U.S. patent application number 12/999931 was filed with the patent office on 2011-04-21 for compressor housing for turbocharger.
This patent application is currently assigned to IHI CORPORATION. Invention is credited to Kiyokazu Iizuka, Takahiro Kobayashi, Atsushi Koike, Fumie Matsuhashi, Yukio Takahashi, Nobuo Takei.
Application Number | 20110091323 12/999931 |
Document ID | / |
Family ID | 41433785 |
Filed Date | 2011-04-21 |
United States Patent
Application |
20110091323 |
Kind Code |
A1 |
Koike; Atsushi ; et
al. |
April 21, 2011 |
COMPRESSOR HOUSING FOR TURBOCHARGER
Abstract
A compressor impeller 2 has a plurality of long blades 2a and
short blades 2b alternately arranged in a circumferential
direction, and an inner surface of a compressor housing 10 is
provided with an annular groove 12 which surrounds vicinities of
leading edge tip portions of the short blades 2b in a
circumferential direction and is concave outward so as not to
communicate with a suction port of a compressor.
Inventors: |
Koike; Atsushi; (Tokyo,
JP) ; Iizuka; Kiyokazu; (Tokyo, JP) ;
Matsuhashi; Fumie; (Tokyo, JP) ; Kobayashi;
Takahiro; (Tokyo, JP) ; Takei; Nobuo; (Tokyo,
JP) ; Takahashi; Yukio; (Tokyo, JP) |
Assignee: |
IHI CORPORATION
Tokyo
JP
|
Family ID: |
41433785 |
Appl. No.: |
12/999931 |
Filed: |
June 17, 2008 |
PCT Filed: |
June 17, 2008 |
PCT NO: |
PCT/JP2008/061012 |
371 Date: |
December 17, 2010 |
Current U.S.
Class: |
416/175 |
Current CPC
Class: |
F04D 29/4213 20130101;
F05B 2260/962 20130101; F04D 29/681 20130101; F04D 29/4206
20130101; F05D 2260/963 20130101; F04D 29/665 20130101; F04D 29/284
20130101; F04D 29/685 20130101; F04D 29/30 20130101; F05B 2260/96
20130101; F05D 2220/40 20130101; F05B 2220/40 20130101 |
Class at
Publication: |
416/175 |
International
Class: |
F04D 1/00 20060101
F04D001/00 |
Claims
1. A compressor housing for a turbocharger for rotationally driving
a turbine impeller using exhaust gas of an internal combustion
engine and transmitting the rotation force to a compressor impeller
to be rotationally driven so that air or air-fuel mixture is
compressed and supplied to the internal combustion engine, wherein
the compressor impeller has a plurality of long blades and short
blades alternately arranged in a circumferential direction, and
wherein an inner surface of the compressor housing is provided with
an annular groove which surrounds vicinities of leading edge tip
portions of the short blades in a circumferential direction and is
concave outward so as not to communicate with a suction port of a
compressor.
2. The compressor housing for the turbocharger according to claim
1, wherein an axial center of the annular groove is located within
5 mm from the leading edge tip portions of the short blades in an
axial direction on an upstream or downstream side thereof, an axial
groove width is no less than 2.5 mm and no more than 10 mm, and a
maximum diameter of the annular groove is less than 1.2 times a
diameter of each leading edge tip portion of the short blades.
3. The compressor housing for the turbocharger according to claim
1, wherein the annular groove extends outward from the inner
surface of the compressor housing so as to be perpendicular or
inclined with respect to a rotary shaft of a compressor.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a compressor housing for a
turbocharger capable of reducing abnormal noise (high-frequency
noise).
[0003] 2. Description of the Related Art
[0004] A supercharging operation means that air or air-fuel mixture
supplied to a cylinder of an internal combustion engine is
compressed in advance, and a compressor used for the supercharging
operation is called a supercharger. In addition, a supercharger for
performing the supercharging operation using exhaust gas of the
internal combustion engine is simply called an exhaust turbine
supercharger or a turbocharger.
