JPS6098128A - Supercharger - Google Patents

Abstract

PURPOSE:To make improvements in durability, by covering a center housing's inner wall surface with a material obtainable as fines in a process of emulsion polymerization of tetrafluoroethylene, while preventing a carbide of lubricating oil from sticking on the housing's inner wall surface. CONSTITUTION:During operation, lubricating oil is led into radial metals 20 and 21 from a feed port 22, while the lubricating oil after beig used is put back to an oil pan from a drain oil port 25. Also during operation, an inner wall of a center housing 15 is cooled by lubricating oil and its temperature becomes about 150 deg.C of less. When an internal-combustion engine is stopped, heat held in a turbine case of a turbine 14 is transmitted to the inner wall surface of which temperature rises up to about 300-400 deg.C whereby lubricating oil sticking to the inner wall surface comes into a state of being liable to be carbonized but owing to covering 24 of a material obtainable as fines in a process of emulsion polymerization of tetrafluororthylene, the sticking of lubricating oil is well reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an improvement in a supercharger for an internal combustion engine.

[Background of the invention]

While using an actual vehicle equipped with a turbocharger for a gasoline engine, as stated in Japanese Utility Model Application Publication No. 48-26304, after the engine stops, the circulation of lubricating oil used for lubrication and cooling stops. will be done. As a result, the inner wall surface of the turbocharger's center housing becomes extremely hot, and the lubricating oil adhering to the inner wall surface becomes carbonized or has a high viscosity, and this state is repeated every time the engine is stopped. They are deposited one after another. As a result, in extreme cases, a problem occurs in which the oil drain port is narrowed and lubricating oil leaks from the piston ring portion, which is the turbine side oil seal mechanism, resulting in a decrease in durability.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a supercharger that can improve durability by preventing carbide of lubricating oil from adhering to the inner wall surface of a center housing.

[Summary of the invention]

The supercharger of the present invention includes a turbine rotatably driven by the exhaust gas of an internal combustion engine, a compressor that pumps air to a cylinder having a launch coaxially fixed to the turbine impeller of the turbine, and a lubrication system for the internal combustion engine. The center housing has a built-in radial metal that supports the shaft that is lubricated with oil, and a center housing that drains the lubricating oil after the radial metal is wetted into the oil pan of the internal combustion engine. The inner wall surface of the housing is coated with a material obtained as fine powder by emulsion polymerization of tetrafluoroethylene.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The supercharger of the present invention will be explained below using an embodiment with reference to FIGS. 1 and 2. FIG. 1 is a sectional view of a part of the supercharger and cylinder, and FIG. 2 is a detailed view of the supercharger of FIG. 1. In FIG. 1, 1 is an internal combustion engine, 2 is a supercharger, 3 is an air cleaner, and 4 is a throttle valve.

A compressor outlet pressure intake port that guides the pressure of the 5-piece compressor 10 to the actuator 6, 7 an exhaust bypass pulp, 8 a muffler, 9 a cylinder, 11 a turbine impeller, and 12 a shaft with the turbine impeller 11 fixed to one end and the other end. The runner 13 of the compressor 10 is fixed to. 14 is a turbine. High-temperature exhaust gas discharged from the cylinder 9 is guided to the turbine 14 side of the supercharger 2 and drives the turbine impeller 11 to rotate. Therefore, the runner 3 of the compressor 10, which is fixed integrally with the turbine impeller 1 through the shaft 12, is driven to rotate, and the air purified by the air cleaner 3 is supercharged to the cylinder 9 through the throttle valve 4 as shown by the arrow. Now, the operating state of the engine is such that the amount of air is controlled by the throttle valve 4. The boost pressure is controlled by driving an actuator 6 using compressed air from the compressor outlet pressure intake 5 to open and close the exhaust bypass pulp 7 and change the rotational speed of the turbine 14.

In FIG. 2, reference numeral 15 denotes a center housing, and inside the center housing 15 are built-in radial metals 20 and 21 that rotatably support the shaft 12. 17 is a heat shield plate,
18 is a pack plate, 19 is a piston ring, 22 is a supply port that supplies lubricating oil to the radial metal 20.21,
23 is a cooling oil passage communicating with the cavity 27, and 24 is a material obtained as a fine powder by emulsion polymerization of tetrafluoroethylene (PTFE, a trade name of DuPont Co., Ltd.), which is coated on the inner wall surface of the center housing 15, especially on the high temperature side. Teflon)
is the coated covering.

16.25 is an oil drain port.

Lubricating oil from the internal combustion engine 1 is introduced into the radial metal 20, 21 from the supply port 22 during operation, and is lubricated from each passage.
The lubricating oil after lubrication is returned to the oil pan of the internal combustion engine through the oil drain port 25. The lubricating oil seal is a mechanical seal 2 housed in the back plate 18 on the compressor 10 side.
6, and the piston ring 19 is installed on the turbine 14 side.
It will be done in good time. During operation, the inner wall of the center housing 15 is cooled by lubricating oil to a temperature of about 150C or less. However, when the internal combustion engine 1 stops, the heat held in the turbine case of the turbine 14 is transferred and the inner wall surface of the center housing rises to about 300 to 400 C, making it easy for the lubricating oil attached to the inner wall surface to carbonize. However, the Teflon coating 24 reduces the adhesion of lubricating oil, and at the same time, the lubricating oil itself washes away the carbide carbonized by the high temperature, thereby reducing the buildup of carbide.

In this way, the turbocharger of this embodiment has a Teflon coating on the inner wall surface of the center housing.
The lubricating oil that adheres to the inner wall of the center housing as in the past is carbonized and deposited due to the high temperature, and as a result, it is discharged to the oil drain port between the radial metal on the turpin side and the piston ring, or to the oil pan. It is possible to reliably prevent a decrease in durability performance due to narrowing of the oil drain port.

[Effects of the Invention] As described above, the supercharger of the present invention has the effect of preventing carbide of lubricating oil from depositing on the inner wall surface of the housing and improving durability.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a part of a supercharger and cylinder of an embodiment of the supercharger of the present invention, and FIG. 2 is a detailed view of the supercharger of FIG. 1.

Claims (1)

[Claims] 1. A compressor that pumps air to a cylinder having a runner fixed coaxially to the turbine impeller of the turbine and a door rotatably driven by the exhaust gas of the internal combustion engine; A center housing that includes a built-in radial metal that supports the shaft that is well-lubricated, and a center housing that discharges the lubricating oil after lubricating the radial metal to the oil pan of the internal combustion engine. A supercharger characterized in that a wall surface is coated with a material obtained as a fine powder by emulsion polymerization of nato-2-fluoroethylene.