JP2010116870A - Internal combustion engine for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an internal combustion engine for a vehicle, which can reduce pumping loss in a fuel cut deceleration region without performing introduction of air. <P>SOLUTION: The internal combustion engine for a vehicle includes an EGR control unit (ECU) 10 for introducing external EGR gas in a combustion chamber 1a by an EGR device 40 when the stop of fuel supply is detected. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an internal combustion engine for a vehicle including an EGR device that introduces external EGR gas into a combustion chamber, and a fuel injection valve control unit that stops fuel supply from the fuel injection valve when a fuel cut deceleration region is detected. .

  This type of internal combustion engine may include an EGR device that introduces a part of the exhaust gas flowing through the exhaust passage into the combustion chamber (see, for example, Patent Document 1). In this EGR device, the introduction of the external EGR gas is stopped during idling operation or extremely low load operation, the introduction is performed during low / medium load operation, and the introduction of external EGR gas is stopped again during high load operation. .

In the internal combustion engine, from the viewpoint of suppressing fuel consumption, the fuel supply from the fuel injection valve may be stopped in the deceleration operation region where the throttle valve is closed.
JP 2005-120888 A

  By the way, in the deceleration region where the fuel is cut, the throttle valve is fully closed and the fuel supply is stopped, so there is a problem that the pumping loss in the intake stroke becomes large.

  Here, during fuel cut deceleration, it is possible to reduce the pumping loss by opening the throttle valve by a predetermined amount and introducing air. However, when air is introduced, the air flows into the exhaust passage as it is and is stored in the catalyst, and there is a concern that the catalyst purification function cannot be sufficiently obtained when returning from the fuel cut operation to the operation operation in which the fuel supply is resumed. Is done.

  The present invention has been made in view of the above-described conventional situation, and an object thereof is to provide an internal combustion engine for a vehicle that can reduce pumping loss in a fuel cut deceleration region without introducing air.

  According to the first aspect of the present invention, a throttle valve that is disposed in the intake passage and variably controls the intake amount, a fuel injection valve that supplies fuel to the intake passage or the combustion chamber, and an EGR passage that connects the exhaust passage and the intake passage An EGR device that introduces external EGR gas into the combustion chamber via a fuel, a fuel cut deceleration region detection unit that detects a fuel cut deceleration region from the engine operating state, and fuel by the fuel injection valve when the fuel cut deceleration region is detected An internal combustion engine for a vehicle having a fuel injection valve control unit for stopping supply, and having an EGR control unit for introducing external EGR gas into the intake passage by the EGR device when a fuel cut deceleration region is detected It is characterized by that.

  According to a second aspect of the present invention, in the internal combustion engine for a vehicle according to the first aspect, a surge tank is disposed in the middle of the intake passage, and the EGR passage is connected to a portion of the intake passage downstream from the surge tank. It is characterized by being.

  According to a third aspect of the present invention, in the internal combustion engine for a vehicle according to the first or second aspect, the EGR control unit detects the external EGR gas when a fuel cut deceleration region is detected during traveling at a predetermined vehicle speed or higher. It is characterized by reducing the introduction amount or stopping the introduction.

  According to a fourth aspect of the present invention, in the internal combustion engine for a vehicle according to the first aspect, the engine has a plurality of cylinders, and the intake passage is branched from the intake merging pipe common to each cylinder and the intake merging pipe to each cylinder An intake branch pipe connected to the intake branch pipe, and the intake branch pipe is provided with an intake control valve for variably controlling a passage area, and the EGR passage is provided. Is connected to the downstream side of the intake control valve of the intake branch pipe, and a check valve that allows only the flow to the intake branch pipe side is interposed in the EGR passage. In the fuel cut deceleration region, the external EGR gas is introduced into the intake branch pipe.

  According to a fifth aspect of the present invention, in the internal combustion engine for a vehicle according to the fourth aspect, a bypass passage is provided for bypassing each intake control valve and allowing a spiral intake flow to flow into each cylinder. A check valve that allows only the flow to the cylinder side is provided.

  According to a sixth aspect of the present invention, there is provided an internal combustion engine for a vehicle according to the first aspect, wherein an overlap amount varying mechanism for changing an overlap amount between the intake valve and the exhaust valve, and the overrun when a fuel cut deceleration region is detected. An overlap amount control unit that expands the overlap amount by the wrap variable mechanism is further provided.

