JP4930274B2 - Control device for internal combustion engine - Google Patents

Description

The present invention relates to a control device for an internal combustion engine , and more particularly to a control device for an internal combustion engine for controlling an in-cylinder direct fuel injection internal combustion engine that reinforces a swirling airflow generated in the cylinder by fuel injection.

  Conventionally, an in-cylinder direct fuel injection type internal combustion engine in which a swirling airflow such as a tumble flow or a swirl flow is generated in the cylinder is known. For example, Patent Document 1 or 2 proposes a technique that is considered to be related to the present invention regarding a fuel injection valve included in such an internal combustion engine.

JP-A-6-81656 JP 2004-316538 A

  By the way, if the swirling airflow generated in the cylinder can be strengthened, generally, it is possible to improve the mixing property of the air-fuel mixture, the propagation property of the flame, the expansion of the lean combustion limit, and the like. In this regard, when focusing on fuel injection in strengthening the swirling airflow generated in the cylinder, fuel is injected along the swirling airflow when the piston is located near the bottom dead center between the intake stroke and the compression stroke. There is a way. According to this fuel injection method, at a timing other than when the piston is located near the bottom dead center between the intake stroke and the compression stroke, there is a possibility that the swirling air flow may be attenuated by the fuel injection. By injecting the fuel in a substantially stationary state, a jet effect that enhances the swirling airflow can be appropriately obtained (see FIG. 8).

  However, even when the fuel is injected when the piston is positioned near the bottom dead center between the intake stroke and the compression stroke by this fuel injection method, for example, at the time of high load operation where the fuel injection amount increases, the injection time As a result, the fuel injection may reach a timing at which the swirling airflow may be attenuated. In this regard, in such a case, it is necessary to inject the remaining fuel at a timing other than when the piston is positioned near the bottom dead center between the intake stroke and the compression stroke. There is no specific technique for injecting the remaining fuel.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide a control device for an internal combustion engine that can suitably enhance a swirling airflow generated in a cylinder by fuel injection.

In order to solve the above-described problems, the present invention provides a part of the total fuel injection amount to be injected from the intake port to the cylinder in the cylinder in which the swirling airflow is generated and toward the intake port when the intake valve is opened. A first fuel injection valve that injects the intake air flow to cancel the swirling airflow in a direction opposite to the swirling direction, and a bottom dead center near the piston between the intake stroke and the compression stroke And a second fuel injection valve that injects fuel into the cylinder along the swirling airflow when the internal combustion engine is in a direct-injection type internal combustion engine. The total fuel injection amount is increased or decreased in accordance with the operating state of the direct injection type internal combustion engine, and the total fuel injection amount is increased by a predetermined ratio to each of the first and second fuel injection valves. From the second fuel injection valve When the fuel injection amount to be injected exceeds a predetermined amount, the predetermined amount is set as the fuel injection amount to be injected from the second fuel injection valve, and the remaining amount obtained by subtracting the predetermined amount from the total fuel injection amount Specific fuel injection amount control means for setting the fuel injection amount to be injected from the first fuel injection valve.

  According to the present invention, the intake air flow that flows into the cylinder can be canceled by the fuel injection so as to form a flow that attenuates the swirling air current, and thus the swirling air current generated in the cylinder can be canceled by the fuel injection. Can be strengthened. In addition, the present invention can be realized in combination with, for example, the fuel injection method capable of appropriately obtaining the jet effect described above, and the swirling airflow generated in the cylinder can be suitably enhanced by fuel injection. In this regard, the present invention is not necessarily limited to being realized in combination with the above-described fuel injection method, but when realized in combination with the above-described fuel injection method, the piston is located near the bottom dead center between the intake stroke and the compression stroke. It is preferable to further include a second fuel injection valve that injects fuel into the cylinder along the swirling airflow when positioned.

