JP2007085229A - Electric power securing device of vaporized fuel processing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a device capable of determining whether leak diagnosis at the stoppage of a vehicle can be performed or not by estimating whether charging to a battery is sufficiently performed or not during traveling. <P>SOLUTION: This electric power securing device of a vaporized fuel processing system 100 purges a vaporized fuel produced by the vaporization of the fuel in a fuel tank 10 to an intake passage 2 according to the operating conditions of an engine 1. The electric power securing device comprises a leak diagnosing means detecting the leakage of the vaporized fuel from the vaporized fuel processing system 100 when the engine 1 is stopped, a battery supplying an electric power to devices used for the leak diagnosis when the vehicle is stopped, an estimating means estimating whether an electric power amount required for the leak diagnosis is charged into the battery or not, and a determination means determining whether the leak diagnosis can be performed or not on the basis of the battery charged amount estimated by the estimating means. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an evaporative fuel processing system for processing evaporative fuel generated by evaporating fuel in a fuel tank, and particularly an apparatus for securing electric power at the time of leak diagnosis.

  In the evaporative fuel processing system, the evaporative fuel generated in the fuel tank is temporarily adsorbed by the adsorbent of the canister. By opening the purge control valve according to the operating conditions, the adsorbed evaporated fuel is introduced into the intake system of the engine by the intake negative pressure of the engine together with fresh air, burned, and evaporated fuel generated in the fuel tank Prevents from spreading into the atmosphere.

  In the evaporative fuel processing system as described above, a system composed of a purge control valve, a canister, and a fuel tank (hereinafter referred to as an evaporation system) is hermetically closed by closing the purge control valve and the air release valve. A leak diagnosis is performed to detect a leak from the change in pressure in the system. If the oil supply port is opened during refueling diagnosis due to refueling or the like, the evaporation system internal pressure is close to the atmospheric pressure as in the case of the occurrence of a leak, and there is a possibility that a misdiagnosis may occur if there is a leak in the evaporation system.

In Patent Document 1, the presence or absence of refueling is detected based on a change in the remaining amount of fuel at each stop, and when it is determined that there is refueling, the power supply to each device required for the leak diagnosis at stop is interrupted. Devices have been proposed that reduce the consumption of energy.
JP 2004-278409 A

  However, in the above-described leak diagnosis device, if it is determined that the fuel is not supplied, the diagnosis is performed even when the battery does not secure the power necessary for the leak diagnosis, which is necessary at the next start-up. There is a problem that the amount of charge cannot be secured.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an apparatus that can determine whether or not to perform a leak diagnosis when the vehicle is stopped by estimating whether or not the battery charge amount is sufficient. And

  The present invention is an electric power securing device for an evaporative fuel processing system that purges evaporative fuel generated by evaporation of fuel in a fuel tank into an intake passage according to engine operating conditions. This power securing device implements leak diagnosis, leakage diagnosis means for detecting leakage of evaporated fuel from the evaporated fuel processing system when the engine is stopped, a battery that supplies power to equipment used for leakage diagnosis when the vehicle is stopped, and leakage diagnosis An estimation means for estimating whether or not the amount of electric power necessary for charging is charged in the battery, and a determination means for determining whether or not leakage diagnosis can be performed based on the battery charge amount estimated by the estimation means. Features.

  According to the present invention, when it is determined that the battery does not have enough power for leak diagnosis at the time of stopping, the leak diagnosis is not performed. Therefore, the standby power of each device before diagnosis and the power consumption at the time of diagnosis are reduced. Therefore, it is possible to secure the amount of battery power required at the next start.

  Embodiments of the present invention will be described below with reference to the drawings.

(First embodiment)
FIG. 1 is a configuration diagram of an evaporated fuel processing system 100 according to a first embodiment of the present invention. Reference numeral 1 denotes an engine, 2 denotes an intake passage of the engine 1, and 3 denotes an exhaust passage. The intake passage 2 is provided with an intake air amount sensor 4 that detects the intake air amount and a throttle valve 5 that is located downstream of the intake passage 2 and controls the intake air amount. Furthermore, a fuel injection valve 6 that is located downstream of the throttle valve 5 and injects fuel is installed in the intake passage 2. Fuel is injected from the fuel injection valve 6 according to the amount of intake air, and the engine 1 generates an output by burning the fuel / air mixture in the engine 1.

  A fuel tank 10 stores fuel to be supplied to the engine 1 for temporarily adsorbing and holding the evaporated fuel generated in the fuel tank 10 and for sucking the evaporated and held fuel into the engine 1 according to vehicle operating conditions. An evaporative fuel processing system 100 is provided.

  The evaporative fuel processing system 100 includes a canister 12 filled with activated carbon that adsorbs and holds evaporative fuel. The canister 12 is connected to the fuel tank 10 via the first passage 11 and adsorbs and holds the evaporated fuel generated in the tank. In addition, an air release valve 8 that adjusts the introduction of fresh air from the atmosphere communication passage 19 that communicates with the atmosphere is provided above the canister 12. Further, the canister 12 is connected to one end of the second passage 13 at an upper portion thereof. The other end of the second passage 13 is connected to a downstream position of the throttle valve 5 in the intake passage 2, and a purge control valve 7 for adjusting the amount of fuel vapor introduced is provided in the middle. Between the purge control valve 7 and the canister 12, a pressure sensor 9 for measuring the pressure in the evaporation system of the evaporated fuel processing system 100 is provided, and the measured pressure is output to the controller 20 described later.

  The fuel tank 10 includes a fuel pump 18 for pumping fuel. The fuel pump 18 is connected to the fuel injection valve 6 through the fuel supply channel 14. Accordingly, the fuel is discharged to the fuel supply path 14 by the fuel pump 18 and is held at a constant pressure by a regulator (not shown), and this fuel pressure acts on the fuel injection valve 6. The fuel tank 10 is provided with a fuel supply pipe 16 for fueling. A detachable filler cap 15 is attached to the oil supply port of the oil supply pipe 16. At the time of fuel supply, the filler cap 15 is removed and fuel supply is performed. A circulation path 17 is branched and connected to the fuel supply pipe 16, and the opening end of the circulation path 17 opens into the upper space of the fuel tank 10.

  The controller 20 includes a CPU, a ROM, a RAM, and the like (not shown), and includes an opening of the throttle valve 5, a pressure sensor 9, an ignition switch 21, a battery voltage sensor 22, a vehicle speed sensor 23, an engine speed sensor 24, and an applied current of a radiator fan. The outputs of the sensor 25, the coolant temperature sensor 26, the intake air temperature sensor 27, and other various sensors that detect the driving state of the vehicle (not shown) are input.

  The controller 20 opens the purge control valve 7 and the atmosphere release valve 8 according to the driving state of the vehicle, thereby causing the negative pressure of the engine 1 to act on the evaporation system, and the evaporated fuel adsorbed by the canister 12 to the atmosphere. Purge control is performed to introduce the intake air 2 together with fresh air from the communication passage 19.

  Furthermore, the controller 20 performs opening / closing control of the purge control valve 7 and the atmosphere release valve 8 when the vehicle is stopped, and performs leak diagnosis in the evaporation system based on the output of the pressure sensor 9. In the stop-time leak diagnosis, the purge control valve 7 and the atmosphere release valve 8 are closed to seal the inside of the evaporation system, and the pressure sensor 9 detects the pressure change due to the temperature change of the fuel in the fuel tank 10. When there is a leak in the evaporation system, the pressure change due to the temperature change is small, and the pressure value detected by the pressure sensor 9 is close to the atmospheric pressure. Then, the occurrence of a leak in the evaporation system is diagnosed by comparing the amount of pressure change that has changed within a predetermined time required for leak diagnosis, for example, from about 40 minutes to 50 minutes, with a set predetermined value. If leakage is confirmed, the driver is warned at the next start.

  Since such a leak diagnosis is performed when the vehicle is stopped, if the battery charge level is not sufficiently secured, there is a possibility that the necessary amount of power cannot be secured at the next start and the battery may be inadvertently discharged. There is.

  Accordingly, an operation for securing electric power in the stoppage leakage diagnosis performed by the controller 20 will be described with reference to FIG.

  FIG. 2 is a flowchart for determining whether or not the amount of battery charge charged during traveling is sufficient to perform the leakage diagnosis during stoppage, and is performed when the internal combustion engine of the vehicle is started. The start of operation of the internal combustion engine is detected by a signal from the ignition switch 23.

  In steps S101 to S104, the battery voltage V indicating the driving state of the vehicle, the vehicle speed S, the engine speed E, and the current R applied to the radiator fan are used as parameters, and the integrated values of these values are calculated to calculate the battery charge amount. To determine whether is sufficient. Each parameter is detected by a battery voltage sensor 22, a vehicle speed sensor 23, an engine speed sensor 24, and an applied current sensor 25 of a radiator fan.

In step S101, the integrated value V _total of the battery voltage V from the start of operation is calculated by the following formula.
V _total = V _total + V (1)

As shown in FIG. 3A, the battery voltage V is constantly monitored simultaneously with the start of operation, and is a value that varies depending on the operation status. Therefore, as shown in FIG. 3B, the calculated integrated value V _total from the start of operation also _changes according to the operation state.

As in step S101, the integrated value S _total in step S102 the vehicle speed S, the integrated value E _total of the engine speed E In step S103, the integrated value R _total applied current R when the switch On of the fan at step S104 Is calculated by the following mathematical formula.
S _total = S _total + S (2)
E _total = E _total + E (3)
R _total = R _total + R (4)

In step S105, the integrated value of each parameter calculated by the equations (1) to (4) and the threshold value V ₁ , threshold value S ₁ , threshold value E ₁ , threshold value R ₁ (first predetermined values) respectively set. ) And each. That is, as shown in FIG. 3B, it is determined whether or not the integrated value V _total of the battery voltage V is equal to or greater than a predetermined threshold value V ₁ .

  If any one of the parameters is not equal to or greater than the predetermined threshold, the process waits until the condition is satisfied. When all the integrated values satisfy the conditions, it is determined that the battery charge amount necessary for the leak diagnosis at the time of stoppage is charged while traveling, and the process proceeds to step S106 and the diagnosis request flag is set and the leak diagnosis at the time of stoppage is performed. Request.

  After the diagnosis request, in step S107, it is determined based on the signal from the ignition switch 23 whether or not the vehicle has been stopped by key-off (hereinafter referred to as Key Off), and the process is terminated. If the vehicle has not stopped, wait until Key Off is confirmed.

As described above, whether or not the battery charge amount necessary for the leak diagnosis has been charged is determined based on the integrated value of each parameter value. Here, as shown in FIG. 4 (A), the time during which the battery voltage V is equal to or greater than the predetermined threshold value V _a is integrated, and as shown in FIG. 4 (B), the integrated time t _total becomes the predetermined threshold value t. You may make it determine whether it is more than _a . Therefore, whether or not the battery power is charged to the battery while traveling is calculated by calculating each accumulated time for each parameter and comparing the accumulated time with predetermined thresholds. Can be determined.

  When the stop of the vehicle is confirmed, the stop leak diagnosis process shown in the flowchart of FIG. 5 is started.

  In step S108, it is determined whether a diagnosis request flag is set. If the diagnosis request flag is confirmed, the atmosphere release valve 8 is closed in step S109 to seal the inside of the evaporation system, and in step S110, diagnostic parameters necessary for the stop-time leak diagnosis are calculated. That is, the pressure transition in the evaporation system during the leak diagnosis detected by the pressure sensor 9 is monitored, the amount of pressure change in the evaporation system within a predetermined time is calculated, and the value is compared with the set predetermined value. To do. When there is no diagnosis request, the process is terminated, and the supply of power to each device used when the leak diagnosis is performed is stopped without performing the leak diagnosis when the vehicle is stopped.

  In step S111, it is determined whether or not a predetermined time required for leak diagnosis, for example, about 40 to 50 minutes has elapsed since the start of leak diagnosis. If the predetermined time has not elapsed, the process returns to step S111 and the diagnosis is continued until the predetermined time elapses. After a predetermined time has elapsed, the air release valve 8 is opened in step S112, and the stop-time leak diagnosis is terminated.

  In step S113, it is determined whether or not a leak has occurred based on the leak diagnosis parameter calculated in step S110. For example, if the amount of pressure change that has changed within a predetermined time is within a set predetermined value from the pressure change in the evaporation system monitored until a predetermined time has elapsed, it is diagnosed that there is no leak in the evaporation system. If it is determined that no leak has occurred, a normal determination (hereinafter referred to as “OK determination”) is made, and the process ends. If it is determined that a leak has occurred, a failure or abnormality determination (hereinafter referred to as NG determination) is made in step S115, and the driver is warned at the next start.

  The overall operation of the first embodiment will be schematically described. In the process of the leak diagnosis apparatus of the evaporated fuel processing system 100, whether or not the battery charge amount necessary for the leak diagnosis at the time of stoppage is charged during traveling is determined based on the battery voltage V, the vehicle speed S, the engine speed E, and the radiator fan. It is estimated based on the integrated value of the applied current R to. When each integrated value is greater than or equal to each predetermined threshold value (first each predetermined value), it is assumed that the battery is sufficiently charged with electric power, and execution of a leakage diagnosis during traveling is requested. After the request, leak diagnosis is performed when the vehicle stops, and if it is determined that there is no leak, OK is determined and the process is terminated.If it is determined that there is a leak, NG is determined and the next start Alert the driver. On the other hand, when it is determined that the amount of charge of the battery is not sufficient, the supply of power to each device used when the leak diagnosis is performed is stopped without performing the leak diagnosis when the vehicle is stopped.

  As described above, in the first embodiment, the amount of battery charge charged during traveling is estimated, and when it is determined that sufficient power is not secured, the leak diagnosis at the time of stopping is not performed. As a result, standby power in each device before the leak diagnosis and power consumed at the time of leak diagnosis can be suppressed, and battery power necessary at the next start-up can be always secured.

  In addition, since the integrated value of each parameter value is calculated using an existing sensor, the battery charge amount can be determined without adding a new device, and the cost can be reduced.

(Second Embodiment)
A second embodiment of the present invention will be described with reference to the flowchart shown in FIG. The configuration of the second embodiment is the same as that of the first embodiment, but is partially different in the determination time of the integrated value calculated from each parameter. That is, in the second embodiment, the integrated value of each parameter is determined after the internal combustion engine is stopped, and the difference will be described below.

  The process for securing electric power in the second embodiment is performed together with the start of operation of the internal combustion engine of the vehicle. The start of operation of the internal combustion engine is detected by a signal from the ignition switch 23.

  In step S201 to step S204, each integrated value for each parameter is calculated in the same manner as in the first embodiment, and the process proceeds to step S205.

  In step S205, it is determined whether or not the vehicle has stopped based on the signal of the ignition switch 23 by Key Off. If it is determined that the vehicle has not stopped, the system waits until the vehicle is confirmed to be stopped.

  When the stop is confirmed, it is determined whether or not each integrated value calculated in step S206 is equal to or greater than a predetermined threshold (first predetermined value). If all the integrated values satisfy the conditions, the battery needs sufficient power to perform the leakage diagnosis when the vehicle is stopped.If the conditions are not met, the leakage diagnosis is performed. The process ends without requesting.

  After this processing, a stop-time leak diagnosis is performed according to steps S108 to S115 as in the first embodiment (FIG. 5).

  As described above, in the second embodiment, it is determined whether or not the battery charge amount is sufficient on the basis of each integrated value immediately before stopping after each trip. When it is determined that the battery charge amount is not sufficient, the leak diagnosis is not performed, so the same effect as in the first embodiment is obtained, and the determination is made based on the latest integrated value immediately before stopping, so the battery state is determined. It is possible to grasp more accurately and improve the reliability of the determination result.

(Third embodiment)
A third embodiment of the present invention will be described with reference to a flowchart shown in FIG. The configuration of the third embodiment is the same as that of the first embodiment. However, after making a diagnosis request, a part of the configuration is re-determined every predetermined time. That is, in the third embodiment, even if it is determined that the amount of battery charge charged during traveling is sufficient for the execution of the leak diagnosis at the time of stoppage and the execution of the leak diagnosis at the time of stop is requested, a predetermined time has elapsed. Each time it is done, it is determined again whether or not the battery charge is sufficiently charged, and the difference will be described below.

  The process for securing electric power in the third embodiment is performed together with the start of operation of the internal combustion engine of the vehicle. The start of operation of the internal combustion engine is detected by a signal from the ignition switch 23.

  In step S301 to step S304, each integrated value for each parameter is calculated in the same manner as in the first embodiment, and in step S305, it is compared with each predetermined threshold value (first predetermined value). If any of the integrated values is not equal to or greater than the predetermined threshold value, the process returns to step S301 and waits until the condition is satisfied. If all the integrated values satisfy the condition, it is determined that the battery charge amount necessary for the leak diagnosis at the time of stoppage is charged to the battery while traveling, and the diagnosis request flag is requested in step S306 to execute the leak diagnosis at the time of stoppage. Stand up.

  In step S307, it is determined whether or not a predetermined time has elapsed since the diagnosis was requested in step S306. If the predetermined time has elapsed, the process returns to step S301, and it is re-determined whether or not the battery power amount necessary for the leakage diagnosis at the time of stopping is charged in the battery.

  If the predetermined time has not elapsed, it is determined in step S308 whether or not the vehicle has stopped based on the signal of the ignition switch 23 by Key Off, and if the stop has been confirmed, the processing ends. If the stop of the vehicle is not confirmed, the process returns to step S307 and waits until the vehicle stops.

  After confirming that the vehicle is stopped, a stop-time leak diagnosis is performed according to steps S108 to S115 shown in FIG.

  As described above, in the third embodiment, after it is determined that the battery charge amount is sufficient for the execution of the leak diagnosis when the vehicle is stopped and the execution of the leak diagnosis is requested, the battery is charged again every time a predetermined time elapses. Determine the quantity status. Thereby, not only the same effect as the first embodiment can be obtained, but also the determination result can be verified and updated by re-determination, so that the accuracy and reliability of the determination result can be improved.

(Fourth embodiment)
A fourth embodiment of the present invention will be described with reference to a flowchart shown in FIG. The configuration of the fourth embodiment is the same as that of the first embodiment, but is partially different in selectively determining the threshold value. That is, in the fourth embodiment, each threshold value can be selectively set according to the temperature state of the engine 1 when the internal combustion engine is started, and the difference will be described below.

  The process for securing electric power in the fourth embodiment is performed together with the start of operation of the internal combustion engine of the vehicle. The start of operation of the internal combustion engine is detected by a signal from the ignition switch 23.

  In step S401, it is determined from the temperature state of the engine 1 at the start of operation whether the engine is cold start or warm-up start. The temperature difference between the cooling water temperature and the intake air temperature at the time of starting is compared with a predetermined value. If the temperature difference is less than the predetermined value, it is determined that the engine is cold. The cooling water temperature and the intake air temperature are detected by a cooling water temperature sensor 26 and an intake air temperature sensor 27, respectively.

  If it is determined that the engine is cold start, a cold start flag is set in step S402, and the process proceeds to step S403. If it is determined that the start is after warm-up, the process proceeds to step S403 as it is. In step S403 to step S406, each integrated value for each parameter is calculated in the same manner as in the first embodiment, and the process proceeds to step S407.

In step S407, it is determined whether or not it is a cold start by detecting a cold start flag. If it is determined that the engine has started after warming up, the threshold value for starting after warming up (first predetermined values) having the same value as that of the first embodiment is selected as a comparison target of integrated values in step S409, and the system is cooled. If it is determined that the engine is a start, cold start thresholds V ₂ , S ₂ , E ₂ , R ₂ (second predetermined values) are selected in step S408.

Since the battery temperature is low at the time of cold start, the amount of power charged in the battery during traveling is less than that in the case of start after warm-up, and the charging efficiency is low. In other words, in order to obtain the same amount of battery charge as the battery charged when starting after warming up, it is necessary to travel for a longer time than when starting after warming up. The integrated value is larger than that at the start after warm-up. Therefore, the threshold values at the time of cold start are set as V ₂ > V ₁ , S ₂ > S ₁ , E ₂ > E ₁ , R ₂ > R _1. It is determined whether or not the battery is charged while traveling.

  In step S410, each integrated value for each parameter is compared with each selected threshold value. If all integrated values are greater than or equal to each threshold, request a diagnosis of leakage diagnosis when stopping (step S411). If any of the integrated values does not satisfy the condition, return to step S403 and wait until the conditions are satisfied To do.

  Thereafter, in step S412, it is determined based on the signal from the ignition switch 23 whether or not the vehicle has stopped due to Key Off. When the vehicle is not stopped, the system waits until Key Off is confirmed. After the vehicle stop is confirmed, a leakage diagnosis is performed according to steps S108 to S115 shown in FIG.

  As described above, in the fourth embodiment, threshold values can be selectively set according to the temperature state of the engine 1 at the time of starting the internal combustion engine. It is set to be equal to or greater than each threshold value. Thereby, since the battery charge amount charged during traveling can be estimated more strictly, the battery charge amount can be more accurately determined according to the temperature state of the engine 1, and the reliability of the determination result is improved. It becomes possible.

(Fifth embodiment)
A fifth embodiment of the present invention will be described with reference to a flowchart shown in FIG. The configuration of the fifth embodiment is the same as that of the first embodiment, but is partially different in selectively determining the threshold value. That is, in the fifth embodiment, each threshold value can be selectively set according to the load state of the engine 1 when the vehicle travels, and the difference will be described below.

  The process for securing electric power in the fifth embodiment is performed together with the start of operation of the internal combustion engine of the vehicle. The start of operation of the internal combustion engine is detected by a signal from the ignition switch 23.

  In step S501, whether the engine 1 during traveling is in a high load state or a normal traveling state is detected by comparing the opening of the throttle valve 5 during traveling and the engine speed. When the throttle opening relative to the engine speed is larger than a predetermined value, it is assumed that the engine is in a high load state, and the time in the high load state is integrated.

  Thereafter, in step S502 to step S505, each integrated value is calculated for each parameter as in the first embodiment. Thereafter, in step S506, the high load operation ratio p is calculated from the accumulated time in the high load state and the total time from the start of operation. The high load operation ratio p is determined by 0 ≦ p ≦ 1.

Since the battery power is consumed in a high load state, the amount of power charged in the battery is small compared to the case of normal running. Therefore, even if each integrated value for each parameter is the same value, the amount of battery charge differs depending on the load state. It needs to be a large value. Therefore, if it is always normal running from the start of operation, and each threshold is compared to the accumulated value to the first embodiment the same value as the normal traveling threshold _{V L, S L, E L} , and R _L, from the start of operation Each threshold value in the case of a constantly high load state is set to a high load state threshold value V _H , S _H , E _H , R _H (fourth predetermined values) larger than the normal running threshold value.

However, since the load state during driving always changes, the battery state can be estimated from the vehicle load state within the range from the normal driving threshold to the high load state threshold based on the battery high load manual operation ratio p. Need to be performed (step S507). That is, the threshold value is set by calculating from the threshold value V ₃ of the battery voltage V = p × V _H + (1−p) × V _L. S ₃ , E ₃ , and R ₃ (third predetermined values) are set by calculating similarly for the other parameters.

  In step S508, each integrated value for each parameter is compared with each threshold set as described above. Here, when all the integrated values are equal to or more than the respective thresholds, a diagnosis request flag for requesting execution of the leak diagnosis at the time of stopping is set (step S509), and when the condition is not satisfied, the process returns to step S501 to satisfy the condition. Wait until.

  Thereafter, in step S510, it is determined based on a signal from the ignition switch 23 whether or not the vehicle has stopped due to Key Off. When the vehicle is not stopped, the system waits until Key Off is confirmed. After the vehicle stop is confirmed, a leakage diagnosis is performed according to steps S108 to S115 shown in FIG.

  As described above, in the fifth embodiment, each threshold value can be selectively set according to the load state of the engine 1 during vehicle travel, and when it is determined that the vehicle is in a high load state, each threshold value is set during normal travel. It is set to be equal to or greater than each threshold value. Thereby, since the battery charge amount charged during traveling can be estimated more strictly, the battery charge amount can be estimated more accurately according to the load state of the engine 1, and the reliability of the determination result is improved. It becomes possible.

  The present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.

  INDUSTRIAL APPLICABILITY The present invention can be used in an apparatus that is mounted on a vehicle and that processes evaporated fuel generated by evaporation of fuel in a fuel tank.

