JP2005201158A - System of adding fuel to exhaust pipe of diesel engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To enable uniform and efficient reduction/ regeneration processing of an exhaust gas purifying catalyst with a small amount of fuel. <P>SOLUTION: A system of adding fuel to an exhaust pipe of a diesel engine, comprising a fuel injection nozzle (20) arranged in an exhaust pipe (10) of a diesel engine (1) having a common rail (2), and a controller (7) which controls the fuel injection of the common rail, and performing the reduction/ regeneration of an exhaust gas purifying catalyst (11) arranged in the exhaust pipe by injecting, from the fuel injection nozzle, the fuel supplied from the common rail by the control of a controller, wherein the fuel injection nozzle comprises a hole type nozzle, and the hole type nozzle has multiple injection holes arranged at its tip end part in a row in the circumferential direction and in multiple rows in the axial direction. The controller performs multiple times of fuel injection from the fuel injection nozzle during one cycle of the reduction/ regeneration processing. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention, as a post-processing apparatus of the exhaust gas, NO _X storage reduction catalyst, is used in a diesel engine equipped with a reduced reproduction catalyst such DPNR preferred, an exhaust pipe fuel addition method of a diesel engine.

Recently, particulate matter in the exhaust gas of a diesel engine (hereinafter, referred to as PM) as a method for reducing or NO _X, it has been developed a variety of things. PM consists of three components, SOF, black smoke, sulfate + combined water. SOF composed of unburned fuel and oil, HC and CO in exhaust gas are oxidized and purified on the oxidation catalyst. The diesel particulate filter (hereinafter referred to as DPF) enables a significant PM reduction as one measure for reducing the pollution of diesel engine vehicles. The DPF is composed of a heat-resistant filter capable of collecting PM with high efficiency and a filter regenerating device for removing the PM collected by the filter. The filter regenerating device, for example, uses the collected PM as a light oil burner. For example, the filter is regenerated by incineration and removal.

On the other hand, the exhaust gas composition of a diesel engine is always in an oxygen-excess region, and there are very few components serving as a reducing agent, and the temperature region is wide, so that it is a very difficult environment for the catalyst. One type of catalyst for purifying NO _x in this oxygen-excess environment is a NO _x storage reduction type catalyst. This NO _x storage reduction type catalyst has a very high NO _x reduction rate, and is one of the promising options when demanding very strict adaptation to NO _x . There is also a diesel particulate-NO _X reduction system (hereinafter referred to as DPNR) in which this NO _X storage reduction catalyst and the above-mentioned DPF are integrated.

_The NO _X storage and reduction type catalyst or DPNR described above, again robbing oxygen from NO ₃ which is formed by adsorbing NO _X, thereby it is necessary to perform a reproduction process of the filter. As one method for this purpose, there is an exhaust pipe fuel addition system in which fuel is added into the exhaust pipe to increase HC, CO, CO _2, H ₂ or the like. In this exhaust pipe fuel addition system, for example, a relatively low pressure fuel of 10 bar or less is supplied and injected from a feed pump or the like, and a high pressure fuel of up to 1500 bar is supplied from the common rail of the engine. There is something to inject. In any case, in order to sufficiently reduce and regenerate the catalyst, it is necessary to instantaneously increase the fuel vapor concentration in the exhaust pipe by fuel injection to obtain a rich air-fuel ratio.

  Here, what leads high pressure fuel from the common rail of the latter engine is shown in FIG. 7 and FIG. 8 that performs fuel injection from a pintle swirl nozzle having a spiral groove at the injection port (see, for example, Patent Document 1). It is known that fuel injection is performed from such a hole type fuel injection nozzle 40. The hole-type nozzle 40 includes a cylindrical nozzle body 41 and a columnar valve shaft 47 inserted into the nozzle body 41 so as to be movable in the axial direction. The nozzle body 41 includes a fuel supply hole 42, a valve seat 43 seated by a conical seat portion 48 at the tip of the valve shaft 47, a guide hole 44 extending from the valve seat 43, and an injection branching from the guide hole 44 in the circumferential direction. And a hole 45. The injection hole 45 is composed of a fine hole. As shown in FIG. 9, the conventional hole type fuel injection nozzle 40 has, for example, eight injection holes 45 arranged in a line at equal intervals in the circumferential direction.

