JP2959143B2 - Turbocharger with generator / motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turbocharger having a generator / motor.

[0002]

2. Description of the Related Art Conventionally, a turbocharger having a generator / motor is constructed, for example, as shown in FIG. In FIG. 6, an engine 1 is provided with a turbocharger 2, and an exhaust manifold 4 of the engine 1 communicates with a turbine 5 of the turbocharger 2 through an exhaust pipe 6. A compressor 8 and a generator / motor 9 are provided on a shaft 10 of the turbocharger 2. The intake air from the compressor 8 is sent to the intake manifold 3 through the intake pipe 11 and the cooler 12, and is taken into the engine 1. In such an engine 1, an exhaust shut-off valve 7 is provided in an exhaust pipe 6 upstream or downstream of the turbine 5 in order to operate an exhaust brake.

[0003] In recent years, a turbocharger having a generator / motor has been evaluated for its utility by recovering exhaust energy, and has been used. As such a turbocharger, for example, Japanese Unexamined Utility Model Publication No. 1-119836
There is a drive device for a turbocharger with a rotating electric machine disclosed in Japanese Patent Application Laid-Open Publication No. H11-163,878.

[0004] The driving device for a turbocharger with a rotating electric machine disclosed in the above-mentioned Japanese Utility Model Laid-Open Publication No. 1-119836 is provided with a rotating electric machine on a rotating shaft of the turbocharger and drives the rotating electric machine with electric power from a battery. Power conversion means comprising a semiconductor control element for converting DC power to AC power, and a transformer for boosting AC power, and after converting power from a battery into AC power by the power conversion means, The electric power is supplied to the rotating electric machine through the electric motor.

[0005]

However, the turbocharger 2 having the above-described generator / motor has a problem in the regeneration of exhaust energy.
In vehicles such as trucks, exhaust brakes are becoming common sense so that they become a social issue. However, since the turbocharger having the generator / motor cannot rotate when the exhaust brake is operated, the generator / motor 9 cannot function as a generator and cannot recover energy.

Generally, in an engine provided with a turbocharger having a generator / motor, the relationship between the engine speed EN and the net average effective pressure Pme (kg / cm ² ) is expressed by a value as shown by a curve E in FIG. Show. When the engine brake is applied, the relationship between the average mechanical loss effective pressure Pmf (kg / cm ² ) due to the engine brake and the engine speed EN indicates a value as shown by a curve H in FIG. Further, when the exhaust brake is operated with the exhaust shut-off valve 7 provided in the exhaust pipe 6 fully closed, the mechanical loss average effective pressure Pmf
The relationship between (kg / cm ² ) and the engine speed EN shows a value as shown by a curve F in FIG.

The relationship between the engine speed EN and the turbine speed TN of a turbocharger having a generator / motor will be described with reference to FIG. In FIG. 10, the horizontal axis represents the engine speed EN and the vertical axis represents the turbine shaft speed TN.
5 is a graph showing the relationship between the two. As shown in FIG. 10, when the turbocharger 2 is operating normally, the relationship between the engine speed EN and the turbine speed TN is, as shown by a curve D, as the engine speed EN increases and the rated speed increases. At the rotation speed EN ₀ , the turbine rotation speed TN also rises to around the full load rated rotation speed TN ₀ . When the fuel is not supplied to the engine 1 and the generator / motor 9 is motoring and the exhaust shut-off valve 7 is opened and the exhaust brake is not operated, as shown by the curve B, the engine speed E is increased.
When N increases, the rotation speed TN of the shaft 10 of the turbine 5 also increases to some extent. However, the exhaust shutoff valve 7
Is closed and the exhaust brake is operated, as shown by the curve A, the shaft 10 of the turbine 5, that is, the turbine speed TN hardly increases even if the engine speed EN increases.

