JP6514052B2 - Control device for internal combustion engine and throttle valve protection device - Google Patents

Description

  The present invention relates to a control device for an internal combustion engine and a throttle valve protection device.

  In an internal combustion engine equipped with a supercharger and an air-cooled intercooler, in order to increase the cooling efficiency of the intercooler, the intercooler needs to be applied to the traveling air, and both the installation location and the shape have been limited. In such a system, the throttle valve can be installed downstream of the intercooler or upstream of the compressor of the supercharger, and the intake air passing through the throttle valve can be installed before or after supercharging. It was cooled by a cooler.

  Further, even in an internal combustion engine adopting a water-cooled intercooler, when the throttle valve is installed downstream of the water-cooled intercooler or upstream of the compressor of the supercharger, the intake air passing through the throttle valve is Before being supercharged, or after being supercharged, it was cooled by the intercooler (see, for example, Patent Document 1), and damage to the throttle valve due to an increase in intake temperature was less likely to occur.

  In such a system, there is known a technique for reducing the intake air temperature after supercharging in order to reduce knocking and exhaust emissions in combustion in a cylinder.

JP, 2010-077864, A

  As described above, in a system employing a water-cooled intercooler, since there is little restriction on the installation location of the intercooler, it is also possible to, for example, integrate the water-cooled intercooler with the collector. Since the collector is provided to equalize the amount of intake air to each cylinder of the internal combustion engine, a throttle valve for adjusting the amount of intake air to the cylinder needs to be installed upstream of the collector.

  In this case, the throttle valve will be installed downstream of the compressor and upstream of the intercooler, and will be exposed to intake air whose temperature has risen by supercharging. Therefore, when the outside air temperature is high or when the supercharging pressure is high, the supercharged intake air may become extremely hot, which may cause the failure of the throttle valve.

  An object of the present invention is to provide a control device for an internal combustion engine and a throttle valve protection device capable of avoiding damage to the throttle valve due to temperature increase of supercharged intake air.

In order to achieve the above object, the present invention provides a control device for an internal combustion engine for controlling an internal combustion engine comprising a throttle valve for adjusting an intake amount and a supercharger for increasing the pressure of intake air. The apparatus calculates the temperature upstream of the throttle valve and downstream of the turbocharger, and the calculated temperature is equal to or higher than a first threshold value which is smaller by an allowance than the upper limit of the heat resistance temperature of the throttle valve. If it is determined that the calculated temperature is equal to or higher than the first threshold value, the supercharging pressure reducing device is operated to reduce the supercharging pressure of the intake air supercharged by the supercharger.

  According to the present invention, damage to the throttle valve due to the temperature rise of the supercharged intake can be avoided. Problems, configurations, and effects other than those described above will be apparent from the description of the embodiments below.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the whole structure of the engine control system containing the control apparatus (ECU) of the internal combustion engine by 1st Embodiment of this invention. It is explanatory drawing of the engine control unit shown in FIG. It is a related figure of the pressure difference and temperature difference of the intake air before and behind supercharging. It is a flowchart which shows the calculation method of throttle valve high temperature avoidance which the control apparatus of the internal combustion engine by the 1st Embodiment of this invention performs. It is a time history waveform of an intake air temperature rise and a throttle valve temperature rise. It is a flowchart which shows the calculation method of throttle valve high temperature avoidance which the control apparatus of the internal combustion engine by the 2nd Embodiment of this invention performs. It is a flowchart which shows the calculation method of throttle valve high temperature avoidance which the control apparatus of the internal combustion engine by the 3rd Embodiment of this invention performs. It is a flowchart which shows the calculation method of throttle valve high temperature avoidance which the control apparatus of the internal combustion engine by the 4th Embodiment of this invention performs.

  Hereinafter, the configuration and effects of the control system for an internal combustion engine according to the first to fourth embodiments of the present invention will be described using the drawings. In the drawings, the same reference numerals indicate the same parts.

First Embodiment
FIG. 1 shows an overall configuration of an engine control system including a control device (ECU 20) for an internal combustion engine according to a first embodiment of the present invention.

