JP2008291688A - Exhaust emission control system of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an exhaust emission control system capable of efficiently evaporating and igniting fuel to be supplied to an exhaust emission control means. <P>SOLUTION: The exhaust emission control system comprises an exhaust emission control device 6 provided in an exhaust passage 4 of an internal combustion engine 1 and controlling emission of exhaust gas, a fuel addition valve 11 supplying fuel to the exhaust emission control device 6 by injecting fuel spray 100 into the exhaust passage 4 on an upstream side of the exhaust emission control device 6, an evaporation member 12 disposed in a state touchable with the fuel spray 100 and heated to a temperature suited for evaporation of the fuel supplied by the fuel addition valve 11, and an ignition member 13 disposed in a state contactable with the fuel spray 100 and heated to a temperature suited for ignition of the fuel supplied by the fuel addition valve 11, wherein each of the evaporation member 12 and the ignition member 13 extends in a direction from a proximal end portion 100a of the fuel spray 100 to its distal end portion 100b without traversing the fuel spray 100. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an exhaust purification system for an internal combustion engine that supplies fuel to exhaust purification means by injecting fuel spray into an exhaust passage of the internal combustion engine.

  An evaporator that heats the fuel injected from the injector to make an air-fuel mixture containing evaporated fuel and an ignition device that ignites the air-fuel mixture. There is known an exhaust purification system in which combustion gas obtained by ignition is supplied to the upstream side of a particulate filter (Patent Document 1). In addition, there is Patent Document 2 as a prior art document related to the present invention.

JP 2005-61249 A JP 2006-57478 A

  The system described in the patent document has no disclosure for effectively evaporating and igniting the injected fuel (fuel spray) injected by the fuel addition injector. For example, in the system of Patent Document 1, since the heating plug element of the evaporator is disposed so as to cross the fuel spray injected by the injector, the progress of the fuel spray is hindered, and the contact time between the plug element and the fuel spray is reduced. It is difficult to lengthen.

  Therefore, an object of the present invention is to provide an exhaust purification system capable of efficiently evaporating and igniting fuel to be supplied to the exhaust purification means.

  An exhaust gas purification system for an internal combustion engine according to the present invention is provided with an exhaust gas purification means provided in an exhaust passage of the internal combustion engine for purifying exhaust gas, and fuel spray is injected into the exhaust gas passage upstream of the exhaust gas purification means. A fuel addition means for supplying fuel to the exhaust purification means; an evaporation member disposed in a state where it can come into contact with the fuel spray and heated to a temperature suitable for evaporation of the fuel supplied by the fuel addition means; An ignition member disposed in a state where it can come into contact with the fuel spray and heated to a temperature suitable for ignition of fuel supplied by the fuel addition means, and each of the evaporation member and the ignition member The above-described problem is solved by extending in the direction from the base end portion of the fuel spray to the tip end portion without traversing the fuel spray (Claim 1).

  According to this exhaust purification system, the evaporation member is heated to a temperature suitable for fuel evaporation, and the ignition member is heated to a temperature suitable for fuel ignition. It extends in the direction from the base end of the fuel spray toward the tip without crossing. Therefore, these members do not hinder the progress of the fuel spray, and the contact time with the fuel spray can be easily extended. Therefore, it is possible to efficiently evaporate and ignite the fuel to be supplied to the fuel purification means.

  In one aspect of the present invention, the evaporating member and the ignition member are adjacent to each other such that the evaporating member is positioned on the base end side of the fuel spray and the ignition member is positioned on the front end side of the fuel spray. (Claim 2). According to this aspect, since the evaporating member is adjacent to the base end side of the fuel spray so that the ignition member is located on the front end side of the fuel spray, the fuel evaporated by the evaporating member is immediately supplied to the ignition member. Thereby, since the process from evaporation of fuel to ignition proceeds without waste, the fuel can be efficiently evaporated and ignited.

  In this aspect, the ignition member is disposed so as to be inclined toward the center side of the fuel spray from the base end side to the tip end side of the fuel spray with reference to a direction in which the evaporation member extends. (Claim 3). According to this aspect, since the evaporated fuel can easily touch the ignition member, there is an advantage that the ignitability of the fuel is improved.

