JP2717268B2 - Supercharging pressure control device for internal combustion engine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supercharging pressure control device for an internal combustion engine, and more particularly, to a supercharging of an internal combustion engine capable of performing a fine supercharging pressure control according to the properties of fuel. The present invention relates to a pressure control device.

[Conventional technology]

2. Description of the Related Art In a supercharger that pumps intake air to an internal combustion engine to improve the output of the internal combustion engine, if the supercharging pressure is too high, the supercharger and the internal combustion engine will be damaged. Therefore, conventionally, when the supercharging pressure reaches a set value determined by the outside air temperature, the engine speed, etc., a part of the intake air downstream of the compressor of the supercharger is relieved to the upstream side to set the set value. In some cases, control is performed so as not to exceed the set value, and in other cases, a part of the exhaust gas upstream of the exhaust turbine of the turbocharger is bypassed to the downstream side so that the set value is not exceeded.

Further, as such a supercharging pressure control device for an internal combustion engine, for example, JP-B-62-30285 and JP-A-62-22571
No. 9 discloses this. Japanese Patent Publication No. Sho 62-30285 discloses a technique in which a measured intake air amount is compared with a target intake air amount to control a supercharging pressure so that an actual intake air amount becomes a target intake air amount. . Japanese Patent Application Laid-Open No. 62-225719 discloses a method of learning a feedback control area based on a deviation between a supercharging pressure of intake air and a predetermined target supercharging pressure. By determining the region, the integral control corresponding to each of the variable capacity region and the exhaust bypass region is made appropriate, and a stable supercharging pressure characteristic is achieved, thereby improving the torque performance of the engine.

[Problems to be solved by the invention]

By the way, in the market of gasoline, which is a fuel for vehicles, high-octane gasoline and regular gasoline can be easily purchased, so that controlling the supercharging pressure corresponding to the octane number increases the protection and high performance of the internal combustion engine. Important to get.

However, conventionally, the control means has a duty value map for operating a control valve for controlling the supercharging pressure.
Had only one. For this reason, the control distinction between regular gasoline and high-octane gasoline is only multiplied by a fixed ratio, and it is not possible to finely control the supercharging pressure according to the properties of gasoline, and as a result, driving performance deteriorates Invited inconvenience.

[Object of the invention]

Therefore, an object of the present invention is to operate the pressure control valve in accordance with a duty value map according to the property of the fuel to be supplied to finely control the supercharging pressure according to the property of the fuel in order to eliminate the above-described disadvantage. It is an object of the present invention to realize a boost pressure control device for an internal combustion engine that can improve operating performance.

[Means for solving the problem]

In order to achieve this object, the present invention relates to a supercharger for an internal combustion engine that controls a supercharging pressure supplied to the internal combustion engine by a waste gate valve provided in a bypass passage that bypasses an exhaust turbine of a supercharger and communicates with an exhaust passage. A pressure control device that is provided with an actuator that operates the waste gate valve and that operates with a duty value to adjust the pressure of the compressor downstream intake passage of the supercharger that acts on the pressure chamber of the actuator. A valve is provided, and the operation region of the internal combustion engine is divided into a low load region, a high load region, and a control region, and when the operation region is in a low load region, the energization of the pressure control valve is turned off. When shifting to the high load area and when shifting from the high load area to the control area, the duty value is calculated by integrating time, and In addition, while performing open control with a preset duty value, in the control region, open control is performed by correcting to a duty value determined by various duty value determining factors, and properties of fuel supplied to the internal combustion engine are controlled. A control means for opening control of the pressure control valve according to a corresponding duty value map is provided.

[Action]

According to the configuration of the present invention, first, the control unit
The operating region of the internal combustion engine is divided into a low load region, a high load region, and a control region. When the operating region is in the low load region, the energization of the pressure control valve is turned off, and when shifting from the low load region to the high load region and when When shifting from the load area to the control area, the duty value is calculated by integrating the time. In the high load area, open control is performed using a preset duty value. In the control area, the duty value is determined by various duty value determining factors. To control the supercharger according to the properties of the fuel, so that the supercharging pressure is finely controlled while taking into account the engine operating state and the properties of the fuel, thereby improving the driving performance. In the low-load region, the power supply to the pressure control valve is cut off by cutting off, preventing the compressor efficiency on the low-load side from deteriorating and improving engine performance. Enough to be exhibited, and further, low,
Since the duty value is shifted by integrating the time when the control range is changed to a high value, there is no sudden change in the engine output, and the drivability can be improved.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail and specifically with reference to the drawings.

