JP4475674B2 - Evaporative fuel leak inspection device - Google Patents

Description

  The present invention relates to an evaporated fuel leakage inspection apparatus.

  An evaporative fuel processing system is known in which evaporative fuel generated in a fuel tank is adsorbed by an adsorbent accommodated in an adsorption vessel, for example, granular activated carbon, and the evaporated fuel adsorbed by the adsorbent is discharged to the intake pipe by negative pressure in the intake pipe. Yes. The evaporated fuel discharged to the intake pipe is burned in the combustion chamber. If there is a leak in the evaporative fuel treatment system, the evaporative fuel will flow out into the atmosphere, so it is necessary to inspect the evaporative fuel treatment system for leaks. 2. Description of the Related Art As a leakage inspection apparatus for an evaporative fuel processing system, there is known an apparatus that detects a leak by pressurizing or depressurizing a sealed evaporative fuel passage with a pump and then changing the pressure (for example, see Patent Document 1).

  Moreover, what detects a leak from the change of the pump characteristic at the time of a pump drive is known (for example, refer patent document 2 and patent document 3).

Japanese Patent Laid-Open No. 11-351078 Japanese Patent Laid-Open No. 10-90107 JP 2002-4959 A

  However, when the adsorbent contained in the adsorption container is deteriorated, or when the adsorbent adsorbs a large amount of evaporated fuel, the pressure of the pump etc. When leak inspection is performed by pressurizing or depressurizing the fuel vapor passage sealed with the means, there are the following problems.

  When performing a leak inspection by pressurizing, when evaporating fuel passage is pressurized, the evaporating fuel passage is decompressed and the air in the evaporating fuel passage is discharged into the atmosphere. Without being released into the atmosphere. When leak inspection is performed by reducing the pressure, when the fuel vapor passage air is discharged into the atmosphere and the fuel vapor passage pressure is reduced, the fuel vapor present in the fuel vapor passage flows out into the atmosphere without being completely adsorbed by the adsorbent. Sometimes. For this reason, even if there is no leakage in the evaporated fuel passage itself, if the adsorption capacity of the adsorbent is reduced, the evaporated fuel may flow out to the atmosphere when performing a leak inspection.

  When judging the leakage of the evaporative fuel passage based on the pressure of the evaporative fuel passage measured by pressurizing or depressurizing the evaporative fuel passage, the evaporative fuel adsorbed on the canister due to the air flow at the time of pressure increase / decrease is When the fuel gas flows out to the side, the pressure of the fuel vapor passage changes according to the fuel vapor concentration that has flowed out, and there is a problem that it is not possible to accurately determine whether the fuel vapor passage leaks.

An object of the present invention is to provide an evaporative fuel leakage inspection device that stops the leakage inspection when the adsorption capacity of the adsorbent is reduced and prevents the evaporated fuel from flowing into the atmosphere during the leakage inspection. .
Another object of the present invention is to provide an evaporative fuel leakage inspection apparatus that prevents the evaporative fuel from flowing into the atmosphere during the leakage inspection regardless of the adsorption capacity of the adsorbent.
Another object of the present invention is to provide an evaporative fuel leakage inspection device that stops leakage determination when the adsorption capacity of the adsorbent is reduced.
Another object of the present invention is to provide an evaporative fuel leak inspection apparatus that corrects the leak amount of the evaporative fuel passage in accordance with the evaporative fuel amount that has flowed out to the atmosphere and performs a leak determination.

According to the fuel vapor leakage inspection apparatus of the first aspect of the present invention, the leakage inspection is stopped when the adsorption capacity of the adsorbent decreases and the fuel vapor flows out to the atmosphere side. For this reason, it is Ri蒸 onset fuel by the leakage inspection is released into the atmosphere is prevented.

According to the evaporative fuel leakage inspection apparatus of the second aspect of the present invention, the second adsorbent that adsorbs the evaporated fuel is installed upstream of the throttle device installed in the intake pipe, and the second adsorbent and the combustion of the engine An intake pipe located between the chamber and the atmosphere side of the pressure means is connected by a connecting pipe. Even when the evaporated fuel flows out into the atmosphere during the leak inspection, the outflowed evaporated fuel flows out from the connection pipe into the intake pipe and is adsorbed by the second adsorbent. Therefore, even when the engine is stopped, the leak test can be executed by operating the pressure means.

According to the fuel vapor leakage inspection apparatus of the third aspect of the present invention, the atmosphere side of the pressure means and the sealed container are connected. Even if the fuel vapor flows out from the pressure means into the atmosphere during the leak inspection, the fuel vapor flowing out from the pressure means is accommodated in the sealed container. Therefore, even in a state where the evaporated fuel flows out into the atmosphere, it is possible to prevent the evaporated fuel from flowing out into the atmosphere and to perform a leak inspection.

According to the evaporative fuel leakage inspection apparatus of the fourth aspect of the present invention, since the inside of the sealed container is set to a negative pressure before the evaporative fuel passage is pressurized or depressurized by the pressure means, the evaporative fuel is surely put into the sealed container. Can be accommodated.
According to the fuel vapor leakage inspection apparatus according to claim 5 of the present invention, since the inside of the sealed container is made negative by the pressure means used for the leakage inspection, it is necessary to newly prepare means for making the inside of the sealed container negative. Absent.

According to the fuel vapor leakage inspection apparatus of the sixth aspect of the present invention, since the inside of the sealed container is made negative by the negative pressure in the intake pipe, means for making the inside of the sealed container negative is unnecessary.
According to the fuel vapor leakage inspection apparatus of the seventh aspect of the present invention, the volume of the sealed container increases or decreases according to the amount of fuel vapor accommodated. Even if there is no means for forcibly sending the evaporated fuel to the sealed container, the evaporated fuel can be accommodated by increasing or decreasing the volume of the sealed container.

Hereinafter, a plurality of examples showing embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
FIG. 1 shows a fuel vapor leakage inspection apparatus according to a first embodiment of the present invention. The evaporative fuel leakage inspection apparatus is an apparatus for inspecting leakage of the evaporative fuel processing system. The evaporative fuel processing system has an intake pipe 12, a fuel tank 40, a canister 50, and a purge valve 64. The evaporated fuel generated in the fuel tank 40 is adsorbed by an adsorbent 52 such as granular activated carbon accommodated in a canister 50 as an adsorption container. The evaporated fuel generated in the fuel tank 40 is adsorbed by the adsorbent 52. An evaporative fuel passage is constituted by the fuel tank 40, the canister 50, the pipe 60 and the pipe 62. When the purge valve 64 and the opening / closing valve 72 serving as a discharge device are opened during engine operation, the air is introduced into the canister 50 through the pump 74 and the opening / closing valve 72 and is located on the downstream side of the throttle device 14. The evaporated fuel adsorbed by the adsorbent 52 due to the negative pressure inside is discharged into the intake pipe 12.
The fuel vapor leakage inspection apparatus includes an air-fuel ratio sensor 22, an electronic control unit (hereinafter referred to as “ECU”) 30, a pressure sensor 54, a pump 74, a reference orifice 76, and an orifice valve 78.

