JP2018091166A - Internal Combustion Engine System - Google Patents

Abstract

PROBLEM TO BE SOLVED: To determine whether a gas pipe is connected to an intake pipe or not.SOLUTION: An internal combustion engine system include the intake pipe, a supercharger provided in the intake pipe, a first valve provided in the intake pipe at its upstream side further than the supercharger, a second valve provided in the intake pipe at its downstream side further than the supercharger, the gas pipe connected to the intake pipe between the first valve and the supercharger, and a third valve provided in the gas pipe. The internal combustion engine system determines whether the gas pipe is connected to the intake pipe or not, on the basis of a difference between a first characteristic value based on the flow amount of gas passing through the third valve at the time of controlling a pressure between the first valve and the supercharger to be the atmospheric pressure and a second characteristic value based on the flow amount of the gas passing through the third valve at the time of controlling the pressure between the first valve and the supercharger to be a negative pressure, when the opening of the third valve is unchanged.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. In this case, a gas pipe for supplying gas generated in the vehicle is connected to the intake pipe. When the gas pipe is detached from the intake pipe, the generated gas is released into the atmosphere. Therefore, it is necessary to determine whether or not the gas pipe is connected to the intake pipe. The present specification discloses an internal combustion engine system capable of determining whether or not a gas pipe is connected to an intake pipe.

  The internal combustion engine system disclosed in the present specification may include an intake pipe, a supercharger, a first valve, a second valve, a gas pipe, and a third valve. Air supplied to the internal combustion engine may pass through the intake pipe. The supercharger may be provided in the intake pipe. The first valve is provided in the intake pipe upstream of the supercharger, and may control the amount of air supplied to the supercharger. The second valve is provided in the intake pipe downstream of the supercharger, and may control the intake amount of the internal combustion engine. The gas pipe is connected to the intake pipe between the first valve and the supercharger, and the gas generated in the vehicle may pass through. The third valve may be provided in the gas pipe and may control the amount of gas supplied to the intake pipe. In the internal combustion engine system, when the opening degree of the third valve is equal, the first characteristic value based on the gas flow rate passing through the third valve when controlling the atmospheric pressure between the first valve and the supercharger; Whether or not the gas pipe is connected to the intake pipe based on the difference from the second characteristic value based on the gas flow rate passing through the third valve when controlling the negative pressure between the first valve and the supercharger. You can judge.

  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 this specification, “when the pressure between the first valve and the supercharger is controlled to a negative pressure” does not mean that the pressure between the first valve and the supercharger is actually a negative pressure. When the gas pipe is disconnected from the intake pipe, air flows from the connecting portion between the gas pipe and the intake pipe even if it is controlled to a negative pressure between the first valve and the supercharger. There is no negative pressure between. “When controlling the pressure between the first valve and the supercharger to a negative pressure” means that if the pressure is normal (the gas pipe is connected to the intake pipe), the pressure between the first valve and the supercharger is set to a negative pressure. For example, to control the first valve to be closed (or to reduce the opening). Hereinafter, the inside of the intake pipe between the first valve and the supercharger may be referred to as a “pressure control unit”. Further, the “characteristic value based on the gas flow rate passing through the third valve (first characteristic value, (second characteristic value)” may be the gas flow rate itself, or a component attached to the gas pipe ( For example, the differential pressure before and after the component (pressure loss of the component through which the gas passes) due to the passage of the gas through the third valve or the like.

  In the internal combustion engine system, the gas pipe is connected to the intake pipe between the first valve and the supercharger. The space between the first valve and the supercharger (pressure control unit) can be adjusted to atmospheric pressure or negative pressure by adjusting the opening of the first valve. When the other conditions are the same, when the pressure control unit is negative, the flow rate of gas supplied from the gas pipe to the intake pipe through the third valve is increased compared to when the pressure control unit is atmospheric pressure. . When the gas pipe is detached from the intake pipe, the outlet of the gas pipe is exposed to the atmosphere. For this reason, even if the pressure control unit is controlled under a negative pressure condition, the gas flow rate passing through the third valve is the same as when the pressure control unit is at atmospheric pressure. The internal combustion engine system determines whether the gas pipe is connected to the intake pipe based on the opening degree of the third valve and the gas flow rate passing through the third valve.

