JPH0466777A - System for starting engine - Google Patents

Abstract

PURPOSE:To enhance the starting properties of an engine by rotating an engine using a starter after blocking an intake passage between an intake port and a compressor, and also rotating the compressor using a rotary electric motor while maintaining the above state, and opening the intake passage when engine speed reaches a predetermined value. CONSTITUTION:To start an engine, the intake shutter 4 of an intake passage 23 is first closed and power of a battery 51 is transmitted to a starter 6 by the turning on of a starter so that the engine is rotated. A compressor 22 is actuated by means of the electric drive of a rotary electric motor 3 immediately after the engine is started by a starter 6 and then that portion of the intake passage which is in front of the intake shutter 4 is filled with air at high pressure. When the number of revolution of a crank shaft detected by an engine speed sensor 17 is greater than a predetermined value No and also boost pressure P7 detected by a boost pressure sensor 15 reaches predetermined pressure P1, electricity is transmitted to an actuator 41 so as to open the intake shutter 4 and compressed air stored in the intake passage 23 is forcibly fed via an intake port 12 at a time, whereby the engine 1 is started.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an engine starting system that improves the startability of an engine by using pressure air from a turbocharger equipped with a rotating electric machine.

(Conventional technology) Engine exhaust gas is guided to a turbine and rotated at high speed.
Turbochargers are widely used, which drive a compressor connected to a turbine shaft to forcefully deliver supercharged air to an engine.

A rotating electrical machine that serves as an electric generator is attached to the rotating shaft of this type of turbocharger, and the exhaust energy is recovered as electric power through the power generation operation of the rotating electrical machine.
A turbocharger with a rotating electric machine has been realized that supplies power from a battery to the rotating electric machine to operate it electrically, assists in the supercharging operation of the compressor, and increases the torque of the engine at low speeds.

(Problem to be solved by the invention) By the way, when the engine starts, there is no exhaust energy, so no pressure can be expected from the turbocharger, and in the case of the above-mentioned turbocharger with a rotating electric machine, the electric motor drives the compressor. However, since there is no throttle valve in diesel engines in particular, the compression pressure is dissipated, causing the problem of poor engine startability.

The present invention was made in view of such problems,
The purpose is to provide an engine starting system that improves the startability of an engine equipped with a rotary coupe charger.

(Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention provides a turbine provided in an exhaust passage of an engine, a compressor provided in an intake passage and rotated by the turbine, and a rotary drive of the compressor. In an engine starting system having a rotating electric machine, the engine is rotated by a starter after an intake passage between an intake port of the engine and a compressor is blocked, and the compressor is rotated by the rotating electric machine with the intake passage blocked. An engine starting system is provided that unblocks the intake passage when the engine reaches a predetermined rotation speed.

(Function) In the present invention, since the intake air is reduced by the closed intake shutter when the engine is started, the compression work of the piston is reduced and the crank rotation speed is increased, and the rotating electric machine disposed in the turbocharger is electrically driven. The intake flow path up to the closed intake shutter is filled with pressurized air, which is then released all at once and forced into the cylinder, so as the crank rotation speed increases, the compression pressure increases, making it easier to start the engine. be exposed.

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

FIG. 1 is a block diagram showing the configuration of an embodiment of an engine starting system according to the present invention.

In the figure, 1 is an engine that drives the vehicle with engine torque generated by the combustion energy of supplied fuel and air through an intake port 11, 13 is a clutch that connects/disconnects the torque, and 14 is a torque This is a transmission that changes speeds.

Reference numeral 12 denotes an exhaust port, which guides exhaust gas from the engine 1 to a turbocharger 2. The turbocharger 2 includes a turbine 2 driven by exhaust gas energy.
1. A compressor 22 is provided which is directly connected to the turbine shaft and compresses the air from the air cleaner 24, and a rotating electric machine 3 is further disposed on the turbine shaft.

The rotating electric machine 3 then operates according to the operating state of the engine 1.
For example, it is configured to function as a generator and recover exhaust energy as electric power, or to be driven as an electric motor by electric power from the battery 51 to assist the supercharging operation of the turbocharger 2. In addition, 52 is a power converter, which is a converter for heavy electric power having a converter and an inverter.
During power generation, the AC output of the rotary unit 3 is converted to DC for battery charging, and the DC power of the battery 52 is converted to AC of a predetermined frequency to electrically drive the rotary unit 3.

Reference numeral 4 denotes an intake shutter, which is arranged in the intake passage 23 leading from the turbocharger 2 to the intake port 11, and is operated by a shack actuator (actuator) 41 to control opening and closing of the flow path of pressurized air from the compressor 22.
A command line from the controller 5 is connected to the actuator 41 . A boost pressure sensor 15 is attached to the intake passage upstream of the intake shutter 4 to measure the air pressure generated by the compressor 22, and transmits the measured signal to the controller 5.

A starter 6 engages with the flywheel 16 of the engine 1 to start the engine. When the key switch 53 is turned on, a relay 61 closes the power supply circuit to the starter 6, drives the starter 6, and starts the engine. The engine 1 is connected to the wheel 16 and drives the crankshaft.
start.

In addition, 17 is an engine rotation sensor, and flywheel 1
It is arranged close to the outer periphery of the engine 6 to detect the rotation speed of the engine 1, and the rotation speed signal is sent to the controller 5.

The controller 5 is composed of a microcomputer, and includes a central control unit that performs arithmetic processing, various memories that store arithmetic processing procedures, control procedures, etc., an input circuit, an output circuit, etc. The input circuit includes the key switch 53, In addition to various signals from the boost pressure sensor 15, engine rotation sensor 17, etc., detection signals from a depression amount sensor 71 that detects the amount of depression of the accelerator pedal 7, etc. are connected. When the various signals described above are input, predetermined processing is performed, and command signals are issued to the power converter 52, shutter actuator 41, etc. connected to the output circuit.

FIG. 2 is a process flow diagram showing an example of the operation of this embodiment, and the operation of this embodiment will be explained using this figure.

When starting the engine, first step 1 is to open the intake passage 2.
The intake shutter 4 of step 3 is closed, and the starter switch is turned on in step 2 to supply power from the battery 51 to the starter 6. During the initial few seconds after the starter 6 starts, the intake shutter 4 is closed to reduce the intake air to the engine 1, thereby reducing the amount of compression work in the cylinder, thereby increasing the rotational speed of the crankshaft.

On the other hand, immediately after startup by the Stark 6, in step 3, the rotary electric machine 3 is electrically driven to operate the compressor 22, and the intake passage up to the closed intake shutter 4 is filled with high-pressure air.

In step 4, the rotation of the crankshaft is checked based on the signal from the engine rotation sensor 17, and if the rotation speed N is greater than the predetermined value NO, the process proceeds to step 5, where the air pressure is checked based on the signal from the boost pressure sensor 15. .

When the detected boost pressure PT has reached the predetermined pressure P, the actuator 41 is energized in step 6 to open the intake shutter 4, and the pressure air stored in the intake passage 23 is immediately released into the intake port 12. The increased rotational speed causes the piston to operate, increasing the compression pressure in the cylinder and starting the engine.

Then, after turning off the starter switch in step 7,
Moving on to the normal control of a turbocharger with a rotating electric machine, for example, when the engine is running at low speeds and under high load, the electric drive of the rotating electric machine is used to improve low-speed torque, and when the engine is at high or medium speeds and the load is light, the electric drive of the rotating electric machine is used to generate electricity. Recover exhaust energy as electricity.

Note that if the engine speed N has not reached the predetermined value No in step 4, the process proceeds to step 9 to suppress the electric operation of the rotating electric machine 3 to reduce the amount of air leaking into the intake port 11 and reduce the compression work of the piston. Decrease and proceed to step 5. Further, if the boost pressure is low in step 5, the power supplied to the rotating electric machine 3 is increased, the compression operation of the compressor 22 is activated, and the air pressure up to the intake shutter 4 is increased, and the process proceeds to step 6.

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

(Effects of the Invention) As described above, according to the present invention, when starting the engine, the intake shutter is closed to reduce the compression work in the cylinder and increase the crankshaft rotation speed, while the rotating electric machine of the turbocharger is closed. After the air is stored until the intake shutter is electrically driven and closed, the air is released to increase the internal pressure of the cylinder, which has the effect of making it easier to start the engine due to high compression and high rotational speed. There is.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of a starting device using a turbocharger according to the present invention, and FIG. 2 is a process flow diagram showing an example of the operation of this embodiment. 1...Engine, 2...Turbocharger, 3...
・Rotating electric machine, 4... Intake shutter, 5... Controller 1-
Roller, 6... Starter, 11... Intake port, 1
7... Engine rotation sensor, 21... Turbine, 2
2...Compressor, 23...Intake passage. Patent applicant Isuta Ceramics Laboratory Co., Ltd.
Attorney: Patent Attorney Minoru Tsuji Figure 2

Claims (1)

[Claims] In an engine starting system that includes a turbine provided in the exhaust passage of the engine, a compressor provided in the intake passage and rotated by the turbine, and a rotating electric machine that rotationally drives the compressor, the intake passage between the engine intake port and the compressor is After the intake passage is blocked, the starter rotates the engine, and with the intake passage blocked, the rotary electric machine rotates the compressor, and when the engine reaches a predetermined rotational speed, the intake passage is unblocked. Engine starting system.