  In one aspect of the present invention, at least one of the evaporation member and the ignition member may be composed of two members arranged so as to sandwich the fuel spray (claim 4). According to this aspect, since the evaporation member or the ignition member is constituted by the two members sandwiching the fuel spray, the contact area between these members and the fuel spray is expanded, and the fuel is evaporated and ignited more efficiently. Can do.

  In the exhaust purification system of the present invention, the configuration of the evaporating member and the igniting member is designed to increase the contact area between the evaporating member or the igniting member and the fuel spray in consideration of the shape of the fuel spray injected by the fuel addition means What is necessary is just to determine suitably so that it may contribute. For example, at least one of the evaporation member and the ignition member may have a flat contact surface that can come into contact with the fuel spray on a side close to the center of the fuel spray (Claim 5). At least one of the member and the ignition member may have a concave contact surface that can come into contact with the fuel spray on a side close to the center of the fuel spray. In particular, in the latter case, the fuel that has bounced off and collided with the contact surface of the evaporating member or the igniting member does not escape and tends to gather in the center direction of the fuel spray. Furthermore, at least one of the evaporating member and the ignition member may be formed in a cylindrical shape so as to have the contact surface as an inner peripheral surface. In this case, the reliability of contact between the evaporation member or the ignition member and the fuel spray is increased.

  1 aspect of this invention WHEREIN: The said ignition member is comprised by the rod shape extended toward the said front-end | tip part from the said base end part of the said fuel spray, The said evaporation member is centered on the said fuel spray of the said ignition member. You may comprise so that the near side may be open | released and the side far from the center of the said fuel spray of the said ignition member may be covered. According to this aspect, the fuel that has bounced off the evaporation member and the fuel evaporated by the evaporation member can easily gather around the ignition member, so that the fuel can be efficiently ignited. In this aspect, the aspect of the evaporating member may be appropriately determined. For example, the evaporating member is an arc extending from the base end portion of the fuel spray toward the front end portion on the side closer to the center of the fuel spray. The ignition member may be arranged so as to be biased toward the side approaching the arc surface from the center of the arc of the evaporation member. In this case, as the light is collected at the focal point by the concave mirror, the fuel and the like that have collided and bounced off the inner surface of the evaporation member can be collected more efficiently around the ignition member, so that the ignitability is further improved.

  Moreover, the evaporation member is arrange | positioned so that these aspects may cover an ignition member. Therefore, as one aspect of the present invention, the ignition member is provided with a predetermined heat source body, and the ignition member is heated to a temperature suitable for the ignition of the fuel by the heat source body, The evaporation member may be heated to a temperature suitable for evaporation of the fuel by radiant heat of the ignition member. Thereby, since it is not necessary to provide a heat source body in an evaporation member, it becomes possible to heat an evaporation member and an ignition member without waste. In this case, the position where the heat source body is provided on the ignition member is arbitrary, but the heat source body may be limitedly provided on the ignition member at a position biased toward the tip end side of the fuel spray. Item 11). By providing the heat source in this manner, the amount of heat received by the evaporating member is biased and the amount of heat received on the base end side is reduced, thereby preventing overheating of the evaporating member. This facilitates setting the evaporation member to a temperature suitable for fuel evaporation.

  In one aspect of the present invention, the exhaust passage is provided with the fuel addition means, the evaporation member, and the ignition member, and extends in a direction intersecting a flow direction of the exhaust led to the exhaust purification means. It has a fuel addition chamber arranged on the upstream side of the purification means, provided on the outlet side of the fuel addition chamber and on the upstream side of the exhaust purification means so as to be arranged in a direction perpendicular to the flow direction, A plurality of plate members extending in the flow direction are further provided, and the positions of the upstream end portions of the plurality of plate members in the flow direction are shifted toward the downstream side in the flow direction as they approach the fuel addition chamber. The plurality of plate members may be arranged (claim 12). According to this aspect, since the fuel flowing out from the fuel addition chamber collides with the plurality of plate members, the direction is changed so as to go toward the exhaust purification means while being dispersed, so that the fuel is uniformly supplied to the exhaust purification means. Will be able to.

