JP5935746B2 - Fuel tank abnormality detection device - Google Patents

Description

  The present invention relates to a fuel tank abnormality detection device.

  As a conventional fuel tank abnormality detection device, a negative pressure is generated by the pump on the adsorber side, and the perforation of the fuel tank is detected based on the detection value of the adsorber internal pressure sensor that detects the pressure in the adsorber Is known (see, for example, Patent Document 1).

JP 2005-291122 A

  However, in the conventional fuel tank abnormality detection apparatus, the fuel tank and the adsorber are defined by a throttle portion provided in a bypass passage of the communication passage communicating the inside of the fuel tank and the adsorber, and a bypass passage on the adsorber side from the throttle portion. However, no consideration has been given to the provision of a sealing mechanism having a sealing valve that opens and closes the communication passage by a pressure difference between the back pressure chamber and the communication passage.

  For this reason, in the conventional fuel tank abnormality detection device, when the sealing mechanism described above is provided, the area of the hole in the fuel tank cannot be detected more than the size of the hole formed by the throttle portion. There was a problem.

  Therefore, the present invention is a case where a blocking valve that opens and closes the communication passage by a pressure difference generated by a throttle portion provided in a bypass passage branched from a communication passage communicating the inside of the fuel tank and the adsorber is provided. However, an object of the present invention is to provide a fuel tank abnormality detection device capable of detecting the area of a hole in the fuel tank that is larger than the size of the hole formed in the throttle portion.

In order to achieve the above object, an abnormality detection device for a fuel tank according to the present invention includes (1) a fuel tank that stores fuel, an adsorber that adsorbs evaporated fuel generated in the fuel tank, A sealing mechanism for blocking a communication path communicating with the inside of the adsorber, and an adsorber internal pressure sensor for detecting a pressure in the adsorber, wherein the blocking mechanism is provided in a bypass path branched from the communication path And a first blocking valve that opens and closes the communication path by a pressure difference between the back pressure chamber defined in the bypass path on the adsorber side from the throttle and the communication path, and the communication path A fuel tank abnormality detecting device, wherein the tank internal pressure sensor for detecting the pressure in the fuel tank and the second sealing valve are closed so An abnormality determination value calculation unit that introduces a negative pressure into the adsorber and calculates an abnormality determination value based on a detection value of the adsorber internal pressure sensor; and in the adsorber with the second blocking valve open A tank hole detector for detecting whether or not there is a hole in the fuel tank by introducing a negative pressure into the fuel tank and comparing the detected value of the adsorber internal pressure sensor with the abnormality determination value. The hole detection unit detects an area of the hole based on a detection value of the tank internal pressure sensor on the condition that the fuel tank has a hole , and the tank hole detection unit On the condition that it is detected that there is no hole in the fuel tank, the detected value of the adsorber internal pressure sensor from when the second blocking valve is opened until after the negative pressure is introduced into the adsorber. The amount of change and the detected value of the tank internal pressure sensor On the basis of the reduction amount, and has a structure for calculating a correction coefficient for correcting the detected value of the tank pressure sensor.

  With this configuration, the fuel tank abnormality detection device according to the present invention calculates the area of the hole in the fuel tank based on the detection value of the tank internal pressure sensor on condition that the fuel tank has a hole. By detecting, the area of the hole in the fuel tank can be detected without being affected by the throttle portion provided in the bypass passage.

  Therefore, the abnormality detection device for a fuel tank according to the present invention is a blockade that opens and closes a communication passage by a pressure difference generated by a throttle portion provided in a bypass passage branched from a communication passage communicating the inside of the fuel tank and the adsorber. Even when the valve is provided, the area of the hole in the fuel tank larger than the size of the hole formed in the throttle portion can be detected.

Furthermore, with this configuration, the abnormality detection device for a fuel tank according to the present invention corrects the detection value of the tank internal pressure sensor by matching the characteristics of the tank internal pressure sensor with the characteristics of the internal pressure sensor of the adsorber. And an error in the detected value due to the difference between the characteristics of the tank internal pressure sensor.

Further, in the fuel tank abnormality detection device according to (1 ) above, ( 2 ) the tank hole detecting section detects that the fuel tank has a hole and the tank internal pressure sensor Based on the detection value, it may be detected whether the area of the hole is larger than a predetermined reference area.

  With this configuration, the fuel tank abnormality detection device of the present invention can detect whether or not the area of the hole in the fuel tank is larger than the reference area used as a criterion for determining the large hole in the fuel tank.

  According to the present invention, there is provided a blocking valve that opens and closes the communication passage by a pressure difference generated by a throttle portion provided in a bypass passage branched from a communication passage communicating between the fuel tank and the adsorber. However, it is possible to provide a fuel tank abnormality detection device that can detect the area of the hole in the fuel tank that is larger than the size of the hole formed in the throttle portion.