  The engine 100 (internal combustion engine) is, as an example, a gasoline engine for an automobile that performs spark ignition combustion. An air flow sensor 1 for measuring the amount of intake air and intake air, a pressure sensor 3 for detecting intake pressure, a compressor 4a of a supercharger for supercharging intake, and intake air for detecting the temperature of supercharged intake The temperature sensor 17, the intercooler 6 for cooling the intake air, the electronically controlled throttle valve 2 for adjusting the intake pipe pressure, and the recirculation valve 18 for adjusting the amount of air flowing from the downstream of the compressor 4a to the upstream of the compressor 4a An appropriate position of each of the tubes is provided.

  Here, the intercooler 6 is integrated with the collector and is installed downstream of the throttle valve 2. The engine 100 is also provided with a fuel injection device (hereinafter referred to as an injector) 13 for injecting fuel into the cylinders 14 of each cylinder, and an ignition plug 16 for supplying ignition energy for each cylinder. In addition, a variable valve 5 is provided in the cylinder head to adjust the gas flowing into and out of the cylinder. By adjusting the variable valve 5, the intake amount and internal EGR amount of all the cylinders are adjusted. Although not shown, a high pressure fuel pump for supplying high pressure fuel to the injector 13 is connected to the injector 13 by a fuel pipe, and a fuel pressure sensor for measuring a fuel injection pressure is provided in the fuel pipe. It is equipped.

  Further, a turbine 4b for applying a rotational force to a compressor 4a of a turbocharger by exhaust energy, an electronic control waste gate valve 11 for adjusting an exhaust flow rate flowing to the turbine, and a three-way catalyst 10 for purifying exhaust gas; An air-fuel ratio sensor 9 for detecting the air-fuel ratio of the exhaust gas on the upstream side of the three-way catalyst 10, which is an aspect of the air-fuel ratio detector, is provided at each appropriate position of the exhaust pipe 15.

  Furthermore, an EGR pipe 40 for recirculating the exhaust gas from the downstream of the catalyst 10 of the exhaust pipe to the upstream of the compressor 4a of the intake pipe is provided. Further, an EGR cooler 42 for cooling the EGR, an EGR valve (EGR mechanism) 41 for controlling the EGR flow rate, a differential pressure sensor 43 for detecting a differential pressure before and after the EGR valve, an EGR temperature sensor 44 for detecting the EGR temperature. Are mounted at appropriate positions of each of the EGR pipes 40. Also, although not shown, a temperature sensor 45 is provided to measure the temperature of the cooling water around the engine.

  Signals obtained from the air flow sensor 1, the intake pressure sensor 3, the intake pressure sensor 22 after the compressor 4 a, the air-fuel ratio sensor 9, the differential pressure sensor 43, and the EGR temperature sensor 44 are sent to an engine control unit (ECU) 20. Further, the amount of depression of the accelerator pedal, that is, a signal obtained from the accelerator opening degree sensor 12 for detecting the accelerator opening degree, and a signal obtained from the brake switch 19 for detecting that the brake is depressed are sent to the ECU 20.

  The ECU 20 calculates the required torque based on the output signal of the accelerator opening degree sensor 12. That is, the accelerator opening degree sensor 12 is used as a required torque detection sensor that detects the required torque for the engine. Further, the ECU 20 calculates the rotational speed of the engine based on the output signal of the crank angle sensor. The ECU 20 optimally calculates the main operation amounts of the engine, such as the air flow rate, the fuel injection amount, the ignition timing, and the fuel pressure, based on the operating state of the engine obtained from the outputs of the various sensors. The throttle valve 2 and the ECU 20 constitute a throttle valve protection device 200.

  The fuel injection amount calculated by the ECU 20 is converted into a valve opening pulse signal and is sent to the injector 13. Further, an ignition signal is sent to the spark plug 17 so as to be ignited at the ignition timing calculated by the ECU 20. Further, the throttle opening degree calculated by the ECU 20 is sent to the electronically controlled throttle 2 as a throttle drive signal. Further, the EGR valve opening calculated by the ECU 20 is sent to the EGR valve 41 as an EGR valve opening drive signal.

