JP5423334B2 - Fuel filter regeneration control device - Google Patents

Description

  The present invention relates to a fuel filter regeneration control device, and more particularly, to a pre fuel filter regeneration control device that regenerates a pre fuel filter installed upstream of a main fuel filter.

[Conventional technology]
Conventionally, a fuel tank comprising a supply pump incorporating a feed pump for pumping fuel from a fuel tank, a common rail into which high-pressure fuel is introduced from the supply pump, and a plurality of injectors to which high-pressure fuel is distributed and supplied from the common rail. A fuel supply system (fuel supply device for an internal combustion engine) for supplying fuel from an engine to an internal combustion engine (engine) is known (see, for example, Patent Document 1).
As shown in FIG. 5, the fuel supply system has a main fuel filter (hereinafter referred to as a main fuel filter) that captures and removes foreign matters contained in the fuel downstream of the feed pump 102 built in the supply pump 101 in the fuel flow direction. A filter 103). In addition, the fuel supply system has a pre-fuel filter (hereinafter referred to as a pre-fuel filter) upstream of the feed pump 102 and the main filter 103 in the fuel flow direction in order to prevent foreign matters contained in the fuel from entering the feed pump 102. A filter 111).
The fuel supply system is configured to inject and supply high-pressure fuel stored (accumulated) in the common rail 104 into the combustion chamber of each cylinder of the engine via each injector 105.

Here, the piping for supplying fuel from the fuel tank 100 to the fuel suction portion (suction side) of the feed pump 102 of the supply pump 101 is not only the pre-filter 111 but also air bleed in the fuel piping when the vehicle is assembled. A priming pump 112 is installed.
A filter element 114 of the main filter 103 is installed in a pipe that supplies fuel from the feed pump 102 to the pressurizing chamber 113 of the supply pump 101 via the main filter 103. Note that an air vent orifice 115 and an air vent relief valve 116 are installed in a pipe that returns air such as bubbles mixed in the fuel flowing into the main filter 103 to the fuel tank 100.
The fuel sucked into the pressurizing chamber 113 is pressurized and increased in pressure as the plunger 119 is driven up and down by a cam 118 integrated with the camshaft 117.

A fuel flow path for supplying fuel from the pre-filter 111 to the feed pump 102 is formed inside the supply pump 101. A goose filter 121 is installed in this fuel flow path.
A fuel flow path for supplying fuel from the feed pump 102 to the main filter 103 is formed inside the supply pump 101. From this fuel flow path, a fuel return flow path connected upstream of the feed pump 102 in the fuel flow direction and a bypass flow path that bypasses the feed pump 102 are branched. A relief valve 122 is installed in the fuel return channel. A priming valve bypass flow path check valve 123 is provided in the bypass flow path.

A fuel flow path for supplying fuel from the main filter 103 to the electromagnetic valve 124 is formed inside the supply pump 101. A pump orifice 125 and a goose filter 126 are installed in the fuel flow path. Further, a fuel return passage connected to the upstream side in the fuel flow direction from the feed pump 102 is branched from the fuel passage. A regulating valve 127 is installed in the fuel return channel. A fuel flow path for supplying fuel to the cam chamber 128 is branched from the fuel return flow path. A cam orifice 130 is installed in the fuel flow path.
In addition, a fuel flow path for supplying fuel from the electromagnetic valve 124 to the common rail 104 through the suction valve 131, the pressurizing chamber 113, and the discharge valve 132 is formed inside the supply pump 101. A fuel return channel connected to the upstream side in the fuel flow direction from the feed pump 102 is branched from the fuel channel. A zero orifice 133 is installed in the fuel return channel.

[Conventional technical problems]
However, in a conventional fuel supply system (see FIG. 5), a fuel in which a large amount of foreign matter is mixed may be used. Alternatively, the conventional fuel supply system (see FIG. 5) may be used in a poor environment where a large amount of foreign matter enters the fuel tank. In such a case, the prefilter 111 installed in the middle of the fuel supply path (fuel intake path of the feed pump 102) for supplying fuel from the fuel tank 100 to the feed pump 102 is removed from the fuel tank 100 by the operation of the feed pump 102. Although foreign matter mixed in the sucked fuel can be captured, the prefilter 111 is clogged because a large amount of foreign matter adheres or accumulates in the prefilter 111 in a period shorter than a preset filter replacement period. May cause.
The prefilter 111 that has become clogged becomes a main factor that causes an abnormally large pressure loss, and an abnormally excessive load is generated in the prefilter 111. In other words, a larger pressure difference between the upstream side and the downstream side in the fuel flow direction than the prefilter 111 may cause problems such as breakage of the prefilter 111 (filter burst).

Further, when the prefilter 111 is clogged, an abnormally excessive suction negative pressure (pressure lower than the atmospheric pressure) is generated on the suction side of the feed pump 102 built in the supply pump 101. In this case, since the discharge pressure of the fuel discharged from the discharge side of the feed pump 102 becomes unstable and pulsates, the relief valve 122 repeats opening and closing operations with a large amplitude. As a result, there is a possibility that problems such as damage to pump built-in components such as the relief valve 122 built in the supply pump 101 may occur.
Further, since it is necessary to replace the prefilter 111 in a period shorter than a preset filter replacement period, the replacement frequency of the prefilter 111 is remarkably increased. Thereby, the problem that the burden (cost) with respect to the maintenance of the prefilter 111 by a user becomes large arises.

JP 2008-180208 A

  An object of the present invention is to provide a fuel filter regeneration control device capable of preventing the occurrence of problems such as damage (filter burst) of a fuel filter by eliminating clogging of the fuel filter. Another object of the present invention is to provide a fuel filter regeneration control device capable of preventing the occurrence of problems such as failure of a pump built-in component by eliminating clogging of the fuel filter. Another object of the present invention is to provide a fuel filter regeneration control device capable of dramatically reducing the frequency of replacement of the fuel filter by performing the fuel filter regeneration process and at the same time achieving maintenance-free fuel filter. .

According to the first aspect of the present invention, the electric pump that generates the fuel flow in the reverse flow direction with respect to the fuel flow when the fuel is supplied to the internal combustion engine is provided, and the fuel is generated by the fuel flow generated by the electric pump. A filter regeneration means for performing a regeneration process of the fuel filter is provided by backwashing the filter.
The fuel filter regeneration process is executed by controlling the operation of the filter regeneration means based on the pressure loss level detected by the pressure loss detection means (the clogged state of the fuel filter).
After the engine key switch is turned off, when the pressure loss level detected by the pressure loss detection means is equal to or higher than the first predetermined value, the operation of the filter regeneration means is controlled to start the fuel filter regeneration process. At this time, the fuel flow rate in the reverse flow direction generated by the electric pump is controlled based on the level of pressure loss detected by the pressure loss detection means.
For example, the pressure loss of the fuel passing through the fuel filter becomes abnormally excessive, or the excessive suction negative pressure is generated on the suction side of the fuel pump (the fuel filter side in the fuel flow direction than the fuel pump). When a large amount of foreign matter is adhered or accumulated on the fuel filter, the fuel filter regeneration process is executed.
When the operation of the filter regeneration means, that is, the regeneration process of the fuel filter is started (implemented), the fuel flows backward from the fuel pump side in the fuel flow direction to the fuel tank through the fuel filter. As a result, a large amount of foreign matter adhering or accumulating on the fuel filter is discharged to the fuel tank side, so that the fuel filter is regenerated.
Then, when the level of the pressure loss of the fuel passing through the fuel filter in the regeneration process of the fuel filter is less than the second predetermined value smaller than the first predetermined value, and terminates the reproduction processing of the fuel filter.

As a result, the pressure loss of the fuel passing through (permeating) the fuel filter due to clogging of the fuel filter is abnormally excessive (for example, the pressure loss level detected by the pressure loss detection means is equal to or higher than the first predetermined value). ), The clogging of the fuel filter can be eliminated, so that an excessive load is not generated on the fuel filter, and it is possible to prevent the occurrence of problems such as damage to the fuel filter (filter burst). it can. That is, damage to the fuel filter due to clogging of the fuel filter can be avoided.
Also, excessive suction negative pressure (for example, the level of pressure loss detected by the pressure loss detection means is equal to or higher than the first predetermined value) is generated on the suction side of the fuel pump (the fuel filter side in the fuel flow direction than the fuel pump). Since the clogging of the fuel filter can be eliminated before, it is possible to prevent the occurrence of problems such as failure of the pump built-in components of the fuel pump. That is, it is possible to prevent failure of the pump built-in components of the fuel pump due to excessive suction negative pressure.
In addition, the fuel filter regeneration process is automatically performed by controlling the fuel flow rate in the reverse flow direction generated by the electric pump based on the pressure loss level detected by the pressure loss detecting means (the clogged state of the fuel filter). Therefore, the replacement frequency of the fuel filter can be drastically reduced. At the same time, maintenance free of the fuel filter can be achieved, so that the burden (cost) on the maintenance of the fuel filter for the user can be reduced.

According to a second aspect of the present invention, the filter regeneration means (filter regeneration system) supplies fuel from the fuel tank, the fuel pump, the fuel filter, and the fuel tank to the fuel pump through the fuel filter. It is incorporated in a fuel supply means (fuel supply system for an internal combustion engine) having a fuel supply path.
According to the invention described in claim 3, the filter regeneration means includes a fuel return path for returning the fuel to the fuel tank from the fuel pump side in the fuel flow direction with respect to the fuel filter through the fuel filter, and a fuel supply path and a fuel return path. Path switching means for switching between. For example, when the fuel filter regeneration process is executed, the filter regeneration control means controls the operation of the path switching means, so that the fuel supply path is switched to the fuel return path.
According to the fourth aspect of the present invention, the path switching means includes a fuel supply pipe that supplies fuel from the fuel tank to the fuel filter, and a reverse that prevents a reverse flow of fuel from the fuel filter toward the fuel tank in the fuel supply pipe. A stop valve, a fuel return pipe for returning the fuel from the fuel filter to the fuel tank, and an electromagnetic switching valve for opening and closing the fuel return pipe are provided.

