JP2022128974A - Defect determination device and defect determination method - Google Patents

Abstract

To provide a defect determination device and a defect determination method which enable a user to grasp defect of an exhaust brake system before engine failure occurs.SOLUTION: A defect determination device is mounted to a moving body having an exhaust brake device enabling exhaust brake by blocking a flow of exhaust gas discharged from an engine. The defect determination device includes: a measurement section measuring a time when a lambda value of the exhaust gas is less than a threshold value when release of the exhaust brake is instructed to the exhaust brake device; and a determination section determining that defect has occurred in the exhaust brake device when the measured time is longer than a predetermined time.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a malfunction determination device and malfunction determination method for determining malfunction of an exhaust brake device.

2. Description of the Related Art Conventionally, it is known that an engine-mounted moving body (for example, an automobile, a ship, etc.) is equipped with an exhaust brake device that implements an exhaust brake by closing an exhaust pipe with a valve to block the flow of exhaust gas. (See, for example, Patent Document 1).

JP 2011-69321 A

If the exhaust brake system malfunctions, it may lead to engine failure.

An object of one aspect of the present disclosure is to provide a malfunction determination device and malfunction determination method that enable a user to grasp the occurrence of a malfunction in an exhaust brake device before an engine failure occurs.

A malfunction determination device according to one aspect of the present disclosure is a malfunction determination device that determines a malfunction of an exhaust brake device that implements an exhaust brake by interrupting the flow of exhaust gas discharged from an engine, On the other hand, when an instruction to release the exhaust brake is given, a measurement unit that measures the time during which the lambda value of the exhaust gas is less than the threshold value, and if the measured time is equal to or longer than a predetermined time, the exhaust brake device and a determination unit that determines that a problem has occurred.

A malfunction determination method according to one aspect of the present disclosure is a malfunction determination method for determining a malfunction of an exhaust brake device that realizes an exhaust brake by interrupting a flow of exhaust gas discharged from an engine, When the release of the exhaust brake is instructed, the step of measuring the time during which the lambda value of the exhaust gas is less than the threshold; and determining that has occurred.

Advantageous Effects of Invention According to the present disclosure, a user can recognize the occurrence of a problem with an exhaust brake device before an engine failure occurs.

Schematic diagram showing an example of components mounted on a vehicle according to an embodiment of the present disclosure Block diagram showing an example of configuration of a failure determination device according to an embodiment of the present disclosure Flowchart showing an example of the operation of the failure determination device according to the embodiment of the present disclosure

Embodiments of the present disclosure will be described below with reference to the drawings.

First, components mounted on a vehicle 1 according to this embodiment will be described with reference to FIG. FIG. 1 is a schematic diagram showing an example of components mounted on a vehicle 1 (specifically, components around an engine).

A vehicle 1 (an example of a moving object) shown in FIG. 1 is, for example, a large vehicle such as a truck or a bus. However, there are no particular limitations on the type, type, application, etc. of the vehicle, and the vehicle 1 may be a small vehicle such as a passenger car. Further, in the present embodiment, a case where the moving body is a vehicle will be described as an example, but the present invention is not limited to this. The mobile object may be, for example, a ship, construction machine, industrial machine, or other mobile object.

As shown in FIG. 1, a vehicle 1 includes an engine 2 (including cylinders 3, injectors 4, and a common rail 5), an air filter 6, an intake pipe 7, a high-pressure side intake pipe 7a, a turbocharger 8 (compressor 9, turbine 10, ), intercooler 11, intake manifold 12, exhaust manifold 13, exhaust pipe 14, high pressure side exhaust pipe 14a, EGR (Exhaust Gas Recirculation) pipe 15, EGR cooler 16, EGR valve 17, lambda sensor 19, precatalyzer 20 , an exhaust brake device 21 (including a butterfly valve 22), and a main catalyzer 23 are mounted.

Engine 2 is, for example, a natural gas engine with four cylinders 3 . Note that the engine 2 may be a multi-cylinder engine other than a four-cylinder engine, or may be a single-cylinder engine.

An intake port 4 and an exhaust port 5 are connected to each cylinder 3 . Each intake port 4 is connected to an intake manifold 12 . Each exhaust port 5 is connected to an exhaust manifold 13 . Each intake port 4 is provided with an injector (not shown) (which may be called a fuel injection valve). Each injector injects fuel (natural gas) into the intake port 4 .

An air filter (which may also be called an air cleaner) 6 is connected to an upstream end of an intake pipe 7 . A downstream end of the intake pipe 7 is connected to an inlet of a compressor 9 of the turbocharger 8 .

