JP2018017170A - Evaporation fuel treatment device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for identifying an amount of purge gas passing through a control valve and then flowing out to an intake passage in a configuration in which a pump for boosting pressure of purge gas is disposed in a purge passage.SOLUTION: An evaporation fuel treatment device 10 includes: a canister 14 disposed in a purge passage 22 to adsorb evaporation fuel in a fuel tank FT; a control valve 34 disposed in the purge passage 22 between an intake passage IW and the canister 14 and switching between a communication state where the canister 14 and the intake passage IW are communicated with each other and a shutoff state where they are shut off from each other; a pump 12 disposed in the purge passage 22 between the control valve 34 and the canister 14; and a control section 102 for identifying purge gas amount in which the evaporation fuel flowing from the pump 12 through the control valve 34 toward the intake passage IW and air are mixed with each other, by using pressure of an intake manifold IM, rotational frequency of the pump 12 and an opening of the control valve 34.SELECTED DRAWING: Figure 1

Description

  The present specification discloses an evaporative fuel processing apparatus.

  The evaporated fuel processing apparatus includes a canister that adsorbs and stores evaporated fuel generated in a fuel tank, and a control valve that is disposed on a purge path that connects the canister and the intake path. The control valve is switched between a communication state in which the canister and the intake path communicate with each other and a shut-off state in which the canister and the intake path do not communicate with each other. When the control valve is in communication, purge gas in which evaporated fuel and air in the canister are mixed passes through the purge path and the intake path and is supplied to the internal combustion engine. Hereinafter, the process in which the purge gas passes through the control valve and is supplied to the internal combustion engine is referred to as a purge process.

  Patent Document 1 discloses a technique for estimating a purge gas amount supplied to an internal combustion engine by a purge process.

JP 2008-121425 A

  In the purge process, the purge gas on the canister side flows toward the intake path using the pressure difference between the canister side and the intake path side of the control valve. For this reason, when the rotational speed of the internal combustion engine is low, or when a supercharger is arranged in the intake path, the pressure on the intake path side of the control valve may not be sufficiently lower than the pressure on the canister side. is there. In this case, it is difficult to sufficiently flow the purge gas using the pressure difference.

  Therefore, a configuration in which a pump for boosting the purge gas is disposed on the canister side of the control valve may be employed. The present specification provides a technique for specifying the amount of purge gas that passes through a control valve and flows out to the intake passage in a configuration in which a pump that boosts the purge gas is disposed in the purge passage.

  The technology disclosed in the present specification is an evaporated fuel processing apparatus mounted on a vehicle in which a fuel tank and an intake manifold of an intake path are communicated with each other through a purge path. The evaporative fuel processing apparatus is disposed in a purge path, and is disposed in a canister for adsorbing evaporated fuel in a fuel tank, and a purge path between the intake path and the canister, and the canister and the intake path are connected via the purge path. A control valve for switching to a communicating state, a shut-off state in which the canister and the intake path are shut off on the purge path, a pump disposed in the purge path between the control valve and the canister, and the pressure of the intake manifold A specifying unit that specifies an amount of purge gas in which evaporated fuel and air flowing through the control valve from the pump toward the intake path are mixed using the number of rotations of the pump and the opening degree of the control valve;

  In this configuration, the amount of purge gas that flows through the control valve changes in correlation with the pressure difference between the upstream side and the downstream side of the control valve in the shut-off state and the opening degree of the control valve. The pressure on the downstream side of the control valve changes according to the pressure of the intake manifold, while the pressure on the upstream side of the control valve changes depending on the rotation speed of the pump. Therefore, the amount of purge gas flowing from the control valve to the intake path changes in correlation with the pressure of the intake manifold and the rotational speed of the pump. According to this configuration, the amount of purge gas flowing from the control valve toward the intake path can be appropriately specified using the pressure of the intake manifold, the rotational speed of the pump, and the opening degree of the control valve.

1 shows an outline of a fuel supply system for an automobile according to a first embodiment. The graph which shows the gas amount data map at the time of a stop of 1st Example is shown. The graph which shows the gas amount data map at the time of a drive of 1st Example is shown. The graph which shows the ratio data map of 1st Example is shown. The schematic diagram for demonstrating the correspondence of the upstream purge path | route and upstream storage area | region of 1st Example is shown. The data map showing the relationship between the intake air amount and the shift number stored in the memory of the first embodiment is shown. The schematic diagram for demonstrating the correspondence of the downstream purge path | route and downstream storage area | region of 1st Example is shown. The flowchart of the purge gas amount calculation process of 1st Example is shown. The flowchart of the upstream purge gas amount determination process of 1st Example is shown. FIG. 4 is a schematic diagram for explaining the shift of the upstream purge gas amount when the intake air amount is small in the memory corresponding to the upstream purge path of the first embodiment. FIG. 4 is a schematic diagram for explaining the shift of the upstream purge gas amount when the intake air amount is large in the memory corresponding to the upstream purge path of the first embodiment. The flowchart of the downstream purge gas amount determination process of 1st Example is shown. The data map stored in the memory of 2nd Example is shown. 7 shows a flowchart of purge gas amount calculation processing of the second embodiment. The schematic diagram for demonstrating the shift of the purge density | concentration in the upstream storage area corresponding to the upstream purge path | route of 2nd Example is shown. The schematic diagram for demonstrating the shift of the purge density | concentration in the downstream storage area corresponding to the downstream purge path | route of 2nd Example is shown. The flowchart of the purge gas amount estimation process of 2nd Example is shown.

  The main features of the embodiments described below are listed. The technical elements described below are independent technical elements and exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Absent.

(Feature 1) In the present specification, a supercharger and a throttle valve located downstream of the supercharger and upstream of the intake manifold may be disposed in the intake path. The purge path includes a downstream purge path connected to the intake path downstream of the throttle valve between the control valve and the intake path, and an upstream purge path connected to the intake path upstream of the supercharger. You may branch to. In the fuel vapor processing apparatus, the specific unit uses the intake manifold pressure, the number of rotations of the pump, and the opening degree of the control valve to determine the upstream purge gas amount flowing from the control valve to the upstream purge path, and from the control valve to the downstream purge path. The amount of the purge gas on the downstream side that flows into the gas may be calculated. When the purge path is branched into an upstream purge path and a downstream purge path, the purge gas that passes through the control valve flows into the intake path while being divided into the upstream purge path and the downstream purge path. For example, during the operation of the supercharger, the pressure in the intake passage on the downstream side of the supercharger (that is, the pressure in the intake manifold) increases, so that a large amount of purge gas flows through the upstream purge route. On the other hand, when the supercharger is stopped, the pressure in the intake path downstream of the throttle valve becomes negative due to the internal combustion engine, so that a large amount of purge gas flows through the downstream purge path. According to the above configuration, it is possible to calculate the amount of purge gas that flows into the intake path separately from the upstream purge path and the downstream purge path, among the purge gas that flows from the control valve to the intake path in consideration of the pressure of the intake manifold. .

