JP2010185375A - Intake control device of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To appropriately control a level difference in supercharging pressure when switching an intake passage in an intake control device of an internal combustion engine containing two lines of intake passages. <P>SOLUTION: An intake control device of an internal combustion engine contains two lines of intake passages to perform impulse charge. A first and second switching valves are respectively arranged in confluent positions on an upstream side and downstream side in two lines of intake passages. A control means for executing control to the first and second switching valves so as to make temporal opening changes of the first and second switching valves substantially identical to each other when switching a passage through which intake air flows to one of the two lines of intake passages. Thus, a level difference in supercharging pressure occurring when switching two lines of intake passages can be appropriately controlled. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an intake control device for an internal combustion engine that performs impulse charging.

  This type of technique is proposed in Patent Document 1, for example. Patent Document 1 proposes that the volume of the intake passage downstream of the intake control valve (impulse valve) is configured to be variable and the volume is reduced when impulse charging (impulse supercharging) is performed. . In this technique, the supercharging effect is enhanced by the pulsation effect.

JP 2006-118369 A

  However, with the technique described in Patent Document 1 described above, the structure is complicated, and it is difficult to quickly respond to region switching during transient operation.

  The present invention has been made to solve the above-described problems, and in an intake control device for an internal combustion engine having two intake passages, appropriately suppresses a boost pressure step at the time of switching between intake passages. For the purpose.

  In one aspect of the present invention, an intake control device for an internal combustion engine includes any one of two intake passages provided on an intake passage from a turbocharger to a cylinder of the internal combustion engine, and the two intake passages. Intake air flows through an intake control valve provided on one of the passages, and a first switching valve and a second switching valve provided at an upstream merging position and a downstream merging position in the two systems of intake passages, respectively. When the passage is switched to one of the two intake passages, the temporal change in opening between the first switching valve and the second switching valve is substantially the same. Control means for controlling the first switching valve and the second switching valve.

  The intake control apparatus for an internal combustion engine includes two intake passages and performs impulse charge. A first switching valve and a second switching valve are provided in each of the upstream merging position and the downstream merging position in the two systems of intake passages. When the control means switches the passage through which the intake air flows to one of the two intake passages, the temporal change in opening of the first switching valve and the second switching valve is substantially the same. In addition, the first switching valve and the second switching valve are controlled. Thereby, the supercharging pressure level difference which may occur when switching between the two intake passages can be appropriately suppressed.

  In another aspect of the present invention, an intake control device for an internal combustion engine includes any one of two intake passages provided on an intake passage from a turbocharger to a cylinder of the internal combustion engine, and the two intake passages. An intake control valve provided on one of the passages, and a passage in the vicinity of a downstream merging position in the two intake passages, which is different from the passage provided with the intake control valve in the two intake passages When the switching valve provided above and the passage for flowing the intake air are switched to one of the two passages, the opening area of the intake control valve and the opening area of the switching valve Control means for controlling the intake control valve and the switching valve so that the sum is substantially the same as the opening area when the intake control valve is fully opened.

  The intake control apparatus for an internal combustion engine includes two intake passages and performs impulse charge. An intake control valve is provided on one of the two systems of intake passages, and a switching valve is provided on the other passage. Specifically, the switching valve is provided near the downstream merging position in the two intake passages. When the control means switches the passage for intake air to one of the two intake passages, the sum of the opening area of the intake control valve and the opening area of the switching valve is determined when the intake control valve is fully opened. The intake control valve and the switching valve are controlled so as to be substantially the same as the opening area at. Thereby, the supercharging pressure level difference which may occur when switching between the two intake passages can be appropriately suppressed.

