JPH06257456A - Abnormality detecting device for switching valve - Google Patents

Abstract

PURPOSE:To be capable of detecting not only full-close failure or full-open failure of a switching valve but also the abnormality such as operation delay caused by increase of friction in opening/closing of a valve body. CONSTITUTION:Pressure of a compressed air S to be fed into the diaphragm chamber 16b of a diaphragm actuator 16 from a solenoid valve is detected by a pressure sensor 71, and the presence or absence of abnormality of a switching valve 17 is judged by a judging means 72 on the basis of the change of the pressure of compressed air S to be detected by the pressure sensor 71 when compressed air S is fed into the diaphragm chamber 16b, and then the judged result is displayed on a display means 73.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a switching valve (opening / closing valve) abnormality detecting device having a valve element disposed in a fluid passage.

[0002]

2. Description of the Related Art An engine main body is provided with two main and sub turbochargers in parallel, and in the low intake air amount range, only the main turbocharger is operated to make one turbocharger. There is known a supercharged engine that employs a so-called two-stage turbo system that operates a charger.

In such an engine with a supercharger, intake and exhaust systems are provided with open / close valves, namely, an intake switching valve and an exhaust switching valve, and both the intake switching valve and the exhaust switching valve are fully closed. As a result, only the main turbocharger is supercharged, and both switching valves are fully opened to supercharge both the main and sub turbochargers.

Since the valve body of the exhaust switching valve is exposed to the high-temperature exhaust gas passing through the exhaust passage, the operating environment is severe and
It may be impossible to rotate due to galling or sticking. Therefore, the applicant of the present invention has previously proposed a technique for indirectly detecting an open / close failure of the intake switching valve and the exhaust switching valve by monitoring the change in the boost pressure (Japanese Patent Laid-Open No. 4-166616).
Issue). As a result, the passengers of the vehicle can know the occurrence of the failure of the intake / exhaust gas switching valve at an early stage, and can take appropriate measures.

[0005]

However, since the device disclosed in Japanese Patent Laid-Open No. 4-166616 discloses the occurrence of a failure due to a change in intake pipe pressure (supercharging pressure), switching is performed. Although it is possible to determine whether the valve is fully open or fully closed, partial open / close or delayed operation due to valve malfunction cannot be detected. Therefore, when the opening / closing operation of the switching valve is abnormal, the switching valve cannot be opened / closed at an appropriate timing, which causes a problem in supercharging performance. Such a problem of the switching valve exists not only in the engine with the supercharger but also in other industrial equipment and facilities.

In view of the above problems, the present invention provides a switching valve abnormality detecting device capable of detecting not only a fully closed failure or a fully opened failure of a valve element but also an abnormality such as a delay in operation. To aim.

[0007]

An abnormality detecting device for a switching valve according to the present invention for achieving the above object is provided with a switching valve having a valve body arranged in a passage and a valve body of the switching valve. A diaphragm actuator that opens and closes the valve body by the pressure of compressed air supplied into the diaphragm chamber; a solenoid valve that supplies the compressed air into the diaphragm chamber of the diaphragm actuator; and a solenoid valve that supplies the compressed air into the diaphragm chamber. A pressure sensor that detects the pressure of compressed air, and a determination unit that determines whether or not there is an abnormality in the switching valve based on a change in the pressure of the compressed air detected by the pressure sensor when the solenoid valve is opened. It consists of

[0008]

In the switching valve abnormality detecting device configured as described above, when compressed air is supplied to the diaphragm actuator by opening the solenoid valve, the pressure acting on the diaphragm chamber of the diaphragm actuator is changed by the pressure sensor. Detected. Since the valve body of the switching valve is driven to open and close by the pressure of the compressed air supplied into the diaphragm chamber, the valve body can be driven to open and close at a low pressure when the movement of the valve body of the switching valve is good, and the valve body moves. If it is bad, the valve body can only open and close without high pressure.

As described above, the change in the rise of the pressure in the diaphragm chamber when the compressed air is supplied to the diaphragm actuator corresponds to the quality of the movement of the valve body. Therefore, based on the change in the pressure of the compressed air detected by the pressure sensor, it is possible to determine whether or not there is an abnormality in the switching valve by the determination means.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a switching valve abnormality detecting device according to the present invention will be described below with reference to the drawings. 1 to 4 show an embodiment of the present invention.
It shows the case where it is applied to an exhaust switching valve of a way twin turbo engine.

