JP2013113249A - Residual fuel determining apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly determine cause of defects when a phenomenon occurs similar to a case of misfire resulting from failures or the like.SOLUTION: A residual fuel determining apparatus includes: a liquid level sensor being a residual fuel detecting element that detects whether the residual fuel is equal to or less than a predetermined value; an acceleration sensor being a vehicle body posture detecting element that detects the posture of the vehicle body; and a control unit that, when the liquid sensor detects that the residual fuel is equal to or less than the predetermined value, calculates the residual fuel based on the ejection amount of the fuel, calculates a residual fuel threshold corresponding to the vehicle posture detected with the vehicle body posture detecting element, and determines whether the residual fuel calculated so as to detect abnormal conditions in the fuel system is less than the residual fuel threshold.

Description

  The present invention relates to a fuel remaining amount determination device used for a vehicle or the like equipped with an internal combustion engine.

  Conventionally, in vehicles equipped with an internal combustion engine, it has been widely practiced to provide fuel detection means for detecting the remaining amount of fuel. As such a fuel detection means, for example, a float whose vertical position changes following a change in the liquid level of the fuel, an arm connected to the float, a main body supporting the arm, A sensor provided with a sensor for detecting a relative position with respect to the main body is widely used. Fuel remaining amount display means for displaying the remaining amount of fuel corresponding to the relative position of the arm detected by the sensor to the driver so as to be visible to the driver is provided in the vehicle (see, for example, Patent Document 1). .

  In such a configuration, when the float reaches the lower limit of its movable range, a certain amount of fuel remains in the fuel tank. When the remaining amount of fuel is less than the amount corresponding to the lower limit of the movable range of the float, only the minimum value is displayed regardless of the actual remaining amount of fuel. That is, since the fuel is normally supplied from the fuel tank to the fuel injection valve for a while after the remaining amount of fuel shows the minimum value, it may occur that the vehicle continues to run without refueling.

  Therefore, when the remaining amount of fuel becomes very small, an abnormality in the fuel system that prevents fuel injection from being normally performed due to air mixed in the path from the fuel tank to the fuel injection valve may occur. As a result, the same phenomenon occurs as when a misfire occurs due to a failure or the like. That is, when such a phenomenon occurs, it is difficult to determine whether the cause of the phenomenon is due to an abnormality in the fuel system such as air mixing described above or a failure or the like. Exists.

JP-A-10-122030

  The present invention pays attention to the above points, and it is an object of the present invention to be able to quickly elucidate the cause when a phenomenon similar to the case where a misfire occurs due to a failure or the like occurs. .

  That is, the fuel remaining amount determination device according to the present invention includes a fuel remaining amount detecting element that detects that the remaining amount of fuel is a predetermined value or less, a vehicle body posture detecting element that detects the posture of the vehicle body, and the fuel remaining amount detecting device. The remaining amount of fuel corresponding to the vehicle body posture detected by the vehicle body posture detection element is calculated based on the fuel injection amount when it is detected by the element that the remaining fuel amount is less than or equal to a predetermined value. And a control device that calculates a threshold value and determines whether or not the remaining amount of fuel calculated to detect an abnormality in the fuel system falls below the remaining fuel threshold value.

  If this is the case, the remaining fuel amount is calculated based on the actual fuel injection amount, and the fuel system abnormality is determined based on the calculated remaining fuel amount and the threshold value corresponding to the posture of the vehicle body. Based on this determination result, it is possible to provide a material for determining whether at least one of the causes of the malfunction is an abnormality in the fuel system.

  According to the present invention, it is possible to detect the occurrence of an abnormality in the fuel system using the remaining amount of fuel charge and the threshold value corresponding to the posture of the vehicle body, so that it is the same as when a misfire occurs due to a failure or the like. When this phenomenon occurs, the cause can be quickly elucidated.

1 is a diagram schematically showing an internal combustion engine according to an embodiment of the present invention. The figure which shows schematically the fuel tank which concerns on the same embodiment. The flowchart which shows the process which the control apparatus which concerns on the same embodiment performs.

  Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

  As shown in FIG. 1, the vehicle according to the present embodiment includes an engine 100 as an internal combustion engine, a fuel tank 1 for storing fuel supplied to the engine 100, a posture of the vehicle body, more specifically, a vehicle body. And an acceleration sensor 2 which is a vehicle body posture detection element for detecting inclination.

  The engine 100 includes a plurality of cylinders 3 (one of which is shown in FIG. 1), an injector 31 that injects fuel into each cylinder 3, and an air-fuel mixture supplied into each cylinder 3. At least an ignition plug 32 for igniting, an intake path 4 for supplying intake air to each cylinder 3, and an exhaust path 5 for discharging exhaust from each cylinder 3 are provided.

