JP2024013539A - engine equipment - Google Patents

Abstract

An object of the present invention is to suppress the temperature of an engine intake pipe downstream of an intercooler from becoming excessively high. [Solution] An engine having an intake pipe, an intercooler attached to the intake pipe, and an exhaust pipe, a compressor placed upstream of the intercooler in the intake pipe, and a compressor placed in the exhaust pipe and rotating integrally with the compressor. A turbocharger having a wastegate valve installed in a bypass pipe installed in an exhaust pipe so as to bypass the turbine, the engine device being installed downstream of an intercooler in an intake pipe. and a control device that prohibits closing control to close the waste gate valve when a detected value of the temperature sensor is equal to or higher than a temperature threshold or when an abnormality occurs in the temperature sensor. [Selection diagram] Figure 3

Description

The present invention relates to an engine device.

BACKGROUND ART Conventionally, as this type of engine device, one including an engine having an intake pipe and an exhaust pipe, an intercooler, and a supercharger has been proposed (see, for example, Patent Document 1). Here, the intercooler is attached to the intake pipe. A supercharger consists of a compressor placed upstream of the intercooler in the intake pipe, a turbine placed in the exhaust pipe and rotating together with the compressor, and a bypass pipe attached to the exhaust pipe to bypass the turbine. A wastegate valve is provided. In this engine device, when a decrease in the cooling capacity of the intercooler is detected, the ignition timing is retarded to prevent knocking.

Japanese Unexamined Patent Publication No. 185627/1983

In engine systems, when the cooling capacity of the intercooler is reduced and the supercharger is operating, the temperature downstream of the intercooler in the intake pipe tends to rise, causing the temperature inside the combustion chamber to rise. Therefore, as mentioned above, ignition retardation is performed to prevent knocking. There is a need for methods other than this ignition retardation to suppress the temperature of the intake pipe downstream of the intercooler from becoming excessively high.

The main purpose of the engine device of the present invention is to suppress the temperature of the intake pipe of the engine downstream of the intercooler from becoming excessively high.

The engine device of the present invention employs the following means to achieve the above-mentioned main purpose.

The engine device of the present invention includes:
an engine having an intake pipe, an intercooler attached to the intake pipe, and an exhaust pipe;
A compressor disposed upstream of the intercooler in the intake pipe, a turbine disposed in the exhaust pipe and rotating together with the compressor, and a bypass pipe attached to the exhaust pipe so as to bypass the turbine. a supercharger having a waste gate valve provided in the
An engine device comprising:
a temperature sensor attached to the intake pipe downstream of the intercooler;
a control device that prohibits closing control to cause the waste gate valve to close when a detected value of the temperature sensor is equal to or higher than a temperature threshold and when an abnormality has occurred in the temperature sensor;
The main point is to have the following.

In the engine device of the present invention, when the detected value of the temperature sensor installed downstream of the intercooler in the intake pipe of the engine is equal to or higher than the temperature threshold, and when an abnormality has occurred in the temperature sensor, the waste gate valve Prohibits closing control that makes the closing side. Thereby, it is possible to suppress the temperature of the intake pipe downstream of the intercooler from becoming excessively high.

1 is a configuration diagram showing an outline of the configuration of an engine device 10. FIG. 7 is an explanatory diagram showing an example of input/output signals of the electronic control unit 70. FIG. It is a flowchart which shows an example of permission/denial determination processing.

Next, a mode for carrying out the present invention will be described using examples.

FIG. 1 is a block diagram schematically showing the structure of an engine device 10 as an embodiment of the present invention. FIG. 2 is an explanatory diagram showing an example of input/output signals of the electronic control unit 70. The engine device 10 of the embodiment is installed in general vehicles that run using power from the engine 12 and various hybrid vehicles that include a motor in addition to the engine 12. This engine device 10 includes an engine 12, a supercharger 40, and an electronic control unit 70, as shown in FIGS. 1 and 2.

The engine 12 is configured as an internal combustion engine that outputs power through four strokes of intake, compression, expansion (explosive combustion), and exhaust using fuel such as gasoline or light oil from a fuel tank. This engine 12 includes an in-cylinder injection valve 28 that injects fuel into a combustion chamber 30 and a spark plug 31 . The in-cylinder injection valve 28 is disposed approximately at the center of the top of the combustion chamber 30, and injects fuel in a spray form. The spark plug 31 is arranged near the in-cylinder injection valve 28 so as to ignite the fuel sprayed from the in-cylinder injection valve 28 .

