JP3612853B2 - Self-recovery collision fuel cut system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a fuel cut system at the time of collision that stops a fuel pump at the time of a vehicle collision, and in particular at the time of an automatic return type collision that drives a fuel pump based on a start signal from an ignition switch when there is no fuel leakage in a fuel pipe after the collision. It relates to a fuel cut system.
[0002]
[Prior art]
Conventionally, a system 200 having a configuration shown in FIG. 6 is known as a fuel cut system at the time of collision that stops the fuel pump at the time of collision and cuts the supply of fuel into the combustion chamber. In the fuel cut system 200 at the time of collision, as shown in FIG. 6A, a signal holding type collision detection sensor 23 whose contact is normally held in an ON state is provided between the ignition switch 22 and the fuel pump 25, When the ignition switch 22 is turned on, electric power is supplied from the battery 21 to the fuel pump 25, and the fuel pump 25 is driven. As a result, the fuel in the fuel tank 26 is discharged to the fuel pipe 27 and supplied to a combustion chamber (not shown).
In the event of a collision, as shown in FIG. 6 (b), the collision detection sensor 23 detects the collision and holds the contact point in the OFF state, so that no power is supplied to the fuel pump 25, so the fuel pump 25 is stopped. To do. As a result, the supply of fuel from the fuel tank 26 to the combustion chamber is cut, and fuel leakage is prevented from occurring at the time of a collision.
In the collision detection sensor 23, the contact is normally kept on, and a mass (not shown) is attracted to a magnet (not shown) without contacting the contact. When a deceleration exceeding a predetermined level is applied, the mass moves against the magnet's attractive force, and the contact is held off. At this time, since the mass does not return to the original position, in the system 200, when starting the engine after the collision, the mass is attracted to the magnet by manually pressing the reset switch 24 provided in the collision detection sensor 23. The engine is started by turning on the ignition switch 23 after the contact is reset to the on state.
[0003]
[Problems to be solved by the invention]
However, in the system 200 described above, the collision detection sensor 23 can be reset regardless of whether or not there is a fuel leak from the fuel pipe 27 after the collision. Therefore, the fuel pump 25 is re-driven when there is a fuel leak. The fuel leak will continue.
In addition, it is confirmed that there is no fuel leakage after the collision, and in order to re-drive the fuel pump 25, it is necessary to press the reset switch 24 to reset the contact of the collision detection sensor 23 to the ON state. There is a problem that it is not easy to use because it is provided in the rear trunk.
Furthermore, even if the operation method of the reset switch 24 is described in a manual or the like, it is difficult for the user to understand, and this is an obstacle when the user re-drives the fuel pump after a collision.
[0004]
Therefore, in view of the above problems, the object of the present invention is to detect the presence or absence of fuel leakage after a collision, and when there is no fuel leakage, does not require the operation of the reset switch, and restarts the fuel pump based on the ignition switch start signal. In principle, when there is a fuel leak, the re-driving of the fuel pump is prevented to reliably prevent the fuel leak from continuing and to prevent an accident caused by the fuel leak.
It also realizes a fuel cut system at the time of collision that allows the user to clearly understand the operation method after the collision.
[0005]
[Means for Solving the Problems]
In order to solve the above problems, the means described in claim 1 can be employed. According to this means, the collision of the vehicle is detected by the collision detection means, the switching means is switched to the stop side by the stop means based on the collision detection signal from the collision detection means, the fuel pump is stopped, and the fuel is supplied to the combustion chamber. Cut. The fuel leakage is detected by the leakage detection means within a predetermined time after the switching means is switched to the stop side. When there is no fuel leakage, the return means switches the switching means to the drive side based on the start signal of the ignition switch, and when there is fuel leakage, the switching means is held at the stop side, and the fuel pump by the start signal from the ignition switch To prevent it from driving.
As a result, the fuel pump is not driven when there is a fuel leak after the collision, so that the continuation of the fuel leak can be prevented more reliably. In addition, since the fuel pump can be driven by starting the ignition switch when there is no fuel leak after the collision, there is no need to operate the reset switch as in the prior art, and the fuel pump can be easily redriven. .
[0006]
According to the second aspect of the present invention, when the leak detection means detects that there is fuel leakage, the release means releases the holding of the switching means to the stop side by the return means, and the ignition switch Based on the start signal, the switching means is switched to the drive side.
This makes it possible to cope with the need to move the vehicle even if there is a fuel leak after the collision.