Here, the fuel injection amount to be injected from the second fuel injection valve increases, and as a result, the fuel must continue to be injected even after the piston leaves the vicinity of the bottom dead center between the intake stroke and the compression stroke. On the contrary, the swirling airflow is attenuated. On the other hand, according to the present invention, the fuel can be injected from the second fuel injection valve within a range in which the jet effect can be appropriately obtained, and the remaining fuel is injected from the first fuel injection valve. The intake air flow that flows into the cylinder can be canceled so as to attenuate the air flow, and thus the swirling airflow generated in the cylinder can be suitably enhanced by fuel injection.

Note that the predetermined ratio may not be a constant value, and may be set to a different ratio depending on, for example, the operating state of the internal combustion engine. In this regard, when the direct injection type internal combustion engine includes a variable valve mechanism, for example, according to the valve lift amount of the intake valve, the first fuel occupies the total fuel injection amount as the lift amount decreases. It is preferable to increase the ratio of the fuel injection amount from the injection valve. As a result, the intake air flow that flows into the cylinder can be suitably canceled so as to attenuate the swirling airflow in accordance with the valve lift amount. Therefore, the swirling airflow can be further suitably enhanced by fuel injection in this respect.

In the above configuration, the specific fuel injection amount control means further includes an intake air to be sucked into the cylinder from the intake port according to an operating state of the direct fuel injection internal combustion engine. When the fuel injection amount is smaller than the amount, the ratio of the fuel injection amount to be injected by the first fuel injection valve in the total fuel injection amount is determined as the intake air amount sucked into the cylinder from the intake port. May be increased compared to before the amount of intake air to be inhaled decreases. According to this structure, the deposit adhering to the intake valve by the fuel injection from the first fuel injection valve can be removed.

ADVANTAGE OF THE INVENTION According to this invention, the control apparatus of the internal combustion engine which can strengthen suitably the whirling airflow produced | generated in a cylinder by fuel injection can be provided.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram schematically showing a main part of an in-cylinder direct fuel injection internal combustion engine (hereinafter simply referred to as an internal combustion engine) 50A according to the present embodiment together with an ECU (Electronic Control Unit) 1A. The internal combustion engine 50A includes a cylinder block 51, a cylinder head 52, a piston 53, and the like. A substantially cylindrical cylinder 51a is formed in the cylinder block 51, and a piston 53 is accommodated in the cylinder 51a.

  A cylinder head 52 is fixed to the cylinder block 51. The combustion chamber 54 is formed as a space surrounded by the cylinder block 51, the cylinder head 52, and the piston 53. The cylinder head 52 is formed with an intake port 52a for introducing intake air into a combustion chamber 54 (hereinafter also referred to as a cylinder) and an exhaust port 52b for exhausting the burned gas from the combustion chamber 54. Further, an intake valve 55 for opening and closing the intake port 52a and an exhaust valve 56 for opening and closing the exhaust port 52b are provided. When the intake valve 55 is opened and intake air flows into the cylinder from the intake port 52a, a tumble flow T (corresponding to the swirling airflow described in the claims) is generated in the cylinder. The internal combustion engine 50A is provided with a crank angle sensor 71 and a water temperature sensor 72 for detecting the rotational speed NE.

  FIG. 2 is a view showing the arrangement of the first and second fuel injection valves 58 and 59 not shown in FIG. 1 using a schematic side view and a schematic top view. Both the first and second fuel injection valves 58 and 59 are disposed around the combustion chamber 54 on the intake port 52a side. Each of the two first fuel injection valves 58 is disposed below each intake port 52a in a state where an injection hole protrudes into the cylinder. The second fuel injection valve 59 is disposed approximately at the center between the intake ports 52a when viewed from above with the injection hole protruding into the cylinder. The first and second fuel injection valves 58 and 59 are both disposed corresponding to the upper portion of the combustion chamber 54.

  The ECU 1A includes a microcomputer (not shown) having a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory), an input / output circuit, and the like. Configured. The ECU 1A is mainly configured to control the internal combustion engine 50A. In the present embodiment, the first fuel injection valve 58, the second fuel injection valve 59, and the like are electrically connected as control targets. The ECU 1A is electrically connected to a crank angle sensor 71, a water temperature sensor 72, an air flow meter (not shown), and the like. In addition, various control objects, sensors, and switches may be electrically connected to the ECU 1.