  As described above, according to the present invention, the evaporation member is heated to a temperature suitable for fuel evaporation, and the ignition member is heated to a temperature suitable for fuel ignition, and these members are injected by the fuel addition means. Since the fuel spray does not cross the fuel spray and extends in the direction from the base end to the tip of the fuel spray, these members do not hinder the progress of the fuel spray and facilitate the contact time with the fuel spray. Can be enlarged. Thereby, the fuel to be supplied to the fuel purification means can be efficiently evaporated and ignited.

(First form)
FIG. 1 shows a main part of an internal combustion engine to which an exhaust purification system of the present invention is applied. The internal combustion engine 1 is mounted on a vehicle (not shown) as a driving power source, and is configured as an in-line four-cylinder diesel engine in which four cylinders 2 are arranged in a row. An intake passage 3 and an exhaust passage 4 are connected to each cylinder 2. The intake passage 3 is provided with an air cleaner 5 for air filtration, and the exhaust passage 4 is provided with an exhaust purification device 6. The internal combustion engine 1 includes a fuel injection valve 7 provided in each cylinder 2 and a common rail 8 that stores high-pressure fuel to be supplied to each fuel injection valve 7. The common rail 8 includes a fuel pump (not shown). The fuel is supplied in a high pressure state.

  The exhaust purification device 6 includes a casing 9 that forms part of the exhaust passage 4 and an NOx storage reduction catalyst 10 that is accommodated in the casing 9. The NOx catalyst 10 is a well-known catalyst that stores NOx in the exhaust gas and purifies the stored NOx by reducing it to nitrogen in the presence of fuel (in a rich atmosphere). In order to supply the fuel necessary for such reduction of NOx, a fuel addition valve 11 as a fuel addition means is arranged upstream of the exhaust purification device 6. The fuel addition valve 11 is accommodated in a fuel addition chamber 4 a that forms part of the exhaust passage 4. The fuel addition chamber 4a is configured so that the flow of exhaust does not directly hit the inside thereof. A fuel having a predetermined fuel pressure is supplied to the fuel addition valve 11 by being branched from a fuel supply path to the cylinder 2. By injecting the solid conical fuel spray 100 from the fuel addition valve 11, the air-fuel ratio of the exhaust gas is temporarily set to the rich side, and the NOx stored in the NOx catalyst 10 can be reduced. Such an operation is a well-known operation called a rich spike.

  The rich spike control is appropriately executed according to the operating state of the internal combustion engine 1. However, when the engine temperature is low, the exhaust temperature and the wall temperature of the exhaust passage 4 are low, so the fuel spray 100 injected from the fuel addition valve 11. As a result, the reaction efficiency in the NOx catalyst 10 deteriorates. Therefore, in order to prevent the reduction efficiency of the NOx catalyst 10 from deteriorating when the engine temperature is low, an evaporation member 12 for evaporating the fuel spray 100 injected by the fuel addition valve 11 is provided in the fuel addition chamber 4a. The ignition member 13 for igniting the fuel spray 100 is provided in a state where it can come into contact with the fuel spray 100. Each of the evaporation member 12 and the ignition member 13 has a built-in heat source body (not shown) such as a heater, and the heat source body causes the evaporation member 12 to have a temperature suitable for fuel evaporation (for example, 250 to 300 ° C.). The ignition member 13 is heated to a temperature suitable for fuel ignition (for example, 800 to 850 ° C.). That is, in this embodiment, the set temperatures are determined so that the temperature of the ignition member 13 is higher than the temperature of the evaporation member 12.

  FIG. 2 is an enlarged view showing the positional relationship between the fuel addition valve 11, the evaporation member 12, and the ignition member 13, and FIG. 3 shows a state seen from the direction of arrow III in FIG. As shown in these drawings, each of the evaporation member 12 and the ignition member 13 extends in a direction from the base end portion 100a of the fuel spray 100 toward the tip end portion 100b without traversing the fuel spray 100, and It arrange | positions along the breadth of the fuel spray 100 so that the spreading angle (theta) may be adapted. These members 12 and 13 are arranged adjacent to each other so that the evaporation member 12 is located on the base end portion 100a side and the ignition member 13 is located on the tip end portion 100b side. The length dimension X1 in the extending direction of the evaporating member 12 is set to a length suitable for fuel evaporation, and the length dimension X2 in the extending direction of the ignition member 13 is set to a length suitable for fuel ignition.

