JP2007192128A - Variable capacity turbocharger - Google Patents

Abstract

A variable capacity turbocharger capable of reducing a loss of exhaust energy due to a decrease in exhaust pressure when a regulating valve reaches an intermediate opening is provided.
A secondary passage 35 of a scroll passage 27 has a first inner wall surface 45 and a second inner wall surface 46 facing each other. The valve body 42 of the regulating valve 41 is provided at a downstream end thereof and is always provided in contact with the first inner wall surface 45. The valve body 42 is provided on the exhaust upstream side of the support portion 47 and uses the support portion 47 as a fulcrum. Along with the rotation of the body 42, an action portion 49 that contacts or separates from the second inner wall surface 46 to close or open the secondary passage 35, and exhaust from the upstream when the valve body 42 opens at an intermediate opening degree. Is provided between the second inner wall surface 46 and the action portion 49. A portion of the valve body 42 facing the secondary passage 35 between the action portion 49 and the support portion 47 gradually approaches the first inner wall surface 45 toward the exhaust downstream side when the valve body 42 opens at an intermediate opening. Is formed.
[Selection] Figure 3

Description

  The present invention relates to a variable capacity turbocharger capable of adjusting an inflow amount of exhaust gas into a turbine wheel chamber.

  As one type of turbocharger, there is known a variable capacity turbocharger in which the amount of exhaust flowing into the turbine wheel chamber can be adjusted in accordance with engine operating conditions such as engine rotation speed. For example, in the variable capacity turbocharger proposed in Patent Document 1, as shown in FIG. 14, a scroll passage 82 formed in a spiral shape around the turbine wheel chamber 81 is formed by an inner peripheral scroll portion 84 by a partition wall 83. And an outer peripheral scroll portion 85. The partition wall 83 is provided with a plurality of communication holes 86 that allow the scroll portions 84 and 85 to communicate with each other. Further, the exhaust introduction port 87 of the outer peripheral scroll portion 85 is provided with an adjustment valve 88 for adjusting the opening degree of the exhaust introduction port 87. The adjustment valve 88 is rotatably supported by a shaft 89 on the upstream side of the outer peripheral scroll portion 85. The regulating valve 88 closes the exhaust introduction port 87 by contacting the partition wall 83 at the downstream end thereof, and opens the exhaust introduction port 87 by separating from the partition wall 83.

  In the variable capacity turbocharger 91 having the above configuration, when the engine is operated in a low rotational speed range where the exhaust flow rate is small, the downstream end of the regulating valve 88 is brought into contact with the partition wall 83 to close the exhaust introduction port 87. . Therefore, the inflow of exhaust gas to the outer scroll part 85 is blocked, and the exhaust gas is guided only to the inner scroll part 84 having a small volume. Therefore, the turbine wheel 92 can be efficiently rotated even with a small amount of exhaust.

  When the engine is operated in a middle / high rotational speed range where the exhaust flow rate is large, the downstream end of the regulating valve 88 is separated from the partition wall 83 and the exhaust inlet 87 is opened at an opening corresponding to the engine rotational speed. . Exhaust gas flows into both the inner scroll portion 84 and the outer scroll portion 85. The exhaust gas flowing into the outer scroll part 85 flows into the inner scroll part 84 through the communication hole 86 of the partition wall 83. As a result, the rotation of the turbine wheel 92 is suppressed, and the compressor wheel is prevented from rotating more than necessary.

As described above, the amount of exhaust flowing into the inner scroll portion 84 and the outer scroll portion 85 is adjusted according to the engine rotation speed, whereby an amount of exhaust gas according to the engine rotation speed is supplied to the turbine wheel chamber 81. The As a result, an appropriate supercharging pressure set in accordance with the engine rotation speed in the compressor wheel can be obtained.
Japanese Patent Laying-Open No. 2003-83076 (FIG. 2)

  However, in the above-described variable capacity turbocharger 91, the following problems may occur when the regulating valve 88 reaches an intermediate opening, particularly when it is slightly opened from the fully closed state. At such an intermediate opening, the passage area at the location corresponding to the regulating valve 88 gradually changes (increases) from the upstream end to the downstream end of the regulating valve 88, but suddenly immediately downstream of the downstream end. By expanding to. When the passage area is rapidly expanded in this way, separation occurs in the exhaust flow. Along with this, the exhaust pressure is reduced, loss of exhaust energy is generated, and the turbine efficiency is lowered.

  Such a problem is not limited to the variable displacement turbocharger 91 described in the above-mentioned Patent Document 1, and may occur in the same manner as long as it is a variable displacement turbocharger provided with a regulating valve that makes the exhaust passage area variable in the scroll passage.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a variable displacement turbo that can reduce exhaust energy loss due to a decrease in exhaust pressure when the regulating valve reaches an intermediate opening. To provide a charger.

In the following, means for achieving the above object and its effects are described.
According to the first aspect of the present invention, in the variable capacity turbocharger including a scroll passage provided around the turbine wheel chamber and an adjustment valve for changing a passage area of the scroll passage, the scroll passages face each other. The adjustment valve has a first inner wall surface and a second inner wall surface, and the valve body of the regulating valve is provided at a downstream end thereof and always in contact with the first inner wall surface, and provided upstream of the same support portion. With the operation of the valve body using the support portion as a fulcrum, the scroll passage is closed by contacting the second inner wall surface, and the scroll passage is opened away from the second inner wall surface. And a guide part that guides exhaust gas from the upstream between the second inner wall surface and the action part when the valve body opens at an intermediate opening, and further, the action part and the support part The scroll through Position facing the said valve body when the valve opening at an intermediate opening degree, and are formed so as to approach gradually as the exhaust downstream side to the first inner wall surface.

  According to the above configuration, the passage area of the scroll passage is adjusted by the operation of the adjustment valve. Accordingly, the amount of exhaust gas flowing through the scroll passage and guided to the turbine wheel chamber is adjusted.

  In the adjustment valve, when the passage area is adjusted, the valve body operates with the support portion as a fulcrum, and the action portion contacts or separates from the second inner wall surface in a state where the support portion contacts the first inner wall surface of the scroll passage. . When the action part comes into contact with the second inner wall surface, the passage area between them becomes zero, and the flow of exhaust is blocked.

  On the other hand, when the action part is separated from the second inner wall surface, the passage area between them is enlarged, and the exhaust gas can be circulated. The passage area between the action portion and the second inner wall surface increases as the action portion moves away from the second inner wall surface toward the first inner wall surface, that is, as the opening of the valve element increases.

  Therefore, when the valve element is opened at an intermediate opening degree (intermediate opening degree) between fully closed and fully open, the exhaust is guided between the second inner wall surface and the action part by the guide part in the process of flowing through the scroll passage. Further, the exhaust gas flows downstream through the valve body and the second inner wall surface.