  The ROM is configured to store programs describing various processes executed by the CPU, map data, and the like. In this embodiment, in addition to the internal combustion engine control program, the following specific injection timing control program and specific program A fuel injection amount control program and the like are also stored. Note that these programs may be configured integrally. The specific injection timing control program includes a first fuel injection timing control program for controlling the fuel injection timing A from the first fuel injection valve 58, and a fuel injection timing B from the second fuel injection valve 59. And a second fuel injection timing control program for controlling the engine. The first fuel injection timing control program is created so as to inject fuel from the first fuel injection valve 58 when the intake valve 55 is opened. The second fuel injection timing control program is created so as to inject fuel from the second fuel injection valve 59 when the piston 53 is positioned near the bottom dead center between the intake stroke and the compression stroke. .

  The specific fuel injection amount control program is created so that the total fuel injection amount to be injected is injected from each of the first fuel injection valve 58 and the second fuel injection valve 59 at a predetermined rate. The predetermined ratio may not be a constant value, and may be set to a different ratio depending on, for example, the operating state of the internal combustion engine 50A. In this embodiment, the ECU 1A performs control based on the specific injection timing control program and the specific fuel injection amount control program so that the first fuel injection valve 58 is directed toward the intake port 52a when the intake valve 55 is opened. A part of the total fuel injection amount to be injected is configured to be injected. Further, the ECU 1A performs control based on the specific injection timing control program and the specific fuel injection amount control program, so that the second fuel injection valve 59 is located near the bottom dead center between the intake stroke and the compression stroke. When positioned, the fuel is injected into the cylinder by subtracting the fuel injection amount injected by the first fuel injection valve 58 from the total fuel injection amount along the tumble flow T.

  In this embodiment, various control means, determination means, detection means, calculation means, etc. are realized by the microcomputer and the program stored in the ROM, and in particular, the specific injection timing control means is realized by the microcomputer and the specific injection timing control program. The microcomputer and the first fuel injection timing control program specify the first fuel injection timing control means, and the microcomputer and the second fuel injection timing control program specify the second fuel injection timing control means as the microcomputer. The specific fuel injection amount control means is realized by the fuel injection amount control program. In this embodiment, the ECU 1A implements a control device for the internal combustion engine.

  FIG. 3 is a graph schematically showing the fuel injection timing A from the first fuel injection valve 58 and the fuel injection timing B from the second fuel injection valve 59. In the graph shown in FIG. 3, the vertical axis represents the valve lift amount, and the horizontal axis represents the crank angle. In this graph, the crank angle is shown from the intake stroke to the compression stroke. As shown in FIG. 3, more specifically, the fuel injection timing A from the first fuel injection valve 58 is such that fuel is injected evenly back and forth around the crank angle at which the valve lift amount is maximum. Is set. 3 that this setting is set so that the fuel is injected from the first fuel injection valve 58 when the intake valve 55 is opened.

  On the other hand, the fuel injection timing B from the second fuel injection valve 59 is more specifically from before the crank angle (BTDC 180 ° CA) corresponding to the bottom dead center between the intake stroke and the compression stroke, that is, from the end of the intake stroke. The fuel is set to be injected, and in the example shown in FIG. 3, the fuel is set to be injected over the compression stroke. 3 that this setting is set so that fuel is injected from the second fuel injection valve 59 when the piston 53 is located near the bottom dead center between the intake stroke and the compression stroke. .

  Returning to FIG. 2, each of the first fuel injection valves 58 injects part of the total fuel injection amount to be injected toward each intake port 52 a when the intake valve 55 is opened. Specifically, each of the first fuel injection valves 58 cancels out the reverse tumble component that flows from each intake port 52a into the cylinder so as to form an intake flow in a direction opposite to the swirling direction of the tumble flow T. Inject fuel. The second fuel injection valve 59 injects fuel into the cylinder along the tumble flow T when the piston 53 is positioned near the bottom dead center between the intake stroke and the compression stroke.

