Patent Publication Number: US-7913667-B2

Title: Fuel supply apparatus for vehicle

Description:
This nonprovisional application is based on Japanese Patent Application No. 2005-057438 filed with the Japan Patent Office on Mar. 2, 2005, the entire contents of which are hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a fuel supply apparatus for a vehicle, and more particularly to a fuel supply apparatus for a vehicle provided with a plurality of fuel supply systems to an internal combustion engine. 
     2. Description of the Background Art 
     As a configuration of an internal combustion engine, one having both an intake manifold injector for injecting fuel into an intake port and an in-cylinder injector for injecting fuel into a cylinder is known. In this internal combustion engine, fuel injection control is carried out by combining intake manifold injection using the intake manifold injector and in-cylinder direct injection using the in-cylinder injector in accordance with an operation state. 
     In such an internal combustion engine, the pressure of the fuel injected from the in-cylinder injector, which sprays the fuel directly into the cylinder, needs to be set to a high pressure. Meanwhile, the pressure of the fuel injected from the intake manifold injector is lower than the pressure required for the in-cylinder injector. As such, in a fuel supply apparatus for the internal combustion engine, a plurality of fuel supply systems different in pressure of the supply fuel are arranged. 
     In particular, in the configuration where a high-pressure fuel pump provided in a fuel supply system supplying fuel to the in-cylinder injector (i.e., high-pressure fuel supply system) discharges excess fuel back to the fuel intake side at every discharge stroke, it has been pointed out that pulsation in fuel pressure occurs in a fuel supply system supplying fuel to the intake manifold injector (i.e., low-pressure fuel supply system) (e.g., Japanese Patent Laying-Open No. 11-351043; hereinafter, referred to as “Patent Document 1”). 
     Patent Document 1 proposes a configuration for suppressing the influence of such pulsation in fuel pressure on the intake manifold injector (auxiliary fuel injection valve), wherein a fuel filter is arranged at a fuel pipe, between a fuel return port of a high-pressure regulator adjusting the fuel injection pressure of the in-cylinder injector (main fuel injection valve) and a connection port to a fuel supply pipe to the intake manifold injector (auxiliary fuel injection valve). In the fuel injection control apparatus disclosed in Patent Document 1, provision of the fuel filter can prevent the pulsation in fuel pressure, generated due to the returned excess fuel, from adversely affecting the fuel pressure of the intake manifold injector (auxiliary fuel injection valve). 
     A configuration for a fuel supply apparatus is also proposed (e.g., Japanese Patent Laying-Open No. 08-082250; hereinafter, referred to as “Patent Document 2”), wherein a fuel supply cutoff valve is arranged at a fuel pipe so as to prevent leakage of fuel when an engine is damaged due to collision of the vehicle or the like. In the fuel leakage preventing apparatus disclosed in Patent Document 2, the fuel supply cutoff valve is closed when an acceleration sensor detects a change in acceleration exceeding a prescribed value. 
     SUMMARY OF THE INVENTION 
     When a pressure attenuation mechanism such as the fuel filter is provided at the high-pressure fuel supply system as in the configuration disclosed in Patent Document 1, however, vapor lock may occur in the high-pressure fuel pump, causing variation in fuel pressure at the in-cylinder injector (main fuel injection valve). Further, neither Patent Document 1 nor Patent Document 2 specifically discloses how the fuel pipes are arranged from the fuel tank to the high-pressure fuel supply system and to the low-pressure fuel supply system in a vehicle. 
     The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a fuel pipe configuration in a fuel supply apparatus for a vehicle provided with a plurality of fuel supply systems to an internal combustion engine, that can suppress pulsation in fuel pressure in the fuel supply systems. 
     A fuel supply apparatus for a vehicle according to the present invention includes a fuel tank, a first fuel supply system, a second fuel supply system, a first fuel pipe, and a second fuel pipe. The fuel tank is arranged in a rear area with respect to the center of the vehicle and stores fuel. The first fuel supply system includes a first fuel injection mechanism for injecting fuel into an internal combustion engine that is arranged in a front area with respect to the center of the vehicle. The second fuel supply system includes a second fuel injection mechanism that is different from the first fuel injection mechanism for injecting fuel into the internal combustion engine. The first fuel pipe is provided to guide the fuel from the fuel tank to the first fuel supply system. The second fuel pipe is provided to guide the fuel from the fuel tank to the second fuel supply system. The first and second fuel pipes are branched in the vicinity of the fuel tank. 
