JP4403818B2 - Surging prevention device, supercharger, and surging prevention method - Google Patents

Description

  The present invention relates to a surging preventing device, a supercharger, and a surging preventing method, and more particularly to a device that prevents surging by detecting vibration of a compressor.

Conventionally, in a turbocharger (supercharger) having an electric motor and a supercharging pressure changing means other than the electric motor, each control of the electric motor and the other supercharging pressure changing means is not interfered, that is, the above other supercharging pressure changing means. It is known that output characteristics and the like can be improved by preferentially executing supercharging pressure control by the supply pressure changing means (see, for example, Patent Document 1).
JP 2003-239755 A

  By the way, in the conventional control described above, when the surging point is shifted due to a change in usage environment or aging (for example, adhesion of foreign matter to the compressor blade), it is not possible to avoid the occurrence of the surging of the compressor There is a problem that there is.

  The present invention has been made in view of the above problems, and in a surging prevention device for preventing surging of a compressor such as a supercharger, the occurrence point of surging is shifted due to a change in usage environment or aging. It is an object of the present invention to provide a surging prevention device and a surging prevention method that can avoid occurrence of surging even in the case of occurrence of surging.

The invention according to claim 1 is a surging prevention device for preventing surging of a compressor driven by a turbine rotating with engine exhaust gas .
Vibration detection means for detecting vibration during operation of the compressor by detecting fluctuations in the rotation speed of the compressor ;
A generator that reduces the supercharging pressure of the compressor by reducing the rotational speed of the compressor by converting the rotational energy of the rotating shaft member that interlocks the turbine and the compressor to electrical energy. When,
When the vibration detecting means detects a fluctuation in the rotation speed of the compressor and has a cycle shorter than the cycle of exhaust gas pulsation in the engine, the generator reduces the rotation speed of the compressor. Control means to control ,
It characterized in that it has a.

According to a second aspect of the invention, the surge protection device according to claim 1, the generator includes a permanent magnet provided on the rotary shaft member, provided around said rotary shaft member and the rotating shaft the member includes a non-contact coil, the vibration detection means, by detecting a change in magnetic flux of the permanent magnet provided on the rotary shaft member in a hall sensor provided in the housing, the compressor it you wherein being configured to detect variations in the rotational speed of the.

According to a third aspect of the present invention, in the surging prevention device according to the first or second aspect , a voltage for suppressing an increase in the electric system voltage of the engine due to the electric energy generated by the generator. it characterized in that it has a rise suppression portion.

According to a fourth aspect of the present invention, in the surging preventing device according to the third aspect , the voltage rise suppression means includes a charging circuit capable of temporarily charging electric power, and the control means includes the compressor. In order to increase the rotational speed of the compressor, the generator is used as an electric motor, and the electric energy stored in the charging circuit is supplied to the electric motor to increase the rotational speed of the compressor. it characterized in that it is a means.

The invention according to claim 5, you comprising the surging prevention device according to any one of claims 1 to 4.

  According to the present invention, in a surging prevention device for preventing surging of a compressor such as a supercharger, occurrence of surging is avoided even when the surging occurrence point is shifted due to a change in usage environment or aging. There is an effect that can be.

  FIG. 1 is a diagram showing a schematic configuration of a supercharger 1 according to an embodiment of the present invention.

  The supercharger 1 includes a housing 3, a rotating shaft member 5 that rotates with respect to the housing 3 via, for example, a fluid bearing (not shown) inside the housing 3, and the rotating shaft member 5. A centrifugal compressor 7 provided on the one end portion 5A side and a centrifugal turbine 9 provided on the other end portion 5B side of the rotary shaft member 5 are provided.

  The compressor 7 includes a compressor disk 11 in which a base end side portion is integrally provided on the rotary shaft member 5 at an end side portion 5A of the rotary shaft member 5, and a distal end portion of the compressor disk 11. And compressor blades 13 provided integrally with the compressor disk 11 on the side.

  The turbine 9 includes a turbine disk 15 in which a base end side part is integrally provided on the rotary shaft member 5 at an end side part 5B of the rotary shaft member 5, and a distal end side of the turbine disk 15 The turbine blades 17 are provided integrally with the turbine disk 15.

  The supercharger 1 is used for a reciprocating engine or a rotary engine. For example, the turbine 9 is rotationally driven by high-temperature and high-pressure exhaust gas G3 emitted from a four-cycle piston engine E1, and the compressor 7 is rotated by this rotation. The compressed air G1 obtained by driving and rotating the compressor 7 is supplied to the engine E1.

  The compressed air G1 is used for the combustion of fuel in the cylinder of the engine E1, and the combustion discharges the high-temperature and high-pressure exhaust gas (combustion gas for rotating the turbine 9) G3. is there.

