JPS601224Y2 - Internal combustion engine supercharging device - Google Patents

Description

[Detailed explanation of the invention] This invention is equipped with an exhaust turbo supercharger to enable effective supercharging over a wide range of engine speeds, from low speed ranges to high speed ranges!
This invention relates to improvements to supercharging devices.

Conventionally, as in the case of Utility Model No. 51-1, the engine was equipped with two exhaust turbo superchargers in parallel, and in the low speed range, the turbine of one exhaust turbo supercharger was By stopping the flow of exhaust gas from the engine into the turbocharger, the operation of that turbocharger is stopped, and by concentrating the exhaust gas to flow only to the turbine of the other exhaust turbosupercharger, that supercharger is stopped. There is a known supercharging device that operates a charger to increase boost pressure, and in high-speed rotation ranges, the exhaust gas is distributed to two turbochargers to optimize the boost pressure. There is.

□By the way, in a supercharging system like the above, even if one exhaust turbo supercharger is stopped, exhaust gas can flow into the second exhaust turbo supercharger and the turbine rotation can be restarted smoothly. As the turbine rotates, lubricating oil under pressure from the engine is supplied between the shaft and the bearings to prevent the turbine shaft and other parts from seizing due to rotation.

However, when the proposed supercharging system is stopped, no pressure is applied to the turbine and compressor, which causes the problem that pressurized lubricating oil leaks from the bearing case to the turbine and compressor. occurs.

As described above, the present invention provides a supercharging system in which two exhaust turbo superchargers are arranged in parallel to the engine, and even when the exhaust gas flow to one of the turbochargers is shut off and the engine is stopped, there is no oil leakage. This prevents leakage and allows the engine to operate smoothly and normally even when the engine is restarted by allowing exhaust gas to flow into the supercharger.

The present invention will be explained below with reference to an embodiment shown in FIGS. 1 and 2.

1 is an internal combustion engine, and 2 and 3 are its intake pipe and exhaust pipe.

49.5 are one and the other (first and second in this example) exhaust turbo superchargers, which are connected to turbines Tl and T2, respectively.
, compressors C1, C2 and shafts S1, S2 that are directly connected to them and supported by bearings B1, B2, and turbines T1, T2, respectively.
The compressors C1 and C2 are connected to the exhaust pipe 3 by second exhaust passages 6 and 7, the compressors C1 and C2 are connected to the intake pipe 2 by first and second intake passages 8 and 9, respectively. are connected in parallel to each other.

Lubricating oil under pressure from the oil pump 10 of the engine 1 is supplied through the pipe 11 between the bearings Bl and B2 of the superchargers 4 and 5 and the shirts 181 and 52. There is.

Reference numerals 12 and 13 designate first and second on-off valves respectively disposed downstream of the turbine T1 and upstream of the compressor C1 of the first exhaust turbo supercharger 4, which close at or below a set engine speed; In the above case, the opening operation is performed.

Reference numeral 14 denotes a control valve disposed on the downstream side of the compressor C1, that is, in the intake passage 8;
The closing operation is performed when the on-off valves 12 and 13 shift from the closing operation to the opening operation, and the opening operation is performed again when the compressor C1 is in a state where normal supercharging pressure is generated after a delay of several seconds between the opening operation of the on-off valves 12 and 13. ing.

That is, FIG. 2 is a connection diagram of the on-off valves 12, 13 and the control valve 14, in which the control valve 14 via the on-off valves 12, 13 and the delay device 16 is are connected.

The delay device 16 includes, for example, a rotary switch 15 and a control valve 14.
Normally closed bimetal switch F6a connected between
and a hot wire 16b connected to the rotary switch 15 that heats the bimetal switch 16a and opens the switch 16a.

Then, the rotation switch 15
When closed, the first and second on-off valves 12 and 13 shift from the closing operation as shown in a to the open operation as shown in FIG. The opening operation and the closing operation are performed, and the hot wire 16b is heated, and when it reaches the set temperature 1 after a few seconds, the bimetal switch 16a is opened and the opening operation is resumed.

As described above, the delay device 16 is set so that the switch 16a opens after the time t (0.5 to 2 seconds) during which the compressor C1 generates normal supercharging pressure by opening the on-off valves 12 and 13. .

Further, the delay device 16 detects the rotational speed of the supercharger 4 or the boost pressure between the compressor C1 and the control valve 14, and opens the control valve 14 when this value reaches a set value. It's okay.