1 shows a schematic configuration of an intake control device for an internal combustion engine in a first embodiment. The figure for demonstrating the structure of the switching valve in 1st Embodiment is shown. The figure for demonstrating the control method of the valve in 1st Embodiment is shown. 6 is a flowchart illustrating processing performed when switching from a first intake passage to a second intake passage in the first embodiment. The schematic structure of the intake control device of the internal combustion engine in 2nd Embodiment is shown. The figure for demonstrating the control method of the valve in 2nd Embodiment is shown. In 2nd Embodiment, it is a flowchart which shows the process performed when switching from a 1st intake passage to a 2nd intake passage. The schematic structure of the intake control device of the internal combustion engine in 3rd Embodiment is shown. The figure for demonstrating the control method of the valve in 3rd Embodiment is shown. It is a flowchart which shows the process performed when switching from a 1st intake passage to a 2nd intake passage in 3rd Embodiment.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.
[First Embodiment]
First, a first embodiment of the present invention will be described.

(Device configuration)
FIG. 1 shows a schematic configuration of an intake air control device 101 for an internal combustion engine in the first embodiment. In the figure, solid arrows indicate an example of gas flow, and broken arrows indicate signal input / output.

  The internal combustion engine intake control device 101 mainly includes an intake passage 1, a turbocharger 2, an intercooler (I / C) 3, a first intake passage 1 a, a second intake passage 1 b, and a surge tank 4. , An impulse valve 5, an intake manifold 6, an engine (internal combustion engine) 7, an exhaust manifold 8, an exhaust passage 9, switching valves 11 and 12, and an ECU (Engine Control Unit) 51. The intake control device 101 for an internal combustion engine is configured as an intake passage switching type impulse charge system.

  Intake air purified by an air cleaner (not shown) is supplied to the intake passage 1. The intake air flowing through the intake passage 1 is supercharged by the compressor 2 a of the turbocharger 2 and cooled by the intercooler 3. The intake passage 1 includes two passages (a first intake passage 1 a and a second intake passage 1 b) on the downstream side of the intercooler 3.

  The first intake passage 1a is configured such that the inner diameter of the pipe is smaller than that of the second intake passage 1b. Basically, the first intake passage 1a is used for flowing intake air at a low to medium engine speed, and the second intake passage 1b is used for flowing intake air at a high engine speed.

  A surge tank 4 configured to store intake air and an impulse valve 5 configured to open and close in a relatively short time are provided on the first intake passage 1a. The impulse valve 5 is controlled by a control signal S5 supplied from the ECU 51. The impulse valve 5 corresponds to an intake control valve.

  In addition, switching valves 11 and 12 are provided at a joining position of the first intake passage 1a and the second intake passage 1b. Specifically, the switching valve 11 is provided at a merging position on the upstream side of the first intake passage 1a and the second intake passage 1b, and the switching valve 12 is on the downstream side of the first intake passage 1a and the second intake passage 1b. Is provided at the merging position. The switching valves 11 and 12 are configured as three-way valves, and are configured so that a passage through which intake air flows can be switched to one of the first intake passage 1a and the second intake passage 1b. The switching valves 11 and 12 are controlled by control signals S11 and S12 supplied from the ECU 51 via actuators (not shown). The switching valves 11 and 12 correspond to the first switching valve and the second switching valve in the present invention.

  The intake air that has passed through the intake passage 1 passes through an intake manifold (intake manifold) 6 and is supplied to the engine 7. The engine 7 outputs a driving power source for the vehicle by burning a mixture of intake air and combustion in the cylinder. For example, the engine 7 is configured by an in-line four-cylinder diesel engine or the like.

  Exhaust gas generated by combustion in the engine 7 passes through an exhaust manifold (exhaust manifold) 8 and is discharged to an exhaust passage 9. A turbine 2b of the turbocharger 2 is provided on the exhaust passage 9, and the turbine 2b is rotated by the energy of the exhaust gas. The exhaust gas that has passed through the turbine 2b is purified by an exhaust purification catalyst (not shown).

  The ECU 51 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like (not shown), and performs various controls on the components in the intake control device 101 of the internal combustion engine. In the present embodiment, the ECU 51 functions as control means in the present invention, and controls the switching valves 11 and 12 to switch the passage through which intake air flows to either the first intake passage 1a or the second intake passage 1b. Do.

