JP4636047B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a vehicle control device, and more particularly to a vehicle control device for a vehicle in which an ejector functions in accordance with fuel cut control.

  Conventionally, a negative pressure such as a brake booster is larger than a negative pressure (hereinafter also simply referred to as an intake pipe negative pressure) to be taken out from an intake passage (for example, an intake manifold or a surge tank) of an intake system of an internal combustion engine in a vehicle. An ejector is used to supply the pressure actuator. Conventionally, an internal combustion engine provided with a variable valve mechanism that can change the valve characteristics of the intake and exhaust valves is known. In these respects, for example, Patent Documents 1 to 6 propose techniques that are considered to be related to the present invention.

JP 2006-70824 A Japanese Patent Laid-Open No. 10-121999 Japanese Patent No. 2005-188332 Japanese Patent No. 2005-263107 Japanese Patent No. 2005-297654 Japanese Patent No. 2005-186708

  In recent years, interest in environmental issues such as global warming and air pollution has increased, and in vehicles, reducing emissions of hydrocarbons such as hydrocarbon HC contained in exhaust gas is an important issue. It has become. For this purpose, it is one of the effective measures to quickly raise the temperature of the catalyst disposed in the exhaust system of the internal combustion engine to the reaction temperature. Therefore, after the internal combustion engine is started, the catalyst is activated. In general, control for retarding the ignition timing of the internal combustion engine is generally performed. At the same time, in order to compensate for the decrease in torque, the throttle valve is also controlled so as to greatly open the intake passage to increase the intake air amount (hereinafter, these controls are simply referred to as catalyst warm-up control). . By performing catalyst warm-up control, more air-fuel mixture can be combusted at a time closer to the exhaust stroke, so that exhaust gas can reach the catalyst at a higher temperature. The temperature can be raised to the reaction temperature.

  However, if the intake passage is largely opened by the throttle valve as described above, the intake pipe negative pressure is reduced. In this case, since the brake booster takes out the intake pipe negative pressure, the function of assisting the brake operation becomes insufficient, and as a result, the operation burden on the driver increases. On the other hand, if the ejector is used when the catalyst warm-up control is performed, a negative pressure larger than the intake pipe negative pressure can be supplied to the brake booster. In this case, since the intake passage is opened relatively large, even if the ejector functions, the degree of fluctuation of the intake air amount relatively decreases. For this reason, idling does not become unstable even if the ejector is made to function.

  On the other hand, when the water temperature of the internal combustion engine exceeds a predetermined value and the catalyst is activated, the catalyst warm-up control becomes unnecessary. In this case, the throttle valve is throttled to an appropriate opening in order to reduce the target rotational speed during idling for the purpose of improving fuel efficiency. However, if the ejector is made to function in this case, it becomes difficult to control the idle speed to the target speed, and as a result, idling may become unstable. The simplest measure for this is to prevent the ejector from functioning. However, if the ejector is not allowed to function, the following problems occur.

  Since the ejector has a structure that generates a large negative pressure by the venturi effect, the passage corresponding to a portion that generates a large negative pressure in the ejector is narrowed down. When the ejector is not allowed to function for a long time, the intake air does not flow, so that the passage is likely to be clogged. The cause of the clogging is, for example, that moisture contained in the intake air condenses and accumulates in this passage and freezes in winter, or intake air containing oil enters the ejector and adheres to the wall surface of this passage. May be generated in a deposit that gradually closes the passage as a result of being combined with dust on the wall surface. Such clogging may occur not only in the ejector itself, but also in the entire flow path of the negative pressure generating device including the ejector.

  On the other hand, if the ejector is made to function when fuel injection is not performed in the combustion cycle of the internal combustion engine, the above-mentioned clogging can be suppressed without adversely affecting idling. In order to make the ejector function in this way, specifically, it is preferable to make the ejector function according to, for example, fuel cut control performed in an internal combustion engine. However, in this case, although the occurrence of clogging described above can be suppressed, the occurrence of clogging may be promoted on the contrary as a result of functioning the ejector according to the viewpoint of more suitably suppressing the occurrence of clogging or fuel cut control. It was found that there was still room for improvement from the viewpoint of considering some cases.

