JPH11182259A - Turbo charger having dynamo machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To certainly restrain rotation speed of a rotation shaft less than a tolerant rotation speed by providing a braking coil for braking a rotator by current-carrying on a stator of a dynamo machine which can generate power according to an engine operation state and by carrying a current to the braking coil when the rotation speed of the rotation shaft exceeds the upper limit. SOLUTION: When an engine 1 is operated and a turbo charger 10 is driven, a dynamo machine 15 attached to a rotation shaft 13 of the turbo charger 10 is selectively operated as a motor or a generator according to an engine operation state. The dynamo machine 15 consists of a rotator 16 fixed to the rotation shaft 13, a stator 17 fixed to a housing so as to surround this, and a generating and driving coil 19 wound around the stator 17. In this case, a braking coil 20 is furthermore wound around the stator 17, and when rotation speed of the rotation shaft 13 exceeds the upper limit, the braking coil is carried a current so that magnetic pole repelling the magnetic pole of an permanent magnet of the rotor 16 is formed on the stator 17, and rotation speed of a rotation shaft 13 is restrained less than a tolerant rotation speed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotating electric machine which is a motor-generator arranged on a rotating shaft of a turbine rotor driven by exhaust gas of an engine, and which recovers exhaust energy as electric energy. Related to turbochargers.

[0002]

2. Description of the Related Art Turbochargers are widely used in which exhaust energy of an engine is guided to a turbine rotor to rotate at high speed, and a compressor rotor connected to a rotating shaft of the turbine rotor is driven to rotate to supply supercharged air to the engine. In recent years, a rotating electric machine that serves as a motor-generator is arranged on the rotating shaft of this turbocharger, and the rotating electric machine that recovers exhaust energy as electric energy and rotates and drives the compressor rotor with electric energy when exhaust energy is insufficient. Various turbochargers have been proposed.

[0003] This type of turbocharger with rotating electric machine is
For example, it is disclosed in JP-A-5-231162. In this turbocharger with a rotating electric machine, in order to prevent the turbocharger from over-rotating, a turbo-charger rotation speed detecting means is provided to set an excessive rotation speed (maximum allowable rotation speed) of the turbo charger, , The power generation output of the rotating electric machine is increased to control the rotation based on the detection of the excessive rotation speed.

[0004]

However, in the above-described conventional turbocharger with a rotating electric machine, since the power generation output is limited, even if the maximum amount of power generation is output, the turbocharger (rotary shaft) cannot be used. In some cases, the rotation speed cannot be suppressed to an excessive rotation speed or less. Further, the amount of power generation is limited depending on the state of the battery to which the power generation output is supplied, and it may not be possible to output a power generation amount sufficient to suppress the rotation speed of the turbocharger to an excessive rotation speed or less. Therefore, there has been a problem that it is impossible to prevent interference between the compressor rotor and the housing due to an increase in the shaft amplitude, damage to a permanent magnet fixed on the rotating shaft and constituting a rotor of the rotating electric machine, and the like.

Therefore, an object of the present invention is to provide a turbocharger with a rotating electric machine in which the rotation speed of a rotating shaft can be accurately suppressed to an allowable rotation speed or less.

[0006]

The technical measures taken in the present invention to solve the above-mentioned technical problems include a housing and a turbine rotor rotatably disposed in the housing by the exhaust energy of the engine. A rotary shaft rotatably supported by the housing, the turbine rotor being fixed to one end of the rotary shaft, a compressor rotor fixed to the other end of the rotary shaft and rotatably housed in the housing; A rotating electric machine comprising a rotor fixed on the rotating shaft, a stator fixed to the housing with a predetermined small gap from the rotor and a coil wound around the stator; In a turbocharger with a rotating electric machine that recovers exhaust energy by causing the rotating electric machine to generate electricity according to a state, the rotor is energized by passing through the stator. The brake coil forming a braking action against provided, the rotational speed of the rotary shaft is that so as to energize the brake coil when exceeding the upper limit.

In the above means, when the rotation speed of the rotating shaft is higher than an upper limit value, the rotating electric machine is operated for power generation to suppress an increase in the rotating speed of the rotating shaft, and the power generation operation of the rotating electric machine is suppressed. Nevertheless, it is desirable that the braking coil be energized when the rotation speed of the rotating shaft is higher than the upper limit value.

According to the above-mentioned means, when the rotation speed of the rotating shaft exceeds the upper limit, the brake coil is energized,
Since a magnetic braking action can be performed on the rotor, the rotation speed of the rotating shaft is suppressed to the upper limit or less without being affected by the power generation output and the power generation amount.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a turbocharger with a rotating electric machine according to the present invention will be described below with reference to the drawings.

