JPS58133425A - Bearing protector of turbocharger - Google Patents

Abstract

PURPOSE:To prevent deterioration of lubricating oil in a bearing part, by introducing a jet stream of high pressure gas to a floating bearing part at stopping of an engine and blowing the lubricating oil accumulated in the bearing part with the jet stream to dry the bearing part. CONSTITUTION:During operation of an engine, a key switch 144 is placed in an ON position and a solenoid 132 is excited. This causes a shut off valve 134 to close. Intake air pressurized by a compressor of a turbocharger is partially accumulated in a surge tank 130 through a supercharge intake pipe 140. When the key switch is turned to an OFF position to stop the engine, an oil pump 108 is also stopped. Action of a delay timer 142 causes the solenoid 132 after opening of the key switch to open after elapsed a prescribed time, and high pressure air in the surge tank is injected toward an oil inlet pipe 112.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a turbocharged internal combustion engine, and more particularly to a device for protecting a turbocharger bearing during hot shutdown of the turbocharger.

In a turbocharger for a vehicle internal combustion engine, the compressor and turbine rotate at a maximum speed of 100,000 revolutions per minute, so a full floating bearing 10.10 is used as the shaft bearing, as shown in Figure 1. . The oil inlet pipe 11 connected to the engine oil pump is connected to the main housing 1 of the turbocharger.
2 is screwed into the nine pipe connection port 13, and the lubricating oil is distributed to the oil supply hole 15 through the distribution hole 14, and the lubricating oil is distributed to each full 70
- fed to the Tei/Ge bearing 10.10;

As shown in an enlarged view in Fig. 2, a minute gap is formed between the inner hole 16 formed in the main housing, the full floating bearing 10, and the turbocharger shaft 17, and this minute gap is formed during engine operation. A gap is formed, and during engine operation, a film of lubricating oil is formed in this minute gap and functions to dampen and absorb rotational vibrations of the shaft. The lubricating oil Fi also has the function of cooling the bearing section, which is heated by the heat propagated from the engine's exhaust system.

When the engine stops, the rotation of the turbocharger stops, and the supply of lubricating oil from the oil pump stops, the lubricating oil inside the turbocharger is
It drips and returns to the engine's oil pan, but in the full 70-ring bearing part, it is very small as shown in No. 38 CI! Lubricating oil remains in the trench. KFi occurs when the engine is stopped immediately after high-speed, high-load operation, such as when parking a vehicle immediately after driving at high speed, and the exhaust system is heated to a high temperature and the turbocharger suddenly rotates and the lubricating oil drains. The supply will stop. This state 5tFi
This is called a turbocharger hot shutdown. During a hot shutdown, the lubricating oil that remains in the tiny gaps in the fully floating bearing becomes oxidized, turns into sludge, or in extreme cases becomes carbonized due to the heat that gradually propagates from the highly heated exhaust system. leading to. In this specification, such change in quality of lubricating oil due to heat is broadly referred to as deterioration. The deteriorated 1llllv oil adheres or sticks to minute gaps in the bearing, leading to insufficient supply of lubricating oil during the next operation of the engine and causing permanent wear of the bearing.

An object of the present invention is to provide a bearing portion 11i4 that can prevent deterioration of the lubricating oil in the full floating bearing portion even during hot shutdown of the turbocharger! I! The goal is to provide a

In order to achieve the above object, the present invention introduces a high-pressure gas jet into the fully floating bearing when the engine is stopped, blows off the fR lubricant that remains in the bearing, and dries the bearing. The purpose is to prevent the deterioration of lubricating oil when it is exposed to water.

Therefore, the bearing part Sat of the present invention has a pressure gas source and -
A pipe is connected to the pressure gas source, and the other end is connected to the full floating bearing part of the turbocharger, and the pipe is installed in the pipe so that the pressure gas is guided from the pressure gas source to the bearing mK. It is equipped with a shutoff valve that is closed during operation and blocks the passage of pressurized gas, but is opened when the engine is stopped to allow pressurized gas to pass through and be ejected to the bearing section. The gist of this is to accomplish the following:

In a specific embodiment of the invention, the source of pressurized gas is a storage container, such as a surge tank, connected to the discharge side of the compressor of the turbocharger and adapted to store the boost pressure of the turbocharger. Can be configured. A check valve can be provided between the storage container and the compressor discharge side to prevent the pressurized air in the container from flowing back to the compressor discharge side when the boost pressure decreases.

