JPH04370322A - Intake air control device for internal combustion engine - Google Patents

Abstract

PURPOSE:To provide an intake air control device for an internal combustion engine wherein an intake control mechanism is installed in the intake air path communicating with each cylinder so that control of intake air quantity in this mechanism can be made accurately. CONSTITUTION:Intake air control mechanisms 191 to 194 are installed in the intake paths 151 to 154 communicating to intake valves 131 to 134 of respective cylinders 121 to 124 in an engine 11. The intake control mechanisms 191 to 194 are provided with control valves 211 to 214 which are set at two positions for fully opening and fully closing the intake path and other positions intermediate between these two positions. When the control valves are set at the intermediate positions, the communication via bypass paths 231 to 234 is made, so that the air flow quantity can be limited. Accordingly, abrupt pressure variation occurring on the intake side of each cylinder following opening and closing of the control vales 191 to 194 can be suppressed.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] This invention provides an intake control mechanism for an internal combustion engine in which an intake control mechanism is provided in each intake passage communicating with each cylinder, in addition to the intake valves provided in each cylinder of the engine. Regarding a control device.

0002

[Prior Art] An intake control mechanism that opens and closes each cylinder and the intake air introduction section is provided for the intake passage communicating with the intake valve section of each cylinder of the internal combustion engine to prevent backflow in the internal combustion engine. It is considered to do.

[0003] In an internal combustion engine, a valve overlap condition occurs in which the intake valve and exhaust valve set for each cylinder are opened simultaneously at the start of the intake stroke. of burned gas flows back into the intake passage. Therefore, the filling efficiency of intake air decreases, and fuel efficiency worsens due to deterioration of the combustion state.

[0004] For this reason, an intake control mechanism is provided for opening and closing the intake passage leading to the intake valve, and in particular, the intake passage is closed in the valve overlap state to prevent air from flowing backwards. , to improve the filling efficiency of the intake air, and to increase the output torque of the internal combustion engine.
Furthermore, it is designed to improve fuel efficiency.

[0005] Such an intake control mechanism is constituted by a valve mechanism, and the intake control valves are set in intake passages corresponding to each cylinder, and each intake control valve is independently driven to open and close by an actuator. Such an intake air control device is disclosed in, for example, Japanese Patent Laid-Open No. 62-294719.

[0006] When such an intake control valve is used to open and close the intake passage set corresponding to each cylinder, the pressure between this intake control valve and the intake valve set in the cylinder section suddenly increases. Change. For this reason, problems such as the generation of noise occur as the intake control valve opens and closes.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and it is an object of the present invention that even when an intake control mechanism is provided in each intake passage corresponding to each cylinder, the intake control mechanism An intake control device for an internal combustion engine that can suppress sudden pressure changes between the intake valve of each cylinder and the intake valve of each cylinder, and improve intake air filling efficiency and fuel efficiency without generating unnecessary noise. This is what we are trying to provide.

[0008]

[Means for Solving the Problems] An intake control device for an internal combustion engine according to the present invention is such that an intake control mechanism is provided in each intake passage communicating with an intake valve portion of each cylinder. a bypass passage comprising a control valve driven and controlled at a position for opening and closing the intake passage and an intermediate position thereof, and further communicating the intake introduction side and the intake valve side with the control valve set at the intermediate position; is formed.

[0009]

[Operation] In other words, in the intake control device for an internal combustion engine configured in this manner, all intake air is supplied to the intake valve section when the control valve is set to the open position, and when the control valve is set to the closed position. The intake passage is closed. When the control valve is set at the intermediate position, the air introduction side and the cylinder are communicated via a bypass passage whose flow rate is restricted, and by controlling the time in this intermediate position, the control valve The supply flow rate of intake air to the downstream (intake valve side) is controlled, and the pressure on this downstream side can be controlled arbitrarily. Therefore, even when the intake control valve is opened and closed, the pressure between this control valve and the intake valve does not change suddenly, noise is not generated due to the opening and closing of the control valve, and fuel efficiency is effectively improved. will be done.

