JP2018091167A - Internal Combustion Engine System - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an internal combustion engine system which is constructed to efficiently treating gas generated in a vehicle.SOLUTION: An internal combustion engine system 10 includes an intake pipe IP, a supercharger CH provided in the intake pipe IP, a first valve 54 provided in the intake pipe IP at its upstream side further than the supercharger CH, a second valve TV provided in the intake pipe IP at its downstream side further than the supercharger CH, a gas pipe 32 connected to the intake pipe IP between the first valve 54 and the supercharger CH, and a third valve 34 provided in the gas pipe 32. Air to be supplied to an internal combustion engine EN passes through the intake pipe IP. The first valve 54 controls the supply amount of the air to the supercharger CH. The second valve TV controls the intake amount of the internal combustion engine EN. Though the gas pipe 32, gas generated in the vehicle passes. The third valve 34 controls the supply amount of the gas to the intake pipe IP.SELECTED DRAWING: Figure 1

Description

  The present specification relates to an internal combustion engine system. In particular, the present invention relates to an internal combustion engine system provided with a supercharger.

  Patent Document 1 discloses an internal combustion engine system provided with a supercharger. In the internal combustion engine system of Patent Document 1, valves are provided in the intake pipe both upstream and downstream of the supercharger. Patent Document 1 improves the responsiveness of the supercharger by changing the opening timing of the upstream valve and the downstream valve of the supercharger.

Japanese Patent Application Laid-Open No. 11-229884

  Gas generated in a vehicle may be introduced into an intake pipe and processed by an internal combustion engine. However, in the internal combustion engine system in which valves are arranged both upstream and downstream of the supercharger, the technology for treating the generated gas has not been sufficiently established. In addition, Patent Document 1 also has no description regarding treatment of gas generated in a vehicle. The present specification discloses an internal combustion engine system having a structure for efficiently processing gas generated in a vehicle.

  In an internal combustion engine system including a supercharger, the pressure in the intake pipe varies depending on the position. The inventor paid attention to the pressure in the intake pipe and studied the position where the gas generated in the vehicle is supplied, and found a structure for efficiently processing the generated gas. An internal combustion engine system disclosed in this specification includes an intake pipe, a supercharger provided in the intake pipe, a first valve provided in the intake pipe upstream of the supercharger, and a supercharger A second valve provided in the intake pipe on the downstream side, a gas pipe connected to the intake pipe between the first valve and the supercharger, and a third valve provided in the gas pipe ing. Air supplied to the internal combustion engine passes through the intake pipe. The first valve controls the amount of air supplied to the supercharger. The second valve controls the intake amount of the internal combustion engine. The gas generated in the vehicle passes through the gas pipe. The third valve controls the gas supply amount to the intake pipe.

  As used herein, “gas generated in the vehicle” includes “evaporated fuel gas” in which the fuel in the fuel tank has evaporated, “exhaust gas” from the internal combustion engine, and “blow-by gas” that has leaked from the combustion chamber of the internal combustion engine. Or the like. These “gases” are supplied from the gas pipe to the intake pipe and processed by the internal combustion engine.

In the internal combustion engine system, the first valve, the supercharger, and the second valve are provided in this order from the atmosphere side (upstream) to the internal combustion engine (downstream) in the intake pipe. Upstream from the first valve, the intake pipe is at atmospheric pressure. Between the first valve and the supercharger, the intake pipe has a negative pressure or an atmospheric pressure depending on the state of the first valve and the supercharger. In the downstream of the supercharger, the inside of the intake pipe changes between a negative pressure and a positive pressure in accordance with the state of the supercharger or the second valve. In the internal combustion engine, the gas pipe is connected between the first valve and the supercharger. That is, the gas pipe is connected to the intake pipe at a position where the inside of the intake pipe does not become a positive pressure and the inside of the intake pipe can be adjusted to a negative pressure. Gas generated in the vehicle can be efficiently introduced into the intake pipe. In addition, it may become a negative pressure downstream from the supercharger depending on the state of the second valve. However, there may be a positive pressure downstream from the supercharger, and if the gas pipe is connected downstream from the supercharger, the generated gas may not easily flow to the intake pipe.

1 shows an internal combustion engine system according to a first embodiment. 2 shows an internal combustion engine system according to a second embodiment. 3 shows an internal combustion engine system according to a third embodiment. 2 shows a timing chart of the operation of the internal combustion engine system. 2 shows a timing chart of the operation of the internal combustion engine system. The flowchart of the abnormality detection method based on valve opening is shown. The flowchart of the abnormality detection method based on an air flow rate is shown. The flowchart of the abnormality detection method based on the pressure in an intake pipe is shown. 2 shows a timing chart of the operation of the internal combustion engine system. 2 shows a timing chart of the operation of the internal combustion engine system. The flowchart of the abnormality detection method based on the pressure in an intake pipe is shown.

  The main features of the internal combustion engine system disclosed in this specification are listed below. Note that the technical elements described below are independent technical elements, and exhibit technical usefulness alone or in various combinations.

  This specification discloses the internal combustion engine system provided with the supercharger. The internal combustion engine system includes an intake pipe through which air supplied to the internal combustion engine passes, a supercharger provided in the intake pipe, and an intake pipe provided upstream of the supercharger. A first valve that controls the amount of air supplied to the supercharger, a second valve that is provided in the intake pipe downstream of the supercharger and controls the intake amount of the internal combustion engine, and a first valve; A gas pipe that is connected to the intake pipe with the turbocharger and through which gas generated in the vehicle passes, and a third valve that is provided in the gas pipe and controls the amount of gas supplied to the intake pipe are provided. ing.

  The internal combustion engine system may include an air cleaner. The air cleaner may be disposed at the upstream end of the intake pipe. The air cleaner has an air filter, and can prevent foreign matter from flowing into the intake pipe.

  The internal combustion engine system may include an air flow meter (flow meter). The amount of air (outside air) introduced into the intake pipe (introduced into the internal combustion engine) can be measured. As the air flow meter, a flap method, a hot wire method, a Kalman flow method, or the like can be used. The air flow meter may be disposed upstream or downstream of the first valve. When the internal combustion engine system includes an air cleaner, the air flow meter may be integrated with the air cleaner or may be separate from the air cleaner. In the case of a separate body, the air flow meter may be provided in the intake pipe between the air cleaner and the first valve (that is, upstream of the first valve).

