JP2010031685A - Spark ignition internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spark ignition internal combustion engine capable of inhibiting excessive internal EGR from flowing in while improving fuel economy in a case where an overlap period is provided. <P>SOLUTION: A secondary throttle valve 23 is arranged near an intake opening side of each intake air passage 15. A primary throttle valve 24 common for each cylinder is arranged at an intake air merging part 17 at an upstream side of the secondary throttle valve 23 of each intake passage 15. The engine includes a throttle valve control means 35 controlling intake air quantity by opening of the primary throttle valve 24 with the secondary throttle valve 23 roughly fully closed in a very light load operation zone including idling operation. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a spark ignition type internal combustion engine provided with an overlap period in which an intake valve and an exhaust valve are simultaneously opened in an intake stroke.

A small internal combustion engine is often operated at a high engine speed in order to obtain a sufficient specific output. In such an internal combustion engine, in order to obtain a sufficient intake air amount at high speed rotation, the opening degree of the intake valve and the exhaust valve is made as wide as possible, and as a result, the overlap period is set long (for example, Patent Document 1).
JP 2006-274951 A

  By the way, when the overlap period is set large as in the conventional internal combustion engine, excessive internal EGR with respect to fresh air flows into the intake passage in the partial load operation region, and combustion may become unstable. There is.

  On the other hand, it is known that an appropriate amount of internal EGR is effective in reducing pumping loss and improving fuel consumption.

  The present invention has been made in view of the above-described conventional situation, and provides a spark ignition type internal combustion engine capable of suppressing excessive inflow of internal EGR while improving fuel efficiency when an overlap period is provided. It is an issue.

  The invention according to claim 1 includes an intake passage communicating with the combustion chamber and an intake valve that opens and closes an intake opening that opens into the combustion chamber of the intake passage, and an overlap period in which the intake valve and the exhaust valve open simultaneously. A spark ignition type internal combustion engine, wherein a secondary throttle valve is disposed close to the intake opening side of the intake passage, a primary throttle valve is disposed upstream of the secondary throttle valve of the intake passage, and the secondary A bypass passage that bypasses the throttle valve and generates an intake vortex flow in the combustion chamber is provided, and a check valve that allows only the flow of the intake air to the cylinder side is disposed in the bypass passage. In the load operating range, the secondary throttle valve is substantially fully closed, and the throttle valve control for controlling the intake air amount by the primary throttle valve is performed. It is characterized by comprising means.

  According to a second aspect of the present invention, in the spark ignition type internal combustion engine according to the first aspect, the throttle valve control means is configured such that the opening degree of the primary throttle valve is larger than the opening degree of the secondary throttle valve in the partial load operation region. It is characterized by controlling as follows.

  According to a third aspect of the present invention, in the spark ignition type internal combustion engine of the first aspect, the throttle valve control means controls the primary throttle valve to fully open prior to the secondary throttle valve.

  According to a fourth aspect of the present invention, in the spark ignition type internal combustion engine according to the first aspect, the communication passage includes a plurality of cylinders and communicates with the downstream side of the check valve of the bypass passage provided for each cylinder. The open / close valve is provided in the communication path, and the open / close valve is controlled to close the open communication path during idling operation.

  According to a fifth aspect of the present invention, in the spark ignition type internal combustion engine according to the fourth aspect, the on-off valve is controlled to open the communication passage in a low / medium load operation region.

  According to a sixth aspect of the present invention, in the spark ignition type internal combustion engine according to the first aspect, an external EGR introduction passage is connected downstream of the primary throttle valve of the intake passage, and an EGR control is provided in the external EGR introduction passage. A valve is disposed, and the EGR control valve is controlled to open later than the opening of the primary throttle valve and to start opening earlier than the opening of the secondary throttle valve.

  The invention according to claim 7 is the spark ignition type internal combustion engine according to claim 6, wherein the EGR control valve is controlled to be fully opened before the secondary throttle valve is fully opened.

  According to the internal combustion engine of the first aspect, the secondary throttle valve is disposed close to the intake opening side of the intake passage, and the check valve that allows only the flow to the cylinder side is disposed in the bypass passage. In the extremely low load operating range including idling, the secondary throttle valve is substantially fully closed and the intake air amount is controlled by the opening of the primary throttle valve. Therefore, the check valve for the secondary throttle valve and the bypass passage is used. As a result, the substantial passage volume of the intake passage can be reduced, so that the amount of inflow of the internal EGR can be suppressed to a small amount, and combustion in the extremely low load operation region can be stabilized.