0010

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is for explaining an intake control device for a four-cylinder engine 11, for example, and each of four cylinders 121 to 124 of the engine 11 has an intake valve 1
31 to 134 and exhaust valves 141 to 144 are provided. The intake valves 131 to 134 are connected to the intake introduction part 16 via intake passages 151 to 154, respectively.
The exhaust valves 141 to 144 are connected to the exhaust section 18 through exhaust passages 171 to 174, respectively.

Intake control mechanisms 191 to 194 are provided in intake passages 151 to 154 that send intake air to each cylinder 121 to 124, respectively. The intake air from the intake introduction section 16 is then transferred to a throttle valve 2 which is driven by the operation of an accelerator pedal (not shown).
0 to each intake passage 151 to 154,
Each intake passage 151 to 154 connects each cylinder 121 to 12 via an intake control mechanism 191 to 194, respectively.
Supplied in 4 parts.

Here, each intake control mechanism 151 to 154
is a control valve 2 which is switched and driven between an open position and a closed position.
11 to 214, and this control valve 211
~214 are also switched to intermediate positions between the open and closed positions, respectively, and the drive mechanisms 221 ~
The switching is controlled by 224. This intake control mechanism 1
51 to 154 are bypass passages 231 to 154, respectively.
234, in which the intake passages 151-154 are switched between two states in which they are opened or closed according to the opening and closing of the control valves 211-214, and the control valves 211-214 are set in an intermediate position. An intake air flow path is formed through the bypass passages 231 to 234, and the amount of intake air is restricted.

Here, the drive mechanisms 221 to 224 that control the control valves 211 to 214, respectively, are controlled by commands from the control circuit 24. This control circuit 24 is constituted by a microcomputer or the like, and includes a CPU 241 that constitutes a calculation section, a ROM 242 that stores program data, etc., and a RAM 24 that stores calculation data, etc.
3, and an input/output section 244 that inputs and outputs data, and the driving mechanisms 221 to 224 are controlled by the output from the input/output section 244.

The input/output section 244 of the control circuit 24 receives a detection signal from the opening sensor 25 of the throttle valve 20,
Further, the engine 11 has a crank angle sensor 26, a rotation sensor 27, an operation detection sensor 28, an intake air amount sensor 29,
Engine detection signals are supplied from a load sensor 30, a vibration sensor 31, an emission detection sensor 32, and the like. Based on these input sensor signals, the engine 11
The system determines the operating status of the engine 11 and calculates electronic control data for the engine 11 such as fuel injection amount and ignition angle.

FIGS. 2 and 3 show the intake control mechanism 19 (19
1 to 194) are taken out and shown, and the intake passage 1
Butterfly type circular control valves 21 (211 to 214) are provided within the control valves 5 (151 to 154). This control valve 21 is integrally attached to a support shaft 35. The support shaft 35 is rotatably supported by a manifold in which the intake passage 15 is formed via a bearing mechanism, and the control valve 21 is rotationally driven as the support shaft 35 rotates.

This control valve 21 is set with a narrow clearance around the intake passage 15, and in the first state where the control valve 21 is perpendicular to the passage 15 as shown by the solid line in FIG. It has a structure in which the air flow in the passage 15 is stopped, and the air flow passage in the passage 15 is opened in a second state set parallel to the passage 15 as shown by the dashed line.

The control valve 21 also operates in a third state between the first state and the second state, as shown by the broken line in FIG.
In this state, the bypass passage 23 (231 to 234) closes the intake passage 15.
are now communicated.

The support shaft 35 of the control valve 21 is connected to the drive mechanism 22 (
221 to 224), and this drive mechanism 22 is equipped with an integral cylindrical magnet member 36, and the outer circumference of this magnet member 36 is divided into four parts, for example, into N and S parts. The magnetic poles are alternately formed. A pair of electromagnetic coils 371 and 372 are arranged around the magnet member 36 at positions symmetrical about the support shaft 35.
are set, and permanent magnets 381 and 382 are placed at positions 90° different from the electromagnetic coils 371 and 372, respectively.
is set.