  Next, a specific configuration of the switching valves 11 and 12 will be described with reference to FIG.

  FIG. 2A shows a schematic configuration of the switching valve 11. In FIG. 2A, the intercooler 3 side is shown below, and the switching valve 12 side is shown above. As shown in the figure, the switching valve 11 is provided at the joining position A11 of the first intake passage 1a and the second intake passage 1b, and is configured as a three-way valve. The switching valve 11 is configured to be able to switch a passage through which intake air flows to either the first intake passage 1a or the second intake passage 1b. Basically, when the switching valve 11 is set to the position b11, the intake air flows only into the first intake passage 1a (does not flow into the second intake passage 1b), and the switching valve 11 is set to the position b12. If so, intake air flows only through the second intake passage 1b (but does not flow through the first intake passage 1a). In the following, the opening degree (opening angle) of the switching valve 11 is defined as indicated by “θ11” in FIG.

  FIG. 2B shows a schematic configuration of the switching valve 12. In FIG. 2B, the switching valve 11 side is shown below, and the intake manifold 6 side is shown above. As shown in the figure, the switching valve 12 is provided at a joining position A12 of the first intake passage 1a and the second intake passage 1b, and is configured as a three-way valve. The switching valve 12 is configured to be able to switch the passage through which intake air flows to either the first intake passage 1a or the second intake passage 1b. Basically, when the switching valve 12 is set at the position b21, intake air flows only into the first intake passage 1a (does not flow into the second intake passage 1b), and the switching valve 12 is set at the position b22. If so, intake air flows only through the second intake passage 1b (but does not flow through the first intake passage 1a). In the following, the opening degree (opening angle) of the switching valve 12 is defined as indicated by “θ12” in FIG.

(Control method)
Next, in the first embodiment, a control method that is performed when the passage for flowing the intake air is switched to one of the first intake passage 1a and the second intake passage 1b will be described. In the first embodiment, the ECU 51 opens the switching valves 11 and 12 so that the boost pressure step (torque step) that can occur when switching between the first intake passage 1a and the second intake passage 1b is suppressed. Is switched between the first intake passage 1a and the second intake passage 1b. Specifically, the ECU 51 switches the switching valve so that the temporal change in opening between the switching valve 11 and the switching valve 12 is substantially the same when switching between the first intake passage 1a and the second intake passage 1b. 11 and 12 are controlled. The supercharging pressure step as described above is such that the intake pipe internal pressure when intake air flows only through the first intake passage 1a is greater than the intake pipe internal pressure when intake air flows through only the second intake passage 1b. Due to the tendency to increase, the change occurs (for example, decreases) in the intake pipe internal pressure due to the switching.

  With reference to FIG. 3, the control method of the switching valves 11 and 12 in 1st Embodiment is demonstrated concretely. Here, a description will be given of a control method that is performed when switching the passage for intake air from the first intake passage 1a to the second intake passage 1b.

  In FIG. 3, the horizontal axis indicates the time after the start of switching (time t11 indicates the time at the start of switching), and the vertical axis indicates the opening of the switching valves 11 and 12. In the first embodiment, the ECU 51 changes the opening degrees of both the switching valve 11 and the switching valve 12 with time according to a function f1 as shown in FIG. That is, control is performed so that the opening degree θ11 of the switching valve 11 and the opening degree θ12 of the switching valve 12 have the same value. Specifically, when the time after the start of switching is “t”, the ECU 51 controls the opening of the switching valve 11 so that “θ11 = f1 (t)” and “θ12 = f1 (t The opening degree of the switching valve 12 is controlled so that “ When controlled in this way, at time t12, the opening θ11 of the switching valve 11 and the opening θ12 of the switching valve 12 are both “90 (deg)”.

  The function f1 shown in FIG. 3 is an example, and the use of such a function f1 is not limited. When switching between the first intake passage 1a and the second intake passage 1b, the function used when controlling the opening degree of the switching valves 11 and 12 is adapted to each vehicle so that a supercharging pressure step does not occur. It is determined.

