JP5754282B2 - Exhaust turbine supercharger and internal combustion engine - Google Patents

Description

  The present invention relates to an exhaust turbine supercharger and an internal combustion engine provided with the supercharger.

  Conventionally, as an exhaust turbine supercharger and an internal combustion engine that perform supercharging with the energy of exhaust gas for the purpose of saving fuel consumption, for example, there is one described in Patent Document 1. In the conventional general exhaust turbine supercharger including the one described in Patent Document 1, a waste gate valve that adjusts the amount of flow into the turbine wheel by diverting a part of the exhaust is provided. This waste gate valve is normally provided inside the turbine housing, and is provided at a passage portion for introducing exhaust gas upstream of the turbine wheel and at a port portion at the tip of the passage portion to open and close the port portion. And a valve body. Incidentally, the passage portion and the turbine housing are integrally formed by casting.

Japanese Utility Model Publication No. 1-76523

By the way, since the conventional turbine housing is formed by casting, it is difficult to reduce the thickness, and there is a limit to reducing the weight.
Therefore, it is conceivable to form the turbine housing by press-molding a sheet metal. In this case, it is conceivable to form the passage portion of the waste gate valve by, for example, burring the turbine housing.

  However, in this case, from the viewpoint of ease of molding and ensuring rigidity, the passage portion has a shape along the axial direction of the turbine wheel. That is, the degree of freedom of the shape of the passage portion is low. As a result, it is difficult to set the flow direction of the exhaust discharged from the waste gate valve in a desired direction.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an exhaust gas discharged from the waste gate valve when the passage portion of the waste gate valve is formed of a sheet metal integrally with the turbine housing. It is an object to provide an exhaust turbine supercharger and an internal combustion engine that can set the flow direction of the engine to a desired direction.

Hereinafter, means for solving the above-described problems and the effects thereof will be described.
The invention according to claim 1 is an exhaust turbine supercharger including a turbine housing formed of sheet metal and surrounding a turbine wheel, wherein an exhaust turbine supercharger is provided in which a waste gate valve is provided. In the machine, a passage portion for introducing exhaust gas to the waste gate valve is formed integrally with the turbine housing, and a port member on which a valve body of the waste gate valve is seated at a tip of the passage portion is the turbine housing. The port member is formed in a separate body, and the gist thereof is that the port member has a cylindrical shape and the axial direction of the internal space is different from the axial direction of the passage portion .

  According to this configuration, since the passage portion for introducing the exhaust gas to the waste gate valve is formed of the sheet metal integrally with the turbine housing, the weight of the turbine housing can be reduced. In addition, since the port member on which the valve body of the waste gate valve is seated is provided separately from the turbine housing, the direction of the exhaust gas discharged from the waste gate valve can be routed by appropriately setting the shape of the port member. It can be set independently of the shape of the part. Therefore, the wastegate valve passage is formed by sheet metal integrally with the turbine housing, and the flow direction of the exhaust gas discharged from the wastegate valve can be set to a desired direction.

The gist of the invention according to claim 2 is that, in the exhaust turbine supercharger according to claim 1 , the port member is fixed to the tip of the passage portion.
According to this configuration, since the port member is fixed to the tip of the passage portion, the flow direction of the exhaust discharged through the waste gate valve can be reliably maintained in a desired direction.

The invention of claim 3 is in the turbocharger according to claim 1, by comprising a variable mechanism for varying the axial inner space of the previous SL port member is provided with its gist.

  According to this configuration, since the axial direction of the internal space of the port member can be changed by the variable mechanism, the flow direction of the exhaust discharged through the waste gate valve can be changed.

According to a fourth aspect of the invention, in an internal combustion engine having an exhaust gas turbine supercharger according to claim 2, the catalyst device is disposed on the downstream side of the waste gate valve in the exhaust passage of an internal combustion engine, before Symbol port member The gist of the present invention is that the axial direction of the internal space is oriented toward the center of the catalyst device rather than the axial direction of the passage portion.