[0005] FIG. 1 is an overall configuration diagram showing an
example of a conventional turbocharger. In the drawing, the
turbocharger includes a turbine rotor shaft 51, a compressor
impeller 52, a bearing housing 53, a turbine housing 54, a
compressor housing 55a, and a seal plate 55b.
[0006] The bearing housing 53, the turbine housing 54, the
compressor housing 55a, and the seal plate 55b are connected to
each other in an order shown in the drawing. In addition, the
turbine rotor shaft 51 is configured by integrally forming a
turbine impeller 51a with a rotor shaft 51b by welding, and is
rotationally supported by the bearing housing 53 so as to be
coaxially connected to the compressor impeller 52.
[0007] With such a configuration, the turbine impeller 51a is
rotationally driven using the exhaust gas of the internal
combustion engine, and the rotation force is transmitted to the
compressor impeller 52 via the rotor shaft 51b to be rotationally
driven so that air (or air-fuel mixture) is compressed and supplied
to the internal combustion engine. Accordingly, it is possible to
remarkably improve performance of the internal combustion
engine.
[0008] FIG. 2 is a performance characteristic diagram showing an
example of a compressor constituting the turbocharger. As shown in
the drawing, in a general compressor, as the rpm N becomes high, a
pressure ratio becomes high and a flow rate becomes large. In the
drawing, the one-point dashed line indicates a surge line. When the
flow rate arrives at the surge line at the same rpm, a surge is
generated in a blade surface of the compressor impeller. As a
result, the compressor hardly performs a compression operation and
violent surge noise (intermittence noise) is observed.
[0009] Accordingly, as shown in the drawing, an operation line of
the engine having the turbocharger is set so as to be sufficiently
away from the surge line.
[0010] In addition, in the past, as means for shifting the surge
line to a side of a small flow rate, there is a conventional
compressor housing provided with a circulation passage for
increasing an intake air amount in appearance, the circulation
passage being used to communicate a suction port of the compressor
with a part in the course of a compression passage of the
compressor.
[0011] The compressor housing provided with the circulation passage
is disclosed in, for example, Patent Documents 1 and 2.
[0012] In `Turbocharger Provided With Sliding Member` disclosed in
Patent Document 1, an object is to obtain high compression
efficiency without deteriorating durability in a turbocharger
configured to prevent surging, choking, etc.
[0013] As shown in FIG. 3, the turbocharger provided with the
sliding member includes a new air passage 63 which guides fresh air
to a compressor impeller in a compressor housing; a first air
intake and exhaust port 68 which is formed on a part of a
compressor housing wall facing to the compressor impeller; a second
air intake and exhaust port 69 which faces the more upstream fresh
air passage than the compressor impeller; and a bypass passage 60
which communicates the first and second air intake and exhaust
ports with each other, wherein a sliding member 65 is attached to
at least a part of the compressor housing wall facing the blade
edge of the compressor impeller.
[0014] In `Inside of Compressor and Turbine and Related
Improvement` disclosed in Patent Document 2, an object is to retain
breakage fragments of a compressor wheel (impeller) inside a
diffuser flange by expectedly destructing the diffuser flange when
the wheel is broken, to prevent serious accidents caused by the
breakage fragments.
[0015] As shown in FIG. 4, a centrifugal compressor 71 includes a
compressor housing 73 and a compressor wheel 74 mounted in the
housing and having a compressor blade 75. The compressor housing 73
includes a cover plate 76 and a diffuser flange 79 fixed to both
the cover plate 76 and a bearing housing. The diffuser flange 79
includes an outer edge portion attached to a cover member and a
radial inside portion attached to the bearing housing. In the
diffuser, a brittle groove portion is defined at a position halfway
between the outer edge portion and the radial inside portion and
thereby the expected breaking of the diffuser flange is made
possible when the compressor wheel is broken.
[0016] Patent Document 1
[0017] Japanese published unexamined application No.11-173153,
`Turbocharger Provided With Sliding Member`
[0018] Patent Document 2
[0019] Japanese published unexamined application No.11-190297,
`Inside of Compressor and Turbine and Related Improvement`
[0020] In the above-described performance characteristic diagram,
the dashed line indicates a pre-surge line, and when a flow rate
becomes smaller than the pre-surge line at the same rpm, the
abnormal noise (high-frequency noise) may be generated. The
high-frequency noise may arrive at a sound pressure level of 90 dB
or more, but does not deteriorate performance of the compressor.