  Therefore, the present invention has been made in view of the above problems, and a vehicle control device that can more appropriately suppress the occurrence of clogging in the negative pressure generating device when the ejector is caused to function in accordance with fuel cut control. The purpose is to provide.

  In order to solve the above problems, the present invention provides an internal combustion engine having a variable valve mechanism, an ejector that generates a negative pressure larger than a negative pressure to be taken out from an intake passage of an intake system of the internal combustion engine, and the ejector. A control device for a vehicle for performing control on a vehicle including a negative pressure generating device configured to have a function or a state change means for stopping the function, according to fuel cut control performed in the internal combustion engine When at least one of the intake valve and the exhaust valve is controlled so that the negative pressure to be taken out from the intake passage becomes larger when the state changing means is controlled to make the ejector function. Specific valve characteristic change control means for controlling the variable valve mechanism to change the characteristic is provided.

  Here, the ejector is generally disposed in a bypass path that bypasses the throttle valve, and accelerates according to the pressure difference between the intake pipe negative pressure and the pressure upstream of the throttle valve (hereinafter simply referred to as the ejector front-rear differential pressure). A negative pressure of a magnitude is generated by the intake air. On the other hand, since the intake pipe negative pressure changes according to the valve characteristics of the intake and exhaust valves, the intake pipe negative pressure becomes smaller depending on the valve characteristics. As a result, the differential pressure across the ejector also becomes smaller. In this case, since the flow rate of the intake air flowing through the ejector is also reduced, the effect of suppressing the occurrence of clogging is also reduced accordingly. In contrast, according to the present invention, the intake pipe negative pressure can be increased by changing the valve characteristics. That is, since the differential pressure across the ejector can be increased, intake air with a larger flow rate can be circulated through the ejector. For this reason, according to this invention, when making an ejector function according to fuel cut control, it can suppress more suitably that clogging generate | occur | produces in a negative pressure generator. The valve characteristics include not only the valve timing but also the valve lift amount or the operating angle (valve opening period).

  In the present invention, the specific valve characteristic changing means may change the valve characteristic of the variable valve mechanism so that the blow back to the intake passage is further reduced. Here, the intake pipe negative pressure changes in accordance with the valve characteristics, but the intake pipe negative pressure is greatly reduced particularly when the valve characteristics are such that a large amount of blowback to the intake passage occurs. In addition, when a large amount of blow-back occurs, fuel or oil reaches the upstream side of the throttle valve, and enters the negative pressure generator and adheres to the wall surface of the flow path, which may promote the generation of deposits. Therefore, specifically, it is preferable to change the valve characteristics as in the present invention. According to the present invention, in addition to the fact that the differential pressure across the ejector can be suitably increased, it is more preferable that it can cope with the possibility that clogging may be promoted as a result of further functioning the ejector. The ejector can function.

  The present invention also includes an internal combustion engine, an ejector that generates a negative pressure larger than the negative pressure to be taken out from the intake passage of the intake system of the internal combustion engine, and a state changing unit that causes the ejector to function or stop functioning. A control device for a vehicle for performing control with a vehicle including a negative pressure generating device configured as described above, wherein the state changing means is configured to cause the ejector to function in accordance with fuel cut control performed in the internal combustion engine. A specific prohibition control means for prohibiting the state changing means from being controlled to function the ejector according to the fuel cut control according to the degree of dust contained in the intake air when controlled; It is characterized by.

  Here, since the intake air sucked into the intake system of the internal combustion engine from the atmosphere is filtered by the air cleaner, it is very unlikely that dust of such a size as to cause clogging in the negative pressure generator is included in the intake air. . However, since clogging also occurs due to the accumulation of deposits, when the ejector was originally operated to suppress clogging, a very small amount of dust would intrude into the negative pressure generator, conversely. There is also a risk that the generation of deposits is encouraged.