The outlet of the compressor 9 is connected to the upstream end of the high pressure side intake pipe 7a. A downstream end of the high-pressure side intake pipe 7 a is connected to the intake manifold 12 . An intercooler 11 is provided in the high pressure side intake pipe 7a. A downstream end of an EGR pipe 15 is connected to a downstream side of the intercooler 11 in the high pressure side intake pipe 7a.

Air taken in from the air filter 6 (hereinafter referred to as intake air) passes through the intake pipe 7 and is compressed by the compressor 9 to become high-pressure intake air.

After that, the intake air flows from the compressor 9 into the high-pressure side intake pipe 7a, is cooled by the intercooler 11, and is mixed with the EGR gas from the EGR pipe 15. Intake air mixed with EGR gas flows into the combustion chamber of each cylinder 3 through the intake manifold 12 and each intake port 4 .

The exhaust manifold 13 is connected to an upstream end of a high pressure side exhaust pipe 14a. An EGR pipe 15 is connected to the high pressure side exhaust pipe 14a. The EGR pipe 15 is provided with an EGR cooler 16 that cools the EGR gas, and an EGR valve 17 that adjusts the flow rate (mass flow rate) of the EGR gas flowing into the high pressure side intake pipe 7a.

A downstream end of the high pressure side exhaust pipe 14 a is connected to an inlet of the turbine 10 of the turbocharger 10 . An exhaust pipe 14 is connected to the outlet of the turbine 10 .

The exhaust pipe 14 is provided with a lambda sensor 19, a precatalyst 20, an exhaust brake device 21, and a main catalyzer 23 in this order from the upstream side.

The lambda sensor 19 detects the oxygen concentration (hereinafter referred to as lambda value) in the exhaust gas flowing through the exhaust pipe 14 . The lambda sensor 19 is electrically connected to a defect determination device 100 (see FIG. 2), which will be described later, and notifies the defect determination device 100 of the detected lambda value.

The precatalyst 20 and the main catalyzer 23 are catalysts that purify the exhaust gas flowing through the exhaust pipe 14 . Examples of the precatalyst 20 and the main catalyzer 23 include, but are not limited to, a three-way catalyst. Note that the precatalyst 20 and the main catalyzer 23 may be of the same type of catalyst, or may be of different types.

A butterfly valve 22 of the exhaust brake device 21 rotates around a shaft (not shown) to close or open the exhaust pipe 14 .

When the butterfly valve 22 is open, the exhaust pipe 14 is opened and the exhaust gas flows downstream of the exhaust brake device 21 .

On the other hand, when the butterfly valve 22 is in the closed state, the exhaust pipe 14 is blocked and the exhaust gas does not flow downstream of the exhaust brake device 21 . That is, the flow of exhaust gas is blocked at the position of the exhaust brake device 21 .

The exhaust brake device 21 is electrically connected to a malfunction determination device 100 (see FIG. 2), which will be described later.

When the exhaust brake device 21 receives a signal indicating an instruction to close the butterfly valve 22 (hereinafter referred to as a valve closing instruction signal) from the failure determination device 100, the butterfly valve 22 is controlled to close. Exhaust braking is thereby performed.

On the other hand, when the exhaust brake device 21 receives a signal indicating an instruction to open the butterfly valve 22 (hereinafter referred to as a valve opening instruction signal) from the failure determination device 100, the butterfly valve 22 is controlled to open. . This releases the exhaust brake.

Exhaust gas from the combustion chamber of each cylinder 3 flows from the exhaust manifold 13 into the high pressure side exhaust pipe 14a. A part of this exhaust gas flows into the EGR pipe 15 and the rest flows into the turbine 10 .

Exhaust gas (that is, EGR gas) that has flowed into the EGR pipe 15 passes through the EGR cooler 16 and the EGR valve 17 in the open state in order, and flows into the high-pressure side intake pipe 7a.

On the other hand, the exhaust gas that has flowed into the turbine 10 flows through the exhaust pipe 14 . That is, the exhaust gas sequentially passes through the precatalyst 20, the exhaust brake device 21 with the butterfly valve 22 in an open state, and the main catalyzer 23, and is finally discharged out of the vehicle.

Although not shown in FIG. 1, the vehicle 1 is equipped with a malfunction determination device 100 shown in FIG. Details of the defect determination device 100 will be described later.

The components mounted on the vehicle 1 have been described above.