1 to 23 show an embodiment of the present invention.
In FIG. 1, reference numeral 2 denotes an internal combustion engine, 4 denotes a supercharger constituted by a compressor 6 and an exhaust turbine 8, 10 denotes an intake passage, and 12 denotes an exhaust passage. An air cleaner 16 is provided in a first intake passage 10- on the upstream side of the compressor 6 of the supercharger 4 via an air flow meter 14. An intercooler 18 and an intake throttle valve are provided in a second intake passage 10-2 on the downstream side of the compressor 6. A surge tank 22 is provided via 20. Also,
The internal combustion engine 2 is provided with an exhaust turbine 8 of the supercharger 4 downstream of the first exhaust passage 12-1 and communicates with a second exhaust passage 12-2 downstream of the exhaust turbine 8.

A first exhaust passage bypassing the exhaust turbine 8 of the supercharger 4
A bypass passage 24 is provided to connect the second exhaust passage 12-2 with the second exhaust passage 12-2. The bypass passage 24 has one end connected to an inlet 26 opening to the first exhaust passage 12-1 and the other end connecting to an outlet 28 opening to the second exhaust passage 12-1.
Connected to The inlet 26 of the bypass passage 24 is opened and closed by a waste gate valve 30. The waste gate valve 30 is operated by an actuator 32.

The actuator 32 includes a diaphragm in a main body 34.
The pressure chamber 38 and the atmosphere chamber 40 are defined by the partition 36. One end of an operating rod 42 is connected to one surface of the diaphragm 36, and the other end of the operating rod 42 is connected to a waste gate valve.
It is connected to a rotating lever 44 connected to 30.

Further, a spring 46 for urging the diaphragm 36 in the contracting direction of the pressure chamber 38 is provided in the atmosphere chamber 40 of the main body 34 of the actuator 32.

In the pressure chamber 38 of the actuator 32, a pressure guiding passage 48 having one end opening to the second intake passage 10-2 on the downstream side of the supercharger 4 is provided.
Is open at the other end. In addition, a first throttle portion 50 having a predetermined opening area is provided on one end side of the pressure guiding passage 48.

In the middle of the pressure guiding passage 48, a pressure control passage 50 having one end opening to the pressure guiding passage 48 and the other end communicating with the first intake passage 10-1 on the upstream side of the supercharger 4 communicates. I have.

In the middle of the pressure control passage 50, there is provided a pressure control valve 52 as a duty solenoid operated by a duty value to adjust the pressure acting on the pressure chamber 38 of the actuator 32 from the pressure guiding passage 48. The pressure control passage 50 has a predetermined opening area on the pressure guiding passage 48 side of the pressure control valve 52 so as to adjust the pressure acting on the pressure control valve 52 from the pressure guiding passage 48 to a predetermined value. A throttle unit 54 is provided.

The pressure control valve 52 is in communication with a control means 56 for opening and controlling the pressure control valve 52 in order to control the supercharging pressure in accordance with the duty value determining factor.

As shown in FIG. 1, the control means 56 includes an ignition signal detection unit 58 for detecting the engine speed, an intake air temperature sensor 60 for detecting the temperature of the cooling water, and a temperature of the cooling water of the internal combustion engine 2. A cooling water temperature sensor 62, an atmospheric pressure sensor 64 for detecting atmospheric pressure, a vehicle speed sensor 66 for detecting acceleration, a knock sensor 68 for detecting knocking, and a throttle sensor 70 are in communication. Further, the control means 56 is in communication with the battery 72.

Further, as shown in FIGS. 4 to 7, the operation region of the internal combustion engine is divided into a low load region, a high load region, and a control region, and when the operation region is in a low load region, the energization of the pressure control valve 52 is turned off. , Stop the duty control of the pressure control valve 52, and
As shown in FIGS. 9 and 10, when shifting from the low load area to the high load area and when shifting from the high load area to the control area, the duty value is calculated by integrating the time. Open control is performed based on the value, and in the control area, the open control is performed by correcting the duty value determined by various duty value determining factors. That is, the duty value for controlling the operation of the pressure control valve 52 is previously stored as a two-dimensional map in the program. That is, the duty value map is a two-dimensional map of the engine speed and the intake air temperature, and this duty value is corrected by the engine cooling water temperature. In the low load range, while cutting off the power supply to the pressure control valve 52,
In the high load area, the duty value is set to 100% or a high value.

Further, the control means 56 determines the properties of the fuel, and when regular gasoline is used, takes into account the correction of the duty value by the regular gasoline, for example, reduces the duty value to reduce the supercharging pressure. It has a gasoline duty value map and a high octane gasoline duty value map that takes into account the correction of the high octane gasoline duty value when high octane gasoline is used. Open control.

As described above, the division into the low load region, the high load region, and the control region is performed based on the opening degree of the throttle valve 20, the intake air amount, the fuel injection amount, the atmospheric pressure, and the like. These low load area, high load area, and control area can be set for each engine speed.