According to the invention described in claim 5, the filter regeneration means changes the fuel flow direction passing through the fuel filter to a reverse flow direction with respect to the fuel flow direction when fuel is supplied to the internal combustion engine. A filter backwashing means for backwashing the fuel filter is provided. For example, when the fuel filter regeneration process is executed, the filter regeneration control means controls the operation of the filter backflow cleaning means, whereby the fuel filter is backwashed .

According to the invention described in 請 Motomeko 6, filter backwashing means includes a fuel storage tank for storing an overflow or discharged excess fuel from the fuel supply device including a fuel pump, stored in the fuel storage tank By cleaning the fuel filter back using the produced fuel, a large amount of foreign matter adhering to or accumulating on the fuel filter is discharged to the fuel tank side, so that the fuel filter is regenerated.
According to the seventh aspect of the present invention, the filter backwashing means comprises a fuel tank for storing the fuel of the internal combustion engine or storing surplus fuel overflowed or discharged from the fuel supply device including the fuel pump. By using the fuel stored in this fuel tank and backwashing the fuel filter, a large amount of foreign matter adhering to or accumulating on the fuel filter is discharged to the fuel tank side. Is done.

According to the eighth aspect of the present invention, the filter regeneration means has the foreign matter recovery filter that recovers foreign matter that has adhered or accumulated on the fuel filter when the fuel filter regeneration process is being executed. As a result, it is possible to prevent a problem that the foreign matter detached from the fuel filter is returned to the fuel tank, sucked up by the fuel pump, and reattached or accumulated on the fuel filter.
According to the invention described in claim 9 , the filter regeneration means has the fuel return path for returning the fuel to the fuel tank from the fuel pump side in the fuel flow direction with respect to the fuel filter through the fuel filter. The foreign matter recovery filter is installed in a fuel return path upstream of the fuel tank in the fuel flow direction and downstream of the fuel filter in the fuel flow direction.
According to the invention described in claim 10 , the filter regeneration means has the fuel return pipe for returning the fuel from the fuel filter to the fuel tank. The foreign matter recovery filter is installed in the fuel return pipe upstream of the fuel tank in the fuel flow direction and downstream of the fuel filter in the fuel flow direction.

According to the invention of claim 1 1, the pressure loss detection means, fuel pressure and fuel flow direction downstream of the fuel filter in the fuel flow direction upstream of the fuel filter (fuel tank side) (fuel pump A differential pressure sensor for detecting a differential pressure with respect to the fuel pressure on the side).
According to the invention described in 請 Motomeko 1 2, filter regeneration controlling means, after the engine key switch is turned off, the level of the detected pressure loss by the pressure loss detection means is smaller than the first predetermined value 2 The fuel filter regeneration process is continued by controlling the operation of the filter regeneration means until the value drops below the predetermined value.

According to the invention described in claims 1 to 3, the filter regeneration control means, while the engine key switch is turned on or after the engine key switch is turned off, the level of the detected pressure loss by the pressure loss detection means, Based on the above, the control data required for the regeneration process of the fuel filter is obtained, and the obtained control data is stored in the memory.
According to the invention described in claims 1 to 4, the fuel pump is a low pressure fuel pump for pumping fuel from a fuel tank through a fuel filter. The low-pressure fuel pump pressurizes the fuel sucked from the fuel filter and discharges the fuel toward the high-pressure fuel pump side.
According to the invention described in claim 1 5, the fuel filter is a pre-fuel filter is disposed upstream of the fuel flow direction than the low-pressure fuel pump. This pre-fuel filter captures and removes foreign matter contained in the fuel sucked into the low-pressure fuel pump.

1 is an overall configuration diagram showing a fuel filter regeneration control device (a fuel supply system, a prefilter regeneration system) for an internal combustion engine (Example 1). 1 is a block diagram showing a fuel filter regeneration control device (fuel supply system, prefilter regeneration system) for an internal combustion engine (Example 1). FIG. 6 is a flowchart illustrating a prefilter regeneration processing method (first embodiment). (Example 2) which is the whole block diagram which showed the fuel filter regeneration control apparatus (fuel supply system, prefilter regeneration system) of an internal combustion engine. 1 is an overall configuration diagram showing a common rail fuel injection system (fuel supply system) (conventional technology).

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The present invention aims to avoid problems such as bursts in the fuel filter, prevent damage to the pump built-in components, and realize maintenance free of the fuel filter. Based on the filter clogging state), the operation of the filter regeneration means is controlled to execute the fuel filter regeneration process.

[Configuration of Example 1]
1 to 3 show a first embodiment of the present invention, and FIGS. 1 and 2 show a fuel filter regeneration control device for an internal combustion engine.

The fuel filter regeneration control device for an internal combustion engine of the present embodiment includes a fuel storage tank (main tank: hereinafter referred to as a fuel tank 1) for storing fuel of an internal combustion engine (engine) such as a diesel engine having a plurality of cylinders (for example, four cylinders). And a fuel supply system (fuel supply device for an internal combustion engine) that supplies fuel from the fuel tank 1 to the engine, and a prefilter regeneration system that is additionally mounted on the fuel supply system.
The fuel supply system is mounted in an engine room of a vehicle such as an automobile, and is configured by a common rail fuel injection system (accumulated pressure fuel injection device) known as a fuel injection system for a diesel engine.

This common rail fuel injection system includes a main fuel filter (hereinafter referred to as a main filter 2) that removes foreign matters in the fuel pumped from the fuel tank 1, and a supply pump that pressurizes the fuel drawn from the main filter 2 to increase the pressure. 3, a common rail 4 into which high-pressure fuel discharged from a fuel discharge port (fuel discharge port) of the supply pump 3 is introduced, and a plurality of injectors 5 to which high-pressure fuel is distributed and supplied from each fuel outlet of the common rail 4, The high-pressure fuel stored (accumulated pressure) inside the common rail 4 is injected and supplied into the combustion chamber of each cylinder of the engine via each injector 5.
Further, the common rail fuel injection system includes a pre-fuel filter (hereinafter referred to as a pre-filter 6) installed upstream of the supply pump 3 in the fuel flow direction, and overflow fuel overflowed from fuel supply equipment such as the supply pump 3. Fuel storage tank (sub tank: hereinafter referred to as fuel storage tank 7) and a foreign matter recovery filter 8 for recovering foreign matter adhering or accumulating on the prefilter 6.

Here, the amount of current supplied to the solenoid valves of the supply pump 3 and the solenoid valves of the plurality of injectors 5 is controlled by an engine including a pump drive circuit (not shown) and an injector drive circuit (not shown). It is configured to be controlled by a unit (filter regeneration control means: hereinafter referred to as ECU 9).
The ECU 9 includes functions of a CPU that performs control processing and arithmetic processing, a storage device (memory such as ROM and RAM) that stores various programs and control data, an input circuit (input unit), an output circuit (output unit), and the like. And a pump drive circuit connected to the solenoid valve of the supply pump 3, and an injector drive circuit connected to each solenoid valve of the plurality of injectors 5. Note that a nonvolatile memory such as an EPROM, an EEPROM, or a flash memory may be used as the ROM.

The sensor signal from the fuel pressure sensor (common rail pressure sensor) 11 attached to the common rail 4 and the sensor signals from various sensors are A / D converted by the A / D conversion circuit and then input to the microcomputer. It is configured as follows. Here, not only the common rail pressure sensor 11 but also a crank angle sensor 12, an accelerator opening sensor 13, a coolant temperature sensor 14, a fuel temperature sensor 15, a differential pressure sensor 16, and the like are connected to the input portion of the microcomputer. .
The output portion of the microcomputer includes not only each solenoid valve (injector solenoid valve) of the plurality of injectors 5 and solenoid valve (electromagnetic fuel metering valve: hereinafter referred to as SCV18) of the supply pump 3, but also electric fuel. A pump (electric motor-driven fuel pump) 21 and an electromagnetic switching valve (electromagnetic path switching valve) 24 are connected.

When the key switch is turned on, the microcomputer calculates the fuel injection pressure into the combustion chamber for each cylinder of the engine, the fuel injection amount from each injector 5 and the like based on the control program stored in the memory. It is configured to calculate and electronically control the amount of current supplied to the SCV 18 of the supply pump 3 (so-called pump driving current) and the amount of current supplied to each solenoid valve of the plurality of injectors 5 (so-called injector driving current).
The ECU 9, particularly the microcomputer, uses a filter regeneration control means for controlling the operation of a prefilter regeneration system, which will be described later, based on the level of pressure loss detected by the differential pressure sensor 16 (the clogged state of the prefilter 6). It is configured to include functions.

  Here, the supply pump 3 is an engine-driven high-pressure fuel pump, and has a built-in feed pump 32 that supplies (discharges) fuel pumped from the pre-filter 6 through the goose filter 31 toward the main filter 2. Yes. The supply pump 3 is provided with a plurality (two or more) of pumping systems that pressurize the fuel sucked into the pressurizing chamber from the filter element 33 of the main filter 2 through the pump orifice 34 and the goose filter 35, that is, the pump element has two cylinders. A high pressure of the type that controls the fuel discharge amount of a plurality of pumping systems by metering the amount of fuel sucked into each pressurizing chamber 19 with one solenoid valve (hereinafter referred to as SCV18). It is a fuel pump.

The common rail fuel injection system includes a fuel supply pipe extending from the fuel tank 1 to the plurality of injectors 5. The fuel supply pipe includes a low-pressure fuel pipe extending from the fuel tank 1 through the main filter 2 to the second intake port of the supply pump 3, and a high-pressure fuel pipe extending from the supply pump 3 through the common rail 4 to each inlet of the plurality of injectors 5. And.
The low-pressure fuel pipe supplies fuel from the fuel tank 1 through the prefilter 6 to the first suction port of the supply pump 3 and supplies the fuel from the first discharge port of the supply pump 3 to the inlet of the main filter 2. A supply pipe 42 and a supply pipe 43 for supplying fuel from the outlet of the main filter 2 to the second suction port of the supply pump 3 are provided.