Then, as shown in FIG. 9, according to a command from the ECU, a predetermined amount f ₀ of fuel is continuously injected from the fuel injection nozzle into the exhaust pipe for a predetermined time, and one cycle of the reduction regeneration process is completed. In this way, what leads high-pressure fuel from the common rail of the engine does not require a dedicated fuel pump, and has an advantage that an O ₂ sensor is not required because injection control is performed by the ECU (for example, patents) This is a highly anticipated technology as a new method of adding exhaust pipe fuel to diesel engines in the future.
JP 2000-356127 A (pages 8-11, FIG. 6)

  Thus, in a diesel engine exhaust pipe fuel addition system that leads high pressure fuel from a common rail of a conventional engine, as a nozzle for injecting fuel into the exhaust pipe, a pintle swirl nozzle having a spiral groove in the injection port, for example, A hole type nozzle 40 in which eight injection holes 45 are arranged in a line at equal intervals in the circumferential direction is known.

  The pintle swirl nozzle having a spiral groove at the injection port, or the hole-type nozzle 40 in which, for example, eight injection holes 45 are arranged in a line at equal intervals in the circumferential direction, the above-described feed pump has been used so far. In the case of injecting a relatively low-pressure fuel supplied from the same, a certain atomization performance has been demonstrated. However, when high pressure fuel of up to 1500 bar supplied from the common rail is continuously injected, the fuel is injected in a streak shape in the radial direction of the exhaust pipe 52 with a strong pressure as shown in FIG. The spray penetration force (penetration) causes a large amount of fuel to adhere to the inner wall 53 of the exhaust pipe 52, so that there is a problem that ideal atomization necessary for reduction regeneration of the exhaust gas purification catalyst cannot be performed.

  Here, when fuel adheres to the inner wall of the exhaust pipe, the fuel vapor evaporated on the inner wall of the exhaust pipe reaches the catalyst with a slight time difference. For this reason, there is a problem that the fuel vapor concentration in the exhaust pipe cannot be increased instantaneously, and the catalyst cannot be sufficiently reduced and regenerated. Further, as shown in FIG. 11, the fuel vapor that has reached the catalyst 55 is supplied non-uniformly onto the catalyst 55, and there is a problem that the uniformity and efficiency of reduction regeneration of the catalyst 55 is reduced. For this reason, in any case, a large amount of fuel must be injected to sufficiently reduce and regenerate the catalyst 55, resulting in a problem of worsening fuel consumption.

  The present invention has been made to solve such problems. In the exhaust pipe fuel addition system of a diesel engine that injects high-pressure fuel supplied from a common rail, the reduction and regeneration treatment of the exhaust gas purification catalyst is uniformly performed with a small amount of fuel. Another object of the present invention is to provide an exhaust pipe fuel addition method for a diesel engine that can be performed efficiently.

  In order to solve the above-mentioned problems, the means employed by the present invention includes a fuel injection nozzle in an exhaust pipe of a diesel engine having a common rail, and fuel supplied from the common rail is injected from the fuel injection nozzle and arranged in the exhaust pipe. In a diesel engine exhaust pipe fuel addition system that performs reduction regeneration treatment of an exhaust gas purification catalyst provided, the fuel injection nozzle is composed of a hole type nozzle, and the hole type nozzle is arranged in a line in the circumferential direction at the tip, and It has a large number of injection holes arranged in a plurality of rows in the axial direction.

  The injection holes of the conventional hole type nozzle are composed of, for example, eight fine holes arranged in a row in the circumferential direction, whereas the injection holes of the hole type nozzle of this means are circumferentially arranged. And, even if high-pressure fuel is supplied from the common rail, the atomized fuel is completely atomized even if high-pressure fuel is supplied from the common rail. Further, since the penetration force of the spray can be suppressed, the fuel adhesion to the inner wall of the exhaust pipe is prevented, and the fuel vapor is uniformly supplied onto the catalyst.