  The internal combustion engine system may include a pressure gauge (pressure sensor) that measures the pressure in the intake pipe. The pressure gauge may be provided in the intake pipe between the first valve and the supercharger. By providing the pressure gauge, the pressure in the intake pipe at the portion (between the first valve and the supercharger) to which the gas pipe is connected can be measured. Further, by adjusting the opening degree of the first valve, the pressure in the intake pipe at the portion to which the gas pipe is connected can be controlled to a predetermined control pressure. Hereinafter, the inside of the intake pipe between the first valve and the supercharger (portion to which the gas pipe is connected) may be referred to as a pressure control unit. It can be said that the above gas pipe is connected to the pressure control unit of the intake pipe. The pressure gauge may be a resistance wire type, a capacitance type, a mechanical type, or the like.

  The first valve may change the opening according to the opening of the third valve, and maintain the pressure in the intake pipe between the first valve and the supercharger at the control pressure. Specifically, when the third valve is turned on (the opening degree is increased) and gas is supplied from the gas pipe to the intake pipe, the first valve does not change the pressure of the pressure control unit. The opening may be reduced. Alternatively, when the third valve is turned off (the opening degree becomes small) and the gas supply from the gas pipe to the intake pipe is stopped, the first valve has an opening degree so that the pressure of the pressure control unit does not change. May be increased.

  The internal combustion engine system may include a control device that controls the supercharger, the first valve, the second valve, and the third valve. The control device may control the supercharger, the first valve, the second valve, and the third valve so that the pressure of the pressure control unit becomes a predetermined control pressure.

  The internal combustion engine system can detect an abnormality (gas pipe omission, breakage (gas leakage), clogging, etc.) of the gas pipe based on the state of the first valve (open / close state) and the state of the third valve. That is, when the opening degree of the third valve changes (when the gas flow in the gas pipe changes), the phenomenon that should occur due to the state of the first valve, and when the opening degree of the third valve changes. The presence or absence of an abnormality in the gas pipe can be determined based on the phenomenon that has actually occurred. The determination of the presence or absence of an abnormality in the gas pipe can also be performed by the above-described control device.

  The internal combustion engine system includes an opening of the first valve that should maintain the control pressure of the pressure control unit when the opening of the third valve changes, and an actual first valve when the opening of the third valve changes. The presence or absence of an abnormality in the gas pipe can be determined based on the opening degree.

  Specifically, when the third valve changes from the closed state to the open state (OFF → ON), gas is supplied from the gas pipe to the intake pipe (pressure control unit). In order to maintain the control pressure of the pressure control unit, it is necessary to limit the introduction of external air into the intake pipe. That is, it is necessary to reduce the intake amount by reducing the opening of the first valve. However, if an abnormality occurs in the gas pipe, gas is not supplied from the gas pipe to the intake pipe (or gas is supplied but the gas supply amount is less than the original amount), so the control pressure of the pressure control unit is maintained. In order to do this, the opening degree of the first valve is larger than when it is normal (a state where no abnormality has occurred in the gas pipe). By comparing the original opening degree of the first valve when the third valve is open and the actual opening degree of the first bubble, it can be determined whether or not an abnormality has occurred in the gas pipe. Note that the presence or absence of an abnormality in the gas pipe can also be determined when the third valve changes from the open state to the closed state (ON → OFF).

  The internal combustion engine system can also determine whether there is an abnormality in the gas pipe based on the pressure change in the intake pipe (pressure adjusting unit) when the opening of the third valve changes. For example, when the gas pipe is disconnected, outside air is introduced into the intake pipe from the connection portion between the gas pipe and the intake pipe, regardless of whether the third valve is open or closed. Further, even if the third valve changes from the closed state to the open state, gas is not supplied from the gas pipe to the intake pipe. Therefore, when feedback control is performed on the pressure of the pressure adjusting unit, the pressure change of the pressure adjusting unit during the period until the pressure of the pressure adjusting unit becomes stable is smaller than that in the normal state. In addition, when the first valve is open-controlled, the opening degree of the first valve is reduced, so that the pressure of the pressure adjustment unit is smaller than that at the normal time. Therefore, by detecting the pressure change for a predetermined period after the third valve changes to the open state, or the pressure after the predetermined period elapses after the third valve changes to the open state, The presence or absence can be determined. Note that the presence or absence of an abnormality in the gas pipe can also be determined when the third valve changes from the open state to the closed state.

  The internal combustion engine system determines whether there is an abnormality in the gas pipe based on the flow rate of air that should pass through the first valve when the opening degree of the third valve changes and the actual flow rate of air that passes through the first valve. You can also The actual air flow rate may be detected using the above-described air flow meter (flow meter), or calculated based on the opening degree of the first valve and the pressure in the pressure adjustment unit (inside the intake pipe downstream of the first valve). May be. When there is no abnormality in the gas pipe, the flow rate of the air passing through the first valve is reduced when the third valve is opened while the pressure of the pressure adjusting unit is maintained at a predetermined pressure. On the other hand, if an abnormality occurs in the gas pipe, the flow rate of the air passing through the first valve does not change even if the third valve is opened (or the flow rate reduction range is smaller than in the normal case). By detecting this difference, an abnormality in the gas pipe can be detected.

  The gas pipe may introduce gas evaporated in the fuel tank (hereinafter sometimes referred to as purge gas) into the intake pipe, or recirculate a part of the exhaust gas of the internal combustion engine (hereinafter, referred to as “purge gas”). EGR (which may be referred to as exhaust gas recirculation) may be introduced into the intake pipe, or gas leaked from the combustion chamber of the internal combustion engine (hereinafter also referred to as blow-by gas) may be introduced into the intake pipe. It may be introduced.

  In the internal combustion engine system disclosed in this specification, at least one of a gas pipe for purge gas, a gas pipe for EGR, and a gas pipe for blow-by gas is provided in the intake pipe between the first valve and the supercharger. It only has to be connected. In the internal combustion engine system, two or more of the gas pipes may be connected to the intake pipe between the first valve and the supercharger.

(First embodiment)
An internal combustion engine system 10 will be described with reference to FIG. The internal combustion engine system 10 includes a fuel supply system 2 and an evaporated fuel processing device 8. The internal combustion engine system 10 is mounted on a vehicle such as an automobile. The evaporated fuel processing device 8 is connected to the fuel supply system 2 that supplies the fuel stored in the fuel tank FT to the engine EN.