  Further, since the secondary throttle valve is fully closed, all the fresh air flows into the cylinder from the bypass passage, so that a strong intake vortex can be generated in the cylinder bore and stable combustion can be obtained. As a result, even when the overlap period is set to be long, stable combustion is possible. For example, a variable valve device such as a VVT can be dispensed with, and the cost can be reduced.

  Thus, since the intake air amount can be secured while suppressing the internal EGR during idling operation, a large amount of internal EGR can be introduced to the upstream side of the secondary throttle valve when the secondary throttle valve is opened. Improvements can be made.

  In the second aspect of the invention, since the opening degree of the primary throttle valve is controlled to be larger than the opening degree of the secondary throttle valve in the partial load operation region, a necessary intake air amount is secured and the bypass passage enters the cylinder. A strong intake eddy current can be generated and stable combustion can be obtained.

  In the invention of claim 3, since the primary throttle valve is made to fully open ahead of the secondary throttle valve, the intake air amount in the high load operation region can be secured.

  According to the fourth aspect of the present invention, the on-off valve is disposed in the communication passage communicating with the bypass passages, and the on-off valve is closed during the idling operation, so that unstable combustion due to an increase in internal EGR can be suppressed. That is, since the amount of fresh air is small during idling, stable combustion cannot be obtained even if the intake vortex is strengthened when the internal EGR increases. For this reason, it is possible to stabilize the combustion during idling by closing the communication path and suppressing the internal EGR amount.

  In the fifth aspect of the invention, since the on-off valve is opened in the low load operation region, the passage volume of each intake passage from the secondary throttle valve to the intake valve can be shared via each bypass passage. As a result, the intake vortex can be further strengthened by the increase in the internal EGR and the amount of air ejected from the bypass passage, and stable combustion can be performed. That is, when one cylinder is in the intake stroke, the air in the intake passage of the other cylinder can be sucked, and the internal EGR of the cylinders in the low-load operation region can be sufficiently secured.

  According to the sixth aspect of the present invention, an external EGR introduction passage is connected downstream of the primary throttle valve in the intake passage, and the EGR control valve disposed in the external EGR introduction passage is opened with a delay from the start of opening of the primary throttle valve. In addition, since the secondary throttle valve starts to open earlier than the start of opening, it is possible to introduce a large amount of external EGR in spite of the low load operating range, reducing pumping loss and improving fuel efficiency. be able to. That is, in a no-load state such as during idling operation, the ratio of internal EGR to fresh air is the largest, and external EGR cannot be introduced under such a condition that the internal EGR is full. For this reason, external EGR cannot be introduced unless the charging efficiency is higher than that under no-load operation.

  In the present invention, as described above, the internal EGR is suppressed to a small amount by the secondary throttle valve and the check valve in the fully closed position. For this reason, by opening the EGR control valve later than the opening of the primary throttle valve, it is possible to introduce external EGR from an early stage and to enable stable combustion. That is, the external EGR has a temperature lower than that of the internal EGR immediately after combustion, and therefore, by introducing the external EGR, combustion with excellent knock resistance can be performed.

  Further, during the low load operation, the secondary throttle valve is almost fully closed, so that the entire external EGR is ejected from the bypass passage to the cylinder, strengthening the intake vortex flow and the residual combustion gas, EGR gas, fresh air Mixing is promoted, and as a result, a larger amount of external EGR becomes possible, and pumping loss can be reduced to improve fuel efficiency.

  In the invention of claim 7, since the EGR control valve is fully opened before the secondary throttle valve is fully opened, a large amount of external EGR can be introduced at the time of partial load.

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

  1 to 5 are views for explaining a spark ignition type internal combustion engine according to a first embodiment of the present invention. FIG. 1 is a schematic configuration diagram of the spark ignition type internal combustion engine, and FIG. 2 is a sectional view of the internal combustion engine. 3 is a characteristic diagram of the opening / closing control of the primary throttle valve and the secondary throttle valve, FIG. 4 is a characteristic diagram of the opening / closing control of the opening / closing valve, and FIG. 5 is a characteristic diagram of the opening / closing control of the EGR valve.