The engine 12 sucks air purified by an air cleaner 22 into an intake pipe 23 , passes through an intercooler 25 , a throttle valve 26 , and a surge tank 27 in this order, and then sucks the air into a combustion chamber 30 via an intake valve 29 . Further, the engine 12 injects fuel from the in-cylinder injection valve 28 once or in multiple times during the intake stroke, compression stroke, or expansion stroke, and causes the fuel to explode and burn due to the electric spark from the ignition plug 31. Then, the engine 12 converts the reciprocating motion of the piston 32, which is pushed down by the energy generated by the explosive combustion, into rotational motion of the crankshaft 14. In particular, when injecting fuel during the expansion stroke, the fuel injection from the in-cylinder injection valve 28 and the ignition from the spark plug 31 during the expansion stroke are synchronized so that the sprayed fuel injected from the in-cylinder injection valve 28 can be ignited. It is done. Exhaust gas discharged from the combustion chamber 30 to the exhaust pipe 35 via the exhaust valve 33 is discharged to the outside air via the purification device 37. The purification device 37 includes a purification catalyst (three-way catalyst) 37a that purifies harmful components such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx).

The supercharger 40 is configured as a turbocharger and includes a compressor 41, a turbine 42, a rotating shaft 43, a wastegate valve 44, and a blow-off valve 45. Compressor 41 is arranged upstream of intercooler 25 in intake pipe 23 . The turbine 42 is disposed upstream of the purifying device 37 of the exhaust pipe 35. The rotating shaft 43 connects the compressor 41 and the turbine 42. The wastegate valve 44 is provided in a bypass pipe 36 that communicates between the upstream side and the downstream side of the turbine 42 in the exhaust pipe 35, and is controlled by the electronic control unit 70. The blow-off valve 45 is provided in the bypass pipe 24 that communicates between the upstream side and the downstream side of the compressor 41 in the intake pipe 23, and is controlled by the electronic control unit 70.

In this supercharger 40, by adjusting the opening degree of the waste gate valve 44, the distribution ratio between the amount of exhaust gas flowing through the bypass pipe 36 and the amount of exhaust gas flowing through the turbine 42 is adjusted, and the rotational driving force of the turbine 42 is adjusted. The amount of compressed air by the compressor 41 is adjusted, and the supercharging pressure (intake pressure) of the engine 12 is adjusted. Here, the distribution ratio is adjusted so that, in detail, the smaller the opening degree of the wastegate valve 44, the smaller the amount of exhaust gas flowing through the bypass pipe 36 and the larger the amount of exhaust gas flowing through the turbine 42. Note that when the wastegate valve 44 is fully open, the engine 12 can operate in the same manner as a naturally aspirated engine that does not include the supercharger 40.

In addition, in the supercharger 40, when the pressure on the downstream side of the compressor 41 in the intake pipe 23 is higher than the pressure on the upstream side to some extent, by opening the blow-off valve 45, the surplus on the downstream side of the compressor 41 is Pressure can be released. Note that the blow-off valve 45 is configured as a check valve that opens when the pressure downstream of the compressor 41 in the intake pipe 23 becomes higher than the pressure upstream to some extent, instead of a valve controlled by the electronic control unit 70. It is also possible to do so.

A cooling device 50 that cools a heat exchange medium (such as cooling water) of the intercooler 25 is attached to the intercooler 25 . The cooling device 50 includes a circulation flow path 52, a radiator 54, and an electric pump 56. The circulation flow path 52 is a flow path for circulating a heat exchange medium (such as cooling water) between the intercooler 25 and the radiator 54 . The radiator 54 exchanges heat between the internal heat exchange medium and the outside air. The circulation pump 56 circulates the heat exchange medium in the circulation flow path 52.