  The fuel supply system 2 supplies fuel injected from a fuel pump (not shown) accommodated in the fuel tank FT to the injector IJ. The injector IJ has an electromagnetic valve whose opening degree is adjusted by an ECU (abbreviation of engine control unit) 100 described later. The injector IJ injects fuel into the engine EN.

  An intake pipe IP and an exhaust pipe EP are connected to the engine EN. The intake pipe IP is a pipe for supplying air to the engine EN by the negative pressure of the engine EN or the operation of the supercharger CH. A throttle valve TV is disposed in the intake pipe IP. The throttle valve TV is an example of a second valve. The throttle valve TV is disposed downstream of the supercharger CH and upstream of the intake manifold IM. The amount of air flowing into the engine EN is controlled by adjusting the opening of the throttle valve TV. That is, the throttle valve TV controls the intake amount of the engine EN. The throttle valve TV is controlled by the ECU 100.

  A supercharger CH is arranged upstream of the throttle valve TV of the intake pipe IP. The supercharger CH is a so-called turbocharger, and rotates the turbine by the gas exhausted from the engine EN to the exhaust pipe EP, whereby the air in the intake pipe IP is pressurized and supplied to the engine EN. The supercharger CH is controlled by the ECU 100 to operate when the rotational speed N of the engine EN exceeds a predetermined rotational speed (for example, 2000 rotations).

  An upstream throttle valve 54 is disposed upstream of the supercharger CH of the intake pipe IP. The upstream throttle valve 54 is an example of a first valve. The upstream throttle valve 54 controls the amount of intake air supplied to the supercharger CH. By adjusting the opening degree of the upstream throttle valve 54, the pressure in the intake pipe IP between the upstream throttle valve 54 and the supercharger CH can be controlled. Hereinafter, the inside of the intake pipe IP between the upstream throttle valve 54 and the supercharger CH is referred to as a pressure control unit 56. The pressure controller 56 is provided with a pressure gauge 58. The detection value of the pressure gauge 58 is transmitted to the ECU 100. The pressure of the pressure control unit 56 is controlled by the ECU 100.

  An air cleaner AC is disposed upstream of the upstream throttle valve 54 of the intake pipe IP. The air cleaner AC has a filter that removes foreign substances from the air flowing into the intake pipe IP. In the intake pipe IP, when the throttle valve TV is opened, the air passes through the air cleaner AC and is sucked into the engine EN. The engine EN burns fuel and air inside, and exhausts the exhaust pipe EP after combustion.

  The ECU 100 is connected to an air-fuel ratio sensor 50 disposed in the exhaust pipe EP. The ECU 100 detects the air-fuel ratio in the exhaust pipe EP from the detection result of the air-fuel ratio sensor 50, and controls the fuel injection amount from the injector IJ.

  The ECU 100 is connected to an air flow meter 52 disposed near the air cleaner AC. The air flow meter 52 is a so-called hot wire type aero flow meter, but may have other configurations. The ECU 100 receives a signal indicating the detection result from the air flow meter 52, and detects the amount of air supplied to the intake pipe IP (the amount of air passing through the upstream throttle valve 54).

  When the supercharger CH is stopped, negative pressure is generated in the intake manifold IM by driving the engine EN. In addition, when stopping the engine EN when the vehicle is stopped, or when the engine EN is stopped and the vehicle is driven by a motor like a hybrid vehicle, in other words, when the drive of the engine EN is controlled for environmental measures, the engine There is no or little negative pressure in the intake manifold IM due to the EN drive. On the other hand, in the situation where the supercharger CH is operating, the downstream side of the supercharger CH is positive pressure, and the upstream side of the supercharger CH is atmospheric pressure or negative pressure.

  The evaporated fuel processing device 8 supplies the evaporated fuel (purge gas) in the fuel tank FT to the engine EN via the intake pipe IP. The evaporated fuel processing apparatus 8 includes a canister 14, a pump 12, a gas pipe 32, and a purge control valve 34. The purge control valve 34 is an example of a third valve. The canister 14 adsorbs the evaporated fuel generated in the fuel tank FT. The canister 14 includes an activated carbon 14d and a case 14e that accommodates the activated carbon 14d. The case 14e has a tank port 14a, a purge port 14b, and an atmospheric port 14c. The tank port 14a is connected to the upper end of the fuel tank FT. As a result, the evaporated fuel in the fuel tank FT flows into the canister 14. The activated carbon 14d adsorbs evaporated fuel from the gas flowing from the fuel tank FT into the case 14e. Thereby, it is possible to prevent the evaporated fuel from being released into the atmosphere.

  The atmosphere port 14c communicates with the atmosphere via the air filter AF. The air filter AF removes foreign matter from the air flowing into the canister 14 through the atmospheric port 14c.

  The purge port 14 b communicates with the gas pipe 32. The gas pipe 32 includes a first hose 22 and a second hose 26. The first hose 22 connects the canister 14 and the pump 12, and the second hose 26 connects the pump 12 and the intake pipe IP. The second hose 26 (gas pipe 32) is connected to the intake pipe IP between the upstream throttle valve 54 and the supercharger CH. That is, the second hose 26 is connected to the pressure control unit 56. The first and second hoses 22 and 26 are made of a flexible material such as rubber or resin.

  The purge gas in the canister 14 flows from the canister 14 into the first hose 22 through the purge port 14b. The purge gas in the first hose 22 is supplied into the intake pipe IP (pressure control unit 56) on the upstream side of the supercharger CH via the pump 12, the purge control valve 34, and the second hose 26.

  The pump 12 is disposed between the canister 14 and the intake pipe IP. The pump 12 is a so-called vortex pump (also called a cascade pump or a Wesco pump) or a centrifugal pump. The pump 12 is controlled by the ECU 100. The suction port of the pump 12 communicates with the canister 14 via the first hose 22.

  The discharge port of the pump 12 is connected to the second hose 26. A purge control valve 34 is provided on the second hose 26. The second hose 26 is connected to the intake pipe IP.

  After removing the second hose 26 from the intake pipe IP for maintenance or the like, there is a case where the user forgets to attach it again or the second hose 26 falls off the intake pipe IP during traveling. The internal combustion engine system 10 can detect whether or not the second hose 26 is connected to the intake pipe IP, as will be described later. The internal combustion engine system 10 can also detect whether or not the gas pipe 32 is clogged.

