JP2009180110A - Turbocharger with variable nozzle mechanism - Google Patents

Abstract

A nozzle vane drive mechanism in a turbocharger with a variable nozzle mechanism is prevented from being damaged by frozen condensed water.
A turbocharger 11 includes a turbine housing 12 including a turbine wheel 17, a compressor housing 13 including a compressor wheel 18, and a center housing 14 connecting the turbine housing 12 and the compressor housing 13. . A nozzle vane drive mechanism 37 is accommodated in the accommodating chamber 27 between the turbine housing 12 and the center housing 14. A water storage wall 39 is formed at the lower part of the connecting cylinder part 123 of the turbine housing 12 so as to protrude outward from the outer circumference of the connecting cylinder part 123. A water storage recess 391 is formed inside the water storage wall 39 so as to protrude outward from the inner periphery of the connecting cylinder portion 123.
[Selection] Figure 1

Description

  The present invention relates to a turbocharger with a variable nozzle mechanism in which a turbine wheel that rotates when an exhaust gas of an internal combustion engine is blown is housed in a turbo housing.

This type of turbocharger can control the gas flow rate by opening and closing a plurality of nozzle vanes arranged in the gas passage (see, for example, Patent Document 1). In the turbocharger disclosed in Patent Document 1, the variable capacity device (variable nozzle mechanism) includes a nozzle support ring (nozzle ring) and a nozzle vane drive mechanism, and the nozzle vane drive mechanism includes a rotatable unison ring, And a plurality of arms that rotate as the unison ring rotates. When the plurality of arms rotate with the rotation of the unison ring, the nozzle vane connected to each arm rotates. A ring-shaped support member (support ring) is interposed between the nozzle ring and the unison ring. The support ring is fixed to the nozzle ring, and the unison ring is pressed against the support ring by a ring-shaped pressing member fixed to the support ring.
JP 2006-125588 A

  In the turbocharger with a variable nozzle mechanism disclosed in Patent Document 1, the exhaust gas enters the drive mechanism installation chamber that houses the nozzle vane drive mechanism. For this reason, immediately after the engine is started, moisture contained in the exhaust gas is condensed and collected at the bottom of the drive mechanism installation chamber. If the engine is not stopped immediately after starting the engine, the water accumulated at the bottom of the drive mechanism installation chamber will evaporate due to the high temperature of the exhaust gas. Is stopped, water accumulated at the bottom of the drive mechanism installation chamber is frozen. Then, the nozzle vane drive mechanism cannot move due to freezing of water, and when the engine is started in this state, the nozzle vane drive mechanism is damaged.

  An object of the present invention is to prevent a nozzle vane drive mechanism in a turbocharger with a variable nozzle mechanism from being damaged by frozen condensed water.

  According to the present invention, a turbine wheel that rotates when exhaust gas of an internal combustion engine is blown is housed in a turbo housing, and a nozzle ring that forms a gas passage that guides the exhaust gas to the turbine wheel, and the nozzle ring There is provided a variable nozzle mechanism including a nozzle vane that is supported to change the flow passage area of the gas passage and a nozzle vane drive mechanism for driving the nozzle vane, and the nozzle vane drive mechanism is provided in the turbo housing. In the first aspect of the present invention, a water storage recess connected to the bottom of the storage chamber is provided in the turbo housing.

The water storage recess stores water condensed in the storage chamber. Therefore, the nozzle vane drive mechanism is not damaged by the frozen water.
In a preferred example, the nozzle vane driving mechanism includes an arm connected to the nozzle vane and a unison ring that is detachably engaged with the arm, and the water storage recess is below the lowermost portion of the unison ring. is there.

  A water storage recess below the bottom of the unison ring stores water condensed in the containment chamber. Therefore, the nozzle vane drive mechanism is not damaged by the frozen water.

  The present invention has an excellent effect that a nozzle vane drive mechanism in a turbocharger with a variable nozzle mechanism is not damaged by frozen water.

Hereinafter, a first embodiment of the present invention will be described with reference to FIGS.
As shown in FIG. 1, a turbocharger 11 includes a turbine housing 12 disposed in an exhaust passage (not shown) of an internal combustion engine (not shown) and a compressor provided in an intake passage (not shown) of the internal combustion engine. A housing 13 and a center housing 14 for connecting the turbine housing 12 and the compressor housing 13 are provided. A connecting cylinder portion 123 is formed in the turbine housing 12, and a flange wall 143 is formed in the center housing 14. A flange wall 143 is joined to the connecting cylinder part 123, and the flange wall 143 is connected to the connecting cylinder part 123 by tightening the screw 10 screwed into the connecting cylinder part 123. As a result, the turbine housing 12 is coupled to the center housing 14.