  Next, with reference to FIG. 4, the process performed when switching from the 1st intake passage 1a to the 2nd intake passage 1b in 1st Embodiment is demonstrated. This process is repeatedly executed by the ECU 51 at a predetermined cycle.

  First, in step S101, the ECU 51 determines whether or not there is a request to switch the passage for intake air from the first intake passage 1a to the second intake passage 1b. Specifically, it is determined whether or not a flag used for the switching (hereinafter referred to as “switching flag”) is on. This switching flag is set based on the state of the engine 7 (engine speed, etc.). For example, the switching flag is set to off at low to medium engine speeds, and the switching flag is set to on at high engine speeds.

  If the switching flag is on (step S101; Yes), the process proceeds to step S102. On the other hand, when the switching flag is not on (step S101; No), the process proceeds to step S106. In this case, the ECU 51 keeps the switching flag off (step S106). Then, the process ends.

  In step S102, the ECU 51 determines whether or not the time t after the start of switching is greater than “0”, that is, whether or not it is a positive value. If “t> 0” (step S102; Yes), the process proceeds to step S104. On the other hand, if “t> 0” is not satisfied (step S102; No), that is, if “t ≦ 0”, the process proceeds to step S103. In step S103, the ECU 51 sets time t after the start of switching to “0”. Then, the process proceeds to step S104.

  In step S104, the ECU 51 controls the opening degree of the switching valve 11 and the switching valve 12 according to a function f1 as shown in FIG. Specifically, the ECU 51 controls the opening degree of the switching valve 11 so that “θ11 = f1 (t)” and the opening degree of the switching valve 12 so that “θ12 = f1 (t)”. Control. Then, the process proceeds to step S105.

  In step S105, the ECU 51 determines whether or not both the opening θ11 of the switching valve 11 and the opening θ12 of the switching valve 12 are “90 (deg)”. That is, it is determined whether or not switching from the first intake passage 1a to the second intake passage 1b is completed. When “θ11 = θ12 = 90” (step S105; Yes), since the switching from the first intake passage 1a to the second intake passage 1b has been completed, the processing ends.

  On the other hand, when “θ11 = θ12 = 90” is not satisfied (step S105; No), the process proceeds to step S106. In this case, since the switching from the first intake passage 1a to the second intake passage 1b has not been completed, the ECU 51 keeps the switching flag off (S106). Then, the process ends.

  According to the first embodiment described above, it is possible to appropriately suppress the supercharging pressure step that can occur when switching from the first intake passage 1a to the second intake passage 1b.

In the above, the control performed when switching from the first intake passage 1a to the second intake passage 1b has been shown (see FIGS. 3 and 4), but when switching from the second intake passage 1b to the first intake passage 1a. The same control can be performed. For example, the opening degree of the switching valves 11 and 12 can be controlled by tracing back the function as shown in FIG. This also makes it possible to appropriately suppress the boost pressure step that can occur when switching from the second intake passage 1b to the first intake passage 1a.
[Second Embodiment]
Next, a second embodiment will be described. In the second embodiment, switching between the first intake passage 1a and the second intake passage 1b is performed using a switching valve constituted by a two-way valve instead of the switching valves 11 and 12 constituted by a three-way valve. This is different from the first embodiment.

(Device configuration)
FIG. 5 shows a schematic configuration of the intake air control device 102 for the internal combustion engine in the second embodiment. In the figure, solid arrows indicate an example of gas flow, and broken arrows indicate signal input / output. In addition, the same code | symbol is attached | subjected to the component same as the intake control device 101 (refer FIG. 1) of the internal combustion engine in 1st Embodiment, and the description is abbreviate | omitted.

  The intake control device 102 for the internal combustion engine is different from the intake control device 101 for the internal combustion engine in that it has switching valves 14 and 15 instead of the switching valves 11 and 12 and an ECU 52 instead of the ECU 51.