  Fuel is injected to air that has flowed into the cylinder 14 from the intake pipe through the intake valve to form an air-fuel mixture. The air-fuel mixture detonates by sparks generated from the spark plug 16 at a predetermined ignition timing, and the combustion pressure pushes down the piston to become the driving force of the engine. Further, exhaust gas after explosion is fed into the three-way catalyst 10 through the exhaust pipe 15, and exhaust components are purified in the three-way catalyst 10 and discharged to the outside.

  As shown in FIG. 2, the ECU 20 incorporates the output values of the sensors installed in the engine 100 and the output values of the sensors for detecting the operation information of the driver of the vehicle in which the internal combustion engine is installed. Each actuator is controlled by converting it into a digital value and performing an operation with an A / D converter or a timer that detects the period of the periodic signal, and outputting the result of the operation as a control signal.

  As a signal to be input to the control unit 20, an airflow sensor 1 also having an intake temperature sensor, an intake pressure sensor 3, an intake pressure sensor 22 after supercharging, an intake temperature sensor 17 after supercharging, an accelerator opening sensor 12, a brake switch 18 There are output signals of the differential pressure sensor 43, the EGR temperature sensor 44, the intake pressure sensor 22, the differential pressure sensor 43, and the like.

  Further, control signals output from the control unit 20 include the electronically controlled waste gate valve 11, the recirculation valve 18, the electronically controlled throttle valve 2, the variable valve 5, the EGR valve 41, the injector 13, the spark plug 16 and the like.

  FIG. 3 is a diagram showing a relationship 201 between the pressure difference between the intake air before and after supercharging by the compressor 4a and the temperature difference between the intake air before and after supercharging by the compressor 4a. As shown in this figure, due to the supercharging by the compressor 4a, the higher the pressure of the supercharged intake air, the higher the temperature of the supercharged intake air. The intercooler 6 is installed to cool the intake air flowing into the cylinder 14 in order to avoid the output increase due to combustion and knocking, but when the throttle valve 2 is installed upstream of the intercooler 6 as in this embodiment The throttle valve 2 is exposed to a supercharged intake air that exceeds the heat-resistant temperature of the throttle valve 2.

  Therefore, in the first embodiment of the present invention, the failure of the throttle valve 2 is avoided by adjusting the intake temperature near the throttle valve 2 according to the flowchart shown in FIG.

First, it is determined whether the temperature of the intake air after supercharging has exceeded a temperature T1 obtained by adding a margin to a temperature at which the throttle valve may fail (S301). As a result of the determination, if the intake air temperature after supercharging does not exceed the temperature T1 (S301: No), the timer C (counter) is initialized to 0 (S302), and the process is ended. If the intake air temperature after supercharging exceeds the temperature T1 (S301: Yes), it is determined whether the intake air temperature after supercharging is higher than the predetermined temperature T2 (S303). Here the predetermined temperature T2, similar to the predetermined temperature T1, the intake air temperature after supercharging, although the temperature at which a margin allowance in temperature that might throttle valve fails, the than the predetermined temperature T 1 of The allowance is reduced.

  If the intake air temperature after supercharging is higher than the predetermined temperature T2, it is necessary to reduce the intake air temperature immediately, close to the temperature at which the throttle valve may fail. Therefore, by opening the recirculation valve 18 and returning the supercharged intake air downstream of the compressor 4a to the upstream side of the compressor 4a, the pressure around the throttle valve 2 downstream of the compressor is reduced, and the intake air temperature around the throttle valve 2 Decrease (S304).

  However, although this method is immediacy, depending on the size of the portion where the recirculation valve 18 is provided, which is connected from the downstream side to the upstream side of the compressor 4a, the supercharging pressure reducing effect is limited. Therefore, after the recirculation valve 18 is opened, waste gate control (S309) and valve-tie control (intake valve timing control) described later, which can be expected fundamentally to reduce the supercharging pressure, are performed (S310).

  If the intake air temperature after supercharging is lower than the predetermined temperature T2, it is determined whether the first calculation is performed after the intake air temperature after supercharging exceeds the predetermined temperature T1 (S305), and if it is the first calculation, its timing The delay time D1 is determined according to the intake air flow rate detected in step S306 (S306). The delay time is a value taking into consideration the time until the temperature of the intake air passing through the throttle valve 2 installation portion is transmitted to the throttle valve 2.