  The supercharger 1 is provided with, for example, a control device 19 that controls the engine E1 or a vehicle in which the engine E1 is provided, and a battery 21 is always connected to the control device 19, Further, a signal line 23A from a hall sensor 23 described later is connected. The battery 21 is also connected to a generator (not shown) (a generator that generates power by the rotational driving force of the crankshaft of the engine E1).

  Further, the supercharger 1 is provided with a generator 25 that can generate electric power by the rotational driving force of the rotary shaft member 5. The generator 25 can also operate as an electric motor under the control of the control device 19 by receiving power from the battery 21 or the like.

  The control device 19 is electrically connected to the generator 25 and is also electrically connected to the brake circuit 27.

  It should be noted that between the control device 19 and the generator 25, the current flow between the control device 19 and the generator 25 can be turned on / off under the control of the control device 19. A machine switch (not shown) is provided.

  In addition, between the control device 19 and the brake circuit 27, a brake circuit capable of turning on and off the current flow between the control device 19 and the brake circuit 27 under the control of the control device. A switch (not shown) is provided.

  The supercharger 1 is provided with a surging preventing device 29 for preventing surging of the compressor 7.

  The surging prevention device 29 is provided with vibration detecting means 31 for detecting vibration during operation of the compressor 7 and supercharging pressure reducing means 33 capable of reducing the supercharging pressure of the compressor 7.

  Then, under the control of the control device 19, when the vibration detection unit 31 detects a short-cycle vibration that is a sign of surging of the compressor 7, the supercharging pressure reduction unit 33 causes the compressor 7 to The supercharging pressure is reduced.

  Here, to explain in more detail with an example, the vibration detecting means 31 detects the vibration of the compressor 7 by detecting the fluctuation of the rotational speed (rotational speed) of the compressor 7. ing. Further, the supercharging pressure reduction means 33 reduces the rotational speed (rotational speed) of the compressor 7 by converting the rotational energy of the compressor 7 into electrical energy by the generator 25. .

  Then, under the control of the control device 19, the fluctuation of the rotation speed of the compressor 7, which is shorter than the pulsation period of the exhaust gas G 3 in the engine E 1 (the vibration detection means 31 can detect the fluctuation). When the vibration detection means 31 detects a vibration frequency within a wide range, the supercharging pressure reduction means 33 reduces the rotational speed of the compressor 7.

  Here, the reason why the rotational speed of the compressor 7 varies will be described. Regardless of whether the engine E1 is a piston engine or a rotary engine, since the engine E1 repeats a cycle such as compression and explosion, the pressure of the exhaust gas G3 discharged from the engine E1 pulsates. ing. That is, if the engine E1 is a six-cylinder four-cycle engine and is rotating at a rotational speed of 6000 rpm, the pressure of the exhaust gas G3 fluctuates at a cycle of about 3.3 msec. And the rotational speed of the said turbine 9 or the compressor 7 also fluctuates by the fluctuation | variation of the said exhaust gas G3.

  Therefore, when the vibration detection means 31 detects, for example, fluctuations in the rotational speed with a period shorter than the 3.3 msec period, the supercharging pressure reduction means 33 operates.

  Further, as described above, the supercharging pressure reduction means 33 includes the generator 25, and the generator 25 integrally includes the permanent magnet 35 on the rotary shaft member 5, A coil 37 that is not in contact with the rotary shaft member 5 (a coil 37 that is provided integrally with the housing 3) is provided around.

  Rotational energy of the turbine 9, the compressor 7, and the rotary shaft member 5 that interlocks and connects the turbine 9 (rotary part of the turbine) and the compressor 7 (rotary part of the compressor) to each other. Can be regeneratively braked and converted into electrical energy.

  The vibration detecting means 31 detects the change in the magnetic flux of the permanent magnet 35 provided on the rotary shaft member 5 by the Hall sensor 23 provided on the housing, thereby changing the rotational speed of the compressor 7. Configured to detect.

  One end of the permanent magnet 35 is an N pole on the rotation circumference of the rotary shaft member 5, and the N pole has a 180 ° centering on the rotation center axis of the rotary shaft member 5. The other end located there is an S pole.

  On the other hand, the hall sensor 23 is provided at a position obtained by dividing the rotation circumference of the rotary shaft member 5 into, for example, three equal parts.

  Here, the case where the generator 25 suppresses the increase in the rotation of the compressor blade 13 (rotary shaft member 5) of the compressor 7 will be described in more detail with an example.

  When the vibration detection means 31 detects a vibration that is a precursor of surging, the control device 19 turns on the generator switch, turns on the brake circuit switch, and turns on the current from the generator 25. All or part of the current flows through the brake circuit 27.

