JP2009052562A - Fuel supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel supply system smoothly supplying fuel to an internal combustion engine. <P>SOLUTION: This fuel supply system 1 is provided for supplying the fuel to the internal combustion engine 7 from a fuel tank 2. The fuel supply system 1 has: the fuel tank 2 for storing the fuel; an injector 5 for injecting and supplying the fuel into the internal combustion engine 7; a common rail 4 for storing the fuel supplied to this injector 5 in a high pressure state and supplying the fuel to the injector 5; and a fuel pump 3 for sending the fuel to this common rail 4. The fuel supply system 1 has a metallic ion removing means 15 for separating and removing metal or a metallic ion included in the fuel from the fuel, between the fuel tank 2 and the injector 5 in a passage up to supplying the fuel to the internal combustion engine 7 from the fuel tank 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a combustion supply system for supplying fuel to an internal combustion engine.

  2. Description of the Related Art Conventionally, as a system for supplying fuel such as diesel fuel to an internal combustion engine (engine), a fuel supply system including, for example, a fuel tank and an injector that injects fuel supplied from the fuel tank to the internal combustion engine. It's being used.

As fuel to be supplied to the internal combustion engine, in recent years, for the effective use of resources, used edible oil is collected and re-processed to produce fatty acid methyl ester, which is used as diesel fuel (biodiesel fuel, BDF). ) Has been attempted.
Further, in order to reduce the emissions of sulfur oxides SO _x is an environmental load substance, the sulfur concentration is low a low sulfur diesel fuel have been developed. The sulfur concentration in the fuel is regulated by the laws of each country, and it is desired to develop a fuel supply system that can handle low-sulfa diesel oil.

In particular, when fuel is supplied to an internal combustion engine such as a diesel engine (diesel engine), the fuel sent to the injector is temporarily stored in a common rail (pressure accumulating chamber) in a high pressure state and then introduced into the injector. Yes. The fuel stored in the common rail is supplied to the injector at a timing when the combustion efficiency is increased by computer control or the like. Therefore, emission of nitrogen oxides (NO _x ) and particulate matter (PM) due to a decrease in fuel combustion efficiency can be suppressed.

  In general, an injector includes a nozzle body having an injection hole through which fuel is injected, and a needle that opens and closes the injection hole by moving up and down in the nozzle body (see Patent Document 1). In this type of injector, the needle includes a cylindrical sliding portion that is slidable in the nozzle body, a cylindrical insertion portion having an outer diameter smaller than the sliding portion, the insertion portion and the sliding portion. The nozzle body has a guide part that slidably holds the sliding part, and an oil reservoir chamber that is provided on the injection hole side of the guide part and through which the insertion part is inserted. The oil reservoir chamber is supplied with high-pressure fuel for injection from the injection hole, and this fuel leaks from the minute gap portion between the sliding portion and the guide portion.

  When fuel containing foreign matter such as dust, rust, and iron is supplied to such an injector, the sliding of the sliding portion may be hindered. Further, there is a possibility that the valve for supplying fuel to the injector and the valve for supplying fuel to the common rail may be clogged with foreign matters. As a result, there is a problem that fuel cannot be sufficiently supplied to the internal combustion engine.

  Therefore, a removal device such as a fuel filter has been developed to remove foreign substances contained in the fuel (see Patent Document 1 and Patent Document 2). Such a removal device can capture and remove foreign matters in the fuel depending on the size and shape thereof, and thus can smoothly supply the fuel to the internal combustion engine.

JP 2004-122100 A JP-A-9-228914

However, even when a conventional removal device is used, foreign matter may be generated in the injector, and fuel may not be smoothly supplied to the internal combustion engine.
That is, before the fuel is supplied from the fuel tank into the injector, metals such as zinc and lead and metal ions are eluted from the metal tank, the oil feed pipe, etc. with which the fuel comes into contact. The metal and metal ions eluted in the fuel are sent into the injector, and, for example, deposit and deposit in the minute gap portion between the sliding portion and the guide portion in the injector, thereby impeding the driving of the injector. There was a fear.

In particular, when a mixed fuel of BDF and low sulfur light oil is used, metal deposition and deposition are likely to occur. Further, when high pressure fuel is supplied to the injector using the common rail, there is a problem that the temperature in the injector is likely to rise, and as a result, metal deposition and deposition are promoted.
Therefore, when BDF or low-sulfur diesel oil is used as the fuel, or when fuel is supplied into the injector using a common rail, problems such as metal precipitation and deposition are likely to occur. There was a problem that it became difficult to supply.

  The present invention has been made in view of such problems, and an object thereof is to provide a fuel supply system capable of smoothly supplying fuel to an internal combustion engine.

The present invention is a fuel supply system for supplying fuel from a fuel tank to an internal combustion engine,
The fuel supply system includes: the fuel tank for storing fuel; an injector for injecting fuel to the internal combustion engine; a common rail for storing fuel to be supplied to the injector in a high pressure state and supplying fuel to the injector; A fuel pump for feeding fuel to the common rail,
Metal ions for separating and removing metal or / and metal ions contained in the fuel from the fuel between the fuel tank and the injector in the path from the fuel tank to the internal combustion engine. Removal means are provided,
The metal ion removing means includes an outer case into which the fuel flows from the outside of the metal ion removing means, an inner case housed inside the outer case and into which the fuel flows in the outer case, and the inner case. A fuel supply system having a metal ion adsorbent disposed therein (claim 1).

In the fuel supply system of the present invention, the most notable point is that the metal contained in the fuel or / or between the fuel tank and the injector in the path from the fuel tank to the internal combustion engine. And metal ion removing means for separating and removing metal ions from the fuel.
Therefore, in the fuel supply system, the metal ion removing means can separate and remove the metal or / and metal ions in the fuel, and the amount of metal ions and metals contained in the fuel can be reduced. Therefore, fuel containing almost no metal ions or metals can be supplied into the injector. As a result, metal deposition / deposition in the injector can be prevented, and the injector can be driven stably for a long period of time. Therefore, fuel can be smoothly supplied to the internal combustion engine.

The fuel supply system has the common rail. Therefore, the injector is supplied with high-pressure fuel from the common rail, and the temperature in the injector is likely to rise. Therefore, if the fuel supplied into the injector contains metal ions or metal, metal deposition / deposition tends to occur in the injector.
In the present invention, as described above, the metal ion removal means can reduce the amount of metal ions and metal in the fuel, so that the high-pressure fuel supplied from the common rail increases the temperature in the injector. However, metal deposition and deposition are unlikely to occur in the injector.