1 is a schematic configuration diagram of a main part including an internal combustion engine for driving driving in a vehicle equipped with an abnormality detection device for a fuel tank according to an embodiment of the present invention and a fuel system thereof. It is a schematic block diagram at the time of oil supply of the sealing mechanism shown in FIG. It is a schematic block diagram at the time of the negative pressure introduction | transduction of the pump module shown in FIG. It is a schematic block diagram at the time of the reference | standard reference pressure measurement of the pump module shown in FIG. It is a schematic block diagram at the time of the negative pressure introduction | transduction of the sealing mechanism shown in FIG. It is a conceptual diagram for demonstrating correction | amendment of the detected value of the tank internal pressure sensor by ECU shown in FIG. It is a flowchart which shows the abnormality detection operation | movement performed by the abnormality detection apparatus of the fuel tank which concerns on embodiment of this invention. It is a timing chart for demonstrating an effect | action of the abnormality detection apparatus of the fuel tank which concerns on embodiment of this invention.

  Embodiments of a fuel tank abnormality detection device according to the present invention will be described below with reference to the drawings.

  FIG. 1 shows a configuration of a main part of a vehicle equipped with an abnormality detection device for a fuel tank according to an embodiment of the present invention, that is, a mechanism of an internal combustion engine for driving and a fuel system for supplying and purging the fuel. Is shown. The internal combustion engine of the present embodiment uses highly volatile fuel and is mounted on a vehicle for driving driving.

  First, the configuration will be described.

  As shown in FIG. 1, the vehicle 1 according to the present embodiment includes an engine 2, a fuel supply mechanism 3, a fuel purge system 4, and an ECU (Electronic Control Unit) 5.

  The engine 2 is constituted by a spark ignition type multi-cylinder internal combustion engine using a spark plug 20 controlled by the ECU 5, for example, a four-cycle in-line four-cylinder engine in the present embodiment.

  Each of the intake ports of the four cylinders 2a (only one is shown in FIG. 1) of the engine 2 is provided with an injector 21 (fuel injection valve), and the plurality of injectors 21 are connected to a delivery pipe 22. Has been.

  A highly volatile fuel, for example, gasoline, is pressurized and supplied to the delivery pipe 22 to a fuel pressure (fuel pressure) required for the engine 2 from a fuel pump 32 described later.

  An intake pipe 23 is connected to the intake port portion of the engine 2, and the intake pipe 23 is provided with a surge tank 23 a having a predetermined volume that suppresses intake pulsation and intake interference.

  An intake passage 23b is formed inside the intake pipe 23, and a throttle valve 24 that is driven by a throttle actuator 24a so that the opening degree can be adjusted is provided on the intake passage 23b.

  The throttle valve 24 adjusts the intake air amount of the engine 2 by adjusting the opening of the intake passage 23 b under the control of the ECU 5. The throttle valve 24 is provided with a throttle sensor 24b for detecting the opening degree.

  The fuel supply mechanism 3 includes a fuel tank 30 that stores the fuel of the engine 2, a fuel pump 32 that pumps up the fuel stored in the fuel tank 30, a fuel supply pipe 33 that connects the fuel pump 32 and the delivery pipe 22, and a fuel And a suction pipe 38 provided on the upstream side of the pump 32.

  The fuel tank 30 is disposed on the lower side of the vehicle body of the vehicle 1 and stores the fuel consumed by the engine 2 in a replenishable manner. In the present embodiment, the fuel pump 32 is accommodated in the fuel tank 30.

  The fuel pump 32 is of a variable discharge capability (discharge amount and discharge pressure) type that can pump up the fuel in the fuel tank 30 and pressurize it to a predetermined feed fuel pressure or more, and is constituted by a circumferential flow pump, for example. . The fuel pump 32 has an impeller for operating the pump and a built-in motor that drives the impeller, although a detailed internal configuration is not shown.

  Further, the fuel pump 32 changes its discharge capacity per unit time by changing at least one of the rotational speed and rotational torque of the impeller for operating the pump according to the drive voltage and load torque of the built-in motor. It can be made to.

  In order to change the discharge capacity of the fuel pump 32 in this way, the fuel supply mechanism 3 is provided with an FPC (Fuel Pump Controller) 10 that controls the drive voltage of the fuel pump 32 in accordance with the control of the ECU 5.

  The fuel supply pipe 33 forms a fuel supply passage that allows the output port of the fuel pump 32 and the inside of the delivery pipe 22 to communicate with each other. The suction pipe 38 forms a suction passage 38a on the upstream side of the fuel pump 32, and a suction filter 38b is provided at the most upstream portion of the suction passage 38a. The suction filter 38b is a known filter that filters the fuel sucked into the fuel pump 32.

  On the other hand, the fuel tank 30 is provided with a fuel supply pipe 34 protruding so as to extend from the fuel tank 30 to the side or rear side of the vehicle 1. An oil supply port 34 a is formed at the tip of the oil supply pipe 34 in the protruding direction. The fuel filler 34 a is accommodated in a fuel inlet box 35 provided in a body (not shown) of the vehicle 1.