  The rotational energy of the rotating shaft member 5 is converted into electric energy by the power generation by the generator 25 and is consumed by the brake circuit 27 or temporarily stored in the brake circuit 27, or stored in the battery 21. The rotational speed of the rotating shaft member 5 is reduced, the rotational speed of the compressor 7 is lowered, and surging of the compressor 7 can be prevented.

  Further, the supercharger 1 is provided with a voltage increase suppressing means 39 for suppressing an increase in the electric system voltage of the engine E1 due to the electric energy generated by the supercharging pressure reducing means 33.

  Here, the voltage rise suppression means 39 will be described.

  The electric energy converted by the generator 25 is normally stored in the battery 21 of the electric system such as the engine E1, but the amount of power generated by the generator 25 is large and cannot be stored in the battery 21. The voltage may increase.

  Therefore, the voltage rise suppression means 39 suppresses an excessive rise in the voltage of the electrical system.

  The voltage rise suppression means 39 will be described in more detail.

  The voltage increase suppression means 39 includes the brake circuit 27 and suppresses an excessive increase in the voltage of the electric system by causing the amount of power that cannot be stored in the battery 21 to flow through the brake circuit 27. It is.

  As the brake circuit 27, for example, a charging circuit such as a capacitor that can temporarily charge electric energy or an electric resistance that converts electric energy into heat can be employed. By adopting a capacitor or an electric resistance, the configuration of the brake circuit can be simplified.

  That is, for example, under the control of the control device 19, the voltage of the electrical system is detected by a voltage detection means (not shown) in a state where the generator switch is turned on, and the voltage of the electrical system is When the voltage exceeds the allowable voltage of the electric system, that is, for example, when the voltage of the electric system increases by a predetermined value or more (for example, 1 V or more) compared to the voltage of the battery 21, the brake switch is turned on. By passing a current through the brake circuit 27, an excessive increase in the voltage of the electrical system is suppressed.

  On the other hand, when the voltage detecting means detects that the voltage of the electrical system is lower than the allowable voltage by a predetermined value with the generator switch turned on, the brake circuit switch Is supposed to turn off.

  Further, when it is no longer necessary to suppress an increase in the speed of the rotating shaft member 5, the brake circuit switch is turned off and the generator switch is turned off.

  Further, the voltage rise suppression means 39 is configured to include a charging circuit capable of temporarily charging electric power, in other words, the brake circuit 27 is configured by a capacitor, a small rechargeable battery, etc., and the compression When the rotational speed of the compressor 7 (the rotational speed of the rotating shaft member 5) is increased, that is, when the rotational speed of the compressor 7 needs to be increased with a force larger than the rotational driving force of the turbine 9. The generator 25 may be used as an electric motor, and the electric energy stored in the charging circuit 27 may be supplied to the electric motor to increase the rotational speed of the compressor 7.

  Next, the operation of the surging prevention device 29 will be briefly described.

  FIG. 2 is a flowchart for explaining the operation of the surging prevention device 29.

  In the start state shown in FIG. 2, it is assumed that the engine E1 and the supercharger 1 are operating.

  In step S1, the vibration detection means 31 detects vibration during operation of the compressor 7, and in step S3, if short-period vibration that is a precursor of surging of the compressor 7 is detected, The supercharging pressure of the compressor 7 is reduced by the supercharging pressure reduction means 33 (generator 25 etc.).

  In step S5, when the voltage of the electric system is higher than the allowable voltage due to the electric energy generated by the supercharging pressure reduction means 33 (generator 25), the brake circuit 27 is turned on in step S7. Used to recover the electrical energy.

According to the surging prevention device 29, when the fluctuation of the short cycle is detected as a vibration that is a precursor to the surging of the compressor 7, the control is performed so as to reduce the supercharging pressure of the compressor 7. Even if the surging occurrence point is shifted due to aging , the occurrence of surging can be easily avoided.

  Further, according to the surging preventing device 29, it is not necessary to find out the surging occurrence point by using the map showing the characteristics of the compressor 7 and the map and the conditional expression. Therefore, surging can be prevented with a simple configuration and operation. be able to.

  Further, according to the surging prevention device 29, since the vibration of the compressor 7 is detected by detecting the fluctuation of the rotation speed of the compressor 7, for example, it passes through the compressor 7 (compressed by the compressor). It is possible to detect a sign of surging more easily and reliably than detecting a change in the flow rate of a fluid such as air.

Further, when a change in the compressor rotational speed having a cycle shorter than the cycle of the exhaust gas pulsation in the engine E1 is detected, a sign of surging can be detected in distinction from the pulsation of the engine E1.

