JPS5815642Y2 - Intake switching device for turbocharged engines - Google Patents

Description

[Detailed explanation of the invention] In general, a turbocharger rotates at high speed immediately after the engine starts, reaching a maximum of 8000 rpm. However, since lubricating oil pressurized by a pump is supplied to the turbocharger after passing through a filter, There is a problem in which the supply of lubricating oil is insufficient, which can cause seizure.As a countermeasure, we have installed a valve parallel to the turbine to prevent exhaust gas from flowing to the turbine side when the lubricating oil pressure is less than the specified value at the beginning of engine rotation. It is conceivable to provide a bypass and a bypass opening/closing device linked to hydraulic pressure.

However, in that case, the turbine (and the blower) does not rotate until the lubricating oil pressure reaches a specified value, so when the intake air passes through the blower side, resistance increases, causing the above-mentioned problem.

The present invention attempts to bypass the intake air to the blower when measures are taken to suppress the rotation of the turbine immediately after startup as described above, and will be explained in conjunction with the drawings as follows.

In the figure, a turbocharger 1 includes a blower 2 and a turbine 3, and is attached to the upper part of the cylinder head of the engine.

An intake passage 4 on the inlet side of the blower 2 is connected to an air purifier 5, and an intake passage 6 on the outlet side is connected to an intake manifold (not shown) of the engine.

A bypass T connecting the inlet side intake passage 4 and the outlet side intake passage 6 is provided in parallel with the blower 2, and this bypass 1 is closed by an on-off valve 8.

The shaft 9 to which the on-off valve 8 is fixed is supported by a bearing on the passage wall at the branching portion of the passage 4 and the bypass 1, and a lever 10 is fixed to the tip of the shaft 9 that protrudes from the passage wall to the outside of the passage. .

In the illustrated embodiment, the lever 10 is connected via the iron 11,
It is connected to a lever 14 of an on-off valve 13 provided in the exhaust bypass 12.

Both the on-off valve 13 and the lever 14 are fixed to a shaft 15,
The shaft 15 connects the inlet side exhaust passage 16 of the turbine 3 and the bypass 1.
The lever 1 is supported by a bearing provided on the passage wall of the branch part of the lever 1.
4 is fixed to the tip of a shaft 15 projecting outward from the passage wall.

The bypass 12 connects the passage 16 and the outlet side exhaust passage 1γ of the turbine 3.

The inlet side exhaust passage 16 is connected to the exhaust manifold of the engine, and the outlet side exhaust passage 11 is connected to a muffler (both not shown).
Connect to.

In order to control the on-off valve 13, a hydraulic cylinder 20 connected to the discharge port of the lubricating oil pump 19 is provided. One end of a tension spring 23 is connected to the tip.

24 is a pressure regulating section, 25 is a filter, 26 to 28 are lubricating oil passages, and 29 is a lubricating oil inlet to the turbocharger 1.

FIG. 1 shows a normal operating state, in which the lubricating oil pressure 29 of the turbocharger 1 is supplied with lubricating oil pressure higher than the specified value, and the hydraulic cylinder 20 is also supplied with the discharge oil pressure of the pump 19, so that the piston 21 The on-off valve 13 moves to the right end position against the elasticity of the spring 23, and the on-off valve 13 closes the bypass 12, so that all the exhaust gas is transferred to the inlet side exhaust passage 16.
It then enters the turbine 3 and drives the turbine 3.

Arrow A indicates the flow direction of exhaust gas at this time.

At this time, on the blower 2 side, the on-off valve 8 closes the bypass 7 in conjunction with the on-off valve 13, so that all intake air enters the blower 2 through the intake passage 4 on the inlet side, where it is pressurized. , is supplied to the engine through the outlet side intake passage 6, and a supercharging effect is performed.

Arrow B indicates the flow direction of the intake air at this time.

When the predetermined hydraulic pressure cannot be supplied to the turbocharger 1 due to a failure of the pump 19, etc., or immediately after the engine is started, the piston 21 is moved by the spring 23 because the hydraulic pressure in the hydraulic cylinder 20 is low or its rise is slow. Due to elasticity, it occupies the left end position in the cylinder 20, and the on-off valve 13
is at position 13' and bypass 12 is open.

Arrow C indicates the flow direction of the exhaust gas at that time, during which the turbine 3 does not rotate.

At the same time, the on-off valve 8 interlocked with the on-off valve 13 occupies the position 8', the bypass 7 is opened, and all the intake air flows through the bypass 7 in the direction of the arrow, bypassing the blower 2.

That is, the intake air does not pass through the stopped blower 2.

As explained above, according to the present invention, an on-off valve 13 (on-off mechanism) is provided in the bypass 12 provided in parallel with the turbine 3, and when the lubricating oil pressure is low, the on-off valve 13 opens the bypass 12, and the exhaust gas flows through the turbine 3. By bypassing the engine, it is possible to prevent the turbine 3 from rotating at high speed in a state of insufficient lubricating oil at the initial stage of engine startup, thereby reliably preventing seizure of the turbine 3.

Moreover, a bypass γ is provided in parallel to the blower 2.

The on-off valve 8 provided on the bypass 7 is connected to the on-off valve 13 via the wand 11, etc., so that the bypass opening and closing operations of both valves 8 and 13 are synchronized with each other, so that the turbine does not rotate at the initial stage of engine startup. Sometimes the intake air can flow to the blower bypass 7 (preventing it from flowing into the blower 2), increasing intake resistance and deteriorating the engine operating condition (
combustion defects, etc.) can be suppressed.

When the oil pressure exceeds the specified value, the valves 8 and 13 are bypassed.
12 is closed, a predetermined supercharging effect can be reliably obtained and normal operating conditions can be maintained.

Note that when embodying the present invention, the on-off valve 8 may be structured to open and close only the bypass γ.

In this case, when the on-off valve opens the bypass 1, the intake air passes through the bypass T side, which has less resistance, so that an increase in intake resistance can be prevented with a simple structure.

[Brief explanation of the drawing]

The figure is a schematic front view of the device according to the invention. 1...Turbocharger, 2...Blower 3...Turbine 4...Inlet side intake passage, 6...Outlet side intake passage , 1...
・Bypass, 8...Opening/closing valve, 12...-...
Bypass, 13... Opening/closing valve (opening/closing mechanism), 16
...Inlet side exhaust passage, 1T...Outlet side exhaust passage.

Claims (1)

[Scope of utility model registration request] A bypass is installed in parallel with the turbocharger turbine to connect the exhaust passage on the turbine inlet side and the exhaust passage on the turbine outlet side, and when the lubricating oil pressure at the beginning of engine startup is less than the specified value, the bypass is opened and the oil pressure exceeds the specified value. In order to close the bypass and guide the exhaust gas to the turbine side, an opening/closing mechanism linked to the lubricating oil pressure is installed in the bypass, and the opening and closing mechanism is connected to the intake passage on the inlet side and the intake passage on the outlet side of the blower in parallel with the blower of the turbocharger. A blower bypass is provided to connect the blower, and an on-off valve is provided on the blower bypass, and the on-off mechanism and the on-off valve are connected so that the bypass opening operation of the on-off mechanism and the on-off valve is synchronized. Air intake switching device for turbocharged engines.