By the way, in the turbocharger, even when the flow rate of the exhaust gas is small, an attempt has been made to improve the energy regeneration by increasing the rotation speed of the turbine shaft. For example, as shown in FIG. 7 or FIG.
Is configured as a twin type, and when the exhaust gas from the engine is small, one of the turbine scrolls 1 in FIG.
5 and the exhaust gas is allowed to flow only through the other turbine scroll 16 to increase the rotation speed of the shaft of the turbine 5, or to close the turbine scroll 17 having a larger flow cross section in FIG. The exhaust gas flows only through the other turbine scroll 18 of the smaller one to increase the rotation speed of the shaft of the turbine 5.
However, in any of the turbochargers, when the exhaust brake is operated by closing the exhaust shutoff valve of the exhaust pipe, the flow of the exhaust gas to the turbine 5 of the turbocharger is almost eliminated, and the effect of the energy regeneration in the power generation / motor is reduced. It is currently gone.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems. In a turbocharger having a generator / motor, an exhaust shutoff valve for operating an exhaust brake is provided in an exhaust pipe upstream of a turbine, and the exhaust shutoff valve is provided. A bypass pipe with a reduced flow cross-sectional area for bypassing the exhaust manifold is provided so as to communicate the exhaust manifold with the turbine blades of the turbine.
An object of the present invention is to provide a turbocharger having a generator / motor capable of satisfactorily regenerating exhaust energy even when exhaust gas is directly blown onto a turbine blade and an exhaust brake is applied to an engine.

[0010]

SUMMARY OF THE INVENTION The present invention relates to a turbocharger driven by the exhaust energy of an engine, which connects a generator / motor provided on a shaft on which the turbine is mounted, an exhaust manifold of the engine, and the turbine. An exhaust pipe, an exhaust shutoff valve provided on the exhaust pipe upstream of the turbine, the exhaust shutoff valve having a function of an exhaust brake, and the exhaust gas can flow from the exhaust manifold to the turbine when the exhaust shutoff valve is closed. Exhaust passage means having a passage cross-sectional area narrowed as compared with an exhaust pipe, wherein the exhaust passage means is constituted by a bypass pipe which bypasses the exhaust cutoff valve and communicates the exhaust manifold with the turbine; The exhaust gas blown out of the bypass pipe is blown directly to the turbine blades of the turbine. On turbocharger with a motor-generator according to claim.

Further, in the turbocharger having the generator / motor, the bypass pipe is constituted by one or a plurality of pipes.

Since the turbocharger having the generator / motor according to the present invention is configured as described above, when the exhaust shut-off valve is closed and the exhaust brake operates, the flow rate of the exhaust gas from the exhaust manifold increases. The exhaust gas flows through a bypass pipe, and is directly blown to the turbine blades of the turbine. The exhaust gas flow most effectively acts on the turbine blades and rotates the turbine shaft.
Energy regeneration can be performed effectively. Further, the bypass pipe can be composed of one or a plurality of pipes.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a turbocharger having a generator / motor according to the present invention will be described below with reference to the drawings. FIG. 1 is a schematic explanatory view showing an embodiment of a turbocharger having a generator / motor according to the present invention, and FIG. 2 is an enlarged explanatory view of a portion denoted by reference numeral I in FIG. The turbocharger shown in FIGS. 1 and 2 has the same configuration as that of FIG. 6 except for the position of the exhaust cutoff valve and the provision of the bypass pipe. In the reference numerals given to the parts shown, the same parts as those shown in FIG. 6 are given the same reference numerals.

As shown in FIGS. 1 and 2, the turbocharger having the generator / motor is a turbocharger 2 driven by the exhaust energy of an engine 1.
The exhaust gas from the engine 1 is sent to the turbine 5 through the exhaust pipe 6, and the turbine 5 is rotated to rotate the compressor 8 through the shaft 10 to supercharge the intake air to the engine 1 and to rotate the generator / motor 9 The power generation / motor 9 is used as a generator to perform energy regeneration.

The turbocharger having this generator / motor is particularly equipped with an exhaust manifold 4 and a turbine 5 of the engine 1.
In other words, the exhaust pipe 6 upstream of the turbine 5 is provided with an exhaust shutoff valve 7 having an exhaust brake function, and the exhaust manifold 4 and the turbine 5 are bypassed by bypassing the exhaust shutoff valve 7. Pipe 2 that communicates with
0 is connected. In the figure, the bypass pipe 20 is connected to the exhaust pipe 6 upstream of the exhaust shutoff valve 7 and the exhaust pipe 6 downstream of the exhaust shutoff valve 7.