According to this configuration, the exhaust discharged through the waste gate valve flows toward the center of the catalyst device. Therefore, the warm-up property of the catalyst device can be improved.
According to a fifth aspect of the present invention, there is provided an internal combustion engine comprising the exhaust turbine supercharger according to the second aspect , wherein an air-fuel ratio sensor for detecting an air-fuel ratio of exhaust gas is provided downstream of a waste gate valve in an exhaust passage of the internal combustion engine. There is arranged, axially of the inner space before Symbol port member is in its gist that of the axis direction of the passage formed by directing the air-fuel ratio sensor.

  In a multi-cylinder internal combustion engine, when an air-fuel ratio imbalance among cylinders occurs, there is a risk that inconveniences such as deterioration of exhaust properties may occur. Therefore, an air-fuel ratio sensor is provided in the exhaust passage, and it is determined whether or not an air-fuel ratio imbalance among cylinders has occurred based on the output of the air-fuel ratio sensor. Here, since the catalyst device is generally arranged on the downstream side of the exhaust turbine supercharger, it is necessary to arrange the air-fuel ratio sensor immediately before the catalyst device, in other words, immediately after the exhaust turbine supercharger. This is desirable for accurately detecting the air-fuel ratio of the exhaust gas flowing into the apparatus.

  According to the above configuration, the exhaust gas discharged through the waste gate valve flows toward the air-fuel ratio sensor. Accordingly, the air-fuel ratio sensor is arranged on the downstream side of the supercharger, and it is possible to accurately determine whether or not an air-fuel ratio imbalance is occurring between the cylinders.

The invention according to claim 6 is an internal combustion engine comprising the exhaust turbine supercharger according to any one of claims 1 to 3 or the internal combustion engine according to claim 4 , wherein the downstream side of the waste gate valve is arranged an air-fuel ratio sensor for detecting an air-fuel ratio of the exhaust gas, before Symbol port member, through the inner circumferential surface and the downstream end surface, different from the axial direction of the passage The gist of the invention is that a communication path extending in the direction and directed to the air-fuel ratio sensor is formed.

  According to this configuration, a part of the exhaust discharged from each cylinder flows toward the air-fuel ratio sensor through the communication passage formed through the port member without passing through the turbine wheel. Accordingly, the air-fuel ratio sensor is arranged on the downstream side of the supercharger, and it is possible to accurately determine whether or not an air-fuel ratio imbalance is occurring between the cylinders.

1 is a partial cross-sectional view showing a partial cross-sectional structure of an exhaust turbine supercharger according to an embodiment of the present invention. The perspective view which shows the perspective structure from the front end side flange side about the turbine housing of the embodiment. The perspective view which shows the perspective structure from the base end side flange side about the turbine housing of the embodiment. Sectional drawing which shows the cross-sectional structure centering on an exhaust turbine supercharger about the exhaust passage of the internal combustion engine in the embodiment. Sectional drawing which shows the cross-section of the wastegate valve | bulb of the embodiment. Sectional drawing which shows the cross-sectional structure centering on an exhaust turbine supercharger about the modification of the embodiment.

Hereinafter, with reference to FIGS. 1 to 5, an embodiment embodying an exhaust turbine supercharger and an internal combustion engine according to the present invention will be described in detail.
In FIG. 1, the partial cross-section of the exhaust turbine supercharger 10 in this embodiment is shown. FIG. 2 shows a perspective structure of the turbine housing 20 from the front flange 14 side. FIG. 3 shows a perspective structure of the turbine housing 20 from the proximal flange 13 side.

  In the following, in the axial direction C of the turbine wheel 11, the side close to the turbine shaft 12 (left side in FIG. 1) is the base end side, and the side away from the turbine shaft 12 (right side in FIG. 1) is the front end side. .

  As shown in FIGS. 1 to 3, the exhaust turbine supercharger 10 includes a turbine shaft 12 rotatably supported by a bearing (not shown), a turbine wheel 11 connected to the turbine shaft 12, and a turbine wheel 11. A turbine housing 20 that surrounds and forms a scroll portion is provided.

