JP4877104B2 - Diesel engine premixing device - Google Patents

Description

  The present invention relates to a premixing device for a diesel engine that premixes fuel in order to self-ignite the fuel.

  In general, diesel engines, etc., generate particulates (particulate matter) mainly composed of soot when oxygen is insufficient during combustion or when the temperature is low. (See, for example, Patent Documents 1 to 4).

  Among these, in recent years, when fuel such as light oil is introduced into a cylinder of a diesel engine, the fuel is premixed in advance and ignited and burned to suppress particulates.

  As a specific example, as shown in FIGS. 6 and 7, there is a diesel engine equipped with a premixing device 2 in an intake manifold 1, and the premixing device 2 has a predetermined space into which liquid fuel such as light oil can be introduced. A case main body 4 that forms a fuel vaporization chamber 3, an inflow portion 6 that allows liquid fuel to flow into the fuel vaporization chamber 3 from a fuel supply source (not shown) via a supply pipe 5, and the surroundings of the fuel vaporization chamber 3 A plurality of (six in FIG. 7) heaters 7 provided in the case body 4 and a supply unit 8 for supplying fuel vapor from the fuel vaporization chamber 3 into the intake manifold 1 are provided. . In FIG. 6, 9 is an intake pipe, 10 is an intake port of a diesel engine, 11 is a cylinder, 12 is a piston, and 13 is an intake valve.

  When the fuel is premixed by the premixing device 2, the fuel is vaporized by heating the liquid fuel in the fuel vaporizing chamber 3 by the heater 7 at the same time as the diesel engine is driven, and the fuel vapor. Is supplied into the intake manifold 1 and premixed so that the fuel can be self-ignited.

On the other hand, as another specific example, as shown in FIG. 8, a premixing device provided with an intake pipe 9 positioned on the upstream side of the intake manifold 1 of a diesel engine and having a configuration substantially similar to that of FIGS. When the fuel is premixed, the fuel is sucked from the intake pipe 9 as the diesel engine is driven, and at the same time, the fuel is heated by the heater 7 in the fuel vaporizing chamber 3 to form fuel vapor. Steam is supplied to the intake pipe 9, and fuel vapor is premixed with the intake air by the mixer 14 so that self-ignition is possible.
JP 2004-346882 A Japanese Unexamined Patent Publication No. 07-011983 JP 2002-030937 A Japanese Patent No. 3310122

  However, when fuel vapor such as light oil is supplied into the intake flow path, the fuel vapor is cooled by the supply unit 8 and cooled by the flow of the intake air, and is liquefied in the flow path. There was a problem that self-ignition of fuel did not occur. Further, when fuel vapor is supplied from the opening 8a via the supply unit 8 by the premixing device 2, there is a problem that fuel vapor or liquid fuel adheres to the wall surface of the flow path and does not premix with intake air. Further, even when the mixer 14 is provided as shown in FIG. 8, there is a problem in that the fuel is not properly premixed with the intake air when the fuel becomes liquid fuel again.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a diesel engine premixing device that prevents liquefaction of fuel vapor and sufficiently premixes fuel vapor with intake air.

The present invention includes a fuel vaporization unit that vaporizes fuel into fuel vapor, and a fuel vapor transport unit that is connected to the fuel vaporization unit and disposed so as to protrude into the intake passage of the diesel engine,
The fuel vapor transport section includes a heat-insulating case portion protruding into the intake passage, a heater disposed along the extending direction of the case portion at the center of the case portion, and the case portion positioned around the heater. A fuel vapor channel disposed along the extending direction of the fuel gas and a jet outlet for ejecting the fuel vapor from the tip of the case portion so as to supply the fuel vapor from the fuel vapor channel to the intake channel. The present invention relates to a premixing device for a diesel engine, which is configured to be heated and supplied to an intake passage.

  In the present invention, it is preferable that the fuel vapor transport part includes an attachment part for fixing the case part to the wall part of the intake passage.

  In the present invention, it is preferable that the jet port of the fuel vapor transport section is arranged at the radial center of the intake passage.

  In the present invention, it is preferable that the fuel vaporization section includes a fuel vaporization chamber for introducing fuel, and a heater for heating and vaporizing the fuel in the fuel vaporization chamber.