As shown in FIG. 2, the electronic control unit 70 includes a microcomputer having a CPU 71, a ROM 72, a RAM 73, a flash memory 74, and an input/output port. Signals from various sensors are input to the electronic control unit 70 via input ports. Signals input to the electronic control unit 70 include, for example, the crank angle θcr from the crank position sensor 14a that detects the rotational position of the crankshaft 14 of the engine 12, and the water temperature sensor 15 that detects the temperature of the cooling water of the engine 12. Examples include the cooling water temperature Tw from the engine oil temperature Tw, and the oil temperature To from the oil temperature sensor 16 that detects the temperature of the engine oil. The throttle opening degree TH from the throttle position sensor 26a that detects the opening degree of the throttle valve 26 can also be mentioned. The intake air amount Qa from the air flow meter 23a installed upstream of the compressor 41 in the intake pipe 23, the intake temperature Tin from the intake temperature sensor 23t installed upstream of the compressor 41 in the intake pipe 23, and the intake air Intake pressure (compressor prepressure) Pin from the intake pressure sensor 23b installed upstream of the compressor 41 in the intake pipe 23, supercharging pressure sensor 23c installed between the compressor 41 and the intercooler 25 in the intake pipe 23 The supercharging pressure Pc from . The surge pressure (throttle back pressure) Ps from the surge pressure sensor 27a attached to the surge tank 27 and the surge temperature Ts from the surge temperature sensor 27b attached to the surge tank 27 can also be mentioned. The front air-fuel ratio AF1 from the front air-fuel ratio sensor 38a installed between the turbine 42 of the supercharger 40 and the purification device 37 in the exhaust pipe 35, and the rear air-fuel ratio installed on the downstream side of the purification device 37 in the exhaust pipe 35. The rear air-fuel ratio AF2 from the air-fuel ratio sensor 38b can also be mentioned.

Various control signals are output from the electronic control unit 70 via an output port. Examples of the signals output from the electronic control unit 70 include a control signal to the throttle valve 26, a control signal to the in-cylinder injection valve 28, and a control signal to the spark plug 31. A control signal to the waste gate valve 44 and a control signal to the blow-off valve 45 can also be mentioned. A control signal to the circulation pump 56 may also be mentioned.

The electronic control unit 70 calculates the rotational speed Ne of the engine 12 and the load factor (ratio of the volume of air actually taken in in one cycle to the stroke volume per cycle of the engine 12) KL. The rotation speed Ne is calculated based on the crank angle θcr from the crank position sensor 14a. The load factor KL is calculated based on the intake air amount Qa from the air flow meter 23a and the rotation speed Ne.

In the engine device 10 of the embodiment configured in this way, the electronic control unit 70 controls the intake air amount to control the opening degree of the throttle valve 26 and the in-cylinder injection valve 28 based on the required load factor KL* of the engine 12. It performs fuel injection control to control the amount of fuel injected from the engine, ignition control to control the ignition timing of the spark plug 31, supercharging control to control the opening degree of the waste gate valve 44, etc.

Next, the operation of the engine device 10 according to the embodiment, particularly the operation of determining whether or not to perform closing control to close the waste gate valve 44 during supercharging control will be described. FIG. 3 is a flowchart illustrating an example of the permission/denial determination process repeatedly executed by the electronic control unit 70.

When the permission/disapproval determination process of FIG. 3 is executed, the electronic control unit 70 first determines whether the surge temperature sensor 27b is normal (step S100). In this determination process, for example, when the surge temperature Ts from the surge temperature sensor 27b is within the allowable temperature range that can be taken when the surge temperature sensor 27b is normal, it is determined that the surge temperature sensor 27b is normal. On the other hand, when the signal (surge temperature Ts) from the surge temperature sensor 27b is interrupted for a predetermined period of time, or when the surge temperature Ts from the surge temperature sensor 27b is outside the allowable temperature range, the surge temperature sensor 27b It is determined that there is an abnormality.

When it is determined in step S100 that the surge temperature sensor 27b is normal, the surge temperature Ts from the surge temperature sensor 27b is input (step S110), and it is determined whether the input surge temperature Ts is equal to or higher than the threshold value Tsref. (Step S130). If the wastegate valve 44 is controlled to close when the cooling performance of the intercooler 25 has decreased, the temperature downstream of the intercooler 25 in the intake pipe 23 (surge temperature Ts and temperature inside the combustion chamber 30) will decrease. tends to be high. The threshold value is a threshold value used to determine whether or not the cooling performance of the intercooler 25 has deteriorated, and is, for example, about 60° C. to 70° C.