The other end of the pressure gas piping may be connected directly to the bearing, but is preferably connected to the oil inlet pipe of the turbocharger. In order to prevent the pressurized gas from flowing back toward the oil pump when the pressurized gas is ejected, the oil inlet pipe is preferably provided with a check valve upstream of the confluence point.

The shutoff valve may be a solenoid-type electromagnetic valve linked to the engine key switch. The turbocharger shaft rotates in an elliptical manner for a short time even after the engine has stopped, but in order to blow out the lubricant only after this elliptical rotation has ended, it is possible to install a delay circuit between the key switch and the solenoid. good.

Hereinafter, the present invention will be explained in detail with reference to the drawings, and the effects of the present invention will also be described.

FIG. 4 is an elevation view of a turbocharger and a lubrication system equipped with an embodiment of the bearing protection device of the present invention.
It is abbreviated as 02. The lubrication system for the engine body and the turbocharger is well known, and the lubricating oil in the oil pan 104 is supplied to the oil pump 10B through the suction pipe 106.
The oil is sucked in, passes through a filter 110, and is sent under pressure to an oil inlet pipe 112 for the turbocharger and an enshiff main body 17 & oil pipe 114. A check valve 116 is installed in the inlet vibe 112. Hall 1
Refer to the figure and it's already K16! As explained above, this oil inlet pipe 112 is formed in the main housing/guage 118 of the turbocharger 1000 and is screwed into the nine inlet pipe connection ports.

Lubricating oil is supplied to the bearing portion 102 through a distribution hole and an oil supply hole (see FIG. 1) in the main housing. The oil that has lubricated the bearing portion is returned to the oil pan through a return pipe 120. On the other hand, the bearing part 1 of the engine body is connected through the oil supply pipe 114.
The lubricating oil used to lubricate 22 is passed through the appropriately formed return pipe 124.
It passes through and returns to the oil pan.

Compressor discharge port 126 of turbocharger 100
A supercharging air duct 128 is attached to the engine, and this supercharging duct connects to the engine's intake manifold (not shown) Kl.
l! It is continued.

A dedicated surge tank 130 is installed at an appropriate location on the engine. This surge tank 130t:t solenoid 1
It is connected to the p-oil inlet pipe 112 by a pressurized air line 136 with an electromagnetic shutoff valve 134 having a diameter of 32. A supercharging air intake pipe 140 equipped with a reverse valve 138 is connected between the pressurized air pipe 136 and the supercharging air duct 128 .

The solenoid 132 of the electromagnetic shutoff valve 134 is connected to a power source 146 via a delay timer 142 and an engine key switch 144.

Next, the operation of the device of the present invention will be described. When the engine is operating, the key switch 144 is in the ON position and the solenoid 132 is energized.

Therefore, the shutoff valve 134 is closed. A portion of the intake air pressurized by the turbocharger compressor is stored in the surge tank 130 via the supercharging air intake pipe 140. Since the supercharging air intake pipe 140 is provided with a check valve 138, the maximum supercharging pressure reached during turbocharger operation is accumulated in the surge tank. Additionally, the higher the engine speed, the higher the boost pressure generated, so the more heat the bearing receives during hot shutdown, the more high pressure air is stored in the surge tank.

When the key switch is turned to the OFF position to stop the engine, the oil pump 108 also stops, and the lubricating oil pressure in the lubrication system disappears. Further, the compressor and turbine of the turbocharger rotate inertia for a short time after the engine is stopped, and then eventually stop. Due to the action of the delay timer 142, the solenoid 132i; t is opened after a predetermined period of time has elapsed after the key switch is opened, and the high pressure air in the surge tank is blown out toward the oil inlet pipe 112.