  Here, in the valve body, the support portion on the downstream side of the action portion is always in contact with the first inner wall surface. An action part contacts or leaves | separates to a 2nd inner wall surface with the action | operation of a valve body. Further, the portion facing the scroll passage between the action portion and the support portion is formed so as to gradually approach the first inner wall surface toward the exhaust downstream side. From these facts, when the valve element opens at an intermediate opening, the distance between the valve element and the second inner wall surface, and hence the passage area, is the smallest in the action part and gradually increases as it approaches the support part. In the part, it is substantially the same as the passage area immediately downstream.

  Accordingly, the passage area does not rapidly increase in the process in which the exhaust passes between the valve body and the second inner wall surface. A problem due to a sudden increase in the passage area, that is, a phenomenon in which when exhaust passes through the valve body, the pressure of the exhaust decreases and exhaust energy is lost, and the turbine efficiency is reduced is suppressed.

According to a second aspect of the present invention, in the first aspect of the present invention, the portion facing the scroll passage between the action portion and the support portion is configured by a flat surface.
According to said structure, the channel | path area when a valve body opens by intermediate opening degree becomes the minimum between an action part and a 2nd inner wall surface, and becomes large toward exhaust downstream. And between the support part and the second inner wall surface, the passage area is substantially the same as the passage area immediately downstream of the valve body. Further, since the portion facing the scroll passage between the action portion and the support portion is constituted by a flat surface, the passage area gradually increases with a certain degree as it approaches the support portion from the action portion.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the guide portion has a curved surface that swells in an arc shape toward the exhaust upstream side.
According to the above configuration, since the curved surface of the guide portion swells in an arc shape to the upstream side of the scroll passage, when the valve body is opened at an intermediate opening, the exhaust gas smoothly flows along the curved surface of the guide portion. It flows and is collected between the action part and the second inner wall surface.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the support portion is rotatably supported on the first inner wall surface by a shaft, and the action portion is It is assumed that the valve body contacts or separates from the second inner wall surface as the valve body rotates with the support portion as a fulcrum.

  According to the above configuration, when the valve body is rotated with the shaft provided in the support portion as a fulcrum, the inclination of the valve body changes, and the action portion on the upstream side of the support portion is the second part of the scroll passage. Contact or leave the inner wall. In this way, the passage area between the valve body and the second inner wall surface is adjusted while the valve body is simply rotated with the support portion as a fulcrum.

According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the valve body has a substantially fan-shaped cross-sectional shape that increases in width as it moves away from the support portion toward the exhaust upstream side.
In the valve body having the above configuration, the downstream end functions as a support portion in the invention according to claim 4, and the corner portion on the second inner wall surface side at the upstream end functions as an action portion. Furthermore, the arc-shaped end surface on the upstream side of the valve body functions as a guide portion.

  According to a sixth aspect of the present invention, in the fifth aspect of the present invention, in the fifth aspect, the adjustment valve accommodates the valve body in a state where the valve body is positioned outside the scroll passage when the valve body is fully opened. Is further provided.

  According to the above configuration, when the operating part is farthest from the second inner wall surface within the movable range and the valve body is fully opened, the valve body is accommodated in the valve accommodating part. In this state, the valve body is located outside the scroll passage. Therefore, the valve body is unlikely to hinder (resistance) the flow of exhaust gas, and the resistance when the exhaust gas passes between the valve body and the second inner wall surface can be reduced.

  The invention according to claim 7 is the invention according to any one of claims 1 to 3, wherein the valve body includes a downstream lever member having the support portion at the downstream end, and the downstream side at the downstream end. An upstream lever member connected to the upstream end of the lever member and functioning as the guide portion, the support portion being rotatably supported by the first inner wall surface by a shaft, and the action portion being the upstream side A lever member and a connecting portion of the downstream lever member are arranged, and the upstream end of the upstream lever member is moved to the exhaust upstream side or the exhaust downstream side, thereby contacting or separating from the second inner wall surface. Suppose there is.

  According to the above configuration, when the upstream end of the upstream lever member is moved to the exhaust upstream side or the exhaust downstream side, the movement is transmitted to the downstream lever member. Here, the downstream lever member is rotatably supported on the first inner wall surface by the shaft at the support portion at the downstream end thereof. The upstream end of the downstream lever member is connected to the downstream end of the upstream lever member. Therefore, when the movement of the upstream lever member is transmitted to the downstream lever member as described above, the downstream lever member rotates about the shaft. Along with this, the inclination of the downstream lever member changes, and the action portion constituted by the connecting portion with the upstream lever member contacts or separates from the second inner wall surface. Thus, the passage area between the downstream lever member and the second inner wall surface is adjusted by the cooperation of the upstream lever member and the downstream lever member.

  When the valve element is opened at an intermediate opening, the upstream lever member functions as a guide portion, and guides exhaust between the second inner wall surface and the action portion. The downstream lever member functions as a portion facing the scroll passage between the action portion and the support portion.

  In the invention according to claim 8, in the invention according to any one of claims 1 to 3, the upstream end of the valve body is rotatably supported by the first inner wall surface by a shaft, and The downstream end is slidably brought into contact with the first inner wall surface as the support portion, and the intermediate portion is bent and formed in a mountain shape so as to be separated from the first inner wall surface, and the shaft serves as a fulcrum. When the valve body is elastically deformed with the rotation, the bent end functions as the action portion and contacts or separates from the second inner wall surface.

  According to said structure, a valve body contacts a 1st inner wall surface in the upstream end and downstream end at the time of valve closing of a valve body. Further, the intermediate portion of the valve body is bent in a mountain shape so as to be separated from the first inner wall surface. The bent end of the valve body contacts the second inner wall surface and functions as an action portion.

  When the valve body is rotated about the upstream end shaft from the above state, the rotation is transmitted to the entire valve body. Here, the downstream end of the valve body is slidably contacted with the first inner wall surface. Therefore, when the valve body is rotated as described above, the support body at the downstream end of the valve body slides along the first inner wall surface, whereby the valve body is elastically deformed. Along with this, the action portion constituted by the bent end of the valve body is separated from the second inner wall surface. Thus, the passage area between the valve body and the second inner wall surface is adjusted by the rotation of the valve body with the upstream end shaft as a fulcrum.

  When the valve element is opened at an intermediate opening, a portion upstream of the bent end (action part) of the valve element functions as a guide part, and guides exhaust between the second inner wall surface and the action part. Further, the portion downstream of the bent end (action portion) of the valve body functions as a location facing the scroll passage between the action portion and the support portion.