  The switching valve 14 is provided on the first intake passage 1 a upstream of the surge tank 4. The switching valve 15 is provided on the second intake passage 1b in the vicinity of the merging position on the downstream side of the first intake passage 1a and the second intake passage 1b. Preferably, the switching valve 15 is arranged as close to the intake manifold 6 as possible. This is to reduce the dead volume and increase the impulse charge effect.

  The switching valves 14 and 15 are configured as two-way valves. Basically, when the switching valve 14 is fully open, intake air tends to flow through the first intake passage 1a, and when the switching valve 14 is fully closed, intake air does not flow through the first intake passage 1a. In addition, basically, when the switching valve 15 is fully open, intake air tends to flow through the second intake passage 1b, and when the switching valve 15 is fully closed, intake air flows into the second intake passage 1b. Not flowing. Further, as described above, the first intake passage 1a has a smaller inner diameter than that of the second intake passage 1b. Therefore, the opening area of the switching valve 14 (meaning the opening area when fully opened) is the same. ) Is smaller than the fully open opening area of the switching valve 15. The switching valves 14 and 15 are controlled by control signals S14 and S15 supplied from the ECU 52 via actuators (not shown).

  The ECU 52 includes a CPU, a ROM, a RAM, and the like (not shown), and performs various controls on the components in the intake control device 102 of the internal combustion engine. In the present embodiment, the ECU 52 functions as the control means in the present invention, and controls the switching valves 14 and 15 to switch the passage through which the intake air flows to either the first intake passage 1a or the second intake passage 1b. Do.

(Control method)
Next, in the second embodiment, a control method that is performed when the passage for flowing the intake air is switched to one of the first intake passage 1a and the second intake passage 1b will be described. Also in the second embodiment, the ECU 52 controls the opening degree of the switching valves 14 and 15 so as to suppress a boost pressure step that may occur when switching between the first intake passage 1a and the second intake passage 1b. Specifically, the ECU 52 determines that the sum of the opening area of the switching valve 14 and the opening area of the switching valve 15 at the time of switching between the first intake passage 1 a and the second intake passage 1 b is the fully open opening area of the switching valve 14. The switching valves 14 and 15 are controlled so as to be substantially the same.

  With reference to FIG. 6, the control method of the switching valves 14 and 15 in 2nd Embodiment is demonstrated concretely. Here, a description will be given of a control method that is performed when switching the passage for intake air from the first intake passage 1a to the second intake passage 1b.

FIG. 6 shows the opening degree of the switching valve 14 on the upper side and the opening degree of the switching valve 15 on the lower side, and the horizontal axis indicates the time after the start of switching (time t21 is the time at the start of switching). Is shown). In the second embodiment, the ECU 52 switches the sum of the opening area of the switching valve 14 (hereinafter referred to as “S21”) and the opening area of the switching valve 15 (hereinafter referred to as “S22”). The switching valves 14 and 15 are controlled so as to be substantially the same as the fully open opening area of the valve 14 (hereinafter referred to as “S21 _max ”). That is, the switching valves 14 and 15 are controlled so that “S21 + S22 = S21 _max ”.

  Specifically, the ECU 52 controls the opening degree of the switching valve 14 according to the function f21 in FIG. 6 (control from fully open to fully closed) and controls the opening degree of the switching valve 15 according to the function f22 in FIG. Control from fully closed to fully open). Specifically, when the time after the start of switching is “t”, the ECU 52 controls the opening of the switching valve 14 so that “S21 = f21 (t)” and “S22 = f22 (t)”. The opening degree of the switching valve 15 is controlled so that

When controlled in this way, the switching valve 14 is fully closed at time t22. At this time t22, the opening area S22 of the switching valve 15 becomes “S21 _max ”. Then, at the subsequent time t23, the switching valve 15 is fully opened. That is, the opening area S22 of the switching valve 15 is “S22 _max ”.

  The functions f21 and f22 shown in FIG. 6 are examples, and the use of such functions f21 and f22 is not limited. When switching between the first intake passage 1a and the second intake passage 1b, the function used to control the opening degree of the switching valves 14 and 15 is adapted to each vehicle so as not to cause a boost pressure step. It is determined.