  Furthermore, in the fuel supply system, biodiesel fuel (BDF), low sulfur gas oil, or the like can be suitably used as the fuel. Conventionally, when BDF or low sulfur light oil is used as described above, there is a problem that the metal is easily deposited and deposited in the injector. However, in the present invention, the metal ion removing means is provided. Such a problem can be avoided. That is, in the fuel supply system, fuel can be smoothly supplied to the internal combustion engine even when BDF, low sulfur light oil, or the like is used as the fuel.

  Thus, according to the present invention, it is possible to provide a fuel supply system capable of smoothly supplying fuel to the internal combustion engine.

Embodiments of the present invention will be described.
The fuel supply system includes the fuel tank, the injector, the common rail, and the fuel pump.
The fuel stored in the fuel tank is sent to the common rail by the fuel pump, and is stored in a high pressure state in the common rail. Generally, in the common rail, fuel is stored at a high pressure of 160 MPa or more. The high-pressure fuel stored in the common rail is supplied to the injector. At this time, the common rail can supply fuel to the injector at a timing when the combustion efficiency is increased by computer control or the like. The fuel supplied to the injector is injected and supplied to the internal combustion engine by the injector.

In the fuel supply system, a metal or metal ion contained in the fuel is supplied between the fuel tank and the injector in a path from the fuel tank to the internal combustion engine. Metal ion removing means for separating and removing from the metal.
The metal ion removing means is between the fuel tank and the injector in the fuel supply path, for example, between the fuel tank and the common rail, or when a fuel filter described later is provided, It can be provided between the filter and between the fuel filter and the common rail.

Next, the metal ion removing means preferably has a metal ion adsorbent that adsorbs metal ions and / or metals in a fuel path in the metal ion removing means.
In this case, the metal ion removing means can easily remove the metal or metal ion from the fuel by the metal ion adsorbing material adsorbing the metal or metal ion in the fuel.
Examples of the metal ion adsorbent include chelate resin and activated carbon. As the chelate resin, an ion exchange resin or the like having a characteristic capable of selectively binding a specific ion by a chelate bond can be used.

Moreover, it is preferable that the said metal ion removal means is formed in the fuel path in this metal ion removal means so that a pair of electrodes with different potentials may sandwich the fuel path.
In this case, the metal ion removing means separates the metal or metal ion contained in the fuel from the fuel by the potential difference between the pair of electrodes having different potentials, and bonds the metal ion or metal ion to the electrode. Can be easily removed from the fuel.
As the electrode, for example, a metal electrode made of Fe, Ni, Cu or the like can be used.

Moreover, it is preferable that the said metal ion removal means has a filter for removing the foreign material in a fuel in the said fuel path | route.
In this case, the metal ion removing means can separate and remove the metal ions and metals in the fuel as described above, and the size of the foreign substances such as dust and rust contained in the fuel by the filter. Can be removed.
For example, filter paper or the like can be used as the filter. The filter paper can be used singly or in a plurality of layers.

Further, when the metal ion removing means is configured by using the metal ion adsorbing material, it is possible to use, for example, a filter made of filter paper in which the metal ion adsorbing material is dispersed. Further, the metal ion adsorbent and the filter can be arranged to be stacked (see FIGS. 4 and 5).
Further, when the metal ion removing means is configured using a pair of electrodes having different potentials as described above, for example, a pair of electrodes and the filter can be combined (see FIG. 6).

The fuel preferably contains a low sulfa light oil having a sulfur concentration of less than 15 ppm and a biodiesel fuel composed of methyl ester obtained by esterifying vegetable oil.
In this case, it is possible it is possible to reduce the sulfur oxide SO _x concentration in the exhaust gas, the effective use of resources.
Further, in this case, the above-described effect that fuel can be smoothly supplied to the internal combustion engine can be more effectively exhibited. That is, when low sulfa diesel oil and biodiesel fuel are used as the fuel for the fuel supply system, the metal contained in the fuel is easily deposited and deposited in the injector, and the driving of the injector is hindered, and the internal combustion engine There is a risk that the fuel cannot be supplied smoothly. However, in the fuel supply system, even if the constant sulfur light oil and the biodiesel are used as the fuel, the metal ion and the metal ions in the fuel can be removed by the metal ion removing means. Smooth fuel supply becomes possible.

When the sulfur content in the low sulfur gas oil exceeds 15 ppm, the sulfur oxide SO _x concentration in the exhaust gas may be increased.
Moreover, the said biodiesel fuel consists of methyl ester formed by esterifying vegetable fats and oils.
Examples of vegetable oils include rapeseed oil, soybean oil, corn oil, and palm oil. The biodiesel fuel can be obtained, for example, by heating a vegetable oil and fat in the presence of an alkali catalyst.

(Reference Example 1)
Next, a reference example of the fuel supply system of the present invention will be described with reference to FIGS.
FIG. 1 is a configuration diagram showing the overall configuration of the fuel supply system of this example. FIG. 2 is a cross-sectional view showing the configuration of the injector in FIG. FIG. 3 is a cross-sectional view showing the nozzle needle and the nozzle body in FIG. FIG. 4 is an explanatory diagram showing the configuration of the metal ion removing means in FIG.
As shown in FIG. 1, the fuel supply system 1 of this example stores a fuel tank 2 for storing fuel, an injector 5 for injecting and supplying fuel to the internal combustion engine 7, and a fuel for supplying to the injector 5 in a high pressure state. A common rail 4 for supplying fuel to the injector 5 and a fuel pump 3 for supplying fuel to the common rail 4 are also provided. The fuel supply system 1 is a metal that separates and removes metal or metal ions contained in fuel from the fuel between the fuel tank 2 and the injector 5 in the path from the fuel tank 2 to the internal combustion engine 7. Ion removal means 15 is provided.

  In the fuel supply system 1 of this example, for example, the operating state, operating conditions, driving state of the vehicle, the driving state of the multi-cylinder (for example, four cylinders) diesel engine (internal combustion engine 7) mounted on a vehicle such as an automobile, The engine control unit (ECU) 100 calculates the optimum target injection amount, target injection timing, target injection period, and target injection pressure based on sensor signals from the various sensors. A plurality of (four in this example; not shown) injectors 5 and fuel pumps 3 to be controlled are commanded.

  The internal combustion engine 7 in this example is a compression ignition internal combustion engine. The internal combustion engine 7 is a four-cycle four-cylinder engine (not shown) that includes a cylinder, a cylinder head, an oil pan, and the like. The intake port of each cylinder of the internal combustion engine 7 is opened and closed by an intake valve (intake valve), and the exhaust port is opened and closed by an exhaust valve (exhaust valve) (not shown). In each cylinder, a piston connected to the crankshaft via a connecting rod is slidably disposed (not shown).

