JPH0647936B2 - Turbo Compound Engine - Google Patents

Description

TECHNICAL FIELD The present invention relates to a turbo compound engine capable of regenerating exhaust energy of an internal combustion engine.

(Prior Art) In recent years, an internal combustion engine having a heat insulating structure has been developed in which ceramics are used for each part of the internal combustion engine, for example, a part such as a combustion chamber or an exhaust pipe. According to this type of internal combustion engine, it is not necessary to radiate the heat generated inside to cool the internal combustion engine, and the energy of the generated high temperature exhaust gas can be regenerated and used for improving the output of the internal combustion engine.

As a method of regenerating exhaust energy, there has been known a method in which the rotational force of a turbine rotated by exhaust gas is decelerated by a multistage gear mechanism and returned to a crankshaft.

Further, in Japanese Unexamined Patent Publication No. 58-216615, a rotating shaft of an AC generator is directly connected to a shaft of an exhaust turbine, and a rotating shaft of a DC motor is connected to a shaft of an engine, which is generated by an AC generator. There has been proposed an exhaust energy recovery system for an engine that drives a DC motor with electric energy to produce an engine output.

(Problems to be Solved by the Invention) In such a method of regenerating exhaust energy, the former method of returning the rotational force to the crankshaft by using the gear mechanism is, for example, usually one step in consideration of gear transmission efficiency. Since the efficiency is 0.9 to 0.95, the efficiency is reduced to about 80% in the three-step deceleration, and the cost is increased because the gear mechanism is complicated.

Next, in the latter proposal of the exhaust energy recovery system, an AC generator is directly connected to the turbine shaft of the exhaust turbine, a DC motor is connected to the rotating shaft of the engine, and the DC motor is driven by electric energy from the AC generator. Since it is rotated and returned to the output shaft of the engine, exhaust energy is recovered, but there is a problem that the DC motor is not sufficiently controlled.

The present invention has been made in view of these conventional problems, and an object thereof is to convert exhaust energy into electric energy by an AC generator directly connected to an exhaust turbine, and convert the electric energy into a rotation speed of a crankshaft. It is to provide a turbo compound engine that measures and regenerates exhaust energy by correspondingly controlling and driving an electric motor coupled to a crankshaft via a planetary gear mechanism.

(Means for Solving the Problems) According to the present invention, a first exhaust turbine provided midway in the exhaust pipe of an internal combustion engine, and an intake air-assisting device attached to a rotary shaft of the first exhaust turbine are provided. A compressor, a first generator, and a second generator provided downstream of the first exhaust turbine.
Exhaust turbine, a second generator driven by the second exhaust turbine, a generator / motor connected to the rotary shaft of the internal combustion engine via a planetary gear mechanism, and a rotary shaft of the internal combustion engine A clutch mechanism attached to the planetary gear mechanism for switching the rotation speed ratio with the electric motor, a rotation sensor for detecting the rotation speed of a flywheel connected to the rotation shaft of the internal combustion engine, and the first and second On / off control means for performing on / off control of the clutch mechanism based on the rotational speed signal of the internal combustion engine and the electric / generator from the electric power generated by the electric generator and the rotational speed signal of the rotation sensor; There is provided a turbo compound engine, comprising: a first rotating machine control means for operating the internal combustion engine; and a second rotating machine control means for operating the motor / generator as a generator based on the operating state of the internal combustion engine.

(Operation) The output of the generator provided in the exhaust turbine driven by the energy of the exhaust gas is controlled by the rotation speed that detects the rotation speed of the flyhole of the internal combustion engine, drives the electric motor that rotates the flywheel, and Since the rotational force of the flywheel is assisted corresponding to the rotational speed of the flywheel, the exhaust energy is efficiently regenerated and the output of the internal combustion engine is improved.

Further, since the planetary gear mechanism having a plurality of reduction ratios is used as the transmission mechanism for assisting the rotation of the flywheel by the electric motor, the output characteristics of the electric motor can be efficiently transmitted to the flywheel.

Further, since the field winding of the electric motor is switched to operate as a generator, the braking force can be recovered as electric energy during engine braking, and the energy can be used to charge the battery.

(Example) Next, the Example of this invention is described in detail using drawing.

FIG. 1 is a structural explanatory view showing an embodiment of a turbo compound engine according to the present invention, and FIG. 2 is a structural explanatory view showing an example of a planetary gear mechanism used in the present embodiment.

In FIG. 1, reference numeral 1 denotes an internal combustion engine having a heat insulating structure, and a combustion chamber such as a piston and a cylinder liner (not shown) and an exhaust port forming a heat insulating structure using ceramics. A turbocharger 3 having a generator A4 is attached.