The high-pressure fuel pipe supplies high-pressure fuel from the second discharge port of the supply pump 3 to the inlet port of the common rail 4, and supplies high-pressure fuel from the outlet ports of the common rail 4 to the inlets of the plurality of injectors 5. A supply pipe 45 and the like are included.
The common rail fuel injection system includes an air vent pipe 46 extending from the main filter 2 to the fuel tank 1, and a fuel return pipe extending from the fuel supply device (such as the supply pump 3, the common rail 4 and the plurality of injectors 5) to the fuel tank 1. (Fuel return pipe) 47, a fuel return pipe 48 extending from the fuel storage tank 7 to the supply pump 3, and a fuel return pipe 49 branching from the supply pipe 41 and extending to the fuel tank 1 are provided.
The air vent pipe 46 is an air vent pipe that returns air accumulated in the filter case of the main filter 2 (air such as bubbles mixed in the fuel) to the fuel tank 1.
Details of the fuel return pipes 47 to 49 will be described later.

  Next, the detailed structure of the main filter 2 of the present embodiment will be described with reference to FIG. The main filter 2 includes a filter element 33 and a filter case that accommodates the filter element 33. The filter element 33 is provided with a filter medium such as filter paper or a honeycomb-shaped filter element in an internal space formed in the filter case. Impurities contained in the fuel flowing from the fuel tank 1 (such as dust and rust) Solid matter, carbon, sludge such as gum, and foreign matters such as moisture are filtered or captured to separate and remove from the fuel. In the filter case, an inlet (inlet port) connected to the downstream end of the supply pipe 42 in the fuel flow direction, an outlet (first outlet port) connected to the upstream end of the supply pipe 43 in the fuel flow direction, and an air vent An outlet (second outlet port) connected to the upstream end of the pipe 46 in the air flow direction is formed.

  The main filter 2 is connected to an air vent pipe 46 that returns air such as bubbles generated in the fuel discharged from the feed pump 32 to the fuel tank 1. The air vent pipe 46 includes an air vent orifice 36 that restricts the flow rate of fuel passing through the filter element 33 by narrowing the flow path diameter (flow path cross-sectional area) of the fuel return flow path formed in the air vent pipe 46. An air vent relief valve 37 is provided that opens when the fuel pressure downstream of the air vent orifice 36 (fuel tank side) exceeds a predetermined value. When the air vent relief valve 37 is opened, part of the fuel in the filter case of the main filter 2 is returned to the fuel tank 1 via the air vent pipe 46.

  The main filter 2 is disposed outside the supply pump 3. The inlet of the main filter 2 is connected to the first discharge port of the supply pump 3 via a supply pipe 42. The outlet of the main filter 2 is connected to the second suction port of the supply pump 3 via a supply pipe 43. Therefore, the fuel discharged from the fuel discharge portion of the feed pump 32 once flows out of the supply pump 3, is filtered by the filter element 33 of the main filter 2, and then flows into the supply pump 3 again. As a result, since the discharge pressure from the feed pump 32 can be applied to the filter element 33, a filter having a fine filtration performance can be adopted for the pre-filter 6 and the goose filter 31. Therefore, the filter element 33 can remove foreign matters such as small foreign matter and moisture that cannot be removed by the pre-filter 6 and the goose filter 31.

The supply pump 3 of the present embodiment has the feed pump 32 and the SCV 18 as described above. Further, the supply pump 3 is provided with a check valve structure suction valve 51 on the upstream side of each pressurizing chamber 19 in the fuel flow direction. Further, the supply pump 3 is provided with a check valve structure discharge valve 52 on the downstream side of each pressurizing chamber 19 in the fuel flow direction. When the discharge valve 52 is opened, high pressure fuel is discharged from the discharge port of the supply pump 3 toward the common rail 4.
The supply pump 3 is driven by a pump drive shaft (hereinafter referred to as a camshaft 53) for driving the feed pump 32 and a cam 54 formed on the camshaft 53 to be between the top dead center and the bottom dead center. A plurality of (two or more) plungers 55 that reciprocate linearly, a pump housing (not shown) that rotatably supports the camshaft 53 via bearings, and a plurality of plungers that are fixed to the pump housing. A cylinder head (not shown) in which (two or more) pressurizing chambers 19 are formed.

The feed pump 32 is an engine-driven low-pressure fuel pump, and is a low-pressure fuel pump that pumps fuel from the fuel tank 1 through the prefilter 6 as the camshaft 53 rotates as the crankshaft of the engine rotates. is there. The feed pump 32 is a low-pressure pump unit that supplies the fuel pumped from the fuel tank 1 to the main filter 2 and a plurality of pumping systems (pump elements). In this embodiment, a trochoid pump that is an internal gear pump is used as the feed pump 32.
The feed pump 32 includes an inner rotor and an outer rotor. One end of the camshaft 53 is connected to the inner rotor and rotates integrally with the camshaft 53. Further, the inner rotor and the outer rotor are accommodated in a pump cover attached to the pump housing in a state where the external teeth and the internal teeth are engaged with each other. Therefore, in the feed pump 32, the outer rotor also rotates with the rotation of the inner rotor.

A camshaft 53 is rotatably supported by the pump housing via a bearing. The camshaft 53 is rotationally driven by the crankshaft of the engine. A drive pulley (not shown) that is belt-driven by a crank pulley coupled to the crankshaft is attached to the outer periphery of the camshaft 53 in the axial direction.
Further, a cam 54 having a circular cross section is formed eccentrically with respect to the rotation center axis of the camshaft 53 on the outer periphery of the intermediate portion of the camshaft 53 in the axial direction. An inner rotor of the feed pump 32 is attached to the outer periphery of the rear end portion in the axial direction of the camshaft 53.

Inside the supply pump 3, a cam chamber 56 is formed in which fuel is supplied from the upstream side in the fuel flow direction with respect to the regulating valve 39. The cam chamber 56 is connected to the fuel storage tank 7 via a fuel flow path 57 and a fuel return pipe 47 that form a leak port of the supply pump 3. A cam 54, a bush (not shown), a cam ring 58, and a coil spring 59 are accommodated in the cam chamber 56.
The cam ring 58 revolves around the cam 54 of the cam shaft 53. The cam ring 58 is slidably held on the outer periphery of the cam 54 via a bush. The cam ring 58 has a quadrangular prism shape and a circular through hole. Plungers 55 that reciprocate following the revolution of the cam ring 58 are disposed on both sides of the cam ring 58.

The bush is formed in a cylindrical shape and is press-fitted into the through hole of the cam ring 58.
The coil spring 59 urges the tappet 60 integrated with the end portion of the cam ring 58 in the cam chamber side end portion of the plunger 55 in the axial direction. That is, the tappet 60 is pressed against the cam ring 58 by the urging force of the coil spring 59.
Further, the contact surface between the cam ring 58 and the tappet 60 of the plunger 55 is formed in a flat shape. Thereby, since rotation of the cam ring 58 is prevented, the cam ring 58 revolves without rotating while sliding with the tappet 60 as the cam 54 rotates.

Here, the first suction port of the supply pump 3 is connected to the outlet port of the pre-filter 6 via the supply pipe 41.
Further, in the supply pump 3, a fuel flow path 61 that supplies fuel from the first suction port of the supply pump 3 to the fuel suction portion of the feed pump 32 (suction side of the feed pump 32), and the fuel of the feed pump 32 A fuel flow path 62 for supplying fuel from the discharge portion (discharge side of the feed pump 32) to the first discharge port of the supply pump 3 is formed.
Further, the fuel flow path 61 is provided with two first and second joining portions. A fuel flow path 63 into which fuel is introduced from the third suction port of the supply pump 3 is connected to the first junction. In addition, a fuel flow path 64 into which fuel is introduced from the fuel flow path 62 is connected to the second junction.
In the middle of the fuel flow path 61, a goose filter 31 for removing foreign matters mixed in the fuel in the fuel flow path after the prefilter 6 is installed. Note that a metal mesh filter similar to the filter element of the pre-filter 6 may be used as the goose filter 31.

Further, the fuel flow path branched from the fuel discharge portion of the feed pump 32 in the fuel flow direction, that is, the fuel flow path 64 branched from the fuel flow path 62 passes through the fuel flow path 64 and the feed pump 32. A relief valve (return valve) 50 for adjusting the fuel flow rate returning to the upstream side is installed. When the relief valve 50 is opened, a part of the fuel discharged from the feed pump 32 passes through the fuel flow path 64 and the fuel flow path 61 and is upstream of the feed pump 32 in the fuel flow direction, that is, in the feed pump 32. Returned to the fuel intake.
Further, inside the supply pump 3, a fuel flow path 65 for supplying fuel from the second suction port of the supply pump 3 to the fuel inlet portion of the SCV 18 and a branch portion from the fuel outlet portion of the SCV 18 are branched. And the fuel flow path 66 for supplying fuel to the inlet port of each pressurizing chamber 19, and the outlet port of each pressurizing chamber 19 joins at the junction through the discharge valve 52 to the second discharge port of the supply pump 3. A fuel channel 67 for supplying fuel is formed.

The fuel flow path 65 includes a pump orifice 34 that restricts the flow rate of the fuel flow path 65 and restricts the flow rate of fuel passing through the filter element 33 of the main filter 2, and fuel in the fuel flow path after the filter element 33. A goose filter 35 is installed to remove foreign matter mixed in. Note that a metal mesh filter similar to the filter element of the pre-filter 6 may be used as the goose filter 35.
Further, between the fuel flow path 65 and the fuel flow path 66, an SCV 18 for adjusting the amount of intake fuel sucked into each pressurizing chamber via each intake valve 51 is installed. The SCV 18 is configured to be electronically controlled by a pump drive current applied from the ECU 9. Thereby, the fuel discharge amount discharged from the second discharge port of the supply pump 3 to the common rail 4 side is controlled.