  According to a ninth aspect of the present invention, in the invention according to any one of the first to eighth aspects, a boundary portion of the scroll passage with the turbine wheel chamber constitutes a nozzle that guides exhaust to the turbine wheel chamber. In the scroll passage, at least a portion including the nozzle is divided into two passages by a partition wall, and the valve body is provided only in one passage.

  According to the above configuration, in the scroll passage, on the side where the valve body of the regulating valve is not provided in the two passages partitioned by the partition wall, the exhaust gas can flow regardless of the opening degree of the valve body. On the other hand, in the passage on the side where the valve body is provided, an amount of exhaust according to the opening of the valve body can flow. Therefore, the flow rate of the exhaust gas guided from the nozzle to the turbine wheel chamber can be adjusted by changing the opening of the valve body. In such a variable capacity turbocharger, by adopting the configuration of the invention according to any one of claims 1 to 8, the passage area rapidly increases when the exhaust gas passes between the valve body and the second inner wall surface. The phenomenon of expansion can be suppressed.

  According to a tenth aspect of the present invention, in the ninth aspect of the invention, the one nozzle partitioned by the partition wall constitutes a primary nozzle facing the leading edge portion of the moving blade of the turbine wheel, and the other nozzle Constitutes a secondary nozzle facing the shroud portion of the rotor blade, and the valve body is provided on the side of the passage having the secondary nozzle, and the opening degree thereof is adjusted according to the operating state of the engine. .

  According to said structure, when a valve body is closed, the channel | path which has a secondary nozzle will be in the closed state, and the inflow of the exhaust_gas | exhaustion from the secondary nozzle to the shroud part of a moving blade will be interrupted | blocked. The passage having the primary nozzle is opened regardless of the opening of the adjusting valve. Therefore, the exhaust gas flowing through the scroll passage is guided only from the primary nozzle to the leading edge portion.

  On the other hand, when the valve body is opened, the passage having the secondary nozzle is opened. A part of the exhaust gas flowing in the scroll passage is guided from the primary nozzle to the leading edge portion of the moving blade, and the rest is guided from the secondary nozzle to the shroud portion of the moving blade. As the secondary nozzle is added, the nozzle of the scroll passage becomes larger and more exhaust gas is guided to the moving blade of the turbine wheel.

  Therefore, for example, the valve body is closed when the amount of exhaust from the engine is small, and the valve body is opened when the amount of exhaust is large. The flow rate of the exhaust can be adjusted to an amount suitable for the same operating state.

  According to an eleventh aspect of the present invention, in the tenth aspect, at least one of the primary nozzle and the secondary nozzle is arranged with a plurality of nozzle vanes arranged in a circumferential direction.

  According to said structure, exhaust_gas | exhaustion is directed from the nozzle of a scroll channel | path toward a turbine wheel chamber vigorously (at a larger flow rate) and directed by the said nozzle vane. Therefore, it becomes possible to take out more exhaust energy through the turbine wheel and further improve the turbine efficiency.

Hereinafter, an embodiment embodying the present invention will be described with reference to FIGS.
As shown in FIG. 1, a variable capacity turbocharger (hereinafter simply referred to as “turbocharger”) 11 according to the present embodiment includes a housing 15 disposed across an exhaust passage 13 and an intake passage 14 of an engine 12. . A shaft 16 is rotatably supported on the housing 15. A turbine wheel 17 and a compressor wheel 18 are provided at both ends of the shaft 16 so as to be integrally rotatable. When the exhaust gas flowing through the exhaust passage 13 is blown to the turbine wheel 17 and the wheel 17 is rotated, the rotation is transmitted to the compressor wheel 18 via the shaft 16. By rotating the compressor wheel 18 in this manner, the pressure of air in the intake passage 14 (supercharging pressure) is increased, and as a result, the air is forcibly sent to the cylinder 19 of the engine 12.

  In terms of function, the turbocharger 11 is divided into a turbine wheel 17 side (turbine side) that is rotationally driven by exhaust as described above, and a compressor wheel 18 side (compressor side) that rotates to increase the pressure of intake air. . The turbocharger 11 of the present embodiment has a feature on the turbine side. For this reason, each part on the turbine side will be mainly described, and description of other parts will be omitted.

  As shown in FIG. 2, the turbine wheel 17 includes a hub 21 provided coaxially with the shaft 16 and a plurality of moving blades (blades) 22 arranged around the hub 21. Each rotor blade 22 is curved so that an intermediate portion along the axis L of the shaft 16 (hereinafter referred to as “axial direction”) swells forward in the rotation direction R of the shaft 16. The moving blade 22 having such a curved surface shape is generally called a reaction type, and rotates by the reaction by receiving exhaust energy.

  Of the outer edge of each rotor blade 22, the portion on the compressor wheel side (left side in FIG. 2) in the axial direction constitutes a leading edge portion 23. Further, the outer edge of each rotor blade 22 on the side opposite to the compressor wheel 18 (the right side in FIG. 2) constitutes a shroud portion 24. In each rotor blade 22, the distance from the axis L to the leading edge portion 23 is set to be larger than the distance from the coaxial line L to most of the shroud portions 24.

  FIG. 3 is a cross-sectional view of the turbocharger 11 on the turbine side. FIG. 4 is a cross-sectional view of the turbocharger 11 on the turbine side at a cutting plane that is approximately 90 ° different from FIG. 3 in the rotational direction R of the turbine wheel 17.

  A turbine side portion of the housing 15 is constituted by a turbine housing 25. The turbine housing 25 includes a turbine wheel chamber 26, a scroll passage 27, and an outlet portion 32. The turbine wheel chamber 26 is formed of a cylindrical space for accommodating the turbine wheel 17 described above, and is provided at a substantially central portion of the turbine housing 25.

  The scroll passage 27 is formed in a spiral shape around the turbine wheel chamber 26. The upstream end of the scroll passage 27 constitutes an exhaust introduction portion 29 for exhaust from the engine 12 (see FIG. 3). The turbine housing 25 is connected to an exhaust pipe 31 constituting the exhaust passage 13 of the engine 12 at the exhaust introduction portion 29. The downstream end of the scroll passage 27, that is, the boundary portion with the turbine wheel chamber 26 constitutes a nozzle 28, and the exhaust gas flowing through the scroll passage 27 is guided from the nozzle 28 to the turbine wheel chamber 26, Sprayed between adjacent rotor blades 22.

  The outlet 32 is provided in the turbine housing 25 on the exhaust downstream side of the turbine wheel chamber 26, and guides the exhaust after being blown to the turbine wheel 17 to the downstream side of the exhaust passage 13.