  A purge control valve 34 is arranged on the second hose 26. The purge control valve 34 is an example of a third valve. When the purge control valve 34 is closed, the purge gas is stopped by the purge control valve 34 and does not flow to the second hose 26. On the other hand, when the purge control valve 34 is opened, the purge gas passes through the second hose 26 and flows into the intake pipe IP. The purge control valve 34 is an electronic control valve and is controlled by the ECU 100.

  The ECU 100 includes a control unit 102 that controls the internal combustion engine system 10. The control unit 102 is disposed integrally with another part of the ECU 100 (for example, a part that controls the engine EN). Control unit 102 may be arranged separately from other parts of ECU 100. The control unit 102 includes a CPU and a memory such as a ROM and a RAM. The control unit 102 controls the internal combustion engine system 10 according to a program stored in advance in the memory. Specifically, the control unit 102 outputs a signal to the pump 12 to control the pump 12. Further, the control unit 102 operates the throttle valve TV and the upstream throttle valve 54, outputs a signal to the purge control valve 34, and executes duty control. The control unit 102 adjusts the valve opening time of the purge control valve 34 by adjusting the duty ratio of the signal output to the purge control valve 34.

(Second embodiment)
The internal combustion engine system 210 will be described with reference to FIG. About the internal combustion engine system 210, about the same structure as the internal combustion engine system 10, description may be abbreviate | omitted by attaching | subjecting the same reference number. The internal combustion engine system 210 includes a fuel supply system 2 and an exhaust gas recirculation device (EGR system) 208. The exhaust gas recirculation device 208 is connected between the exhaust pipe EP and the intake pipe IP, and circulates a part of the exhaust gas of the engine EN from the exhaust pipe EP to the intake pipe IP. The internal combustion engine system 210 may include the evaporated fuel processing device 8 (see FIG. 1) in addition to the exhaust gas recirculation device 208.

  The exhaust gas recirculation device 208 includes a gas pipe 232 and an EGR control valve 234. The EGR control valve 234 is an example of a third valve. The gas pipe 232 communicates the exhaust pipe EP and the intake pipe IP. Specifically, one end of the gas pipe 232 is connected to the exhaust pipe EP. The other end of the gas pipe 232 is connected to the intake pipe IP (pressure control unit 56) between the upstream throttle valve 54 and the supercharger CH.

  When the EGR control valve 234 is in the closed state, the exhaust gas is stopped by the EGR control valve 234 and is not introduced into the pressure control unit 56. If the EGR control valve 234 is opened while the pressure control unit 56 is at a negative pressure, the exhaust gas flows into the intake pipe IP (pressure control unit 56). The EGR control valve 234 is an electronic control valve and is controlled by the control unit 102 of the ECU 100.

(Third embodiment)
The internal combustion engine system 310 will be described with reference to FIG. About the internal combustion engine system 310, about the structure same as the internal combustion engine system 10 or 210, description may be abbreviate | omitted by attaching | subjecting the same reference number. The internal combustion engine system 310 includes a fuel supply system 2 and a blow-by gas processing device 308. The blow-by gas processing device 308 is connected between the engine EN and the intake pipe IP, and circulates gas (blow-by gas) leaking from the combustion chamber of the engine EN to the intake pipe IP. The internal combustion engine system 310 may include the evaporated fuel processing device 8 (see FIG. 1) and / or the exhaust gas recirculation device 208 (see FIG. 2) in addition to the blow-by gas processing device 308.

  The blow-by gas processing device 308 includes a gas pipe 332 and a PCV valve (Positive Crankcase Ventilation Valve) 334. The PCV valve 334 is an example of a third valve. One end of the gas pipe 332 is connected to the lower part of the engine EN. The other end of the gas pipe 332 is connected to the intake pipe IP (pressure control unit 56) between the upstream throttle valve 54 and the supercharger CH. When the PCV valve 334 is in a closed state, the blow-by gas is stopped by the PCV valve 334 and is not introduced into the pressure control unit 56. When the PCV valve 334 is opened while the pressure control unit 56 is at negative pressure, blow-by gas flows into the intake pipe IP (pressure control unit 56). The PCV valve 334 is an electronic control valve and is controlled by the control unit 102 of the ECU 100.

  In the first to third embodiments, the internal combustion engine systems 10, 210, and 310 are common in that gas pipes 32, 232, and 332 are connected between the upstream throttle valve (first valve) 54 and the supercharger CH. It has the characteristics of The internal combustion engine systems 10, 210, and 310 have a common feature that the third valves 34, 234, and 334 are disposed on the gas pipes 32, 232, and 332. In the internal combustion engine systems 10, 210, and 310, it is possible to determine whether or not an abnormality has occurred in the gas pipes 32, 232, and 332 by performing the control described below. Hereinafter, a method for determining whether or not the gas pipe 32 is abnormal in the internal combustion engine system 10 will be described. However, the method described below can also be applied to the internal combustion engine systems 210 and 310.

  With reference to FIGS. 4 and 5, the operation of the internal combustion engine system 10 will be described by comparing the state in which the gas pipe 32 is normal and the state in which the gas pipe 32 is abnormal. 4 and 5 show a form in which the pressure of the pressure control unit 56 is feedback-controlled. FIG. 4 shows a comparison between a state where the gas pipe 32 is normally connected to the intake pipe IP and a state where the gas pipe 32 is disconnected from the intake pipe IP. FIG. 5 shows a comparison between a normal state of the gas pipe 32 and a state where the gas pipe 32 is clogged. In FIGS. 4 and 5, the normal state is indicated by a solid line, and the state where an abnormality has occurred is indicated by a broken line.

  First, the state in which the gas pipe 32 is normal (the state in which no abnormality has occurred in the gas pipe 32) in the embodiment in which the pressure of the pressure control unit 56 is feedback-controlled will be described with reference to FIGS. As shown in FIGS. 4 and 5, after the engine EN is started (timing t0), when the engine speed, the engine load factor, the amount of gas flowing into the intake pipe IP, and the like become stable (timing t1), the pressure gauge 58 Based on the measured pressure, the opening degree of the first valve (upstream throttle valve) 54 (the amount of air passing through the first valve) is adjusted, and the pressure of the pressure control unit 56 is adjusted to the control pressure. Note that the timing t0 is not limited to the start of the engine EN, but includes a state in which the engine speed, the load factor, the amount of gas flowing into the intake pipe IP, and the like change and the pressure of the pressure control unit 56 is not stable.