  Thereby, the tumble flow T generated in the cylinder can be strengthened by the fuel injection from the first fuel injection valve 58 and the second fuel injection valve 59. Further, the strengthening of the tumble flow T by the fuel injection from the first fuel injection valve 58 can be realized in combination with the strengthening of the tumble flow T by the fuel injection from the second fuel injection valve 59. Thus, the tumble flow T generated in the cylinder can be suitably strengthened by fuel injection. As described above, the internal combustion engine 50A and the ECU 1A that can suitably enhance the tumble flow T generated in the cylinder by fuel injection can be realized.

  The internal combustion engine 50B according to the present embodiment is substantially the same as the internal combustion engine 50A according to the first embodiment, except that a variable valve mechanism (not shown) is provided. The ECU 1B is substantially the same as the ECU 1A except that a specific fuel injection amount control program created as described later is stored in the ROM. The variable valve mechanism is not particularly limited as long as the valve lift amount of the intake valve 55 is variable. FIG. 4 is a diagram schematically showing the inflow mode of the intake air flowing into the cylinder when the valve lift amount of the intake valve 55 is large (in the case of high lift) and small (in the case of low lift).

  As shown in FIG. 4A, in the case of a high lift, the intake port 52a is largely opened, so that the intake air easily flows into the cylinder as it is according to inertia. For this reason, in the case of high lift, the forward tumble component generated in the tumble flow T is stronger than the reverse tumble component in the flow of intake air flowing into the cylinder. On the other hand, as shown in FIG. 4B, at the time of low lift, the intake port 52a is throttled by the intake valve 55, so that the flow of intake air flowing into the cylinder becomes substantially uniform around the intake valve 55. For this reason, it is more necessary to cancel the reverse tumble component by the fuel injection from the first fuel injection valve 58 at the time of low lift than at the time of high lift.

  For this reason, in this embodiment, the ratio of the fuel injection amounts from the first and second fuel injection valves 58 and 59 to the total fuel injection amount is set in advance according to the valve lift amount of the intake valve 55. FIG. 5 is a diagram schematically showing the ratio of the fuel injection amounts from the first and second fuel injection valves 58 and 59 to the total fuel injection amount. As shown in FIG. 5, the ratio of the fuel injection amount from the first fuel injection valve 58 to the total fuel injection amount is specifically set so as to increase as the valve lift amount of the intake valve 55 decreases. Yes.

  In the present embodiment, such settings are stored in advance in the ROM as map data, and the specific fuel injection amount control program is based on this map data, from the total fuel injection amount to the first fuel injection valve 58 and the second fuel injection. The fuel injection amount of the valve 59 is determined. The ratio of the fuel injection amount from the first fuel injection valve 58 to the total fuel injection amount as the valve lift amount of the intake valve 55 decreases as the ECU 1B performs control based on the specific fuel injection amount control program. The first fuel injection valve 58 is configured to increase. As a result, the reverse tumble component can be suitably canceled in accordance with the valve lift amount. Therefore, according to the internal combustion engine 50B, the tumble flow T can be further suitably strengthened by fuel injection.

  In this embodiment, various control means, determination means, detection means, calculation means, and the like are realized by the microcomputer and the program stored in the ROM. In particular, the specific fuel injection amount control is performed by the microcomputer and the specific fuel injection amount control program. Each means is realized. In the present embodiment, the control device for the internal combustion engine is realized by the ECU 1B. As described above, the internal combustion engine 50B and the ECU 1B that can suitably enhance the tumble flow T generated in the cylinder by fuel injection can be realized.

  In this embodiment, a control device for an internal combustion engine realized by the ECU 1C will be described in detail. The ECU 1C is configured to control the internal combustion engine 50B. A specific fuel injection amount control program created as described below is further added to the specific fuel injection amount control program described in the second embodiment. Except for the point stored in the ROM, it is substantially the same as the ECU 1B. The specific fuel injection amount control program can also be created as described below with respect to the specific fuel injection amount control program described in the first embodiment. At this time, the ECU 1C sets the internal combustion engine 50A. You may control.