(Characteristic 2) The fuel vapor processing apparatus of the present specification includes a purge control unit that repeatedly switches the canister and the intake path between the communication state and the cutoff state by repeatedly switching the control valve between the fully open state and the fully closed state. May be. The purge control unit repeatedly switches between the fully open state and the fully closed state, and adjusts the period of the fully open state in the purge period in which purge gas is supplied from the control valve to the intake path, whereby the amount of purge gas flowing from the control valve to the intake path May be controlled. The specific part includes purge gas amount data representing the relationship between the pressure of the intake manifold, the number of rotations of the pump, and the fully opened purge gas amount flowing from the control valve to the intake passage when the control valve is maintained in the fully opened state during the purge period; The pressure of the intake manifold and ratio data indicating the ratio of the upstream purge gas amount to the purge gas amount flowing from the control valve to the intake path may be stored in advance. The specific unit uses the intake manifold pressure, the pump speed, the purge gas amount data, the ratio data, and the ratio of the fully open period to the purge period to determine the upstream purge gas amount and the downstream purge gas amount. May be specified. According to this configuration, the amount of evaporated fuel supplied from the canister can be adjusted by adjusting the period of the fully opened state of the control valve in the purge period. Further, since the purge gas amount data and the ratio data are stored in advance, the upstream purge gas amount and the downstream purge gas are determined using the pump rotation speed, the intake manifold pressure, and the ratio of the fully open period. The amount can be specified.

(Characteristic 3) The fuel vapor processing apparatus of the present specification includes a purge control unit that repeatedly switches the canister and the intake path between the communication state and the cutoff state by repeatedly switching the control valve between the fully open state and the fully closed state. May be. The purge control unit repeatedly switches between the fully open state and the fully closed state, and adjusts the period of the fully open state in the purge period in which purge gas is supplied from the control valve to the intake path, whereby the amount of purge gas flowing from the control valve to the intake path May be controlled. The specific unit includes upstream purge gas amount data representing the relationship between the intake manifold pressure, the pump speed, and the upstream purge gas amount when the control valve is kept fully open during the purge period, and the intake manifold pressure Downstream purge gas amount data representing the relationship between the number of rotations of the pump and the downstream purge gas amount when the control valve is kept fully open during the purge period may be stored in advance. The specific unit uses the intake manifold pressure, the pump speed, the upstream purge gas amount data, the downstream purge gas amount data, and the ratio of the fully open period to the purge period to determine the upstream purge gas amount The downstream purge gas amount may be specified. According to this configuration, the amount of evaporated fuel supplied from the canister can be adjusted by adjusting the period of the fully opened state of the control valve in the purge period. Further, since the upstream purge gas amount data and the downstream purge gas amount data are stored in advance, the upstream purge gas amount is determined by using the rotation speed of the pump, the pressure of the intake manifold, and the ratio of the fully open period. The amount and the downstream purge gas amount can each be specified.

(Characteristic 4) In the fuel vapor processing apparatus of the present specification, the specifying unit includes the upstream purge gas amount specified at the first timing and the downstream purge gas amount specified at the second timing different from the first timing. By adding, the amount of purge gas that reaches the internal combustion engine at the third timing after the first timing and the second timing may be calculated. The path from the upstream purge path to the internal combustion engine is longer than the path from the downstream purge path to the internal combustion engine. For this reason, the timing at which the purge gas that has passed through the control valve simultaneously reaches the internal combustion engine from the upstream purge path is different from the timing from the downstream purge path to the internal combustion engine. In the above configuration, the amount of purge gas that reaches the internal combustion engine at the third timing is calculated by adding the upstream purge gas amount at the first timing and the downstream purge gas amount at the second timing. As a result, the amount of purge gas that reaches the internal combustion engine can be calculated in consideration of the timing lag that reaches the internal combustion engine.

(First embodiment)
The evaporated fuel processing apparatus 10 will be described with reference to the drawings. As shown in FIG. 1, the evaporated fuel processing apparatus 10 is mounted on a vehicle such as an automobile, and is disposed in a fuel supply system 2 that supplies fuel stored in a fuel tank FT to an 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 controls the amount of air flowing into the engine EN by adjusting the opening of the intake pipe IP. 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, 2500 rotations).

  An air cleaner AC is disposed upstream of the supercharger CH 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.

  In a situation where the supercharger CH is stopped, negative pressure is generated in the intake pipe IP 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 pipe IP due to the EN drive. On the other hand, in a situation where the supercharger CH is operating, the atmospheric pressure is upstream on the upstream side of the supercharger CH, while positive pressure is generated on the downstream side of the supercharger CH.

  The evaporated fuel processing apparatus 10 supplies the evaporated fuel in the fuel tank FT to the engine EN via the intake pipe IP. The fuel vapor processing apparatus 10 includes a canister 14, a pump 12, a purge pipe 32, a control valve 34, a control unit 102 in the ECU 100, check valves 80 and 83, and a pressure sensor 16. The canister 14 adsorbs the evaporated fuel generated in the fuel tank FT. The canister 14 includes 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.

  A purge pipe 32 communicates with the purge port 14b. A mixed gas (hereinafter referred to as “purge gas”) with air containing evaporated fuel in the canister 14 flows into the purge pipe 32 from the canister 14 through the purge port 14b. The purge pipe 32 defines purge paths 22, 24 and 26. The purge gas in the purge pipe 32 flows through the purge paths 22, 24, and 26 and is supplied to the intake path IW.

  The purge pipe 32 branches into two at a branch position 32a intermediate between the canister 14 and the intake path IW. One of the purge pipes 32 after branching is connected to an intake manifold IM arranged in the intake pipe IP on the engine EN side (that is, downstream side) from the throttle valve TV and the supercharger CH. The other of the pipes 32 is connected to the air cleaner AC side (that is, the upstream side) from the throttle valve TV and the supercharger CH. A purge path 22 is defined by a purge pipe 32 closer to the canister 14 than the branch position 32a, and a purge path 24 is defined by a purge pipe 32 connected downstream from the branch position 32a of the purge pipe 32, A purge path 26 is defined by the purge pipe 32 connected upstream from the branch position 32 a of the purge pipe 32.

  A pump 12 is disposed at an intermediate position of the purge path 22. 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 control unit 102. The suction port of the pump 12 communicates with the canister 14 via the purge path 22.

  The discharge port of the pump 12 communicates with the purge pipe 32. The pump 12 delivers purge gas to the purge path 22. The purge gas sent to the purge path 22 passes through the purge path 24 or the purge path 26 and is supplied to the intake path IW.

  A check valve 83 is disposed in the purge path 24. The check valve 83 allows the gas to flow through the purge path 24 toward the intake path IW, and prohibits the gas from flowing toward the canister 14. A check valve 80 is disposed in the purge path 26. The check valve 80 allows the gas to flow through the purge path 26 toward the intake path IW, and prohibits the gas from flowing toward the canister 14.