[0007]
According to the third aspect of the present invention, the pressure in the fuel supply line is detected by the pressure sensor, and it is determined that the fuel leaks when the detected value or the pressure decrease rate falls below a predetermined value. If there is a fuel leak from the fuel supply line, the pressure drops rapidly, so that the fuel leak can be reliably detected from the pressure in the fuel supply line.
[0008]
According to the means described in claim 4, the gas concentration of the fuel in the vicinity of the fuel supply line is detected by the gas sensor, and it is determined that the fuel leaks when the detected value exceeds a predetermined value. Thereby, the same effect as that of the means described in claim 3 can be obtained.
[0009]
According to the means of claim 5, the presence or absence of fuel leakage and the operation instruction after the collision are visually displayed or displayed by the display means.
This allows the user to quickly deal with the collision.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on specific examples.
FIG. 1 is a schematic structural diagram showing a configuration of an automatic return collision fuel cut system 100 according to the present invention.
A fuel pump 12 (corresponding to a fuel pump) is disposed in a fuel tank 11 that stores fuel therein. The fuel pump 12 is connected to the other end of a fuel pipe 10 (corresponding to a fuel supply line) whose one end is connected to an unillustrated injector. A pressure sensor P is attached to the fuel pipe 10, detects the internal pressure of the fuel pipe 10, and outputs the detected value to the control ECU 5 (corresponding to stop means and return means).
The fuel pump 12 is electrically connected to the battery 6 via a relay 8 (corresponding to switching means) and a relay 9. The relays 8 and 9 are composed of exciting coils 8a and 9a and contacts 8b and 9b, respectively. The relay 8 is turned on and off by a control signal from the control ECU 5, and the relay 9 is turned on and off by switching of an ignition switch (hereinafter abbreviated as IG switch) 7.
[0011]
The IG switch 7 is switched by a user operation. The IG switch 7 has a rotary structure that can be switched to at least OFF, ON, and START. When the IG switch 7 is OFF, power is not supplied from the battery 6 into the system 100. When the IG switch 7 is ON, the excitation coil 9a of the relay 9 is energized from the battery 6 and the contact 9b is turned on. When the IG switch 7 is START, a start signal is output to the ECU 5. At this time, energization to the exciting coil 9a is maintained.
The control ECU 5 includes a storage unit 5a that stores various data, and an arithmetic processing unit 5b that performs arithmetic processing based on the data stored in the storage unit 5a. The pump 12 is driven or stopped. When the start signal is input from the IG switch 7, the ECU 5 energizes the exciting coil 8 a and turns on the contact 8 b of the relay 8. As a result, the contact 9b of the relay 9 is already turned on, so that electric power is supplied from the battery 6 to the fuel pump 12, the fuel pump 12 is driven, and the fuel in the fuel tank 11 is discharged to the fuel pipe 10.
[0012]
The pulse output type collision detection sensor 2 (corresponding to a collision detection means) outputs a collision detection signal to the control ECU 5 when the vehicle collides. FIG. 5 is a schematic diagram showing a cross-sectional structure of the collision detection sensor 2.
Usually, the contact of the contact 14 and the contact of the contact 15 are held in a non-contact manner. When the deceleration acting on the vehicle reaches a predetermined level, the weight 13 tilts toward the tip 16 and displaces the tip 16. Due to the displacement of the chip 16, the distance between the contacts between the contact 14 and the contact 15 is narrowed to make contact. At this time, an electrical signal is output to the control ECU 5 as a collision detection signal via the plates 17 and 18.
Thereafter, when the deceleration acting on the vehicle falls below a predetermined level, the weight 13 returns to the initial position, the contact of the contact 14 and the contact of the contact 15 are brought into a non-contact state, and the output of the collision detection signal is stopped. . Thus, the collision detection sensor 2 outputs a pulse-like collision detection signal at the time of a collision.
[0013]
The reset switch 3 (corresponding to the release means) is a push-type switch. When there is a fuel leak after the collision, a reset signal is output to the ECU 5 by manually pressing the reset switch 3, and the fuel pump 12 is exceptionally turned off. It is a switch that can be driven.
The information device 4 (corresponding to the display means) is a device for notifying the user of the presence or absence of fuel leakage after a collision and an operation instruction, and displays it on the instrument panel.