  The total fuel injection amount is increased or decreased according to the operating state (specifically, load here) of the internal combustion engine 50B based on the internal combustion engine control program. The total fuel injection amount is injected from the first and second fuel injection valves 58 and 59 at a predetermined rate based on the specific fuel injection amount control program. On the other hand, in this embodiment, when the specific fuel injection amount control program further increases the fuel injection amount to be injected from the second fuel injection valve 59 to a predetermined amount α or more, the second fuel injection valve The fuel injection amount to be injected from 59 is set to a predetermined amount α, and the fuel injection amount to be injected from the first fuel injection valve 58 is set to a remaining injection amount obtained by subtracting the predetermined amount α from the total fuel injection amount. Has been created. In this embodiment, various control means, determination means, detection means, and calculation means are realized by the microcomputer and the program stored in the ROM, and in particular, the specific fuel injection is performed by the microcomputer and the above-described specific fuel injection amount control program. A quantity control means is realized.

  FIG. 6 is a diagram schematically showing how the fuel injection amounts from the first and second fuel injection valves 58 and 59 change according to the load. As shown in FIG. 6, the total fuel injection amount increases as the load increases. At this time, the ECU 1C performs control based on the specific fuel injection amount control program, so that the fuel injection amount from the first fuel injection valve 58 increases as the load increases. On the other hand, the fuel injection amount from the second fuel injection valve 59 increases as the load increases until reaching the predetermined amount α, and after reaching the predetermined amount α, the fuel injection amount remains at the predetermined amount α even if the load increases. Become.

  This predetermined amount α is the maximum at which the jet effect can be appropriately obtained by fuel injection from the second fuel injection valve 59 when the piston 53 is located near the bottom dead center between the intake stroke and the compression stroke. The fuel injection amount is set in advance. Thus, fuel can be injected from the second fuel injection valve 59 within a range in which the jet effect can be appropriately obtained, and the reverse tumble component can be canceled by injecting the remaining fuel from the first fuel injection valve 58. Therefore, the tumble flow T can be suitably strengthened by fuel injection. As described above, the ECU 1 </ b> C that can suitably enhance the tumble flow T generated in the cylinder by fuel injection can be realized.

  The ECU 1D according to the present embodiment is substantially the same as the ECU 1C except that the following specific injection period control program is further stored in the ROM. It is also possible to store the following specific injection period control program in the ECU 1A or ECU 1B ROM. The specific injection period control program is a program for changing the injection period of the fuel injected from the first and second fuel injection valves 58 and 59 according to the rotational speed NE of the internal combustion engine 50B. Is created to change the injection period longer as the rotational speed NE increases. In this embodiment, various control means, determination means, detection means, and calculation means are realized by the microcomputer and the program stored in the ROM, and in particular, the specific injection period control means is realized by the microcomputer and the specific injection period control program. ing.

  FIG. 7 is a diagram schematically showing the state before and after the fuel injection period of the first and second fuel injection valves 58 and 59 is changed according to the rotational speed NE. In the example shown in FIG. 7, before the rotational speed increases, the fuel injection period of the first fuel injection valve 58 is set to a crank angle corresponding to the maximum valve lift amount of the intake valve 55 as shown in FIG. As a center, it is set to inject fuel evenly in the front and rear. On the other hand, the fuel injection period of the second fuel injection valve 59 is set so as to inject fuel from before the crank angle (BTDC 180 ° CA) corresponding to the bottom dead center between the intake stroke and the compression stroke to BTDC 180 ° CA. Yes.