  In a space downstream of the exhaust introduction portion 29 in the scroll passage 27, a partition wall 33 that partitions the space into two passages along the axial direction of the shaft 16 is provided. The upstream end of the partition wall 33 is located in the vicinity of the exhaust introduction portion 29, and the downstream end is located in the vicinity of the turbine wheel chamber 26. In order to distinguish the two passages, here, the passage on the compressor wheel 18 side is referred to as a primary passage 34, and the passage on the opposite side of the compressor wheel 18 is referred to as a secondary passage 35. The primary passage 34 has an annular primary nozzle 36 at a downstream end thereof, that is, at a boundary portion with the turbine wheel chamber 26. The primary nozzle 36 opens at a location facing the leading edge portion 23 of the moving blade 22. Accordingly, the exhaust gas flowing through the primary passage 34 is blown from the primary nozzle 36 between the leading edge portions 23 of the adjacent moving blades 22. Moreover, the secondary channel | path 35 has the annular | circular shaped secondary nozzle 37 in the downstream end. The secondary nozzle 37 is opened at a location facing the shroud portion 24 of the rotor blade 22. Accordingly, the exhaust gas flowing through the secondary passage 35 is blown between the shroud portions 24 of the adjacent moving blades 22 from the secondary nozzle 37.

  As described above, in this embodiment, the nozzle 28 is divided into the primary nozzle 36 and the secondary nozzle 37 by the partition wall 33. In other words, the secondary nozzles 37 are arranged side by side across the partition wall 33 on the opposite side of the primary nozzle 36 from the compressor wheel 18.

  Each of the primary nozzle 36 and the secondary nozzle 37 is provided with a plurality of nozzle vanes 38 and 39 arranged at equal angles over the entire circumference. Each of the nozzle vanes 38 and 39 has a thin plate shape and is disposed so as to extend in a substantially tangential direction of a circle centered on the axis L (see FIG. 5). These nozzle vanes 38 and 39 are provided for the purpose of directing exhaust gas to the turbine wheel chamber 26 and increasing the flow rate of exhaust gas blown to the rotor blades 22 of the turbine wheel 17. The flow rate of the exhaust gas varies depending on the gap between adjacent nozzle vanes 38 (or 39). If the gap is small, the flow velocity of exhaust becomes large, and if the gap is large, the flow velocity of exhaust becomes small. Then, by adjusting the flow velocity of the exhaust gas blown to the turbine wheel 17, the rotational speeds of the turbine wheel 17, the shaft 16 and the compressor wheel 18, and thus the supercharging pressure are adjusted.

  The turbocharger 11 is provided with an adjustment valve 41 that makes the passage area of the secondary passage 35 variable so as to adjust the flow rate of the exhaust gas guided from the nozzle 28 to the turbine wheel chamber 26. The adjustment valve 41 transmits the valve body 42 directly related to the opening and closing of the secondary passage 35, the actuator 43 such as an electric motor operated by energization, and the power of the actuator 43 to the valve body 42 to operate the valve body 42. And a transmission mechanism 44 composed of a link mechanism or the like.

  The adjustment valve 41 will be described in detail with a focus on the valve body 42. The secondary passage 35 has a first inner wall surface 45 and a second inner wall surface 46 facing each other at least in the vicinity of the exhaust introduction part 29. . Here, the second inner wall surface 46 is constituted by the wall surface of the partition wall 33.

  As shown in FIGS. 6-8, the said valve body 42 has a substantially fan-shaped cross-sectional shape, and the wide side is located in an exhaust upstream side, and a narrow side is located in an exhaust downstream side. Has been placed. The downstream end of the valve body 42 constitutes a support portion 47 that always contacts the first inner wall surface 45. The valve body 42 is rotatably supported on the first inner wall surface 45 by the shaft 48 in the support portion 47. The transmission mechanism 44 is connected to the shaft 48, transmits the power of the actuator 43 to the valve body 42 through the shaft 48, and rotates the valve body 42 with the shaft 48 as a fulcrum.

  A corner portion on the second inner wall surface 46 side that is the upstream end of the valve body 42 constitutes an action portion 49, and the second inner wall surface 46 is moved along with the rotation of the valve body 42 with the support portion 47 as a fulcrum. The secondary passage 35 is closed by contact (see FIG. 6), and is separated from the second inner wall surface 46 to open the secondary passage 35 (see FIGS. 7 and 8). The degree of opening, that is, the area of the passage between the action portion 49 and the second inner wall surface 46 increases as the action portion 49 moves away from the second inner wall surface 46 toward the first inner wall surface 45.

  An upstream end portion of the valve body 42 is a guide portion that guides exhaust from upstream between the action portion 49 and the second inner wall surface 46 when the valve body 42 opens at an intermediate opening as shown in FIG. 51 is constituted. The guide part 51 has a curved surface 52 that swells in an arc shape toward the exhaust upstream side. In the valve body 42 of the present embodiment having a substantially sector cross-sectional shape, the upstream end surface of the valve body 42 corresponds to the curved surface 52.

  Further, a portion facing the secondary passage 35 between the action portion 49 and the support portion 47 is constituted by a flat surface 53. In the valve body 42 of the present embodiment having a substantially sector cross-sectional shape, the side surface of the valve body 42 corresponds to the flat surface 53. Therefore, when the valve element 42 is opened at an intermediate opening (see FIG. 8), the above-described portion is formed so as to gradually approach the first inner wall surface 45 toward the exhaust downstream side.

  Further, the turbine housing 25 is provided with a valve housing portion 54 that protrudes outward from the secondary passage 35. The valve housing portion 54 is for housing the valve body 42 in a state where the valve body 42 is positioned outside the secondary passage 35 when the valve body 42 shown in FIG. 7 is fully opened. For this purpose, the valve accommodating portion 54 is formed with an accommodating space 55 having a shape substantially similar to the valve body 42, that is, a substantially fan-shaped cross-sectional shape.

  Incidentally, as shown in FIG. 3, various sensors are provided for detecting the operating state of the engine 12. As various sensors, for example, a crank angle sensor 61, an air flow meter 62, a throttle sensor 63, an accelerator sensor 64, and the like are used. The crank angle sensor 61 generates a pulse signal every time the crankshaft that is the output shaft of the engine 12 rotates by a certain angle. This signal is used to calculate a crank angle that is a rotation angle of the crankshaft, an engine rotation speed that is a rotation speed of the crankshaft per unit time, and the like. The air flow meter 62 detects the amount of air flowing through the intake passage 14 (intake air amount), and the throttle sensor 63 opens the throttle valve for adjusting the intake air amount provided in the intake passage 14 (throttle opening). The accelerator sensor 64 detects the amount of depression of the accelerator pedal by the driver. The intake air amount or parameters related thereto (for example, throttle opening, accelerator depression amount, etc.) are used for calculating the engine load.