  A control valve 34 is disposed in the purge path 22 between the pump 12 and the branch position 32a. When the control valve 34 is closed, the control valve 34 enters a shut-off state in which the canister 14 and the intake path IW are blocked in the purge path 22. In the shut-off state, the purge gas in the purge path 22 is stopped by the control valve 34 and does not flow toward the intake path IW. On the other hand, when the control valve 34 is opened, a communication state is established in which the canister 14 and the intake path IW are connected via the purge path 22. As a result, the purge gas flows toward the intake path IW. The control valve 34 is an electronic control valve and is controlled by the control unit 102. Of the purge paths 22, the purge path 22 positioned downstream of the control valve 34 is referred to as “purge path 22 a”, and the purge path 22 positioned upstream of the control valve 34 is referred to as “purge path 22 b. "

  A pressure sensor 16 is disposed in the intake manifold IM. The pressure sensor 16 detects the pressure of the intake manifold IM. The pressure sensor 16 may be disposed at a position where the pressure matches the intake manifold IM, that is, between the throttle valve TV and the engine EN.

  The control unit 102 is a part of the ECU 100 and 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 104 such as a ROM and a RAM. The control unit 102 controls the evaporated fuel processing apparatus 10 according to a program stored in the memory 104 in advance. Specifically, the control unit 102 outputs a signal to the pump 12 to control the pump 12. In addition, the control unit 102 outputs a signal to the control valve 34 to execute duty control. That is, the control unit 102 adjusts the valve opening time of the control valve 34 by adjusting the duty ratio of the signal output to the control valve 34.

  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 air 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 gas sucked into the engine EN (that is, the amount of intake air).

  Next, a purge process for supplying purge gas from the canister 14 to the intake path IW will be described. When the engine EN is being driven and the purge condition is satisfied, the control unit 102 performs a purge process by duty-controlling the control valve 34. The purge condition is a condition that is established when a purge process for supplying purge gas to the engine EN is to be executed, and is preset in the control unit 102 by the manufacturer according to the specific situation of the coolant temperature and purge concentration of the engine EN. It is a condition. The controller 102 constantly monitors whether the purge condition is satisfied while the engine EN is being driven.

  In the purge process, purge gas is supplied from the canister 14 via the purge paths 22 and 24 to the intake path IW on the downstream side of the throttle valve TV, or from the canister 14 via the purge paths 22 and 26 and the supercharger. It is supplied to the intake path IW upstream of CH. Which path is supplied varies depending on the pressure of the intake manifold IM (that is, the pressure of the intake path IW downstream of the throttle valve TV).

  When the supercharger CH is not operating, the intake passage IW on the downstream side of the throttle valve TV becomes negative pressure by driving the engine EN. On the other hand, the intake path IW on the upstream side of the throttle valve TV is substantially equal to the atmospheric pressure. As a result, the purge gas is mainly supplied from the canister 14 via the purge paths 22 and 24 to the intake path IW (that is, in the intake manifold IM) on the downstream side of the throttle valve TV. A path of purge gas supplied from the control valve 34 to the engine EN through the purge paths 22a and 24 and the intake path IW is referred to as a downstream purge path FP.

  On the other hand, while the supercharger CH is operating, the air on the downstream side of the supercharger CH is pressurized by the supercharger CH. For this reason, the pressure of the intake passage IW is higher on the downstream side than the supercharger CH than on the upstream side of the supercharger CH. As a result, the purge gas is mainly supplied from the canister 14 via the purge paths 22 and 26 to the intake path IW on the upstream side of the supercharger CH. Note that the intake path IW on the upstream side of the supercharger CH approximates atmospheric pressure, and a slight negative pressure is generated by the supercharger CH. A path of purge gas supplied from the control valve 34 to the engine EN through the purge paths 22a and 26 and the intake path IW is referred to as an upstream purge path SP. The upstream purge path SP is longer than the downstream purge path FP.

  When the purge process is performed while the supercharger CH is operating, the control unit 102 drives the pump 12 to pump the purge gas, so that a larger amount of the purge gas is supplied to the upstream purge path SP. On the other hand, when the purge process is executed while the supercharger CH is not operating, a large amount of purge gas is supplied to the downstream purge path FP. If the negative pressure of the intake passage IW is small and the purge gas is not sufficiently supplied to the intake passage IW due to, for example, when the opening of the throttle valve TV is large, the control unit 102 drives the pump 12 to supply the purge gas to the intake passage. Supply to IW. The control unit 102 controls the rotational speed of the pump 12 in accordance with the negative pressure state of the intake path IW. Specifically, the control unit 102 drives or stops the pump 12 at any of a plurality of rotation speeds (for example, 0, 4000, 8000, and 12000 rpm) among 0 to 12000 rpm. In the modification, the control unit 102 may be able to control the rotation speed of the pump 12 with an arbitrary value between 0 and 12000 rpm.

  While the purge process is being performed, the engine EN is supplied with the fuel supplied from the fuel tank FT via the injector IJ and the evaporated fuel by the purge process. The control unit 102 adjusts the air-fuel ratio of the engine EN to an optimal air-fuel ratio (for example, ideal air-fuel ratio) by adjusting the fuel injection time from the injector IJ and the duty ratio of the control valve 34.

  Therefore, it is desired that the control unit 102 appropriately grasps the amount of fuel supplied from the injector IJ to the engine EN and the amount of fuel supplied to the engine EN by the purge process. The fuel supplied from the injector IJ to the engine EN is determined by the fuel injection time from the injector IJ. On the other hand, the fuel supplied by the purge process varies depending on the purge concentration and the purge gas amount from the control valve 34.

  A method for estimating the purge gas amount supplied to the engine EN will be described. First, the memory 104 will be described.

  As shown in FIG. 2, the memory 104 stores a stop gas amount data map indicating the relationship between the pressure of the intake manifold IM and the purge gas amount passing through the control valve 34 when the pump 12 is stopped. . In the memory 104, the relationship between the pressure of the intake manifold IM shown in the graph of FIG. 2 and the amount of purge gas passing through the control valve 34 is digitized and stored. The purge gas amount is a purge gas amount when the duty ratio of the control valve 34 is 1.0 (that is, a state in which the control valve 34 is maintained in the fully open state during the purge process) (hereinafter referred to as “a fully opened purge gas amount”). Call it.) When the pump 12 is stopped, the pressure in the purge path 22b upstream of the control valve 34 approximates atmospheric pressure. For this reason, when the pressure of the intake manifold IM increases (that is, when the negative pressure decreases), the purge gas amount decreases. When the pressure of the intake manifold IM reaches atmospheric pressure, there is no pressure difference upstream and downstream of the control valve 34, and the purge gas does not substantially flow.

  Further, as shown in FIG. 3, the memory 104 is a driving gas amount data map showing the relationship between the pressure of the intake manifold IM and the fully opened purge gas amount passing through the control valve 34 when the pump 12 is driven. Storing. The driving gas amount data map is data indicating the relationship between the pressure of the intake manifold IM and the fully opened purge gas amount passing through the control valve 34 for each of a plurality of rotation speeds (for example, 4000, 8000, 12000 rpm) of the pump 12. Have. In FIG. 3, among the plurality of rotation speeds, the pressure of the intake manifold IM having the maximum rotation speed (for example, 12000 rpm) indicated by a solid line and the minimum rotation speed (for example, 4000 rpm) indicated by a broken line passes through the control valve 34. The relationship with the fully opened purge gas amount is shown. However, the operating gas amount data map has a relationship between the pressure of the intake manifold IM and the fully opened purge gas amount passing through the control valve 34 for each of the plurality of rotation speeds of the pump 12. In the memory 104, the relationship between the pressure of the intake manifold IM shown in the graph of FIG. 3 and the fully opened purge gas amount passing through the control valve 34 is digitized and stored.

