JP2012180799A - Gas flow control device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To control a gas flow in a gas passage without installing a moving part such as a valve in the gas passage.SOLUTION: A plasma actuator 1 is installed in the gas passage 11 of an internal combustion engine through which a gas flows, to change the gas flow in the gas passage 11 by its electric action. The plasma actuator 1 includes a surface electrode 2 arranged to be exposed in the gas passage 11 and a back-surface electrode 3 disposed with a dielectric 4 therebetween. An AC voltage is applied between the surface electrode 2 and the back-surface electrode 3 to cause barrier discharge of the dielectric 4, thereby generating a blowing force 9 directed from the surface electrode 2 to the back-surface electrode 3 so that the gas flow is changed in the gas passage 11.

Description

  The present invention relates to an air flow control device for an internal combustion engine that is provided in a tubular gas passage through which gas flows, such as an intake passage, an exhaust passage, and an external EGR passage of the internal combustion engine, and changes the flow of the gas in the gas passage. .

  When controlling the flow (typically speed and direction) of a gas flowing in a gas passage such as an intake passage or an exhaust passage in an internal combustion engine, generally, as described in Patent Document 1, a tumble control valve is used. Valves such as are used. Alternatively, in the case of an internal combustion engine equipped with a supercharger, the intake flow can be made faster by supercharging.

JP 2008-232095

  Thus, in order to control the gas flow in the gas passage of the internal combustion engine, when the passage cross-sectional area is changed using a valve such as a tumble control valve, there is a problem that the pressure loss increases. In addition, when a movable part such as a valve is provided in the gas passage, in addition to an increase in ventilation resistance, there is a possibility that deposits may be caught in the movable part, or the movable part may be fixed to cause malfunction.

  In addition, although the intake flow can be increased by supercharging as described above, a supercharger is required in this case, and the cost is increased, the weight increases, and the size is large. There are problems such as receiving.

  The present invention has been made in view of such circumstances, and the flow (speed and direction) of the gas in the gas passage of the internal combustion engine can be changed without using a moving part such as a valve or a supercharger. It is an object of the present invention to provide a novel air flow control device for an internal combustion engine. Therefore, in the present invention, a plasma actuator is provided in the gas passage of the internal combustion engine through which gas flows, and the gas flow in the gas passage is changed.

  According to the present invention, the flow of gas can be controlled by using a plasma actuator and changing the flow of gas in the gas passage of the internal combustion engine by its electrical action. For this reason, in order to control the flow of gas, it is not necessary to provide a movable part such as a valve in the gas passage, and pressure loss due to narrowing of the gas passage does not occur. In addition, since there is no need to provide a movable part such as a valve in the gas passage, there is no possibility of causing a malfunction due to the biting of foreign matter into the movable part or the fixing of the movable part.