  On the other hand, according to the present invention, it is possible to prevent or suppress the formation of deposits due to the entry of a very small amount of dust into the negative pressure generator, and as a result of functioning the ejector according to the fuel cut control. Conversely, it is possible to prevent or suppress the occurrence of clogging from being promoted. For this reason, according to this invention, when making an ejector function according to fuel cut control, it can suppress more suitably that clogging generate | occur | produces in a negative pressure generator. The specific prohibition control means prohibits the state change means from being controlled when the intake air contains a lot of dust. Specifically, the specific prohibition control means is preferably prohibited when the state changing means is controlled so that the ejector functions according to the fuel cut control as in the present invention. However, the state changing means may be appropriately prohibited from controlling the ejector to function according to the degree of dust contained in the intake air.

  In the present invention, the specific prohibition control unit may prohibit the vehicle depending on whether or not the vehicle is traveling on a rough road. In other words, when performing control that is prohibited according to the degree of dust contained in the intake air, specifically, for example, the vehicle travels on a rough road such as an unpaved road having a high correlation with the degree of dust contained in the intake air. It is preferable to perform control that is prohibited depending on whether or not there is. Note that the fact that the vehicle is traveling on a rough road corresponds to the case where the intake air contains a lot of dust, and the specific prohibition control means is that the state changing means is controlled when the vehicle is traveling on a rough road. Is prohibited.

  ADVANTAGE OF THE INVENTION According to this invention, when making an ejector function according to fuel cut control, the control apparatus of the vehicle which can suppress more appropriately generation | occurrence | production of clogging in a negative pressure generator can be provided.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram schematically showing a vehicle control device according to the present embodiment realized by an ECU (Electronic Control Unit) 40A together with a negative pressure generating device 100. The components shown in FIG. 1 including the internal combustion engine 50A are mounted on a vehicle (not shown). The intake system 10 of the internal combustion engine 50A includes an air cleaner 11, an air flow meter 12, an electric throttle 13, an intake manifold 14, an intake port (not shown) that communicates with each cylinder (not shown) of the internal combustion engine 50A, and these configurations. For example, intake pipes 15a, 15b and the like are appropriately disposed between the two. The air cleaner 11 is configured to filter the intake air supplied to each cylinder of the internal combustion engine 50A, and communicates with the atmosphere via an air duct (not shown). The air flow meter 12 is configured to measure the intake air amount and outputs a signal corresponding to the intake air amount.

  The electric throttle 13 has a throttle valve 13a, a throttle body 13b, a valve shaft 13c, and an electric motor 13d. The throttle valve 13a is configured to adjust the amount of intake air supplied to the internal combustion engine 50A by changing the opening. The throttle body 13b is composed of a cylindrical member in which an intake passage is formed, and supports a valve shaft 13c of a throttle valve 13a disposed in the intake passage. The electric motor 13d is configured to change the opening degree of the throttle valve 13a under the control of the ECU 40A, and a step motor is adopted as the electric motor 13d. The electric motor 13d is fixed to the throttle body 13b, and its output shaft (not shown) is connected to the valve shaft 13c. The opening degree of the throttle valve 13a is detected by the ECU 40A based on an output signal from a throttle opening degree sensor (not shown) built in the electric throttle 13.

  In addition to the throttle-by-wire system in which the throttle valve 13a such as the electric throttle 13 is driven by an actuator, the throttle mechanism is linked to an accelerator pedal (not shown) via a wire or the like instead of the electric throttle 13, and the throttle valve A mechanical throttle mechanism in which the opening degree of 13a is changed may be applied. The intake manifold 14 is configured to branch one intake passage on the upstream side corresponding to each cylinder of the internal combustion engine 50A on the downstream side, and distributes the intake air to each cylinder of the internal combustion engine 50A.

  The brake device 20 includes a brake pedal 21, a brake booster (negative pressure operating device) 22, a master cylinder 23, and a wheel cylinder (not shown). The brake pedal 21 operated by the driver to brake the rotation of the wheel is connected to an input rod (not shown) of the brake booster 22. The brake booster 22 is configured to generate an assist force with a predetermined boost ratio with respect to the pedal depression force, and a negative pressure chamber (not shown) internally partitioned on the master resin 23 side To the intake passage of the intake manifold 14. The output rod (not shown) of the brake booster 22 is further connected to the input shaft (not shown) of the master cylinder 23. The master cylinder 23 receives the assist force in addition to the pedal depression force. Hydraulic pressure is generated according to the applied force. The master cylinder 23 is connected to each wheel cylinder provided in a disc brake mechanism (not shown) of each wheel via a hydraulic circuit, and the wheel cylinder generates a braking force with the hydraulic pressure supplied from the master cylinder 23. . The brake booster 22 is not particularly limited as long as it is a pneumatic type, and may be a general one.