  The injector 5 is attached to the cylinder head of the internal combustion engine 7 corresponding to each cylinder. These injectors 5 include a fuel injection nozzle (nozzle portion) 50 in which a nozzle needle 59 for opening and closing the injection hole 511 is slidably accommodated in a nozzle body 51 in which the injection hole 511 is formed, and a command piston for driving the nozzle needle 59. 52, a control chamber (pressure control chamber) 53 formed at an end of the command piston 52 opposite to the nozzle needle 59, a solenoid valve 54, and the like. Fuel injection from these injectors 5 to the internal combustion engine 7 is electronically controlled by energizing and stopping energization (ON / OFF) of the electromagnetic valve 54 that controls the fuel pressure in the pressure control chamber 53 of the command piston 52. In the injector 5, internal leak fuel (described later) or fuel discharged from the pressure control chamber 53 (fuel used to open and close the injector 5) returns to the fuel tank 2 (2 a, 2 b) via the return pipe 851. It is configured as follows. In FIG. 1, the fuel tank 2 a and the fuel tank 2 b are separately arranged, but both can be configured by one fuel tank 2.

Hereinafter, the structure of the injector in this example is demonstrated using FIG.2 and FIG.3.
As shown in FIG. 2, the injector 5 includes a nozzle needle 59, a nozzle body 51, a nozzle holder 55, a command piston 52, a pressure control chamber 53, an electromagnetic valve 54, and the like. The nozzle needle 59 and the nozzle body 51 constitute a nozzle part 50. As shown in FIGS. 2 and 3, the nozzle needle 59 is assembled inside the nozzle body 51 so as to be slidable in the axial direction.

  As shown in FIG. 3, the nozzle body 51 is a bottomed, generally hollow cylindrical body, in which a guide hole 512, a valve seat 513, an injection hole 511, and a sack portion 514 are formed. The guide hole 512 extends in the axial direction inside the nozzle body 51, and has one end connected to the opening end (the upper end in FIG. 3) of the nozzle body 51 and the other end connected to the valve seat 513. . The inner wall of the guide hole 512 is formed with substantially the same inner diameter from the open end of the nozzle body 51 to the vicinity of the bottomed valve seat 513. As shown in FIG. 3, the valve seat 513 has a truncated cone surface, one end on the large diameter side is continuous with the guide hole 512, and the other end on the small diameter side is connected to the sack portion 514. A contact portion 516 of the nozzle needle 59 is disposed on the valve seat 513 so as to be able to contact and separate. The contact part 516 has a substantially circular shape. The sack portion 514 is a sack hole formed in a bag shape with a small space volume on the tip side of the nozzle body 51. The opening side of the sack hole continues to the small diameter side of the valve seat 513. Here, the sac portion 514 constitutes a sac chamber having a bag-like predetermined space volume. As shown in FIG. 3, the injection hole 511 is formed as a passage communicating with the sack portion 514 of the nozzle body 51 through the inside and outside of the nozzle body 51. As shown in FIG. 3, the oil reservoir chamber (fuel reservoir chamber) 517 is formed in an annular recess in the middle of the inner wall forming the guide hole 512 of the nozzle body 51. A fuel supply hole 518 through which fuel is supplied is connected to the fuel reservoir chamber 517. The fuel reservoir chamber 517 divides the guide hole 512 into a guide hole upper part 512a and a guide hole lower part 512b.

  The nozzle needle 59 has a solid cylindrical shape as a basic shape, and includes a large-diameter cylindrical portion 591, a small-diameter cylindrical portion 592, a truncated cone portion 593, and a conical portion 594 as shown in FIG. 3. The large-diameter cylindrical portion 591 has an outer shape with substantially the same diameter, and is loosely fitted into the guide hole 512 (guide hole upper portion 512a) through a predetermined gap. Therefore, the large diameter cylindrical portion 591 can reciprocate in the axial direction. The small-diameter cylindrical portion 592 extends in the axial direction from the vicinity of the fuel reservoir 517 to the vicinity of the valve seat 513. The outer diameter of the small diameter cylindrical portion 592 is smaller than that of the large diameter cylindrical portion 591. A gap between the small diameter cylindrical portion 592 and the inner wall of the guide hole 512 becomes a fuel passage. One end portion of the truncated cone portion 593 is continuous with the small-diameter cylindrical portion 594, and the other end portion is continuous with the conical portion 594 through the circular contact portion 516. A connecting portion between the truncated cone portion 593 and the conical portion 594 has a substantially circular shape, and this substantially circular portion becomes a contact portion when the valve is closed. The conical portion 594 has an inclination angle larger than the inclination angle of the valve seat 513. This is for ensuring contact between the contact portion 516 and the valve seat 513 when the valve is closed. The tip of the conical portion 593 is positioned to face the sack portion 514 when the valve is closed.

  The large-diameter cylindrical portion 591 constitutes a sliding portion that is slidable in the nozzle body 51. The small diameter cylindrical portion 592, the truncated cone portion 593 and the conical portion 594 constitute an insertion portion having a smaller diameter than the sliding portion. The substantially truncated cone part connecting the large diameter cylindrical part 591 and the small diameter cylindrical part 592 constitutes a pressure receiving part. The pressure receiving portion is pressed in the direction in which the contact portion 516 is separated from the valve seat 513, that is, the direction in which the nozzle needle 59 is opened, by the high pressure fuel guided to the fuel reservoir chamber 517. The insertion portions 592, 593, and 594 pass through the fuel reservoir chamber 517.

  The guide hole upper portion 512a (specifically, the guide hole upper portion 512a and the wall portion forming the guide hole upper portion 512a) constitutes a guide portion that holds the sliding portion 591 in a slidable manner. The nozzle needle 59 having the sliding portion 591 and the nozzle body 51 having the guide portion 512a constitute a high-pressure fuel sliding portion.

  In this example, a minute gap portion (clearance portion) 55 is formed between the sliding portion 591 and the guide portion 512a. The clearance portion 515 is set to predetermined gaps εh and εl. It is preferable that the predetermined gaps εh and εl become smaller toward the fuel reservoir chamber 517 side. In this example, the guide portion, that is, the guide hole upper portion 512 a is reduced in diameter toward the fuel reservoir chamber 517. In the assembled state of the nozzle body 51 and the nozzle needle 59 (see FIG. 3), of the predetermined gaps εh and εl, the gap εh on the fuel reservoir 517 side and the gap on the opposite end to the gap εh on the fuel reservoir 517 side The relationship with εl (hereinafter referred to as the opposite end gap) is formed so that εh <εl. The pressure range of the high-pressure fuel used by the injector 5 may be set so that εh≈εl when in the predetermined pressure range. As a result, when high-pressure fuel is guided to the fuel reservoir chamber 517, the fuel leaks from the clearance 515 and the gap εh on the fuel reservoir chamber 517 side toward the opposite end clearance εl. Since the pressure of the high-pressure fuel stored in the fuel reservoir chamber 517 directly acts on the inner periphery of the guide hole upper portion 512a on the fuel reservoir chamber 517 side, the inner periphery of the guide hole 512a is deformed by the pressure and the gap εh increases. In the opposite end gap εl where the leaked fuel flows out, the pressure is attenuated and the deformation becomes slight, and the gap εl increases little. As a result, the gap εh on the fuel reservoir chamber 517 side and the opposite end gap εl can be made substantially equal within a predetermined pressure range, so that the clearance of the clearance portion 515 is substantially constant, and the large diameter cylindrical portion 591 and the guide are guided. Since the hole upper part 512a is in contact with a wide area, the contact surface pressure can be reduced to make it difficult to wear.

