JP4632076B2 - Exhaust turbine turbocharger - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an exhaust turbine supercharger, and is intended to improve the efficiency of a compressor treatment for circulating air in order to improve compressor characteristics.
[0002]
[Prior art]
With the exhaust gas and environmental issues of automobiles being highlighted around the world, the use of turbochargers is becoming essential in order to meet emission regulations, reduce fuel consumption, and improve performance in the passenger car-class small diesel engine market In order to improve performance in a wide range from low speed to high speed, various improvements have been made.
[0003]
For example, in an exhaust turbine supercharger, as one method for improving the characteristics of a compressor, a compressor treatment is provided in a compressor housing, and a surging characteristic is improved.
[0004]
In this compressor treatment, as shown in FIG. 5, an air inlet c is formed in a portion of the compressor housing a facing the outer peripheral portion of the compressor impeller b, and an air outlet is provided in the compressor housing a in front of the compressor impeller b on the suction side. d is formed, and a substantially cylindrical circulation passage e communicating with the air inlet c and the air outlet d is formed in the compressor housing a. An insert ring f is attached to the inner periphery of the suction side of the compressor housing a to guide the sucked air to the compressor impeller b.
[0005]
By providing such a compressor treatment in the compressor, a part of the backflowing air generated in the compressor impeller b when the amount of passing air is small (surge side) from the air inlet c to the air outlet through the circulation passage e. Returning to d and circulating it back to the compressor impeller b prevents surging so that the operating range on the low flow rate side can be expanded.
[0006]
When the amount of passing air is large (choke side), the air sucked from the air discharge port d ahead of the suction side of the compressor impeller b is sent from the air inlet c to the compressor impeller b through the circulation passage e. The efficiency is prevented from decreasing.
[0007]
The shape of the compressor treatment that improves the performance characteristics of such a compressor is difficult to design theoretically due to insufficient analysis of the flow in the circulation passage, and is designed based on experience based on experimental results In many cases, the specific shape is determined by the similarity rule.
[0008]
[Problems to be solved by the invention]
However, when it is applied to an actual compressor, there is a problem that the effect of the compressor treatment greatly changes because the experimental result is not sufficiently reflected due to the difference in shape due to individual circumstances.
[0009]
The present invention has been made in view of the above-described problems of the prior art, and is intended to provide an exhaust turbine supercharger that can improve the characteristics of a compressor by smoothing the flow in a circulation passage. is there.
[0010]
[Means for Solving the Problems]
As a result of repeated investigations on compressor treatments so far, there is no significant difference in the degree of circulating flow caused by the pressure difference between the upstream and downstream, even though there are differences in individual shapes, but the air flow from the compressor impeller to the compressor treatment Effect of compressor treatment depending on how well the swirl component (circumferential flow component) of the flow entering the inlet can be diverted into the circulation flow and returned from the air outlet to the front side of the compressor impeller suction side Has been found to be different, and the present invention has been completed.
[0011]
Specifically, in order to solve the above-described problems of the prior art, the specific configuration of the exhaust turbine supercharger according to claim 1 of the present invention is that a first air port is formed in the compressor housing facing the outer peripheral portion of the compressor impeller. And an exhaust turbine supercharger in which a second air port is formed in the compressor housing in front of the suction side of the compressor impeller and these are communicated with each other via a substantially cylindrical air passage formed in the compressor housing. The compressor housing has a divided structure of a scroll portion and a shroud portion, while the first and second air ports and the air passage are formed in the divided portion of the scroll portion and the shroud portion, and The second air port side of the substantially cylindrical air passage is inflated to the outer peripheral side to increase the cross-sectional area of the passage. A passage enlarging portion for generating a tangential flow in the air is formed, and a rib for forming the substantially cylindrical air passage is provided in the divided portion between the inner and outer peripheral surfaces, and at least one surface of the rib is formed. An insert ring portion that is formed on a curved surface that changes the air flow into an axial component flow while flowing from the first air port and discharging from the second air port, and guides the flow of air into the compressor to the scroll portion. Are integrally formed .
