JP2723681B2 - Engine with turbocharger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine having two superchargers, a first supercharger having a substream turbine and a second supercharger having an axial turbine.

[0002]

2. Description of the Related Art Conventionally, a turbocharger for a vehicle engine has a turbine and a compressor on the same rotating shaft as the turbine. As a turbine, exhaust gas from the engine flows into a spiral chamber at right angles to a rotating shaft from an outer periphery. 2. Description of the Related Art There is known an apparatus using a substream turbine that rotates a rotor blade by exhaust gas that has been turned into a high-speed swirling flow in a spiral chamber. This substream turbine can compress the intake air relatively efficiently for a wide range of exhaust gas flow from a low-speed rotation range to a high-speed rotation range of the engine.

[0003]

However, the above-mentioned substream turbine has a problem that the turbine efficiency is reduced when the engine speed is increased and the exhaust gas flow rate is increased.

It is an object of the present invention to provide a supercharged engine capable of improving the fuel consumption rate of the engine.

[0005]

According to the present invention, as shown in FIG.
each other to compress a, turbine 11a is rotated 12a, 12a of the same rotary shaft 11c, a compressor 11b on 12c, the air intake of the engine 13 by driving the 12b
First and second superchargers 11, 12 provided in parallel to each other;
The exhaust of the engine 13 is supplied to the turbine 11a of the first supercharger or
Switching to flow into turbine 12a of second supercharger
The first switching valve 21 and the intake air of the engine 13 are connected to a first supercharger.
The compressor 11b or the compressor 12 of the second supercharger
b to be switched to flow into the intake manifold 18 from
The two-way switching valve 22 and the first
And controller 2 for operating second switching valves 21 and 22
8 is an improvement of the supercharged engine equipped with Its characteristic configuration is that the turbine of the first supercharger is
is used, and the axial turbine 1
2a is used at the inlet 11d of the substream turbine 11a.
Nozzle vane 11e driven by air cylinder 26 is provided.
Controller 28 responds to the operating state of the engine 13
The cross-sectional area of the inlet 11d by the nozzle vane 11e.
That is, the air cylinder 26 is controlled as described above.

[0006]

In the low-speed rotation range of the engine 13, the controller 28 switches the first and second switching valves 21 and 22 so that the exhaust gas flows into the substream turbine 11a.
b, the compressed air flows into the intake manifold 18, and further flows through the air cylinder 26 into the nozzle vanes 11 e
To reduce the cross-sectional area of the inlet 11d of the substream turbine 11a.
You. In the medium-speed rotation region of the engine 13,
a and exhaust air into controller a.
By the nozzle vane 11e through the cylinder 26,
The cross-sectional area of the inlet 11d of the bin 11a is increased. In the high-speed rotation range of the engine 13, the controller 28 switches the first and second switching valves 21 and 22 to flow exhaust gas into the axial turbine 12a and flow compressed air into the intake manifold 18 from the second compressor 12b. .

[0007]

Next, an embodiment of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, first and second superchargers 11 and 12 are connected to the vehicle engine 13 in parallel. The first supercharger 11 has a substream turbine 11a and a first compressor 11b on the same rotating shaft 11c as the substream turbine 11a.
The second supercharger 12 has an axial turbine 12a and a second compressor 12b on the same rotary shaft 12c. In the substream turbine 11a, the exhaust gas of the engine flows into the swirl chamber from the outer periphery at right angles to the rotating shaft 11c, and the rotating blades are rotated by the high-speed swirling exhaust gas in the swirl chamber.
In addition, the axial flow turbine 12a uses the rotating shaft 12
and flows in substantially parallel to c to rotate the rotor. First and second exhaust pipes 31 and 32 are branched and connected to an exhaust manifold 14 connected to an exhaust port 13 a of the engine 13 via a first switching valve 21. The first switching valve 21 is a three-way switching solenoid valve of a spring return type. When the switching valve 21 is turned on, the exhaust manifold 14 and the first exhaust pipe 31 communicate with each other. When the switching valve 21 is turned off, the exhaust manifold 14 and the second exhaust pipe 32 are connected. It is configured to communicate. A substream turbine 11a is provided in the middle of the first exhaust pipe 31, and an axial turbine 12a is provided in the middle of the second exhaust pipe 32. Further, these exhaust pipes 31 and 32 are assembled to form an exhaust pipe 16. Connected.

First and second intake pipes 41 and 42 are connected to an intake pipe 17 connected to an air cleaner (not shown). A first compressor 11b is provided in the middle of the first intake pipe 41, and a second compressor 12b is provided in the middle of the second intake pipe 42. Further, these intake pipes 41 and 42 are connected to the second switching valve 22 and the intercooler. 19
Is connected to the intake manifold 18 via the air inlet. The second switching valve 22 is a spring return type three-way switching solenoid valve,
When the switching valve 22 is turned on, the first intake pipe 41 and the intake manifold 18 communicate with each other.
2 and the intake manifold 18 are configured to communicate with each other.

An engine rotation sensor 23 is provided on the crankshaft 13b of the engine 13, and a load sensor 24 for detecting the amount of depression is provided on the accelerator pedal. A nozzle vane 1 is provided at the inlet 11d of the substream turbine 11a.
The nozzle vane 11e is provided with an air cylinder 26 so that the cross-sectional area of the inlet 11d can be reduced in two stages. The air cylinder 26 is connected to an air tank 29 via a cylinder control valve 27. The detection outputs of the engine rotation sensor 23 and the load sensor 24 are connected to the control input of the controller 28, and the control output of the controller 28 is transmitted to the first switching valve 21, the second switching valve 22, Connected to valve 27. The memory in the controller 28 stores predetermined engine rotation speeds N ₁ and N ₂ (N ₁ <
N ₂ ) and predetermined engine loads L ₁ and L ₂ (L ₁ <L ₂ ) are stored.