     According to the fuel supply apparatus for a vehicle described above, the branch point between the first and second fuel pipes for guiding the fuel from the fuel tank to the first and second fuel supply systems, respectively, is arranged in the vicinity of the outlet side of the fuel tank. This can secure a sufficiently long fuel pipe length between the first and second fuel supply systems, and thus, it is possible to prevent the factor of variation in fuel pressure in one fuel supply system from adversely affecting the other fuel supply system. Accordingly, a fuel pipe configuration capable of suppressing variation (pulsation) in fuel pressure in the respective fuel supply systems can be implemented. 
     Preferably, in the fuel supply apparatus for a vehicle according to the present invention, one and the other of the first and second fuel pipes are arranged in a right area and a left area, respectively, with respect to the center of the vehicle. 
     According to the fuel supply apparatus for a vehicle described above, the first fuel pipe for guiding the fuel to the first fuel supply system and the second fuel pipe for guiding the fuel to the second fuel supply system are arranged in one and the other of the left and right areas with respect to the center of the vehicle. Thus, even in the case where one fuel pipe and/or one fuel supply system is damaged due to collision on a side of the vehicle, for example, the other fuel pipe and the other fuel supply system can continue fuel injection to the internal combustion engine. This allows the driver to move the vehicle to safety at the time of collision on a side of the vehicle. 
     Still preferably, in the fuel supply apparatus for a vehicle according to the present invention, the first fuel supply system includes a high-pressure fuel pump that pressurizes the fuel guided by the first fuel pipe and discharges the resultant fuel, and controls a pressure of the fuel injected from the first fuel injection mechanism to a prescribed pressure. Further, the second fuel supply system sets a pressure of the fuel injected from the second fuel injection mechanism to a pressure lower than the prescribed pressure. 
     According to the fuel supply apparatus for a vehicle described above, the pressure of the fuel injected by the first fuel supply system can be maintained at a high level, and thus, the fuel can be injected directly into the cylinder with the first fuel supply system. Meanwhile, the intake manifold injection mechanism (for example, intake manifold injector) can inject the fuel at a pressure lower than the prescribed pressure via the second fuel supply system. Accordingly, in the internal combustion engine provided with both the in-cylinder injection mechanism (e.g., in-cylinder injector) and the intake manifold injection mechanism, a fuel pipe configuration that can suppress variation in fuel pressure in the respective injectors can be implemented. 
     Still preferably, the fuel supply apparatus for a vehicle according to the present invention further includes a fuel cutoff valve. The fuel cutoff valve is arranged in at least one of the first and second fuel pipes, between a branch point of the first and second fuel pipes and the first or second fuel supply system, in the vicinity of the branch point. 
     According to the fuel supply apparatus for a vehicle described above, the fuel cutoff valve capable of stopping fuel supply from the fuel tank is provided in at least one of the first and second fuel pipes. The fuel cutoff valve is arranged in the vicinity of the branch point of the first and second fuel pipes, which can minimize fuel leakage upon breakage of the fuel pipe. 
     In the above-described configuration, particularly, the fuel supply apparatus for a vehicle further includes an acceleration sensor. The acceleration sensor is provided for at least one of the first and second fuel pipes, corresponding to the fuel cutoff valve. The fuel cutoff valve is actuated in accordance with a detected value of the corresponding acceleration sensor to cut off the fuel. 
     According to the fuel supply apparatus for a vehicle described above, the acceleration sensor can be used to determine the presence/absence of collision on the side of the vehicle on which the corresponding fuel pipe is arranged, and the fuel cutoff valve can be used to automatically cut off the fuel supply upon occurrence of the collision. As a result, it is possible to minimize the fuel leakage upon breakage of the fuel pipe due to the collision. 
     A fuel supply apparatus for a vehicle according to another aspect of the present invention includes a fuel tank, a first fuel supply system, a second fuel supply system, a first fuel pipe, and a second fuel pipe. The fuel tank is arranged in a rear area with respect to the center of the vehicle and stores fuel. The first fuel supply system includes a first fuel injection mechanism for injecting fuel into an internal combustion engine that is arranged in a front area with respect to the center of the vehicle. The second fuel supply system includes a second fuel injection mechanism that is different from the first fuel injection mechanism for injecting fuel into the internal combustion engine. The first fuel pipe is provided to guide the fuel from the fuel tank to the first fuel supply system. The second fuel pipe is provided to guide the fuel from the fuel tank to the second fuel supply system. The first and second fuel pipes are branched in the rear area of the vehicle. 