  (E) When the third valve (purge control valve) 34 opens at timing t2, (d) purge gas starts to be supplied from the evaporated fuel processing device 8 to the intake pipe IP, and the purge gas flow rate becomes constant after a predetermined time (timing t2). ~ T2a). At timings t2 to t2a, in order to feedback control the pressure control unit 56 to the control pressure, (c) the opening degree of the first valve 54 is reduced, and (b) the flow rate of outside air (air) supplied to the intake pipe IP. Reduce. When the purge gas starts to be supplied to the intake pipe IP, (a) the pressure of the pressure control unit 56 increases for a predetermined time (timing t2 to t2a), but feedback control is performed (the opening degree of the first valve 54 is reduced). Thus, the control pressure is maintained after timing t2a.

  When the third valve 34 is closed at the timing t3, the supply of the purge gas to the intake pipe IP is stopped (timing t3 to t3a). At timings t3 to t3a, in order to feedback control the pressure control unit 56 to the control pressure, the opening degree of the first valve 54 is increased, and the outside air (air) supplied to the intake pipe IP through the first valve 54 is supplied. Increase the flow rate. Since the supply of the purge gas is stopped, the pressure of the pressure control unit 56 decreases for a predetermined time (timing t3 to t3a), but by performing feedback control (increasing the opening degree of the first valve 54), after the timing t3a Maintained at control pressure. At timings t4 to t4a, the same adjustment as at timings t2 to t2a is performed, and at timings t5 to t5a, the same adjustment as at timings t3 to t3a is performed.

  Next, a state where the gas pipe 32 is removed from the intake pipe IP will be described with reference to FIG. When the gas pipe 32 is removed from the intake pipe IP, outside air is supplied to the intake pipe IP from the connection portion between the gas pipe 32 and the intake pipe IP regardless of whether the third valve 34 is opened or closed. Therefore, in order to control the pressure control unit 56 to the control pressure, the opening degree of the first valve 54 is smaller than the opening degree at the normal time, and the flow rate of the outside air that passes through the first valve 54 and is supplied to the intake pipe IP is also Less (timing t1 to t2).

  When the third valve 34 opens at the timing t2, the flow rate of the purge gas passing through the gas pipe 32 increases, and the purge gas flow rate becomes constant after a predetermined time (timing t2 to t2a). As in the normal state, the opening degree of the first valve 54 is reduced to maintain the pressure control unit 56 at the control pressure, and the flow rate of the outside air supplied to the intake pipe IP is reduced. However, even if the third valve 34 is opened, the purge gas is not supplied to the intake pipe IP. Therefore, the pressure of the pressure control unit 56 decreases by the amount that the opening degree of the first valve 54 is reduced during the timing t2 to t2a. However, since the purge gas is not supplied to the intake pipe IP, the amount of change in pressure (absolute value) is smaller than that in the normal state. Further, since feedback control is performed (the opening degree of the first valve 54 is restored), after the timing t2a, before the flow rate of the outside air passing through the first valve 54 opens the third valve 34 (before timing t2). Returning, the pressure control unit 56 is maintained at the control pressure.

  When the third valve 34 is closed at the timing t3, the opening degree of the first valve 54 increases, and the flow rate of the outside air that passes through the first valve 54 and is supplied to the intake pipe IP increases (timing t3 to t3a). As the outside air supplied to the intake pipe IP increases, the pressure of the pressure control unit 56 increases. However, since the amount of outside air flowing in from the connection part of the intake pipe IP and the gas pipe 32 (the part from which the gas pipe 32 is removed) does not change, the amount of change in pressure (absolute value) is smaller than that in the normal state. Further, since feedback control is performed (the opening degree of the first valve 54 is restored), after the timing t3a, the flow rate of the outside air passing through the first valve 54 is before the third valve 34 is closed (before the timing t3). Returning, the pressure control unit 56 is maintained at the control pressure. Even when the gas pipe 32 is removed from the intake pipe IP, the same adjustment as the timing t2 to t2a is performed at the timing t4 to t4a, and the same adjustment as the timing t3 to t3a is performed at the timing t5 to t5a.

  As described above, when the pressure of the pressure control unit 56 is feedback controlled, the following features (1) to (3) are obtained when the gas pipe 32 is removed from the intake pipe IP. (1) When the third valve 34 is turned on → off (or off → off), the first valve before and after the state change of the third valve 34 (before the state change and after a predetermined time elapses after the state change). The opening of 54 does not change. (2) When the third valve 34 is turned on → off (or off → off), the flow rate of the outside air passing through the first valve 54 does not change before and after the state change of the third valve 34. (3) The amount of change in the pressure of the pressure control unit 56 within a predetermined time after the third valve 34 is turned on → off (or off → off) is smaller than that in the normal state.

  Next, a state where the gas pipe 32 is clogged will be described with reference to FIG. When the gas pipe 32 is clogged, the purge gas is not supplied to the intake pipe IP regardless of whether the third valve 34 is opened or closed. However, unlike the case where the gas pipe 32 is removed from the intake pipe IP, the outside air is not supplied to the intake pipe IP from the connection portion between the gas pipe 32 and the intake pipe IP. Therefore, when the third valve 34 is closed, the opening degree of the first valve 54 is the same as that at the normal time (timing t1 to t2).

  Even if the third valve 34 is opened at the timing t2, the purge gas does not pass through the gas pipe 32, and the purge gas is not supplied to the intake pipe IP. Therefore, in accordance with the operation of the third valve 34, the opening degree of the first valve 54 is reduced in order to maintain the pressure control unit 56 at the control pressure, and the first valve 54 passes through the first valve 54 and is supplied to the intake pipe IP. However, the opening degree of the first valve 34 is restored to the original by feedback control, and the flow rate of the outside air supplied to the intake pipe IP through the first valve 54 is also the original. (Timing t2a). That is, when the gas pipe 32 is clogged. Before and after opening and closing the third valve 34, the opening degree of the first valve 34 and the flow rate of the outside air passing through the first valve do not change. Further, similarly to the case where the gas pipe 32 is removed from the intake pipe IP, the purge gas does not flow into the intake pipe IP, so that the pressure control unit during the period until the pressure of the pressure control unit 56 becomes stable (timing t2 to t2a) The amount of change in the pressure 56 is small as compared with the normal time. Although detailed description is omitted, even when the third valve 34 is closed at the timing t3, the opening degree of the first valve 34 and the flow rate of the outside air passing through the first valve change before and after the third valve 34 is opened and closed. Without change, the amount of change in the pressure of the pressure control unit 56 during the period until the pressure of the pressure control unit 56 stabilizes (timing t3 to t3a) is smaller than that during normal operation. Even when the gas pipe 32 is clogged, the same characteristics as the characteristics (1) to (3) described above can be obtained.