  Next, with reference to FIG. 7, the process performed when switching from the 1st intake passage 1a to the 2nd intake passage 1b in 2nd Embodiment is demonstrated. This process is repeatedly executed by the ECU 52 at a predetermined cycle.

  Since the processes of steps S201 to S203 and S206 are the same as the processes of steps S101 to S103 and S106 described above (see FIG. 4), description thereof will be omitted. Here, the processing in steps S204 and S205 will be described.

  In step S204, the ECU 52 controls the opening degree of the switching valve 14 according to a function f21 as shown in FIG. 6, and controls the opening degree of the switching valve 15 according to a function f22 as shown in FIG. Specifically, the ECU 52 controls the opening degree of the switching valve 14 so as to be “S21 = f21 (t)” and the opening degree of the switching valve 15 so as to be “S22 = f22 (t)”. Control. Then, the process proceeds to step S205.

In step S205, the ECU 52 determines whether the opening area S21 of the switching valve 11 is “0” and the opening area S22 of the switching valve 15 is “S21 _max ”. That is, it is determined whether or not switching from the first intake passage 1a to the second intake passage 1b is completed. When “S21 = 0” and “S22 = S21 _max ” (step S205; Yes), since the switching from the first intake passage 1a to the second intake passage 1b has been completed, the processing ends.

In contrast, if not "S21 = 0" and "S22 _{= S21 max"} (step S205; No), the process proceeds to step S206. In this case, since the switching from the first intake passage 1a to the second intake passage 1b has not been completed, the ECU 52 keeps the switching flag off (S206). Then, the process ends.

  Also according to the second embodiment described above, it is possible to appropriately suppress the boost pressure level difference that can occur when switching from the first intake passage 1a to the second intake passage 1b.

In the above, the control performed when switching from the first intake passage 1a to the second intake passage 1b has been shown (see FIGS. 6 and 7), but when switching from the second intake passage 1b to the first intake passage 1a. The same control can be performed. For example, the opening degree of the switching valves 14 and 15 can be controlled by tracing back the function as shown in FIG. This also makes it possible to appropriately suppress the boost pressure step that can occur when switching from the second intake passage 1b to the first intake passage 1a.
[Third Embodiment]
Next, a third embodiment will be described. In the third embodiment, instead of the switching valves 11 and 12 and the switching valves 14 and 15 described above, a switching valve constituted by an impulse valve (intake control valve) 5 and a two-way valve is used, and the first intake passage 1a. And the second intake passage 1b are different from the first and second embodiments in that they are switched.

(Device configuration)
FIG. 8 shows a schematic configuration of the intake air control device 103 for the internal combustion engine in the third embodiment. In the figure, solid arrows indicate an example of gas flow, and broken arrows indicate signal input / output. In addition, the same code | symbol is attached | subjected to the component same as the intake control device 101 (refer FIG. 1) of the internal combustion engine in 1st Embodiment, and the description is abbreviate | omitted.

  The intake control device 103 for the internal combustion engine is different from the intake control device 101 for the internal combustion engine in that it has a switching valve 17 instead of the switching valves 11 and 12 and an ECU 53 instead of the ECU 51.

  The switching valve 17 is provided on the second intake passage 1b in the vicinity of the merging position on the downstream side of the first intake passage 1a and the second intake passage 1b. Preferably, the switching valve 17 is disposed as close to the intake manifold 6 as possible. This is to reduce the dead volume and increase the impulse charge effect.

  The switching valve 17 is configured as a two-way valve. Basically, when the switching valve 17 is fully open, intake air tends to flow through the second intake passage 1b. When the switching valve 17 is fully closed, intake air does not flow through the second intake passage 1b. In addition, basically, when the impulse valve 5 is fully open, intake air tends to flow through the first intake passage 1a, and when the impulse valve 5 is fully closed, intake air flows through the first intake passage 1a. Absent. Furthermore, as described above, the first intake passage 1a is configured such that the inner diameter of the pipe is smaller than that of the second intake passage 1b. Therefore, the fully open opening area of the switching valve 17 is larger than the fully open opening area of the impulse valve 5. The switching valve 17 is controlled by a control signal S17 supplied from the ECU 53 via an actuator (not shown).

