JPS63248920A - Controller for turbocharger of internal combustion engine - Google Patents

Abstract

PURPOSE:To secure a proper supercharging effect all the time, by attaching a motor generator to the shaft of a turbocharger, making this motor generator operate as a motor or a generator on the basis of a rotor rotating position of the motor generator and load and speed of an internal combustion engine. CONSTITUTION:In this turbocharger 1, a compressor impeller 8 and a turbine impeller 9 both are attached to both ends of its shaft 7. In this case, a magnet rotor 13 is attached to the central part of the shaft 7, while a stator core 15 and a stator coil 16 both are attached to the inner circumference of a center housing 4 being opposed to this magnet rotor, whereby a motor-generator MG is constituted. In addition, a rotor rotating position sensor 40 is attached to the shaft 7, while a load sensor 20 and an engine speed sensor 21 both attached to an internal combustion engine 1, and each output of these sensors is inputted into a controller 22. And, the motor-generator MG is selectively operated as a motor or a generator according to each output out of these sensors 20, 21 and 40.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a control device for a turbocharger of an internal combustion engine, and more particularly to a control device for a motor-generator in which a turbocharger is provided with a motor-generator.

(Prior Art) Since the output of an internal combustion engine is obtained by mixing and burning fuel and air, it is necessary to absorb as much air as possible into the cylinder in order to increase the output.

For this reason, today, the energy of the exhaust gas is used to drive a turbine, which in turn drives a near compressor that is either in motion or integrated, to supercharge more than the normal amount of air into the cylinder, making it more efficient. Turbochargers, which burn fuel, began to be attached to internal combustion engines.

In other words, such an internal combustion engine has the advantage of increasing air filling efficiency, achieving high output and high torque, and improving fuel efficiency.

In such an internal combustion engine with a turbocharger, a TL dynamic generator is further provided on the shaft of the turbine,
In the low-speed rotation range of the engine, power is supplied from the battery mounted on the vehicle to operate the electric motor-generator as a motor, thereby increasing the A supply pressure during low-speed rotation and improving the engine output and torque. can be done. On the other hand, when the engine is in a high-speed rotation range, or when the engine load is small even if the rotation speed is low,
By operating the motor-generator as a generator, surplus power can be extracted and used or charged to a battery. Therefore, by detecting the rotational speed and load value of the engine, it is possible to control the operation as the electric motor or generator.

However, in order to ensure proper motor or generator operation, the rotational speed of the motor-generator rotor must be adjusted at least while maintaining a constant rotational speed and load condition of the engine. It also needs to be stable.

On the other hand, in the operation of a generator, when the magnet rotor rotates at an extremely high speed, the generated power has a high frequency, and the phase difference between the voltage and the current becomes large, resulting in a decrease in the power factor. Therefore, in order to appropriately perform this type of control, a means for continuously detecting the rotational state of the rotor is required. However, the rotation speed of the turbine reaches 20,000 to 100,000 revolutions per minute, and the temperature near the rotor is high, so rotary encoders for low rotation speeds are not suitable for use, and it is extremely difficult to detect the rotational phase of the magnetic rotor. It was difficult.

(Problems to be Solved by the Invention) The present invention has been made in view of the above-mentioned problems, and by detecting the rotational speed and acceleration/deceleration states of the rotor, the motor or generator of the electric motor or The purpose is to ensure that the generator operation is appropriately selected to obtain an appropriate supercharging effect.

(Means for Solving the Problems) In the present invention, an electric motor-generator is provided on the shaft of a turbocharger that supercharges intake air using exhaust gas energy of an internal combustion engine, and a rotor rotates on the rotation axis of the electric motor-generator. Means for detecting the position is provided, and means for detecting the load of the internal combustion engine and means for detecting the rotation speed of the internal combustion engine are provided, and depending on signals from these, the motor-generator is turned into a motor or a generator. A control device for a turbocharger of an internal combustion engine is provided.