  As shown in FIG. 2, the nozzle portion 50 is coupled to the lower portion of the nozzle holder 55 by a retaining nut 501. The nozzle holder 55 has a cylinder 525 into which the command piston 52 is inserted, a fuel passage 61 that guides high-pressure fuel supplied from the common rail to the nozzle side, a fuel passage 62 that guides the orifice plate 535, and high-pressure fuel to the low-pressure side. A discharge passage 63 and the like are formed.

  The command piston 52 is slidably inserted into the cylinder 525 of the nozzle holder 55 and is connected to the nozzle needle 59 via a pressure pin (not shown) that is also inserted into the cylinder 525. The pressure pin is interposed between the command piston 52 and the nozzle needle 59 and is urged by a spring 56 disposed around the pressure pin to press the nozzle needle 59 in the valve closing direction (downward in FIG. 2). Yes.

  The orifice plate 535 is disposed on the end face of the nozzle holder 55 where the upper end of the cylinder 525 is open, and a pressure control chamber 53 communicating with the cylinder 525 is formed. The orifice plate 535 is provided with orifices (inlet side orifice (not shown) and outlet side orifice 536) on the upstream side and downstream side of the pressure control chamber 53, respectively, and the outlet side orifice 536 is more than the inlet side orifice. The flow path diameter (inner diameter) is set large. The inlet-side orifice is formed in the orifice plate 535 and is provided between the pressure control chamber 53 and the fuel passage 62, and the orifice outlet opens to the side surface (tapered surface) of the pressure control chamber 53. The outlet-side orifice 536 is formed above the pressure control chamber 53 and is provided so as to communicate with the discharge passage 63 via the electromagnetic valve 54.

  The electromagnetic valve 54 includes an armature 541 that intermittently connects between the outlet-side orifice 536 and the discharge passage 63, a spring 542 that biases the armature 541 in the valve closing direction (downward in FIG. 2), and the armature 541 in the valve opening direction. A driving solenoid 543 and the like are built in, and are assembled to the upper portion of the nozzle holder 55 via an orifice plate 535 and coupled by a retaining nut 544. When the solenoid 543 is energized, the armature 541 is attracted upward against the biasing force of the spring 542 to open the outlet-side orifice 536, and when the solenoid 543 is deenergized, the armature 541 is pushed back by the biasing force of the spring 542. And close the outlet orifice 536.

  Here, the command piston 52 includes a second sliding portion 521 slidable in a cylinder 525 serving as a second guide portion, and a second insertion portion 522 having a smaller diameter than the second sliding portion 521. It is comprised including. The nozzle holder 55 includes a cylinder 525 and a pressure control chamber 53 provided at the opposite end of the command piston 52 to the nozzle needle 59. A second clearance portion 523 is formed between the second sliding portion 521 and the second guide portion 525. The command piston 52 having the second sliding portion 521 and the nozzle holder 55 having the cylinder 525 constitute a second high-pressure fuel sliding portion. A space between the cylinder 525 and the second insertion portion 522 communicates with a discharge passage 64 that communicates with the discharge passage 63 and forms a back pressure space for the nozzle needle 59. Return fuel, that is, as shown in FIG. It is connected to the fuel on the fuel tank 2 side.

  It is preferable that the second clearance portion 523 formed between the cylinder 525 and the second sliding portion 521 is smaller toward the pressure control chamber 53. In this example, the inner circumference of the cylinder 525 is reduced in diameter toward the pressure control chamber 53. In the assembled state of the nozzle holder 55 and the command piston 52 (see FIG. 2), the gap εh on the pressure control chamber 53 side of the second sliding portion 521 of the second clearance portion 523 is the second sliding portion. It is formed smaller than the clearance εl on the side opposite to the pressure control chamber 53 of the part 521 (εh <εl). The pressure range of the high-pressure fuel supplied from the common rail used by the injector 5 may be set such that εh≈εl when in the predetermined pressure range.

The fuel passage 61, the fuel supply hole 518, and the fuel passage 62 constitute a high-pressure fuel path that supplies high-pressure fuel to the fuel reservoir chamber 517. As shown in FIG. 1, the high-pressure pipes 32 and 33 also constitute a high-pressure fuel path.
As shown in FIG. 2, the fuel reservoir chamber 517 and the pressure control chamber 53 each form a fuel reservoir chamber, and high-pressure fuel flows through the fuel reservoir chamber. The space between the cylinder 525 and the second insertion portion 522 and the discharge passages 63 and 64 are provided in the clearance portion 515 or the second clearance portion 523 when high-pressure fuel is supplied to at least one of the fuel reservoir chambers 517 and 53. A leak fuel path is formed through which the fuel leaked through and flows through the inside. The fuel pressure in the pressure control chamber 53 is adjusted by opening and closing the electromagnetic valve 54, and the passage through which the discharged fuel flows from the pressure control chamber 53 to the discharge passage 63 when the electromagnetic valve 54 is opened also forms a leak fuel path. ing.

  As shown in FIG. 1, the fuel pump 3 is a high-pressure supply pump that pressurizes the fuel sucked through the fuel pipe 345 and feeds the high-pressure fuel from the discharge port to the common rail 4 through the supply pipe 32. A low-pressure supply pump (feed pump) 34 for pumping fuel from is provided. In the fuel path 345 from the feed pump 34 to the pressurizing chamber 36 of the fuel pump 3, the fuel from the fuel pump 3 to the common rail 4 is adjusted by adjusting the opening degree (valve opening or opening area) of the fuel path 345. A suction metering valve 38 having an electromagnetic actuator for changing a discharge amount (also called a pump discharge amount or a pump pumping amount) is attached. The intake metering valve 38 is electronically controlled by a pump drive signal from the ECU 100 via a pump drive circuit (not shown), so that the amount of fuel drawn from the feed pump 34 into the pressurized chamber of the fuel pump 3 is sucked. The fuel injection pressure (common rail pressure) to be injected and supplied from each injector 5 into each cylinder of the internal combustion engine 7 is changed. The fuel pump 3 sucks fuel from the fuel tank 2 and pressurizes it, and pumps the fuel discharge amount commanded by the ECU 100 to the common rail 4. The common rail pressure in the common rail 4 is measured by a fuel pressure sensor 41 as a fuel pressure detecting means, and a pump drive command value (pump drive current value) and an injection amount command value (pulse-like injector drive current, injector injection command pulse). ) Is calculated by the ECU 100.