Further, from the fuel flow path 65 downstream of the pump orifice 34 and upstream of the SCV 18, a part of the fuel flowing through the fuel flow path 65 is upstream of the feed pump 32 in the fuel flow direction (Goes filter). The fuel flow path 68 returning to the fuel flow path 61) on the downstream side in the fuel flow direction with respect to 31 is branched. A regulating valve 39 that controls the fuel pressure downstream of the pump orifice 34 to a certain value or less is disposed in the fuel flow path 68. Further, a fuel flow path 69 that leads the fuel to the cam chamber 56 from the upstream side in the fuel flow direction from the regulating valve 39 branches from the fuel flow path 68. A cam orifice 70 that restricts the flow rate of fuel flowing into the cam chamber 56 by restricting the diameter of the fuel passage 69 is disposed in the fuel passage 69.
Further, the fuel flow path 66 downstream of the SCV 18 in the fuel flow direction and upstream of the intake valve 51 in the fuel flow direction is upstream of the feed pump 32 via the zero orifice 71 in the fuel flow direction. The fuel flow path 72 connected to the side (the fuel flow path 61 on the downstream side in the fuel flow direction with respect to the goose filter 31) is branched. The fuel flow path 72 can return excess fuel downstream from the SCV 18 to the upstream side in the fuel flow direction from the feed pump 32 when the SCV 18 is closed.

Further, a plurality of pumping systems (pump elements) are installed at the downstream end of the fuel flow path 66 on the downstream side in the fuel flow direction with respect to the SCV 18. The pump element includes a plurality of cylinder heads fixed to the pump housing and a plurality of plungers 55 slidably supported in the cylinder holes (sliding holes) of these cylinder heads. The pump element is a high-pressure fuel pump (high-pressure fuel of the supply pump 3) that pressurizes the fuel sucked into each pressurizing chamber to increase the pressure as each plunger 55 reciprocally slides in the sliding hole of the cylinder head. Pump part).
In each cylinder head fixed to the pump housing, a suction valve 51 that opens and closes a fuel passage 66 that supplies fuel from a fuel outlet portion of the SCV 18 to an inlet port of the pressurizing chamber 19, and a supply from the outlet port of the pressurizing chamber 19 A discharge valve 52 for opening and closing a fuel flow path 67 for supplying fuel to the second discharge port of the pump 3 is provided.

The common rail 4 of the present embodiment is a pressure accumulating container that accumulates high-pressure fuel corresponding to the fuel injection pressure, and is connected to one fuel inlet (inlet) connected to the second discharge port of the supply pump 3 via the supply pipe 44. Port). Further, the common rail 4 has a plurality of fuel outlets (outlet ports) connected to the inlets of the injectors 5 through a plurality of fuel pipes 45. The leaked fuel from the common rail 4 is returned to the fuel storage tank 7 via the fuel return pipe 47.
Here, a pressure limiter 73 is liquid-tightly attached between the leak port of the common rail 4 and the branch pipe of the fuel return pipe 47. The pressure limiter 73 is a pressure relief valve that opens when the internal pressure of the common rail 4 (so-called common rail pressure) exceeds a set value (limit set pressure) and keeps the internal pressure of the common rail 4 below the limit set pressure. is there.

The injector 5 of this embodiment is mounted corresponding to each cylinder of the engine. Each injector 5 is a direct injection type fuel injection valve that supplies the high pressure fuel accumulated in the common rail 4 directly into the combustion chamber in the form of a mist. Each injector 5 is connected to the downstream end in the fuel flow direction of a fuel pipe 45 branched from the common rail 4, and a fuel injection nozzle for injecting fuel into the combustion chamber of each cylinder of the engine, and a valve of this fuel injection nozzle It is an electromagnetic fuel injection valve constituted by a nozzle needle which is a body and an electromagnetic valve which drives a command piston connected to the nozzle needle in the valve opening operation direction.
Here, the solenoid valve is configured to be electronically controlled by an injector drive current applied from the ECU 9. As a result, the fuel injection amount and the injection timing injected from each injector 5 are controlled.

Next, the detailed structure of the pre-filter 6 of a present Example is demonstrated based on FIG. The prefilter 6 is installed in the middle of a supply pipe 41 of a fuel supply pipe (low pressure fuel pipe). The pre-filter 6 has a filter element and a filter case for housing the filter element. The filter element is formed of a metal mesh filter or the like, and filters or removes impurities (solid matter such as dust and rust, sludge such as carbon and gum-like substances, and foreign matters such as moisture) contained in the fuel flowing from the fuel tank 1 Capture and separate from fuel.
The filter case includes an internal space that accommodates the filter element, a fuel inlet portion (inlet port) provided upstream of the internal space in the fuel flow direction, and a fuel outlet provided downstream of the internal space in the fuel flow direction. Part (outlet port).
The filter case may be the supply pipe 41 itself. Further, the priming pump 112 shown in FIG. 5 may be installed in the prefilter 6.

In the prefilter regeneration system of the present embodiment, the pressure loss of the fuel that passes (permeates) the prefilter 6 is abnormally excessively high (a level at which abnormally excessive negative suction pressure is generated on the intake side of the feed pump 32). ), The fuel flows backward from the fuel storage tank 7 through the prefilter 6 toward the fuel tank 1, and the foreign matter adhered or accumulated on the prefilter 6 is discharged to the fuel tank side (that is, the prefilter 6). The filter regeneration means executes the regeneration process of the pre-filter 6 by performing reverse flow cleaning.
This prefilter regeneration system includes a fuel supply path for supplying fuel from a fuel tank 1 to each fuel supply device (supply pump 3, common rail 4 and a plurality of injectors 5) via a prefilter 6, and each fuel supply device (supply pump). 3, a fuel return path for returning the fuel from the common rail 4 and the plurality of injectors 5) to the fuel tank 1 via the prefilter 6, a filter backwashing means for backwashing the prefilter 6, a fuel supply path and a fuel return path. Route switching means for switching.

As described above, the fuel supply path includes supply pipes 41 to 45, fuel flow paths 61 and 62, fuel flow paths 65 to 67, and the like. Note that the fuel supply path may be configured by only the supply pipe 41 that supplies fuel from the fuel tank 1 to the suction side of the feed pump 32 built in the supply pump 3 via the prefilter 6.
The fuel return path includes a fuel return pipe 47 extending from the fuel supply device (the supply pump 3, the common rail 4 and the plurality of injectors 5) to the fuel tank 1, and a fuel return extending from the fuel storage tank 7 to the third suction port of the supply pump 3. A fuel return pipe 49 that branches off from the pipe 48 and the supply pipe 41 and extends to the fuel tank 1, fuel flow paths 61 and 63, and the like are included.

The fuel return pipe 47 returns the return fuel (including surplus fuel and leaked fuel) overflowed from the fuel supply device (the supply pump 3, the common rail 4 and the plurality of injectors 5) to the fuel tank 1 via the fuel storage tank 7. Overflow piping (overflow pipe).
The overflow pipe includes a first flow pipe 81 connecting the leak port (overflow port) of the supply pump 3 and the first junction, and a second flow connecting the leak port (overflow port) of the common rail 4 and the first junction. A path pipe 82, a third flow path pipe 83 connecting each leak port (overflow port) of the plurality of injectors 5 and the second junction, a first junction pipe 84 connecting the first junction and the second junction, A second merging pipe 85 connecting the two merging portions and the fuel storage tank 7 and a fuel return pipe (overflow pipe) 86 for returning the return fuel overflowed from the fuel storage tank 7 to the fuel tank 1 are provided.

  The filter backflow cleaning means changes the fuel flow direction passing through the pre-filter 6 to a reverse flow direction with respect to the fuel flow direction when fuel is supplied to the combustion chamber of each cylinder of the engine (that is, the fuel storage tank 7). In this system, the pre-filter 6 is back-washed by allowing the fuel to flow backward toward the fuel tank through the pre-filter 6. This filter backwashing means includes a fuel storage tank 7 for storing return fuel (including surplus fuel and leaked fuel) overflowed from the fuel supply equipment (supply pump 3, common rail 4 and plural injectors 5), and a fuel return path ( The fuel return pipe 48, the fuel flow paths 61 and 63, the supply pipe 41, the fuel return pipe 49, etc.) and the electric fuel pump 21 for generating a fuel flow in the reverse direction, and the inside of the fuel return pipe 48 on the suction side of the feed pump 32 And a check valve 22 for preventing the reverse flow of fuel from the fuel flow toward the electric fuel pump side.

  The fuel storage tank 7 is provided separately from the fuel tank 1, and is installed closer to the feed pump in the fuel flow direction than the prefilter 6. The fuel storage tank 7 is connected in the middle of the fuel return pipe 47, that is, between the second junction pipe 85 and the overflow pipe 86 of the overflow pipe. The fuel storage tank 7 can store a predetermined amount of return fuel that has overflowed from the fuel supply device (the supply pump 3, the common rail 4, and the plurality of injectors 5).

The electric fuel pump 21 is a motor-driven fuel pump that receives a supply of electric power and generates a fuel flow. In the electric fuel pump 21, the discharge flow rate (fuel discharge amount) of the fuel discharged from the discharge port of the electric fuel pump 21 changes in accordance with the level of supply power (supply voltage) supplied from the ECU 9. For example, the discharge flow rate (fuel discharge amount) of the electric fuel pump 21 increases as the supply voltage to the electric fuel pump 21 increases. In addition, the electric fuel pump 21 generates a fuel flow in the reverse flow direction with respect to the fuel flow at the time of fuel injection supply to the engine. Further, the electric fuel pump 21 uses the fuel stored in the fuel storage tank 7 to back-wash the prefilter 6.
The check valve 22 includes a housing having a valve seat (valve seat) in which a flow path hole (valve hole) is formed, a valve that opens and closes the flow path hole, and biases the valve in the valve closing operation direction. And a spring. The channel hole formed in the valve seat communicates with the fuel return channel formed inside the fuel return pipe 48. This check valve 22 is located in the middle of the fuel return pipe 48, that is, between the downstream side of the fuel flow from the fuel discharge port of the electric fuel pump 21 and the upstream side of the fuel flow from the third suction port of the supply pump 3. A fuel return pipe 48 is installed.