     A fuel supply apparatus for a vehicle according to still another aspect of the present invention includes a fuel tank, a first fuel supply system, a second fuel supply system, a first fuel pipe, and a second fuel pipe. The fuel tank is configured to store fuel. The first fuel supply system includes a first fuel injection mechanism for injecting fuel into an internal combustion engine. The second fuel supply system includes a second fuel injection mechanism that is different from the first fuel injection mechanism for injecting fuel into the internal combustion engine. The first fuel pipe is provided to guide the fuel from the fuel tank to the first fuel supply system. The second fuel pipe is provided to guide the fuel from the fuel tank to the second fuel supply system. A branch point between the first and second fuel pipes is arranged such that a fuel pipe length between the branch point and the fuel tank is shorter than a fuel pipe length between the branch point and each of the first and second fuel supply systems. 
     As described above, a main advantage of the present invention is that it is readily possible to implement a fuel pipe configuration capable of suppressing pulsation in fuel pressure in each of a plurality of fuel supply systems to an internal combustion engine. 
     The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic configuration diagram of an engine system incorporating a fuel supply apparatus according to an embodiment of the present invention. 
         FIG. 2  is a block diagram illustrating a configuration of the fuel supply apparatus according to the embodiment of the present invention. 
         FIG. 3  is a conceptual diagram illustrating an operation of a high-pressure fuel pump shown in  FIG. 2 . 
         FIGS. 4 and 5  are block diagrams illustrating first and second examples, respectively, of the fuel pipe configuration in the fuel supply apparatus according to the embodiment of the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In the following, the same or corresponding portions in the drawings have the same reference characters allotted, and detailed description thereof will not be repeated where appropriate. 
       FIG. 1  schematically shows an engine system incorporating a fuel supply apparatus according to an embodiment of the present invention. Although an in-line 4-cylinder gasoline engine is shown in  FIG. 1 , application of the present invention is not restricted to the engine shown. 
     As shown in  FIG. 1 , the engine (internal combustion engine)  10  includes four cylinders  112 , which are connected via corresponding intake manifolds  20  to a common surge tank  30 . Surge tank  30  is connected via an intake duct  40  to an air cleaner  50 . In intake duct  40 , an airflow meter  42  and a throttle valve  70 , which is driven by an electric motor  60 , are disposed. Throttle valve  70  has its degree of opening controlled based on an output signal of an engine ECU (Electronic Control Unit)  300 , independently from an accelerator pedal  100 . Cylinders  112  are connected to a common exhaust manifold  80 , which is in turn connected to a three-way catalytic converter  90 . 
     For each cylinder  112 , an in-cylinder injector  110  for injecting fuel into the cylinder and an intake manifold injector  120  for injecting fuel into an intake port and/or an intake manifold are provided. Injectors  110 ,  120  are controlled based on output signals of engine ECU  300 . 
     In-cylinder injectors  110  are connected to a common fuel delivery pipe (hereinafter, also referred to as “high-pressure delivery pipe”)  130 , and intake manifold injectors  120  are connected to a common fuel delivery pipe (hereinafter, also referred to as “low-pressure delivery pipe”)  160 . Fuel supply to fuel delivery pipes  130 ,  160  is carried out by a fuel supply portion  150 , which will be described later in detail. Low-pressure delivery pipe  160 , fuel supply portion  150 , and high-pressure delivery pipe  130  constitute the fuel supply apparatus in the engine system shown in  FIG. 1 . 
     Engine ECU  300  is configured with a digital computer, which includes a ROM (Read Only Memory)  320 , a RAM (Random Access Memory)  330 , a CPU (Central Processing Unit)  340 , an input port  350 , and an output port  360 , which are connected to each other via a bidirectional bus  310 . 