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. 6 shows an internal combustion engine system according to a fourth embodiment. The flowchart of the method of judging the connection state of a gas pipe is shown. The flowchart of the method of judging the connection state of a gas pipe is shown. The flowchart of the method of judging the connection state of a gas pipe is shown. The flowchart of the method of judging the connection state of a gas pipe is shown. The flowchart of the method of judging the connection state of a gas pipe is shown. The flowchart of the method of judging the connection state of a gas pipe is shown. The table in which the duty ratio D and the pressure loss P1 were described is shown. An example of the relationship between the duty ratio D and the predetermined value α is shown. The process of updating the pressure loss P1 of a table is shown. A process of creating a table of duty ratio D and pressure loss P1 is shown. An approximate line obtained from a function of the duty ratio D and the pressure loss P1 is shown. The table in which the duty ratio D and the gas flow rate Q1 were described is shown. The process of updating the gas flow rate Q1 of a table is shown. A process of creating a table of duty ratio D and gas flow rate Q1 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 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 that controls the intake amount of the internal combustion engine; The turbocharger is connected to an intake pipe, and is provided with a gas pipe through which gas generated in the vehicle passes, and a third valve that controls the amount of gas supplied to the intake pipe. It's okay. The internal combustion engine system has a first characteristic value based on a gas flow rate passing through the third valve when the opening between the first valve and the supercharger is controlled to atmospheric pressure when the opening degree of the third valve is equal, It is determined whether or not the gas pipe is connected to the intake pipe based on the difference from the second characteristic value based on the gas flow rate passing through the third valve when the negative pressure is controlled between the 1 valve and the supercharger. You can do it.

  The first characteristic value and the second characteristic value may be the gas flow rate itself passing through the third valve. The gas flow rate passing through the third valve may be detected by a flow meter provided in the gas pipe. Alternatively, the gas flow rate passing through the third valve may be estimated based on a detection value of the first pressure gauge provided in the gas pipe upstream of the third valve.

  Further, the first characteristic value and the second characteristic value may not be the gas flow rate itself. The first characteristic value and the second characteristic value may be pressure or differential pressure. Specifically, the first characteristic value and the second characteristic value are the values of the third valve indicated by the difference between the detected value of the first pressure gauge and the pressure between the first valve and the supercharger (pressure control unit). It may be a pressure loss. The pressure loss of the third valve increases as the gas flow rate through the third valve increases. Therefore, if the gas pipe is connected to the intake pipe, the pressure loss (second characteristic value) of the third valve when the pressure control unit is controlled to negative pressure is the same as that when the pressure control unit is controlled to atmospheric pressure. It becomes larger than the pressure loss (first characteristic value) of the third valve. On the other hand, when the gas pipe is disconnected from the intake pipe, the second characteristic value is substantially equal to the first characteristic value or smaller than the second characteristic value when the gas pipe is connected to the intake pipe.

  A pump may be provided upstream of the third valve. By providing the pump, gas can be sufficiently supplied to the intake pipe (pressure control unit) even when the pressure control unit is at atmospheric pressure. When a pump is provided upstream of the third valve, the first pressure gauge may be provided between the third valve and the pump, or may be provided upstream of the pump. Alternatively, the first pressure gauge may be provided between the third valve and the pump and upstream of the pump.

  Even when the first pressure gauge is provided upstream of the pump, the first characteristic value and the second characteristic value may be values based on the detected value of the first pressure gauge. Even when a pump is provided upstream of the third valve, if the gas pipe is disconnected from the intake pipe, the gas flow rate around the first pressure gauge is such that the gas pipe is connected to the intake pipe. Decrease than when you are. That is, when the gas pipe is disconnected from the intake pipe, the difference between the pressure around the first pressure gauge and the atmospheric pressure is smaller than when the gas pipe is connected to the intake pipe. The difference between the pressure around the first pressure gauge and the atmospheric pressure can also be expressed as the pressure loss of components provided upstream of the pump. When the first pressure gauge is a type that detects the gauge pressure, the detected value of the first pressure gauge indicates the pressure loss of the components provided upstream of the pump.