The path switching means performs the foreign matter recovery filter 8 for recovering the foreign matter adhered or accumulated on the prefilter 6 and the inside of the supply pipe 41 of the fuel supply path from the prefilter 6 during the regeneration process of the prefilter 6. A check valve 23 for preventing the back flow of fuel toward the fuel tank side, an electromagnetic switching valve 24 for opening and closing the fuel return pipe 49, and the like are provided.
The foreign matter collection filter 8 has a filter element and a filter case for housing the filter element. The filter element is made of an equivalent or higher metal mesh filter or the like. The foreign matter recovery filter 8 is installed in a fuel return pipe 49 upstream of the fuel tank 1 in the fuel flow direction and downstream of the prefilter 6 in the fuel flow direction. Note that a metal mesh filter having finer filtration performance than the pre-filter 6 may be employed as the foreign matter collection filter 8.

The check valve 23 includes a housing having a valve seat (valve seat) in which a flow path hole (valve hole) is formed, a valve that opens and closes the flow path hole, and biases the valve in the valve closing operation direction. And a spring. The flow path hole formed in the valve seat communicates with the fuel supply flow path formed inside the supply pipe 41. The check valve 23 is installed in the supply pipe 41 on the fuel tank side in the fuel flow direction from the junction with the fuel return pipe 49.
The electromagnetic switching valve 24 includes a housing having a valve seat (valve seat) in which a flow path hole (valve hole) is formed, a valve that opens and closes the flow path hole, and biases the valve in the valve closing operation direction. A spring and an electromagnetic actuator that drives the valve in the valve opening operation direction are provided. The passage hole formed in the valve seat communicates with the fuel return passage formed inside the fuel return pipe 49. The electromagnetic switching valve 24 switches from the fuel supply path to the fuel return path by opening a fuel return pipe 49 connecting the branch portion of the supply pipe 41 and the fuel tank 1. Further, the electromagnetic switching valve 24 is switched from the fuel return path to the fuel supply path by closing the fuel return pipe 49.

Here, the amount of current supplied to the electric fuel pump (electric pump) 21 and the electromagnetic switching valve (electromagnetic valve) 24 includes an electric pump drive circuit (not shown) and an electromagnetic valve drive circuit (not shown). The ECU 9 is configured to be controlled.
The ECU 9, particularly the microcomputer built in the ECU 9, operates the electric fuel pump 21 and the electromagnetic switching valve 24 based on the level of pressure loss detected by the differential pressure sensor 16 (the prefilter 6 is clogged). It includes the function of filter regeneration control means for electronically controlling.
Further, the ECU 9, particularly a microcomputer (filter regeneration control means) built in the ECU 9 variably controls the electric power (supply voltage or the like) supplied to the electric fuel pump 21 to rotate the electric fuel pump 21 (or the discharge flow rate or the discharge flow rate). A fuel pump control means for controlling the discharge pressure). The ECU 9 calculates (sets) a target rotational speed (or target discharge amount or target fuel pressure) corresponding to the clogged state of the pre-filter 6 detected by the differential pressure sensor 16, and corresponds to the target rotational speed. An optimal supply voltage is obtained, and this supply voltage is applied to the electric fuel pump 21 to control the discharge flow rate (back flow rate) of the fuel discharged from the discharge port of the electric fuel pump 21.

  The differential pressure sensor 16 includes a pressure in the supply pipe 41 upstream of the pre-filter 6 in the fuel flow direction (fuel pressure on the upstream side of the filter) and a supply pipe 41 downstream of the pre-filter 6 in the fuel flow direction. The internal pressure (fuel pressure on the downstream side of the filter) is introduced through pressure introduction pipes 25 and 26. As a result, the differential pressure sensor 16 is configured so that the pressure difference between the upstream side in the fuel flow direction from the prefilter 6 and the downstream side in the fuel flow direction from the prefilter 6 (the fuel pressure difference before and after the prefilter 6; Pressure). The ECU 9, particularly the microcomputer, is pressure loss detection means for detecting (calculating) the pressure loss of the fuel passing through the pre-filter 6 based on the sensor signal output from the differential pressure sensor 16.

The ECU 9, particularly the microcomputer, controls the operation of the filter regeneration means when the pressure loss level detected by the differential pressure sensor 16 is equal to or higher than a predetermined value after the engine key switch is turned off. The playback process is started. Further, the microcomputer controls the operation of the electric fuel pump 21 and the electromagnetic switching valve 24 until the level of pressure loss detected by the differential pressure sensor 16 falls below a predetermined value after the engine key switch is turned off. Then, the regeneration process of the prefilter 6 is continued.
The ECU 9, particularly the microcomputer, regenerates the pre-filter 6 based on the pressure loss level detected by the differential pressure sensor 16 while the engine key switch is turned on or after the engine key switch is turned off. Control data required for processing (start timing for starting the electric fuel pump 21, target rotational speed (or target discharge amount or target fuel pressure) of the electric fuel pump 21, and switching from the closed state to the open state of the electromagnetic switching valve 24 (Switching timing) is obtained, and the obtained control data is stored in the memory.

Further, the ECU 9, particularly the microcomputer, is designed to stop the engine operation during the engine operation (E / G: ON). When switched to the OFF position, it is determined whether or not the control data necessary for the regeneration process of the prefilter 6 is stored in the memory. If the control data is stored, the regeneration process of the prefilter 6 is performed.
When the control data necessary for the regeneration process of the prefilter 6 is not stored in the memory, and when the regeneration process of the prefilter 6 is completed, the power supply to the SCV 18 of the supply pump 3 and the plurality of injectors 5 are performed. The engine is completely stopped (E / G: OFF) by stopping (off) the power supply to each solenoid valve.

[Control Method of Example 1]
Next, the regeneration processing method of the prefilter 6 of the present embodiment will be briefly described with reference to FIGS. FIG. 3 is a flowchart showing a prefilter regeneration processing method.

When it is time to start the control routine of FIG. 3, it is first determined whether or not the engine key switch is turned on. Alternatively, it is determined whether or not the engine is operating (step S1). If this determination is NO, the control routine of FIG. 3 is terminated.
When the determination result in step S1 is YES, the differential pressure sensor 16 monitors (measures) the pressure loss of the fuel passing through the prefilter 6 at a predetermined control interval (sampling interval). Specifically, the sensor signal output from the differential pressure sensor 16 is input via an A / D conversion circuit, and the pressure loss of the prefilter 6 is detected based on the sensor signal output from the differential pressure sensor 16 ( (Pressure loss detection means: step S2).

Next, it is determined whether or not the differential pressure sensor 16 has detected an abnormally excessive suction negative pressure on the suction side of the feed pump 32, that is, clogging of the pre-filter 6. Specifically, it is determined whether or not the pressure loss level (clogged state) of the pre-filter 6 is equal to or higher than a first predetermined value measured and set in advance through experiments or the like (step S3). If the determination result is NO, the filter regeneration process flag (FLAG = 0) is turned off, and the process of step S2 is repeated at a predetermined control interval (sampling interval).
If the determination result at step S3 is YES, a filter regeneration process flag (FLAG = 1) is set (step S4).

  Next, the pressure loss (clogged state) of the pre-filter 6 detected in step S2 and a control map (correlation map between pressure loss and discharge flow rate, or pressure loss and accumulated amount of foreign matter) previously measured through experiments or the like. From the correlation map with the discharge flow rate), a target discharge flow rate of fuel that flows backward through the prefilter 6 from the fuel outlet portion to the fuel inlet portion is determined (calculated). Specifically, based on the pressure loss (clogged state) of the prefilter 6 detected by the differential pressure sensor 16, the amount of accumulated foreign matter adhered or accumulated on the prefilter 6 is calculated (calculated), and the calculated prefilter Based on the amount of foreign matter accumulated in the filter 6, the target rotational speed (pump rotational speed, pump rotational speed) or target discharge flow rate (or target fuel pressure) of the electric fuel pump 21 is calculated (calculated), and the calculated target rotational speed is calculated. Based on the speed or target discharge flow rate (or target fuel pressure), a supply current amount (for example, supply voltage) to the electric fuel pump 21 is determined (calculated) (step S5).

  Next, control data required for the regeneration process of the prefilter 6 (pressure loss of the prefilter 6, amount of foreign matter accumulated in the prefilter 6, start timing of the electric fuel pump 21, target rotational speed or target discharge of the electric fuel pump 21) The flow rate or the target fuel pressure, the supply voltage to the electric fuel pump 21, the switching timing of the electromagnetic switching valve 24, etc.) are stored in the memory (step S6). 3 is repeatedly executed at predetermined control intervals (sampling intervals) while the engine key switch is turned on, a plurality of control data is accumulated in the memory. For this reason, when there are a plurality of control data, the latest (current) control data or relatively new control data may be updated and stored in the memory.

Next, it is determined whether or not the engine key switch has been turned off (step S7). If the determination result is NO, the process of step S2 is repeated at a predetermined control interval (sampling interval).
If the decision result in the step S7 is YES, it is judged whether or not a filter regeneration process flag (FLAG = 1) is set (step S8). If the determination result is NO, it is determined that the prefilter 6 is not clogged, and the control routine of FIG. 3 is terminated without operating the prefilter regeneration system.

