JPH1162598A - Intake swirl control device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To optimally control intensity of a swirl by variably controlling a swirl control valve by means of a blade pitch controlling means. SOLUTION: An internal combustion engine of this type has a swirl generation means for generating a swirl with specified intensity, in order for intake from intake ports 11, 12 to a cylinder. In such a case, a swirl control valve 31 is provided which is composed of a plurality of blades 32 spirally arranged fron a center of a sectional surface of the intake port with variable pitch angles in positive and negative directions. A blade pitch control means are arranged for controlling the pitch angles of the blades of the swirl control valve 31 in the positive and negative directions, and for controlling rotational intensity of the swirl. The blade pitch control means makes the blades rotate in the positive or negative direction for controlling the pitch angles in both positive and negative directions. Intensity of the swirl generated by the swirl generating means is thus adjusted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an intake swirl control device for an internal combustion engine.

[0002]

2. Description of the Related Art In an internal combustion engine, a swirl flow (swirl) of intake air is generated in a cylinder to improve fuel combustion characteristics. Among them, an intake swirl variable device for generating a swirl intensity corresponding to the load of an internal combustion engine is disclosed in Japanese Utility Model Laid-Open Publication No. 61-140132.
An apparatus described in Japanese Unexamined Patent Publication (Kokai) No. HEI 9-209 is known.

In this device, as shown in FIG. 12, in a four-stroke engine, a guide blade rotating shaft 5 is provided in a suction port and fixed to a shaft support and an intake port wall. , A guide blade 6 and a pinion 7 integral with the guide blade are attached, and the pinion 7 is engaged with an annular rack 8 with a shaft.

This device has a structure in which the swirl flow is generated by rotating the fresh air flowing into the intake port by the guide blades 6, and by rotating the annular rack 8 with a shaft to rotate the pinion, the guide blades are rotated. To change the swirl strength by changing the intensity of fresh air turning by the guide vanes.

[0005]

In such a swirl variable device, since the swirl is generated and variably controlled by the guide blade itself, the pitch angle of the guide blade can be controlled in a positive or negative range. This is inevitable, and it is not always possible to achieve desirable fine control.

In an internal combustion engine having two intake ports, a swirl generating means is provided in one intake port, and when a swirl flow is generated in intake air from one intake port, intake air from the other intake port is generated. Also exists,
Even if the swirl control by the conventional method is performed,
The control of the swirl flow generated by the guide vanes is influenced by the intake from the other intake port.

There is no consideration for this point in the conventional apparatus, and it cannot be expected that an appropriate swirl control is performed. The present invention has been made in view of the above, and in an internal combustion engine,
It is an object to provide an intake swirl control device capable of optimally controlling the intensity of a swirl flow.

[0008]

According to the present invention, there is provided an internal combustion engine provided with a swirl generating means for generating a swirl flow of a constant intensity upon intake from a suction port into a cylinder. Was taken.

That is, a swirl control valve comprising a plurality of blades provided in the intake port and arranged radially from the center of the cross section of the intake port and capable of changing the pitch angle in both positive and negative directions, and the swirl control valve. Blade pitch control means for controlling the pitch angle of the blades in both directions, and controlling the rotational intensity of the swirl flow, the blade pitch control means rotating the blades in a positive or negative direction. An intake swirl control apparatus for an internal combustion engine, characterized in that the pitch angle is controlled in both positive and negative directions to adjust the intensity of the swirl flow generated by the swirl generating means.

The present invention is most characterized in that a swirl control valve is provided separately from a swirl generating means for generating a swirl flow having a constant intensity, and the swirl control valve is variably controlled by a blade pitch control means.

As the swirl generating means, a so-called helical port in which the intake port is formed in a spiral shape can be exemplified. The basic premise of the present invention is that a swirl flow having a constant intensity is generated in the intake air by the swirl generating means.

The swirl control valve is controlled by the blade pitch control means to control the pitch angle of the blade in the forward or negative direction by rotating the blade forward or backward, thereby controlling the swirl control valve in the forward or negative direction generated by the swirl control valve. The swirl intensity is controlled by adding the swirl flow in the negative direction to the swirl flow having the constant intensity.

That is, when the pitch angle is controlled in the positive or negative direction, a swirl flow having an intensity corresponding to the pitch angle is generated by the blade, and this is added to the swirl flow generated by the swirl generating means, and the final swirl flow is generated. Can be controlled in a direction to increase the strength of the light.