  The flow meter 16 measures the amount of intake air flowing through the intake pipe 12. An air-fuel ratio sensor 22 installed in the exhaust pipe 20 measures the air-fuel ratio in the exhaust gas. The ECU 30 as the control means inputs an ignition signal, engine speed, engine coolant temperature, accelerator opening, intake air amount, air-fuel ratio from the flow meter 16, the air-fuel ratio sensor 22, and the like, and opens the throttle device 14 The injection amount of the injector 18 is controlled. The air-fuel ratio sensor 22 and the ECU 30 constitute calculation means. Instead of the air-fuel ratio sensor 22, an exhaust oxygen sensor may be used. A pressure sensor 54 as a leak detection means for measuring the pressure in the evaporated fuel passage is installed in the canister 50. In addition to the canister 50, if the pressure in the evaporated fuel passage can be measured, the pressure sensor 54 is installed in the fuel tank 40, the pipes 60 and 62, or the pipe 70 positioned between the pump 74 and the canister 50. Also good.

  The canister 50 is connected to the fuel tank 40 by a pipe 60 and the intake pipe 12 by a pipe 62. A purge valve 64 as a discharge device is installed in the pipe 62. By opening the on-off valve 72, the canister 50 can be opened to the atmosphere side via the pipe 70. The pipe 70 is provided with an on-off valve 72 and a pump 74 as pressure means. When the on-off valve 72 is opened, the inside of the canister 50 is opened to the atmosphere via the pump 74 and the pipe 70. A reference orifice 76 and an orifice valve 78 are installed in a pipe branched from the pipe 70. The pump 74 is used to depressurize the evaporated fuel passage. The reference orifice 76 is an orifice for determining how many leak holes are formed in the evaporated fuel passage.

Next, the operation of the fuel vapor leakage inspection apparatus will be described based on the time chart of FIG. 2 and the flowchart of FIG. The flowchart shown in FIG. 4 is a main routine for leak inspection, and is periodically executed.
In step 100, the ECU 30 determines whether a leakage inspection condition is satisfied. Leakage inspection conditions determine whether operating conditions, temperature conditions, etc. satisfy predetermined conditions. When the leak inspection condition is not satisfied, the ECU 30 does not execute the leak inspection.

  If the leak inspection condition is satisfied, in step 101, the exhaust evaporated fuel concentration calculated in advance by the ECU 30 based on the measurement signal of the air-fuel ratio sensor 22 is read. The ECU 30 calculates the concentration of the evaporated fuel discharged from the canister 50 into the intake pipe 12 from the amount of deviation between the air-fuel ratio in the exhaust gas detected by the air-fuel ratio sensor 22 and the stoichiometric air-fuel ratio. Instead of the discharged evaporated fuel concentration, the amount of discharged evaporated fuel may be used. There is a relationship shown in FIG. 3 between the discharged evaporated fuel concentration and the amount of evaporated fuel adsorbed in the canister 50. If a map of the exhausted evaporated fuel concentration and the evaporated fuel adsorption amount in the canister 50 is created based on the relationship shown in FIG. 3, the evaporated fuel adsorption amount M1 adsorbed in the canister 50 is calculated from the discharged evaporated fuel concentration. Can be calculated (step 102). In step 103, the adsorption amount M1 stored in the memory is updated with the calculated adsorption amount M1 of the evaporated fuel.

In step 104, it is determined whether the ignition key is turned off. Steps 101, 102, and 103 are repeated until the ignition key is turned off.
When the ignition key is turned off, the routine proceeds to step 105. Immediately after the ignition key is turned off, the state in the fuel tank is not stable. Therefore, in step 105, the timer t is initialized, and steps 106 and 107 are repeatedly executed until a predetermined time elapses to stand by.

  When a predetermined time elapses after the ignition key is turned off, it is determined in step 108 whether the adsorption amount M1 is larger than the predetermined amount M0. When the adsorption amount M1 is larger than the predetermined amount M0, the leakage inspection is not executed. If the adsorption amount M1 is equal to or less than the predetermined amount M0, a leakage inspection is executed in step 109. The predetermined amount M0 is a threshold value of the adsorption amount M1 that is allowed when the evaporated fuel flows out to the atmosphere side when the leak inspection is performed.

Details of the leakage inspection execution routine in step 109 will be described based on the flowcharts shown in FIGS.
When the execution of the leak inspection is permitted, the purge valve 64 and the orifice valve 78 are closed and the on-off valve 72 is opened in step 110 shown in FIG. Next, in step 111, the pump 74 is turned on, and the pressure in the evaporated fuel passage is reduced between a and b as shown in FIG. The timing for closing the purge valve 64 and the orifice valve 78 and the timing for turning on the pump 74 may be the same. In the first embodiment, in order to prevent the pressure from being released from each valve due to a difference in opening / closing timing of each valve, the pump 74 is turned on in step 111 after the opening / closing operation of each valve in step 110. Even if the evaporative fuel passage has the same leak hole as the reference orifice 76, the pump 74 sets the evaporative fuel passage pressure to a predetermined value while the purge valve 64 and the orifice valve 78 are closed and the evaporative fuel passage is sealed. The capacity is set so that the pressure can be reduced below the pressure P0.

In step 112, the pressure P of the evaporative fuel passage is measured by the pressure sensor 54, and in step 113, it is determined whether or not the pressure P of the evaporative fuel passage has become smaller than the predetermined pressure P0.
If the pressure ta does not become lower than the predetermined pressure P0 even if the time ta during which the pump 74 is driven passes the predetermined time ta1 (step 114), the routine proceeds to step 136 shown in FIG. The warning light as a warning means is turned on, the driver is notified of the abnormality, and the leak inspection is terminated. A warning sound may be sounded as a warning means. The predetermined time ta1 is a time during which the pressure P can be made smaller than the predetermined pressure even when the leak inspection apparatus has a leak similar to that of the reference orifice 76.

  When the pressure P becomes equal to or lower than the predetermined pressure P0 within the predetermined time ta1, the on-off valve 72 is closed at step 115, the pump 74 is turned off at step 116, and the orifice valve 78 is opened at step 117. The operation timings of the on-off valve 72, the pump 74, and the orifice valve 78 may be the same, but in the first embodiment, the on-off valve is used to prevent the negative pressure in the evaporated fuel passage from being released from the on-off valve 72 due to the difference in the operation timing. 72 is closed first.

  Since the purge valve 64 and the on-off valve 72 are closed, when the orifice valve 78 is opened, the atmosphere flows from the orifice valve 78 through the reference orifice 76 into the evaporated fuel passage. Accordingly, as shown in FIG. 2, the pressure in the evaporated fuel passage gradually increases between bc. When there is a leak in the evaporated fuel passage, the atmosphere flows into the evaporated fuel passage from both the leak location and the reference orifice 76.

  When the orifice valve 78 is opened, the timer t1 is initialized at step 118, and the pressure P of the evaporated fuel passage is measured at step 119. In steps 120 and 121, the time during which the pressure P is higher than the predetermined pressure P1 is measured. When the pressure P becomes higher than the predetermined pressure P1, the required time, that is, the value of the timer t1 is stored in the memory in step 122.

  In step 123, the orifice valve 78 is closed again, and the on-off valve 72 is opened. Next, in step 124, the pump 74 is turned on, and the vaporized fuel passage is depressurized between cd in FIG. In steps 125 and 126, the process waits until the pressure P becomes lower than the predetermined pressure P0.

  When the pressure P becomes lower than the predetermined pressure P0, the on-off valve 72 is closed at step 127, and the pump 74 is turned off at step 128. Since the orifice valve 78 is closed, the atmosphere flows into the evaporated fuel passage only from the leak hole of the evaporated fuel passage. When the pump 74 is turned off, the timer t2 is initialized in step 129, and the timer t2 is counted up in steps 130, 131, and 132 until the pressure P becomes higher than the predetermined pressure P1 during the period d-e in FIG.