  The intake path 4 takes in air from the outside and guides it to the intake port of the cylinder 3. On the intake path 4, an intake duct 41, an air cleaner 42, a throttle valve 43, a surge tank 44, and an intake manifold 45 are arranged in this order from the upstream side.

  The exhaust path 5 guides combustion gas generated by burning fuel in the cylinder 3, that is, exhaust gas, from the exhaust port of the cylinder 3 to the outside. An exhaust manifold 52 and a three-way catalyst 51 are disposed on the exhaust path 5.

  On the other hand, as shown in FIG. 2, the fuel tank 1 includes a fuel tank main body 11, a fuel pump 12 for supplying fuel stored in the fuel tank main body 11 toward the fuel injection valve 31, Similarly, a float 13a that is provided inside the fuel tank body 11 and moves up and down following the fuel level, an arm 13b that has a tip connected to the float 13a, and a pivot that pivotally supports the base end of the arc 13b. It includes at least a support 13c and a liquid level sensor 13 as a fuel remaining amount detecting element formed by using a sensor main body 13d that detects the position of the arm 13b. The float 13a and the arm 13b of the liquid level sensor 13 detect the remaining amount of fuel as shown by the solid line in FIG. 2 from the highest liquid level when the tank is full as shown by the imaginary line in FIG. It is possible to move up and down between the minimum liquid level and the minimum liquid level. The liquid level sensor 13 outputs a liquid level signal f indicating the fuel level to the control device 6. However, when the fuel level is equal to or lower than the minimum liquid level, a liquid level signal f indicating the minimum liquid level is output to the control device 6 regardless of the actual liquid level, that is, the remaining amount of fuel.

  The acceleration sensor 2 detects the acceleration applied to the lateral direction and the front-rear direction of the vehicle body in order to detect the posture of the vehicle body, more specifically, the inclination of the vehicle body. Is output.

  The control device 6 that controls operation of the engine 100 is a microcomputer system having a central processing unit, a memory, an input interface, an output interface, and the like. Here, the “memory” is a concept generically referring to the internal memory and the external storage device.

  The input interface includes a vehicle speed signal a output from the vehicle speed sensor 91 that detects the vehicle speed, a rotation speed signal b output from the rotation speed sensor 92 that detects the engine speed, and an accelerator sensor 93 that detects the amount of depression of the accelerator pedal. Is output from a temperature sensor 95 that detects the intake air temperature of the surge tank 24. The accelerator opening request signal c is output from the intake pressure signal d that is output from the intake pressure sensor 94 that detects the intake pressure in the surge tank 24. An intake air temperature signal e, a liquid level signal f output from the liquid level sensor 13, an acceleration signal g output from the acceleration sensor 2, and the like are input.

  From the output interface, the fuel injection signal m is output to the injector 11 and the ignition signal n is output to the ignition plug 12 (ignition coil thereof).

  The central processing unit of the control device 6 interprets and executes a program stored in advance in memory to control the operation of the engine 100. The control device 6 acquires various information a, b, c, d, e, f, and g necessary for operation control of the engine 100 via the input interface, and based on them, the intake air amount, the required fuel injection amount, the ignition The time, required EGR gas amount, etc. are calculated. Then, various control signals m and n corresponding to the calculation result are applied through the output interface.

  Therefore, in this embodiment, when the remaining amount of fuel indicated by the liquid level signal f from the liquid level sensor 13 is less than a predetermined value in the memory of the control apparatus, the central processing unit of the control apparatus executes it. The fuel remaining amount is calculated based on the fuel injection amount, the fuel remaining amount threshold corresponding to the posture of the vehicle body detected by the acceleration sensor 2 is determined, and air is mixed into the fuel system. A remaining amount detection program for executing control for determining whether or not the remaining amount of fuel calculated to determine whether or not a fuel system abnormality has occurred is below a determined remaining fuel threshold value Built in.

  Hereinafter, the procedure of processing performed by the control device 6 based on the remaining amount detection program will be described below with reference to FIG. 3 which is a flowchart.

  First, it is determined whether or not the remaining amount of fuel indicated by the liquid level signal f from the liquid level sensor 13 is equal to or less than a predetermined value (S1). The injection amount is determined (S2), and the determined injection amount is subtracted from the remaining amount of fuel (S3). Further, the acceleration corresponding to the acceleration signal g, that is, the inclination of the vehicle body is obtained from the acceleration sensor 2, and the fuel remaining amount threshold value is determined using this vehicle body inclination as a parameter (S4). (S5), and information indicating that there is a possibility that an abnormality in the fuel system has occurred, such as when air is mixed into the fuel when the remaining amount of fuel is lower than the fuel remaining amount threshold value. Is recorded in a predetermined area of the storage device (S6). Then, fuel cut control is performed (S7), and learning of the fuel injection amount at the time of air-fuel ratio feedback control is stopped (S8). On the other hand, when the remaining amount of fuel exceeds the remaining fuel threshold, the process returns to step S2. Note that the determination in step S5 is actually performed with reference to the remaining fuel threshold determination map. This fuel remaining amount threshold determination map uses the remaining amount of fuel and the inclination of the vehicle body corresponding to the acceleration signal g as parameters, and for each representative remaining amount of fuel, air flows into the fuel at a representative inclination of each vehicle body. One of a flag indicating whether or not there is a possibility of mixing, that is, “1” indicating that air may be mixed into the fuel and “0” indicating that there is no possibility that air is mixed into the fuel Is stored in a predetermined area of the memory. The actual determination is performed using the representative value closest to the remaining fuel amount calculated in step S3 and the representative value closest to the vehicle body inclination corresponding to the acceleration signal g as parameters.