  The fuel supply pipe 34 is provided with a circulation pipe 36 that communicates the upper portion of the fuel tank 30 with the upstream portion in the fuel supply pipe 34. The fuel inlet box 35 is provided with a fuel lid 37 that is opened to the outside when fuel is supplied.

  When fuel is supplied, the fuel lid 37 is opened, and the cap 34b detachably attached to the fuel supply port 34a is removed, so that the fuel can be injected into the fuel tank 30 from the fuel supply port 34a.

  The fuel purge system 4 is interposed between the fuel tank 30 and the intake pipe 23, more specifically, between the fuel tank 30 and the surge tank 23a. The fuel purge system 4 is configured such that the evaporated fuel generated in the fuel tank 30 can be discharged into the intake passage 23b and combusted during intake of the engine 2.

  The fuel purge system 4 includes a canister 41 that constitutes an adsorber that adsorbs the evaporated fuel generated in the fuel tank 30, and purge gas containing air and fuel that has been desorbed from the canister 41 through the canister 41. 23 includes a purge mechanism 42 that performs a purge operation to be sucked into the engine 23, and a purge control mechanism 45 that controls the amount of purge gas sucked into the intake pipe 23 to suppress fluctuations in the air-fuel ratio in the engine 2. Yes.

  The canister 41 has an adsorbent 41b such as activated carbon built in a canister case 41a, and is installed outside the fuel tank 30. The interior of the canister 41 (adsorbent storage space) communicates with the upper space in the fuel tank 30 via a vapor pipe 49 that forms a communication passage 48 that communicates the interior of the fuel tank 30 and the canister 41. Yes.

  Therefore, the canister 41 can adsorb the evaporated fuel by the adsorbent 41b when the fuel evaporates in the fuel tank 30 and the evaporated fuel accumulates in the upper space in the fuel tank 30.

  In the fuel tank 30, an ORVR valve 50 and a blocking mechanism 51 are provided in the vapor pipe 49. The ORVR valve 50 is closed when the liquid level rises during refueling to block communication between the vapor pipe 49 and the fuel tank 30.

  Further, the ORVR valve 50 blocks the communication between the vapor pipe 49 and the fuel tank 30 even when the vehicle falls or the like, so that the fuel in the fuel tank 30 does not leak outside through the vapor pipe 49. It has become.

  As shown in FIG. 2, the blocking mechanism 51 has a throttle portion 53 provided in a bypass passage 52 branched from the communication passage 48. In the present embodiment, the diameter of the hole formed in the narrowed portion 53 is 1.5 mm.

  A back pressure chamber 54 is defined in the bypass passage 52 closer to the canister 41 than the throttle portion 53. A positive pressure chamber 56 is defined in the communication passage 48. The sealing mechanism 51 has a diaphragm valve 55 that opens and closes the communication passage 48 by a pressure difference between the back pressure chamber 54 and the positive pressure chamber 56, that is, a pressure difference between the back pressure chamber 54 and the communication passage 48.

  Diaphragm valve 55 constitutes the 1st blockade valve in the present invention. The diaphragm valve 55 includes a diaphragm 60 that separates the back pressure chamber 54 and the positive pressure chamber 56, a spring 61 that biases the diaphragm 60 from the back pressure chamber 54 toward the positive pressure chamber 56, and a midway in the communication passage 48. It has the sealing member 62 affixed on the diaphragm 60 so that it can do.

  In the diaphragm valve 55, the diaphragm 60 is deformed according to the pressure of the back pressure chamber 54, the biasing force of the spring 61, the pressure of the positive pressure chamber 56, and the pressure of the communication passage 48 on the canister 41 side, and the seal member 62 opens and closes the middle of the communication path 48.

  The blocking mechanism 51 has an electromagnetic valve 63 that opens and closes the joining passage 52 a of the bypass passage 52 with respect to the communication passage 48. The electromagnetic valve 63 constitutes a second blocking valve in the present invention. The solenoid valve 63 is a normally closed solenoid valve that closes in a non-energized state and opens in an energized state.

  When refueling is controlled by the EUC 5 so that the electromagnetic valve 63 of the blocking mechanism 51 is opened and fuel is supplied into the fuel tank 30, the pressure in the fuel tank 30 increases. As a result, the gas in the fuel tank 30 flows into the back pressure chamber 54 and the positive pressure chamber 56, but the pressure in the positive pressure chamber 56 becomes higher than the back pressure chamber 54 due to the throttle 53, and the back pressure chamber A pressure difference is generated with respect to the positive pressure chamber 56.

  Due to this pressure difference, the diaphragm 60 is deformed upward in the drawing, and the middle of the communication passage 48 that is sealed by the seal member 62 is opened. For this reason, the gas flows in from the fuel tank 30, the gas passes through the blocking mechanism 51 along the path indicated by the arrow in the drawing, and the gas flows out to the canister 41 side.

  In FIG. 1, the purge mechanism 42 includes a purge pipe 43 that communicates the interior of the canister 41 with the internal portion of the surge tank 23 a in the intake passage 23 b of the intake pipe 23, and the interior of the canister 41, for example, a fuel inlet box 35. And an atmospheric pipe 44 that opens to the atmospheric pressure space inside.