  According to the internal combustion engine of the first aspect of the invention, when the fuel cut deceleration region is detected, the external EGR gas is introduced into the combustion chamber, so that the negative pressure state of the combustion chamber is eliminated by the external EGR gas. The pumping loss in the intake stroke can be reduced. Thus, the pumping loss can be reduced without introducing air, and the catalyst purification function immediately after returning from the fuel cut operation to the operation operation in which the fuel supply is resumed can be sufficiently exhibited.

  In the invention of claim 2, since the external EGR gas is introduced downstream of the surge tank in the intake passage, the responsiveness when returning from the fuel cut operation to the operation operation can be improved. That is, in the fuel cut deceleration region, for example, when external EGR gas is introduced into the surge tank, the EGR gas in the surge tank continues to be supplied to the combustion chamber even after switching to operation, and stable combustion is performed during this period. It cannot be done, and the responsiveness decreases accordingly. In the present invention, since the external EGR gas is introduced at a position close to the combustion chamber of the intake passage, stable combustion can be performed immediately upon return to the operation operation.

  When a vehicle traveling at high speed decelerates, an excessive load is applied to the brake device of the vehicle. According to the third aspect of the present invention, the amount of external EGR gas introduced is reduced or stopped at the time of deceleration during high-speed traveling, so that the braking force by the internal combustion engine itself acts and an excessive load is applied to the brake device of the vehicle. Can be suppressed.

  In the fourth aspect of the invention, the intake control valve is disposed in each intake passage, and the external EGR gas is introduced downstream of the intake control valve in the intake passage in the fuel cut deceleration region. External EGR gas can be introduced downstream of the intake control valve by using sufficient time, negative pressure in the intake passage can be reduced, and pumping loss can be reduced.

  In the invention of claim 5, since the bypass passage for bypassing the intake control valve is provided in the intake passage so that a vortex-like intake flow is generated in the combustion chamber, the EGR resistance in the case of returning from the fuel cut operation to the operation operation. The stability can be improved and stable combustion can be performed. That is, when returning from the fuel cut operation to the idling operation or the extremely low load operation, it is necessary to restart the fuel supply and reduce the introduction of the external EGR gas in a short time. However, such an operation is likely to cause a delay in response, and combustion may not be performed satisfactorily. In the present invention, since a strong vortex intake air flow is generated in the combustion chamber, combustion when returning from the fuel cut operation to the operation operation can be stabilized.

  In the invention of claim 6, when the stop of the fuel supply is detected, the external EGR gas is introduced into the combustion chamber and the overlap amount between the intake valve and the exhaust valve is increased, so that the pumping loss is reduced by the external EGR gas. The pumping loss can be reduced by the internal EGR gas by increasing the overlap amount.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  FIGS. 1 to 4 are views for explaining a vehicle internal combustion engine according to a first embodiment of the present invention. FIG. 1 is a schematic configuration diagram of the internal combustion engine, FIG. 2 is a cross-sectional view of the internal combustion engine, and FIG. FIG. 4 is a flowchart for explaining the operation of the internal combustion engine.

  In the figure, reference numeral 1 denotes a vehicle four-cycle four-cylinder spark ignition internal combustion engine. The internal combustion engine 1 includes an intake device 2 that supplies combustion air to each combustion chamber 1a, an overlap variable mechanism (variable valve timing mechanism) that variably controls the amount of overlap between the intake valve 5 and the exhaust valve 6, ECU 10 that functions as a fuel cut deceleration region detection unit that detects a fuel cut deceleration region from the engine operating state and also functions as a fuel injection valve control unit that stops fuel supply by the fuel injection valve 4 when the fuel cut deceleration region is detected. In detail, it has the following configuration.

  The internal combustion engine 1 includes a cylinder block 12 in which four cylinder bores (cylinders) 12a are formed in parallel, and a cylinder head 13 that is coupled to the cylinder block 12 and has a combustion recess 13a that is opposed to the cylinder bore 12a. It has. A piston 15 is slidably inserted into each cylinder bore 12a, and the piston 15 is connected to the crankshaft 16 via a connecting rod 16a.

  A combustion chamber 1 a is formed by a space surrounded by the cylinder bore 12 a, the combustion recess 13 a and the top surface of the piston 15.

  Each combustion recess 13a of the cylinder head 13 is formed with one intake opening 13b and one exhaust opening 13c communicating with the combustion chamber 1a. The intake opening 13b is disposed on one side of the straight line C parallel to the crankshaft 16, and the exhaust opening 13c is disposed on the other side.