[0012]
According to this exhaust turbine supercharger, the first air port is formed in the compressor housing facing the outer peripheral portion of the compressor impeller, and the second air port is formed in the compressor housing in front of the compressor impeller on the suction side. And an exhaust turbine supercharger in which these are communicated via a substantially cylindrical air passage formed in the compressor housing , wherein the compressor housing is divided into a scroll part and a shroud part, while the scroll part and the The first and second air ports and the air passage are formed in the divided portion with the shroud portion, and the second air port side of the substantially cylindrical air passage is inflated to the outer peripheral side so that the cross-sectional area of the flow path And a passage enlargement portion for generating a tangential flow in the passing air is formed, and the substantially cylindrical portion is formed in the divided portion. A rib for forming the air passage is provided between the inner and outer peripheral surfaces, and at least one surface of the rib flows in from the first air port and is discharged from the second air port. It is formed on a curved surface that changes into flow, and an insert ring part that guides the inflow of air to the compressor is formed integrally with the scroll part, and the flow passage cross-sectional area is greatly enlarged by the passage enlarged part. The flow passing through this portion is pressed against the outer peripheral side, and a force that strongly generates the subsequent circulation flow is obtained so that the swirl component can be diverted to the circulation flow.
[0014]
In addition, the swirl component can be diverted to the circulation flow more efficiently by changing the air flow direction by using one or both surfaces of the rib provided between the inner and outer peripheral surfaces as a curved surface to form the air passage. ing.
[0016]
Furthermore, the first and second air ports of the compressor treatment , the air passage, and the passage enlarged portion are formed in a divided portion of the scroll portion and the shroud portion, and the insert ring portion is integrally formed in the scroll portion. Therefore, the swirl component can be diverted to the circulation flow without increasing the number of parts.
[0017]
According to the present invention, since the swirl component can be diverted to the circulation flow, the compressor characteristics can be improved by the compressor treatment.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
1 and 2 relate to a reference example of an exhaust turbine supercharger according to the present invention. FIG. 1 is a partially enlarged sectional view of a compressor housing, an explanatory view of a flow seen from the A direction, and an explanatory view of a flow seen from the B direction. FIG. 2 is an overall cross-sectional view and a cross-sectional view taken along the line AA of the variable capacity supercharger in which the compressor treatment according to an example of the exhaust turbine supercharger is omitted.
[0019]
First, the overall structure of an exhaust turbine supercharger to which the present invention is applied will be described with reference to a variable displacement supercharger 1 shown in FIG.
In the variable capacity supercharger 1, a bearing housing 4 is disposed between a turbine housing 2 and a compressor housing 3 so as to be integrally connected, and a turbine impeller 5 in the turbine housing 2 and a compressor in the compressor housing 3 are connected. The impeller 6 is integrally connected via a turbine shaft 7 that is rotatably supported in the bearing housing 4. The turbine housing 2 is provided with a scroll passage 9 having a gas inlet 8 at one end, and an annular gas passage 10 is provided at an inner peripheral portion of the scroll passage 9 to introduce gas into the turbine impeller 5. The gas after driving the turbine impeller 5 is discharged from a gas outlet 11 formed at the center.
[0020]
The annular gas flow path 10 of the turbine housing 2 is provided with a plurality of nozzle vanes 12 that constitute a vane nozzle so as to be rotatable. The nozzle drive mechanism 13 such as a slide joint system adjusts and controls the angle of the nozzle vane 12 from the outside. Thus, the flow rate of the gas introduced into the turbine impeller 5 can be changed (in FIG. 2, the nozzle vane 12 at the upper part of the page is fully opened and the nozzle vane 12 at the lower part of the page is fully closed) As shown).
[0021]
In such a variable capacity turbocharger 1, since the nozzle side clearance C has a great influence on the performance, an optimum gap is determined from the operation, performance and reliability of the nozzle, and the side of the nozzle vane 12 of the vane nozzle is determined. The clearance control plate 14 is attached to the turbine housing 2 so as to secure the clearance C when hot and to suppress the performance deterioration due to the exhaust gas flowing out without passing through the nozzle.
[0022]
Therefore, according to such a variable capacity supercharger 1, when the gas flow rate at the low speed of the engine is small, the nozzle vane 12 is rotated to throttle the vane nozzle, and the gas flow rate at the high speed of the engine is reduced. In many cases, the nozzle vane 12 is rotated and opened, and the vane nozzle is opened until it hits the stopper pin 15 as the maximum position. The performance can be improved.