  The method of setting the delay time will be described with reference to FIG. FIG. 5 is a time history waveform of the temperature of the throttle valve 2 when it is assumed that the intake air temperature 202 passing through the throttle valve 2 rises in a step-like manner. The temperatures 203 and 204 of the throttle valve 2 gradually approach the intake temperature after the intake temperature 202 passing through the throttle valve 2 rises. This time (Td_203, Td_204) changes according to the intake flow passing through the throttle valve 2. When the intake flow is large, the temperature rise of the throttle valve 2 is quick (intake temperature 203), and when the intake flow is small. The temperature rise of the throttle valve 2 is delayed (intake temperature 204).

In this embodiment, as shown in FIG. 4, the delay time D1 is determined once at the above timing (S306), but if the flow rate of intake air increases thereafter, the delay time D1 may be changed to a shorter value. Good. Further, in the present embodiment, by comparing the intake air temperature after the boost with the predetermined value T1, T 3, may be measured the temperature of the throttle valve directly, the delay time D1 and 0 in this case .

  Thereafter, the timer C is compared with the delay time D1 (S307), and if the timer C is smaller than the delay time D1 (S307: No), the value of the timer C is incremented (S308), and the processing is ended.

  If the timer C is longer than the delay time D1 (S307: Yes), the electronic waste gate control is performed (S309) to reduce the supercharging by the compressor 4a and reduce the supercharging pressure after the compressor, The pressure of the intake air at the throttle passage portion (throttle valve installation portion) is reduced to lower the temperature of the intake air at the throttle passage portion.

  Also, the throttle valve 2 is controlled to the open side (S310), and the intake valve timing is adjusted (S311), and the intake air amount in the cylinder intake process is increased to reduce the pressure of intake air in front of the cylinder. Thus, the pressure of the intake air at the throttle passage portion is reduced, and the temperature of the intake air at the throttle passage portion is reduced.

  The step S309 has the function of reducing the air flow downstream of the compressor 4a, that is, the function of reducing the amount of air taken into the cylinder. On the other hand, the operations described in S310 and S311 have the effect of increasing the amount of air drawn into the cylinder. Therefore, both control amounts are set so that the amount of air flowing into the cylinder does not change before and after the decrease in intake pressure and intake temperature after supercharging according to the embodiment of the present invention, and a desired engine torque can be obtained. desirable.

  Here, the ECU 20 functions as a device control unit that controls at least one of the waste gate valve 11 and the throttle valve 2 and the intake valve so that the amount of air flowing into the cylinder does not change. As a result, the boost pressure can be lowered to lower the temperature of the intake air around the throttle valve 2 and the required engine torque can be maintained.

  However, when the post-supercharge intake pressure and intake temperature decrease state continues for a long time according to the embodiment of the present invention, or after the post-supercharge intake pressure and intake temperature decrease according to the embodiment of the present invention. If the intake air temperature after supercharging is very high, priority is given to protection of the throttle valve 2 even if the desired engine torque can not be obtained, and a reduction in the supercharging rate of the compressor 4a by the power control of waste gate The intake valve timing is adjusted to increase the amount of intake air in the cylinder intake process.

  The waste gate valve 11, the throttle valve 2 or the intake valve constitutes a boost pressure reducing device for reducing the boost pressure of the intake air supercharged by the supercharger.

  When the intake temperature after supercharging (a parameter representing the temperature of the throttle valve 2 for adjusting the intake amount) is equal to or higher than a first threshold T1, the ECU 20 connects a passage connecting the upstream and the downstream of the turbine 4b of the turbocharger. It functions as a device control unit that increases the degree of opening of the installed waste gate valve 11.

  Thus, the temperature of the intake air around the throttle valve 2 can be reduced while reducing the engine torque.

  When the intake temperature after supercharging is equal to or higher than the first threshold T1, the ECU 20 (device control unit) increases the opening degree of the throttle valve 2, or the intake temperature after supercharging is equal to or higher than the first threshold T1. If so, the intake valve is controlled to increase the amount of intake air flowing into the cylinder of the engine (internal combustion engine).

  Thereby, the temperature of the intake air around the throttle valve 2 can be reduced while increasing the engine torque.