The block diagram which shows the airflow control apparatus of the internal combustion engine to which the plasma actuator which concerns on 1st Example of this invention is applied. The block diagram which shows the airflow control apparatus of the internal combustion engine to which the plasma actuator which concerns on 2nd Example of this invention is applied. The block diagram which shows the airflow control apparatus of the internal combustion engine to which the plasma actuator which concerns on 3rd Example of this invention is applied. The block diagram which shows the airflow control apparatus of the internal combustion engine to which the plasma actuator which concerns on 4th Example of this invention is applied. The block diagram which shows the airflow control apparatus of the internal combustion engine to which the plasma actuator which concerns on 5th Example of this invention is applied. The block diagram which shows the airflow control apparatus of the internal combustion engine to which the plasma actuator which concerns on 6th Example of this invention is applied. The block diagram which shows the airflow control apparatus of the internal combustion engine to which the plasma actuator which concerns on 7th Example of this invention is applied. The block diagram which shows the airflow control apparatus of the internal combustion engine to which the plasma actuator which concerns on 8th Example of this invention is applied. The block diagram which shows the airflow control apparatus of the internal combustion engine to which the plasma actuator which concerns on 9th Example of this invention is applied. The block diagram which shows the airflow control apparatus of the internal combustion engine to which the plasma actuator which concerns on 10th Example of this invention is applied. The block diagram which shows the airflow control apparatus of the internal combustion engine to which the plasma actuator which concerns on 11th Example of this invention is applied. The block diagram which shows the airflow control apparatus of the internal combustion engine to which the plasma actuator which concerns on 12th Example of this invention is applied. The block diagram which shows the airflow control apparatus of the internal combustion engine to which the plasma actuator which concerns on 13th Example of this invention is applied. The block diagram which shows the airflow control apparatus of the internal combustion engine to which the plasma actuator which concerns on 14th Example of this invention is applied. The block diagram which shows the airflow control apparatus of the internal combustion engine to which the plasma actuator based on 15th Example of this invention is applied. The block diagram which shows the airflow control apparatus of the internal combustion engine to which the plasma actuator which concerns on 16th Example of this invention is applied. The block diagram which shows the airflow control apparatus of the internal combustion engine to which the plasma actuator which concerns on 17th Example of this invention is applied. The block diagram which shows the airflow control apparatus of the internal combustion engine to which the plasma actuator based on 18th Example of this invention is applied. The block diagram which shows the airflow control apparatus of the internal combustion engine to which the plasma actuator based on 19th Example of this invention is applied. The block diagram which shows the airflow control apparatus of the internal combustion engine to which the plasma actuator based on 20th Example of this invention is applied. The block diagram which shows the airflow control apparatus of the internal combustion engine to which the plasma actuator based on 21st Example of this invention is applied. The block diagram which shows the airflow control apparatus of the internal combustion engine to which the plasma actuator based on 22nd Example of this invention is applied. The block diagram which shows the airflow control apparatus of the internal combustion engine to which the plasma actuator based on 23rd Example of this invention is applied. The block diagram which shows the airflow control apparatus of the internal combustion engine to which the plasma actuator based on 24th Example of this invention is applied. The block diagram which shows the airflow control apparatus of the internal combustion engine to which the plasma actuator based on 25th Example of this invention is applied. The block diagram which shows the airflow control apparatus of the internal combustion engine to which the plasma actuator based on 26th Example of this invention is applied. The block diagram which shows the airflow control apparatus of the internal combustion engine to which the plasma actuator based on 27th Example of this invention is applied. Explanatory drawing which shows the operating principle of the plasma actuator which concerns on this invention.

  Hereinafter, the present invention will be described with reference to illustrated embodiments. As a configuration common to the embodiments described later, a plasma actuator 1 that changes the flow of gas in the gas passage by an electrical action is provided in a gas passage that forms a tube of an internal combustion engine through which gas flows. Since this plasma actuator itself is known, its operation principle will be briefly described with reference to FIG.

  The plasma actuator 1 has a surface electrode 2 that is exposed in the gas passage 11 and a back electrode 3 that is disposed with the surface electrode 2 and the dielectric 4 interposed therebetween. Then, by applying an AC voltage between the front surface electrode 2 and the back surface electrode 3 by the AC power source 6 in the electric circuit 5 having the ground portion 7, the dielectric 4 is discharged in the vicinity of the dielectric 4. Plasma is generated in the discharge region 8, and a blowing force 9 from the front electrode 2 to the back electrode 3 is generated by receiving a force from the electric field. Since the blowing force 9 changes according to the AC voltage applied from the AC power source 6, the operation of the AC power source 6 is controlled by the control unit (air flow control unit) 12, so that the vicinity of the surface electrode 2 in the gas passage 11. It is possible to appropriately control the flow of gas, that is, the flow velocity and direction.

The characteristics of the plasma actuator 1 include the following.
• Completely electrically driven and requires no moving parts. It is also very lightweight.
・ Low power consumption.
・ Because it is very thin, aerodynamic influence is small.
・ High speed drive and excellent followability to input.

  As a method for using such a plasma actuator, for example, a plasma actuator is installed on the surface of a vehicle body or aircraft body to suppress separation, and in the present invention, such a plasma actuator is used in the present invention. It is installed in a tubular gas passage in an internal combustion engine and changes the flow in the gas passage. By strengthening the flow in a part of the gas passage, as described later, for example, swirl flow and tumble The flow is strengthened, or the flow rate of the EGR gas is increased / decreased according to the operating conditions, or the flow at the bent portion or step portion in the gas passage where separation is likely to occur is promoted.