  As described above, in the form in which the pressure of the pressure control unit 56 is feedback-controlled, when an abnormality occurs in the gas pipe 32, both when the gas pipe 32 comes out of the intake pipe IP and when the gas pipe 32 is clogged. In (3), the features (1) to (3) are confirmed as compared with the normal state. The internal combustion engine system 10 can determine whether or not an abnormality has occurred in the gas pipe 32 by detecting the features (1) to (3). Hereinafter, a procedure for determining whether or not the gas pipe 32 is abnormal will be described.

  FIG. 6 shows a procedure for determining whether there is an abnormality in the gas pipe 32 based on the opening degree of the first valve 54 when the state of the third valve 34 changes (ON → OFF or OFF → ON). ing. That is, the presence or absence of abnormality of the gas pipe 32 is determined using the feature (1). First, it is determined whether or not the pressure in the intake pipe IP (pressure control unit 56) can be controlled (step S2). That is, it is determined whether or not the state is after the timing t1 in FIGS. When the pressure of the pressure control unit 56 is not in a controllable state (step S2: NO), the process does not proceed to the next step and waits until the pressure of the pressure control unit 56 becomes stable (controllable).

  If the pressure in the intake pipe IP (pressure control unit 56) is in a controllable state (step S2: YES), is the condition for switching the state of the third valve 34 (ON → OFF or OFF → ON)? (Step S4, timing t2, t3, t4, t5). If it is not a condition for switching the state of the third valve 34 (step S4: NO), the process returns to step S2 without proceeding to the next step. When the condition is that the third valve 34 is switched (step S4: YES), the opening degree D1 of the first valve 54 before the third valve 34 is switched is read (step S6), and a predetermined time after the third valve 34 is switched. The opening degree D2 of the first valve 54 is detected (after timing t2a, t3a, t4a, t5a) (step S8). The predetermined times (t2 to t2a, t3 to t3a, t4t to 4a, t5 to t5a) are set to 0.2 to 1.5 seconds.

  Next, the determination valve opening D3 is read (step S12), and the absolute value of the difference between the opening D1 and the opening D2 is compared with the opening D3 (step S14). The determination valve opening is determined from Table 1 below according to the flow rate of the gas (purge gas) passing through the third valve 34. The “purge flow rate variation ΔQ” in Table 1 is, for example, the difference between the gas flow rate that flows after the timing t2a and the gas flow rate that flows before the timing t2 (zero flow rate) before and after the timing t2. Further, in the case before and after the timing t3, it is the difference between the gas flow rate flowing up to the timing t3 and the gas flow rate flowing after the timing t3a (zero flow rate). That is, when the third valve 34 changes from on to off, it is the gas flow rate before the state of the third valve 34 changes, and when the third valve 34 changes from off to on, the state of the third valve changes. This is the gas flow rate after the change.

  If the absolute value of the difference between the opening D1 and the opening D2 is greater than or equal to the opening D3 (step S14: YES), it is determined that no abnormality has occurred in the gas pipe 32 (step S18). On the other hand, if the absolute value of the difference between the opening D1 and the opening D2 is smaller than the opening D3 in step S14 (step S14: NO, it is determined that an abnormality has occurred in the gas pipe 32 (step S16). In addition, the internal combustion engine 10 can determine whether the gas pipe 32 is abnormal by comparing the opening degree of the first valve 56 before and after the opening and closing of the third valve 34.

  Referring to FIG. 7, whether there is an abnormality in the gas pipe 32 based on the change in the air flow rate passing through the first valve 54 when the state of the third valve 34 changes (ON → OFF or OFF → ON). The procedure for determining the will be described. That is, the presence or absence of abnormality of the gas pipe 32 is determined using the feature (2). First, it is determined whether or not the pressure in the intake pipe IP (pressure control unit 56) is controllable (step S22). When the pressure of the pressure control unit 56 is not in a controllable state (step S22: NO), the process does not proceed to the next step, but waits until the pressure of the pressure control unit 56 becomes stable (controllable).

  If the pressure in the intake pipe IP (pressure control unit 56) is in a controllable state (step S22: YES), is the condition for switching the state of the third valve 34 (ON → OFF or OFF → ON)? (Step S24, timing t2, t3, t4, t5). If it is not a condition for switching the state of the third valve 34 (step S24: NO), the process returns to step S22 without proceeding to the next step. When the condition is that the third valve 34 is switched (step S24: YES), the flow rate Q1 of the gas (outside air) that has passed through the first valve 54 before the third valve 34 is switched is read (step S26). The flow rate Q2 of the gas passing through the first valve 54 is detected after a predetermined time from the switching of 34 (after timing t2a, t3a, t4a, t5a) (step S28).

  The results detected by the air flow meter 52 can be used for the flow rates Q1 and Q2 (see FIG. 1). Alternatively, the flow rates Q1 and Q2 can be determined from the openings D1 and D2 of the first valve 54 (see also FIG. 6). For example, the flow rate Q1 is created by the difference between the pressure P1 of the pressure control unit 58 and the atmospheric pressure P0 (P1−P0) when the opening degree D1 is read in step S6 and the opening degree D1 is detected, as in FIG. It can be determined by a two-dimensional map (not shown) (Q1∝D1 × (P1-P0)). Similarly, the flow rate Q2 is a two-dimensional map (P2−P0) created by the opening degree D2 detected in step S8 and the difference (P2−P0) between the pressure P2 of the pressure control unit 58 and the atmospheric pressure P0 when the opening degree D2 is detected. (Not shown) can be determined (Q2∝D2 × (P2-P0)).

  Next, the determination flow rate Q3 is read (step S32), and the absolute value of the difference between the flow rate Q1 and the flow rate Q2 is compared with the determination flow rate Q3 (step S34). The determination flow rate Q3 is obtained by subtracting a predetermined value α from the flow rate change amount ΔQ of the gas (purge gas) passing through the third valve 34 (Q3 = ΔQ−α). The predetermined value α is set to a value smaller than the flow rate of the purge gas that passes through the third valve 34 when the third valve 34 is in the ON state. Specifically, the predetermined value α is 5 of the flow rate of the purge gas that passes through the third valve 34. ~ 15% of value, for example 0.3-0.7 L / min. Set to Theoretically, the flow rate variation ΔQ of the gas passing through the third valve 34 is equal to the absolute value of the difference between the flow rate Q1 and the flow rate Q2. The predetermined value α is a margin for not determining that the gas pipe 32 is in an abnormal state due to an error in the flow rate Q1, Q2 or the flow rate change amount ΔQ.