A shaft hole 141 is provided in the center housing 14, and a rotor shaft 15 is rotatably disposed in the shaft hole 141 via a radial bearing 16.
A turbine wheel 17 is disposed in the turbine housing 12, and a compressor wheel 18 is disposed in the compressor housing 13. The turbine wheel 17 and the compressor wheel 18 are connected by a rotor shaft 15, and the turbine wheel 17, the rotor shaft 15, and the compressor wheel 18 can rotate integrally around a rotation axis 151.

  The turbine housing 12 is attached to one end of the center housing 14 so as to surround the outer periphery of the turbine wheel 17. The turbine housing 12 and the center housing 14 constitute a turbo housing that houses the turbine wheel 17.

  A spiral scroll passage 121 is provided in the turbine housing 12. The scroll passage 121 communicates with an exhaust passage of the internal combustion engine, and exhaust gas discharged from the combustion chamber to the exhaust passage is sent into the scroll passage 121. A ring-shaped passage forming flange 124 is integrally formed on the inner peripheral surface of the connecting cylinder portion 123. The passage forming flange 124 is a wall that forms the scroll passage 121.

  A nozzle ring 19 is provided in the turbine housing 12. The nozzle ring 19 is fitted into the ring of the ring-shaped passage forming flange 124. The nozzle ring 19 and the passage forming portion 126 of the turbine housing 12 are connected by a plurality of connecting screws 24 (three in this embodiment as shown in FIGS. 3 and 4). An annular swirl passage 122 is formed between the first and second fans 126. The exhaust gas in the scroll passage 121 is blown toward the turbine wheel 17 through the turning passage 122. The scroll passage 121 and the turning passage 122 constitute a gas passage 120 that guides exhaust gas to the turbine wheel 17. The nozzle ring 19 is a wall that forms a gas passage 120 that guides exhaust gas to the turbine wheel 17.

  Exhaust gas blown toward the turbine wheel 17 through the turning passage 122 is discharged from the outflow passage 125 in the turbine housing 12 to the atmosphere via an exhaust passage (not shown).

  A plurality of nozzle vanes 21 are disposed in the middle of the turning passage 122. The nozzle vane 21 is rotatably supported by the nozzle ring 19 via the support shaft 22. The nozzle vane 21 can change the flow path cross-sectional area between the adjacent nozzle vanes 21.

  The compressor housing 13 is attached to the other end of the center housing 14 so as to surround the outer periphery of the compressor wheel 18. The compressor housing 13 is provided with an inflow passage 131 that opens to the outside in the direction of the rotation axis 151. A spiral compressor passage 132 and an annular delivery passage 133 are provided in the compressor housing 13. The compressor passage 132 communicates with the combustion chamber of the internal combustion engine via the intake passage, and the delivery passage 133 is provided along the compressor passage 132. The delivery passage 133 is formed between a passage forming wall 134 that is a part of the compressor housing 13 and an end wall 142 that is a part of the center housing 14.

  The turbine wheel 17 includes a shaft portion 171 that increases in diameter from the turbine housing 12 side toward the compressor housing 13 side, and a plurality of blades 172 that are integrally formed on the peripheral surface of the shaft portion 171. Exhaust gas discharged from the combustion chamber of the internal combustion engine to the exhaust passage is blown to the blades 172 via the scroll passage 121 and the turning passage 122. Thereby, the turbine wheel 17 is rotated.

  The compressor wheel 18 includes a shaft portion 181 whose diameter increases from the compressor housing 13 side toward the turbine housing 12 side, and a plurality of blades 182 integrally formed on the peripheral surface of the shaft portion 181. The compressor wheel 18 rotates integrally with the rotation of the turbine wheel 17, and the rotating blades 182 introduce air (gas) in the intake passage into the inflow passage 131, and at the same time, the discharge passage 133 by centrifugal action. To release. The air released into the delivery passage 133 is supercharged into the combustion chamber via the scroll passage 121.

