JPH02181023A - Exhaust turbine supercharging device - Google Patents

Abstract

PURPOSE:To prevent pressure fluctuation at the time of flow-passage-switching by switching the compressor-side flow-passage when the supercharging pressure of a second, exhaust turbine supercharger coincides with that of a first, exhaust turbine supercharger together with operating a relief valve linked with a flow- passage cutoff valve. CONSTITUTION:When the number of revolutions or the load of an engine 1 increased to raise the supercharging pressure in a suction pipe 32, a diaphragm 10 is pressed, so that a cutoff valve 6 opens a cutoff port 5. As a result, a part of exhaust gas is introduced from a sub-exhaust pipe 4 into a sub-turbine 15, while a sub-compressor 17 rotates, so that the pressure is generated in a sub-suction pipe 21. However, when the pressure in the sub-suction pipe 21 does not reach the pressure in a regular suction pipe 20, a cutoff valve 23 closes a cutoff port 24, and at the same time a relief valve 26, which is linked with the cutoff valve 23, opens a relief port 25. On the other hand, when the pressure in the sub-suction pipe 21 becomes higher than that in the regular suction pipe 20, the cutoff valve 23 opens the cutoff port 24, while the relief valve 26 closes the relief port 25.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an exhaust turbine supercharger for an engine, and particularly relates to an exhaust turbine supercharger for an engine.
The present invention relates to control when two exhaust turbine superchargers are used in parallel.

[Conventional technology]

Conventionally, as described in Utility Model Application Publication No. 58-33738, a plurality of turbochargers, for example two turbochargers, were connected to the engine in parallel, and a cutoff valve was installed at the turbine inlet and compressor outlet of one turbocharger. It has an intervening configuration, and when the air volume is low in the engine speed range, the shutoff valve is closed and only one supercharger is operated, and when the engine speed is high and the air volume is large, the shutoff valve is opened. This was an attempt to obtain good supercharging characteristics over a wide operating range of the engine by operating both superchargers.

However, the engine torque characteristics may not be smooth and shock may occur, and the response of the second supercharger may be delayed during acceleration, resulting in a suffocating phenomenon. In other words, when the shutoff valve is opened to operate the second supercharger, the
Since the compressor pressure of the first supercharger has not yet been generated, a backflow occurs from the compressor of the first supercharger to the compressor side of the second supercharger, and this state is caused by the rotation of the second supercharger. This continues until the number becomes sufficiently high that the pressures of the two compressors become comparable, and the temporary drop in boost pressure at this time causes problems in operability.

The object of the present invention is to eliminate such problems during valve switching, smooth the pressure connection, and further improve responsiveness during transients, thereby eliminating sudden changes in engine torque characteristics.

[Means to solve the problem]

In order to achieve the object described in item 1, the present invention provides that among the turbine-side and compressor-side cutoff valves that control the operation of the second, auxiliary exhaust turbine supercharger, the compressor-side cutoff valve is the first and second cutoff valves. In other words, it is opened and closed by the differential pressure between the outlet pressures of the main and auxiliary compressors, and a relief valve is provided at the outlet of the auxiliary compressor to release some air, which is linked to a shutoff valve on the compressor side. be.

[Effect]

Even if the turbine-side isolation valve opens, the compressor-side isolation valve remains closed until the compressor pressure of the auxiliary exhaust turbine supercharger reaches the compressor pressure of the main exhaust turbine supercharger. Since the compressor is opened only after the compressor pressure exceeds the compressor pressure of the main exhaust turbine supercharger, there is no sudden change in pressure due to backflow of the compressor flow rate, and the action of the relief valve linked to the shutoff valve on the compressor side is When the shutoff valve closes, it relieves at least the surging flow rate of the compressor of the auxiliary exhaust turbine supercharger, so there is no inconvenience caused by the surging of the compressor of the auxiliary exhaust turbine supercharger, and switching between the main and auxiliary exhaust turbine superchargers is smooth. It is done.

〔Example〕

An embodiment of the present invention will be described below with reference to FIG.

