JP2007303295A - Method and device for controlling turbo compound engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To keep performance of a turbo compound engine high by preventing a power turbine from becoming a load in a low speed light load domain of the engine. <P>SOLUTION: When engine rotation speed and fuel injection quantity is in a power collection domain where power of the power turbine 7 can be absorbed, power of the power turbine 7 is collected by a crankshaft 11 by changing over a fluid coupling 9 to a transmission condition by a change over valve 20. When engine rotation speed and fuel injection quantity is out of the power collection domain of the power turbine 7, power loss transmitted from the power turbine 7 to the crankshaft 11 is shut off by changing over a fluid coupling 9 to a non-transmission condition by the change over valve 20. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method and an apparatus for controlling a turbo compound engine.

  Conventionally, a turbocharger that recovers power from exhaust gas and a power turbine that recovers power from exhaust gas that has passed through the turbine of the turbocharger are provided, and the power recovered by the turbocharger is used as supercharging power to pressurize the intake air. A turbo compound engine is known in which power recovered by a power turbine can be effectively used as engine driving force.

  FIG. 6 shows an example of a general turbo compound engine. In the example shown here, the exhaust gas 2 discharged from the engine 1 is guided to the turbocharger 4, and the energy of the exhaust gas 2 is converted by the turbine 6. The engine 5 is recovered as power, and the compressor 5 driven by the turbine 6 pressurizes the intake air entering the engine 1, while the exhaust gas 2 that has passed through the turbine 6 further recovers energy as power from the power turbine 7, and the recovered power is The first gear train 8, the fluid coupling 9, and the second gear train 10 are transmitted to the crankshaft 11 of the engine 1. Here, the reason why the fluid coupling 9 is included in the power transmission system from the power turbine 7 to the crankshaft 11 is to prevent a sudden rotational fluctuation such as torsional vibration or engine stall of the engine 1 from being transmitted.

  Further, in FIG. 6, 12 is an input gear of the fluid coupling 9 which is an element of the first gear train 8, 13 is an output gear of the fluid coupling 9 which is an element of the second gear train 10, and 14 is to clean the atmosphere. Indicates an air cleaner to perform.

  FIG. 7 shows the details of the fluid coupling 9. In the fluid coupling 9, a turbine impeller 22 having a large number of turbine blades 21 in an annular shape and an impeller having a large number of impeller blades 23 in an annular shape. A turbine chamber 26 is formed on the turbine impeller 22 side of the space defined between the impeller 24 and the impeller 24 in the casing 25, and the impeller chamber 24 is formed on the impeller impeller 24 side. 27 is formed.

  The turbine impeller 22 is attached to an output shaft 28 that rotates integrally with an output gear 13 that is an element of the second gear train 10 (see FIG. 6), and the impeller impeller 24 is connected to the output shaft 28. It is attached to an input shaft 29 that is rotatably fitted on the end opposite to the output gear 13, and this input shaft 29 is an input that constitutes one element of the first gear train 8 (see FIG. 6). A gear 12 is integrally provided.

  Between the turbine impeller 22 and the impeller impeller 24, hydraulic oil 15 (engine oil) from the supply line 16 is drilled at the end of the output shaft 28 opposite to the output gear 13. The hydraulic oil 15 is supplied through the oil passage 17 and the passage 18, and the hydraulic oil 15 is provided even when the engine is stopped by the cover 19 attached to the outer peripheral portion of the impeller impeller 24 so as to enclose the turbine impeller 22. About half of the amount is stored.

  Further, the hydraulic oil 15 is supplied to the fluid coupling 9 to the supply line 16 to switch between the power transmission state and the supply of the hydraulic oil 15 to the fluid coupling 9 is cut off to switch to the power non-transmission state. The switching valve 20 (switching means) is provided.

Incidentally, there is Patent Document 1 or the like as prior art document information related to this kind of turbo compound engine.
JP-A-9-2222026

  However, in such a conventional turbo compound engine, during operation of the engine 1, the fluid coupling 9 is kept in a transmission state by always opening the switching valve 20 and supplying the hydraulic oil 15 to the fluid coupling 9. Therefore, the power of the power turbine 7 can be effectively transmitted to the crankshaft 11 by the fluid coupling 9 in the high speed / high load range of the engine 1 and recovered. The power turbine 7 becomes a load and a power loss of the crankshaft is generated, which causes a problem that the performance of the turbo compound engine cannot be sufficiently exhibited.