However, since the abnormal noise contributes to one of noise
sources in an automobile requiring a silent state, it is necessary
to prepare a countermeasure for the abnormal noise.
[0021] When the flow rate becomes small at the same rpm, the
abnormal noise (high-frequency noise) is continuously generated up
to the surge point. The abnormal noise is not generated in a surge
state, but instead surge noise (intermittence noise) is
observed.
[0022] In the past, since a generation cause of the abnormal noise
(high-frequency noise) is not clear, in general, a sound isolator
has been used in order to isolate the noise generated from the
turbocharger, but a problem arises in that it takes a cost to
perform the sound isolation.
[0023] The abnormal noise (high-frequency noise) can be reduced or
removed by shifting the surge line to the side of the small flow
rate by using the compressor housing provided with the
above-described circulation passage, but in the compressor housing
provided with the circulation passage, a problem arises in that a
structure is complex and a manufacture cost is more expensive than
that of the compressor housing without the circulation passage.
SUMMARY OF THE INVENTION
[0024] The present invention is contrived to solve the
above-described problems. That is, an object of the invention is to
provide a compressor housing for a turbocharger capable of
remarkably reducing or removing abnormal noise (high-frequency
noise) generated from a pre-surge line to a surge line without a
sound isolator or a circulation passage.
[0025] According to an aspect of the invention, there is provided a
compressor housing for a turbocharger for rotationally driving a
turbine impeller using exhaust gas of an internal combustion engine
and transmitting the rotation force to a compressor impeller to be
rotationally driven so that air or air-fuel mixture is compressed
and supplied to the internal combustion engine, wherein the
compressor impeller has a plurality of long blades and short blades
alternately arranged in a circumferential direction, and wherein an
inner surface of the compressor housing is provided with an annular
groove which surrounds vicinities of leading edge tip portions of
the short blades in a circumferential direction and is concave
outward so as not to communicate with a suction port of a
compressor.
[0026] According to a preferred embodiment of the invention, an
axial center of the annular groove is located within 5 mm from the
leading edge tip portions of the short blades in an axial direction
on an upstream or downstream side thereof, an axial groove width is
no less than 2.5 mm and no more than 10 mm, and a maximum diameter
of the annular groove is less than 1.2 times a diameter of each
leading edge tip portion of the short blades.
[0027] The annular groove extends outward from the inner surface of
the compressor housing so as to be perpendicular or inclined with
respect to a rotary shaft of a compressor.
[0028] The inventors of the invention have independently examined
and found out that the abnormal noise is generated by a rotating
stall of the impeller and peeling becomes large to thereby contact
with the short blade. The invention is based on the above-described
new viewpoints.
[0029] That is, according to the above-described configuration of
the invention, since the inner surface of the compressor housing is
provided with the annular groove which surrounds vicinities of the
leading edge tip portions of the short blades in a circumferential
direction and is concave outward so as not to communicate with the
suction port of the compressor, a sectional area of a flow passage
in the annular groove is suddenly enlarged. Accordingly, it is
possible to silence the noise.
[0030] In addition, the silencing advantage is shown in the
embodiments described below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 is an overall configuration diagram showing an
example of a conventional turbocharger.
[0032] FIG. 2 is a performance characteristic diagram of a
compressor constituting the turbocharger.
[0033] FIG. 3 is a schematic diagram showing `Turbocharger Provided
With Sliding Member` disclosed in Japanese published unexamined
application No.11-173153.
[0034] FIG. 4 is a schematic diagram showing an apparatus disclosed
in Japanese published unexamined application No.11-190297.
[0035] FIG. 5 is an overall configuration diagram showing a
turbocharger having a compressor housing according to the
invention.
[0036] FIG. 6 is a sectional diagram showing the compressor housing
in FIG. 5.
[0037] FIG. 7 is a perspective diagram showing a compressor
impeller.