  The means employed by the present invention includes a fuel injection nozzle disposed in an exhaust pipe of a diesel engine having a common rail, and a controller for controlling fuel injection of the common rail, and the fuel supplied from the common rail is a fuel injection nozzle. In a diesel engine exhaust pipe fuel addition system that performs reduction regeneration of an exhaust gas purification catalyst that is injected from the exhaust pipe and is disposed in the exhaust pipe, the controller performs multiple fuel injections from the fuel injection nozzle during one cycle of the reduction regeneration process. There is to do.

  According to this means, it is possible to control the penetration force of the spray per injection, the fuel adhesion to the inner wall of the exhaust pipe is prevented, and the fuel vapor is uniformly supplied onto the catalyst. . In particular, in a diesel engine having a common rail, the controller for controlling the common rail can easily inject the fuel into the exhaust pipe a plurality of times.

  Furthermore, the means employed by the present invention includes a fuel injection nozzle disposed in an exhaust pipe of a diesel engine having a common rail, and a controller that controls fuel injection of the common rail, and the fuel supplied from the common rail is controlled by the controller. In a diesel engine exhaust pipe fuel addition system that performs reduction and regeneration of an exhaust gas purification catalyst that is injected from a fuel injection nozzle and disposed in an exhaust pipe, the fuel injection nozzle comprises a hole-type nozzle, and the hole-type nozzle has a tip. The controller has a large number of injection holes arranged in a row in the circumferential direction and in a plurality of rows in the axial direction, and the controller performs a plurality of fuel injections from the fuel injection nozzle during one cycle of the reduction regeneration process. There is.

  According to this means, since the injection hole of the hole type nozzle is composed of a large number of fine holes arranged in the circumferential direction and the axial direction, even if high-pressure fuel is supplied from the common rail, A complete atomization of the injected fuel takes place. Further, since the penetration force of the spray can be suppressed, the fuel adhesion to the inner wall of the exhaust pipe is prevented, and the fuel vapor is uniformly supplied onto the catalyst. At the same time, since the fuel injection nozzle performs a plurality of fuel injections during one cycle of the reduction regeneration process, it is possible to control the penetration force of the spray per injection, and the fuel adheres to the inner wall of the exhaust pipe. This further prevents the fuel vapor from being supplied more uniformly onto the catalyst. In particular, in a diesel engine having a common rail, the controller for controlling the common rail can easily inject the fuel into the exhaust pipe a plurality of times.

  The number of injection holes is desirably 10 or more and 40 or less. When the number of injection holes is less than 10, it is necessary to increase the diameter of the injection holes, which may increase the penetration force of the spray and increase the fuel adhesion to the inner wall of the exhaust pipe. When the number of holes exceeds 40, processing of the injection holes may be difficult. The number of injection holes is more preferably 20 or more and 40 or less.

  For example, six to twelve injection holes are arranged in one row in the circumferential direction and three rows in the axial direction, and the injection holes in the base end row have an opening angle of approximately 155 ° on both sides of the distal end portion. The injection holes in the central row are opened at approximately 105 ° on both sides of the tip portion, and the injection holes in the tip row are opened at approximately 55 ° on both sides of the tip portion.

  The diameter of the injection hole is preferably 0.05 mm or more and 0.20 mm or less. When the diameter of the injection hole is less than 0.05 mm, it may be difficult to process the injection hole, and when the diameter of the injection hole exceeds 0.20 mm, the penetration force of the spray increases. There is a risk that fuel adhesion to the inner wall of the exhaust pipe will increase. In addition, it is more desirable that the diameter of the injection hole is 0.05 mm or more and 0.10 mm or less.

  As described above in detail, the diesel engine exhaust pipe fuel addition system of the present invention includes a fuel injection nozzle in the exhaust pipe of a diesel engine having a common rail, and injects fuel supplied from the common rail from the fuel injection nozzle. In an exhaust pipe fuel addition system for a diesel engine that performs reduction regeneration treatment of an exhaust gas purification catalyst disposed in an exhaust pipe, the fuel injection nozzle is composed of a hole type nozzle, and the hole type nozzle is arranged in a row in the circumferential direction at the tip. And a large number of injection holes arranged in a plurality of rows in the axial direction.