(Function) The present invention detects the rotational speed of the rotor and its acceleration/deceleration state using the rotor rotational position sensor of the motor-generator, and performs control to perform appropriate intake supercharging over a wide range from low speed to high speed. is to be done.

(Example) Next, embodiments of the present invention will be described in detail using the drawings.

FIG. 1 is a longitudinal sectional view schematically showing a turbocharger 1. FIG. In the figure, 2 is a compressor housing, 3 is a turbine housing, and 4 is a center housing. At both ends of the center housing 4, a fixed bearing 5 and a floating metal 6 that slides and rotates within the fixed bearing 5 are provided. ing. Further, both ends of a shaft 7 are rotatably supported by the floating metal 6.

A compressor impeller 8 and a turbine impeller 9 are attached to both ends of the shaft 7, and these are connected to the compressor housing 2 and the turbine housing 3.
It is coming within. The turbine impeller 9 rotates upon receiving exhaust gas energy sent to the scroll 10, and the compressor impeller 8 acts to convert the pressure of air introduced from the intake port into the diffuser 12 and send it to the cylinders of the engine. .

On the other hand, near the center of the shaft 7, a ring-shaped magnet rotor 13 that is long in the axial direction is attached. This magnet rotor 13 is made of a rare earth magnet with extremely strong magnetic force.
Since this has extremely low transverse rupture strength and tensile strength, each end face is fixedly held by a high tensile strength metal disc 14, such as titanium or high strength aluminum material, and the 6I 1 stone rotor 1
3. Wrap the outer periphery with carbon fiber or use non-6i! The magnetic rotor has a structure in which the outer shell is made of flexible metal, and has excellent durability as a magnetic rotor with a strong structure even when subjected to centrifugal force or vibration.

Furthermore, a stator core 15 and a stator coil 1 are provided on the inner periphery of the center housing 4 facing the magnet rotor 13.
6 is arranged, and the rotation of the magnet rotor 13 induces an alternating current voltage in the stator coil 16. These magnet rotor 13, stator core 15, and stator coil 16 constitute a motor-generator MG. Further, 40 is a rotor rotational position sensor provided on a part of the rotating shaft (shaft) 7.

FIG. 2 is an explanatory diagram showing the relationship between an internal combustion engine 17 equipped with such a turbocharger 1 and a control device. In the figure, reference numeral 18 denotes an exhaust manifold that communicates with an exhaust boat of the internal combustion engine 17, and the scroll 10 of the turbocharger 1 communicates with this. Reference numeral 19 denotes a fuel injection pump attached to the main body of the internal combustion engine 17, and a load sensor 20 for detecting the amount of fuel injection, that is, the magnitude of the load, is provided here.

Further, the crankcase of the internal combustion engine 17 is provided with a rotation sensor 21 that detects the engine rotation speed, that is, the crank rotation speed.

Reference numeral 22 denotes a control device that controls the motor-generator MG to operate as a motor or a generator using the outputs of the rotor rotational position sensor 40 and the two sensors 20 and 21 as human power; rotor I3
When the rotational speed of the internal combustion engine 17 is low, or even if the rotational speed is high, the rotation is in a decelerating state, the motor-generator MG is operated as an electric motor depending on the rotational speed of the internal combustion engine 17 and its load. 13, that is, the turbine impeller 9 is urged to rotate to improve supercharging efficiency. Further, when the rotational speed of the rotor 13 is high and the rotation is in an accelerated state, the motor-generator MG is operated as a generator,
Electric power can be extracted while continuing the supercharging operation.

Next, the rotor rotational position sensor 40 will be explained based on FIGS. 3 and 4.

FIG. 3 is an enlarged view of the main parts of the rotor rotational position sensor 40. The rotating shaft 7 is formed into a cylindrical shape with a hollow part 7a cut out in the axial direction, and three sets of through holes are bored through the tube wall part, and the first through holes 41a and 41b are on the same diameter.
A second set of through holes 42a, 42b are located on the other diameter making an angle of 01 with this pair, and a third through hole 43a, 43b is located on the diameter making an angle of θ2. ing.