When the pressure P becomes higher than the predetermined pressure P1, the value of the timer t2 at that time is stored in the memory at step 133. When the atmosphere flows into the sealed fuel vapor passage from the leak hole, according to Bernoulli's theorem (see Equation 1), if the pressure is constant, the velocity of the atmosphere flowing from the leak hole is the same.
^{(V 2/2) + (} P / ρ) + gz = constant (1)
v: flow velocity, ρ: density, P: pressure, g: gravitational acceleration, z: position

  Therefore, if the pressure P is the same, the flow rate of the leak (flow rate Q = flow velocity v × leakage cross-sectional area A) is proportional to the leak cross-sectional area A. If the cross-sectional area of the leak hole is doubled, the amount of leak is also doubled. Therefore, if the cross-sectional area of the leak hole is doubled, the pressure increase rate of the sealed space is also doubled. In other words, if there is a leak in the sealed space reduced to the same pressure, the time required to increase the same pressure P will be halved if the cross-sectional area of the leak hole is doubled. When this is applied to the first embodiment, when the leak inspection apparatus has a leak hole having the same cross-sectional area as that of the reference orifice 76, the second pressure increase causes the orifice valve 78 to be closed compared to the first pressure increase. Therefore, the leakage cross-sectional area becomes 1/2. Therefore, the time required to increase to the predetermined pressure P1, that is, the value of the timer t2, is twice t1 (t2 = t1 × 2). When the leak inspection apparatus has a leak hole having a cross-sectional area larger than that of the reference orifice 76, the ratio of the leak cross-sectional area between the first time and the second time is larger than ½. The value of the timer t2 required to increase to the predetermined pressure P1 as shown by the dotted line shown in FIG. 6 is shorter than twice t1 (t2 <t1 × 2).

  As described above, in step 134, the magnitudes of t2 and t1 × 2 are compared, and when the value of timer t2 is not larger than t1 × 2, the rate of increase in pressure is high, that is, the cross-sectional area of the leak hole is the reference area. It is determined that it is larger than the cross-sectional area of the orifice 76, an abnormality is determined in step 136, and a warning lamp is turned on in step 137. If the value of the timer t2 is greater than t1 × 2, it is determined as normal in step 135, and the leak test is terminated.

  In the first embodiment, the evaporated fuel passage having the same volume is decompressed in the first time (ab in FIG. 2) and the second time (cd in FIG. 2), so that the remaining amount of fuel in the fuel tank 40 It is not necessary to correct the measured value due to the difference. In addition, since the temperature conditions are the same, it is not necessary to correct the measured value by temperature.

  In the first embodiment, when the pressure is reduced to the predetermined pressure P0, the pump 74 is stopped. Therefore, if the pressure reducing capacity of the pump 74 has a margin, the pressure reducing time is short. Therefore, the life of the pump 74 is extended and power consumption can be reduced. When performing a leak inspection while the engine is stopped, reducing power consumption is effective.

  As described above, the fuel vapor passage is decompressed by the pump 74 and the leak inspection is executed. However, the fuel vapor passage may be pressurized and the leakage inspection may be executed. The flowchart in this case is shown in FIGS. The magnitude relationship in steps 143, 150, 156, 161 for comparing the pressure P of the evaporated fuel passage with the predetermined pressures P0, P1 is opposite to steps 113, 120, 126, 131 in the flowcharts shown in FIGS. The processing is the same except that it is.

  In the first embodiment, in the main routine, it is determined whether or not the adsorption amount M1 of the canister 50 is larger than the predetermined amount M0 before executing the leakage inspection execution routine (step 109), and if the adsorption amount M1 is larger than the predetermined amount M0. Do not execute the leak inspection execution routine. Therefore, it is possible to prevent the evaporated fuel from flowing out to the atmosphere during the leak inspection.

  The content of the leak test execution routine in step 109 in FIG. 4 is any leak test method (for example, the leak test method of the leak test execution routine in FIGS. 25 and 26 in the configuration of FIG. 21 as in the eleventh embodiment described later). However, the same effect can be obtained if the main routine of FIG. 4 is used.

(Second embodiment)
9 and 10 are flowcharts of a leakage inspection execution routine according to the second embodiment of the present invention. The configuration of the fuel vapor leakage inspection apparatus is substantially the same as that of the first embodiment. The main routine of the leak inspection is the same as that of the first embodiment shown in FIG. In the leakage inspection execution routine, steps 170 to 184 shown in FIG. 9 and steps 185 to 189 shown in FIG. 10 are the same as steps 110 to 124 shown in FIG. 5 and steps 125 to 129 shown in FIG.

  In the first embodiment, the timer t2 is counted up and waited until the pressure P of the evaporated fuel passage after the pressure reduction reaches a predetermined pressure P1. However, when there is almost no leakage in the evaporated fuel passage, the pressure increase after the second decompression (de shown in FIG. 2) becomes very gradual, and it takes a long time to reach the predetermined pressure P1.

Therefore, in the second embodiment, in step 190 after the pressure reduction, first, the magnitude relationship between t1 × 2 and t2 is determined, and then in step 192, the magnitude of the pressure P and the predetermined pressure P1 is compared. Therefore, if t2 becomes larger than t1 × 2 before the pressure P becomes higher than the predetermined pressure P1, a normal determination is made in step 194 and the leakage inspection is terminated.
If the pressure P becomes higher than the predetermined pressure P1 before t2 becomes larger than t1 × 2, it is determined that the cross-sectional area of the leak hole is larger than the cross-sectional area of the reference orifice 76, and an abnormality is determined in step 195. In 196, a warning light is turned on.

Since the elapsed time is compared before the pressure comparison, when the cross-sectional area of the leak hole is small, the inspection time is shorter than that of the first embodiment.
Since the main routine of the leak test of the second embodiment is the same as that of the first embodiment, the leak test execution routine is not executed if the adsorption amount M1 of the canister 50 is larger than the predetermined amount M0. Therefore, it is possible to prevent the evaporated fuel from flowing out to the atmosphere during the leak inspection.

(Third embodiment)
FIG. 11 shows a flowchart of a main routine for leak inspection according to the third embodiment of the present invention. The configuration of the fuel vapor leakage inspection apparatus is substantially the same as that of the first embodiment.
For example, when the temperature is high or the temperature fluctuates greatly, if the leak inspection is executed while the vehicle is stopped, the amount of evaporated fuel adsorbed by the canister 50 between the stop of the vehicle and the inspection of the leak increases. Therefore, the amount of adsorption of the canister 50 calculated from the amount of evaporated fuel discharged when the evaporated fuel adsorbed on the adsorbent 52 during the traveling of the vehicle is discharged to the intake pipe 12 and the amount of adsorption of the canister 50 at the time of performing the leak inspection May be different.
Therefore, in the third embodiment, the amount of evaporated fuel that is adsorbed by the canister 50 from when the vehicle stops to when the leakage inspection is executed is calculated, and the leakage inspection execution routine (step 214) is executed according to the calculated amount of evaporated fuel. To determine.

First, in steps 200 to 204, when the leak inspection condition is satisfied, the adsorption amount M1 of the evaporated fuel in the canister 50 is updated, and after the ignition key is turned off, in step 205, the level gauge of the fuel tank 40, etc. The remaining fuel level is measured by the sensor. Next, in step 206, the ambient temperature T1 immediately after the vehicle is stopped is measured by a temperature sensor such as an intake air temperature sensor or a vehicle room temperature sensor.
Since the state in the fuel tank 40 immediately after the ignition key is turned off is not stable, the process waits until a predetermined time elapses after the ignition key is turned off in steps 207, 208, and 209.

