JP6097603B2 - Air cleaner snow clog progression prevention system - Google Patents

Description

The present invention relates to a snow clogging progress prevention system for an air cleaner in a vehicle equipped with an internal combustion engine such as a diesel engine.

In cold and high mountain areas, if a vehicle travels in the middle of a large amount of snow, the air cleaner will become clogged with snow that has entered through the air intake during travel, increasing the negative suction pressure, resulting in insufficient engine output and eventually stalling the engine. It is known that this can lead to
Therefore, in order to avoid such a problem, there is a technique in which the switching valve is switched to the heated intake duct side when the intake negative pressure on the engine side of the air cleaner body becomes a negative pressure larger than a set value. It is disclosed (for example, Patent Document 1).

Japanese Utility Model Publication No. 01-158548

On the other hand, when the air cleaner is clogged in the process of verifying the malfunction due to snow clogging of the air cleaner, the present inventor has negative pressure in the intake manifold, and oil flows out from the shaft of the turbo compressor and flows into the cylinder. Sometimes. And it found out that it might cause engine run-on (dieseling).
Especially in diesel engines, except for special conditions such as during warm-up, the intake throttle may not be throttled depending on the load, and the engine may always be fully opened. Intake flow is higher than gasoline engines. As a result, in the diesel engine, the amount of snow sucked together with the air from the intake duct increases, and the risk of snow clogging in the air cleaner during heavy snowfall increases.

However, in the technique disclosed in Patent Document 1, it is necessary to newly provide a heating intake duct having a heater and a switching valve in addition to the original intake duct, and therefore measures for preventing the progress of snow clogging. Therefore, there is a demerit that the number of parts increases.
Further, the technology disclosed in Patent Document 1 is switched when the outside air temperature is lower than a set value and the intake air negative pressure on the engine side of the air cleaner body becomes a negative pressure larger than the set value, regardless of the operating state of the engine. The valve is merely switched to the heated intake duct side. For this reason, there is a risk that it may be erroneously determined as snow clogging when the engine is operating, for example, when the throttle is fully closed. That is, the technique of Patent Document 1 has a problem that it is impossible to prevent the progress of snow clogging of the air cleaner according to the operating state of the engine.

This invention is made | formed in view of such a subject, The place made into the objective is to provide the technique which can prevent the progress of the snow clogging of an air cleaner, without adding a large-scale component. .
Another object of the present invention is to provide a technique capable of accurately detecting snow clogging in an air cleaner according to the operating state of a diesel engine and effectively preventing the progress of snow clogging.

In order to achieve the above object, the present invention provides:
An intake pipe for introducing air into the diesel engine, the air cleaning apparatus for cleaning air introduced into the diesel engine is provided upstream of the intake pipe, on the way from the air cleaning device of an intake passage leading to the intake pipe and provided with an intake control valve, the flow rate of the control means for controlling the amount and intake air amount to be introduced into the diesel engine fuel injected into the diesel engine, an intake passage for snow clogging judgment set according to the operating conditions A vehicle air cleaner snow clogging progress prevention system comprising storage means for storing values ,
Comprising a plurality of detecting means for grasping the operating conditions including the flow rate detecting means provided on a side closer to the air cleaning device of the previous SL intake passage,
The control means includes
Based on the outside air temperature, the engine speed, the accelerator opening, the vehicle speed, and the flow rate of the intake passage, the operation state is grasped, and the flow rate detected by the flow rate detection means is determined as the snow clogging corresponding to the operation state at that time. When the air flow rate becomes lower than the flow rate value, it is determined that the air purifier is causing snow clogging,
When it is determined that the air purifier is causing snow clogging, control is performed so that the opening degree of the intake control valve is reduced.

According to the above configuration, the control means grasps the operating state based on signals from the plurality of detecting means including the flow rate detecting means, and controls the intake control valve so as to have a suitable opening degree according to the operating state. Therefore, the progress of snow clogging can be prevented more accurately as compared with the conventional method in which the switching valve is switched to the heated intake duct side based only on the outside air temperature and the intake negative pressure on the diesel engine side. Further, since it is not necessary to provide a heated intake duct and a switching valve, it is possible to prevent the progress of snow clogging in the compressed air cooling device (air cleaner) without adding large parts.