  A pump module 64 is provided in the middle of the atmospheric piping 44. As shown in FIG. 3, the pump module 64 includes a negative pressure pump 70, a canister internal pressure sensor 71 constituting an adsorber internal pressure sensor according to the present invention, a switching valve 72, an actuator 73, a reference throttle unit 74, and a reverse And a stop valve 75.

  The negative pressure pump 70 is driven under the control of the ECU 5 and introduces a negative pressure to the canister 41 side. The check valve 75 blocks the gas flow from the negative pressure pump 70 toward the canister internal pressure sensor 71.

  The reference throttle portion 74 is formed with a reference hole provided for measuring a reference reference pressure Pref that is referred to by the ECU 5 as will be described later. In the present embodiment, the diameter of the hole formed in the reference throttle portion 74 is 0.5 mm.

  In the switching valve 72, passages 72a and 72b are formed. The switching valve 72 is driven by an actuator 73 controlled by the ECU 5, and has a first position where the atmospheric passage formed by the atmospheric piping 44 communicates with the passage 72 a, and the atmospheric passage and the passage 72 b formed by the atmospheric piping 44. Any one of the second positions that communicate with each other is taken.

  That is, when the switching valve 72 is in the first position, the atmospheric piping 44 on the canister 41 side is connected to the negative pressure pump 70. On the other hand, when the switching valve 72 is in the second position, the atmospheric air pipe 44 is connected to the negative pressure pump 70 via the reference throttle 74.

  The canister internal pressure sensor 71 detects the pressure in the canister 41 (hereinafter referred to as “canister internal pressure”) in a state where the switching valve 72 is in the first position. When the negative pressure pump 70 is driven while the switching valve 72 is in the first position, the pump module 64 draws gas from the canister 41 through the path indicated by the arrow in the figure and releases the gas to the atmosphere. It is supposed to be.

  Also, as shown in FIG. 4, the pump module 64 drives the negative pressure pump 70 with the switching valve 72 in the second position, thereby allowing the gas that has passed through the reference restrictor 74 along the path indicated by the arrow. The negative pressure pump 70 is used for suction, and the canister internal pressure sensor 71 is configured to detect the standard reference pressure Pref.

  In FIG. 1, the purge mechanism 42 introduces the intake negative pressure through the purge pipe 43 to one end side inside the canister 41 when the intake negative pressure is generated inside the surge tank 23 a during the operation of the engine 2. The atmosphere can be introduced through the atmosphere pipe 44 to the other end side of the inside.

  In this way, the purge mechanism 42 can cause the fuel adsorbed by the adsorbent 41b of the canister 41 and held in the canister 41 to be desorbed from the canister 41 and sucked into the surge tank 23a.

  The purge control mechanism 45 includes a purge vacuum solenoid valve (hereinafter referred to as “purge VSV”) 46 controlled by the ECU 5. The purge VSV 46 is provided in the middle of the purge pipe 43. The purge VSV 46 can variably control the flow rate of the evaporated fuel desorbed from the canister 41 by changing the opening degree in the middle of the purge pipe 43.

  Specifically, the purge VSV 46 can change the opening degree by the duty of the excitation current being controlled by the ECU 5, and the purge VSV 46 can be changed by the intake negative pressure in the intake pipe 23 at a purge rate corresponding to the duty ratio. The evaporated fuel desorbed from the canister 41 can be sucked into the surge tank 23a as purge gas together with air.

  The ECU 5 includes a CPU (Central Processing Unit) 80, a RAM (Random Access Memory) 81, a ROM (Read Only Memory) 82, a flash memory 83, and an input / output port (hereinafter referred to as “I / O port”) 84. It is comprised by the computer apparatus provided with these.

  The ROM 82 of the ECU 5 stores a program for causing the computer device to function as the ECU 5. That is, when the CPU 80 executes a program stored in the ROM 82 using the RAM 81 as a work area, the computer device functions as the ECU 5.

  In addition to the throttle sensor 24 b and the canister internal pressure sensor 71, the input side of the I / O port 84 includes a tank internal pressure sensor 31 that detects the pressure in the fuel tank 30 (hereinafter simply referred to as “tank internal pressure”). Various sensors are connected.

  Further, various control objects such as the FPC 10, the spark plug 20, the throttle actuator 24a, the purge VSV 46, the electromagnetic valve 63, the negative pressure pump 70, and the actuator 73 are connected to the output side of the I / O port 84.

  The ECU 5 controls various control objects based on information detected by various sensors. For example, the ECU 5 can control the purge rate by duty-controlling the purge VSV 46 based on various sensor information.

  Specifically, when the engine 2 is in a predetermined operation state, the ECU 5 is provided on the condition that the opening degree of the throttle valve 24 obtained from the throttle sensor 24b is smaller than a preset opening degree. By operating the purge VSV 46, the purge mechanism 42 is caused to execute a purge operation.

