JP5445413B2 - Fuel supply device - Google Patents

Description

  The present invention relates to a fuel supply device, and more particularly, a fuel configured to supply fuel stored in a fuel tank to a fuel injection valve by a fuel pump, and to prevent generation and promotion of fuel vapor in the supply path. It relates to a supply device.

  In a fuel supply device for an internal combustion engine mounted on a vehicle or the like, in general, a fuel supply pressure from a fuel pump that pumps up fuel in a fuel tank to an injector (fuel injection valve) is adjusted by a pressure regulator or a relief valve. While the fuel pressure (hereinafter referred to as fuel pressure) is increased to such an extent that fuel vapor does not form inside the supply pipe, etc., the injector leaks even when the vehicle is hot soaked. The fuel pressure is suppressed to such an extent that it does not occur.

  In this type of fuel supply device, for example, the fuel pump is controlled so that the pressure in the fuel pipe for supplying the fuel from the fuel pump to the fuel injection valve approaches the target fuel pressure, while the fuel injection by the fuel injection valve is stopped. When the pressure in the fuel pipe becomes higher than the target fuel pressure in the fuel cut state, the relief valve is opened to return the fuel in the fuel pipe to the fuel tank, and the engine is hot. There is known one that can prevent the fuel pressure from rising above the target fuel pressure even if the fuel pressure is below (see, for example, Patent Document 1).

  In addition, during a predetermined period after the start switch is turned ON, the fuel supply cut valve is closed and the vapor processing valve connected to the high-pressure side fuel pipe is opened so that the fuel pressure becomes equal to or higher than the reference pressure. Until the fuel vapor amount in the pipe is sufficiently reduced and the fuel pressure starts to rise, the fuel vapor discharge process in the pipe is executed (for example, patent document) 2).

  Further, when starting the engine, the low-pressure fuel pump is operated prior to driving the high-pressure fuel pump, and fuel discharged from the low-pressure fuel pump is supplied to the common rail through the stopped high-pressure fuel pump. Open the connected vapor discharge valve to open the common rail to the fuel tank side, and discharge the vapor into the fuel tank together with the fuel even if the fuel vapor stays in the common rail. A device that shortens the boosting time in the common rail by driving is known (for example, see Patent Document 3).

  Further, the energization of the fuel pump is controlled by a duty control signal from an ECU (electronic control unit), the fuel pump is driven with a large current when the engine is started, and the holding time of the large current becomes longer as the engine cooling water temperature is higher. Thus, there is also known one that prevents vapor lock in the fuel supply device (see, for example, Patent Document 4).

JP 2010-071132 A JP-A-10-131820 JP-A-11-257177 JP 2007-126986 A

  However, in any of the above-described conventional fuel supply devices, there is a case where the fuel cannot be pumped from the fuel pump to the injector side particularly at the time of return from the fuel cut state and immediately after the return from the fuel cut state. .

  That is, if the fuel cut state continues for a relatively long time, heat from a high temperature part such as an engine or an exhaust device is received by a delivery pipe, fuel piping, a fuel pump, etc. For example, the state where the temperature of gasoline (particularly alcohol-containing fuel) rises becomes longer. Therefore, the fuel in the fuel supply device may reach the boiling point of the low boiling point component (the temperature at which the vapor pressure in the liquid state of the low boiling point fuel component is equal to the external pressure) or close to it. In this case, since a large amount of fuel vapor is generated, a so-called empty pumping state may occur even if a pump for pressurizing and pumping fuel is operated.

  Even when the fuel vapor is discharged by opening the electromagnetic relief valve, if the amount of vapor generated is large, the electromagnetic relief valve is required to have its reliability at a stage where the fuel vapor cannot be completely discharged ( The upper limit time of continuous energization set from the necessity of suppressing the possibility of disconnection or the like is reached, and energization of the electromagnetic relief valve is stopped.

  The present invention has been made to solve the above-described conventional problems, and provides a fuel supply device that can quickly and reliably pump fuel by a fuel pump when returning from a fuel cut state. is there.

  In order to solve the above problems, the fuel supply device according to the present invention includes: (1) a fuel supply state in which fuel is supplied through a supply pipe to the fuel injection valve when fuel injection is performed by the fuel injection valve of the internal combustion engine; A fuel supply means capable of switching to a supply stop state for stopping the supply of the fuel to the fuel injection valve; and connected to a downstream portion of the supply pipe; A fuel supply apparatus comprising: relief means capable of discharging a part of the supply pipe to the outside; and control means for controlling the operation of the fuel supply means and the relief means, wherein the control means includes: When the fuel injection by the fuel injection valve is temporarily stopped during the rotation of the internal combustion engine, the supply pressure of the fuel through the supply pipe and the supply flow of the fuel through the supply pipe It controls the fuel supply means so as to increase at least one of, and controlling the relief means so as to discharge a portion of the fuel to the outside of the supply pipe.

  With this configuration, even when the supply pipe or the like receives heat from the high temperature part in the fuel cut state, at least one of the supply pressure and the supply flow rate of the fuel through the supply pipe is controlled to increase from the fuel supply state. In addition, the relief means is controlled to discharge the fuel to the outside of the supply pipe at the downstream portion of the supply pipe, and even if the fuel cut state continues for a long time, the temperature of the fuel in the supply pipe does not easily rise. At the same time, fuel vapor is less likely to occur. Accordingly, the fuel supply device can quickly and surely pump the fuel by the fuel pump when returning from the fuel cut state. The state in which the fuel injection by the fuel injection valve is temporarily stopped during the rotation of the internal combustion engine here refers to all of the plurality of fuel injection valves connected to the same supply pipe in the case of a multi-cylinder internal combustion engine. If the fuel injection state is a fuel cut state where fuel injection is temporarily stopped and the fuel system is one system, the fuel injection of all the fuel injection valves is stopped. If there are a plurality of fuel systems, one system ( The fuel injection of all the fuel injection valves in the same system) is stopped.

  In the fuel supply device described in (1) above, (2) the fuel supply means at least one of a supply pressure of the fuel through the supply pipe and a supply flow rate of the fuel through the supply pipe. It is desirable to have a variable fuel pump that can be increased.

  With this configuration, the variable fuel pump can easily and quickly change at least one of the fuel supply pressure and the supply flow rate through the supply pipe, and the fuel temperature rise in the supply pipe and the fuel vapor in the fuel cut state. Can be effectively suppressed.

  In the fuel supply apparatus described in (2) above, (3) the variable fuel pump is preferably a feed pump that feeds fuel in a fuel tank through the supply pipe.