  The internal combustion engine system may include a second pressure gauge provided in the intake pipe between the first valve and the supercharger (pressure control unit). As described above, when the first characteristic value and the second characteristic value are the pressure loss of the third valve, it is necessary to detect the pressure of the pressure control unit. By providing the second pressure gauge in the pressure control unit, the accurate pressure of the pressure control unit can be detected. In addition, you may estimate the pressure of a pressure detection part based on the opening degree of a 1st valve | bulb. In this case, the number of parts of the internal combustion engine system can be reduced. Note that the above-described pressure gauges (first pressure gauge, second pressure gauge) may be a resistance wire type, a capacitance type, a mechanical type, or the like.

  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 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).

  As described above, the internal combustion engine system can determine whether or not the gas pipe is connected to the intake pipe based on the difference between the first characteristic value and the second characteristic value. Since the first characteristic value is a value when the inside of the intake pipe (pressure control unit) is controlled at atmospheric pressure, if the opening of the third valve does not change, whether the gas pipe is connected to the intake pipe or not. Regardless, it does not change. Therefore, the internal combustion engine system may include storage means for storing the first characteristic value corresponding to the opening degree of the third valve. When controlling the negative pressure of the pressure control unit, the second characteristic value is measured, the first characteristic value is read from the storage means, and the difference between the second characteristic value and the first characteristic value is calculated. (Whether or not connected to the intake pipe) can be determined.

  The storage means may store a table (one-dimensional map) in which the first characteristic value corresponding to the opening degree of the third valve is written. The table may be created in advance, or may be created by measuring the first characteristic value while driving the internal combustion engine system. Alternatively, the first characteristic value may be measured while the internal combustion engine system is being driven with respect to the table in which the first characteristic value is described in advance, and the value of the first characteristic value may be updated.

  A function of the first characteristic value and the third valve may be created using the opening degree of the third valve and the first characteristic value. In this case, when the space between the first valve and the supercharger (pressure control unit) is controlled to atmospheric pressure, the first characteristic value is measured at the opening of two or more different third valves. And a function of the opening degree of the third valve. Thereafter, when the pressure control unit is under negative pressure, the second characteristic value is measured, the first characteristic value is calculated by substituting the opening degree of the third valve into the function, and the second characteristic value and the first characteristic value are calculated. By calculating the difference, it can be determined whether the gas pipe is connected to the intake pipe.

(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. That is, by adjusting the opening degree of the upstream throttle valve 54, the inside of the intake pipe IP between the upstream throttle valve 54 and the supercharger CH can be adjusted to atmospheric pressure or negative pressure. 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 control unit 56 is controlled to atmospheric pressure or negative pressure. The pressure control unit 56 is provided with a second pressure gauge 58. The detection value of the second 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, air passes through the air cleaner AC and is sucked toward 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 fuel vapor processing apparatus 8 includes a canister 14, a pump 12, a gas pipe 32, a purge control valve 34, and a first pressure gauge 30. 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. As will be described later, the internal combustion engine system 10 can determine whether or not the second hose 26 is connected to the intake pipe IP.

  A purge control valve 34 is arranged on the second hose 26. 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.

  A first pressure gauge 30 is disposed on the second hose 26. The first pressure gauge 30 is. It is arranged between the pump 12 and the purge control valve 34. The pressure loss of the purge control valve 34 can be measured by the first pressure gauge 30 and the second pressure gauge 58. The pressure loss of the purge control valve 34 changes as the flow rate of the purge gas passing through the purge control valve 34 changes. Specifically, the pressure loss of the purge control valve 34 increases as the flow rate of the purge gas passing through the purge control valve 34 increases.

  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 10a will be described with reference to FIG. The internal combustion engine system 10a is a modification of the internal combustion engine system 10. About the internal combustion engine system 10a, about the same structure as the internal combustion engine system 10, description may be abbreviate | omitted by attaching | subjecting the same reference number. In the internal combustion engine system 10 a, the first pressure gauge 30 a is disposed upstream of the pump 12. More specifically, the first pressure gauge 30 a is disposed on the second hose 26 between the pump 12 and the canister 14. The pressure loss of the canister 14 and the air filter AF can be measured from the value of the first pressure gauge 30a and the value of the atmospheric pressure. The pressure loss of the canister 14 and the air filter AF increases as the amount of gas passing through the canister 14 and the air filter AF increases.