  Further, in each combustion recess 13a, two spark plugs 19, 19 are arranged between the intake opening 13b and the exhaust opening 13c and slightly positioned on the exhaust opening 13c side from the straight line C. ing.

  The intake valve 5 and the exhaust valve 6 are disposed in the intake opening 13b and the exhaust opening 13c. Each intake valve 5 is driven to open and close by an intake cam shaft 17, and each exhaust valve 6 is driven to open and close by an exhaust cam shaft 18.

  Each intake opening 13b is led to one side wall of the cylinder head 13 by an intake port 13d, and each exhaust opening 13c is led to the other side wall of the cylinder head 3 by an exhaust port 13e.

  An exhaust branch pipe 23 is connected to each exhaust port 13e. A single exhaust merging pipe 24 is connected to the downstream end of each exhaust branch pipe 23, and a catalyst 25 for purifying exhaust gas is provided in the middle of the exhaust merging pipe 24. A muffler (not shown) is connected.

  The intake device 2 is connected to each intake port 13d. The intake device 2 includes an intake merging pipe 28 common to each cylinder, an intake branch pipe 2a connected to the intake port 13d of each cylinder, and interposed between each intake branch pipe 2a and the intake merging pipe 28. A surge tank 27.

  The throttle valve 3 common to each cylinder is arranged in the intake merging pipe 28. Here, the intake passage in this embodiment includes the intake port 13d, the intake branch pipe 2a, the surge tank 27, the intake merging pipe 28, and the air cleaner 29 from the intake opening 13b.

  A fuel injection valve 4 is mounted at the downstream end of each intake branch pipe 2a, and is arranged to inject and supply fuel toward the valve back of the intake valve 5 through the intake port 13d.

  The internal combustion engine 1 of the present embodiment includes an EGR device 40 that recirculates a part of the exhaust gas flowing through the exhaust merging pipe 24 to the combustion chamber 1a. The EGR device 40 includes an EGR introduction pipe 41 connected to the exhaust merging pipe 24, an EGR cooler 42 that is interposed in the middle of the EGR introduction pipe 41, and cools the external EGR gas to a predetermined temperature, and an EGR introduction And an EGR control valve 43 provided on the downstream side of the EGR cooler 42 of the pipe 41. Further, a particulate trap 44 for removing particulates such as carbon mixed in the EGR gas is interposed on the upstream side of the EGR cooler 42 of the EGR introduction pipe 41.

  The EGR introduction pipe 41 is connected to a header pipe 45. The header pipe 45 connects the intake branch pipes 2a.

  The overlap variable mechanism 7 changes both the opening timing of the intake valve 5 in the intake stroke and the closing timing of the exhaust valve 6 in the exhaust stroke, whereby the intake valve 5 and the exhaust valve 6 are simultaneously changed. Change the amount of overlap to open.

  The overlap variable mechanism 7 includes actuators 7a and 7b including hydraulic control valves that continuously change the opening and closing timings of the intake valve 5 and the exhaust valve 6 through the intake cam shaft 17 and the exhaust cam shaft 18, respectively. And the ECU 10 functioning as an overlap variable mechanism control unit that drives and controls the actuators 7a and 7bb. Specifically, the ECU 10 changes the overlap amount in the crank angle, for example, in the range of 20 degrees to 90 degrees according to the engine operating state.

  The internal combustion engine 1 according to the present embodiment includes an operation state detection sensor 8. The driving state detection sensor 8 includes an intake cam angle sensor 8a, an exhaust cam angle sensor 8b, an engine speed sensor (crank angle sensor) 8c, an accelerator pedal sensor (throttle opening sensor) 8d, a vehicle speed sensor 8e, a water temperature sensor 8f, The intake air temperature sensor 8d is used.

  The ECU 10 detects a fuel cut deceleration region based on detection values from various operation state detection sensors 8 and controls the fuel injection amount and injection timing of each fuel injection valve 4 and the ignition timing of each spark plug 19. Further, the EGR control valve 43 is controlled to open and close.

  For example, when a fuel cut deceleration region is detected by a signal from the operation state detection sensor 8, the fuel supply from each fuel injection valve 4 is stopped, each intake control valve 20 is fully closed, and the overlap amount is maximized. The value is expanded to a value (for example, 90 degrees in crank angle).

  Further, the ECU 10 controls the opening / closing operation by the EGR control valve 43 based on the engine operating state based on the detected value. For example, the EGR control valve 43 is closed in an idling operation and an extremely low load operation region, the EGR control valve 43 is half open to fully open in a low / medium load operation region, and the EGR control valve 43 is closed in a high load operation region. .