  In the modified example, the driving gas amount data map is data indicating the relationship between the pressure of the intake manifold IM and the fully opened purge gas amount passing through the control valve 34 for the maximum number of rotations of the pump 12 (for example, 12000 rpm). You may have. In this case, the control unit 102 detects the difference between the fully opened purge gas amount when the pump 12 is at the maximum rotation speed and the fully opened purge gas amount when the pump is at the minimum rotation number, and the fully opened purge gas representing the change due to the pressure of the intake manifold IM A quantity difference data map may be further stored. The control unit 102 uses the pressure of the intake manifold IM and the current rotation speed of the pump 12 to determine the difference between the maximum open purge gas amount at the maximum opening−the purge gas amount × (the current rotation speed of the pump 12−the minimum rotation speed). The fully purged purge gas amount may be calculated by calculating (the number of rotations (for example, 4000 rpm)) / (maximum number of rotations−minimum number of rotations).

  When the negative pressure of the intake manifold IM is large and the pump 12 is driven, the purge gas that has passed through the control valve 34 passes through the downstream purge path FP. When the negative pressure of the intake manifold IM is reduced and the difference from the pressure of the intake passage IW upstream of the throttle valve TV (ie, atmospheric pressure) is reduced, the purge gas also flows through the upstream purge passage SP. When the pressure of the intake manifold IM exceeds the atmospheric pressure (that is, when the supercharger CH operates), the purge gas flows through the upstream purge path SP and hardly flows through the downstream purge path FP. For this reason, when the pressure of the intake manifold IM exceeds atmospheric pressure, the amount of purge gas does not change even if the pressure of the intake manifold IM increases.

  As shown in FIG. 4, the memory 104 further stores a ratio data map indicating the relationship between the intake manifold pressure and the upstream flow rate. The upstream flow rate indicates the ratio of the upstream purge gas amount flowing through the upstream purge path SP out of the fully opened purge gas amount passing through the control valve 34.

  The stop gas amount data map in FIG. 2, the drive gas amount data map in FIG. 3, and the ratio data map in FIG. 4 are specified in advance by experiments and stored in the memory 104.

  As shown in FIG. 5, the memory 104 has 300 upstream storage areas 104 a (No. 1 and No. 2 are only given signs) from No. 1 to No. 300. Each upstream storage area 104a stores the upstream purge gas amount of each of the 300 partial paths 26a when the upstream purge path SP is divided into 300 equal parts by volume. 300 partial paths 26a from the control valve 34 to the engine EN correspond to the first to 300th upstream storage areas 104a in order from the control valve 34. The division of the purge path 26 and the like is not limited to the volume, and may be divided on the basis of the length.

  As shown in FIG. 7, the memory 104 further has 50 downstream storage areas 104 b from No. 1 to No. 50 (in FIG. 7, only No. 1 and No. 2 are given symbols). Each downstream storage area 104b stores the downstream purge gas amount of each of the 50 partial paths 24a when the downstream purge path FP is divided into 50 equal parts by volume. Fifty partial paths 24a from the control valve 34 to the engine EN correspond to the first to 50th downstream storage areas 104b in order from the control valve 34. The division of the purge path 26 and the like is not limited to the volume, and may be divided on the basis of the length.

  As shown in FIG. 6, the memory 104 is further used in a data map 106 used in an upstream purge gas amount determination process (see FIG. 9) described later and in a downstream purge gas amount determination process (see FIG. 12). The data map 107 is stored. The data maps 106 and 107 are clarified in each purge gas amount determination process described later.

  When the ignition switch is turned on, the control unit 102 passes the control valve 34 and flows through the upstream purge path SP, and the downstream side flows through the control valve 34 and flows through the downstream purge path FP. A purge gas amount calculation process for calculating the purge gas amount is started. The control unit 102 executes a purge gas amount calculation process periodically (for example, every 16 ms).

  As shown in FIG. 8, in the purge gas amount calculation process, first, in S1, the control unit 102 determines whether or not the purge process is being executed. Specifically, it is determined whether the control valve 34 is duty controlled. If the control valve 34 is duty controlled, it is determined that the purge process is being executed (YES in S1), and the process proceeds to S2. In S2, the control unit 102 determines whether or not the pump 12 is being driven. When the pump 12 is not being driven (NO in S2), in S4, the control unit 102 specifies the fully opened purge gas amount using the stop gas amount data map (see FIG. 2). Specifically, the control unit 102 acquires the pressure of the intake manifold IM from the pressure sensor 16. Next, the control unit 102 specifies the fully opened purge gas amount corresponding to the acquired pressure in the stop gas amount data map, and proceeds to S5.

  On the other hand, when the pump 12 is being driven (YES in S2), in S3, the control unit 102 specifies the fully opened purge gas amount using the driving gas amount data map (see FIG. 3). Specifically, the control unit 102 acquires the pressure of the intake manifold IM from the pressure sensor 16 and acquires the rotation speed from the pump 12. Next, the control unit 102 specifies the fully opened purge gas amount using the relationship between the acquired intake manifold IM pressure and the fully opened purge gas amount corresponding to the acquired rotation speed in the driving gas amount data map. Then, the process proceeds to S5.

  In S5, the control unit 102 specifies the upstream flow rate using the ratio data map (see FIG. 4). Specifically, the control unit 102 specifies the upstream flow rate corresponding to the pressure of the intake manifold IM acquired in S3 or S4. Next, in S6, the control unit 102 calculates the upstream purge gas amount. Specifically, the control unit 102 first acquires the duty ratio of the control valve 34. Next, the control unit 102 multiplies the fully opened purge gas amount specified in S3 or S4 by the duty ratio. Thus, the amount of purge gas that actually passes through the control valve 34 (hereinafter referred to as “actual purge gas amount”) is calculated. Next, the control unit 102 calculates the upstream purge gas amount by multiplying the actual purge gas amount by the upstream flow rate specified in S5.

  Next, in S7, the control unit 102 calculates the downstream purge gas amount. The control unit 102 calculates the downstream purge gas amount by multiplying the actual purge gas amount calculated in S6 by the value obtained by subtracting the upstream flow rate specified in S5 from 1.0. In the modification, the control unit 102 may calculate the downstream purge gas amount by subtracting the upstream purge gas amount calculated in S6 from the actual purge gas amount calculated in S6. When the downstream purge gas amount is calculated, the purge gas amount calculation process ends.

  On the other hand, if the control valve 34 is not duty-controlled in S1, it is determined that the purge process is not being executed (NO in S1), and the process proceeds to S8. In S8, the control unit 102 specifies both the upstream purge gas amount and the downstream purge gas amount as 0 liter / minute, and the purge gas amount calculation processing is completed.