Since the KVi check valve 116 is provided on the upstream side of the oil inlet pipe, the jet of air is blown onto the full floating bearing through the inlet vibe connection port, distribution hole, and oil supply hole without flowing back to the oil pump side. . As a result, the lubricating oil adhering to the gap in the bearing portion is blown away as shown in Fig. 5. Therefore, even if heat is transferred from the exhaust system to the bearing during a hot shutdown, the lubricating oil does not remain in the bearing, which often causes problems such as sticking, sludge, or carbonization of the lubricating oil. . Note that when the amount of heat received in the bearing portion is large, the viscosity of the lubricating oil is reduced, so that the effect of blowing off the lubricating oil by the air jet is large.

Also, by blowing air onto the bearing part, g! A cooling effect can also be expected.O As described above, according to the i & armor of the present invention, the fi4 which deteriorated to a full floating bearing part during hot shutdown
This prevents oil from building up and prevents roughening of the bearing surface and abnormal wear and tear. In addition, since this device automatically operates when the engine is stopped75, it is recommended that after high-speed, high-load operation, stop the extractor/gin that has been running idly for a while.
There is no need to perform cumbersome driving precautions,

[Brief explanation of the drawing]

Figure 1 is a reference diagram showing a vertical cross section of the turbocharger, Figure 2 is a cross-sectional view of the bearing showing the lubrication state when the engine is running, Figure 3 is a cross-sectional view of the bearing when the engine is stopped, and Figure 4 is a cross-sectional view of the bearing when the engine is stopped. FIG. 5 is an elevational view of the apparatus of the present invention, and is a cross-sectional view of the bearing section illustrating the state in which lubricating oil is blown away from the bearing section. 100--turbocharger, 102--full floating bearing, 112--oil inlet pipe, 1
16...Check valve, 126...Compressor discharge port, 1
28...Supercharging air tank, 130...Surge tank,
132... Solenoid of electromagnetic shutoff valve, 134... Denken type cutoff valve, 136 - Pressure air piping, 138... Reverse valve, 140... Supercharge air intake pipe, 142... Delay timer, 144 ...Engine key switch. Figure 1 Figure 5 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. A pressure gas source, one end of which is connected to the pressure gas source and the other end communicated with the full floating bearing of the turbocharger, and the pressure gas is supplied from the pressure gas source to the full floating bearing. A fully floating bearing section that is interposed in the piping and is closed during engine operation to block the flow of pressurized gas, but is opened when the engine is stopped to allow pressurized gas to pass through. It is equipped with a shutoff valve that allows the water to flow out,
When the engine is stopped, the lubricating oil remaining in the fully floating bearing part Kfi is blown away by a jet of pressurized gas.
A full-floating bearing protection device for a turbocharger, characterized in that it is capable of preventing deterioration of lubricating oil in a full-floating bearing during hot shutdown of a turbocharger. 2. The pressure gas source consists of a storage container connected to the discharge side of the compressor of the turbocharger and capable of accumulating the supercharging pressure of the turbocharger, and between the storage container and the compressor discharge side, the supercharging The bearing image according to claim 1, characterized in that a check valve is provided to prevent the pressurized air accumulated in the container from flowing back to the compressor discharge side when the pressure decreases. S device. 3. The other end of the piping is connected to the oil inlet pipe of the turbocharger, and this oil inlet vibe is equipped with a check valve upstream of the confluence with the piping to prevent the pressure air from flowing when it is jetted out. The bearing protection device according to claim 1i2, characterized in that it is capable of preventing backflow toward the upstream side. 4. The above-mentioned shutoff valve is an electromagnetic connection valve having a solenoid, and the solenoid is energized to close the shutoff valve when the engine key switch is ON, and demagnetized to open the shutoff valve when the key switch is OFF. The bearing maintenance II device according to claim 3, characterized in that the bearing maintenance II device is capable of 5. A delay circuit is inserted between the engine key switch and the solenoid, so that the K11 cutoff valve opens after a predetermined period of time after the engine stops, and the pressure air is spouted out. The scope of patent claims! Bearing maintenance device according to item 4.