If the pitch angle is controlled in the negative direction, a swirl flow in the negative direction having a strength corresponding to the pitch angle is generated by the blade, and this is added in a direction to cancel the swirl flow generated by the swirl generating means. It is possible to control the strength of the final swirl flow to be weakened.

In this respect, a conventional example of Japanese Utility Model Application Laid-Open No. 61-140 is known.
In No. 132, the pitch angle of the guide vanes is merely controlled in the positive direction. This is because, unlike the present invention, since the guide vanes exist to generate the swirl flow, it is impossible that the guide vanes generate a swirl flow in the reverse direction to the original swirl flow in the original direction. is there.

The swirl intensity control according to the present invention is preferably performed in accordance with the operating condition of the internal combustion engine. That is, the blade pitch control means, when the intensity of the swirl flow generated by the swirl generation means is stronger than necessary than the intensity of the swirl flow required for the operating state of the internal combustion engine, in the direction to reduce the swirl intensity The pitch angle of the blade is controlled. Also, when the swirl flow intensity required for the operation state of the internal combustion engine is weaker than necessary, the pitch angle of the blades can be controlled in a direction to increase the swirl intensity.

Here, when the present invention is applied to an internal combustion engine having, as intake ports, a first intake port having the swirl generating means and a second intake port having no swirl generating means, The control valve is provided in one of the first and second intake ports.

The swirl control valve is provided with a first
The blade pitch control means controls the pitch angle of the blades in the negative direction to reduce the swirl intensity by the swirl generation means.

The swirl control valve is provided with a second
When provided at the intake port, the blade pitch control means controls the pitch angle of the blade in the positive direction to increase the intake air from the second intake port, so that the blade pitch control means relatively moves from the first intake port. Is controlled to weaken the intensity of the swirl flow.

In the above description, it is preferable to provide a helical intake port as the swirl generating means, but the present invention is not limited to this as long as swirl can be generated.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing a part of an internal combustion engine to which the present invention is applied. This internal combustion engine is a 4-cycle gasoline engine, and has a first intake port 11 and a second intake port 12 for introducing fresh air into the cylinder 10, and further has a cylinder 10 as shown in FIG.
First exhaust port 21 and second exhaust port 21
Exhaust port 22 is provided.

An intake valve 13 is provided on each of the first and second intake ports 11 and 12 so as to be openable and closable, and an exhaust valve (not shown) is openable and closable on each of the first and second exhaust ports 21 and 22. Is provided.

Further, the first intake port 11 is formed as a swirl-shaped helical port 11a as a swirl generating means, and a small projection 11b is provided in the vicinity of the entrance to the cylinder, so that the port shape and the small projection 11b are formed. As a result, a swirl flow of a constant intensity is generated in the intake air passing through the helical port 11a. The swirl generating means includes a helical port 11
It is not limited to a, and a propeller-like blade that generates a swirling flow in the intake air may be used. Further, a swirling flow may be generated depending on the positions of the intake ports and the exhaust ports that are opened to the cylinders. In short, any means may be used as long as it can generate a swirl of a certain strength. Further, the second intake port 12 is formed as a straight port, and a swirling flow is prevented from occurring due to the shape of the port.

In FIG. 1, 25 is a fuel injection valve, and 26 is a piston. On the premise of the above configuration, the following embodiments will be exemplified.

<Embodiment 1> In the first embodiment, as shown in FIG. 2, a swirl control valve 31 is provided in a helical port 11a.

As shown in FIGS. 3 and 4, the swirl control valve 31 is arranged radially from the center of the cross section of the intake port 11 and has a plurality of blades 32 whose pitch angle can be changed in both positive and negative directions.

More specifically, the swirl control valve 31 is provided with a bearing block 34 in the center of the cross section of the intake manifold 33 in a cylindrical intake manifold 33 (also substantially an intake port) connected to the intake port. In this configuration, four blades 32 are attached at the same pitch angle around four rotating shafts 35 radially provided between the bearing block 34 and the wall 33a of the intake manifold 33. .

Circular gears 36 are respectively attached to the tips of the four rotating shafts 35 penetrating the wall 33a of the intake manifold 33, and further mesh with the respective circular gears 36 around the outer wall of the intake manifold 33. The rotation of the ring gear 37 causes the four rotation shafts 35 to rotate synchronously via the circular gear 36, thereby adjusting the pitch angle of each blade 32. ing. Also, the ring gear 3
7 is provided with an engagement member 38 at one end thereof, a support shaft 40 is rotatably inserted into a connection hole 39 provided at the engagement member 38, and a push rod 41a of an actuator 41 is inserted into the support shaft 40. Is attached. The ring gear 37 is rotated in the circumferential direction of the intake manifold 33 by the advance and retreat of the push rod 41a.