The turbine blade 3 is attached to the rotary shaft of the turbocharger 3.
a, the rotor 4a of the AC generator A4, and the compressor blade 3b are coaxially directly connected to each other. When the turbine blade 3a is driven by the exhaust gas from the exhaust manifold 2, the compressor blade 3
b is for feeding the supercharged air to the intake pipe 1a, and for the rotor 4a.
Is driven. The rotor 4a is made of a permanent magnet having a strong residual magnetism, generates alternating current power by electromagnetic induction in the opposing stator 4b, and the alternating current power is rectified by the rectifier 4c and sent to the inverter 5.

On the other hand, an exhaust turbine 6 having a turbine blade 6a is connected to the exhaust port 3c of the turbocharger 3, and the rotor 7a of the alternator B7 is coaxial with the turbine blade 6a.
Is provided. Then, by the exhaust gas having residual energy from the exhaust port 3c of the turbocharger 3,
When the turbine blade 6a is driven, AC power is induced in the winding of the stator 7b provided correspondingly by the rotation of the rotor 7a having a permanent magnet, and is input to the connected rectifier 7c to become DC, DC power is transmitted to the inverter 5.

A large gear 1d is provided around the flywheel 1c of the internal combustion engine 1.
The large gear 1d meshes with a small gear 8b provided coaxially with an internal gear 8a which is an outside of the planetary gear mechanism 8 described later.

The planetary gear mechanism 8 shown in FIG.
A sun gear 8c is provided on the rotor shaft 9a of the cage 8 and a plurality of planet gears 8d that surround the sun gear 8c and mesh with each other are provided in the cage 8
It is attached to e and is also configured to mesh with the inner gear 8a.

Further, a clutch shoe 8g made of a magnetic material that serves as a means for fixing the sun gear 8c and the planet gear 8d is attached to the shaft 8f of the planet gear 8d, and when the electromagnetic coil 9b provided on the rotor shaft 9a is energized, the clutch Since the shoe 8g is sucked and the cage 8e does not rotate with respect to the rotor shaft 9a, the small gear 8b provided on the outer periphery of the planetary gear mechanism 8 rotates in the same manner as the rotor shaft 9a. Therefore, when the electromagnetic coil 9b is not energized, the rotation speed of the rotor shaft 9a is reduced at a predetermined ratio by the planetary gear mechanism 8 to rotate the gear shaft of the small gear 8b, and further, the small gear 8b.
The flywheel 1c is rotated by the gear ratio of the large gear 1d and the cage 8e when the electromagnetic coil 9b is energized.
Is fixed, the rotor shaft 9a rotates the flywheel 1c at a reduction ratio of only the gear ratio between the small gear 8b and the large gear 1d. The function implementing means for energizing or de-energizing the electromagnetic coil 9b to perform the suction and suction release operations of the clutch shoe 8g is referred to as on / off control means.

In FIG. 1, reference numeral 10 is a rotation sensor which serves as a rotation speed detecting means of the flywheel 1c and sends a detection signal to the inverter 5. Inverter 5 that received this detection signal
Controls the electric power of the alternating-current generator A4 and the alternating-current generator B7 rectified into direct current to alternating-current power having a frequency corresponding to the detection signal, and transmits the electric power to the induction motor 9. Then, when the rotation of the flywheel 1c is slow, the frequency of the alternating current controlled by the detection signal is low, so that the rotation of the induction motor 9 is slow, but the flywheel 1c passes through the gear mechanism 8.
Assists the rotational force of. When the flywheel 1c rotates at high speed, the induction motor 9 is driven under the control of the detection signal so that the frequency of the AC output of the inverter 5 becomes high, and the flywheel 1c rotating at high speed is rotated through the gear mechanism. In order to assist the force, the induction motor 9 always assists to increase the rotational force in accordance with the level of rotation of the flywheel 1c. The function realizing means for driving the induction motor 9 in the power running mode is referred to as a first rotating machine control means.

Next, 12 is a regulator, 12 is a rectifier, and 14 is a battery, which detects a clutch pedal, an accelerator pedal, and a vehicle speed, which are not shown, when the internal combustion engine 1 is in an engine braking operation depending on the operating condition of the vehicle. The controller 11 operates in response to an input signal from the sensor to switch the field winding of the induction motor 9 to operate as an induction generator, and sends the generated AC power to the regulator 12. Then, this AC power is input to the rectifier 13 to generate DC, and the battery 14 is charged. In addition, by switching the field winding of the induction motor 9,
The second function realizing means for making this act as an induction generator
It is called a rotating machine control means.

Further, reference numeral 15 is an inverter, which controls the direct current from the battery 14 by the detection signal of the rotation sensor 10 at the time of starting the internal combustion engine 1 to form alternating current power of a predetermined frequency, and supplies it to the induction motor 9 to operate the gear mechanism. The internal combustion engine 1 is driven via this.