  The ejector 30 generates a negative pressure larger than the negative pressure (intake pipe negative pressure) to be taken out from the intake system 10, more specifically, the intake manifold 14 on the downstream side of the throttle valve 13 a, thereby generating the brake booster 22. It is the structure for supplying to the negative pressure chamber. The ejector 30 has an inflow port 31a, an outflow port 31b, and a negative pressure supply port 31c. Among these, the negative pressure supply port 31c is connected to the negative pressure chamber of the brake booster 22 by the air hose 5c. The inflow port 31a is connected to the intake passage of the intake pipe 15a by an air hose 5a, and the outflow port 31b is connected to the intake passage of the intake manifold 14 by an air hose 5b so as to sandwich the electric throttle 13, more specifically, the throttle valve 13a. ing. Thus, a bypass path B that bypasses the electric throttle 13 is formed by the air hoses 5 a and 5 b including the ejector 30. When the ejector 30 is not functioning, the negative pressure chamber of the brake booster 22 is routed from the intake passage of the intake manifold 14 through the air hose 5b, the outlet port 31b of the ejector 30, the negative pressure supply port 31c, and the air hose 5c. Negative pressure is supplied.

  A VSV (vacuum switching valve) 1 is interposed in the air hose 5a. The VSV 1 is configured to communicate and block the bypass path B under the control of the ECU 40A. In the present embodiment, a 2-position 2-port normally closed solenoid valve is employed. However, the present invention is not limited to this, and the VSV 1 may be another appropriate electromagnetic valve or the like, and may be, for example, a flow rate adjustment valve that can control the degree of shielding of the flow path. The VSV 1 is configured to cause the ejector 30 to function or stop functioning by communicating and blocking the bypass path B. In the present embodiment, the state changing means is realized by VSV1.

  FIG. 2 is a diagram schematically showing the internal configuration of the ejector 30. The ejector 30 includes a diffuser 32 inside. The diffuser 32 includes a tapered taper portion 32a, a divergent taper portion 32b, and a negative pressure extraction portion 32c corresponding to a passage communicating these. The tapered taper portion 32a is opened so as to face the inflow port 31a, and the divergent taper portion 32b is opened so as to face the outflow port 31b. Moreover, the negative pressure extraction part 32c is connected to the negative pressure supply port 31c. The inflow port 31a is provided with a nozzle 33 for injecting the inflowing intake air toward the tapered portion 32a. The intake air injected from the nozzle 33 flows through the diffuser 32, and further from the outflow port 31b to the air hose 5b. To leak. At this time, a high-speed jet is generated in the diffuser 32 to generate a large negative pressure in the negative pressure extraction portion 32c due to the venturi effect, and this negative pressure is further reduced from the negative pressure supply port 31c through the air hose 5c to the negative pressure chamber. To be supplied. Due to such a function of the ejector 30, the brake booster 22 can obtain a negative pressure larger than that of taking out from the intake manifold 14, that is, a negative pressure higher than the intake pipe negative pressure.

  The internal flow path between the negative pressure extraction part 32c and the negative pressure supply port 31c, the internal flow path between the outflow port 31b and the negative pressure supply port 31c, and the air hose 5c connection part of the brake booster 22 The provided check valves 34 are for preventing backflow. Further, the ejector 30 is not limited to the one having the internal structure shown in FIG. 2, and an ejector having another different internal structure may be applied instead of the ejector 30. In this embodiment, the negative pressure generating device 100 is realized by including the VSV 1 and the ejector 30. More specifically, the negative pressure generating device 100 has air hoses 5a, 5b and 5c and a check valve 34. Configured.