  An electronic control unit 65 is provided to control the operation of the actuator 43 based on the detection signals of the various sensors 61 to 64. The electronic control unit 65 is configured with a microcomputer at the center, and a central processing unit (CPU) performs arithmetic processing according to a control program, initial data, control map, etc. stored in a read-only memory (ROM). Various controls are executed based on the calculation result. The calculation result by the CPU is temporarily stored in a random access memory (RAM).

  When controlling the actuator 43, the electronic control unit 65 determines the operating state of the engine 12 based on the detection signals of the various sensors 61 to 64, controls the energization of the actuator 43 based on the determination result, and controls the valve element 42. Operate.

  For example, when the electronic control unit 65 determines that the engine 12 is operating in a low load range where the exhaust flow rate is small, the electronic control unit 65 sets the action portion 49 of the valve body 42 through the energization control of the actuator 43 as shown in FIG. 2. Contact the inner wall surface 46. By this contact, the valve body 42 is positioned between the first inner wall surface 45 and the second inner wall surface 46, and the valve body 42 is closed. The passage area between the action part 49 and the second inner wall surface 46 becomes zero, and the flow of exhaust is blocked.

  Therefore, the exhaust does not flow through the secondary passage 35. The exhaust is not guided from the secondary nozzle 37 to the turbine wheel chamber 26 and is not blown between the shroud portions 24 of the adjacent moving blades 22. The exhaust passes through the primary passage 34 and is guided to the turbine wheel chamber 26 only from the primary nozzle 36. Exhaust gas flows from the leading edge portion 23 between the adjacent moving blades 22 to the outlet portion 32 of the turbine housing 25. As a result, it is possible to sufficiently circulate even with a small exhaust flow rate and increase the supercharging pressure.

When the valve is closed, a part of the valve body 42 remains in the valve housing portion 54 and the opening portion of the valve housing portion 54 is closed. Therefore, the phenomenon in which the exhaust enters the valve accommodating portion 54 is suppressed.
On the other hand, when the electronic control unit 65 determines that the engine 12 is operated in the middle load region and the high load region where the exhaust gas flow rate is larger than that in the low load region, as shown in FIG. 7 and FIG. 42 is rotated to the valve accommodating portion 54 side with the shaft 48 as a fulcrum in the support portion 47 at the downstream end thereof. With this rotation, the inclination of the valve body 42 changes, and when the action portion 49 formed by the upstream end corner portion of the valve body 42 is separated from the second inner wall surface 46, the valve body 42 opens with an intermediate opening. It becomes a state. The passage area between the action part 49 and the second inner wall surface 46 is enlarged, and the exhaust gas can be circulated. At this time, the valve body 42 is rotated more greatly as the engine load is larger. Along with this, the passage area between the action portion 49 and the second inner wall surface 46 is expanded in accordance with an increase in engine load. An amount of exhaust gas according to the passage area of the exhaust passage 13 adjusted as described above flows between the valve body 42 and the second inner wall surface 46.

  7, when the entire valve element 42 enters the accommodating space 55 of the valve accommodating portion 54 as shown in FIG. 7, the operating portion 49 is in the state farthest from the second inner wall surface 46 in the movable range. The valve 41 is fully opened. At this time, the flat surface 53 of the valve body 42 is located on substantially the same plane as the first inner wall surface 45. The valve body 42 does not enter the secondary passage 35. Therefore, the valve body 42 is unlikely to obstruct (resistance) the flow of exhaust gas, and the resistance when the exhaust gas passes through the regulating valve 41 is small. The passage area of the exhaust passage 13 between the valve body 42 and the second inner wall surface 46 is substantially the same at any location of the valve body 42.

  As shown in FIG. 8, when the valve element 42 is opened at an intermediate opening, the action portion 49 is slightly separated from the second inner wall surface 46 as described above, and the exhaust gas can be circulated. In addition, the valve body 42 has a substantially sector cross-sectional shape, and the upstream end surface of the valve body 42 is a curved surface 52 that swells in an arc shape upstream. Therefore, the upper end portion including the curved surface 52 of the valve body 42 functions as a guide portion. The exhaust from the upstream is smoothly guided to the downstream side along the curved surface 52 and collected between the action portion 49 and the second inner wall surface 46.

  Here, in the valve body 42, the support portion 47 at the downstream end is always in contact with the first inner wall surface 45 regardless of the opening degree of the valve body 42. In addition, the action portion 49 located on the upstream side of the support portion 47 is separated from the second inner wall surface 46 as the valve body 42 rotates. Further, the portion facing the secondary passage 35 between the action portion 49 and the support portion 47 is formed so as to gradually approach the first inner wall surface 45 toward the exhaust downstream side.

  From these facts, when the valve element 42 is opened at an intermediate opening, the distance between the valve element 42 and the second inner wall surface 46, and hence the passage area, becomes the smallest in the action part 49 and becomes closer to the support part 47. It gradually increases and becomes substantially the same as the passage area immediately downstream of the support portion 47.

  In particular, in the present embodiment, in the valve body 42, a portion (side surface of the valve body 42) facing the secondary passage 35 between the action portion 49 and the support portion 47 is configured by the flat surface 53. For this reason, when the valve element 42 is opened at an intermediate opening as described above, the passage area between the valve element 42 and the second inner wall surface 46 gradually increases with a certain degree as it approaches the support part 47 from the action part 49. To do.

  Therefore, unlike the variable capacity turbocharger 91 described in Patent Document 1, in this embodiment, the exhaust gas is between the valve body 42 and the second inner wall surface 46 with the action portion 49 slightly spaced from the second inner wall surface 46. When passing through, the passage area does not expand rapidly.

  As described above, the regulating valve 41 is opened when the engine 12 is operating at a medium load or a high load with a large exhaust flow rate. Therefore, part of the exhaust gas flowing through the scroll passage 27 passes through the primary passage 34 and is blown from the primary nozzle 36 to the leading edge portion 23 of the rotor blade 22. Further, the remaining exhaust gas flowing through the scroll passage 27 passes through the secondary passage 35, is led from the secondary nozzle 37 to the turbine wheel chamber 26, and is blown to the shroud portion 24 of the rotor blade 22 of the turbine wheel 17. Therefore, when the exhaust flow rate is large, the nozzle 28 is larger by the secondary nozzle 37 facing the shroud portion 24 of the moving blade 22 than when the flow rate is small. Even if the exhaust gas flow rate is large, the exhaust gas is appropriately guided to the turbine wheel chamber 26 and reaches the moving blade 22 of the turbine wheel 17 without wasting exhaust energy. The exhaust energy recovery efficiency is high, the turbine efficiency is improved, and the pressure (engine back pressure) of the exhaust introduction part 29 is reduced.