  In this case, an increase in fuel temperature and generation of fuel vapor can be effectively suppressed over the entire fuel supply path from the upstream side of the supply pipe to the fuel injection valve.

  In the fuel supply device described in (3) above, (4) the fuel supply means is arranged in the middle of the supply pipe so as to pass the fuel supplied from the feed pump to the fuel injection valve side when not operating. And a high-pressure fuel pump that sucks the fuel fed from the feed pump during operation, pressurizes the fuel pump to a pressure higher than the discharge pressure of the feed pump, and discharges the fuel to the fuel injection valve side. It is preferable that the high pressure fuel pump is in the inactive state when the fuel injection is switched to a temporarily stopped state.

  With this configuration, in a fuel cut state in which the high-pressure fuel pump is stopped, the feed pump increases at least one of the supply pressure and the supply flow rate of the fuel through the supply pipe, and the relief means is the fuel at the downstream portion of the supply pipe. To the outside of the supply piping. Therefore, even if the fuel cut state continues for a long time, the temperature of the fuel in the supply pipe does not rise easily, and fuel vapor does not easily occur, and when returning from the fuel cut state to the normal operation state, the high pressure fuel pump The high-pressure fuel pumping can be resumed quickly and reliably.

  (5) In the fuel supply device according to any one of (1) to (4), (5) the fuel supply unit is connected to the supply pipe and changes the supply pressure of the fuel through the supply pipe. It may have a fuel pressure adjusting means capable of switching the set pressure. With this configuration, fuel vapor is less likely to be generated in the supply pipe, and even if fuel vapor is generated, it can be quickly discharged into the fuel tank.

  (6) In the fuel supply device according to any one of (1) to (5), (6) the relief means opens the supply pipe downstream to discharge a part of the fuel to the outside of the supply pipe. The control means is energized when the fuel supply means is switched to the fuel injection temporarily stopped state according to the length of time during which the fuel injection is temporarily stopped. It is preferable to set the operation timing by driving.

  With this configuration, when the time during which the fuel supply means is switched to the fuel cut state becomes long, the relief means is intermittently and periodically with a necessary stop time so as to be equal to or less than a preset continuous operation time, for example. Can be operated. Therefore, even if the amount of fuel vapor generated increases, the electromagnetically driven relief means is operated until the fuel vapor in the supply pipe can be sufficiently discharged into the fuel tank without reducing its reliability. Can do.

  According to the present invention, when the fuel injection is temporarily stopped during the rotation of the internal combustion engine, the fuel supply means increases at least one of the supply pressure and the supply flow rate of the fuel through the supply pipe from the fuel supply state. Since the fuel is discharged to the outside of the supply pipe at the downstream portion of the supply pipe by the relief means, even if the fuel cut state in which the supply pipe etc. receives heat from the high temperature part continues for a long time, It is possible to provide a fuel supply device that can effectively suppress the temperature rise of the fuel in the supply pipe and the generation of fuel vapor, and can quickly and reliably pump fuel by the fuel pump when returning from the fuel cut state.

It is a schematic block diagram of the fuel supply apparatus which concerns on one Embodiment of this invention. 1 is a configuration diagram including an internal combustion engine equipped with a fuel supply device according to an embodiment of the present invention and a control system of the fuel supply device. It is a schematic block diagram of the feed pump of the fuel supply apparatus which concerns on one Embodiment of this invention. It is sectional drawing which shows schematic structure of the high pressure fuel pump of the fuel supply apparatus which concerns on one Embodiment of this invention. It is a timing chart which shows the content of the fuel supply control at the time of engine starting in the fuel supply apparatus which concerns on one Embodiment of this invention. It is a timing chart which shows the content of the fuel supply control before and behind the fuel cut in the fuel supply apparatus which concerns on one Embodiment of this invention. It is a timing chart which shows the contents of fuel supply control when a fuel cut state is continued over a long time in a fuel supply device concerning one embodiment of the present invention. It is the schematic block diagram which shows the other aspect of the fuel pressure adjustment means in the fuel supply apparatus which concerns on one Embodiment of this invention.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

  1-4 has shown schematic structure of the fuel supply apparatus which concerns on one Embodiment of this invention.

  The fuel supply device for an internal combustion engine of the present embodiment is mounted on, for example, a multi-cylinder engine 10 shown in FIG. 1, and this engine 10 is mounted on an automobile (vehicle).

  First, the configuration will be described.

  An engine 10 shown in FIG. 1 has an internal combustion engine in which a plurality of cylinders 11a, for example, four cylinders 11a indicated by # 1, # 2, # 3, and # 4 are arranged in series (in-line) on an engine body 11 including the cylinder block. As shown in FIG. 2, a piston 12 is housed in each cylinder 11a and a combustion chamber 13 is defined. A crankshaft 15 is connected to the piston 12 in each cylinder 11 a via a connecting rod 14. An intake valve 16 and an exhaust valve 17 are provided on the upper side of the combustion chambers 13 of the plurality of cylinders 11a. The intake valve 16 and the exhaust valve 17 are not shown so as to open and close at a predetermined timing. Equipped with a valve mechanism. Further, the engine 10 has an ignition device (not shown in detail) having an ignition plug 18 exposed in the combustion chamber 13 and air in the cylinder 11 a according to the displacement of the piston 12 and the opening operation of the intake valve 16. An intake device 21 for intake and an exhaust device 26 for discharging exhaust gas from the cylinder 11a according to the displacement of the piston 12 and the opening operation of the exhaust valve 17 are provided, and the fuel supply device 30 of the present embodiment is provided. Has been. Note that the piston crank mechanism, the valve mechanism, the ignition device, and the like of the engine 10 can be configured in the same manner as known ones, and will not be described in detail here.

  The intake device 21 forms a surge tank 25 between an upstream intake passage portion 21a provided with an air cleaner 22 and a plurality of downstream intake passage portions 21b connected to intake ports of the plurality of cylinders 11a. An air flow meter 23 and a throttle valve 24 are provided between the surge tanks 25. Here, a filter element (not shown) is housed in the air cleaner 22, and air from which dust or the like has been removed by the air cleaner 22 is taken into the upstream intake passage portion 21 a. Further, the downstream side intake passage portion 21b is formed by a cylinder head 11h constituting the shape of the engine body 11 and an intake manifold (not shown in detail) fastened and fixed thereto.

