JPS58150028A - Flow changeable turbine - Google Patents

Abstract

1. An exhaust gas turbine with a variable flow, in particular for driving turbochargers of internal combustion engines, comprising a rotor (28) which is rotatable about an axis and which has a multiplicity of rotor blades (34) which are arranged at peripheral spacings from each other, a turbine casing (13) in which the rotor is rotatable and which has an outlet (32) which is coaxial with respect to the rotor, a volute casing portion (16) and a curved intake portion (14) with an inlet (22) arranged at a spacing from the axis, a partitioning wall which forms an outer and an inner flow path (56, 54) in the intake portion (14) and in the volute casing portion (16), which is curved within the volute casing portion (16) in the same direction as said volute casing portion and which is so arranged in the volute casing portion (16) that there is formed a fixed guide surface tip (52) which lies substantially tangentially at the outer periphery of the rotor (22) and which keeps the outer and inner flow paths separate and the inner flow path (54), within the volute casing portion (16) to directly to the periphery of the rotor (28), is of a cross-sectional area which decreases as said flow path (54) increasingly approaches the rotor, and a valve-like member (36) with actuating means for varying the intake flow cross-section of one of the two flow paths in the intake portion (14), characterised in that the intake portion (14) which extends between its connection (18) to the exhaust gas manifold of the internal combustion engine and the connection to the volute casing portion (16) and the part of the partitioning wall (50) which is disposed in the intake portion (14) are curved in the same direction as the volute casing portion (16), that the partitioning wall (50) extends in the volute casing portion (16) in such a way that the end thereof itself forms the guide surface tip (52) which lies substantially tangentially at the periphery of the rotor (28) and the cross-sectional areas of the outer flow path (56) as well as those of the inner flow path (54), within the volute casing to directly to the periphery of the rotor (28), progressively decrease in the direction in which the flow path increasingly approaches the rotor (28), and that the valve-like member (36) is so associated with the inner flow path (54) that upon movement of the valve-like member (36) towards the position of closing off the inner flow path (54) both the average radius of curvature of the mass flow and the flow speed of the exhaust gases increase.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention This invention relates to variable flow turbines and, more particularly, to an improved variable flow turbine for a turbocharger installed in an internal combustion engine.

BACKGROUND OF THE INVENTION There are currently two types of radial float turbines used in turbochargers. The first type is such that the shape and area of the flow path from the gas inlet to the turbine rotor cannot be changed.

Its structure is fixed. One such example is that disclosed in US Pat. No. 3,664,761. The second type is known as a variable flow turbine, one design having radially inner and outer passages.

One passage is provided with a pulp that regulates the flow therethrough. Moving this pulp adjusts the size of the passage opening and changes the flow cross-sectional area, thereby compensating for changes in exhaust gas flow rate and pressure caused by operating the engine at different speeds and loads. An example of this variable flow turbine is U.S. Pat. No. 4,177.00.
There is something shown in No. 6. In this patented invention,
The turbine has a straight gas section extending into the vortex section. Each channel is further only within the volute.

A wall integrally formed in the housing separates the primary and secondary flow paths. Additionally, a piece of pulp is provided across the secondary flow path at the gas inlet section and rotated to direct the waste flow away from the wall, so as to adjust the gas flow.

Of the two types of turbines, engines using fixed structure turbines are less efficient. This is because in turbocharged engines with fixed structure turbines, the turbine is mated to a compressor that is typically designed for maximum efficiency when the engine is at its peak torque. Therefore, at rated speed and load, the engine cannot be operated at optimal efficiency because the compressor's efficient operating range is lower than that required by the engine. On the other hand, variable flow turbines have high efficiency at rated speed and load.

Also, by using a compressor that is efficient when the engine is at peak torque, the efficiency at the engine's rating point can be increased. In addition, engines with variable flow turbines can be used at speeds and loads below the maximum speed and load where maximum charge air pressure is not required.
More efficient.

In recent years, there has been a need to develop variable flow turbochargers that are highly efficient throughout the operating range of the engine.

OBJECTS, STRUCTURES, AND EFFECTS OF THE INVENTION In view of these points, the present invention provides a variable flow turbine that enables a turbocharger to operate more efficiently. The purpose is to spread the word.

