JP4885180B2 - Variable capacity exhaust gas turbine - Google Patents

Description

  The present invention is used in an exhaust turbocharger of a relatively small and medium-sized internal combustion engine, and a scroll portion in which a passage cross-sectional area of exhaust gas from an engine (internal combustion engine) gradually decreases between an exhaust inlet portion and a turbine rotor. The inner scroll portion and the outer scroll portion are provided by insert vanes arranged in a row in the circumferential direction of the lid member. The present invention relates to a variable capacity exhaust gas turbine that allows exhaust gas to flow through.

FIG. 4 is a cross-sectional view of a main part perpendicular to the rotational axis of the variable capacity exhaust gas turbine disclosed in Patent Document 1 (Japanese Patent No. 3958884). 5 is a cross-sectional view taken along line YY of FIG.
In such a variable capacity exhaust gas turbine, a turbine rotor 10 that is rotationally driven by exhaust gas is accommodated in a central portion of a turbine housing 01 (rotation axis 100a).
The turbine housing 01 has an exhaust inlet portion 20 and an exhaust outlet portion 20a, and has a scroll portion 12 between which the passage sectional area gradually decreases between the exhaust inlet portion 20 and the turbine rotor 10 on the inner periphery.

The scroll portion 12 is divided into two in the radial direction of the turbine rotor 10 to form an inner peripheral scroll portion 2 and an outer peripheral scroll portion 1.
The inner scroll portion 2 and the outer scroll portion 1 are divided through a plurality of insert vanes 6a arranged in the circumferential direction along the boundary wall 2a of the scroll portion 12, and each insert vane is divided. An exhaust passage 6b is formed between 6a.
As shown in FIG. 5, a plurality of insert vanes 6a project from the main body portion of the lid member 6 in the circumferential direction. The insert vanes 6a allow the inner peripheral scroll portion 2 and the outer peripheral scroll portion to be projected. 1 is separated.
Further, as shown in FIG. 5, the lid member 6 is a ring circle 8 on the outer edge of the lid member by using two bolts 29 for fastening the turbine housing 01 to the bearing housing 11 together with two heat shield plates 6c. The turbine housing 01 is tightened while being sandwiched between the support portions 1s.

At the inlet portion of the inner peripheral scroll portion 2, an exhaust gas is guided to the inlet portion, and a tongue portion 5 for smoothly flowing the exhaust gas flow into the inner peripheral scroll portion 2 is provided in the exhaust gas flow. Are formed along.
In addition, a control valve 4 is installed on the exhaust inlet side of the outer peripheral scroll portion 1, and the control valve 4 contacts and departs from the peripheral wall 4 a of the turbine housing 01, thereby exhausting the inner scroll portion 2. The gas flow rate and the exhaust gas flow rate to the outer scroll portion 1 are controlled.

That is, when the low rotation of the engine, the control valve 4 is closed the outer scroll part 1 by closing against the peripheral wall 4a, the exhaust gas flows only into the inner scroll part 2 side as U _2.
Also at the time of high rotation of the engine, the control valve 4 to open away from the peripheral wall 4a, the exhaust gas flows through the outer scroll part 1 as U _1, the inner scroll part via the exhaust passage 6b of the insert vanes 6a with flows 2, it flows like U ₂ also to the inner scroll part 2.
Therefore, the exhaust gas flow rate can be changed by the control valve 4 when the engine is rotating at low speed and when the engine is rotating at high speed.

Japanese Patent No. 3956884

However, in Patent Document 1 (Japanese Patent No. 3958884), as shown in FIG. 5, the lid member 6 and the heat shield plate 6 c are formed by integrating the turbine housing 01 with the bearing housing 11 and the two bolts 29. It is tightened together.
A plurality of the insert vanes 6a project from the body portion of the lid member 6 in the circumferential direction, and the inner scroll portion 2 and the outer scroll portion 1 are separated from each other by the configuration of the insert vanes 6a. is doing.

That is, in such a prior art, the lid member 6 and the heat shield plate 6c are separately configured and are integrally tightened by the bolts 29, so that the lid member 6 and the heat shield plate 6c are separated from each other. To increase.
Further, since the heat shield 6c is manufactured separately from the lid member 6, as shown in FIG. 5, the lid member 6 and the heat shield from the opening end surface 100b side of the turbine housing located on the exhaust outlet portion 20a side during assembly. Since it is difficult to assemble the plate 6c at the same time, it is necessary to assemble each of the two sheets, which requires a lot of assembly steps.
Further, since the heat shield plate 6c is a thin single plate and easily deforms, the plate tends to be deformed or falls when the temperature is high, and there is an accident that the heat shield plate 6c contacts the turbine rotor 10 due to the deformation. Can happen.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems of the prior art. The structure of the lid member and the heat shield plate is simplified to reduce the number of parts, the assembly of the lid member supporting the heat shield plate and the insert vane is facilitated, and It is an object of the present invention to provide a variable capacity exhaust gas turbine in which the deformation of the engine is reduced.