When the predetermined time has elapsed, in step 210, the ambient temperature T2 is measured again. In step 211, the amount of evaporated fuel M2 generated in the fuel tank 40 while the vehicle is stopped is calculated from the remaining fuel amount and the temperature change after the vehicle stops (T2-T1). In step 212, the adsorption amount M1 updated in step 203 and the evaporated fuel amount M2 generated after the vehicle stops are added to update the adsorption amount M1, and it is determined that the adsorption amount M1 updated in step 213 is equal to or less than the predetermined amount M0. Then, a leakage inspection execution routine (step 214) is executed. If it is determined that the adsorption amount M1 updated in step 213 is larger than the predetermined amount M0, the leakage inspection execution routine (step 214) is not executed. Therefore, it is possible to prevent the evaporated fuel from flowing out to the atmosphere during the leak inspection. The leak inspection execution routine is the same as in the first embodiment or the second embodiment.
The contents of the leak inspection execution routine (step 214) can obtain the same effect as long as the main routine of FIG. 11 is the same regardless of the leak inspection method.

(Fourth embodiment)
FIG. 12 shows a flowchart of a main routine for leak inspection according to the fourth embodiment of the present invention. The configuration of the fuel vapor leakage inspection apparatus is substantially the same as that of the first embodiment.
In addition to the case where the temperature is high or the fluctuation of the temperature is large, when fuel is supplied to the fuel tank 40, the evaporated fuel generated in the fuel tank 40 increases and the amount of evaporated fuel adsorbed in the canister 50 increases. Accordingly, the adsorption amount of the canister 50 calculated from the amount of evaporated fuel when the purge is executed while the vehicle is running may differ from the adsorption amount of the canister 50 when the leak inspection is executed during refueling.
Therefore, in the fourth embodiment, it is determined whether or not refueling has been performed after the vehicle has stopped. Steps 220 to 224 and steps 226 to 235 shown in FIG. 12 are the same as steps 200 to 214 of the third embodiment shown in FIG.

In the fourth embodiment, after determining that the ignition key is turned off in step 224 of the main routine, it is determined in step 225 whether or not fueling has been performed. Whether or not fuel has been supplied is determined, for example, by detecting whether or not the fuel cap has been opened by a sensor as a fuel supply detecting means. If the fuel is supplied, the leakage inspection execution routine (step 235) is not executed. If it is not refueled, the same processing as in the third embodiment is performed after step 225.
The content of the leak inspection execution routine (step 235) can obtain the same effect as long as the main routine of FIG.

(5th Example)
FIG. 13 shows a fuel vapor leakage inspection apparatus according to a fifth embodiment of the present invention. The same components as those in the first embodiment are denoted by the same reference numerals. A concentration sensor 56 is installed on the atmosphere side of the canister 50 as concentration measuring means for measuring the evaporated fuel concentration. The concentration sensor 56 may be installed anywhere on the atmosphere side of the canister 50.

  FIG. 14 shows a flowchart of a main routine for leak inspection. Steps 240 to 244 are the same as steps 100 and 104 to 107 in the first embodiment, and thus description thereof is omitted. Immediately before executing the leak inspection, the concentration sensor 56 measures the evaporated fuel concentration C1 on the atmosphere side of the canister 50 (step 245). In step 246, it is determined whether the evaporated fuel concentration C1 is greater than a predetermined value C0. If the fuel vapor concentration C1 is greater than the predetermined value C0, the leak inspection is not executed. If the fuel vapor concentration C1 is less than or equal to the predetermined value C0, a leakage inspection is executed at step 247. The predetermined value C0 is a threshold value of the evaporated fuel concentration C1 that is allowed when the evaporated fuel flows out to the atmosphere side when the leak inspection is executed. The leak inspection execution routine is the same as in the first embodiment or the second embodiment.

  In the first to fifth embodiments described above, whether or not the leakage inspection execution routine is executed by determining whether the adsorption amount of the canister 50, the evaporated fuel concentration, or whether fuel has been supplied after the vehicle is stopped in the main routine. Decide whether or not. Therefore, it is possible to prevent the evaporated fuel from flowing into the atmosphere during the leak inspection.

  Further, since the main routine shown in FIG. 4, FIG. 11, FIG. 12 or FIG. 14 is periodically executed, if the leak inspection is stopped because the adsorption amount of the canister 50 is large, the evaporation adsorbed in the canister 50 When the fuel is discharged to the intake pipe 12 and the adsorption amount M1 becomes smaller than the predetermined amount M0, the leak inspection is resumed. Alternatively, a vehicle traveling condition in which the adsorption amount M1 is equal to or less than the predetermined amount M0 may be set in advance, and the leakage inspection may be performed if the traveling condition is satisfied.

(Sixth embodiment)
FIG. 15 shows a fuel vapor leakage inspection apparatus according to a sixth embodiment of the present invention. Components that are substantially the same as those of the fuel vapor leakage inspection apparatus of the first embodiment are denoted by the same reference numerals.
A pipe 70 as a connection pipe connected to the pump 74 is connected to the intake pipe 12 between the throttle device 14 and the air cleaner 80 on the upstream side of the throttle device 14. The pipe 70 may be connected to the intake pipe 12 anywhere between the adsorbent 82 and the combustion chamber of the engine 10.

The air cleaner 80 accommodates a filter 81 in a case and an adsorbent 82 as a second adsorbent or an intake adsorber on the downstream side of the filter 81. An adsorbent 52 as a first adsorbent is accommodated in the canister 50. If evaporative fuel is contained in the air discharged from the pump 74 when the evaporative fuel passage is decompressed, the evaporative fuel is adsorbed by the adsorbent 82 through the pipe 70 and the intake pipe 12. The air from which the evaporated fuel is removed by the adsorbent 82 passes through the filter 81 and flows out into the atmosphere. Even if the evaporated fuel is discharged from the pump 74 during the leak inspection, the evaporated fuel is prevented from flowing into the atmosphere. Unlike the main routine shown in FIG. 4 in the first embodiment, the main routine in the sixth embodiment shown in FIG. 16 is different from the main routine shown in FIG. Does not calculate the amount of adsorption.
If the atmosphere side of the pump 74 and the intake pipe 12 are connected by a pipe 70 and an adsorbent 82 is installed in the vicinity of the intake port of the intake pipe 12, the structure of the evaporation system has changed as shown in FIG. Can achieve the same effect.

(Seventh embodiment)
FIG. 17 shows a fuel vapor leakage inspection apparatus according to the seventh embodiment of the present invention. Components that are substantially the same as those of the fuel vapor leakage inspection apparatus of the first embodiment are denoted by the same reference numerals.
A sealed container 84 is connected to the end of the pipe 70 connected to the pump 74. The air discharged from the pump 74 is accommodated in the sealed container 84 by the discharge pressure of the pump 74. Therefore, even if the evaporated fuel is discharged from the pump 74 during the leak inspection, the evaporated fuel is prevented from flowing into the atmosphere. Since the leakage inspection can be executed regardless of the amount of evaporated fuel adsorbed in the canister 50, the amount of evaporated fuel adsorbed in the canister 50 is not calculated in the main routine of the leakage inspection in the seventh embodiment, as in the sixth embodiment.
If the sealed container 84 is connected to the atmosphere side of the pump 74 by the pipe 70, the same effect can be obtained even if the structure of the evaporation system is changed as shown in FIG.

(Eighth embodiment)
FIG. 18 shows a fuel vapor leakage inspection apparatus according to the eighth embodiment of the present invention. Components that are substantially the same as those of the evaporative fuel leakage inspection apparatus of the seventh embodiment are denoted by the same reference numerals.
A switching valve 86 is connected to the canister 50 side of the pump 74, and a switching valve 87 is connected to the atmosphere side of the pump 74. A sealed container 84 is installed in a negative pressure introduction pipe 88 that connects the switching valve 86 and the switching valve 87. The switching valve 86 switches between a first state in which the canister 50 and the pump 74 are connected and a second state in which the pump 74 and the sealed container 84 are connected. The switching valve 87 switches between a first state in which the pump 74 and the sealed container 84 are connected and a second state in which the pump 74 and the atmosphere side are connected.

  Before executing the leak inspection, the switching valves 86 and 87 are set to the second state, and the pump 74 as the negative pressure means is operated. Thereby, the air in the sealed container 84 is sucked by the pump 74 and passes through the switching valve 87 and is discharged to the atmosphere side. Therefore, the sealed container 84 has a negative pressure. By switching the switching valve 86 to the first state when the inside of the sealed container 84 becomes negative pressure, the inside of the sealed container 84 can be held at negative pressure.

  By setting the switching valves 86 and 87 to the first state when the leak inspection is performed, the evaporated fuel that cannot be adsorbed by the adsorbent 52 in the canister 50 passes through the switching valve 86, the pump 74, and the switching valve 87 and is sealed container. 84 is aspirated. Since the evaporated fuel is sucked into the sealed container 84 by the negative pressure, it is not necessary to forcibly send the evaporated fuel into the sealed container 84 by the pump 74. Therefore, the discharge pressure of the pump 74 can be reduced as compared with the seventh embodiment.

Even if the fuel discharged from the pump 74 contains evaporated fuel, the evaporated fuel is accommodated in the sealed container 84. When the pump 74 is stopped after the leak inspection is completed, the evaporated fuel in the sealed container 84 is sucked into the canister 50 that has been decompressed by the pump 74, and thus the evaporated fuel is prevented from flowing into the atmosphere. Since the leakage inspection can be executed regardless of the amount of evaporated fuel adsorbed in the canister 50, the amount of evaporated fuel adsorbed in the canister 50 is not calculated in the main routine of the leakage inspection in the eighth embodiment, as in the sixth embodiment.
If the sealed container 84 is connected to the atmosphere side of the pump 74 with the same configuration, the same effect can be obtained even if the configuration of the evaporation system is changed as shown in FIG.

(Ninth embodiment)
FIG. 19 shows a fuel vapor leakage inspection apparatus according to a ninth embodiment of the present invention. Components that are substantially the same as those of the evaporative fuel leakage inspection apparatus of the seventh embodiment are denoted by the same reference numerals.
A pipe 70 connected to the pump 74 is connected to the intake pipe 12 on the downstream side of the throttle device 14. A sealed container 84 is installed between the pump 74 of the pipe 70 and the intake pipe 12. An on-off valve 90 is installed on the side of the intake pipe 12 of the sealed container 84.

The on-off valve 90 is opened before executing the leak inspection. Thereby, the air in the sealed container 84 is sucked into the intake pipe 12 by the negative pressure in the intake pipe 12. Therefore, the sealed container 84 has a negative pressure. When the inside of the sealed container 84 becomes negative pressure, the inside of the sealed container 84 can be held at negative pressure by closing the on-off valve 90.
When the leak inspection is executed, the evaporated fuel discharged from the pump 74 is sucked into the sealed container 84 by a negative pressure, so that it is not necessary to force the pump 74 to send the evaporated fuel into the sealed container 84. Therefore, the discharge pressure of the pump 74 can be reduced as compared with the seventh embodiment.

Even if the fuel discharged from the pump 74 contains evaporated fuel, the evaporated fuel is accommodated in the sealed container 84. When the pump 74 is stopped after the leak inspection is completed, the evaporated fuel in the sealed container 84 is sucked into the canister 50 that has been decompressed by the pump 74, and thus the evaporated fuel is prevented from flowing into the atmosphere. Since the leakage inspection can be executed regardless of the amount of evaporated fuel adsorbed in the canister 50, the amount of evaporated fuel adsorbed in the canister 50 is not calculated in the main routine of the leakage inspection in the ninth embodiment, as in the sixth embodiment.
If the sealed container 84 is connected to the atmosphere side of the pump 74 with the same configuration, the same effect can be obtained even if the evaporation system configuration is changed as shown in FIG.

(Tenth embodiment)
FIG. 20 shows a fuel vapor leakage inspection apparatus according to the tenth embodiment of the present invention. Components that are substantially the same as those of the fuel vapor leakage inspection apparatus of the first embodiment are denoted by the same reference numerals.
A bellows-like variable container 92 is connected to the end of the pipe 70 connected to the pump 74 as a sealed container. The volume of the sealed container 92 can be increased or decreased. Instead of the bellows shape, a variable volume sealed container may be formed using a diaphragm.

  When the leak inspection is performed, the volume of the variable container 92 increases due to the discharge pressure of the pump 74 that depressurizes the evaporated fuel passage, so that the variable container 92 accommodates the evaporated fuel discharged from the pump 74. If the variable container 92 is formed so that the volume increases even if the discharge pressure of the pump 74 is small, the pump 74 can send the evaporated fuel to the variable container 92 with a small discharge pressure. Therefore, the discharge pressure of the pump 74 can be reduced as compared with the seventh embodiment.

Even if the fuel discharged from the pump 74 contains evaporated fuel, the evaporated fuel is accommodated in the variable container 92. When the pump 74 is stopped after the leak test is completed, the evaporated fuel in the variable container 92 is sucked into the canister 50 that has been decompressed by the pump 74, and thus the evaporated fuel is prevented from flowing into the atmosphere. Since the leakage inspection can be executed regardless of the amount of evaporated fuel adsorbed in the canister 50, the amount of evaporated fuel adsorbed in the canister 50 is not calculated in the main routine of the leakage inspection in the tenth embodiment, as in the sixth embodiment.
If the variable container 92 is connected to the atmosphere side of the pump 74 with the same configuration, the same effect can be obtained even if the configuration of the evaporation system is changed as shown in FIG.

(Eleventh embodiment)
FIG. 21 shows a fuel vapor leakage inspection apparatus according to the eleventh embodiment of the present invention. Components that are substantially the same as those of the fuel vapor leakage inspection apparatus of the first embodiment are denoted by the same reference numerals.
A pressure sensor 54 as a pressure measuring means is installed between the switching valve 73 and the pump 74. The switching valve 73 is installed in a pipe 66 that connects the canister 50 and the pump 74, and is turned on and off by an instruction from the ECU 30 as a control means. The switching valve 73 is in a first state in which the piping 66 side and the piping 70 side are communicated when turned off, and in a second state in which the piping 66 side and the pump 74 side are communicated when turned on. The reference orifice 76 is installed in a pipe 77 that crosses the switching valve 73 and connects the pipe 66 and the pump 74.

  When the switching valve 73 is off, that is, when the pump 74 is operated with the piping 66 side and the piping 70 side communicating, the air is supplied to the atmosphere side of the pump 74, the piping 70, the switching valve 73, the piping 66, and the reference. It passes through the orifice 76 and is discharged from the pump 74 to the atmosphere side. Accordingly, the pressure between the pump 74 and the reference orifice 76 is reduced.

  When the switching valve 73 is on, that is, when the pump 74 is operated while the piping 66 side and the pump 74 side are in communication, the air passes through the fuel tank 40, the piping 60, the canister 50, the piping 66, and the switching valve 73. It is discharged from the street pump 74 to the atmosphere side. Therefore, the fuel vapor passage is depressurized.

Next, the operation of the fuel vapor leakage inspection apparatus will be described with reference to FIGS. The leakage inspection execution routine shown in FIGS. 25 and 26 is executed by the ECU 30. Since the main routine of the leak inspection is the same as that of the first embodiment, description thereof is omitted.
When execution of the leak test is permitted in the main routine, the purge valve 64 is closed in step 300 of FIG. Since the switching valve 73 is in an OFF state, the pipe 66 side and the pipe 70 side communicate with each other. Next, in step 301, the pump 74 is turned on, and the pressure between the reference orifice 76 and the pump 74 is reduced as shown in FIG. At this time, the evaporated fuel passage is not decompressed. The pressure measured by the pressure sensor 54 is the pressure of the reference orifice 76.

  In the loop from step 303 to 305, when the pressure between the reference orifice 76 and the pump 74 satisfies P (i-1) -P (i) <Pa and reaches a constant pressure, the loop is exited and the current value is obtained in step 306. The pressure P (i) is set as the first reference orifice pressure P1.

  In step 307, the switching valve 73 is turned on to connect the piping 66 side and the pump 74 side, thereby reducing the pressure of the evaporated fuel passage formed by the fuel tank 40, the piping 60, the piping 62, the canister 50, and the piping 66 (FIG. 22 b-c). The pressure measured by the pressure sensor 54 is the passage pressure of the evaporated fuel passage.

  When the passage pressure of the evaporated fuel passage becomes smaller than the first reference orifice pressure P1 in the loop from Step 309 to Step 312, the switching valve 73 is turned off at Step 313, and the leakage of the evaporated fuel passage is smaller than the reference orifice 76 at Step 314. Determined to be normal. In step 322, the pump 74 is turned off and the leakage inspection execution routine is terminated.

  When the passage pressure of the evaporative fuel passage does not become smaller than the first reference orifice pressure P1 and reaches a constant pressure in the loop from step 309 to step 312, the loop is exited and the routine proceeds to step 315. The fact that the passage pressure of the evaporated fuel passage does not become smaller than the first reference orifice pressure P1 and reaches a constant pressure means that the leakage of the evaporated fuel passage is more than the leakage of the reference orifice 76.

  However, when the vaporized fuel passage is depressurized, the fuel tank 40 is depressurized, and vaporized fuel may be further generated from the fuel in the fuel tank 40. In the main routine of the leak inspection shown in FIG. 4, it is determined that the adsorption amount M1 of the canister 50 allowed when the evaporated fuel flows out to the atmosphere before the leak inspection is performed, and the adsorption of the canister 50 is determined. Although it has been confirmed that the material has a predetermined adsorption capacity, if the evaporated fuel generated from the fuel tank 40 flows into the canister 50 by depressurizing the evaporated fuel passage, the adsorption capacity of the canister 50 decreases, and the canister 50 May be discharged to the atmosphere without being adsorbed on the surface. As shown in FIG. 23, the passage pressure of the fuel vapor passage measured by the pressure sensor 54 increases as the fuel vapor concentration increases.

  The pressure P (i) of step 309 measured in a state where the adsorption capacity of the canister 50 is reduced and the evaporated fuel is flowing out of the canister 50 includes a factor of the evaporated fuel concentration in addition to the leakage of the evaporated fuel passage. Yes. Therefore, in step 310, if the measured pressure P (i) of the evaporated fuel passage is smaller than the first reference orifice pressure P1, the leakage of the evaporated fuel passage is surely smaller than the leakage of the reference orifice 76.

  On the other hand, the fact that the measured pressure P (i) of the evaporative fuel passage has reached a constant pressure rather than being smaller than the first reference orifice pressure P1 means that the evaporative fuel passage leak may be larger than the leak of the reference orifice 76. It is considered that the evaporated fuel may have flowed out of the canister 50. Therefore, when the measured pressure P (i) in the evaporated fuel passage does not become smaller than the first reference orifice pressure P1 and reaches a constant pressure, the switching valve 73 is turned off in step 315 (FIG. 22c), and the pump 74 and the reference orifice are The pressure is again reduced to 76 (cd in FIG. 22).

Here, the flow rate Q of the gas passing through the reference orifice 76 is shown in the following equation (2).
Q = A × α × (2 × ΔP / ρ) ^1/2 (2)
A: Channel area of the reference orifice 76, α: flow coefficient, ΔP: differential pressure across the reference orifice, and ρ: gas density. When the evaporated fuel flows out of the canister 50, the gas density ρ, that is, the evaporated fuel concentration increases, and the flow rate Q decreases. When the fuel vapor concentration increases and the flow rate decreases, the pressure of the reference orifice 76 measured by the pressure sensor 54 in cd of FIG. 22 becomes lower than when the fuel vapor concentration is low as shown in FIG.

  In the leak inspection execution routine shown in FIGS. 25 and 26, when the reference orifice pressure becomes a constant value in the loop from step 317 to step 319, the pressure P (i) at that time is changed to the second reference orifice pressure P2 in step 321. To do. In step 321, the second reference orifice pressure P2 is compared with the first reference orifice pressure P1. If P2 <P1, it is determined that the second reference orifice pressure P2 is lower than the first reference orifice pressure P1 because the evaporated fuel flows out of the canister 50 and the evaporated fuel concentration increases. If the fuel vapor concentration is high, the fuel pressure of the fuel vapor passage measured in bc of FIG. 22 also increases, and therefore, the first reference orifice pressure P1 and the fuel pressure of the fuel vapor passage are compared with each other, so that accurate leak determination cannot be performed. . Therefore, if P2 <P1 in step 321, the pump 74 is turned off in step 322, the leak determination is stopped, and the leak inspection execution routine is terminated.

  In step 321, when the second reference orifice pressure P2 becomes equal to or higher than the first reference orifice pressure P1, it is determined that the evaporated fuel does not flow out of the canister 50. The fact that the vapor pressure of the vaporized fuel passage has not become smaller than the first reference orifice pressure P1 even though the vaporized fuel does not flow out of the canister 50 means that there is a leak in the vaporized fuel passage beyond the reference orifice 76. Therefore, it is determined in step 323 that there is a leak in the evaporated fuel passage and that it is abnormal. In step 324, the warning lamp 34 is turned on. In step 322, the pump 74 is turned off, and the leakage inspection execution routine is terminated.

In the eleventh embodiment, when it is determined that the evaporated fuel is flowing out from the canister 50 during the leak inspection, the leak inspection is stopped because the leak inspection is impossible. Thereby, it is possible to prevent inaccurate leak determination.
In the eleventh embodiment, the concentration of the evaporated fuel flowing out of the canister 50 is calculated from the pressure change amount between the first reference orifice pressure P1 and the second reference orifice pressure P2, and from the calculated evaporated fuel concentration, bc of FIG. You may correct | amend the passage pressure of the evaporative fuel passage measured by these. By comparing the corrected passage pressure of the evaporated fuel passage with the first reference orifice pressure, an accurate leak determination can be performed.