Here, preferably,
The said storage means, in response to engine Rotation speed and fuel injection amount, a plurality of intake air flow rate determination threshold and the intake control valve opening is stored in advance,
As the plurality of detection means,
A rotation speed detecting means for detecting the engine Rotation speed,
An accelerator opening detecting means for detecting the opening of the accelerator;
Further wherein the control means, the fuel injection amount determined according to the accelerator opening detected by the accelerator opening detection means, when a predetermined operating condition, engine Rotational speed and fuel injection amount The intake flow rate determination threshold value is acquired from the storage unit in response to the determination, and the intake control valve is determined to be greater than the threshold value by comparing the determination threshold value with the intake flow rate measured by the flow rate detection unit. configured to control so narrow the opening to a Jo Tokoro opening degree.

Compressed air cooling apparatus (air cleaner) is determined whether the cause snow clogging on the basis of the intake air flow rate detected with the intake air flow rate determination threshold in accordance with the operating state, as squeezing to a predetermined opening degree in accordance with the operating conditions Since the intake control valve is controlled, the progress of snow clogging can be prevented accurately.

Preferably, as the plurality of detection means,
Outside air temperature detecting means for detecting the temperature of air or intake air in the vicinity of the air cleaning device;
Vehicle speed detecting means for detecting the traveling speed of the vehicle;
The control means grasps the driving state based on signals from the flow rate detection means, the rotation speed detection means, the accelerator opening detection means, the outside air temperature detection means, and the vehicle speed detection means. and, in the case of predetermined operating conditions, engine Rotational speed and obtains the intake air flow rate determination threshold from the storage means in accordance with the fuel injection amount, measured by the flow rate detecting unit and the determination threshold intake If it is determined to exceed the threshold value by comparing the flow rate, configured to control so as to narrow the opening degree of the intake control valve to a predetermined opening degree.

As a result, the control means grasps the driving state based on signals from the outside air temperature detecting means and the vehicle speed detecting means in addition to the flow rate detecting means, the rotation speed detecting means and the accelerator opening degree detecting means, so that the driving can be performed more accurately. the opening of the intake control valve by grasping the state can be controlled to narrow the predetermined opening.

Further, preferably, includes an air compressor for compressing air introduced from the front Symbol air cleaning device, and a compressed air cooler for cooling the air compressed by the air compressor, the intake control valve is the compression It is configured to be provided between the air cooling device and the intake pipe.

  Since the intake control valve is provided between the compressed air cooling device (air cleaner) and the intake pipe (manifold), when it is determined that the air cleaner is causing snow clogging, the intake control valve is throttled, It is possible to make it difficult to transmit negative pressure to the air cleaner. As a result, it is possible to effectively prevent the snow clogging of the air cleaner from proceeding in a diesel engine having a larger intake flow rate than a gasoline engine.

According to the present invention, the progress of snow clogging of the air cleaner can be prevented without adding large parts. Further, there is an effect that snow clogging of the air cleaner can be accurately detected according to the operation state of the diesel engine, and the progress of snow clogging can be effectively prevented.

FIG. 1 is a schematic configuration diagram illustrating an example of an engine to which an air cleaner snow clogging progress prevention system according to the present invention can be applied, and an intake system and an exhaust system thereof. FIG. 2 is a block diagram showing a configuration of a control system by the engine control unit in the embodiment. FIG. 3 is a flowchart illustrating an example of a procedure of air cleaner snow clogging detection and prevention control processing by the engine control unit in the embodiment.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a diagram showing a schematic configuration of an internal combustion engine to which an air cleaner snow clogging progress prevention system according to the present embodiment is applied, and an intake system and an exhaust system thereof. The internal combustion engine 10 shown in FIG. 1 is not particularly limited, but is a water-cooled four-cycle diesel engine having a plurality of cylinders.

  An internal combustion engine (hereinafter referred to as an engine) 10 is connected to an intake manifold 11 serving as an intake pipe and an exhaust manifold 12 serving as an exhaust pipe. Although not shown, an EGR (exhaust gas recirculation device) that returns a part of the exhaust gas to the intake manifold 11 may be provided between the intake manifold 11 and the exhaust manifold 12 as an exhaust pipe.