When shifting from the low load area to the high load area and when shifting from the high load area to the control area, the duty value is shifted by integration of time. The duty value is corrected at the atmospheric pressure.

At the time of rapid acceleration, the duty value is corrected for a certain period of time and then attenuated by integration of time.

Acceleration determination at the time of rapid acceleration is performed based on a change amount of the throttle valve 20, a change amount of the intake air amount, and the like.

In combination with the knock sensor 68, when knocking occurs, the duty value is corrected for a certain time, and then attenuated by integration of time. For example, in a high-octane gasoline specification vehicle, when regular gasoline is supplied, regular gasoline is determined based on the knocking degree, the duty value is reduced, and the supercharging pressure is reduced. Further, when the engine speed and the vehicle speed become too high, the duty value is reduced to lower the supercharging pressure.

It goes without saying that the present invention is applicable not only to the internal combustion engine 2 with the air flow sensor 14 but also to the internal combustion engine with the pressure sensor.

Next, the operation of this embodiment will be described with reference to the flowchart of FIG.

In the control means 56, when the program is started (step 102), first, the energization of the pressure control valve 52 as a duty solenoid is turned off (step 104), and then the operation region of the internal combustion engine 2 is determined (step 106). This operation region is divided into a low load region, a high load region, and a control region.

If the operation region is the low load region a in step 106, the process returns to step 104. Further, in the case of the high load region b in step 106, the duty is set to X% as shown in FIGS. 4, 8, 9 and 10 (step 10).
8). Then, in step 110, the operation region is determined again.

In the case of the low load area a in step 110,
Return to step 104. If it is determined in step 110 that the region is the high load region b, the process returns to step 108.

On the other hand, if it is the control device c in steps 106 and 110, the open duty control value is calculated in step 112. That is, the open duty control is based on the duty map value shown in FIG.
OPDTY = DTYMP × (1−TWK + HACK + ΔTHV−KN) is corrected.

Here, DTYMP is determined by the duty map value shown in FIG. TWK is a coolant temperature correction, HACK is an atmospheric pressure correction, ΔTHV is an acceleration correction, and KN is a knocking correction. More specifically, the correction amount of the cooling water temperature is obtained in accordance with the cooling water temperature as shown in FIGS. 11 to 13, and is constant above a set value. The correction amount of the atmospheric pressure corresponds to the atmospheric pressure as shown in FIGS. 14 to 16, and is obtained by changing positive and negative values in the set value. Further, as shown in FIGS. 17 to 19, the correction amount at the time of acceleration is obtained by comparing the value ΔTH from the throttle sensor 70 with the set value ΔTHVK, confirming the control area, and calculating the elapsed time.

Further, the knocking correction amount is, as shown in FIGS.
The detected knock amount KNOCK is compared with the set value KNK, which is obtained from the table shown in FIG. 23 and changes with the elapsed time.

After calculating the open duty control value in step 112, the fuel property is determined in step 114.

If the fuel is regular gasoline in step 114, the operation of the pressure control valve 52 is controlled in step 116 according to the regular gasoline duty value map. On the other hand, if the fuel is high-octane gasoline in step 114, the operation of the pressure control valve 52 is controlled in step 118 according to the high-octane gasoline duty value map. As described above, by controlling the operation of the pressure control valve 52 in accordance with the state of the fuel, the pressure to the pressure chamber 38 of the actuator 32 is finely adjusted, and the supercharging pressure is finely controlled.

Next, after steps 116 and 118, it is determined in step 120 whether or not an overrun has occurred. And
If overrun and step 120 is YES, OPDTY = RN
(%) (Step 122).

However, RN is the overrun duty (%). If step 120 is NO and after step 122, the duty value of the pressure control valve 52 is set to the OPDTY value in step 124, and the end (step 126). .

As a result, the control means 56 has a regular gasoline duty value and a map and a high-octane gasoline duty value map, and controls the supercharging pressure with a duty value that matches the properties of the supplied gasoline. It is possible to achieve fine supercharging pressure control, thereby drawing out the maximum engine performance that matches the octane number regardless of whether regular gasoline or high-octane gasoline is supplied,
Driving performance can be improved.

Further, when the internal combustion engine 2 is at a low temperature, an unreasonable load is not applied to the internal combustion engine 2, and the durability of the internal combustion engine 2 can be improved.

Further, it is possible to prevent the engine output from decreasing at high temperature of the internal combustion engine 2.

Furthermore, the characteristics of the components such as the fuel injection valve need only be examined at room temperature only, and the characteristics of the components can be easily determined.

Also, it is not necessary to increase the size of the components in consideration of the low temperature, and the cost can be reduced.

