JPH04365932A - Device for improving performance of turbine - Google Patents

Abstract

PURPOSE:To improve performance of a turbine by supplying slow exhaust flow under a partial load of an engine to the turbine of a turbocharger. CONSTITUTION:A plurality of opening/closing valves 3 which partially close a nozzle part 12 of a turbine scroll are arranged on an exhaust flow passage of the turbine scroll 1, while a closing part 13 is structured on the nozzle part near a gas inlet. A specified portion of the nozzle part 12 is closed by the valves 3 under a partial load of an engine to reduce an area of the nozzle part 12 and thottle exhaust gas. A turbine 2 is thus driven with efficiency.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turbine performance improving device for improving the performance of a turbine of an engine equipped with a turbocharger at partial load.

0002

[Prior Art] In recent years, turbochargers that recover engine exhaust energy to increase supercharging pressure have been widely used. Engines equipped with such turbochargers have high output and a large amount of exhaust gas. In this case, the driving force of the turbine is strong and therefore high boost pressure can be obtained, but when the engine is at partial load, sufficient boost pressure cannot be obtained because the amount of exhaust gas is small, so the turbine performance at partial load is improved. Various attempts have been made to do so.

FIG. 4 is an explanatory diagram of the most common method for improving turbine performance of this type, in which a partition plate S is provided at the nozzle part of the exhaust flow path of the turbine housing H, and when the engine is under partial load, the Guide exhaust gas only to part A,
This narrows the flow path and drives the turbine.

FIG. 5 shows a guide vane G arranged in the exhaust flow path, which provides a restriction and improves the efficiency of exhaust energy.

[0005]

[Problems to be Solved by the Invention] The method shown in FIG. 4 for improving turbine performance during engine partial load is as follows:
The area of part A is narrowed and the gas flow speed increases, but the area of part B of the turbine increases and further expands in part C, so
Although the effect of increasing the speed due to the restriction of the section A can be obtained, it is difficult to increase the turbine output during partial load. That is, the problem is that under partial load, the flow rate of exhaust gas decreases, so no restriction occurs in the wide turbine nozzle section, and therefore the turbine cannot perform expansion work.

[0006]Also, in the attempt shown in FIG. 5, the exhaust gas flow path is guided, but it has the same drawback that it does not provide a fundamental solution.

The present invention was made in view of these problems, and its purpose is to provide a turbine performance improvement device for improving the performance of a turbine driven by weak exhaust energy when the engine is partially loaded. It is about providing.

[0008]

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention improves the performance of a turbine driven by an exhaust gas flow pumped from a nozzle portion of a turbine scroll close to the outer periphery of the turbine. In a turbine performance improvement device for improving engine performance during partial load, a turbine is provided with a closing part in a nozzle part near the gas inlet of the turbine scroll, and a plurality of on-off valves for partially closing nozzle parts other than the closing part. A performance enhancement device is provided.

[0009]

Embodiments Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is an explanatory diagram showing one embodiment of the turbine performance improvement device according to the present invention, and FIG. 2 is an explanatory diagram cut along the cutting line α-α in FIG. 1 and viewed from the turbine axial direction.

In the figure, reference numeral 1 denotes a turbine scroll of a turbocharger, which guides exhaust gas that is pressure-fed from an exhaust gas inlet 11 to a turbine 2 and efficiently rotates the turbine scroll.

The cross-sectional shape of the exhaust flow path of the turbine scroll 1 is formed in the shape of a shown in the figure.
A nozzle portion 12 with a narrowed flow path is formed in a portion near the outer periphery of the nozzle, excluding the illustrated closing portion 13.

Reference numerals 3 and 4 each designate an on-off valve for a predetermined portion of the nozzle portion 12, and the shaft portions 31 and 41 at one end are fixed to the inner wall portion of the turbine scroll 1, and are made of, for example, a heat-resistant ceramic material. At the other end, valve parts 32 and 42, which engage with the nozzle part 12 and close the flow path, are provided, respectively, and rod-shaped handle parts 33 and 43 shown in FIG.
It is connected to the shaft parts 31 and 41 by.