  A throttle valve 13 is provided in the intake passage on the upstream side of the intake manifold 11, and the throttle valve 13 is configured such that the valve opening degree is controlled by an ECU (engine control unit) 14. An intercooler 15 is provided on the upstream side of the throttle valve 13, and a turbo compressor 16 that operates using the energy of exhaust gas as a driving force is provided on the upstream side of the intercooler 15. The intake air compressed and heated by the turbo compressor 16 is cooled by the intercooler 15 and supplied to the engine 10 through the intake manifold 11.

  Further, an intake passage 17 is provided on the upstream side of the turbo compressor 16, and an air cleaner 18 is provided at the inlet of the intake passage 17. On the other hand, an exhaust passage 19 is connected to the exhaust outlet side of the turbo compressor 16, and a muffler (silencer) 20 is disposed at the outlet of the exhaust passage 19. Further, a DPF (exhaust gas purification device) 21 for purifying the exhaust gas is provided in the middle of the exhaust passage 19.

  The DPF 21 has an oxidation catalyst and a particulate filter downstream of the oxidation catalyst, and an occlusion reduction type NOx catalyst is supported on the filter. The filter collects particulate matter in the exhaust. Further, the NOx catalyst occludes nitrogen oxide (NOx) in the exhaust when the oxygen concentration of the exhaust flowing into the NOx catalyst is high, and occludes when the oxygen concentration of the exhaust flowing into the NOx catalyst decreases. Releases NOx. When NOx is released from the NOx catalyst, if there is a reducing component such as hydrocarbon (HC) or carbon monoxide (CO) in the exhaust around the NOx catalyst, the NOx released from the NOx catalyst is N2 or the like. Reduced to

Further, in this embodiment, an air flow sensor 22 capable of measuring the intake air flow rate is provided on the side near the air cleaner 18 in the intake passage 17 for sending intake air from the air cleaner 18 to the turbo compressor 16. A detection signal of the airflow sensor 22 is supplied to an ECU (engine control unit) 14, and the valve opening degree of the throttle valve 13 is controlled by the ECU 14.
The airflow sensor 22 may be capable of measuring the intake air flow rate and the intake air temperature. Although not shown, a recirculation passage (low pressure side EGR) for recirculating a part of the exhaust gas from the middle of the exhaust passage 19 to the intake passage 17 may be provided.

Further, the engine 10 is provided with a fuel injection nozzle 23 and a rotation speed sensor 24 for detecting the rotation speed of the engine. As shown in FIG. 2, the detection signal of the rotation speed sensor 24 and the detection signal of the airflow sensor 22 are provided. Is input to the ECU 14. The airflow sensor 22 may be composed of a flow meter and a temperature sensor. Further, the ECU 14 includes an outside air temperature sensor 25 that detects the outside air temperature, a vehicle speed sensor 26 that detects the traveling speed of the vehicle, an ignition key (or start switch) 27, and an accelerator opening sensor 28 provided on the accelerator pedal. A signal is being input.
The outside air temperature sensor 25 may measure the temperature of the intake air immediately after the air cleaner 18 or may measure the temperature of the air before being sucked in the vicinity of the air cleaner 18.

Based on these inputs, the ECU 14 drives the motor of the throttle valve 13 to control the valve opening. Further, the ECU 14 controls the drive of a fuel injection pump (not shown) according to the accelerator opening so that an appropriate amount of fuel is injected from the fuel injection nozzle 23. Note that a signal from a supercharging pressure sensor provided in the intake manifold 11 is input to the ECU 14, and the engine can be controlled based on a detection signal from the sensor.
Note that the ECU 14 calculates the amount of fuel injected from the fuel injection nozzle 23 based on the signal from the accelerator opening sensor 28 and controls the fuel injection pump accordingly, so the fuel injection amount is always grasped. Yes.

Further, the ECU 14 is connected to a storage device 29 composed of a nonvolatile semiconductor memory such as a flash memory or a magnetic disk. The storage device 29 stores (stores) a control program executed by the ECU 14 and map data for determining snow clogging of the air cleaner.
The map data for judging snow clogging is created in the form of a map or table by calculating the intake air amount that can be considered that the air cleaner has clogged, using the fuel injection amount representing the engine speed and load as parameters in advance through experiments and simulations. It is a thing. The map data, according to the operating state when it is determined that clogging snow, the opening degree of the throttle valve 13, the peripheral device control data for preventing the progression of clogging snow (e.g. opening data of the throttle valve) It is included.