Next, the operation of the present embodiment thus configured will be described.

High-temperature exhaust gas from the internal combustion engine 1 having a heat insulating structure is guided to the turbocharger 3 through the exhaust manifold 2 and drives the turbine blade 3a to rotate the compressor blade 3b and the rotor 4a of the AC generator A4. Therefore, the supercharged air is pressure-fed to the intake pipe 1a, and the AC power from the stator 4b is rectified by the rectifier 4c to be DC and transmitted to the inverter 5.

On the other hand, the exhaust gas having residual energy discharged from the exhaust port 3c by driving the turbine blade 3a is guided to the exhaust turbine 6 to drive the turbine blade 6a.
Then, the rotor 7a of the alternating-current generator B7 is rotated, the alternating-current power induced by the stator 7b is guided to the rectifier 7c, converted into direct current and transmitted to the inverter 5, and the direct current from the rectifier 4c is used together with the predetermined direct-current by the inverter 5. Electric power is added by the method.

Since the detection signal from the rotation sensor 10 that detects the rotation speed of the flywheel 1c and outputs a detection signal is sent to the inverter 5, the added DC power is the AC power of the frequency corresponding to this detection signal. Is converted to. That is, when the rotation of the flywheel 1c is slow, the frequency of the AC power is low, and when the rotation of the flywheel 1c is fast, the AC frequency is high. And flywheel 1
Since c is rotated by the induction motor 9 driven by the above-mentioned AC power via the planetary gear mechanism 8, the flywheel 1c is always assisted in rotational force by the induction motor 9 according to its rotation speed. become.

Further, a planetary gear mechanism 8 is provided for power transmission between the induction motor 9 and the flywheel 1c, and the planetary gear 8d is a means for fixing the planetary gear 8d to the rotor shaft 9a provided with the sun gear 8c and the clutch shoe. Since 8 g is provided, the speed reduction ratio of the planetary gear mechanism 8 can be changed in a plurality of stages by these operations. Therefore, it is possible to control the speed reduction ratio of the planetary gear mechanism 8 according to the output characteristics of the induction motor 8 and efficiently assist the rotational force of the flywheel 1c to increase the output of the internal combustion engine 1. is there.

Next, at the time of engine brake operation, when signals from the accelerator pedal, the clutch pedal, and the vehicle speed sensor are input to the controller 11, the field winding of the induction motor 9 is switched to serve as an induction generator, which serves as an induction generator. The rotational force is converted into electric energy to generate electricity, the battery 14 is charged through the regulator 12 and the rectifier 13, and the electric energy is stored.

Further, when the internal combustion engine 1 is started, the DC power from the battery 14 is converted into AC by the inverter 15, and the induction motor 9
Drive the flywheel 1 via the planetary gear mechanism 8.
The rotating engine 1 is started by rotating c. At this time,
In the inverter 15 to which the detection signal of the rotation sensor 10 is input, the direct current of the battery 14 is converted into an alternating current having a frequency suitable for starting, and the electromagnetic coil 9b of the planetary gear mechanism 8 is not operated to increase the reduction ratio. , The induction motor 9 is driven to perform an efficient starting operation.

Next, the control when the induction motor 9 is switched to the generator and used will be described with reference to the flowchart of FIG.

When the induction motor 9 is driven as an electric motor, the start switch is turned on (step P ₁ ) and the controller 11 turns off the electromagnetic coil 9b of the clutch to set a large reduction ratio (step P ₂ ). Next, the controller 11 switches the induction motor 9 to drive the motor (step P ₃ ), supplies the power of the battery 14 to the inverter 15, and the inverter 15 is operated by the controller 11 at a predetermined voltage and frequency (step P ₄ ). . Since the three-phase AC voltage is obtained from the output side of the inverter 15 and applied to the induction motor 9, the crankshaft of the internal combustion engine 1 starts rotating. The output signal of the position sensor that detects the position of the rotating shaft of the induction motor 9 is also input to the controller 11 (step P ₅ ), and the controller 11 drives the induction motor 9 according to the rotation state of the internal combustion engine 1. The necessary phase control signal is output to the inverter 15 (step P ₆ ).

When there is no output signal from the position sensor, that is, when the rotation of the induction motor 9 is stopped, the output power of the battery 14 is detected (step P ₇ ), and when the output voltage of the battery 14 exceeds the set power Wc (step P ₇ ). P ₈ ), an alarm lamp or the like is operated (step P ₉ ), and the internal combustion engine 1 rotates by itself (step P ₁₀ ). If the internal combustion engine 1 does not rotate by itself, the processing from step P ₁ onward is repeated.