  The internal combustion engine 50A has an intake side VVT (Variable Valve Timing) mechanism and an exhaust side VVT mechanism (not shown). An intake side VVT mechanism (hereinafter simply referred to as InVVT) is a configuration for changing the valve timing of an intake valve (not shown), and includes an intake side camshaft and a hydraulic device (not shown). The hydraulic device includes a mechanism that can continuously change the phase of the intake camshaft. Under the control of the ECU 40A, the hydraulic device changes the phase of the intake camshaft with respect to the phase of the crankshaft (not shown), thereby changing the valve timing of the intake valve.

  The exhaust side VVT mechanism (hereinafter simply referred to as ExVVT) is a configuration for changing the valve timing of an exhaust valve (not shown), and includes an exhaust side camshaft and a hydraulic device (not shown). ExVVT can continuously change the valve timing of the exhaust valve under the control of the ECU 40A in the same manner as InVVT. Instead of InVVT or ExVVT, for example, a variable valve mechanism that can change the valve lift amount or the operating angle together with the valve timing may be applied. In this embodiment, a variable valve mechanism is realized by InVVT and ExVVT.

  The ECU 40A is a microcomputer (hereinafter simply referred to as a microcomputer) that includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory) (not shown). And an input / output circuit. The ECU 40A mainly has a configuration for controlling the internal combustion engine 50A. In this embodiment, the ECU 40A also controls the VSV 1, the electric throttle 13, and the like. In addition to the VSV 1, the electric throttle 13, the InVVT, and the ExVVT, various control objects are connected to the ECU 40A. The ECU 40A is connected to various sensors such as a throttle opening sensor, a water temperature sensor 71 for detecting the water temperature of the internal combustion engine 50A, and a crank angle sensor 72 for detecting the rotational speed NE of the internal combustion engine 50A. ing. Various sensors (for example, a valve timing detection sensor) provided in InVVT and ExVVT are also connected to ECU 40A.

  The ROM has a configuration for storing a program in which various processes executed by the CPU are described. In this embodiment, in addition to the program for controlling the internal combustion engine 50, the electric throttle 13 is controlled by ISC (Idle Speed Control). For controlling the VSV 1 so as to cause the ejector 30 to function or stop functioning under various conditions (hereinafter also referred to simply as opening or closing the VSV 1). Also stores programs. In this embodiment, the VSV 1 is basically opened in the cold state (for example, 75 ° C. or less) and closed in the warm state by the VSV 1 control program. The fuel cut (hereinafter simply referred to as F / C) control program is configured as a part of the program for controlling the internal combustion engine 50, and the F / C control program has a certain rotational speed NE. It is created to perform F / C when the accelerator pedal is released in a high state. Moreover, these programs may be combined together.

  The VSV1 control program has a cleaning control program that opens VSV1 when F / C control is started in accordance with F / C control performed by the internal combustion engine 50A. Further, in this embodiment, the VSV1 control program is based on the cleaning control program described above, and the valve characteristic of the exhaust valve is set so that the intake pipe negative pressure becomes larger when the VSV1 is opened according to the F / C control. A specific valve characteristic change control program for controlling the ExVVT to change is configured.

  In the present embodiment, the specific valve characteristic change control program is specifically created to change the valve timing as the valve characteristic. Further, the specific valve characteristic change control program is created so as to change the valve timing so that the return to the intake passage is further reduced. In this regard, in the present embodiment, the optimal valve timing data that best achieves both the reduction of the blowback amount and the increase of the intake pipe negative pressure is stored in the ROM in advance, and is used for specific valve characteristic change control. More specifically, the program detects the valve timing of the exhaust valve, calculates the VVT correction amount for changing the detected valve timing to the optimal valve timing, and further calculates the control amount of ExVVT by the VVT correction amount. It is created to control ExVVT by correcting. In this embodiment, various control means, detection means, determination means, and the like are realized by the microcomputer and the above-described various programs. In particular, the specific valve characteristic change control means is realized by the microcomputer and the specific valve characteristic change control program. Has been.