  Further, in the present embodiment, the ECU 5 at a specific timing when the vehicle 1 according to the present invention is dead soaked (for example, 5 hours after the engine 2 is stopped), for example, the engine water temperature is determined from a predetermined water temperature. If the state of the vehicle 1 satisfies a predetermined condition such as low, a hole in the fuel system is detected.

  For example, the ECU 5 forms an abnormality determination value calculation unit according to the present invention, introduces a negative pressure into the canister 41 with the electromagnetic valve 63 closed, and determines an abnormality determination value based on the detection value of the canister internal pressure sensor 71. Is calculated.

  Specifically, the ECU 5 controls the electromagnetic valve 63 to close, and controls the actuator 73 so that the switching valve 72 takes the second position, until the detection value of the canister internal pressure sensor 71 is stabilized. The negative pressure pump 70 is driven.

  As a result, in the pump module 64, the pressure of the gas that has passed through the reference restrictor 74 is detected by the canister internal pressure sensor 71. Therefore, in the present embodiment, a hole having a diameter of 0.5 mm is detected. Standard reference pressure Pref at the time is detected.

  The ECU 5 calculates the hole detection determination value Psl as an abnormality determination value for detecting whether or not there is a hole in the fuel tank 30 by subtracting a predetermined value α from the reference reference pressure Pref. ing. Here, the value α is a negative value close to approximately 0, and is stored in the ROM 82.

  Further, the ECU 5 determines whether or not the fuel tank 30 has a hole wider than a predetermined reference area (hereinafter simply referred to as “large hole”) by multiplying the reference reference pressure Pref by a predetermined value β. The large hole detection determination value Pgl is calculated as an abnormality determination value for detection.

  Here, the value β is a positive value greater than 0 and less than 1, and is stored in the ROM 82. In the present embodiment, the value β is 0.2. Therefore, in the present embodiment, the reference area is the area of a hole having a diameter of 2 mm.

  The ECU 5 controls the actuator 73 so that the switching valve 72 takes the first position in a state where the electromagnetic valve 63 is closed, and drives the negative pressure pump 70 until the detected value of the canister internal pressure sensor 71 is stabilized. It has become. Thereby, the canister internal pressure is detected by the canister internal pressure sensor 71.

  Here, the ECU 5 compares the canister internal pressure with the reference reference pressure Pref, and if the canister internal pressure is less than the reference reference pressure Pref, the ECU 5 determines that there is no hole on the canister 41 side from the pump module 64, and the canister If the internal pressure is equal to or higher than the standard reference pressure Pref, it is determined that the pump module 64 has a hole on the canister 41 side.

  The ECU 5 constitutes a tank hole detection unit in the present invention, and when it is determined that there is no hole on the canister 41 side from the pump module 64, the negative pressure is applied to the canister 41 with the electromagnetic valve 63 opened. And comparing the detected value of the canister internal pressure sensor 71 with the abnormality determination value to detect whether or not the fuel tank 30 has a hole, and to detect that the fuel tank 30 has a hole. As a condition, the area of the hole in the fuel tank 30 is detected based on the detection value of the tank internal pressure sensor 31.

  Specifically, the ECU 5 controls the solenoid valve 63 to open, controls the actuator 73 so that the switching valve 72 takes the second position, and performs negative pressure until the detected value of the canister internal pressure sensor 71 becomes stable. The pump 70 is driven.

  Thus, if the fuel tank 30 has a hole, the canister internal pressure sensor 71 detects a pressure equal to or higher than the hole detection determination value Psl. Therefore, if the detection value of the canister internal pressure sensor 71 is less than the hole detection determination value Psl, the ECU 5 determines that there is no hole in the fuel tank 30, and the detection value of the canister internal pressure sensor 71 is equal to or greater than the hole detection determination value Psl. If so, it is determined that the fuel tank 30 has a hole.

  However, the ECU 5 controls the solenoid valve 63 to open, controls the actuator 73 so that the switching valve 72 takes the second position, and controls the negative pressure pump 70 until the detected value of the canister internal pressure sensor 71 becomes stable. When driven, in the blocking mechanism 51, as shown in FIG. 5, the diaphragm valve 55 is not opened by the negative pressure generated by the negative pressure pump 70. The passed gas flows to the pump module 64.

  For this reason, even if a hole having a diameter of 1.5 mm or more is opened in the fuel tank 30, the gas that has passed through the throttle portion 53 of the blocking mechanism 51 flows to the pump module 64. The hole having a diameter of 1.5 mm is detected as being in the fuel tank 30.

  Therefore, in FIG. 1, on the condition that the ECU 5 detects that the fuel tank 30 has a hole, whether or not the hole area is larger than the reference area based on the detection value of the tank internal pressure sensor 31. Is supposed to be detected.

  Specifically, if the detection value of the tank internal pressure sensor 31 is less than the large hole detection determination value Pgl, the ECU 5 has a hole with an area less than the reference area (hereinafter simply referred to as “small hole”) in the fuel tank 30. If the detected value of the tank internal pressure sensor 31 is equal to or larger than the large hole detection determination value Pgl, it is determined that the large hole is in the fuel tank 30.