  The common rail 4 includes a predetermined fuel space and a fuel pressure sensor 41 that detects the fuel pressure in the fuel space, and is a pressure accumulating device that continuously accumulates high-pressure fuel corresponding to the fuel injection pressure. The high-pressure fuel accumulated in the common rail 4 is supplied from the fuel pump 3 via a supply pipe (high-pressure pipe) 32. The high-pressure fuel accumulated in the common rail 4 is supplied to the injector 5 through the high-pressure pipe 33.

  The fuel tank 2, the fuel pump 3, the common rail 4, and the injector 5 constitute a fuel supply system 1 that supplies fuel to the internal combustion engine 7. The fuel pump 3 pressurizes and feeds fuel from the fuel tank 2 to the injector 5 via the common rail 4.

Further, as shown in FIG. 1, in the fuel supply system 1 of this example, the fuel is contained in the fuel between the fuel tank 2 and the injector 5 in the path from the fuel tank 2 to the internal combustion engine 7. Metal ion removing means 15 for separating and removing the metal or metal ions to be removed from the fuel is provided. More specifically, the metal ion removing means 15 is provided between the fuel pump 3 and the fuel tank 2.
As shown in FIG. 4, in this example, the metal ion removing means 15 includes a metal ion adsorbing material 155. Specifically, the metal ion removing means 15 has a metal ion adsorbing material 155 and a case 151 for housing it. The metal ion adsorbent 155 is made of particles of chelate resin (CR20 manufactured by Mitsubishi Chemical Corporation), and is filled in the case 151. The case 151 is provided with a fuel inlet 152 to which the fuel from the fuel tank 2 is supplied and a fuel outlet 153 for sending the fuel from the metal ion removing means 15. Further, in the case 15, filters 157 and 158 made of filter paper (FG-1 manufactured by Toyo Filter Paper Co., Ltd.) are arranged on the fuel inlet side and the fuel outlet side so as to sandwich the metal ion adsorbent 155. Yes. In this example, a chelate resin is used as the metal ion adsorbent 155, but activated carbon or the like can be used instead of the chelate resin. Moreover, chelate resin and activated carbon can also be used together.

  Further, in the fuel system 1 of this example, as shown in FIG. 1, a fuel filter is provided between the metal ion removing means 15 and the fuel pump 3 in the path from the time when the fuel is supplied from the fuel tank 2 to the internal combustion engine 7. 16 is arranged. The fuel filter 16 is made of filter paper, and can remove foreign matters such as dust, rust, and iron contained in the fuel sucked up from the fuel tank 2 by the fuel pump 3. In this example, the fuel filter 16 is arranged between the metal ion removing means 15 and the fuel pump 3, but the position of the fuel filter 16 is from the time when the fuel tank 2 is supplied to the injector 5. If it is between, it can change suitably. For example, it can be disposed between the fuel tank 2 and the metal ion removing means 15 or between the fuel pump 3 and the common rail 4. One or a plurality of fuel filters 16 can be arranged.

  The ECU 100 includes a CPU for performing control processing and arithmetic processing, a storage device (memory such as ROM and RAM) for storing various programs and data, an input circuit, an output circuit, a power supply circuit, an injector drive circuit, and a pump drive circuit. A microcomputer having a well-known structure configured to include the above functions is provided. The detection signal (voltage signal) output from the fuel pressure sensor 41, the detection signal output from the fuel temperature sensor 101, and sensor signals from other various sensors are A / D converted by the A / D converter. Later, it is configured to be input to a microcomputer built in the ECU 100. Further, when the engine key is set to the IG position and an ignition switch (not shown) is turned on (ON), the ECU 100 controls, for example, the solenoid valve 54 of the injector 5 and the fuel pump 3 based on the control program stored in the memory. The actuator 103 of each control component such as an intake metering valve 38, an actuator 102 that drives a throttle valve (not shown), and an EGR valve (not shown) that adjusts an exhaust gas recirculation amount (EGR amount) is electronically controlled. It is configured.

  Then, ECU 100 uses the crankshaft rotation pulse and camshaft rotation pulse signals from crank angle sensor 104 attached to the crankshaft and cam angle sensor 105 attached to the camshaft as the reference for the injector of each cylinder. The actual fuel pressure in the common rail 4 (actual common rail pressure) is held at the command injection pressure by determining the injection timing of 5 and the pumping period of the fuel pump 3. The crank angle sensor 104 is a magnetic timing rotor (signal rotor) 71 fixed to the crankshaft of the internal combustion engine 7, and an electromagnetic pickup coil (not shown) arranged to face the peripheral surface of the timing rotor 71. , And a permanent magnet (magnet) (not shown) that generates magnetic flux, etc., and detects the rotation angle of the crankshaft. The ECU 100 detects the engine speed (NE) by measuring the interval time of the crank angle signal (NE pulse signal). A plurality of convex teeth are formed on the timing rotor 71 at predetermined angles (for example, 10 °). When the timing rotor 71 rotates, the convex teeth approach and move away from the electromagnetic pickup coil, so that a crank angle signal (NE pulse signal) is output from the electromagnetic pickup coil by electromagnetic induction. The cam angle sensor 105 includes a magnetic timing rotor (signal rotor) 72 fixed to the cam shaft of the internal combustion engine 7, and an electromagnetic pickup coil (illustrated) disposed so as to face the peripheral surface of the timing rotor 72. (Not shown) and a permanent magnet (magnet) (not shown) for generating magnetic flux, etc., and detects the rotation angle of the camshaft. The timing rotor 72 is provided with a plurality of convex teeth for each predetermined angle.

  Further, the ECU 100 is configured to input sensor signals from an accelerator opening sensor 106 that measures an accelerator pedal depression amount (accelerator operation amount, accelerator opening), a fuel temperature sensor 101, and the like. Then, the ECU 100 calculates an optimal command injection pressure (= target fuel pressure: PFIN) according to the operating condition of the internal combustion engine 7 and discharges the fuel metering valve 38 of the fuel pump 3 via the pump drive circuit. It has quantity control means. Specifically, the ECU 100 calculates a target fuel pressure (PFIN) according to the engine speed (NE) and the command injection amount (QFIN), and in order to achieve the target fuel pressure (PFIN), the fuel pump The pump drive signal (pump drive current value) to the three intake metering valves 38 is adjusted to control the pumping amount (pump discharge amount) of the fuel discharged from the fuel pump 3.