The exhaust pipe 2 of the engine 1 is branched into main and auxiliary exhaust pipes 3 and 4, which are connected to the main and auxiliary turbines 12 and 15, respectively, and the respective turbine outlets are combined into one and connected to an exhaust pipe 18. In addition, the intake pipe 32 of the engine 1 is also branched into a main and auxiliary intake pipe 20, 21, which are connected to the main and auxiliary compressors 14 and 17, respectively, and the inlets of the respective compressors are combined into one and connected to the intake pipe 19. ing. The main turbine 12, the main compressor 14, the auxiliary turbine 15, and the auxiliary compressor 17 rotate coaxially around shafts 13 and 16, respectively, and constitute a main and auxiliary exhaust turbine supercharger, respectively, and are connected in parallel to the engine 1. . A cutoff valve 6 is provided in the middle of the sub-exhaust pipe 4 and has a structure to open and close the cutoff hole 5. That is, the isolation valve 6 is connected to the valve shaft 8
The pressure of the intake pipe 32 is guided into the diaphragm chamber by a pressure introduction pipe 7, and the back side of the diaphragm is opened to the atmosphere through a hole 9, and a spring 11 is connected to the back side of the diaphragm. A spring force is applied to push the valve shaft 8 to the left.

A cutoff valve 23 is provided in the middle of the rigid trachea 21 to open and close a cutoff hole 24, and a relief valve 26 is provided upstream of the cutoff hole 24 to operate the relief hole 25 in conjunction with the cutoff valve 23. That is, the cutoff valve 23 and the relief valve 26 are connected by the same valve shaft 27, and are further connected to a diaphragm 29. A spring 28 is provided on the right side of the diaphragm, and the spring force is applied to pull the valve shaft 27 to the right. has been added. Moreover, the outlet pressure of the main compressor and the outlet pressure of the sub-compressor are introduced to the left and right chambers partitioned by the diaphragm through pressure introduction pipes 30 and 31, respectively.

When the operating state of the engine 1 is low speed or low load and the supercharging pressure of the intake pipe 32 is low, the diaphragm]O is pushed to the left by the spring 11, and the shutoff valve 6 closes the shutoff hole 5. All exhaust gas from the engine 1 is guided to the main turbine 12 through the upper trachea 3. The rotation of the main compressor 14, which is coaxial with the main turbine 12, causes the main intake pipe 20 to
The supercharged air inside the engine is directed to the engine 1 through the intake pipe 32. At this time, the sub-compressor 5 does not operate at 112, so the sub-compressor 17 does not rotate and no pressure is generated in the sub-intake pipe 21, and the diaphragm 29 is connected to the spring 28 and the pressure introduction pipe 30.
, 3], the shutoff valve 23 closes the shutoff hole 24 and the main compressor 14
All of the supercharged air obtained is guided to the intake pipe 32, and of the two exhaust turbine superchargers, only the main exhaust turbine supercharger consisting of 12, 13 and 14 is operated, and at low engine speeds Sufficient supercharging characteristics can be obtained even with a small air flow rate.

Intake pipe 3 due to increase in engine speed and engine load.
When the supercharging pressure of 2 increases, the diaphragm 10 is pushed from the pressure introduction pipe 7 to the right against the spring 1, and the shutoff valve 6 begins to open the shutoff hole 5, and part of the exhaust gas is transferred from the auxiliary exhaust pipe 4 to the auxiliary exhaust pipe 4. It is guided to the turbine 15. When the auxiliary compressor 17 starts rotating and pressure is generated in the auxiliary intake pipe 2 but does not reach the pressure in the exhaust intake pipe 20, the shutoff valve 23 remains closed to the shutoff hole 24, and at this time the shutoff valve 23 is linked to the shutoff valve. The relief valve 26 opens the relief hole 25, and the air in the sub-intake pipe is released from the relief hole.

If the flow path area of this relief hole is set to such an extent that the sub compressor 17 does not enter the surging region, the cutoff valve 6 can operate as a conventional exhaust bypass valve while supercharging is performed only by the main exhaust turbine supercharger. Since the excess exhaust gas is guided to the auxiliary turbine 15, the supercharging pressure of the intake pipe 32 is prevented from becoming excessive, and the auxiliary compressor 17 can be preliminarily rotated without entering surging.