(Third embodiment)
The internal combustion engine system 10b will be described with reference to FIG. The internal combustion engine system 10b is a modification of the internal combustion engine system 10. About the internal combustion engine system 10b, about the same structure as the internal combustion engine system 10, description may be abbreviate | omitted by attaching | subjecting the same reference number. In the internal combustion engine system 10 b, the first pressure gauge 30 b is disposed upstream of the canister 14. More specifically, the first pressure gauge 30b is disposed on the second hose 26 between the canister 14 and the air filter AF. The pressure loss of the air filter AF can be measured from the value of the first pressure gauge 30b and the value of atmospheric pressure. The pressure loss of the air filter AF increases as the amount of gas (air amount) passing through the air filter AF increases.

(Fourth embodiment)
The internal combustion engine system 10c will be described with reference to FIG. The internal combustion engine system 10a is a modification of the internal combustion engine system 10. About the internal combustion engine system 10a, about the same structure as the internal combustion engine system 10, description may be abbreviate | omitted by attaching | subjecting the same reference number. In the internal combustion engine system 10c, the gas pipe 32 is branched into the second hose 26 and the third hose 24 at a branch point 32a at an intermediate position. The second hose 26 is connected to the pressure control unit 56 via a check valve 80. The check valve 80 allows gas supply from the second hose 26 to the intake pipe IP, but prohibits gas supply from the intake pipe IP to the second hose 26. The third hose 24 is connected to the intake pipe IP between the throttle valve TV and the engine EN. The third hose 24 is detachably connected to the intake manifold IM. A check valve 83 is disposed at an intermediate position of the third hose 24. The check valve 83 allows gas to flow in the third hose 24 toward the intake manifold IM, and prohibits the gas from flowing toward the canister 14.

  In the internal combustion engine system 10c, when the control unit 102 opens the purge control valve 34 in a situation where the supercharger CH is not operating, the purge gas passes from the canister 14 through the first hose 22 and the third hose 24. The intake manifold IM is supplied downstream of the supercharger CH. At this time, the control unit 102 controls to drive or stop the pump 12 according to the state of the negative pressure of the intake manifold IM (for example, the rotational speed of the engine EN).

  When a transition is made from a situation where the supercharger CH is not operating to a situation where the supercharger CH is operating, the purge gas passes from the canister 14 through the first hose 22 and the second hose 26, and the supercharger Supplied to the intake pipe IP upstream of CH. At this time, when the inside of the intake pipe IP (pressure control unit 56) is controlled to atmospheric pressure, the control unit 102 may drive the pump 12 to send out purge gas. Thereby, in a situation where the supercharger CH is operating, it is not necessary to supply purge gas to the intake manifold IM on the downstream side of the supercharger CH that is positive pressure.

  On the other hand, when a transition is made from a situation where the supercharger CH is operating to a situation where the supercharger CH is not operating, the purge gas passes through the first hose 22 and the third hose 24 from the canister 14 and takes in the intake gas. Supplied to manifold IM.

  The configuration in which the gas pipe 32 branches into the second hose 26 and the third hose 24 and the purge gas is supplied to both the pressure control unit 56 and the intake manifold IM can also be applied to the internal combustion engine systems 10a and 10b ( (See also FIGS. 2 and 3).

  Hereinafter, a method for determining whether or not the gas pipe 32 (second hose 26) is connected to the intake pipe IP (pressure control unit 56) will be described. 5 to 7 show a flow for confirming the connection of the gas pipe 32 based on the pressure loss of the components of the evaporated fuel processing device 8 when the purge gas is supplied to the intake pipe IP. That is, an example in which the first characteristic value and the second characteristic value are pressure losses is shown. 8 to 10 show a flow for confirming the connection of the gas pipe 32 based on the gas flow rate passing through the components of the evaporated fuel processing apparatus 8 when the purge gas is supplied to the intake pipe IP. Yes. That is, an example in which the first characteristic value and the second characteristic value are gas flow rates is shown.

  With reference to FIG. 5, the procedure for determining whether or not the gas pipe 32 is connected to the intake pipe IP in the internal combustion engine systems 10, 10a, 10b and 10c will be described. FIG. 5 shows a procedure in the case where the pressure loss of the purge control valve 34 with respect to the opening degree of the purge control valve 34 when the pressure control unit 56 is at atmospheric pressure is stored in the ECU 100 in advance. The flow shown in FIG. 5 is executed at a period of about 16 milliseconds.