That is, the variable flow turbine according to the present invention consists of a curved part and a thinly wound part, the curved part has an inlet at one end and is connected to a spiral part at the other end, and the spiral part has one spiral part. a housing formed about an axis and having an outlet coaxially aligned with the axis; housed in the spiral portion and rotatable about the axis and in a plurality of circumferential directions; a rotor having spaced blades; a valve pulp means located at said inlet for controlling gas flow through said inlet; a dividing wall extending in the direction of the winding and dividing the two sections into radially inner and outer flow passages; each flow passage having a cross-sectional area that gradually decreases as it approaches the rotor in the spiral direction; It is characterized by being

In the turbine having the above configuration according to the present invention,
By operating the valve means, the gas flow within the turbine can be controlled from flowing through both the inner and outer flow paths to flowing only through the outer flow path. As the flow in the inner j channel decreases and the flow in the outer channel increases, the overall velocity and radius of curvature of the flow increases. Therefore, the momentum of the gas flow can be adjusted by manipulating this pulp. In the present invention, the turbine rotor can be rotated in the best condition by adjusting this momentum.

This allows the air to be charged to the engine to be appropriate. Therefore, by using a charger equipped with a turbine according to the present invention, efficient output can be obtained under all operating conditions of the engine. In addition, the transient response of the engine can also be improved.

Description of Examples Below 1 This invention? Embodiments will be described in detail based on embodiments shown in the accompanying drawings.

The accompanying drawings, in particular FIG. 6, show a turbocharger 10 with a variable flow turbine 11 according to the invention.

The turbine 11 connected to the compressor 12 is as shown in FIGS. 1 and 2.

It is composed of a curved part 14 and a spiral part 16.
・It has Uzing 16. The curved portion 14 is connected to the engine exhaust manifold at the first flanged end 18 by bolts (not shown) threaded through port holes 20 (FIG. 4).

The curved portion 14 has an angular range of at least 60, preferably 3
0 to 180. More preferably it has an angular range of about 45 to 90 degrees. The curved section 14 has a projection 22 formed at the flanged end 18 and is connected to the spiral section 16 at an opposite end 24. The spiral portion 16 has an angular range of at least 2700 - preferably about 660. The arc of the spiral portion 16 is formed around an axis extending perpendicular to the plane of the paper, as shown in FIG. Connecting shaft 2
6 rotatably connects the turbine housing 16 to the compressor 12 and rotates around the axis of the spiral portion.

The connecting shaft 26 supports a turbine rotor 28 and a compressor wheel 30 at both ends thereof. Turbine housing 13
The turbine rotor 28 is disposed within the turbine rotor 28 and has a plurality of circumferentially spaced blades 34 extending radially outwardly from a central axis. blade 6
The shape and profile of 4 may be varied as desired, as is well known to those skilled in the art. Turbine housing 16 also.

It has an outlet 62 as shown in FIG. When the exhaust gases are directed into turbine 11 , they rotate turbine rotor 28 .

As turbine rotor 28 rotates, it rotates compressor wheel 30i. Compressor wheel 60 thereby delivers relatively high pressure charge air to the engine.

A control pulp 66 is provided near gas inlet 220 to control gas flow into turbine housing 16 . Konoil J pulp 66, which is preferably rotary pulp
fits inside the curved portion 14. control valve 6
6 has a pulp body 40 which is moved between open and closed positions to regulate gas flow through the turbine 11. In the open position (FIG. 2), the pulp body 40
coincides with the inner surface of the curved portion 14, and the gas flows through the entire curved portion 14.
allows the river to flow westward. In the closed position shown in phantom in FIG. 2, the pulp body 40 constrains the gas flow path through the curved portion 14. Control valve 36 is operated by control mechanism 4'2 via bottle 46 and link 44. The control mechanism 42 is pivotally connected at one end to a fixed support 48, and linear movement of the link 44 causes rotational movement of the control valve. Control mechanism 42 can be operated manually or automatically. The control mechanism 42 also includes: engine operating speed,
It can respond substantially linearly or non-linearly to changes in parameters such as engine load, manifold pressure, exhaust gas smoke concentration exiting the engine, atmospheric concentration entering the engine, exhaust gas temperature, combinations thereof, and the like. Additionally, control mechanism 42 may be adapted to parameters such as turbine rotor 28 speed and throttle position.