  A specific illustrated embodiment using such a plasma actuator 1 will be described below. In the present specification, “upper and lower” basically refers to the case where the combustion chamber side is up and the crankshaft side is down in the cylinder axis direction.

[First embodiment]
Referring to FIG. 1, a piston 23 is slidably disposed in a cylinder 22 formed in a cylinder block 21 of an internal combustion engine. A pent roof type combustion chamber 25 is recessed in the lower surface of the cylinder head 24 fixed to the upper surface of the cylinder block 21, and an intake valve 27 that opens and closes an intake port 26 that opens to the combustion chamber 25; Similarly, an exhaust valve 29 that opens and closes an exhaust port 28 that opens to the combustion chamber 25 is provided. A pair of intake valves 27 and a pair of exhaust valves 29 are provided for one cylinder (see FIG. 9). A partition plate 30 that divides the intake port 26 into two upper and lower flow paths 26A and 26B is provided in the intake port 26 that is a part of the intake passage (gas passage) of the internal combustion engine.

  And in this 1st Example, plasma actuator 1A is installed in the upper surface side of said partition plate 30 so that the tumble flow 31 in the combustion chamber 25 may be strengthened according to a driving | running state. Here, the front surface electrode 2 exposed in the upper flow path 26A is arranged on the upstream side and the anti-combustion chamber side (right side in FIG. 1) with respect to the back surface electrode 3 embedded with the dielectric 4 interposed therebetween. Thereby, the forward flow (blowing force) 9A of the intake air toward the combustion chamber 25 can be generated in the upper flow path 26A, the flow in the upper flow path 26A is accelerated, and the flow velocity is increased. Thus, the tumble flow 31 swirling in the vertical direction can be appropriately strengthened according to the operating conditions. Here, the tumble flow 31 swirls in the combustion chamber 25 in the clockwise direction of FIG. 1 and flows downward on the exhaust valve side and then flows upward on the intake valve side.

  In addition, including the examples described later, the dielectric 4 is provided with recesses in the wall surfaces of the partition plate 30 and the intake port 26 and embedded in the recesses, and the surface is flush with the wall surfaces to allow ventilation. It is configured to suppress resistance. However, since the dielectric 4 is very thin as described above, it may be more easily fixed on the wall surface without being embedded in the wall surface of the gas passage.

  Also, in the embodiment of FIGS. 1 to 27, the electric circuit 5 and the control unit 12 shown in FIG. 28 are omitted for the sake of simplicity, but in reality, these components are provided. Yes.

  In the embodiments described below, the same components as those in the above-described embodiments are denoted by the same reference numerals, and redundant descriptions are omitted as appropriate.

[Second Embodiment]
Referring to FIG. 2, the second embodiment is different from the first embodiment in that plasma actuator 1 is installed on the lower surface side of partition plate 30. In this case, the front surface electrode 2 exposed to the lower flow path 26 </ b> B is disposed on the downstream side / combustion chamber side of the back surface electrode 3. Therefore, by generating a flow 9B in the reverse direction from the downstream side / combustion chamber side to the upstream side with respect to the lower flow path 26B, the flow of the lower flow path 26B is decelerated, and the upper flow path 26B is relatively The tumble flow 31 can be strengthened by increasing the flow velocity of the flow path 26A.

[Third embodiment]
Referring to FIG. 3, in the third embodiment, the above-described first and second embodiments are combined, and plasma actuators 1 </ b> A and 1 </ b> B are installed above and below the partition plate 30, respectively. The upper plasma actuator 1A generates a forward flow 9A as in the first embodiment, and the lower plasma actuator 1B generates a reverse flow 9B as in the second embodiment. The tumble flow 31 can be greatly enhanced by increasing the flow velocity of the upper flow passage 26A relative to the flow velocity of the flow passage 26B.

[Fourth embodiment]
In the first to third embodiments so far, the internal combustion engine of the type that strengthens the tumble flow 31 by increasing the flow velocity of the upper flow passage 26A has been described, but the flow velocity of the lower flow passage 26B is increased. In the case of the internal combustion engine of the type that strengthens the tumble flow 31 by causing the surface electrode 2 to be downstream of the back electrode 3 in the plasma actuator 1C of the upper flow path 26A as in the fourth embodiment shown in FIG. -Installed on the combustion chamber side to generate a reverse flow 9C, and in the plasma actuator 1 of the lower flow path 26B, the surface electrode 2 is installed upstream of the back electrode 3 and on the anti-combustion chamber side. A forward flow 9D may be generated.

