JPS5848716A - Controller of turbo charger for engine - Google Patents

Abstract

PURPOSE:To improve the acceleration response of a turbo charger when an engine load rises up by controlling the rotational speed of a turbo charger to a predetermined rotational number in a range where deterioration of fuel cost is not caused upon the low-load drive of the engine. CONSTITUTION:An inflow valve 16 for controlling the opening and closing of a passage is provided in the inlet part of an exhaust passage 14, and a bypass valve 17 for performing the opening and closing of the passage is provided in a bypass passage 15. In the above described construction, when the engine load is less than a predetermined value, a controller 22 operates so that the controller 22 supplies a relatively small quantity of exhaust gas to a turbine 8, and the rotational speed of the tarbine 8 is maintained to a predetermined value. By this operation, the engine load rises up, and when all the exhaust gas has been supplied to the turbine 8, the rotational speed of the turbine 8 rises quickly.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a control device for a turbocharger for an engine used in a vehicle such as an automatic spitter.

In an intake throttle speed controlled engine such as a gasoline engine, a turbocharger is incorporated, which has a turbine driven by the engine's exhaust gas and a compressor driven by the turbine, and supercharges the engine by the compressor. something has been known for a long time. In an intake throttle control type engine, during partial load operation, the intake passage downstream of the compressor is throttled by the throttle valve, so even if the compressor is driven during partial load operation, the intake pressure upstream of the throttle valve remains the same. Although the degree increases,
The intake pressure downstream of the throttle valve is approximately the same as that of an engine without a turbocharger,
At this time, no substantial supercharging effect is produced by the turbocharger.

However, conventionally, in a turbocharged engine, all of the exhaust gas passes through the turbine even in the operating range where the supercharging effect of the turbocharger does not occur, as described above, and as a result, the exhaust pressure and intake air concentration are In this operating range, engine power and fuel efficiency may be worse than engines without a turbocharger.

In view of the above-mentioned problems, in the operating range where the supercharging effect of the turbocharger does not occur, that is, during low to medium load operation, all of the exhaust gas is allowed to bypass the turbine, and the turbocharger is not operated at all in this operating range. The idea is to prevent this from happening. However, if the operation of the turbocharger is completely stopped during low to medium load operation, and one revolution of the turbine wheel is completely stopped, when the operation range shifts from these operating ranges to the high load operating range, The startup of the turbocharger operation, that is, the responsiveness is poor, and the turbocharger does not improve acceleration performance. 1. Furthermore, during acceleration during low to medium load operation, the turbocharger may not operate effectively, so that sufficient acceleration performance may not be obtained.

The present invention aims to provide a turbocharger vehicle device that can operate the turbocharger effectively and responsively without causing deterioration of engine output and fuel efficiency in operating ranges where the turbocharger does not operate effectively. It is something.

The main object of the present invention is that when the engine load is above a predetermined value, the entire amount of exhaust gas discharged from the engine is supplied to the turbine of the turbocharger, and when the engine load is below a predetermined value, the entire amount of exhaust gas discharged from the engine is supplied to the turbine of the turbocharger. A relatively passive exhaust gas is supplied, which maintains the turbine wheel speed at a predetermined value, so that when the engine load rises above a predetermined value, the turbine wheel speed increases quickly, and the turbocharger The goal is to reduce response delay.

Another object of the present invention is to supply substantially all of the exhaust gas discharged from the engine to the turbine when the engine is accelerated even if the engine is operated at a load below a predetermined value. The purpose of this invention is to improve acceleration performance by making the turbocharger operate effectively even during acceleration in a low to medium load range.

The invention will be explained in more detail below by way of example embodiments with reference to the attached figures.

FIG. 1 is a schematic diagram showing one embodiment of a turbocharged engine incorporating a control device according to the present invention. In the figure, 1 indicates an engine, which takes in air through an air cleaner 2, an air flow meter 3, a compressor housing 5 of a turbocharger 4, a throttle body 10 with a throttle valve 11, and an intake manifold 12. At the same time, fuel such as gasoline is supplied from a fuel injection valve (not shown) provided in the intake manifold 12, and exhaust gas is discharged into the atmosphere through the exhaust manifold 13 and the turbine housing 7 of the turbocharger 4. It has become.

The turbocharger 4 has a compressor wheel 6 on the compressor housing 5 and a turbine wheel 8' on the turbine housing 7, both wheels being drivingly connected by 10. The turbine housing 7 includes an exhaust passage 14 including a turbine wheel 8 in the middle, and a bypass exhaust passage 1 provided to bypass the turbine wheel 8.
5. The turbine wheel 8 is an exhaust passage 14
The compressor wheel 6 is rotationally driven by the exhaust gas flowing through the compressor wheel 6, and the compressor wheel 6 is rotationally driven by the turbine wheel 8 to supercharge the engine 1.

An inlet valve 16 for opening and closing the cough passage is provided at the entrance of the exhaust passage 14, and a bypass valve 17 for opening and closing the cough passage is provided for the bypass exhaust passage 15. The inflow valve 16 and the bypass valve 17 are configured as butterfly valves carried on respective valve shafts 16a, 17a, and levers 18.
drivingly connected to actuator 20.21 via 19;
Opening and closing are individually controlled by these actuators. The actuators 21,22 may be any suitable actuators, such as hydraulic or electric. The actuators 20 and 21 are controlled in their operation by a control@1122.

The control device 22 receives an input air amount signal generated by the air 70-meter 3, an engine rotation speed signal generated by the engine rotation speed sensor 23, a cooling water temperature signal generated by the water temperature sensor 24, and a knock sensor 25 generated. The knock signal generated by the compressor rotation speed sensor 26 and the compressor rotation speed signal generated by the compressor rotation speed sensor 26 are inputted, and control signals are outputted to the actuators 20 and 21 according to the flowchart shown in FIG. It has become.

In addition, air 70-meter 3 and engine speed sensor 2
3 may be provided for controlling fuel injection.

Next, the operation of controlling the turbocharger according to the present invention will be explained with reference to the flowchart shown in FIG.

First, in step 1, it is determined whether the engine cooling water temperature measured by the water temperature sensor 24 is equal to or higher than a predetermined value, that is, whether or not the engine 1 has been heated. Step 2 if the engine has not warmed up completely.
In this step, the control 11122 sends a fully close command signal to the actuator 20,
A full open command signal is output to each. As a result, the inflow valve 16
is brought to the fully closed position as shown, and the bypass valve 17 is brought to the fully open position. Therefore, at this time, substantially all of the exhaust gas emitted by the engine 1 is transferred to the exhaust passage 1.
4 and flows through the bypass exhaust passage 15.

This improves the warm-up performance of devices, such as the exhaust purification catalytic converter and the Ot sensor, which are provided in the exhaust system on the downstream side of the turbine housing 7.

If it is determined in step 1 that the engine has been warmed up, the process proceeds to step 3, where it is determined whether or not the engine 1 is being operated under high load. This determination of high load operation may be made based on the air 70 - the intake air measured by the meter 3 - and the engine speed measured by the engine speed sensor 23, or based on the opening of the throttle valve 11. It's okay. If it is determined in step 3 that the engine 1 is not being operated under high load, then the process proceeds to step 4, where it is determined whether or not the engine 1 is being operated at an accelerated rate.

This acceleration operation may be determined based on the intake air amount measured by the air flow meter 3 and the temporal change in the engine speed measured by the engine speed sensor 23. It may also be determined based on speed. When it is detected in step 4 that the engine 1 is not in an acceleration state, the process proceeds to step 5, in which the compressor rotation speed N measured by the compressor rotation speed sensor 26 reaches a predetermined value. A determination is made as to whether the value is greater than or not. At this time N>A
If not, the process proceeds to step 6, and in this step, 14'lJ@@22 outputs a valve opening command signal to the actuator 20 and a valve opening command signal to the actuator 21. 'This causes the inflow valve 16 to open and the bypass valve 17 to close. As a result, at least a portion of the exhaust gas discharged by the engine 1 flows through the exhaust passage 14, and this exhaust gas causes the turbine wheel 8
rotates. When N〉8 in step 5, the process advances to step 7, and in this step, the control @1122
outputs a valve closing command signal to the actuator 20 and a valve opening command signal to the actuator 21. As a result, inflow valve 1
6 decreases its opening, and bypass valve 17 increases its opening. In this way, when the engine 1 is not being operated under high load and is not in an acceleration state, the opening degrees of the inlet valve 16 and the bypass valve 17 are constantly controlled as described above, thereby controlling the rotation of the turbine wheel 8. The number is kept approximately at the predetermined value A. This predetermined value A may be a relatively low rotational speed, so that at this time most of the exhaust gas discharged by the engine 1 flows through the bypass exhaust passage 15,
As a result, the exhaust pressure is prevented from increasing significantly, and the intake air concentration is also prevented from increasing significantly.

This prevents deterioration of engine output and fuel efficiency in an operating range in which the turbocharger 4 does not produce a substantial supercharging effect.

If it is detected in step 3 that the engine 1 is being operated at ^ speed, and if it is detected in step 4 that the engine is in an accelerating state, the process proceeds to step 8;
In this step, the knock sensor 25 determines whether or not the engine 1 is knocking.

If knocking has not occurred at this time, proceed to step 9. In this step, a fully open command signal is output to the actuator 20 and a fully close command signal is output to the actuator 21, whereby the inflow valve 16 is fully opened, and the bypass valve 1 is fully opened.
7 will be fully opened. Therefore, all of the exhaust gas discharged by the engine 1 flows through the exhaust passage 14, causing the turbine wheel 8 to rotate at high speed, and in conjunction with this, the hump register wheel 6 to rotate at high speed, so that supercharging is performed. Become. At this time, the turbine wheel 8 is accelerated not from a stopped state but from a low speed single rotation state, so its speed increasing response is good.
As a result, the turbocharger 4 quickly produces a supercharging effect when the engine 1 shifts from a low to medium load operating range to a load slow rotation range and when accelerating, improving the acceleration characteristics of the engine 1. If the occurrence of knock is detected in step 8, the process proceeds to step 7, in which the opening of the inflow valve 16 is reduced and the opening of the bypass valve 17 is increased by 11 degrees to reduce the flow rate of exhaust gas flowing through the bypass exhaust passage 15. is increased, and the rotational speed of the turbine wheel 8 is decreased to reduce the supercharging pressure. This prevents the engine 1 from knocking.

Although the present invention has been described in detail with respect to specific embodiments above, it will be appreciated by those skilled in the art that the present invention is not limited thereto and that various embodiments can be made within the scope of the present invention. It should be obvious.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing one embodiment of a turbocharged engine incorporating a control device according to the present invention, and FIG. 2 is a flowchart illustrating the operation of the v4Ill device according to the present invention. 1...Engine, 2...Air cleaner, 3...Air 70-meter, 4...Turbocharger, 5...
Compressor housing, 6... Compressor wheel. 7...Turbine housing, 8...Turbine wheel. 9... Axis, 10... Throttle body, 11...
Throttle valve, 12...Intake manifold, 13
...Exhaust manifold, 14...Exhaust passage, 15.
...Bypass exhaust passage, 16...Inflow valve, 17...
Bypass valve. 18.19...Lever, 20.21...Actuator, 22...-device, 23...Engine 1 rotation speed sensor, 24...Water temperature sensor, 25...Knock sensor, 26...・Compressor rotation speed sensor

Claims (2)

[Claims] (1) A rotation speed measuring means for measuring the rotation speed of the turbocharger, a load measuring means for measuring the load on the engine, and a flow of exhaust gas supplied to the turbine of the turbocharger.
and exhaust gas flow rate control means for controlling substantially the entire amount of exhaust gas discharged from the engine when the engine load measured by the load measuring means is equal to or higher than a predetermined value. Exhaust gas that is supplied to the turbine and is supplied to the turbine in order to prevent the turbocharger rotational speed measured by the rotational speed measuring means from increasing beyond a predetermined value when the engine load is below a predetermined value. #1IIlli%lF of an engine turbocharger, characterized in that it is configured to variably control the flow rate of. (2) a rotational speed measuring means for measuring the number of revolutions of the turbocharger; a load measuring means for measuring the load on the engine; an engine acceleration detecting means for detecting whether the engine is in an accelerated state; and the turbine and an exhaust gas flow rate control means for controlling the flow rate of exhaust gas supplied to the engine, and the exhaust gas flow rate control means determines whether the engine load measured by the load measuring means is equal to or higher than a predetermined value or not by the engine acceleration detecting means. Substantially the entire amount of exhaust gas discharged from the engine is supplied to the turbine when it is detected that the engine is in an accelerating operating state, and when the engine load is below a predetermined value and the engine acceleration is detected. When the means detects that the engine is not in an acceleration state, the exhaust gas supplied to the turbine is controlled to prevent the turbocharger rotational speed measured by the rotational speed measuring means from increasing beyond a predetermined value. A control device for an engine turbocharger, characterized in that it is configured to variably control a flow rate.