  Although not shown in detail, the exhaust device 26 includes a plurality of upstream exhaust passage portions 26a connected to the exhaust ports of the plurality of cylinders 11a, and a downstream exhaust passage portion 26b where the plurality of upstream exhaust passage portions 26a merge. doing. A catalyst device 28 for exhaust purification is mounted on the upstream portion of the downstream exhaust passage portion 26b, and a silencer (not shown) having a known silencing structure is mounted on the downstream portion of the downstream exhaust passage portion 26b. Yes.

  A plurality of injectors (fuel injection valves) 31 are mounted on the cylinder head 11h so as to be exposed in the combustion chambers 13 of the plurality of cylinders 11a. The fuel supply apparatus of the present embodiment includes the plurality of injectors. 31 is configured as an in-cylinder injection fuel supply device 30 (fuel supply means) for injecting fuel into the combustion chambers 13 of the plurality of cylinders 11a. The fuel supply device 30 may be of a dual injection type having a port injection injector separately from the in-cylinder injector 31. Further, it may be configured as a port injection type in which fuel is injected by an injector (fuel injection valve) 31 into the air sucked into each cylinder 11a through the plurality of downstream intake passage portions 21b.

  In addition to the injector 31 that injects the fuel into the cylinder 11 a, the fuel supply device 30 distributes and supplies the fuel pressurized to the same pressure to the plurality of injectors 31, and the high-pressure side fuel pipe to the delivery pipe 32. 33 and a high pressure fuel pump 35 of a plunger type that supplies pressurized fuel through a check valve 34, and an electric motor that feeds fuel pumped up from a vertical fuel tank 41 to the high pressure fuel pump 35 through a low pressure side fuel pipe 36. Feed pump 37 (fuel pump) and a pressure regulator 43 (feed pressure adjustment) for adjusting the pressure of the fuel in the low-pressure side fuel pipe 36 fed from the feed pump 37 to the high-pressure fuel pump 35 to a preset feed pressure. And surplus discharged into the fuel tank 41 by the pressure regulator 43 It is configured to include a known jet pump 44 for pumping fuel from the other side of the fuel storage portion 41b of the fuel tank 41 of the saddle type, the by fee.

  A plurality of injectors 31 are connected to the delivery pipe 32 at equal intervals in the series arrangement direction of the plurality of cylinders 11a. The delivery pipe 32 has one end in the longitudinal direction extending in the series arrangement direction of the plurality of cylinders 11a. On the side, it is connected to the high-pressure side fuel pipe 33. The delivery pipe 32 is also equipped with a fuel pressure sensor 45 that detects the internal fuel pressure. The piping here is an arbitrary member that forms a fuel passage, and is not limited to a fuel pipe. A member that penetrates the fuel passage, or a fuel passage that is formed between the members. A plurality of members may be used.

  The feed pump 37, the pressure regulator 43, and the jet pump 44 are each disposed inside the fuel tank 41, and a strainer 42 is attached to the suction portion of the feed pump 37.

  Here, the feed pump 37 is, for example, a pump operating portion 37p having an impeller for operating the pump, like a conventional turbine fuel pump (see, for example, Japanese Patent Application Laid-Open Nos. 2006-300035 and 2004-52742). And a built-in DC motor 37m for driving the pump operating portion 37p and an outlet check valve 37v.

  The feed pump 37 pumps fuel from the fuel storage portion 41a on one side of the vertical fuel tank 41 and applies the pumped fuel to a first pressure level (for example, a pressure within a constant variable range of less than 1 MPa). Further, the discharge amount per unit time can be changed by changing the rotation speed [rpm] of the built-in motor 37m. That is, the feed pump 37 can be variably controlled in its discharge amount per unit time by being turned on and off and controlled in rotation speed by an ECU (Electronic Control Unit) 70 described later. This is a variable fuel pump, for example, a variable fuel pressure pump, capable of increasing at least one of the supply pressure and the supply flow rate of the fuel through the supply pipe.

  The plunger type high pressure fuel pump 35 has a fuel introduction port 35 i connected to the downstream end of the low pressure side fuel pipe 36 and a fuel discharge port 35 e connected to the upstream end of the high pressure side fuel pipe 33. It is arranged in the middle of a supply pipe L (hereinafter referred to as fuel pipe L such as the delivery pipe 32) including the low-pressure side fuel pipe 36, the high-pressure side fuel pipe 33 and the delivery pipe 32. During operation, the high-pressure fuel pump 35 sucks fuel pressurized by the feed pump 37 from the fuel introduction port 35i, pressurizes the fuel, and discharges it from the fuel discharge port 35e. The second pressure level The pressurized fuel is supplied into the delivery pipe 32 through the check valve 34 and the high-pressure side fuel pipe 33. Further, the high pressure fuel pump 35 is configured to allow the fuel fed from the feed pump 37 to pass to the injector 31 side when not operating.

  Specifically, the high-pressure fuel pump 35 has a pressurizing chamber 35a that introduces fuel, which is pressurized by the feed pump 37 and regulated and fed by the pressure regulator 43, through the low-pressure side fuel pipe 36. The fuel in the pressure chamber 35 a is pressurized to a second pressure level (for example, 4 to 13 MPa) that is sufficiently higher than the first pressure level, and discharged to the high-pressure side fuel pipe 33.

  As shown in FIG. 4, the high-pressure fuel pump 35 includes a plunger 35p that is slidably reciprocated in the pump housing 35h so as to change the volume of the pressurizing chamber 35a, and for example, an engine 10 for driving the plunger 35p. A camshaft 35s provided at one end of an exhaust camshaft (not shown), a follower lifter 35f driven up and down in the vertical direction in the figure by a cam portion Cp of the camshaft 35s, and the follower lifter 35f as a cam of the camshaft 35s A compression spring 35g that urges the portion Cp, and a pressurizing chamber 35a defined between the pump housing 35h and the plunger 35p changes its volume by the reciprocating movement of the plunger 35p, and feeds So as to perform the suction, pressurization and discharge of fuel from the pump 37 You have me.

  The fuel pressure on the high-pressure fuel pump 35 side is injected into the injector between the pressurizing chamber 35a of the high-pressure fuel pump 35 and the high-pressure fuel pipe 33, that is, between the high-pressure fuel pump 35 and the injector 31. With a spring that opens when the pressure on the side 31 increases with a significant differential pressure (for example, less than 100 kPa) and closes when the pressure on the high-pressure fuel pump 35 is approximately equal to or lower than the pressure on the injector 31 The check valve 34 is provided so as to partition the high-pressure fuel pipe 33 into an upstream portion 33a and a downstream portion 33b.