[0038] FIG. 8A is a diagram showing the compressor housing
according to a first embodiment of the invention.
[0039] FIG. 8B is a diagram showing the conventional compressor
housing provided with a circulation passage.
[0040] FIG. 9A is a test result of the conventional compressor
housing, where a turbo rpm is 160,000 rpm and a flow rate is 6
m.sup.3/min.
[0041] FIG. 9B is a test result of the conventional compressor
housing, where a turbo rpm is 160,000 rpm and a flow rate is 5
m.sup.3/min.
[0042] FIG. 9C is a test result of the conventional compressor
housing, where a turbo rpm is 160,000 rpm and a flow rate is 4.3
m.sup.3/min.
[0043] FIG. 10A is a test result of the compressor housing
according to the invention, where a turbo rpm is 160,000 rpm and a
flow rate is 6 m.sup.3/min.
[0044] FIG. 10B is a test result of the compressor housing
according to the invention, where a turbo rpm is 160,000 rpm and a
flow rate is 5 m.sup.3/min.
[0045] FIG. 10C is a test result of the compressor housing
according to the invention, where a turbo rpm is 160,000 rpm and a
flow rate is 4.3 m3/min.
[0046] FIG. 11A is a diagram showing an original compressor
housing.
[0047] FIG. 11B is a diagram showing a second compressor housing
according to a second embodiment of the invention.
[0048] FIG. 11C is a diagram showing a third compressor housing
according to the second embodiment of the invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0049] Hereinafter, preferred embodiments of the invention will be
described with reference to the accompanying drawings. In the
respective drawings, the same reference numerals are given to the
same components, and the repetitive description will be
omitted.
[0050] FIG. 5 is an overall configuration diagram showing a
turbocharger having a compressor housing according to the
invention.
[0051] The turbocharger rotationally drives a turbine impeller 1 by
use of exhaust gas of an internal combustion engine, and a rotation
force thereof is transmitted to a compressor impeller 2 to
rotationally drive the compressor impeller 2 so that air or
air-fuel mixture is compressed and supplied to the internal
combustion engine.
[0052] FIG. 6 is an enlarged sectional diagram showing the
compressor housing in FIG. 5, and FIG. 7 is a perspective diagram
showing the compressor impeller 2.
[0053] As shown in FIG. 7, in this invention, the compressor
impeller 2 includes a plurality of long blades 2a and short blades
2b alternately arranged in a circumferential direction.
[0054] As shown in FIG. 6, a compressor housing 10 according to the
invention has an inner surface in which an annular groove 12 is
formed. The annular groove 12 surrounds vicinities of the leading
edge tip portions of the short blades 2b of the compressor impeller
2 and is concave outward so as not to communicate with a suction
port of the compressor.
[0055] An axial center a of the annular groove 12 is located within
5 mm from the leading edge tip portions of the short blades 2b in
an axial direction on an upstream or downstream side thereof. An
axial groove width b of the annular groove 12 is no less than 2.5
mm and no more than 10 mm. A maximum diameter d of the annular
groove 12 is desirably less than 1.2 times a diameter of each
leading edge tip portion of the short blades 2b.
[0056] In this example, the annular groove 12 extends outward from
the inner surface of the compressor housing 10 so as to be
perpendicular with respect to a rotary shaft of the compressor, but
may extend so as to be inclined thereto.
First Embodiment
[0057] In the turbocharger mounted to an engine for an automobile,
the above-described abnormal noise (high-frequency noise) was
observed during an engine test. For this reason, a component
performance test of a turbo unit was carried out. Even in this
component performance test, the abnormal noise was observed at a
turbo rpm of 160,000 rpm and 180,000 rpm, and the generation
frequency was about 2.3 kHz equivalent to an engine.
[0058] The inventors of the invention have independently examined
and found out that the abnormal noise is generated by a rotating
stall of the impeller. That is, as shown in FIG. 7 in which a flow
state of a compressed fluid is schematically illustrated, peeling
which is generated in the vicinity of an inlet or a tip of the long
blade becomes large to thereby contact with the short blade at a
position indicated by a dashed line in the drawing.