  The control unit 102 sequentially executes an upstream purge gas amount determination process shown in FIG. 9 and a downstream purge gas amount determination process shown in FIG. 12 independently of the purge gas amount calculation process. In the upstream purge gas amount determination process, the upstream purge gas amount supplied to the engine EN through the upstream purge path SP is determined using the upstream purge gas amount stored in the upstream storage area 104a. On the other hand, in the downstream purge gas amount determination process, the downstream purge gas amount supplied to the engine EN through the downstream purge path FP is determined using the downstream purge gas amount stored in the downstream storage region 104b.

  Each purge gas amount determination process is started when the ignition switch is turned on, and is repeatedly executed periodically (for example, every 16 ms) until the ignition switch is switched from on to off. At the timing when these purge gas amount determination processes are started, default values are stored in the storage areas 104 a and 104 b of the memory 104. The contents in the storage areas 104a and 104b are replaced with default values when the ignition switch is switched from OFF to ON.

  As shown in FIG. 9, in the upstream purge gas amount determination process, first, in S12, the control unit 102 determines whether or not a default value is stored in all the upstream storage areas 104a. If default values are stored in all the upstream storage areas 104a (YES in S12), in S14, the control unit 102 stores 0 in all the upstream storage areas 104a and proceeds to S16. On the other hand, if a value other than the default value is stored in any of the upstream storage areas 104a (NO in S12), S14 is skipped and the process proceeds to S16.

  In the processing of S16 to S20, the upstream purge gas amount stored in the upstream storage region 104a is shifted in accordance with the intake amount per unit time in the intake path IW. The intake air amount is a value obtained by adding the value detected by the air flow meter 52 to the actual purge gas amount calculated in S5 of the purge gas amount calculation process most recently. In S16, the control unit 102 specifies the number of the upstream storage area 104a to which the upstream purge gas amount stored in the first upstream storage area 104a is moved (hereinafter referred to as “shift number”). To do.

  As shown in FIG. 6, the memory 104 stores a data map 106 in which the intake amount per second and the shift number are associated with each other. The data map 106 is calculated in advance and stored in the memory 104. The data map 106 is calculated and created based on the following. That is, it is assumed that the upstream purge path SP has a volume of 7 liters, 300 upstream storage areas 104a, and an upstream purge gas amount determination process execution period of 16 ms.

  In this case, one upstream storage area 104a corresponds to a volume of 0.023 liters (≈7 liters / 300 pieces) of the upstream purge path SP. Therefore, when the intake amount per second is 0.023 liters / 16 ms≈1.44 liters / second, every time the upstream purge gas amount determination process is executed (that is, every 16 ms), the first to 299th When the purge concentration in the upstream storage area 104a is stored in place of the upstream purge gas amount stored in the upstream storage area 104a of No. 2 to 300 (that is, shift number = 1), The upstream purge gas amount in the upstream storage area 104a is shifted in accordance with the purge gas flow. Based on this, the number of shifts is determined in accordance with the intake amount per second. For example, when the intake amount per second is 10.0 liters / second, the shift number is 7 (≈10.0 / 1.44).

  In S <b> 16, the control unit 102 specifies the shift number (hereinafter, “300−M” (an integer of 1 ≦ M ≦ 300)) using the intake air amount and the data map 106. In subsequent S18, the control unit 102 replaces the upstream purge gas amount stored in the 1st to Mth upstream storage areas 104a with the 300th to 300-M + 1th upstream storage areas 104a and stores them. . As a result, the upstream purge gas amount stored in the 300th upstream storage region 104a, that is, the upstream purge gas amount supplied to the engine EN via the upstream purge path SP is updated. Note that the purge gas flows in the purge path 26 even when the supercharger CH is not operating. Therefore, the upstream purge gas amount in the upstream storage area 104a is shifted regardless of whether or not the supercharger CH is operating. In the modification, the number of shifts may be changed in consideration of the upstream purge gas amount flowing through the purge path 26 according to whether the blow-off valve of the supercharger CH is operating.

  Next, in S20, the control unit 102 changes the upstream purge gas amount calculated in S6 of the most recently executed purge gas amount calculation process or the upstream purge gas amount (that is, 0) specified in S8 from the 300-Mth. Substituting and storing in the first upstream storage area 104a, the upstream purge gas amount determination processing is terminated.

  In the evaporated fuel processing apparatus 10, the purge gas amount passing through the control valve 34 is specified in the purge gas amount calculation processing. It takes time for the purge gas of the specified purge gas amount to reach the engine EN. In the upstream purge gas amount determination process, the purge gas amount in the engine EN is changed as the purge gas flows through the upstream purge path SP.

  As shown in FIG. 10, when the intake air amount is relatively small at 2.0 liters / second and the shift number = 300−M = 1 (that is, M = 299) is specified in S16, the processing in S18 and S20 is performed. , The upstream purge gas amounts α1 to α299 stored in the first to 299th upstream storage regions 104a are changed to the upstream purge gas amounts α2 stored in the second to 300th upstream storage regions 104a, respectively. ˜α300 is replaced and stored. Then, the latest upstream purge gas amount β is stored in the first upstream storage area 104a.

  On the other hand, as shown in FIG. 11, when the purge flow rate is relatively large as 144 liters / second and the shift number = 300−M = 100 (that is, M = 200) is specified in S16, the processing of S18 and S20 The upstream purge gas amounts α1 to α200 stored in the first to 200th upstream storage regions 104a are respectively converted into the upstream purge gas amounts α101 stored in the 101st to 300th upstream storage regions 104a. Replace with each of ~ 300 and store. Then, the latest upstream purge gas amount β is stored in the first to 100th upstream storage areas 104a.

  According to this configuration, the upstream purge gas amount supplied to the engine EN through the upstream purge path SP can be changed in accordance with the intake air amount.

  When the upstream purge gas amount determination process is completed, the downstream purge gas amount determination process shown in FIG. 12 is subsequently performed. In the downstream purge gas amount determination process, first, the processes of S112 to S118 similar to S12 to S18 of the upstream purge gas amount determination process are executed. In S116, the control unit 102 moves the downstream purge gas amount stored in the first downstream storage area 104b to which downstream storage area 104b (hereinafter referred to as “shift number”). Is identified.

  As shown in FIG. 6, the memory 104 stores a data map 107 in which the intake amount per second and the shift number are associated with each other. The data map 107 is calculated in advance and stored in the memory 104. The data map 107 is calculated and created based on the following. That is, it is assumed that the volume of the downstream purge path FP is 1.2 liters, the downstream storage area 104b is 50, and the execution period of the downstream purge gas amount determination process is 16 ms.