  The turbine housing 20 is disposed between a proximal flange 13 connected to a bearing housing (not shown) and a distal flange 14 connected to a downstream exhaust pipe 3 to be described later. The housing member 21 and the inner housing member 24 provided inside the outer housing member 21 are configured.

  The outer housing member 21 has a divided structure of a proximal end side housing member 22 and a distal end side housing member 23. 2 and 3, the portion indicated by reference numeral “6” is an upstream flange 15 connected to an exhaust manifold (not shown).

  The base end side housing member 22 constitutes a base end side portion of the outer housing member 21 and is provided so as to cover the base end side of the turbine wheel 11. The proximal end portion 22 a of the proximal end side housing member 22 is joined to the distal end outer peripheral surface of the proximal end side flange 13. The base end side housing member 22 is formed with a base end side scroll portion 22c extending from the base end portion 22a to the outer peripheral side. Moreover, the front-end | tip part 22b is extended along the axial direction C from the outer peripheral side edge part of the base end side scroll part 22c.

  The distal end side housing member 23 constitutes a portion on the distal end side of the outer housing member 21 and is provided so as to cover an inner housing member 24 and a support pipe 25 described later. The proximal end portion 23 a of the distal end side housing member 23 extends along the axial direction C, and the inner peripheral surface thereof is joined to the outer peripheral surface of the distal end portion 22 b of the proximal end side housing member 22. Further, the distal end side housing member 23 has a first reduced diameter portion 23b having a diameter smaller than that of the proximal end portion 23a on the distal end side of the proximal end portion 23a, and the first distal end side of the first reduced diameter portion 23b. The second reduced diameter portion 23c is further reduced in diameter than the reduced diameter portion 23b. In addition, the inner peripheral surface of the front end side flange 14 is joined to the outer peripheral surface of the second reduced diameter portion 23c.

  The inner housing member 24 has a substantially S-shaped cross section, and has a shroud surface 24 d that faces the blade portion 11 a of the turbine wheel 11 in the axial direction C. The proximal end portion 24 a of the inner housing member 24 extends along the axial direction C, and the outer peripheral surface thereof is joined to the inner peripheral surface of the distal end portion 22 b of the proximal end side housing member 22. That is, the distal end portion 22b of the proximal end side housing member 22, the proximal end portion 23a of the distal end side housing member 23, and the proximal end portion 24a of the inner housing member 24 are joined by arc welding so as to overlap each other. Further, a distal end side scroll portion 24c having a substantially arc-shaped cross section extends from the proximal end portion 24a. The distal end side scroll portion 24c and the proximal end side scroll portion 22c of the proximal end side housing member 22 discharge from the exhaust manifold. The scroll part which is a channel | path for introducing the exhaust_gas | exhaustion exhausted into the blade | wing part 11a of the turbine wheel 11 is comprised. Further, a portion having a shroud surface 24d having a substantially arc-shaped cross section extends from the distal end side scroll portion 24c toward the distal end side, and the distal end portion 24b extends along the axial direction C.

  Here, in this embodiment, the base end side housing member 22, the front end side housing member 23, and the inner side housing member 24 are each formed by press-molding the plate shape which consists of stainless steel.

  A support pipe 25 is connected to the inner peripheral surface of the distal end side housing member 23. Specifically, the support pipe 25 extends along the axial direction C of the turbine wheel 11, and the distal end portion 25 b has a smaller diameter than the proximal end portion 25 a. The outer peripheral surface of the base end portion 25 a is joined to the inner peripheral surface of the first reduced diameter portion 23 b of the distal end side housing member 23. Here, the base end portion 25a is disposed so as to cover the front end portion 24b of the inner housing member 24, and the gap between the inner peripheral surface of the base end portion 25a and the outer peripheral surface of the front end portion 24b is sealed. A sealing member 26 is provided. Here, the seal member 26 is a so-called ceramic mat formed by bonding ceramic fibers (for example, alumina) to each other with a known binder. The front end 24b of the inner housing member 24 is supported by the support pipe 25 via the seal member 26 so as to be displaceable in the axial direction C.