  The fuel introduction port 35i of the pressurizing chamber 35a of the high-pressure fuel pump 35 has a check valve function that prevents high-pressure backflow when the valve is closed in response to an input signal, while the plunger is open when the valve is opened in response to the input signal. An electromagnetic spill valve 38 is provided that allows intake of fuel into the pressurizing chamber 35a or leakage of fuel in the pressurizing chamber 35a to the low-pressure side fuel pipe 36 in accordance with the displacement of 35p.

  The electromagnetic spill valve 38 includes a poppet-shaped valve body 38v, an electromagnetic drive coil 38c that is energized by an ECU 70 to electromagnetically drive the valve body 38v, and a spring 38k that constantly biases the valve body 38v in the valve opening direction. have. Then, the valve body 38v opens so that the fuel pressure fed from the feed pump 37 is introduced into the pressurizing chamber 35a when the electromagnetic drive coil 38c is in a non-excited state, and the electromagnetic drive coil 38c is The valve is closed so as to enable the pressurization / discharge operation of the high-pressure fuel pump 35 at the time of driving in an excited state.

  Specifically, the valve body 38v has a poppet valve body shape that can open and close the fuel introduction port 35i on one end side located in the pressurizing chamber 35a, and is inserted into the central portion of the electromagnetic drive coil 38c on the other end side. The valve body 38v can be opened in response to a change in fuel pressure in the pressurizing chamber 35a in a non-excited state where no exciting current is supplied to the electromagnetic drive coil 38c. ing. The electromagnetic spill valve 38 closes the fuel introduction port 35i of the pressurizing chamber 35a by the valve body 38v when the electromagnetic drive coil 38c is excited, and the volume change of the pressurizing chamber 35a due to the reciprocating movement of the plunger 35p. Accordingly, the suction of fuel into the pressurizing chamber 35a, the pressurization within the pressurizing chamber 35a, and the discharge operation from the pressurizing chamber 35a are enabled.

  A feed pump 37, a low-pressure side fuel pipe 36, a high-pressure fuel pump 35, a check valve 34, a high-pressure side fuel pipe 33 and a delivery pipe 32 that constitute a fuel supply path from the feed pump 37 in the fuel tank 41 to the injector 31 are as follows. Together with the pressure regulator 43 and the jet pump 44, a fuel supply mechanism 40 (fuel supply means) is constituted. The fuel supply mechanism 40 has a fuel supply state in which fuel is supplied to the injectors 31 through a supply pipe such as a delivery pipe 32 when fuel injection is performed by the injectors 31 of the engine 10, and fuel injection by the injectors 31 is stopped. When the engine 10 is stopped (when the engine 10 is stopped and when fuel is cut later), it is possible to switch to a supply stop state in which the fuel supply to the injector 31 is stopped.

  Although not shown in detail, the pressure regulator 43 includes a diaphragm as a valve body that receives the pressure of fuel discharged from the feed pump 37 in the valve opening direction, and a compression coil spring that urges the diaphragm in the valve closing direction. have. The pressure regulator 43 opens when the pressure of the fuel received by the diaphragm exceeds the set pressure, and maintains the valve closed state while the pressure of the fuel received by the diaphragm is less than the set pressure. This is a pressure adjusting means capable of adjusting the fuel pressure (feed fuel pressure) in the side fuel pipe 36 to a preset feed pressure.

  The pressure regulator 43 has a constant discharge flow rate at which a discharge amount of excess fuel (discharge amount per unit time (L / h)) for adjusting the feed fuel pressure in the low-pressure side fuel pipe 36 to a set pressure is set in advance. Within the range, the feed fuel pressure in the low-pressure fuel pipe 36 can be maintained at a substantially constant set pressure as described above. However, when the fuel is discharged / supplied from the feed pump 37 at a flow rate exceeding that range, the feed fuel pressure in the low-pressure side fuel pipe 36 cannot be maintained at the normal set pressure level, and the feed fuel pressure is maintained at the feed pump 37. According to the discharge amount, the pressure is allowed to rise to a pressure exceeding the normal feed pressure within the range of the first pressure level.

  On the other hand, in addition to the fuel supply mechanism 40, the fuel supply device 30 is provided on a relief pipe 46 interposed between the other end side in the longitudinal direction of the delivery pipe 32 and the fuel tank 41, and the relief pipe 46. And an electromagnetic relief valve 47.

  The relief pipe 46 is constituted by a high-pressure side pipe part 46a on the delivery pipe 32 side from the electromagnetic relief valve 47 and a low-pressure side pipe part 46b on the fuel tank 41 side from the electromagnetic relief valve 47, and these supply pipes L as a whole. The downstream part of this is comprised.

  The electromagnetic relief valve 47 is separated from the delivery pipe 32 in FIG. 2, but is disposed at a position relatively close to the delivery pipe 32. The electromagnetic relief valve 47 receives the fuel pressure in the delivery pipe 32 introduced into the high-pressure side piping portion 46a as a pilot pressure, and urges the valve body 47v in the normally closed direction, When the pressure reaches a preset pressure, the spring 47k is compressed in the valve opening direction by the valve body 47v, and the valve body 47v is urged in the valve opening direction similar to the pilot pressure against the urging force of the spring 47k. And an electromagnetic operation unit 47n that can perform the operation.

  The electromagnetic relief valve 47 is a relief valve that operates according to the pilot pressure acting on the valve body 47v and the urging force of the spring 47k when the electromagnetic operation portion 47n is not energized, and the fuel pressure in the delivery pipe 32 Is adjusted so as not to exceed a set pressure (for example, about 15 MPa) set according to the in-cylinder injection pressure during normal operation of the engine 10, and delivery is performed when the electromagnetic operation unit 47 n energized by the ECU 70 is energized. The valve is opened even when the fuel pressure in the pipe 32 is sufficiently lower than the set pressure when the electromagnetic operating portion 47n is not energized (pressure lower than the first pressure level). Note that the electromagnetic relief valve 47 shown in FIG. 2 is a simplified illustration of the main components, and does not indicate a specific valve type with a symbol.

  The relief pipe 46 and the electromagnetic relief valve 47 are connected to the downstream portion of the delivery pipe 32 (supply pipe) as a whole, and the supply pipe L such as the delivery pipe 32 is opened on the downstream side, and one of the fuel inside the relief pipe 46 and the electromagnetic relief valve 47 is connected. The electromagnetic drive type relief means 48 which can discharge a part to the exterior of the supply piping L is comprised.