In FIGS. 1 and 2, reference numeral 1 denotes an engine, which is a prime mover of a vehicle, or a power source of a main generator (not shown) in an electric vehicle. A turbocharger 10 with a rotating electric machine is connected to the intake pipe 2 and the exhaust pipe 3 of the engine 1. The turbocharger 10 with a rotating electric machine includes a housing 14 and a turbine housing portion 14A of the housing 14.
The turbine rotor 11 is housed in the compressor housing portion 14B of the housing 14 and is rotatably driven by the exhaust gas energy when the exhaust gas of the exhaust pipe 3 is introduced.
, And a compressor rotor 12 that rotates integrally with the turbine rotor 11. Rotating shaft 13
Is a housing 14 fixed to the turbine housing portion 14A.
Is rotatably supported by the support portion 14C via bearings 18a and 18b. The exhaust gas from the exhaust pipe 3 is introduced from an inlet 14a1 of the turbine housing 14A, drives the turbine rotor 11 to rotate, and is discharged from an outlet 14a2.
Air from an air cleaner (not shown) is introduced into the inlet 14b1 of the compressor accommodating portion 14B through the duct portion 2a, is pressurized by the compressor rotor 12, and is discharged from the outlet 14b2 as supercharged air into the intake pipe 2. You. In FIG. 1, reference numeral 7 denotes a throttle valve disposed in the intake pipe 2, which is opened and closed by a throttle actuator (not shown) according to a signal from the controller 4.
8 is a pressure sensor which detects the intake pressure of the engine,
A detection signal is sent to the controller 4.

As shown in FIG. 2, a case 14D is sandwiched and fixed between the support portion 14C of the housing 14 and the compressor accommodating portion 14B, and is located between the compressor rotor 12 and the bearing 18a in the case 14D. The rotating electric machine 15 is disposed on the rotating shaft 13. The rotating electric machine 15 includes a rotor 16 composed of a permanent magnet fixed to the rotating shaft 13, and a housing 14 surrounding the rotor 16.
And a plurality of power generation and drive coils 19 wound around the stator 17 (three phases in this embodiment)
Which can be selectively operated as a motor or a generator. The power generation and drive coil 19 wound around the stator 17 is connected to the battery 6 via the power converter 5 including an AC / DC bidirectional converter having an inverter and a converter.
When the turbine rotor 11 is driven to rotate and the rotor 16 is rotated in the stator 17, an AC current is generated by the power generation and the drive coil 19, and an AC current is generated. 5, the battery 6 is charged. Conversely, when current is supplied to the power generation and drive coil at the time of starting or sudden acceleration, for example, the rotor 16
Is rotated, and the supercharging operation by the compressor rotor 12 is energized.

In the present embodiment, a braking coil 20 is further wound around the stator 17, and the braking coil 2
Numeral 0 is connected to the battery 6 via the power converter 5 like the power generation and drive coil 19. Braking coil 19
The current is supplied from the battery 6 so that a magnetic pole repelling the magnetic pole of the permanent magnet of the rotor 16 is formed in the stator 17 when the rotation speed of the rotating shaft 13 described later exceeds the upper limit value. When the rotation speed of the rotating shaft 13 does not exceed the upper limit value, it is operable as a generator or motor coil together with the power generation and drive coil 19.

In the above configuration, when the engine 1 is started, the turbine rotor 11 is rotated by the exhaust energy, and the supercharging by the compressor rotor 12 is started. At this time, the rotary electric machine 15 is selectively operated as an electric motor or a generator by the controller 4 according to the operating state of the engine 1 as described above. That is, at the time of low, medium load operation, and acceleration of the engine, the rotating electric machine 15 is operated as an electric motor, energizing the supercharging operation by the compressor rotor 12, and increasing the intake pressure to improve the engine torque. At this time, a current may be supplied to the braking coil 20 together with the power generation and the drive coil 19 at a predetermined timing according to the rotational position of the rotor 16. When the engine is operating under a high load, the rotating electric machine 15 is operated as a generator to charge the battery 6 as described above.
At this time, the power generation and drive coil 19
An excitation current is generated in the same manner as described above, and the current is converted from AC to DC by the power converter 5 and supplied to the battery 6, and the battery 6 is charged. As a result, compared to the power generation and the power generation using only the drive coil 19, the generated current is reduced, and the load on the elements of the power converter 5 is reduced.

In the above-described power generation operation, the rotation speed of the rotating shaft 13 is detected from the power generation sent to the controller 4 via the power converter 5 and the voltage waveform of the drive coil 19.
If the rotation speed of the rotating shaft 13 exceeds, for example, 150,000 rpm, the compressor rotor 12
In this embodiment, the rotation speed of the rotating shaft 13 may exceed the upper limit, as shown in FIG. 3, since there is a possibility that interference between the rotating shaft 13 and the compressor accommodating portion 14B and breakage of the permanent magnet constituting the rotor 16 may occur. According to the flowchart shown, the controller 4 prevents the following.