Next, the configuration of the waste gate valve 30 will be described.
FIG. 4 shows a cross-sectional structure of the exhaust passage 2 of the internal combustion engine 1 of the present embodiment, centering on the exhaust turbine supercharger 10. FIG. 4 shows a cross-sectional structure at a different rotational position in the exhaust turbine supercharger 10 from the cross-sectional structure shown in FIG. Moreover, in FIG. 4, the turbine wheel 11 is not illustrated for convenience.

FIG. 5 shows a cross-sectional structure of the waste gate valve 30.
As shown in FIG. 4, the downstream exhaust pipe 3 is connected to the exhaust downstream side of the front end flange 14 in the exhaust passage 2 via the downstream flange 3 a. A catalyst device 4 for purifying exhaust gas is disposed inside the downstream exhaust pipe 3. Incidentally, the catalyst device 4 has a substantially cylindrical shape.

  Inside the turbine housing 20, a waste gate valve 30 for adjusting a flow amount into the turbine wheel 11 by diverting a part of the exhaust from the exhaust manifold is provided.

  The waste gate valve 30 is provided with a passage portion 31 for introducing the exhaust on the upstream side of the turbine wheel 11, a port member 32 attached to the tip of the passage portion 31, and a seat member provided on the port member 32 so as to be seated. And a valve body 33 that opens and closes the distal end opening of the member 32. The port member 32 is fixed with respect to the passage portion 31. In FIG. 4, the valve element 33 is not shown for convenience.

  As shown in FIG. 5, the passage portion 31 has a cylindrical shape and is formed by burring the member 24 when the inner housing member 24 is formed. That is, the passage portion 31 is formed integrally with the turbine housing 20. Further, the passage portion 31 is formed so that the axial direction Q thereof is along the axial direction C of the turbine wheel 11. This is due to the reason that the burring process is easy and the rigidity of the passage portion 31 is ensured.

  The port member 32 has a cylindrical shape and an insertion portion 32a that is inserted into the passage portion 31, and a disc-shaped valve seat 32b that is formed at the tip of the insertion portion 32a and on which the valve body 33 can be seated. Have. The valve seat 32b protrudes in the outer circumferential direction from the insertion portion 32a over the entire circumference. That is, the port member 32 is provided separately from the turbine housing 20.

  Here, the internal space 35 of the port member 32 has a substantially cylindrical shape, and the axial direction P of the internal space 35 is formed to be different from the axial direction Q of the passage portion 31. Specifically, as shown in FIG. 4, the passage portion 31 of the waste gate valve 30 is located on the outer peripheral side with respect to the center Ccat of the catalyst device 4, whereas the opening portion on the front end side of the internal space 35. (The opening on the right side in FIG. 4) is located on the inner peripheral side with respect to the opening on the base end side (the opening on the left side in FIG. 4). Further, as shown in FIG. 5, the opening on the distal end side of the internal space 35 is positioned in front of the base B side opening in the direction B in which the exhaust gas flows in the scroll portion of the exhaust turbine supercharger 10. . That is, the axial direction P of the port member 32 is directed to the center Ccat of the catalyst device 4 more than the axial direction Q of the passage portion 31.

The valve body 33 is of a flap type and is driven by a known actuator (not shown).
Next, the operation of this embodiment will be described.

  When the valve element 33 of the waste gate valve 30 is seated on the valve seat 32b and is closed, all the exhaust gas flowing into the turbine housing 20 from the exhaust manifold flows into the turbine wheel 11 through the scroll portion.

  On the other hand, when the waste gate valve 30 is opened, a part of the exhaust gas flowing into the turbine housing 20 from the exhaust manifold is passed through the passage portion 31 and the port member 32 of the waste gate valve 30 to the outside of the turbine housing 20. The gas flows out and bypasses the turbine wheel 11.