According to the embodiment described in detail above, the following effects can be obtained.
(1) As the valve body 42 of the regulating valve 41, a valve body having a support portion 47, an action portion 49, and a guide portion 51 is used. A support portion 47 is provided at the downstream end of the valve body 42 and is always in contact with the first inner wall surface 45, and the valve body 42 is operated with the support portion 47 as a fulcrum. Further, the action portion 49 is provided on the upstream side of the support portion 47, and the action portion 49 is brought into contact with or separated from the second inner wall surface 46 with the operation of the valve body 42 with the support portion 47 as a fulcrum. Is closed or opened. When the valve body 42 opens at an intermediate opening, the exhaust gas upstream of the valve body 42 is guided between the second inner wall surface 46 and the action portion 49 by the guide portion 51. Further, the portion facing the secondary passage 35 between the action portion 49 and the support portion 47 is formed so as to gradually approach the first inner wall surface 45 toward the exhaust downstream side when the valve body 42 opens at an intermediate opening. ing.

  Therefore, the passage area rapidly increases in the process of exhaust gas passing between the valve body 42 and the second inner wall surface 46, and the pressure of the exhaust gas is reduced, exhaust gas energy loss is generated, and the turbine efficiency is reduced. can do.

(2) A portion facing the secondary passage 35 between the action portion 49 and the support portion 47 is constituted by the flat surface 53.
Therefore, when the valve element 42 is opened at an intermediate opening, the passage area between the valve element 42 and the second inner wall surface 46 is gradually increased by a certain degree as the distance from the action part 49 to the support part 47 increases. ) Can be made more reliable.

  (3) The guide portion 51 has a curved surface 52 that swells in an arc shape toward the exhaust upstream side. Therefore, when the valve body 42 is opened at an intermediate opening, the exhaust gas can be smoothly collected between the action portion 49 and the second inner wall surface 46 along the curved surface 52.

  (4) The valve body 42 is configured to be rotatably supported on the first inner wall surface 45 by the shaft 48 in the support portion 47. Then, with the rotation of the valve body 42 using the support portion 47 as a fulcrum, the action portion 49 is brought into contact with or separated from the second inner wall surface 46. Therefore, the passage area between the valve body 42 and the second inner wall surface 46 can be adjusted with a simple configuration in which the valve body 42 is rotated with the support portion 47 as described above as a fulcrum.

  (5) As the valve body 42, a valve body having a substantially fan-shaped cross-sectional shape that becomes wider as it moves away from the support portion 47 to the exhaust upstream side is used. Therefore, while having such a simple cross-sectional shape, the downstream end of the valve body 42 functions as the support portion 47, and the corner portion on the second inner wall surface 46 side at the upstream end functions as the action portion 49. These end surfaces can function as the guide portion 51. The valve body 42 having the support portion 47, the action portion 49, and the guide portion 51 can be established without using a large number of parts or having a complicated shape.

  (6) A valve accommodating portion 54 is provided in the secondary passage 35. Therefore, when the valve element 42 is fully opened, the valve element 42 can be positioned outside the scroll passage 27 by accommodating the valve element 42 in the accommodating space 55 of the valve accommodating portion 54. Therefore, it is possible to suppress the valve body 42 from obstructing (resistance) the flow of exhaust gas, and to reduce the resistance when the exhaust gas passes between the valve body 42 and the second inner wall surface 46.

  (7) The part including at least the nozzle 28 in the scroll passage 27 is divided into two passages (primary passage 34 and secondary passage 35) by the partition wall 33, and the valve body 42 is provided only in one of the passages (secondary passage 35). Yes.

Therefore, the flow rate of the exhaust gas guided from the nozzle 28 to the turbine wheel chamber 26 can be adjusted by changing the opening degree of the valve body 42.
(8) One nozzle partitioned by the partition wall 33 is a primary nozzle 36 that faces the leading edge portion 23 of the rotor blade 22 of the turbine wheel 17, and the other nozzle is a secondary that faces the shroud portion 24 of the rotor blade 22. The nozzle 37 is used. And the valve body 42 is provided in the secondary channel | path 35 side which has the secondary nozzle 37, and the opening degree is adjusted according to the driving | running state of the engine 12. FIG.

  Therefore, the flow rate of the exhaust gas to the turbine wheel chamber 26 can be adjusted to an amount suitable for the operation state by opening and closing the adjustment valve 41 according to the operation state of the engine 12.

(9) A plurality of nozzle vanes 38 and 39 are arranged in the primary nozzle 36 and the secondary nozzle 37, respectively, in the circumferential direction.
Therefore, the exhaust from the primary nozzle 36 and the secondary nozzle 37 toward the turbine wheel chamber 26 can be guided vigorously (at a higher flow rate) and directed by the nozzle vanes 38 and 39, and more exhaust energy can be extracted. Thus, the turbine efficiency can be further improved.

Note that the present invention can be embodied in another embodiment described below.
-As the valve body 42, you may use a different thing from the said embodiment. 9 to 13 show an example thereof. In these FIGS. 9-13, the same code | symbol is attached | subjected to the member, location, etc. similar to the said embodiment.

  FIG. 9 shows an example of a valve body 42 having a cross-sectional shape different from that of the above embodiment. Here, the cross-sectional shape is based on a substantially fan-shaped cross-sectional shape, but the portion 66 separated from the flat surface 53 and the curved surface 52 is removed, as indicated by a two-dot chain line in FIG. Thus, even if the cross-sectional shape is changed, the same operation and effect as the above-described embodiment can be obtained, and the weight of the valve body 42 can be reduced.

  10 and 11 show an example of the valve body 42 having a configuration different from that of the above embodiment. The valve body 42 includes a downstream lever member 67 and an upstream lever member 68. The downstream end of the downstream lever member 67 constitutes a support portion 47, and the downstream lever member 67 is rotatably supported on the first inner wall surface 45 by the shaft 48. The upstream lever member 68 is a member that functions as the guide portion 51, and is connected to the upstream end of the downstream lever member 67 by a pin 69 at the lower end thereof. The connecting portion of the downstream lever member 67 and the upstream lever member 68 constitutes a working portion 49, and the upstream end 71 of the upstream lever member 68 is located on the exhaust upstream side or the exhaust downstream side as indicated by an arrow in FIG. The second inner wall surface 46 is contacted or separated by being moved to the side.