As shown in FIG. 5, a drive circuit 51 for controlling the actuator 41 is provided, and the drive circuit 51 is controlled by a computer. This computer includes a CPU 52 and a ROM 53, and performs swirl control by a program stored in the ROM 53 in advance.

The relationship between the operating condition and the swirl intensity and the relationship between the swirl intensity in the cylinder 10 and the pitch angle of the blades 32 of the swirl control valve 31 are stored in the ROM 53 in the form of a map in advance. .

When the program in the ROM 53 is executed, the CPU 52 realizes the operating condition determining means 54 for determining the operating condition of the internal combustion engine and the pitch angle determining means 55 as the blade pitch controlling means. It has become. In determining the driving situation, an accelerator sensor S for detecting whether or not the accelerator pedal is depressed
1. Intake pressure sensor S for detecting intake pressure to the internal combustion engine
2. Water temperature sensor S for detecting the temperature of the cooling water of the internal combustion engine
3. An engine speed sensor (N
Information from various sensors required for vehicle control, such as an E sensor S4, an aero flow meter S5 for detecting the amount of air sucked into the internal combustion engine, a G sensor S6 for detecting inertial force applied to the vehicle, and the like are used.

The swirl control according to the above configuration will be described with reference to the flowchart of FIG. In the initial state, the blades 32 of the swirl control valve 31 are parallel to the flow direction of the intake air, and this position is set as a reference position at a pitch angle of 0 degree.

First, information from the various sensors is input to a computer (S100). The operating condition of the internal combustion engine is determined by the operating condition determining means 54 based on information from various sensors (S101). When it is determined that the internal combustion engine has a low load or a low rotation, the pitch angle determination unit 55 refers to the map and issues a command to the drive circuit 51 so as to have a predetermined positive pitch angle (S102). The drive circuit 51 supplies a drive current having a duty ratio according to the command to the actuator (S104). The actuator 41 projects the push rod with a projection width corresponding to the duty ratio, and sets the pitch angle of the blade 32 to a predetermined pitch angle in the positive direction (S105).

Then, in the helical port 11a, the swirling flow (swirl flow) in the forward direction is generated in the intake air by the blades 32 having the pitch angle in the forward direction, and as shown in FIG. The swirl flow by the blades 32 is added to the swirl flow in the positive direction (FIG. 7A), and the swirl strength in the cylinder 10 is increased as shown in FIG. 7B.

On the other hand, when the operating condition determining means 54 determines that the internal combustion engine is at a high load or a high speed, the pitch angle determining means 55 refers to the map and sets the driving circuit so that the predetermined pitch angle in the negative direction is obtained. 51 (S10)
3). The drive circuit 51 supplies a drive current having a duty ratio according to the command to the actuator 41 (S104). The actuator projects the push rod 41a with a protrusion width corresponding to the duty ratio, and sets the pitch angle of the blade 32 to a predetermined pitch in the negative direction. It becomes a corner (S105).

As a result, in the helical port 11a, the swirl flow (reverse swirl flow) in the reverse direction is generated in the intake air by the blade 32 having the pitch angle in the negative direction.
As shown in (c), the blade 32 moves in the direction to cancel the swirl flow in the positive direction originally generated by the helical port 11a.
Reverse swirl flow acts to weaken the swirl strength in the cylinder.

In the swirl generating means having a fixed shape by the helical port, the swirl intensity becomes excessively high when the intake air becomes strong, such as during high-speed operation. Therefore, the swirl intensity can be reduced by the above control, and appropriate combustion can be achieved. realizable.

This is an example of controlling the pitch angle of the blades in a direction to decrease the swirl intensity when the intensity of the swirl flow required for the operation state of the internal combustion engine is more than necessary. is there.

The blade pitch control is based on the pitch angle determined by the pitch angle determining means 55.
1. Since it is executed by the actuator 41, all of them may be regarded as blade pitch control means.

In this example, one intake port may be provided, and the intake port may be a helical port.

<Second Embodiment> A second embodiment is the same as the first embodiment except that a swirl control valve 31 is provided in the second intake port 12 as shown in FIG. is there.

The swirl control according to the above configuration will be described with reference to the flowchart of FIG. In the initial state, the blades 32 of the swirl control valve 31 are parallel to the flow direction of the intake air, and this position is set as a reference position at a pitch angle of 0 degree.