(Twelfth embodiment)
FIG. 27 shows a fuel vapor leakage inspection apparatus according to a twelfth embodiment of the present invention. Components that are substantially the same as those of the fuel vapor leakage inspection apparatus according to the eleventh embodiment are denoted by the same reference numerals.
In the twelfth embodiment, in addition to the configuration of the leak inspection apparatus of the eleventh embodiment shown in FIG.

  Next, the operation of the evaporated fuel leakage inspection apparatus will be described based on the flowchart of the leakage inspection execution routine shown in FIGS. Since the main routine of the leak inspection is the same as that of the first embodiment, description thereof is omitted. The flowcharts shown in FIGS. 28 and 29 and the flowcharts shown in FIGS. 25 and 26 of the eleventh embodiment correspond to the following combinations. Steps 330 to 336 and Steps 300 to 306, Steps 338 to 343 and Steps 307 to 312, Steps 344 and 345 and Steps 313 and 314.

In the twelfth embodiment, after the first reference orifice pressure P1 is stored in step 336, the first evaporated fuel concentration C1 discharged to the atmosphere side in step 337 is measured by the concentration sensor 56.
Then, when it is determined in the loop from step 340 to step 343 that the fuel vapor passage is depressurized and becomes a constant pressure, the pressure is determined to be equal to or higher than the first reference orifice pressure P1, the second evaporation discharged to the atmosphere side in step 346 is performed. The fuel concentration C2 is measured by the concentration sensor 56. In step 347, the switching valve 73 is turned off.

  In step 348, the first evaporative fuel concentration C1 and the second evaporative fuel concentration C2 are compared. If the second evaporative fuel concentration C2 is larger than the first evaporative fuel concentration C1, the canister 50 evaporates during decompression of the evaporative fuel passage. It is judged that fuel leaks and accurate leak judgment cannot be made, and leak judgment is stopped. In step 349, the pump 74 is turned off and the leakage inspection execution routine is terminated.

  When the second evaporated fuel concentration C2 is equal to or lower than the first evaporated fuel concentration C1, it is determined that the evaporated fuel does not flow out of the canister 50 during the decompression of the evaporated fuel passage. The fact that the vaporized fuel passage pressure does not become lower than the first reference orifice pressure P1 even though the vaporized fuel does not flow out of the canister 50 means that there is a leak in the vaporized fuel passage beyond the reference orifice 76. In step 350, it is determined that there is a leak in the evaporated fuel passage and it is abnormal. In step 351, the warning lamp 34 is turned on. In step 349, the pump 74 is turned off, and the leak inspection execution routine ends.

In the twelfth embodiment, when it is determined that the evaporated fuel is flowing out from the canister 50 during the leak inspection, the leak inspection is stopped because the leak inspection is impossible. Thereby, it is possible to prevent inaccurate leak determination.
In the twelfth embodiment, the concentration sensor 56 is installed on the atmosphere side of the pump 74, but it may be installed anywhere on the atmosphere side of the canister 50.

  In the twelfth embodiment, the evaporated fuel concentration flowing out from the canister 50 is calculated from the concentration change amount between the first evaporated fuel concentration C1 and the second evaporated fuel concentration C2, and the evaporation measured in step 340 from the calculated evaporated fuel concentration. The pressure in the fuel passage may be corrected. By comparing the corrected passage pressure of the evaporated fuel passage with the first reference orifice pressure, an accurate leak determination can be performed.

In the eleventh embodiment and the twelfth embodiment, while the ignition key is turned off and the leakage inspection execution routine is executed, or during execution of the leakage inspection, the adsorption capability of the canister is reduced, and the evaporated fuel flows out of the canister 50 to accurately detect the leakage. Even when it cannot be determined, it is possible to prevent an incorrect leak determination. Alternatively, the leak fuel can be accurately determined by correcting the pressure of the evaporated fuel passage based on the evaporated fuel flowing out of the canister 50.
Further, the main routines of the third embodiment and the fourth embodiment may be used as the main routine of the leakage inspection execution routine of the eleventh embodiment and the twelfth embodiment.

In the eleventh and twelfth embodiments, the amount of adsorption of the canister 50 is calculated in the same manner as in the first embodiment before the leakage inspection is performed while the vehicle is stopped. did. On the other hand, the leak inspection execution routine shown in the eleventh and twelfth embodiments may be executed without calculating the adsorption amount of the canister 50. Further, the leak inspection execution routine shown in the eleventh embodiment and the twelfth embodiment may be executed not only when the vehicle is stopped but also when the vehicle is running. In the eleventh embodiment and the twelfth embodiment, even if the leakage judgment of the evaporated fuel passage is stopped due to the decrease in the adsorption capacity of the canister 50, if the adsorption capacity of the canister 50 is recovered by purging during traveling of the vehicle, the eleventh embodiment and The leak can be accurately determined by the leak inspection execution routine shown in the twelfth embodiment.
In the eleventh embodiment and the twelfth embodiment, the leakage of the evaporated fuel passage is inspected by the pressure change when the pressure is reduced by the pump 74. However, the pressure change when the atmosphere is discharged from the evaporated fuel passage after being pressurized by the pump 74 Thus, the leakage of the evaporated fuel passage may be inspected.

(13th to 17th examples)
FIGS. 30 to 34 show the fuel vapor leakage inspection apparatus according to the thirteenth to seventeenth embodiments of the present invention. Components that are substantially the same as those in the first to twelfth embodiments are given the same reference numerals, and descriptions thereof are omitted.
FIG. 30 shows a thirteenth embodiment. In the eleventh embodiment and the twelfth embodiment, the atmosphere side of the pump 74 is opened, but in the thirteenth embodiment, the adsorbent as the first adsorbent housed in the canister 50 is the same as the sixth embodiment. Separately, an adsorbent 82 as a second adsorbent or an intake adsorbent that adsorbs evaporated fuel is installed on the upstream side of the throttle device 14 installed in the intake pipe 12, and the adsorbent 82 and the engine combustion chamber The intake pipe 12 positioned therebetween and the atmosphere side of the pump 74 are connected by a pipe 70 as a connection pipe.

  In the fourteenth embodiment shown in FIG. 31, in the eleventh and twelfth embodiments, the sealed container 84 is connected to the piping 70 on the atmosphere side of the pump 74 as in the seventh embodiment, and the pump 74 is inspected during the leak inspection. Even if the evaporated fuel is discharged from the fuel, the evaporated fuel is prevented from flowing into the atmosphere.

  In the fifteenth embodiment shown in FIG. 32, in the eleventh and twelfth embodiments, the switching valve 86 is connected to the canister 50 side of the pump 74 and the switching valve 87 is connected to the atmosphere side of the pump 74 as in the eighth embodiment. In addition, a sealed container 84 that stores the evaporated fuel is installed in a negative pressure introduction pipe 88 that connects the switching valve 86 and the switching valve 87.

  In the sixteenth embodiment shown in FIG. 33, in the eleventh embodiment and the twelfth embodiment, the pipe 70 connected to the atmosphere side of the pump 74 is connected to the intake pipe on the downstream side of the throttle device 14 as in the ninth embodiment. 12 and a sealed container 84 is installed between the pump 74 of the pipe 70 and the intake pipe 12. An on-off valve 90 for interrupting communication between the sealed container 84 side and the intake pipe 12 side is installed on the intake pipe 12 side of the sealed container 84.