  First, it is determined whether or not the supply of the purge gas to the intake pipe IP has been started (step S2). If the supply of purge gas has not been started (step S2: NO), the determination in step S2 is repeated. When supply of the purge gas is started (step S2: YES), the duty ratio D of the purge control valve 34 is read (step S4), and the inside of the intake pipe IP (pressure control unit 56) on the upstream side of the supercharger CH is read. It is determined whether or not the negative pressure is controlled (step S6). In step S6, it is not necessary to measure the pressure itself of the pressure control unit 56, and it is determined whether or not the pressure control unit 56 is performing control to adjust to negative pressure.

  When the pressure control unit 56 is not negative pressure control (that is, atmospheric pressure control) (step S6: NO), the process is terminated. When the pressure control unit 56 is under negative pressure control (step S6: YES), the pressure loss P2 of the specific part in the purge passage is measured (step S8). Specifically, in the case of the internal combustion engine systems 10 and 10c, the pressure loss P2 of the purge control valve 34 is measured from the difference between the value of the first pressure gauge 30 and the value of the second pressure gauge 58 (FIGS. 1 and 4). See). In the case of the internal combustion engine system 10a, the pressure loss P2 of the canister 14 and the air filter AF is measured from the difference between the value of the first pressure gauge 30a and the atmospheric pressure (see FIG. 2). In the case of the internal combustion engine system 10b, the pressure loss P2 of the air filter AF is measured from the difference between the value of the first pressure gauge 30b and the atmospheric pressure (see FIG. 3). In the internal combustion engine systems 10a and 10b, if pressure gauges of the type that measure gauge pressure are used as the first pressure gauges 30a and 30b, the values of the first pressure gauges 30a and 30b represent the pressure loss P2.

  Next, the pressure loss P1 corresponding to the duty ratio D read in step S4 is read from the table shown in FIG. 11 (step S10). The table of FIG. 11 describes the pressure loss P1 of a specific part of the purge passage at each duty ratio D when the inside of the intake pipe IP (pressure control unit 56) on the upstream side of the supercharger CH is atmospheric pressure. . For example, when the duty ratio D read in step S4 is 40%, A4 is read as the pressure loss P1, and when the duty ratio D is 60%, A6 is read as the pressure loss P1. The table in FIG. 11 is stored in the ECU 100.

  Next, the pressure loss P1 and the pressure loss P2 are compared. Specifically, it is determined whether or not “pressure loss P2> pressure loss P1 + predetermined value α” (step S12). When the second hose 26 is connected to the intake pipe IP and the opening degree (duty ratio D) of the purge control valve 34 is the same, the pressure loss of the purge control valve 34 is negative in the pressure control unit 56. The time when the pressure is controlled (pressure loss P2) is larger than the time when the pressure controller 56 is under atmospheric pressure control (pressure loss P1). Therefore, when “pressure loss P2> pressure loss P1 + predetermined value α” is satisfied (step S12: YES), it is determined that the second hose 26 (gas pipe 32) is normally connected to the intake pipe IP (step). S14).

  On the other hand, when the second hose 26 is detached from the intake pipe IP, the end of the second hose 26 is exposed to the atmosphere. Therefore, the pressure loss P2 of the purge control valve 34 is substantially equal to the pressure loss (pressure loss P1) when the atmospheric pressure is controlled in the intake pipe IP. Therefore, “pressure loss P2> pressure loss P1 + predetermined value α” is not satisfied. When “pressure loss P2> pressure loss P1 + predetermined value α” is not satisfied (step S12: NO), it is determined that an abnormality has occurred in which the second hose 26 is disconnected from the intake pipe IP (step S16).

  Theoretically, when the second hose 26 is disconnected from the intake pipe IP, the pressure loss P2 and the pressure loss P1 become equal. However, due to an error or the like, the pressure loss P2 may be larger than the pressure loss P1 even though the second hose 26 is disconnected from the intake pipe IP. The predetermined value α is a margin for not determining that the second hose 26 is normal even though the second hose 26 is disconnected from the intake pipe IP.