The operation of the supercharged engine having the above configuration will be described. An engine rotation sensor 23 detects the engine rotational speed is less than N _1, and the load sensor 24 is L ₁
When an engine load of less than
Reduces the cross-sectional area of the inlet 11d of the substream turbine 11a by the nozzle vane 11e via the cylinder control valve 27 and the air cylinder 26 based on these detected outputs. At the same time, the first switching valve 21 is turned on to switch the exhaust of the engine 13 so as to flow into the substream turbine 11a.
2 is turned on to switch the intake air to flow into the intake manifold 18 via the first intake pipe 41 and the first compressor 11b, and the first supercharger 11 compresses the intake air. At this time, since the inlet 11d of the substream turbine 11a is narrowed, the flow velocity of the exhaust gas can be increased even if the displacement of the engine 13 is small, and the substream turbine 11a can be efficiently rotated.

[0011] engine speed and load increases, the engine rotation sensor 23 detects the engine rotational speed is less than N ₁ or more N _2, and the load sensor 24 is L ₁ or L ₂
When an engine load of less than
Increases the cross-sectional area of the inlet 11d by the nozzle vane 11e. The first and second switching valves 21 and 22 are maintained in the above-described state, and the first supercharger 11 compresses the intake air. At this time, since the inlet portion 11d of the substream turbine 11a is widened, it is possible to obtain a flow rate of exhaust gas according to the displacement of the engine 13, and to efficiently rotate the substream turbine 11a.

[0012] The engine speed and the load are further increased.
Therefore, the engine rotation sensor 23 N_TwoMore than engine times
The rotation speed is detected and the load sensor 24 detects L_TwoMore than
When the controller 28 detects the gin load,
When the valve 21 is turned off, the exhaust of the engine 13 is
2a, and the second switching valve 22 is turned off.
The intake air is supplied to the second intake pipe 42 and the second compressor 12.
Switched to flow into intake manifold 18 via b
Then, the intake air is compressed by the second supercharger 12. At this time
The engine 13 has a large displacement and the axial flow turbine 12
a can be rotated.

In the embodiment, the second switching valve is provided at the connection between the first and second intake pipes and the intake manifold. However, this is merely an example, and the intake air is supplied from the first or second intake pipe to the intake manifold. The switching valve may be provided in the first and second intake pipes or at other positions as long as the switching can be performed so that the gas flows in. The same applies to the first switching valve. Further, although a three-way switching solenoid valve of a spring return type is used as the first and second switching valves, the present invention is not limited to this, and the first and second switching valves are switched using fluid pressure such as air pressure or hydraulic pressure. Is also good. Furthermore, in the embodiment, a nozzle vane whose cross-sectional area can be reduced to two stages by an air cylinder is used at the inlet of the substream turbine, but a nozzle vane that can be narrowed to three or more stages or a fixed nozzle vane may be used. Good.

[0014]

As described above, according to the present invention, the controller switches the first switching valve so that the exhaust gas of the engine flows into the auxiliary turbine or the axial turbine, and switches the second switching valve to the intake air of the engine. Is switched so as to flow from the first compressor or the second compressor into the intake manifold, so that a turbine with good turbine efficiency can always be used depending on operating conditions such as engine speed and engine load,
As a result, the fuel consumption rate of the engine can be improved. In addition, a nozzle vane was provided at the inlet of the substream turbine so that this cross-sectional area could be gradually reduced by an air cylinder or the like .
Thus, the fuel consumption rate of the engine can be further improved.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a supercharged engine according to an embodiment of the present invention.

[Explanation of symbols]

11 1st supercharger 11a Substream turbine 11b 1st compressor 11c, 12c Rotary shaft 11d Inlet 11e Nozzle vane 2 2nd supercharger 12a Axial turbine 12b 2nd compressor 13 Engine 18 Intake manifold 21 1st switching valve 22 First 2 switching valve 26 Air cylinder 28 Controller

Claims (1)

(57) [Claims] 1. A turbine (11a, 12a) is rotated by the exhaust energy of an engine (13) to drive a compressor (11b, 12b) on the same rotating shaft (11c, 12c) as the turbine (11a, 12a). Compress the intake air of the engine (13) by parallel with each other
First and second turbochargers (11, 12) provided in
The exhaust of the gin (13) is supplied to the turbine (11a) of the first turbocharger or
Switching to flow into the turbine (12a) of the second supercharger
The first switching valve (21), and the intake air of the engine (13)
The compressor (11b) of the first supercharger or the compressor (11b) of the second supercharger
Flows from the compressor (12b) to the intake manifold (18)
Switching valve (22), which switches the engine (13)
The first and second switching valves (21, 22) are operated according to the operation state.
Supercharged engine equipped with a controller (28) to operate
In the above , a substream turbine (11a) is used as a turbine of the first supercharger.
And an axial turbine (12a) is used for the turbine of the second turbocharger.
The air cylinder (2) is provided at the inlet (11d) of the substream turbine (11a).
6) A driving nozzle vane (11e) is provided, and the controller (28) operates the engine (13) in an operating state.
The nozzle vane (11e) responds to the entrance (11d)
An engine with a supercharger , wherein the air cylinder (26) is controlled so as to reduce a cross-sectional area .