[0023]
In such a variable capacity turbocharger 1, as a so-called compressor treatment 20, as shown in FIG. 1, an air inflow port serving as a first air port is provided at a portion of the compressor housing 3 facing the outer peripheral portion of the compressor impeller 6. 21, an air discharge port 22 as a second air port is formed in the compressor housing 3 in front of the suction side of the compressor impeller 6, and the air inlet 21 and the air discharge port 22 communicate with each other as an air passage. A substantially cylindrical circulation passage 23 is formed in the compressor housing 3. An insert ring portion 24 a is formed integrally on the suction side inner periphery of the compressor housing 3 to guide the sucked air to the compressor impeller 6.
[0024]
Further, in the compressor treatment 20, the air inlet 21 is formed in a slit shape that is inclined from the upstream side to the downstream side of the flow of intake air in the compressor (inclined to the right in FIG. 1A), while the air Similarly, the discharge port 22 is also formed in a slit shape that is inclined from the upstream side to the downstream side of the flow of intake air in the compressor (inclined to the right in FIG. 1A).
[0025]
The circulation passage 23 for communicating the air inlet 21 and the air outlet 22 is provided with ribs 23a at approximately three locations in the circumferential direction in order to secure a cylindrical gap. It is a cylindrical passage.
[0026]
Furthermore, the substantially cylindrical circulation passage 23 that connects the air inlet 21 and the air discharge port 22 has a passage expanding portion 23b that is expanded from the intermediate portion toward the air discharge port 22 toward the outer periphery to expand the cross-sectional area of the flow path. The air outlet 22 side of the passage expanding portion 23b is the same inclined surface as the air outlet 22, and the air inlet 21 side is also the same inclined surface as the air outlet 22, and substantially parallel sides. It has a cross-sectional shape.
[0027]
As a result, the circulation passage 23 has a substantially cylindrical shape, and swells from the middle of the portion having a small channel cross-sectional area to the outer peripheral side and communicates with the air discharge port 22 through the passage expanding portion 23b having a large channel cross-sectional area. become.
[0028]
In the variable capacity turbocharger 1 in which such a compressor treatment 20 is provided in the compressor, air flowing backward from the intake air generated by the compressor impeller 6 when the amount of passing air is small (surge side) is supplied from the air inlet 21. The return to the intake air from the air discharge port 22 through the circulation passage 23 and the passage enlargement portion 23b, which is again sucked into the compressor impeller 6 and circulated, prevents surging, and the operating region on the low flow rate side. Can be enlarged.
[0029]
In the case of a flow that circulates the backflowing air generated in the compressor impeller 6 as described above, the compressor treatment 20 uses the air X that enters from the air inlet 21 as shown in FIGS. However, since a strong swirl component Xa flow (circumferential flow) remains, ribs 23a are formed in the circulation passage 23 to form a cylindrical gap. By accelerating with the vector component (circulation flow component) Xb in the direction of the outlet 22 and further increasing the flow path cross-sectional area by the passage expanding portion 23b, a tangential flow Xc is generated in the air X, and the vector of these components As a sum, the air X is pressed to the outer peripheral side.
[0030]
Then, since there is a wall of the passage expanding portion 23b (a wall of an extended portion of the air discharge port 22) immediately before the air X pressed to the outer peripheral side, the flow of the air X from the outer peripheral side along the wall and the circulating flow It can be converted to the direction along the air and can be smoothly returned to the intake air, thereby obtaining a great treatment effect.
[0031]
That is, an air flow having a swirl component generated in the compressor impeller is introduced from the air inlet 21 and is diverted to a flow having the same axial component as the air sucked into the compressor impeller while being discharged from the air outlet 22. And so on.
[0032]
In the variable capacity supercharger 1 provided with such a compressor treatment 20, it is possible to expand the operating range when the amount of passing air is small by suppressing the occurrence of surging.
[0033]
Further, in this variable displacement turbocharger 1, the compressor housing 3 is divided into an outer scroll portion 3a and an inner shroud portion 3b, each of which is manufactured by die casting, and then shrink fit (warming). And the intake ring portion 3c and the insert ring portion 24a fitted to the inner periphery thereof are integrally formed in the scroll portion 3a, and are already formed in the divided portion of the scroll portion 3a and the shroud portion 3b. The described compressor treatment 20 is formed.
