JPS62253924A - Turbocharger for engine - Google Patents

Abstract

PURPOSE:To make it possible to use the turbocharger in the titled in a highland place and to obtain the high operating efficiency, by varying a slant angle of a guide vane provided at a compressor entrance side of the turbocharger according to an engine speed and load. CONSTITUTION:A turbocharger 10 is composed of a turbine 12 driven by exhaust gas and compressor 14 rotated by said turbine 12, and the compressor 14 is provided with a guide vane 16 at the entrance side thereof. In this arrangement, the guide vane 16 varies the slant angle by means of a driving control means 26 to which, respective output signals of a displacement gage 24 acting as an engine load detection means for detecting the rack positions of an engine tachometer 22 and fuel injection pump, are inputted. And the slant angle of the guide vane 16 is variably controlled in order to determine a fluid inlet angle of an impeller 14a in the compressor 14 so that an engine actuating range may not approach a surge line and said range can have a good operating efficiency.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine turbocharger, and more particularly to an improvement in a barrier-pull geometry turbocharger having a guide vane on the inlet side of a compressor.

(Conventional technology*) An engine turbocharger consists of a turbine that is rotated by exhaust gas supplied from the engine's exhaust passage and a combination leaf that is rotated by this turbine. Place a guide vane on the entrance side. Third
The figure shows the pressure ratio (compressor output/input) πC to the flow rate Q of this barrier-pull geometry turbocharger.
As can be seen from this characteristic, there are cases where the engine operating region is operated near the surge line S, such as when the engine is operated at full load as shown by Ll of 4/4 load. This tendency is particularly noticeable when the vehicle is operated at high altitudes or in environments with low atmospheric pressure, and the vehicle may run beyond the surge line S and stall.

For this reason, conventional engines cannot be used in such environments, and are inefficient because they are operated in an area with low operating efficiency to prevent the engine operating area from exceeding the surge line S. There were drawbacks.

(Object of the Invention) An object of the present invention is to provide an engine turbocharger that can be used at high altitudes or in environments with low atmospheric pressure, and which can be operated with high operating efficiency.

(Structure of the Invention) The engine turbocharger according to the present invention includes a turbine rotated by exhaust gas supplied from an exhaust passage of the engine and a compressor rotated by the turbine, and a guide vane is provided on the inlet side of the compressor. The present invention is directed to a barrier-pull geometry turbocharger having a guide vane whose inclination angle can be varied according to the engine speed and load.

In this way, when the engine is used at high altitude or in an environment with low atmospheric pressure, the engine speed or load changes, and the engine can be controlled in a direction away from the surge line in response to this change, resulting in a stall condition. In addition, the engine can be operated while maintaining maximum operating efficiency.

(Example) An example of the present invention will be described in detail with reference to the drawings. Fig. 1 shows a turbocharger 10 of an engine according to the present invention.
This turbocharger 10 consists of a turbine 12 that is rotated by exhaust gas co-fed from an exhaust passage of an engine (not shown) and a compressor 14 that is rotated by the turbine 12. A guide vane 16 is provided on the inlet side of the compressor 14. It is intended for barrier-pull geometry turbochargers with The turbine 12 has a variable nozzle 20 within its housing 18, and its flow rate can be varied by tilting the variable nozzle 20.

The angle of inclination of the guide vane 16 can be varied depending on the engine speed and load.

As shown in Fig. 2, the engine speed can be detected from the engine tachometer 22, and the engine load can be determined by, for example, the displacement of the rack of the fuel injection needle pump or the actuator. Displacement meter 24 that detects displacement
These output signals are supplied to a drive control means 26 for driving the guide vane 16. This drive control means 26 controls the inflow of the impeller 14a of the compressor 14 so that the engine operating range does not approach the surge line S in FIG. 3 and is as efficient as possible based on the engine speed and load. The inclination angle of the guide vane 15 is variably controlled to determine the angle.

Next, a method of varying the operating range of the engine by varying the guide vanes using the turbocharger of the present invention will be described. First, as shown in FIG. 4(A), when the guide vane 16 is tilted so as to widen with respect to the impeller 14a of the compressor 14, the line Ll becomes the third line as shown in FIG. 4(B) at 4/4 load. Since it is tilted away from the surge line S compared to the line Ll in the figure, it can be operated safely even at high altitudes or in environments with low atmospheric pressure. Also.

When the guide vane 16 is displaced toward the center with respect to the impeller 14a of the compressor 14 as shown in FIG. 5(A), the operating region of the engine approximates that in FIG. 3 as shown by lines Ll and L2, respectively. . Therefore, the engine can be operated efficiently in this state in places other than highlands or low atmospheric pressure environments.

(Effects of the Invention) According to the present invention, as described above, when the engine is used at a high altitude or in an environment with low atmospheric pressure and the engine speed or load changes, the engine moves away from the surge line in response to this change. Since the engine can be controlled in the same direction, there will be no stalling, and the engine can be operated at the highest efficiency at all times, which is a practical benefit.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram of an engine turbocharger according to the present invention, Fig. 2 is a system diagram showing a control system used in the present invention, Fig. 3 is a characteristic diagram of a barrier-pull geometry turbocharger, and Fig. 4 (A ) (B) and Figure 85 (A) CB
) are schematic diagrams of different states of the guide vane and respective characteristic diagrams. i o---m-engine turbocharger, 12
--1--Turbine, 14--Compressor,
l 6-----Guide vane, 22-----1 engine tachometer, 24-----Displacement meter, 26-----Guide vane drive control means.

Claims (1)

[Claims] In an engine turbocharger, the engine turbocharger includes a turbine rotated by exhaust gas supplied from an exhaust passage of the engine and a compressor rotated by the turbine, and has a guide vane on the inlet side of the compressor. An engine turbocharger characterized by varying its inclination angle depending on the rotation speed and load.