  In addition, the diesel engine exhaust pipe fuel addition system of the present invention includes a fuel injection nozzle disposed in an exhaust pipe of a diesel engine having a common rail, and a controller that controls fuel injection of the common rail, and is supplied from the common rail. In a diesel engine exhaust pipe fuel addition system in which fuel is injected from a fuel injection nozzle to perform reduction regeneration of an exhaust gas purification catalyst disposed in the exhaust pipe, a controller is provided with a plurality of controllers from the fuel injection nozzle during one cycle of reduction regeneration processing. Fuel injection.

  Therefore, the exhaust pipe fuel addition method of the diesel engine that injects high-pressure fuel supplied from the common rail has an excellent effect that the reduction regeneration process of the exhaust gas purification catalyst can be performed uniformly and efficiently with a small amount of fuel.

  BEST MODE FOR CARRYING OUT THE INVENTION The best mode for carrying out an exhaust pipe fuel addition system for a diesel engine according to the present invention will be described in detail with reference to FIGS.

  FIG. 1 is a schematic diagram showing an exhaust pipe fuel addition system of a diesel engine of the present invention, FIG. 2 is a front sectional view showing the fuel injection nozzle of FIG. 1, and FIG. 3 is a front end portion of the fuel injection nozzle of FIG. 4 is a side sectional view showing an injection state of the fuel injection nozzle of FIG. 1, FIG. 5 is a graph showing an injection method of the fuel injection nozzle of FIG. 1, and FIG. 6 is a fuel injection nozzle of FIG. It is a schematic diagram which shows the supply state to the catalyst of the fuel vapor | steam by.

  As shown in FIG. 1, a diesel engine 1 has a common rail 2 that can supply high-pressure fuel up to 1500 bar to a fuel injection nozzle in the engine 1, and a supply that supplies this high-pressure fuel to the common rail 2. Pump 3, feed pump 4 for supplying low-pressure fuel from the fuel tank 5 to the supply pump 3, fuel filter 6 interposed between the supply pump 3 and the feed pump 4, ECU 7 for controlling the fuel of the diesel engine 1, etc. Is disposed.

In the exhaust pipe 10, one hole type fuel injection nozzle 20, an NO _x storage reduction type catalyst 11, which is an example of a reduction regeneration type catalyst, a muffler 12, and the like are disposed. The ECU 7 is electrically connected to the fuel injection nozzle of the engine 1, the common rail 2, the supply pump 3, the feed pump 4, the fuel injection nozzle 20 in the exhaust pipe 10, and the like.

_The NO _X storage reduction type catalyst 11, while absorbing the NO _X in the exhaust gas flowing through the exhaust pipe 10, by increasing HC in exhaust gas, CO, a CO ₂ or H _2, regeneration processes occluded NO _X This is a so-called NO _x storage reduction catalyst. The catalyst 11 has a monolith support having a grid-like passage formed in the flow direction of the exhaust gas, and a coat layer formed on the monolith support and supporting a noble metal and a NO _x storage agent. Examples of the noble metal include Pt, and examples of the NO _x storage agent include alkali metals such as Li, Na, K, and Cs, alkaline earth metals such as Mg, Ca, and Ba, Y, La, Ce, and the like. There are rare earth metals such as Pr, Nd, Eu, Gd, and Dy. As the coating layer, alumina or the like is used.

  As shown in FIG. 2, the hall type fuel injection nozzle 20 includes a cylindrical nozzle body 21 and a columnar valve shaft 30 that is inserted into the nozzle body 21 so as to be movable in the axial direction. The nozzle body 21 branches in the circumferential direction from the fuel supply hole 22, the valve seat 23 seated by the conical seat portion 31 at the tip of the valve shaft 30, the guide hole 24 extending from the valve seat 23, and the guide hole 24. It has injection holes 25, 26, and 27. The valve shaft 30 is opened and closed by an electromagnetic solenoid (not shown) controlled by the ECU 7. As shown in FIG. 4, the fuel injection nozzle 20 is attached to the corner portion 10 a of the exhaust pipe 10 such that its injection axis is directed in the axial direction of the exhaust pipe 10.