[0034]
Therefore, when the compressor treatment 20 is provided, it is necessary to attach an insert ring 24 manufactured separately to the intake inlet portion 3c of the compressor housing 3 later, which increases the number of parts and manufacturing man-hours. In the feeder 1, the intake inlet portion 3c and the insert ring portion 24a are manufactured integrally with the scroll portion 3a, and the shroud portion 3b is shrink-fitted, so that the compressor treatment 20 can also be formed in the divided portion, increasing the number of parts and manufacturing. It can be manufactured without increasing man-hours.
[0035]
As the shape of the compressor treatment 20 of such a variable capacity supercharger 1, for example, various shapes as shown in FIG. 3 can be used, and the compressor treatment 20 is circulated from the air inlet 21 as shown in FIG. It may be directly connected to the end of the passage 23 and the passage enlarged portion 23b may be formed larger than the air discharge port 22. Further, as shown in FIG. 4B, the air inflow port 21 is directly communicated with the end of the circulation passage 23, the passage enlargement portion 23b is formed to be small, and the inner peripheral surface 22a of the air discharge port 22 is tapered. It may be a slanted surface. Furthermore, as shown in FIG. 5C, the air inlet 21 is formed into a straight slit without tilting, and the air inlet 21 is directly communicated with the end of the circulation passage 23, so that the passage expanding portion 23b is connected to the air. It may be larger than the discharge port 22. In the figure, reference numeral 24 denotes an insert ring that is attached as a solid, but in this case as well, it may be formed integrally with the scroll portion 3a.
[0036]
Regardless of the shape of any of these compressor treatments 20, an air flow having a swirl component generated by the compressor impeller is introduced from the air inlet 21 and is diverted into an axial component flow while being discharged from the air outlet 22. It is possible to suppress the occurrence of surging and to expand the operating range when the amount of passing air is small.
[0037]
The shape of the compressor treatment 20 is not limited to the specific shapes shown in the drawings, but may be other shapes that include a passage expanding portion that swells on the outer periphery and can divert an air flow having a swirl component to a flow of an axial component. May be.
[0038]
Next, a description will be given of an embodiment of a turbocharger of the invention with reference to FIG. 4, denoted by the same symbols in the form of the same portion of the embodiment already described, description thereof is omitted.
[0039]
In this exhaust turbine supercharger, the basic structure is the same as that of the variable capacity supercharger 1 already described, and a part of the configuration of the shape of the compressor treatment 20 is different.
[0040]
Here, both surfaces on the air inlet 21 side of the ribs 23a forming the gap between the inner and outer circumferences of the circulation passage 23 constituting the air passage of the compressor treatment 20 are the curved surfaces 23c.
[0041]
As a result, on the surge side where the amount of passing air is small, as shown in FIG. 4B, the air X flowing from the air inlet 21 is smoothly converted from the circumferential direction to the axial direction by being guided by the curved surface 23c. The air flow having the swirl component generated by the compressor impeller can be more efficiently introduced from the air inlet 21 and diverted to the axial component flow while being discharged from the air outlet 22 to obtain a circulation flow. Therefore, it is possible to expand the operating range when the amount of passing air is small by suppressing the occurrence of surging.
[0042]
In this embodiment, both surfaces of the ribs 23a are curved surfaces 23c. However, as shown by a broken line in the figure, one surface may be a flat surface, which facilitates manufacture.
[0043]
In the above embodiment, the variable capacity supercharger has been described as an example of the exhaust turbine supercharger. However, the present invention can be similarly applied to other types of exhaust turbine superchargers.