In FIG. 3, the rotation speed of the rotating shaft 13 during the above-described power generation operation (hereinafter referred to as turbine rotation speed).
Is compared with the upper limit in step S1. Step S1
When the turbine speed is equal to or lower than the upper limit, the normal power generation operation described above is continued in step S3. When the turbine speed exceeds the upper limit value in step S1, the generated current limit value is compared with the battery charge allowable value in step S2. When the battery charge allowable value is larger than the generated current limit value, the set current value of the power generation and drive coil 19 is set to the generated current limit value in step S4, and the set current value of the power generation and drive coil 19 (step S6). (Generation current limit value). When the allowable battery charge value is equal to or less than the generation current limit value in step S2, the set current value of the power generation and drive coil 19 is set to the allowable battery charge value in step S5.
In step S6, the power generation amount is increased to the power generation and set current value of the drive coil 19 (battery charge allowable value). Here, the power generation and the set current value of the drive coil 19 are set in the power converter 5, and the charge state of the battery 6 is constantly monitored by the controller 4.

In step S6, the power generation and drive coil 19
Is set, it is determined in step S7 whether or not the turbine speed has decreased. That is, the turbine speed r1 in step S1 is compared with the current turbine speed r2, and if r1> r2, step S1 is performed.
Proceeding to step S8, if it is lower than r1 than r2, the procedure proceeds to step S1 and the above steps are repeated. In step S8, the braking current is applied to the braking coil 20 in accordance with the rotational position of the rotor so that the magnetic pole having the same polarity as the magnetic pole of the permanent magnet of the rotating rotor 16 is formed and the rotor 16 performs a braking action. Is turned on. Thereafter, the turbine speed is compared with the upper limit in step S9, and when the turbine speed exceeds the upper limit, the application of the braking current in step S8 is continued. If it is determined in step S9 that the turbine speed is equal to or lower than the upper limit value, the application of the braking current is stopped in step S10, and normal control is performed. The above-described rotation speed control is repeatedly executed at predetermined time intervals during the above-described power generation operation, so that the rotation speed of the rotation shaft 13 can be prevented from becoming equal to or more than the upper limit value without being affected by the power generation output or the power generation amount limitation. Is done.

[0017]

As described above, according to the present invention, when the rotation speed of the rotating shaft exceeds the upper limit value, the braking coil is energized to perform a magnetic braking action on the rotor. Therefore, the rotation speed of the rotating shaft can be suppressed to the upper limit or less without being affected by the limitation of the power generation output and the power generation amount. Therefore, when the rotation speed of the rotating shaft exceeds the upper limit, it is possible to prevent interference between the compressor rotor and the housing due to an increase in the amplitude of the rotating shaft and breakage of the permanent magnet constituting the rotor, and the like. The reliability of the turbocharger with a rotating electric machine can be improved.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram of an embodiment of a turbocharger with a rotating electric machine according to the present invention.

FIG. 2 is a sectional view of the turbocharger with a rotating electric machine in the embodiment of FIG. 1;

FIG. 3 is a control flowchart for preventing the rotation shaft from over-rotating in the embodiment of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Engine 4 Controller 5 Power converter 6 Battery 10 Turbocharger with rotating electric machine 10 11 Turbine rotor 12 Compressor rotor 13 Rotating shaft 14 Housing 15 Rotating electric machine 16 Rotor 17 Stator 19 Power generation and drive coil (coil) 20 Braking coil

Claims (2)

[Claims] 1. A housing, a turbine rotor rotatably disposed in the housing by exhaust energy of an engine, and a rotating shaft rotatably supported by the housing and having one end fixed to the turbine rotor. A compressor rotor fixed to the other end of the rotation shaft and rotatably housed in the housing, a rotor fixed on the rotation shaft, and fixed to the housing with a predetermined small gap from the rotor. A rotating electric machine comprising a stator provided and a coil wound around the stator, and a rotating electric machine-equipped turbocharger for recovering exhaust energy by operating the rotating electric machine to generate power in accordance with an operating state of an engine; The stator is provided with a braking coil that performs a braking action on the rotor by energizing the stator, and the braking is performed when the rotation speed of the rotating shaft exceeds an upper limit value. A turbocharger with a rotating electric machine, characterized in that a dynamic coil is energized. 2. When the rotation speed of the rotating shaft is higher than an upper limit value, the rotating electrical machine is operated to generate power to suppress an increase in the rotating speed of the rotating shaft. The turbocharger with a rotating electric machine according to claim 1, wherein the brake coil is energized when the rotation speed of the rotating shaft is higher than an upper limit value.