The bypass pipe 20 has a narrow passage cross-sectional area as compared with the exhaust pipe 6, and when the exhaust shut-off valve 7 is open, almost no exhaust gas from the engine 1 is exhausted. 6 and a small amount of exhaust gas flows into the bypass pipe 20. However, when the exhaust shutoff valve 7 is closed, the exhaust gas from the engine 1 cannot flow through the exhaust pipe 6 and is exhausted, and the exhaust manifold 4 and the exhaust pipe 6 in the exhaust pipe 6 on the upstream side of the exhaust shutoff valve 7 are disposed. The pressure rises, for example, to 2.5-5 kg / cm ² . Normally, high-pressure exhaust gas flows backward through the engine cycle toward the intake pipe 11 in search of an outlet.
0, the exhaust gas flows through the bypass pipe 20, but the flow rate of the exhaust gas flowing through the bypass pipe 20 is increased by the high pressure, flows at high speed, and is blown to the turbine blade 13 of the turbine 5. The exhaust gas is blown out to the nozzle of the turbine 5 through the bypass pipe 20, acts on the turbine blade 13 to rotate the shaft 10 of the turbine 5, causes the power generation / motor 9 to function as a power generator, and performs energy regeneration. Therefore, this power generation
The turbocharger having the electric motor can sufficiently exhibit the function of the exhaust brake and perform the energy regeneration by closing the exhaust cutoff valve 7.

With respect to the turbocharger having this generator / motor, for example, the turbine speed TN of the shaft 10 of the turbine 5 with respect to the engine speed EN is obtained by the curve A in FIG. What was small and hardly rotated as shown
In the turbocharger having this generator / motor, FIG.
As shown by the curve C, the turbine speed TN is considerably increased, and the power generated by the generator / motor 9 is also increased. At this time, the relationship between the mechanical loss average effective pressure Pmf (kg / cm ² ) and the engine speed EN is a value indicated by the locus of the curve G in FIG. That is, when the engine speed EN is small, the mechanical loss average effective pressure Pmf is smaller than that of the conventional one.

In a conventional turbocharger having a generator / motor, power cannot be generated by the generator / motor during exhaust braking. However, according to the turbocharger having a generator / motor according to the present invention, the braking force of the exhaust brake is reduced. The power can be generated by the power generation / motor 9 without sacrificing the power itself, energy can be regenerated and the power can be stored in the battery, and sufficient power can be stored in the battery. Therefore, when the vehicle is predicted to accelerate next time, the stored electric power is consumed, and the generator / motor 9 of the turbocharger 2 is operated as a motor so as to meet the energy demand during acceleration.

Further, by optimizing the diameter of the bypass pipe 20 and the like, it is also possible to reduce the amount of air blown back to the intake pipe via the engine cycle and to reduce noise such as exhaust brake. it can.

Further, in the turbocharger having the generator / motor according to the present invention, the bypass pipe 20 can be connected to the turbine 5 in various configurations. For example, the bypass pipe 20 can be configured as shown in FIG. 3, FIG. 4 or FIG. 3 is an explanatory view showing an example of a connection structure of a bypass pipe in the turbocharger of FIG. 1, FIG. 4 is an explanatory view showing another example of a connection structure of a bypass pipe in the turbocharger of FIG. 1, and FIG. FIG. 10 is an explanatory view showing still another example of the connection structure of the bypass pipe in the turbocharger of FIG.

FIG. 3 shows an example of a connection structure of the bypass pipe. The turbine 5 is formed in a twin scroll type, and large and small turbine scrolls 17 and 18 are formed by dividing a turbine scroll surrounded by a turbine housing 14 into two by a partition plate 19. The bypass pipe 20 penetrates the partition plate 19, and the exhaust gas outlet 22 of the bypass pipe 20 is arranged to face the nozzle 21 of the turbine blade 13. Therefore, the exhaust gas blown out from the exhaust gas outlet 22 of the bypass pipe 20 is directly blown to the turbine blade 13, acts on the turbine blade 13 most effectively, drives the turbine 5, and rotates the shaft 10. The rotation of the shaft 10 causes the generator / motor 9 to function as a generator and perform energy regeneration.