  In the figure, reference numeral 1 denotes a 4-cycle parallel 2-cylinder spark ignition internal combustion engine. The internal combustion engine 1 is connected to a cylinder block 2 in which two cylinder bores (cylinders) 2a and 2a are formed, and a cylinder head 3 in which a combustion recess 3a is formed so as to oppose each cylinder bore 2a. The piston 4 is slidably disposed on the piston 4, and the piston 4 is connected to the crankshaft 11 via a connecting rod 4a. A combustion chamber 5 is formed by a space surrounded by the cylinder bore 2 a, the combustion recess 3 a and the top surface of the piston 4.

  In the combustion recess 3 a of the cylinder head 3, one intake opening 3 b communicating with the combustion chamber 5 and one exhaust opening 3 c are formed. The intake openings 3b and the exhaust openings 3c are arranged so as to face each other on one side and the other side across the axis c of the crankshaft when viewed in the cylinder axis direction.

  The intake opening 3b and the exhaust opening 3c are provided with an intake valve 6 and an exhaust valve 7, respectively. The intake valve 6 and the exhaust valve 7 are driven to open and close by an intake cam shaft 8 and an exhaust cam shaft 9, respectively. .

  In the internal combustion engine 1 of the present embodiment, the ignition interval of each cylinder 2a, 2a is set to 360 degrees, so that the open periods of the intake valves of each cylinder do not overlap. Further, an overlap period in which the intake valve and the exhaust valve are opened simultaneously is provided, and the overlap period is set to, for example, 30 degrees in terms of the crankshaft rotation angle.

  Two spark plugs 10 are mounted on the cylinder head 3 so as to face the combustion recess 3a for each cylinder bore 2a. Each of the spark plugs 10 is disposed slightly displaced from the crankshaft axis c toward the exhaust valve 7 and is disposed between the intake opening 3b and the exhaust opening 3c and on both outer sides in the camshaft direction. Has been.

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

  Exhaust pipes 12 and 12 are connected to the respective exhaust ports 3 e, and each exhaust pipe 12 is connected to one exhaust junction pipe 13. A catalyst 14 for purifying exhaust gas is interposed in the middle of the exhaust merging pipe 13, and a muffler (not shown) is connected to the downstream end.

  An intake pipe 15 is connected to each intake port 3d via a throttle body 15a, and a common surge tank 16 is connected to the upstream end of the intake pipe 15. An air cleaner 18 is connected to the surge tank 16 through an intake pipe 17. An air flow sensor 19 is disposed in the vicinity of the air cleaner 18 of the intake pipe 17. The parts from the intake port 3d to the intake introduction pipe 17 constitute the intake passage of the present invention.

  A liquid fuel injection valve 20 for injecting liquid fuel such as gasoline is mounted on the throttle body 15a. The liquid fuel injection valve 20 is disposed with its fuel injection port 20 a directed toward the center of the back of the intake valve 6.

  The internal combustion engine 1 includes a secondary throttle valve 23 for each cylinder disposed in the throttle body 15 a and a common primary throttle for each cylinder disposed in the intake air introduction pipe 17 upstream of the secondary throttle valve 23. And a valve 24.

  Each secondary throttle valve 23 is arranged in the vicinity of the intake port 3d and upstream of the injection port 20a of the liquid fuel injection valve 20. That is, fuel is supplied downstream from the secondary throttle valve 23.

  The secondary throttle valve 23 of each cylinder can be integrally opened and closed by a common valve shaft 23a, and an actuator 33 for opening and closing the secondary throttle valve 23 is connected to the valve shaft 23a.

  An actuator 34 for opening and closing the primary throttle valve 24 is connected to the valve shaft 24a of the primary throttle valve 24.

  The internal combustion engine 1 further includes a bypass pipe (bypass passage) 25 provided to bypass the secondary throttle valve 23 and a check valve 26 interposed in the bypass pipe 25.

  The bypass pipe 25 is configured to be directed and jetted to the intake air flow so that a horizontal vortex or vertical vortex air vortex (see arrow a in FIG. 2) is generated in the cylinder bore 2a. The bypass pipe 25 is disposed below the intake pipe 15 along the intake pipe 15.

  The downstream portion of each bypass pipe 25 is branched into two branch pipes 25a and 25a, and the downstream end opening 25a 'is connected to the vicinity of the intake opening 3b of the intake port 3d. Accordingly, the bypass pipe 25 communicates with the intake pipe 15 via the downstream end opening 25a ′. The upstream end 25 b of the bypass pipe 25 is connected to the surge tank 16.