  The fuel supply device 30 further includes an ECU 70 as a control means in addition to the fuel supply mechanism 40 and the relief means 48.

  Although the detailed hardware configuration is not illustrated, the ECU 70 includes a backup memory including a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and a nonvolatile memory, and further A / D conversion. An input interface circuit including a device, an output interface circuit including a driver and a relay switch, and a constant voltage circuit are included. The ECU 70 is in accordance with a control program stored in advance in the ROM, based on sensor information, setting value information stored in the backup memory in advance, and other on-vehicle ECUs (Electronic Control Units). For example, while outputting the injection command signal to the injector 31 at the injection timing and time (fuel injection amount) according to the operating state of the engine 10 and the acceleration request, etc., and the optimal timing for each cylinder In addition, an ignition signal is output to the ignition device, and further, a valve closing drive signal to the electromagnetic spill valve 38 of the high-pressure fuel pump 35, a power supply control signal to the feed pump 37, and the like are output in a timely manner.

  The ECU 70 further exhibits each function as control means described below in accordance with a control program stored in the ROM.

  First, the ECU 70 optimally controls the closing timing and time of the electromagnetic spill valve 38 during the pressurization stroke of the plunger 35p of the high pressure fuel pump 35, so that the fuel supplied from the high pressure fuel pump 35 to the delivery pipe 32 is controlled. The pressure and supply amount are controlled to optimum values in accordance with the operating state of the engine 10 and the injection characteristics of the injector 31.

  Whether the ECU 70 generates fuel vapor in the fuel supply path based on the coolant temperature of the engine 10 and / or the detection information of the fuel pressure sensor 45 after the operation of the high-pressure fuel pump 35 is started when the engine 10 is started. If it is determined whether or not fuel vapor is generated, cranking of the engine 10 is prohibited during a short waiting time from the ignition signal output time point (ignition ON) and feed by the feed pump 37 is performed. The start-up vapor discharge control is performed such that the rotational speed of the feed pump 37 is increased so that the fuel pressure becomes larger than normal, and the electromagnetic relief valve 47 is opened.

  When the ECU 70 determines that the waiting time required for discharging the fuel vapor in the fuel supply path of the fuel supply mechanism 40 has elapsed, the ECU 70 returns the rotation speed of the feed pump 37 to the normal rotation speed and changes the feed fuel pressure to the normal pressure. The opening of the electromagnetic relief valve 47 by energization of the electromagnetic operating portion 47n is stopped and the electromagnetic relief valve 47 is closed, and then the cranking of the engine 10 is permitted. Note that the waiting time here corresponds to the waiting time T1 shown in FIG. 5 and may be a predetermined time set in advance or set according to the cooling water temperature, the oil temperature, or the like when the engine 10 is started. May be a variable setting time. Further, during the start-up vapor discharge control, the electromagnetic drive coil 38c of the electromagnetic spill valve 38 is not energized, and the ECU 70 keeps the high-pressure fuel pump 35 in a non-operating state in which the pressurization / discharge operation cannot be performed.

  Further, the ECU 70 detects the first fuel necessary for fuel injection by the injector 31 when the fuel pressure in the delivery pipe 32 on the high pressure side detected by the fuel pressure sensor 45 exceeds a preset pressure value close to the second pressure level. It is determined that the fuel pressure level of 2 can be reached, and output of the injection command signal to the injector 31 is started.

  By the way, in the fuel supply mechanism 40 of the fuel supply device 30, when fuel injection is performed by the injector 31, the fuel supply state is set to supply pressurized fuel to the injector 31. When the fuel injection by the engine 31 is stopped, the supply stop state in which the supply of the pressurized fuel to the injector 31 is interrupted. Furthermore, not only when the engine 10 is stopped, but also during its rotation (engine rotation), when the fuel cut state in which fuel injection by all the injectors 31 in the same fuel system connected to the delivery pipe 32 is temporarily stopped is entered. In addition, the fuel supply mechanism 40 is in a supply stop state in which the supply of pressurized fuel to the injector 31 is interrupted.

  Accordingly, the ECU 70 controls the fuel supply mechanism 40 to control the fuel supply pressure through the supply pipe such as the delivery pipe 32 and the like when the fuel cut state in which the fuel injection by the injector 31 is stopped during the rotation of the engine 10. At least one of the supply flow rates is increased, and the relief means 48 is controlled to discharge part of the fuel in the delivery pipe 32 into the fuel tank 41 outside the delivery pipe 32 and the relief pipe 46. Yes.

  Specifically, the ECU 70 determines from the sensor information indicating the load state of the engine 10 and / or the control state of the injector 31 or the calculated value of the required pumping amount of the high-pressure fuel pump 35 according to the required injection amount at the time of deceleration, etc. The fuel cut state in which the fuel injection from the injector 31 is temporarily stopped at the time of low load of the engine 10 (including the state in which the required pumping amount of the high-pressure fuel pump 35 becomes zero during the rotation of the engine 10) ), And at the time of detection, the rotational speed [rpm] of the feed pump 37 is increased so as to maximize the feed fuel pressure in the low-pressure side fuel pipe 36, and the electromagnetic operating portion 47n of the electromagnetic relief valve 47 is detected. Is energized to open the electromagnetic relief valve 47. When the fuel supply mechanism 40 is switched to the supply stop state in the fuel cut state of the engine 10, the electromagnetic drive coil 38c of the electromagnetic spill valve 38 is not energized, and the ECU 70 pressurizes and discharges the high pressure fuel pump 35. Keep it in an unexecutable state.

  When returning from the fuel cut state of the engine 10 to the normal operation state (state in which fuel injection is performed), immediately before the return, the rotational speed of the feed pump 37 is returned to the normal value to return the feed fuel pressure to the normal value. In addition, the valve opening operation by the electromagnetic operation portion 47n of the electromagnetic relief valve 47 is stopped to close the electromagnetic relief valve 47 so that the relief valve function during normal operation is exhibited.

  That is, when switching the fuel supply mechanism 40 to the fuel cut state, the ECU 70 controls the fuel supply mechanism 40 so as to increase at least one of the fuel supply pressure and the supply flow rate through the supply pipe such as the delivery pipe 32. At the same time, the relief means 48 is controlled so that a part of the fuel is discharged into the fuel tank 41 outside the supply pipe such as the delivery pipe 32.

