JPH0579806B2 - - Google Patents

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an energy recovery device for a turbo compound engine using an exhaust turbine capable of regenerating the exhaust energy of an internal combustion engine, and particularly relates to an energy recovery device for a turbo compound engine that uses an exhaust turbine capable of regenerating the exhaust energy of an internal combustion engine. This invention relates to an energy recovery device for a turbo compound engine that uses the output of a generator to rotate an electric motor installed on an axle to regenerate energy.

(Prior Art) In recent years, heat-insulating internal combustion engines have been developed that use ceramics for various parts of the engine, such as the outer wall of the exhaust manifold, the cylinder liner, the cylinder head insulation plate, and the piston. According to this internal combustion engine, there is no need to cool the internal combustion engine by dissipating the heat generated inside the engine, and the energy of the generated high temperature exhaust gas is regenerated and returned to the output shaft of the internal combustion engine. It can be used to improve the output of the engine.

As this type of exhaust energy regeneration method, a method is known in which the rotational force of a turbine rotated by exhaust gas is decelerated by a multi-stage gear mechanism and then returned to the crankshaft.

In addition, as an exhaust energy regeneration device,
59-141713, an exhaust turbine having an alternator is rotated by the energy of exhaust gas, and the output of the alternator drives an induction motor provided on the output shaft of an internal combustion engine to regenerate exhaust energy. In addition, proposals have been made to control the amount of intake air by providing means for determining the magnitude of the load on the internal combustion engine, and to raise the exhaust gas temperature when the load is small.

(Problem to be Solved by the Invention) In such a method of regenerating exhaust energy, the former method of returning rotational force to the crankshaft using a gear mechanism is usually one-stage, for example, considering the transmission efficiency of the gear. Since its efficiency is 0.9 to 0.95, the efficiency decreases to about 80% with three stages of deceleration.
Moreover, the gear mechanism becomes complicated and its cost increases. In addition, since the space in the engine compartment of a small passenger car is narrow, a problem arises in the installation location of the gear mechanism. The latter proposal for an exhaust energy regeneration device uses exhaust gas energy to first control AC power to drive an induction motor and rotate the output shaft of an internal combustion engine, so it does not require a gear mechanism.
Although the amount of intake air is controlled depending on the load on the internal combustion engine, there is still room for improvement in terms of the efficiency of exhaust energy recovery.

The present invention has been made in view of these points, and its purpose is to convert exhaust energy into electrical energy using an AC motor without using a gear mechanism, and to provide an electric motor that efficiently drives an axle with the electrical energy. An object of the present invention is to provide an energy recovery device for a turbo compound engine, which is highly effective in recovering exhaust energy.

(Means for Solving the Problems) The energy recovery device for a turbo compound engine of the present invention is a turbo compound engine in which an exhaust turbine having a generator is installed in the exhaust pipe of an internal combustion engine whose combustion chamber, exhaust pipe, etc. have an insulated structure. In the engine energy recovery device, there is provided a detection means for detecting the rotation speed of an axle driven by the internal combustion engine, an AC motor provided on the axle, and an AC motor based on the detected wheel rotation speed. The motor includes means for generating a frequency for powering the motor, and a motor driving means for supplying power at the frequency generated by the means to the AC motor to drive the AC motor.

(Function) In the recovery device of the present invention, the generator installed in the exhaust turbine driven by the energy of the exhaust gas is converted into electrical energy whose frequency is controlled by the detection signal of the rotation speed of the axle. Since the electric motor that drives the motor is powered to assist the rotational force of the wheels, the energy becomes exhaust energy → electrical energy → wheel driving force, and it functions as a highly efficient energy recovery device.

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

FIG. 1 is a configuration explanatory diagram showing one embodiment of the engine energy recovery device according to the present invention, and FIG.
The figure is a partial configuration diagram showing a partially modified configuration.

In FIG. 1, 1 is an engine, in which a combustion chamber including a piston 1a, a cylinder liner 1b, etc., and an exhaust port 1c constitute a heat insulating structure made of ceramics, and an exhaust manifold 2 has an exhaust turbine equipped with an alternator 4. 3 is installed.

The rotating shaft of an alternator 4 is directly connected to and attached to the rotating shaft of the exhaust turbine 3, and when the turbine blades 3a are driven by high-temperature exhaust gas discharged from the exhaust manifold 2, the alternating current generator 4 has a high temperature. Generates alternating current power at a frequency. Note that 5 is an injection pump that injects fuel into the engine 1, and detects the fuel injection amount of the injection pump 5 and outputs a load signal FS.
A load sensor 6 is attached that emits a signal. A converter 7 is constituted by, for example, a cycloconverter, and when high frequency AC power is input from an AC generator, it efficiently converts it into low frequency AC power and outputs it. This frequency conversion operation is controlled by a rotation signal WS from a rotation sensor 8 that detects the rotation speed of the axle and a load signal FS from the load sensor 6.

Reference numeral 9 denotes an electric motor having a rotating shaft coaxial with the axle 10, and is supplied with AC power output from the converter 7 to drive the wheels 11. The frequency of the AC power supplied to the electric motor 9 is
It is always controlled by the rotation signal WS and the load signal FS, and is outputted from the converter 7 at a frequency that drives the electric motor 9 in power running. Therefore, due to the driving force generated by the electric motor 9, the wheels 1
1 is always driven with the aid of rotational force, regardless of its rotational speed.

In FIG. 2, 12 is a rectifier, and 13 is an inverter. The output of the alternating current generator 4 shown in FIG. A rotation signal WS from the rotation sensor 8 that detects the rotation speed of the axle, and a load signal FS from the load sensor 6
It is controlled by After converting the AC power into alternating current power at a predetermined frequency, the electric motor 9 is driven.

Next, the operation of this embodiment having such a configuration will be explained.

High-temperature exhaust gas from an engine 1 with a heat-insulating structure is guided to an exhaust turbine 3 via an exhaust manifold 2, and drives an alternator 4 directly connected to turbine blades 3a. And AC generator 4
The AC power generated by the converter 7 is input to the converter 7 .

The converter 7 receives the load signal FS from the load sensor 6 and the rotation signal from the rotation sensor 8 of the axle 10, and changes the high frequency of the power generated by the alternator 4 in response to these signals. As mentioned above, the electric motor 9 is driven by converting it into low frequency AC power that is supplied to the electric motor 9. For this reason,
The electric motor 9 always performs power running to drive the axle 10 and assist the rotational force of the wheels 11, regardless of the rotational speed of the axle 10.

Also, in the configuration shown in FIG. 2, the AC generator 4
converts exhaust energy into electrical energy,
This electric energy can be used to power the electric motor 9 in accordance with the rotational speed of the axle 10 to drive the wheels 11, and these operations are similar to those shown in FIG. 1.
However, the rectifier 12 in the electrical energy delivery path
When the inverter 13 and the inverter 13 are inserted, losses in these electrical devices are added to the weight, so the overall efficiency of exhaust energy recovery is inevitably lower than that of the configuration shown in FIG.

As mentioned above, although the present invention has been explained using the above embodiments, various modifications can be made within the scope of the gist of the present invention, and these are not excluded from the scope of the present invention.

(Effects of the Invention) As described above in detail, the present invention guides exhaust gas from an engine having a heat-insulating structure to an exhaust turbine to drive an alternator, converts the exhaust energy into electrical energy, and inputs the electrical energy to the converter. However, the frequency of the AC power converted by the converter is controlled by the rotation signal of the axle and the load signal, so that the AC power is always at a frequency that powers the motor.
It is possible to obtain an exhaust energy recovery device that does not require a gear mechanism and is also very efficient in the delivery of electrical energy.

In addition, the rotation speed of the exhaust turbine is unrelated to the rotation speed of the drive shaft, which is the engine load, so the rotation of the exhaust turbine can be maintained to maximize turbine efficiency, and energy recovery efficiency can also be maintained at a high level. can.

In addition, the present invention recovers exhaust energy,
Since the number of components used in the energy delivery path is reduced, energy loss is reduced, and the reliability of the components used is improved, resulting in reduced maintenance costs.

[Brief explanation of the drawing]

FIG. 1 is a configuration explanatory diagram showing one embodiment of an engine exhaust energy recovery device according to the present invention, and FIG. 2 is a partial configuration diagram showing a partially modified configuration. 1...engine, 1a...piston, 1b...
Cylinder liner, 3... Exhaust turbine, 4... Alternator, 6... Load sensor, 7... Converter, 8... Rotation sensor, 9... Electric motor, 10...
Axle, 11...wheel.

Claims (1)

[Claims] 1. In an energy recovery device for a turbo compound engine in which an exhaust turbine with a generator is installed in the exhaust pipe of an internal combustion engine whose combustion chamber, exhaust pipe, etc. have a heat-insulated structure, the rotational speed of an axle driven by the internal combustion engine is detected. a detecting means, an AC motor provided on the axle, a means for generating a frequency for powering the AC motor based on the detected rotational speed of the wheel, and a means for generating electric power at the frequency generated by the means. An energy recovery device for a turbo compound engine, comprising a motor drive means for supplying energy to an AC motor to drive the AC motor.