  On the other hand, when the rotational speed NE rises, the ECU 1D performs control based on the specific fuel injection period control program, thereby changing the fuel injection period as shown in FIG. Specifically, the fuel injection period of the first fuel injection valve 58 is evenly expanded back and forth around the crank angle corresponding to the maximum valve lift amount of the intake valve 55. The fuel injection period of the second fuel injection valve 59 is evenly expanded before and after the crank angle (BTDC 180 ° CA) corresponding to the bottom dead center between the intake stroke and the compression stroke. As a result, even when the rotational speed NE rises, the injection time can be secured, so that the fuel injection amount to be injected can be reliably injected, and the tumble flow T generated in the cylinder is injected into the fuel. Can be suitably strengthened. As described above, the ECU 1D that can suitably enhance the tumble flow T generated in the cylinder by fuel injection can be realized.

  The ECU 1E according to the present embodiment, except that the specific fuel injection amount control program created as described below with respect to the specific fuel injection amount control program described in the third embodiment is stored in the ROM, It is substantially the same as the ECU 1D. The specific fuel injection amount control program can also be created as described below with respect to the specific fuel injection amount control program described in the first or second embodiment. At this time, the ECU 1E 50A may be controlled. Also in the present embodiment, the total fuel injection amount is increased or decreased according to the operating state (specifically, load here) of the internal combustion engine 50B based on the internal combustion engine control program. The total fuel injection amount is injected from the first and second fuel injection valves 58 and 59 at a predetermined rate based on the specific fuel injection amount control program.

  On the other hand, in this embodiment, the specific fuel injection amount control program further sets the fuel injection amount from the first fuel injection valve 58 to the predetermined amount β that will be injected beyond the time when the intake valve 55 is opened. In this case, the fuel injection amount from the first fuel injection valve 58 is set to a predetermined value β, and the fuel injection amount from the second fuel injection valve 59 is subtracted from the total fuel injection amount by the predetermined amount β. Created to be a quantity. In this embodiment, various control means, determination means, detection means, and calculation means are realized by the microcomputer and the program stored in the ROM, and in particular, the specific fuel injection amount control is performed by the microcomputer and the above-described specific fuel injection amount control program. Means are realized. This makes it possible to reliably prevent the tumble flow T generated in the cylinder from being injected by the fuel in that the fuel is reliably prevented from being injected from the first fuel injection valve 58 except when the intake valve 55 is opened. Can be strengthened. As described above, the ECU 1D that can suitably enhance the tumble flow T generated in the cylinder by fuel injection can be realized.

  The ECU 1F according to the present embodiment, except that the specific fuel injection amount control program created as described below with respect to the specific fuel injection amount control program described in the fifth embodiment is stored in the ROM, It is substantially the same as the ECU 1E. The ECU 1F is configured to control the internal combustion engine 50B having a variable valve mechanism. The specific fuel injection amount control program can also be created as described below with respect to the specific fuel injection amount control program described in the first, second, or third embodiment. The internal combustion engine 50B will be controlled.

  Here, when deposit is accumulated on the intake valve 55, the intake air amount sucked into the cylinder when the intake valve 55 is in a low lift is reduced from the air amount to be sucked in accordance with the operating state of the internal combustion engine 50B. . On the other hand, in the present embodiment, the specific fuel injection amount control program further determines that the intake air amount sucked into the cylinder when the intake valve 55 is low lifted is the air to be sucked according to the operating state of the internal combustion engine 50B. When the fuel injection amount is smaller than the fuel injection amount, the fuel injection amount from the first fuel injection valve 58 occupies the total fuel injection amount. Whether or not the intake air amount has decreased is detected, for example, by detecting A / F and emission after injecting fuel corresponding to the amount of air to be sucked according to the operating state of the internal combustion engine 50B. It can be determined by determining whether or not the value is an appropriate value. In this embodiment, various control means, determination means, detection means, and calculation means are realized by the microcomputer and the program stored in the ROM, and in particular, the specific fuel injection amount control is performed by the microcomputer and the above-described specific fuel injection amount control program. Means are realized.

