JPS60166718A - exhaust turbine supercharger - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an exhaust turbine supercharger, and particularly to an improvement of a turbine scroll.

[Background of the invention]

To explain a conventional exhaust turbine supercharger with reference to FIG.
v3 is connected, and the exhaust gas from the engine 1 drives the turbine 5. A compressor 6 is fixed to the other end of the rotating machine to which the turbine 5 is fixed, and is driven at the same rotation speed as the turbine 5. The air compressed by the compressor 6 is sent into the intake pipe 4, but the boost pressure at this time is as shown in P0' in Figure 3, and there is sufficient boost pressure in the low and medium speed range of the engine. There are some drawbacks that cannot be obtained.

Therefore, in order to improve this difficulty even a little, it is common to use a turbine scroll having a relatively small flow passage area that is suitable for the low speed range of the engine. but,
In this case, the supercharging pressure becomes too high when the engine rotates at high speed, so an exhaust bypass valve 7 is provided in the exhaust pipe 3 at the turbine inlet, as illustrated in FIG.
The supercharging pressure is controlled by a supercharging pressure detector 8 equipped with a suction pipe 4 so that the supercharging pressure is below a certain value, and the supercharging pressure is adjusted to p in Fig. 3.
Improve like y.

However, when exhaust bypass control is performed, the turbine inlet pressure becomes higher than the supercharging pressure Pc', such as Pt'', due to the energy lost with the bypassed exhaust gas.
The problem was that the exhaust efficiency decreased.

[Purpose of the invention]

This invention not only improves the turbine scroll described above to effectively utilize the engine from low speed to high speed ranges, but also provides excellent exhaust performance by avoiding excessive turbine inlet pressure. The purpose of this invention is to provide an exhaust turbine supercharger with good boost pressure characteristics.

[Summary of the invention]

In this invention, the inside of a turbine scroll is divided into two passages in the axial direction by a partition wall, one of the exits of this passage is configured as a bladed nozzle with arranged blades, and the other is configured as a bladeless nozzle. connects the exhaust pipes of the engine divided into two groups, and when the exhaust gas flow rate is low in the low speed rotation range of the engine, the exhaust gas is guided only to the scroll passage with the vaned nozzle, and even with a small exhaust gas flow rate. To obtain large turbine output. In this case, it is desirable that the vaned nozzles be arranged to suit the low speed rotation range of the engine.

In addition, in the high speed rotation range of the engine, if there is a lot of exhaust gas, the engine air is also guided to the other scroll passage with a bladeless nozzle, increasing the capacity of the turbine and causing excessive turbine output. Control the boost pressure so that it does not occur. As mentioned above, by effectively utilizing the advantages of the bladeless nozzle, which has good efficiency over a wide flow rate range, and the bladed nozzle, which has good efficiency within a constant flow rate range, and by changing the capacity of the turbine, the engine can be adjusted from low speed to high speed. This technology has been implemented to ensure good supercharging performance over a wide operating range.

[Embodiments of the invention]

Embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 4 is a sectional view of a main part of the turbine section of the exhaust turbine supercharger, and FIG. 5 is a sectional view taken along line AA in FIG. 4. 14 is a turbine rotor, 15 is a bearing casing, and a turbine scroll 9 is attached to this casing 15. A partition wall 11 is provided on the inner peripheral surface of the turbine scroll 9 and faces the outer peripheral surface of the turbine rotor 14.
It is divided into two passages 10a and 10b. The outlet of one of the passages 10a constitutes a bladed nozzle, and the outlet of the other passage 10b constitutes a bladeless nozzle 12b. And this passage 10a.

Each tab is an exhaust pipe divided into two groups (not shown)
is connected to.

142 Passage 10b17 having a bladeless nozzle 12b
is the piston 1 housed in the cylinder 21 via the shaft 18
It is connected to 9. A spring 20 is installed on the opposite shaft side of the piston 19.
is mediated. The cylinder 21 is configured such that pressure introduction holes 22a and 22b are provided at both ends thereof. Therefore, when pressure is introduced into the introduction hole 22a, the valve 17 moves to the left in the figure to open the passage tab, and when pressure is introduced to the introduction hole 22b, the valve 7 moves to the right and operates to close the passage j1310b. do. Note that the introduction hole 22b is connected to the spring 20.
It is also possible to open the tank to the atmosphere by adjusting the tension.