[0044]
【The invention's effect】
As described above in detail with reference to the embodiment, according to the exhaust turbine supercharger according to claim 1 of the present invention, the first air port is formed in the compressor housing facing the outer peripheral portion of the compressor impeller. together with the second air inlet formed on the suction side ahead of the compressor housing of the compressor impeller, these exhaust turbine supercharger communicates via a substantially cylindrical air passage formed in the compressor housing, wherein While the compressor housing is divided into a scroll part and a shroud part, the first and second air ports and the air passage are formed in the divided part of the scroll part and the shroud part, and the substantially cylindrical shape The second air port side of the air passage is expanded to the outer peripheral side to increase the flow passage cross-sectional area and tangential to the passing air And a rib for forming the substantially cylindrical air passage is provided between the inner and outer peripheral surfaces, and at least one surface of the rib is formed in the first air. Formed in a curved surface that changes the air flow into an axial component flow while flowing in from the port and discharging from the second air port, and an integrated insert ring portion that guides the flow of air into the compressor in the scroll portion since the circulating swirl component to obtain the force flow passing therethrough by a flow path cross-sectional area by the passage enlarged portion is expanded greatly pressed against the outer peripheral side, causing strong subsequent circulation flow Can be diverted to flow.
[0045]
By diverting the swirl component to the circulating flow, the characteristics on the surge side and the choke side of the compressor can be improved.
[0046]
In addition, the swirl component can be more efficiently diverted to the circulation flow by changing the air flow direction by using one or both surfaces of the rib provided between the inner and outer peripheral surfaces to form an air passage as a curved surface. It is possible to improve the characteristics on the surge side of the compressor.
[0047]
Furthermore, the first and second air ports of the compressor treatment , the air passage, and the passage enlarged portion are formed in a divided portion of the scroll portion and the shroud portion, and the insert ring portion is integrally formed in the scroll portion. Thus, the swirl component can be diverted to the circulation flow without increasing the number of parts, and the compressor characteristics can be improved by the compressor treatment.
[Brief description of the drawings]
FIG. 1 is a partially enlarged cross-sectional view of a compressor housing according to a reference example of an exhaust turbine supercharger of the present invention, an explanatory view of a flow seen from the A direction, and an explanatory view of a flow seen from the B direction.
FIGS. 2A and 2B are an overall cross-sectional view and a cross-sectional view taken along line AA of a variable capacity supercharger in which a compressor treatment according to a reference example of the exhaust turbine supercharger of the present invention is omitted.
FIG. 3 is a partial enlarged cross-sectional view of a compressor housing according to a reference example of the exhaust turbine supercharger of the present invention.
FIG. 4 is a partially enlarged cross-sectional view of a compressor housing according to an embodiment of the exhaust turbine supercharger of the present invention, and an explanatory view of a surge side flow as viewed from the direction A.
FIG. 5 is a partially enlarged cross-sectional view of a compressor treatment of a conventional exhaust turbine supercharger.
[Explanation of symbols]
1 Variable capacity turbocharger (exhaust turbine turbocharger)
DESCRIPTION OF SYMBOLS 2 Turbine housing 3 Compressor housing 3a Scroll part 3b Shroud part 3c Intake inlet part 4 Bearing housing 5 Turbine impeller 6 Compressor impeller 7 Turbine shaft 8 Gas inlet 9 Scroll passage 10 Annular gas flow path 11 Gas outlet 12 Nozzle vane 13 Nozzle drive mechanism 14 Clearance Control plate 15 Stopper pin 20 Compressor treatment 21 Air inlet (first air inlet)
22 Air outlet (second air outlet)
22a Inner peripheral surface 23 Circulation passage (air passage)
23a rib 23b passage enlarged portion 23c curved surface 24 insert ring 24a insert ring portion X air flow Xa swirl component Xb vector component Xc tangential flow C nozzle side clearance

Claims (1)

A first air port is formed in the compressor housing facing the outer periphery of the compressor impeller, and a second air port is formed in the compressor housing in front of the compressor impeller on the suction side, and these are formed in the compressor housing. An exhaust turbine supercharger communicated through a cylindrical air passage,
While the compressor housing is divided into a scroll part and a shroud part, the first and second air ports and the air passage are formed in the divided part of the scroll part and the shroud part, and the substantially cylindrical shape The second air port side of the air passage is expanded to the outer peripheral side to increase the flow passage cross-sectional area to form a passage expanding portion that causes a tangential flow in the passing air, and further, the substantially cylindrical portion is formed in the divided portion. A rib for forming the air passage is provided between the inner and outer peripheral surfaces, and at least one surface of the rib flows in the axial direction component while flowing in from the first air port and discharging from the second air port. An exhaust turbine supercharger characterized in that it is formed on a curved surface that changes to the flow of air, and an insert ring part that guides the inflow of air into the compressor is formed integrally with the scroll part .

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