Next, the configuration of defect determination apparatus 100 according to the present embodiment will be described with reference to FIG. FIG. 2 is a block diagram showing a configuration example of the defect determination device 100. As shown in FIG.

Although illustration is omitted, the defect determination apparatus 100 includes hardware such as a CPU (Central Processing Unit), a ROM (Read Only Memory) that stores a computer program, and a RAM (Random Access Memory) that is a working memory. have. Each function of the defect determination device 100 described below is implemented by the CPU executing a computer program read from the ROM in the RAM. The malfunction determination device 100 may be realized by an ECU (Electronic Control Unit), for example.

As shown in FIG. 2 , the defect determination device 100 has a control section 110 , a measurement section 120 and a determination section 130 .

The control section 110 controls the state of the butterfly valve 22 of the exhaust brake device 21 .

Specifically, when the occupant of the vehicle 1 performs an operation instructing execution (which may be called start) of the exhaust brake, the control unit 110 closes the butterfly valve 22. A valve closing instruction signal is output to the exhaust brake device 21 .

On the other hand, when the occupant of the vehicle 1 performs an operation instructing release (which may be called termination) of the exhaust brake, the control unit 110 issues the above-described valve opening instruction to open the butterfly valve 22. A signal is output to the exhaust brake device 21 .

When the valve opening instruction signal is output to the exhaust brake device 21 (in other words, when the release of the exhaust brake is instructed), the measurement unit 120 determines the lambda value detected by the lambda sensor 19 in advance. time is less than a threshold (eg, 1).

The determination unit 130 determines whether the lambda value detected by the lambda sensor 19 is less than the threshold.

The determination unit 130 also determines whether or not the time measured by the measurement unit 120 (hereinafter referred to as measurement time) is equal to or longer than a predetermined time (hereinafter referred to as set time).

If the measured time is equal to or longer than the set time, the determination unit 130 determines that the shaft of the butterfly valve 22 has become stiff.

On the other hand, if the lambda value is not less than the threshold value, or if the measured time is less than the set time, the determination unit 130 determines that the shaft of the butterfly valve 22 is not stiff.

Below, stiffness of the shaft of the butterfly valve 22 is referred to as "shaft stiffness". The tightness of the shaft corresponds to an example of a malfunction of the exhaust brake device 21 (more specifically, delayed release of the butterfly valve 22). In the present embodiment, shaft tightness is given as an example of a cause of release delay of the butterfly valve 22, and the case of determining whether or not the shaft tightness has occurred will be described as an example. , but not limited to shaft astringency.

When the determination unit 130 determines that the shaft stiffness has occurred, the determination unit 130 activates a notification device (not shown) provided in the vehicle interior so as to notify the passenger (an example of the user) of the occurrence of the shaft stiffness. Control.

Notification devices include lamps, displays, speakers, and the like. If the notification device is a lamp, the determination unit 120 may light (or blink) the lamp. If the notification device is a display, the determination unit 120 may cause the display to display an image indicating that shaft stiffness has occurred. If the notification device is a speaker, the determination unit 120 may cause the speaker to output a sound (or a sound effect) indicating that shaft stiffness has occurred.

In addition, although the case where the determination part 130 controls the device for information provided in the vehicle 1 was mentioned as an example and this Embodiment demonstrated it, it is not limited to this. For example, the determination unit 130 may transmit notification information indicating that shaft stiffness has occurred to a notification device installed outside the vehicle 1 (remote location). ) may be controlled. As a result, notification information is output from the notification device in the remote location, and the operation manager (an example of the user) of the vehicle 1 can grasp that the shaft stiffness has occurred.

The configuration of the defect determination device 100 has been described above.

Next, the operation of the defect determination device 100 will be described with reference to FIG. FIG. 3 is a flowchart showing an operation example of the defect determination device 100. As shown in FIG. The flow shown in FIG. 3 is started when the exhaust brake is released.

First, the control unit 110 outputs a valve opening instruction signal to the exhaust brake device 21 (step S1).

Next, the determination unit 130 determines whether the lambda value detected by the lambda sensor 19 is less than the threshold (step S2).

If the lambda value is less than the threshold (step S2: YES), the flow proceeds to step S3, which will be described later. On the other hand, if the lambda value is not less than the threshold (step S2: NO), the flow proceeds to step S7, which will be described later.

Next, the measurement unit 120 measures the time during which the lambda value is less than the threshold (step S3).

Next, the determination unit 130 determines whether or not the measurement time measured by the measurement unit 120 is equal to or longer than the set time (step S4).

