JPS63302134A - Exhaust gas turbine supercharger - Google Patents

Abstract

PURPOSE:To enhance the effect of supercharger in a low speed range by dividing the inside of a turbine scroll into two scroll chambers with the use of a partition wall, and by extending the inlet part of a turbine impeller in one of nozzle parts formed respectively in these scroll chambers, which is used in a low speed range. CONSTITUTION:A turbine scroll 4 of an exhaust turbine impeller is divided into a two scroll chambers 4a, 4b by a partition wall 5 which also divides a nozzle section into two nozzle parts 6a, 6b. The part 1b of the inlet part of a turbine impeller 1, which faces the scroll chamber 4b, has a shape such that it extends in the nozzle part 6b. Further, the partition wall 5 is connected to a partition plate 8 in a turbine inlet 7, and a control valve 12 is provided in an aperture 11 which is formed in the partition plate 8 so as to communicate between an open scroll 9 and a closed scroll 10. Further, a bypass valve 22 is provided in a bypass aperture 21 formed in a closed scroll 22 downstream of a control valve 12.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to an exhaust turbine supercharger in which a turbine and a compressor are arranged on the same axis, and particularly relates to an exhaust turbine supercharger equipped with a variable displacement turbine suitable for passenger car engines. This relates to a turbine supercharger.

[Conventional technology]

Conventional exhaust turbine superchargers with a structure that allows the turbine capacity to be made variable have a structure in which the tip of the partition wall is separated from the inlet of the turbine impeller and the nozzle part is integrated, as described in U.S. Pat. No. 3,614,259. What I did, again.

As described in Japanese Utility Model Application Laid-Open No. 61-88002, it is known that the tip of the partition wall is positioned close to the inlet of the turbine impeller.

[Problem that the invention seeks to solve]

The above conventional technology concentrates the exhaust gas into only one scroll chamber when the engine is operating in a low speed range and the exhaust flow rate is small, and the exhaust gas is sufficiently sped up with a scroll passage area suitable for the small flow rate to drive the turbine impeller. It leads to the inlet and increases the turbine rotation speed to obtain sufficient supercharging performance. but,
As shown in FIG. 3, two scroll chambers 4a are constructed in this way.
, if the exhaust gas is guided only to one side of the scroll chamber 4b, no consideration is given to the fact that part of the exhaust gas will bypass the partition wall tip 5' and leak into the other scroll chamber as shown by arrow B. There was a problem that a sufficient effect could not be obtained due to loss due to leakage flow6 [Means to solve the problem] The above purpose was to install a turbine impeller inlet part in the nozzle part on the small capacity side used in the low speed range of the engine. This is achieved by stretching the exhaust gas so that when it is introduced only into the scroll chamber on the small capacity side, the exhaust gas does not leak into the other scroll chamber and always flows into the turbine impeller.

[Effect]

By extending the part of the turbine impeller inlet facing the low-speed nozzle part in the radial direction and inserting it into the partition wall and side wall, the exhaust gas concentrated on the low-speed scroll in the low engine speed range will always flow directly into the turbine impeller. If the flow leaks to the other scroll chamber, work is applied to the turbine impeller once, and the flow that has lost energy, that is, the flow that has decreased in velocity, leaks, so the turbine fluid loss at low capacity is reduced. This significantly reduces the supercharging effect in the low speed range of the engine.

〔Example〕

Hereinafter, an embodiment of the present invention will be explained with reference to FIG. 1, and in FIG. 6, a description of the compressor portion of the exhaust turbine supercharger will be omitted since it is not a target portion of the present invention. 1st
In the figure, a turbine impeller 1 and a compressor impeller (not shown) are fixedly arranged by a shaft 2 . A bearing casing 3 is disposed around the outer periphery of this shaft 2 and is attached to a turbine scroll 4.

The turbine scroll 4 is divided by a partition wall 5 into two scroll chambers 4a and 4b. The nozzle portion is also divided into two by this partition to form 6a and 6b. Of the inlet portion of the turbine impeller 1, the portion 1a facing the scroll chamber 4a is located close to the tip 5' of the partition wall 5, and the other portion 1b facing the scroll chamber 4b is shaped to extend into the nozzle portion 6b. do.

The partition wall 5 is connected to a partition plate 8 of the turbine-entering lower, and the flow path of the turbine-entering lower is defined by this partition plate 8.

It is divided into an open scroll 9 and a closed scroll 10. The open scroll 9 communicates directly with the turbine inlet 9, and the closed scroll 10 communicates with the open scroll 9 through holes 11 drilled in the partition plate 8. A control valve 12 is disposed in this hole 11 to communicate and cut off the open scroll 9 and the closed scroll 10, that is, to communicate and cut off the closed scroll 10 with respect to the turbine lower.