  The ECU 5 writes the determination result in the flash memory 83, so that the determination result can be output to the test apparatus in a state where the test apparatus (not shown) is connected to the ECU 5.

  By the way, even when the fuel tank 30 has no hole, an error occurs between the detection value of the tank internal pressure sensor 31 and the detection value of the canister internal pressure sensor 71. For example, when the tolerance between the tank internal pressure sensor 31 and the canister internal pressure sensor 71 is ± 5%, the maximum value between the detection value of the tank internal pressure sensor 31 and the detection value of the canister internal pressure sensor 71 is 10%. An error occurs.

  Further, in consideration of variations in parts, deterioration, and assembly of the tank internal pressure sensor 31 and the canister internal pressure sensor 71, the detection value between the tank internal pressure sensor 31 and the detection value of the canister internal pressure sensor 71 is An error of 10% or more may occur.

  Therefore, on the condition that the ECU 5 detects that the fuel tank 30 is not perforated, the ECU 5 detects the canister internal pressure sensor 71 from when the electromagnetic valve 63 is opened until after the negative pressure is introduced into the canister 41. Based on the detection value change amount dPc and the detection value change amount dPt of the tank internal pressure sensor 31, a correction coefficient for correcting the detection value of the tank internal pressure sensor 31 is calculated.

  Specifically, as indicated by reference numeral 100 in FIG. 6, the ECU 5 stores the detection value Pt1 of the tank internal pressure sensor 31 when the electromagnetic valve 63 is opened and the detection value Pc1 of the canister internal pressure sensor 71 in the RAM 81. When the detection value of the canister internal pressure sensor 71 is stabilized (tn), the detection value Pt2 of the tank internal pressure sensor 31 and the detection value Pc2 of the canister internal pressure sensor 71 are stored in the RAM 81.

  On the condition that the ECU 5 detects that the fuel tank 30 is not perforated, the change amount dPc (= Pc2−Pc1) of the detection value of the tank internal pressure sensor 31 and the change amount of the detection value of the canister internal pressure sensor 71 are detected. The correction coefficient Kc (= dPc / dPt) is calculated by calculating dPt (= Pt2−Pt1) and dividing the change amount dPc by the change amount dPt.

  The ECU 5 stores the previous correction coefficient K and the number n of calculation times of the correction coefficient K in the flash memory 83. The ECU 5 calculates a correction coefficient Ka (= (K × n + Kc) / (n + 1)) obtained by averaging the calculated correction coefficient Kc and the correction coefficient K stored in the flash memory 83.

  The ECU 5 updates the correction coefficient K and the calculation number n stored in the flash memory 83 with the correction coefficient Ka and the calculation number (n + 1). Further, the ECU 5 corrects the detection value of the tank internal pressure sensor 31 by multiplying the detection value of the tank internal pressure sensor 31 by the correction coefficient K stored in the flash memory 83.

  In this way, in FIG. 6, the ECU 5 corrects the detection value of the tank internal pressure sensor 31 so that the characteristic 110 of the tank internal pressure sensor 31 matches the characteristic 111 of the canister internal pressure sensor 71.

  Therefore, the ECU 5 can suppress the error of the detected value indicated by reference numeral 101 due to the difference between the characteristic 110 of the tank internal pressure sensor 31 and the characteristic 111 of the canister internal pressure sensor 71 as indicated by reference numeral 102.

  Next, the abnormality detection operation of the fuel tank abnormality detection device according to the present embodiment will be described with reference to the flowchart shown in FIG. Note that the abnormality detection operation described below is executed when the state of the vehicle 1 satisfies a predetermined condition at a specific timing during the dead soak of the vehicle 1 as described above. Further, the electromagnetic valve 63 is closed at the start of execution of the abnormality detection operation.

  First, the ECU 5 controls the actuator 73 so that the switching valve 72 takes the second position, and drives the negative pressure pump 70 until the detected value of the canister internal pressure sensor 71 is stabilized, thereby obtaining the reference reference pressure Pref. Detect (step S1).

  Next, the ECU 5 detects a hole detection determination value Psl for detecting whether or not the fuel tank 30 has a hole and whether or not the fuel tank 30 has a large hole based on the reference reference pressure Pref. The large hole detection determination value Pgl for this is calculated as an abnormality determination value (step S2).

  Next, the ECU 5 controls the actuator 73 so that the switching valve 72 takes the first position, and drives the negative pressure pump 70 until the detected value of the canister internal pressure sensor 71 becomes stable, thereby causing the canister 41 side from the pump module 64. A negative pressure is introduced into (step S3).

  Next, the ECU 5 confirms the reference reference pressure Pref as in step S1 (step S4). That is, the ECU 5 confirms that the detected reference reference pressure Pref is equal to the reference reference pressure Pref detected in step S1.

  Note that if the detected reference reference pressure Pref and the reference reference pressure Pref detected in step S1 are not equal, the ECU 5 determines that the vehicle 1 has become unable to perform an abnormality detection operation, The determination result is written in the flash memory 83, and the abnormality detection operation is terminated.