  According to the above-described diesel engine premixing device of the present invention, the fuel vaporization unit vaporizes the fuel into fuel vapor, and the fuel vapor transport unit heats the fuel vapor and supplies it to the intake passage. Cooling can be reduced to prevent liquefaction of fuel vapor and fuel vapor can be sufficiently premixed with intake air. In addition, fuel vapor is supplied to the inner space separated from the wall surface of the intake flow path by the fuel vapor transport part that is arranged so as to protrude to the intake flow path, so that the fuel vapor is prevented from adhering to the wall surface of the intake flow path. In addition, various excellent effects can be obtained that fuel vapor can be sufficiently premixed with intake air.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
1 to 3 show a first example of an embodiment of a diesel engine premixing device according to the present invention, and the same reference numerals as those in FIG. 6 denote the same components.

  In the diesel engine, an intake passage 15 formed from the intake pipe 9 to the intake port 10 through the intake manifold 1 is provided so that intake air (intake air) flows. A fuel vaporization section 16 fixed to a fixed portion (not shown) and a fuel vapor transport section 17 connected to the fuel vaporization section 16 and disposed so as to protrude into the intake manifold 1 are provided.

  The fuel vaporization section 16 constitutes a fuel vaporization chamber 22 in a predetermined space by a cylindrical peripheral portion 18 and lid portions 20 and 21 fixed by bolts 19 or the like on both sides of the peripheral portion 18. An inflow pipe 23 extending from a supply source (not shown) is connected to one lid portion 20 of the fuel vaporization chamber 22 so that fuel can flow to the fuel vaporization chamber 22. The other lid portion 21 is provided with a convex lead-out portion 24 connected to the fuel vapor transport portion 17 so that fuel can flow from the fuel vaporization chamber 22 to the fuel vapor transport portion 17. In addition, a rod-shaped heater 25 extending substantially parallel to the axial direction of the peripheral portion 18 is provided in the peripheral portion 18 of the fuel vaporizing chamber 22. Here, the number and shape of the heaters 25 are not particularly limited, and may be one as long as the inside of the fuel vaporization chamber 22 can be evenly heated, may have other shapes, and may be provided with fuel vaporization. A plurality of rod-shaped members may be provided along the circumferential direction of the chamber 22.

  The fuel vapor transport part 17 includes a case part 26 that protrudes from the outlet part 24 of the fuel vaporization part 16 into the intake manifold 1 and constitutes a heat insulating layer. A rod-shaped heater 28 that is fixed by an upper fixing member 27 and extends from above the lead-out portion 24 to the lower end of the case portion 26 along the axis of the case portion 26 is disposed in the case portion 26. . A cylindrical inner flow path member 30 formed along the direction in which the heater 28 extends so as to fit the heater 28 is disposed around the heater 28 and is larger than the outer diameter of the inner flow path member 30. A cylindrical outer flow path member 31 having an inner diameter and concentrically disposed on the outer periphery of the inner flow path member 30 is disposed. A gap between the inner flow path member 30 and the outer flow path member 31 communicates from the fuel vaporization chamber 22 of the fuel vaporization section 16 via the lead-out section 24 and is provided to the lower end along the extending direction of the case section 26. The fuel vapor channel 32 is formed. A plate-like lower end portion 33 having a shape for closing the lower end opening of the inner flow path member 30 is disposed at the lower ends of the inner flow path member 30 and the outer flow path member 31 so as to seal the arrangement space of the heater 28. The lower end portion 33 further closes the lower end opening of the outer flow path member 31 and forms an oblique opening at a predetermined position to form a jet port 34 that circulates downward from the fuel vapor flow path 32 to the outside. Here, a gap 35 formed along the extending direction of the case portion 26 is provided between the outer flow path member 31 and the case portion 26 so as to suppress heat transfer. In addition, a support member 37 that includes an opening 36 and supports the lower end portion 33 is provided at the lower end of the case portion 26 so as not to affect the injection direction of the outlet 34. Further, the heat insulating layer of the case portion 26 is not particularly limited as long as it can be insulated, but a material that can protect the inside of the case portion 26 from the cold of intake air is preferable.

  The fuel vapor transport section 17 includes a bowl-shaped inner mounting section 38 and a bowl-shaped outer mounting section 39 in the upper middle position of the case section 26, and the inner mounting section 38 and the outer mounting section 39 are provided with intake air. The fuel vapor transport section 17 is fixed at the optimum position by sandwiching the wall section 15a constituting the intake flow path 15 of the manifold 1 from the inside and the outside through the washer 40. Further, the tip of the case portion 26 is disposed near the boundary between the intake manifold 1 and the intake port 10, the jet port 34 is located in the center in the radial direction of the intake passage 15 of the intake port 10, and the flow of the intake port 10 is It is going to the road direction.