  If the determination result in step S8 is YES, that is, if the pressure loss level (clogged state) of the prefilter 6 is greater than or equal to the first predetermined value, the control data (electromagnetic switching valve) stored in the memory 24), a control signal (opening signal) is transmitted to the electromagnetic switching valve 24 to open the electromagnetic switching valve 24. For example, energization to the electromagnetic switching valve 24 is started (ON) (step S9). Next, based on the control data (start timing of the electric fuel pump 21) stored in the memory, the electric fuel pump 21 is started by transmitting a control signal (start signal) to the electric fuel pump 21. For example, energization to the electric fuel pump 21 is started (ON) (step S10). Next, the control data (supply voltage to the electric fuel pump 21) calculated in step S5 is given to the electric fuel pump 21, and the target rotational speed, target discharge flow rate, or target fuel pressure of the electric fuel pump 21 is changed to the prefilter 6. The pressure is controlled to be an optimum value corresponding to the pressure loss or the amount of foreign matter accumulated in the prefilter 6 (step S11).

Next, it is determined whether or not a predetermined time has elapsed since the start of the operation of the prefilter regeneration system (step S12). If this determination is NO, the process of step S12 is repeated. Note that the processing in step S12 may be omitted.
If the determination result in step S12 is YES, the differential pressure sensor 16 monitors (measures) the pressure loss of the fuel passing through the prefilter 6 at a predetermined control interval (sampling interval). Specifically, the sensor signal output from the differential pressure sensor 16 is input via an A / D conversion circuit, and the pressure loss of the prefilter 6 is detected based on the sensor signal output from the differential pressure sensor 16 ( (Pressure loss detecting means: step S13).

  Next, the pressure loss level (clogged state) of the pre-filter 6 decreases to a second predetermined value (a value in which the amount of accumulated foreign matter is less than the first predetermined value) set by measurement in advance through experiments or the like. It is determined whether or not (step S14). When the determination result is NO, the pressure loss (clogged state) of the pre-filter 6 detected in step S12 and a control map (correlation map between pressure loss and discharge flow rate, or a measurement map prepared in advance by experiment or the like) A target discharge flow rate of the fuel that flows backward through the prefilter 6 from the fuel outlet portion to the fuel inlet portion is determined (calculated) from the pressure loss, the foreign matter accumulation amount and the discharge flow rate). Specifically, similarly to step S5, based on the pressure loss of the prefilter 6 detected by the differential pressure sensor 16, the amount of accumulated foreign matter adhered or accumulated on the prefilter 6 is calculated, and the calculated prefilter 6 is calculated. The target rotational speed or target discharge flow rate or target fuel pressure of the electric fuel pump 21 is calculated (calculated) based on the amount of foreign matter accumulated in the motor. Based on the calculated target rotational speed or target discharge flow rate or target fuel pressure, The supply voltage to the electric fuel pump 21 is determined (calculated) (step S15). Next, the process after step S12 is repeated.

Here, the control data (supply voltage to the electric fuel pump 21) calculated in step S15 is given to the electric fuel pump 21, and the target rotational speed, the target discharge flow rate, or the target fuel pressure of the electric fuel pump 21 is changed to the prefilter 6. The pressure is controlled to be an optimum value corresponding to the pressure loss or the amount of foreign matter accumulated in the prefilter 6. Specifically, the target rotational speed (pump rotational speed) of the electric fuel pump 21 is increased (increased) continuously or stepwise for the purpose of shortening the control time for performing the regeneration process of the prefilter 6.
In step S15, the pump rotation speed may be increased (increased) or decelerated continuously or stepwise in accordance with the decrease in the amount of foreign matter accumulated in the prefilter 6.

  If the determination result in step S14 is YES, it is determined that the regeneration process of the prefilter 6 has been completed, and the filter regeneration process flag (FLAG = 0) is defeated (step S16). Next, a control signal (valve closing signal) is transmitted to the electromagnetic switching valve 24 to close the electromagnetic switching valve 24. For example, energization to the electromagnetic switching valve 24 is stopped (OFF) (step S17). Next, the supply of electric power to the electric fuel pump 21 is stopped. For example, energization to the electric fuel pump 21 is stopped (OFF) (step S18). Thereafter, the control routine of FIG. 3 is terminated.

[Operation of Example 1]
Next, the internal combustion engine fuel supply device (common rail fuel injection system) of this embodiment will be briefly described with reference to FIGS.

When the camshaft 53 of the supply pump 3 is driven and rotated by the crankshaft of the engine, the feed pump 32 built in the supply pump 3 rotates as the camshaft 53 rotates. As a result, the fuel stored in the fuel tank 1 is sucked from the fuel suction port of the supply pipe and flows into the supply pump 3 through the supply pipe 41, the prefilter 6 and the supply pipe 41. Here, when the fuel passes through the pre-filter 6, the foreign matters contained in the fuel are separated and removed.
Then, the fuel that has been filtered and purified by the prefilter 6 flows into the fuel flow path 61 from the first discharge port of the supply pump 3. Then, the fuel that has flowed into the fuel flow path 61 is sucked into the feed pump 32 through the goose filter 31. Here, when the fuel passes through the goose filter 31, foreign substances contained in the fuel are separated and removed.

The feed pump 32 discharges the fuel that has been filtered and purified by the goose filter 31 to the fuel flow path 62. The fuel discharged to the fuel flow path 62 is discharged from the first discharge port of the supply pump 3 and flows into the main filter 2 through the supply pipe 42.
When the fuel that has flowed into the inner space from the inlet of the filter case passes through the filter element 33 installed in the inner space of the filter case, the foreign matters contained in the fuel are separated and removed. The fuel that has been filtered and purified by the filter element 33 flows out from the outlet of the filter case, and flows into the supply pump 3 through the supply pipe 43.

Here, the cam 54 rotates with the rotation of the camshaft 53, and the plunger 55 reciprocates between the top dead center and the bottom dead center with the rotation of the cam 54. When the plunger 55 at the top dead center moves toward the bottom dead center with the rotation of the cam 54, the fuel discharged from the feed pump 32 and passing through the filter element 33 is pump orifice 34, the goose filter 35, the SCV 18, and the intake. It flows into the pressurizing chamber 19 through the valve 51.
Then, when the plunger 55 that has reached the bottom dead center moves again toward the top dead center, the suction valve 51 is closed, and the fuel pressure in the pressurizing chamber 19 increases. When the fuel pressure in the pressurizing chamber 19 rises, the discharge valve 52 opens and high pressure fuel is discharged to the common rail side.
In this way, the supply pump 3 pressurizes the fuel supplied from the feed pump 32 to the main filter 2 and cleans it to increase the pressure, and discharges the high-pressure fuel from the second discharge port of the supply pump 3. To the common rail 4.
The high-pressure fuel discharged from the second discharge port of the supply pump 3 flows into the common rail 4 (pressure accumulation chamber) from the inlet port via the supply pipe 44 and is temporarily accumulated in the pressure accumulation chamber.

Here, when the injection timing (injection timing) of the injector 5 mounted in the first cylinder among the plurality of cylinders (first to fourth cylinders) of the engine is reached, energization to the solenoid valve of the injector 5 is started. . Thereby, fuel injection into the combustion chamber of the first cylinder of the engine is started. And if the command injection period passes from injection timing, electricity supply to the solenoid valve of injector 5 will be stopped. As a result, the injector 5 mounted in the first cylinder of the engine is closed, and fuel injection into the combustion chamber of the first cylinder of the engine is completed.
Further, fuel is distributed and supplied from the common rail 4 to the injectors 5 mounted on the other cylinders (second to fourth cylinders) excluding the first cylinder of the engine, and sequentially injected into the combustion chambers of the second to fourth cylinders of the engine. Supplied. As a result, the engine is operated.

Here, the fuel that has overflowed (overflowed or discharged) from the fuel flow path 57 that is the leak port of the supply pump 3 flows through the first flow path pipe 81, and then the leak port (pressure limiter 73) of the common rail 4 or The fuel flowing out from the leak ports of the plurality of injectors 5 joins and flows into the fuel return pipe 47.
Further, the fuel overflowed (overflowed or discharged) from the leak port (pressure limiter 73) of the common rail 4 flows through the second flow path pipe 82, and then leaks from the leak port of the supply pump 3 or each of the plurality of injectors 5. The fuel flowing out from the port merges and flows into the fuel return pipe 47.

The fuel that has overflowed (overflowed or discharged) from the leak port of each injector 5 flows from the leak port of the supply pump 3 or the leak port (pressure limiter 73) of the common rail 4 after flowing through the third flow path pipe 83. The fuel that has flowed out joins and flows into the fuel return pipe 47.
That is, the overflow fuel from the leak ports of the supply pump 3, the common rail 4, and the plurality of injectors 5 flows into the fuel storage tank 7 via the fuel return pipe 47 and is temporarily stored in the fuel storage tank 7.
Further, the fuel overflowed (overflowed or discharged) from the fuel storage tank 7 is returned to the fuel tank 1 through the overflow pipe 86.

Here, while the engine is operated (that is, during engine operation), the pressure loss of the fuel passing through the prefilter 6 is monitored by the differential pressure sensor 16.
Then, based on the pressure loss (clogged state) of the prefilter 6 detected by the differential pressure sensor 16, the target discharge flow rate (or target rotational speed or target) of the fuel that flows backward through the prefilter 6 from the fuel outlet portion to the fuel inlet portion. Fuel pressure). Based on the determined target discharge flow rate (or target rotational speed or target fuel pressure), a supply current amount (for example, supply voltage) to the electric fuel pump 21 is determined. The obtained control data is stored (updated) in the memory of the microcomputer.

Then, after the engine key switch is turned off, when the differential pressure sensor 16 detects an abnormally excessive suction negative pressure on the suction side of the feed pump 32 during the operation of the engine, that is, the pressure loss of the prefilter 6. When the level (clogged state) is equal to or higher than the first predetermined value, the prefilter regeneration system is activated.
At this time, by opening the electromagnetic switching valve 24, the fuel flow path is switched from the fuel supply path to the fuel return path. Then, by supplying the electric fuel pump 21 with a supply voltage corresponding to the amount of foreign matter accumulated in the prefilter 6 calculated from the pressure loss of the prefilter 6, the flow rate of fuel discharged from the electric fuel pump 21 (reverse flow) (Flow rate, fuel discharge amount) are optimum values corresponding to the amount of foreign matter accumulated in the pre-filter 6.