  Next, the ECU 5 compares the canister internal pressure detected by the canister internal pressure sensor 71 when the step S3 is completed with the reference reference pressure Pref to determine whether or not there is a hole from the pump module 64 to the canister 41 side. Judgment is made (step S5).

  If it is determined that the pump module 64 has a hole on the canister 41 side, the ECU 5 writes in the flash memory 83 that the pump module 64 has a hole on the canister 41 side, and performs an abnormality detection operation. Exit.

  On the other hand, when it is determined that there is no hole on the canister 41 side from the pump module 64, the ECU 5 controls to open the electromagnetic valve 63 (step S6). When the electromagnetic valve 63 is opened, the ECU 5 stores the detection value Pt1 of the tank internal pressure sensor 31 and the detection value Pc1 of the canister internal pressure sensor 71 in the RAM 81 (step S7).

  Next, the ECU 5 controls the actuator 73 so that the switching valve 72 takes the second position, and drives the negative pressure pump 70 until the detected value of the canister internal pressure sensor 71 becomes stable, thereby applying a negative pressure to the fuel tank 30. Introduce (step S8). When step S8 is completed, the ECU 5 stores the detection value Pt2 of the tank internal pressure sensor 31 and the detection value Pc2 of the canister internal pressure sensor 71 in the RAM 81 (step S9).

  Next, the ECU 5 determines whether or not the detection value Pc2 of the canister internal pressure sensor 71 is less than the hole detection determination value Psl (step S10). Here, when it is determined that the detection value Pc2 is less than the hole detection determination value Psl, the ECU 5 determines that there is no hole in the fuel tank 30 (step S11), and the determination result is stored in the flash memory 83. Write.

  Next, the ECU 5 calculates the change amount dPc (= Pc2−Pc1) of the detection value of the tank internal pressure sensor 31 and the change amount dPt (= Pt2−Pt1) of the detection value of the canister internal pressure sensor 71, and calculates the change amount dPc. By dividing by the change amount dPt, a correction coefficient Kc (= dPc / dPt) is calculated (step S12).

  Next, the ECU 5 calculates a correction coefficient Ka (= (K × n + Kc) / (n + 1)) obtained by averaging the calculated correction coefficient Kc and the correction coefficient K stored in the flash memory 83, and calculates the correction coefficient Ka. The correction coefficient K and the calculation number n stored in the flash memory 83 are updated with the number (n + 1) (step S13).

  Next, the ECU 5 checks the reference reference pressure Pref as in step S1 (step S14). Here, as in step S4, the ECU 5 confirms that the detected reference reference pressure Pref is equal to the reference reference pressure Pref detected in step S1, and ends the abnormality detection operation.

  If it is determined in step S5 that the pump module 64 has a hole on the canister 41 side, the ECU 5 multiplies the detection value Pt2 of the tank internal pressure sensor 31 by the correction coefficient K stored in the flash memory 83. The detection value Pt2 is corrected (step S15).

  Next, the ECU 5 determines whether or not the corrected detection value Pt2 is less than the large hole detection determination value Pgl (step S16). If it is determined that the detection value Pt2 is less than the large hole detection determination value Pgl, the ECU 5 determines that there is a small hole in the fuel tank 30 (step S17), and writes the determination result in the flash memory 83. Then, the process of step S14 is executed.

  On the other hand, if it is determined that the detection value Pt2 is not less than the large hole detection determination value Pgl, the ECU 5 determines that there is a large hole in the fuel tank 30 (step S18), and the determination result is stored in the flash memory 83. Write and execute the process of step S14.

  Next, the operation of the fuel tank abnormality detection device according to the present embodiment will be described with reference to FIG. Note that the timing chart shown in FIG. 8 shows an example in which a large hole is formed in the fuel tank 30. In order to facilitate understanding of the present invention, description of correction of the detection value of the tank internal pressure sensor 31 is omitted.

  From time t1 to t2, the ECU 5 detects the reference reference pressure Pref. Here, the ECU 5 calculates the hole detection determination value Psl and the large hole detection determination value Pgl based on the standard reference pressure Pref.

  At times t2 to t3, the ECU 5 introduces a negative pressure to the canister 41 side. Here, since there is no hole on the canister 41 side, the detected value of the canister internal pressure sensor 71 is less than the reference reference pressure Pref.

  From time t4 to t5, the ECU 5 checks the reference reference pressure Pref. At time t6, the ECU 5 opens the electromagnetic valve 63, controls the actuator 73 so that the switching valve 72 takes the second position, and operates the negative pressure pump 70 until time t7 when the detected value of the canister internal pressure sensor 71 becomes stable. By driving, a negative pressure is introduced into the fuel tank 30.

  From time t6 to time t7, the detection value of the canister internal pressure sensor 71 does not exceed Pgl due to the influence of the throttle 53 even though the fuel tank 30 has a large hole. On the other hand, the detection value of the tank internal pressure sensor 31 is Pgl or more. For this reason, the ECU 5 determines that the fuel tank 30 has a large hole. From time t8 to t9, the ECU 5 confirms the reference reference pressure Pref.