[0014]
A processing procedure of the ECU 5 at the time of a collision in the fuel cut system 100 at the time of the collision having the above configuration will be described with reference to a flowchart shown in FIG. In this embodiment, the flow shown in FIG. 2 is activated by an interrupt process when a collision detection signal from the collision detection sensor 2 is input.
First, when the deceleration generated in the vehicle due to the collision exceeds a predetermined level, the ECU 5 inputs the collision detection signal output from the collision detection sensor 2 (step 102), and sets a prohibition flag for turning off the relay 8, The prohibition flag is held in the Hi state (step 104). When the prohibition flag is set, the ECU 5 stops energizing the exciting coil 8a and turns off the contact 8b of the relay 8 (step 106).
Then, the fuel pump 12 stops and waits for a predetermined time until it is estimated that the vehicle has stopped (step 108). Thereafter, the detection signal from the pressure sensor P is read (step 110), and a message “Checking for fuel leakage” is displayed on the information device 4 (step 112).
[0015]
After displaying the message in step 112, it is determined whether or not a predetermined determination time has elapsed (step 114). If there is a fuel leak from the fuel pipe 10, the internal pressure gradually decreases. Therefore, the determination time in step 114 is necessary to detect the internal pressure of the fuel pipe 10 and determine the presence or absence of fuel leak from the detected value. It's time. If the determination time has elapsed, a message “no fuel leakage” is displayed on the information device 4 (step 116), and the prohibition flag is set to Lo to enable the fuel pump 12 to be re-driven. (Step 118).
Thereafter, it is determined whether or not there is a start signal from the IG switch 7 (step 120). If there is no start signal, the process is returned. If there is a start signal in step 120, the contact 8b of the relay 8 is turned on to redrive the fuel pump 12 (step 122), and the process returns.
[0016]
If it is determined in step 114 that the determination time has not elapsed, the routine proceeds to step 124 where it is determined whether or not there is a fuel leak from the fuel pipe 10 based on the detected value of the pressure sensor P. If the detected value of the pressure sensor P is not less than the predetermined value, that is, if no pressure drop in the fuel pipe 10 is observed, it is determined that there is no fuel leakage from the fuel pipe 10, and the process returns to step 110.
If the detected value of the pressure sensor P falls below a predetermined value in step 124, that is, if a pressure drop in the fuel pipe 10 is observed, it is determined that there is fuel leakage from the fuel pipe 10, and the process proceeds to step 126. A message “Fuel is leaking” is displayed on the information device 4.
After that, it is determined whether or not there is a reset signal from the reset switch 3 (step 128). The process waits until there is a reset signal and starts from the IG switch 7 so as not to drive the fuel pump 12 in the presence of fuel leakage. The prohibition flag is held in a Hi state so that the relay 8 is not turned on even if a signal is input. If there is a reset signal in step 128, the process proceeds to step 130, the prohibition flag is set to Lo, and the relay 8 is kept off. Subsequently, it is determined whether or not there is a start signal from the IG switch 7 (step 132). If there is no start signal, return is made. If there is a start signal, the relay 8 is turned on, and an exceptionally fuel leakage state occurs. Is allowed to re-drive the fuel pump 12 (step 134), and the process returns.
[0017]
FIG. 3 and FIG. 4 show timing charts based on the contents shown in the flowchart. FIG. 3 shows a timing chart when there is no fuel leakage from the fuel pipe 10 after the collision.
At time _{t 1} when the IG switch 7 is switched to ON (FIG. 3 (a)), the exciting coil 9a of the relay 9 is energized, its contacts 9b is turned on (Figure 3 (b)).
At time _{t 2} when the IG switch 7 is switched to START (FIG. 3 (c)), the start signal is output from the IG switch 7 to the ECU 5. When the start signal is input, the ECU 5 energizes the excitation coil 8a of the relay 8, the contact 8b is turned on (FIG. 3 (d)), the fuel pump 12 is supplied with power from the battery 6, and the fuel pump 12 is driven (FIG. 3). 3 (e)). The pressure sensor P outputs a detection value that periodically fluctuates as the fuel pump 12 is driven (FIG. 3 (f)). Collision under conditions that do not occur the output of the collision detection sensor 2 in (between times t ₃₎ is off, prohibiting flag holds the Lo state (FIG. 3 (g)).
[0018]
Vehicle collision detection sensor 2 and a collision occurs at time t ₃ and outputs a pulse-like collision detection signal (FIG. 3 (g)). In response to this collision detection signal, the ECU 5 sets the prohibition flag to the state of Hi (FIG. 3 (h)), cuts off the energization to the relay 8 and turns off the contact 8b (FIG. 3 (d)). The pump 12 is stopped (FIG. 3 (e)).