  The evaporation member 12 has a flat contact surface 12 a that can come into contact with the fuel spray 100 on the side close to the center of the fuel spray 100. Similarly, the ignition member 13 has a flat contact surface 13 a that can come into contact with the fuel spray on the side close to the center of the fuel spray 10. The contact surface 13a of the ignition member 13 may carry a catalyst material such as Pt that facilitates the ignition of fuel. Moreover, it is preferable that the evaporation member 12 and the ignition member 13 have an appropriate heat capacity so that the temperature decrease due to evaporation accompanying the fuel contact is small and the heating time by the heat source body is shortened.

  According to the above configuration, even when the exhaust temperature at which the fuel spray 100 is difficult to vaporize is low, a part of the fuel spray 100 can be easily ignited and burned by the evaporation member 12 and the ignition member 13. Since the exhaust gas temperature is increased by the combustion, vaporization of the fuel spray 100 can be promoted. Since the fuel is supplied to the NOx catalyst 10 in a sufficiently vaporized state, the reduction of NOx stored in the NOx catalyst 10 can be realized even when the exhaust temperature is low. Further, even when the NOx catalyst 10 has not reached the activation temperature, the fuel spray 100 can be combusted. Therefore, the temperature rise of the NOx catalyst 10 can be promoted by the rise in the exhaust temperature due to the combustion. For this reason, NOx can be purified even when the exhaust gas temperature is lower.

  Further, since each of the evaporation member 12 and the ignition member 13 extends in the traveling direction of the fuel spray 100 without crossing the fuel spray 100 (the direction from the base end portion 100a toward the tip end portion 100b), these members 12, 13 However, the progress of the fuel spray 100 is not hindered, and the contact time with the fuel spray 100 can be easily extended. Further, since the evaporation member 12 and the ignition member 13 are disposed adjacent to each other as shown in the drawing, the fuel evaporated by the evaporation member 12 is immediately supplied to the ignition member 13. Thereby, since the process from evaporation of fuel to ignition proceeds without waste, the fuel can be efficiently evaporated and ignited. Moreover, since these members 12 and 13 have the flat contact surfaces 12a and 13a, a contact area with the fuel spray 100 can be expanded.

  Next, a modification of the first embodiment will be described with reference to FIGS. FIG. 4 shows a modification in which the ignition member 13 is inclined. The ignition member 13 in the example of FIG. 4 is disposed so as to be inclined toward the center of the fuel spray 100 from the base end portion 100a side to the tip end portion 100b side of the fuel spray 100 with reference to the direction D in which the evaporation member 12 extends. Has been. This inclination angle α can be set as appropriate. According to the example of FIG. 4, the fuel evaporated by the evaporation member 12 becomes easy to touch the ignition member 13, and there is an advantage that the ignitability of the fuel is improved.

  FIG. 5 shows a modification in which two evaporation members 12 and two ignition members 13 are arranged. In the example of FIG. 5, the two ignition members 13 are disposed so as to sandwich the fuel spray 100 so that the two evaporation members 12 sandwich the fuel spray 100. In this example, only the evaporation member 12 or only the ignition member 13 may be arranged as shown in the figure. According to the example of FIG. 5, the contact area between the fuel spray 100 and the evaporation member 12 or the ignition member 13 is further expanded. In this modification, the combination of the two evaporation members 12 corresponds to the evaporation member according to the present invention, and the combination of the two ignition members corresponds to the ignition member according to the present invention.

  6 and 7 show modifications in which the evaporation member 12 and the ignition member 13 are changed to those having different structures. As shown in FIG. 6, the evaporation member 16 has a concave contact surface 16 a that can come into contact with the fuel spray 100 on the side near the center of the fuel spray 100, and the ignition member 17 has a fuel spray on the side near the center of the fuel spray 100. Each has a concave contact surface 17a that can be contacted. Note that any one of these members 16 and 17 can be changed to the evaporation member 12 or the ignition member 13 described above. According to the modification of FIG. 6, the fuel that collides and bounces against the contact surfaces 16 a and 17 a does not deviate and easily collects in the center direction of the fuel spray 100, so that it easily recontacts the evaporation member 16 or the ignition member 17. .