  The check valve 26 allows only the flow of intake air from the surge tank 16 to the cylinder side and blocks the flow in the reverse direction, and is disposed at the upstream end of the bypass pipe 25. .

  A communication passage 21 that connects the bypass pipes 25 to each other is provided on the downstream side of the check valves 26 of the bypass pipes 25. An opening / closing valve 22 is interposed in the communication path 21 and the opening / closing valve 22 is driven to open and close by a stepping motor 22a.

  The internal combustion engine 1 includes an external EGR device 27 that recirculates a part of the exhaust gas to the combustion chamber 5 to recombust it.

  The external EGR device 27 is interposed between an external EGR introduction pipe (external EGR introduction passage) 28 connected to the upstream side of the catalyst 14 of the exhaust merging pipe 13 and a middle portion of the external EGR introduction pipe 28, and An EGR cooler 29 that cools the gas, and an EGR control valve 30 that is interposed downstream of the external EGR introduction pipe 28 are provided.

  The downstream end inlet 28 a of the external EGR introduction pipe 28 is connected to the downstream side of the primary throttle valve 24 of the intake introduction pipe 17. A venturi portion 17a that generates a negative pressure by reducing the passage area of the intake air introduction pipe 17 is formed at the connection portion of the intake port 28a of the intake air introduction pipe 17.

  The internal combustion engine 1 includes an ECU (throttle valve control means) 35 that controls opening and closing of the secondary throttle valve 23 and the primary throttle valve 24 according to the operating state of the internal combustion engine 1.

  As shown in FIG. 3, the ECU 35 is configured to control the opening degree of the secondary throttle valve 23 and the primary throttle valve 24 in accordance with the accelerator operation amount. In an extremely low load range from when the accelerator operation amount is zero to 20%, the secondary throttle valve 23 is fully closed and the primary throttle valve 24 is set to an opening proportional to the accelerator operation amount.

  In the low / medium load partial load region where the accelerator operation amount exceeds 20%, the primary throttle valve 24 is controlled so that the opening increase amount thereof is larger than the increase amount of the accelerator operation amount, and the secondary throttle valve 23 is The opening increase amount is controlled to be the same as the accelerator operation amount increase amount. That is, the opening increase amount of the primary throttle valve 24 with respect to the accelerator operation amount is set to be larger than the opening increase amount of the secondary throttle valve 23.

  When the accelerator operation amount exceeds 60%, the primary throttle valve 24 is fully opened, and when the accelerator operation amount is 100%, the secondary throttle valve 23 is fully opened.

  As shown in FIG. 4, the ECU 35 controls the opening / closing valve 22 according to the engine operating state. Specifically, the on-off valve 22 is fully closed in an extremely low load range where the accelerator operation amount is 10% from idling, and the accelerator operation amount is 60% from a low / medium load region where the accelerator operation amount exceeds 10%. The operating range up to is fully open, and in the high load range where the accelerator operation amount exceeds 60%, it is fully closed again.

  The ECU 35 controls the opening and closing of the EGR control valve 30 according to the engine operating state, as shown in FIG. Specifically, the EGR control valve 30 is set to open after the primary throttle valve 24 starts to open, and to start opening earlier than the secondary throttle valve 24 starts to open.

  When the accelerator operation amount including idling is 15% or less, the EGR control valve 30 is fully closed, and when the accelerator operation amount exceeds 15%, the EGR control valve 30 is primary. After the primary throttle valve 24 is fully opened, the secondary throttle valve 24 is fully opened before the secondary throttle valve 24 is fully opened. In the high load operation region, the EGR control valve 30 starts to close when the secondary throttle valve 23 is fully opened, and is fully closed when the accelerator operation amount reaches 100%.

  As described above, according to the present embodiment, the secondary throttle valve 23 is disposed in the vicinity of the intake port 3d of the intake pipe 15, and the secondary throttle valve 23 is fully closed in an extremely low load operation region including idling. Since the intake air amount is controlled by the opening degree of the valve 24, the substantial passage volume of the intake passage is reduced by the secondary throttle valve 23 and the check valve 26 of the bypass pipe 25, and the inflow of the internal EGR accordingly. The amount can be suppressed to a small amount, and combustion in an extremely low load operation region can be stabilized.