FIG. 4 shows an excitation current circuit for the electromagnetic coils 371 and 372 constituting the drive mechanism 22, and the transistors Tr1 and Tr are connected in series.
An electromagnetic coil 371 is connected between the connection points of Tr2, Tr3, and Tr4. Further, transistors Tr5, Tr6 and Tr7, Tr8 are connected in series, respectively.
An electromagnetic coil 372 is connected between the respective connection points. These transistors Tr1 and Tr2, Tr3 and T
A DC power source E is connected via a switch circuit S to the series circuits r4, Tr5 and Tr6, and Tr7 and Tr8, respectively. These transistors Tr1 to Tr8 and the switch circuit S are each controlled by commands from the control circuit 24.

That is, the direction of the current flowing through the electromagnetic coil 371 is reversed when the transistors Tr1 and Tr4 are made conductive and when the transistors Tr2 and Tr3 are made conductive.
By selecting the conduction state of Tr7 and Tr7, the direction of the current flowing through the electromagnetic coil 372 is reversed. That is, the direction of the magnetic pole formed by the electromagnetic coils 371 and 372 is controlled to be reversed, and this magnetic pole is turned on and off by the switch circuit S.

Therefore, for example, if the direction of the excitation current is set so that the electromagnetic coil 371 forms an S pole and the electromagnetic coil 372 forms an N pole, the N pole of the magnet member 36 faces the electromagnetic coil 371, Similarly, the south pole is now opposed to the electromagnetic coil 372,
The control valve 21 is set, for example, to the first state shown by the solid line in FIG. 3(A). In addition, electromagnetic coils 371 and 37
When a current in the opposite direction is supplied to control valve 2, the magnetic poles of electromagnetic coils 371 and 372 are reversed, and control valve 2
1 moves from the first state to the second state shown by the dashed line. That is, by switching the direction of the excitation current of the electromagnetic coils 371 and 372, the control valve 21 is driven to be switched between a first state in which the intake passage 15 is closed and a second state in which the intake passage 15 is opened.

Furthermore, when the switch circuit S is opened to cut off the excitation current circuit for the electromagnetic coils 371 and 372, the magnet member 36 is connected to the permanent magnets 381 and 382.
Its angular position is set by the magnetic pole set by the control valve 21, and the control valve 21 is set to the third state shown by the broken line between the first state and the second state. Therefore, the intake passage 15 is communicated with the bypass passage 23, and the amount of intake air is restricted.

In the system of the engine 11, the intake valve 13
1 to 134 and exhaust valves 141 to 144 are engine 1
The cam is adjusted so that the valve overlap during high-speed rotation is a predetermined amount, and under such conditions, engine efficiency may deteriorate during low-speed rotation such as idling. Therefore, by delaying the opening timing of the intake control valves 211 to 214 as the rotational speed of the engine 11 decreases, substantial valve overlap is reduced and a decrease in engine efficiency is prevented.

That is, in the high speed rotation range of the engine 11,
At the start of the intake stroke, the intake valves 131 to 134 and the exhaust valve 1
31 to 134, the control valves 211 of the intake control mechanisms 191 to 194
The excitation currents of the electromagnetic coils 371 and 372 are controlled so that the coils 371 and 372 change from the fully open state to the fully closed state. Through such control, burned gas in the cylinders 121 to 124 and in the exhaust passages 171 to 174 is transferred to the intake passage 151.
~154 is prevented from flowing backwards, increasing the intake air filling efficiency.

On the other hand, when the engine 11 is in an idling operating state or in a low-speed rotation/low-load operating range such as when driving in a city, the amount of intake air is small, so that the intake control mechanisms 191 to 194 control valve 211
~214 are switched from the intermediate state to the fully closed state. Therefore, in such a state, the fluctuation width of the intake air amount is reduced, and control responsiveness is also improved. Furthermore, when the control valves 211 to 214 are set at intermediate positions, no current flows through the electromagnetic coils 371 and 372, so power consumption can be reduced.

FIG. 5 shows the relationship between the amount of intake air corresponding to the opening time of the control valve 21, where A represents the amount of air flowing through the main passage of the intake passage 15, and B represents the amount of air flowing through the main passage of the intake passage 15.
It shows the amount of air flowing through 3.