  The ECU 10 incorporates an operation operation map in which an external EGR gas introduction amount according to a normal engine operation state is described and a deceleration operation map in which an external EGR gas introduction amount according to a fuel cut deceleration region is described. .

  Then, as shown in FIG. 4, the ECU 10 reads the detected values of the engine speed sensor 8c, the accelerator pedal sensor 8d and the like in the control of the EGR gas introduction amount (step S1), and the engine speed and the throttle valve opening degree. From the above, it is determined whether the engine operating state is in the fuel cut deceleration region (step S2). If not, the EGR introduction amount is determined in the normal operation state from the operation map (step S6). ), An EGR gas introduction amount control signal is output to the EGR control valve 43 (step S5). Thereby, the EGR gas introduction amount becomes the EGR gas introduction amount in the operation state.

  On the other hand, when it is determined in step S2 that the vehicle is in the fuel cut deceleration range, the ECU 10 determines whether the vehicle speed is equal to or higher than a predetermined value, that is, whether the vehicle is traveling at high speed (step S3), and is not traveling at high speed. In this case, the EGR introduction amount in the fuel cut deceleration region is determined from the deceleration operation map (step S7), and an EGR gas introduction amount control signal is output to the EGR control valve 43 (step S5). Then, the EGR control valve 43 is fully opened, and EGR gas is introduced into the combustion chamber 1a from each intake branch pipe 2a.

  If it is determined in step S3 that the ECU 10 is traveling at a high speed, the EGR gas introduction amount in the deceleration operation map is corrected to a smaller side (step S4), and the corrected EGR gas introduction amount is set according to the corrected EGR gas introduction amount. A control signal is output to the EGR control valve 43 (step S5). Then, for example, the EGR control valve 43 is half open. Note that when the vehicle is traveling at a high speed, the introduction of EGR gas may be stopped.

  According to the present embodiment, when the fuel cut deceleration region where the fuel supply from the fuel injection valve 4 is stopped is detected, the EGR device 40 introduces the external EGR gas into the combustion chamber 1a. Thus, the negative pressure state is eliminated, and the pumping loss can be reduced accordingly. Thereby, the pumping loss can be reduced without introducing air, and the purification function of the catalyst 25 when returning from the fuel cut operation to the operation operation in which the fuel supply is started can be exhibited.

  Further, since combustion is not performed in the fuel cut deceleration region, even if a large amount of external EGR gas is introduced, there is no effect on stable combustion. Moreover, since the vehicle speed is not reduced more than necessary, energy loss can be reduced. For example, when mounted on a hybrid vehicle, regenerative energy can be increased.

  In the present embodiment, since the external EGR gas is introduced into each intake branch pipe 2a downstream of the surge tank 27, the responsiveness when returning from the fuel cut operation to the operation operation can be enhanced. That is, when an external EGR gas is introduced into, for example, the surge tank 27 in a transient condition where the fuel cut operation is switched to the operation operation, stable combustion can be performed until the discharge of the EGR gas from the surge tank 27 is completed. Therefore, the responsiveness is lowered accordingly. In the present embodiment, the external EGR gas is introduced into the intake branch pipe 2a at a position close to the combustion chamber 1a, so that the operation operation can be restored in a short time.

  When a vehicle traveling at high speed decelerates, an excessive load is applied to the brake device of the vehicle. In this embodiment, at the time of deceleration during high-speed traveling, the amount of external EGR gas introduced is reduced or stopped, so that the braking force by the internal combustion engine itself can act to prevent an excessive load from being applied to the vehicle brake device. .

  In the embodiment, the case where only the external EGR gas is introduced when the fuel cut operation region is detected has been described. However, in the present invention, the introduction of the external EGR gas and the introduction of the intake valve 5 and the exhaust valve 6 together. You may control to enlarge the amount of overlaps. In this case, the pumping loss can be reduced by the external EGR gas, and the pumping loss can also be reduced by the internal EGR gas due to the increase in the overlap amount.

  FIGS. 5-10 is a figure for demonstrating the internal combustion engine for vehicles by 2nd, 3rd, 4th embodiment of this invention, respectively. In the figure, the same reference numerals as those in FIGS. 1 to 4 denote the same or corresponding parts.

  The basic structure of the internal combustion engine 1 of the second to fourth embodiments is the same as that of the first embodiment. Hereinafter, only different portions for each embodiment will be described.