First, information from the various sensors is input to a computer (S200). The operating state of the internal combustion engine is determined by the operating state determining means 54 based on information from various sensors (S201). When it is determined that the internal combustion engine has a low load or a low rotation, the pitch angle determination unit 55 refers to the map and issues a command to the drive circuit 51 so as to have a predetermined negative pitch angle (S202). The drive circuit 51 supplies a drive current having a duty ratio according to the command to the actuator 41 (S204). Actuator 41
Protrudes the push rod 41a with a protrusion width corresponding to the duty ratio, and sets the pitch angle of the blade 32 to a predetermined pitch angle in the negative direction (S205).

Then, in the second intake port 12, a swirl flow (reverse swirl flow) in the reverse direction is generated in the intake air by the blades 32 having the negative pitch angle. In swirl style,
The reverse swirl flow by the blades 32 collides in the cylinder 10, and the swirl strength in the cylinder 10 decreases.

When it is determined that the internal combustion engine has a low load or a low rotation, the pitch angle may be maintained at 0 degree. On the other hand, when the operating condition determining means 54 determines that the internal combustion engine is at a high load or a high speed (S2
01), the pitch angle determination means 55 issues a command to the drive circuit 51 so that the pitch becomes a predetermined pitch angle in the forward direction with reference to the map (S203). The drive circuit 51 supplies a drive current having a duty ratio according to the command to the actuator 41 (S20).
4), the actuator 41 protrudes the push rod 41a with a protruding width corresponding to the duty ratio, and
Is set to a predetermined positive pitch angle (S20).
5).

As a result, in the second intake port 12, a forward swirling flow (swirl flow) is generated in the intake air by the blades 32 having the forward pitch angle. In swirl style,
The swirl flow by the blades 32 merges in the cylinder, and the cylinder 10
To increase the swirl strength inside.

As described above, in the second embodiment, since the swirl strength is adjusted in the cylinder 10, more direct and dynamic adjustment is possible. As in the above embodiment,
A helical port and a straight port are provided as the two intake ports, and a swirl control valve can be provided in either of them.

In addition to the above-described embodiment, the present invention relates to an internal combustion engine having a third intake port in addition to a first intake port having a swirl generating means and a second intake port having no swirl generating means. It is also possible to apply the present invention.

Finally, the relationship between the swirl control and the port shape will be described. FIG. 10 shows a swirl ratio control width when the number of intake ports is one, the intake port is a helical port, and a swirl control valve is provided in the helical port. On the other hand, the swirl ratio control width when there is one intake port, the intake port is a straight port, and a swirl control valve is provided in the straight port is shown in FIG.
It is shown in FIG.

As shown in FIG. 11, when the swirl control valve is provided in the straight port, there is almost no room for changing the swirl ratio in the region where the valve pitch angle on the horizontal axis is negative, and the swirl ratio can be controlled as a whole. Small width. On the other hand, in FIG. 10, the swirl ratio can be increased by adding swirl by the helical port.

[0051]

According to the present invention, a swirl control valve is provided separately from the swirl generating means for generating a swirl flow having a constant intensity, and the swirl control valve is controlled by the blade pitch control means to adjust the pitch angle in the positive or negative direction. By controlling the magnitude, the blade generates a swirl flow in the positive or negative direction with an intensity corresponding to the pitch angle, and adds this to the swirl flow generated by the swirl generation means,
As we controlled the intensity of the final swirl flow,
Appropriate control of the swirl flow can be performed.

When the pitch angle is controlled in the positive or negative direction, a swirl flow having an intensity corresponding to the pitch angle is generated by the blades, and this is added to the swirl flow generated by the swirl generating means, and the intensity of the final swirl flow is increased. When the pitch angle is controlled in the negative direction, a swirl flow in the negative direction having an intensity corresponding to the pitch angle is generated by the blade, and this is the swirl generated by the swirl generating means. Since the flow can be controlled in a direction to cancel the flow and to reduce the intensity of the final swirl flow, the swirl intensity can be variably controlled according to the operating condition of the internal combustion engine.

When the present invention is applied to an internal combustion engine having, as intake ports, a first intake port having the swirl generating means and a second intake port having no swirl generating means, the swirl control valve is used. When the first intake port is provided, the swirl intensity at the first intake port can be controlled on the first intake port side by controlling the blade pitch angle of the swirl control valve by the blade pitch control means. On the other hand, when the swirl control valve is provided in the second intake port, the blade pitch control means controls the blade pitch angle of the swirl control valve. The swirl flow intensity can be controlled. In this case, more direct and dynamic adjustment is possible as compared with the former.