  If the valve body 42 having the above configuration is used, when the upstream end 71 of the upstream lever member 68 is moved to the exhaust upstream side or the exhaust downstream side, the movement is transmitted to the downstream lever member 67. Here, the downstream lever member 67 is rotatably supported on the first inner wall surface 45 by the shaft 48 at the support portion 47 at the downstream end thereof. Further, the upstream end of the downstream lever member 67 is connected to the downstream end of the upstream lever member 68 by a pin 69. Therefore, when the movement of the upstream lever member 68 is transmitted to the downstream lever member 67 as described above, the downstream lever member 67 rotates about the shaft 48 as a fulcrum. Along with this, the inclination of the downstream lever member 67 changes, and the action portion 49 constituted by the connecting portion with the upstream lever member 68 contacts or separates from the second inner wall surface 46. If the action part 49 contacts the 2nd inner wall surface 46, the passage area between them will become zero, and the distribution | circulation of exhaust_gas | exhaustion will be interrupted | blocked.

  On the other hand, as shown in FIG. 10, when the action part 49 is slightly separated from the second inner wall surface 46, the passage area between them is enlarged and the exhaust gas can be circulated. The passage area between the action portion 49 and the second inner wall surface 46 is such that the upstream end 71 of the upstream lever member 68 is greatly moved to the exhaust upstream side, so that the action portion 49 moves from the second inner wall surface 46 to the first inner wall surface 45 side. It gets bigger as you move away. In this way, the passage area between the downstream lever member 67 and the second inner wall surface 46 is adjusted by the cooperation of the upstream lever member 68 and the downstream lever member 67. As shown in FIG. 11, when the action portion 49 is farthest from the second inner wall surface 46 in the movable range, the valve body 42 is fully opened.

  By the way, as shown in FIG. 10, when the valve element 42 is opened at an intermediate opening, the upstream lever member 68 functions as the guide portion 51, and guides exhaust between the second inner wall surface 46 and the action portion 49. Further, the downstream lever member 67 functions as a portion facing the secondary passage 35 between the action portion 49 and the support portion 47.

  Therefore, even when the valve body 42 having a different configuration as described above is used, the same operation and effect as in the above embodiment can be obtained. In this case, the valve accommodating portion 54 in the embodiment is not necessary.

  12 and 13 show an example of the valve body 42 having a configuration different from that of the embodiment. The valve body 42 is constituted by a single plate-like member made of a material having high heat resistance and flexibility. The valve body 42 is rotatably supported on the first inner wall surface 45 by a shaft 73 at the upstream end 72 thereof. Further, the downstream end of the valve body 42 constitutes a support portion 47 and is in contact with the first inner wall surface 45 so as to be slidable in the exhaust flow direction (vertical direction in FIGS. 12 and 13). Further, an intermediate portion 74 between the upstream end 72 of the valve body 42 and the support portion 47 is bent and formed in a mountain shape so as to be separated from the first inner wall surface 45. The action portion 49 is configured by the bent end in the intermediate portion 74. The action portion 49 contacts or separates from the second inner wall surface 46 by elastically deforming the valve body 42 as the valve body 42 rotates with the shaft 73 as a fulcrum.

  If the valve body 42 having the above-described configuration is used, the valve body 42 always contacts the first inner wall surface 45 at the upstream end 72 and the support portion 47. Further, the intermediate portion 74 of the valve body 42 is bent in a mountain shape so as to be separated from the first inner wall surface 45. When the action part 49 constituted by the bent end of the valve body 42 contacts the second inner wall surface 46, the passage area between them becomes zero, and the flow of exhaust is blocked.

  As shown in FIG. 12, when the valve body 42 is rotated counterclockwise around the shaft 73 at the upstream end 72 from the above state, the rotation is transmitted to the entire valve body 42. Here, the support portion 47 at the downstream end of the valve body 42 is slidably brought into contact with the first inner wall surface 45. Therefore, when the valve body 42 is rotated as described above, the support portion 47 slides along the first inner wall surface 45 toward the exhaust downstream side, whereby the valve body 42 is elastically deformed. Accordingly, the action part 49 of the valve body 42 is separated from the second inner wall surface 46. The passage area between the action part 49 and the second inner wall surface 46 is enlarged, and the exhaust gas can be circulated. The passage area between the action portion 49 and the second inner wall surface 46 increases as the action portion 49 moves away from the second inner wall surface 46 toward the first inner wall surface 45, that is, as the opening of the valve element 42 increases. Thus, the passage area between the valve body 42 and the second inner wall surface 46 is adjusted by the rotation of the valve body 42 with the shaft 73 as a fulcrum and the elastic deformation of the valve body 42 accompanying the rotation. . And as shown in FIG. 13, when the action part 49 is furthest away from the 2nd inner wall surface 46 in a movable range, the valve body 42 will be in a fully open shape.

When the valve body 42 is rotated clockwise from the state of FIG. 13 with the shaft 73 as a fulcrum, the valve body 42 tends to return to its original shape by its elastic restoring force.
By the way, as shown in FIG. 12, when the valve body 42 is opened at an intermediate opening, a portion of the intermediate portion 74 upstream of the action portion 49 functions as the guide portion 51, and the exhaust is discharged to the second inner wall surface 46. And between the working parts 49. In addition, a portion of the intermediate portion 74 that is on the exhaust downstream side of the action portion 49 functions as a portion that faces the secondary passage 35 between the action portion 49 and the support portion 47.

  Therefore, even when the valve body 42 having a different configuration as described above is used, the same operation and effect as in the above embodiment can be obtained. In this case also, the valve accommodating portion 54 in the above embodiment is not necessary.

In the valve body 42, a portion facing the secondary passage 35 between the action portion 49 and the support portion 47 may be configured by a convex or concave curved surface instead of the flat surface 53.
-The partition wall 33 should just partition at least the nozzle 28 in the scroll channel | path 27 into two nozzles (primary nozzle, secondary nozzle 37). Therefore, it does not have to be provided over substantially the entire scroll passage 27 from the substantially upstream end to the downstream end of the scroll passage 27 as in the above embodiment.

In the above-described embodiment, the moving blade 22 having the reaction type shape is employed, but instead, the moving blade 22 having a so-called impact shape may be employed.
-You may control the action | operation of the adjustment valve 41 based on the engine operating state different from the said embodiment. Such an engine operating state may be each of the pressure in the exhaust passage 13, the engine speed, the intake air amount, the throttle opening degree, and the accelerator depression amount, or may be appropriately combined. For example, the adjustment valve 41 is closed in a region where the engine rotation speed is lower than a predetermined value (low rotation range), and the adjustment valve 41 is set in a region where the engine rotation speed is higher than the predetermined value (medium / high rotation range). The valve may be opened at an opening corresponding to the engine speed.

  In place of the actuator 43, the outlet pressure (supercharging pressure) of the compressor may be used for driving the valve body 42. In this case, for example, the valve body 42 may be closed when the outlet pressure is equal to or lower than a predetermined value, and the valve body 42 may be opened when the outlet pressure is higher than the predetermined value. When the valve is opened, the opening degree of the valve body 42 may be changed according to the outlet pressure.