  By controlling the ECU 1F based on the above-described specific fuel injection amount control program, the ratio of the fuel injection amount from the first fuel injection valve 58 is greatly changed when the intake air amount has decreased. . Thereby, the deposit adhering to the intake valve 55 by the fuel injection from the first fuel injection valve 58 can be removed. When the intake air amount becomes an appropriate amount as a result of removing the deposit, the ratio of the fuel injection amount from the first fuel injection valve 58 to the total fuel injection amount is restored. It is also possible to create a program for controlling the specific fuel injection amount. Thereby, even when deposits are accumulated on the intake valve 55, the intake valve 55 can be suitably cleaned by fuel injection. As described above, it is possible to realize the ECU 1F that can suitably enhance the tumble flow T generated in the cylinder by fuel injection and can clean the intake valve 55 by fuel injection even when deposits are accumulated on the intake valve 55.

  The embodiment described above is a preferred embodiment of the present invention. However, the present invention is not limited to this, and various modifications can be made without departing from the scope of the present invention.

It is a figure which shows typically the cross section for the principal part of 50 A of internal combustion engines per cylinder. It is a figure which shows each arrangement | positioning of the 1st and 2nd fuel injection valve 58, 59 using a side surface schematic diagram and a top surface schematic diagram. It is a figure which shows typically fuel injection timing A from the 1st fuel injection valve 58, and fuel injection timing B from the 2nd fuel injection valve 59 with a graph. It is a figure which shows typically the inflow mode of the inflow which flows in in a cylinder, respectively, when the valve lift amount of the intake valve 55 is large (in the case of high lift) and small (in the case of low lift). It is a figure which shows typically the ratio of the fuel injection quantity from the 1st and 2nd fuel injection valves 58 and 59 which occupies for the total fuel injection quantity. It is a figure which shows typically a mode that the fuel injection quantity from the 1st and 2nd fuel injection valves 58 and 59 changes according to load. It is a figure which shows typically the mode before and after the fuel injection period of the 1st and 2nd fuel injection valves 58 and 59 is changed according to the rotation speed NE, respectively. It is a figure which shows typically the fuel-injection method which can obtain appropriately the jet effect which strengthens a swirl | vortex airflow compared with the case where a fuel is injected at the time of a piston fall.

Explanation of symbols

1 ECU
50 internal combustion engine 51 cylinder block 52 cylinder head 52a intake port 53 piston 55 intake valve 58 first fuel injection valve 59 second fuel injection valve

Claims (2)

A part of the total fuel injection amount to be injected into the cylinder in which the swirling airflow is generated and toward the intake port when the intake valve is opened is reverse to the swirling direction of the swirling airflow from the intake port into the cylinder. A first fuel injection valve that injects to cancel the intake air flow that flows in to form a directional flow, and the swirl airflow when the piston is located near the bottom dead center between the intake stroke and the compression stroke And a second fuel injection valve for injecting fuel into the cylinder, and a control device for the internal combustion engine for controlling the cylinder direct fuel injection internal combustion engine,
The total fuel injection amount is increased or decreased according to the operating state of the direct injection type internal combustion engine, and the total fuel injection amount is injected from each of the first and second fuel injection valves at a predetermined rate. When
When the fuel injection amount to be injected from the second fuel injection valve exceeds a predetermined amount, the predetermined amount is set as the fuel injection amount to be injected from the second fuel injection valve, and the total fuel injection A control apparatus for an internal combustion engine, comprising: specific fuel injection amount control means for setting a remaining injection amount obtained by subtracting the predetermined amount from a amount to be a fuel injection amount to be injected from the first fuel injection valve . The specific fuel injection amount control means is further configured such that the intake air amount sucked into the cylinder from the intake port is smaller than the intake air amount to be sucked according to the operating state of the direct fuel injection internal combustion engine. In this case, the ratio of the fuel injection amount to be injected by the first fuel injection valve in the total fuel injection amount is set to the intake air amount sucked into the cylinder from the intake port. 2. The control apparatus for an internal combustion engine according to claim 1 , wherein the control unit increases the intake air amount before the intake air amount is decreased .

Images