A flexible fiberscope 41c serving as a light guide is inserted into the first set of through holes 41a and 41b, and the second
and a third set of through holes 42a.

42b; 43a, 43b also have light guides 42c, 43
c are respectively inserted through the hollow portion 7a, and are arranged so as to be somewhat curved in the hollow portion 7a, as shown in FIG. 4, so that light can be guided independently of each other. Therefore, the first light guide 41
Both ends E1 and E4 of c are open in the 180° direction on the same circumference, and the second and third light guides 42c and 43c
The same applies to the opening ends E1゜E2 in total, six opening ends E1゜E2.
．． E3. and E4. E5. E6 is all the same circumference K
It is opened along. In addition, Fig. 4 shows A- in Fig. 3.
A sectional view shows the arrangement of light guides 41c, 42c, and 43c. A light emitting element 45 such as a light emitting diode,
A light receiving element 46 such as a photosensor is arranged at a 180° angle with respect to each other, and 46a is a pulse waveform shaping circuit.

Next, the operation of the rotor rotational position sensor 40 to detect the rotational speed and acceleration/deceleration state of the rotor 13 of the motor-generator MG will be explained based on FIGS. 5 to 7. In FIGS. 5 and 6, it is assumed that the rotating shaft 40 is rotating in the direction of the arrow, that is, in the clockwise direction, and in FIG. 5, one end of the first light guide 41c, that is, the first open end E1 shows the relative position at the time of passing in front of. Furthermore, the sixth
The figure shows the state after rotation by 180 degrees, that is, π radians, from FIG. It's a point we're passing through.

Further, FIG. 7 shows a pulse signal generated by one rotation, that is, a 360° rotation of the rotor 13 and thus the rotating shaft 7, and will be explained below based on the above-mentioned figures. As shown in FIG. 5, when the rotor 13 is rotating in the direction of the arrow (clockwise), the first, second, and third
Frontage end E1 of each light guide 41c, 42c, 43c
゜E2. Each time E3 passes in front of the light emitting element 45, the light guide 41C142c, 43c is detected by the light receiving element 46.
The light passing through the first, second, and third
Pulses PL, P2°P3 are generated. Next, as shown in Fig. 6, open end E on the opposite side 4. Each time E 5 , E passes in front of the light emitting element 45, the fourth, fifth, and sixth pulses P4 . p=, ps occurs. In response to these pulses, the peripheral speed, acceleration, etc. of the rotor 13 are calculated by the calculation function of the control device 22.

Hereinafter, referring to FIG. 7, the time intervals between the first to sixth pulses will be sequentially changed to Δt1. Δt2.
t3. Δt1' and Δt2', and based on these, the peripheral velocity V 1 '' rθ1/Δt.

V2"rθ2/Δt2°V2'=rθ2/Δt2' is calculated, and the distinction between acceleration and deceleration is Δt2 and Δt2'
The value of the speed change rate is determined by the following calculation. In the case of deceleration state, α, = (V□-V2)/(Δt2-Δt1)...
(1) In the case of acceleration state, α1' = (V2-Vl)/(Δt2-Δ11)
... (2) is calculated.

As mentioned above, the absolute value of the speed change rate is used in all cases, and in the following explanation, the speed change rate in the case of deceleration will be expressed by its absolute value α1, while the speed change rate in the acceleration state will be expressed as α1 ' It is written as (>O).

Next, the third and fourth positions, that is, the third and fourth open ends E3. The calculation of the time interval t3 of E4 will be explained. Assuming that the peripheral distance between them is 53-4, the velocity v=ds/dt=v2+at of an arbitrary point is integrated with respect to time t, and by setting t=t3, S5 4 =V2 t3+1/2 ·ate2 is obtained.