A dividing wall 50 is provided from the control valve 66 to the curved and spiral portion of the turbine housing 16 . Vaginal wall 50 is tapered such that its tip 52 is substantially tangential to the outer periphery of turbine rotor 28 . This dividing wall 50 is an arc-shaped part that is integral with the turbine housing 16, and connects the turbine housing to the primary (i.e., external) li1!
I) Divided into a flow path 56 and a secondary (inner) flow path 54. Preferably, the area of outer channel 56 is greater than the area of inner channel 540, and more preferably, the area of outer channel 560 is about six times the area of inner channel 54. Inner and outer υ1 channels 54
．． When the area of 56 is placed in a relationship of approximately 1:6.

The outer flow passage is approximately 6 times larger than the inner flow passage around the turbine rotor 28.
intersects with the periphery of Furthermore, in addition to the difference in size between channels 54 and 56, dividing wall 50 cooperates with the inner surface of spiral portion 16 to reduce the cross-sectional area of outer channel 56 (FIG. 2). Preferably, the cross-sectional area of the channels 54, 56 is made to constantly decrease through the curved and spiral portions 14.16, respectively. In this manner, the exhaust gases entering the turbine blades 34 have a relatively uniform velocity. Partial rotation of the control valve 66 from the open position to the closed position directs the exhaust gases outwardly towards the dividing wall 50, thereby increasing the velocity of the exhaust gases flowing within the inner and outer flow passages 54,56. increase respectively. This speed increase, combined with the increased average radius of curvature of the exhaust gases, causes the turbine 11 to
Increase the output power of.

When control valve 66 is rotated to the fully closed position (as shown by the dashed line in FIG. 2), all exhaust gases are directed into outer flow path 56. As a result, the velocity and average radius of curvature of the exhaust gas are further increased to increase the output power of the turbine. Maximize.

The curved portion 14 forms, together with the inner surface 58 of the spiral portion 16, a tongue-like portion 60fz having a tip 62=i.

Pointed portion 62 is located at end 24 of curved portion 14 .

Near the periphery of turbine rotor 28 , preferably tangential to the periphery of turbine rotor 28 . Pointed portion 62 is positioned at an angle of approximately 90' from tip portion 52 of dividing wall 50 such that approximately 75% of the circumferential area of turbine rotor 28 faces outer flow passage 56 . The pointed portion 62 and the inner surface 58 suppress exhaust gas flowing between the outer peripheral edge of the turbine rotor 28 and the tongue portion 6o. Pointed portion 62
It also suppresses the clockwise flow of exhaust gases that would cause a pulsating effect on the turbine rotor 28.

5-7, the control valve 64 is shown in the inner flow passage 54.
Another embodiment of a variable flow turbine is shown across the. Control valve 6 with pulp body 67
4 as shown in FIG.

It is rotated on the 7-rule 65 by the control link 66. When control pulp 64 is rotated, pulp body 67 is moved between open and closed positions. In the open position, the fifth
As shown, the pulp body 67 mates with the inner surface of the curved portion 14, allowing exhaust gas to flow through the outer and inner channels 54,56. When the pulp body 67 is moved toward the dividing wall 51 to a partially closed position, a portion of the inner flow path 54 is closed. In the fully closed position (shown in phantom in FIG. 5), the pulp body 67 occludes the inner channel 54. This increases the velocity and average radius of curvature of the exhaust gas, increasing the output power of the turbine. As shown in FIGS. 6 and 7, in this embodiment, the dividing wall 68
have. This dividing wall is substantially perpendicular to the dividing wall 51 and extends from the gas port 22 into the curved and spiral portion of the turbine housing 16. This dividing wall 68
divides the turbine housing 16 into a pair of axially separated passages 70, 72, each passage 70, 72
include inner and outer flow passages 54, 56, respectively. Each flow path 70,72 is aligned with a separate exhaust gas manifold pipe so that the exhaust gases are mixed before entering the turbine blades 64? prevent.

In the steerable variable flow turbine 11, exhaust gases from the engine manifold pass through passages 54,56.

This corresponds to the blades 64 of the turbine rotor 28. The turbine rotor 28 is driven at a speed related to the exhaust gas speed and the engine speed. Therefore, the rotational speed of the turbine rotor 28 is related to engine operating conditions such as engine speed and load. Furthermore, the cross-sectional area and shape of the flow passages 54, 56 and the shape of the dividing wall 50 affect the exhaust gas velocity and therefore also. This affects the rotational speed of the turbine rotor 28. By making the cross-sectional area of the outer passage 56 approximately six times that of the inner passage 54 and by providing the curved section 14 in front of the spiral section 16, the velocity of the exhaust gases can be better controlled.