When it is determined in step S130 that the surge temperature Ts is less than the threshold value Tsref, it is determined that the cooling performance of the intercooler 25 has not deteriorated, and the closing control of the waste gate valve 44 is permitted (step S140), and the main processing end. This allows the load factor KL to be relatively high.

When it is determined in step S130 that the surge temperature Ts is equal to or higher than the threshold value Tsref, it is determined that the cooling performance of the intercooler 25 has decreased, and the closing control of the waste gate valve 44 is prohibited (step S150), and the main processing end. Thereby, it is possible to suppress the temperature (surge temperature Ts and temperature inside the combustion chamber 30) of the intake pipe 23 downstream of the intercooler 25 from becoming excessively high. As a result, it is possible to suppress the ignition retardation for preventing knocking due to the temperature in the combustion chamber 30 becoming excessively high.

When it is determined in step S100 that the surge temperature sensor 27b is abnormal, the surge temperature Ts is set to a predetermined value Ts1 higher than the above-mentioned threshold value Tsref (step S120), and the processes from step S130 onwards are executed. As a result, when the surge temperature sensor 27b is abnormal, it is determined in step S130 that the surge temperature Ts is equal to or higher than the threshold value Tsref, and the closing control of the waste gate valve 44 is prohibited in step S150. Therefore, even if the actual surge temperature is high, the temperature downstream of the intercooler 25 in the intake pipe 23 (the surge temperature Ts and the temperature inside the combustion chamber 30) can be suppressed from becoming excessively high.

In the engine device 10 of the embodiment described above, when the surge temperature sensor 27b is normal and the surge temperature Ts detected by the surge temperature sensor 27b is equal to or higher than the threshold value Tsref, the closing control of the waste gate valve 44 is prohibited. Further, when the surge temperature sensor 27b is abnormal, closing control of the waste gate valve 44 is prohibited by setting the surge temperature Ts to a predetermined value Ts1 higher than the threshold value Tsref and comparing it with the threshold value Tsref. As a result, it is possible to suppress the temperature (surge temperature Ts and temperature inside the combustion chamber 30) of the intake pipe 23 downstream of the intercooler 25 from becoming excessively high.

In the embodiment, when the surge temperature sensor 27b is abnormal, the electronic control unit 70 closes the waste gate valve 44 by setting the surge temperature Ts to a predetermined value Ts1 higher than the threshold value Tsref and comparing it with the threshold value Tsref. control is prohibited. However, when the surge temperature sensor 27b is abnormal, the closing control of the waste gate valve 44 may be prohibited without setting the surge temperature Ts. Even in this case, the same effects as in the embodiment can be achieved.

In the embodiment, when the surge temperature sensor 27b is normal, the electronic control unit 70 allows or prohibits the closing control of the waste gate valve 44 depending on whether the surge temperature Ts is equal to or higher than the threshold value Tsref. . However, in order to avoid frequent switching between permission and prohibition of closing control of the waste gate valve 44, a hysteresis (margin) regarding temperature may be provided.

In the embodiment, the intercooler 25 is cooled by a water-cooled cooling device 50, but it may be cooled by an air-cooled cooling device.

Although the embodiments of the present invention have been described above using examples, the present invention is not limited to these examples in any way, and may be modified in various forms without departing from the gist of the present invention. Of course, it can be implemented.

INDUSTRIAL APPLICATION This invention can be utilized for the manufacturing industry of an engine device, etc.

Reference Signs List 10 engine device, 12 engine, 27b surge temperature sensor, 40 supercharger, 70 electronic control unit.

Claims (1)

an engine having an intake pipe, an intercooler attached to the intake pipe, and an exhaust pipe;
A compressor disposed upstream of the intercooler in the intake pipe, a turbine disposed in the exhaust pipe and rotating together with the compressor, and a bypass pipe attached to the exhaust pipe so as to bypass the turbine. a supercharger having a waste gate valve provided in the
An engine device comprising:
a temperature sensor attached to the intake pipe downstream of the intercooler;
a control device that prohibits closing control to cause the waste gate valve to close when a detected value of the temperature sensor is equal to or higher than a temperature threshold and when an abnormality has occurred in the temperature sensor;
An engine device comprising:

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