JPH03246323A - Supercharger of internal combustion engine - Google Patents

Abstract

PURPOSE:To perform proper supercharging operation required by a driver by parallelly providing a motor-driven supercharger and a turbocharger with a generator, storing electric power generated in the turbocharger with the generator, and driving the motor-driven supercharger with the stored electric power. CONSTITUTION:There is provided a motor-driven supercharger 2 which has a pair of centrifugal compressors for compressing intake air fed from both left and right ends. A turbocharger 3 with a generator is installed with its shaft 33 for connecting a turbine driven by exhaust gas energy to a compressor which supercharges intake air provided with rotary electric machines (34, 35). Compressed air from the supercharger 2 and the turbocharger 3 is supplied to a chargecooler 4 via throttle mechanisms 2a, 3a, and it is supplied to an engine 1 after being cooled. Electric power generated at the time when the rotary electric machines are driven by exhaust energy is charged to a battery 8 via a regular 7 so as to drive the motor of the supercharger 2 by the electric power of the battery 8.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a supercharging device for an internal combustion engine, which is used in a diesel engine, a gasoline engine, etc., and operates by recovering exhaust energy from the engine.

(Prior Art) Various proposals have been made to recover exhaust energy by attaching a turbocharger to the exhaust pipe of an engine and directly connecting an electric motor-generator to the rotating shaft of the turbocharger.

A turbocharger for an internal combustion engine in which a rotating electric machine serving as an electric generator is attached to such a turbocharger and operates as an electric motor or a generator depending on the operating state of the internal combustion engine is disclosed in Japanese Patent Laid-Open No. 60-195329, for example. Disclosed in the official gazette. We also propose a control device for a turbocharger with a rotating electric machine that charges the battery or assists the supercharging operation of the turbocharger based on signals from an internal combustion engine rotational speed detection means and a load detection means. is shown, for example, in Japanese Patent Application No. 105981/1981.

(Problems to be Solved by the Invention) In these conventional turbocharger generators, the rotating electric machine is operated by an electric motor or a generator to control the supercharging pressure, but when the engine is idling or rotating at low speed, The exhaust energy decreases, and there is a possibility that the power generation of the rotating electrical machine attached to the turbocharger will decrease, or that the battery will not be able to be charged.

In addition, whether it is a conventional supercharging device such as a turbocharger, supercharger, or complex supercharger, it is important to control boost pressure and ensure compatibility with the engine to effectively use exhaust energy. However, due to the effects of fluctuations in exhaust pressure, complex control is required to accurately perform the supercharging operation intended by the driver. In particular, with conventional turbocharger generators, the exhaust turbine pressure is low. Sometimes, there is a problem in that even if the rotary electricity is operated electrically, there is a delay in the supercharging operation.

The present invention was made in view of such problems,
It is an object of the present invention to provide a supercharging device for an internal combustion engine that simplifies the control of supercharging operation, eliminates the influence of fluctuations in exhaust pressure as much as possible, and enables efficient supercharging operation.

(Means for Solving the Problems) According to the present invention, in a supercharging device for an internal combustion engine that performs supercharging operation using the energy of the exhaust gas of the internal combustion engine, the supercharging device is driven by the exhaust gas discharged from the internal combustion engine. a power generation means for generating electricity from the rotational force of a turbine; a power storage means for charging the electric energy generated by the power generation means; There is provided a supercharging device for an internal combustion engine, comprising a supercharging means for supercharging intake air, and a control means for supplying electric power from the electricity storage means to the supercharging means when supercharging of the internal combustion engine is required. Ru.

(Function) In the supercharging device for an internal combustion engine of the present invention, the supercharging means for supercharging and feeding the intake air of the internal combustion engine is provided in a system separate from the turbine drive system of the power generation means, which is a so-called turbocharger generator.
The system is controlled to supply a predetermined boost pressure to the internal combustion engine by performing supercharging when the vehicle starts or accelerates when the load on the vehicle increases, and assists the supercharging operation by utilizing the energy of the internal combustion engine's exhaust gas.

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

FIG. 1 is a configuration block diagram showing an embodiment of the present invention, in which 1 has an exhaust pipe 1a and an intake pipe 1b;
This is a vehicle engine that uses the combustion energy of supplied fuel to rotate the wheels and drive the vehicle. 2 has a pair of centrifugal compressors that compress air taken in from both left and right ends, and a supercharger (motoring supercharger: MSC) that is electrically driven by a synchronous motor in the center.
The details will be explained later based on FIG. 2. 3
is a so-called turbocharger with generator (turbocharger generator: TCG), and the above engine 1
A first motor having a turbine driven by exhaust gas energy from the exhaust pipe 1a of the engine, a compressor for supercharging intake air, and a rotating electric machine operating as an electric motor or a generator.
constitutes a supercharging means. The details will be explained later based on FIG. 3.

The electrically driven supercharger 2 and the turbocharger with generator 3 each have a throttle mechanism 2a.

3a, and the compressed air cooled by the charge cooler 4 flows into the intake pipe 1b.
is supplied to the engine 1 via. These throttle mechanisms 2a and 2b are controlled to open and close by control signals from an electronic control device 5.
includes a microcomputer, and receives signals from various sensors such as an engine rotation sensor IC, an engine load signal corresponding to the amount of depression of an accelerator (not shown), and the like. That is, this electronic control device 5 includes a central processing unit that performs arithmetic processing and comparison of counts, various memory devices that store control programs and various data, and a person/person who receives various signals and issues control commands. It has an output device, etc.

The engine 1 further includes a clutch 6 that connects and disconnects engine torque by pressing a clutch pedal, and a transmission 6b that changes the engine torque.
A clutch sensor 6a is attached to detect whether or not the clutch is engaged, and the detected signal is sent to the electronic control unit 5. Further, the pressure of the exhaust gas supplied from the exhaust pipe 1a to the generator-equipped turbocharger 3 is detected by a sensor 3b provided at the inlet thereof, and similarly the electronic control device 5
is being sent to. Reference numeral 7 denotes a regulator that converts the power generated when the turbocharger 3 is rotationally driven by exhaust energy. The electric power transmitted to the regulator charges the vehicle-mounted battery 8 and is also supplied to the electric drive supercharger 2 via the inverter 9.
This is rotated at a predetermined speed.

Note that the state of charge of the battery 8 is transmitted to the electronic control device 5 by a signal from the voltage detector 8a, and the regulator 7 and the inverter 9 are controlled via the electronic control device 5 accordingly. Furthermore, the electronic control device 5 also issues a control signal for the fuel supplied to the engine 1, and for this reason, various memories of the electronic control device 5 store the amount of fuel supplied corresponding to the accelerator pedal position and the amount of intake air corresponding to the position of the accelerator pedal. Data such as boost pressure, engine speed corresponding to the accelerator pedal position, and map data corresponding to these are stored.

FIG. 2 is a sectional view showing the configuration of the electrically driven supercharger 2. As shown in FIG.

A pair of compressor wheels 21, 22 are connected to the shaft 2
3, and a synchronous electric motor consisting of a permanent magnet 24 and an electromagnetic coil 25 is provided at the center of the shaft 23. And this coil 25
AC power whose frequency is adjusted to a predetermined value is supplied from the inverter 9 to the winding. These compressor wheels 21 and 22 are constructed of aluminum blades to reduce weight, and are designed to have a low moment of inertia, so that they can be quickly activated by commands from the electronic control device 5, for example, during acceleration. By rotating at high speed within the compressor housing 26, 27, a predetermined energy can be imparted to the intake air. Further, the bearing portion of the shaft 23 is a ball bearing to reduce friction, and as a result, the size is reduced by eliminating the thrust bearing.

FIG. 3 is a sectional view showing an example of the turbocharger with generator (TCG).

This consists of a turbine section 31 that absorbs energy in exhaust gas from the engine 1, a compressor section 32 that generates supercharging pressure, and a center bearing section that supports a shaft 33 that connects these sections. This center bearing portion is provided with a conductive coil connected to the regulator, and a permanent magnet 34 constituting a rotating electric machine that operates as an electric motor or a generator is attached to this shaft 33. When the shaft 33 is rotationally driven by the exhaust energy, the 8-conductor coil 35 of the rotating electric machine becomes a generator mode, and the generated power is transmitted to the regulator, which charges the on-board battery 8 by operating the regulator, and also charges the compressor. The pressure of the air introduced from the intake port of the section 32 is converted by the diffuser 37, and the compressed air is sent to each cylinder of the engine 1.

The turbine scroll 36 of the turbine section 31 is divided into two parts, a small scroll 36a and a large scroll 36b, and the exhaust pipe 1a connected to the turbine scroll 36 is opened and closed as a speed increasing means for increasing boost pressure in supercharging operation. Control valve (
(not shown) is provided. With this control pulp, even when the amount of exhaust gas is small, such as when the engine is idling, the entire exhaust gas flow is directed to the small scroll 36a.
By introducing this, the range in which the engine 1 can generate power is expanded, such as by ensuring the rotation of the turbine shaft 33.

Next, the operation of this embodiment will be briefly explained based on FIG.

In Figure 4, the vertical axis is the boost pressure immediately after startup, and the horizontal axis is the time elapsed since the start, and the solid line indicates the boost component of the compressed air sent from the electric drive supercharger 2, and the broken line indicates 1 and 2 respectively show the pressure components of the compressed air sent from the generator-equipped charger 3.

First, when starting the vehicle, the throttle mechanism 211 is opened, and a predetermined electric power is sent from the inverter 9 to the electric drive supercharger 2 to electrically drive it. This is because the exhaust gas energy from the engine 1 is small immediately after starting, and sufficient boost pressure cannot be obtained only from the generator-equipped turbocharger 3. The air taken in by the rotation of the pair of compressor wheels 21 and 22 of the electrically driven supercharger 2 contributes to a rapid increase in boost pressure, increasing the combustion efficiency of the fuel supplied into the cylinder.

During this period, the generator I' turbocharger 3 gradually performs normal turbine supercharging operation while introducing all the exhaust gas flow into the small scroll 36a. Then, the exhaust gas amount is detected by the sensor 3b installed in the population area, and the time t1
When the engine speed increases and surplus gas energy is generated by the time the differential user 37 outputs a predetermined supercharging pressure, the operation of the electrically driven supercharger 2 is stopped.

That is, when sufficient boost pressure can be obtained only on the generator-equipped turbocharger 3 side, the power supply to the electrically driven supercharger 2 is stopped. Then, the generated power generated by the stator coil 35 of the generator-equipped turbocharger 3 is stored in the battery 8 via the regulator 7. In this way, by operating the independently installed electrically driven supercharger 2 even when the engine 1 is running at low speed, it is possible to obtain a large boost pressure immediately after starting, thereby ensuring engine torque and acceleration performance at the time of starting. can be further increased.

Further, even when the vehicle is accelerating, the electric drive supercharger 2 can be electrically driven by giving a command from the driver. In this case, the electronic control unit 5 adjusts the power supplied from the battery 8 to the inverter 9, and even when the pressure of the exhaust turbine is low, the electrically driven supercharger is controlled separately from the generator-equipped turbocharger 3. Even when 2 is operated electrically, there is no delay in the supercharging operation, and the control can be easily performed. Moreover, the turbocharger 3 with a generator has two large and small scrolls 36a in which the turbine scroll is made into a twin stage.
36b, the generator-equipped turbocharger 3 can efficiently generate electricity even when the engine speed subsequently decreases.

Furthermore, the electric drive supercharger 2 constituting the above-mentioned embodiment shown in FIG. This makes it easier to install an electrically driven supercharger.

In addition, because the shaft assembly is small and the weight of the shaft assembly is light, the rotational moment generated during rotation can be reduced, eliminating the turbo lag that was considered unavoidable with conventional equipment, and enabling high-speed rotation with small electric power, resulting in a flying boost-up effect. This is the optimal system configuration for implementing this.

Although the present invention has been described above with reference to the above-mentioned embodiment, various modifications can be made within the scope of the present invention, and these are not excluded from the scope of the present invention.

(Effects of the Invention) In the supercharging device for an internal combustion engine of the present invention, the supercharging means for supercharging the intake air of the internal combustion engine is provided in a separate system from the turbine drive system of the power generation means, which is a so-called turbocharger generator.
The system is controlled so that supercharging is activated to supply a predetermined boost pressure to the internal combustion engine when the vehicle is starting or accelerating, when the load on the vehicle increases, and assists the supercharging operation that utilizes the energy of the internal combustion engine's exhaust gas. Therefore, the control of the supercharging operation can be simplified, and the influence of fluctuations in exhaust pressure can be eliminated as much as possible, making it possible to perform an efficient supercharging operation. Therefore, the influence of fluctuations in exhaust pressure can be eliminated, and the supercharging operation intended by the driver can be performed accurately.

[Brief explanation of drawings]

FIG. 1 is a configuration block diagram showing one embodiment of the present invention, FIG. 2 is a sectional view showing the configuration of an electrically driven supercharging means,
FIG. 3 is a sectional view showing an example of a turbocharger with generator (TCG), and FIG. 4 is a diagram showing an example of the operation of this embodiment. 1... Engine, 2... Supercharging means (electric drive supercharger) 3... Turbocharger with generator (TCG), 4
...Charge cooler 5...Electronic control device, 8.
...Battery, 9...Inverter.

Claims (3)

[Claims] (1) In a supercharging device for an internal combustion engine that performs supercharging operation using the energy of the exhaust gas of the internal combustion engine, a power generation means that generates electricity by the rotational force of a turbine driven by the exhaust gas discharged from the internal combustion engine; a power storage means for charging the electrical energy generated by the power generation means; a supercharging means driven by the stored energy of the power storage means and supercharging the intake air of the internal combustion engine in a system separate from the turbine drive system;
A supercharging device for an internal combustion engine, comprising: control means for supplying electric power from the electricity storage means to the supercharging means when supercharging of the internal combustion engine is required. (2) The supercharging means has a centrifugal compressor section at both ends of a shaft, and a synchronous electric motor is provided at the center of the shaft. Internal combustion engine supercharging device. (3) The internal combustion engine according to claim 1, wherein the turbine of the power generation means has a speed increasing means that divides the exhaust gas of the internal combustion engine into two to increase the boost pressure for supercharging operation. Engine supercharging device.