  If the absolute value of the difference between the flow rate Q1 and the flow rate Q2 is greater than or equal to the determination flow rate Q3 (step S34: YES), it is determined that no abnormality has occurred in the gas pipe 26 (step S38). On the other hand, when the absolute value of the difference between the flow rate Q1 and the flow rate Q2 is smaller than the determination flow rate Q3 (step S34: NO, it is determined that an abnormality has occurred in the gas pipe 32 (step S36). By comparing the flow rate of the gas passing through the first valve 56 before and after the opening and closing of the valve 34, the presence or absence of an abnormality in the gas pipe 32 can be determined.

  Referring to FIG. 8, a procedure for determining whether there is an abnormality in the gas pipe 32 based on the pressure change of the pressure control unit 56 when the state of the third valve 34 changes (ON → OFF or OFF → ON). Will be explained. That is, the presence or absence of abnormality of the gas pipe 32 is determined using the feature (3). First, it is determined whether or not the pressure in the intake pipe IP (pressure control unit 56) is controllable (step S42). If the pressure of the pressure control unit 56 is not in a controllable state (step S42: NO), the process does not proceed to the next step and waits until the pressure of the pressure control unit 56 becomes stable (controllable).

  If the pressure in the intake pipe IP (pressure control unit 56) is in a controllable state (step S42: YES), is the condition for switching the state of the third valve 34 (ON → OFF or OFF → ON)? (Step S44, timing t2, t3, t4, t5). If it is not a condition for switching the state of the third valve 34 (step S44: NO), the process returns to step S42 without proceeding to the next step. If the condition is that the third valve 34 is switched (step S44: YES), the pressure P1 of the pressure control unit 56 before the third valve 34 is switched is read (step S46), and within a predetermined time after the third valve 34 is switched ( At the timings t2 to t2a, t3 to t3a, t4 to t4a, t5 to t5a), the maximum pressure or the minimum pressure P2 of the pressure controller 56 is detected (step S48). Specifically, when the third valve 34 is switched from OFF to ON (timing t2, t4), the minimum pressure P2 within a predetermined time (timing t2 to t2a, t4 to t4a) is detected. When the third valve 34 is switched from on to off (timing t3, t5), the maximum pressure P2 within a predetermined time (timing t3 to t3a, t5 to t5a) is detected.

  Next, the determination pressure P4 is read (step S52), and the absolute value of the difference between the pressure P1 and the pressure P2 is compared with the determination pressure P4 (step S54). The determination pressure P4 is determined from Table 2 below according to the flow rate of the gas (purge gas) passing through the third valve 34.

  If the absolute value of the difference between the pressure P1 and the pressure P2 is greater than or equal to the determination pressure P4 (step S54: YES), it is determined that no abnormality has occurred in the gas pipe 32 (step S58). On the other hand, when the absolute value of the difference between the pressure P1 and the pressure P2 is smaller than the determination pressure P4 (step S54: NO, it is determined that an abnormality has occurred in the gas pipe 32 (step S58). The internal combustion engine 10 is a third valve. By comparing the magnitude of the pressure fluctuation of the pressure control unit 56 within a predetermined time after the opening and closing of 34, the presence or absence of abnormality of the gas pipe 32 can be determined.

  Next, the operation of the internal combustion engine system 10 will be described with reference to FIGS. 9 and 10 by comparing the state in which the gas pipe 32 is normal and the state in which the gas pipe 32 is abnormal. 9 and 10 show a form in which the first valve 54 is open-controlled (the pressure of the pressure control unit 56 is not feedback-controlled). FIG. 9 shows a comparison between a state where the gas pipe 32 is normally connected to the intake pipe IP and a state where the gas pipe 32 is disconnected from the intake pipe IP. FIG. 10 shows a comparison between a normal state of the gas pipe 32 and a state where the gas pipe 32 is clogged.

  As shown in FIGS. 9 and 10, in a normal state (a state where no abnormality has occurred in the gas pipe 32), the opening degree of the first valve 34 and the air flow rate passing through the first valve 34 perform feedback control. (See also FIGS. 4 and 5). Further, since the first valve 54 is controlled to open, (c) the opening degree of the first valve 54 and (b) the flow rate of the outside air passing through the first valve 54 are the same during normal operation and abnormal operation. When the first valve 54 is subjected to open control, (a) the pressure of the pressure control unit 56 is different between normal and abnormal.

  As shown in FIG. 9, when the gas pipe 32 is removed from the intake pipe IP, the outside air is introduced into the intake pipe IP (pressure control) from the connection portion between the gas pipe 32 and the intake pipe IP regardless of whether the third valve 34 is opened or closed. Part 56). Therefore, when the third valve 34 is closed, the measured pressure of the pressure control unit 56 is higher than normal (control pressure) (after timing t11 to t12, t13 to t14, t15). In other words, the control pressure cannot be maintained when the third valve 34 is closed. On the other hand, when the third valve 34 is opened, since the purge gas flows into the intake pipe IP at normal times, the opening degree of the first valve 34 becomes small. As a result, the pressure of the pressure control unit 56 after a predetermined time has elapsed is substantially equal to that at the normal time, and the control pressure is maintained (timing t12a to t13, t14a to t15). That is, when the first valve 54 is open-controlled, if the gas pipe 32 is removed from the intake pipe IP, the control pressure cannot be maintained when the third valve 34 is in the OFF state, and when the third valve 34 is in the ON state. Control pressure can be maintained. When the third valve 34 is turned on → off (or off → off), the measured pressure of the pressure control unit 56 is shifted before and after the state change of the third valve 34 (feature (4)).