When the engine load is high and the amount of exhaust gas is large, a storage section 34 provided on the outside of the inner wall of the turbine scroll 1 with the shaft sections 31 and 41 as axes is used.
and 44, and the entire circumference of the nozzle portion 12 except for the closed portion 13 is open. Further, when the engine is partially loaded, the on-off valves 3 and 4 move in the directions of arrows P and Q shown in the figure, respectively, so that the valve parts 32 and 42 are connected to the nozzle part 1.
The turbine 2 is configured to block a predetermined portion of the turbine 2 to throttle a small exhaust flow during partial load, and to divide the direction of exhaust gas blown to the turbine 2 into three directions.

Next, the operation of this embodiment constructed as described above will be explained. When the engine is under high load, the on-off valves 3 and 4 are housed in the housing sections 34 and 44 of the turbine scroll 1, respectively, so that the exhaust gas with a large flow rate is passes through the flow path of the turbine scroll 1 without any hindrance and reaches the turbine 2 via the wide nozzle part 12, and the turbine 2 shown in FIG.
Sufficient expansion work is performed in the expansion chamber 21 between the blades, and the gas is released from the gas outlet 14 to the outside air.

[0016] Also, when the engine is under partial load, the on-off valve 3
and 4 move in the directions of arrows P and Q shown in FIG. 1, respectively, and the valve parts 32 and 33 partially close the predetermined nozzle part 12. Therefore, the area of the closed portion of the nozzle portion 12 on the outer periphery of the turbine 2 is reduced, the flow path is narrowed, and the nozzle is divided into three directions, so that a small amount of exhaust gas can be efficiently blown to the turbine 2. , expansion chamber 21
The work at is performed to drive the turbine 2. In this case, the handle portions 33 and 43 of the on-off valves 3 and 4 that close the nozzle portion 12 are shaped like thin rods, and therefore have little influence on the flow of exhaust gas.

Although the present invention has been described above with reference to the above-mentioned embodiments, various modifications can be made within the scope of the gist of the present invention, and these modifications are not excluded from the scope of the present invention.

[0018]

As described above, according to the present invention, when the engine is partially loaded, the nozzle section is closed by the valve sections of the plural on-off valves to reduce the area of the nozzle section, so that the weak exhaust flow during the partial load is reduced. The gas is constricted and reaches the turbine, where sufficient expansion work can be performed between the turbine blades, driving the turbine more powerfully and improving its performance.

Furthermore, in the present invention, since the nozzle section is partially closed by a plurality of on-off valves, the exhaust flow pumped from the unclosed nozzle sections in three directions is dispersed around the outer circumference of the turbine, thereby efficiently driving the turbine. This is an advantage.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an embodiment of a turbine performance improvement device according to the present invention.

FIG. 2 is an explanatory diagram cut along the cutting line α-α in FIG. 1;

FIG. 3 is a partially cutaway perspective view showing the relationship between a turbine scroll and a turbine.

FIG. 4 is a sectional view showing an example of a conventional turbine performance improvement device.

FIG. 5 is an explanatory diagram showing another example of a conventional turbine performance improvement device.

[Explanation of symbols]

1...Turbine scroll 2...Turbine 3...Opening/closing valve 4...Opening/closing valve 12...Nozzle part 13...Closing part 32...Valve part 33...Handle 42...Valve part 43...Handle

Claims (2)

[Claims] 1. A turbine performance improvement device for improving the performance of a turbine driven by an exhaust gas flow pumped from a nozzle portion of a turbine scroll close to the outer periphery of the turbine when the engine is at partial load. A turbine performance improvement device characterized in that a closing section is provided in a nozzle section near a gas inlet, and a plurality of on-off valves are arranged to partially close nozzle sections other than the closing section. 2. The on-off valve has a valve portion that engages with the nozzle portion at one end of the handle, and the other end is pivotally supported by an outer portion of the inner wall of the turbine scroll. Item 1. Turbine performance improvement device according to item 1.