Closing control valve 36 provides high velocity gas flow through the outer flow path at relatively low engine speeds. When the inner flow path 54i is closed, the entire gas flows through the outer flow path 56. This insures sufficient gas velocity to drive the turbine rotor 28 at sufficient speed to increase the charge air to the engine by the compressor wheel 60.

As engine speed or load increases: - The velocity and amount of exhaust gases increases. At some point above the engine's torque curve, the velocity and volume of exhaust gases (mass fl
ow) rotates the turbine rotor at a speed such that the parts of the turbocharger 10 exceed critical operating limits or the turbocharger creates an increased pressure total that exceeds the engine operating limits. When either of those occurs, the control pulp 66 is rotated toward the open position, allowing incoming gas to pass through both the inner and outer flow passages 54,56.

By partially closing the control valve 66, the gas flow is directed away from the central axis of the turbine rotor 28, increasing its average radius of curvature. Also the speed.

This is increased by reducing the cross-sectional area of the curved portion 14.

For each position of control valve 66, the velocity of gas flowing perpendicular to the radius of curvature immediately downstream of control pulp 66 produces a constant angular momentum. By closing valve 56, the average velocity and average radius of curvature of the exhaust gas increases, thereby increasing the angular momentum.

The increase in average speed can be expressed approximately at the periphery of the turbine rotor by the following equation:

C = - where C is the average velocity of the exhaust gases; KU, a constant determined by C and R immediately downstream of the control pulp that produces the desired value of Kel C at the periphery of the turbine rotor; is the average radius of curvature of the gas flow.

The above formula applies to all turbines with a spiral section when friction and compressibility are omitted.

By partially or completely closing the control pulp 66, the velocity of the exhaust gas impinging on the blades 64 of the turbine rotor 28 is increased; the energy transferred to the turbine rotor 28 is thereby increased according to the following Euler turbine equation: be done.

gc where H is the energy transferred to the turbine rotor per unit amount of exhaust gas; U is the speed of the turbine blades 64 at the periphery of the turbine rotor 28; Cut is the tangent to the periphery of the turbine rotor 28 velocity of the exhaust gas in the direction; Cu, l'j:, average tangential velocity of the exhaust gas leaving the turbine rotor 28: U, H, velocity of the turbine blades 64 at the average radius of curvature of the exhaust gas leaving the turbine rotor 28; as well as.

gc is Makoto Dosada;

Partially or completely closing control pulp 66 increases the charge air to the engine.

As a result, without exceeding the exhaust gas smoke concentration limit,
More fuel can be delivered to the engine for higher engine torque and instantaneous response can be improved. For engine loads above the maximum torque curve, control pulp 6
6 can be adjusted to provide the optimum combination of differential pressure across the engine and air-fuel ratio for maximum engine efficiency. Similarly, partially or fully opening the control pulp 66 at high engine speeds and loads increases the cross-sectional area of the gas flow and decreases the average radius of curvature of the gas flow to increase air pressure to the engine and to the turbo. Control charger speed.

The vaneless nozzle turbine of the present invention can handle exhaust gas flows with velocities greater than about 1.5 mm without choking problems. This ability to handle speeds in excess of supersonic speeds does not exist in turbines with vanes.

[Brief explanation of the drawing]

Fig. 1 is a side view of a variable flow turbine according to the present invention; Fig. 2 is an I analysis side view of the turbine shown in Fig. 1; Fig. 6 is a sectional view taken along line 6-6 in Fig. 1; Fig. 4 The figure is a sectional view taken along the line 4-4 in Figure 2; Figure 5 is a diagram showing a modification of the turbine inlet; Figure 6 is a
FIG. 7 is a sectional view taken along line 7-7 in FIG. 5; 16... Housing; 14.・, curved part; 16...
・Spiral part; 28...rotor; 66...pulp;
50...Dividing wall. Patent applicant Deere & Co. FIG.
/ 5 FIG, 6

Claims (1)