[Fifth embodiment]
Referring to FIG. 5, in the fifth embodiment, the tumble flow 31 is strengthened by the plasma actuator 1E with a simple configuration that does not use the partition plate 30 as in the first to fourth embodiments. ing. That is, the plasma actuator 1 </ b> E is installed on the upper surface on the port wall surface of the intake port 26. Here, the front surface electrode 2 exposed on the upper surface of the intake port 26 is disposed on the upstream side and the anti-combustion chamber side with respect to the rear surface electrode 3. Therefore, the forward flow 9E can be generated near the upper surface of the intake port 26, thereby accelerating the flow in the upper portion of the intake port 26 and locally flowing the flow through the upper portion of the intake valve. By strengthening, the tumble flow 31 in the combustion chamber can be strengthened.

[Sixth embodiment]
Referring to FIG. 6, in the sixth embodiment, plasma actuators 1E and 1F are installed on both the upper surface side and the lower surface side of the port wall surface of intake port 26, respectively. As for the plasma actuator 1E installed on the upper surface side of the port, the surface electrode 2 exposed on the upper surface of the intake port 26 is arranged on the upstream side and the anti-combustion chamber side with respect to the rear surface electrode 3, as in the fifth embodiment of FIG. Thus, a forward flow 9E is generated in the vicinity of the upper surface of the intake port 26. On the other hand, for the plasma actuator 1F installed on the lower surface side, the front surface electrode 2 is arranged on the downstream side / combustion chamber side with respect to the rear surface electrode 3, and a reverse flow 9F is generated near the lower surface of the intake port 26. The flow in the lower portion of the intake port 26 is decelerated. Thereby, the flow in the upper part of the intake port 26 can be further accelerated with respect to the flow in the lower part, and the tumble flow 31 can be further strengthened.

[Seventh embodiment]
In the fifth and sixth embodiments shown in FIGS. 5 and 6 described above, the internal combustion engine of the type in which the tumble flow 31 is strengthened by increasing the flow velocity of the upper portion of the intake port 26 has been described. In the case of an internal combustion engine of the type that strengthens the tumble flow 31 by increasing the flow velocity of the lower portion of the port 26, as in the seventh embodiment shown in FIG. 7, the plasma actuator installed on the upper surface side of the intake port 26 In 1G, the surface electrode 2 is installed on the downstream side / combustion chamber side of the back electrode 3 to generate a reverse flow 9G. In the plasma actuator 1H installed on the bottom surface, the surface electrode 2 is connected to the back electrode 3 May be installed on the upstream side and the anti-combustion chamber side to generate the forward flow 9H.

[Eighth embodiment]
In the eighth embodiment shown in FIG. 8, the plasma actuator 1 </ b> A is used in combination with the tumble control valve 32. The tumble control valve 32 opens and closes the lower flow path 26B at the upstream end of the partition plate 30, and in the state where the lower flow path 26B is closed by the tumble control valve 32, the flow velocity of the upper flow path 26A. Increases and the tumble flow 31 is strengthened, and the tumble flow 31 is weakened in a state where the lower flow path 26B is opened. As in the first embodiment, the plasma actuator 1A is installed with respect to the upper flow path 26A, and the surface electrode 2 exposed to the upper flow path 26A is disposed upstream of the back electrode 3 and on the side of the anti-combustion chamber. Is arranged. Accordingly, a forward flow (blowing force) 9A in the upper flow path 26A can be generated, and the flow of the upper flow path 26A is accelerated to increase the flow velocity thereof. In addition, the tumble flow 31 can be greatly enhanced.