Furthermore, fluctuations in engine output performance due to changes in atmospheric pressure can be prevented, and substantially constant output performance can be obtained under any atmospheric conditions.

In the low load region, the energization of the pressure control valve 52 is cut, so that the efficiency of the low load side compressor 6 is prevented from deteriorating.
The engine performance can be fully exhibited.

In the high load area, the duty of the pressure control valve 52 is set to 100%
Alternatively, since the pressure is set high and the amount of pressure leak to the actuator 32 is increased to increase the supercharging pressure quickly, the acceleration performance can be improved.

When shifting to the low, high, and control regions, the duty value is shifted by integration of time, so that there is no rapid change in the engine output, and the drivability can be improved.

At the time of acceleration, the duty value is increased for a certain period of time to accelerate the increase of the supercharging pressure, thereby improving the acceleration performance.

When knocking occurs, the supercharging pressure is reduced to suppress the occurrence frequency of knocking, so that an overload on the internal combustion engine 2 can be prevented.

For high-octane gasoline-equipped vehicles, lower the supercharging pressure when refueling regular gasoline.
It can be used without causing abnormal knocking.

When the engine speed and the vehicle speed are too high, the supercharging pressure is reduced to cope with the problem, and the load on the internal combustion engine 2 can be reduced.

〔The invention's effect〕

As apparent from the above detailed description, according to the present invention, an actuator for operating the waste gate valve is provided, and the duty value is adjusted so as to adjust the pressure of the compressor downstream intake passage of the supercharger acting on the pressure chamber of the actuator. The operation range of the internal combustion engine is divided into a low load region, a high load region, and a control region, and the energization of the pressure control valve is turned off when the operation region is in the low load region. When shifting from the high load area to the high load area and when shifting from the high load area to the control area, the duty value is calculated by integrating the time, and in the high load area, open control is performed with a preset duty value, and in the control area, Open control is performed by correcting the duty value determined by the duty value determining factor, and the fuel supplied to the internal combustion engine is controlled. By providing control means for opening the pressure control valve according to the duty value map according to the condition, it is possible to achieve fine supercharging pressure control that matches the properties of the fuel, improve operating performance, and reduce In the range, the power supply to the pressure control valve is cut off by turning it off, preventing deterioration of the efficiency of the compressor on the low load side, fully exhibiting engine performance, and further reducing the duty value when shifting to the low, high, Since the transition is made by integrating the time, there is no sudden change in the engine output, and the operability can be improved.

[Brief description of the drawings]

1 to 23 show an embodiment of the present invention, FIG. 1 is a schematic diagram of a supercharging pressure control device, FIG. 2 is a flowchart for explaining the operation of the present invention, and FIG. 3 is intake air temperature and engine speed. 4 to 10 are explanatory diagrams showing a divided state of the operation area, FIGS. 11 to 13 are diagrams for explaining a cooling water temperature correction amount, and FIGS. 14 to 16 are an atmospheric pressure correction amount. Illustration to explain, 17th to 19th
The drawings illustrate the amount of acceleration correction, and FIGS. 20 to 23 illustrate the amount of knocking correction. In the figure, 2 is an internal combustion engine, 4 is a supercharger, 10 is an intake passage, 18 is an intake throttle valve, 24 is a bypass passage, 26 is an inlet, 28
Is an outlet, 30 is a waste gate valve, 32 is an actuator, 38 is a pressure chamber, 48 is a pressure guiding passage, 50 is a pressure control passage,
52 is a pressure control valve, 56 is control means, 58 is an ignition signal detector,
60 is an intake air temperature sensor, 62 is a cooling water temperature sensor, and 70 is a throttle sensor.

Claims (1)

(57) [Claims] 1. A supercharging pressure control device for an internal combustion engine, which controls a supercharging pressure supplied to an internal combustion engine by a waste gate valve provided in a bypass passage that bypasses an exhaust turbine of a supercharger and communicates with an exhaust passage. An actuator for operating the waste gate valve is provided, and a pressure control valve that is operated at a duty value so as to adjust a pressure of a compressor downstream intake passage of the supercharger that acts on a pressure chamber of the actuator is provided. The operation region of the engine is divided into a low load region, a high load region, and a control region. When the operation region is a low load region, the power supply to the pressure control valve is turned off, and the operation shifts from the low load region to the high load region. At the time and when shifting from the high load region to the control region, the duty value is calculated by integrating the time, and in the high load region, a preset value is used. Open control based on the duty value, and in the control region, perform open control by correcting to a duty value determined by various duty value determining factors, and according to a duty value map corresponding to properties of fuel supplied to the internal combustion engine. A supercharging pressure control device for an internal combustion engine, further comprising control means for opening and controlling the pressure control valve.