  In this case, one downstream storage area 104b corresponds to a volume of 0.023 liters (≈1.2 liters / 50 pieces) of the downstream purge path FP. For this reason, when the intake amount per second is 0.023 liters / 16 ms≈1.44 liters / second, every time the downstream purge gas amount determination process is executed (that is, every 16 ms), No. 1 to 49 When the purge concentration in the No. 2 downstream storage area 104b is stored in place of the downstream purge gas amount stored in the No. 2 to No. 50 downstream storage areas 104b (that is, the shift number = 1), The downstream purge gas amount in the downstream storage area 104b is shifted in accordance with the purge gas flow. Based on this, the number of shifts is determined in accordance with the intake amount per second. For example, when the intake amount per second is 10.0 liters / second, the shift number is 7 (≈10.0 / 1.44).

  In S116, the control unit 102 specifies the number of shifts (hereinafter referred to as “50−Y” (1 ≦ Y ≦ 50)) using the intake air amount and the data map 107. In subsequent S118, the control unit 102 replaces the downstream purge gas amount stored in the 1st to Yth downstream storage areas 104b with the 50th to 50-Y + 1th downstream storage areas 104b and stores them. . As a result, the downstream purge gas amount stored in the 50th downstream storage region 104b, that is, the downstream purge gas amount supplied to the engine EN via the downstream purge path FP is updated. Note that the purge gas flows in the purge path 24 even when the supercharger CH is operating. Therefore, the downstream purge gas amount in the downstream storage area 104b is shifted regardless of whether or not the supercharger CH is operating. In the modification, the number of shifts may be changed in consideration of the downstream purge gas amount flowing through the purge path 24 in accordance with the presence or absence of the operation of the blow-off valve of the supercharger CH.

  Next, in S120, the control unit 102 sets the downstream purge gas amount calculated in S7 of the most recently executed purge gas amount calculation process or the downstream purge gas amount (ie, “0”) specified in S8 to 50-Y. No. 1 to No. 1 downstream storage area 104b and store, and the downstream purge gas amount determination processing ends.

  In the fuel vapor processing apparatus 10, the downstream purge gas amount passing through the control valve 34 is specified in the purge gas amount calculation processing. It takes time for the specified amount of the purge gas on the downstream side to reach the engine EN. In the downstream purge gas amount determination process, the downstream purge gas amount in the engine EN is changed as the purge gas flows through the downstream purge path FP.

  According to the downstream purge gas amount determination process, as in the upstream purge gas amount determination process, the shift number is large when the intake amount is relatively large, and the shift number is small when the intake amount is relatively small. According to this configuration, the downstream purge gas amount supplied to the engine EN through the downstream purge path FP can be changed in accordance with the intake air amount.

  The control unit 102 determines the total purge gas amount of the upstream purge gas amount currently stored in the No. 300 upstream storage region 104a and the downstream purge gas amount stored in the No. 50 downstream storage region 104b. Can be estimated as the amount of purge gas supplied to the engine EN.

  The ECU 100 adjusts the fuel injection time from the injector IJ so that the air-fuel ratio detected by the air-fuel ratio sensor 50 becomes a predetermined reference air-fuel ratio (for example, ideal air-fuel ratio), and is supplied to the engine EN. Control the fuel injection amount. When the purge process is executed, the air-fuel ratio changes to the rich side. At this time, the ECU 100 assumes that the purge concentration is a predetermined X%. Then, using the estimated purge gas amount, the amount of fuel supplied by the purge process is specified. The ECU 100 adjusts the fuel injection time from the injector IJ based on the specified fuel amount, and controls the fuel injection amount (that is, decreases the fuel injection amount). At this time, when the air-fuel ratio is maintained rich, the ECU 100 further adds X% to the assumed purge concentration and specifies the amount of fuel supplied by the purge process in the same manner as described above. The ECU 100 repeats the above processing so that the air-fuel ratio becomes the reference air-fuel ratio. If the purge gas amount supplied to the engine EN by the purge process is appropriately estimated, the air-fuel ratio can be controlled to the reference air-fuel ratio at an early stage after the purge process is started.

  In this embodiment, in the purge gas amount calculation process, the flow from the control valve 34 toward the intake path IW using the pressure of the intake manifold IM, the rotational speed of the pump 12, and the opening degree (that is, the duty ratio) of the control valve 34. The amount of purge gas can be specified appropriately.

  Further, by executing the upstream purge gas amount determination process and the downstream purge gas amount determination process, the purge gas reaches the engine EN due to the difference in length between the upstream purge path SP and the downstream purge path FP. Considering that the timing is different, the amount of purge gas reaching the engine EN can be specified. Further, by using the stop gas amount data map, the drive gas amount data map, and the ratio data map, the pressure of the intake manifold IM, the rotation speed of the pump 12, and the opening degree (that is, the duty ratio) of the control valve 34 are used. Thus, the purge gas amount can be calculated appropriately.

(Second embodiment)
In the second embodiment, the purge gas amount calculation process (see FIG. 8) executed by the control unit 102 is different. Further, the control unit 102 does not execute the upstream purge gas determination process (see FIG. 9) and the downstream purge gas determination process (see FIG. 12). As shown in FIG. 15, the memory 104 has 313 upstream storage areas 204a instead of the upstream storage area 104a of the first embodiment. The upstream storage area 204a does not correspond to a section of the upstream purge path SP. Further, as shown in FIG. 16, the memory 104 has 53 downstream storage areas 204b instead of the downstream storage area 104b of the first embodiment. The downstream storage area 204b does not correspond to a section of the downstream purge path FP.

  Further, as shown in FIG. 13, the memory 104 stores data maps 206 and 207 in which the intake amount per second, the number, and the coefficient are associated with each other instead of the data maps 106 and 107. The data maps 206 and 207 are calculated in advance and stored in the memory 104. The data map 206 is calculated and created as follows. In other words, when the upstream purge path SP has a volume of 7.0 liters, and the minimum value of the intake air amount is 1.4 liters / second, the purge gas moves through the upstream purge path SP with the minimum purge flow rate. It takes 5000ms to flow from the engine to the engine EN. If the execution period of the upstream purge gas amount determination process is 16 ms, 5000 ms / 16 ms = 313 upstream storage areas 204a are prepared, and when the purge flow rate is 1.4 liters / second, the upstream side of No. 313 The storage area 204a is created to be selected. The upstream coefficient is used when calculating the upstream purge gas amount in S54 described later.

  The data map 207 is calculated and created as follows. That is, when the volume of the upstream purge path SP is 1.2 liters, and the minimum value of the intake air amount is 1.4 liters / second, the purge gas moves through the upstream purge path SP at the minimum purge flow rate. It takes 850 ms to flow from the engine to the engine EN. Assuming that the execution cycle of the upstream determination process is 16 ms, the downstream storage area 204b of 850 ms / 16 ms = 53 is selected when the purge flow rate is 1.4 liters / second. The downstream coefficient is used when calculating the downstream purge gas amount in S56 described later.

  The memory 104 further includes a downstream purge gas amount data map 208 and a replacement gas amount data map (see FIG. 2), a driving gas amount data map (see FIG. 3), and a coefficient data map (see FIG. 4). The upstream purge gas amount data map 210 is stored in advance.

  These data maps 206, 207, 208 and 210 are specified in advance by experiments and stored in the memory 104.