As a result, fuel flows from the fuel storage tank 7 to the supply pump 3 via the fuel return pipe 48. Thus, the fuel that has flowed from the third suction port of the supply pump 3 into the inside of the supply pump 3 (particularly the upstream side of the feed pump 32) passes through the fuel flow paths 63 and 61 and passes through the first suction port of the supply pump 3. Spill from.
Then, the fuel that has flowed out of the supply pump 3 flows into the prefilter 6 through the supply pipe 41 of the fuel supply pipe. Thus, the fuel that has flowed from the fuel outlet of the prefilter 6 into the internal space of the prefilter 6 (the space that houses the filter element) passes through the filter element and flows out of the fuel inlet of the prefilter 6.
The fuel flow from the fuel outlet portion of the prefilter 6 through the filter element toward the fuel inlet portion, that is, the flow direction of the fuel flow at the time of fuel injection into the combustion chamber of each cylinder of the engine (when the engine is operating) When the fuel flows in the reverse flow direction with respect to the fuel flow direction), that is, when the prefilter regeneration system is started up (at the time of operation), the foreign matter adhered or accumulated on the filter element of the prefilter 6 is 21 is discharged from the prefilter 6 together with the fuel flow generated by the fuel cell 21. The so-called pre-filter 6 is back-washed.

Then, the fuel containing the foreign matter flows out from the prefilter 6 and then branches from the branch portion through the supply pipe 41 and flows into the fuel return pipe 49. The fuel containing the foreign matter flowing into the fuel return pipe 49 is returned to the fuel tank 1 through the valve-opening electromagnetic switching valve 24 and the foreign matter collection filter 8. Here, when the fuel passes through the foreign matter collecting filter 8, the foreign matter contained in the fuel is separated and removed. That is, the foreign matter adhering or accumulating on the filter element of the pre-filter 6 is collected by the foreign matter collecting filter 8.
Here, when the regeneration process of the prefilter 6 is not completed even after a predetermined control time has elapsed since the operation of the prefilter regeneration system has started, the ECU 9 increases (increases) the pump rotation speed of the electric fuel pump 21. ), A drive signal may be sent to the electric fuel pump 21.

[Effect of Example 1]
As described above, in the fuel filter regeneration control device of the present embodiment, after the engine key switch is turned off, an abnormally excessive suction negative pressure is generated on the suction side of the feed pump 32 during the operation of the engine. Is detected, that is, when the pressure loss level (clogged state) of the prefilter 6 is equal to or higher than a first predetermined value (for example, a state in which the prefilter 6 is clogged even a little), the prefilter regeneration system. Is activated and the pre-filter 6 is regenerated.
In the prefilter regeneration system of the present embodiment, a fuel storage tank 7 that stores return fuel that has overflowed from a fuel supply device (supply pump 3, common rail 4, and a plurality of injectors 5) is installed in the middle of a fuel return pipe 47. . A large amount of foreign matter adhering or accumulating on the prefilter 6 is discharged from the prefilter 6 to the fuel tank side by backwashing the prefilter 6 using the fuel stored in the fuel storage tank 7. The Thereby, since the prefilter 6 is automatically regenerated, the clogged state of the prefilter 6 is eliminated.
In addition, after the engine key switch is turned off, the pressure loss level (clogged state) of the prefilter 6 decreases to a second predetermined value (for example, the clogged state of the prefilter 6) or lower, that is, the prefilter. The regeneration process of the pre-filter 6 is continued until the clogging state 6 is completely eliminated.

As a result, the pressure loss of the fuel that passes (permeates) the prefilter 6 due to clogging of the prefilter 6 is abnormally excessive (for example, the level of pressure loss detected by the differential pressure sensor 16 is the first predetermined level). Before reaching the value), the clogging of the prefilter 6 can be eliminated, so that an excessive load is not generated on the prefilter 6 and the prefilter 6 is broken (filter burst) or the like. Can be prevented. That is, damage to the prefilter 6 due to clogging of the prefilter 6 can be avoided.
Further, the clogging of the prefilter 6 is eliminated before an excessive suction negative pressure is generated on the suction side of the feed pump 32 built in the supply pump 3 (the prefilter side in the fuel flow direction with respect to the feed pump 32). Therefore, it is possible to prevent the occurrence of problems such as failure of the pump built-in parts (for example, the relief valve 50) of the supply pump 3. That is, it is possible to prevent a failure of the pump built-in component of the supply pump 3 due to an excessive suction negative pressure.

  Further, the amount of foreign matter accumulated in the prefilter 6 is calculated based on the pressure loss level of the prefilter 6 detected by the differential pressure sensor 16 (the clogged state of the prefilter 6), and based on this amount of foreign matter accumulated. The flow rate of fuel discharged from the electric fuel pump 21 (reverse flow rate necessary to eliminate clogging of the prefilter 6) is calculated, and a supply voltage corresponding to this discharge flow rate is supplied to the electric fuel pump 21. Since the regeneration process of the prefilter 6 can be automatically performed by opening the electromagnetic switching valve 24, the replacement frequency of the prefilter 6 can be drastically reduced. At the same time, maintenance-free of the prefilter 6 can be achieved, so that the burden (cost) for maintenance of the prefilter 6 on the user can be reduced.

  Further, in the prefilter regeneration system of the present embodiment, when the regeneration process of the prefilter 6 is being executed, that is, the electromagnetic switching valve 24 is opened and the fuel flow path is switched from the fuel supply path to the fuel return path. At this time, a foreign matter recovery filter 8 for recovering foreign matter that has adhered or accumulated on the prefilter 6 is installed in the fuel return pipe 49. As a result, the foreign matter that has left the prefilter 6 (foreign matter discharged from the fuel inlet of the prefilter 6 together with the fuel flow) is returned to the fuel tank 1 together with the fuel and sucked up by the feed pump 32 during the next engine operation. Thus, it is possible to prevent a problem that the gas flows into the prefilter 6 and adheres or accumulates again on the filter element of the prefilter 6.

  FIG. 4 shows a second embodiment of the present invention, and FIG. 4 shows a fuel filter regeneration control device.

The fuel filter regeneration control device of the present embodiment is based on the prefilter regeneration system and the actuator (electric fuel pump 21) of the prefilter regeneration system based on the pressure loss detected by the differential pressure sensor 16 (the clogged state of the prefilter 6). , An electromagnetic switching valve 24 and the like)).
The prefilter regeneration system includes a fuel supply path for supplying fuel from the fuel tank 1 through the prefilter 6 to each fuel supply device (supply pump 3, common rail 4 and a plurality of injectors 5), and each fuel supply device (supply pump 3). The fuel return path for returning the fuel from the common rail 4 and the plurality of injectors 5) to the fuel tank 1 via the prefilter 6, the filter backflow cleaning means for backwashing the prefilter 6, the fuel supply path and the fuel return path are switched. Route switching means.
The fuel return path includes a fuel return pipe 47 extending from the fuel supply device (the supply pump 3, the common rail 4 and the plurality of injectors 5) to the fuel tank 1, and a fuel return pipe extending from the fuel tank 1 to the third suction port of the supply pump 3. 48, a fuel return pipe 49 branched from the supply pipe 41 and extending to the fuel tank 1, and fuel flow paths 61, 63 and the like.

The fuel return pipe 47 is an overflow pipe (overflow pipe) that returns the return fuel (including surplus fuel and leaked fuel) overflowed from the fuel supply device (the supply pump 3, the common rail 4 and the plurality of injectors 5) to the fuel tank 1. .
The overflow pipe includes a first flow pipe 81 connecting the leak port (overflow port) of the supply pump 3 and the first junction, and a second flow connecting the leak port (overflow port) of the common rail 4 and the first junction. A path pipe 82, a third flow path pipe 83 connecting each leak port (overflow port) of the plurality of injectors 5 and the second joining section, and a first joining pipe 84 connecting the first joining section and the second joining section, A second merging pipe 85 connecting the second merging portion and the fuel tank 1 is provided.

  The filter backflow cleaning means changes the flow direction of the fuel passing through the prefilter 6 to a reverse flow direction with respect to the fuel flow direction when fuel is supplied to the combustion chamber of each cylinder of the engine (that is, from the fuel tank 1). This is a system in which the pre-filter 6 is back-washed by allowing the fuel to flow backward through the pre-filter 6 toward the fuel tank. This filter backflow cleaning means includes a fuel tank 1 for storing engine fuel and fuel in a backflow direction in a fuel return path (fuel return pipe 48, fuel flow paths 61 and 63, supply pipe 41, fuel return pipe 49, etc.). An electric fuel pump 21 that generates a flow and a check valve 22 that prevents a reverse flow of fuel from the inlet port side of the electric fuel pump 21 toward the fuel tank side in the fuel return pipe 48 are provided.

In the same manner as in the first embodiment, the path switching means moves the foreign matter collection filter 8 that collects foreign matter that has adhered or accumulated on the prefilter 6 and the fuel supply path supply pipe 41 from the prefilter 6 toward the fuel tank. A check valve 23 for preventing the back flow of fuel and an electromagnetic switching valve 24 for opening and closing the fuel return pipe 49 are provided.
The prefilter regeneration system of this embodiment uses the fuel stored in the fuel tank 1 to backwash the prefilter 6 so that a large amount of foreign matter adhered or accumulated on the prefilter 6 is prefiltered. 6 is discharged to the fuel tank side. Thereby, the pre-filter 6 is automatically reproduced.
As described above, the fuel filter regeneration control device according to the present embodiment can achieve the same effect as that of the first embodiment. Moreover, since the fuel storage tank 7 can be abolished, the number of parts in the prefilter regeneration system can be reduced, and cost reduction and space saving can be achieved.