  FIG. 12 shows an example of the predetermined value α. The predetermined value α is not a fixed value but differs depending on the size of the duty ratio D. Typically, as the duty ratio D of the purge control valve 34 increases, the amount of purge gas passing through the purge control valve 34 increases, and the pressure loss of the purge control valve 34 increases. Therefore, the predetermined value α is set to a large value as the duty ratio D increases. For example, the predetermined value α is set to a value of 10 to 30% of the pressure loss P1.

  Next, another procedure for determining whether or not the gas pipe 32 is connected to the intake pipe IP will be described with reference to FIG. In FIG. 5, when the pressure control unit 56 is atmospheric pressure control (step S6: NO), the process is terminated without proceeding to the next step. In this method, the pressure loss P1 is measured when the pressure control unit 56 is under atmospheric pressure control, and the value of the pressure loss P1 stored in the table is updated. Note that the processing of steps S2 to S16 in FIG. 6 is the same as the processing shown in FIG.

  As shown in FIG. 6, in this process, whether the pressure control unit 56 is negative pressure control (step S6: YES) or not negative pressure control (step S6: NO), The pressure loss is measured (Step S8, Step S20). The description of the processes in steps S8 to S16 is omitted. The value (pressure loss P1) obtained in step S20 is stored in association with the duty ratio D of the purge control valve 34 (step S22).

  Specifically, as shown in FIG. 13, when the duty ratio D obtained in step S4 is 40% and the pressure loss P1 obtained in step S20 is A4.1, the original table is represented by a table (a When the state of the gas pipe 32 is next determined (step S12), the state of the gas pipe 32 is determined based on the pressure loss P1 read from the table (a). Further, when the duty ratio D = 70% is obtained in step S4 and the pressure loss P1 = A7.1 is obtained in step S20, the table (a) is updated as shown in the table (b), and then the gas pipe 32 is replaced. When determining the state, the state of the gas pipe 32 is determined based on the pressure loss P1 read from the table (b) (step S12).

  In the case of the process shown in FIG. 6, it is not necessary to store a table in which the pressure loss P1 is recorded in advance as shown in FIG. For example, as shown in FIG. 14, each time the relationship between the duty ratio D and the pressure loss P <b> 1 when the pressure control unit 56 performs atmospheric pressure control is obtained, the table may be stored and the table may be completed. In this case, when the pressure loss P1 corresponding to step S10 in FIG. 6 does not exist in the table, for example, the duty ratio D = 80% is read in step S4, and the pressure loss P1 corresponding to the duty ratio D = 80% is read into the table. If not, the process ends without proceeding to the process of step S12.

  Next, still another procedure for determining whether or not the gas pipe 32 is connected to the intake pipe IP will be described with reference to FIG. In this method, the table relating to the pressure loss P1 described in FIG. 5 or FIG. 6 is not required. In this method, a function is created for the duty ratio D and the pressure loss P1 when the pressure controller 56 is under atmospheric pressure control, and the pressure loss P1 is determined from the function. Note that the processing in steps S2 to S16 in FIG. 7 is the same as the processing shown in FIG. 5 and FIG.

  As shown in FIG. 7, in this process, whether the pressure control unit 56 is negative pressure control (step S6: YES) or not negative pressure control (step S6: NO), The pressure loss is measured (Step S8, Step S30). Description of the processing in steps S8 to S16 is omitted. The value (pressure loss P1) obtained in step S30 is stored in association with the duty ratio D of the purge control valve 34 (step S32).

  Next, it is determined whether or not two or more related data of the duty ratio D and the pressure loss P1 are stored (step S34). For example, when the pressure loss P1 for the duty ratio D = 40% and the pressure loss P1 for the duty ratio D = 70% are stored, it is determined that two or more related data are stored. In the past, when the pressure loss P1 for the duty ratio D = 40% was measured in step S30 in the past, and the pressure loss P1 for the duty ratio D = 40% was measured this time, the related data is 1, and 2 or more are stored. Do not judge. If two or more pieces of related data are not stored (step S34: NO), the process ends.

  When two or more related data are stored (step S34: YES), a function P1 = f (D) of the duty ratio D and the pressure loss P1 is created (step S36). This function is used when determining the pressure loss P1 to be read in step S10 when the state of the gas pipe 32 is next determined (step S12). For example, as shown in FIG. 15, a function P1 = f (D) is created from the value of the pressure loss P1 with respect to the duty ratio D = 40% and 80% obtained in step S32. Next, when determining the state of the gas pipe 32, if the duty ratio D is 60% in step S4, the value calculated from P1 = f (60) is read in step S10.