  As shown in FIG. 4, an arm 26 is fixed to a support shaft 22 that is rotatable with respect to the nozzle ring 19, and a unison ring 25 is engaged with the arm 26 so as not to be detached. As shown in FIG. 1, the unison ring 25 and the arm 26 are accommodated in an accommodation chamber 27 between the flange wall 143 of the center housing 14 and the turbine housing 12. The unison ring 25 can be rotated around the rotation axis 151. When the unison ring 25 rotates about the rotation axis 151, the arm 26 rotates about the support shaft 22, and all the nozzle vanes 21 rotate about the support shaft 22 in the same direction.

  The nozzle vane 21 indicated by the solid line in FIG. 3 is at the maximum open position where the flow path cross-sectional area between the adjacent nozzle vanes 21 is maximized, and the nozzle vane 21 indicated by the chain line indicates that the flow cross-sectional area between the adjacent nozzle vanes 21 is zero. In the closed position.

  As shown in FIGS. 1 and 2, a holding ring 29 is fixed to the nozzle ring 19 by a plurality of connecting screws 24 in the accommodation chamber 27. As shown in FIG. 4, a plurality of pressing protrusions 291 are integrally formed on the pressing ring 29. The pressing protrusion 291 presses the unison ring 25 against the passage forming flange 124 of the turbine housing 12, and the unison ring 25 can be pivoted from the passage forming flange 124 so as not to fall off.

The unison ring 25, the pressing ring 29 and the arm 26 in the storage chamber 27 constitute a nozzle vane drive mechanism 37 that is stored in the storage chamber 27.
As shown in FIG. 1, a support shaft 34 is rotatably supported on the flange wall 143 of the center housing 14, and a drive arm 35 is fixed to one end of the support shaft 34 in the accommodation chamber 27. . The drive arm 35 is engaged with the unison ring 25, and when the drive arm 35 rotates about the support shaft 34, the unison ring 25 rotates.

  A drive lever 36 is fixed to the other end of the support shaft 34 outside the center housing 14. The drive lever 36 is rotated around the support shaft 34 by the operation of an actuator (not shown). When the drive lever 36 is rotated, the drive arm 35 and the unison ring 25 are rotated.

  The drive lever 36, the support shaft 34, the drive arm 35, the nozzle vane drive mechanism 37, the nozzle ring 19, the support shaft 22, and the nozzle vane 21 constitute a variable nozzle mechanism 38 that can change the flow path cross-sectional area between adjacent nozzle vanes 21. .

  As shown in FIGS. 2 and 4, a water storage wall 39 is formed on the lower portion of the connecting cylinder portion 123 of the turbine housing 12 so as to protrude outward from the outer circumference of the connecting cylinder portion 123. A water storage recess 391 is formed inside the water storage wall 39 so as to protrude outward from the inner periphery of the connecting cylinder portion 123. The water storage recess 391 is below the lowermost part 251 of the unison ring 25 and continues to the bottom 270 of the storage chamber 27.

  As shown in FIG. 5, a closing wall 40 is formed on the lower part of the flange wall 143 of the center housing 14 so as to protrude outward from the outer periphery of the circumferential shape of the flange wall 143. The closing wall 40 and the water storage wall 39 overlap each other, and the water storage recess 391 is located between the turbine housing 12 and the center housing 14.

In the first embodiment, the following effects can be obtained.
(1) If the engine is stopped immediately after the engine is started, moisture in the exhaust gas in the turbocharger 11 is condensed. Since the exhaust gas also enters the storage chamber 27, the moisture in the exhaust gas is condensed in the storage chamber 27. The water condensed in the storage chamber 27 falls to the bottom 270 of the storage chamber 27 and is stored in the water storage recess 391. Therefore, even if the water in the water storage recess 391 freezes in a low temperature environment where the water freezes, the nozzle vane drive mechanism 37 is not damaged by the frozen water.

Next, a second embodiment of FIGS. 6 and 7 will be described. The same reference numerals are used for the same components as those in the first embodiment, and detailed description thereof is omitted.
As shown in FIG. 6A, a nozzle ring 19 and a ring-shaped shroud 31 are provided in the turbine housing 12 so as to face each other. The shroud 31 includes a plate-shaped passage forming portion 311 and a cylindrical portion 312. The nozzle ring 19 and the passage forming portion 311 of the shroud 31 are connected by a plurality of connecting pins 32 (three in this embodiment as shown in FIG. 7), and the nozzle ring 19 and the passage forming portion 311 of the shroud 31 are connected. An annular swirl passage 122 is formed between the two.