Further, the ECU 100 has a function of individually controlling the fuel injection amount injected from the injector 5 of each cylinder. Specifically, the ECU 100 includes basic injection amount determination means, command injection amount determination means, injection timing determination means, injection period determination means, and injector drive means. The basic injection amount determination means has a function of calculating an optimum basic injection amount (Q) based on the engine speed (NE), the accelerator opening (ACCP), and a characteristic map created by measurement in advance through experiments or the like. The command injection amount determination means adds a command injection amount (QFIN) to the basic injection amount (Q) by adding an injection amount correction amount that takes into account the fuel leak temperature (fuel temperature: THF) detected by the fuel temperature sensor 101. It has the function to calculate. The injection timing determining means has a function of calculating a command injection timing (TFIN) from a command injection amount (QFIN), an engine rotation speed (NE), and a characteristic map created by measurement in advance through experiments or the like. The injection period determining means calculates the common pulse pressure (NPC), the command injection amount (QFIN), and the energization pulse time (injection command pulse time: TQ) to the injector 5 from the characteristic map previously measured through experiments or the like. Have The injector drive means applies a pulsed injector drive current (injector injection command pulse) to the solenoid valve 54 of the injector 5 of each cylinder until the injection command pulse time (TQ) elapses from the command injection timing (TFIN). It has a function to apply.

Next, the operation and effect of the fuel supply system having the above configuration will be described.
As shown in FIG. 1, the fuel pump 3 sucks up the fuel in the fuel tank 2, pressurizes it, and pumps high-pressure fuel to the common rail 4. At this time, the sucked-up fuel is pumped to the common rail 4 through the metal ion removing means 15 and the fuel filter 16.
As shown in FIG. 4, in the metal ion removing means 15, the fuel introduced from the fuel inlet 152 passes through the filter 157, the metal ion adsorbent 155, and the filter 158 in this order, and passes through the fuel outlet 153 to the metal ion removing means 15. Sent to the outside. In the filter 157, foreign matters such as dust and rust contained in the fuel are separated and removed according to their shapes and sizes. In the metal ion adsorbent 155, metals and metal ions such as zinc and lead contained in the fuel are adsorbed by the metal ion adsorbent 155 and separated and removed from the fuel. In the filter 158, foreign matters such as dust and rust contained in the fuel can be separated and removed again. The fuel that has passed through the metal ion adsorbent 155 may contain a small amount of metal ion adsorbent as a foreign substance, and this metal ion adsorbent can also be separated and removed by the filter 158.
The fuel sent out from the fuel outlet 153 of the metal ion removing means 15 is further pressure-fed to the common rail 4 after the foreign matter in the fuel is removed by the fuel filter 16.

  The common rail 4 accumulates high-pressure fuel. The common rail 4 supplies the accumulated high-pressure fuel to the injector 5 via the high-pressure pipe 33. As shown in FIGS. 1 and 2, the high-pressure fuel supplied to the injector 5 is supplied to the fuel supply hole 518 side of the nozzle portion via the fuel passage 61, and the pressure control chamber 53 via the fuel passage 62. And introduced into the high-pressure fuel path leading to At this time, if the electromagnetic valve 54 is closed (the armature 541 closes the outlet-side orifice 536; see FIG. 2), the pressure of the high-pressure fuel introduced into the pressure control chamber 53 is changed to the command piston 52 and the pressure. It acts on the nozzle needle 59 via the pin, and urges the nozzle needle 59 together with the spring 56 in the valve closing direction. On the other hand, the high-pressure fuel introduced into the fuel supply hole 518 of the nozzle portion is introduced into the fuel reservoir chamber 517 and acts on the pressure receiving surface of the nozzle needle 59 to urge the nozzle needle 59 in the valve opening direction. When the solenoid valve 54 is closed, the force that biases the nozzle needle 59 in the valve closing direction exceeds the force that biases the nozzle needle 59 in the valve opening direction, so the nozzle needle 59 does not lift and the injection hole Since 511 is closed, no fuel is injected.

  When the solenoid 543 of the solenoid valve 54 is energized to open (the armature 541 opens the outlet orifice 536), the outlet orifice 536 communicates with the discharge passage 63 provided in the nozzle holder 55, so that the pressure control chamber 53 The fuel is discharged from the discharge passage 63 through the outlet orifice 536. Even if the solenoid valve 54 is opened, the high-pressure fuel continues to be supplied to the pressure control chamber 53 through the inlet-side orifice. However, since the outlet-side orifice 536 has a larger flow path diameter than the inlet-side orifice, The fuel pressure in the pressure control chamber 53 acting on the piston 52 decreases. As a result, the balance between the fuel pressure in the pressure control chamber 53, the force that pushes the nozzle needle 59 in the valve opening direction, and the spring force that pushes the nozzle needle 59 in the valve closing direction is lost, and the nozzle needle 59 is attached in the valve opening direction. When the energizing force exceeds the energizing force in the valve closing direction, the nozzle needle 59 is lifted to open the injection hole 511, whereby fuel is injected.

  Thereafter, when the armature 541 closes the outlet-side orifice 536 by stopping energization of the solenoid 543, the fuel pressure in the pressure control chamber 53 rises again, and the force for urging the nozzle needle 59 in the valve closing direction is applied in the valve opening direction. When the force exceeds the energizing force, the nozzle needle 59 is pushed down and the injection hole 511 is closed, thereby terminating the injection.

As shown in FIGS. 2 and 3, when high-pressure fuel is introduced into the fuel reservoir chamber 517 of the nozzle portion, a clearance portion 515 formed between the sliding portion 591 of the nozzle needle 59 and the guide portion 512 a of the nozzle body 51. High pressure fuel leaks inside. The leaked fuel flows at high speed in the clearance portion 515 and causes friction between the sliding portion 591 forming the clearance portion 515 and the inner wall of the guide portion 512a. This friction increases the temperature of the leaked fuel.
Further, high pressure fuel is introduced into the pressure control chamber 53 when the electromagnetic valve 54 is closed. At this time, the high pressure fuel leaks in the second clearance portion 523 formed between the second sliding portion 521 of the command piston 52 and the second guide portion 525 of the nozzle holder 55. The temperature of the leak fuel rises due to friction between the sliding portion 521 forming the second clearance portion 523 and the inner wall of the guide portion 525. These leak fuels are discharged out of the injector 5 through the leak fuel path.