  As shown in FIG. 2, the injection holes 25, 26, 27 are arranged in the hemispherical tip portion 28 of the nozzle body 21 in one row in the circumferential direction and three rows in parallel in the axial direction. All are formed to 0.10 mm. The diameter of the injection holes 25, 26 and 27 is not limited to 0.10 mm, but is desirably 0.05 mm or more and 0.20 mm or less. If the diameter of the injection holes 25, 26, 27 is less than 0.05 mm, the processing of the injection holes may be difficult, and if it exceeds 0.20 mm, the penetration force of the spray increases, and FIG. This is because there is a possibility that fuel adhesion to the illustrated exhaust pipe inner wall 10b may increase. The diameter of the injection holes 25, 26, 27 is more preferably 0.05 mm or more and 0.10 mm or less.

  As shown in FIGS. 2 and 3, the injection holes 25 in the base end row of the nozzle 20 are opened at an opening angle of 155 ° on both sides of the distal end portion 28 of the nozzle body 21, and 12 nozzle holes are equally spaced in the circumferential direction. Arranged. The central row of injection holes 26 are opened at an opening angle of 105 ° on both sides of the tip portion 28 of the nozzle body 21, and twelve are arranged at equal intervals in the circumferential direction. Further, the injection holes 27 in the tip row of the nozzles 20 are opened at both sides of the tip portion 28 of the nozzle body 21 at an opening angle of 55 °, and six are arranged at equal intervals in the circumferential direction. Thus, a total of 30 injection holes 25, 26, and 27 are disposed.

  The number of the injection holes is not limited to 30, but is preferably 10 or more and 40 or less. If the number of injection holes is less than ten, it is necessary to increase the diameter of the injection holes, so that the penetration force of the spray increases and the fuel adhesion to the exhaust pipe inner wall 10b shown in FIG. 4 may increase. In addition, if the number exceeds 40, processing of the injection holes may be difficult. The number of the injection holes is more preferably 20 or more and 40 or less. On the other hand, the number of columns in the axial direction is not necessarily limited to three, and may be two or four or more. Also, the columns need not necessarily be parallel to each other.

  Next, the operation of the exhaust pipe fuel addition method of the diesel engine will be described.

  The ECU 7 operates the feed pump 4 to supply fuel from the fuel tank 5 to the supply pump 3 via the fuel filter 6. The ECU 7 operates the supply pump 3 to further pressurize the fuel and supply high-pressure fuel of up to 1500 bar to the common rail 2. Therefore, the common rail 2 is always filled with high-pressure fuel, and this high-pressure fuel is used for fuel injection of the engine 1.

The NO _x emission amount from the engine 1 varies depending on the engine speed, the accelerator opening, and the like. The ECU7 shown in FIG. 1, NO _X emission map for NO _X emissions changed by thus operating state is stored. The ECU 7 calculates the NO _x emission amount of the engine 1 based on this NO _x emission amount map, and integrates the NO _x occlusion amount occluded in the catalyst 11.

As _the NO _X storage agent carried on the coat layer of the catalyst 11, for example in the case of using Ba, the NO _X discharged from the engine 1 is reacted with O ₂ in the exhaust gas in the catalyst 11, further catalyst 11 in Ba (NO ₃ ) ₂ is produced by reacting with BaO and BaCO _3, and is stored in the catalyst 11 in this state. Thus, the exhaust gas is discharged into the atmosphere through the muffler 12 and the like in a state where the NO _x concentration is extremely low.

When the ECU 7 determines that the NO _x storage amount by the catalyst 11 exceeds a predetermined amount and the catalyst temperature is equal to or higher than the catalyst reducible temperature (for example, 200 to 450 ° C.), the fuel injection in the exhaust pipe 10 is performed. The electromagnetic solenoid of the nozzle 20 is activated. When the electromagnetic solenoid is activated, the valve shaft 30 shown in FIG. 2 is pulled up in the fuel injection nozzle 20, and the seat portion 31 of the valve shaft 30 is separated from the valve seat 23 of the nozzle body 21.

At the same time, the ECU 7 operates an electromagnetic solenoid (not shown) of the common rail 2 to supply high-pressure fuel filled in the common rail 2 to the fuel injection nozzle 20 in the exhaust pipe 10. As a result, the high-pressure fuel is injected from the fuel supply hole 22 through the guide hole 24 into the exhaust pipe 10 through the 30 ejection holes 25, 26, and 27. As shown in FIG. 5, the ECU 7 does not continuously inject with the predetermined injection amount f ₁ during one reduction regeneration processing cycle, but performs, for example, three pulse fuel injections.