  Here, the air mixing information recorded in the predetermined area of the memory of the control device 6 by the processing in step S5 described above is transmitted to the information processing device provided outside the vehicle, thereby the information processing device. Visualized. That is, when an engine misfire or a problem similar thereto occurs, various information stored in the memory of the control device 6 is transferred from the control device 6 by connecting the information processing device to the control device 6 of the vehicle. When air mixing information is included in the various types of information transmitted to the processing device, the air mixing information is visualized and displayed on the display device of the information processing apparatus.

  That is, in this embodiment, the liquid level sensor 13, the acceleration sensor 2, and the control device 6 function as a fuel remaining amount determination device in the claims.

  As described above, according to the present embodiment, after the remaining amount of fuel indicated by the liquid level signal from the liquid level sensor 13 becomes equal to or less than a predetermined value, the control device 6 sets the actual fuel injection amount. The remaining amount of fuel is calculated based on the calculated remaining amount of fuel and the threshold corresponding to the attitude of the vehicle body, so that the remaining amount of fuel such as air mixing into the fuel system is reduced, and the fuel liquid in the fuel tank 1 is reduced. It is determined whether or not a fuel system failure has occurred due to the surface becoming lower than the fuel intake port of the fuel pump 12, and if the remaining fuel amount falls below a threshold value as a result of the determination, the fact is recorded. Therefore, based on this record, it is possible to provide a material for determining whether or not at least one of the causes of the malfunction is the occurrence of the malfunction of the fuel system such as the mixing of air into the fuel system. Therefore, when a phenomenon similar to the case where a misfire occurs due to a failure or the like, the cause can be quickly elucidated.

  Further, in the present embodiment, since the fuel cut is performed when the remaining amount of fuel falls below the fuel remaining amount threshold, air is mixed into the fuel and the actual fuel injection amount is estimated from the fuel injection time. And the catalyst can be prevented from being damaged due to combustion in an over-lean state.

  Further, in the present embodiment, when the fuel remaining amount falls below the fuel remaining amount threshold value, learning of the fuel injection amount at the time of air-fuel ratio feedback control is stopped, so when the fuel remaining amount decreases. It is possible to prevent erroneous learning that occurs when learning is performed and the actual air-fuel ratio becomes richer than the stoichiometric air-fuel ratio because the fuel injection amount reflects this learned value after fuel filling.

  The present invention is not limited to the embodiment described above.

  For example, instead of the acceleration sensor described in the above-described embodiment, a tilt sensor that detects the tilt of the vehicle body may be used as the vehicle body posture detection element.

  In the above-described embodiment, when the remaining amount of fuel falls below the remaining fuel threshold, the fuel cut is performed to prevent the catalyst from being melted. However, the fuel temperature is not cut and the combustion temperature is lowered. Other treatments may be performed.

  Further, in the above-described embodiment, when the remaining amount of fuel falls below the fuel remaining amount threshold, learning of the fuel injection amount accompanying the air-fuel ratio feedback control is stopped to prevent erroneous learning. When the remaining amount of fuel falls below the remaining amount threshold, the learning value of the fuel injection amount is stored in a region different from the region of the storage device used for normal air-fuel ratio feedback control, and after fuel filling, the normal empty You may make it perform control which memorize | stores the learning value of fuel injection quantity in the area | region of the memory | storage device used for fuel ratio feedback control.

  In addition, various modifications may be made without departing from the spirit of the present invention.

13. Liquid level sensor (fuel remaining amount detection element)
2. Acceleration sensor (body posture detection element)
6. Control device

Claims (1)

A fuel remaining amount detecting element for detecting that the remaining amount of fuel is less than or equal to a predetermined value, a vehicle body posture detecting element for detecting the posture of the vehicle body, and the fuel remaining amount being less than or equal to a predetermined value by the fuel remaining amount detecting element When this is detected, the remaining amount of fuel is calculated based on the fuel injection amount, and the fuel remaining amount threshold value corresponding to the vehicle body posture detected by the vehicle body posture detecting element is calculated to detect an abnormality in the fuel system. And a control device for determining whether or not the calculated remaining fuel amount is lower than the remaining fuel threshold value.

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