Next, the content of the air cleaner snow clogging detection and prevention control processing by the ECU (engine control unit) 14 in the embodiment will be described with reference to the flowchart of FIG. The control process may be executed repeatedly in the main control flow, or may be executed at predetermined time intervals by a timer interrupt or the like.
In the snow clogging detection and prevention control process by the ECU 14, first, signals from the rotation speed sensor 24, the outside air temperature sensor 25, the vehicle speed sensor 26, and the accelerator opening sensor 28 are read (step S1). Based on the signals from these sensors, the outside air temperature, accelerator opening, engine speed, and vehicle speed are calculated (step S2).

Next, based on these calculated values, the outside air temperature is lower than 0 ° C., the accelerator opening is larger than 1.0%, the engine speed is higher than 1600 rpm, and the vehicle speed is 60 km / h. It is determined whether it is faster (step S3).
The determination threshold value for performing these determinations is the magnitude of the signal itself of each sensor before conversion into a physical quantity such as outside air temperature or a percentage value, that is, the sensor value corresponding to the determination threshold value (0 ° C. or the like). May be stored in the storage device 29 in advance and used for determination. In that case, the calculation process in step S2 of FIG. 3 is not necessary. The same applies to the detection signal of the airflow sensor 22 described later.

In step S3, it is determined that the outside air temperature is not lower than 0 ° C., the accelerator opening is not larger than 1.0%, the engine speed is not higher than 1600 rpm, or the vehicle speed is not faster than 60 km / h (No). If so, the process returns to step S1 to repeat the above process.
On the other hand, when it is determined that the outside air temperature is lower than 0 ° C., the accelerator opening is larger than 1.0%, the engine speed is higher than 1600 rpm, and the vehicle speed is faster than 60 km / h (step S3: Yes), the process proceeds to step S4. . Then, the fuel injection amount determined based on the signal from the accelerator opening sensor 28 is read (step S4).

Next, referring to the map data stored in the storage device 29, a snow clogging determination threshold value of the intake air flow rate according to the engine speed calculated in step S2 and the fuel injection amount read in step S3 is acquired ( Step S5). Subsequently, the detection signal of the airflow sensor 22 is read to calculate the intake air flow rate (step S6). Next, it is determined whether or not the calculated intake flow rate is lower than the snow clogging determination threshold acquired in step S5 (step S7).
Here, if it is determined that the calculated intake air flow rate is not lower than the snow clogging determination threshold value acquired in step S5 (step S7: No), the process is repeated from step S1.

  On the other hand, if it is determined in step S7 that the intake air flow rate is lower than the snow clogging determination threshold acquired in step S5 (Yes), it is considered that the air cleaner 18 is clogged with snow, and the process proceeds to step S8. Then, the opening degree of the throttle valve 13 corresponding to the engine speed and the fuel injection amount is output based on the map data (step S8). Specifically, the throttle valve 13 is throttled to make it difficult for the negative suction pressure in the intake manifold 11 to be transmitted to the air cleaner 18. Thereafter, by outputting an alarm (step S9) such as turning on an alarm lamp provided on the console panel of the driver's seat, a warning is given to the user and the control process is terminated.

As described above, when it is determined that the air cleaner 18 is clogged with snow, by controlling the opening of the throttle valve 13, it is possible to prevent the clogging of the air cleaner 18 from proceeding. As a result, it is possible to prevent the suction negative pressure in the intake manifold 11 from increasing due to snow clogging, resulting in insufficient engine output, and hence engine stall. Further, it is possible to prevent the suction negative pressure in the intake manifold 11 from increasing due to snow clogging, causing oil to flow out from the shaft of the turbo compressor and into the cylinder of the engine, resulting in a state of causing engine run-on. Can do.

  In the above-described embodiment, as an example, the present invention is applied to an engine control system in which the throttle valve 13 is provided between the intake manifold 11 and the intercooler 15. The present invention can also be applied to a system in which the throttle valve 13 is provided between the intercooler 15 and the turbo compressor 16 or an engine control system in which the throttle valve 13 is provided between the turbo compressor 16 and the air cleaner 18.