That is, the amount of air corresponding to a certain time range is such that the amount of air flowing through the bypass passage 23 is very small compared to the main passage, so the amount of intake air corresponding to the opening time using the bypass passage 23 is This enables highly accurate control. That is, for the same time width Δt, in the case of the characteristic A of the main passage, the air amount changes by ΔQM, but in the case of the characteristic B due to control of the bypass passage, ΔQB is sufficiently smaller than ΔQM.

FIG. 6 shows the movement of the control valve of the intake control mechanism and the pressure in the intake passage 15 during partial load control in the engine 11. In this example, when the control valve 21 changes from open to closed or from closed to open, the intake passage pressure changes rapidly, and noise is generated due to this pressure change. Similarly, engine 1
Even during full-open operation in step 1, the control valve 21
The intake passage pressure changes rapidly during operation.

On the other hand, in the device shown in the embodiment, the control valves 211 of the intake control mechanisms 191 to 194
~214, in addition to the fully open and fully closed positions,
A position in between is set. Therefore, even when the control valve 21 is in a state of low speed rotation and low load as shown in FIG. 8, and in a fully open operating state as shown in FIG. Even in this case, the pressure in the intake passage does not change suddenly, and unnecessary noise does not occur.

FIG. 10 shows the flow of intake pressure control using the intake air control mechanism. First, in step 101,
The state of the accelerator depression amount (load) is read from the throttle opening sensor 25, and the rotational speed Ne of the engine 11 is also read from the rotation sensor 27. Then, in step 102, it is determined whether or not the vehicle is in a full load state based on the amount of accelerator depression.

If it is determined in step 102 that the load is full, the process proceeds to step 103, and the opening timing To and closing timing Tc of the control valve 21 of the intake control mechanism are determined as shown in FIG.
It is determined from the map A corresponding to the fully open position of the control valve 21 as shown in 1, and control is performed at the fully open and fully closed positions of the control valve 21 in step 104.

If it is determined in step 102 that the load is not full load but partial load, the process proceeds to step 105 where map A shown in FIG. 11 and control valve 2 shown in FIG.
From map B corresponding to the fully closed position of control valve 21,
Find oa, Tca, and Tcb. Here, Toa and Tca are the time for fully open and fully closed control of the control valve 21, T
ob and Tcb indicate the control time by intermediate position control, and the control mode is determined in step 105. Specifically, “Tcb-Tob” is “30/N
e”, that is, the time from TDC to BDC of inspiration (
Select the control mode based on the comparison with the intake time
Proceed to 06 or 107.

In step 106, the opening/closing timing of the control valve 21 of the intake control mechanism is set to Toa and Tca, and in the next step 108, the opening/closing position of the intake control valve 21 is set to the fully open position. Further, in step 107, the opening/closing timing of the control valve 21 is set to Tob and Tcb, and in step 109, the open position of the intake control valve 21 is set to an intermediate position.

Electromagnetic coils 371 and 372 shown in FIG.
In the current control circuit, the direction of the excitation current was switched by transistors Tr1 to Tr8, and the amount of current was kept constant. However, if this excitation current amount is also controlled, the first state shown by the solid line in FIG. 3A, the second state shown by the chain line, and the third state shown by the broken line in between The control valve 21 can be set at any position, regardless of the state, as long as it is between the first state and the second state.

FIG. 13 shows the configuration of the intake control mechanism 19 suitable for the case where the control valve 21 can be set at a position other than such an intermediate position. A cylindrical opening 40 corresponding to the locus of the rotating tip of the cylindrical opening 40 is processed 41 to widen its inner wall surface,
A bypass passage is formed in this processed portion 41.

With this configuration, the intake passage 15 is blocked when the control valve 21 is set in the first state shown by the solid line, and is opened when the control valve 21 is set in the second state shown by the chain line. Furthermore, in a third state between the first state and the second state, the amount of intake air per unit time is set corresponding to the angular position. That is, the intake air amount is determined not only by the time, but also by a parameter corresponding to the change in the air amount per unit time, and the degree of freedom in control is further improved.