  In the seventeenth embodiment shown in FIG. 34, in the eleventh and twelfth embodiments, as in the tenth embodiment, the end of the pipe 70 connected to the atmosphere side of the pump 74 has a bellows shape as a sealed container. A variable container 92 is connected to accommodate the evaporated fuel discharged from the pump 74.

1 is a configuration diagram illustrating an evaporated fuel leakage inspection apparatus according to a first embodiment of the present invention. It is a time chart which shows the leak test | inspection of the fuel vapor leak test | inspection apparatus by 1st Example. It is a characteristic view which shows the relationship between the adsorption amount of a canister, and discharge | emission evaporative fuel concentration. It is a flowchart of the evaporative fuel leak test | inspection by 1st Example. It is a flowchart of the evaporative fuel leak test | inspection by 1st Example. It is a flowchart of the evaporative fuel leak test | inspection by 1st Example. It is a flowchart of the fuel vapor leak test | inspection by the modification of 1st Example. It is a flowchart of the fuel vapor leak test | inspection by the modification of 1st Example. It is a flowchart of the evaporative fuel leak test | inspection by 2nd Example of this invention. It is a flowchart of the evaporative fuel leak test | inspection by 2nd Example. It is a flowchart of the evaporative fuel leak test | inspection by 3rd Example of this invention. It is a flowchart of the evaporative fuel leak test | inspection by 4th Example of this invention. It is a block diagram which shows the evaporative fuel leak test | inspection apparatus by 5th Example of this invention. It is a flowchart of the fuel vapor leak test | inspection by 5th Example. It is a block diagram which shows the evaporative fuel leak test | inspection apparatus by 6th Example of this invention. It is a flowchart of the evaporative fuel leak test | inspection by 6th Example. It is a block diagram which shows the evaporative fuel leak test | inspection apparatus by 7th Example of this invention. It is a block diagram which shows the evaporative fuel leak test | inspection apparatus by 8th Example of this invention. It is a block diagram which shows the evaporative fuel leak test | inspection apparatus by 9th Example of this invention. It is a block diagram which shows the evaporative fuel leak test | inspection apparatus by 10th Example of this invention. It is a block diagram which shows the evaporative fuel leak test | inspection apparatus by 11th Example of this invention. It is a time chart which shows the leak test | inspection of the fuel vapor leak test | inspection apparatus in 11th Example. It is a characteristic view which shows the relationship between the pump operation time according to the fuel vapor concentration in 11th Example, and fuel vapor passage pressure. It is a characteristic view which shows the relationship between the pump operation time according to the fuel vapor concentration in 11th Example, and a reference | standard orifice pressure. It is a flowchart of the evaporative fuel leak test | inspection by 11th Example. It is a flowchart of the evaporative fuel leak test | inspection by 11th Example. It is a block diagram which shows the evaporative fuel leak test | inspection apparatus by 12th Example of this invention. It is a flowchart of the fuel vapor leak test | inspection by 12th Example. It is a flowchart of the fuel vapor leak test | inspection by 12th Example. It is a block diagram which shows the evaporative fuel leak test | inspection apparatus by 13th Example of this invention. It is a block diagram which shows the evaporative fuel leak test | inspection apparatus by 14th Example of this invention. It is a block diagram which shows the evaporative fuel leak test | inspection apparatus by 15th Example of this invention. It is a block diagram which shows the evaporative fuel leak test | inspection apparatus by 16th Example of this invention. It is a block diagram which shows the evaporative fuel leak test | inspection apparatus by 17th Example of this invention.

Explanation of symbols

    10: engine, 12: intake pipe, 30: ECU (control means, calculation means), 40: fuel tank, 50: canister (adsorption container), 52: adsorbent (first adsorbent), 54: pressure sensor (leakage) Detection means), 56: Concentration sensor (concentration measurement means), 64: Purge valve (discharge device), 70: Piping (connection pipe), 73: Switching valve, 74: Pump (pressure means, negative pressure means), 76: Reference orifice, 82: adsorbent (second adsorbent, intake adsorbent), 84: sealed container, 92: variable container (sealed container)

Claims (7)

A fuel tank, an adsorption container containing an adsorbent that adsorbs the evaporated fuel generated in the fuel tank, and the evaporated fuel adsorbed on the adsorbent is discharged to the intake pipe by a negative pressure of the intake pipe An apparatus for inspecting evaporative fuel leakage in an evaporative fuel processing system, comprising: a discharge device installed in a discharge passage and intermittently communicating between the inside of the adsorption container and the intake pipe;
With the exhaust device blocking communication between the adsorption vessel and the intake pipe, an evaporative fuel passage formed between the fuel tank and the adsorption vessel and to the exhaust device is added. Pressure means for depressurizing or depressurizing;
Leakage detecting means for detecting leakage of the evaporated fuel passage after pressurizing or depressurizing the evaporated fuel passage by the pressure means;
A concentration measuring means installed on the atmosphere side of the adsorbent to measure the evaporated fuel concentration;
Control means for stopping leak inspection when the concentration measuring means detects evaporated fuel;
An evaporative fuel leakage inspection device comprising: A fuel tank; an adsorbing container that contains a first adsorbent that adsorbs the evaporated fuel generated in the fuel tank; and an evaporative fuel adsorbed on the first adsorbent by an intake pipe by a negative pressure of the intake pipe A device for inspecting evaporative fuel leakage in an evaporative fuel processing system, comprising: a discharge device that is installed in a discharge passage for discharging to and from the intake vessel and intermittently communicates with the inside of the intake pipe;
With the exhaust device blocking communication between the adsorption vessel and the intake pipe, an evaporative fuel passage formed between the fuel tank and the adsorption vessel and to the exhaust device is added. Pressure means for depressurizing or depressurizing;
Leakage detecting means for detecting leakage of the evaporated fuel passage after pressurizing or depressurizing the evaporated fuel passage by the pressure means;
A second adsorbent, which is installed upstream of the throttle device installed in the intake pipe and adsorbs the evaporated fuel;
A connection pipe connecting the intake pipe located between the second adsorbent and the combustion chamber of the internal combustion engine and the atmospheric side of the pressure means;
An evaporative fuel leakage inspection device comprising: A fuel tank, an adsorption container containing an adsorbent that adsorbs the evaporated fuel generated in the fuel tank, and an exhaust for discharging the evaporated fuel adsorbed on the adsorbent to the intake pipe by the negative pressure of the intake pipe An apparatus for inspecting evaporative fuel leakage in an evaporative fuel processing system, comprising: a discharge device installed in a passage and intermittently communicating between the inside of the adsorption container and the intake pipe;
With the exhaust device blocking communication between the adsorption vessel and the intake pipe, an evaporative fuel passage formed between the fuel tank and the adsorption vessel and to the exhaust device is added. Pressure means for depressurizing or depressurizing;
Leakage detecting means for detecting leakage of the evaporated fuel passage after pressurizing or depressurizing the evaporated fuel passage by the pressure means;
A sealed container connected to the atmosphere side of the pressure means;
An evaporative fuel leakage inspection device comprising: 4. The evaporative fuel leakage inspection apparatus according to claim 3 , further comprising negative pressure means for making the inside of the sealed container negative before pressurizing or depressurizing the evaporative fuel passage by the pressure means. 5. The evaporative fuel leakage inspection apparatus according to claim 4, wherein the negative pressure means is the pressure means. 5. The evaporative fuel leakage inspection apparatus according to claim 4, wherein the negative pressure means is a negative pressure in the intake pipe. The evaporative fuel leakage inspection apparatus according to claim 3, wherein the sealed container has a variable volume.

Images