[Ninth embodiment]
Referring to FIG. 9, in the ninth embodiment, the swirl flow 33 rotating in the circumferential direction in the combustion chamber 25 is realized by using the plasma actuator 1J. Here, the intake port 26 of this embodiment branches from a single collecting flow path 34 to a pair of first and second branch flow paths 35A and 35B, and each branch flow path 35A and 35B is an intake valve. And communicates with the combustion chamber 25. The plasma actuator 1J is installed on the side surface of the collecting passage 26C on the upstream side of the intake port 26 near the first branch channel 35A on one side (upper side in the drawing). In this plasma actuator 1J, the surface electrode 2 exposed on the side surface of the port is arranged on the upstream side and the anti-combustion chamber side with respect to the back electrode 3. Therefore, by generating a forward flow 9J by the plasma actuator 1, the flow of one first branch flow path 35A in the intake port 26 is accelerated / accelerated with respect to the flow of the other second branch flow path 35B. Thus, the swirl swirl flow 33 can be strengthened in the circumferential direction in the clockwise direction of FIG.

[Tenth embodiment]
In the tenth embodiment shown in FIG. 10, plasma actuators 1 </ b> J and 1 </ b> K are installed on both side surfaces of the upstream collecting passage 34 in the intake port 26. In the plasma actuator 1J near the first branch flow path 35A, as in the ninth embodiment, the front electrode 2 is arranged on the upstream side and the anti-combustion chamber side with respect to the back electrode 3, and a forward flow 9J is generated. Thus, the flow of the first branch flow path 35A can be accelerated and the swirl flow 33 can be strengthened. Further, the plasma actuator 1K near the second branch flow path 35B has the front electrode 2 disposed on the downstream side / combustion chamber side with respect to the rear electrode 3, and generates the flow 9K in the reverse direction, thereby generating the second branch. The flow of the flow path 35B can be decelerated to relatively strengthen the flow of the first branch flow path 35A, and the swirl flow 33 can be further strengthened.

  In the tenth embodiment, a pair of plasma actuators 1J and 1K are provided, but one is omitted, and only the plasma actuator 1J near the first branch flow path 35A or the plasma actuator near the second branch flow path 35B is provided. Only 1K may be provided.

[Example of FIG. 11]
As in the eleventh embodiment shown in FIG. 11, in order to further strengthen the swirl flow 33, the plasma actuator 1J may be used in combination with the swirl control valve. Similar to the ninth embodiment, the plasma actuator 1J is installed on the side surface of the collecting channel 34 of the intake port 26 near the first branch channel 35A, and the surface electrode 2 exposed on this side surface is used as the back electrode. By disposing on the upstream side / anti-combustion chamber side from 3, forward flow 9J can be generated and swirl flow 9J can be strengthened. The swirl control valve 36 opens and closes the portion near the second branch flow path 35B in the collecting flow path 34, thereby restricting the flow to the second branch flow path 35B and relatively reducing the flow of the first branch flow path 35A. By strengthening, the swirl flow 36 is strengthened. Thus, the swirl flow 33 can be further enhanced by using the actuator 1J in combination with the swirl control valve 36.

[Twelfth embodiment]
As shown in FIGS. 12 to 14, the plasma actuator can be applied to an internal combustion engine including an intake port 26 of a type in which a pair of branch flow paths opened to the combustion chamber 25 extend independently. In the twelfth embodiment shown in FIG. 12, the plasma actuator 1J is installed on the side surface of the first branch flow path 35A of the intake port 26 that is far from the second branch flow path 35B. Similar to the ninth embodiment, the plasma actuator 1J is configured to generate a forward flow 9J by disposing the front surface electrode 2 on the upstream side and the anti-combustion chamber side with respect to the rear surface electrode 3, and to generate an intake port. The swirl flow 33 can be strengthened by accelerating the flow on the first branch flow path 35A side in FIG.

[Thirteenth embodiment]
In the thirteenth embodiment shown in FIG. 13, in contrast to the twelfth embodiment, the plasma actuator 1K is installed on the side surface of the other second branch channel 35B far from the first branch channel 35A. Yes. Similar to the plasma actuator 1K of the tenth embodiment, this plasma actuator 1K generates a flow 9K in the reverse direction by disposing the front surface electrode 2 on the downstream side and the combustion chamber side of the back surface electrode 3. By decelerating the flow of the two-branch flow path 35B, the flow of the first branch flow path 35A is relatively strengthened, and the swirl flow 33 in the combustion chamber 25 is strengthened.