On the other hand, if we express this 53-4 as the distance along the periphery of the rotor 13, it is equal to r=(π-(θ1+02)), so v2 t5 + 1/2・αt32=(π-(θ1
+02 ) ) (3) holds, and time t3
By solving for , the third and fourth time intervals can be obtained. All of the above calculations are performed by the control device 22.

FIG. 8 is a rotation speed-torque characteristic diagram of an ordinary internal combustion engine equipped with a turbocharger, where Ta indicates the torque of the ordinary internal combustion engine, and Tb indicates the torque of the internal combustion engine equipped with the turbocharger. Tb' is the rotor rotational position sensor 40,
The internal combustion engine load sensor 20 and the rotation sensor 21 detect the operating state of the turbocharger 1 and the internal combustion engine 17, and the control circuit 22 operates the motor-generator MG as an electric motor to indicate a state in which the torque is increased. It is something that

Next, an example of the processing of the embodiment will be explained with reference to the processing flow diagram of FIG. First, when the internal combustion engine 17 is started under certain load conditions, the turbocharger 1 also begins to rotate.

After the internal combustion engine 17 is started and its rotational state reaches a stable state, the rotor rotational position sensor 40 starts its detection operation. As described above, when the radius of the rotor 13 is r, the time interval Δt1 between the first and second pulse signals and the first and second pulse signals are determined by comparing with a reference pulse (for example, an IMHz clock pulse). Based on the angular interval (10th angular interval) θ1 between the second light guides 41c and 42c, the first
The peripheral velocity V1=rθ1/Δti is calculated (steps a, b, c, d, e), and the angular spacing between the second and third light guides 42c, 43c (second angular spacing) is θ
2, the time interval Δt2 between these corresponding second and third pulses is detected (step f).

Next, open end E5 on the opposite side of the second and third light guides 42c and 43c. The pulses generated when E6 passes through the front surface of the light emitting element 45 are the fifth and sixth pulses P5. P6
and their time interval Δt2' is detected (step g).

Next, the process moves to step h in which the time intervals Δt2 and Δt2' are compared.

If Δt2=Δt2', the rotor 13 is in a constant speed rotation state, and the current phase difference between voltage and current stored in the control device 22 is checked, and this is set as the optimum phase difference at the speed v1 (step i). The load condition of the internal combustion engine 17 is detected by the load sensor 20 (step j
), the control operation returns to ◎ at the top of the diagram.

In step, it is determined that Δt2<Δt2',
If YES, the vehicle is in a deceleration state. Since the angular intervals of the first, second, and third light guides 41c, 42c, and 43c are θ1 and 02, respectively, as described above, the peripheral speeds of the rotor 13 corresponding to Δt1 and Δt2 are respectively V 1 ” It is calculated as rθ1/Δt1 and V2″rθ2/Δt2 (step l). deceleration state (i.e. Vl
>v2), the above equation (1), ie, α1=(VIV2)/(Δt2−Δ11), is calculated (step m).

Next, the time interval t3 from when the third open end E3 passes the light emitting element 45 until the fourth open end E4 passes is,
Obtained by equation (3) in the above explanation (step n)
.

Next, the load of the internal combustion engine 17 is detected by the load sensor 20 (step p), and the rotation speed is detected by the rotation sensor 21 (step q).

When the load is large or the rotational speed is small, step r sets the amount of current to be supplied to the motor-generator MG based on the control program stored in the control device 22.
), operates as an electric motor, and is controlled by A at the top of the diagram.
to move to. Furthermore, when the rotational speed is low and the load is also small, the control shifts to the upper part of the diagram, and the motor-generator MG is operated as a generator.

As mentioned above, when the control operation returns to A or B, in either case, steps b to h are reached again, and Δ
t2=Δt2', but still Δt2<Δ
When t2', steps k to r are further repeated until Δt2=Δt2'.