  Further, there has not been proposed in the past that uses the turbo compound engine to increase the braking force of the engine.

  The present invention has been made in view of the above circumstances, and it is possible to prevent the power turbine from becoming a load in the low speed / low load region of the engine and maintain the performance of the turbo compound engine high. An object of the present invention is to provide a turbo compound engine control method and apparatus capable of effectively increasing the braking force.

  The turbo compound engine control method of the present invention includes a turbocharger that recovers power from exhaust gas, a power turbine that further recovers power from exhaust gas that has passed through the turbine of the turbocharger, and power recovered by the power turbine by hydraulic oil. A turbo compound comprising: a fluid coupling that transmits to a crankshaft; and a switching means that switches between a power transmission state by supplying hydraulic fluid to the fluid coupling and a power non-transmission state by shutting off the supply of hydraulic fluid. When the engine speed and fuel injection amount are within a power recovery region where the power of the power turbine can be recovered, the fluid coupling is switched to the transmission state by the switching means and the power of the power turbine is crankshaft. The engine speed and fuel injection amount are When in the extracellular region characterized by interrupting the power loss transmitted from the power turbine to the crankshaft by switching the fluid coupling to the non-transmission state by the switching means.

  According to the above means, when the engine speed and the fuel injection amount are outside the power recovery area of the power turbine, the switching means switches the fluid coupling to the non-transmission state to cut off the power loss transmitted from the power turbine to the crankshaft. Therefore, it is possible to keep the performance of the turbo compound engine high by preventing the power turbine from becoming a load at the time of low speed and low load of the engine.

  In the turbo compound engine control method, the operation of switching the fluid coupling between the transmission state and the non-transmission state by the switching means is performed by a recovery boundary obtained from a two-dimensional map of the engine speed and the fuel injection amount. Thus, switching between the power transmission state and the power non-transmission state by the fluid coupling can be performed automatically and suitably.

  Further, in the above turbo compound engine control method, a bypass duct having a bypass valve is provided in the middle of bypassing the power turbine by connecting the outlet of the turbocharger and the outlet of the power turbine, and the bypass valve is opened during braking. The exhaust gas is caused to flow through the bypass duct, the fluid coupling is switched to the transmission state by the switching means, and the braking force is increased by resistance by driving the power turbine by the crankshaft. The braking force can be increased using the resistance driven by the crankshaft.

  The turbo compound engine control apparatus of the present invention includes a turbocharger that recovers power from exhaust gas, a power turbine that recovers power from exhaust gas that has passed through the turbine of the turbocharger, and power recovered by the power turbine by hydraulic oil. A turbo compound comprising: a fluid coupling that transmits to a crankshaft; and a switching means that switches between a power transmission state by supplying hydraulic fluid to the fluid coupling and a power non-transmission state by shutting off the supply of hydraulic fluid. An engine control device for calculating whether the engine speed / fuel injection amount is within a power recovery area where the power of the power turbine can be recovered or outside the power recovery area, and the engine speed / When the fuel injection amount is within the power recovery area, the switching valve is opened, and the engine speed and fuel injection amount are opened. If outside the power recovery area, characterized in that and a control means for closing operation of the switching valve.

  According to the above means, when the engine speed and the fuel injection amount are outside the power recovery area of the power turbine, the fluid coupling is switched to the non-transmission state by the switching valve to cut off the power loss transmitted from the power turbine to the crankshaft. Therefore, it is possible to provide a device that can prevent the power turbine from becoming a load at a low speed and a low load of the engine and maintain the performance of the turbo compound engine high.

  In the turbo compound engine control device, a bypass duct having a bypass valve is provided in the middle of connecting the outlet of the turbocharger and the outlet of the power turbine to bypass the power turbine, and a brake signal is input to the control means. The control means is characterized in that when a brake signal is inputted, the bypass valve is opened to flow the exhaust gas to the bypass duct, and the fluid coupling is switched to the transmission state by the switching valve. It is possible to provide a device that can increase the braking force by utilizing the resistance that drives the power turbine with the crankshaft.