  Here, since the passage portion 31 of the waste gate valve 30 is formed of sheet metal integrally with the turbine housing 20 (specifically, the inner housing member 24), compared to the conventional configuration in which these are formed by casting, The turbine housing 20 can be reduced in weight.

  Further, since the port member 32 is provided separately from the turbine housing 20 (passage portion 31), the flow direction of the exhaust gas discharged from the waste gate valve 30 is set independently of the shape of the passage portion 31. Is possible. In the present embodiment, since the axial direction P of the port member 32 is directed to the center Ccat of the catalytic device 4 rather than the axial direction Q of the passage portion 31, the exhaust discharged through the waste gate valve 30 is the catalytic device. It flows toward the center Ccat of 4.

According to the exhaust turbine supercharger and the internal combustion engine according to the present embodiment described above, the following operational effects can be obtained.
(1) A passage portion 31 for introducing exhaust gas into the waste gate valve 30 is formed integrally with the turbine housing 20. Further, a port member 32 on which the valve body 33 of the waste gate valve 30 is seated is provided separately from the turbine housing 20 at the tip of the passage portion 31. According to such a configuration, the passage portion 31 of the waste gate valve 30 is formed by sheet metal integrally with the turbine housing 20, and the flow direction of the exhaust discharged from the waste gate valve 30 is set to a desired direction. can do.

  (2) The port member 32 is formed in a cylindrical shape so that the axial direction P of the internal space 35 is different from the axial direction Q of the passage portion 31. Specifically, the axial direction P of the port member 32 is directed to the center Ccat of the catalyst device 4 more than the axial direction Q of the passage portion 31. According to such a configuration, the exhaust gas discharged through the waste gate valve 30 flows toward the center Ccat of the catalyst device 4, so that the warm-up property of the catalyst device 4 can be improved.

  (3) The port member 32 is fixed to the tip of the passage portion 31. According to such a configuration, it is possible to reliably maintain a state in which the exhaust discharged through the waste gate valve 30 flows toward the center Ccat of the catalyst device 4.

  The exhaust turbine supercharger and the internal combustion engine according to the present invention are not limited to the configurations exemplified in the above-described embodiment, and can be implemented as, for example, the following forms appropriately modified.

  In a multi-cylinder internal combustion engine, when an air-fuel ratio imbalance among cylinders occurs, there is a risk that inconveniences such as deterioration of exhaust properties may occur. Therefore, as shown in FIG. 6, an air-fuel ratio sensor 40 is arranged in the exhaust passage 2 immediately before the catalyst device 4, in other words, immediately after the exhaust turbine supercharger 10, and between cylinders based on the output of the air-fuel ratio sensor 40. It may be determined whether or not an air-fuel ratio imbalance has occurred. In this case, in addition to the internal space 135, the port member 132 is formed with a communication passage 134 that penetrates the inner peripheral surface and the front end side end surface (downstream end surface) of the port member 132 and faces the air-fuel ratio sensor 40. Can also be adopted. In this case, a part of the exhaust discharged from each cylinder flows toward the air-fuel ratio sensor 40 through the communication passage 134 formed through the port member 132 without passing through the turbine wheel 11. Therefore, it is possible to accurately determine whether or not an air-fuel ratio imbalance among cylinders has occurred.

  -In above-mentioned embodiment and its modification, it illustrated about what the axial direction P of the internal spaces 35 and 135 of the port members 32 and 132 points to the center Ccat of the catalyst apparatus 4. FIG. Alternatively, the port member can be formed so that the axial direction P of the internal space of the port member is directed to the air-fuel ratio sensor more than the axial direction Q of the passage portion. In this case, the exhaust discharged through the waste gate valve flows toward the air-fuel ratio sensor. Therefore, it is possible to accurately determine whether or not an air-fuel ratio imbalance among cylinders has occurred.