  Next, processing performed by the ECU 40A will be described in detail with reference to the flowchart shown in FIG. The ECU 40A executes the processing shown in the flowchart in a very short time based on the various programs stored in the ROM, so that the valve timing of the exhaust valve when the VSV 1 is opened according to the F / C control. ExVVT is controlled so as to change. In addition, the process shown to this flowchart is performed at the time of warm in a present Example. When the process returns to step S11 following step S16, the processes shown in steps S12 to S16 may be skipped until a negative determination is made in step S11. The CPU executes processing for determining whether or not F / C deceleration is in progress (step S11). If the determination is negative, no special process is required, so the CPU executes a process for closing VSV1 (step S17).

  On the other hand, if an affirmative determination is made in step S11, the CPU executes a process of calculating the VVT correction amount of ExVVT (step S12). FIG. 4 is a diagram showing the correlation between the valve timing, the intake pipe negative pressure, and the amount of blowback to the intake passage. Specifically, FIG. 4 shows the valve timing when the exhaust valve is closed. In FIG. 4, the intake pipe negative pressure is shown as an absolute pressure. As shown in FIG. 4, during F / C deceleration, the valve timing when the exhaust valve is closed is set by default to before the top dead center of the intake stroke. At this time, since the exhaust valve is closed early, the pressure in the combustion chamber is further increased, and the amount of blowback generated when the intake valve is opened increases. For this reason, the intake pipe negative pressure is greatly reduced under the influence of the blowback (the absolute pressure is increased).

  On the other hand, when the valve timing is changed toward the top dead center of the intake stroke, the blowback amount decreases and the intake pipe negative pressure increases (the absolute pressure decreases). On the other hand, if the valve timing is further changed beyond the top dead center of the intake stroke, the intake pipe negative pressure gradually decreases due to the expansion of the valve overlap of the intake and exhaust valves. In this embodiment, the optimum valve timing of the exhaust valve is specified in advance based on such correlation, and this optimum valve timing is the valve timing at which the blowback amount is the smallest and the intake pipe negative pressure is the largest in the present embodiment. ing. In step S12, the valve timing of the exhaust valve is detected from ExVVT, and a process of calculating a VVT correction amount for changing the detected valve timing to the optimum valve timing is executed.

  When changing the valve characteristics, as described above, grasping the change in the blowback amount and the intake pipe negative pressure according to the valve characteristics, reducing the blowback amount, and increasing the intake pipe negative pressure. However, it is preferable that the variable valve mechanism is controlled so that the valve characteristic that is most suitable is the optimum valve characteristic and the valve characteristic is changed to the optimum valve characteristic. The optimum valve characteristics may be defined by map data according to, for example, the valve characteristics of the intake valve, other valve characteristics of the exhaust valve, the operating state of the internal combustion engine 50A, and the like. At this time, the map data is stored in the ROM, and the corresponding optimum valve characteristic is read with reference to the map data, whereby the processing for calculating the VVT correction amount can be executed in step S12.

  Subsequently, the CPU executes processing for calculating an ISC (Idle Speed Control) correction amount (step S13). This ISC correction amount is a correction amount for correcting the ISC control amount for the electric throttle 13, and after the VSV 1 is opened, the intake air amount corresponding to the increased intake air amount flowing through the ejector 30 is set to the electric throttle. By reducing it by 13, it is calculated in order to suppress fluctuations in the rotational speed NE. Further, the CPU executes a process of correcting the ExVVT control amount with the VVT correction amount calculated in step S12 (step S14). Thus, ExVVT is controlled to change the valve timing according to the VVT correction amount calculated in step S12, and the valve timing of the exhaust valve is changed and the intake pipe negative pressure becomes larger. Further, since the blowback amount is suppressed to be smaller, the fuel and oil are also prevented from reaching the upstream side of the throttle valve 13a.

  Subsequently, the CPU executes a process for opening VSV1 (step S15). Accordingly, since the ejector 30 functions in a state where the ejector front-rear differential pressure is larger, a larger flow rate of intake air can be circulated to the ejector 30, and thus the negative pressure generating device 100 is clogged. It can suppress more suitably. Further, since the fuel and oil are also prevented from reaching the upstream side of the throttle valve 13a, the fuel and oil enter the negative pressure generating device 100 and adhere to the wall surface of the flow path, thereby promoting the generation of deposits. Can also be suppressed. Subsequently, the CPU executes processing for correcting the ISC control amount with the ISC correction amount calculated in step S13 (step S16). Thereby, the electric throttle 13 is controlled according to the ISC correction amount calculated in step S13, and fluctuations in the rotational speed NE caused by opening the VSV 1 are also suppressed.