[Claims] (11) A variable flow turbine for enabling a turbocharger to operate more efficiently. It consists of a curved part and a thinly wound part, and the curved part has a population at one end and a winding part at the other end. a housing connected to the spiral portion at the spiral portion, the spiral portion being formed about an axis and having an outlet coaxially aligned with the axis; a rotor rotatable about an axis and having a plurality of circumferentially spaced blades; provided at the inlet;
valve means for controlling gas flow through the inlet; a dividing wall extending inwardly from the pulp means through the curved section and into the spiral section to divide the section into radially inner and outer flow passages; a variable flow turbine, wherein each flow passage has a spiral portion whose cross-sectional area gradually decreases as it approaches the rotor. (2) The turbine according to claim 1, wherein the curved portion is provided with an angle range of 60° to 180°. (3) The turbine according to claim 1, wherein the curved portion is provided in an angular range of 45 to 90 degrees. (4) In variable flow turbines to make the turbocharger operate more efficiently over the operating range of the engine. It consists of a curved section and a spiral section, the curve extending over at least 60 angular ranges, having an inlet at one end and connected to a spiral section at the other end, the spiral section extending along one axis. shouldering an outlet extending over at least 270 angular ranges about the axis and coaxially aligned with said axis, with the inner surface of the curved section converging on the inner surface of the spiral section to form the entrance of the spiral section. a plurality of circumferentially spaced blades contained within the housing for rotation about the axis of each of the spiral sections; a rotor having one circumferential edge substantially tangential to the tongue; a pulp disposed at the port for controlling gas flow through the inlet; a rotor disposed within the housing from the valve; a dividing wall extending approximately 900 degrees apart from the terminal end of the tongue substantially tangent to the circumference of the rotor and dividing the housing into radially inner and outer flow passages; , a variable flow turbine in which the cross-sectional area of each flow path constantly decreases as it approaches the rotor. (5) The turbine according to claim 4, wherein the outer passage has a larger cross-sectional area than the inner passage. (6) The turbine of claim 5, wherein the outer passage has a cross-sectional area approximately six times that of the inner passage. (7) The turbine according to claim 6, wherein the outer flow passage faces the periphery of the rotor over an area approximately six times larger than the inner flow passage. (8) Claim 4, wherein the valve is capable of assuming a required position between a first position in which the inner flow path is fully opened and a 20th upright position in which the inner flow path is closed. Turbine described in. (9) The turbine according to claim 8, wherein the valve is rotatable so as to direct the gas flowing through the inner flow path toward the dividing wall. 00) a dividing wall extending from the inlet into the housing in substantially perpendicular relation to the dividing wall to divide the housing into a pair of axially spaced flow passages; 5. The turbine of claim 4, wherein each of the passages includes said outer and inner flow passages. aυ The curved section and each section are distinct, and the curved section extends over at least 60 angular ranges and has an inlet at one end and is connected to each section of the spiral at the other end, and each section of the spiral is connected to one axis. and having an outlet coaxially aligned with said axis, the inner surface of the curved portion converging with the inner surface of each portion of the vortex to form an inlet of each portion of the vortex. a housing comprising a tongue-like portion terminating in a portion; and a plurality of circumferentially spaced blades housed within the housing for rotation about the axis of each portion of the spiral. a rotor having two circumferential edges substantially tangential to the tongue; a first dividing wall extending into the housing from the inlet and dividing the housing into a pair of axially spaced passages; extending from said inlet within the housing to a location approximately 90 degrees apart from the terminal end of said tongue generally tangential to the circumference of the rotor and connecting said passages to radially inner and outer passages; a second dividing wall for dividing, the cross-sectional area of each of the inner and outer flow paths constantly decreasing as it approaches the rotor; a rotary valve disposed upstream at the inlet and movable between a first position opening the inner flow passage and a second position closing the inner flow passage for controlling gas flow through the inlet; a variable flow turbine comprising; means for moving the pulp between first and second positions; 12. The turbine of claim 11, wherein the pulp is rotatable to direct gas flowing in the inner channel towards the second dividing wall. 03) The turbine according to claim 11, wherein the flow passage within the curved portion has a cross-sectional area that constantly decreases from the inlet toward each portion of the vortex. 04) The turbine according to claim 11, wherein the inner and outer flow passages in the curved portion have a radius of curvature that decreases as they approach each spiral portion from the inlet.