  Further, when the fuel cut state is longer than a preset threshold continuous time, the ECU 70 may increase the coil temperature and cause a disconnection if the electromagnetic relief valve 47 is continuously energized. The electromagnetic operation unit 47n of the electromagnetic relief valve 47 is energized at a repetition cycle including a continuous operation time with a low possibility of occurrence and an energization stop time corresponding thereto, and the electromagnetic relief valve 47 is periodically restarted to intermittently operate the electromagnetic relief valve 47. By this, the vapor is discharged. That is, the ECU 70 as the control means determines the relief operation timing (operation start timing and operation duration time) by electromagnetic driving of the relief means 48 according to the length of time during which the fuel supply mechanism 40 is switched to the fuel cut state. ) Is set.

  Next, the operation will be described.

  In the fuel supply device for an internal combustion engine of the present embodiment configured as described above, when the engine 10 is started, the ECU 70 opens the electromagnetic relief valve 47 for a predetermined time without operating the high-pressure fuel pump 35. Vapor discharge control is executed.

  That is, as shown in FIG. 5, first, when the ignition is turned on (ignition signal output; IGON in the figure), the supply piping is based on sensor information such as the coolant temperature and oil temperature of the engine 10 at the time of the IGON. It is determined whether or not fuel vapor is generated in the fuel supply path in L and in the injector 31, and when it is determined that fuel vapor is generated, the rotational speed of the feed pump 37 is increased to a high rotational speed. By setting, the feed fuel pressure in the low-pressure side fuel pipe 36 is increased to a value close to the maximum value within the range of the first pressure level, and the electromagnetic relief valve 47 of the relief means 48 is opened by energization, The supply pipe L such as the delivery pipe 32 becomes a relief state opened on the downstream side. Further, during the waiting time T1 from the time of IGON, cranking of the engine 10 is prohibited, and the electromagnetic drive coil 38c of the electromagnetic spill valve 38 is not energized, so that the high-pressure fuel pump 35 performs the pressurization / discharge operation. Maintained in a non-operable state.

  In this state, fuel is supplied from the feed pump 37 into the supply pipe L such as the delivery pipe 32 at a higher supply flow rate and / or higher supply pressure than usual, and the supply pipe L such as the delivery pipe 32 is on the downstream side thereof. Since the relief state is opened in the fuel tank 41 by the opening operation of the electromagnetic relief valve 47 provided in the portion, the fuel vapor is supplied to the supply pipe L such as the delivery pipe 32 at a high temperature restart or the like. Even when it occurs, the feed fuel pressure from the feed pump 37 is increased to about the maximum value of the first pressure level, so that the vapor discharge time is greatly shortened, and the waiting time T1 until the start of cranking can be shortened, The fuel vapor can be reliably discharged.

  Next, when the waiting time T1 required for discharging the fuel vapor in the fuel supply path of the fuel supply mechanism 40 elapses, the rotation speed of the feed pump 37 is returned to the normal rotation speed, and the feed fuel pressure in the low-pressure side fuel pipe 36 is reduced. While the pressure is reduced to the normal pressure, the energization of the electromagnetic operation part 47n of the electromagnetic relief valve 47 is stopped, the forced valve opening operation is released, and the cranking of the engine 10 is started.

  During operation of the engine 10, an injection command signal to the injector 31 is output at an injection timing and a fuel injection amount corresponding to the operating state, required load, etc., and fuel is injected into the cylinder 11a.

  In this state, the fuel supply mechanism 40 is in a fuel supply state in which high-pressure fuel is distributed and supplied to the plurality of injectors 31 through the delivery pipe 32, and the electromagnetic spill during the pressurization stroke of the plunger 35p of the high-pressure fuel pump 35. The timing and time for closing the valve 38 are optimally controlled, so that the fuel pressure and supply amount supplied from the high-pressure fuel pump 35 to the delivery pipe 32 correspond to the operating state of the engine 10 and the injection characteristics of the injector 31. It is controlled to the optimum value.

  On the other hand, when the accelerator opening is reduced, such as when the vehicle is decelerating or downhill, and the engine 10 is in a low-load operation state, the ECU 70 determines the engine 10 to improve fuel consumption and reduce exhaust emissions. Depending on the load state, the engine 10 may be shifted to a so-called fuel cut state in which the fuel injection by the injector 31 is temporarily stopped during its rotation.

  At this time, the fuel supply mechanism 40 is in a supply stop state in which the supply of pressurized fuel to the injector 31 is interrupted for a time Tfc during which the fuel cut state is continued.

  On the other hand, at this time, when it is detected that the fuel cut state is started from the sensor information indicating the load state of the engine 10 and / or the control state of the injector 31, as shown in FIG. The rotational speed of the feed pump 37 is changed to a high rotational speed so as to maximize the feed fuel pressure, and the electromagnetic relief valve 47 is opened by energizing the electromagnetic operating portion 47n. Further, the electromagnetic spill valve 38 that is not energized to the electromagnetic drive coil 38c is opened, and the high-pressure fuel pump 35 is inactivated so that the pressurization / discharge operation cannot be performed.

  In this state, fuel is supplied from the feed pump 37 into the supply pipe L such as the delivery pipe 32 at a higher supply flow rate and / or higher supply pressure than usual, and the supply pipe L such as the delivery pipe 32 is on the downstream side thereof. Since the relief state opened in the fuel tank 41 is achieved by opening the electromagnetic relief valve 47 provided in the part, the fuel cut state continues for a long time in the operation state in which the engine 10 and the supply pipe L are at a high temperature. Even in such a case, the fuel vapor is reliably discharged from the supply pipe L such as the delivery pipe 32. In addition, since the feed fuel pressure from the feed pump 37 is increased to about the maximum value of the first pressure level, the discharge time of the fuel vapor from the supply pipe L such as the delivery pipe 32 is greatly shortened. Therefore, the high pressure fuel pump 35 is prevented from being in a so-called empty pumping state when the fuel cut state is returned to the normal operation state, and the high pressure fuel pump 35 is operated to return to the high pressure fuel pump 35 when returning from the fuel cut state to the normal operation state. Fuel supply can be restarted quickly and reliably.

  That is, even if the supply pipe L such as the delivery pipe 32 receives heat from the high temperature part such as the engine 10 or the exhaust device 26 in the fuel cut state, the supply pressure and the supply flow rate of the fuel through the supply pipe L At least one of them, for example, the feed fuel pressure is controlled to increase to a high feed fuel pressure higher than the feed fuel pressure in the normal fuel supply state, and the relief means 48 supplies fuel in the downstream portion of the supply pipe L of the supply pipe L. Since the fuel is controlled to be discharged to the outside, even if the fuel cut state of the engine 10 continues for a long time in a high-temperature environment, the temperature of the fuel in the supply pipe L is difficult to rise and the supply It becomes difficult for fuel vapor to occur in the pipe L. Therefore, in the fuel supply device 30, the high-pressure fuel can be pumped quickly and reliably by the high-pressure fuel pump 35 when the engine 10 returns from the fuel cut state.