Furthermore, when the engine becomes high speed and has a high load, the opening degree of the shutoff valve 6 increases, and the auxiliary turbine 15 and the auxiliary compressor 17
rotates at high speed and the pressure in the auxiliary intake pipe 21 becomes higher than the pressure in the main intake pipe 20, the diaphragm 29 is pushed to the left against the spring 28 by the pressure guided by the pressure introduction pipe 30, 31-, and the shutoff valve is closed. 23 opens the blocking hole 24, and a relief valve 26 coaxial with the valve shirt 1-27 closes the relief hole 25. Therefore, the supercharged air obtained by the auxiliary compressor smoothly merges with the starting air of the main compressor, and no large pressure fluctuations occur at this time. In this explanation, the case where the operating state of the engine 1 gradually becomes high speed and high load has been described, but in the case of a sudden acceleration transient, after the shutoff valve 6 is opened, the auxiliary turbine 15 and the auxiliary compressor 1 are
However, in this case as well, the shutoff valve 23 is closed until the sub compressor rotates at a sufficiently high speed and the supercharging pressure of the sub compressor reaches a sufficient value, and when the shutoff valve 23 opens, the high supercharging pressure No fluctuations occur. Conversely, even when the engine 1 changes from a high load to a low load, pressure fluctuations at the time of valve switching can be similarly suppressed by simply reversing the operating order of each valve.

FIG. 2 shows another embodiment of the present invention, in which the exhaust pipe 2 is provided with a bypass valve 36 operated by the pressure of the intake pipe 32, and the cutoff valve 6 is turned on and off by an actuator 32 using an electromagnet. The cutoff valve 23 and the relief valve 26 are also turned on and off by an electromagnetic actuator 33, and the main and auxiliary compressors 14. ．． The outlet pressures of 17 can be detected by pressure sensors 34 and 35, respectively.

In this embodiment, after the engine load increases and the supercharging pressure is controlled by the exhaust bypass valve 36, the actuator 32 is actuated depending on the engine operating condition and the cutoff valve is opened.
7 starts rotating.

The actuator 33 is a pressure sensor 34. , 35, when the sub compressor outlet pressure becomes equal to the main compressor pressure, the shutoff valve 23 is opened and the relief valve 26 is operated to close.

In this embodiment, the valves are opened and closed on and off, but the effect of the exhaust bypass valve 36 suppresses fluctuations in boost pressure, and when the shutoff valve 6.23 is opened, it is instantaneously fully opened, so there is no pressure loss. Moreover, there is an advantage that the supercharging device can be precisely controlled by the computer according to the operating state of the engine.

〔Effect of the invention〕

According to the present invention, when two exhaust turbine superchargers arranged in parallel with the engine are switched to one or two, the supercharging pressure of the second exhaust turbine supercharger is reduced to one. When the boost pressure almost matches the boost pressure of the second exhaust turbine supercharger, switch the flow path on the compressor side, and then interlock the relief valve to prevent the compressor of the second exhaust turbine supercharger from surging. With this configuration, there is no fluctuation in engine torque due to pressure fluctuations during valve switching, and by controlling the two exhaust turbine superchargers, good characteristics can be obtained over a wide operating range from low engine speeds to high speeds.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an exhaust turbine supercharging device according to one embodiment of the present invention, and FIG. 2 is a diagram showing an exhaust turbine supercharging device according to another embodiment. 1...Engine, 12...Main turbine, 14...Main compressor, 15...Sub-turbine, 17...Sub-compressor, Lube. Shutoff valve, 26 Relief bar

Claims (1)

[Claims] 1. Two main and auxiliary exhaust turbine superchargers are arranged in parallel with the engine, and cutoff valves are provided at the turbine inlet and compressor outlet of the auxiliary exhaust turbine supercharger, respectively. In an exhaust turbine supercharging device that controls the operation of a sub-exhaust turbine supercharger by controlling these valves, the cutoff valve on the compressor outlet side is configured such that the compressor outlet pressure of the sub-exhaust turbine supercharger is controlled by the main exhaust turbine supercharger. A discharge valve is provided at the compressor outlet of the auxiliary exhaust turbine supercharger that opens when the pressure exceeds the compressor outlet pressure of the sub-exhaust turbine supercharger, and releases a part of the air.
The discharge valve is synchronized with the cutoff valve at the outlet of the compressor, so that when the cutoff valve opens, the release valve closes, and when the cutoff valve closes, the release valve opens. Feeding device.