JP2010190113A - Supercharging system for internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a supercharging system for an internal combustion engine, immediately mixing low-temperature exhaust gas driving a turbine rotor with high-temperature exhaust gas bypassing the turbine rotor before reaching an exhaust emission control catalyst. <P>SOLUTION: This supercharging system for the internal combustion engine is applied to the internal combustion engine 1 provided with the exhaust emission control catalyst 3 in an exhaust passage 2, and includes a turbosupercharger 10 having a turbine 11 provided upstream of the exhaust emission control catalyst 3 and discharging the exhaust gas rotatively driving the turbine rotor 13 from the turbine 11 while turning in a predetermined direction. In the supercharging system, exhaust gas passed through a wastegate port 19 is introduced to a wastegate passage 20 formed in the periphery of an exhaust gas outlet 18 introducing the exhaust gas driving the turbine rotor 13, and the end 19a of the wastegate port 19 on the side of the wastegate passage 20 is arranged to discharge the exhaust gas from the wastegate port 19 while turning in a reverse direction opposite to a predetermined direction. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a supercharging system for an internal combustion engine that includes a turbocharger that is applied to an internal combustion engine in which an exhaust gas purification catalyst is provided in an exhaust passage and in which a turbine is provided upstream of the exhaust gas purification catalyst.

  There is known an internal combustion engine in which an exhaust purification catalyst is provided in an exhaust passage and a turbocharger turbine is provided upstream of the exhaust purification catalyst. In such an internal combustion engine, when warming up the exhaust purification catalyst, the waste gate valve provided in the turbine is opened to guide the exhaust that bypasses the turbine rotor to the exhaust purification catalyst, thereby warming up the exhaust purification catalyst. What promotes is known (see Patent Document 1). In addition, there is Patent Document 2 as a prior art document related to the present invention.

JP 2003-240551 A JP 2007-303394 A

  As is well known, there is a large difference between the temperature of the exhaust after the turbine rotor is rotationally driven by the turbine and the temperature of the exhaust before the turbine rotor is rotationally driven. In the internal combustion engine of Patent Document 1, both the exhaust gas before rotating the turbine rotor and the exhaust gas after being driven to rotate are caused to flow into the exhaust gas purification catalyst. Generally, the distance between the turbine and the exhaust gas purification catalyst is small. Since it cannot be taken for a long time when mounted on a vehicle, these exhaust gases may flow into the exhaust purification catalyst without being sufficiently mixed. In this case, since temperature distribution occurs in the exhaust, temperature distribution also occurs in the exhaust purification catalyst into which the exhaust flows, and there is a possibility that deterioration of the exhaust purification catalyst proceeds.

  Accordingly, the present invention provides a supercharging system for an internal combustion engine that can quickly mix a low-temperature exhaust that rotationally drives a turbine rotor and a high-temperature exhaust that bypasses the turbine rotor before reaching the exhaust purification catalyst. The purpose is to provide.

  The internal combustion engine supercharging system of the present invention is applied to an internal combustion engine in which an exhaust gas purification catalyst is provided in an exhaust passage, and a turbine is disposed in a section upstream of the exhaust gas purification catalyst in the exhaust passage. In a supercharging system for an internal combustion engine having a turbocharger that exhausts exhaust gas that rotates the turbine rotor from a turbine while rotating in a predetermined direction, the exhaust gas that rotates the turbine rotor is guided to the turbine. An exhaust outlet portion to be discharged, a bypass passage that guides the exhaust gas flowing into the turbine to a high-temperature exhaust outlet portion that bypasses the rotor housing portion in which the turbine rotor is housed and is provided radially outside the exhaust outlet portion, A bypass valve that opens and closes an end of the bypass passage on the high-temperature exhaust outlet side, and an end of the bypass passage on the high-temperature exhaust outlet side is Exhausted from bypass passage wherein the predetermined direction is provided so as to be discharged while turning in the opposite reverse direction (claim 1).

  According to the supercharging system of the present invention, the exhaust discharged from the exhaust outlet, that is, the low-temperature exhaust that rotationally drives the turbine rotor (hereinafter sometimes referred to as low-temperature exhaust) is turning in a predetermined direction. Discharged from the turbine. On the other hand, the exhaust gas that has passed through the bypass passage, that is, high-temperature exhaust gas that bypasses the turbine rotor (hereinafter sometimes referred to as high-temperature exhaust gas) is swirling in a direction opposite to the swirling direction of the low-temperature exhaust gas. Discharged from. By rotating the low temperature exhaust gas and the high temperature exhaust gas in opposite directions in this way, it is possible to increase the turbulence caused by the collision of the exhaust gas that occurs when the exhaust gas merges. Therefore, when these exhaust gas merges, these exhaust gases can be quickly mixed. Therefore, the low temperature exhaust gas and the high temperature exhaust gas can be quickly mixed before reaching the exhaust purification catalyst. In addition, since exhaust gas having a uniform temperature at various locations can be caused to flow into the exhaust purification catalyst, deterioration of the exhaust purification catalyst can be suppressed.