[14th embodiment]
In the fourteenth embodiment shown in FIG. 14, plasma actuators 1J and 1K are installed in both the pair of branch flow paths 35A and 35B in the intake port 26, respectively. Similar to the twelfth embodiment shown in FIG. 12, the plasma actuator 1J installed in the first branch flow path 35A is arranged in the forward direction by disposing the surface electrode 2 on the upstream side and the anti-combustion chamber side from the back electrode 3. The flow 9J is generated and the flow of the first branch flow path 35A is accelerated to strengthen the swirl flow 33. As in the thirteenth embodiment shown in FIG. 13, the plasma actuator 1K installed in the other second intake port 26 is arranged in the reverse direction by disposing the front electrode 2 on the downstream side and the combustion chamber side from the back electrode 3. The flow 9K is generated and the flow of the second branch flow path 35B is decelerated, so that the flow of the first branch flow path 35A can be relatively accelerated and increased to further strengthen the swirl flow 33. it can.

  Regarding the first to fourteenth embodiments described above, when a conventional valve such as a tumble control valve or a swirl control valve is used in place of the plasma actuator 1, if the valve is throttled to strengthen the flow, pressure loss (pump loss) may occur. The energy loss increases due to the increase in power consumption for the actuator that drives the valve. On the other hand, unlike the conventional valve method, the method of generating a flow equivalent to that of the valve using the plasma actuator 1 as in the first to fourteenth embodiments differs from the pressure loss (pump loss) accompanying the flow enhancement. There is no deterioration. In addition, power is consumed for driving the plasma actuator 1, but this is sufficiently smaller than the pressure loss improvement allowance. Therefore, by using a plasma actuator, it is possible to significantly reduce energy consumption and improve fuel efficiency as compared with the case where a valve is used.

[Fifteenth embodiment]
As shown in FIG. 15, the gas passage 11 such as an intake passage or an exhaust passage in the internal combustion engine has a bent portion 37 that bends and bends due to layout restrictions. In the fifteenth embodiment, the plasma actuator is connected to the inner peripheral portion 37A of the bent portion 37 of the gas passage 11, that is, the inner peripheral portion 37A that has a large curvature (small curvature radius) and easily causes flow separation. 1L is installed. Specifically, the surface electrode 2 is disposed upstream of the back electrode 3 in the flow direction, and a forward flow 9L is generated with respect to the flow direction, thereby increasing the flow velocity and causing pressure loss due to peeling. Can be reduced or eliminated. As a result, when installed in a bent portion in the intake passage, it is possible to suppress the pressure loss particularly in the high load region, improve the charging efficiency, and improve the engine output / torque. In addition, when installed in a bent portion in the exhaust passage, the scavenging performance is improved because the exhaust pressure decreases due to the decrease in pressure loss and the increase in flow velocity at the bent portion, thereby reducing the amount of residual gas in the cylinder. Thus, the charging efficiency is improved and the occurrence of knocking is suppressed, so that the engine output / torque can be improved.

[Sixteenth embodiment]
Due to layout restrictions, a stepped portion 38 may occur in the gas passage 11. For example, in the sixteenth embodiment shown in FIG. 16, the upstream channel 39 has a larger channel cross-sectional area than the downstream channel 40 in the flow direction of the gas passage 11. A stepped portion 38 that bends (curves) in a step shape exists at the joint portion. Therefore, in this embodiment, one or more (two in this embodiment) plasma actuators 1M are installed on the inner peripheral surface of the flow path 40 on the downstream side in the vicinity of the stepped portion 38. Then, by disposing the front surface electrode 2 on the upstream side of the back surface electrode 3, a forward flow 9M is generated with respect to the flow direction, and pressure loss due to separation at the stepped portion 38 is reduced / eliminated. The pressure loss can be compensated by the increase in flow velocity. As a result, when installed in a stepped portion in the intake passage, it is possible to suppress the pressure loss particularly in the high load region, improve the charging efficiency, and improve the engine output and torque. In addition, when installed in a stepped part in the exhaust passage, the scavenging performance is improved because the exhaust pressure decreases due to the decrease in pressure loss and the increase in flow velocity at the bent part, thereby reducing the amount of residual gas in the cylinder. Thus, the charging efficiency is improved and the occurrence of knocking is suppressed, so that the engine output / torque can be improved.