  Furthermore, according to the surging prevention device 29, in order to prevent the occurrence of surging of the compressor 7, the rotational energy of the compressor 7 is converted into electrical energy by the generator 25, and the rotational speed of the compressor 7 is reduced. Therefore, a complicated and expensive device such as an air bypass path that connects the upstream side and the downstream side of the compressor 7 or an air bypass valve provided in the middle of the path to prevent surging is used. There is no need to use it, and a surging prevention device with a simple configuration can be obtained.

  Further, according to the surging preventing device 29, the generator 25 is the one in which the rotating shaft member 5 is provided with the permanent magnet 35 and the coil 37 that is not in contact with the rotating shaft member 5 is provided around the rotating shaft member 5. Since it is used, it is easy to reduce the size of the device compared to the induction generator.

  Further, the hall sensor 23 provided in the housing 3 uses the permanent magnet 35 provided in the rotary shaft member 5, that is, the permanent magnet 35 provided for the generator 25, for example. Since a change in the number of rotations of the member (rotating member of the compressor) 5 (vibration of the compressor 7) can be detected, vibration of the compressor 7 can be detected with a simple configuration.

  Further, according to the surging prevention device 29, a charging circuit capable of temporarily charging electric power is adopted as the voltage rise suppression means 39, and the generator 25 is used as an electric motor. Since the electric energy stored in the circuit is supplied to increase the rotation speed of the compressor 7, energy efficiency can be improved and the rotation speed of the compressor 7 can be increased quickly.

  Note that the vibration detecting means 31 may detect, for example, vibration in the extending direction of the rotation center axis of the rotating shaft member 5, or may detect vibration of changes in the inlet pressure or outlet pressure of the compressor 7. May be.

  Further, as the supercharging pressure reduction means 33, means for lowering the pressure downstream of the compressor 7 by intake side air bypass valve control, means for lowering the rotational speed of the turbine 9 by waste gate valve control, variable to the inlet of the turbine 9 A means for lowering the rotational speed of the turbine 9 by providing a nozzle and a means for lowering the rotational speed of the compressor 7 by A / R variable control for changing the capacity of the turbine 9 can be adopted.

  The above-described embodiment can also be applied to a compressor that is rotationally driven by the rotation output shaft of the engine E1. In this case, as the supercharging pressure reducing means 33, for example, a clutch provided between the rotating shaft of the engine E1 and the compressor and turning on / off the clutch to reduce the rotational speed of the compressor may be adopted. it can.

It is a figure which shows schematic structure of the supercharger which concerns on embodiment of this invention. It is a flowchart explaining operation | movement of a surging prevention apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Supercharger 3 Case 5 Rotating shaft member 7 Compressor 9 Turbine 19 Control device 23 Hall sensor 25 Generator 27 Brake circuit 29 Surging prevention device 31 Vibration detection means 33 Supercharging pressure reduction means

Claims (5)

In a surging prevention device for preventing surging of a compressor driven by a turbine rotated by engine exhaust gas ,
Vibration detection means for detecting vibration during operation of the compressor by detecting fluctuations in the rotation speed of the compressor ;
A generator that reduces the supercharging pressure of the compressor by reducing the rotational speed of the compressor by converting the rotational energy of the rotating shaft member that interlocks the turbine and the compressor to electrical energy. When,
When the vibration detecting means detects a fluctuation in the rotation speed of the compressor and has a cycle shorter than the cycle of exhaust gas pulsation in the engine, the generator reduces the rotation speed of the compressor. Control means to control ,
A surging preventing device comprising: The surging prevention device according to claim 1 , wherein
The generator includes a permanent magnet provided on the rotating shaft member, and a coil provided around the rotating shaft member and not in contact with the rotating shaft member ,
The vibration detecting means is configured to detect a change in the rotational speed of the compressor by detecting a change in magnetic flux of a permanent magnet provided in the rotating shaft member by a hall sensor provided in the casing. An anti-surging device characterized by the above. The surging preventing device according to claim 1 or 2 ,
A surging prevention device comprising voltage rise suppression means for suppressing an increase in electrical system voltage of the engine due to electrical energy generated by the generator . The surging preventing device according to claim 3 , wherein
The voltage rise suppression means includes a charging circuit capable of temporarily charging power,
The control means uses the generator as an electric motor to increase the rotational speed of the compressor, and supplies the electric motor with the electric energy stored in the charging circuit. A surging preventing apparatus, characterized in that it is means for increasing the rotational speed of a compressor. A supercharger for a reciprocating engine or a rotary engine, comprising the surging prevention device according to any one of claims 1 to 4 .

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