  The modified example of FIG. 7 is an extension of the modified example of FIG. 6, and each of the evaporating member and the igniting member is configured to have a cylindrical shape having a concave contact surface as an inner peripheral surface. That is, the evaporation member 18 has an inner peripheral surface 18a that can come into contact with the fuel spray 100, and the ignition member 19 has an inner peripheral surface 19a that can come into contact with the fuel spray. According to the modification of FIG. 7, the inner peripheral surface 18 a of the evaporation member 18 and the inner peripheral surface 19 a of the ignition member 19 are arranged substantially coaxially with the fuel spray 100, so that the contact area with the fuel spray 100 is increased. The reliability of the contact with the fuel spray 100 is increased as well as the operation.

(Second form)
Next, a second embodiment of the present invention will be described with reference to FIGS. In this embodiment, the evaporation member is arranged so as to cover the rod-like ignition member. Since the other points are the same as those of the first embodiment, description of the configuration common to the first embodiment is omitted. FIG. 8 is an enlarged view showing the second embodiment, and FIG. 9 is an enlarged view of the state seen from the direction of arrow IX in FIG.

  As shown in these drawings, the evaporation member 22 and the ignition member 23 each extend in a direction from the base end portion 100a of the fuel spray 100 toward the tip end portion 100b. The ignition member 23 is formed in a round bar shape extending in that direction, and the evaporation member 22 is disposed so as to cover one side of the ignition member 23. That is, the evaporating member 22 is configured to open the side near the center of the fuel spray 100 of the ignition member 23 and cover the side far from the center. The evaporation member 22 has an arcuate surface 22a that extends in the direction from the base end portion 100a toward the tip end portion 100b on the side close to the center of the fuel spray 100. The ignition member 23 is disposed so as to be biased from the center C of the arc of the evaporation member 22 toward the side approaching the arc surface 22a. The ignition member 23 incorporates a heat source body (not shown) such as a heater and is heated to a temperature suitable for fuel ignition by this, but the evaporation member 22 is not provided with such a heat source body. That is, the evaporation member 22 is heated to a temperature suitable for fuel evaporation by the radiant heat from the ignition member 23.

  According to the second embodiment, the fuel that has bounced off the evaporation member 22 and the fuel evaporated by the evaporation member 22 are likely to gather around the ignition member 23, so that the fuel can be efficiently ignited. . In particular, in this embodiment, the evaporation member 22 has an arc surface 22a, and the ignition member 23 is arranged so as to be biased from the center C of the arc toward the arc surface 22a. As described above, the fuel or the like that bounces off the inner surface of the evaporation member 22 can be efficiently collected around the ignition member 23. Moreover, since the evaporation member 22 is heated by the radiant heat of the ignition member 23, it is not necessary to provide the heat source body in the evaporation member 22. Therefore, it is possible to heat the evaporation member 22 and the ignition member 23 without waste.

  Although the position where the heat source body is built in the ignition member 23 is arbitrary, for example, as shown in FIG. 10, the heat source body is built in a limited manner at the position shown by hatching biased toward the tip end 100 b side of the fuel spray 100. You may let them. By doing so, the amount of heat received by the evaporating member 22 is biased and the amount of heat received on the base end 100a side is reduced, so that excessive heating of the evaporating member 22 is prevented. This facilitates setting the evaporation member 22 to a temperature suitable for fuel evaporation.

(Third form)
Next, a third embodiment of the present invention will be described with reference to FIG. This form is for supplying the exhaust gas purification device 6 uniformly. About the structure which is common in each above-mentioned form, description is abbreviate | omitted by attaching | subjecting the same code | symbol to FIG. As shown in FIG. 11, each of the fuel addition valve 11, the evaporation member 12, and the ignition member 13 is provided in the fuel addition chamber 4 a ′ forming a part of the exhaust passage 4 in the exhaust passage 4. The fuel addition chamber 4 a ′ is disposed on the upstream side of the exhaust purification device 6 and extends in a direction crossing the exhaust flow direction Fe guided to the exhaust purification device 6. On the outlet side of the fuel addition chamber 4a ′ and on the upstream side of the exhaust purification device 6, there are four dispersion plates 31A to 31D as a plurality of plate members extending in the direction orthogonal to the paper surface of FIG. Provided. The respective dispersion plates 31A to 31D are arranged at equal intervals in a direction orthogonal to the flow direction Fe. The dispersion plates 31A to 31D are arranged so that the upstream end portion 32 in the flow direction Fe is shifted toward the downstream side in the flow direction Fe as it approaches the fuel addition chamber 4a ′. That is, the end 32 of the dispersion plate 31B adjacent to the end 32 of the dispersion plate 31A farthest from the fuel addition chamber 4a 'is shifted to the downstream side in the flow direction Fe, and hereinafter the end 32 of the dispersion plate 31B. Also, the end 32 of the adjacent dispersion plate 31C is shifted downstream in the flow direction Fe, and the end 32 of the adjacent dispersion plate 31D is shifted downstream of the flow direction Fe from the end 32 of the dispersion plate 31C.