     Airflow meter  42  generates an output voltage that is proportional to an intake air quantity, and the output voltage of airflow meter  42  is input via an A/D converter  370  to input port  350 . A coolant temperature sensor  380  is attached to engine  10 , which generates an output voltage proportional to an engine coolant temperature. The output voltage of coolant temperature sensor  380  is input via an A/D converter  390  to input port  350 . 
     A fuel pressure sensor  400  is attached to high-pressure delivery pipe  130 , which generates an output voltage proportional to a fuel pressure in high-pressure delivery pipe  130 . The output voltage of fuel pressure sensor  400  is input via an A/D converter  410  to input port  350 . An air-fuel ratio sensor  420  is attached to exhaust manifold  80  located upstream of three-way catalytic converter  90 . Air-fuel ratio sensor  420  generates an output voltage proportional to an oxygen concentration in the exhaust gas, and the output voltage of air-fuel ratio sensor  420  is input via an A/D converter  430  to input port  350 . 
     Air-fuel ratio sensor  420  in the engine system of the present embodiment is a full-range air-fuel ratio sensor (linear air-fuel ratio sensor) that generates an output voltage proportional to an air-fuel ratio of the air-fuel mixture burned in engine  10 . As air-fuel ratio sensor  420 , an O 2  sensor may be used which detects, in an on/off manner, whether the air-fuel ratio of the mixture burned in engine  10  is rich or lean with respect to a theoretical air-fuel ratio. 
     Accelerator pedal  100  is connected to an accelerator press-down degree sensor  440  that generates an output voltage proportional to the degree of press-down of accelerator pedal  100 . The output voltage of accelerator press-down degree sensor  440  is input via an A/D converter  450  to input port  350 . An engine speed sensor  460  generating an output pulse representing the engine speed is connected to input port  350 . Further, acceleration sensors (G sensors)  480 L,  480 R each measure acceleration at the position where it is located, and transmit an output voltage proportional to the measured acceleration to engine ECU  300 . The output voltages of acceleration sensors  480 L,  480 R are input via an A/D converter  455  to input port  350 . 
     ROM  320  of engine ECU  300  prestores, in the form of a map, values of fuel injection quantity that are set corresponding to operation states based on the engine load factor and the engine speed obtained by the above-described accelerator press-down degree sensor  440  and engine speed sensor  460 , respectively, and the correction values based on the engine coolant temperature. Engine ECU  300  generates various control signals for controlling the overall operations of the engine system based on signals from the respective sensors by executing a prescribed program. The control signals are transmitted to the devices and circuits constituting the engine system via output port  360  and drive circuits  470 . 
       FIG. 2  illustrates a configuration of the fuel supply apparatus according to the embodiment of the present invention. 
     In  FIG. 2 , the portions other than in-cylinder injectors  110 , high-pressure delivery pipe  130 , intake manifold injectors  120  and low-pressure delivery pipe  160  correspond to the fuel supply portion  150  of  FIG. 1 . 
     Low-pressure fuel pump  170  draws fuel from a fuel tank  165 , and discharges it at a prescribed pressure (low-pressure set value). The fuel discharged from low-pressure fuel pump  170  is delivered via a fuel filter  175  and a fuel pressure regulator  180  to a low-pressure fuel path. Low-pressure fuel pump  170  is of an electrically driven type, and its actuation timing and discharge quantity (flow rate) can be controlled by engine ECU  300 . 
     The low-pressure fuel path is branched at a branch point Na into a fuel pipe  190  extending to low-pressure delivery pipe  160  and a fuel pipe  192  connected to high-pressure fuel pump  200 . Fuel pressure regulator  180  is opened when the fuel pressure in the low-pressure system begins to increase, to form a route through which the fuel in the low-pressure fuel path in the vicinity of fuel pressure regulator  180 , i.e., the fuel having just been pumped by low-pressure fuel pump  170 , is returned to fuel tank  165 . This can maintain the fuel pressure in the low-pressure fuel path at a prescribed level. Further, the fuel returned to fuel tank  165  is the one having just been pumped from fuel tank  165 , which prevents a temperature increase in fuel tank  165 . 