  According to the above-described turbo compound engine control method and apparatus of the present invention, when the engine speed and the fuel injection amount are outside the power recovery region of the power turbine, the switching means switches the fluid coupling to the non-transmission state to By blocking the power loss transmitted from the turbine to the crankshaft, it is possible to prevent the power turbine from becoming a load in the low speed / low load range of the engine and to achieve an excellent effect of maintaining the performance of the turbo compound engine high. .

  Also, when braking, the bypass valve is opened to allow exhaust gas to flow into the bypass duct, and the fluid coupling is switched to the transmission state, so that the braking force is enhanced by the resistance that drives the power turbine with the crankshaft. obtain.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows an example of an embodiment of the present invention, and relates to a turbo compound engine configured substantially the same as FIGS. 6 and 7 described above, in which a power turbine becomes a load in a low speed / low load region of the engine 1. This prevents the turbo compound engine from maintaining high performance.

  For this reason, in the example shown in FIG. 1, based on the engine speed 31 and the fuel injection amount 32, the switching valve 20 (switching means) provided in the supply line 16 for supplying the hydraulic oil 15 to the fluid coupling 9 in FIG. ) Is controlled. The control device 30 inputs the engine speed 31 and the fuel injection amount 32, and determines whether the engine speed and the fuel injection amount are within a power recovery area where the power of the power turbine 7 can be recovered or outside the power recovery area. When the calculation means 33 for calculation and the engine speed and fuel injection amount obtained by the calculation means 33 are within the power recovery region, the switching valve 20 is opened to switch the fluid coupling 9 to the transmission state. When the power of the turbine 7 is recovered by the crankshaft 11 and the engine speed and the fuel injection amount are outside the power recovery area of the power turbine, the switching valve 20 is closed and the fluid coupling 9 is switched to the non-transmission state. And a control means 34 for controlling the power loss transmitted from the power turbine 7 to the crankshaft 11 to be cut off.

  The calculation means 33 creates a recovery boundary 35 that can recover power turbine power from the two-dimensional map of the engine speed and the fuel injection amount shown in FIG. 2, and therefore the control means 34 allows the engine 1 to perform the calculation. The switching valve 20 is opened in a high speed / high load region that is greater than or equal to the recovery boundary 35 obtained by the means 33, and the engine 1 is in the low speed / low load region lower than the recovery boundary 35 obtained by the computing means 33. The switching valve 20 is closed.

  In the above-described form of FIG. 1, as shown in the control flowchart of FIG. 3, the engine speed / fuel injection amount is in the power recovery region above the recovery boundary 35 of the two-dimensional map shown in FIG. Since the power of the power turbine 7 can be recovered in the high-speed / high-load range of 1, the switching valve 20 is opened to hold the fluid coupling 9 in the transmission state, whereby the power of the power turbine 7 is supplied to the crankshaft. 11 to collect and collect. Therefore, the performance of the turbo compound engine can be sufficiently exhibited in the high speed / high load range of the engine 1.

  On the other hand, the power of the power turbine 7 cannot be recovered in the low speed / low load region of the engine 1 outside the power recovery region where the engine speed and fuel injection amount are lower than the recovery boundary 35 of the two-dimensional map shown in FIG. Therefore, the switching valve 20 is closed to keep the fluid coupling 9 in a non-transmitting state, thereby blocking the load of the power turbine 7 from being transmitted to the crankshaft 11 and causing a power loss. Therefore, it is possible to prevent the problem that the performance of the turbo compound engine is deteriorated due to the load of the power turbine 7 in the low speed / low load region of the engine 1.

  FIG. 4 shows another example of the embodiment of the present invention. The turbo compound engine configured substantially the same as the above-described FIG. 6 and FIG. 7 relates to the turbo compound engine shown in FIG. It is used to increase the braking force of the turbo compound engine.

  For this reason, in the example shown in FIG. 4, the outlet 4a of the turbocharger 4 and the outlet 7a of the power turbine 7 are connected to bypass the power turbine 7, and a bypass duct 37 having a bypass valve 36 is provided in the middle. Yes.