  Since the third embodiment is provided with such a plurality of dispersion plates 31A to 31D, the fuel flowing out from the fuel addition chamber 4a 'collides with the dispersion plates 31A to 31D and is dispersed to the exhaust purification device 6. The direction is changed as follows. As a result, the fuel can be uniformly supplied to the exhaust purification device 6. Further, in the embodiment of FIG. 11, for example, the fuel supply valve 11 is limited in the space for mounting the fuel addition valve 11 such as upstream of the turbocharger, and the fuel is supplied under conditions that make it difficult to disperse the fuel spray well in the exhaust passage. Suitable for cases. In addition, it is preferable to make the length dimension regarding the flow direction Fe of each dispersion plate 31A-31D substantially the same. By doing in this way, since the flow resistance of the exhaust gas between the dispersion plates becomes substantially uniform, it is possible to suppress the occurrence of bias in the exhaust flow.

  In addition, although the evaporation member 12 and the ignition member 13 were illustrated in FIG. 11 for convenience, these can also be replaced with each form shown in FIGS. 11 is an exhaust purification system in which the fuel addition valve 11, the evaporation member 12, and the ignition member 13 are provided in the fuel addition chamber 4a ', respectively, but the evaporation member 12 and the ignition member 13 are not present. However, the fuel spray 100 injected by the fuel addition valve 11 can be uniformly supplied to the exhaust purification device 6. Therefore, it is possible to grasp the form of FIG. 11 as an embodiment of the exhaust purification system that does not assume the evaporation member and the ignition member according to the present invention.

  The present invention is not limited to the above embodiments, and can be implemented in various forms. The purpose of the fuel addition valve 11 injecting fuel spray is not limited to the rich spike. For example, the fuel addition valve 11 may inject fuel spray for the purpose of performing so-called S regeneration for eliminating sulfur poisoning of the NOx catalyst 10. Moreover, the structure of the exhaust gas purification apparatus 6 described above is an example, and a particulate filter for capturing particulate matter in the exhaust gas may be provided as the exhaust gas purification means of the present invention. In this case, the fuel addition valve 11 may inject fuel spray for the purpose of performing so-called PM regeneration that eliminates clogging of the particulate filter.

The figure which showed the principal part of the internal combustion engine to which the exhaust gas purification system of this invention was applied. The enlarged view which showed each positional relationship of a fuel addition valve, an evaporation member, and an ignition member. The figure which showed the state seen from the direction of arrow III of FIG. The figure which showed the modification which inclined the ignition member. The figure which showed the modification which has arrange | positioned two evaporation members and two ignition members. The figure which showed the 1st modification which each changed the evaporation member and the ignition member into the thing of a different structure. The figure which showed the 2nd modification which each changed the evaporation member and the ignition member into the thing of a different structure. The enlarged view which showed the 2nd form. The figure which expanded and showed the state seen from the direction of the arrow IX of FIG. The figure which showed the form which provides a heat-source body limitedly in the position where the ignition member was biased. The figure which showed the principal part of the internal combustion engine to which the exhaust gas purification system which concerns on a 3rd form was applied.