The control valve 12 is configured to be rotatable around a shaft 13, and the shaft 13 is connected to a shaft 15 of an actuator 17 via an arm 14.
It is connected to the. The actuator 17 includes a spring member 16 that presses the shaft 15 in one direction, and a bellows 18 that is arranged to resist the spring member 16. The bellows 18 is provided with a hole 19 for introducing supercharging pressure or the like. Further, a bypass hole 21 is bored in the closed scroll 1o downstream of the control valve 12, and communicates with a bypass passage 20 leading to the turbine outlet. A bypass valve 22 is provided in the bypass hole 21.
is configured to be able to rotate around a shaft 23, and the shaft 23 is connected to a shaft 25 of an actuator 27 via an arm 24. The actuator 27 consists of a bellows 28 arranged so as to resist a spring member 26 that presses the shaft 25 in one direction, and the bellows 28 is provided with a hole 29 through which supercharging pressure or the like is introduced.

The present invention has the above configuration, and when the control valve 12 closes the hole 11, the exhaust gas from the turbine lower passes through the open scroll 9 and concentrates into the scroll chamber 4b.

FIG. 2 is an enlarged view of the scroll and turbine impeller. The impeller inlet part 1b of the turbine impeller 1, which faces the scroll chamber 4b, is extended radially outward from the partition wall tip position 5', and the impeller inlet part 1a, which faces the scroll chamber 4a, is brought close to the partition wall tip part 5'. Therefore, all the exhaust gas concentrated in the scroll chamber 4b flows into the impeller 1 as shown by the arrow A in FIG. Since the energy of the fluid is given to the turbine impeller while flowing to the turbine impeller, and the low-speed exhaust gas leaks, loss is small and supercharging performance can be greatly improved.

If the boost pressure is introduced into the hole 19 of the bellows 18, the control valve 12 will be closed as described above when the boost pressure does not reach the set value in the low engine speed range, and the control valve 12 will be closed as described above. When the supercharging pressure increases sufficiently, the force based on the pressure inside the bellows 18 becomes larger than the force of the spring member 16, and the shaft 1 of the actuator 17
5 is pressed, the control valve 12 opens the hole 11, and the exhaust gas flows into the turbine impeller 1 from both the scroll chambers 4a and 4b, thereby preventing the capacity of the turbine scroll from increasing and the supercharging pressure from becoming excessive. can do.

In addition, by introducing supercharging pressure into the hole 29 of the bellows 28 and adjusting the spring force of the spring member 26 so that the futurator 27 operates when the supercharging pressure is about to become excessive, the bypass valve By opening 22, it is possible to control the boost pressure to an appropriate level over a wider operating range.

〔Effect of the invention〕

As explained above, according to the present invention, the inside of the turbine scroll is divided into two scroll chambers by the partition wall,
The exhaust gas flowing through the scroll chamber is controlled according to the engine operating condition, and when only one scroll chamber is used in the low engine speed range, losses due to leakage to the other scroll chamber can be significantly reduced. Sufficient boost pressure can be obtained from the low engine speed range, resulting in good running performance and improved fuel efficiency over a wide operating range.

[Brief explanation of drawings]

FIG. 1 is a sectional view of essential parts showing an embodiment of the present invention, FIG. 2 is an enlarged sectional view of the scroll and turbine impeller shown in FIG. 1,
FIG. 3 is a sectional view of a main part of a conventional turbine. DESCRIPTION OF SYMBOLS 1... Turbine impeller, la, lb... Turbine impeller inlet part, 4... Turbine scroll, 4a, 4b
...Scroll chamber, 5...Partition wall, 12...Control valve, 22...Bypass valve.

Claims (1)

[Claims] 1. In an exhaust turbine supercharger in which a turbine and a compressor are fixedly arranged on the same axis, the inside of the scroll of the turbine is divided into two scroll chambers in the axial direction by a partition, and the tip of the partition and the side wall of the turbine casing are separated. Two nozzle parts are configured, and among the turbine impeller inlet parts facing the two nozzle parts, the turbine impeller inlet part facing one nozzle part extends radially outward from the partition wall tip position to form the inside of the nozzle. An exhaust turbine supercharger, characterized in that the exhaust turbine supercharger is equipped with means for controlling the flow rate of the scroll chamber that is inserted into the scroll chamber and communicates with the nozzle section on the side where the turbine impeller inlet section is not extended, depending on the operating state of the engine. .