  Further, since the secondary throttle valve 23 is fully closed, a strong vertical vortex can be generated in the cylinder bore 2a by the intake air flow from the bypass pipe 25, and stable combustion can be obtained regardless of the extremely low load range. As a result, stable combustion is possible although the overlap period is as long as 30 degrees in crank angle. Thus, for example, the internal EGR can be controlled without using a variable valve system such as a hydraulically controlled VVT, and good operating performance with excellent responsiveness can be obtained at low cost.

  Thus, since the intake air amount can be secured while suppressing the internal EGR during idling operation, a large amount of internal EGR can be introduced to the upstream side of the secondary throttle valve 23 when the secondary throttle valve 23 is opened. The fuel consumption can be improved.

  In this embodiment, since the opening degree of the primary throttle valve 24 is set to be larger than the opening degree of the secondary throttle valve 23 in the partial load operation region, the cylinder bore from the bypass pipe 25 is secured while ensuring the necessary intake air amount. A strong turbulence air vortex can be generated in 2a, and stable combustion can be obtained.

  Further, since the primary throttle valve 24 is fully opened ahead of the secondary throttle valve 23, a sufficient amount of intake air can be secured while generating turbulence in a high-load operation region.

  In the present embodiment, the communication passage 21 that connects the bypass pipes 25 to each other is provided, and the on-off valve 22 is provided in the communication passage 21, and the on-off valve 22 is fully closed at the time of idling. Can prevent excessive combustion. That is, during idling, since the amount of fresh air is small, stable combustion cannot be obtained if the internal EGR increases due to turbulence enhancement. For this reason, by closing the communication path 21, it is possible to suppress the internal EGR amount and thereby stabilize the combustion during idling.

  Further, since the on-off valve 22 is driven to open and close by the stepping motor 22a, continuous and smooth control without a step can be performed.

  In the above embodiment, the on-off valve 22 is driven to open and close by the stepping motor 22a. However, the present invention may be driven to open and close by a solenoid valve. In this case, as shown in FIG. 4, the on / off valve 22 is controlled to be turned on / off.

  In the low / medium load operation region, the on-off valve 22 is fully opened, so that the passage volume from the secondary throttle valve 23 of each intake pipe 15 to the intake valve 6 can be shared. Thereby, the turbulence by the increase in internal EGR and the increase in the amount of gas ejected from the bypass pipe 25 can be further strengthened, and stable combustion can be performed. That is, when one cylinder is in the intake stroke, the air in the intake passage of the other cylinder can be sucked, and a sufficient amount of intake air can be secured in the low load operation region.

  In the present embodiment, an external EGR introduction pipe 28 is connected to the downstream side of the primary throttle valve 24 of the intake introduction pipe 17 in which the primary throttle valve 24 is disposed, and an EGR provided in the external EGR introduction pipe 28. Since the control valve 30 is opened later than the opening of the primary throttle valve 24 and is started earlier than the opening of the secondary throttle valve 23, a large amount of external EGR is generated in spite of the low load operating range. Can be introduced, pumping loss can be reduced, and fuel consumption can be improved. That is, in a no-load state such as during idling operation, the ratio of internal EGR to fresh air is the largest, and external EGR cannot be introduced under such a condition that the internal EGR is full. For this reason, external EGR cannot be introduced unless the charging efficiency is higher than that under no-load operation.

  In the present embodiment, the inflow of the internal EGR is suppressed to a small amount by the secondary throttle valve 23 and the check valve 26. Therefore, by opening the EGR control valve 30 later than the opening of the primary throttle valve 24, the external EGR can be introduced from an early stage, and stable combustion is possible. That is, the external EGR has a lower temperature than that of the internal EGR immediately after combustion, and therefore, by introducing the external EGR, combustion with high knock resistance can be performed.

  Further, at the time of low load operation, since the secondary throttle valve 23 is fully closed, the entire amount of the external EGR is ejected from the bypass pipe 25 into the cylinder bore 2a, strengthening the turbulence, residual combustion gas, EGR gas, Mixing of fresh air is promoted, and as a result, a larger amount of external EGR becomes possible, and pumping loss can be reduced and fuel consumption can be improved.

  Further, since the EGR control valve 30 is fully opened before the secondary throttle valve 23 is fully opened, it is possible to introduce a large amount of external EGR at the time of partial load.

  FIG. 6 is a view for explaining a spark ignition internal combustion engine according to the second embodiment of the present invention. In the figure, the same reference numerals as those in FIG. 1 denote the same or corresponding parts.