  The ECU 20 (device control unit) increases the opening degree of the recirculation valve 18 when the intake air temperature after supercharging is equal to or higher than the first threshold T1.

  Thereby, the supercharging pressure can be reduced in a short time, and the temperature of the intake air around the throttle valve 2 can be reduced.

  As described above, according to the present embodiment, damage to the throttle valve due to the temperature rise of the supercharged intake can be avoided.

Second Embodiment
FIG. 6 is a flowchart showing processing of a control device of an internal combustion engine according to a second embodiment of the present invention.

  In the present embodiment, assuming the engine 100 in which the post-charging intake air temperature sensor 17 shown in FIG. 1 is not installed, the intake air temperature downstream of the compressor 4 a is estimated as described below.

  First, the intake air temperature downstream of the compressor 4a is calculated from the output value of the intake temperature sensor 1 before the compressor 4a, the intake pressure sensor 3, the pressure sensor 22 after the compressor 4a, the EGR temperature sensor 44, and the EGR valve control amount (S401 ). Basically, based on the temperature detected by the intake air temperature sensor 1 and the pressure before and after the compressor obtained from the pressure sensor 3 before the compressor 4a and the pressure sensor 22 after the compressor 4a using the relationship shown in FIG. The temperature downstream of the compressor 4a is calculated. The relationship shown in FIG. 3 is stored in a memory (storage device) of the ECU 20 as, for example, a map or a function.

  Here, the ECU 20 determines the intake air temperature after supercharging (a parameter representative of the temperature of the throttle valve 2) based on the intake air temperature upstream of the compressor 4a of the turbocharger and the pressure upstream and downstream of the compressor 4a. It functions as a first estimation unit to estimate. As a result, the intake air temperature sensor 17 becomes unnecessary, and the manufacturing cost can be reduced.

  However, when the EGR valve is open, this influence is taken into consideration because the intake air temperature before the compressor 4a changes according to the EGR temperature and the ratio of the EGR gas.

  Here, the ECU 20 corrects the estimated intake air temperature after supercharging based on the EGR amount indicating the amount of air recirculating upstream of the compressor 4a and the EGR temperature indicating the temperature of air recirculating upstream of the compressor 4a. Function as a correction unit. This improves the accuracy of the estimated intake air temperature after supercharging.

  Next, it is determined whether the intake air temperature after supercharging has exceeded a temperature T1 obtained by adding a margin to a temperature at which the throttle valve may fail (S402).

  As a result of the determination, if the intake air temperature after supercharging exceeds the temperature T1 (S402: Yes), the power control with wastegate is performed (S403), the supercharging by the compressor 4a is reduced, and the post-compressor excess By reducing the supply pressure, the pressure of the intake air at the throttle passage portion is reduced, and the temperature of the intake air at the throttle passage portion is reduced.

  As a result of the determination, if the intake air temperature after supercharging does not exceed the temperature T1 (S402: No), it is determined whether the intake air temperature after supercharging is higher than the predetermined temperature T3 (S404). Here, like the predetermined temperature T1, the predetermined temperature T3 is a temperature at which the intake air temperature after supercharging has an allowance for the temperature at which the throttle valve may fail, but the temperature is higher than the predetermined temperature T1. The allowance is increased.

  If the intake air temperature after supercharging is higher than the predetermined temperature T3 (S404: No), the process is ended (RETURN).

  If the intake air temperature after supercharging is lower than the predetermined temperature T3 (S404: Yes), it is determined whether or not the power control for reducing the supercharging pressure is being performed (S405). If not (S405: No), the process is ended, and if it is performed, the electric control for wastegate control for reducing the supercharging pressure is ended, and the control shifts to the usual electric control for wastegate control ( S406).

  As described above, according to the present embodiment, damage to the throttle valve due to the temperature rise of the supercharged intake can be avoided.

Third Embodiment
FIG. 7 is a flowchart showing processing of a control device of an internal combustion engine according to a third embodiment of the present invention.

  First, it is determined whether the intake air temperature after supercharging is greater than a predetermined temperature T4 (S501). Here, like the predetermined temperature T1, the predetermined temperature T4 is a temperature at which the intake air temperature after supercharging has an allowance for the temperature at which the throttle valve may fail, but the predetermined temperature T4 is higher than the predetermined temperature T2. The allowance is increased.