  The ECU 53 includes a CPU, a ROM, a RAM, and the like (not shown), and performs various controls on the components in the intake control device 103 of the internal combustion engine. In the present embodiment, the ECU 53 functions as control means in the present invention, and controls the impulse valve 5 and the switching valve 17 to switch the passage through which the intake air flows to either the first intake passage 1a or the second intake passage 1b. Take control.

(Control method)
Next, in the third embodiment, a control method that is performed when the passage for flowing the intake air is switched to one of the first intake passage 1a and the second intake passage 1b will be described. Also in the third embodiment, the ECU 53 controls the opening degree of the impulse valve 5 and the switching valve 17 so as to suppress a boost pressure step that may occur when switching between the first intake passage 1a and the second intake passage 1b. To do. Specifically, the ECU 53 determines that the sum of the opening area of the impulse valve 5 and the opening area of the switching valve 17 at the time of switching between the first intake passage 1 a and the second intake passage 1 b is the fully open opening area of the impulse valve 5. Are controlled with respect to the impulse valve 5 and the switching valve 17.

  With reference to FIG. 9, the control method of the impulse valve 5 and the switching valve 17 in 3rd Embodiment is demonstrated concretely. Here, a description will be given of a control method that is performed when switching the passage for intake air from the first intake passage 1a to the second intake passage 1b.

  FIG. 9 shows the opening degree of the impulse valve 5 on the upper side and the opening degree of the switching valve 17 on the lower side, and the horizontal axis shows the time after the start of switching (time t31 is the time at the start of switching). Is shown). In the third embodiment, first, the ECU 53 sets the impulse valve 5 to be fully open when there is a request to switch from the first intake passage 1a to the second intake passage 1b. Specifically, the ECU 53 sets the impulse valve 5 to be fully open when the impulse valve 5 is not fully opened at the time of the request. In FIG. 9, the impulse valve 5 is fully opened at time t32.

Thereafter, the ECU 53 sums the opening area of the impulse valve 5 (hereinafter referred to as “S31”) and the opening area of the switching valve 17 (hereinafter referred to as “S32”). The impulse valve 5 and the switching valve 17 are controlled so as to be substantially the same as the fully open opening area (hereinafter referred to as “S31 _max ”). In other words, the impulse valve 5 and the switching valve 17 are controlled so that “S31 + S32 = S31 _max ”.

  Specifically, the ECU 53 controls the opening degree of the impulse valve 5 (control from fully open to fully closed) according to the function f31 in FIG. 9 and controls the opening degree of the switching valve 17 according to the function f32 in FIG. Control from fully closed to fully open). Specifically, when the time after the start of switching is “t”, the ECU 53 controls the opening degree of the impulse valve 5 so that “S31 = f31 (t)” and “S32 = f32 (t)”. The opening degree of the switching valve 17 is controlled so that

When controlled in this way, the impulse valve 5 is fully closed at time t33. At the time t33, the opening area S32 of the switching valve 17 becomes “S31 _max ”. Then, at the subsequent time t34, the switching valve 17 is fully opened. That is, the opening area S32 of the switching valve 17 is “S32 _max ”.

  The functions f31 and f32 shown in FIG. 9 are examples, and the use of such functions f31 and f32 is not limited. When switching between the first intake passage 1a and the second intake passage 1b, the function used to control the opening degree of the impulse valve 5 and the changeover valve 17 is adapted to each vehicle so that a supercharging pressure step does not occur. Etc.

  Next, with reference to FIG. 10, the process performed when switching from the 1st intake passage 1a to the 2nd intake passage 1b in 3rd Embodiment is demonstrated. This process is repeatedly executed by the ECU 53 at a predetermined cycle.