[0059] The reason is because an abnormal noise frequency does not
depend on a first rotation, an abnormal noise start point is
identical with a pre-surge point (a pressure variation start point
of the inlet), the abnormal noise is continuously generated in an
unstable region of the compressor (a pressure characteristic in
which a pressure increases rightward), and the compressor housing
is vibrated.
[0060] In addition, the inventors of the invention have considered
that a high abnormal noise generation frequency of 2.3 kHZ is
generated by a characteristic of the impeller, that is, generated
by the fact that the number of stall cells (the number of stall
blades) is large.
[0061] On the basis of the above-described new viewpoints, the
inventors of the invention have prepared two types of compressor
housings for delaying a stall and have carried out the component
performance test of the turbo unit.
[0062] FIG. 8A is a diagram showing the compressor housing
according to a first embodiment of the invention. FIG. 8A shows the
compressor housing according to the invention and FIG. 8B shows the
conventional compressor housing provided with a circulation
passage.
[0063] The compressor housing 10 according to the invention is
configured by additionally forming the annular groove 12 in an
inner surface of the compressor housing of the turbocharger in
which the abnormal noise (high-frequency noise) was observed.
[0064] In this example, an axial center of the annular groove 12 is
located at a position shifted by 4 mm from the leading edge tip
portions of the short blades 2b in an axial direction on the
upstream side thereof, an axial groove width b of the annular
groove 12 is 2.5 mm, and a depth c of the annular groove 12 is 4
mm. In addition, in this example, the annular groove 12 extends
outward from the inner surface of the compressor housing 10 so as
to be perpendicular with respect to the rotary shaft of the
compressor.
[0065] Meanwhile, a shape of the inner surface of the conventional
compressor housing provided with the circulation passage is
identical with that of the compressor housing of the turbocharger
in which the abnormal noise (high-frequency noise) was observed,
but its molding is newly manufactured. The circulation passage of
the compressor housing communicates a suction port of the
compressor with the same position as the position of the compressor
housing 10 of the present invention. A groove width b' of the
circulation passage is 2.5 mm and a groove width e of an outlet
port is 6 mm.
[0066] FIGS. 9A, 9B, and 9C are test results of the conventional
compressor housing. FIGS. 9A, 9B, and 9C show cases where a turbo
rpm is 160,000 rpm, and flow rates are about 6, 5, and 4.3
m.sup.3/min in order of the diagrams. In each of FIGS. 9A, 9B, and
9C, the left side indicates a noise measurement value and the right
side indicates a pressure variation measurement value.
[0067] In these diagrams, at positions when a turbo rpm is 160,000
rpm, a flow rate is about 6 m.sup.3/min, and a frequency is about
2.3 kHz, large peaks are generated in the noise and the pressure
variation, which corresponds to the above-described abnormal noise
(high-frequency noise).
[0068] FIGS. 10A, 10B, and 10C are test results of the compressor
housing according to the invention. FIGS. 10A, 10B, and 10C show
cases where a turbo rpm is 160,000 rpm, and flow rates are about 6,
5, and 4.3 m.sup.3/min in order of the diagrams. In each of FIGS.
10A, 10B, and 10C the left side indicates a noise measurement value
and the right side indicates a pressure variation measurement
value.
[0069] In these diagrams, at positions when a turbo rpm is 160,000
rpm, a flow rate is about 6 m.sup.3/min, and a frequency is about
2.3 kHz, peaks are hardly generated in the noise and the pressure
variation, which shows that the above-described abnormal noise
(high-frequency noise) is hardly generated.
[0070] Table 1 shows a measurement result of an abnormal noise
output at an abnormal noise start point in this embodiment.
[0071] In this Table, the conventional compressor housing without a
countermeasure for abnormal noise corresponds to `Original`, the
compressor housing according to the invention corresponds to `With
Annular Groove`, and a reference comparative example corresponds to
`With Circulation Passage` as another countermeasure for abnormal
noise.