  A seal ring 33 is interposed between the outer peripheral surface of the cylindrical portion 312 of the shroud 31 and the turbine housing 12. The seal ring 33 prevents the exhaust gas from leaking from the scroll passage 121 to the outflow passage 125 via the gap K between the shroud 31 and the turbine housing 12.

  The nozzle vane 21 disposed in the middle of the turning passage 122 is rotatably supported by the nozzle ring 19 via the support shaft 22 and is rotatably supported by the shroud 31 via the support shaft 23. . The nozzle vane 21 can change the flow path cross-sectional area between the adjacent nozzle vanes 21.

  As shown in FIG. 6B, the support ring 28 and the pressing ring 29 are fixed to the nozzle ring 19 in the housing chamber 27 by a plurality of connecting pins 32. The support ring 28 includes a flat joint 281 joined to the nozzle ring 19, a flat holding part 282 connected to the joint 281 through a step, a cylindrical part 283 connected to the outer periphery of the holding part 282, and a cylindrical part 283. And a flange portion 284 connected to the head. The flange portion 284 is sandwiched and supported between the flange wall 143 of the center housing 14 and the connecting cylinder portion 123 of the turbine housing 12. The cylindrical portion 283 surrounds the unison ring 25 so as to restrict movement in the radial direction. The cylindrical portion 283 is separated from the connecting cylinder portion 123 of the turbine housing 12, and the support ring 28 divides the storage chamber 27 into a drive chamber 271 and a drain chamber 272.

  As shown in FIG. 7, the pressing protrusion 291 formed integrally with the pressing ring 29 presses the unison ring 25 against the holding portion 282 of the support ring 28, and the unison ring 25 is separated from the support ring 28 by this pressing. It cannot be removed. The unison ring 25 is rotatable within the cylinder of the cylindrical portion 283 of the support ring 28.

  The nozzle ring 19, the shroud 31, the nozzle vane 21, the support shafts 22 and 23, the arm 26, the unison ring 25 and the pressing ring 29 shown in FIG. 6A are connected to the support ring 28. Only the support ring 28 of these members is directly connected to the turbine housing 12 and the center housing 14. That is, the nozzle ring 19, the shroud 31, the nozzle vane 21, the support shafts 22 and 23, the arm 26, the unison ring 25 and the pressing ring 29 are indirectly connected to the turbine housing 12 and the center housing 14 via the support ring 28. Yes.

  The unison ring 25, the holding ring 29 and the arm 26 in the storage chamber 27 constitute a nozzle vane drive mechanism 37 which is separated from the nozzle ring 19 by the support ring 28 and stored in the storage chamber 27.

  The drive lever 36, the support shaft 34, the drive arm 35, the nozzle vane drive mechanism 37, the nozzle ring 19, the shroud 31, the support shafts 22 and 23, and the nozzle vane 21 are variable nozzles that can change the flow path cross-sectional area between adjacent nozzle vanes 21. The mechanism 38A is configured.

A communication hole 30 is provided through the lowermost portion of the cylindrical portion 283 of the support ring 28. The water storage recess 391 communicates with the drive chamber 271 through the communication hole 30.
In the second embodiment, the following effects can be obtained.

  (2) The nozzle ring 19, the shroud 31, the nozzle vane 21, the support shafts 22 and 23, the arm 26, the unison ring 25 and the pressing ring 29 are supported by a support ring 28, and these members 19, 31, 21 and 22 are supported. , 23, 26, 25, 29 will not interfere with the turbine housing 12 even if they are thermally expanded after the engine is started. If these members 19, 31, 21, 22, 23, 26, 25, 29 are thermally expanded and interfere with the turbine housing 12, the variable nozzle mechanism 38 may be deformed and the nozzle vane 21 may not move properly. .

  The structure in which the nozzle ring 19, the shroud 31, the nozzle vane 21, the support shafts 22 and 23, the arm 26, the unison ring 25, and the pressing ring 29 are supported by the support ring 28 is a member 19, 31, 22, 22, 23, 26, 25. 29 to avoid interference with the turbine housing 12 due to thermal expansion.

  If the engine is stopped immediately after the engine is started, moisture in the exhaust gas in the turbocharger 11 employing the support ring 28 having the above-described advantages is condensed. Since the exhaust gas also enters the driving chamber 271, the moisture in the exhaust gas is condensed in the driving chamber 271. The water condensed in the drive chamber 271 falls to the bottom of the drive chamber 271, but if the water dropped on the bottom of the drive chamber 271 freezes at the bottom of the drive chamber 271, the nozzle vane drive mechanism 37 is frozen and the engine During startup, the nozzle vane drive mechanism 37 is damaged.