  As a result, when the intake air temperature after supercharging is lower than the predetermined temperature T4 (S501: No), the process is ended. If the intake air temperature after supercharging is higher than the predetermined temperature T4, it is determined from the accelerator opening degree and the state of the brake switch whether there is a request for deceleration, that is, a request for engine torque reduction (S502). If it is determined that there is no engine torque reduction request (S502: No), the process ends.

  If it is determined that the engine torque reduction request is present (S502: Yes), the electronic control of the waste gate is performed to reduce the supercharging by the compressor 4a and reduce the supercharging pressure after the compressor. This is because, if the throttle valve is closed in order to throttle the intake air amount according to the engine torque reduction request, the pressure of the intake air from the compressor 4a to the throttle valve 2 rises and the temperature is also raised in advance. is there.

  Here, the ECU 20 is a second estimation unit that estimates in advance whether reduction of the torque of the internal combustion engine is required based on at least one of the operation amount of the accelerator and the brake, and after supercharging It functions as a second determination unit that determines whether the intake air temperature (a parameter representing the temperature of the throttle valve 2 that adjusts the intake air amount) is equal to or higher than a second threshold T4 that is smaller than the first threshold T1.

  Further, the ECU 20 is estimated in advance that torque reduction is required, and if it is determined that the intake air temperature after supercharging is equal to or higher than a second threshold value lower than the first threshold value Functions as a device control unit for operating the electronically controlled waste gate valve 11, the throttle valve 2 or the intake valve).

  Thereby, it is possible to prevent the intake temperature around the throttle valve 2 from rising due to the engine torque reduction request (deceleration request).

  As described above, according to the present embodiment, damage to the throttle valve due to the temperature rise of the supercharged intake can be avoided.

Fourth Embodiment
FIG. 8 is a flowchart showing processing of a control device of an internal combustion engine according to a fourth embodiment of the present invention.

  In the present embodiment, first, it is determined whether or not the electric control waste gate control, valve timing control, throttle valve opening control, etc., which are the supercharging pressure reduction control, are performed (S601).

  If the supercharging pressure reduction control has not been performed (S601: No), the process ends. When the supercharging pressure reduction control is performed (S601: Yes), the intake air temperature after supercharging is compared with the predetermined temperature T5 (S602).

  Here, like the predetermined temperature T1, the predetermined temperature T5 is a temperature at which the intake air temperature after supercharging has an allowance for the temperature at which the throttle valve 2 may fail, but is higher than the predetermined temperature T1. It is assumed that the margin is increased.

  If the intake air temperature after supercharging is higher than the predetermined temperature T5 (S602: No), the process is ended. If the intake air temperature after supercharging is lower than the predetermined temperature T5 (S602: Yes), the throttle valve is controlled in the closing direction for a predetermined time to increase the flow rate of the intake air amount when passing through the throttle valve 2; Increase the cooling efficiency of

  The ECU 20 functions as a device control unit that reduces the opening degree of the throttle valve 2 after operating the supercharging pressure reduction device (including the electronically controlled waste gate valve 11, the throttle valve 2 or the intake valve). Thereby, the throttle valve 2 can be cooled quickly.

  The effects of the embodiment of the present invention can be obtained by a part or a combination of the flows described above with reference to FIGS.

(Modification)
In the first embodiment, as shown in FIG. 4, when the predetermined conditions (S301, S303, S305, S307) are satisfied, the ECU 20 executes the supercharging pressure reduction processing (S309, S310, S311). .

  However, simply, the ECU 20 (control device for an internal combustion engine) sets the intake temperature after supercharging (a parameter representative of the temperature of the throttle valve 2 for adjusting the intake amount) smaller than the upper limit of the heatproof temperature of the throttle valve 2 A first determination unit that determines whether or not the threshold temperature is equal to or higher than the threshold T1, and when the intake air temperature after supercharging is equal to or higher than the first threshold T1, the supercharging pressure of the supercharged intake air is It may function as a device control unit that operates the boost pressure reducing device (including the electronically controlled waste gate valve 11, the throttle valve 2 or the intake valve) to be lowered.