  The downstream purge gas amount data map 208 shows the relationship between the rotational speed of the pump 12, the pressure of the intake manifold IM, and the downstream purge gas amount flowing through the control valve 34 to the downstream purge path FP. The downstream purge gas amount in the downstream purge gas amount data map 208 is the downstream side when the duty ratio when the control valve 34 is duty controlled is 1.0 (that is, the state is maintained in the fully opened state during the purge process). This is the purge gas amount (hereinafter referred to as “the downstream side purge gas amount when fully opened”). For example, when the rotational speed of the pump 12 is 8000 rpm and the pressure of the intake manifold IM is 100 kPa, the downstream purge gas amount when fully opened is 9 liters / minute. It should be noted that the fully opened downstream purge gas amount when the pressure of the intake manifold IM is 110 kPa or more matches the case where the pressure of the intake manifold IM is 110 kPa.

  The upstream gas amount data map 210 shows the relationship between the rotational speed of the pump 12, the pressure of the intake manifold IM, and the upstream purge gas amount that flows through the control valve 34 and flows into the upstream purge path SP. The upstream purge gas amount in the upstream purge gas amount data map 210 is referred to as an upstream purge gas amount when the duty ratio of the control valve 34 is 1.0 (hereinafter referred to as “upstream purge gas amount when fully open”). ). For example, when the rotational speed of the pump 12 is 8000 rpm and the pressure of the intake manifold IM is 100 kPa, the upstream purge gas amount when fully opened is 9 liters / minute. It should be noted that the fully opened upstream purge gas amount when the pressure of the intake manifold IM is 110 kPa or more matches the case where the pressure of the intake manifold IM is 110 kPa. Further, the fully purged upstream purge gas amount when the pressure of the intake manifold IM is 90 kPa or less coincides with the case where the pressure of the intake manifold IM is 90 kPa.

  The rotational speed of the pump 12 in the downstream purge gas amount data map 208 and the upstream purge gas amount data map 210 is determined by how the pump 12 is controlled. When the rotation speed of the pump 12 is switched in stages, the upstream and downstream purge gas amounts when fully opened may be recorded for each of the rotation speeds to be switched.

  Next, a purge gas amount calculation process executed by the control unit 102 will be described with reference to FIG. The purge gas amount calculation process is executed periodically (for example, every 16 ms). First, in S60, as in S1 of FIG. 8, it is determined whether the purge process is being executed. When the purge process is being executed (YES in S60), in S62, the control unit 102 specifies the rotation speed of the pump 12. Next, in S64, the control unit 102 specifies the pressure of the intake manifold IM. In subsequent S66, the control unit 102 calculates the upstream purge gas amount. Specifically, the control unit 102 uses the upstream purge gas amount data to determine the fully opened upstream purge gas amount corresponding to the rotational speed of the pump 12 specified in S62 and the pressure of the intake manifold IM specified in S64. It is specified from the map 210. Next, the control unit 102 calculates the upstream purge gas amount by multiplying the fully purged upstream purge gas amount by the duty ratio.

  Next, in S68, the control unit 102 calculates the downstream purge gas amount. Specifically, the control unit 102 obtains the downstream-side purge gas amount corresponding to the rotational speed of the pump 12 specified in S62 and the pressure of the intake manifold IM specified in S64 as downstream purge gas amount data. It is specified from the map 208. Next, the control unit 102 calculates the downstream purge gas amount by multiplying the fully purged downstream purge gas amount by the duty ratio, and ends the purge gas amount calculation process.

  On the other hand, when the purge process is being executed (NO in S60), in S69, the control unit 102 specifies the upstream purge gas amount and the downstream purge gas amount as 0 liter / min, and ends the purge gas amount calculation process. .

  Each time the control unit 102 executes the purge gas amount calculation process, the control unit 102 stores the upstream purge gas amount (hereinafter, “β”) calculated in S66 in the storage area 204a, and the storage area 204b calculated in S68. The downstream purge gas amount (hereinafter, “δ”) is stored. Specifically, as shown in FIG. 15, the control unit 102 converts the upstream purge gas amounts α1 to α312 stored in the upstream storage areas 204a from No. 1 to 312 to Nos. 2 to 313, respectively. The upstream purge gas amounts α2 to α313 stored in the upstream storage area 204a are replaced and stored. Then, the control unit 102 stores the upstream purge gas amount β in the first upstream storage area 204a. Similarly, as shown in FIG. 16, the control unit 102 converts the downstream purge gas amounts γ1 to γ52 stored in the 1st to 52nd downstream storage areas 204b into the 2nd to 53rd storage areas. The downstream purge gas amounts γ2 to γ53 stored in 204b are replaced and stored. Then, the control unit 102 stores the downstream purge gas amount δ in the first downstream storage area 204b.

  Next, a purge gas amount estimation process for estimating a purge gas amount in the engine EN will be described with reference to FIG. First, in S52, the control unit 102 specifies the number of the upstream storage area 204a and the upstream coefficient using the intake air amount of the engine EN and the data maps 206 and 207, and stores the data in the downstream storage area 204b. The number and the downstream coefficient are specified. The intake amount of the engine EN is the sum of the intake amount detected by the air flow meter 52, the upstream purge gas amount specified by the purge gas amount calculation process, and the downstream purge gas amount.

  Next, in S54, the control unit 102 determines the upstream purge gas amount estimated in the previous S54 (default value (for example, “0”) in the absence) (hereinafter referred to as “upstream previous gas amount”), and in S52. Using the upstream purge gas amount (hereinafter referred to as “upstream specific gas amount”) stored in the upstream storage area 204 a of the number specified from the data map 206 and the coefficient, the upstream previous gas amount is used. The upstream purge gas amount supplied from the upstream purge path SP is estimated by calculating + (upstream specific gas amount−upstream previous gas amount) / coefficient. When the intake amount is 75.0 liters / second or more, the number of the downstream storage area 204b is 1, and the downstream coefficient is 1.

  Next, in S56, the control unit 102 determines the downstream purge gas amount estimated in the previous S56 (default value (for example, “0”) in the absence) (hereinafter referred to as “downstream previous gas amount”), and in S52. Using the purge gas amount (hereinafter referred to as “downstream specific gas amount”) stored in the downstream storage area 204b of the number specified from the data map 207 and the coefficient, the downstream previous gas amount + ( By calculating (downstream specific gas amount−downstream previous gas amount) / coefficient, the downstream purge gas amount supplied from the downstream purge path FP is estimated.

  Next, in S58, the control unit 102 estimates the sum of the upstream purge gas amount estimated in S54 and the downstream purge gas amount estimated in S56 as the purge gas amount in the engine EN.

  In the present embodiment, the purge gas amount estimation process is executed, considering that the arrival timing of the purge gas to the engine EN differs depending on the length difference between the upstream purge path SP and the downstream purge path FP. The amount of purge gas that reaches the engine EN can be specified. Further, by using the downstream purge gas amount data map 208 and the upstream purge gas amount data map 210, the pressure of the intake manifold IM, the rotational speed of the pump 12, and the opening degree (that is, the duty ratio) of the control valve 34 are used. The purge gas amount can be calculated appropriately.