In FIG. 4, 1 is an engine, 2 is a surge tank, and 3 is an exhaust manifold. The exhaust manifold 3 includes the cylinder groups # 1 to # 3 and the cylinder groups # 4 to # 3 that do not cause exhaust interference.
It is assembled into two of the 6-cylinder group, and the assembly part is connected by the communication passage. Reference numerals 7 and 8 denote a main turbocharger and a sub turbocharger arranged in parallel with each other. The turbines 7 a and 8 a of the turbochargers 7 and 8 are connected to the collecting portion of the exhaust manifold 3. The compressors 7b and 8b of the turbochargers 7 and 8 are the intercooler 6,
It is connected to the surge tank 2 via the throttle valve 4.

The main turbocharger 7 is operated from the low intake air amount region to the high intake air amount region, and the sub turbocharger 8 is stopped in the low intake air amount region. In order to enable both the turbochargers 7 and 8 to operate and stop, the exhaust switching valve 1 is provided downstream of the turbine 8a of the auxiliary turbocharger 8.
7, an intake switching valve 18 is provided downstream of the compressor 8b. When both the intake and exhaust switching valves 18 and 17 are open, both turbochargers 7 and 8 are operated.

The downstream of the turbine 8a of the auxiliary turbocharger 8 and the downstream of the turbine 7a of the main turbocharger 7 are
Communication is possible through the exhaust bypass passage 40.
In the exhaust bypass passage 40, the exhaust bypass passage 40
An exhaust bypass valve 41 for opening and closing is provided. The exhaust bypass valve 41 is opened and closed by a diaphragm actuator 42.

The intake passage 15 is connected to an air cleaner 23 via an air flow meter 24. Exhaust passage 2
The front pipe 20 forming 0a is the exhaust gas catalyst 2
1 to the exhaust muffler. Intake switching valve 18
Is opened and closed by the diaphragm actuator 11,
The exhaust gas switching valve 17 is adapted to be opened and closed by the diaphragm actuator 16. The waste gate valve 31 is adapted to be opened and closed by the diaphragm actuator 9.

A pressure accumulating tank (positive pressure tank) 51 is connected to an intake passage between the compressor downstream of both turbochargers 7 and 8 and the intercooler 6. Accumulation tank 5
1 is provided with a check valve 51a for storing only positive pressure. The volume of the accumulator tank 51 is, for example, 30
It is 0 cc.

Diaphragm actuators 9, 11, 1
6 and 42 are activated by the introduction of supercharging pressure. Each diaphragm actuator 9, 11, 1
In order to selectively switch the supercharging pressure from the pressure accumulating tank 51 and the atmospheric pressure from the downstream of the air flow meter 24, the first, the fourth, the fifth, and the sixth solenoid valves 2 and 6 are provided.
5, 28, 32, 44 are connected. Each solenoid valve 2
Switching of 5, 28, 32, and 44 is performed according to a command from the engine control computer 29 shown in FIG.

Engine control computer 29
Is electrically connected to various operating condition detection sensors of the engine, and signals from the various sensors are input. The engine operating condition detection sensor includes an intake pipe pressure sensor, a throat opening sensor, an air flow meter as an intake air amount measuring sensor, an engine speed sensor, and an oxygen sensor.

Engine control computer 29
Is a central processor unit (CPU) for calculation, a read-only memory (ROM) that is a read-only memory, a random access memory (RAM) for temporary storage, an input / output interface (I / O interface), various sensors It is equipped with an A / D converter that converts the analog signal from the digital signal into a digital value.

As shown in FIG. 1, the valve body 17a of the exhaust switching valve 17 as a switching valve is adapted to be opened / closed by a diaphragm actuator 16. The diaphragm actuator 16 has a diaphragm chamber 16b defined by the diaphragm 16a. A compression spring 16d that presses the diaphragm 16a is provided in the chamber 16c that faces the diaphragm chamber 16b.

A rod 16e extending outward is attached to the other side of the diaphragm 16a. A tip portion of the rod 16e is connected to a valve body 17a arranged in the exhaust passage 20a via a lever 17b of the exhaust switching valve 17.
Diaphragm chamber 16 of diaphragm actuator 16
Compressed air S is introduced into b through the passage 75 from the fourth solenoid valve 28.