FIG. 4 shows another example of the connection structure of the bypass pipe. In the connection structure of the bypass pipe 20 shown in FIG. 4, the bypass pipe 20 is arranged to face the nozzle 21 of the turbine blade 13 from the side of the turbine housing 14. And the exhaust gas outlet 2 of the bypass pipe 20
The exhaust gas blown out of the turbine blade 2 is blown in the direction in which the turbine blade 13 is formed.

FIG. 5 shows still another example of the connection structure of the bypass pipe. The connection structure of the bypass pipe 20 shown in FIG. 5 includes one or a plurality of bypass pipes (four in the figure). The connection structure of the bypass pipe 20 is shown in FIG.
Alternatively, the configuration is the same as that of FIG. 4, and a duplicate description will be omitted.

[0024]

Since the turbocharger having the generator / motor according to the present invention is constructed as described above, when the exhaust shut-off valve is closed and the exhaust brake operates, the exhaust gas from the exhaust manifold has a reduced flow rate. Ascending and flowing through the exhaust passage means, the exhaust gas flow can act on turbine blades of the turbine to rotate the shaft of the turbine. Further, the bypass pipe includes one or a plurality of pipes, and the exhaust gas blown out of the bypass pipe is directly blown to the turbine blade of the turbine, so that the flow of the exhaust gas most effectively acts on the turbine blade. ， Performs effective energy regeneration.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view showing one embodiment of a turbocharger having a generator / motor according to the present invention.

FIG. 2 is an enlarged explanatory view of a portion denoted by reference numeral I in FIG.

FIG. 3 is an explanatory view showing one embodiment of a connecting portion of a bypass pipe in the turbocharger having the power generating / motor of FIG. 1;

FIG. 4 is an explanatory view showing another embodiment of a connecting portion of a bypass pipe in the turbocharger having the generator / motor of FIG. 1;

FIG. 5 is an explanatory view showing still another embodiment of a connecting portion of a bypass pipe in the turbocharger having the generator / motor of FIG. 1;

FIG. 6 is an explanatory diagram showing an example of a conventional turbocharger having a generator / motor.

FIG. 7 is an explanatory view showing an example of a turbine scroll of a conventional turbocharger having a generator / motor.

FIG. 8 is an explanatory diagram showing another example of a turbine scroll of a conventional turbocharger having a generator / motor.

FIG. 9 is a graph showing a relationship between an engine rotation speed, a net average effective pressure, and a mechanical loss average effective pressure of an engine including a turbocharger having a generator / motor.

FIG. 10 is a graph showing a relationship between an engine speed of an engine including a turbocharger having a generator / motor and a speed of a turbine shaft.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 2 Turbocharger 4 Exhaust manifold 5 Turbine 6 Exhaust pipe 7 Exhaust shutoff valve 9 Generator / motor 10 Shaft 13 Turbine blade 20 Bypass pipe

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) F02B 37/10 F02B 37/00 302

Claims (2)

(57) [Claims] 1. A turbocharger driven by the exhaust energy of the engine, attach the turbine
Was motor-generator provided in the shaft, an exhaust pipe for connecting the exhaust manifold of an engine turbine, exhaust cutoff valve having a function of an exhaust brake disposed on the exhaust pipe upstream of the turbine, and the the exhaust gas in the closed state of the exhaust cutoff valve has a comparison passage sectional area is narrowing down Mareta exhaust passage means to the exhaust pipe can flow from the exhaust manifold to the turbine, the exhaust passage hands
A stage bypasses the exhaust shutoff valve and the exhaust manifold
And a bypass pipe that communicates with the turbine.
The exhaust gas blown out of the bypass pipe is
It can be sprayed directly on turbine blades.
Turbocharger with a motor-generator to be. 2. The bypass pipe comprises one or a plurality of pipes.
The power generation system according to claim 1,
Turbocharger with electric motor.