Next, when stopping the rotation of the internal combustion engine 1, setting a small reduction ratio by energizing the electromagnetic coil 9b by a signal from the controller 11 (step P _11). continue,
The internal combustion engine 1 is disconnected from the load and it is checked whether the engine load has become zero (step P ₁₂ ). While the engine load does not become zero, the processes in and after step P ₃ are repeated, and when the engine load becomes zero, the controller 11 switches the induction motor 9 to the generator drive (step P ₁₃ ). At this time, the regulator 12 and the rectifier 1
3 operates so as to convert the electric power from the induction motor 9 that operates as a generator into direct current and supply the power to the battery 14 (step P ₁₄ ), and according to the detection signal from the position sensor (step P ₁₅ ), The controller 11 controls the phase of the induction motor 9 (step P ₁₆ ). By thus operating the induction motor 9 as a generator, the braking force of the internal combustion engine 1 is converted and the electric power is stored in the battery 14.

When the controller 11 cannot obtain the output signal from the position sensor, that is, when the rotation of the induction motor 9 is stopped, the integrated power amount is detected by the power integrator or the like (step P ₁₇ ), When the amount of electric power W is smaller than the set value Wm, that is, when the voltage of the battery 14 is higher, the process proceeds to step P _{3 and} subsequent steps, and when the amount of electric power W is larger than the set value Wm, the regulator The operation of 12 is stopped (step P ₁₉ ).

Although the present invention has been described with reference to one embodiment, various modifications are possible within the scope of the gist of the present invention, and these modifications are not excluded from the scope of the present invention.

(Effect of the Invention) According to the present invention, the output of the generator provided in the exhaust turbine driven by the energy of the exhaust gas is controlled by the rotation speed that detects the rotation speed of the fuller wheel of the internal combustion engine, and the flywheel is rotated. Since the electric motor for driving the flywheel is driven and its rotational force is constantly assisted in accordance with the rotational speed of the flywheel, exhaust energy is efficiently regenerated and the output of the internal combustion engine is improved. Further, since the planetary gear mechanism having a plurality of reduction ratios is used as the transmission mechanism for assisting the rotation of the flywheel by the electric motor, the output characteristics of the electric motor can be efficiently transmitted to the flywheel. Further, when the vehicle is decelerated or stopped, the braking force is converted into the generated electric power and stored in the battery, so that the energy conversion efficiency is improved. That is, since the electric motor operates as a generator by switching the field winding, the braking force can be converted into electric energy during engine braking, the battery can be charged, and the energy can be recovered.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a structural explanatory view showing an embodiment of a turbo compound engine according to the present invention, and FIG. 2 is a structural explanatory view showing an example of a planetary gear mechanism used in the present embodiment. FIG. 3 is a diagram showing a control flow for operating the electric motor. 1 ... Internal combustion engine, 2 ... Exhaust manifold, 3 ... Turbocharger, 4 ... Alternator A, 5 ... Inverter, 7 ... Alternator B, 8 ... Planetary gear mechanism, 8a ...
… Internal gear, 8c …… Sun gear, 8d …… Planetary gear, 8g
...... Clutch shoe, 9 ... Induction motor, 9b ... Electromagnetic coil, 10 ... Rotation sensor, 11 ... Controller,
12 ... Regulator, 13 ... Rectifier, 14 ... Battery, 15 ... Inverter.

Claims (4)

[Claims] 1. A first exhaust turbine provided in the middle of an exhaust pipe of an internal combustion engine, an intake-assisting compressor attached to a rotary shaft of the first exhaust turbine, and a first generator, A second exhaust turbine provided downstream of the first exhaust turbine, a second generator driven by the second exhaust turbine, and power generation that is connected to the rotary shaft of the internal combustion engine via a planetary gear mechanism. An electric motor, a clutch mechanism attached to the planetary gear mechanism for switching the rotational speed ratio between the rotary shaft of the internal combustion engine and the generator / motor, and detecting the rotational speed of a flywheel connected to the rotary shaft of the internal combustion engine. The on / off control of the clutch mechanism based on the rotation speed ratio between the internal combustion engine and the motor / generator based on the rotation sensor, the generated power of the first and second generators, and the rotation speed signal of the rotation sensor. Off control means, A turbo compound, comprising: a first rotating machine control means for driving the electric motor / generator to perform a power running operation; and a second rotating machine control means for operating the electric motor / generator as a generator from the operating state of the internal combustion engine. engine. 2. The first rotating machine control means controls the power running operation of the motor / generator by using the electric power generated by the first and second generators. Turbo compound engine as described in paragraph. 3. The turbo compound engine according to claim 1, wherein the first rotating machine control means includes a start control means for an internal combustion engine. 4. The turbo compound engine according to claim 1, wherein the second rotating machine control means includes a dynamic braking means for an internal combustion engine.