  In this embodiment, the ExVVT is controlled so as to change the valve timing of the exhaust valve when increasing the intake pipe negative pressure and further reducing the blowback amount. However, the present invention is not limited to this. InVVT may be controlled to change the valve timing of the valve, and InVVT and ExVVT may be controlled to simultaneously change the valve timing of the intake valve and the exhaust valve. Further, when increasing the intake pipe negative pressure and further reducing the amount of blowback, it is not limited to the valve timing. For example, the valve lift amount or the working angle may be changed, and these may be changed in combination. May be. These can be realized by appropriately creating a specific valve characteristic change control program according to these. As described above, when the ejector 30 is caused to function in accordance with the F / C control, it is possible to realize the ECU 40A that can more suitably suppress the occurrence of clogging in the negative pressure generating device 100.

  The ECU 40B according to this embodiment is different from the ECU 40A except that the specific valve characteristic change control program is not stored in the ROM, and the specific prohibition control program and the prohibition condition determination program described below are stored in the ROM. It is the same. The internal combustion engine 50B is the same as the internal combustion engine 50A except that it does not include InVVT and ExVVT. However, the internal combustion engine 50B may be the same as the internal combustion engine 50A. At this time, the ECU 40B may store a specific valve characteristic change control program in the ROM. Each configuration of the vehicle to which the ECU 40B is applied is different from that the ECU 40A is changed to the ECU 40B, the internal combustion engine 50A is changed to the internal combustion engine 50B, and an electronically controlled suspension device and a navigation device (not shown) are further provided. The configuration is the same as that shown in FIG. These electronically controlled suspension device and navigation device are also connected to the ECU 40B.

  In the specific prohibition control program, when VSV1 is opened according to F / C control based on the cleaning control program, VSV1 is opened according to F / C control according to the degree of dust contained in the intake air. Created to ban that. For this reason, the ROM also stores a prohibition condition determination program for determining whether or not the intake air contains a lot of dust. In this embodiment, the specific prohibition control program and the prohibition condition determination program are configured as part of the VSV1 control program.

  In the present embodiment, the specific prohibition control program is specifically controlled according to the degree of dust contained in the intake air, so that the VSV 1 performs F / C control depending on whether or not the vehicle is traveling on a rough road. It is created to prohibit opening according to the. The specific prohibition control program is created so as to prohibit the VSV 1 from being opened in accordance with the F / C control when the vehicle is traveling on a rough road. For this reason, in the present embodiment, specifically, the prohibition condition determination program is created so as to determine whether or not the intake air contains a lot of dust depending on whether or not the vehicle is traveling on a rough road. In this embodiment, the specific prohibition control means is realized by the specific prohibition control program and the microcomputer, and the vehicle control apparatus is realized by the ECU 40B.

  Next, processing performed by the ECU 1B will be described in detail with reference to the flowchart shown in FIG. In addition, the process shown to this flowchart is performed at the time of warm in a present Example. The CPU executes processing for determining whether or not F / C deceleration is in progress (step S21). If the determination is negative, no special process is required, so the CPU executes a process for closing VSV1 (step S25). On the other hand, if an affirmative determination is made in step S21, the CPU executes a process of detecting information for determining whether or not the vehicle is traveling on a rough road (step S22).

  Here, the ECU 40B holds suspension stroke history data based on the output from the electronically controlled suspension device, and the CPU executes processing for detecting this stroke history data in this step. However, the present invention is not limited to this, and the CPU detects, for example, information obtained or detected by the navigation device from the navigation device as information for determining whether or not the vehicle is traveling on a rough road. Also good.