     High-pressure fuel pump  200  of an engine driven type is attached to a cylinder head (not shown). In high-pressure fuel pump  200 , a plunger  220  within a pump cylinder  210  is driven in a reciprocating manner by rotation of a cam  202  for the pump that is provided at a camshaft  204  of an intake valve (not shown) or an exhaust valve (not shown) of engine  10 . High-pressure fuel pump  200  further includes a high-pressure pump chamber  230  delimited by pump cylinder  210  and plunger  220 , a gallery  245  connected to fuel pipe  192 , and an electromagnetic spill valve  250  serving as a metering valve. Electromagnetic spill valve  250  is a valve that controls connection/disconnection between gallery  245  and high-pressure pump chamber  230 . 
     The discharge side of high-pressure fuel pump  200  is connected via a high-pressure fuel path  260  to high-pressure delivery pipe  130  that delivers fuel to in-cylinder injectors  110 . High-pressure fuel path  260  is provided with a check valve  240  that suppresses reverse flow of the fuel from fuel delivery pipe  130  toward high-pressure fuel pump  200 . Further, low-pressure fuel pump  170  provided in fuel tank  165  is connected to the intake side of high-pressure fuel pump  200  via fuel pipe  192  and branch point Na. 
     Referring to  FIG. 3 , in the intake stroke where the lifted amount of plunger  220  along with the rotation of cam  202  for the pump decreases, the volumetric capacity of high-pressure pump chamber  230  increases with the reciprocating motion of plunger  220 . In the intake stroke, electromagnetic spill valve  250  is maintained in the open state. 
     Referring again to  FIG. 2 , during the valve-opening period of electromagnetic spill valve  250 , gallery  245  is in communication with high-pressure pump chamber  230 , so that the fuel is drawn from fuel pipe  192  via gallery  245  into high-pressure pump chamber  230  in the intake stroke. 
     Referring again to  FIG. 3 , in the discharge stroke where the lifted amount of plunger  220  by rotation of cam  202  for the pump increases, the volumetric capacity of high-pressure pump chamber  230  decreases with the reciprocating motion of plunger  220 . In the discharge stroke, engine ECU  300  controls opening/closing of electromagnetic spill valve  250 . 
     Referring again to  FIG. 2 , during the valve-opening period of electromagnetic spill valve  250  in the discharge stroke, gallery  245  is in communication with high-pressure pump chamber  230 . Thus, the fuel drawn into high-pressure pump chamber  230  overflows to the side of fuel pipe  192  via gallery  245 . That is, the fuel is discharged back toward fuel pipe  192  via gallery  245 , rather than being delivered via high-pressure fuel path  260  to fuel delivery pipe  130 . 
     Meanwhile, during the valve-closed period of electromagnetic spill valve  250 , gallery  245  is not in communication with high-pressure pump chamber  230 . Thus, the fuel pressurized in the discharge stroke is delivered via high-pressure fuel path  260  toward fuel delivery pipe  130 , rather than reversely flowing into gallery  245 . 
     Engine ECU  300  controls the opening/closing timing of electromagnetic spill valve  250  by referring to the fuel pressure detected by fuel pressure sensor  400  and the fuel injection quantity controlled by the ECU. As such, engine ECU  300  can control the quantity of the fuel pressurized at high-pressure fuel pump  200  and delivered to high-pressure delivery pipe  130 , to thereby adjust the fuel pressure within high-pressure delivery pipe  130  to a required level. 
     As described above, in the fuel supply apparatus shown in  FIG. 2 , low-pressure fuel pump  170  commonly supplies fuel to a low-pressure fuel supply system  11 , which is configured with intake manifold injectors  120  and low-pressure delivery pipe  160 , and to a high-pressure fuel supply system  12 , which is configured with in-cylinder injectors  110 , high-pressure delivery pipe  130  and high-pressure fuel pump  200 . This means that the fuel discharged from high-pressure fuel pump  200  back to fuel pipe  192  can cause pulsation in fuel pressure in low-pressure fuel supply system  11 . 
       FIG. 4  shows a first example of a fuel pipe configuration in the fuel supply apparatus according to the embodiment of the present invention. 
     Referring to  FIG. 4 , in a vehicle incorporating the fuel supply apparatus according to the embodiment of the present invention, front wheels  500  and engine  10  are arranged in a front area  600 F with respect to a center line  600  of the vehicle, and rear wheels  510  and fuel tank  165  are arranged in a rear area  600 R. Low-pressure fuel pump  170  is arranged in fuel tank  165  in an integrated manner, as shown in  FIG. 2  as well. 