  5 and 6 showing the second embodiment, the internal combustion engine 1 includes an intake control valve 20 in each intake branch pipe 2a, and introduces EGR into each intake branch pipe 2a of a header pipe 45 that supplies EGR gas. The check valve 46 is arranged in the mouth 2b. The check valve 46 allows only the flow of the external EGR gas to the combustion chamber 1a side and blocks the flow in the reverse direction.

  Each intake control valve 20 is disposed upstream of the EGR gas inlet 2b of the intake branch pipe 2a and in the vicinity of the connection portion of the surge tank 27.

  The intake control valves 20 are connected by a common valve shaft 20a, and are driven to open and close by a drive motor 21 connected to an end of the valve shaft 20a.

  Each intake control valve 20 is controlled to be opened and closed by the ECU 10 together with the aforementioned EGR control valve 43. For example, in the idling operation and the extremely low load operation region, the intake control valve 20 is closed and the EGR control valve 43 is closed, and in the low / medium load operation region, the intake control valve 20 is opened according to the accelerator operation amount and the EGR. The control valve 43 is half open to fully open. In the high load operation region, the intake control valve 20 is fully opened and the EGR control valve 43 is closed.

  Then, the ECU 10 closes the intake control valve 20 and opens the EGR control valve 43 in the fuel cut deceleration region.

  In the second embodiment, the intake control valve 20 is arranged in each intake branch pipe 2a, and in the fuel cut deceleration region, the intake control valve 20 is closed and the EGR control valve 43 is opened. The intake branch pipe 2a is introduced to the downstream side of the intake control valve 20, and the intake control valve 20 blocks the flow to the upstream side, so that the pumping loss can be further reduced.

  That is, even outside the intake stroke, the external EGR gas can be introduced downstream from the intake control valve 20 of the intake branch pipe 2a by using sufficient time, the negative pressure of the intake branch pipe 2a is reduced, and the pumping loss is reduced. Can do.

  7 and 8 show a vehicle internal combustion engine according to the third embodiment, in which the same reference numerals as those in FIGS. 5 and 6 denote the same or corresponding parts.

  The internal combustion engine 1 according to the third embodiment includes an intake control valve 20 in each intake branch pipe 2a and a bypass passage 36 that bypasses the intake control valve 20.

  Each bypass passage 36 is disposed so as to generate an intake air flow A having a horizontal vortex or a vertical vortex in the combustion chamber 1a.

  The downstream portion of each bypass passage 36 is branched into two, and the downstream end opening 36a of the branch portion is located at a position avoiding the valve shaft of the intake valve 6 of the intake port 13d and close to the intake opening 13b. Are arranged to be. The upstream end opening 36 b of the bypass passage 36 is connected to the surge tank 27.

  An intake check valve 35 is disposed in the upstream end opening 36 b of each bypass passage 36. The intake check valve 35 allows only the flow of intake air from the surge tank 27 to the cylinder side and blocks the flow in the reverse direction.

  In the third embodiment, the bypass passages 36 that bypass the intake control valve 20 are formed in each intake branch pipe 2a, and the bypass passage 36 is formed so that a spiral intake flow A is generated in the combustion chamber 1a. EGR resistance when returning to operation from the cut deceleration region can be improved, and stable combustion can be performed.

  That is, when returning to the idling operation or the extremely low load operation from the fuel cut deceleration range, it is necessary to restart the fuel supply and reduce the amount of external EGR gas introduced in a short time. However, such an operation is likely to cause a response delay, and combustion may not be performed satisfactorily.

  In the present embodiment, since a strong spiral intake air flow A is generated in the combustion chamber 1a, combustion when returning from the fuel cut operation region to the operation operation can be stabilized. Further, by closing the intake control valve 20, the influence of the intake negative pressure of the other cylinders can be suppressed, and the pumping loss can be reduced.

  9 and 10 show the internal combustion engine for a vehicle according to the fourth embodiment, in which the same reference numerals as those in FIGS. 7 and 8 denote the same or corresponding parts.

  The internal combustion engine 1 according to the fourth embodiment has an intake control valve 20 in each intake branch pipe 2a, a bypass passage 36 that bypasses the intake control valve 20, and an external EGR gas in the bypass passage 36. It has the structure which introduces.

  An EGR introduction port 36 c is formed on the downstream side of the intake check valve 35 in the bypass passage 36, and a header pipe 45 is connected to the EGR introduction port 36 c with a check valve 46 interposed. The check valve 46 allows only the flow of the external EGR gas to the combustion chamber 1a side and blocks the flow in the reverse direction.