[Modification]
In the present embodiment, the present invention is applied to the fuel filter regeneration control device that executes the regeneration process of the prefilter 6. However, the present invention is applied to the fuel filter regeneration control device that performs the regeneration process of the main filter 2. You may do it. In this case, the main filter (fuel filter) 2 is installed upstream of the feed pump 32 in the fuel flow direction. As the fuel pump, a supply pump 3 incorporating a feed pump 32 that pumps fuel from the fuel tank 1 through the main filter 2 may be used.

In this embodiment, the electromagnetic switching valve 24 that drives the valve by the electromagnetic actuator is used as the path switching means. However, the electric switching valve that drives the valve by the electric actuator including the motor, or a machine that is not electrically driven as the path switching means. A type switching valve may be used.
In this embodiment, the pressure loss of the prefilter 6 is monitored by using the differential pressure sensor 16 that detects the fuel pressure difference between the front and rear of the prefilter 6 (differential pressure before and after the filter) as the pressure loss detection means. As a detection means, the pressure loss of the prefilter 6 may be monitored using only a pressure sensor that detects a fuel pressure downstream of the prefilter 6 in the fuel flow direction. Further, the fuel pressure upstream of the prefilter 6 in the fuel flow direction may be estimated using engine information.

In the present embodiment, the prefilter 6 is based on the pressure loss level (clogged state) of the prefilter 6 detected by the pressure loss detection means (differential pressure sensor 16) during the operation of the engine or after the engine is stopped. Control data required for the regeneration process (pressure loss of the prefilter 6, accumulated amount of foreign matter in the prefilter 6, start timing of the electric fuel pump 21, target rotational speed or target discharge flow rate or target fuel pressure of the electric fuel pump 21, The supply voltage to the electric fuel pump 21, the switching timing of the electromagnetic switching valve 24, etc.) are obtained, and the obtained control data is stored in the memory of the microcomputer. At least the supply voltage to the electric fuel pump 21 is obtained. Alternatively, control data such as the switching timing of the electromagnetic switching valve 24 may be stored in a memory.
Further, the target rotational speed of the electric fuel pump 21 or the power supplied to the electric fuel pump 21 (for example, supply voltage) may be directly calculated from the pressure loss of the prefilter 6.

  In this embodiment, when the pressure loss level of the prefilter 6 is equal to or higher than the first predetermined value, the operation of the prefilter regeneration system is controlled to start the regeneration process of the prefilter 6. If it is detected that the filter is clogged even a little, the regeneration of the prefilter 6 is started by controlling the operation of the prefilter regeneration system corresponding to the pressure loss level of the prefilter 6. Also good.

1 Fuel tank 2 Main filter (Main fuel filter)
3 Supply pump (high pressure fuel pump)
6 Pre-filter (pre-fuel filter)
7 Fuel storage tank (overflow fuel storage tank)
8 Foreign matter recovery filter 9 ECU (filter regeneration control means, engine control unit)
16 Differential pressure sensor (pressure loss detection means)
21 Electric fuel pump (filter backwashing means, electric motor driven fuel pump)
22 Check valve (filter backwashing means)
23 Check valve (route switching means)
24 Electromagnetic switching valve (path switching means, electromagnetic path switching valve)
41 Supply pipe (fuel supply path, fuel supply pipe, low-pressure fuel pipe)
42 Supply pipe (fuel supply path, fuel supply pipe, low-pressure fuel pipe)
43 Supply pipe (fuel supply path, fuel supply pipe, low-pressure fuel pipe)
44 Supply pipe (fuel supply path, fuel supply pipe, high-pressure fuel pipe)
45 Supply pipe (fuel supply path, fuel supply pipe, high-pressure fuel pipe)
47 Fuel return piping (fuel return path)
48 Fuel return piping (fuel return path)
49 Fuel return piping (fuel return path)
61 Fuel flow path (fuel supply path, fuel return path)
62 Fuel flow path (fuel supply path)
63 Fuel flow path (fuel return path)
65 Fuel flow path (fuel supply path)
66 Fuel flow path (fuel supply path)
67 Fuel flow path (fuel supply path)

Claims (15)

(A) a fuel tank for storing fuel of the internal combustion engine;
(B) a fuel pump that pressurizes the fuel drawn from the fuel tank and discharges the fuel toward the internal combustion engine;
(C) a fuel filter that is installed between the fuel tank and the fuel pump and removes foreign matters contained in the fuel from the fuel tank toward the fuel pump;
(D) having an electric pump for generating a fuel flow in a reverse flow direction with respect to the fuel flow at the time of supplying the fuel to the internal combustion engine, and back-washing the fuel filter with the fuel flow generated by the electric pump; And filter regeneration means for performing regeneration processing of the fuel filter;
(E) pressure loss detecting means for detecting the pressure loss of the fuel passing through the fuel filter, and controlling the operation of the filter regeneration means based on the level of pressure loss detected by the pressure loss detecting means. Filter regeneration control means,
The filter regeneration control means controls the operation of the filter regeneration means when the pressure loss level detected by the pressure loss detection means is equal to or higher than a first predetermined value after the engine key switch is turned off to control the fuel regeneration. While starting the regeneration process of the filter , based on the pressure loss level detected by the pressure loss detection means, to control the fuel flow in the reverse flow direction generated by the electric pump,
Further, when the pressure loss level of the fuel passing through the fuel filter during the regeneration process of the fuel filter is equal to or lower than a second predetermined value that is smaller than the first predetermined value, the regeneration process of the fuel filter is terminated. A fuel filter regeneration control device. The fuel filter regeneration control device according to claim 1,
A fuel supply path for supplying fuel from the fuel tank to the fuel pump via the fuel filter;
A fuel filter regeneration control device comprising: a fuel return path for returning fuel to the fuel tank from the fuel pump side in the fuel flow direction with respect to the fuel filter through the fuel filter. The fuel filter regeneration control device according to claim 2,
The fuel filter regeneration control device, wherein the filter regeneration means includes a path switching means for switching between the fuel supply path and the fuel return path. In the fuel filter regeneration control device according to claim 3,
The fuel supply path has a fuel supply pipe for supplying fuel from the fuel tank to the fuel filter,
The fuel return path has a fuel return pipe that returns fuel from the fuel filter to the fuel tank;
The path switching means includes a check valve for preventing a reverse flow of fuel from the fuel filter to the fuel tank in the fuel supply pipe, and an electromagnetic switching valve for opening and closing the fuel return pipe. A fuel filter regeneration control device. In the fuel filter regeneration control device according to any one of claims 1 to 4,
The filter regeneration means is a filter that backwashes the fuel filter by changing a fuel flow direction passing through the fuel filter to a reverse flow direction with respect to a fuel flow direction when fuel is supplied to the internal combustion engine. A fuel filter regeneration control device comprising a backwashing means. In the fuel filter regeneration control device according to claim 5,
The filter backwashing means has a fuel storage tank for storing surplus fuel overflowed or discharged from a fuel supply device including the fuel pump, and the fuel filter is stored using the fuel stored in the fuel storage tank. The fuel filter regeneration control device is characterized by performing reverse flow cleaning . In the fuel filter regeneration control device according to claim 5 ,
The fuel filter regeneration control device, wherein the filter backwashing means backwashes the fuel filter using the fuel stored in the fuel tank. In the fuel filter regeneration control device according to any one of claims 1 to 7 ,
The fuel filter regeneration control characterized in that the filter regeneration means has a foreign matter recovery filter for recovering foreign matter adhering to or accumulating on the fuel filter when the fuel filter regeneration process is being executed. apparatus. The fuel filter regeneration control device according to claim 8 ,
The filter regeneration means has a fuel return path for returning fuel to the fuel tank from the fuel pump side in the fuel flow direction than the fuel filter through the fuel filter,
The fuel filter regeneration control , wherein the foreign matter recovery filter is installed in the fuel return path upstream of the fuel tank in the fuel flow direction and downstream of the fuel filter in the fuel flow direction. apparatus. The fuel filter regeneration control device according to claim 8 ,
The filter regeneration means has a fuel return pipe that returns fuel from the fuel filter to the fuel tank,
The fuel filter regeneration control , wherein the foreign matter recovery filter is installed in the fuel return pipe upstream of the fuel tank in the fuel flow direction and downstream of the fuel filter in the fuel flow direction. apparatus. In the fuel filter regeneration control device according to any one of claims 1 to 10 ,
The pressure loss detecting means includes a differential pressure sensor for detecting a differential pressure between an upstream side in the fuel flow direction from the fuel filter and a downstream side in the fuel flow direction from the fuel filter. Fuel filter regeneration control device. The fuel filter regeneration control device according to any one of claims 1 to 11,
The filter regeneration control means, after the engine key switch is turned off, until the pressure loss level detected by the pressure loss detection means falls below a second predetermined value smaller than the first predetermined value. A fuel filter regeneration control device characterized by controlling the operation of the filter regeneration means to continue the regeneration process of the fuel filter. The fuel filter regeneration control device according to any one of claims 1 to 12,
The filter regeneration control means performs the fuel filter regeneration process based on the pressure loss level detected by the pressure loss detection means while the engine key switch is turned on or after the engine key switch is turned off. A fuel filter regeneration control device characterized by obtaining control data required for the operation and storing the obtained control data in a memory . In the fuel filter regeneration control device according to any one of claims 1 to 13,
The fuel pump is a low-pressure fuel pump that pumps fuel from the fuel tank through the fuel filter,
The fuel filter regeneration control device , wherein the low-pressure fuel pump pressurizes the fuel sucked from the fuel filter and discharges the fuel toward the high-pressure fuel pump side . The fuel filter regeneration control device according to claim 14 ,
The fuel filter is a pre-fuel filter installed upstream of the low-pressure fuel pump in the fuel flow direction,
The fuel filter regeneration control device , wherein the pre-fuel filter captures and removes foreign matters contained in fuel sucked into the low-pressure fuel pump .

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