Compressed air S is supplied to the fourth solenoid valve 28 from the positive pressure tank 51 through the passage 76. When the fourth solenoid valve 28 is opened, the positive pressure tank 5
The compressed air S from 1 is introduced into the diaphragm chamber 16b of the diaphragm actuator 16 via the fourth electromagnetic valve 28, and the valve body 17a of the exhaust gas switching valve 17 is opened. When the fourth solenoid valve 28 is closed, the compressed air S in the diaphragm chamber 16b is discharged to the atmosphere from the port 28a of the fourth solenoid valve 28 and the compression spring 16d.
The valve element 17a of the exhaust switching valve 17 is closed by the urging force of.

A diaphragm chamber 16 is provided in a passage 75 between the diaphragm actuator 16 and the fourth solenoid valve 28.
Pressure sensor 7 for detecting the pressure of compressed air supplied to b
1 is connected. The signal from the pressure sensor 71 is input to the determination means 72 formed in the engine control computer 29.

The judging means 72 causes the diaphragm actuator 16 to receive the compressed air S by opening the fourth electromagnetic valve 28.
Has a function of determining whether or not there is an abnormality in the exhaust switching valve 17 based on a change in the pressure of the compressed air S detected by the pressure sensor 71 when the air is supplied. The judging means 72 is composed of a program stored in the engine computer 29.

An alarm lamp 73 as a display means is connected to the judging means 72. The alarm lamp 73 is lit when the determination means 72 determines that the exhaust gas switching valve 17 is abnormal.

Next, the operation of this embodiment will be described. In the high intake air amount range, both the intake switching valve 18 and the exhaust switching valve 17 are opened. As a result, the two turbochargers 7 and 8 are driven, a sufficient amount of supercharged air is obtained, and the output is improved.

When the exhaust gas switching valve 17 is opened, the diaphragm actuator 16 that drives the exhaust gas switching valve 17 is opened.
Based on the pressure in the diaphragm chamber 16b, the determination means 72 of the engine control computer 29 determines whether the exhaust switching valve 17 is abnormal. FIG. 2 shows changes in the pressure in the diaphragm chamber 16b when the exhaust switching valve 17 opens, and the pressure P ₁ shown by the solid line is the case where the exhaust switching valve 17 is normal, and the pressure P shown by the broken line. ₂ shows the case of abnormality.

As shown in characteristic of the pressure P ₁ in FIG. 2, after the pressure has increased to _a point a, to once lowered to _a point b, the diaphragm 1 of the diaphragm actuator 16
This is because 6a is deformed by the pressure and the volume of the diaphragm chamber 16b increases. The pressure increases again after the point b ₁ . If the operation of the exhaust switching valve 17 is abnormal,
After the pressure exceeds a ₁ point at normal time and rises to a ₂ point,
b It drops to ₂ points and then rises again. Thus, when the operation of the exhaust switching valve 17 is abnormal, the pressure in the diaphragm chamber 16b is significantly increased as compared with the normal state.

FIG. 3 shows a processing procedure for judging whether or not there is an abnormality in the exhaust gas switching valve 17 in the judging means 72. In FIG. 3, the process is started in step 101, the process proceeds to step 102, and it is determined whether or not the fourth solenoid valve (VSV) 28 is ON. If it is determined that the fourth solenoid valve 28 is not ON, then the routine proceeds to step 105.

In step 105, P _EX (pressure _{inside the} diaphragm chamber) is initialized (initial setting) as P _EXH (maximum pressure _{inside the} diaphragm chamber). When the process of step 105 is completed, the process proceeds to step 106,
P _EX is initialized as P _EXL (minimum pressure in the diaphragm chamber). When the process of step 106 is completed, the process proceeds to step 114 and the process returns.

In step 102, the fourth solenoid valve 2
When it is determined that 8 is ON (energized), the process proceeds to step 103. In step 103, it is determined whether P _EXH is smaller than P _EX . Here, if it is determined that P _EXH <P _EX , the process proceeds to step 104 and P _EX
Will be initialized as P _EXH . Step 104
When the process in 1 is completed, the process proceeds to step 114, and the process is returned.

When it is judged in step 103 that P _EXH <P _EX is not satisfied, the _routine proceeds to step 107. In step 107, it is determined whether P _EXL > P _EX . If it is determined that P _EXL > P _EX ,
_Proceeding to step 108, P _EX is initialized as P _EXL . When the process of step 108 is completed, the process proceeds to step 114 and the process returns.

If it is determined in step 107 that P _EXL > P _EX is not established, the process proceeds to step 109 and P _EX
EXH and the judgment value K shown in FIG. 2 are compared. If it is determined that P _{EX H} <K, then step 1
10, the flag indicating that the exhaust gas switching valve 17 is normal is set. When the normal flag is set in step 110, the process proceeds to step 114, and the process returns.

If it is determined in step 109 that P _EXH <K is not satisfied, the process proceeds to step 111. In step 111, P _EXL is subtracted from P _EXH to calculate the differential pressure A. When the differential pressure A is calculated in step 111,
In step 112, it is determined whether the differential pressure A is greater than 50 mmHg. Here, when it is determined that A> 50 mmg, the routine proceeds to step 113, where a flag indicating that the exhaust gas switching valve 17 is abnormal is set.

When the abnormality flag is set in step 113, the fact that the exhaust gas switching valve 17 is abnormal is displayed on the display means 73 via the engine control computer 29. When the process of step 113 is completed, the process proceeds to step 114 and the process returns. When it is determined in step 112 that the differential pressure A is smaller than 50 mmHg, it is considered that there is substantially no hindrance to the operation of the exhaust gas switching valve 17, and the routine proceeds to step 110, where a normal flag is set.

As described above, when the operation of the exhaust switching valve 17 is normal, the valve body 17a moves with a small force, so that the pressure in the diaphragm chamber 16b may be small. Therefore, when the fourth solenoid valve 28 is opened, the diaphragm chamber 16b
When the pressure increase of 1 is smaller than the determination value K, it can be considered that the operation of the exhaust gas switching valve 17 is normal.

When the valve body 17a of the exhaust switching valve 17 becomes stuck due to the influence of high-temperature exhaust gas and the valve body 17a becomes extremely difficult to move, the pressure in the diaphragm chamber 16b must be higher than the judgment value K. The valve body 17a does not move. Therefore, when the pressure increase in the diaphragm chamber 16b is higher than the determination value K when the fourth solenoid valve 28 is opened, it can be considered that the operation of the exhaust switching valve 17 is abnormal.

When the exhaust switching valve 17 opens,
Diaphragm 16a of diaphragm actuator 16
Due to the deformation, the volume of the diaphragm chamber 16b changes, so that the pressure in the diaphragm chamber 16b temporarily decreases and then rises again, as shown at points b _{1 and} b _{2 in} FIG. When the exhaust switching valve 17 does not move at all in the fully open state or the fully closed state, the phenomenon in which the pressure in the diaphragm chamber 16b temporarily decreases unlike the point b ₁ or the point b ₂ does not occur. Based on the change in the internal pressure, it is possible to detect whether the exhaust switching valve 17 is fully opened or abnormal in the fully opened state.

This embodiment has shown the case where it is applied to the exhaust gas switching valve of the engine with a supercharger, but this is an example, and if it is a switching valve (open / close valve) by an actuator using the pressure of compressed air However, the present invention is not limited to this, and can be applied to general industrial equipment and facilities.

[0039]

According to the present invention, the pressure of compressed air supplied from the solenoid valve to the diaphragm chamber of the diaphragm actuator is detected by the pressure sensor, and detected by the pressure sensor when compressed air is supplied to the diaphragm chamber. The determination means determines whether or not there is an abnormality in the switching valve based on the change in compressed air pressure.Therefore, not only is the switching valve fully closed or fully opened, but the operation delay due to increased friction when the valve is opened and closed. It is possible to grasp abnormalities such as the above and take appropriate measures.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a switching valve abnormality detection device according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram showing a change in pressure inside the diaphragm chamber when the switching valve of FIG. 1 is opened.

FIG. 3 is a flowchart showing a control processing procedure in the determination means of FIG.

FIG. 4 is a schematic configuration diagram of an engine with a supercharger to which the present invention is applied.

[Explanation of symbols]

 16 diaphragm actuator 16b diaphragm chamber 17 switching valve (exhaust gas switching valve) 17a valve body 28 electromagnetic valve (fourth electromagnetic valve) 20a passage (exhaust passage) 29 engine control computer 71 pressure sensor 72 determination means 73 display means

Claims (1)

[Claims] 1. A switching valve having a valve element disposed in a passage, a diaphragm actuator connected to the valve element of the switching valve, and driving the valve element to open and close by the pressure of compressed air supplied into a diaphragm chamber, An electromagnetic valve that supplies the compressed air into the diaphragm chamber of the diaphragm actuator, a pressure sensor that detects the pressure of the compressed air supplied from the electromagnetic valve into the diaphragm chamber, and a pressure sensor when the electromagnetic valve is opened. An abnormality detecting device for a switching valve, comprising: a determination unit that determines whether or not there is an abnormality in the switching valve based on a detected change in pressure of compressed air.