  According to this method, even if the value of the pressure loss P1 with respect to the current duty ratio D is not stored, the pressure loss P1 can be calculated from the function P1 = f (D) and the state of the gas pipe 32 can be determined. . Compared with the method of creating a table, it is easier to determine the state of the gas pipe 32.

  Next, referring to FIG. 8, a procedure for determining whether or not the gas pipe 32 is connected to the intake pipe IP based on the gas flow rate passing through the purge passage (purge control valve 34) of the evaporated fuel processing device 8. Will be explained. The flow shown in FIG. 8 is also executed at a period of about 16 milliseconds. Steps S52 to S66 in FIG. 8 are substantially the same as steps S2 to S16 in FIGS.

  When the pressure controller 56 is under negative pressure control (step S56: YES), the gas flow rate Q2 passing through the purge control valve 34 is measured (step S58). The gas flow rate Q2 may be measured by providing a flow meter in the gas pipe 32, or may be estimated from the opening degree of the purge control valve 34 and the value of the first pressure gauge 30, 30a or 30b (FIG. 1 to 4).

  Next, the gas flow rate Q1 corresponding to the duty ratio D read in step S54 is read from the table shown in FIG. 16 (step S60), and the gas flow rate Q1 and the gas flow rate Q2 are compared (step S62). For example, when the duty ratio D read in step S54 is 60%, B6 is read as the gas flow rate Q1. When “gas flow rate Q2> gas flow rate Q1 + predetermined value α” is satisfied (step S62: YES), it is determined that the second hose 26 is normally connected to the intake pipe IP (step S64), and “gas flow rate Q2 If “> gas flow rate Q1 + predetermined value α” is not satisfied (step S62: NO), it is determined that an abnormality has occurred in which the second hose 26 is disconnected from the intake pipe IP (step S66). The predetermined value α is set to a value of 10 to 30% of the gas flow rate Q1, for example. In addition, the predetermined value α is a margin for not determining that the second hose 26 is normal although the second hose 26 is disconnected from the intake pipe IP.

  Next, referring to FIG. 9, it is determined whether or not the gas pipe 32 is connected to the intake pipe IP based on the gas flow rate passing through the purge passage (purge control valve 34) of the evaporated fuel processing device 8. The procedure of will be described. Since steps S52 to S66 in FIG. 9 are the same as steps S52 to S66 in FIG. 8, description thereof may be omitted.

  As shown in FIG. 9, in this process, whether the pressure control unit 56 is under negative pressure control (step S56: YES) or not under negative pressure control (step S56: NO), the gas flow rate ( The gas flow rate passing through the purge control valve 34 is measured (step S58, step S70). The description of steps S60 to S66 is omitted. The value (gas flow rate Q1) obtained in step S70 is stored in association with the duty ratio D of the purge control valve 34 (step S72). That is, as shown in FIG. 17, the gas flow rate Q1 obtained in steps S70 and S72 is updated each time it is measured. Next, when determining the state of the gas pipe 32, the state of the gas pipe 32 is determined based on the latest table (step S62).

  In the case of the process shown in FIG. 9, a table in which the gas flow rate Q1 is shown in advance as shown in FIG. 17 may not be stored. As shown in FIG. 18, the table may be stored each time the relationship between the duty ratio D and the gas flow rate Q1 when the pressure control unit 56 performs atmospheric pressure control is obtained, and the table may be completed. In this case, when the corresponding gas flow rate Q1 does not exist in the table in step S60 of FIG. 9, the process ends without proceeding to the process of step S62.

  Next, referring to FIG. 10, it is determined whether or not the gas pipe 32 is connected to the intake pipe IP based on the gas flow rate passing through the purge passage (purge control valve 34) of the evaporated fuel processing device 8. Another procedure will be described. In this method, the table relating to the gas flow rate Q1 described in FIG. 8 or FIG. 9 is not required. In this method, as in the process described with reference to FIG. 7, a function is created for the duty ratio D and the gas flow rate Q1 when the pressure control unit 56 is under atmospheric pressure control, and the gas flow rate Q1 is determined from the function. Note that the processing in steps S52 to S66 in FIG. 10 is the same as steps S52 to S66 in FIGS.