  As described above, in the present embodiment, the area of the hole in the fuel tank 30 based on the detection value of the tank internal pressure sensor 31 on the condition that the fuel tank 30 is detected to have a hole. By detecting this, it is possible to detect the area of the hole in the fuel tank 30 without being affected by the throttle 53 provided in the bypass passage 52.

  Therefore, in the present embodiment, the diaphragm that opens and closes the communication passage 48 by the pressure difference generated by the throttle portion 53 provided in the bypass passage 52 branched from the communication passage 48 that connects the inside of the fuel tank 30 and the canister 41. Even when the valve 55 is provided, it is possible to detect the area of the hole in the fuel tank 30 larger than the size of the hole formed in the throttle portion 53.

  In the present embodiment, the ECU 5 stores the correction coefficient K and the calculation coefficient n of the correction coefficient K in the flash memory 83, and the newly calculated correction coefficient Kc and the correction coefficient K stored in the flash memory 83. Correction coefficient Ka (= (K × n + Kc) / (n + 1)) is calculated, and the correction coefficient K stored in the flash memory 83 and the calculation number n are calculated using the correction coefficient Ka and the calculation number (n + 1). Although described as updating, the method of calculating the correction coefficient K in the present invention is not limited.

  For example, the ECU 5 stores the correction coefficient K in the flash memory 83 and averages the newly calculated correction coefficient Kc and the correction coefficient K stored in the flash memory 83 (= (K + Kc) / 2). And the correction coefficient K stored in the flash memory 83 may be updated with the correction coefficient Ka.

  In the present embodiment, the fuel pump 32 is described as being housed in the fuel tank 30. However, in the present invention, the fuel pump 32 may be provided outside the fuel tank 30. .

  In the present embodiment, the canister 41 is described as being provided outside the fuel tank 30. However, in the present invention, the canister 41 may be accommodated inside the fuel tank 30.

  As described above, the abnormality detection device for a fuel tank according to the present invention has a communication passage due to a pressure difference generated by a throttle portion provided in a bypass passage that branches from a communication passage that connects the fuel tank and the adsorber. Even when a sealing valve for opening and closing is provided, the area of the hole in the fuel tank can be detected more than the size of the hole formed in the throttle portion. This is useful for a fuel tank abnormality detection device applied to an engine.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle, 2 ... Engine (internal combustion engine), 5 ... ECU (abnormality judgment value calculation part, tank hole detection part), 30 ... Fuel tank, 31 ... Tank internal pressure sensor, 41 ... Canister (adsorber), 49 ... Ream Passage 51, Blocking mechanism 52 ... Bypass passage 53 ... Throttling part 54 ... Back pressure chamber 55 ... Diaphragm valve (first blocking valve) 63 ... Solenoid valve (second sealing valve) 71 ... Canister internal pressure sensor (Adsorber internal pressure sensor)

Claims (2)

A fuel tank for storing fuel;
An adsorber for adsorbing the evaporated fuel generated in the fuel tank;
A blocking mechanism for blocking a communication path communicating between the inside of the fuel tank and the inside of the adsorber;
An adsorber internal pressure sensor for detecting the pressure in the adsorber,
The blocking mechanism is
A throttle portion provided in a bypass passage branched from the communication passage;
A first blocking valve that opens and closes the communication path by a pressure difference between a back pressure chamber defined in the bypass path on the adsorber side from the throttle and the communication path;
A fuel tank abnormality detection device comprising: a second blocking valve that opens and closes a merging passage of the bypass passage with respect to the communication passage;
A tank internal pressure sensor for detecting the pressure in the fuel tank;
An abnormality determination value calculation unit that introduces a negative pressure into the adsorber in a state where the second blocking valve is closed, and calculates an abnormality determination value based on a detection value of the adsorber internal pressure sensor;
Whether the fuel tank has a hole by introducing a negative pressure into the adsorber with the second blocking valve opened and comparing the detected value of the adsorber internal pressure sensor with the abnormality determination value A tank hole detection unit for detecting whether or not,
The tank hole detection unit detects an area of the hole based on a detection value of the tank internal pressure sensor on the condition that the fuel tank has a hole .
The tank hole detection unit, on the condition that it has been detected that there is no hole in the fuel tank, from when the second blockade valve is opened until after the negative pressure is introduced into the adsorber An abnormality detection device for a fuel tank that calculates a correction coefficient for correcting the detection value of the tank internal pressure sensor based on the change amount of the detection value of the adsorber internal pressure sensor and the change amount of the detection value of the tank internal pressure sensor . Whether the area of the hole is larger than a predetermined reference area based on a detection value of the tank internal pressure sensor on the condition that the tank hole detecting unit detects that the fuel tank has a hole. 2. The fuel tank abnormality detection device according to claim 1, wherein the abnormality detection device detects whether or not.

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