  Here, the tip structure of the fuel vapor transport part 17 is provided with the tip part 41 shown in FIG. 4, and a confluence chamber 42 of the fuel vapor channel 32 is formed at the lower ends of the inner channel member 30 and the outer channel member 31. At the same time, an outlet 43 may be provided so as to inject in a desired direction.

  The operation of the first example of the embodiment of the present invention will be described below.

  When fuel such as light oil is premixed, the fuel is supplied from the supply source to the fuel vaporization unit 16 at the same time as intake from the intake passage 15 is accompanied by driving of the diesel engine.

  In the fuel vaporization unit 16, the fuel supplied to the fuel vaporization chamber 22 is heated and vaporized by the heater 25, and the fuel vapor is supplied from the lead-out unit 24 to the fuel vapor transport unit 17.

  In the fuel vapor transport section 17, the fuel vapor flows down to the jet outlet 34 through the fuel vapor channel 32, and at the same time, heated by the heater 28 so as to prevent the fuel vapor from being cooled.

  Then, the fuel vapor injected from the jet port 34 at the tip of the case portion 26 to the intake flow path 15 is supplied to the center of the intake port 10 in the radial direction, diffuses, and sufficiently premixes with the intake air and flows down. Self-ignited to suppress the generation of particulates.

  Thus, with such a configuration of the first example, fuel such as light oil is vaporized into fuel vapor by the fuel vaporization unit 16, and the fuel vapor is heated by the fuel vapor transport unit 17 to the intake passage 15. Since the fuel vapor is supplied, cooling of the fuel vapor can be reduced to prevent liquefaction of the fuel vapor, and the fuel vapor can be sufficiently premixed with the intake air. In addition, since the fuel vapor is supplied to the inner space separated from the wall surface of the intake flow path 15 by the fuel vapor transporting portion 17 arranged to protrude to the intake flow path 15 of the intake manifold 1, the fuel vapor is supplied to the intake flow path 15. It is possible to prevent the fuel vapor from adhering to the wall surface and sufficiently mix the fuel vapor with the intake air.

  The fuel vapor transport section 17 includes a case portion 26 protruding into the intake passage 15, a heater 28 disposed in the case portion 26, a fuel vapor passage 32 that can heat the fuel vapor by the heater 28, When the fuel vapor is supplied from the fuel vapor passage 32 to the intake passage 15, the fuel vapor is ejected from the intake passage 15 by the configuration of the case portion 26, the heater 28, and the fuel vapor passage 32. Since the fuel vapor is supplied to the intake flow path 15 without being cooled down, the fuel vapor can be prevented from being liquefied appropriately and the fuel vapor can be sufficiently premixed with the intake air.

  The fuel vapor transport section 17 includes a heat-insulating case section 26 protruding into the intake passage 15, a heater 28 disposed along the extending direction of the case section 26 at the center of the case section 26, A fuel vapor passage 32 positioned around and extending along the extending direction of the case portion 26, and a fuel vapor from the tip of the case portion 26 so as to supply the fuel vapor from the fuel vapor passage 32 to the intake passage 15. If the air outlet 34 is provided, the fuel vapor is not cooled to the ejection position of the intake passage 15 due to the heat insulation of the case portion 26, the arrangement of the heater 28, and the configuration of the fuel vapor passage 32. Since it is supplied into the flow path 15, liquefaction of the fuel vapor can be optimally prevented, and the fuel vapor can be premixed more sufficiently with the intake air.

  Further, when the fuel vapor transporting portion 17 includes an attachment portion of an inner attachment portion 38 and an outer attachment portion 39 for fixing the case portion 26 to the wall portion 15 a of the intake passage 15, the jet outlet 34 is appropriately connected to the intake passage 15. Since the fuel vapor is supplied at such a position, it is possible to suppress the fuel vapor from adhering to the wall surface of the intake passage 15 and to sufficiently premix the fuel vapor with the intake air.

  Further, when the jet port 34 of the fuel vapor transport section 17 is arranged in the radial center of the intake flow path 15, the fuel vapor is supplied to the innermost space farthest from the wall surface of the intake flow path 15. Adhering to the wall surface of the flow path 15 is suitably suppressed, and the fuel vapor can be sufficiently premixed with the intake air.

  Further, when the fuel vaporization section 16 includes a fuel vaporization chamber 22 for introducing fuel and a heater 25 for heating and vaporizing the fuel in the fuel vaporization chamber 22, the fuel vaporization section 16 heats the fuel vapor to intake air flow path 15. Therefore, the fuel vapor can be supplied to the fuel vapor transport part 17.