[Seventeenth embodiment]
Some gas passages in an internal combustion engine have a sub-flow path that joins in the middle of the main flow path or a branch of the sub-flow path in the middle of the main flow path due to layout and performance requirements. As an example of the former, in the seventeenth embodiment shown in FIG. 17 and the eighteenth embodiment shown in FIG. 18, the external EGR passage 41 for returning a part of the exhaust gas to the intake air has a predetermined angle (in this embodiment, about 90 degrees) from the middle of the exhaust passage 42. Then, the plasma actuator 1N is installed on one side (FIG. 17) or several places (FIG. 18) of the inner surface of the external EGR passage 41 in the vicinity of the EGR inlet portion / joint portion 43 branched from the exhaust passage 42 to the external EGR passage 41. ing. In this plasma actuator 1N, the surface electrode 2 is installed on the upstream side of the flow from the back electrode 3, and the flow 9N in the EGR introduction direction is generated, thereby increasing the flow velocity / flow rate branched to the external EGR passage 41, More EGR gas can be introduced even at a high load with a low negative pressure.

[Examples 19 and 20]
As the latter example, in the nineteenth embodiment shown in FIG. 19 and the twentieth embodiment shown in FIG. 20, the external EGR passage 41 joins at a predetermined angle (approximately 90 degrees in this embodiment) in the middle of the intake passage 44. ing. Then, the plasma actuator 1P is installed on one side (FIG. 19) or several places (FIG. 20) of the inner surface of the EGR passage 41 in the vicinity of the outlet portion and the joint portion 45 of the external EGR passage 41 that merges with the intake passage 44. Yes. The plasma actuator 1P has the surface electrode 2 installed upstream of the back electrode 3 and generates a flow 9P in the EGR introduction direction, thereby increasing the flow rate and flow rate of the EGR gas. More EGR gas can be introduced even at a high load with a low negative pressure.

  The plasma actuators may be installed in both the inlet portion 43 and the outlet portion 45 of the EGR passage 41 by combining the seventeenth and eighteenth embodiments and the nineteenth and twentieth embodiments.

[Examples 21 and 22]
In the twenty-first embodiment shown in FIG. 21 and the twenty-second embodiment shown in FIG. 22, the inner surface of the EGR passage 41 in the vicinity of the joint portion (EGR outlet portion) 45 of the external EGR passage 41 that joins the intake passage 44 is provided. The plasma actuator 1Q is installed on one side (FIG. 21) or several places (FIG. 22). However, in these 21st and 22nd embodiments, contrary to the 19th and 20th embodiments, the front surface electrode 2 is installed on the downstream side / intake passage side of the flow with respect to the back surface electrode 3, and the reverse direction of the EGR introduction direction The flow rate / flow rate of the EGR gas is reduced by generating the flow 9Q. As a result, for example, in a transition period in which the intake gas amount suddenly decreases, the EGR gas amount can be quickly reduced, and the EGR gas amount can be prevented from becoming excessive and the in-cylinder EGR rate from being overshot.

[Examples 23 and 24]
In the twenty-third embodiment shown in FIG. 23 and the twenty-fourth embodiment shown in FIG. 24, the plasma actuator 1R is provided on one side (FIG. 23) or several places (FIG. 24) of the inner surface of the exhaust port. Here, the front surface electrode 2 is disposed on the upstream side closer to the combustion chamber 25 than the back surface electrode 3, and the flow 9R is generated in the forward direction of the exhaust flow, thereby increasing the flow velocity and flow rate of the exhaust. As a result, for example, by increasing the exhaust flow rate at high loads, the increase in exhaust pressure is suppressed to improve scavenging performance, the amount of residual gas in the cylinder is reduced to improve charging efficiency, and the occurrence of knocking It is possible to improve the engine output and torque by suppressing the engine.

[Twenty-fifth embodiment]
In the twenty-fifth embodiment shown in FIG. 25, an inner portion of the bent portion 46 connected to the combustion chamber 22 side of the intake port 26 is used as the inner peripheral portion of the bent portion of the gas passage that is likely to cause flow separation. A plasma actuator 1S is installed in the peripheral portion 46A. In this plasma actuator 1S, the flow rate coefficient Cv is improved by arranging the front electrode 2 on the upstream side and the anti-combustion chamber side with respect to the flow from the back electrode 3 and generating the flow 9S in the forward direction of the intake air flow. Thus, the torque can be improved by improving the filling efficiency.