  In one form of the supercharging system for an internal combustion engine of the present invention, an end of the bypass passage on the high temperature exhaust outlet side may be provided inclined with respect to a plane orthogonal to the rotation axis of the turbine rotor. (Claim 2). By providing the end of the bypass passage on the high temperature exhaust outlet side in this way, the high temperature exhaust can be easily swirled.

  In one form of the supercharging system for an internal combustion engine of the present invention, a partition wall that separates the high temperature exhaust outlet portion and the exhaust outlet portion may be provided on an outer periphery of the exhaust outlet portion over the entire circumference. (Claim 3). By partitioning in this way, the low-temperature exhaust discharged from the rotor housing portion and the high-temperature exhaust discharged from the end portion of the bypass passage on the high-temperature exhaust outlet side interfere with each other immediately after being discharged. Can be prevented. Therefore, strong swirl flows can be formed by the low temperature exhaust and the high temperature exhaust, respectively. Thereby, the disturbance when these exhausts merge and collide can be further increased. Accordingly, the low temperature exhaust gas and the high temperature exhaust gas can be quickly mixed when passing through the downstream end of the partition wall and joining.

  As described above, according to the supercharging system for an internal combustion engine of the present invention, the low-temperature exhaust that rotationally drives the turbine rotor and the high-temperature exhaust that bypasses the turbine rotor can be turned in directions opposite to each other. it can. Therefore, when these exhaust gases are merged, they can be quickly mixed. Therefore, the low temperature exhaust gas and the high temperature exhaust gas can be quickly mixed before reaching the exhaust purification catalyst.

The figure which shows the principal part of the internal combustion engine in which the supercharging system which concerns on one form of this invention was integrated. The figure which looked at the turbine in the II-II line | wire of FIG. 1 from the downstream of the exhaust flow. The figure which shows the cross section of the turbine in the III-III line of FIG.

  FIG. 1 shows a main part of an internal combustion engine in which a supercharging system according to an embodiment of the present invention is incorporated. The internal combustion engine 1 is mounted on a vehicle as a driving power source and includes an exhaust passage 2. The exhaust passage 2 is provided with a turbine 11 of the turbocharger 10 and an exhaust purification catalyst 3 for purifying exhaust. The turbine 11 is disposed upstream of the exhaust purification catalyst 3 in the exhaust flow. The turbocharger 10 includes a compressor 12 provided in an intake passage of the internal combustion engine 1, a rotor shaft 15 that connects a turbine rotor 13 of the turbine 11 and a compressor rotor 14 of the compressor 12 so as to rotate integrally, a rotor A center housing 16 that rotatably supports the shaft 15 is provided. In addition, since these parts may be the same as a well-known turbocharger, detailed description is abbreviate | omitted.

  In the turbine 11, the rotor accommodating portion 17 in which the turbine rotor 13 is accommodated, the exhaust outlet portion 18 connected to the rotor accommodating portion 17, and the exhaust gas flowing into the turbine 11 bypasses the rotor accommodating portion 17 and is led downstream. A waste gate port 19 as a bypass passage and a waste gate passage 20 as a high-temperature exhaust outlet to which the waste gate port 19 is connected are provided. Exhaust gas discharged from the rotor accommodating portion 17, that is, low-temperature exhaust gas that rotates the turbine rotor 11 is guided to the exhaust outlet portion 18. At this time, the low-temperature exhaust gas is guided to the exhaust outlet 18 while turning in the same direction as the rotation direction of the turbine rotor 11. FIG. 2 shows a view of the turbine taken along line II-II in FIG. 1 as viewed from the downstream side of the exhaust flow, that is, from the right side of FIG. As shown in this figure, the end portion 19 a of the waste gate port 19 on the waste gate passage 20 side is provided on the radially outer side of the exhaust outlet portion 18. In addition, the waste gate passage 20 is provided on the entire outer periphery of the exhaust outlet portion 18. A waste gate valve 21 serving as a bypass valve for opening and closing the end is provided at the end of the waste gate port 19 on the waste gate passage 20 side. FIG. 3 shows a section of the turbine 11 taken along line III-III in FIG. As shown in this figure, the end 19a of the waste gate port 19 on the waste gate passage 20 side is provided so as to be inclined with respect to a plane orthogonal to the rotation axis Ax of the turbine rotor 11. The end 19 a is inclined in a direction in which the exhaust discharged from the waste gate port 19 turns in the opposite direction opposite to the rotation direction of the turbine rotor 11. A partition wall 22 is provided on the outer periphery of the exhaust outlet 18 over the entire periphery. The partition wall 22 separates the exhaust outlet 18 and the waste gate passage 20.

