JPH11303642A - Supercharger - Google Patents

Abstract

(57) [Problem] To provide a supercharger capable of suppressing occurrence of erosion on an inner wall of a scroll flow path. SOLUTION: A casing main body 2 in which a scroll flow path 1 whose flow passage cross-sectional area is gradually reduced in the circumferential direction at an inner peripheral edge portion, and a compressor disposed at an inner center of the casing main body 2 are provided. A turbine rotor 3 to be driven, a gas supply port communicating with the end of the maximum flow path cross-sectional area of the scroll flow path 1, a gas discharge port 5 communicating from the interior space of the turbine rotor 3 of the casing body 2 to the outside, The casing body 2 extends from the mouth along the inner wall of the scroll flow path 1 to a portion just before the end of the minimum cross-sectional area of the scroll flow path 1 and projects from the inner wall of the scroll flow path 1 in the radial direction of the turbine rotor 3. And a flow path wall 9 provided therein.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a supercharger.

[0002]

2. Description of the Related Art FIGS. 4 and 5 show an example of a twin-flow type supercharger applied to a multi-cylinder large-displacement engine for ships and the like. This supercharger has an inner peripheral portion. The casing body 2 includes a scroll main body 2 in which the cross-sectional area of the flow path gradually decreases in the circumferential direction, and a turbine rotor 3 disposed at an inner center of the casing main body 2.

The casing body 2 has a turbine rotor 3
Gas supply port 4 extending in a tangential direction to the outside of the casing main body 2 and communicating with the end of the maximum flow path cross-sectional area of the scroll flow path 1
And a gas outlet 5 extending in the axial direction of the turbine rotor 3 and communicating from the interior space of the turbine rotor 3 of the casing main body 2 to the outside of the casing main body 2.

[0004] The casing body 2 is attached to the turbine rotor 3.
A shaft 7 that rotatably penetrates a heat shield plate 6 fitted at the end of the anti-gas discharge port 5 is integrally formed, and a tip portion of the shaft 7 has an impeller (not shown) of a compressor. Is installed.

Further, inside the casing main body 2, the gas supply port 4 extends along the inner wall of the scroll flow path 1 to the end of the minimum flow path cross-sectional area of the scroll flow path 1, and extends from the inner wall of the scroll flow path 1 to the turbine. A flow path wall 8 that protrudes in the radial direction of the rotor 3 is provided.

Gas (exhaust) exhausted from half of the cylinders of the multi-cylinder engine is introduced into a portion near one side of the scroll flow path 1 divided by the flow path wall 8.
The gas (exhaust) discharged from the remaining half of the cylinders, which does not serve as a gas supply source to the one-sided portion, is introduced into the portion near the other side of the scroll flow path 1 that is divided by I have.

That is, in the twin-flow type turbocharger, fluctuations in the rotation speed of the turbine rotor 3 due to the pulsation of the gas discharged from each of the cylinders, and gas discharged from a plurality of cylinders having the same supercharger Exhaust interference caused by being supplied to the compressor is suppressed, and the dynamic pressure component of the gas discharged from each cylinder is effectively converted as the rotational force of the compressor.

[0008]

However, in the twin-flow type supercharger, the cross-sectional shape of the scroll flow path 1 is gradually reduced. When 1 is viewed in the axial direction of the turbine rotor 3, the portion indicated by the dashed line A in FIG.
(A portion that exceeds 180 ° in the circumferential direction as a degree) increases the gas flow velocity, and centrifugal force acts on fine particles such as silicon dioxide and aluminum oxide contained in the gas, and these fine particles are formed in the scroll flow path. In some cases, the inner wall may collide with the inner wall and erosion may occur as if the inner wall was cut off.

The occurrence of such erosion is a phenomenon peculiar to a twin-flow type supercharger. In a single-flow type supercharger in which the flow path wall 8 is not provided in the scroll flow path 1, the erosion is reduced. It rarely occurs remarkably.

The present invention has been made in view of the above circumstances, and has as its object to provide a supercharger capable of suppressing the occurrence of erosion on the inner wall of a scroll passage.

[0011]

According to a first aspect of the present invention, there is provided a supercharger in which a cross-sectional area of a flow passage is gradually reduced toward an inner peripheral portion in a circumferential direction. A casing body in which a flow path is formed, a turbine rotor disposed at an inner center of the casing body and driving a compressor, and a gas supply communicating from outside the casing body to an end of a maximum flow path cross-sectional area of the scroll flow path Port, a gas discharge port communicating from the turbine rotor interior space of the casing main body to the outside of the casing main body, and a portion from the gas supply port along the inner wall of the scroll flow path to a portion just before the end of the minimum flow path cross-sectional area of the scroll flow path. A channel wall provided in the casing body so as to extend and protrude from the inner wall of the scroll channel in the radial direction of the turbine rotor.

Further, in the supercharger according to a second aspect of the present invention, in addition to the supercharger according to the first aspect of the present invention, a minimum flow path without a flow path wall of a scroll flow path is provided. A coating layer is formed on the inner wall near the end of the cross-sectional area by thermal spraying.

In any of the superchargers according to the first and second aspects of the present invention, the flow path wall is formed only between the gas supply port and the end of the minimum flow path cross-sectional area end of the scroll flow path. Provided to suppress fluctuations in the rotation speed of the turbine rotor caused by pulsation of gas discharged from individual cylinders and exhaust interference caused by gas discharged from multiple cylinders being supplied to the same turbocharger At the same time, fine particles that collide with the inner wall near the end of the minimum flow path cross-sectional area of the scroll flow path are dispersed to suppress erosion of the inner wall of the scroll flow path.