  A second example of the embodiment of the present invention will be described below with reference to the drawings.

  FIG. 5 shows a second example of an embodiment of the present invention, in which the arrangement of the fuel vapor transport section 17 in the first example is changed to an intake pipe 9 provided with a mixer 14, 1 to 4 denote the same parts.

  The second example includes a fuel vaporization unit 16 and a fuel vapor transport unit 17 that are substantially the same as those in the first example. The fuel vaporization unit 16 is provided at a fixed portion (not shown) adjacent to the intake pipe 9. In addition to being fixed, the fuel vapor transport part 17 is connected to the fuel vaporization part 16 and is disposed so as to protrude into the intake pipe 9.

  The fuel vapor transport section 17 includes a bowl-shaped inner mounting section 38 and a bowl-shaped outer mounting section 39 in the upper middle position of the case section 26, and the inner mounting section 38 and the outer mounting section 39 are connected to the intake pipe 9. The fuel vapor transport section 17 is fixed at the optimum position by sandwiching the wall section 15a constituting the intake flow path 15 from the inside and the outside through a washer. The tip of the case portion 26 is arranged at the center of the intake pipe 9, and the jet outlet is located in the center in the radial direction of the intake flow path 15 of the intake pipe 9 and is directed toward the inflow direction of the mixer 14. Yes.

  The operation of the second example of the embodiment for carrying out the present invention will be described below.

  When premixing fuel such as light oil, the fuel is vaporized by the fuel vaporization unit 16 and the fuel vapor is heated down by the fuel vapor transport unit 17 as in the first example.

  Then, the fuel vapor injected from the jet outlet 34 at the tip of the case portion 26 to the intake passage 15 is supplied and diffused to the radial center of the intake pipe 9 and further premixed with the intake air by the mixer 14. Flow down and self-ignite in the engine to suppress the generation of particulates.

  Thus, with the configuration of the second example, it is possible to obtain the same operational effects as the first example. Further, by disposing a mixer in the intake passage 15, the fuel vapor can be premixed more sufficiently with the intake air.

  In addition, the diesel engine premixing device of the present invention is not limited to the above-described embodiment, and can be applied to premixing devices other than diesel engines, and the fuel is not necessarily limited to light oil. Of course, other structures may be used as long as the fuel vapor can be supplied to the intake passage without cooling, and various modifications can be made without departing from the scope of the present invention.

It is a conceptual diagram which shows the 1st example of the form which implements this invention. It is the schematic which shows the fuel vapor transport part in this invention. FIG. 3 is an arrow view in the III-III direction of FIG. 2. It is the schematic which shows the front-end | tip part in the other example of a fuel vapor transport part. It is a conceptual diagram which shows the 2nd example of the embodiment which implements this invention. It is a conceptual diagram which shows a prior art example. It is an arrow directional view of the VII-VII direction of FIG. It is a conceptual diagram which shows the other example of the past.

Explanation of symbols

DESCRIPTION OF SYMBOLS 15 Intake flow path 15a Wall part 16 Fuel vaporization part 17 Fuel vapor | steam transport part 22 Fuel vaporization chamber 25 Heater 26 Case part 28 Heater 32 Fuel vapor flow path 34 Jet outlet 38 Inner attachment part (attachment part)
39 Outer mounting part (Mounting part)
43 Spout

Claims (4)

A fuel vaporization unit that vaporizes the fuel into fuel vapor, and a fuel vapor transport unit that is connected to the fuel vaporization unit and arranged to protrude into the intake passage of the diesel engine,
The fuel vapor transport section includes a heat-insulating case portion protruding into the intake passage, a heater disposed along the extending direction of the case portion at the center of the case portion, and the case portion positioned around the heater. A fuel vapor channel disposed along the extending direction of the fuel gas and a jet outlet for ejecting the fuel vapor from the tip of the case portion so as to supply the fuel vapor from the fuel vapor channel to the intake channel. A diesel engine premixing device configured to be heated and supplied to an intake passage. 2. The diesel engine premixing device according to claim 1 , wherein the fuel vapor transport part includes an attachment part that fixes the case part to a wall part of the intake passage. 3. 3. The diesel engine premixing device according to claim 1, wherein the jet port of the fuel vapor transport section is arranged at a center in a radial direction of the intake passage.   2. The diesel engine premixing device according to claim 1, wherein the fuel vaporization section includes a fuel vaporization chamber for introducing fuel, and a heater for heating and vaporizing the fuel in the fuel vaporization chamber. .

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