Furthermore, as shown in FIG. 8, in the control operation of the control valve 21, the control valve 21 is driven from the intermediate position to the fully open position when the relevant cylinder enters the intake stroke. The operation may be maintained at an intermediate position even after entering the intake stroke, and the closing timing may be delayed to obtain the required amount of intake air. Through this kind of control, the intake air flow during the intake stroke is sustained for a long time, increasing the swirl effect on the air-fuel mixture in the combustion chamber of the internal combustion engine, increasing the combustion temperature at the time of ignition, and achieving good combustion. be able to.

[0038]

As described above, according to the intake control device for an internal combustion engine according to the present invention, the control valve of the intake control mechanism can be set in three states: fully open, fully closed, and a position in between, depending on the operating state. It is possible to switch and control the intake efficiency, and the intake air amount can be controlled with high precision. Therefore, fluctuations in the amount of intake air can be prevented in the low speed rotation range, and the level of controllability of intake air can be effectively improved. In addition, the generation of noise at the intake control valve is prevented,
It is also possible to increase the swirl by utilizing the change in flow velocity due to the bypass passage. Here, in the case of a configuration in which a bypass passage does not exist, a small error in the full-open time of the control valve causes a large error in the intake air amount, and it is necessary to control the full-open time of the control valve with high precision. However, by forming a bypass passage and using this bypass passage to form an intake passage at an intermediate position of the control valve, intake air amount control is greatly simplified and the accuracy of intake air amount control is improved. It can be easily improved.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram illustrating an intake control device for an internal combustion engine according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing the intake control mechanism section of the above embodiment.

3A and 3B are cross-sectional views corresponding to the a-a line and the bb line of the intake control mechanism shown in FIG. 2, respectively.

FIG. 4 is a diagram illustrating an excitation control circuit for the electromagnetic coil of the intake control mechanism.

FIG. 5 is a diagram showing the relationship between time and air amount at a fully open position and an intermediate position of the control valve.

FIG. 6 is a diagram showing the movement of the control valve and the pressure in the intake passage during partial load control of the engine when there is no bypass passage.

FIG. 7 is a diagram showing the movement of the control valve and the pressure in the intake passage during partial load control of the engine at full load.

FIG. 8 is a diagram showing the movement of the control valve and the pressure in the intake passage during partial load control of the engine in the device shown in the example.

FIG. 9 is a diagram showing the movement of the control valve and the pressure in the intake passage during partial load control of the engine at full load in the same example device.

FIG. 10 is a flowchart showing the operation flow of the control circuit of the embodiment device.

FIG. 11 is a diagram showing a map A stored in the control circuit.

FIG. 12 is a diagram showing a map B similarly stored in the control circuit.

FIG. 13 is a sectional view illustrating an intake control mechanism section according to another embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 11... Engine, 12, 121, 122,... Intake control mechanism, 131, 132,... Intake valve, 141, 1
42,...exhaust valve, 15, 151, 152,...intake passage, 16...intake introduction part, 19, 191, 192,
...Intake control mechanism, 20...Throttle valve, 21, 211
, 212 , ... control valve, 22, 221 , 222 , ...
Drive mechanism, 23, 231, 232... bypass passage,
24... Control circuit, 35... Support shaft, 36... Magnet member, 37
1, 372...Electromagnetic coil, 381, 382...Permanent magnet.

Claims (1)

[Claims] [Claim 1] An intake valve and an exhaust valve set for each cylinder of an internal combustion engine, and a valve set corresponding to each cylinder that communicates with the intake valve and is supplied with intake air from an intake introduction section. an intake passage, an intake control mechanism corresponding to each cylinder provided between the air introduction part side of each intake passage and the exhaust valve, and a control means for controlling the air passage of this intake control mechanism. The intake control mechanism includes a control valve that is drive-controlled to open and close the intake passage, and a control valve that is set at an intermediate position between an open position and a closed position on the air introduction part side. and a bypass passage communicating with the exhaust valve side, and the control means includes bypass passage formation timing calculation means for calculating the timing at which the control valve is set to the intermediate position in accordance with the rotation speed of the internal combustion engine. An intake control device for an internal combustion engine, comprising: