JPH05209530A - Air turbine device of engine - Google Patents

Abstract

PURPOSE:To provide an air turbine device provided with a bypass route of an expanded turbine, in which air feeding temperature will not be overcooling at the time of low load, and the structure is made compact, while switching of a switching valve is simplified. CONSTITUTION:A bypass route 12 which does not pass a turbine wing chamber 4 is provided on a scroll part of an expanded turbine 1. Switching of a switching valve 13 for preferentially opening/closing the bypass route 12 is carried out interlocking and linking with a diaphragm valve 12 operated according to the discharge pressure of a compressor 2.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air turbine device used particularly in an engine with a supercharger.

[0002]

2. Description of the Related Art It is known that an air turbine device having a compressor and an expansion turbine is provided downstream of a supercharger. That is, although an intercooler is usually provided on the downstream side of the supercharger, the combustion temperature at high load can be lowered and the amount of NOx generated can be reduced by efficiently cooling the air by the air turbine. However, if the cooling is performed by the air turbine even under a low load, NOx will be consumed because of rapid combustion due to ignition delay.
As a result, the amount of generation of is increased. Therefore, in order to solve this problem, there is a system in which the supercharger directly supplies the power to the engine via an intercooler.
-See Japanese Patent Publication No. 51652).

However, as described above, when the engine is directly supplied from the intercooler, the cooling by the air turbine is not performed at all, so that the cooling is insufficient and the NOx reduction effect is not always sufficiently obtained. There is an inconvenience. In order to solve such a problem, it is conceivable that an aftercooler installed between the compressor and the expansion turbine of the air turbine bypasses the expansion turbine and supplies it to the engine. ing. 11 and 12 show the structure.

In these drawings, (3) is an air turbine device in which a compressor (32) and an expansion turbine (33) are arranged coaxially, and an after-cooler arranged laterally of the expansion turbine (33). The inlet and the outlet of the compressor (32) are connected by a pipe (35), and the scroll inlet (36) of the expansion turbine (33) is connected to the outlet of the aftercooler (34). Furthermore, the outlet of the expansion turbine (33)
It is connected to the intake manifold (39) via the intake pipe (37). The aftercooler (34) is provided with another outlet (38), and the outlet (38) and the middle of the intake pipe (37) are connected by a bypass pipe (40). The bypass pipe (40) is provided with a switching valve (41), and as described above, when the load is low, the bypass pipe (40) is passed to supply air of an appropriate temperature to the engine. I have to.

[0005]

However, in the structure in which the aftercooler (34) and the intake pipe (37) are connected by piping as described above, the bypass piping (4
Since 0) significantly protrudes, there is a drawback that the entire size increases. Moreover, the pipe (40) has a large overall height when placed on the upper side, and interferes with the expansion turbine (33) and the like when placed on the side. Therefore, as shown in the figure, the lower portion must be detoured in a curved shape. However, there is a disadvantage that the lower part of the pipe becomes a kind of trap and the moisture in the air accumulates in this lower part. Therefore, when the switching valve (41) is opened, the accumulated water flows into the intake pipe (37) all at once.

Further, in the conventional device, the switching valve (41) is switched by a complicated control device, which has a drawback that the structure is complicated.

The present invention eliminates the above-mentioned conventional drawbacks and provides a bypass passage for an expansion turbine so that the intake air temperature does not become supercooled when the load is low.
Moreover, it is an object of the present invention to provide an air turbine device that can be made compact and that can switch the switching valve with a simple structure.

[0008]

In order to solve the above-mentioned problems, the first invention of the present application comprises a compressor and an expansion turbine, and the air compressed by the compressor is expanded by the expansion turbine to obtain an engine. In an air turbine adapted to supply air to the expansion turbine, a bypass portion for selectively supplying air to the engine side without passing through the turbine blade chamber is integrally provided with a scroll portion for introducing air into the turbine blade chamber of the expansion turbine. It is characterized by being provided in.

Similarly, the second invention of the present application is a switching valve in an air turbine comprising a compressor and a compression turbine, wherein the air compressed by the compressor is expanded by the expansion turbine and supplied to the engine. By providing a bypass passage for supplying air to the engine side without passing through the turbine blade chamber of the expansion turbine, a diaphragm valve that operates according to the discharge pressure of the compressor is provided, and this diaphragm valve and the switching valve are connected. When the discharge pressure of the compressor is high, the bypass passages are closed so as to close each other.

[0010]

According to the above construction, since the bypass passage is integrally provided in the scroll portion to the turbine blade chamber of the air turbine apparatus, the engine is passed through the bypass passage from the downstream of the after cooler provided in this type of air turbine. Will not be overcooled even when the load is low. Moreover, since it is formed integrally with the scroll portion, it can be made compact as compared with the case where a pipe is connected.

In the second invention of this application, a diaphragm valve which operates by the outlet pressure of the expansion turbine is provided,
Since it is linked with the switching valve, the switching valve can be automatically switched with a simple mechanical device.

[0012]

FIG. 1 shows a first embodiment of the present invention. The expansion turbine (1) and the compressor (2) are axially directly connected so that their axial outlets (3) or inlets (14) are opposite to each other. A turbine blade (5) arranged in the turbine blade chamber (4) of the expansion turbine (1) and a turbine blade (6) also arranged in the turbine blade chamber of the compressor (2) are arranged in the axial direction. Mounted at both ends of the shaft (7). The inside of the scroll portion (9) extending from the scroll inlet (8) protruding on the side surface of the expansion turbine (1) in a direction perpendicular to the outlet (3) to the inside of the turbine blade chamber (4) has a partition wall along the scroll direction. It is divided into two by (10) and one of them, that is, the passage (1
1) is the main passage connected to the inside of the turbine blade chamber (4), and the passage (12) on the other outlet (3) side does not pass through the turbine blade chamber (4) but directly to the outlet (3) side. It is a bypass passage that communicates. As shown in the figure, the bypass passage (12) has a structure that covers the main passage (11) from the outside in the axial direction. The end of the switching valve (13) is pivotally attached to the end portion of the partition wall (10) on the scroll inlet side, and the switching valve (13) separates the main passage (11) and the bypass passage (12). , So that it can be selectively switched.

Therefore, when the switching valve (13) is rotated rightward to close the main passage (11) as shown in the figure, air from an aftercooler (not shown) passes through the turbine blade chamber (4). Instead, the air flows directly to the outlet (3) side, so that the air having a temperature suitable for a low load is supplied to the engine side without undergoing an expansion stroke. On the other hand, when the main passage (11) is opened, the entire amount of air is expanded by the turbine blade chamber (4), so that lower temperature air is supplied to the engine side.

FIG. 2 shows the values of NOx and the like when the switching by such a switching valve (13) is switched at the 2/4 load of the engine as a boundary. The broken line in the figure shows the bypass passage (12 ) Is opened, and thus, at low load, by passing the bypass passage (12),
NOx can be reduced by increasing the intake air temperature and intake pressure as compared with the normal case, reducing the ignition delay and suppressing rapid combustion.

3 to 6 show the main passage (11) as follows.
Along the middle of the flow direction, another partition (1
It is divided into two systems by partitioning in 5). In this case, the passage (16) on the outlet (3) side in the figure is the inner passage (1
It is a small capacity passage for 7). In addition, in this embodiment, in addition to the first switching valve (13) that opens and closes the bypass passage (12), the first passage of the main passage (11)
-By providing a second switching valve (18) for switching the second passages (16) (17) and appropriately switching these,
The control is performed so that the air temperature corresponding to each load is obtained.

FIG. 3 shows the case where only the passage (17) inside the main passage is opened, and is used when the load is maximum. FIG. 4 shows a case where only the passage (16) outside the main passage (11) is opened, and is used when the load is medium. FIG. 5 shows a case where the main passage (11) is fully opened and is used when the load is small. Further, FIG. 6 shows the bypass passage (1
2) It is used when there is no load when only the case is opened. FIG. 7 shows a change accompanying the switching of NOx and the like in this case. A broken line in the figure shows a case where such control is performed, and a solid line in the figure shows a case where no control is performed.

FIGS. 8 and 9 show an embodiment manufactured in accordance with the second invention of the present application, in which one bypass passage (12) and one main passage (11) are provided as in the case of FIG. In the switching by the switching valve (13), the switching valve (13) is automatically switched by the diaphragm valve (21). That is, as shown in FIG. 10, the diaphragm valve (21) has a diaphragm (2
It has a spring chamber (23) and a pressure receiving chamber (24) partitioned by 2), and the pressure receiving chamber (24) communicates with the discharge passage (25) side of the compressor (2) and the other side thereof A spring (26) is arranged to balance the pressure in the pressure receiving chamber (24). The diaphragm (22) is connected to the switching valve (13) via the link (27).
Is linked to.

FIG. 8 shows the case where the discharge pressure of the compressor (2) is low, and in this case, the spring (26) moves the link (27) to the right side of the drawing, which causes the switching valve. (13) is held so that the bypass passage (12) side is open. From this state, when the discharge pressure of the compressor (2) rises due to the rise of the exhaust pressure of the engine, the pressure receiving chamber (24)
The link (27) is pushed to the left in the figure by the pressure acting on the valve, and as shown in FIG. 9, the switching valve (13) is held so that the bypass passage (12) side is closed. As a result, the combustion temperature is controlled so as not to become too high, and an increase in NOx is prevented. Although a device for opening and closing a compressor using such a diaphragm valve (21) is known in superchargers, the diaphragm valve (21) of the present invention is known.
Is not used for a supercharger like that, and is characterized in that the expansion turbine (1) side of the air turbine device is opened and closed to control the supply air temperature, which is essentially different from the supercharger. It is a thing.

[0019]

According to the present invention, the air discharged from the aftercooler is directly supplied to the engine when the load is low, so that it is most suitable for the low load as compared with the case where the air is directly supplied from the supercharger to the engine. Not only can the supply air temperature be obtained and NOx can be reduced, but since the direct supply passage is integrally formed in the scroll portion of the expansion turbine, the overall construction can be made compact. effective. That is, in the conventional structure in which the pipe is connected to the intake pipe side, no matter how small the pipe portion is, the entire size must be increased, whereas in the present invention, the scroll portion is slightly The effect is that it can be achieved by increasing the size. Moreover, the appearance is also good because things like piping are not exposed to the outside. In addition, as described above, in the case of piping, it is necessary to lower the front height or to detour the lower side of the device into a curved shape in order to avoid interference with the expansion turbine or the like, which causes water drops to accumulate. Although inconvenient, the present invention solves this drawback by only making the scroll part slightly larger and providing such a water collecting part. Further, by disposing the bypass passage outside the main passage as shown in the embodiment, the bypass passage functions as a heat insulating space for the main passage, and the temperature of the cooled air is raised by the outside air. Since it can be prevented, the one having more excellent cooling performance can be obtained.

Further, in the second invention of this application, since the switching valve is switched by the diaphragm valve which is operated by the pressure of the compressor, a complicated control device is not required, and it is simple and compact. There is an effect that can be configured.

[Brief description of drawings]

FIG. 1 is a horizontal sectional view of an expansion turbine and a compressor showing an embodiment of the present invention.

FIG. 2 is a graph showing changes in values of NOx and the like accompanying switching of the switching valve in the embodiment of FIG.

FIG. 3 is a horizontal sectional view of an expansion turbine and a compressor showing another embodiment of the present invention.

FIG. 4 is a horizontal sectional view showing a switching state of the switching valve in the embodiment of FIG.

FIG. 5 is a horizontal sectional view showing another switching state of the switching valve.

FIG. 6 is a horizontal sectional view showing still another switching state of the switching valve.

FIG. 7 is a graph showing changes in values of NOx and the like due to switching of the switching valve in the embodiment of FIG.

FIG. 8 is a horizontal sectional view of an expansion turbine and a compressor showing another embodiment of the present invention.

9 is a horizontal sectional view showing a switching state of the switching valve in the embodiment of FIG.

10 is an enlarged view of a main part of FIG.

FIG. 11 is an overall front view showing an embodiment of an air turbine apparatus having a conventional bypass passage.

FIG. 12 is a right side view of the main part of FIG.

[Explanation of symbols]

 (1) Expansion turbine (2) Compressor (3) Outlet (4) Turbine blade chamber (9) Scroll section (11) Main passage (12) Bypass passage (13) Switching valve (21) Diaphragm valve

Claims (2)

[Claims] 1. An air turbine comprising a compressor and an expansion turbine, wherein air compressed by the compressor is expanded by the expansion turbine and supplied to an engine.
The scroll portion for introducing air into the turbine blade chamber of the expansion turbine is integrally provided with a bypass passage for selectively supplying air to the engine side without passing through the turbine blade chamber. Air turbine equipment. 2. An air turbine comprising a compressor and an expansion turbine, wherein air compressed by the compressor is expanded by the expansion turbine and supplied to the engine.
By providing a bypass passage for supplying air to the engine side without passing through the turbine blade chamber of the expansion turbine by switching the switching valve, a diaphragm valve that operates according to the discharge pressure of the compressor is provided. Is connected to each other so as to close the bypass passage when the discharge pressure of the compressor is high.