  Subsequently, the CPU executes a process for determining whether or not the vehicle is traveling on a rough road (step S23). Specifically, whether or not the vehicle is traveling on a rough road can be determined based on whether or not the stroke frequency is greater than a predetermined value. If the determination is affirmative, the CPU executes a process for opening VSV1 (step S24). Thereby, it is possible to suppress the occurrence of clogging in the negative pressure generating device 100 by causing the intake air to flow through the ejector 30. On the other hand, if it is negative determination, it will progress to step S25. As a result, it is possible to prevent or suppress a very small amount of dust from entering the negative pressure generator 100 and generating deposits. As a result, the ejector 30 is made to function according to the F / C control. It is possible to prevent or suppress the occurrence of this.

  In this embodiment, in order to perform the control that is prohibited according to the degree of dust contained in the intake air, the case where the control is prohibited according to whether or not the vehicle is traveling on a rough road is illustrated. For example, a sensor that can detect the degree of dust contained in the intake air is further provided, and the VSV 1 is opened according to the F / C control when the intake air contains a lot of dust based on the output of the sensor. May be prohibited. In this embodiment, since there is a high correlation between the degree of dust contained in the intake air and whether or not the vehicle is traveling on a rough road, depending on whether or not the vehicle is traveling on a rough road Although the prohibition control is performed, the present invention is not limited to this, and even if the VSV 1 is prohibited from being opened according to the F / C control in accordance with other information having a high correlation with the degree of dust contained in the intake air Good.

  For example, on roads where the amount of vehicle traffic is very high, there is a possibility that a large amount of PM (particulate matter) is contained in the atmosphere. For this reason, for example, it is possible to detect current position information from the navigation device in consideration of such circumstances, and to perform control that is prohibited depending on whether the vehicle is traveling on a specific road or intersection. These can be realized by appropriately creating a specific prohibition control program and a prohibition condition determination program according to these. As described above, when the ejector 30 is caused to function in accordance with the F / C control, it is possible to realize the ECU 40B that can more appropriately suppress the occurrence of clogging in the negative pressure generating device 100.

  The embodiment described above is a preferred embodiment of the present invention. However, the present invention is not limited to this, and various modifications can be made without departing from the scope of the present invention.

2 is a diagram schematically showing an ECU 40A together with a negative pressure generator 100. FIG. 3 is a diagram schematically showing an internal configuration of an ejector 30. FIG. It is a figure which shows the process performed by ECU40A with a flowchart. It is a figure which shows the correlation with the valve timing at the time of an exhaust valve closing, an intake pipe negative pressure, and the amount of blowback to an intake passage. It is a figure which shows the process performed by ECU40B with a flowchart.

Explanation of symbols

1 VSV
30 Ejector 40 ECU
50 Internal combustion engine 100 Negative pressure generator

Claims (4)

An internal combustion engine having a variable valve mechanism, an ejector for generating a negative pressure larger than the negative pressure to be taken out from an intake passage of an intake system of the internal combustion engine, and a state changing unit for functioning or stopping the ejector A control device for a vehicle for performing control with a vehicle including a negative pressure generator configured to have,
At least the intake valve so that the negative pressure to be taken out from the intake passage becomes larger when the state changing means is controlled to function the ejector according to fuel cut control performed in the internal combustion engine. Alternatively, the vehicle control device includes a specific valve characteristic change control unit that controls the variable valve mechanism so as to change a valve characteristic of any one of the exhaust valves. 2. The vehicle control device according to claim 1, wherein the specific valve characteristic change control means changes the valve characteristic of the variable valve mechanism so that the blow back to the intake passage is further reduced. An internal combustion engine, an ejector that generates a negative pressure larger than the negative pressure to be taken out from the intake passage of the intake system of the internal combustion engine, and a state changing unit that causes the ejector to function or stop functioning. A vehicle control device for controlling a vehicle equipped with a negative pressure generator,
When the state changing means is controlled to cause the ejector to function in accordance with fuel cut control performed in the internal combustion engine, the state changing means is configured to change the fuel cut according to the degree of dust contained in the intake air. A vehicle control apparatus comprising: a specific prohibition control unit that prohibits the ejector from being controlled to function in accordance with control. 4. The vehicle control device according to claim 3, wherein the specific prohibition control unit prohibits the vehicle depending on whether or not the vehicle is traveling on a rough road.

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