The present invention achieves such an object, and includes a shaft that is pivotally supported by a bearing housing, a turbine rotor that is fixed to one end of the shaft and is driven to rotate by exhaust gas, and the turbine rotor is housed in a central portion and exhausted. A turbine housing having an inlet portion and an exhaust outlet portion, and having a scroll portion in which a passage cross-sectional area gradually decreases between the exhaust inlet portion and the turbine rotor; and dividing the scroll portion in a radial direction of the turbine rotor. A flow of exhaust gas directly flowing into the inner peripheral scroll portion and the outer peripheral scroll portion by an insert vane provided in a plurality in the circumferential direction of the turbine rotor, the inner peripheral scroll portion and the outer peripheral scroll portion being formed. It is configured to control the flow of exhaust gas that flows into the inner scroll part.
Provided with a control valve that is disposed on the exhaust inlet side of the outer scroll portion and controls the exhaust gas flow rate to the inner scroll portion and the exhaust gas flow rate to the outer scroll portion, respectively.
In the variable capacity exhaust gas turbine in which a lid member defining the inner and outer peripheral scroll portions is disposed on the opening end face of the turbine housing, and the insert vane protrudes on the exhaust passage side of the lid member,
The lid member is integrally formed with a reduced diameter plate whose inner diameter side extends in the direction perpendicular to the shaft along the gap between the bearing housing and the turbine rotor, and the reduced diameter plate faces the turbine rotor. It is configured as a heat shield plate that cuts off heat flow, and the inner diameter side of the lid member and the reduced diameter plate are integrally formed via a ring circle protruding from the bearing housing side. And

  Further, in this invention, preferably, a reinforcing rib is formed radially on the lid member located on the outer peripheral side of the ring circle, while a reinforcing rib is formed on the reduced diameter plate side located on the inner peripheral side of the ring circle. do not do.

According to the present invention, the scroll portion of the turbine housing is divided into an inner scroll portion and an outer scroll portion, and a lid member that defines the inner and outer scroll portions is disposed on the opening end surface of the turbine housing, In the variable capacity exhaust gas turbine in which the insert vane protrudes on the exhaust passage side of the lid member,
The lid member is integrally formed with a reduced diameter plate whose inner diameter side extends in the direction orthogonal to the shaft along the gap between the bearing housing and the turbine rotor, and the reduced diameter plate is opposed to the turbine rotor. Because it is configured as a heat shield that blocks heat flow,
The inner and outer scroll portions are defined on the opening end face side of the turbine housing, the insert vane is protruded on the exhaust passage side, the inner rotor extends in the direction perpendicular to the shaft, and is connected to the turbine rotor. A plurality of insert vanes are formed by integrally forming a reduced-diameter plate configured as a heat-shielding plate that opposes and blocks the heat flow, and integrating the lid member and the reduced-diameter plate (heat-shielding plate). One component can have both the configuration of the lid member projecting from each and the configuration as a heat shield that blocks the heat flow. Therefore, the number of parts is reduced as compared with the conventional technique in which the lid member and the heat shield plate are separately clamped together with the bolts.

  Further, according to the above configuration, the lid member in which the insert vane protrudes on the exhaust passage side and the reduced-diameter plate configured as a heat shield that blocks the heat flow by facing the turbine rotor on the inner periphery are integrated. The integrated lid member and the reduced diameter plate (heat shield plate) are assembled from the opening end side of the turbine housing on the exhaust outlet side, and the integrated product of the lid member and the reduced diameter plate (heat shield plate) is assembled. It is easy to assemble, and it is not necessary to assemble the two pieces as in the conventional products shown in FIGS.

Further, according to the invention, between the inner diameter side and the condensation径板of said lid member by integrally formed via a ring circle protruding from the bearing housing side, the lid member via a ring circle since the inner diameter side of the condensed径板(heat shielding plate) is connected, the heat of condensation径板(heat shielding plate) becomes a high temperature, to relax with gentle circular portion of the ring circular, cover member side and By connecting to the circular step portion side on the bearing housing side, excessive deformation of the lid member in which the insert vane protrudes on the exhaust passage side is eliminated.