  Thereby, the supercharging pressure can be reduced, and the temperature of the intake air around the throttle valve 2 can be reduced. As a result, damage to the throttle valve 2 can be avoided.

  The function of the ECU 20 is realized by the microcomputer 121 (arithmetic unit) of the ECU 20 executing a predetermined program stored in an internal memory or an external memory (storage device).

  The ECU 20 controls the supercharging pressure (the electronic control waste gate valve 11, the throttle valve 2, and the like) after the intake air temperature after supercharging reaches the first threshold T1 or more according to the amount of intake air passing through the throttle valve 2. Alternatively, it may function as a determination unit that determines a delay time indicating a time until the intake valve is activated. In this case, after the delay time D1 has elapsed since the intake temperature after supercharging has reached the first threshold T1 or more, the ECU 20 (device control unit) reduces the supercharging pressure (the electronic control waste gate valve 11, the throttle Operate the valve 2 or the intake valve).

  Thus, the temperature of the intake air around the throttle valve 2 can be reduced according to the amount of intake air passing through the throttle valve 2.

  The present invention is not limited to the above-described embodiment, but includes various modifications. For example, the above-described embodiment is described in detail to explain the present invention in an easy-to-understand manner, and is not necessarily limited to one having all the described configurations. Further, part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Moreover, it is possible to add, delete, and replace other configurations for part of the configurations of the respective embodiments.

  In the above embodiment, whether or not the equal sign is included in the determination process (S302, S303, S402, S404, S501, S602) which compares the intake air temperature after supercharging with the magnitude of the predetermined temperatures T1 to T5 (threshold) It is optional.

  In the above embodiment, assuming that the upper limit of the heat resistant temperature of the throttle valve is Tupper, then Tupper> T2> T1. In addition, although the relationship of T1> T4> T5> T3 is materialized as an example, the magnitude correlation of T3, T4, and T5 is not this limitation.

  In addition, each of the configurations, functions, and the like described above may be realized by hardware by designing part or all of them, for example, by an integrated circuit. Information such as a program, a table, and a file for realizing each function can be stored in a storage medium such as a memory.

  The embodiment of the present invention may have the following aspects.

[First aspect]
The parameter representative of the temperature of the throttle valve 2 for adjusting the intake amount is the temperature of the throttle valve 2 or the intake temperature around the throttle valve 2.

[Second aspect]
The throttle valve is disposed downstream of the compressor 4 a of the turbocharger and upstream of the intercooler 6.

[Third aspect]
The intercooler 6 is integrated with the collector.

[Fourth aspect]
The waste gate valve 11 is electronically controlled by the ECU 20 (control device for an internal combustion engine).

DESCRIPTION OF SYMBOLS 1 ... Air flow sensor 2 which measures intake air quantity and intake temperature 2 ... electronically controlled throttle valve 3 ... intake pressure sensor 4a ... compressor 4b of a supercharger .... turbine .. 5 variable valve 6 .. Original catalyst 11 ... Electronic control waste gate valve 12 ... Accelerator opening sensor 13 ... Injector 14 ... Cylinder 15 ... Exhaust pipe 16 ... Ignition plug 17 ... Intake temperature sensor 18 after supercharging ... Recirculation valve 19 ... Brake switch 20 ... Engine Control unit 40 ... EGR pipe 41 ... EGR valve 42 ... EGR cooler 43 ... Differential pressure sensor 44 for detecting the differential pressure before and after the EGR valve ... EGR temperature sensor 45 ... engine coolant temperature sensor 100 ... engine (internal combustion engine)
200: Throttle valve protection device

Claims (12)