Further, in the system provided with the low pressure side EGR, when the snow clogging of the air cleaner is detected, for example, the throttle valve 13 is controlled to open and the low pressure EGR valve is opened. As a result, it is possible to induce a part of the exhaust gas to the intake passage side and warm the air cleaner with the heat of the exhaust gas to eliminate snow clogging.
Furthermore, in the above-described embodiment, the case where the present invention is applied to the detection and prevention of snow clogging in an air cleaner of a diesel engine has been described. However, the present invention can be used for a gasoline engine and other internal combustion engines generally equipped with an air cleaner.

10 Engine (Internal combustion engine)
11 Intake manifold (intake pipe)
12 Exhaust manifold 13 Throttle valve (intake control valve)
14 ECU (engine control unit: control means)
15 Intercooler (Compressed air cooling device)
16 Turbo compressor (air compressor)
17 Air intake passage 18 Air cleaner (Air purifier)
19 Exhaust passage 20 Muffler (silencer)
21 DPF (exhaust gas purifier)
22 Airflow sensor (flow rate detection means)
23 Fuel injection nozzle 24 Rotation speed sensor (Rotation speed detection means)
25 Outside air temperature sensor (outside air temperature detection means)
26 Vehicle speed sensor (vehicle speed detection means)
28 Accelerator opening sensor (opening detection means)

Claims (4)

An intake pipe for introducing air into the diesel engine, the air cleaning apparatus for cleaning air introduced into the diesel engine is provided upstream of the intake pipe, on the way from the air cleaning device of an intake passage leading to the intake pipe and provided with an intake control valve, the flow rate of the control means for controlling the amount and intake air amount to be introduced into the diesel engine fuel injected into the diesel engine, an intake passage for snow clogging judgment set according to the operating conditions A vehicle air cleaner snow clogging progress prevention system comprising storage means for storing values ,
Comprising a plurality of detecting means for grasping the operating conditions including the flow rate detecting means provided on a side closer to the air cleaning device of the previous SL intake passage,
The control means includes
Based on the outside air temperature, the engine speed, the accelerator opening, the vehicle speed, and the flow rate of the intake passage, the operation state is grasped, and the flow rate detected by the flow rate detection means is determined as the snow clogging corresponding to the current operation state. When the air flow rate becomes lower than the flow rate value, it is determined that the air purifier is causing snow clogging,
Wherein when the air cleaning device is determined to be caused snow clogging, air cleaner snow clogging progression prevention system, characterized by controlling so as to narrow the opening degree of the intake control valve. The said storage means, in response to engine Rotation speed and fuel injection amount, a plurality of intake air flow rate determination threshold and the intake control valve opening is stored in advance,
As the plurality of detection means,
A rotation speed detecting means for detecting the engine Rotation speed,
An accelerator opening detecting means for detecting the opening of the accelerator;
Further wherein the control means, the fuel injection amount determined according to the accelerator opening detected by the accelerator opening detection means, when a predetermined operating condition, engine Rotational speed and fuel injection amount The intake flow rate determination threshold value is acquired from the storage unit in response to the determination, and the intake control valve is determined to be greater than the threshold value by comparing the determination threshold value with the intake flow rate measured by the flow rate detection unit. cleaner snow clogging progression prevention system according to claim 1, wherein the controller controls so narrow the opening to a Jo Tokoro opening degree. As the plurality of detection means,
Outside air temperature detecting means for detecting the temperature of air or intake air in the vicinity of the air cleaning device;
Vehicle speed detecting means for detecting the traveling speed of the vehicle;
The control means grasps the driving state based on signals from the flow rate detection means, the rotation speed detection means, the accelerator opening detection means, the outside air temperature detection means, and the vehicle speed detection means. and, in the case of predetermined operating conditions, engine Rotational speed and obtains the intake air flow rate determination threshold from the storage means in accordance with the fuel injection amount, measured by the flow rate detecting unit and the determination threshold intake 3. The air cleaner according to claim 2 , wherein when the flow rate is compared and it is determined that the threshold value is exceeded, the opening degree of the intake control valve is controlled to be reduced to a predetermined opening degree. Progress prevention system. An air compressor for compressing air introduced from the front Symbol air cleaning device, and a compressed air cooler for cooling the air compressed by the air compressor, the intake control valve and the compressed air cooling system wherein The snow clogging progress preventing system for an air cleaner according to any one of claims 1 to 3 , wherein the system is provided between the intake pipes.

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