Generally, when the fuel contains so-called biodiesel fuel (BDF) mainly composed of fatty acid methyl ether, specifically when a mixed fuel of BDF and low sulfur light oil is used, the temperature of the leaked fuel increases as described above. When this occurs, it is thought that the fuel is oxidized and altered to produce hydroperoxide. Due to the alteration of the fuel, metal components such as zinc and lead are eluted into the fuel from the fuel tank and the metal hose (fuel passage), and the carbon such as (R—COO) ₂ Zn and (R—COO) ₂ Pb. Acid esters are easily generated. As a result, metal may accumulate in the clearance portion 515, the second clearance portion 523, etc. in the injector 5, and the operation of the nozzle needle may be hindered.

  In the fuel supply system of this example, as shown in FIGS. 1 and 4, metal ion removing means 15 is provided between the fuel tank 2 and the fuel pump 3, and is sucked up from the fuel tank 2 by the fuel pump 3. The obtained fuel is sent to the injector 5 through the metal ion removing means 15. Since the metal ion removing means 15 can separate and remove metals and / or metal ions in the fuel, the amount of metal ions and metals contained in the fuel can be reduced. Therefore, the fuel containing almost no metal ions or metals can be supplied into the injector 5. As a result, metal deposition / deposition in the injector 5 can be prevented, and the injector 5 can be driven stably for a long period of time. Therefore, the fuel can be smoothly supplied to the internal combustion engine 7.

  Thus, according to the fuel supply system of this example, the fuel can be smoothly supplied to the internal combustion engine 7.

(Experimental example)
This example is an example in which the metal ion removal performance of the metal ion removal means is studied.
First, a filter paper sandwiching a metal ion adsorbent was prepared as a model of the metal ion removal means. As a metal ion adsorbent, a chelate resin (CR20 manufactured by Mitsubishi Chemical Corporation) was used as in Reference Example 1, and a filter paper for fuel filter (FG-1 manufactured by Toyo Filter Paper Co., Ltd.) was used as the filter paper. . This filter paper for a fuel filter has a thickness of 0.3 mm, an air permeability of 2.5 sec / 300 ml, and a mass per unit area of 67 g / m ² . The model of the metal ion removing means of this example is configured by sandwiching a chelate resin between two filter papers. This is designated as Sample E.

Next, sample E was placed in a glass funnel to constitute a filter, and this filter was placed on top of the Erlenmeyer flask.
In addition, a fuel sample was prepared as follows.
That is, first, as BDF, RME (Rapeseed
Methyl Ester (rapeseed oil) was prepared, and 1 L of RME was put in a container in an explosion-proof device and heated at a temperature of 120 ° C. for 1 hour. 1.5 g of Zn (flaky) was mixed in the heated RME, and further heated at a temperature of 80 ° C. for 24 hours to prepare a fuel sample.
Next, the fuel sample was poured into a filter placed on an Erlenmeyer flask and filtered, and the fuel sample collected in the Erlenmeyer flask was recovered. This is designated as a measurement sample Eα.

Moreover, in this example, as a sample for comparison, a filter in which two sheets of filter paper for fuel filter (FG-1 manufactured by Toyo Filter Paper Co., Ltd.) were laminated was prepared. This is designated as Sample C. Sample C does not contain a chelating resin.
Sample C was also placed in a glass funnel in the same manner as Sample E, and a filter was constructed. Then, the fuel sample was filtered using the filter and the filtrate (fuel sample) was collected. This is designated as a measurement sample Cα.

  Next, the zinc (Zn) concentration in the measurement samples Eα and Cα was measured using an inductively coupled high-frequency plasma emission analyzer (ICP emission analyzer, ICPS8000 manufactured by Shimadzu Corporation).

As a result, in the sample Cα, Zn ions having a concentration of 0.7 ppm were detected. On the other hand, in the sample Eα, the Zn ion concentration was 0.4 ppm.
Therefore, it can be seen that the metal ion concentration in the fuel can be reduced by passing the fuel containing metal ions through the filter paper sandwiching the chelate resin (metal ion adsorbent) as in sample E.

(Example 1)
This example is an example of a fuel supply system having a metal ion removing means in which a fuel inlet and a fuel outlet are provided in the upper part of the case.
As shown in FIG. 5, in the metal ion removing means 8 of this example, as in Reference Example 1, filters 87 and 88 made of filter paper (FG-1 manufactured by Toyo Roshi Kaisha, Ltd.) and chelate resin (Mitsubishi Chemical Corporation) And a metal ion adsorbent 85 made of CR20) particles manufactured by the company.
These filters 87 and 88 and the metal ion adsorbent 85 are housed in a case (inner case) 81.
In the inner case 81, a fuel inlet 84 serving as a fuel inlet is formed at a lower portion of the case 81, and a fuel outlet 89 for discharging the fuel is formed at an upper portion opposite to the fuel inlet 84. The fuel outlet 89 is connected to discharge passages 891, 892, and 893, and the discharge passages 891 and 892 are formed by branching from the discharge passage 893.
In the inner case 81, the filters 87 and 88 are laminated so as to sandwich the metal ion adsorbent 85. In this example, the filter 87 disposed on the fuel inlet 84 side of the inner case 81 and the filter 88 disposed on the fuel outlet 89 side are both made of filter paper (one sheet).

  Further, in the metal ion removing means 8 of this example, the inner case 81 is further accommodated in the outer case 82. The discharge passage 893 of the inner case 81 extends to the outside of the outer case 82. In the outer case 82, two fuel supply ports 83 for supplying fuel from the fuel tank are formed on the same side as the fuel outlet 89 of the inner case 81, that is, on the upper portion of the outer case 82. A space 825 is provided between the inner case 81 and the outer case 82, and forms a passage (fuel path) for the fuel supplied from the fuel supply port 83. Other configurations are the same as those in Reference Example 1.

  In the metal ion removing means 8 of this example, when fuel is supplied from a fuel supply port 83 formed in the upper part of the outer case 82, the supplied fuel is a space between the inner case 81 and the outer case 82. 825 is filled. The fuel filled in the space 825 is sent from the fuel inlet 84 of the inner case 81 into the inner case 81, and passes through the filter 87, the metal ion adsorbent 85, and the filter 88 disposed in the inner case 81. Thereafter, the fuel is collected in the discharge passage 893 through the discharge passages 891 and 892, and is sent to the outside of the metal ion removing means 8 from the fuel outlet 89. Although not shown in FIG. 5, the fuel sent to the outside of the metal ion removing means is sent to the injector through the common rail and injected from the injector to the internal combustion engine, as in the first reference example.