In a control device of an internal combustion engine for controlling an internal combustion engine, the control device comprising: a throttle valve for adjusting an intake air amount; and a turbocharger for increasing a pressure of intake air,
The controller is
The temperature on the upstream side of the throttle valve and on the downstream side of the turbocharger is calculated, and it is determined whether or not the calculated temperature is equal to or higher than a first threshold value smaller by an allowance than the upper limit of the heat resistance temperature of the throttle valve. Judge
A control device for an internal combustion engine, which operates a supercharging pressure reducing device for reducing supercharging pressure of intake air supercharged by the supercharger when the calculated temperature is equal to or higher than the first threshold value. The control device for an internal combustion engine according to claim 1,
The controller is
The compressor upstream of the intake air temperature of the turbocharger, and on the basis of the upstream and downstream pressure of the compressor, upstream of the throttle valve, and the calculating means calculates the temperature of the downstream side of the turbocharger Control system for internal combustion engines. The control device for an internal combustion engine according to claim 1,
The supercharging pressure reducing device is
Including a waste gate valve installed in a passage connecting the upstream and the downstream of the turbocharger turbine,
The controller is
The control device for an internal combustion engine, wherein the opening degree of the waste gate valve is increased when the calculated temperature is equal to or higher than the first threshold value. The control device for an internal combustion engine according to claim 1,
The supercharging pressure reducing device is
At least one of the throttle valve and the intake valve;
The controller is
When the calculated temperature is equal to or higher than the first threshold value, the opening degree of the throttle valve is increased, or
A control device for an internal combustion engine, which controls the intake valve to increase an intake amount flowing into a cylinder of the internal combustion engine when the calculated temperature is equal to or higher than the first threshold. The control device for an internal combustion engine according to claim 3,
The supercharging pressure reducing device is
Wherein comprises a throttle valve and the intake valves,
The controller is
When the calculated temperature is equal to or higher than the first threshold value, the opening degree of the throttle valve is increased, or
A control device for an internal combustion engine, which controls the intake valve to increase an intake amount flowing into a cylinder of the internal combustion engine when the calculated temperature is equal to or higher than the first threshold. The control device for an internal combustion engine according to claim 1,
The controller is
The larger the intake air amount temperature pre SL calculated passes through the throttle valve delay time indicating the time until activating the supercharging pressure reducing device from equal to or more than the first threshold value, to be shorter Decide
A control device for an internal combustion engine, wherein the supercharging pressure reducing device is operated after the delay time has elapsed since the calculated temperature becomes equal to or higher than the first threshold value. The control device for an internal combustion engine according to claim 1,
The controller is
A control device for an internal combustion engine, wherein an opening degree of the throttle valve is reduced after operating the supercharging pressure reducing device. The control device for an internal combustion engine according to claim 1,
The controller is
Based on the operation amount of the access Le, it estimates whether the torque reduction of the internal combustion engine is required in advance,
It is determined whether or not the calculated temperature is equal to or greater than a second threshold that is smaller than the first threshold and is larger than the first threshold.
The boost pressure reducing device is operated when it is estimated in advance that the torque reduction is required, and it is determined that the calculated temperature is equal to or higher than the second threshold. Control device. The control device for an internal combustion engine according to claim 1,
The supercharging pressure reducing device is
Including a recirculation valve disposed in a passage connecting the upstream and downstream of the compressor of the turbocharger,
The controller is
The control device of an internal combustion engine, wherein the opening degree of the recirculation valve is increased when the calculated temperature is equal to or higher than the first threshold value. The control device for an internal combustion engine according to claim 2,
The controller is
A control device for an internal combustion engine, which corrects the calculated temperature based on an EGR amount indicating an amount of air recirculated upstream of the compressor and an EGR temperature indicating a temperature of air recirculated upstream of the compressor. . The control device for an internal combustion engine according to claim 5,
The controller is
The way to the inflow air quantity into the opening greatly to be the cylinder of the waste gate valve is not changed, the intake stroke in the previous SL adjusts the or intake valve timing of the intake valve to open the throttle valve the cylinder A control device for an internal combustion engine, which is controlled to increase an intake amount in the control unit. A throttle valve to adjust the intake amount,
A throttle valve protection device, comprising: a control device for an internal combustion engine that controls an internal combustion engine including the throttle valve and a supercharger that raises the pressure of intake air.
The controller is
The temperature on the upstream side of the throttle valve and on the downstream side of the turbocharger is calculated, and it is determined whether or not the calculated temperature is equal to or higher than a first threshold value smaller by an allowance than the upper limit of the heat resistance temperature of the throttle valve. A throttle pressure protection device characterized in that if determined and the calculated temperature is equal to or higher than the first threshold value, the supercharge pressure reducing device for reducing supercharge pressure of intake air supercharged by the supercharger is operated. apparatus.

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