  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.

(1) In each of the above embodiments, the upstream purge path SP connected to the upstream side of the supercharger CH and the downstream purge path FP connected to the downstream side of the supercharger CH are provided. Yes. However, the downstream purge path FP may not be provided. In this case, in the purge gas amount estimation process, the estimation may be performed without considering the purge gas amount from the downstream purge path FP. Further, the control unit 102 may not execute the downstream purge gas amount determination process.

(2) In each of the above embodiments, the supercharger CH is disposed in the intake path IW. However, the supercharger CH may not be arranged. In this case, the upstream purge path SP may not be provided. In the purge gas amount estimation process, the purge gas amount from the upstream purge path SP may be estimated without considering it. Further, the control unit 102 may not execute the upstream purge gas amount determination process.

(3) In the first embodiment, the data maps 106 and 107 associate the intake air amount and the shift number. However, the parameter associated with the shift number may be a plurality of parameters including the engine speed, the purge gas amount, and the pressure on the downstream side of the supercharger CH in addition to the intake air amount. In this case, a data map in which a plurality of parameters and shift numbers are associated may be specified in advance and stored in the memory 104. Further, the control unit 102 may specify a plurality of parameters in S16 of FIG. 9 and S116 of FIG. 12, and may specify the number of shifts associated with the specified parameters from the data maps 106 and 107. .

(4) In the second embodiment, the data maps 206 and 207 associate the intake air amount, the storage area number, and the coefficient. However, the parameter associated with the delivery area number and the coefficient may be a plurality of parameters including the engine speed and the purge gas amount in addition to the intake air amount. In this case, a data map in which a plurality of parameters, storage area numbers, and coefficients are associated may be specified in advance and stored in the memory 104. In addition, the control unit 102 may specify a plurality of parameters in S52 of FIG. 17 and specify a storage area number and a coefficient associated with the specified parameters from the data maps 206 and 207.

(5) In each of the above embodiments, the control valve 34 is duty-controlled. That is, in each of the above embodiments, the duty ratio of the control valve 34 (ratio of the valve opening period to the duty control period) is an example of “the opening degree of the control valve”. However, the control valve 34 may be a valve (for example, a servo valve) whose opening area can be adjusted stepwise or steplessly from the fully open state to the fully closed state. In this case, the control unit 102 may control the amount of purge gas supplied to the engine EN by adjusting the opening area of the control valve 34. In this modification, the opening area of the control valve 34 may be “the opening degree of the control valve”.

(6) In the first embodiment, the amount of purge gas supplied to the engine EN is specified. However, when the purge gas amount passing through the control valve 34 is to be specified, the upstream purge gas amount determination process and the downstream purge gas amount determination process need not be executed. Further, in S5 of the purge gas amount calculation process of FIG. 8, the actual purge gas amount may be calculated, and the processes of S6 and S7 need not be executed.

  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.

2: Fuel supply system 10: Evaporative fuel processing device 12: Pump 14: Canister 16: Pressure sensor 22: Purge path 22a: Purge path 22b: Purge path 24: Purge path 26: Purge path 34: Control valve 102: Control unit 104 : Memory 104a: Upstream storage area 104b: Downstream storage area CH: Supercharger EN: Engine FP: Downstream purge path FT: Fuel tank IJ: Injector IM: Intake manifold IW: Intake path SP: Upstream purge path TV : Throttle valve

Claims (5)

An evaporative fuel processing apparatus mounted on a vehicle in which a fuel tank and an intake manifold of an intake path are communicated with each other through a purge path,
A canister that is disposed in the purge path and adsorbs the evaporated fuel in the fuel tank;
It is arranged in the purge path between the intake path and the canister, and switches between a communication state in which the canister and the intake path are communicated via the purge path and a shut-off state in which the canister and the intake path are blocked on the purge path. A control valve;
A pump disposed in a purge path between the control valve and the canister;
A specific unit that specifies the amount of purge gas in which evaporated fuel and air flowing through the control valve from the pump toward the intake path are determined using the pressure of the intake manifold, the rotation speed of the pump, and the opening of the control valve; An evaporative fuel processing apparatus. In the intake path, a supercharger and a throttle valve located downstream of the supercharger and upstream of the intake manifold are arranged,
The purge path includes a downstream purge path connected to the intake path downstream of the throttle valve and an upstream purge path connected to the intake path upstream of the supercharger between the control valve and the intake path. Branch,
The specifying unit uses the pressure of the intake manifold, the number of rotations of the pump, and the opening of the control valve to determine the upstream purge gas amount from the control valve to the upstream purge path, and the downstream purge gas amount flowing from the control valve to the downstream purge path. The evaporative fuel processing device according to claim 1, wherein A purge control unit that repeatedly switches the canister and the intake path between a communication state and a shut-off state by repeatedly switching the control valve between a fully open state and a fully closed state;
The purge control unit repeatedly switches between the fully open state and the fully closed state, and adjusts the period of the fully open state in the purge period in which purge gas is supplied from the control valve to the intake path, whereby the amount of purge gas flowing from the control valve to the intake path Control
The specific part
Purge gas amount data representing the relationship between the pressure of the intake manifold, the number of rotations of the pump, and the purge gas amount at the time of full opening flowing from the control valve to the intake path when the control valve is kept fully open during the purge period;
The pressure data of the intake manifold and the ratio data indicating the ratio of the upstream purge gas amount to the purge gas amount flowing from the control valve to the intake passage are stored in advance,
Using the intake manifold pressure, the number of revolutions of the pump, purge gas amount data, ratio data, and the ratio of the fully open period to the purge period, the upstream purge gas amount and the downstream purge gas amount are identified. The evaporative fuel processing apparatus according to claim 2. A purge control unit that repeatedly switches the canister and the intake path between a communication state and a shut-off state by repeatedly switching the control valve between a fully open state and a fully closed state;
The purge control unit repeatedly switches between the fully open state and the fully closed state, and adjusts the period of the fully open state in the purge period in which purge gas is supplied from the control valve to the intake path, whereby the amount of purge gas flowing from the control valve to the intake path Control
The specific part
Upstream purge gas amount data representing the relationship between the intake manifold pressure, the number of rotations of the pump, and the upstream purge gas amount when the control valve is maintained fully open during the purge period;
Downstream purge gas amount data representing the relationship between the pressure of the intake manifold, the rotational speed of the pump, and the downstream purge gas amount when the control valve is kept fully open during the purge period;
Is stored in advance,
Using the intake manifold pressure, pump speed, upstream purge gas amount data, downstream purge gas amount data, and the ratio of the fully open period to the purge period, the upstream purge gas amount and the downstream purge gas amount The evaporative fuel processing apparatus according to claim 2, wherein:   The identifying unit adds the upstream purge gas amount identified at the first timing and the downstream purge gas amount identified at the second timing different from the first timing, so that the identifying unit adds more than the first timing and the second timing. The evaporated fuel processing apparatus according to any one of claims 2 to 4, wherein an amount of purge gas that reaches the internal combustion engine at a later third timing is calculated.

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