  Further, in this invention, reinforcing ribs are formed radially on the lid member positioned on the outer peripheral side of the ring circle, while reinforcing ribs are not formed on the reduced diameter plate side positioned on the inner peripheral side of the ring circle. By comprising, the radial reinforcement rib formed in the cover member located in the outer peripheral side of the said ring circle raises an intensity | strength, raises rigidity without raising the weight of a cover member, and prevents the deformation | transformation by a heat | fever. Further, the high-diameter reduced-diameter plate side located on the inner peripheral side of the ring circle does not form the reinforcing rib because the thickness suppressing effect of the reinforcing rib is low due to the plate thickness. Thereby, there is no thermal constraint and thermal deformation can be prevented.

  Hereinafter, the present invention will be described in detail with reference to the embodiments shown in the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the component parts described in this example are not intended to limit the scope of the present invention only to specific examples unless otherwise specified. Only.

FIG. 1 is a cross-sectional view taken along a turbine axis of a variable capacity exhaust gas turbine according to an embodiment of the present invention. 2A is a cross-sectional view of the lid member and the reduced diameter plate in the above embodiment, FIG. 2B is a view as viewed from the arrow A in FIG. 2A, and FIG. 2C is a view as viewed from the arrow B in FIG. is there. 3 is a cross-sectional view taken along the line CC of FIG.
In FIG. 1, in such a variable capacity exhaust gas turbine, a turbine rotor 10 that is rotationally driven by exhaust gas is disposed in a turbine housing 01 at the center of the turbine housing 01, and the turbine rotor 10 is connected to the turbine shaft 10a. , The compressor 10b housed in the compressor housing 13 is directly connected and driven (100a is the rotational axis).
The compressor housing 13 is connected to the turbine housing 01 via a bearing housing 11.

FIG. 3 shows a planar shape of the turbine housing 01. The turbine housing 01 has an exhaust inlet portion 20 and an exhaust outlet portion 20a (see FIG. 1). As shown in FIG. Between the turbine rotor 10 and the inner peripheral turbine rotor 10 is provided with a scroll portion 12 whose passage sectional area gradually decreases.
The scroll portion 12 is formed by dividing the scroll portion 12 into an inner scroll portion 2 and an outer scroll portion 1 in the radial direction of the turbine rotor 10. A control valve, which will be described later, is denoted by reference numeral 4, and a tongue is denoted by reference numeral 5.

  The above basic configuration is the same as that of the prior art shown in FIGS. The present invention relates to an improvement of the insert member 60 composed of the lid member 6 and the reduced diameter plate 62.

That is, in FIG. 1, the turbine housing 01 is provided with an integrated insert member 60 composed of the lid member 6 and the reduced diameter plate 62 so as to be covered from the opening end face 100b side.
In this embodiment, the insert member 60 comprising the lid member 6 and the reduced diameter plate 62 is formed by precision casting.

As shown in FIG. 2, the lid member 6 of the insert member 60 divides and forms the inner scroll portion 2 and the outer scroll portion 1, and the space between the inner scroll portion 2 and the outer scroll portion 1 is A boundary wall 2a of the scroll portion 12 shown in FIG. 3 is provided, and a plurality of insert vanes 6a described later are provided along the boundary wall 2a.
That is, as shown in FIG. 2, the lid member 6 has a plurality of insert vanes 6a integrally projecting in the axial direction on the exhaust side so as to control the flow of exhaust gas. Yes. And between each insert vane 6a, the exhaust passage 6b is formed along the circumferential direction of this insert vane 6a.

Further, on the inner diameter side of the lid member 6 of the insert member 60, a reduced diameter plate 62 extending in the direction perpendicular to the turbine shaft 10 a along the gap between the bearing housing 11 and the turbine rotor 10 is provided on the lid member 6. And is formed integrally.
The reduced diameter plate 62 is used as a heat shield plate that opposes the back side 10 s of the turbine rotor 10 and blocks the heat flow from the rear surface of the turbine rotor 10.
As described above, the lid member 6 provided with the plurality of insert vanes 6a and the reduced diameter plate 62 extending in the direction perpendicular to the turbine shaft 10a are integrally formed.