  -In above-mentioned embodiment and its modification, although illustrated about what the port member 32 is fixed to the front-end | tip of the channel | path part 31, it replaces with this and makes the axial direction P of the internal space of a cylindrical port member variable. A variable mechanism may be provided. That is, for example, if the port member is rotatably supported by the tip of the passage portion, and an actuator that rotates the port member is provided, the port member is rotated with respect to the tip of the passage portion by the actuator. Can be moved. For this reason, it becomes possible to change the flow direction of the exhaust discharged through the waste gate valve.

  -In above-mentioned embodiment and its modification, although illustrated about what the axial direction of the internal space of a port member makes linear form, this invention is not limited to this. The axial direction of the internal space of the port member may be curved.

  DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 2 ... Exhaust passage, 3 ... Downstream side exhaust pipe, 3a ... Downstream side flange, 4 ... Catalyst apparatus, 10 ... Exhaust turbine supercharger, 11 ... Turbine wheel, 11a ... Blade | wing part, 12 ... Turbine shaft , 13 ... proximal flange, 14 ... distal flange, 15 ... upstream flange, 20 ... turbine housing, 21 ... outer housing member, 22 ... proximal housing member, 22a ... proximal end, 22b ... distal end, 22c: proximal end scroll portion, 23 ... distal end side housing member, 23a ... proximal end portion, 23b ... first reduced diameter portion, 23c ... second reduced diameter portion, 24 ... inner housing member, 24a ... proximal end portion, 24b ... tip part, 24c ... tip side scroll part, 24d ... shroud surface, 25 ... support pipe, 25a ... diameter-increased part, 25b ... diameter-reduced part, 26 ... seal member, 30, 130 ... waste gate Valve, 31, 131 ... passage, 32, 132 ... port member, 32a ... inner interpolator, 32 b ... valve seat, 33 ... valve body, 35,135 ... internal space, 134 ... communicating passage, 40 ... air-fuel ratio sensor.

Claims (6)

An exhaust turbine supercharger comprising a turbine housing formed of sheet metal and surrounding a turbine wheel, wherein an exhaust turbine supercharger is provided with a waste gate valve inside the turbine housing.
A passage portion for introducing exhaust gas into the wastegate valve is integrally formed with the turbine housing;
A port member on which the valve body of the waste gate valve is seated is provided separately from the turbine housing at the tip of the passage portion ,
The port member has a cylindrical shape, and an axial direction of an internal space thereof is different from an axial direction of the passage portion . In the exhaust turbine supercharger according to claim 1 ,
The exhaust turbine supercharger, wherein the port member is fixed to a tip of the passage portion. In the exhaust turbine supercharger according to claim 1 ,
Before SL port turbocharger variable mechanism for varying the axial inner space, it characterized in that the thus provided the member. An internal combustion engine comprising the exhaust turbine supercharger according to claim 2 ,
A catalyst device is arranged on the downstream side of the waste gate valve in the exhaust passage of the internal combustion engine,
The internal combustion engine axial direction, characterized in that of the axis direction of the passage formed by directing the center of the catalytic converter of the internal space in front Symbol port member. An internal combustion engine comprising the exhaust turbine supercharger according to claim 2 ,
An air-fuel ratio sensor for detecting the air-fuel ratio of the exhaust is disposed downstream of the waste gate valve in the exhaust passage of the internal combustion engine,
The internal combustion engine axial direction, characterized in that of the axis direction of the passage formed by directing the air-fuel ratio sensor in the inner space before Symbol port member. In an internal combustion engine provided with the exhaust-turbine supercharger as described in any one of Claims 1-3, or the internal combustion engine of Claim 4 .
An air-fuel ratio sensor for detecting the air-fuel ratio of the exhaust is disposed downstream of the waste gate valve in the exhaust passage of the internal combustion engine,
The front Stories port member, and characterized in that the inner through the peripheral surface and the downstream end face, the communicating passage for directing the air-fuel ratio sensor extends in a direction different from the axial direction of the passage is formed An internal combustion engine.

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