  In the present embodiment, the water dropped on the bottom of the drive chamber 271 is stored in the water storage wall 39 through the communication hole 30. Therefore, even in a low temperature environment where water freezes, the water that has dropped to the bottom of the drive chamber 271 is frozen in the water storage recess 391. As a result, the nozzle vane drive mechanism 37 is not damaged by the frozen water.

  (3) In the configuration in which the seal ring 33 is interposed between the outer peripheral surface of the shroud 31 and the turbine housing 12, the assembly including the members 19, 31, 22, 22, 23, 26, 25, 28, and 29 is a rotation axis. It is allowed to expand and contract by thermal expansion in the direction of 151. Therefore, even if the members 19, 31, 21, 22, 23, 26, 25, and 29 are thermally expanded after the engine is started, they do not interfere with the turbine housing 12.

In the present invention, the following embodiments are also possible.
In the first and second embodiments, the water storage recess 391 may be recessed in the center housing 14.

In the first and second embodiments, the water storage recess 391 may be formed in both the center housing 14 and the turbine housing 12.
The technical idea that can be grasped from the embodiment described above will be described below.

  [1] The variable nozzle mechanism includes a support ring connected to the nozzle ring, and the nozzle vane drive mechanism is separated from the nozzle ring by the support ring and is accommodated in the accommodation chamber. The turbocharger with a variable nozzle mechanism according to any one of claims 1 and 2, wherein a communication passage is provided through the lower portion of the support ring to reach the water storage recess.

  [2] The storage chamber is divided into a drive chamber and a drain chamber by the support ring, the nozzle vane drive mechanism is stored in the drive chamber, and the water storage recess opens into the drain chamber. The turbocharger with a variable nozzle mechanism according to the item [1], wherein the communication passage is provided through the support ring and communicates with the drainage chamber.

  [3] The variable nozzle mechanism includes a shroud connected to the nozzle ring, the nozzle vane supported between the nozzle ring and the shroud, and a unison ring for changing the opening degree of the nozzle vane. A variable transmission mechanism, and the support ring interposed between the unison ring and the nozzle ring, and the shroud includes a passage forming portion and a cylindrical portion, and an outer peripheral surface of the cylindrical portion. The turbocharger with a variable nozzle mechanism according to any one of [1] and [2], wherein a seal ring is interposed between the turbine housing and the turbine housing.

The side sectional view of the turbocharger which shows a 1st embodiment. FIG. AA sectional view taken on the line AA of FIG. FIG. 3 is a sectional view taken along line BB in FIG. 1. The CC sectional view taken on the line of FIG. A 2nd embodiment is shown and (a) is a fragmentary sectional side view. (B) is a partial expanded side sectional view. The DD sectional view taken on the line of Fig.6 (a).

Explanation of symbols

  11 ... Turbocharger. 12: Turbine housing constituting the turbo housing. 120: Gas passage. 14: Center housing constituting the turbo housing. 120: Gas passage. 17 ... Turbine wheel. 19 ... Nozzle ring. 21 ... Nozzle vane. 25 ... Unison ring. 251 ... Bottom. 26 ... arm. 27: Containment room. 270 ... Bottom. 391 ... Water storage recess. 37: Nozzle vane drive mechanism. 38, 38A ... Variable nozzle mechanism.

Claims (2)

A turbine wheel that rotates by blowing exhaust gas of an internal combustion engine is accommodated in a turbo housing, a nozzle ring that forms a gas passage that guides the exhaust gas to the turbine wheel, and a nozzle ring that is supported by the nozzle ring and There is provided a variable nozzle mechanism including a nozzle vane for changing a flow passage area of the gas passage and a nozzle vane driving mechanism for driving the nozzle vane, and the nozzle vane driving mechanism is provided in a storage chamber in the turbo housing. In the turbocharger with a variable nozzle mechanism that is housed,
A turbocharger with a variable nozzle mechanism, wherein a water storage recess connected to the bottom of the storage chamber is provided in the turbo housing.   The nozzle vane driving mechanism includes an arm connected to the nozzle vane and a unison ring engaged with the arm in a non-detachable manner, and the water storage recess is below a lowermost portion of the unison ring. Turbocharger with variable nozzle mechanism as described.

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