If the measured time is equal to or longer than the set time (step S4: YES), the determination unit 130 determines that shaft stiffness has occurred (step S5).

Then, the determination unit 130 controls the notification device to notify the occurrence of shaft stiffness (step S6). As a result, the occupant of the vehicle 1 can grasp (or recognize) that the shaft stiffness has occurred.

On the other hand, if the lambda value is not less than the threshold (step S2: NO), or if the measured time is not equal to or longer than the set time (step S4: NO), determination unit 130 determines that shaft stiffness has not occurred. (Step S7). In this case, no notification is made by the notification device.

The operation of the defect determination device 100 has been described above.

For example, when a malfunction of the exhaust brake system (specifically, shaft stiffness caused by frequent exhaust braking) occurs, the exhaust gas pressure rises instantaneously, and the oxygen concentration in the exhaust gas decreases due to the increase in the EGR rate. do. The present disclosure takes advantage of such phenomena. That is, when the exhaust brake is released, the failure determination device 100 of the present embodiment measures the time during which the lambda value of the exhaust gas is less than the threshold, and if the time is equal to or longer than the set time, the exhaust brake device 21 malfunction (specifically, shaft tightness) is determined to have occurred. This allows the occupant to know that the exhaust brake device 21 has a problem before a failure of the engine 2 (for example, a road failure of the vehicle 1) occurs.

It should be noted that the present disclosure is not limited to the description of the above embodiments, and various modifications are possible without departing from the scope of the present disclosure. Modifications will be described below.

[Modification 1]
In the embodiment, the case where the malfunction determination device 100 has the control unit 110 that controls the exhaust brake device 21 (specifically, the opening and closing of the butterfly valve 22) has been described as an example, but the present invention is not limited to this.

For example, control unit 110 may be realized by a device (for example, an ECU) different from malfunction determination device 100 . In that case, instead of step S1 in FIG. 3, the failure determination device 100 recognizes that the valve opening instruction signal has been output to the exhaust brake device 21 by notification from the other device, and then performs step S1 in FIG. You may perform after S2.

[Modification 2]
In the embodiment, the case where the threshold value to be compared with the lambda value detected by the lambda sensor 19 is 1 has been described as an example, but the present invention is not limited to this.

For example, the threshold may be a value less than 1 (eg, 0.8). By using a threshold smaller than 1, it is possible to determine that the shaft stiffness is in a more serious state (that is, a state in which vehicle failure is imminent).

The failure determination device and failure determination method of the present disclosure are useful for determining failure of an exhaust brake device.

1 Vehicle 2 Engine 3 Cylinder 4 Intake Port 5 Exhaust Port 6 Air Filter 7 Intake Pipe 7a High Pressure Side Intake Pipe 8 Turbocharger 9 Compressor 10 Turbine 11 Intercooler 12 Intake Manifold 13 Exhaust Manifold 14 Exhaust Pipe 14
14a High-pressure side exhaust pipe 15 EGR pipe 16 EGR cooler 17 EGR valve 19 Lambda sensor 20 Precatalyzer 21 Exhaust brake device 22 Butterfly valve 23 Main catalyzer 100 Defect determination device 110 Control unit 120 Measurement unit 130 Determination unit

Claims (6)

A malfunction determination device that determines a malfunction of an exhaust brake device that realizes an exhaust brake by interrupting the flow of exhaust gas discharged from an engine,
a measuring unit that measures the time during which the lambda value of the exhaust gas is less than a threshold when the exhaust brake device is instructed to release the exhaust brake;
a determination unit that determines that a malfunction has occurred in the exhaust brake device when the measured time is equal to or longer than a predetermined time;
Defect determination device. The determination unit
controlling an informing device provided inside or outside the moving body on which the malfunction determination device is mounted so as to notify that the exhaust brake device has malfunctioned;
The malfunction determination device according to claim 1. The above defects are
The tightness of the shaft of the butterfly valve that opens or closes the exhaust pipe,
3. The defect determination device according to claim 1 or 2. the threshold is 1;
The malfunction determination device according to any one of claims 1 to 3. wherein the threshold is a value smaller than 1;
The malfunction determination device according to any one of claims 1 to 3. A defect determination method for determining a defect of an exhaust brake device that implements an exhaust brake by interrupting the flow of exhaust gas discharged from an engine, comprising:
measuring the time for which the lambda value of the exhaust gas is less than a threshold when the exhaust brake device is instructed to release the exhaust brake;
determining that a malfunction has occurred in the exhaust brake device when the measured time is equal to or longer than a predetermined time;
defect determination method.

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