As described above, the insert member 60 including the lid member 6 and the reduced-diameter plate 62, which are formed by precision casting, has an inner peripheral side of the ring circle 7 of the lid member 6 as shown in FIG. (Diameter D ₁ ) is cut to fit and support the inner periphery of the ring circle 7 and the circular step portion 11a on the bearing housing 11 side.
That is, as shown in FIG. 2A, the cover member 6 is connected to the reduced diameter plate 62 in the inner ring circle 7. 2, an inner diameter D ₁ becomes ring yen 7, the ring yen 7, circular stepped portion formed in the bearing housing 11 so as to be fitted to the convex portion 7a and the convex portion 7a formed on the lid member 6 11a (see FIG. 1) is fitted. The ring member 7 supports the lid member 6 and the reduced diameter plate 62 on the bearing housing 11.

  As shown in FIG. 1, the lid member 6 is connected to the turbine housing 01 between the turbine housing 01 and the bearing housing 11 by bolts 29 that fasten the turbine housing 01 and the bearing housing 11. It is clamped between the bearing housings 11 via a stop pin 30.

As described above, in this embodiment, the cover member 6 in which the insert vane 6a protrudes on the exhaust passage side, and the reduced diameter configured as a heat shield plate that opposes the turbine rotor 10 on the inner periphery and blocks the heat flow. Since the plate 62 is integrally formed as the insert member 60, as shown in FIG. 1, the insert member 60 composed of the integral lid member 6 and the reduced diameter plate (heat shield plate) 62 is connected to the exhaust outlet 20a as shown in FIG. Such an integrated product can be easily assembled from the open end face 100b side of the turbine housing 01 on the side, and there is no need to assemble each two pieces as in the conventional product shown in FIGS. .
Moreover, the structure of the lid member 6 projecting from each of the plurality of insert vanes 6a and the structure as the heat shield plate 62 for blocking the heat flow can be combined with one part, and therefore, as in the prior art, The number of parts can be reduced as compared with the case in which the lid member 6 and the heat shield plate 62 are separated and tightened integrally with a bolt.

  In this embodiment, the inner diameter side of the lid member 6 and the reduced diameter plate 62 are integrally formed via a ring circle 7 protruding from the bearing housing 11 side. 7, the inner diameter side of the lid member 6 and the reduced-diameter plate (heat shield plate) 62 are connected to each other. The diameter of the lid member 6 is reduced by the circular coupling portion and connected to the circular step portion 11a side on the lid member 6 side and the bearing housing 11 side, and the insert vane 6a is projected from the exhaust passage side. Unnecessary deformation by the plate (heat shield plate) 62 side is eliminated.

In this embodiment, the ring circle 7 is supported so as to be fitted to the circular step portion 11a on the bearing housing 11 side.
With this configuration, the thermal expansion of the reduced diameter plate (heat shield plate) 62 is caused to flow through the ring circle 7 to the circular step portion 11a on the bearing housing 11 side, so that the deformation of the ring circle 7 can be alleviated, and the ring circle 7 is securely fitted to the circular step portion 11a on the bearing housing 11 side, so that the integrated member of the lid member 6 and the reduced diameter plate (heat shield plate) 62 can be securely fixed.

Further, as shown in FIG. 2 (C), the lid member 6 positioned on the outer peripheral side of the ring circle 7 is formed with a plurality of reinforcing ribs 7c radially, while being positioned on the inner peripheral side of the ring circle 7. On the reduced diameter plate 62 side, the reinforcing rib 7c is not formed and a flat structure is adopted.
In this way, the reinforcing ribs 7c are radially formed on the outer lid member 6 to increase the strength, and the reinforcing ribs 7c are not formed on the high temperature reduced diameter plate 62 side located on the inner peripheral side. By having a uniform thickness (flat structure), there is no thermal constraint and thermal deformation can be prevented. In FIGS. 2B and 2C, reference numeral 5 denotes a tongue, and 100a denotes a rotation axis (see FIG. 4).

The lid member 6 can also be manufactured by separately manufacturing the plurality of insert vanes 6a separately, and fixing the insert vane 6a to the surface of the lid member 6 by brazing or the like. is there.
In this way, if the insert vane 6a and the lid member 6 are made separate and fixed by brazing or the like, only the insert vane whose temperature rises at high temperatures is manufactured with a high-grade member, By connecting with the lid member, the cost is lower than when the insert vane and the lid member are all made of a high-quality member.

As in the prior art shown in FIG. 4, the ring circle 8 located on the outer edge of the lid member 6 is a ring circle 8 having an inner diameter D ₂ as shown in FIG. There is a gap between the convex portion 8a formed on the outer edge of the lid member 6 and the concave portion 1s (see FIG. 1) formed in the turbine housing 01. This gap is thermally expanded in the circumferential direction of the lid member 6. Then, it is prevented from interfering with and deforming with the turbine housing recess 1s.
Further, the center of the ring circle 7 and the bearing housing 11 are aligned with each other, and the bearing housing 11 and the turbine housing 01 are engaged with each other with the outer shape of the bearing housing 11, and the centers thereof are aligned therewith. As a result, the centers of the three members are aligned on the same axis.
Further, as shown in FIG. 3, an exhaust gas is guided to the inlet portion of the inner scroll portion 2 to smoothly flow the exhaust gas into the inner scroll portion 2. A tongue 5 is formed along the exhaust gas flow.