The ECU5 the detected value is the predetermined value of the pressure sensor P at a predetermined time after the relay 8 is turned off between the time t ₄ when has elapsed (to between vehicle stops) to time t ₅ (determination time) When confirming that no less than the V _t (FIG. 3 (f)), determines that there is no fuel leakage from the fuel pipe 10, the prohibition flag to the state of Lo at time _{t 5} (FIG. 3 (h)) .
At after time t ₅ at time t ₆ when the start signal from the IG switch 7 is output (FIG. 3 (c)), the ECU5 since already prohibition flag is Lo state its contacts by energizing the relay 8 8b is turned on (FIG. 3D), and the fuel pump 12 is re-driven (FIG. 3E).
[0019]
FIG. 4 shows a timing chart when there is a fuel leak from the fuel pipe 10 after the collision. Collision of the vehicle occurs, and outputs a collision detection signal in the collision detection sensor 2 is the time t _3, prohibition flag is set, the relay 8 is turned off, to the point where the fuel pump 12 is stopped is similar to that shown in FIG. 3 is there.
The ECU 5 detects that the detected value of the pressure sensor P falls below the predetermined value V _t at the time t ₇ during the time t ₄ to the time t ₅ (determination time) after a predetermined time has elapsed since the relay 8 was turned off. Is detected (FIG. 4 (f)), it is determined that fuel is leaking from the fuel pipe 10. The ECU5 even after time _{t 5} holds the prohibition flag to the state of Hi (Fig. 4 (h)). In the state under the prohibition flag, even if the start signal from the IG switch 7 at after time t ₅ at time t ₆ is outputted (Fig. 4 (c)), ECU 5 is energized the relay 8 so prohibition flag is set (FIG. 4D), the fuel pump 12 is not driven again (FIG. 4E).
Here, when the reset signal from the reset switch 3 is output at time _{t 8} (FIG. 4 (i)), ECU5 is the prohibition flag to the state of Lo (Fig. 4 (h)). As a result, even if fuel is leaking from the fuel pipe 10, the fuel pump 12 can be re-driven if there is a start signal from the IG switch 7. When the start signal from the IG switch 7 at time _{t 8} after the time _{t 9} is output (FIG. 4 (c)), by energizing the relay 8 and the contact 8b is turned on (FIG. 4 (d)), the fuel The pump 12 is driven again (FIG. 4 (e)).
[0020]
By performing such a process, the fuel pump 12 is not driven even if a start signal is input to the ECU 5 when there is a fuel leak in the fuel pipe 10 after the collision. Can be prevented.
Further, when there is no fuel leakage from the fuel pipe 10, the fuel pump 12 can be re-driven only by operating the IG switch 7, so that a system with excellent operability can be obtained.
Furthermore, since it is the structure which displays the presence or absence of the fuel leak from the fuel pipe 10 on the information apparatus 4, the user can perform the process after a collision quickly by confirming the display.
In addition, even in a state where fuel is leaking from the fuel pipe 10 after the collision, the prohibition flag can be canceled by pressing the reset switch 3, and the fuel pump 12 can be driven exceptionally, and the state of fuel leakage If you need to move the vehicle, you can deal with it.
[0021]
In the above embodiment, the pressure sensor P is used to detect fuel leakage from the fuel pipe 10, but a gas sensor may be provided in the vicinity of the fuel pipe 10 to detect the fuel vaporization concentration. In this case, it may be determined that the fuel leaks when the detection value of the gas sensor exceeds a predetermined level.
In the above embodiment, the detection direction of the deceleration by the collision detection sensor 2 is not particularly limited. In addition to using the collision detection sensor 2 corresponding to all directions in FIG. 5, a frontal collision, a side collision, a rear collision, etc. You may provide the collision detection sensor 2 corresponding to each direction.
In the above embodiment, the collision detection sensor 2 shown in FIG. 5 is used to output a pulse signal at the time of collision, but other structures may be used. For example, the detected value may be signal-processed by the ECU 5 using a G sensor provided in the airbag device, and a collision may be detected when the processed detected value reaches a predetermined level. The ignition signal of the bag device may be used as the collision detection signal.