In the above configuration, the rotation switch 15 is open when the engine rotational speed is below the set engine speed, the first and second on-off valves 12 and 13 perform a closing operation, and the control valve 14 performs an opening operation.

Therefore, although exhaust gas acts on the first exhaust turbo supercharger 4, it does not operate, and in this state, the exhaust pipe 3 and the exhaust path 7
More exhaust gas flows concentratedly into the turbine T2 of the second exhaust turbo supercharger 5, and the compressor C2- via the shaft S2 increases the overpressure air even in the low speed rotation range of the engine to increase the output. increase

On the other hand, the bearing Bl of each exhaust turbo supercharger 4, 5
, B2 and the shaft Sl, S2 are equipped with an oil pump 10.
Although the second supercharger 5 is operating normally, there is no problem with oil leakage, and even when the first supercharger 4 is stopped, Opening/closing valve 12,1
3, the exhaust gas is blocked downstream of the turbine T1 and the intake air is blocked upstream of the compressor C1, and the control valve 14 between the compressor C1 and the intake pipe 2 is opened, so that the turbine Tl has no exhaust gas. Pipe 3, exhaust path 6
The exhaust gas pressure is applied to the compressor C1, and the supercharging pressure from the second supercharger 5 is applied to the compressor C1 via the intake pipe 2 and the intake path 8. Prevent oil leakage.

Next, when the engine speed reaches the set value N (the transition point from the low-speed rotation range to the high-speed rotation range), the rotation switch 15 closes, and the first and second on-off valves 12 and 13 stop operating. As the control valve 14 shifts to the opening operation, the control valve 14 performs the closing operation.

Exhaust gas then flows into the turbine T1 and drives it.

At the same time, the compressor C1 is rotated via the shaft S1, but since the turbine T1 and the compressor C1 have inertia, sufficient supercharging pressure is not generated at the beginning of the switching transition of the on-off valves 12 and 13.

For this reason, communication between the compressor C1 and the intake pipe 2 is cut off by the control valve 14 until sufficient boost pressure is generated to prevent overpressure air from flowing back from the intake pipe 2.When the boost pressure increases At this point, the control valve 14 is reopened by the action of the delay device 16, and overpressure air is also supplied to the engine 1 by the first exhaust turbo supercharger 4.

That is, it prevents the boost pressure from decreasing in the transition from the low-speed rotation range to the high-speed rotation range, and also reduces the boost pressure in the high-speed rotation range by distributing exhaust gas to the two superchargers 4 and 5. (optimization) supercharging.

As described above, the present invention arranges two exhaust turbo superchargers 4.5 in parallel to the engine 1 and operates only the second exhaust turbo supercharger 5 in the low speed rotation range to increase supercharging pressure. In this state, the lubricating pressure oil supplied to the first supercharger 4, which has stopped operating, in preparation for the next restart of rotation, is transferred to the turbine T.
Since pressure is applied to the turbine T1 and the compressor C1 by closing the on-off valves 12 and 13 disposed downstream of the turbine T1 and upstream of the compressor C1, oil leakage does not occur.

Furthermore, when the first exhaust turbo supercharger 4 is activated due to the transition from a low speed rotation range to a high speed rotation range, the control valve 14 is closed until the supercharging pressure by the compressor C1 reaches a normal value. There is no performance deterioration due to a drop in supercharging pressure accompanying the transition, and output can be increased from low speed to high speed.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention, with FIG. 1 showing a schematic system diagram and FIG. 2 showing a connection diagram of an on-off valve and a control valve. FIG. 3 is an explanatory diagram showing the operation of the on-off valve and the control valve. 1; Internal combustion engine, 2; Intake pipe, 3; Exhaust pipe, 4° 5; One and the other (first and second) exhaust turbo supercharger, 6
, 7; first and second exhaust passages, 8.9; first and second intake passages, 10; oil pump, 11 oil pipes, 12, 13; first and second on-off valves, 14; Control valve, 15; rotary switch, 16; delay device.

Claims (1)

[Scope of Claim for Utility Model Registration] Two exhaust turbo superchargers are arranged in parallel to the engine, and one exhaust turbo supercharger is located upstream of the compressor and downstream of the tanibin, and does not close when the engine speed is below a set engine speed. In the above, the on-off valve is operated to open, and further downstream of the compressor, the on-off valve is closed when transitioning from the closed operation to the open operation, and is again opened with a delay of several seconds after the opening operation of the on-off valve. A supercharging device for an internal combustion engine, characterized in that each control valve is provided with a control valve that performs the following. .