Further, in the supercharger according to the second aspect of the present invention, a coating layer formed by thermal spraying is formed in a portion near the end of the minimum flow path cross-sectional area of the scroll flow path, and fine particles are formed in this portion. Erosion due to collision is effectively suppressed.

[0015]

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

FIGS. 1 and 2 show an embodiment of the present invention, in which the same components as those in FIGS. 4 and 5 are denoted by the same reference numerals.

In this supercharger, a portion (the scroll passage) in front of the minimum passage cross-sectional area end of the scroll passage 1 along the inner wall of the scroll passage 1 from the gas supply port 4 inside the casing main body 2. 1 when viewed in the axial direction of the turbine rotor 3, the portion indicated by the one-dot chain line A in FIG. 3, a radially protruding flow path wall 9 is provided, and a coating layer 10 formed by thermal spraying is formed on the inner wall of the scroll flow path 1 near the end of the minimum flow path cross-sectional area where the flow path wall 9 is not provided. .

FIG. 3 shows an example of a thermal spraying device used for forming the coating layer 10. The thermal spraying device has a device main body 11 having a combustion chamber therein at the lower part, and an emission tube 12.

The fuel (hydrogen, hydrocarbon) supplied from the fuel supply port 13 is supplied to the combustion chamber in a high pressure state together with the oxygen supplied from the oxygen supply port 14 to complete combustion, and the combustion gas generated by the complete combustion Is emitted as a hypersonic jet through the emission tube 12 from the tip of the emission tube 12.

On the other hand, the thermal spraying material in the powder state is
1 is introduced into the center of the combustion gas by an inert gas through a powder supply port 15 provided at a rear portion of the combustion gas, and is heated to a high temperature and injected as high-speed moving particles along the flow of the combustion gas. The coating layer 10 is formed by welding to the target portion.

Reference numeral 16 denotes a cooling water inlet, and reference numeral 17 denotes a cooling water outlet.

In the supercharger shown in FIG. 1, since the flow path wall 9 is provided between the gas supply port 4 and a position just before the end of the minimum cross-sectional area of the scroll flow path 1, the supercharger is discharged from each cylinder. Of the scroll flow path 1 while suppressing fluctuations in the rotation speed of the turbine rotor 3 due to the pulsation of the gas and exhaust interference caused by the gas discharged from the plurality of cylinders being supplied to the same supercharger. Erosion of the inner wall of the scroll flow path 1 can be suppressed by dispersing fine particles that collide with the inner wall near the end of the minimum cross-sectional area.

Further, since the coating layer 10 is formed by thermal spraying in the vicinity of the end of the minimum flow path cross-sectional area of the scroll flow path 1, the occurrence of erosion due to the collision of fine particles with the spray flow is effectively suppressed. can do.

The above-described coating layer 10 can be formed because the flow path wall 9 is not provided in the portion of the scroll flow path 1 near the end of the minimum flow path cross-sectional area, and is shown in FIGS. If the flow path wall 8 is formed up to the end of the minimum flow path cross-sectional area of the scroll flow path 1 as described above, it is difficult to weld particles to the inner wall of the scroll flow path 1 by the thermal spraying device shown in FIG.

It should be noted that the supercharger of the present invention is not limited to the above-described embodiment, but may have a configuration in which the coating layer is omitted according to the use conditions, and does not deviate from the gist of the present invention. Of course, various changes can be made within the range.

[0026]

As described above, according to the supercharger of the present invention, various excellent effects can be obtained as follows.

(1) In any one of the superchargers according to the first and second aspects of the present invention, only the portion from the gas supply port to a portion immediately before the end of the minimum flow path cross-sectional area of the scroll flow path. Since the flow path walls are provided, fluctuations in the rotation speed of the turbine rotor due to pulsation of gas discharged from individual cylinders, and gas discharged from multiple cylinders are supplied to the same turbocharger While suppressing the exhaust interference caused by the above, the fine particles colliding with the inner wall near the end of the minimum flow path cross-sectional area of the scroll flow path can be dispersed to suppress the erosion of the inner wall of the scroll flow path.

(2) In the supercharger according to the second aspect of the present invention, since the coating layer formed by thermal spraying is formed in the vicinity of the end of the minimum cross-sectional area of the scroll flow channel, the coating layer is formed in the portion. Erosion caused by collision of fine particles can be effectively suppressed.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an example of an embodiment of a supercharger according to the present invention.

FIG. 2 is a cross-sectional view perpendicular to the axis of a casing main body related to FIG. 1;

FIG. 3 is a conceptual diagram of an example of a thermal spraying apparatus.

FIG. 4 is a cross-sectional view of an example of a conventional turbocharger.

FIG. 5 is an axially orthogonal cross-sectional view of a casing main body related to FIG. 4;

[Description of Signs] 1 scroll flow path 2 casing body 3 turbine rotor 4 gas supply port 5 gas discharge port 9 flow path wall

Claims (2)

[Claims] 1. A casing main body having a scroll flow path in which a flow passage cross-sectional area is gradually reduced in a circumferential direction at an inner peripheral edge portion, and a compressor disposed at an inner center of the casing main body and driving a compressor. A gas supply port communicating from the outside of the casing body to the end of the maximum cross-sectional area of the scroll flow path; a gas discharge port communicating from the turbine rotor interior space of the casing body to the outside of the casing body; A flow provided in the casing body so as to extend from the mouth along the inner wall of the scroll flow path to a portion just before the end of the minimum flow path cross-sectional area of the scroll flow path, and to protrude from the inner wall of the scroll flow path in the radial direction of the turbine rotor. A supercharger comprising a road wall. 2. The supercharger according to claim 1, wherein a coating layer formed by thermal spraying is formed on an inner wall of a portion of the scroll flow path where the flow path wall is not provided and near the end of the minimum flow path cross-sectional area.