  Next, a state where the gas pipe 32 is clogged will be described with reference to FIG. When the gas pipe 32 is clogged, the purge gas is not supplied to the intake pipe IP regardless of whether the third valve 34 is opened or closed. Further, outside air is not supplied to the intake pipe IP from the connection portion between the gas pipe 32 and the intake pipe IP. Therefore, when the third valve 34 is closed, the pressure of the pressure control unit 56 is equal to that in the normal state, and the control pressure is maintained (timing t11 to t12, t13a to t14, and after t15a). On the other hand, when the third valve 34 is opened, since the purge gas flows into the intake pipe IP at normal times, the opening degree of the first valve 34 becomes small. As a result of the decrease in the air flow rate passing through the first valve 34, the pressure of the pressure control unit 56 becomes smaller than normal, and the control pressure cannot be maintained (timing t12 to t13, t14 to t15). When the gas pipe 32 is clogged, the period during which the pressure control unit 56 can be maintained at the control pressure is opposite to the period during which the pressure control unit 56 cannot be maintained compared to the case where the gas pipe 32 is removed from the intake pipe IP. . Although the period during which the control pressure can be maintained is different, the common feature of “the measured pressure of the pressure control unit 56 deviates before and after the state change of the third valve 34” described in the above feature (4) is obtained. Hereinafter, a procedure for determining whether or not the gas pipe 32 is abnormal using the feature (4) will be described.

  Referring to FIG. 11, a procedure for determining whether there is an abnormality in the gas pipe 32 based on the pressure change of the pressure control unit 56 when the state of the third valve 34 changes (ON → OFF or OFF → ON). Will be explained. First, it is determined whether or not the pressure in the intake pipe IP (pressure control unit 56) can be controlled (step S62). If the pressure in the intake pipe is not in a controllable state (timing t0 to t11, step S62: NO), the process does not proceed to the next step and waits until the pressure of the pressure control unit 56 becomes stable (controllable).

  When the pressure in the intake pipe IP (pressure control unit 56) is in a controllable state (step S62: YES, timing t11), the condition for switching the state of the third valve 34 (ON → OFF or OFF → ON) It is determined whether or not there is (step S64, timing t12, t13, t14, t15). If it is not a condition for switching the state of the third valve 34 (step S64: NO), the process returns to step S62 without proceeding to the next step. If the condition is that the third valve 34 is switched (step S64: YES), the pressure P11 of the pressure control unit 56 before the third valve 34 is switched is read (step S66), and a predetermined time after the third valve 34 is switched ( The pressure P12 of the pressure control unit 56 at timings t12a, t13a, t14a, and after t15a) is detected. The predetermined times (t12 to t12a, t13 to t13a, t14t to 14a, t15 to t15a) are set to 0.2 to 1.5 seconds.

  Next, the determination pressure P13 is read (step S72), and the absolute value of the difference between the pressure P11 and the pressure P12 is compared with the determination pressure P13 (step S74). The determination pressure P13 is determined according to the flow rate of the gas (purge gas) passing through the third valve 34. Specifically, the determination pressure P13 shown in Table 2 is used as the determination pressure P13.

  If the absolute value of the difference between the pressure P11 and the pressure P12 is greater than or equal to the determination pressure P13 (step S74: YES), it is determined that no abnormality has occurred in the gas pipe 32 (step S78). On the other hand, when the absolute value of the difference between the pressure P11 and the pressure P12 is smaller than the determination pressure P3 (step S74: NO, it is determined that an abnormality has occurred in the gas pipe 32 (step S78). The internal combustion engine 10 is a third valve. By comparing the pressure of the pressure control unit 56 before and after opening and closing 34, it is possible to determine whether or not the gas pipe 32 is abnormal.

  In the first embodiment, the evaporative fuel processing apparatus including the pump has been described. However, the evaporative fuel processing apparatus may not include the pump. Since the evaporated fuel processing device is connected to the intake pipe upstream from the supercharger, the evaporated fuel can be supplied to the intake pipe when the pressure in the intake pipe upstream from the supercharger is negative.

  As mentioned above, although embodiment of this invention was described in detail, these are only illustrations and do not limit a claim. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology illustrated in the present specification or the drawings achieves a plurality of objects at the same time, and has technical utility by achieving one of the objects.

10: Internal combustion engine system 32: Gas pipe 34: Third valve 54: First valve CH: Supercharger EN: Internal combustion engine IP: Intake pipe TV: Second valve

Claims (9)

An intake pipe through which air supplied to the internal combustion engine passes;
A turbocharger provided in the intake pipe;
A first valve that is provided in the intake pipe upstream of the supercharger and controls the amount of air supplied to the supercharger;
A second valve that is provided in the intake pipe downstream of the supercharger and controls the intake air amount of the internal combustion engine;
A gas pipe connected to the intake pipe between the first valve and the supercharger, through which gas generated in the vehicle passes;
A third valve provided in the gas pipe for controlling the amount of gas supplied to the intake pipe;
An internal combustion engine system comprising: Furthermore, a pressure gauge is provided in the intake pipe between the first valve and the supercharger,
The internal combustion engine system according to claim 1, wherein the first valve changes the opening degree according to the opening degree of the third valve, and maintains the pressure between the first valve and the supercharger at a control pressure.   Based on the phenomenon that should occur due to the state of the first valve when the opening of the third valve changes, and the phenomenon that actually occurred when the opening of the third valve changes, The internal combustion engine system according to claim 2, wherein presence or absence is determined.   Based on the opening of the first valve that should maintain the control pressure when the opening of the third valve changes, and the actual opening of the first valve when the opening of the third valve changes, the gas The internal combustion engine system according to claim 3, wherein the presence or absence of abnormality of the pipe is determined.   The internal combustion engine system according to claim 3, wherein the presence or absence of an abnormality in the gas pipe is determined based on a change in pressure in the intake pipe when the opening of the third valve changes.   4. The method according to claim 3, wherein the presence or absence of an abnormality in the gas pipe is determined based on the flow rate of air that should pass through the first valve when the opening degree of the third valve changes and the actual flow rate of air that passes through the first valve. The internal combustion engine system described.   The internal combustion engine system according to claim 6, wherein the flow rate of air passing through the first valve is detected based on the opening degree of the first valve and the pressure in the intake pipe downstream of the first valve. Furthermore, it has a flow meter provided on the intake pipe upstream from the connection of the gas pipe,
The internal combustion engine system according to claim 6, wherein an actual flow rate of air passing through the first valve is detected by a detection value of the flow meter. Furthermore, a pressure gauge is provided in the intake pipe between the first valve and the supercharger,
The first valve changes the opening according to the opening of the third valve,
The internal combustion engine system according to claim 1, wherein the presence or absence of an abnormality in the gas pipe is determined based on a pressure change in the intake pipe when the opening of the third valve changes.

Images