In the metal ion removing means 8 of the present example, as described above, the fuel supplied from the upper part (fuel supply port 83) of the outer case 82 passes through the filters 87 and 88 and the metal from the lower part (fuel inlet 84) of the inner case 81. The space 825 between the outer case 82 and the inner case 81 is filled before being introduced into the ion adsorbent 85. Therefore, impurities such as metal and moisture having a density higher than that of oil contained in the fuel can be settled to the bottom of the outer case 82 by its own weight and separated from the fuel. That is, foreign matters and impurities in the fuel can be removed before the introduction into the filters 87 and 88 and the metal ion adsorbent 85. Thereafter, the fuel introduced from the fuel inlet 84 of the inner case 81 is separated and removed by the filter 87 in the same manner as in Reference Example 1 according to the shape and size of dust and rust. Further, in the metal ion adsorbing material 85, metals such as zinc and lead and metal ions contained in the fuel are adsorbed by the metal ion adsorbing material 85 and separated and removed from the fuel. In the filter 158, foreign matters such as dust, rust, and metal ion adsorbent contained in the fuel are separated and removed.
Thereafter, as in Reference Example 1, the fuel delivered from the fuel outlet 89 of the metal ion removing means 8 is pumped to the common rail.

  Also in this example, the metal ion removing means 8 can remove foreign substances such as metals and metal ions in the fuel, so that the fuel containing almost no such foreign substances can be supplied to the injector. Therefore, it is possible to prevent metal deposition and accumulation in the injector, drive the injector stably for a long period of time, and smoothly supply fuel to the internal combustion engine.

(Example 2)
This example is an example of a fuel supply system having metal ion removing means having a pair of electrodes having different potentials.
As shown in FIG. 6, the metal ion removing means 9 of this example is formed such that a pair of electrodes 93 and 94 having different potentials are sandwiched between fuel electrodes in the metal ion removing means 9. The electrodes 93 and 94 are accommodated in the outer case 91.
In the outer case 91, an inner case 92 containing a filter 925 made of filter paper (FG-1 manufactured by Toyo Filter Paper Co., Ltd.) is disposed.
The inner case 92 is formed with a fuel inlet 95 serving as a fuel inlet at a lower portion thereof and a fuel outlet 96 for discharging the fuel at an upper portion opposite to the fuel inlet 95. The fuel outlet 96 is connected to the discharge passages 961, 962, and 963, and the discharge passages 961, 962 are formed by branching from the discharge passage 963. The discharge passage 963 of the inner case 92 extends to the outside of the outer case 91.

  In the present example, one electrode 93 of the pair of electrodes 93 and 94 is disposed on the fuel inlet 95 side of the inner case 92. The other electrode 94 is disposed in the outer case 91 so as to face the electrode 93. In this example, the electrode 93 is set to 0 V (ground), and the electrode 94 is set to a high potential (several kV), thereby generating a potential difference between the electrodes 93 and 94.

  In the outer case 91, two fuel supply ports 97 for supplying fuel from the fuel tank are formed on the same side as the fuel outlet 96 of the inner case 92, that is, on the upper portion of the outer case 91. A space 915 is provided between the outer case 91 and the inner case 92 and forms a passage (fuel path) for the fuel supplied from the fuel supply port 97. Other configurations are the same as those in Reference Example 1.

  In the metal ion removing means 9 of this example, the fuel supplied from the fuel supply port 97 is filled in the space 915 between the inner case 92 and the outer case 91 as in the first embodiment. The fuel filled in the space 915 is sent from the fuel inlet 95 of the inner case 92 into the inner case 92 and passes through a filter 925 disposed in the inner case 92. Thereafter, the fuel is collected in the discharge passage 963 through the discharge passages 961 and 962, and is sent to the outside of the metal ion removing means 9 from the fuel outlet 96. Although not shown in FIG. 6, the fuel sent to the outside of the metal ion removing means is sent to the injector via the common rail and injected from the injector to the internal combustion engine, as in Reference Example 1.

In the fuel supply system of this example, the fuel supplied from the fuel supply port 97 is filled in the space 915 between the outer case 91 and the inner case 92. At this time, since there is a potential difference between the pair of electrodes 93 and 94 arranged in the fuel path in the case, metal ions and metals contained in the fuel are separated from the fuel and adhere to the electrodes. Therefore, metal ions and metals can be separated and removed from the fuel.
The fuel from which metal ions and metals have been separated and removed is introduced into the inner case 92 from the fuel inlet 95, and foreign matters such as dust and rust contained in the fuel are separated and removed by the filter 925 according to its shape and size. The
Thereafter, as in Reference Example 1, the fuel delivered from the fuel outlet 96 of the metal ion removing means 9 is pumped to the common rail.

  Thus, also in this example, the metal ion removing means 9 can remove foreign matters such as metals and metal ions in the fuel, so that the fuel containing almost no such foreign matter can be supplied to the injector. . Therefore, it is possible to prevent metal deposition and accumulation in the injector, drive the injector stably for a long period of time, and smoothly supply fuel to the internal combustion engine.

Explanatory drawing which shows the whole structure of the fuel supply system concerning the reference example 1. FIG. It is sectional drawing which shows the structure of the injector concerning the reference example 1. FIG. Explanatory drawing which shows the structure of the nozzle part in FIG. Explanatory drawing which shows the structure of the metal ion removal means concerning the reference example 1. FIG. FIG. 3 is an explanatory diagram illustrating a configuration of a metal ion removing unit according to the first embodiment. Explanatory drawing which shows the structure of the metal ion removal means concerning Example 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Fuel supply system 15 Metal ion removal means 2 Fuel tank 3 Fuel pump 4 Common rail 5 Injector 51 Nozzle body 517 Fuel reservoir chamber 52 Command piston 53 Pressure control chamber 55 Nozzle holder 59 Nozzle needle 54 Electromagnetic valve 7 Internal combustion engine

Claims (2)

A fuel supply system for supplying fuel from a fuel tank to an internal combustion engine,
The fuel supply system includes: the fuel tank for storing fuel; an injector for injecting fuel to the internal combustion engine; a common rail for storing fuel to be supplied to the injector in a high pressure state and supplying fuel to the injector; A fuel pump for sending fuel to the common rail,
Metal ions for separating and removing metal or / and metal ions contained in the fuel from the fuel between the fuel tank and the injector in the path from the fuel tank to the internal combustion engine. Removal means are provided,
The metal ion removing means includes an outer case into which the fuel flows from the outside of the metal ion removing means, an inner case housed inside the outer case and into which the fuel flows in the outer case, and the inner case. A fuel supply system comprising: a metal ion adsorbent disposed inside.   2. The fuel supply port according to claim 1, wherein a fuel supply port is formed at an upper portion of the outer case, a fuel inlet is formed at a lower portion of the inner case, and a fuel outlet is formed at an upper portion of the inner case. The fuel supplied from the fuel supply port flows into the inner case from the fuel inlet, and is sent out from the fuel outlet through the metal ion adsorbent in the inner case. Fuel supply system.

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