JPH08200117A - Boost pressure detecting device of diesel engine with supercharger - Google Patents

Abstract

PURPOSE: To avoid deterioration of control precision of adjusting pressure and delay of judgement of the operating state of boost pressure by suitably detecting adjusting pressure and boost pressure according to the operating state in a diesel engine with a supercharger provided with an injection amount compensating device. CONSTITUTION: A boost controller 22 for controlling the maximum fuel injection amount according to boost pressure is provided on a fuel injection pump 2. An intake air pressure sensor 44 detects boost pressure in a boost pressure passage 25 and control negative pressure in a negative pressure passage 16. A detecting switching valve (a third VSV) 29 is provided in order to selectively detect the boost pressure or the control negative pressure. The negative pressure from a vacuum pump 20 is supplied to a negative pressure chamber 24 of the boost controller 22 through a pressure adjusting valve (EVRV) 17. An electronic control unit (ECU) 47 controls the third VSV 29, the EVRV 17, etc. The ECU 47 judges the precedence of control of control negative pressure or judgement of boost pressure on the basis of the operating state, and pressure detection in which precedence of time sharing is secured is applied according to the judged result.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supercharging pressure detecting device for a diesel engine equipped with a supercharger such as a turbocharger. More specifically, the present invention relates to a supercharging pressure detection device that controls the detection of the supercharging pressure used to determine the operating state of the supercharger.

[0002]

2. Description of the Related Art Conventionally, in a diesel engine equipped with a supercharger such as a turbocharger, the fuel injection amount to be supplied to the diesel engine in order to reliably increase the engine output as the supercharging pressure increases. Is generally controlled according to the boost pressure. Further, as a fuel injection pump used for a diesel engine, there is a fuel injection pump provided with a boost and altitude compensation stopper (BACS) that controls the maximum fuel injection amount according to supercharging pressure in the engine. Are known.
As is well known, the BACS is provided with a supercharging pressure chamber and a negative pressure chamber which are vertically divided by a diaphragm. Further, the diaphragm is connected to the governor mechanism via a stopper rod. Then, due to the relationship between the supercharging pressure introduced into the supercharging pressure chamber and the pressure introduced into the negative pressure chamber,
When the diaphragm is displaced and the stopper rod moves up and down, the governor mechanism operates and the maximum fuel injection amount from the fuel injection pump is determined. Therefore, when the accelerator lever provided on the fuel injection pump is fully opened by the driver, that is, when the diesel engine is fully loaded, the fuel injection pump changes to the diesel engine based on the maximum fuel injection amount determined by BACS. And fuel is pumped and injected.

A technique for controlling the fuel injection amount of a diesel engine with a supercharger by using the fuel injection pump having the BACS as described above is disclosed, for example, in Japanese Patent Laid-Open No. 6-101525. You can list things. In this technique, an EGR valve for recirculating a part of exhaust gas to intake air, that is, for performing EGR is provided. Then, the operating state of the diesel engine is "E
In the “GR control region”, the EGR flow rate is controlled by adjusting the opening degree of the EGR valve by the adjusting pressure introduced into the negative pressure chamber. Further, when the operating state of the diesel engine is in the "BACS region", the supercharging pressure introduced into the supercharging pressure chamber of the BACS and the adjustment pressure introduced into the negative pressure chamber due to the operation of the turbocharger By displacing the diaphragm according to the relationship, the governor mechanism operates and the fuel injection amount from the fuel injection pump is compensated. That is, the maximum fuel injection amount in the fuel injection pump is determined.

The adjustment pressure introduced into the negative pressure chamber of the EGR valve and the adjustment pressure introduced into the negative pressure chamber of the BACS are the opening degree of one electric vacuum regulating valve (EVRV). Is controlled by duty control. Further, by switching the vacuum switching valve (VSV), the adjustment pressure introduced into the negative pressure chamber of the EGR valve or the negative pressure chamber of the BACS is switched. Further, the adjustment pressure adjusted by the EVRV and the supercharging pressure obtained by the turbocharger are detected by one intake pressure sensor by selectively switching different passages by the detection VSV. Then, the opening degree of the EVRV is feedback-controlled based on the adjustment pressure detected by the intake pressure sensor, so that the adjustment pressure introduced into the negative pressure chamber of the EGR valve or the negative pressure chamber of the BACS is feedback-controlled.

For example, when the operating state of the diesel engine shifts from the "EGR control region" to the "BACS region", it is based on the accelerator lever opening, the engine speed and the boost pressure at the time of the shift. Then, the negative pressure required value to be introduced into the negative pressure chamber of the BACS is obtained. Then, after the negative pressure command value for EVRV is once set to "0", it is gradually increased until the negative pressure command value becomes the negative pressure required value. As a result, the adjustment pressure (negative pressure) introduced into the negative pressure chamber of the BASC gradually increases, and the amount of fuel pumped from the fuel injection pump to the diesel engine gradually increases toward the maximum injection amount. In this technique, the intake pressure sensor and the EVRV are used for both the control of the EGR flow rate and the control of the maximum fuel injection amount, so that the number of component parts of the device is reduced.

By the way, conventionally, in a vehicle equipped with a turbocharger, the operating state of the turbocharger is determined based on the supercharging pressure detected by an intake pressure sensor. Then, there is a system in which the driver is informed of the operating state of the turbocharger by controlling the lighting of the turbo indicator based on the determination result to prevent excessive supercharging (supercharging).

Therefore, it is practically possible to apply the lighting control of the turbo indicator to the technique proposed in the above-mentioned JP-A-6-101525. More specifically, when the operating range is in the BACS control range, the EVRV is adjusted and controlled based on the adjusted pressure detected by the intake pressure sensor, and the VSV is switched for a fixed time by the time sharing to increase the boost pressure. Is detected by the intake pressure sensor (Japanese Patent Laid-Open No. 6-17375).
2). That is, in the BACS control region, the main EVRV feedback control and the subordinate boost pressure determination are alternately performed at predetermined time intervals.

[0008]

However, in the above conventional technique, there is a possibility that the following problems may occur. That is, when a vehicle equipped with a diesel engine is normally traveling, it is almost always operated in the EGR control range.
Driving in the area is limited to acceleration, traveling on a long slope, and the like. Therefore, in the normal operation, there are very few opportunities to continue the operation in the BACS control region for a long time.

Therefore, in the above-mentioned prior art, it is extremely difficult to detect the adjustment pressure and the supercharging pressure alternately within a very short time in the BACS control region, and to detect them accurately and surely. It was very difficult. That is, when the detection time of the adjusted pressure is simply set to be relatively long, it is not possible to accurately determine the magnitude of the supercharging pressure, and it may not be possible to promptly notify the driver of the abnormality. there were. On the other hand, on the contrary, when the supercharging pressure detection time is set to be relatively long, the accuracy of the feedback control of the adjusted pressure is lowered, which in turn causes the generation of smoke when traveling at high altitude or when starting. There was a fear.

The present invention has been made in view of the above-mentioned circumstances, and its object is to increase the supercharging pressure introduced into the supercharging pressure chamber along with the operation of the supercharger and the opening degree of the negative pressure adjusting valve. In a supercharging pressure detection device for a diesel engine with a supercharger, which is equipped with an injection amount compensating device for compensating the fuel injection amount of a fuel injection pump by operating according to the adjustment pressure introduced into the pressure chamber during adjustment. The control pressure and the supercharging pressure can be appropriately detected according to the operating state, and thus the control accuracy of the control pressure and the supercharging can be prevented from delaying the determination of the operating state of the supercharging pressure. An object of the present invention is to provide a supercharging pressure detection device for a diesel engine equipped with an engine.

[0011]

In order to achieve the above object, in the invention described in claim 1, as shown in FIG. 1, the intake air taken into the engine body M2 of the diesel engine through the intake passage M1. Supercharger M3 for boosting pressure
A fuel injection pump M4 for sending fuel to the engine body M2 and a supercharging pressure chamber M5 communicating with the supercharger M3.
And a pressure chamber M7 communicating with a negative pressure generation source M6 that generates a negative pressure. The supercharging pressure introduced into the supercharging pressure chamber M5 along with the operation of the supercharger M3, and the pressure chamber The injection amount compensating device M8, which operates according to the pressure introduced into M7 to compensate the fuel injection amount of the fuel injection pump M4, and the negative pressure generating source M6, is connected to the injection amount compensating device M8. Of the pressure chamber M7, which is opened and closed to adjust the negative pressure introduced into the pressure chamber M7, and which can be opened to the atmospheric pressure, and the regulated pressure or the atmospheric pressure from the side of the pressure regulating valve M9. A pressure switching valve M10 that is switched to be selectively introduced into M7, and one pressure detection means M11 that communicates with the pressure regulating valve M9 and the supercharger M3 and that detects one of the pressures. The pressure adjusting valve M9 and the pressure A switching valve for detection M12 for selectively switching communication between the detection means M11 and communication between the supercharger M3 and the pressure detection means M11, and operating state detection means for detecting the operating state of the engine body M2. M13
And based on the detection result of the operating state detection means M13,
At this time, the operating state of the engine body M2 is in the fuel injection amount compensation control region, and the control region determination means M14 for determining whether or not it is in the fuel injection amount compensation control region, and at least the determination result of the control region determination means M14 is in the fuel injection amount compensation control region. In some cases, in order to control the magnitude of the adjusted pressure and determine the operating state of the supercharger M3, the detection switching valve M12 is switching-controlled by time sharing, and the pressure detection means M1.
1. A supercharging pressure detection device for a diesel engine with a supercharger, comprising: a switching control means M15 for selectively switching between the adjustment pressure and the supercharging pressure detection by No. 1 described above. Is a priority determination means M15A for determining the priority of the control of the magnitude of the adjusted pressure and the determination of the operating state of the supercharger M3 based on the detection result of the operating state detection means M13, and the priority determination. When the means M15A determines that the control of the magnitude of the regulated pressure has a higher priority, the communication between the pressure regulating valve M9 and the pressure detecting means M11 is prioritized to give priority to the control of the magnitude of the regulated pressure. When the determination of the operating state of the supercharger M3 is determined to have a higher priority, the supercharger M3 and the supercharger M3 are prioritized to give priority to the determination of the operating state of the supercharger M3. The above That it contains a time-sharing adjustment means M15B which allowed to prioritize communication opportunities with the force detecting means M11 is set to its gist.

Further, in the invention described in claim 2,
The supercharging pressure detection device for a diesel engine with a supercharger according to claim 1, wherein the priority determination means 15A uses the operating state detection means M13 to determine the rotational speed and the load of the diesel engine and the rate of change thereof. The gist of the invention is to judge that the control of the magnitude of the adjusted pressure has a higher priority when at least one of them exceeds a predetermined reference value.

Further, in the invention according to claim 3, in the supercharging pressure detecting device for a diesel engine with a supercharger according to claim 1 or 2, the priority determining means M1.
5A is a determination of the operating state of the supercharger M3 when the detection result by the operating state detection means M13 is when the diesel engine is warming up or when there is a rapid change in the environment. The main point is to judge that has higher priority.

In addition, in the invention described in claim 4, in the supercharging pressure detecting device for a diesel engine with a supercharger according to any one of claims 1 to 3, the diesel engine further comprises the engine. An exhaust gas recirculation passage that connects the exhaust passage through which the exhaust gas from the main body M2 flows and the intake passage M1, and the exhaust gas recirculation passage that is provided in the exhaust gas recirculation passage, and is provided when atmospheric pressure is introduced. Is closed, and when a negative pressure is introduced from the negative pressure generation source 6, the exhaust gas recirculation passage is opened according to the negative pressure, and a recirculation amount of the exhaust gas flowing through the passage is adjusted. The pressure adjusting valve M9 has a circulation amount adjusting valve.
Is opened and closed to adjust the negative pressure introduced into the pressure chamber M7 of the injection amount compensator M8 or the recirculation amount adjusting valve in communication with the negative pressure generating source M6, and is also opened to the atmospheric pressure. Further, the control region determination means M14 determines that the operating state of the engine body M2 at that time is based on the detection result of the operating state detection means M13, that is, the exhaust gas recirculation control region and the fuel injection amount. Compensation control area,
Its gist is to determine which of the other areas it is.

[0015]

According to the invention described in claim 1, as shown in FIG. 1, the intake air taken into the engine body M2 of the diesel engine through the intake passage M1 is boosted by the supercharger M3. Further, fuel is pumped to the engine body M2 by the fuel injection pump M4. Injection amount compensator M8
A supercharging pressure is introduced into the supercharging pressure chamber M5 communicating with the supercharging device M3 along with the operation of the supercharging device M3.
The negative pressure generated by the negative pressure generation source M6 can be introduced into the pressure chamber M7 that is communicated with the pressure chamber M6. Then, the injection amount compensating device M8 operates according to the supercharging pressure introduced into the supercharging pressure chamber M5 and the pressure introduced into the pressure chamber M7, whereby the fuel injection amount of the fuel injection pump M4 is compensated. It

The negative pressure introduced into the pressure chamber M7 of the injection amount compensator M8 is adjusted by opening / closing the pressure adjusting valve M9 connected to the negative pressure source M6 or opening it to the atmospheric pressure. To be done. Further, by switching the pressure switching valve M10, the regulated pressure or the atmospheric pressure from the pressure regulating valve M9 side is selectively introduced into the pressure chamber M7. Further, one pressure detecting means M11 is communicated with the pressure regulating valve M9 and the supercharger M3. By switching the detection switching valve M12, the communication between the pressure adjusting valve M9 and the pressure detecting means M11 and the communication between the supercharger M3 and the pressure detecting means M11 are selectively switched. By this switching, Either pressure is detected.

Further, the operating state detecting means M13 detects the operating state of the engine body M2, and based on the detection result, whether the operating state of the engine body M2 at that time is in the fuel injection amount compensation control region or not. Control area determination means M
Judgment by 14. Then, at least when the determination result of the control region determination unit M14 is in the fuel injection amount compensation control region, the switching control unit M15 controls the magnitude of the adjusted pressure and the operating state of the supercharger M3 by the switching control unit M15. The detection switching valve M12 is switch-controlled by time sharing, and the detection of the adjusted pressure and the boost pressure by the pressure detection means M11 is selectively switched.

In the present invention, the priority determination means M15A, which is a constituent element of the switching control means M15,
Based on the detection result of the operating state detection means M13, the priority of the control of the magnitude of the adjusted pressure and the determination of the operating state of the supercharger M3 is determined. Then, the priority determination means M15A
When it is determined that the control of the magnitude of the regulated pressure has a higher priority, the time sharing regulating means M15B, which is a constituent element of the switching control means M15, controls the pressure regulating valve M9 and the pressure detecting means M11. Opportunity for communication is prioritized, and control of magnitude of regulated pressure is prioritized. On the other hand, when the priority determination unit M15A determines that the determination of the operating state of the supercharger M3 has a higher priority, the time sharing adjustment unit M15B also causes the supercharger M3 to be determined.
And the pressure detection means M11 are connected with each other, and the determination of the operating state of the supercharger M3 is prioritized.

For this reason, when in the fuel injection amount compensation control region, the pressure detection means M11 is used between the adjusted pressure and the supercharging pressure with the priority according to the operating state at that time.
Thus, the pressure is detected respectively.

According to the second aspect of the invention, in addition to the operation of the first aspect of the invention, in particular, the engine speed and load of the diesel engine and the rate of change thereof are determined by the operating state detecting means M13. When at least one of them exceeds a predetermined reference value, the priority determination means 15A determines that the control of the magnitude of the adjusted pressure has a higher priority. Therefore, when there is a concern about supercharging, such as when the engine is running at high speed and under high load, the supercharging pressure is reliably detected with priority.

Further, according to the invention of claim 3,
In addition to the effects of the invention described in claims 1 and 2, particularly when the detection result by the operating state detection means M13 is when the diesel engine is warming up or when there is a rapid change in the environment. In addition, the priority determination means M15A determines that the determination of the operating state of the supercharger M3 has a higher priority. For this reason, when there is a concern that smoke will occur due to the operation of the injection amount compensator M8, such as during warm-up or when the environment changes suddenly, the adjusted pressure is reliably detected with priority. It will be.

In addition, according to the invention of claim 4,
In addition to the operation of the invention described in claims 1 to 3, the exhaust gas recirculation passage further connects the exhaust passage through which the exhaust gas from the engine body M2 flows with the intake passage M1. When the atmospheric pressure is introduced into the recirculation amount adjusting valve provided in the exhaust gas recirculation passage, the exhaust gas recirculation passage is closed, and when the negative pressure is introduced from the negative pressure generation source 6, the negative pressure thereof is introduced. Accordingly, the exhaust gas recirculation passage is opened, and the recirculation amount of the exhaust gas flowing through the passage is adjusted.

Further, the pressure chamber M of the injection amount compensator M8 is opened and closed by opening and closing the pressure adjusting valve M9 communicating with the negative pressure generating source M6.
7 or the negative pressure introduced into the recirculation amount adjusting valve can be adjusted. Further, based on the detection result of the operating state detecting means M13 by the control area determining means M14, the operating state of the engine body M2 at that time is the exhaust gas recirculation control area,
It is determined which of the fuel injection amount compensation control region and the other region.

Therefore, according to the present invention, the pressure regulating valve M9
The pressure detecting means M11 is also used for controlling the exhaust gas recirculation amount and for compensating the fuel injection amount.
The number of component parts of the apparatus can be reduced.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying a supercharging pressure detecting device for a diesel engine with a supercharger according to the present invention will now be described with reference to FIG.
~ It demonstrates in detail based on FIG.

FIG. 2 shows a schematic structure of a diesel engine system with a supercharger mounted on an automobile in this embodiment. This system includes a diesel engine 1 and a fuel injection pump 2 for pumping fuel to the engine 1.

The engine body 3 constituting the diesel engine 1 is composed of a plurality of cylinders, and fuel injection nozzles (not shown) are provided corresponding to the combustion chambers of the respective cylinders. An intake manifold 4 and an exhaust manifold 5 are connected to the engine body 3, respectively. Intake manifold 4
An intake passage 6 is connected to the exhaust manifold 5, and an exhaust passage 7 is connected to the exhaust manifold 5. A compressor 8 is provided upstream of the intake passage 6, and a turbine 9 is provided downstream of the exhaust passage 7. The compressor 8 and the turbine 9 constitute a turbocharger 10 as a supercharger. As is well known, the turbocharger 10 uses the exhaust gas flowing through the exhaust passage 7 to drive the turbine 9
Is rotated, and the compressor 8 is rotated by its rotational force to increase the pressure of intake air taken into each combustion chamber of the engine body 3 through the intake passage 6 and the intake manifold 4.

In order to recirculate a part of the exhaust gas discharged from the engine body 3 to the intake air taken into the engine body 3, that is, to perform exhaust gas recirculation (EGR), the intake passage 6 and the exhaust gas are exhausted. An EGR passage 11 that connects the both 6 and 7 is provided between the passage 7 and the passage 7. An EGR valve 12 that opens and closes the EGR passage 11 is provided in the middle of the EGR passage 11. And these E
With the GR passage 11 and the EGR valve 12, the EGR device 13
Is configured. The EGR valve 12 is a diaphragm type negative pressure operated valve. The EGR valve 12 includes a valve body 12a for opening and closing the EGR passage 11, a diaphragm 12b connected to the valve body 12a, a negative pressure chamber 12c partitioned by the diaphragm 12b, and a diaphragm 12c disposed in the negative pressure chamber 12c.
It is composed of a spring 12d for urging b. Then, in the state where the negative pressure is not introduced into the negative pressure chamber 12c, the diaphragm 12b is biased by the spring 12d, and the valve body 12a is arranged at a position to close the EGR passage 11. That is, the EGR valve 12 is closed. On the other hand, when the negative pressure is introduced into the negative pressure chamber 12c, the diaphragm 12b is pulled by the negative pressure and displaced, so that the valve body 12a becomes EGR.
It is arranged at a position where the passage 11 is opened. That is, the EGR valve 1
2 is opened.

The negative pressure chamber 12c of the EGR valve 12 is connected through a negative pressure passage 14 to a first vacuum switching valve (first VSV) 15 which can form a pressure switching valve. The first VSV 15 is a three-system solenoid valve having an input port, an output port and an atmosphere port, and one end of the negative pressure passage 14 is connected to the output port.
The input port of the first VSV 15 is connected to the negative pressure passage 16
Through an electric vacuum regulating valve (EVRV) 17 as a pressure regulating valve. A known vacuum damper 18 is provided in the middle of the negative pressure passage 16.
The EVRV 17 is a solenoid valve whose opening is adjusted by duty control, and its input port is connected through a negative pressure passage 19 to a vacuum pump 20 which is a negative pressure generation source. The vacuum pump 20 is drivingly connected to the crankshaft of the engine body 3, and
The negative pressure is supplied to the EVRV 17 by being driven in conjunction with the operation of.

When the first VSV 15 is turned on, the negative pressure chamber 12c of the EGR valve 12 is moved to the negative pressure passage 1
4, through the first VSV 15 and the negative pressure passage 16, etc.,
It is connected to the output port of VRV17. At this time, the negative pressure supplied from the vacuum pump 20 to the EVRV 17 is the negative pressure passage 1 by opening the EVRV 17.
6, through the first VSV 15 and the negative pressure passage 14, etc.
It is supplied to the negative pressure chamber 12c of the R valve 12. Further, the vibration of the negative pressure supplied to the negative pressure chamber 12c at this time is smoothed by the action of the vacuum damper 18. On the other hand, when the first VSV 15 is turned off, the negative pressure chamber 12c of the EGR valve 12 is opened to the atmosphere through the negative pressure passage 14.

In addition, the engine body 3 is provided with a water temperature sensor 41 for detecting the temperature (cooling water temperature) THW of the cooling water. The fuel injection pump 2 is a distribution type and is drivingly connected to a crankshaft of the engine body 3. A drive shaft is provided inside the fuel injection pump 2, and the drive shaft is connected to the plunger via a cam mechanism. Then, the drive shaft of the fuel injection pump 2 is rotated in conjunction with the crank shaft, so that the plunger is reciprocated by the same number as the number of cylinders of the engine body 3 during one rotation of the drive shaft to discharge the fuel. The fuel is pumped to the fuel injection nozzle for each cylinder.

The fuel injection pump 2 has an accelerator lever 2 which is rotated in association with the operation of an accelerator pedal (not shown).
1 is provided. The accelerator lever 21 is connected to a spill ring (not shown) on the plunger. Then, by appropriately changing the rotational position of the accelerator lever 21, that is, the accelerator lever opening ACCP, the position of the spill ring is changed and the effective stroke of the plunger is changed, so that the maximum fuel injection from the fuel injection pump 2 is changed. The quantity is determined.

A lever sensor 42, which is a rotary position sensor for detecting the accelerator lever opening ACCP, is provided near the accelerator lever 21. In this lever sensor 42, the Alcel lever 21
Accelerator lever opening ACC with full opening of "100%"
P is detected. Further, the fuel injection pump 2 is provided with a rotation speed sensor 43 for detecting the rotation speed of the crankshaft of the engine body 3, that is, the engine rotation speed NE from the rotation of the drive shaft thereof.

The fuel injection pump 2 has a boost and altitude compensation stopper (BACS) for controlling the maximum fuel injection amount according to the supercharging pressure PiM in the engine body 3 and the like, hereinafter simply referred to as "boocon". 22) is provided. This boocon 2
2 includes a diaphragm 22a, and the diaphragm 22a
It has two rooms divided by a into upper and lower parts. The diaphragm 22a has a stopper rod 22b.
Has one end fixed, and the rod 22b is connected to the spill ring described above via a governor mechanism (not shown). Here, the upper chamber partitioned by the diaphragm 22a is a supercharging pressure chamber 23 into which supercharging pressure is introduced, and the lower chamber is a negative pressure chamber 24 into which negative pressure or atmospheric pressure is introduced. ing. The diaphragm 22a is displaced by the relationship between the pressure in the supercharging pressure chamber 23 and the pressure in the negative pressure chamber 24. Therefore, the vertical position of the stopper rod 22b, which is determined by the displacement of the diaphragm 22a, restricts the movement of the spill ring in the fuel increasing direction, and determines the maximum fuel injection amount from the fuel injection pump 2.

Since the detailed configuration of the boocon 22 is basically the same as that disclosed in, for example, Japanese Patent Laid-Open No. 2-61330, detailed description thereof will be omitted here.

The supercharging pressure chamber 23 of the boocon 22 is communicated with the intake passage 6 through the supercharging pressure passage 25. As a result, the boost pressure boosted by the compressor 8 is introduced into the boost pressure passage 25. Further, the negative pressure chamber 24 of the boocon 22 is connected to a second VSV 27 that can form a pressure switching valve through a negative pressure passage 26. Second VSV
Reference numeral 27 is a three-system solenoid valve having an input port, an output port and an atmosphere port, and one end of the negative pressure passage 26 is connected to the output port. Also, the second VSV2
The input port of 7 is connected to the EVRV 17 through the negative pressure passage 28.
Connected to the output port of.

Then, when the second VSV 27 is turned on, the negative pressure chamber 24 of the boocon 22 is moved to the negative pressure passage 26,
Through the second VSV 27 and the negative pressure passage 28, the EVRV
It is connected to 17 output ports. At this time, the negative pressure supplied from the vacuum pump 20 to the EVRV 17 is EV
When the RV 17 is opened, it is supplied to the negative pressure chamber 24 of the boocon 22 through the negative pressure passage 28, the second VSV 27 and the negative pressure passage 26. On the other hand, when the second VSV 27 is turned off, the negative pressure chamber 24 of the boocon 22 becomes
It is opened to the atmosphere through the negative pressure passage 26.

In this embodiment, in order to detect the above-mentioned supercharging pressure PiM in the supercharging pressure passage 25 and the control negative pressure CNP as the adjusting pressure in the negative pressure passage 16, one of the pressure detecting means is constituted. An intake pressure sensor 44 is provided. Further, in order to selectively detect the supercharging pressure PiM or the control negative pressure CNP by the intake pressure sensor 44, a third VSV 29 as a switching valve for detection is provided. Third V
The SV 29 is a three-way solenoid valve having two input ports and one output port, one input port is connected to the supercharging pressure passage 25 through the communication passage 30, and the other input port is the communication passage 31. Through the negative pressure passage 16. The remaining output ports are connected to the intake pressure sensor 44 through the communication passage 32.

When the third VSV 29 is turned on, the intake pressure sensor 44 causes the communication passage 32, the third VS.
It communicates with the supercharging pressure passage 25 through the V 29 and the communication passage 30. As a result, the intake pressure sensor 44 detects the supercharging pressure PiM applied to the supercharging pressure passage 25. Also, the third
When the VSV 29 of is turned off, the intake pressure sensor 4
4 is communicated with the negative pressure passage 16 through the communication passage 32, the third VSV 29, and the communication passage 31. As a result, in the intake pressure sensor 44, the control negative pressure CNP applied to the negative pressure passage 16 is obtained.
Is detected. Further, since the EVRV 17 is opened, the control negative pressure CNP becomes zero, and the intake pressure sensor 44
At, the atmospheric pressure PA is detected.

In the present embodiment, in order to detect the operating state of the diesel engine 1, in addition to the water temperature sensor 41, the lever sensor 42, the rotation speed sensor 43, etc., the traveling speed (vehicle speed) SPD of the automobile is detected. Vehicle speed sensor 4 for
5 are provided. The vehicle speed sensor 45 is provided in an automatic transmission (not shown), and detects the vehicle speed SPD from the rotation of the gear of the automatic transmission. Further, the automatic transmission is provided with a shift position sensor 46 that outputs a signal instructing the shift position ShP. In the present embodiment, these various sensors 41 to 46 and the like constitute an operating state detecting means.

In addition, in this embodiment, the operating state of the turbocharger 10, that is, the "effectiveness" of the turbocharger 10
A turbo indicator 33 is provided in the driver's seat to notify the driver of the. This turbo indicator 33
Is a green lamp (GL) 34 and an amber lamp (A
L) 35. The green lamp 34 is turned on to inform that the "effectiveness" of the turbocharger 10 is normal. On the other hand, the amber lamp 35 is turned on to notify that the "effectiveness" of the turbocharger 10 is excessive and abnormal.

In this embodiment, the EVRV described above is used.
17, each VSV 15, 27, 29 and each lamp 34, 3
Each of 5 is drive-controlled by an electronic control unit (hereinafter simply referred to as “ECU”) 47. In the present embodiment, the ECU 47 constitutes a control area determination means, a switching control means, a priority determination means, and a time sharing adjustment means. The ECU 47 includes a central processing unit (CPU), various memories that pre-store a predetermined control program and the like and a primary storage of the calculation result of the CPU, and these units, an external input circuit, an external output circuit, and the like. It is configured as a logical operation circuit connected by. In this embodiment, the CPU also has the function of a counter. The water temperature sensor 41, the lever sensor 42, the rotation speed sensor 43, the intake pressure sensor 44, the vehicle speed sensor 45, the shift position sensor 46, and the like are connected to the external input circuit of the ECU 47.
In addition, the external output circuit of the ECU 47 has the above-mentioned EVR.
V17, each VSV15, 27, 29 and each lamp 34,
35 and the like are respectively connected. Since the detailed electrical configuration of the ECU 47 is well known, its description is omitted here.

Next, the contents of the processing operations executed by the ECU 47 in the diesel engine system with a supercharger configured as described above will be described. Figure 3 is E
It is a flow chart explaining "atmospheric pressure learning * EGR * BACS control routine" which is one of the processing contents performed by CU47, and is performed for every predetermined time interval.

When the processing shifts to this routine, first, at step 110, the cooling water temperature THW, the accelerator lever opening ACCP, the engine speed NE, the supercharging pressure PiM, based on the detection signals from the various sensors 41 to 46, etc. The control negative pressure CNP, the vehicle speed SPD, the shift position ShP, etc. are read.

Next, at step 120, the region of the present operating state is calculated based on the accelerator lever opening ACCP and the engine speed NE which are read this time.
That is, based on the accelerator lever opening ACCP and the engine speed NE, it is calculated whether or not the current operating region is the “BACS control region” in which the boocon 22 should control the maximum fuel injection amount. In addition, the EGR device 13 is in the “EGR control region” in which the EGR flow rate should be controlled, or E
It is calculated whether it is the “atmospheric pressure learning region” in which the learning of the atmospheric pressure PA should be performed without controlling the GR flow rate. This calculation is shown in FIG.
As shown in FIG. 5, the process is performed with reference to a map which is predetermined by the relationship between the engine speed NE and the accelerator lever opening ACCP and stored in the memory.

Then, in step 130, it is determined whether or not the result of the area calculation is the "atmospheric pressure learning area". Here, when the result of the area calculation is the "atmospheric pressure learning area", the process proceeds to step 200 to execute learning control of the atmospheric pressure PA.

In step 200, the second VSV
27 and the third VSV 29 are turned off, and the first VS
V15 is turned on. Further, the EVRV 17 is fully closed to set its output negative pressure to zero (atmospheric pressure PA). Therefore, the intake pressure sensor 44 includes the EVRV 17 and the communication passage 3
Atmospheric pressure P through the first and third VSVs 29 and the communication passage 32
A acts, and the intake pressure sensor 44 detects the atmospheric pressure PA. Then, in step 210, learning control of the magnitude of the detected atmospheric pressure PA is executed. Here, detailed description of the processing content for the learning control of the atmospheric pressure PA will be omitted. And step 210
After the processing of (1) is finished, the subsequent processing is once finished.

On the other hand, if the result of the area calculation is not the "atmospheric pressure learning area" in step 130, the process proceeds to step 140 and it is determined whether the result of the area calculation is the "EGR control area". . Here, when the result of the area calculation is the “EGR control area”, the process proceeds to step 300 to execute the normal EGR control.

In step 300, the second VSV
27 and the third VSV 29 are turned off, and the first VS
V15 is turned on. Then, in step 310, normal EGR control is executed. That is, EVRV1
The opening degree of 7 is duty-controlled. This allows EVRV
At 17, the negative pressure from the vacuum pump 20 is adjusted and output as the control negative pressure CNP. Then, the control negative pressure CNP is introduced into the negative pressure chamber 12c of the EGR valve 12 through the negative pressure passage 16, the first VSV 15 and the negative pressure passage 14, and the EGR valve 12 is responsive to the magnitude of the control negative pressure CNP. The valve is opened with a large opening. That is, the EGR flow rate flowing through the EGR passage 11 is controlled. At this time, in the intake pressure sensor 44, the control negative pressure CNP acts through the communication passage 31, the third VSV 29, and the communication passage 32, and the intake pressure sensor 44 detects the control negative pressure CNP. Then, the opening degree of the EVRV 17 is feedback-controlled based on the detected control negative pressure CNP. Here, detailed description of the processing contents of the EGR control is omitted. Then, after the processing of step 310 is completed, the subsequent processing is once completed.

On the other hand, in step 140, if the result of the area calculation is not the "EGR control area", "BAC"
Assuming that it is the "S control area", the process proceeds to step 400 to execute the BACS control. In step 400, the second VSV 27 is turned on and the first VSV 27 is turned on.
Turn 15 off. As a result, the output port of the EVRV 17 is communicated with the negative pressure chamber 24 of the boocon 22 through the negative pressure passage 28, the second VSV 27 and the negative pressure passage 26. Further, the intake pressure sensor 44 includes a supercharging pressure passage 25,
The supercharging pressure PiM acts through the communication passage 30, the third VSV 29, and the communication passage 32, or the control negative pressure CNP acts through the EVRV 17, the communication passage 31, and the communication passage 32. Boost pressure Pi
M or control negative pressure CNP is detected. Then, in step 410, E is basically determined based on the control negative pressure CNP.
By duty-controlling the opening of VRV17, B
Execute ACS control. As a result, in the EVRV 17, the negative pressure from the vacuum pump 20 is adjusted and output as the control negative pressure CNP. Then, the control negative pressure C
NP is introduced into the negative pressure chamber 24 of the boocon 22 through the negative pressure passage 28, the second VSV 27 and the negative pressure passage 26,
The boocon 22 operates according to the magnitude of the control negative pressure CNP, and the maximum fuel injection amount from the fuel injection pump 2 is determined. At this time, the "effectiveness" of the turbocharger 10 is determined according to the magnitude of the supercharging pressure PiM detected by the intake pressure sensor 44 by time sharing, and the lighting of the turbo indicator 33 is controlled according to the determination result. To be done. These controls will be described later in detail. Then, after the processing of step 410 is completed, the subsequent processing is once completed.

Now, FIG. 5 is a flowchart for explaining the "BACS control region pressure detection routine" separately executed by the ECU 47, which is executed at predetermined time intervals.
When the processing shifts to this routine, first, step 501
In accordance with the detection signals from the various sensors 41 to 46, etc., the engine speed NE, the accelerator lever opening AC
CP, cooling water temperature THW, atmospheric pressure PA, etc. are read respectively.

Next, in step 502, the current operating state is calculated, and the result of the area calculation is "B
It is determined whether or not it is the “ACS control area”. If the current time is not "BACS control area", step 5
Move to 04.

In step 504, BACS control is not performed, and B is assumed to be irrelevant to this control.
The ACS flag XT1 is set to "0", and the subsequent processing is temporarily terminated.

If the result of the area calculation relating to the current operating state is the "BACS control area", the routine proceeds to step 503. In step 503, BA
It is determined whether or not the state in which the CS flag XT1 is "1" is continuing. This BACS flag XT1
Is set to "1" when the current operating state is in the "BACS control region", and is set to "0" otherwise.

If the BACS flag XT1 is still in the state of "1", the step 50 described later will be performed.
Jump to 7. On the other hand, when the state in which the BACS flag XT1 is “1” is not continued, step 5
At 05, the BACS flag XT1 is set to "1". Further, in the following step 506, the cooling water temperature THW and the atmospheric pressure PA at the time point when the BACS flag XT1 is set to "1" and a predetermined time (for example, "300" seconds) are read back, and these are respectively subjected to initial cooling. Set as water temperature THW0 and initial atmospheric pressure PA0.

At step 507, the current cooling water temperature T is reached after shifting from step 503 and step 506.
It is determined whether a value obtained by subtracting the initial cooling water temperature THW0 from HW is larger than a predetermined reference value THW1.
Along with this, the current atmospheric pressure PA and the initial atmospheric pressure P
It is determined whether the difference from A0 is larger than a predetermined reference value PA1. Here, if the value obtained by subtracting the initial cooling water temperature THW0 from the current cooling water temperature THW is larger than the reference value THW1, it can be determined that the diesel engine 1 is currently warming up. Further, when the difference between the current atmospheric pressure PA and the initial atmospheric pressure PA0 is larger than the reference value PA1, it can be determined that the environment is changing suddenly (for example, when moving from a lowland to a highland).

If at least one of these two judgment results is affirmative, it is determined that the present time is warming up or a sudden environmental change, and the routine proceeds to step 508. In step 508, in order to prioritize the feedback control of the control negative pressure CNP, the processing of case 1 described later is executed, and the subsequent processing is temporarily ended. If both of the determination results are negative, it is determined that the present is not warm-up time or sudden environmental change, and the process proceeds to step 509. In step 509, in order to prioritize the detection of the supercharging pressure PiM, the processing of case 2 described later is executed, and the subsequent processing is temporarily ended.

Thus, "atmospheric pressure learning / EGR / BA
In addition to the processing of the "CS control routine", the processing of the "BACS control region pressure detection routine" is executed. Here, the contents of the processing performed by the ECU 47 in Case 1 and Case 2 will be described with reference to the timing charts of FIGS. 6 and 7. First, in case 1, as shown in FIG. 6, when the time when the BACS flag XT1 is set from “0” to “1” is time t1, the time when a predetermined time (for example, 30 seconds) has elapsed from the time t1. At t2, the ECU
47 sets the supercharging pressure detection flag XT2 which has been set to "0" until then to "1". Then, at a time t3 when a predetermined time (for example, 15 seconds) has elapsed from the time t2, the supercharging pressure detection flag X which has been set to "1" until then.
Set T2 to "0". Further, at time t4 when a predetermined time (for example, 15 seconds) has elapsed from the time t3, the supercharging pressure detection flag XT2, which has been set to "0" until then, is set to "1" again. Further, at a time t5 when a predetermined time (for example, 30 seconds) has elapsed from the time t4, the supercharging pressure detection flag XT2 which has been set to "1" until then is set to "0". Furthermore, at time t6 when a predetermined time (for example, 15 seconds) has elapsed from the time t5, the supercharging pressure detection flag XT2, which has been set to "0" until then, is set to "1", and the predetermined time has elapsed from the time t6. (Eg 1
At time t7 when 5 seconds have elapsed, the supercharging pressure detection flag XT2, which has been set to "1" until then, is set to "0". Then, the time t7 is regarded as the time t1 and the series of processes is repeated.

Further, the ECU 47 controls on / off switching of the third VSV 29 based on the boost pressure detection flag XT2 set as described above. That is, while the boost pressure detection flag XT2 is "0" (t1 to t2, t3 to.
At t4, t5 to t6), the third VSV 29 is turned off. Then, the third VSV 29 is switched to “OFF”, so that the intake pressure sensor 44 is moved to the communication passage 32, the third.
It is communicated with the negative pressure passage 16 through the VSV 29 and the communication passage 31. This allows the intake pressure sensor 44 to detect the control negative pressure CNP applied to the negative pressure passage 16. On the other hand, while the supercharging pressure detection flag XT2 is "1" (t2 to t3, t4 to t5, t6 to t7), the third VSV 29 is turned on. And the third VS
When the V29 is switched to "OFF", the intake pressure sensor 44 causes the communication passage 32, the third VSV 29, and the communication passage 3 to move.
0 to the supercharging pressure passage 25. This allows the intake pressure sensor 44 to detect the supercharging pressure PiM applied to the supercharging pressure passage 25.

Actually, as shown in the figure, the control negative pressure C
NP detection and supercharging pressure PiM detection are performed by the third VSV2.
It is allowed after a predetermined time α (for example, 3 seconds) has elapsed since the time 9 was switched. This is to secure the time until the control negative pressure CNP or the supercharging pressure PiM becomes stable after the switching. Therefore, the control negative pressure CNP is from time t1 + α to time t2, from time t3 + α to time t4, and from time t5 + α to time t6.
Is permitted, and feedback control for the control negative pressure CNP is performed. Further, at other times, detection of the control negative pressure CNP is prohibited, and feedback control regarding the control negative pressure CNP is not performed.
On the other hand, from time t2 + α to time t3, time t4 +
From α to time t5 and from time t6 + α to time t7
Until the boost pressure PiM is detected, the boost pressure PiM is detected.
A determination as to the size of M will be made. Further, at other times, detection of the boost pressure PiM is prohibited.

For the detection of the supercharging pressure PiM, the following processing is performed, for example. That is, the ECU 47
Indicates that the detected boost pressure PiM is the turbo indicator 33.
It is determined whether or not it is larger than the minimum value P1 at which the green lamp 34 of No. 1 should be turned on. Then, when the supercharging pressure PiM is not larger than the minimum value P1, the ECU 47 turns off the green lamp 34 and the amber lamp 35, respectively.

When the supercharging pressure PiM is larger than the minimum value P1, the ECU 47 determines that the supercharging pressure PiM is the minimum value P2 (P2> P1) at which the amber lamp 35 should be turned on.
Is greater than or equal to. Here, the boost pressure PiM
Is greater than the minimum value P2, the ECU 47 determines that the "effectiveness" of the turbocharger 10 is excessive and abnormal, and there is a risk of supercharging, and notifies the driver of that fact by the amber. The lamp 35 is turned on. When the supercharging pressure PiM is not larger than the minimum value P2, the ECU 47 determines that the "effect" of the turbocharger 10 is normal, and turns on the green lamp 34 to inform the driver of that. Turn on the light.

Next, the contents of processing performed by the ECU 47 of Case 2 will be described. As shown in FIG. 7, at time t1 when the BACS flag XT1 is set from “0” to “1”, the ECU 47 sets the supercharging pressure detection flag XT2, which has been set to “0” until then, to “1”. Set. Then, at a time t2 when a predetermined time (for example, 30 seconds) has elapsed from the time t1, the supercharging pressure detection flag XT2, which has been set to "1" until then, is set to "0". Also, the time t
At a time t3 when a predetermined time (for example, 15 seconds) has elapsed from 2, the supercharging pressure detection flag XT2, which has been set to "0" until then, is set to "1" again. Further, the time t3
At time t4 when a predetermined time (for example, 15 seconds) has elapsed from that, the supercharging pressure detection flag X that has been set to "1" until then
Set T2 to "0". Furthermore, at a time t5 when a predetermined time (for example, 30 seconds) has elapsed from the time t4, the supercharging pressure detection flag X that has been set to “0” until then.
Set T2 to "1". At a time t6 when a predetermined time (for example, 15 seconds) has elapsed from the time t5, the supercharging pressure detection flag XT2 which has been set to "1" until then is "0".
Is set to a predetermined time (for example, 15 seconds) from the time t6.
At the elapsed time t7, the supercharging pressure detection flag XT2, which has been set to "0" until then, is set to "1". Then, the time t7 is regarded as the time t1 and the series of processes is repeated.

Further, as in the case 1, the ECU 47 controls the on / off switching of the third VSV 29 based on the boost pressure detection flag XT2 set as described above.
That is, while the supercharging pressure detection flag XT2 is "0" (t2 to t3, t4 to t5, t6 to t7), the third value is set.
Turn off the VSV29 of. And the third VSV
29 is switched to “OFF”, so that the intake pressure sensor 44 causes the communication passage 32, the third VSV 29, and the communication passage 31.
Through the negative pressure passage 16. As a result, in the intake pressure sensor 44, the control negative pressure C applied to the negative pressure passage 16 is obtained.
The NP can be detected. On the other hand, while the supercharging pressure detection flag XT2 is "1" (t1 to t2, t3 to
At t4, t5 to t6), the third VSV 29 is turned “on”. Then, the third VSV 29 is switched to “OFF”, so that the intake pressure sensor 44 is moved to the communication passage 32, the third.
Through the VSV 29 and the communication passage 30 of
Be communicated to. This allows the intake pressure sensor 44 to detect the supercharging pressure PiM applied to the supercharging pressure passage 25.

However, as in case 1, in practice,
The control negative pressure CNP and the supercharging pressure PiM are detected by the third
Is allowed after a predetermined time α has elapsed since the VSV 29 of was switched. Therefore, from time t2 + α to time t3, from time t4 + α to time t5 and at time t
From 6 + α to time t7, detection of the control negative pressure CNP is permitted, and feedback control regarding the control negative pressure CNP is performed. At other times, the detection of the control negative pressure CNP is prohibited, and the control negative pressure CNP is detected.
Feedback control is not performed. On the other hand, from time t1 + α to time t2, from time t3 + α to time t4, and from time t5 + α to time t6, detection of the supercharging pressure PiM is permitted, and the determination of the magnitude of the supercharging pressure PiM is made. Will be done. Further, at other times, detection of the boost pressure PiM is prohibited.

As described above, according to this embodiment,
Learning control of atmospheric pressure PA, normal EGR control, or BACS control is executed in accordance with the operating region of diesel engine 1. Further, according to the present embodiment, in parallel with the above control, the detection of the control negative pressure CNP and the detection of the supercharging pressure PiM are executed in the BACS control region.
That is, the control negative pressure CNP and the supercharging pressure PiM are alternately detected by time sharing with one cycle from time t1 to time t7. Here, in the present embodiment, the priorities for the detection of the control negative pressure CNP and the supercharging pressure PiM are determined according to the operating state at that time. That is, the cooling water temperature THW and the atmospheric pressure PA
Is calculated, and it is determined based on the calculation result whether or not the present time is warming up or a sudden change in environment.

If the present time is warming up or a sudden environmental change, the process of case 1 is executed and the control negative pressure CN
Feedback control of P is preferentially performed. here,
Since the detection permission time of the total control negative pressure CNP and the detection permission time of the supercharging pressure PiM in one cycle are equal to each other, it may be considered that priority is not ensured at first glance. However, first, the feedback control of the control negative pressure CNP is performed first, and further, the BACS control region is unlikely to continue for more than one cycle (for example, 120 seconds).
It can be said that the priority of detection of the control negative pressure CNP in the S control region is secured. If the present time is not during warm-up or when there is a sudden change in environment, the process of Case 2 is executed, and the supercharging pressure PiM is detected with priority.

Therefore, when the operating state is in the BACS control region, the intake pressure sensor 44 is used between the control negative pressure CNP and the supercharging pressure PiM with the priority according to the operating state at that time. Each pressure will be detected. Therefore, in an operating state in which the accuracy of the feedback control of the control negative pressure CNP is required, the decrease in the accuracy can be surely suppressed, and the smoke is not generated when the vehicle is running at high altitude or when starting. Can be prevented. Further, in the operating state in which the accurate determination of the magnitude of the supercharging pressure PiM is required, the supercharging pressure PiM can be accurately detected. As a result, the supercharging can be suppressed more reliably, and the supercharging pressure P
Turbo indicator 3 even if iM is abnormal
By turning on 3, the driver can be promptly notified of the abnormality.

The present invention is not limited to the above embodiment, but may be configured as follows, for example. (1) In the above embodiment, when the value obtained by subtracting the initial cooling water temperature THW0 from the current cooling water temperature THW is larger than the reference value THW1, it is determined that the diesel engine 1 is currently warming up, and the current large Atmospheric pressure PA and initial atmospheric pressure PA0
When the difference between and is larger than the reference value PA1, it is determined that the environment is at a sudden change. If at least one of these two judgment results is affirmative, it is assumed that the present time is warming up or a sudden environmental change, and feedback control of the control negative pressure CNP is prioritized. If it is not, it is determined that the present is not the time of warm-up or the time of sudden environmental change, and the detection of the supercharging pressure PiM is prioritized. On the other hand, it is determined whether or not the current operating state is high rotation / high load, and when the high rotation / high load is detected, the boost pressure PiM is prioritized to be detected. The feedback control of the pressure CNP may be prioritized.

(2) The control contents of Case 1 and Case 2 in the above embodiment are merely one specific example,
The control is not necessarily limited to this. That is, the control content can be freely determined as long as the time sharing is adjusted in consideration of the priority of detection of the control negative pressure CNP or the supercharging pressure PiM.

(3) In the above embodiment, each control of the "atmospheric pressure learning region", the "BACS control region" and the "EGR control region" in the diesel engine equipped with the EGR device 13 has been described. On the other hand, in a diesel engine with a supercharger that does not include the EGR device 13, for example, an electronically controlled diesel engine, it may be embodied in a case where the operation state of the supercharger is simply determined and the boocon 22 is controlled. it can.

(4) In each of the above embodiments, the diesel engine 1 having the turbocharger 10 as the supercharger is embodied, but it may be embodied as a diesel engine having a supercharger or other supercharger. Good.

The technical idea which is not described in each claim of the claims and which can be understood from the above-mentioned embodiment will be described below together with its effect. (A) In the supercharging pressure detection device for a diesel engine with a supercharger according to any one of claims 1 to 4, the time sharing adjusting means constituting the switching control means gives priority to control of the magnitude of the adjusted pressure. In this case, the pressure regulating valve and the pressure detecting means are communicated with each other first, and when the operation state of the supercharger is prioritized, the supercharger and the pressure detecting means are communicated with each other. The feature is that it is done first.

With such a structure, priority can be secured even when the operating state is in the fuel injection amount compensation control region for a relatively short period.

[0075]

As described in detail above, according to the present invention,
The fuel injection pump operates by operating according to the supercharging pressure introduced into the supercharging pressure chamber with the operation of the supercharger and the regulating pressure introduced into the pressure chamber with the opening adjustment of the negative pressure regulating valve. In a supercharging pressure detection device for a diesel engine with a supercharger, which comprises an injection amount compensating device for compensating the fuel injection amount of
The adjusted pressure and the supercharging pressure can be appropriately detected according to the operating state, and thus it is possible to avoid a decrease in the control accuracy of the regulated pressure and a delay in the determination of the operating state of the supercharging pressure. Produce an effect.

In particular, according to the invention described in claim 2, in addition to the above-mentioned effects, in the case where supercharging is concerned, for example, at the time of high rotation and high load, more reliably and It is possible to quickly avoid a delay in determining the operating state of the boost pressure.

According to the invention described in claim 3, in addition to the above effects, when the diesel engine is warming up or when there is a rapid change in the environment,
When there is a concern that smoke may be generated due to the operation of the injection amount compensation device, it is possible to further improve the control accuracy of the adjusted pressure.

Further, according to the invention described in claim 4,
In addition to the above effects, the number of component parts of the device is reduced,
Therefore, the cost can be remarkably reduced.

[Brief description of drawings]

FIG. 1 is a conceptual configuration diagram illustrating a basic conceptual configuration of the present invention.

FIG. 2 is a schematic configuration diagram showing a supercharging pressure detection device for a diesel engine.

[Fig. 3] "Atmospheric pressure learning / EGR executed by the ECU
Is a flowchart showing a "BACS control routine".

FIG. 4 is a map for determining various control areas.

FIG. 5 is a flowchart showing a “BACS control region pressure detection routine” executed by the ECU.

[Fig. 6] Prohibition of detection of supercharging pressure and control negative pressure in case 1
6 is a timing chart showing permission.

FIG. 7 is a timing chart of case 2 as well.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Diesel engine, 2 ... Fuel injection pump, 3 ... Engine main body, 6 ... Intake passage, 7 ... Exhaust passage, 10 ... Turbocharger as supercharger, 11 ... EGR passage, 12
... EGR valve, 15 ... First VS that can constitute a pressure switching valve
V, 17 ... EVRV constituting pressure adjusting valve, 20 ... Vacuum pump as negative pressure generating source, 22 ... Bocon as injection amount compensating device, 23 ... Supercharging pressure chamber, 24 ... Negative pressure chamber,
27 ... A second VSV capable of constituting a pressure switching valve, 27 ... A third VSV constituting a detecting switching valve, 41 ... A water temperature sensor constituting an operating state detecting means, 42 ... A lever constituting an operating state detecting means Sensors, 43 ... Rotation speed sensor constituting driving state detecting means, 44 ... Intake pressure sensor constituting driving state detecting means and pressure detecting means, 45 ... Vehicle speed sensor constituting driving state detecting means, 46 ... Driving state detecting means A shift position sensor, 47 ... Control area determination means,
An ECU that constitutes a switching control means, a priority determination means, and a time sharing adjustment means.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location F02D 41/04 380 B 45/00 364 E

Claims (4)

[Claims] 1. A supercharger for boosting the intake air taken into an engine body of a diesel engine through an intake passage, a fuel injection pump for pressure-feeding fuel to the engine body, and a supercharger communicating with the supercharger. A pressure chamber and a pressure chamber communicating with a negative pressure source are provided, and the supercharging pressure introduced into the supercharging pressure chamber along with the operation of the supercharger and the pressure introduced into the pressure chamber. And a negative pressure introduced into the pressure chamber of the injection amount compensating device, which communicates with the injection amount compensating device for compensating the fuel injection amount of the fuel injection pump, and adjusts the negative pressure introduced into the pressure chamber of the injection amount compensating device. A pressure control valve that is opened and closed for the purpose of being opened to atmospheric pressure, and a pressure switching valve that is switched to selectively introduce the regulated pressure from the pressure control valve side or atmospheric pressure into the pressure chamber, The pressure regulating valve and the supercharging One pressure detecting means for detecting one of the pressures, communication between the pressure regulating valve and the pressure detecting means, and communication between the supercharger and the pressure detecting means are selectively performed. Switching valve for detecting the operating state of the engine body, operating state detecting means for detecting the operating state of the engine body, based on the detection result of the operating state detecting means, the operating state of the engine body at that time, the fuel injection amount compensation A control region determining means for determining whether or not it is in a control region, and a control of the magnitude of the adjusted pressure and the supercharger when at least the determination result of the control region determining means is in the fuel injection amount compensation control region. In order to determine the operating state of, the detection switching valve is switch-controlled by time sharing to selectively detect the adjusted pressure and the supercharging pressure by the pressure detecting means. A supercharging pressure detection device for a diesel engine with a supercharger, comprising: a switching control means configured to change, wherein the switching control means is based on a detection result of the operating state detection means, and the magnitude of the adjusted pressure. When the priority determination means for determining the priority of the control and the determination of the operating state of the supercharger and the control of the magnitude of the adjusted pressure are determined to have higher priority by the priority determination means. In order to give priority to the control of the magnitude of the regulated pressure, the opportunity of communication between the pressure regulating valve and the pressure detecting means is prioritized, and it is determined that the determination of the operating state of the supercharger has higher priority. In the case where the supercharger is operated, the supercharger includes a time-sharing adjusting means for giving priority to an opportunity of communication between the supercharger and the pressure detecting means in order to give priority to the determination of the operating state of the supercharger. Diesel engine with feeder Down of the supercharging pressure detector. 2. The supercharging pressure detection device for a diesel engine with a supercharger according to claim 1, wherein the priority determination means is configured to operate by the operation state detection means.
When at least one of the rotation speed and the load of the diesel engine and the rate of change thereof exceeds a predetermined reference value, it is determined that the control of the magnitude of the adjusted pressure has a higher priority. Supercharging pressure detection device for diesel engine with supercharger. 3. The supercharging pressure detecting device for a diesel engine with a supercharger according to claim 1 or 2, wherein the priority determining means determines that the detection result of the operating state detecting means indicates that the diesel engine is warming up. When it is time or when there is a sudden change in the environment,
A supercharging pressure detection device for a diesel engine with a supercharger, characterized in that it is determined that the determination of the operating state of the supercharger has a higher priority. 4. The supercharging pressure detection device for a diesel engine with a supercharger according to claim 1, wherein the diesel engine further includes an exhaust passage through which exhaust gas from the engine body flows. An exhaust gas recirculation passage that communicates with the intake passage, and the exhaust gas recirculation passage are provided. When the atmospheric pressure is introduced, the exhaust gas recirculation passage is closed, and a negative pressure is generated from the negative pressure generation source. When introduced, the exhaust gas recirculation passage is opened according to its negative pressure, and a recirculation amount adjusting valve for adjusting the recirculation amount of the exhaust gas flowing through the passage is provided, and the pressure adjusting valve is It is connected to the negative pressure generation source and opened / closed to adjust the negative pressure introduced into the pressure chamber of the injection amount compensation device or the recirculation amount adjusting valve, and can be opened to the atmospheric pressure. And the above The control area determination means is based on the detection result of the operation status detection means, and the operating state of the engine body at that time is an exhaust gas recirculation control area, a fuel injection amount compensation control area, and other areas. A supercharging pressure detection device for a diesel engine with a supercharger, characterized in that it determines which of the two.