[Brief description of the drawings]

FIG. 1 is a partially broken view of an internal combustion engine according to the present invention.

FIG. 2 is a conceptual diagram showing Embodiment 1 of the present invention.

FIG. 3 is a longitudinal sectional view of an intake port showing an example of a swirl control valve.

FIG. 4 is a cross-sectional view of an intake port showing an example of a swirl control valve.

FIG. 5 is a control block diagram according to the present invention.

FIG. 6 is a flowchart showing the operation of the first embodiment.

FIGS. 7A and 7B are conceptual diagrams showing a swirl control state in the first embodiment. FIG. 7A shows a swirl state in a steady state, and FIG. 7B shows a swirl state in a case where a forward pitch angle is given. FIG. 7 (c) shows a swirl state when a negative pitch angle is given.

FIG. 8 is a conceptual diagram showing a second embodiment of the present invention.

FIG. 9 is a flowchart showing the operation of the second embodiment.

FIG. 10 is a graph showing a control width of a swirl ratio when a swirl control valve is provided in a helical port.

FIG. 11 is a graph showing a control width of a swirl ratio when a swirl control valve is provided in a straight port.

FIG. 12 shows a conventional example.

[Explanation of symbols]

 5. Guide vane rotating shaft 6. Guide vane 7. Pinion 8. Annular rack with shaft 10. Cylinder 11. First intake port 11a Helical port (swirl generating means) 11b Small Projection 12 Second intake port 13 Intake valve 21 First exhaust port 22 Second exhaust port 25 Fuel injector 26 Piston 31 Swirl control valve 32 Blade 33 Intake manifold 34 Bearing block 33a Intake manifold wall 35 Rotary shaft 36 Circular gear 37 Ring gear 38 Engaging member 39 Connection hole 40 Shaft 41a Push rod 51 Drive circuit 52 CPU 53 ROM 54 Operating condition determining means 55 Pitch angle determining means (blade pitch control Stage) S1 · · accelerator sensor S2 · · intake pressure sensor S3 · · water temperature sensor S4 · · engine speed sensor (NE sensor) S5 · · Aero Flowmeter S6 · · G sensor S · · · swirl

Claims (6)

[Claims] 1. An internal combustion engine provided with a swirl generating means for generating a swirl flow of a constant intensity upon intake from a suction port into a cylinder, wherein the swirl generating means is provided in the intake port and is radially arranged from a center of a cross section of the intake port. And a swirl control valve having a plurality of blades whose pitch angle can be changed in both positive and negative directions, and controlling the pitch angle of the blades of the swirl control valve in both positive and negative directions to control the rotational intensity of the swirl flow. A blade pitch control unit, wherein the blade pitch control unit controls the pitch angle in both positive and negative directions by rotating the blade in a positive direction or a negative direction, and the swirl flow generated by the swirl generation unit. An intake swirl control device for an internal combustion engine, characterized by adjusting the strength of the intake air. 2. The blade pitch control means, when the intensity of the swirl flow generated by the swirl generation means is stronger than necessary than the intensity of the swirl flow required for the operation state of the internal combustion engine, sets the swirl intensity. 2. The intake swirl control device for an internal combustion engine according to claim 1, wherein a pitch angle of the blades is controlled in a weakening direction. 3. A first intake port having the swirl generating means and a second intake port having no swirl generating means as the intake port, wherein the swirl control valve includes the first and second swirl control valves. 2. The intake swirl control device for an internal combustion engine according to claim 1, wherein the intake swirl control device is provided in any one of the intake ports. 4. A first intake port having the swirl generating means and a second intake port having no swirl generating means as the intake port, and the swirl control valve is provided in the first intake port. 3. The intake swirl control of an internal combustion engine according to claim 2, wherein said blade pitch control means controls the pitch angle of the blades in a negative direction so as to weaken the swirl intensity by said swirl generating means. apparatus. 5. A first intake port having the swirl generating means and a second intake port having no swirl generating means as the intake port, and the swirl control valve is provided in a second intake port. The blade pitch control means controls the pitch angle of the blades in the positive direction to increase the intake from the second intake port, thereby relatively controlling the intensity of the swirl flow from the first intake port. 3. The intake swirl control apparatus for an internal combustion engine according to claim 2, wherein 6. The intake swirl control device for an internal combustion engine according to claim 1, wherein the swirl generating means includes a helical intake port.