  As shown in FIG. 10, in this process, the gas flow rate in the purge passage (NO in step S56: NO) or not in the negative pressure control (step S56: NO) (step S56: NO). The gas flow rate passing through the purge control valve 34 is measured (step S58, step S80). The description of steps S60 to S66 is omitted. The value (gas flow rate Q1) obtained in step S80 is stored in association with the duty ratio D of the purge control valve 34 (step S82).

  Next, it is determined whether or not two or more related data of the duty ratio D and the gas flow rate Q1 are stored (step S84). If two or more related data are not stored (step S84: NO), the process ends. When two or more related data are stored (step S84: YES), a function Q1 = f (D) of the duty ratio D and the gas flow rate Q1 is created (step S86). This function is used when determining the gas flow rate Q1 to be read in step S60 when the state of the gas pipe 32 is next determined (step S62). Specifically, the vertical axis of the graph of FIG. 15 is read as gas flow rate Q1, the function is read as Q1 = f (D), and the function Q1 = f (from the value of gas flow rate Q1 with respect to the duty ratio D obtained in step S82. D) is created, and the next time the state of the gas pipe 32 is determined, the duty ratio D obtained in step S54 is substituted into the function Q1 = f (D), and the calculated value is read in step S60. According to this method, even if the value of the gas flow rate Q1 with respect to the current duty ratio D is not stored, the gas flow rate Q1 can be calculated from the function Q1 = f (D), and the state of the gas pipe 32 can be determined. .

  In the above embodiment, an example in which the gas introduced into the intake pipe is a gas evaporated in the fuel tank (hereinafter sometimes referred to as purge gas) has been described. It may be a part of the exhaust gas (EGR) of the engine or a gas (blow-by gas) leaking from the combustion chamber of the internal combustion engine. Further, the evaporated fuel processing apparatus may not include a 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 (12)

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 that is provided in the gas pipe and controls the amount of gas supplied to the intake pipe;
The first characteristic value based on the gas flow rate passing through the third valve when controlling the atmospheric pressure between the first valve and the supercharger when the opening degree of the third valve is equal, and the first valve and the supercharger An internal combustion engine system for determining whether or not a gas pipe is connected to an intake pipe based on a difference from a second characteristic value based on a gas flow rate passing through a third valve when controlling the pressure between the machines. A first pressure gauge is provided upstream of the third valve;
The internal combustion engine system according to claim 1, wherein the first characteristic value and the second characteristic value are values based on a detection value of the first pressure gauge.   The first characteristic value and the second characteristic value are pressure losses of a third valve indicated by a difference between a detected value of the first pressure gauge and a pressure between the first valve and the supercharger. Internal combustion engine system. A pump is provided upstream of the third valve,
The internal combustion engine system according to claim 1 or 2, wherein the first pressure gauge is provided upstream of the pump.   5. The internal combustion engine system according to claim 4, wherein the first characteristic value and the second characteristic value are pressure losses of components provided upstream of the pump indicated by a difference between a detected value of the first pressure gauge and atmospheric pressure.   The internal combustion engine system according to claim 5, wherein the first pressure gauge is of a type that detects a gauge pressure.   The internal combustion engine system according to any one of claims 1 to 6, wherein a pressure between the first valve and the supercharger is determined based on an opening degree of the first valve.   The internal combustion engine system according to any one of claims 1 to 6, wherein the second pressure gauge is provided in the intake pipe between the first valve and the supercharger.   9. The storage device according to claim 1, further comprising storage means for storing a first characteristic value corresponding to an opening degree of the third valve when the pressure between the first valve and the supercharger is controlled to atmospheric pressure. An internal combustion engine system according to claim 1.   The internal combustion engine system according to claim 9, wherein the storage unit stores a table in which a first characteristic value corresponding to an opening of the third valve is written.   The internal combustion engine system according to claim 10, wherein a first characteristic value is detected when the pressure between the first valve and the supercharger is controlled to atmospheric pressure, and the detection result is recorded in the table.   The first characteristic value is detected when the pressure between the first valve and the supercharger is controlled to atmospheric pressure, and the first characteristic value and the third valve are opened using the opening degree of the third valve and the first characteristic value. The internal combustion engine system according to claim 9, wherein a function relating to degree is created.

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