As in the prior art shown in FIG. 4, a control valve 4 is installed on the exhaust inlet side of the outer scroll portion 1, and the control valve 4 comes into contact with and disengages from the peripheral wall 4 a of the turbine housing 01. The exhaust gas flow rate to the inner scroll portion 2 and the exhaust gas flow rate to the outer scroll portion 1 are respectively controlled.
That is, when the low rotation of the engine, the control valve 4 is closed the outer scroll part 1 by closing against the peripheral wall 4a, the exhaust gas flows only into the inner scroll part 2 side as U _2.
Also at the time of high rotation of the engine, the control valve 4 to open away from the peripheral wall 4a, the exhaust gas flows through the outer scroll part 1 as U _1, the inner scroll part via the exhaust passage 6b of the insert vanes 6a with flows 2, it flows like U ₂ also to the inner scroll part 2.
Therefore, the exhaust gas flow rate can be changed by the control valve 4 when the engine is rotating at low speed and when the engine is rotating at high speed.

  According to the present invention, the structure of the lid member and the heat shield plate is simplified to reduce the number of parts, the assembly of the lid member supporting the heat shield plate and the insert vane is facilitated, and the deformation of the heat shield plate is reduced. A variable displacement exhaust gas turbine can be provided.

It is sectional drawing which follows the turbine axis line of the variable capacity exhaust gas turbine which concerns on the Example of this invention. (A) is sectional drawing of the cover member and reduced diameter board in the said Example, (B) is A arrow directional view of (A), (C) is B arrow directional view of (A). It is CC sectional drawing of FIG. It is principal part sectional drawing orthogonal to the rotating shaft center of the variable capacity exhaust gas turbine concerning a prior art. It is YY sectional drawing of FIG. 4 concerning a prior art.

Explanation of symbols

01 turbine housing 1 outer peripheral scroll portion 2 inner peripheral scroll portion 2a boundary wall 4 control valve 4a peripheral wall 5 tongue portion 6 lid member 6a insert vane 6b exhaust passage 7 ring circle 7c reinforcing rib 8 ring circle 10 turbine rotor 11 bearing housing 12 scroll portion 20 Exhaust inlet portion 20a Exhaust outlet portion 29 Bolt 30 Stop pin 62 Reduced diameter plate (heat shield plate)
100b Open end face

Claims (2)

A shaft pivotally supported by a bearing housing, a turbine rotor fixed to one end of the shaft and driven to rotate by exhaust gas, the turbine rotor being housed in a central portion and having an exhaust inlet portion and an exhaust outlet portion, A turbine housing having a scroll portion in which a passage sectional area gradually decreases between the exhaust inlet portion and the turbine rotor, and an inner scroll portion and an outer scroll portion formed by dividing the scroll portion in the radial direction of the turbine rotor. And a plurality of insert vanes arranged in the circumferential direction of the turbine rotor to flow the exhaust gas flowing directly into the inner scroll portion and the exhaust gas flowing through the outer scroll portion into the inner scroll portion. Configured to control the flow of exhaust gas,
Provided with a control valve that is disposed on the exhaust inlet side of the outer scroll portion and controls the exhaust gas flow rate to the inner scroll portion and the exhaust gas flow rate to the outer scroll portion, respectively.
In the variable capacity exhaust gas turbine in which a lid member defining the inner and outer peripheral scroll portions is disposed on the opening end face of the turbine housing, and the insert vane protrudes on the exhaust passage side of the lid member,
The lid member is integrally formed with a reduced diameter plate whose inner diameter side extends in the direction perpendicular to the shaft along the gap between the bearing housing and the turbine rotor, and the reduced diameter plate faces the turbine rotor. It is configured as a heat shield plate that cuts off heat flow, and the inner diameter side of the lid member and the reduced diameter plate are integrally formed via a ring circle protruding from the bearing housing side. A variable displacement exhaust gas turbine. 2. A reinforcing rib is formed radially on the lid member located on the outer peripheral side of the ring circle, whereas no reinforcing rib is formed on the reduced diameter plate side located on the inner peripheral side of the ring circle. The variable displacement exhaust gas turbine described.

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