[Twenty-sixth embodiment]
In the twenty-sixth embodiment shown in FIG. 26, one end of the intake passage 44 is connected / opened to the wall surface 47A of the intake collector 47 as an opening peripheral portion of the wall surface of the gas chamber in which one end of the gas passage is likely to cause flow separation. The plasma actuator 1 </ b> T is installed at the opening peripheral edge of the intake passage 44. The plasma actuator 1T has the front electrode 2 installed on the outer peripheral side far from the intake passage 44 with respect to the back electrode 3, and generates a flow 9T toward the intake passage 44, whereby intake air from the intake collector 47 to the intake passage 44 is generated. Flow can be promoted, and a decrease in flow rate due to peeling can be suppressed.

[Twenty-seventh embodiment]
In the twenty-seventh embodiment shown in FIG. 27, one end of the intake passage 44 is connected and opened to the wall surface 48A of the air cleaner 48 as an opening peripheral portion of the wall surface of the gas chamber in which one end of the gas passage is likely to cause flow separation. The plasma actuator 1U is installed at the opening peripheral edge of the intake passage 44. The plasma actuator 1U has the front electrode 2 installed on the outer peripheral side far from the intake passage 44 with respect to the back electrode 3, and generates a flow 9U toward the intake passage 44, whereby intake air from the air cleaner 48 to the intake passage 44 is generated. The flow can be promoted, and a decrease in flow rate due to peeling can be suppressed.

  As described above, the present invention has been described based on the specific embodiments. However, the present invention is not limited to the above-described embodiments, and includes various modifications and changes. For example, the plasma actuator may be applied to various parts that are liable to cause separation of the flow in the gas passage of the internal combustion engine, such as a branching part or a collecting part of the intake manifold or the exhaust manifold.

1 (1A to 1U) ... Plasma actuator 2 ... Front electrode 3 ... Back electrode 4 ... Dielectric 9 (9A to 9U) ... Blowing force

Claims (7)

  An airflow control device for an internal combustion engine, comprising a plasma actuator that is provided in a gas passage that forms a tube of an internal combustion engine through which gas flows, and that changes the flow of gas in the gas passage.   The plasma actuator includes a surface electrode that is exposed and disposed in the gas passage, and a back electrode that is disposed with the surface electrode and a dielectric interposed between the surface electrode and the back electrode. 2. The gas flow in the gas passage is changed by applying an alternating voltage to generate a blowing force from the front electrode to the back electrode by barrier discharge of the dielectric. An air flow control device for an internal combustion engine according to claim 1.   The plasma actuator is provided in the intake passage of the internal combustion engine, and is configured to enhance the flow component of the intake air supplied into the combustion chamber by increasing the flow velocity of the intake air flowing through a part of the intake passage. The airflow control device for an internal combustion engine according to claim 1, wherein   The said plasma actuator is provided in this inner peripheral side part so that the flow of the inner peripheral side part of the bending part which the said gas channel curves or bends may be strengthened. 3. An airflow control device for an internal combustion engine according to 2. The gas passage is branched from the middle of the main flow path to the sub flow path,
The said plasma actuator is provided in the inlet_port | entrance part by the side of the main flow path of this subflow path so that the flow branched from the said main flow path to a subflow path may be strengthened. An airflow control device for an internal combustion engine. The gas passage is joined to the sub flow path in the middle of the main flow path,
The said plasma actuator is provided in the exit part by the side of the main flow path of the said subflow path so that the flow which joins from the said subflow path to the main flow path may be strengthened. An airflow control device for an internal combustion engine.   The plasma actuator is provided at a stepped portion connecting the large diameter portion and the small diameter portion so as to enhance the flow from the large diameter portion having a large passage cross-sectional area in the gas passage to the small diameter portion having a small passage cross-sectional area. The airflow control device for an internal combustion engine according to claim 1, wherein the airflow control device is an internal combustion engine.

Images