The case where it is determined in the step above that Δt2>Δt2', that is, the state is in an accelerated state, will be explained. As mentioned above, V 1 = rθ1/Δt1 and V2 = rθ2/Δt2
is calculated, and since v2<v2', the above formula (2), that is, α1'= (V2 Vl )/(Δ
t2-Δ11), the acceleration rate α1' is calculated (step U).

Next, as in the case of deceleration, as a solution to the equation (3), the time interval t3 between the third and fourth pulses P3.24 is calculated.
′ is required. Naturally, this value t3' (during acceleration) is determined as a value smaller than the above-mentioned tg (during deceleration), and the acceleration phase is determined (step ■). Similarly to the above, after sequentially measuring the load on the internal combustion engine 17 (step x) and checking the rotation speed (step y), the control program stored in the control device 22 causes the motor-generator MG to operate as a generator. The supply current amount is set to (step Z)
, control returns to B at the top of the figure. In addition, in this case as well, when the control operation returns to the previous state, steps b to h are reached again, and if Δt2=Δt2' is still not satisfied and Δt2<Δt2', steps k to r are further carried out. repeated, while Δt2>Δt2
', steps t to Z are further repeated, and the control operation is repeated until Δt2=Δt2'.

In each of the above embodiments, an optical rotor rotation sensor is used as an example, but a magnetic type, magnetic saturation type, or other type of rotation sensor may be used to achieve the same function. Various modifications are possible within the scope of the present invention, and these are not excluded from the scope of the present invention.

(Effects of the Invention) As explained in detail above, according to the present invention, the rotational speed of the rotor is determined by detecting the rotational position of the rotor of the electric motor-generator provided in the turbocharger driven by exhaust gas energy. and its acceleration/deceleration state is detected, the appropriate rotational state is always maintained, and appropriate motor operation and immediate power generation operation are selected.
Power generation (it becomes possible to always maintain a good power factor).

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a turbocharger in a control device for a turbocharger for an internal combustion engine according to the present invention, and FIG. 2 is a relationship between an internal combustion engine equipped with the turbocharger of the present invention and the control device. FIG. 3 is a front view of the rotor rotational position sensor according to the present invention, FIG. 4 is a cross-sectional perspective view taken along line A-A in FIG. 3, and FIGS. FIG. 7 is an explanatory diagram showing pulse signals, FIG. 8 is a rotation speed-torque characteristic diagram of an internal combustion engine equipped with a turbocharger, and FIG. 9 is a processing flow diagram of an embodiment of the present invention. . DESCRIPTION OF SYMBOLS 1... Turbocharger, 3... Turbine housing, 7... Shaft (rotating shaft), 8... Compressor impeller, 9... Turbine impeller, 13... Rotor, 17... Internal combustion engine , 20... Load sensor, 21... Rotation sensor, 22... Control device, 40... Rotor rotation position sensor, 41c, 42c, 43c... Light guide 45... Light emitting element, 46 ...Photodetector, MG...
Electric - Generator. Figure 5 Figure 6 Figure 7 Figure 8 Engine rotation shaft (/?PM shaft)

Claims (2)

[Claims] (1) An electric motor-generator is provided on the shaft of a turbocharger that supercharges intake air using exhaust gas energy of an internal combustion engine, and a means for detecting the rotational position of the rotor is provided on the rotating shaft of the electric motor-generator, and furthermore, the internal combustion engine An internal combustion engine characterized in that means for detecting the load of the engine and means for detecting the rotational speed of the internal combustion engine are provided, and the motor-generator is operated as a motor or a generator in response to signals from these. Turbocharger control device. (2) The means for detecting the rotational position of the rotor includes a plurality of light guides disposed on the rotation axis of the rotor, light emitting elements disposed at both opening ends of the light guide, and light receiving elements. A control device for a turbocharger of an internal combustion engine according to claim (1), characterized in that the control device comprises a control device for a turbocharger of an internal combustion engine.