 15, and the switching of the bypass valve 15 causes the upstream side of the main passage 13 to communicate with the downstream side of the main passage 13. Thus, the gaseous fuel that has been pressure-fed from the fuel tank 12 to the bypass valve 15 through the upstream portion of the main passage 13 is pressure-fed to the delivery pipe 17 through the downstream portion of the main passage 13 without passing through the bypass passage 40.

Subsequently, the flow shifts to S48, where a valve timing control signal is output from the ECU 50 to the variable valve timing mechanism 30, and normal VVT control is performed. That is, as described above with reference to FIG. 4, the closing of the intake valve 27 is performed during the compression stroke after the intake bottom dead center, and the valve closing timing is appropriately set according to the rotational state of the engine 20 and the like. .

Then, the flow shifts to S50, where an injection control signal is output from the ECU 50 to the injector 22, and normal gaseous fuel injection is performed. That is, as described above with reference to FIG. 4, the injection of the gaseous fuel is performed in the compression stroke after the bottom dead center of the intake of the crankshaft.

As described above, according to the internal combustion engine control device 10a according to the present embodiment, when the pressure of the gaseous fuel supplied to the engine 20 is smaller than the reference pressure set in the ECU 50 in advance, the fuel by the injector 22 The injection is performed mainly in the first half of the compression stroke. For this reason, since the pressure of the combustion chamber 21 is small in the first half of the compression stroke, it is possible to reliably inject the gaseous fuel even at a low pressure. Therefore,
Even when the remaining amount of gaseous fuel in the fuel tank 12 decreases and the pressure in the fuel tank 12 decreases, gaseous fuel can be injected and the cruising distance of a vehicle or the like can be increased.

When the pressure of the gaseous fuel is lower than the reference pressure, the closing time of the intake valve 27 is set near the intake bottom dead center, and the closing timing of the intake valve 27 is advanced. The gaseous fuel that has flowed back through the intake port 25 can be prevented.

Further, when the pressure of the gaseous fuel is lower than the reference pressure, the gaseous fuel can be pumped to the injector 22 through the bypass passage 40 without passing through the regulator 16. Therefore, a decrease in the flow rate of the gaseous fuel accompanying the passage through the regulator 16 can be avoided, and more gaseous fuel can be supplied to the injector 22. Therefore, the fuel tank 1
Even when the remaining amount of gaseous fuel in the fuel tank 12 decreases and the pressure in the fuel tank 12 decreases, gaseous fuel can be injected, and the cruising distance of a vehicle or the like can be increased.

[0050]

As described above, according to the present invention, when the pressure of the gaseous fuel supplied to the internal combustion engine is lower than the reference pressure, the injection of the gaseous fuel by the injector is performed in the intake stroke, so that the low-pressure gas is injected. Fuel can be reliably injected into the combustion chamber. Therefore, even when the remaining amount of gaseous fuel in the fuel tank decreases and the pressure in the fuel tank decreases, gaseous fuel can be injected, and the cruising distance of a vehicle or the like can be increased.

Further, when the pressure of the gaseous fuel is lower than the reference pressure, the closing timing of the intake valve is set near the bottom dead center of the intake air, so that the closing timing of the intake valve is advanced, so that the fuel is injected from the injector. It is possible to prevent the gaseous fuel from flowing back to the intake pipe side.

Further, when the pressure of the gaseous fuel supplied to the internal combustion engine is smaller than the reference pressure, the injection of the gaseous fuel by the injector is performed immediately after the intake bottom dead center, so that the pressure of the combustion chamber during the compression stroke is small. Since fuel injection can be mainly performed in the first half, even low-pressure gaseous fuel can be reliably injected. Therefore, even when the remaining amount of gaseous fuel in the fuel tank decreases and the pressure in the fuel tank decreases, gaseous fuel can be injected, and the cruising distance of a vehicle or the like can be increased.

Further, when the pressure of the gaseous fuel supplied to the internal combustion engine is low, the gaseous fuel is supplied through the bypass passage without passing through the regulator as the pressure adjusting means, so that the flow rate of the gaseous fuel accompanying the passage of the regulator is reduced. Avoided, it is possible to supply more gaseous fuel to the injector.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an internal combustion engine control device according to a first embodiment.

FIG. 2 is a flowchart illustrating an operation of the internal combustion engine control device according to the first embodiment.

FIG. 3 is a timing chart showing an operation of the internal combustion engine control device according to the first embodiment.

FIG. 4 is a timing chart showing an operation of the internal combustion engine control device according to the first embodiment.

FIG. 5 is a flowchart showing an operation of the internal combustion engine control device according to the second embodiment.

FIG. 6 is a timing chart showing the operation of the internal combustion engine control device according to the second embodiment.

FIG. 7 is a diagram showing a relationship between a fuel pressure and an injectable time in an internal combustion engine control device according to a second embodiment.

[Explanation of symbols]

10: internal combustion engine control device, 20: engine, 22: injector (fuel injection means), 31: pressure sensor (fuel pressure detection means), 27: intake valve.

Claims (3)

[Claims] 1. A control apparatus for an internal combustion engine having an injector for directly injecting gaseous fuel into a combustion chamber, wherein the control means detects a pressure of gaseous fuel supplied to the internal combustion engine; Fuel pressure determining means for determining whether or not the pressure is smaller than a reference pressure; and when the fuel pressure determining means determines that the pressure of the gaseous fuel is smaller than the reference pressure, the closing timing of the intake valve is set to the intake pressure. Valve closing setting means for setting near the bottom dead center; and, when the fuel pressure determining means determines that the pressure of the gaseous fuel is smaller than the reference pressure, injection control means for performing injection of the injector during an intake stroke. An internal combustion engine control device comprising: 2. A control device for an internal combustion engine having an injector for directly injecting gaseous fuel into a combustion chamber, wherein the fuel pressure is detected by the fuel pressure detecting means for detecting the pressure of gaseous fuel supplied to the internal combustion engine. Fuel pressure determining means for determining whether or not the pressure is smaller than a reference pressure; and when the fuel pressure determining means determines that the pressure of the gaseous fuel is smaller than the reference pressure, the closing timing of the intake valve is set to the intake pressure. Valve closing setting means for setting near the bottom dead center; and injection for performing injection of the injector immediately after intake bottom dead center when the fuel pressure determining means determines that the pressure of the gaseous fuel is smaller than the reference pressure. Control means;
An internal combustion engine control device comprising: 3. A passage for supplying the gaseous fuel to the internal combustion engine, the passage being provided with a regulator for adjusting fuel pressure in the middle of the passage, and a branch from the main passage at an upstream portion of the regulator. A bypass passage that merges at a downstream portion of the regulator, and is installed at a branch position of the main passage and the bypass passage;
A supply path switching unit configured to switch a supply path of the gaseous fuel downstream of the branch position to the main passage or the bypass passage by switching a valve; and a pressure of the gaseous fuel determined by the fuel pressure determination unit. The supply path switching control means for causing the supply path switching means to switch the supply path of the gaseous fuel to the bypass passage when it is determined that the gaseous fuel is smaller than the supply path switching means. Internal combustion engine control device.