  In the present embodiment, the fuel supply mechanism 40 includes the feed pump 37 that can increase at least one of the supply pressure and the supply flow rate of the fuel through the supply pipe L. At least one of the supply pressure and the supply flow rate can be easily and quickly changed, and the increase in the fuel temperature and the generation of fuel vapor in the supply pipe L in the fuel cut state can be effectively suppressed.

  Further, since at least one of the supply pressure and the supply flow rate of the fuel is increased by the feed pump 37 located at the upstream end of the supply pipe L, the fuel is supplied to the entire fuel supply path from the upstream side of the supply pipe L to the injector 31. A rise in temperature and generation of fuel vapor can be effectively suppressed.

  In addition, the high-pressure fuel pump 35 of the fuel supply mechanism 40 is arranged in the middle of the supply pipe L so as to pass the fuel fed from the feed pump 37 to the injector 31 side when not operating, and the vicinity of the discharge port is checked. Since the valve 34 is configured to open with a differential pressure before and after the first pressure level, even if the fuel cut state continues for a long time, the temperature of the fuel in the supply pipe L is difficult to rise and the fuel Vapor is less likely to be generated, and when returning from the fuel cut state to the normal operation state, the high pressure fuel pump 35 can resume the pumping of the high pressure fuel quickly and reliably.

  On the other hand, when the time Tfc during which the fuel cut state is continued becomes longer than a preset threshold continuous time, the supply pipe L is turned on according to the length of time during which the operating state of the engine 10 is switched to the fuel cut state. The timing of energizing the electromagnetic relief valve 47 of the relief means 48 for opening the downstream side into the fuel tank 41 is variably set, and the electromagnetic relief valve 47 is periodically restarted as shown in FIG. The fuel vapor is continuously discharged over a long time by the intermittent operation. Accordingly, if the electromagnetic relief valve 47 is continuously energized for a long time, the coil temperature of the electromagnetic operation unit 47n may increase and the possibility of disconnection may occur, but in this embodiment, the continuous operation time T2a where the possibility of occurrence of disconnection is low. Further, since the electromagnetic operating portion 47n of the electromagnetic relief valve 47 is intermittently energized at a repetition cycle T2 including the energization stop time T2b corresponding thereto, the reliability of the electromagnetic relief valve 47 does not need to be lowered. As a result, even if the amount of fuel vapor generated in the supply pipe L such as the delivery pipe 32 increases, the electromagnetically driven relief means 48 can reduce the fuel in the supply pipe L without reducing its reliability. The vapor can be reliably operated until it can be sufficiently discharged into the fuel tank 41.

  Thus, in the fuel supply device for an internal combustion engine of the present embodiment, even when the supply pipe L such as the delivery pipe 32 receives heat from the high temperature portion of the engine 10 or the like in the fuel cut state of the engine 10, Control is performed so that at least one of the supply pressure and the supply flow rate of the fuel through the supply pipe L and the like is increased from the normal operation state, and the relief means 48 supplies the fuel to the fuel tank 41 in the downstream portion of the supply pipe L. Therefore, even if the fuel cut state of the engine 10 continues for a long time, the temperature rise of the fuel in the supply pipe L and the generation of fuel vapor can be effectively suppressed. When returning from the state, the high-pressure fuel pump 35 can resume the pumping of the high-pressure fuel quickly and reliably.

  Further, in the above-described embodiment, it is assumed that the pressure regulator 43 maintains the fuel pressure to be controlled at a substantially set pressure within a predetermined discharge flow rate range of the surplus fuel, and the delivery pipe 32 and the pipes 33 and 36 under the fuel cut state. When the fuel vapor in the high-pressure fuel pump 35 is discharged, the discharge amount per unit time of the feed pump 37 is increased or decreased. However, the pressure regulator set pressure at the time of fuel cut is higher than that during normal operation. You may comprise the fuel pressure adjustment means variably set to setting pressure. It is also conceivable to insert a shut-off valve or a throttle between the low pressure side fuel pipe 36 and the pressure regulator 43.

  For example, as in a conventional fuel supply device that switches the fuel pressure between two stages of high and low (see, for example, Japanese Patent Application Laid-Open No. 2007-303372), a low discharge amount and a low discharge amount are changed according to changes in the discharge amount per unit time of the feed pump The fuel pressure adjusting means can be configured so that the low-pressure pressure regulator operates in the fuel pressure stage, and the high-pressure pressure regulator operates in the high discharge amount / high fuel pressure stage.

  Specifically, a fuel pressure adjusting mechanism 80 (fuel pressure adjusting means) as shown in FIG. 8 can be configured. In this fuel pressure adjusting means 80, a low-pressure pressure regulator 81 and a high-pressure pressure regulator 82 are connected to the low-pressure side fuel passage 36 on the discharge side of the feed pump 37. The low pressure regulator 81 has an adjustment pressure port 81a connected to the low pressure side fuel passage 36 on the discharge side of the feed pump 37, and a return port 81b communicating with the fuel tank 41 side. The first set pressure is set. The high pressure regulator 82 has an adjustment pressure port 82a connected to the low pressure side fuel passage 36 and a return port 82b communicating with the fuel tank 41 side. The second set pressure is set higher than the set pressure of 1. Further, in the return side fuel passage R1, the flow rate of the fuel returning from the return port 81b of the low pressure pressure regulator 81 into the fuel tank 41 is limited in accordance with the differential pressure between the front and rear (the differential pressure between the upstream side and the downstream side). An orifice 83 is provided, and the low-pressure pressure regulator 81 is operated until a predetermined flow rate is reached by the orifice 83. In addition, on the return fuel passage R1 side that returns from the return port 81b of the low-pressure pressure regulator 81 into the fuel tank 41, the fuel storage portion on the other side in the fuel tank 41 according to the flow rate of fuel in the return fuel passage R1. Well-known jet pumps 85 and 86 (transfer pumps) that can transfer fuel from 41b to one side fuel reservoir 41a, or can transfer fuel from the outside of internal tank 41c to the inside of one side fuel reservoir 41a. ) Is provided. Of course, in such a configuration, the set pressure of the high pressure regulator 82 can be set to a set pressure suitable for discharging the fuel vapor.