  In this turbine 11, when the waste gate valve 21 is opened, the low-temperature exhaust discharged from the rotor accommodating portion 17 and the high-temperature exhaust that bypasses the rotor accommodating portion 17 at the waste gate port 19 are discharged from the turbine 11. The At this time, the low-temperature exhaust discharged from the rotor accommodating portion 17 is swung in the same direction as the rotation direction of the turbine rotor 11 as indicated by an arrow F1 in FIGS. To be discharged. On the other hand, the high-temperature exhaust that bypasses the rotor housing portion 17 swirls in the direction opposite to the rotation direction of the turbine rotor 11, that is, the swirl direction of the low-temperature exhaust, as indicated by an arrow F2 in FIGS. While being discharged from the waste gate passage 20 to the exhaust passage 2. Thus, by rotating the low-temperature exhaust gas and the high-temperature exhaust gas in opposite directions, it is possible to increase the turbulence caused by the collision of the exhaust gas that occurs when the exhaust gas merges. Therefore, these exhaust gases can be quickly mixed.

  As described above, according to the supercharging system of the present embodiment, the low-temperature exhaust gas that has passed through the rotor housing portion 17 and the high-temperature exhaust gas that has bypassed the rotor housing portion 17 can be swirled in opposite directions. These exhaust gases can be quickly mixed when they pass through the downstream end of the partition wall 22 and merge. Therefore, the low temperature exhaust gas and the high temperature exhaust gas can be quickly mixed before reaching the exhaust purification catalyst 3. As a result, the exhaust gas having a uniform temperature can be caused to flow into the exhaust purification catalyst 3, so that deterioration of the exhaust purification catalyst 3 can be suppressed.

  Further, in the supercharging system of the present embodiment, since the partition wall 22 for separating the exhaust outlet portion 18 and the waste gate passage 20 is provided on the entire periphery of the exhaust outlet portion 18, the waste gate passage of the waste gate port 19 is provided. It is possible to prevent the high-temperature exhaust just after exiting from the end portion 19a on the 20 side and the low-temperature exhaust passing through the rotor housing portion 17 from joining. Therefore, a strong swirl flow can be formed by high-temperature exhaust. Similarly, a strong swirl flow can be formed by low-temperature exhaust. Further, by strengthening the swirl flow formed by each exhaust gas in this way, it is possible to further increase the turbulence caused by the collision of the exhaust gas that occurs when these exhaust gases merge. Therefore, these low temperature exhaust and high temperature exhaust can be mixed more rapidly.

  The present invention is not limited to the above-described form and can be implemented in various forms. For example, there may be no partition wall that separates the exhaust outlet and the waste gate passage. The waste gate valve may be controlled to be opened when the exhaust purification catalyst is warmed up.

DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Exhaust passage 3 Exhaust purification catalyst 10 Turbo supercharger 11 Turbine 13 Turbine rotor 17 Rotor accommodating part 18 Exhaust outlet part 19 Waste gate port (bypass passage)
19a End of waste gate port on waste gate passage side 20 Waste gate passage (high temperature exhaust outlet)
21 Wastegate valve (bypass valve)
22 Bulkhead Ax Rotation axis

Claims (3)

Applied to an internal combustion engine provided with an exhaust purification catalyst in the exhaust passage;
A turbine is disposed in a section upstream of the exhaust purification catalyst in the exhaust passage, and a turbocharger is provided that exhausts exhausted by rotating the turbine rotor while rotating in a predetermined direction from the turbine. In the supercharging system of an internal combustion engine,
The turbine is provided with an exhaust outlet portion through which exhaust gas that rotationally drives the turbine rotor is guided, and the exhaust gas flowing into the turbine bypasses the rotor housing portion in which the turbine rotor is housed and is radially outside the exhaust outlet portion. A bypass passage leading to a high temperature exhaust outlet portion provided in the bypass passage, and a bypass valve that opens and closes an end portion of the bypass passage on the high temperature exhaust outlet portion side,
The supercharging system for an internal combustion engine, wherein an end of the bypass passage on the high-temperature exhaust outlet side is provided such that exhaust gas is exhausted from the bypass passage while turning in a direction opposite to the predetermined direction.   2. The supercharging system for an internal combustion engine according to claim 1, wherein an end of the bypass passage on the high temperature exhaust outlet side is inclined with respect to a plane orthogonal to a rotation axis of the turbine rotor.   The supercharging system for an internal combustion engine according to claim 1 or 2, wherein a partition wall that separates the high temperature exhaust outlet portion and the exhaust outlet portion is provided on an outer periphery of the exhaust outlet portion.

Images