     Low-pressure fuel supply system  11  including low-pressure delivery pipe  160  and high-pressure fuel supply system  12  including high-pressure fuel pump  200  are also arranged in front area  600 F in association with engine  10 . 
     In  FIG. 4 , a vehicle of the V-type engine arrangement is shown by way of example, in which low-pressure delivery pipes  160   a ,  160   b  are arranged for the respective banks. Hereinafter, low-pressure delivery pipes  160   a ,  160   b  are collectively referred to as low-pressure delivery pipe  160 . As to high-pressure fuel supply system  12 , the stages following high-pressure fuel pump  200 , not shown in  FIG. 4 , are configured as shown in  FIG. 2 . 
     In the fuel supply apparatus according to the embodiment of the present invention, branch point Na between fuel pipe  190 , which guides the fuel from fuel tank  165  (i.e., the fuel discharged from low-pressure fuel pump  170 ) to low-pressure fuel supply system  11 , and fuel pipe  192 , which guides the fuel from fuel tank  165  to high-pressure fuel supply system  12 , is provided in the vicinity of fuel tank  165 . 
     This configuration guarantees a long pipe length between low-pressure fuel supply system  11  and high-pressure fuel supply system  12 , or more specifically, from high-pressure fuel pump  200  to low-pressure delivery pipe  160 . As a result, it is possible to suppress variation in fuel pressure at low-pressure fuel supply system  11  due to the fuel discharged from high-pressure fuel pump  200  back to fuel pipe  192 , and thus to stabilize the fuel pressure in respective fuel supply systems  11  and  12 . It is noted that each of fuel pipes  190  and  192  may be arranged in a spiral manner or in a folded manner, to secure a longer pipe length. 
     Further, in the fuel supply apparatus according to the embodiment of the present invention, fuel pipe  190  for low-pressure fuel supply system  11  and fuel pipe  192  for high-pressure fuel supply system  12  are arranged in a left area  650 L and a right area  650 R, respectively, with respect to a center line  650  of the vehicle. Alternatively, fuel pipe  192  and fuel pipe  190  may be arranged in left area  650 L and right area  650 R, respectively, opposite to the arrangement shown in  FIG. 4 . 
     When one and the other of fuel pipes  190 ,  192  are arranged at left and right areas  650 L,  650 R, respectively, of the vehicle as described above, even if one of the fuel pipes,  190  or  192 , is damaged due to collision at the side of the vehicle, for example, the remaining fuel pipe,  192  or  190 , can continuously supply fuel to the corresponding fuel supply system,  12  or  11 . This allows the driver to move the vehicle to safety with either in-cylinder injector  110  or intake manifold injector  120 . 
     Further, fuel cutoff valves  700  and  702  may be arranged for fuel pipes  190  and  192 , respectively, as shown in  FIG. 5 . Fuel cutoff valve  700  is actuated in response to a control signal GL from engine ECU  300 , to cut off the fuel supply from fuel tank  165  to low-pressure fuel supply system  11 . Similarly, fuel cutoff valve  702  is actuated in response to a control signal GR from engine ECU  300 , to cut off the fuel supply from fuel tank  165  to high-pressure fuel supply system  12 . 
     Control signal GL is output when the acceleration detected by acceleration sensor  480 L arranged in left area  650 L of the vehicle attains a prescribed level or more. Similarly, control signal GR is output when the acceleration detected by acceleration sensor  480 R arranged in right area  650 R of the vehicle becomes equal to or greater than a prescribed threshold value. This threshold value is set such that collision at the side of the vehicle leading to breakage of fuel pipe  190  or  192  can be detected. 
     With the configuration shown in  FIG. 5 , when there occurs a collision at the side of the vehicle, fuel cutoff valve  700  or  702  on the damaged side can be actuated in response to the acceleration detected by acceleration sensor  480 L or  480 R at the relevant side exceeding the threshold value. As such, it is possible to automatically detect occurrence of collision at the side of the vehicle and to suppress occurrence of fuel leakage due to damage to fuel pipe  190 ,  192  and/or low-pressure fuel supply system  11  or high-pressure fuel supply system  12  on the collided side. Although the configuration where fuel cutoff valves  700 ,  702  are arranged for fuel pipes  190 ,  192  has been shown by way of example in  FIG. 5 , a configuration having a fuel cutoff valve arranged for only one fuel pipe is also possible. 
     Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims.