JPS63179131A - Supercharged pressure control device for engine with supercharger - Google Patents

Abstract

PURPOSE:To prevent lowering of an engine output especially during working of an external load under a full opening state of a throttle valve, by a method wherein, when the external load of an engine is in operation, the supercharged pressure of a supercharger supercharging intake air fed to the engine. CONSTITUTION:A supercharged pressure control means 3 is provided for controlling the supercharged pressure from a supercharger 2, supercharging intake air fed to an engine 1, to a given value through the working of, for example, a waste gate valve. An external load detecting means 4 is provided for detecting working of the external load of en engine 1 from the working of, for example, an air conditioner switch. Further, a set supercharged pressure varying means 5 is provided for outputting a signal, by means of which a set supercharged pressure is increased for a given period during working of an external load, to the supercharged pressure control means 3. The means improves an engine output through increase of a supercharged pressure especially during working of an external load under the full opening state of a throttle valve, and ensures excellent operation performance.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a boost pressure control device for an engine equipped with a supercharger.

(Prior art) Conventionally, in engine output control, when an external load such as an air conditioner compressor is activated, the throttle opening is increased or bypass air is turned on to increase the engine idle speed. A technique for increasing the amount of is known (for example, see Japanese Patent Application Laid-open No. 13141/1983).

The above-mentioned external load control is such that when an external load is activated in a low-load state such as when idling, the increase in load causes a decrease in output, which impedes engine performance and causes a significant drop in engine speed. This is done in response to a problem that causes the engine to stop.

(Problem to be Solved by the Invention) However, in the above-mentioned device in which the output is controlled by controlling the throttle opening or the bypass air pressure, when an external load is operated with the throttle valve fully open, Since it is not possible to increase the amount of intake air above the above, it is not possible to increase the output.

In view of the above-mentioned circumstances, the present invention has been developed because an engine equipped with a supercharger is capable of increasing output even when the throttle valve is fully open. It is an object of the present invention to provide a supercharging pressure control device for a supercharged engine that increases the output and ensures good operating performance.

(Means for Solving the Problems) The boost pressure control device of the present invention includes a boost pressure control means for keeping the boost pressure at a set value, an external load detection means for detecting the operating state of the external load, and an external load detection means for detecting the operating state of the external load. It is characterized by comprising a set supercharging pressure changing means that receives a signal from the load detecting means and changes the set supercharging pressure in the supercharging pressure control means so as to increase it at least when an external load is applied during running with the throttle valve fully open. That is.

FIG. 1 is a block diagram for clearly showing the configuration of the present invention.

A supercharger 2 for supercharging intake air supplied to the engine 1 is installed, and a supercharging pressure control means 3 is attached for controlling the supercharging pressure by the supercharger 2 to a predetermined value by, for example, operating a waste gate valve. ing.

Further, an external load detecting means 4 is provided for detecting the operation of an external load of the engine 1 from, for example, the operation of an air conditioner switch, and a detection signal of the external load detecting means 4 is outputted to the set boost pressure changing means 5. The set supercharging pressure changing means 5 outputs a signal to the supercharging pressure control means 3 to increase the set supercharging pressure for a predetermined period when an external load is operated.

(Function) In the above-mentioned supercharging pressure control device, when an external load such as a cooler compressor operates, the set supercharging pressure is controlled to be increased, and the increase in supercharging pressure causes the engine output to increase. Even when the throttle valve is fully open, a large drop in output due to external load input is suppressed to ensure good operating performance.

Incidentally, even if the supercharging pressure is increased during the short 71 IJ period when an external load is input, there is almost no damage to the engine side, and there is no reduction in reliability.

(Example) The present invention will be described in detail below with reference to the drawings.

FIG. 2 is an overall configuration diagram of a specific example.

An intake boat 10 opened and closed by an intake valve 9 and an exhaust port 12 opened and closed by an exhaust valve 11 are opened in the combustion chamber 8 of the engine 1. Exhaust passages 14 are connected to each other.

A supercharger 2 (turbo supercharger) is provided for supercharging the intake air supplied from the intake passage 13 to the combustion chamber 8. , and a blower 2b interposed in the intake passage 13, the two are connected, and the blower 2b is driven by the turbine 2a rotated by the energy of the exhaust gas to supercharge the intake air. An air cleaner 15 and an air flow meter 16 are disposed in the upstream intake passage 13, and a surge tank 17 is interposed in the intake passage 13 downstream of the blower 2b.

Further, a bypass passage 19 is provided that bypasses the turbine 2a of the supercharger 2, and a wastegate valve 20 is interposed in the bypass passage 19 to adjust the supercharging pressure. The waste gate valve 20 is opened and opened by operating an actuator 21. This actuator 21 is provided in a diaphragm type, and its pressure chamber 21a
During the wastegate valve 20, the boost pressure generated in the intake passage 13 downstream of the blower 2b is used as an operating source in the pressure passage 2.
Introduced by 2. Then, the boost pressure increases to spring 2.
When the pressure rises beyond the set value set at 1b, the actuator 21 is actuated to open the wastegate valve 20 to suppress the turbine rotation speed and maintain the boost pressure at the set value.

Furthermore, a leak passage 23 is connected to the pressure passage 22 to release the supercharging pressure acting on the pressure passage 22 to the intake passage 13 upstream of the blower 2b, and a solenoid valve 24 is interposed in the leak passage 23. . When this solenoid valve 24 is operated to open, the supercharging pressure acting on the actuator 21 becomes lower than the supercharging pressure generated in the intake passage 13, and the wastegate valve 20 is operated in the closing direction, thereby effectively achieving the set supercharging. It acts to increase pressure.

On the other hand, an air conditioner compressor 25 that is driven by the output of the crankshaft 18 of the engine 1 is installed as an external load on the engine 1 .

The output of the crankshaft 18 of the engine 1 is transmitted to the compressor 25 via an electromagnetic clutch 26, and when the electromagnetic clutch 26 is in a connected state, the compressor 25 is driven.

The operation of the electromagnetic clutch 26 and the supercharging pressure adjusting solenoid valve 24 are controlled by a control signal output from a controller 27. The controller 27 receives an on/off signal from the air conditioner switch 28, which operates in conjunction with the thermostat or manual operation, and controls the operation of the electromagnetic clutch 260 in accordance with the signal from the air conditioner switch 28. The operation of the air conditioner compressor 25 as an external load of the engine 1 is detected from the signal. Further, a boost pressure signal from a pressure sensor 29 that detects boost pressure is input to the controller 27 .

Note that other external loads include the operation of electric loads such as headlights, and their operation signals may be similarly input to the controller 27.

The controller 27 is an air conditioner switch 28.
When the electromagnetic clutch 26 is actuated to start driving the compressor 25 based on the signal, a control signal (duty signal) is first output to the solenoid valve 24 of the leak passage 23 so that the leak passage 23 is moved to a predetermined position. After the engine output is increased by increasing the supercharging pressure by a predetermined value, a drive signal is output to the electromagnetic clutch 26 to suppress a decrease in the output of the compressor 25 at the initial stage of operation.

Further, feedback control is performed based on the detection signal of the pressure sensor 29 so that the detected boost pressure matches the set boost pressure.

The operation of the controller 27 will be explained based on the flowchart in FIG. After starting the engine, the supercharging pressure P is read from the pressure sensor 29 in step S1, and the signal from the air conditioner switch 28 is read in step S2.

Then, in step S3, it is determined whether or not the air conditioner switch 28 is in the on state. If the air conditioner switch 28 is off and the air conditioner is not operating (No), the supercharging pressure set value Ps is set to the normal supercharging pressure in step S4. Set the supply pressure setting value P1 and reset the flag F to O (85) L
After that, in step S6, an off signal is output to the electromagnetic clutch 26, and the compressor 25 is brought into a non-driving state.

On the other hand, if the air conditioner switch 28 is manually operated or linked to the thermostat and turned from the off state to the on state and the determination in step S3 becomes Y or ES, it is determined in step S7 whether or not the 7 lag F has been reset. , if the air conditioner switch 28 was off last time and turned on this time, this determination is YES, and step S
In step 8, set the boost pressure setting ps to the setting value P for when the air conditioner is operating.
Set to 2. Setting 1a P for when this air conditioner is running
2 is a higher amount than the normal setting 1 shift P1.

Then, when the detected supercharging pressure P reaches the set value P2 and the engine output increases due to the feedback control of the supercharging pressure after step 815, which will be described later, it is determined whether the detected supercharging pressure P is equal to or higher than the setting I P 2 in step S9. If the determination is YES, 7lag F is set to 1 in step S10, and a drive signal is output to the electromagnetic clutch 26 in step 811, and the electromagnetic clutch 26 is connected to start driving the compressor 25. It is.

On the other hand, until the supercharging pressure P reaches the set value P2, if the determination in step S9 is No, the process proceeds to steps S5 and S6, and the electromagnetic clutch 26 is maintained in the non-operating state while the flag F is reset. It is.

As described above, when the flag F is set to 1 in step SIO due to the operation of the electromagnetic clutch 26, the set value ps of the supercharging pressure is subtracted by a minute value ΔP in step S12 due to the No determination in step S7. and set it to a low value to gradually reduce the boost pressure.

Then, in step 813, it is determined whether or not the set value PS is equal to or lower than the normal supercharging pressure set value P1.If this determination is YES, the set value ps is changed to the normal set value Pl in step S14.
Set to .

The supercharging pressure control routine based on the supercharging pressure setting 1117PS as described above determines in step S15 whether or not the detected supercharging pressure P is less than a predetermined value α smaller than the set value PS; Similarly, in S16, the detected supercharging pressure P is set to the setting till! It is determined whether the value exceeds a value larger than Ps by a predetermined value α. The predetermined value ±α is the width of a dead zone for hunting prevention in boost pressure feedback control, and when the boost pressure P is lower than this dead zone, a YES determination in step S15 causes a duty signal to be sent to the solenoid valve 24 in step S17. S is set to a smaller value than a predetermined value ΔS, while when the boost pressure P is higher than the dead zone, a YES determination is made in step S16, and the duty signal S to the solenoid valve 24 is set to a predetermined value ΔS in step 820.
When the supercharging pressure P is within the dead zone, the previous duty signal S is used as it is due to the No determination in steps 815 and 816. In addition, step S
18 and 19 are for regulating the lower limit value of the duty signal S to O, and steps 821 and 22 are for regulating the upper limit value of the duty signal S to 100, respectively.

Then, in step 823, the duty signal S set as described above is outputted to the solenoid valve 24 installed in the leak passage 23. When the duty signal S is made smaller, the solenoid valve 24 widens the opening of the leak passage 23 in response to the signal, thereby reducing the pressure in the pressure passage 22, which reduces the opening degree of the waste gate valve 20 and increases the pressure in the combustion chamber. On the other hand, when the duty signal S is increased, the opening degree of the stator gate valve 20 increases and the supercharging pressure supplied to the combustion chamber 8 is decreased. By the above operation, feedback control is performed so that the detected supercharging pressure P matches the set fIPs.

FIG. 4 shows a time chart of the control of the controller 27 as described above. First, when the ON signal of the air conditioner switch 28 is input at point a, the set value ps of the supercharging pressure is increased from the normal set value P1 (upper limit value) to the set value P2 for external load operation.

Accordingly, when the actual supercharging pressure P increases and reaches the set value P2 at point b, an on signal is output to the electromagnetic clutch 26 to start driving the compressor 25, and the output when the external load is activated. This is to reduce the drop shock and gradually lower the set value Ps of the supercharging pressure to reduce the supercharging pressure P so that no shock occurs.

In the above embodiment, the turbocharger 2 is used, and the actual operation is delayed from the input of the external load operation signal until the boost pressure rises to a predetermined value. We try to deal with the time lag, but if we adopt another type of supercharger with a small time lag,
In some cases, processing to delay the operation of external loads is unnecessary. In addition to controlling the waste gate valve as described above, a conventionally known supercharging pressure control mechanism can be used to control the supercharging pressure.

On the other hand, as mentioned above, if the boost pressure is increased during external load operation, non-knocking is likely to occur as the boost pressure increases (so even if you simultaneously retard the ignition timing to prevent knocking, good.

Furthermore, in addition to measures against external loads through boost pressure control as described above, a mechanism is also used to increase output by increasing the throttle opening or amount of bypass air when external loads are activated during low loads such as during idling. You may.

(Effects of the Invention) According to the present invention as described above, when an external load such as a tala compressor is operated, the set supercharging pressure is controlled to increase, so that the boost pressure increases as the supercharging pressure increases. The engine output increases, and even when the throttle valve is fully open, it is possible to suppress a large output drop due to external load input.
Good operating performance can be ensured without reducing engine reliability.

[Brief Description of the Drawings] Fig. 1 is a block diagram of a supercharging pressure control device for a supercharged engine to clearly demonstrate the configuration of the present invention, Fig. 2 is an overall configuration diagram of a specific example engine, and Fig. 3 FIG. 4 is a flow chart for explaining the operation of the controller, and FIG. 4 is a time chart showing operation characteristics under control of the controller. 1...Engine 2...Supercharger 3...Supercharging pressure control means 4...External load detection means 5...Setting excessive Supply pressure changing means 20... Waste gate valve 21...
・Actuator 22...Pressure passage 23...
... Leak passage 24 ... Solenoid valve 25 ... Air conditioner compressor 26 ...
...Electromagnetic clutch 27...Controller 2
8... Air conditioner switch 29... Pressure sensor Figure 1 Figure 2 Figure 4

Claims (1)

[Claims] (1) In an engine equipped with a supercharger that performs intake supercharging, a boost pressure control means for maintaining boost pressure at a set value, an external load detection means for detecting the operating state of an external load, and an external load detection means and a set supercharging pressure changing means for changing the set supercharging pressure in the supercharging pressure control means so as to increase the set supercharging pressure in the supercharging pressure control means when an external load is applied at least when running with the throttle valve fully open. Boost pressure control device for charged engines.