In the above configuration, when the supercharging pressure is low when the engine speed is low, the valve 17 is pushed to the right by the force of the spring 20, and the passage tab is closed.

Therefore, the exhaust gas from the engine flows only into the passage 10a as indicated by the arrow 16a in the figure and is ejected from the vaned nozzle 12a, thereby rotationally driving the turbine rotor 14.

In this case, it is possible to determine the shape of the bladed nozzle so that it fits the inlet part of the turbine rotor 14 and provides a sufficiently high-speed flow even with a small engine exhaust flow rate, and it is possible to increase the 82 of the turbine rotor 14 at low engine speeds, The boost pressure can be greatly increased from P, / to PC# as shown in Fig. 3. Further, when the supercharging pressure is high when the engine is running at high speed, when the supercharging pressure is introduced into the pressure introduction hole 22a, the piston 19 moves to the left and the control valve 17 opens the passage 10b. As a result, the engine exhaust gas is
It also flows into the passage 10b as shown in FIG.
Like O2, it is controlled to below a certain value in the engine high speed range.

The vaneless nozzle has good efficiency over a wide flow range, so even at high engine speeds, the turbine inlet pressure, pt'', is similar to the boost pressure, and is much wider than Pt' in the case of an exhaust bypass valve. This results in a lower value and can improve engine performance.

The same effect can be obtained by providing guide vanes 12c' and 12c' on both side walls of the nozzle part 12c as shown in FIGS. 6 and 7 instead of the vaned nozzle 12a shown in FIGS. 4 and 5. Furthermore, as shown in FIG. 8, the guide vanes 12d may extend from one side of the wall surface.

〔Effect of the invention〕

As explained above, according to the present invention, the turbine scroll is divided into two passages, a passage having a bladed nozzle and a scroll having a bladeless nozzle, and the bladed nozzle is provided so as to be suitable for a state where the turbine flow rate is low. A control valve at the entrance of the vaned nozzle passage concentrates the flow to the vaned nozzle when the exhaust flow rate is low at low engine speeds.
Since the bladeless nozzle with a wide operating range is activated when the engine is at high speed, the turbine capacity can be efficiently varied over a wide range, which has the effect of improving the engine's low-speed torque characteristics and responsiveness during sudden acceleration. Moreover, the turbine input pressure, that is, the engine exhaust pressure when the engine is running at high speed, does not become abnormally high, which has the effect of improving fuel efficiency.

[Brief explanation of the drawing]

Figures 1 and 2 are system diagrams of conventional superchargers, Figure 3 is a diagram showing engine speed, turbine inlet pressure, and boost pressure;
FIG. 4 is a cross-sectional view of a main part of a turbocharger turbine section of the present invention, FIG. 5 is a cross-sectional view taken along line AA in FIG. 4, and FIG. 6 is a supercharger turbine section showing another embodiment of the present invention. 7 is a sectional view taken along line BB in FIG. 6, and FIG. 8 is a sectional view of essential parts of a supercharger turbine section showing still another embodiment of the present invention. 9... Turbine scroll, 10a, 10b... Passage, 1, 2 a... Vane nozzle, 12b... Vaneless nozzle, 17... Control valve, 19... Piston, 21.22nd 1st spear 2nd figure 4th sensai 5 nagi ootokuni -q” 7 I2]

Claims (1)

[Claims] 1, -e, 'c 26 internal 9. In an exhaust turbine supercharger in which a partition wall is provided, the turbine scroll is divided into two passages in the axial direction, and exhaust pipes of an engine divided into two groups are connected to the passage, one of the outlet of the passage is equipped with a blade. An exhaust turbine over-kissing machine, characterized in that the other layer is a nozzle, the other layer is a bladeless nozzle, and means for controlling the flow rate of one of the passages leading to the nozzle depending on the operating state of the engine. 2. The exhaust turbine supercharger according to claim 1, wherein the means for controlling the flow rate is disposed in a passageway of the bladeless nozzle. 3. In claim 1 or 2, the means for controlling the flow rate includes a control valve arranged in the passage, a shaft connected to the valve, and a cylinder connected to the shaft. An exhaust turbine supercharger comprising a piston housed in the cylinder and a pressure introduction hole provided in the cylinder to move the piston.