In the above embodiment, the control ECU 5 performs the processing shown in FIG. 2 by the interruption of the collision detection signal from the collision detection sensor 2, but the ECU 5 periodically checks the output of the collision detection sensor 2 and performs a collision at the time of the check. If there is a detection signal, the processing of FIG. 2 may be performed.
[0022]
In this embodiment, the message is displayed on the instrument panel as a display means. However, the message may be output from the speaker. In the above-described embodiment, the presence / absence of fuel leakage from the fuel pipe 10 is displayed. However, a procedure for operating the vehicle after the collision may be displayed as a message.
In the present embodiment, the fuel pump 12 is driven and stopped using the relay 8 as the switching means. However, the switching means may be constituted by a power transistor or the like, as long as it has a switching function.
The ECU 5 may be configured separately, or an ECU such as an electronic fuel injection device may be used.
In the above embodiment, the push type reset switch 3 is provided. However, the structure of the reset switch 3 such as a rotary type, a lever type, and a slide type is not limited.
[0023]
As described above, according to the present invention, when the fuel leaks from the fuel pipe after the collision, the fuel pump is prevented from being re-driven, thereby preventing the fuel leak from continuing more reliably. Can do. Further, when the fuel does not leak from the fuel pipe, the fuel pump can be easily redriven by operating the ignition switch, and the operability can be improved. Further, even when the fuel is leaking, when the vehicle needs to be moved, the fuel pump can be driven by operating the reset switch.
[Brief description of the drawings]
FIG. 1 is a schematic structural diagram showing the configuration of a first embodiment according to the present invention.
FIG. 2 is a flowchart showing the processing contents of the ECU according to the first embodiment of the present invention.
FIG. 3 is a timing chart when there is no fuel leakage in the first embodiment according to the present invention.
FIG. 4 is a timing chart when there is a fuel leak in the first embodiment according to the present invention.
FIG. 5 is a structural diagram showing the configuration of a collision detection sensor according to a first embodiment of the present invention.
FIG. 6 is a schematic structural diagram showing a configuration of a conventional fuel cut system at the time of collision.
[Explanation of symbols]
2 Pulse output type collision detection sensor 3 Reset switch 4 Information device 5 Control ECU
6 Battery 7 Ignition switch 8, 9 Relay 8a, 9a Excitation coil 8b, 9b Contact 10 Fuel pipe 11 Fuel tank 12 Fuel pump 100 Automatic return type fuel cut system P at collision P Pressure sensor

Claims (5)

A fuel cut system that stops the fuel pump at the time of a collision and cuts the supply of fuel from the fuel tank to the combustion chamber of the engine,
A collision detection means for detecting a vehicle collision and outputting a collision detection signal;
A fuel pump for discharging the fuel in the fuel tank to the outside;
A fuel supply line for introducing the fuel discharged by the fuel pump into the combustion chamber;
Leak detection means for detecting the presence or absence of fuel leakage in the fuel supply line;
Switching means for switching driving or stopping of the fuel pump;
Stop means for controlling the switching means to the stop side based on the collision detection signal from the collision detection means and stopping the fuel pump;
If the leakage detection means detects that there is fuel leakage within a predetermined time after the switching means is switched to the stop side by the stop means, the switching means is held on the stop side, and the leakage detection means And a return means for returning the switching means to the drive side based on a start signal from an ignition switch when it is detected that there is no fuel leakage. When the leakage detecting means detects that there is fuel leakage, the return means releases the holding of the switching means to the stop side, and the switching means is set to the driving side based on the start signal from the ignition switch. 2. The automatic return-type collision fuel cut system according to claim 1, further comprising a release means for switching. The leak detection means includes a pressure sensor for detecting a pressure in the fuel supply line;
2. A determination means for determining that there is a fuel leak when a detected value of the pressure sensor or a pressure drop rate falls below a predetermined value, and for determining that there is no fuel leak otherwise. An automatic return type fuel cut system described in 1. The leak detection means comprises a gas sensor for detecting a vapor concentration of the fuel in the vicinity of the fuel supply line;
2. The automatic determination device according to claim 1, further comprising: a determination unit that determines that there is fuel leakage when a detection value of the gas sensor exceeds a predetermined value, and determines that there is no fuel leakage in other cases. Return-type collision fuel cut system. 2. The display unit according to claim 1, further comprising: a display unit that visually displays or voice-displays whether or not there is a fuel leak in the fuel supply line or an operation instruction after a collision based on a detection signal of the leak detection unit. Automatic return type fuel cut system at the time of collision.

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