  Further, a brake signal 38 is input to the control means 34 of the control device 30. In the embodiment of FIG. 4, as shown in the control flowchart of FIG. 5, when the switching valve 20 is open and the fluid coupling 9 is in the transmission state, and when the switching valve 20 is closed and the fluid coupling 9 is in the non-transmission state. In any case, when the brake signal 38 is input to the control means 34, the control means 34 opens the bypass valve 36 and causes the exhaust gas to flow through the bypass duct 37 (bypassing the power turbine 7). The switching valve 20 is opened to hold the fluid coupling 9 in the transmission state. As a result, the power turbine 7 is driven by the crankshaft 11, and the power turbine 7 becomes a load on the crankshaft 11. Therefore, the braking force of the turbo compound engine can be increased using the resistance of the power turbine 7. it can.

  The turbo compound engine control method and apparatus of the present invention are not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

It is a schematic explanatory drawing which shows an example of the form which implements this invention. 2 is a two-dimensional map of engine speed and fuel injection amount. It is a control flowchart of the form of FIG. It is outline | summary explanatory drawing which shows the other example of the form which implements this invention. It is a control flowchart of the form of FIG. It is an outline explanatory view showing an example of a general turbo compound engine. It is sectional drawing which shows the detail of a fluid coupling.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Engine 2 Exhaust gas 4 Turbocharger 7 Power turbine 9 Fluid coupling 11 Crankshaft 15 Hydraulic oil 20 Switching valve (switching means)
30 Control Device 31 Engine Speed 32 Fuel Injection Amount 33 Calculation Means 34 Control Means 35 Recovery Boundary Line 36 Bypass Valve 37 Bypass Duct 38 Brake Signal

Claims (5)

  A turbocharger that recovers power from exhaust gas; a power turbine that recovers power from exhaust gas that has passed through the turbine of the turbocharger; a fluid coupling that transmits hydraulic power recovered by the power turbine to the crankshaft by hydraulic oil; A control method for a turbo compound engine comprising a switching means for switching between a power transmission state by supplying hydraulic oil to a joint and a power non-transmission state by shutting off the supply of hydraulic oil, the engine speed・ When the fuel injection amount is within the power recovery area where the power of the power turbine can be recovered, the fluid coupling is switched to the transmission state by the switching means and the power of the power turbine is recovered by the crankshaft. Is outside the power recovery area of the power turbine, the fluid coupling is Control method for turbocompound engine, characterized by interrupting the power loss transmitted from the power turbine to the crankshaft to switch to reach the state.   2. The turbo according to claim 1, wherein the operation of switching the fluid coupling between the transmission state and the non-transmission state by the switching unit is performed by a recovery boundary line obtained from a two-dimensional map of the engine speed and the fuel injection amount. Compound engine control method.   By connecting the outlet of the turbocharger and the outlet of the power turbine to bypass the power turbine, a bypass duct having a bypass valve is provided in the middle, and at the time of braking, the bypass valve is opened to allow exhaust gas to flow through the bypass duct, and The turbo compound engine control method according to claim 1 or 2, wherein the brake force is increased by resistance by switching the fluid coupling to the transmission state by the switching means and driving the power turbine by the crankshaft.   A turbocharger that recovers power from exhaust gas; a power turbine that recovers power from exhaust gas that has passed through the turbine of the turbocharger; a fluid coupling that transmits hydraulic power recovered by the power turbine to the crankshaft by hydraulic oil; A turbo compound engine control device comprising a switching means for switching between a power transmission state by supplying hydraulic oil to a joint and a power non-transmission state by cutting off the supply of hydraulic oil, the engine speed・ Calculation means for calculating whether the fuel injection amount is within the power recovery region where the power of the power turbine can be recovered or outside the power recovery region, and when the engine speed and fuel injection amount obtained by the calculation means are within the power recovery region The switching valve is opened, and when the engine speed and fuel injection amount are outside the power recovery area, the switching valve is closed. Control device for turbocompound engine comprising: the means.   A bypass duct having a bypass valve is provided in the middle of connecting the outlet of the turbocharger and the outlet of the power turbine to bypass the power turbine, and a brake signal is input to the control means, and the brake signal is input to the control means 5. The turbo compound engine control device according to claim 4, wherein the bypass valve is opened to allow exhaust gas to flow through the bypass duct, and the fluid coupling is switched to the transmission state by the switching valve.

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