  In the internal combustion engine 1 of the present embodiment, the secondary throttle valve 23 is disposed in the vicinity of the intake port 3d, a check valve 26 is provided upstream of the bypass pipe 25, and in an extremely low load operation region including an AND ring operation. The secondary throttle valve 23 is fully closed, and the intake air amount is controlled by the opening degree of the primary re-throttle valve 24. Since the basic configuration is the same as that of the first embodiment, only different portions are used. explain.

  In each cylinder bore 2a of the present embodiment, two intake openings 3b and 3b and one exhaust opening 3c are arranged, and three first to third spark plugs 10a to 10c are arranged in each cylinder bore 2a. .

  The first spark plug 10a is positioned substantially at the center of the cylinder bore 2a, and is disposed slightly on the intake side of the crankshaft axis c and between the intake openings 3b. The second and third spark plugs 10b and 10c are arranged slightly on the exhaust side from the axis c and close to both outer sides of the exhaust opening 3c.

  In the second embodiment, since the first spark plug 10a is arranged on the intake side from the axis c and between the intake openings 3b and 1 in each, the flame propagation can be shortened and the anti-knock performance can be improved.

  Further, since the second and third spark plugs 10b and 10c are arranged on both outer sides of the exhaust opening 3c, the combustion in the vicinity of the exhaust valve having a high mixture temperature is completed early, so that the knock resistance is improved.

1 is a schematic configuration diagram of a spark ignition internal combustion engine according to a first embodiment of the present invention. It is sectional drawing of the said internal combustion engine. FIG. 3 is a characteristic diagram of the internal combustion engine. FIG. 3 is a characteristic diagram of the internal combustion engine. FIG. 3 is a characteristic diagram of the internal combustion engine. It is a schematic block diagram of the internal combustion engine by 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Spark ignition internal combustion engine 3b Intake opening 5 Combustion chamber 6 Intake valve 7 Exhaust valve 15 Intake pipe (intake passage)
17 Intake merging pipe (intake merging section)
21 Communication passage 22 On-off valve 23 Secondary throttle valve 24 Primary throttle valve 25 Bypass pipe (bypass passage)
26 Check valve 28 External EGR introduction pipe (external EGR introduction passage)
30 EGR valve 35 ECU (throttle valve control means)

Claims (7)

An intake passage communicating with the combustion chamber;
An intake valve that opens and closes an intake opening that opens to the combustion chamber of the intake passage;
A spark ignition type internal combustion engine having an overlap period in which the intake valve and the exhaust valve open simultaneously,
A secondary throttle valve is arranged close to the intake opening side of the intake passage,
A primary throttle valve is disposed upstream of the secondary throttle valve in the intake passage,
A bypass passage for bypassing the secondary throttle valve and generating an intake vortex flow in the combustion chamber;
A check valve that allows only the flow of intake air to the cylinder side is disposed in the bypass passage,
A spark ignition type internal combustion engine characterized by comprising throttle valve control means for controlling the intake air amount by the primary throttle valve in the extremely low load operation region including idling operation, wherein the secondary throttle valve is substantially fully closed. . The spark ignition internal combustion engine according to claim 1,
The spark ignition type internal combustion engine, wherein the throttle valve control means controls the opening of the primary throttle valve to be larger than the opening of the secondary throttle valve in a partial load operation region. The spark ignition internal combustion engine according to claim 1,
The spark ignition type internal combustion engine, wherein the throttle valve control means controls the primary throttle valve to fully open prior to the secondary throttle valve. The spark ignition internal combustion engine according to claim 1,
With multiple cylinders,
A communication passage is provided that communicates the downstream sides of the check valve of the bypass passage provided for each cylinder;
An opening / closing valve is interposed in the communication path,
The spark-ignition internal combustion engine, wherein the on-off valve is controlled to close the communication path during idling operation. The spark ignition internal combustion engine according to claim 4,
The spark-ignition internal combustion engine, wherein the on-off valve is controlled to open the communication passage in a low / medium-load operating range. The spark ignition internal combustion engine according to claim 1,
An external EGR introduction passage is connected downstream of the primary throttle valve of the intake passage,
An EGR control valve is disposed in the external EGR introduction passage,
The spark ignition type internal combustion engine, wherein the EGR control valve is controlled to open later than the opening of the primary throttle valve and to start opening earlier than the opening of the secondary throttle valve. The spark ignition internal combustion engine according to claim 6,
The spark ignition internal combustion engine, wherein the EGR control valve is controlled to be fully opened before the secondary throttle valve is fully opened.

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