It is a block diagram of the evaporative fuel processing system 100 which concerns on the 1st-5th embodiment of this invention. It is a flowchart which shows the operation | movement of the electric power ensuring which concerns on the 1st Embodiment of this invention. The time chart which shows the battery voltage V which concerns on this invention, and the integrated value _Vtotal calculated. The time chart which shows the battery voltage V which concerns on this invention, and the integration time _ttotal calculated. It is a flowchart which shows operation | movement of the leak diagnosis at the time of a stop based on this invention. It is a flowchart which shows the operation | movement of the electric power ensuring which concerns on the 2nd Embodiment of this invention. It is a flowchart which shows the operation | movement of the electric power ensuring which concerns on the 3rd Embodiment of this invention. It is a flowchart which shows the operation | movement of the electric power ensuring which concerns on the 4th Embodiment of this invention. It is a flowchart which shows the operation | movement of the electric power ensuring which concerns on the 5th Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Evaporative fuel processing system 1 Engine 2 Intake passage 4 Intake amount sensor 5 Throttle valve (load detection means)
7 Purge control valve 8 Atmospheric release valve 9 Pressure sensor 10 Fuel tank 12 Canister 20 Controller 21 Ignition switch 22 Vehicle speed sensor 23 Engine speed sensor (load detection means)
24 Battery voltage sensor 25 Radiator fan applied current sensor 26 Cooling water temperature sensor (temperature detection means)
27 Intake air temperature sensor (temperature detection means)
S101 to S104, S201 to S204, S301 to S304, S403 to S406, S502 to S505 Integration means
S101 to S105, S201 to S206, S301 to S305, S401 to S410, S501 to S509 estimation means
S105 to S106, S206 to S207, S305 to S307, S410 to S411, S508 to S509 judging means
S506 Ratio calculation means

Claims (8)

In an evaporative fuel processing system for purging evaporative fuel generated by evaporation of fuel in a fuel tank to an intake passage according to engine operating conditions,
Leak diagnosis means for detecting leakage of the evaporated fuel from the evaporated fuel processing system when the engine is stopped;
A battery for supplying electric power to the equipment used for the leak diagnosis at the time of stopping,
Estimation means for estimating whether or not the battery has been charged with the amount of power required to perform the leak diagnosis;
A power securing device for an evaporative fuel processing system, comprising: a determination unit that determines whether or not the leak diagnosis can be performed based on a battery charge amount estimated by the estimation unit. The estimation means includes
Detecting means for detecting the battery voltage of the vehicle, the vehicle speed, the engine speed, and the current applied to the radiator fan;
An integrating means for integrating the detected values of the parameters, respectively;
The integrated value and the set first predetermined values are compared, and if all are equal to or higher than the predetermined value, it is estimated that the battery is sufficiently charged, and any one of the predetermined values exceeds the predetermined value. The power securing device for an evaporative fuel processing system according to claim 1, wherein when the battery is small, it is estimated that the battery is not sufficiently charged with electric power. The determination means includes
When it is estimated by the estimation means that the battery is sufficiently charged with electric power, the leakage diagnosis is requested when the vehicle is stopped, and when it is estimated that the battery is not sufficiently charged with electric power, the leak is detected. The power securing device for an evaporative fuel processing system according to claim 1 or 2, wherein power supply to the equipment used for the leak diagnosis is cut off without requiring diagnosis. The determination means includes
The apparatus for securing electric power of an evaporated fuel processing system according to any one of claims 1 to 3, wherein whether or not the leak diagnosis can be performed is determined after the engine is stopped. The determination means includes
4. The apparatus according to claim 1, wherein after the stop leak diagnosis is requested, whether or not the leak diagnosis can be performed is re-determined based on the estimation unit at every elapse of a predetermined time. The electric power securing apparatus of the evaporative fuel processing system as described in one. Temperature detection means for detecting the coolant temperature and intake air temperature of the vehicle,
When the difference between the cooling water temperature detected by the temperature detection means and the intake air temperature is larger than a set value, the estimation means selects each first predetermined value as a comparison target of the integrated value, and is less than the set value In the case of (2), the second predetermined value larger than each first predetermined value is selected, and the power securing device for the evaporated fuel processing system according to claim 2. Load detecting means for detecting the opening of the throttle valve of the vehicle and the engine speed,
The estimation means selects a first predetermined value as a comparison target of the integrated value when the engine speed value relative to the throttle opening value detected by the load detection means is smaller than a set predetermined value. 3. An apparatus for securing power in an evaporative fuel processing system according to claim 2, wherein a third predetermined value larger than the first predetermined value is selected when the set value is exceeded. Load detecting means for detecting the opening of the throttle valve of the vehicle and the engine speed;
A ratio calculating means for calculating a ratio of a high load state during traveling based on the load detecting means;
The third predetermined value is set within a range of the first predetermined value to a fourth predetermined value that is larger than the first predetermined value based on the ratio calculating means. The power securing device of the evaporative fuel processing system according to claim 7.

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