  In the fourth embodiment, since the external EGR gas is introduced into the bypass passage 36, when the fuel cut deceleration region is detected, the external EGR gas having a high flow velocity flows into the combustion chamber 1a, thereby further reducing the pumping loss. Can be reduced.

  Further, in the low / medium load operation region, the external EGR gas from the bypass passage 36 and the fresh air from the intake branch pipe 2a flow in a stratified manner in the combustion chamber 1a, so that stable combustion is obtained and fuel consumption is improved. Can be improved.

1 is a schematic configuration diagram of an internal combustion engine for a vehicle according to a first embodiment of the present invention. It is sectional drawing of the said internal combustion engine. It is a control block diagram of the internal combustion engine. It is a flowchart for demonstrating operation | movement of the said internal combustion engine. It is a schematic block diagram of the internal combustion engine for vehicles by 2nd Embodiment of this invention. It is sectional drawing of the said internal combustion engine. It is a schematic block diagram of the internal combustion engine for vehicles by 3rd Embodiment of this invention. It is sectional drawing of the said internal combustion engine. It is a schematic block diagram of the internal combustion engine for vehicles by 4th Embodiment of this invention. It is sectional drawing of the said internal combustion engine.

Explanation of symbols

1 Internal combustion engine 1a Combustion chamber 2a Intake branch pipe (intake passage)
3 Throttle valve 4 Fuel injection valve 5 Intake valve 6 Exhaust valve 10 ECU (fuel injection valve control unit, fuel cut deceleration region detection unit, EGR control unit)
12a Cylinder bore (cylinder)
20 Intake control valve 23 Exhaust branch pipe (exhaust passage)
24 Joint exhaust pipe (exhaust passage)
27 Surge tank 28 Junction intake pipe (merging section)
35 Check valve 36 Bypass passage 40 EGR device 41 EGR introduction pipe (EGR passage)
45 EGR branch pipe (EGR passage)
46 Check valve A Intake flow

Claims (6)

A throttle valve disposed in the intake passage and variably controlling the intake amount;
A fuel injection valve for supplying fuel to the intake passage or the combustion chamber;
An EGR device for introducing external EGR gas into the combustion chamber via an EGR passage connecting the exhaust passage and the intake passage;
A fuel cut deceleration region detection unit for detecting a fuel cut deceleration region from the engine operating state;
An internal combustion engine for a vehicle comprising a fuel injection valve control unit that stops fuel supply by the fuel injection valve when a fuel cut deceleration region is detected;
An internal combustion engine for a vehicle, comprising: an EGR control unit that introduces an external EGR gas into the intake passage by the EGR device when a fuel cut deceleration region is detected. The internal combustion engine for a vehicle according to claim 1,
A surge tank is arranged in the middle of the intake passage,
The internal combustion engine for vehicles, wherein the EGR passage is connected to a portion of the intake passage downstream of the surge tank. The internal combustion engine for a vehicle according to claim 1 or 2,
The internal combustion engine for a vehicle, wherein the EGR control unit reduces the introduction amount of the external EGR gas or stops the introduction when a fuel cut deceleration region is detected during traveling at a predetermined vehicle speed or higher. The internal combustion engine for a vehicle according to claim 1,
Have multiple cylinders,
The intake passage has an intake merging pipe common to each cylinder, and an intake branch pipe branched from the intake merging pipe and connected to each cylinder,
The throttle valve is disposed in the intake merging pipe;
Each intake branch pipe is provided with an intake control valve that variably controls the passage area,
The EGR passage is connected downstream of the intake control valve of the intake branch pipe,
The EGR passage is provided with a check valve that allows only the flow to the intake branch pipe side, and the EGR control section introduces the external EGR gas into the intake branch pipe in the fuel cut deceleration region. An internal combustion engine for a vehicle. The internal combustion engine for a vehicle according to claim 4,
A bypass passage is provided for bypassing each intake control valve and allowing a spiral intake flow to flow into each cylinder.
An internal combustion engine for a vehicle, wherein the bypass passage is provided with a check valve that allows only a flow to the cylinder side. The internal combustion engine for a vehicle according to claim 1,
An overlap amount variable mechanism that changes the overlap amount between the intake valve and the exhaust valve, and an overlap amount control unit that expands the overlap amount by the overlap variable mechanism when a fuel cut deceleration region is detected The internal combustion engine for vehicles characterized by the above-mentioned.

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