TABLE-US-00001 TABLE 1 ABNORMAL NOISE START POINT IN CASE OF NOISE
COUNTERMEASURE NOISE REVOLUTION Nt FLOW RATE Q PRESSURE ABNORMAL
NOISE MEASURE TYPE (rpm) (m3/min) RATIO .pi. OUTPUT (V) FREQUENCY
(kHz) WITH ANNULAR 160,000 (2.67 kHz) (6.015) (2.627) (0.0153)
(2.21) GROOVE 180,000 (3.00 kHz) 7.526 3.190 0.1856 2.39 WITH
160,000 (2.67 kHz) -- -- -- -- CIRCULATION 180,000 (3.00 kHz) -- --
-- -- PASSAGE ORIGINAL 160,000 (2.67 kHz) 6.177 2.597 0.3706 2.15
(NO MEASURE) 180,000 (3.00 kHz) 7.503 3.099 0.5468 2.26 WITH
ANNULAR GROOVE: NO ABNORMAL NOISE IS OBSERVED AT 160,000 rpm.
VALUES IN PARENTHESES ARE REFERENCE VALES OF PRE-SURGE POINT
[0072] In this Table, at both turbo rpm of 160,000 rpm and 180,000
rpm, it is observed that an abnormal noise output is more reduced
than that of `Original`.
[0073] In addition, in `With Circulation Passage` as a reference
comparative example, it is possible to obtain the same advantage,
but the compressor housing provided with the circulation passage
has a problem that a structure is complex and a manufacture cost is
more expensive than that of the compressor housing without the
circulation passage. Accordingly, it is not possible to obtain the
object of the invention.
Second Embodiment
[0074] FIGS. 11B and 11C are diagrams showing the compressor
housing according to a second embodiment of the invention. FIG. 11A
shows an original compressor housing, FIG. 11B shows a second
compressor housing according to the invention, and FIG. 11C shows a
third compressor housing according to the invention.
[0075] An original turbocharger is different from that of the first
embodiment, and in these diagrams, diameters d1 and d2 are 62 mm
and 82 mm, respectively.
[0076] The second compressor housing shown in FIG. 11B is
configured in such a manner that the annular groove 12 is
additionally formed in the inner surface of the original compressor
housing shown in FIG. 11A.
[0077] In this example, an axial center of the annular groove 12 is
identical with that of each leading edge tip portion of the short
blades 2b, an axial groove width b1 of the annular groove 12 is 3.5
mm, and an outer diameter d3 of the annular groove 12 is 80 mm. In
addition, in this example, the annular groove 12 extends outward
upstream from the inner surface of the compressor housing 10 so as
to be inclined at 60 degree with respect to the rotary shaft of the
compressor.
[0078] The third compressor housing shown in FIG. 11C is configured
in such a manner that an annular cavity having an inner diameter
(d4) of 75 mm, an outer diameter (d5) of 90 mm, and a length (b2)
of 22.5 mm is formed in an outer side of the annular groove 12 of
the second compressor housing shown in FIG. 11B.
[0079] As a test result of the turbocharger having the compressor
housings shown in FIGS. 11A, 11B, and 11C, at a pressure ratio of
2.4, a surge flow rate can be reduced from about 8.4 m.sup.3/min of
the original compressor housing shown in FIG. 11A to about 7.7
m.sup.3/min in the case of FIG. 11B and about 7.6 m.sup.3/min in
the case of FIG. 11C.
[0080] Accordingly, as obviously shown in the results, it is
possible to reduce a surge line by using the compressor housing
according to the invention including those shown in FIGS. 11B and
11C, and thus to reduce an abnormal noise output.
[0081] As described above, according to the configuration of the
invention, since the inner surface of the compressor housing 10 is
provided with the annular groove 12 which surrounds vicinities of
the leading edge tip portions of the short blades in a
circumferential direction and is concave outward so as not to
communicate with the suction port of the compressor, a sectional
area of the flow passage is suddenly enlarged by the annular groove
12. As a result, it is possible to silence noise and to remarkably
reduce or remove the abnormal noise (high-frequency noise)
generated from a pre-surge line to a surge line without a sound
isolator or a circulation passage.
[0082] The invention is not limited to the preferred embodiments,
but may be, of course, modified into various forms without
departing from the spirit and the scope of the invention.
* * * * *