Explanation of symbols

1 Internal combustion engine 4 Exhaust passages 4a, 4a 'Fuel addition chamber 6 Exhaust purification device (exhaust purification means)
11 Fuel addition valve (fuel addition means)
12, 16, 18, 22 Evaporating members 13, 17, 19, 23 Ignition members 12a, 13a, 16a, 17a Contact surfaces 18a, 19a Inner circumferential surfaces 22a Arc surfaces 31A to 31D Dispersion plates (plate members)
32 End portion 100 Fuel spray 100a Base end portion 100b End portion C Center of arc D Direction in which evaporation member extends Fe Flow direction of exhaust gas

Claims (12)

Exhaust purification means for purifying exhaust provided in an exhaust passage of an internal combustion engine, and fuel addition means for injecting fuel spray into the exhaust passage upstream of the exhaust purification means and supplying fuel to the exhaust purification means And an evaporation member that is arranged in contact with the fuel spray and heated to a temperature suitable for evaporation of the fuel supplied by the fuel addition means, and is arranged in contact with the fuel spray. An ignition member heated to a temperature suitable for ignition of the fuel supplied by the fuel addition means,
Each of the said evaporation member and the said ignition member is extended in the direction which goes to the front-end | tip part from the base end part of the said fuel spray, without traversing the said fuel spray, The exhaust gas purification system of the internal combustion engine characterized by the above-mentioned.   The evaporating member and the ignition member are disposed adjacent to each other so that the evaporating member is positioned on the base end side of the fuel spray and the ignition member is positioned on the front end side of the fuel spray. The exhaust gas purification system for an internal combustion engine according to claim 1, wherein the exhaust gas purification system is an internal combustion engine.   The ignition member is disposed so as to be inclined toward the center side of the fuel spray from the base end side of the fuel spray toward the tip end side with reference to a direction in which the evaporation member extends. The exhaust gas purification system for an internal combustion engine according to claim 2.   The exhaust purification of an internal combustion engine according to claim 1 or 2, wherein at least one of the evaporating member and the ignition member is composed of two members arranged so as to sandwich the fuel spray. system.   The at least one of the said evaporation member and the said ignition member has a flat contact surface which can contact the said fuel spray on the side close | similar to the center of the said fuel spray, The any one of Claims 1-4 characterized by the above-mentioned. An exhaust purification system for an internal combustion engine according to claim 1.   The at least one of the said evaporation member and the said ignition member has the concave contact surface which can contact the said fuel spray in the side close | similar to the center of the said fuel spray. An exhaust purification system for an internal combustion engine according to claim 1.   The exhaust purification system for an internal combustion engine according to claim 6, wherein at least one of the evaporation member and the ignition member is configured in a cylindrical shape so as to have the contact surface as an inner peripheral surface. The ignition member is configured in a rod shape extending from the base end portion of the fuel spray toward the tip end portion,
The evaporating member is configured to open a side near the center of the fuel spray of the ignition member and cover a side far from the center of the fuel spray of the ignition member. An exhaust purification system for an internal combustion engine as described. The evaporating member has a circular arc surface extending from the base end portion of the fuel spray toward the tip end portion on a side close to the center of the fuel spray.
9. The exhaust gas purification system for an internal combustion engine according to claim 8, wherein the ignition member is arranged so as to be biased from a center of an arc of the evaporation member toward a side approaching the arc surface.   The ignition member is provided with a predetermined heat source body, and the ignition member is heated to a temperature suitable for the ignition of the fuel by the heat source body, and the evaporation member is radiated heat of the ignition member. The exhaust purification system for an internal combustion engine according to claim 8 or 9, wherein the exhaust gas is heated to a temperature suitable for evaporation of the fuel.   11. The exhaust gas purification system for an internal combustion engine according to claim 10, wherein the heat source body is limitedly provided at a position biased toward the tip end side of the fuel spray on the ignition member. The exhaust passage is provided with the fuel addition means, the evaporating member, and the ignition member, extends in a direction intersecting with the flow direction of the exhaust led to the exhaust purification means, and is disposed upstream of the exhaust purification means. A fuel addition chamber,
A plurality of plate members provided on the outlet side of the fuel addition chamber and on the upstream side of the exhaust purification means so as to be arranged in a direction orthogonal to the flow direction, and extending in the flow direction;
The plurality of plate members are arranged so that the positions of the end portions on the upstream side in the flow direction of the plurality of plate members are shifted toward the downstream side in the flow direction as they approach the fuel addition chamber. The exhaust gas purification system for an internal combustion engine according to any one of claims 1 to 11.

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