By adding fuel into the exhaust pipe 10, the oxygen concentration in the exhaust gas decreases, and HC, CO, CO ₂ or H _{2 in} the exhaust gas as a reducing agent increases. As a result, Ba (NO ₃ ) ₂ stored in the catalyst 11 reacts with the reducing agent and is reduced to N ₂ . Further, the catalyst 11 acts as a highly selective reduction catalyst, and the NO ₃ reacts with HC and CO in the exhaust gas to become harmless N ₂ , CO ₂ and H ₂ O, and is discharged into the atmosphere. In this manner, the ECU 7 appropriately controls the injection amount, the number of injections, the injection timing, etc. of the fuel injection in the exhaust pipe 10 by operating the electromagnetic solenoid of the common rail 2.

  When the ECU 7 estimates that the reduction regeneration process of the catalyst 11 is almost completed, the ECU 7 operates the electromagnetic solenoid of the common rail 2 to stop the fuel supply from the common rail 2 to the fuel injection nozzle 20 and the electromagnetic of the fuel injection nozzle 20. The solenoid is actuated to seat the seat portion 31 of the valve shaft 30 onto the valve seat 23 of the nozzle body 21, and the fuel injection in the reduction regeneration cycle is stopped.

  As shown in FIGS. 2 and 3, the exhaust pipe fuel addition method of this diesel engine is composed of a large number of, for example, 30 fine holes in which the hole type fuel injection nozzle 20 is arranged in the circumferential direction and the axial direction. Since the injection holes 25, 26, and 27 are provided, even if high-pressure fuel supplied from the common rail 2 is injected, most of the fuel injected from the fuel injection nozzle 20 is fogged in the exhaust gas as shown in FIG. And is prevented from adhering to the inner wall 10b of the exhaust pipe 10, and the fuel vapor is uniformly supplied onto the catalyst 11 as shown in FIG. For this reason, even with a small amount of fuel, the fuel vapor concentration in the exhaust pipe 10 suddenly rises to near the theoretical fuel concentration, the air-fuel ratio of the exhaust gas instantly becomes rich, and the reduction regeneration process of the exhaust gas purification catalyst is performed uniformly and It can be done efficiently. Therefore, it is not necessary to inject a large amount of fuel for reduction regeneration of the exhaust gas purification catalyst, and the fuel consumption is remarkably improved.

Further, since the ECU 7 does not continuously inject the predetermined fuel f ₁ during one cycle of the reduction regeneration process, for example, the ECU 7 performs fuel injection in three pulse forms. As shown in FIG. 4, the fuel can be prevented from adhering to the exhaust pipe inner wall 10b, and the fuel vapor is uniformly supplied onto the catalyst 11 as shown in FIG. Therefore, the reduction and regeneration of the exhaust gas purification catalyst can be performed uniformly and efficiently with a small amount of fuel. For this reason, sufficient reduction and regeneration processing can be performed with a small amount of fuel, and fuel consumption is remarkably improved. The number of injections performed during one reduction regeneration cycle is not necessarily limited to 3 times, and can be 2 times or 4 times or more. Further, the form of injection is not necessarily limited to a pulse shape, and the time and interval of one injection can be changed variously.

Although the above-described diesel engine exhaust pipe fuel addition method is implemented for the NO _x storage reduction catalyst 11, it is not limited to this, but other reduction regeneration type such as DPNR. Of course, the same can be applied to the catalyst.

It is a trial figure which shows the exhaust pipe fuel addition system of the diesel engine of this invention. It is front sectional drawing which shows the fuel-injection nozzle of FIG. It is a bottom view which shows the front-end | tip part of the fuel-injection nozzle of FIG. It is side surface sectional drawing which shows the injection state of the fuel-injection nozzle of FIG. It is a graph which shows the injection system of the fuel-injection nozzle of FIG. FIG. 2 is a schematic diagram showing a supply state of fuel vapor to a catalyst by the fuel injection nozzle of FIG. 1. It is front sectional drawing which shows the conventional fuel-injection nozzle. It is a bottom view which shows the conventional fuel injection nozzle. It is a graph which shows the injection system of the conventional fuel injection nozzle. It is side surface sectional drawing which shows the injection state of the conventional fuel injection nozzle. It is a schematic diagram which shows the supply state to the catalyst of the fuel vapor | steam by the conventional fuel injection nozzle.