  Since the process of step S301 is the same as the process of step S101 described above (see FIG. 4), description thereof is omitted.

  In step S302, the ECU 53 determines whether or not the impulse valve 5 is fully open. If the impulse valve 5 is fully open (step S302; Yes), the process proceeds to step S304. On the other hand, when the impulse valve 5 is not fully opened (step S302; No), the process proceeds to step S303. In this case, the ECU 53 performs control to fully open the impulse valve 5 (step S303). Then, the process ends.

  Since the processing of steps S304 and S305 is the same as the processing of steps S102 and S103 described above (see FIG. 4), the description thereof is omitted.

  In step S306, the ECU 53 controls the opening degree of the impulse valve 5 according to a function f31 as shown in FIG. 9, and controls the opening degree of the switching valve 17 according to a function f32 as shown in FIG. Specifically, the ECU 53 controls the opening degree of the impulse valve 5 so as to satisfy “S31 = f31 (t)” and the opening degree of the switching valve 17 so as to satisfy “S32 = f32 (t)”. Control. Then, the process proceeds to step S307.

In step S307, the ECU 53 determines whether or not the opening area S31 of the impulse valve 5 is “0” and the opening area S32 of the switching valve 17 is “S31 _max ”. That is, it is determined whether or not switching from the first intake passage 1a to the second intake passage 1b is completed. When “S31 = 0” and “S32 = S31 _max ” (step S307; Yes), since the switching from the first intake passage 1a to the second intake passage 1b has been completed, the processing ends.

On the other hand, when “S31 = 0” and “S32 = S31 _max ” are not satisfied (step S307; No), the process proceeds to step S308. In this case, since the switching from the first intake passage 1a to the second intake passage 1b has not been completed, the ECU 53 maintains the switching flag off (S308). Then, the process ends.

  Also according to the third embodiment described above, it is possible to appropriately suppress the boost pressure level difference that can occur when switching from the first intake passage 1a to the second intake passage 1b.

  In the above description, the control performed when switching from the first intake passage 1a to the second intake passage 1b has been described (see FIGS. 9 and 10), but when switching from the second intake passage 1b to the first intake passage 1a. The same control can be performed. For example, the opening degree of the impulse valve 5 and the switching valve 17 can be controlled by tracing back the function as shown in FIG. This also makes it possible to appropriately suppress the boost pressure step that can occur when switching from the second intake passage 1b to the first intake passage 1a.

DESCRIPTION OF SYMBOLS 1 Intake passage 1a 1st intake passage 1b 2nd intake passage 2 Turbocharger 3 Intercooler 4 Surge tank 5 Impulse valve 6 Intake manifold 7 Engine 8 Exhaust manifold 9 Exhaust passage 11, 12, 14, 15, 17 Switching valve 51, 52 53 ECU
101, 102, 103 Intake control device for internal combustion engine

Claims (2)

Two intake passages provided on the intake passage from the turbocharger to the cylinder of the internal combustion engine;
An intake control valve provided on any one of the two intake passages;
A first switching valve and a second switching valve respectively provided at an upstream merging position and a downstream merging position in the two systems of intake passages;
When the passage for intake air is switched to one of the two intake passages, the temporal change in opening of the first switching valve and the second switching valve is substantially the same. And an intake control device for an internal combustion engine, comprising: control means for controlling the first switching valve and the second switching valve. Two intake passages provided on the intake passage from the turbocharger to the cylinder of the internal combustion engine;
An intake control valve provided on any one of the two intake passages;
A switching valve provided in a vicinity of a downstream merging position in the two intake passages and provided on a passage different from the passage provided with the intake control valve in the two intake passages;
When the passage for intake air is switched to one of the two passages of the two systems, the sum of the opening area of the intake control valve and the opening area of the switching valve is the total opening of the intake control valve. And an intake control device for controlling the intake control valve and the switching valve so as to be substantially the same as the opening area at the time.

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