  The nozzle vanes 38 and 39 may be provided only on the primary nozzle 36 or only on the secondary nozzle 37. Further, both the nozzle vane 38 of the primary nozzle 36 and the nozzle vane 39 of the secondary nozzle 37 may be omitted.

  Instead of the above-described fixed type as the nozzle vanes 38 and 39, movable nozzle vanes may be used, and the angles of these nozzle vanes may be controlled according to the operating state of the engine 12.

  The present invention is a variable capacity turbocharger of the type described in the background art, that is, the scroll passage is divided into an inner scroll portion and an outer scroll portion by a partition, and an adjustment valve is provided at the exhaust inlet of the outer scroll portion. It is also applicable to types. In short, the present invention can be widely applied to any variable-capacity turbocharger provided with a regulating valve that makes the exhaust passage area variable in the scroll passage.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic which shows the variable capacity | capacitance turbocharger in one Embodiment which actualized this invention, and its application location. The front view of a turbine hall. Sectional drawing which shows the structure by the side of the turbine of a variable capacity | capacitance turbocharger. FIG. 4 is a cross-sectional view of the turbine side cut along a cutting plane that is approximately 90 ° different from the cutting plane of FIG. 3. The side view which shows the arrangement | positioning state of a nozzle vane. Sectional drawing which expands and shows the A section in FIG. Sectional drawing of the A section when a valve body rotates from the state of FIG. 6 to a full open state. Sectional drawing of the A section when a valve body rotates a little from the state of FIG. Sectional drawing which expands and shows a valve body and its peripheral part corresponding to the A section of FIG. 8 about another embodiment of a valve body. Sectional drawing which expands and shows a valve body and its peripheral part corresponding to the A section of FIG. 8 about another embodiment of a valve body. Sectional drawing of the A section when a valve body act | operates from the state of FIG. Sectional drawing which expands and shows a valve body and its peripheral part corresponding to the A section of FIG. 8 about another embodiment of a valve body. Sectional drawing of the A section when a valve body act | operates from the state of FIG. Sectional drawing which shows the variable capacity | capacitance turbocharger which concerns on background art.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 11 ... Variable capacity turbocharger, 12 ... Engine, 17 ... Turbine wheel, 22 ... Moving blade, 23 ... Leading edge part, 24 ... Shroud part, 26 ... Turbine wheel room, 27 ... Scroll passage, 28 ... Nozzle, 33 ... Partition 34 ... Primary passage, 35 ... Secondary passage, 36 ... Primary nozzle, 37 ... Secondary nozzle, 38, 39 ... Nozzle vane, 41 ... Adjustment valve, 42 ... Valve element, 45 ... First inner wall surface, 46 ... Second inner wall surface , 47 ... support part, 48, 73 ... shaft, 49 ... action part, 51 ... guide part, 52 ... curved surface, 53 ... flat surface, 54 ... valve housing part, 67 ... downstream lever member, 68 ... upstream lever member, 71, 72 ... upstream end, 74 ... intermediate portion.

Claims (11)

In a variable capacity turbocharger provided with a regulating valve that makes the passage area of the scroll passage variable in a scroll passage provided around the turbine wheel chamber,
The scroll passage has a first inner wall surface and a second inner wall surface facing each other,
The valve body of the regulating valve is provided at a downstream end thereof and is always provided in contact with the first inner wall surface, and is provided on the exhaust upstream side of the support portion, and the valve body using the support portion as a fulcrum. With the operation, the working portion that contacts the second inner wall surface to close the scroll passage and is spaced apart from the second inner wall surface to open the scroll passage, and the valve body at an intermediate opening degree. A guide portion that guides exhaust gas from upstream when the valve is opened between the second inner wall surface and the action portion;
Further, the portion facing the scroll passage between the action portion and the support portion is formed so that the exhaust gas downstream side gradually approaches the first inner wall surface when the valve body is opened at an intermediate opening. A variable capacity turbocharger characterized in that The variable capacity turbocharger according to claim 1, wherein a portion facing the scroll passage between the action portion and the support portion is configured by a plane. The variable capacity turbocharger according to claim 1, wherein the guide portion has a curved surface that swells in an arc shape toward the exhaust upstream side. The support portion is rotatably supported on the first inner wall surface by a shaft, and the action portion contacts or separates from the second inner wall surface with the rotation of the valve body with the support portion as a fulcrum. The variable capacity turbocharger according to any one of claims 1 to 3. 5. The variable capacity turbocharger according to claim 4, wherein the valve body has a substantially fan-shaped cross-sectional shape that increases in width as it moves away from the support portion toward the exhaust upstream side. The variable capacity turbocharger according to claim 5, wherein the adjustment valve further includes a valve housing portion that houses the valve body in a state where the valve body is positioned outside the scroll passage when the valve body is fully opened. The valve body includes a downstream lever member having the support portion at the downstream end, and an upstream lever member connected to the upstream end of the downstream lever member at the downstream end and functioning as the guide portion,
The support portion is rotatably supported on the first inner wall surface by a shaft,
The action portion is constituted by a connecting portion of the upstream lever member and the downstream lever member, and the upstream end of the upstream lever member is moved to the exhaust upstream side or the exhaust downstream side, thereby The variable capacity turbocharger according to claim 1, wherein the variable capacity turbocharger is in contact with or separated from a wall surface. In the valve body, an upstream end thereof is pivotally supported by the first inner wall surface by a shaft, and a downstream end is slidably contacted with the first inner wall surface as the support portion, and an intermediate portion is It is bent and formed in a mountain shape so as to be separated from the first inner wall surface,
4. The valve body according to any one of claims 1 to 3, wherein the bent body functions as the action portion and comes into contact with or separates from the second inner wall surface by elastic deformation of the valve body with rotation about the shaft. The variable capacity turbocharger as described in one. A boundary portion of the scroll passage with the turbine wheel chamber constitutes a nozzle that guides exhaust to the turbine wheel chamber, and at least a portion including the nozzle in the scroll passage is divided into two passages by a partition wall. The variable capacity turbocharger according to claim 1, wherein the valve body is provided only in one of the passages. One nozzle partitioned by the partition wall constitutes a primary nozzle that faces the leading edge portion of the moving blade of the turbine wheel, and the other nozzle constitutes a secondary nozzle that faces the shroud portion of the moving blade,
The variable capacity turbocharger according to claim 9, wherein the valve body is provided on a side of the passage having the secondary nozzle, and the opening degree is adjusted according to an operating state of the engine. The variable capacity turbocharger according to claim 10, wherein a plurality of nozzle vanes are arranged in a circumferential direction on at least one of the primary nozzle and the secondary nozzle.

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