Explanation of symbols

1 Diesel Engine 2 Common Rail 3 Pressure Pump 4 Feed Pump 5 Fuel Tank 6 Fuel Filter 7 ECU
DESCRIPTION OF SYMBOLS 10 Exhaust pipe 10a Corner part 10b Inner wall 11 Catalyst 12 Muffler 20 Fuel injection nozzle 21 Nozzle main body 22 Fuel supply hole 23 Valve seat 24 Guide hole 25, 26, 27 Injection hole 28 Tip part 30 Valve shaft 31 Seat surface 40 Fuel injection nozzle 41 Nozzle body 42 Fuel supply hole 43 Valve seat 44 Guide hole 45 Injection hole 47 Valve shaft 48 Seat part 52 Exhaust pipe 53 Inner wall 55 Catalyst

Claims (6)

  A fuel injection nozzle (20) is provided in an exhaust pipe (10) of a diesel engine (1) having a common rail (2), and fuel supplied from the common rail is injected from the fuel injection nozzle and disposed in the exhaust pipe. In the exhaust gas fuel addition system of the diesel engine for performing the reduction regeneration process of the exhaust gas purification catalyst (11), the fuel injection nozzle is composed of a hole type nozzle, and the hole type nozzle is circumferentially arranged at the tip (20a). A diesel engine exhaust pipe fuel addition system characterized in that it has a large number of injection holes (25, 26, 27) arranged in a row and in a plurality of rows in the axial direction.   A fuel injection nozzle (20) disposed in an exhaust pipe (10) of a diesel engine (1) having a common rail (2) and a controller (7) for controlling the fuel injection of the common rail are provided from the common rail. In a diesel engine exhaust pipe fuel addition system in which exhausted fuel is injected from the fuel injection nozzle and the exhaust gas purification catalyst (11) disposed in the exhaust pipe is reduced and regenerated, the controller performs the reduction regeneration process. An exhaust pipe fuel addition method for a diesel engine, wherein fuel injection is performed a plurality of times from the fuel injection nozzle during one cycle.   A fuel injection nozzle (20) disposed in an exhaust pipe (10) of a diesel engine (1) having a common rail (2) and a controller (7) for controlling the fuel injection of the common rail, the control of the controller In the exhaust pipe fuel addition system of a diesel engine, the fuel supplied from the common rail is injected from the fuel injection nozzle to reduce and regenerate the exhaust gas purification catalyst (11) disposed in the exhaust pipe. Consists of a hole type nozzle, and the hole type nozzle has a large number of injection holes (25, 26, 27) arranged in a row in the circumferential direction and in a plurality of rows in the axial direction at the tip (20a). And the controller performs fuel injection a plurality of times from the fuel injection nozzle during one cycle of the reduction regeneration process. Exhaust fuel addition scheme I over diesel engines.   The exhaust pipe fuel addition system for a diesel engine according to claim 1 or 3, wherein the number of the injection holes (25, 26, 27) is 10 or more and 40 or less.   Six to twelve injection holes are arranged in one row in the circumferential direction and three rows in the axial direction, and the injection holes (25) in the base end row are formed on both sides of the distal end portion (28). Opening at an opening angle of approximately 155 °, the central row of injection holes (26) opens at both sides of the tip portion at an opening angle of approximately 105 °, and the injection hole (27) of the tip row is formed at the tip portion. The diesel engine exhaust pipe fuel addition system according to any one of claims 1, 3 and 4, wherein the both sides open at an opening angle of approximately 55 °.   The exhaust pipe fuel of a diesel engine according to any one of claims 1, 3, 4, and 5, wherein the diameter of the injection hole (25, 26, 27) is 0.05 mm or more and 0.20 mm or less. Addition method.

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