  Alternatively, unlike the embodiment of FIG. 8, the diaphragm closes the valve body depending on whether or not a back pressure fluid is introduced into the back pressure chamber on the back side of the diaphragm for pressure adjustment, for example, while using a single pressure regulator. By changing the urging force for urging in the direction to high or low, a setting pressure that can be switched between a low pressure value and a high pressure value can be changed. Needless to say, it can be used as a means capable of adjusting the pressure, or a pressure regulator with a variable set pressure of another system can be used.

  That is, the fuel supply mechanism 40 is connected to a low-pressure side fuel pipe 36 that is a part of the supply pipe L, and is capable of switching the set pressure so as to change the fuel supply pressure through the supply pipe L. It may have. By doing so, fuel vapor is less likely to be generated in the supply pipe L, and even if fuel vapor is generated, it can be quickly discharged into the fuel tank 41.

  In the above-described embodiment, the engine 10 is an in-cylinder injection type. However, the present invention can be applied to a case where a dual-injection type fuel supply device is mounted on the engine 10. In this case, the ECU 70 is based on the in-cylinder injection from the injector 31 and is in a specific operating state in which the mixture formation is insufficient in the in-cylinder injection, such as when the engine 10 is warmed up or under a low rotation and high load. The port injection is used together, or the port injection from the port injection injector is performed at the time of high rotation and high load in which the port injection is effective.

  Further, the state in which fuel injection by the fuel injection valve is temporarily stopped during the rotation of the internal combustion engine according to the present invention refers to the fuel for all of the plurality of fuel injection valves connected to the same supply pipe in the case of a multi-cylinder internal combustion engine. This means that the injection is stopped. That is, if the fuel system is one system, the fuel injection of all the fuel injection valves is stopped. However, as described above, the fuel system is a plurality of systems of the low pressure system and the high pressure system, or corresponds to a plurality of banks. In the case of a plurality of fuel systems, the fuel injection of all the fuel injection valves in any one of the plurality is stopped.

  The feed pump 37 may be composed of another rotary fuel pump instead of the turbine fuel pump, or may be composed of a plunger type or other non-rotational fuel pump. In addition, instead of changing the rotational speed of the rotary fuel pump (the number of revolutions per unit time), by changing the capacity (discharge capacity) of one suction / discharge operation per revolution or one time, the unit time The fuel discharge amount per hit may be changed. As described above, it can be determined that the shift to the fuel cut state is made when the required pumping amount of the high-pressure fuel pump becomes zero.

  As described above, when the fuel injection is temporarily stopped during the rotation of the internal combustion engine, the fuel supply device according to the present invention has at least one of the fuel supply pressure and the supply flow rate through the supply pipe by the fuel supply means. Since one of the fuel supply states is increased from the fuel supply state and the fuel is discharged to the outside of the supply pipe at the downstream portion of the supply pipe by the relief means, the fuel such that the supply pipe receives heat from the high temperature portion. Even if the cut state continues for a long time, it is possible to effectively suppress the temperature rise of the fuel in the supply pipe and the generation of fuel vapor, and the fuel can be pumped quickly and reliably by the fuel pump when returning from the fuel cut state This provides an effect that the supply device can be provided, and the fuel stored in the fuel tank is supplied to the fuel injection valve by the fuel pump. Useful for construction fuel supply system in general to achieve prevention and discharged promote fuel vapor in the feed path in addition to.

10 Engine (Internal combustion engine)
11a Cylinder 11h Cylinder head 12 Piston 13 Combustion chamber 22 Air cleaner 23 Air flow meter 24 Throttle valve 25 Surge tank 30 Fuel supply device 31 Injector (fuel injection valve)
32 Delivery pipe (supply pipe)
33 High-pressure side fuel piping 34 Check valve 35 High-pressure fuel pump 36 Low-pressure side fuel piping 37 Feed pump (fuel pump)
38 Electromagnetic spill valve 40 Fuel supply mechanism (fuel supply means)
41 Fuel tank 43 Pressure regulator (pressure adjusting means)
45 Fuel pressure sensor 46 Relief piping (downstream part of supply piping)
47 Electromagnetic relief valve 48 Relieving means 70 ECU (electronic control unit; control means)
80 Fuel pressure adjustment mechanism (pressure adjustment means)
L supply piping R1 return fuel passage T1 waiting time T2 repetition period T2a continuous operation time T2b energization stop time

Claims (4)

When fuel injection is executed by a fuel injection valve of an internal combustion engine, switching between a fuel supply state in which fuel is supplied to the fuel injection valve through a supply pipe and a supply stop state in which supply of the fuel to the fuel injection valve is stopped A possible fuel supply means, a relief means connected to a downstream portion of the supply pipe, the relief pipe capable of opening the supply pipe downstream and discharging a part of the fuel to the outside of the supply pipe; A fuel supply device comprising: a fuel supply means; and a control means for controlling the operation of the relief means,
The fuel supply means has a feed pump that is arranged upstream of the supply pipe and feeds fuel in a fuel tank through the supply pipe, and a high-pressure fuel pump that is arranged in the middle of the supply pipe,
When the fuel injection by the fuel injection valve is temporarily stopped during rotation of the internal combustion engine, the control means supplies the fuel supply pressure through the supply pipe and the fuel through the supply pipe. The fuel supply device is characterized in that the feed pump is controlled to increase at least one of the supply flow rates, and the relief means is controlled to discharge a part of the fuel to the outside of the supply pipe. It said high pressure fuel pump, when not in operation is passed through the fuel fed from the feed pump to the fuel injection valve side, is in operation than the discharge pressure of the feed pump sucks the fuel fed from the feed pump pressurized to high pressure by discharging the fuel injection valve side, the fuel according to claim 1, wherein the fuel supply means, characterized in said that the non-operating state when switched to the pause state of the fuel injection Feeding device. A fuel pressure adjusting means connected to the supply pipe and capable of switching a set pressure so as to change a supply pressure of the fuel through the supply pipe from the feed pump to the high-pressure fuel pump ; the fuel supply apparatus according to claim 1 or claim 2, characterized in that it has. The relief means is of an electromagnetic drive type that is energized when the supply pipe is opened downstream so that a part of the fuel is discharged to the outside of the supply pipe, and the control means is the fuel supply means according to the length of time that has been switched to the pause state of the fuel injection, which of the claims 1 to 3, characterized in that setting the operation timing of the electromagnetic drive of the relief means A fuel supply device according to claim 1.

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