JP2009156104A - Intake control device of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an intake control device of an internal combustion engine capable of ensuring a sufficient intake filling amount in a wide range of rotations. <P>SOLUTION: In an engine system 10 having an impulse valve 226 installed in an intake pipe 204, a surge tank 223 communicated with the intake pipe 204 via a branch pipe 222, and a surge tank valve 224 provided in the branch pipe 222, the ECU 100 executes the valve drive control. During the valve drive control, when the engine speed Ne of an engine 200 belongs to a first zone below the first reference value Ne1, the first control mode for executing the impulse charge by opening the surge tank valve 224 is executed; when the engine speed belongs to the second zone of equal to or higher than the first reference value Ne1 and below the second reference value Ne2, the second control mode for stopping the impulse charge while opening the surge tank valve 224 is executed; and when the engine speed belongs to the third zone of equal to or higher than the second reference value Ne2, the third control mode for reducing the intake resistance by opening the surge tank valve 224 is executed, respectively. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a technical field of an intake control device for an internal combustion engine capable of inertia supercharging such as impulse charge.

  As this type of apparatus, an apparatus in which an intake control valve is provided in an intake passage downstream of a surge tank has been proposed (see, for example, Patent Document 1). According to the intake control device for an internal combustion engine disclosed in Patent Document 1 (hereinafter referred to as “prior art”), an inertia supercharging effect is obtained by opening the intake control valve after opening the intake valve downstream of the intake port. It is said that it can be obtained.

  In the technical field for reducing the intake noise, there has been proposed one that controls the capacity of the resonator chamber connected to the intake passage to a capacity suitable for suppressing intake pulsation according to the operating state of the engine. (For example, refer to Patent Document 2).

  In addition, when a subtank is provided between the surge tank and the intake port via a communication part equipped with a control valve, when the engine shifts from a high load state to a low load state and the control valve switches from open to closed, There has also been proposed a technique for realizing an appropriate ignition timing by maintaining the opening degree of the EGR valve at a predetermined operation delay time and an opening degree before switching (for example, see Patent Document 3).

JP-A-5-187238 JP-A-6-117257 JP 2004-245062 A

  In the high speed range, this kind of inertia supercharging is often not necessary because the pulsation of the intake air is originally large.However, in the conventional technology, the surge tank is provided at a position that penetrates the intake passage, so the intake air is inertial. Passes through the surge tank regardless of the need for supercharging. Accordingly, in the high rotation region, the surge tank increases the resistance of the intake passage, and reduces the charging efficiency of the intake air. That is, the conventional technique has a technical problem that it is difficult to obtain a sufficient intake charge amount in a wide operating range of the internal combustion engine.

  The present invention has been made in view of the above-described problems, and an internal combustion engine intake control device capable of ensuring a sufficient intake charge amount from a low rotation region to a high rotation region in an internal combustion engine capable of inertia supercharging. The issue is to provide.

  In order to solve the above-mentioned problems, an intake control device for an internal combustion engine according to the present invention is mounted on a vehicle and is installed in an intake passage communicating with the inside of a cylinder and the intake passage, and the open / close state is controlled according to predetermined open / close control. An intake control valve capable of realizing inertia supercharging utilizing intake air pulsation, and at least one opening, and communicates with the intake passage through the opening on the upstream side of the intake control valve. An intake control device for an internal combustion engine comprising a tank arranged in parallel as possible, wherein the tank and the intake passage are communicated when the valve is opened and the communication between the tank and the intake passage is blocked when the valve is closed It comprises an on-off valve and a control means for controlling an on-off state of the on-off valve based on an operating condition of the vehicle.

  The “internal combustion engine” according to the present invention has one or a plurality of cylinders, and various fuels such as gasoline, light oil, various alcohols, or mixed fuels of various alcohols and gasoline in each of the cylinders. Or the force generated when an air-fuel mixture containing various fuels explodes or burns can be extracted as a driving force through a physical or mechanical transmission path such as a piston, a connecting rod and a crankshaft. It is a concept encompassing a structured organization. An “intake engine control device for an internal combustion engine” relating to this type of internal combustion engine includes intake air (ie, intake air as air sucked from the outside world) as a part of the concept, and the intake air itself. Or, for example, when an exhaust gas recirculation device such as an EGR device is provided, for example, a mixture of EGR gas (that is, a part of exhaust gas) and the intake air according to the open / close state of a flow rate adjusting means such as an EGR valve, etc. The device can control the supply of various forms of the above.

  The “intake passage” in the intake control apparatus for an internal combustion engine according to the present invention is the intake passage described above. As a preferred embodiment, for example, an air cleaner, an air flow meter, a throttle valve (ie, an intake throttle valve). The intake port and the like can be connected or communicated with each other as appropriate, for example, in the form of a single or a plurality of tubular members. Further, as a preferred embodiment, the internal combustion engine according to the present invention is a part formed by excluding a part to be provided in an exhaust system such as a turbocharger (of course, a turbine or the like) in the intake passage. In this case, the downstream side (in addition, “downstream” and “upstream” is one of the directional concepts based on the direction of intake air flow. In this case, An intake air cooling means such as an intercooler may be provided on the downstream side (that is, the cylinder side). The intake air cooling means is a physical unit capable of cooling intake air supplied via a supercharger (may be irrelevant whether or not supercharging by the supercharger is performed in practice). Means having mechanical, mechanical, electrical, magnetic or chemical aspects, at least somewhat more and relatively cooling the intake air, thereby increasing the intake air density relatively Efficiency can be improved.

  On the other hand, the internal combustion engine according to the present invention includes an intake control valve in the intake passage. This intake control valve is capable of adjusting the intake amount as the intake amount in accordance with, for example, an open / close state that can be controlled in a binary, stepwise or continuous manner. It is a means that can take various forms such as a valve operating mechanism or a valve operating apparatus that appropriately includes a drive device that drives the valve body, and when the internal combustion engine is equipped with a so-called intake throttle valve such as a throttle valve, As a preferred embodiment, it is installed on the downstream side of the intake throttle valve.

  The installation mode of the intake control valve may take various forms depending on, for example, the physical configuration of the intake passage. That is, the intake passage may be branched to each cylinder on the downstream side of the intake control valve (that is, a mode similar to a so-called one-valve intake system), or each cylinder provided with an intake control valve. Corresponding communication pipes or intake branch pipes (including similar ones) may be provided (that is, a mode similar to a so-called multi-valve intake system).

  On the other hand, the internal combustion engine according to the present invention is provided with a tank such as a surge tank, for example, which is provided adjacent to the intake passage through the opening. Here, the “parallel arrangement” is a concept comprehensively arranged in a positional relationship where the flow of the intake air in the intake passage is not blocked even when communication through at least the opening is blocked. As a preferred form, the opening and the intake passage are connected by a predetermined pipe branching from the intake passage (preferably, the pipe diameter may be substantially the same as the intake passage). This includes the configuration and the like.

  Here, the intake control valve according to the present invention, whether single or plural, is configured to generate intake air pulsation through a predetermined open / close control to control the open / close state of the intake control valve. Is used as means for inverting the phase of the pulsating wave, so that inertia supercharging (or also referred to as pulse supercharging or impulse charging) using the pulsation of intake air can be realized.

  Here, the “predetermined opening / closing control” is, for example, the opening / closing timing, opening period or opening degree of the intake control valve (that is, the degree of opening of the intake control valve) to achieve this kind of inertia supercharging. For example, a valve closing timing of an intake valve (that is, a valve for controlling the communication state between the combustion chamber and the intake passage as a preferred embodiment), and the like. This is intended to include control to synchronize the time when the peak of the pulsation wave (positive pressure wave) of intake reaches the intake valve (not necessarily representing only coincidence).

  More specifically, the open / close control is, for example, that the intake control valve is opened after an appropriate time elapse (may be defined as an angle concept by a crank angle or the like) after the intake valve is opened (that is, the intake control). Combustion chamber of each cylinder that generates a positive pressure wave by opening the valve in a state where the downstream side of the valve is negative pressure and the upstream side of the intake control valve is at or above atmospheric pressure, etc. When a negative pressure wave is reflected in the vicinity of the entrance and this negative pressure wave is reflected at the open end of the tank again at the open end, so-called secondary positive pressure wave is used, for example, when natural intake is performed (a suitable one) As a form, the intake air can be basically taken into the cylinder as a pulsation wave regardless of the presence or absence of the intake control valve, but the pulsation caused by the opening / closing control applied to the intake control valve is a suitable form. The pulsation of Also meant to comprise control, etc. to be made to incorporate a strong pulsation in a) compared to the cylinder in the intake stroke a large amount of intake air.

  It should be noted that the intake control valve, whether singular or plural, is mainly intended to realize inertial supercharging using the pulsation of intake air (however, apart from the generation of this type of pulsation, for example, a throttle valve, etc. When the intake air adjustment (intake throttle) that can be suitably performed by opening and closing the intake throttle valve can be practiced to such a degree that there is no practical problem, the action of the intake throttle valve such as the throttle valve is applied to the present invention. The intake control valve may be substituted (or, conversely, the intake throttle valve may be substituted for the function as the intake control valve according to the present invention). It may be installed at a position close to the intake valve of each cylinder so that at least the pulsation of intake sufficient for practical use can be generated.

  An intake control device for an internal combustion engine according to the present invention is provided, for example, in a pipe line connecting the above-described opening and an intake passage (of course, it can be established even if such a pipe does not exist), and a tank is opened when the valve is opened. And an open / close valve that controls the open / close state of the tank and the intake passage in a binary, stepwise, or continuous manner.

  Here, to the extent that the pulsation of the original intake can substantially negate the significance of this type of inertial supercharging (i.e., at least practically, this type of inertial supercharging increases the intake charge ( (Or an increase in the charging efficiency) that can be judged to not contribute to the high rotation range, which may be large, or exceeding the operating limit caused by the operating speed of the actuator that drives the intake control valve, etc. When the intake control valve is shared and shared by a plurality of cylinders, it is necessary to complete the opening and closing of the intake control valve within the intake stroke, so the time required for the intake stroke is shortened. In the high rotation region, the operation limit may naturally occur due to the operation speed or the like of the actuator or the like that drives the intake control valve), and the necessity of inertia supercharging does not occur (or its execution becomes difficult).

  Here, in particular, under various conditions including the case where the necessity of inertia supercharging is reduced in this way, the tank according to the present invention becomes an intake resistance that hinders the flow of intake air, and the intake charge amount ( Or it may become a factor which reduces filling efficiency.

  Therefore, according to the intake air control apparatus for an internal combustion engine according to the present invention, during its operation, it is configured as various processing units such as an ECU (Electronic Control Unit), various controllers or various computer systems such as a microcomputer device, or the like. The open / close state of the open / close valve is controlled by the obtained control means based on the vehicle operating conditions as a concept that may include, for example, the engine rotational speed or required load of the internal combustion engine or various index values corresponding to them.

  At this time, when the on-off valve is opened, the tank can function as the above-described phase inverting means, contributing to the generation of intake pulsation when the on-off control is executed, and when the on-off valve is closed, the tank is disconnected from the intake passage. Therefore, apart from the magnitude of the effect, the intake resistance in the intake passage is somewhat lowered, and the charging of the intake air into the cylinder is at least relatively accelerated.

  That is, according to the intake control apparatus for an internal combustion engine according to the present invention, the control means controls the open / close state of the open / close valve, thereby increasing the intake charge amount (or improving the charge efficiency) due to inertia supercharging. In addition, it is possible to prevent a decrease in the filling amount of the intake air in the high rotation region (decrease in charging efficiency) due to the intake resistance of the tank, and a sufficient intake air filling amount from the low rotation region to the high rotation region can be achieved. It is possible to secure it.

  Note that the control mode of the on-off valve related to the control means is not limited as long as the intake amount can be increased (improvement of charging efficiency) under a considerably wider range of conditions than at least when this type of control is not performed. It is not limited, and it is not always necessary for the on-off valve to take a binary state of fully open and fully closed. For example, in advance, experimentally, empirically or theoretically, considering the effect of inertia supercharging, the effect of the tank on the generation of intake pulsation, the interaction of the effect of the tank on the intake resistance, etc. Based on simulation, etc., increase the intake charge amount (improvement of filling efficiency) in the widest possible range from the low rotation range to the high rotation range (in this case, “high and low” refers to the qualitative concept) It may be set to a control mode that can be achieved.

  In one aspect of the intake control device for an internal combustion engine according to the present invention, the control means is configured to (i) turn on the on-off valve when the vehicle accelerates from a state in which the internal combustion engine is in a predetermined low rotation region. A first control mode for opening the valve and allowing the execution of the opening / closing control; (ii) a second control mode for opening the opening / closing valve and prohibiting the execution of the opening / closing control; and (iii) closing the opening / closing valve. One control mode is selectively executed sequentially in the order of the third control mode that prohibits the execution of the opening / closing control.

  According to this aspect, at the time of acceleration from the low rotation region (including that the vehicle speed is in the low speed region), one control mode is selectively executed in the order of the first, second, and third control modes ( Note that “execution of the control mode” means that the on-off valve and the intake control valve are driven and controlled within a range satisfying the requirements stipulated by the one control mode) as a preferred form) The discontinuous change in the intake charge amount (i.e., the output torque) is suppressed in response to the change in the operating conditions, and at least sensational while ensuring a sufficient intake charge amount from the low rotation range to the high rotation range As a result, it is possible to suppress a decrease in power performance and a deterioration in drivability.

  In this aspect, at least a part of the essential point is that a transient condition (substantially, it does not make sense to execute one control mode selectively in a sequential manner, or there is no such time margin, etc. (Condition)), the second control mode is executed prior to the third control mode, and the first control mode is executed somewhat prior to the second control mode. For example, the “predetermined low rotation region” in this aspect does not necessarily have to be strictly defined by the engine rotation speed or the vehicle speed. Similarly, it is not always necessary to execute these three types of control modes during this type of acceleration.

  In one aspect of the intake control device for an internal combustion engine according to the present invention in which one control mode is selectively executed, the control means includes a first rotation region in which the engine rotation speed is less than a first reference value, In the case of belonging to a second rotation region that is less than a second reference value defined as a value that is greater than or equal to the first reference value and a third rotation region that is greater than or equal to the second reference value, the first control mode and second The control mode and the third control mode are selected.

  According to this aspect, the execution conditions of the first, second and third control modes are defined based on the engine speed as one of the “vehicle driving conditions” according to the present invention, and the first, second and second control modes are defined. Three control modes are executed in the first, second and third rotation regions, respectively. The degree of intake pulsation that occurs independently of the opening / closing control of the intake control valve, the intake resistance due to the tank, the theoretical, substantial or practical effect of inertial supercharging, or the physical, mechanical, mechanical, electrical Alternatively, the driving conditions of the on-off valve and the intake control valve, such as whether or not to perform inertia supercharging due to electromagnetic reasons, have a high correlation with the engine speed, and thus the various control modes are based on the engine speed. When the execution condition is defined, it is beneficial to optimize the intake charge amount (filling efficiency) simply and effectively.

  In the present invention, `` more than '' and `` less than '' are concepts that can be easily replaced with `` greater than '' and `` less than '', respectively, depending on the setting of the reference value. It is unrelated to the essence of the invention.

  In another aspect of the internal combustion engine according to the present invention in which one control mode is selectively executed, the control means continues the second control mode for a predetermined time when the second control mode is selected. And execute.

  The second control mode is a control mode in which the intake air pulsation is actively generated by the tank while the inertia supercharging is not executed, and the first control mode (the mode in which inertia supercharging is executed) and the third control mode. This is a control mode having an intermediate meaning with (a mode in which inertia supercharging is not performed and an increase in intake resistance due to communication between the tank and the intake passage is prevented). In other words, the control mode plays a role of alleviating a sudden change in the intake charge amount when the control mode finally transitions from the first control mode to the third control mode.

  On the other hand, if this type of control mode switching is defined solely by the engine speed, the second control mode may not be executed for a substantially significant period, and the intake charge amount is relatively abrupt. The possibility of changes is not necessarily excluded. In that respect, when the second control mode is executed for a predetermined time in this way, in other words, when the second control mode is interposed in time series between the first control mode and the third control mode, This is preferable because a sudden or large change in the intake charge amount hardly occurs.

  In another aspect of the intake control device for an internal combustion engine according to the present invention, the tank has a plurality of openings in a direction along the intake passage, and the on-off valve is provided in each of the openings. When the opening / closing valve is opened, the control means is provided with one of the plurality of opening / closing valves located upstream from the increase in the engine speed of the internal combustion engine. The valves are opened sequentially from the on-off valve.

  According to this aspect, since the tank has a plurality of openings in the direction along the intake passage, and the on-off valves are provided corresponding to the respective openings, for example, one on-off valve is provided in the tank. When the valve is opened to allow the intake passage to communicate with the intake passage, the distance from the opening to the intake control valve (or the intake valve of each cylinder) changes.

  On the other hand, this distance is the propagation state of the positive pressure wave of the intake pulsation when at least the diameter of the intake passage (or in addition to that, a conduit suitably connected to the opening and the intake passage) is unchanged. (Propagation speed, intake control valve or intake valve arrival phase, etc.) are highly correlated, and qualitatively, this is equivalent to the fact that the distance is shorter on the downstream side (that is, on the cylinder side). ) Opening tends to cause inertial supercharging on the higher rotation side. Of course, by optimizing the opening / closing timing of the intake control valve (ie, the predetermined opening / closing control according to the present invention), the effect of increasing the intake charge amount due to inertia supercharging is optimized within a certain range of engine speed. Similarly, it is also possible to compensate for the deviation in the distance from the intake control valve to the cylinder, but in any case, it is better that the tank and the intake passage communicate with each other at the opening on the downstream side. The advantage that is advantageous in the case of inertia supercharging on the high rotation side remains unchanged.

  According to this aspect, as the engine speed increases, the open / close valve is opened sequentially from the upstream open / close valve among the multiple open / close valves (preferably, one open / close valve is always open). Because it is controlled, for example, it is possible to enjoy the benefits of inertial supercharging more efficiently and effectively in a range in which it is prescribed that inertial supercharging is executed (for example, the first rotation region described above). It becomes.

  In another aspect of the intake control device for an internal combustion engine according to the present invention, based on an intake pressure related to the intake when the open / close control is performed in a period in which the open / close valve is controlled to open, It further comprises a discriminating means for discriminating whether or not the on-off valve controlled to be opened is closed.

  According to this aspect, for example, a closing failure (that is, a closed sticking or the like) of the on-off valve instructed to open by the determining means that can be configured as various processing units such as an ECU, various controllers or various computer systems such as a microcomputer device, etc. The presence / absence of a failure that is preferably not included with a significant valve opening amount is determined.

  Here, in view of the fact that the phase inversion of the negative pressure wave by the tank is important in inertia supercharging, when the on-off valve that is instructed to open when the on-off control is performed on the intake control valve is normal, The intake pressure varies depending on whether the on-off valve is open (ie, the inertia supercharging action occurs in short) or the valve is closed (similarly, the inertia supercharging action does not occur). Significant deviation is likely to occur. On the other hand, when the on-off valve has a closed failure, the intake pressure at the time of valve opening (that is, when the valve is instructed to open and remains closed) and the intake pressure at the time of valve closing are Substantial deviations are unlikely to occur between them. Therefore, it is possible to appropriately determine whether or not the on-off valve is closed due to the intake pressure.

  The intake pressure is the pressure of the intake air, and may be, for example, the pressure at any part of the intake passage, but is closer to the cylinder such as a communication pipe or an intake manifold (hereinafter referred to as “in manifold” as appropriate). The intake pressure in the intake passage on the side is suitable for this type of determination because it has a relatively small number of pulsation peaks and is unlikely to be erroneously detected. Note that “based on the intake pressure” does not only indicate that the intake pressure itself is used as an index value for determination, but by using various index values correlated with the intake pressure for this type of determination. It is intended to include indirectly using this kind of discrimination.

  In one aspect of the intake control device for an internal combustion engine according to the present invention, the tank has a plurality of openings in a direction along the intake passage, and the on-off valve has the openings. The control means determines that there is a closed fault when it is determined that there is the closed fault with respect to the on-off valve that is controlled to open. Instead of the open / close valve, the open / close state of the other open / close valves other than the open / close valve determined to have the closed failure is controlled.

  According to this aspect, unless one of the on-off valves has a closed failure, it is possible to open one on-off valve and execute inertia supercharging. Therefore, it is possible to suppress a decrease in the intake charge amount in the low rotation region, and it is possible to suppress a decrease in power performance in the low rotation region.

  In this aspect, when the open / close state of the other open / close valve is controlled, a correction means for correcting the open / close timing of the intake control valve related to the open / close control may be further provided.

  As described above, when one on-off valve is replaced with an on-off valve that has caused a closed failure, the distance from the opening to the intake control valve or the intake valve of the target cylinder is different. If the opening / closing timing is not changed, the positive pressure peak deviates from the position corresponding to the combustion chamber, and the effect of inertia supercharging may be reduced. According to this aspect, the opening / closing timing of the intake control valve is corrected by correction means that can be configured as various processing units such as an ECU, various controllers or various computer systems such as a microcomputer device, etc. When the on-off valve that has caused the closing failure is replaced, it is possible to prevent a decrease in the effect related to the improvement of the intake charge amount related to the inertia supercharging.

  In another aspect of the intake control device for an internal combustion engine according to the present invention, comprising the determination means, the execution of the opening / closing control is performed when it is determined that the closing failure is detected for the opening / closing valve controlled to open. There is further provided a limiting means for limiting.

  According to this aspect, for example, when it is determined that a closing failure has occurred in the on-off valve by a restriction unit that can be configured as various processing units such as an ECU, various controllers or various computer systems such as a microcomputer device, Since the execution of open / close control for the control valve is limited, the fuel consumption and emissions deteriorate due to the increase in fuel, etc., despite the fact that inertia supercharging does not actually act significantly due to the closing failure of the open / close valve Is prevented and suitable. Note that “restrict” is a concept that includes prohibition as a preferable aspect, and that execution is considerably hindered compared to a case where this kind of restriction is not made.

  Such an operation and other advantages of the present invention will become apparent from the embodiments described below.

<Embodiment of the Invention>
Various preferred embodiments of the present invention will be described below with reference to the drawings.
<First Embodiment>
<Configuration of Embodiment>
First, the configuration of the engine system 10 according to the first embodiment of the present invention will be described with reference to FIG. FIG. 1 is a schematic configuration diagram conceptually showing the configuration of the engine system 10.

  In FIG. 1, an engine system 10 is mounted on a vehicle (not shown) and includes an ECU 100 and an engine 200.

  The ECU 100 is an electronic control unit that includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like, and is configured to be able to control the entire operation of the engine 200. Is an example of “control means”, “discrimination means”, and “limitation means”. The ECU 100 is configured to be able to execute later-described valve drive control and failure response control in accordance with a control program stored in the ROM.

  The engine 200 is an in-line four-cylinder diesel engine that is an example of an “internal combustion engine” according to the present invention that uses light oil as fuel. The outline of the engine 200 will be described. The engine 200 has a configuration in which four cylinders 202 are arranged in parallel in a cylinder block 201. In the compression stroke in each cylinder, the force generated when the mixture of the fuel and the intake air directly injected into the cylinder in the compression stroke or the intake stroke is compressed and spontaneously ignited is not shown. This is converted into rotational movement of a crankshaft (not shown) via a piston and a connecting rod. The rotation of the crankshaft is transmitted to drive wheels of a vehicle on which the engine system 10 is mounted, and the vehicle can travel. Below, the principal part structure of the engine 200 is demonstrated with a part of the operation | movement. Since the configurations of the individual cylinders 202 are equal to each other, only one cylinder 202 will be described here.

  In FIG. 1, intake air that is air guided from the outside is guided to an intake pipe 204 that is an example of an “intake passage” according to the present invention. The intake pipe 204 is provided with a diesel throttle valve 205 capable of adjusting the amount of intake air guided to the intake pipe 204. The diesel throttle valve 205 is a rotary valve that is configured to be rotatable by a driving force supplied from a throttle valve motor (not shown) that is electrically connected to the ECU 100 and controlled by the ECU 100 in a higher level. The rotation position is continuously controlled from the fully closed position where the upstream portion and the downstream portion of the intake pipe 204 at the boundary of 205 are substantially blocked to the fully open position where the intake portion 204 communicates almost entirely. Thus, in the engine 200, a kind of electronically controlled throttle device is configured by the diesel throttle valve 205 and the throttle valve motor.

  Engine 200 is a diesel engine, and its output is controlled through injection amount increase / decrease control, unlike air-fuel ratio control (fuel injection control based on intake air amount) in an engine using gasoline or the like as fuel. The Therefore, the amount of intake air sucked through the diesel throttle valve 205 is not substantially limited at least on the upper limit side, and the diesel throttle valve 205 is basically used in most regions of the engine 200 operation period. Therefore, it is controlled to the fully open position.

  The intake pipe 204 is connected to the communication pipe 206 on the downstream side of the diesel throttle valve 205 and is configured to communicate with the communication pipe 206 therein. The communication pipe 206 communicates with each intake port (not shown) of each cylinder 202, and the intake air guided to the intake pipe 204 is guided to the intake port corresponding to each cylinder via the communication pipe 206. It is configured to be written. Two intake ports are provided for each cylinder 202, and each intake port is configured to communicate with the inside of the cylinder 202. The intake pipe 204 and the communication pipe 206 constitute an example of the “intake passage” according to the present invention.

  The communication state between the intake port and the cylinder 202 is controlled by an intake valve 207 provided at each intake port. The intake valve 207 is fixed to the intake camshaft 208 that rotates in conjunction with the crankshaft. The cam profile of the intake cam 209 that has an elliptical cross section perpendicular to the extending direction of the intake camshaft 208 (in short, The opening / closing characteristics are defined according to the shape), and the intake port and the inside of the cylinder 202 can communicate with each other when the valve is opened. As described above, in the engine 200, the communication pipe 206 is concentrated on the upstream side of the portion corresponding to each cylinder 202 (more specifically, the intake port), so that a so-called single valve type intake manifoldless intake system is realized. Yes.

  A fuel injection valve as a part of the in-cylinder injector 203 is exposed inside the cylinder 202, and is configured so that light oil as fuel can be directly injected into the high-temperature and high-pressure cylinder. Here, the fuel is stored in a fuel tank (not shown). The fuel stored in the fuel tank is pumped out of the fuel tank by the action of a feed pump (not shown) and is pumped to a high pressure pump (not shown) through a low pressure pipe (not shown). This high pressure pump is configured to be able to supply fuel to the common rail 203A. The high-pressure pump can take various known modes, and the details thereof will be omitted here.

  The common rail 203A is electrically connected to the ECU 100, and is configured to store high pressure fuel supplied from the upstream side (that is, the high pressure pump side) up to a target rail pressure set by the ECU 100. It is. The common rail 203A is provided with a rail pressure sensor capable of detecting the rail pressure and a pressure limiter for limiting the amount of fuel accumulated so that the rail pressure does not exceed the upper limit value. The illustration is omitted. The injector 203 is mounted for each cylinder 202, and each is connected to the common rail 203A via the high-pressure delivery 203B.

  Here, to supplement the configuration of the injector 203, the injector 203 includes an electromagnetic valve that operates based on a command supplied from the ECU 100, and a nozzle (both not shown) that injects fuel when the electromagnetic valve is energized. Prepare. The solenoid valve is configured to be able to control the communication state between the pressure chamber to which the high pressure fuel of the common rail 203A is applied and the low pressure side low pressure passage connected to the pressure chamber. The pressurizing chamber and the low pressure passage are communicated with each other, and the pressurizing chamber and the low pressure passage are shut off from each other when energization is stopped.

  On the other hand, the nozzle has a built-in needle for opening and closing the nozzle hole, and the fuel pressure in the pressure chamber urges the needle in the valve closing direction (direction in which the nozzle hole is closed). Accordingly, when the solenoid chamber is energized, the pressurizing chamber communicates with the low-pressure passage, and when the fuel pressure in the pressure chamber decreases, the needle rises in the nozzle and opens (opens the nozzle hole), thereby causing the common rail 203A. The high-pressure fuel supplied more can be injected from the injection hole. In addition, when the energization of the solenoid valve is stopped, the pressurization chamber and the low pressure passage are cut off from each other and the fuel pressure in the pressure chamber rises, and the needle is lowered in the nozzle to close the valve, thereby terminating the injection. It has become. In addition, such a structure is an example, for example, the fuel injection process itself may be electronically controlled (that is, fuel is injected without using pressure as a medium).

  Here, according to the injector 203, it is possible to precisely control the fuel injection amount. In the engine 200, the fuel corresponding to the target injection amount is supplied to the fuel in each cylinder 202 via the injector 203. Mainly equivalent to the difference between one or more pilot injections to promote premixing with intake air (of course, also to prevent rapid temperature rise in the combustion chamber) and the target injection amount and pilot injection amount It becomes the structure divided | segmented into injection and injecting.

  Note that the high-pressure pump, the common rail 203A, the high-pressure delivery 203B, and the injector 203 may be configured as an integrated common rail system. Further, the mode for injecting fuel into the high-temperature and high-pressure cylinder is not limited to those exemplified here, and various known modes may be adopted.

  In any case, the air-fuel mixture formed in the cylinder 202 is self-ignited and burned in the compression stroke, and is opened and closed in conjunction with opening and closing of the intake valve 207 as a burned gas or a partially unburned air-fuel mixture. When the exhaust valve 210 is opened, exhaust gas is guided to the exhaust manifold 213 through an exhaust port (not shown). The exhaust valve 210 is fixed to the exhaust camshaft 211 that rotates in conjunction with the crankshaft, and the cam profile of the exhaust cam 212 having an elliptical cross section perpendicular to the extending direction of the exhaust camshaft 211 (in short, The opening / closing characteristics are defined according to the shape), and the exhaust port and the cylinder 202 can be communicated with each other when the valve is opened. The exhaust gas collected in the exhaust manifold 213 is supplied to the exhaust pipe 214 communicating with the exhaust manifold 213.

  A turbine 216 is installed in the exhaust pipe 214 so as to be accommodated in the turbine housing 215. The turbine 216 is a ceramic impeller configured to be rotatable about a predetermined rotation axis by the pressure of exhaust gas (that is, exhaust pressure) guided to the exhaust pipe 214. The rotating shaft of the turbine 216 is shared with the compressor 218 installed in the intake pipe 204 so as to be accommodated in the compressor housing 217. When the turbine 216 is rotated by exhaust pressure, the compressor 218 is also centered on the rotating shaft. It is configured to rotate.

  The compressor 218 is configured to be able to pump and supply intake air sucked into the intake pipe 204 from the outside via the air cleaner 219 to the downstream side by the pressure accompanying its rotation. A so-called supercharging is realized by the pumping effect. That is, in the engine 200, the turbine 216 and the compressor 218 constitute a kind of turbocharger. In the following description, the term “turbocharger” will be used as appropriate as a comprehensive concept including the turbine 216 and the compressor 218.

  A hot wire type air flow meter 220 capable of detecting the mass flow rate of the intake air is installed between the air cleaner 219 configured to purify the intake air and the compressor 218. The air flow meter 220 is electrically connected to the ECU 100, and the detected intake air amount Ga is grasped by the ECU 100 at a constant or indefinite period. In the present embodiment, the detected intake air amount Ga has a unique relationship with the amount of intake air sucked into the cylinder 202 (that is, the intake air amount), and defines the actual load of the engine 200. Treated as an index value.

  In the intake pipe 204, an intercooler 221 is installed on the downstream side of the compressor 218 and the upstream side of the diesel throttle valve 205. The intercooler 221 has a heat exchange wall inside thereof, and when the supercharged intake air passes (similarly in the low rotation region where the compressor 218 does not act substantially), The intake air can be cooled by heat exchange via the heat exchange wall. The engine 200 can increase the density of the intake air by the cooling by the intercooler 221, so that the supercharging via the compressor 218 can be performed more efficiently.

  Here, on the downstream side of the diesel throttle valve 205 in the intake pipe 204, a branch pipe 222 having the same diameter as that of the intake pipe 204 is branched in a state where the communication with the intake pipe 204 is maintained. The inside of the branch pipe 222 is further connected to a surge tank 223 that communicates with the branch pipe 222 through a communication hole (that is, an example of the “opening” according to the present invention). That is, the surge tank 223 is configured to communicate with the intake pipe 204 through the communication hole and the branch pipe 222.

  The surge tank 223 suppresses irregular pulsation of the intake air supplied while appropriately receiving the above-described turbocharger supercharging action, and stably supplies the intake air to the downstream side (that is, the cylinder 202 side). In addition, the storage means is configured to be able to invert the phase of the negative pressure wave at the time of execution of impulse charge described later. However, since the intake air is basically supplied to the cylinder 202 while pulsating to a greater or lesser extent, the intake air passing through the surge tank 223 is also a kind of pulsating wave.

  On the other hand, the branch pipe 222 is provided with a surge tank valve 224 capable of controlling the communication state between the surge tank 223 and the intake pipe 204. The surge tank valve 224 is an example of an “open / close valve” according to the present invention, whose open / close state is controlled in accordance with the driving force supplied from the actuator 225. The actuator 225 is electrically connected to the ECU 100, and the driving state is controlled by the ECU 100. That is, the open / close state of the surge tank valve 224 is controlled by the ECU 100.

  The surge tank valve 224 is configured such that the opening degree that defines its open / close state is continuously variable, but here, for the sake of simplicity of explanation, the opening degree is determined by the intake air via the branch pipe 222. Switching is made in a binary manner between a fully closed opening that blocks communication between the pipe 204 and the surge tank 223 and a fully opened opening that allows the intake pipe 204 and the surge tank 223 to communicate with each other via the branch pipe 222. Shall.

  A single impulse valve 226 is provided in a section of the intake pipe 204 between the branch position with the branch pipe 222 and the connection position with the communication pipe 206. The impulse valve 226 has an opening degree defined by the position of the valve body, a fully-closed opening degree that blocks communication between the intake pipe 204 and the communication pipe 206, and almost complete communication between the intake pipe 204 and the communication pipe 206. It is an electromagnetic control valve as an example of the “intake control valve” according to the present invention, which is configured to continuously change between the fully opened opening. The impulse valve 226 is configured such that its opening degree is controlled by the driving force supplied from the actuator 227. The actuator 227 is electrically connected to the ECU 100, and the driving state of the actuator 227 is controlled by the ECU 100. That is, the opening degree of the impulse valve 226 is controlled by the ECU 100.

  A DPF (Diesel Particulate Filter) 228 is installed in the exhaust pipe 214. The DPF 228 is configured to collect and purify PM (Particulate Matter) discharged from the engine 200. A water temperature sensor 229 is disposed in the cylinder block 201 that houses the cylinder 202. Inside the cylinder block 201, a water jacket serving as a flow path of cooling water (for example, LLC) for cooling the cylinder 202 is stretched, and the cooling water acts on a circulation system (not shown) inside the water jacket. Is circulated by The water temperature sensor 229 has a part of its detection terminal exposed inside the water jacket, and is configured to detect the temperature of the cooling water. The water temperature sensor 229 is electrically connected to the ECU 100, and the detected cooling water temperature is grasped by the ECU 100 at a constant or indefinite period. Further, the communication pipe 206 is provided with an intake manifold pressure sensor 230 that can detect the intake manifold pressure Pim that is the pressure inside the communication pipe 206. The intake manifold pressure sensor 230 is electrically connected to the ECU 100, and the detected intake manifold pressure Pim is grasped by the ECU 100 at a constant or indefinite period.

  In the engine system 10 according to the present embodiment, the engine 200 as a diesel engine is employed as an example of the “internal combustion engine” according to the present invention. However, the internal combustion engine according to the present invention refers only to a diesel engine. Of course, a gasoline engine, an engine using alcohol mixed fuel, or the like may be used. Further, for the purpose of preventing the explanation from being complicated, the engine 200 according to the present embodiment is not equipped with an exhaust gas recirculation device such as an EGR device. However, as a preferred embodiment, the engine 200 is equipped with an exhaust gas recirculation device. It may be. Here, in view of the configuration in which the exhaust gas recirculation device is not mounted, in the engine 200 in the present embodiment, the intake air that is sucked into each cylinder 202 via the intake port is only by the intake air that is guided via the intake pipe 204. Composed.

  As described above, the engine 200 according to the present embodiment has a so-called one-valve in-maniless intake system in which the communication pipe 206 branches to each cylinder on the downstream side of the impulse valve 226. However, the impulse valve 226 may not be configured to be shared and shared by the respective cylinders 202 as described above, and a plurality of impulse valves 226 may be provided for each cylinder 202 in a portion corresponding to each cylinder in the communication pipe 206.

  The required load of the engine 200 is determined according to an accelerator opening degree Ta which is an operation amount (that is, an operation amount by a driver) of an unillustrated accelerator pedal. The accelerator opening degree Ta is detected by the accelerator opening degree sensor 11 and is grasped at a constant or indefinite period by the ECU 100 electrically connected to the accelerator opening degree sensor 11. In general, the smaller the accelerator opening, the smaller the required load, and the larger the accelerator opening, the larger the required load. Since the magnitude of the required load correlates with the magnitude of the required output, in the engine system 10, the engine required output changes according to the accelerator opening degree Ta.

<Operation of Embodiment>
<Overview of impulse charge>
In the engine system 10, the impulse charge is executed when the ECU 100 executes predetermined opening / closing control on the impulse valve 226. Here, the impulse charge refers to inertial supercharging utilizing intake air pulsation caused by opening and closing of the impulse valve 226. More specifically, when one cylinder 202 reaches the intake stroke with the impulse valve 226 closed, the intake valve 207 of the cylinder 202 is opened, and the piston of the cylinder 202 starts to descend. At this time, since the impulse valve 226 is closed, the internal pressure of the communication pipe 206 becomes negative, and the pressure difference from the internal pressure of the intake pipe 204 maintained at atmospheric pressure or higher due to supercharging is increased. To do.

  In this state, when the impulse valve 226 is opened (that is, opened during a valve opening period after the opening timing of the intake valve 207), the intake pipe 204 and the corresponding cylinder 202 (that is, the intake stroke at that time). And the intake air flows into the combustion chamber inside the cylinder 202 at once as an intake air via the impulse valve 226.

  On the other hand, the communication pipe 206 is a so-called open end at the communication part with the combustion chamber, and the positive pressure wave caused by the inflow of the intake air into the combustion chamber is reflected by the combustion chamber, so that the phase is inverted. It becomes a pressure wave. The negative pressure wave reaches the surge tank 205 sequentially through the communication pipe 206, the impulse valve 226, and the branch pipe 222, and is reflected back to the combustion chamber as a positive pressure wave whose phase is inverted by the open end reflection at the open end communication hole. To reach. When the peak of the positive pressure wave reaches the combustion chamber (or to the intake valve 207) (not necessarily limited to that point in time, but includes that point as long as the charging efficiency of the intake can be improved to some extent) The valve opening timing of the impulse valve 226 may be such that the positive pressure wave reaches the combustion chamber by closing the intake valve 207 or at the timing when the intake valve 207 is closed. By controlling this (this embodiment is adopted here), the pressure in the combustion chamber rises, and the intake charging efficiency is improved. Impulse charging using the impulse valve 226 is executed in this way.

<Details of valve drive control>
The engine 200 is provided with a surge tank valve 224, and the communication between the surge tank 223 and the intake pipe 204 can be appropriately cut off. In the engine system 10, the opening / closing of the surge tank valve 224 is controlled in cooperation with the opening / closing of the impulse valve 226 by valve drive control executed by the ECU 100. Here, the details of the valve drive control will be described with reference to FIG. FIG. 2 is a flowchart of the valve drive control.

  In FIG. 2, the ECU 100 acquires the driving conditions of the vehicle (step S101). In the present embodiment, the engine speed Ne and the accelerator opening degree Ta are acquired as the operating conditions. When the engine rotational speed Ne and the accelerator opening degree Ta are acquired, it is subsequently determined whether or not the acquired accelerator opening degree Ta is larger than a reference value Tath (step S102).

  Here, the accelerator opening degree Ta is an index value corresponding to the required load of the engine 200, and the reference value Tath is a value that can make a determination that inertia supercharging is necessary from the viewpoint of the required load. is there. In other words, in the low load region below the reference value Tath, it is not necessary to increase the intake charge amount from the beginning, and therefore it is not necessary to execute the impulse charge.

  When the accelerator opening degree Ta is equal to or less than the reference value Tath (step S102: NO), the ECU 100 sets an execution flag Fg_ip that specifies whether or not to execute impulse charge to an off state indicating that impulse charge is not performed (step S102). In addition, the open / close flag Fg_sg that defines the open / close state of the surge tank valve 224 is set to an off state indicating that the surge tank valve 224 is closed (step S110). Control after the setting of each flag will be described later.

  When it is determined in the determination process according to step S102 that the accelerator opening degree Ta is equal to or less than the reference value Tath (step S102: YES), the ECU 100 determines that the engine speed Ne is the first reference value Ne1 (for example, around 2000 rpm). It is determined whether it is less than (step S103). The first reference value Ne1 is a value of the engine speed that regulates whether or not the impulse charge can be performed, and is an example of the “first reference value” according to the present invention.

  When the engine speed Ne is less than the first reference value Ne1 (step S103: YES), the ECU 100 sets the execution flag Fg_ip to an on state indicating that the impulse charge is executed (step S104), and the open / close flag. Fg_sg is set to an on state indicating that the surge tank valve 224 is opened (step S105).

  On the other hand, when the engine speed Ne is equal to or higher than the first reference value Ne1 (step S103: NO), the ECU 100 further determines whether or not the engine speed Ne is less than the second reference value Ne2 (Ne2> Ne1). (Step S106). Here, the second reference value Ne2 is a value of the engine speed that defines whether or not the surge tank valve 224 is open, and is an example of the “second reference value” according to the present invention. Note that the value of the second reference value Ne2 is set to a value that is small enough that at least the change in the intake air amount accompanying the opening and closing of the surge tank valve 224 can be overlooked in practice.

  When the engine speed Ne is less than the second reference value Ne2 (step S106: YES), the ECU 100 sets the execution flag Fg_ip to an off state (step S107), and sets the open / close flag Fg_sg to an on state (step S106). S108). When the engine speed Ne is equal to or higher than the second reference value Ne2 (step S106: NO), the ECU 100 executes the processes related to step S109 and step S110 described above.

  When the processes according to steps S104 and S105, steps S107 and S108, or steps S109 and S110 are executed, the ECU 100 shifts the process to step S111 and executes the impulse valve control according to the execution flag Fg_ip (step S111). At the same time, the surge tank valve control according to the open / close flag Fg_sg is executed (step S112). When both controls are executed, the process returns to step S101, and a series of processes is repeated.

  When the processing according to steps S111 and S112 is executed through the processing according to steps S104 and S105, that is, when the execution flag Fg_ip is in the on state and the open / close flag Fg_sg is in the on state, the ECU 100 promptly turns on the surge tank valve 224. The impulse valve 226 is opened / closed at the opening / closing timing for realizing the impulse charge described above. That is, an example of “predetermined opening / closing control” according to the present invention is executed. That is, the control mode of each valve performed in this case is an example of the “first control mode” according to the present invention (in addition, the concept of the “first control mode” according to the present invention relates to the intake control valve). Execution of opening / closing control is not necessarily included). Hereinafter, this control mode is referred to as “first control mode” as appropriate.

  When the processing according to steps S111 and S112 is executed through the processing according to steps S107 and S108, that is, when the execution flag Fg_ip is in the off state and the open / close flag Fg_sg is in the on state, the ECU 100 opens the surge tank valve 224. While maintaining the valve state, the opening / closing control of the impulse valve 226 is stopped, and the impulse valve 226 is fixed to the open state. That is, the control mode of each valve performed in this case is an example of the “second control mode” according to the present invention (in addition, the concept of the “second control mode” according to the present invention relates to the intake control valve). The stop of the open / close control is not necessarily included). Hereinafter, this control mode is appropriately referred to as a “second control mode”.

  When the processing according to steps S111 and S112 is executed through the processing according to steps S109 and S110, that is, when the execution flag Fg_ip is in the off state and the open / close flag Fg_sg is in the off state, the ECU 100 opens the impulse valve 226. The surge tank valve 224 is quickly closed while maintaining the above. That is, the control mode of each valve performed in this case is an example of the “third control mode” according to the present invention (in addition, the concept of the “third control mode” according to the present invention relates to the intake control valve). The stop of the open / close control is not necessarily included). Hereinafter, this control mode will be referred to as a “third control mode” as appropriate.

  Here, with reference to FIG. 3, the relationship between each control mode mentioned above and the driving | running condition of the engine 200 is demonstrated. FIG. 3 is a schematic diagram of each control mode associated with the operating conditions of the engine 200.

  In FIG. 3, the vertical axis and the horizontal axis represent the torque Tr of the engine 200 and the engine rotational speed Ne, respectively, and the maximum torque curve of the engine 200 is represented as PRF_Tr in the drawing. In FIG. 3, the range of the engine speed that the engine 200 can take is equal to or higher than the minimum rotation speed NeL (NeL <Nel, which is the minimum rotation speed at which self-rotation is possible) and the maximum rotation speed NeH (NeH> Ne2). It is assumed that the torque corresponding to the reference value Tath of the accelerator opening is Tr1 in the figure.

  In this case, the first control mode described above is an example of a first region in which the torque Tr is Tr1 or more and the engine rotation speed Ne is NeL or more and less than Ne1 (that is, the “first rotation region” according to the present invention, The second control mode is executed in the hatched region shown in the figure, and the second control mode is a second region where the torque Tr is Tr1 or more and the engine rotational speed Ne is Ne1 or more and less than Ne2 (ie, the “second rotation region” according to the present invention). The third control mode is executed in the third region including the region where the torque Tr is less than Tr1 and the region where the engine rotational speed Ne is Ne2 or more and NeH or less (that is, the white region shown in the drawing). This is an example of the “third rotation area” according to the present invention, and is executed in the hatched area shown in the figure.

  Here, as is apparent from FIG. 3, except for the low load region where the torque Tr is less than Tr1, the operating point of the engine 200 is a preferred form of acceleration from the first region (that is, the overall tendency). (That is, a situation where the first region moves from the left side to the right side in the figure) (that is, the first region is an example of the “first rotation region” according to the present invention and at the same time the “low rotation region” according to the present invention). The first control mode is selectively executed sequentially in the order of the first control mode → the second control mode → the third control mode.

  Here, in particular, according to the first control mode, an effect of increasing the intake charge amount is obtained by the impulse charge described above, and according to the second control mode, the pulsation generation by the surge tank 223 is performed while the impulse charge is not executed. As a result, the effect of increasing the intake charge amount is obtained. According to the third control mode, the surge tank 223 is prevented from acting as an intake resistance, and the intake charge amount is relatively reduced by the intake air pulsation sufficiently larger than the original. The effect of increasing is obtained. Therefore, according to the valve drive control according to the present embodiment, the intake air amount that is sufficient for practical use is generated from the low rotation region to the high rotation region without causing a change in the intake charge amount that causes at least some practical problem. It is possible to obtain the effect of increasing the filling amount.

<Details of failure response control>
The engine 200 includes a surge tank valve 224 that controls the communication state between the intake passage 204 and the surge tank 223. When the surge tank valve 224 has a closed failure, for example, the impulse charge is performed in the first region described above. Even if trying to do so, the effect of phase inversion of the negative pressure wave by the surge tank 223 cannot be obtained, so that a sufficient effect cannot be obtained. On the other hand, if the above-described opening / closing control of the impulse valve 226 is performed without detecting the occurrence of such a closed failure, in some cases, only the fuel injection amount is increased without increasing the intake charge amount. Emissions can be worsened. Therefore, the ECU 100 responds to the closed failure of the surge tank valve 224 by executing failure response control. Here, the details of the failure handling control will be described with reference to FIG. FIG. 4 is a flowchart of the failure handling control.

  In FIG. 4, the ECU 100 executes a failure detection process (step S300). Here, the details of the failure detection process will be described with reference to FIG. FIG. 5 is a flowchart of the failure detection process.

  In FIG. 5, the ECU 100 determines whether or not it is an impulse charge region (step S301). Here, the impulse charge region according to the present embodiment refers to the above-described first region, which is a region defined by the required load and the engine speed.

  The engine speed that defines the impulse charge region (that is, Ne1 here) is an engine speed that can be executed with a margin of at least an impulsive charge failure (preferably, it can be executed for all cylinders). It may be a value that defines the range of the above, and has a property that can change depending on the installation mode of the impulse valve 226. More specifically, the engine 200 according to the present embodiment employs a so-called single valve type intake manifold intake system, and the impulse charge in all the four cylinders 202 is covered by the single impulse valve 226. It is the composition that is called. Therefore, at least in engine 200, impulse valve 226 is configured to close during the intake stroke of one cylinder 202 in order to prepare for the intake stroke of the next cylinder. Therefore, when each of the cylinders is provided with an impulse valve, a value on the higher rotation side than this embodiment may be taken.

  If it is not the impulse charge region (step S301: NO), the ECU 100 temporarily controls the process to be in a standby state, and if it is the impulse charge region (step S301: YES), sets the execution flag Fg_ip to an on state ( In step S302), an open / close flag Fg_sg is set to an on state (step S303).

  When the setting of each flag is completed, the ECU 100 executes an average intake manifold pressure calculation process (step S400). Here, the details of the average intake manifold pressure calculation process will be described with reference to FIG. FIG. 6 is a flowchart of the average intake manifold pressure calculation process.

  In FIG. 6, the ECU 100 executes the impulse valve control according to the already set flag (step S401), and similarly executes the surge tank valve control (step S402). That is, these processes correspond to executing the first control mode described above.

  On the other hand, when the first control mode is executed and the impulse charge is started, the ECU 100 clears the counter i (step S403) and increments the counter i by “1” (step S404). The counter i is a counter representing the number of samples of the intake manifold pressure Pim. When the increment of the counter i is completed, the ECU 100 acquires the intake manifold pressure Pim_i as the i-th sample (step S405). The intake manifold pressure Pim is the pressure of the communication pipe 206, is acquired from the intake manifold pressure sensor 230, and is temporarily written in a rewritable storage means such as a RAM or a flash memory.

  When the intake manifold pressure Pim_i as the i-th sample value is acquired, the ECU 100 determines whether or not an elapsed time T (the reference time is not limited thereto) after the counter i is cleared exceeds a predetermined threshold Tth. Is determined (step S406). Note that the value of the threshold value Tth is set to a value that ensures the reliability of the average intake manifold pressure Pimave obtained in the subsequent processing so as not to cause any trouble in practice.

  When the elapsed time T is less than the threshold value Tth (step S406: NO), the ECU 100 returns the process to step S404, increments the counter i, and repeats a series of processes. When the elapsed time T exceeds the threshold value Tth through such a process (step S406: YES), the ECU 100 calculates an average intake manifold pressure Pimave according to the following equation (1) (step S407). When the average intake manifold pressure Pimave is calculated, the average intake manifold pressure calculation process ends. Note that the average intake manifold pressure Pimave obtained here is handled as the average intake manifold pressure Pim_on at the time of impulse charge execution.

Pimave = ΣPim_i / i (1)
Returning to FIG. 5, when the average intake manifold pressure calculation process at the time of executing the impulse charge is completed, the execution flag Fg_ip is set to the off state (step S304), and the open / close flag Fg_sg is set to the on state (step S305). . When the setting of each flag is completed, the ECU 100 executes the above-described average intake manifold pressure calculation process again (step S400). The average intake manifold pressure Pimave obtained here is handled as the average intake manifold pressure Pim_off when the impulse charge is not executed in the impulse charge region.

  When the average intake manifold pressure calculation process when the impulse charge is not executed is completed, the ECU 100 calculates the intake manifold pressure deviation ΔPim according to the following equation (2) (step S306). When the intake manifold pressure deviation ΔPim is calculated, the failure detection process ends.

ΔPim = Pim_on−Pim_off (2)
Returning to FIG. 4, the ECU 100 determines whether or not the intake manifold pressure deviation ΔPim obtained in the failure detection process is less than a preset reference value ΔPimth (step S201). Here, the principle of failure determination based on the intake manifold pressure deviation ΔPim will be described with reference to FIG. FIG. 7 is a schematic diagram showing a one-time characteristic of the intake manifold pressure Pim.

  In FIG. 7, the vertical axis represents the intake manifold pressure Pim, and the horizontal axis represents time. Here, the characteristic of the intake manifold pressure Pim when the impulse charge is executed when the surge tank valve 224 is normal is expressed as Prf_ON (see the solid line) in the figure, and similarly, the characteristic of the intake manifold pressure Pim when the impulse charge is not executed is , Represented as Prf_OFF (see broken line). As shown in the figure, when the surge tank valve 224 is normal, the average intake manifold pressure Pimave is Pimave1 when the impulse charge is executed, and Pimave2 (Pimave2 <Pimave1) when the impulse charge is not executed. Value (for example, about 10 kPa).

  On the other hand, when the surge tank valve 224 has a closed failure, the communication between the surge tank 223 and the intake pipe 204 is cut off when the above-described predetermined opening / closing control is performed on the impulse valve 226 to execute the impulse charge. Inertia supercharging action does not occur. As a result, there is no deviation in the average intake manifold pressure Pimave between when the impulse charge is performed and when it is not performed, or at least a value smaller than when the surge tank valve 224 normally opens and closes when it occurs. . For this reason, it becomes possible to detect the closing failure of the surge tank valve 224 with high accuracy based on the intake manifold pressure Pim.

  Returning to FIG. 4, when the intake manifold pressure deviation ΔPim is equal to or greater than the reference value ΔPimth (step S201: NO), the ECU 100 ends the failure response control assuming that the surge tank valve 224 does not have a closed failure. On the other hand, when the intake manifold pressure deviation ΔPim is less than the reference value ΔPimth (step S201: YES), the ECU 100 sets a fail flag Fg_fail indicating whether or not the surge tank valve 224 has a closed failure, and causes the closed failure to occur. (Step S202) and the prohibition flag Fg_stp indicating whether or not the execution of the impulse charge is prohibited is controlled to the on state indicating that the execution of the impulse charge is prohibited (step S202). Step S203).

  When the setting of the fail flag Fg_fail and the prohibition flag Fg_stp is completed, the ECU 100 writes the information of these flags in a predetermined storage unit (for example, RAM or flash memory) (step S204), and ends the failure handling control. As described above, when the closed failure has occurred in the surge tank valve 224, the prohibition flag Fg_stp is set to the on state. Therefore, the impulse charge is not executed thereafter, assuming that the execution requirement for the impulse charge is satisfied. For this reason, an unnecessary increase in fuel does not occur, and deterioration of economic performance represented by fuel consumption and environmental performance represented by emissions is prevented. In addition, the information regarding the closing failure of the surge tank valve 224 and the information indicating that the execution of the impulse charge is prohibited may be provided to, for example, an OBD (On Board Diagnosis) provided in the vehicle.

Second Embodiment
Next, a second embodiment of the present invention will be described.

<Configuration of Embodiment>
First, the configuration of the engine system 20 according to the second embodiment of the present invention will be described with reference to FIG. FIG. 8 is a schematic configuration diagram conceptually showing the configuration of the engine system 20. In addition, in the same figure, the same code | symbol is attached | subjected to the location which overlaps with FIG. 1, and the description shall be abbreviate | omitted suitably.

  In FIG. 8, the engine system 20 is different from the engine system 10 according to the first embodiment in that an engine 300 is provided instead of the engine 200. The engine 300 includes a first branch pipe 301, a first surge tank valve 302, a first actuator 303, a second branch pipe 304, a second surge tank valve 305, and a branch pipe 222 instead of the surge tank valve 224 and the actuator 225. The second actuator 306 is different from the engine 200 in that the second actuator 306 is provided.

  In FIG. 8, the first branch pipe 301 has the same diameter as the intake pipe 204 that branches from the downstream side of the diesel throttle valve 205 in the intake pipe 204 to the surge tank 223 while maintaining communication with the intake pipe 204. This is a tubular member.

  The first surge tank valve 302 is a valve device similar to the surge tank valve 224 according to the first embodiment, which is provided in the first branch pipe 301 and can control the communication state between the surge tank 223 and the intake pipe 204. is there. The first surge tank valve 302 is another example of the “open / close valve” according to the present invention, the open / close state of which is controlled according to the driving force supplied from the first actuator 303. The first actuator 303 is electrically connected to the ECU 100, and the driving state of the first actuator 303 is controlled by the ECU 100. That is, the open / close state of the first surge tank valve 302 is controlled by the ECU 100.

  Similarly, the second branch pipe 304 is branched from the branch position downstream of the first branch pipe 301 in the intake pipe 204 to the surge tank 223 while maintaining communication with the intake pipe 204. It is a tubular member having the same diameter.

  The second surge tank valve 305 is a valve device similar to the first surge tank valve 302 provided in the second branch pipe 304 and capable of controlling the communication state between the surge tank 223 and the intake pipe 204. The second surge tank valve 305 is another example of the “open / close valve” according to the present invention, whose open / close state is controlled according to the driving force supplied from the second actuator 306. The second actuator 306 is electrically connected to the ECU 100, and the driving state of the second actuator 306 is controlled by the ECU 100. That is, the open / close state of the second surge tank valve 305 is controlled by the ECU 100.

  In FIG. 8, the first and second branch pipes are arranged in parallel in the direction along the intake pipe 204. Accordingly, two communication holes (that is an example of “a plurality of openings” according to the present invention) communicating with each of the branch pipes in the surge tank 223 are also arranged in parallel in the direction along the intake pipe 204. Yes. For this reason, the distance between each communication hole and the impulse valve 226 is different, and the length of the path communicating with the surge tank 223 via the first branch pipe 301 (hereinafter referred to as “L1”) is the second branch pipe. It is longer than the length of the path communicating with the surge tank 223 via 304 (hereinafter referred to as “L2”).

<Operation of Embodiment>
Next, with reference to FIG. 9, the details of the valve drive control for controlling the operation states of the first surge tank valve 302, the second surge tank valve 305, and the impulse valve 226 will be described as operations of the present embodiment. FIG. 9 is a flowchart of the valve drive control. In the figure, the same reference numerals are given to the same portions as those in FIG. 2, and the description thereof will be omitted as appropriate.

  In FIG. 9, when the accelerator opening degree Ta is larger than the reference value Tath (step S102: YES), the ECU 100 determines whether or not the engine speed Ne is the 0th reference value Ne0 (Ne0 <Ne1) (step S102). S501). Here, the 0th reference value Ne0 is a value for determining a surge tank valve to be opened among the first surge tank valve 302 and the second surge tank valve 305.

  When the engine speed Ne is less than the 0th reference value Ne0 (step S501: YES), the ECU 100 sets the execution flag Fg_ip to an on state (step S502) and defines the open / close state of the first surge tank valve 302. The open / close flag Fg_sg1 is set to an on state indicating that the first surge tank valve 302 is to be opened (step S503), and an open / close flag Fg_sg2 that defines the open / close state of the second surge tank valve 305 is set to the second surge tank. The valve 305 is controlled to be in an off state indicating that the valve 305 is closed (step S504).

  On the other hand, when the engine speed Ne is equal to or greater than the 0th reference value Ne0 (step S501: NO), the ECU 100 determines whether the engine speed Ne is less than the first reference value Ne1 as in the first embodiment. Is determined (step S103). When the engine speed Ne is less than the first reference value (step S103: YES), the ECU 100 sets the execution flag Fg_ip to the on state (step S104), and then sets the open / close flag Fg_sg1 to the off state (step S505). ) And the open / close flag Fg_sg2 is controlled to be on (step S506).

  On the other hand, when the engine rotational speed Ne is equal to or higher than the first reference value Ne1 (step S103: NO), the ECU 100 determines whether the engine rotational speed Ne is less than the second reference value Ne2 as in the first embodiment. Is determined (step S106). When the engine speed Ne is less than the second reference value (step S106: YES), the ECU 100 sets the execution flag Fg_ip to the off state (step S107), and then sets the open / close flag Fg_sg1 to the off state (step S507). ) And the open / close flag Fg_sg2 is set to an off state (step S508).

  On the other hand, when the engine rotational speed Ne is equal to or higher than the second reference value (step S106: NO), the ECU 100 sets the execution flag Fg_ip to the off state (step S109) after the execution flag Fg_ip is set as in the first embodiment. Fg_sg1 is set to the off state (step S509), and the open / close flag Fg_sg2 is set to the off state (step S510).

  When each flag is set by the processing according to steps S502 to S504, steps S104 to S506, steps S107 to S508, or steps S109 to S510, the ECU 100 controls the impulse valve according to the set flag (step S111). The first surge tank valve 302 is controlled (step S511), and the second surge tank valve 305 is controlled (step S512). When the process related to step S512 ends, the process returns to step S101, and a series of processes is repeated.

  Here, when the processing according to steps S111 to S512 is executed through the processing according to steps S107 to S508, the state of the engine 300 is an impulse with the communication between the surge tank 223 and the intake pipe 204 maintained. In this state, charging is stopped, and the second control mode described above is executed. Further, when the processes according to steps S111 to S512 are executed through the processes according to steps S109 to S510, the engine 300 is in a state where the communication between the surge tank 223 and the intake pipe 204 is cut off and the impulse charge is also performed. This is equivalent to the state in which the third control mode described above is executed.

  On the other hand, when the processes according to steps S111 to S512 are executed through the processes according to steps S502 to S504 and steps S104 to S506, the engine 300 is in a state where impulse charge is executed anyway. This is equivalent to the state in which the first control mode described above is executed.

  Here, with reference to FIG. 10, the relationship between each control mode mentioned above and the operating condition of the engine 300 is demonstrated. FIG. 10 is a schematic diagram of each control mode associated with the operating conditions of the engine 300. In FIG. 10, the same reference numerals are given to the same portions as those in FIG. 3, and the description thereof is omitted as appropriate.

  In FIG. 10, the first control mode described above is a fourth region in which the torque Tr is Tr1 or more and the engine speed Ne is NeL or more and less than Ne0 (that is, another example of the “first rotation region” according to the present invention). And a fifth region in which the torque Tr is Tr1 or more and the engine rotational speed Ne is Ne0 or more and less than Ne1 (that is, another example of the “first rotation region” according to the present invention). Yes, in the illustrated hatching area). At this time, a combination of the fourth region and the fifth region is equivalent to the first region according to the first embodiment.

  Here, in particular, the length of the conduit from the impulse valve 226 to the communication hole of the surge tank 223 is different between the fourth region and the fifth region when the impulse charge is performed. In the fourth region, the length is set to L1 by using the first branch pipe 301, and in the fifth region on the higher rotation side, the length is set to L2 by using the second branch pipe 304 (described above). (L2 <L1).

  As already described, the surge tank 223 is a means for reversing the phase of the negative pressure wave and reflecting it as a positive pressure wave. The shorter the length of the pipe, the faster the positive pressure wave reaches the combustion chamber in time. Will do. In other words, if the valve opening timing of the impulse valve 226 is fixed, the effect of the impulse charge depends on the physical configuration (in short, the length described here) of one pipe that is used to generate pulsation. Is the engine speed that is most efficiently defined. Therefore, in the engine 300 according to the present embodiment, there are two values of the engine speed at which the effect of the impulse charge can be utilized to the maximum (note that the above-described zeroth reference value Ne0 is ideal) Is set between these two values, in other words, one peak (the peak of the effect of impulse charge) appears in each of the fourth region and the fifth region). The pipe including the second branch pipe 304 is used as a pipe for a relatively high rotation area, and the pipe including the second branch pipe 304 is used as a pipe for a relatively high rotation area.

  In the present embodiment, a plurality of pipelines to be selected in advance (two types in the present embodiment) are set in advance, so that the practical benefits related to the increase in the intake charge amount due to the impulse charge can be more suitably enjoyed. This makes it possible to further increase the intake charge amount while suppressing the change in the intake charge amount.

  In the present embodiment, the two communication holes of the surge tank 223 are formed along the intake pipe 204. However, at least the number of the communication holes, the installation mode, and the like are, for example, mountability related to enlargement of the surge tank. The number of communication holes and the installation mode are freely defined as long as they can be enjoyed as a practically significant difference in profits unless other problems such as lowering of the load and increase of the control load are actualized. Good.

  Note that the reference value of the engine speed is used when switching the control mode in each of the above-described embodiments. At this time, each reference value may be appropriately subjected to correction processing for imparting hysteresis characteristics. That is, for example, assuming that the correction value related to this correction processing is a value of ΔNe, for example, as the engine rotation speed increases, the engine rotation speed Ne exceeds the first reference value Ne1, and the second control mode is executed. In this case, the time point at which the first control mode is executed again with the decrease in the engine speed is not the time when the engine speed Ne falls below the first reference value Ne1, but the time when the engine speed Ne falls below Ne1-ΔNe. May be. Thus, by providing the hysteresis characteristic, hunting in control is prevented.

  By the way, also in this embodiment, since it is necessary to cope with the closing failure of each surge tank valve as in the first embodiment, the failure handling control is executed. Here, details of the failure handling control according to the present embodiment will be described with reference to FIG. FIG. 11 is a flowchart of the failure handling control. In the figure, the same reference numerals are given to the same portions as those in FIG. 4, and the description thereof will be omitted as appropriate.

  In FIG. 11, the above-described failure detection process is executed for the first surge tank valve 302. That is, the failure detection process is executed when the engine speed Ne exists in the fourth region below the 0th reference value Ne0. When the failure detection process for the first surge tank valve 302 ends, the intake manifold pressure deviation ΔPim1 representing the intake manifold pressure deviation calculated for the first surge tank valve 302 is a reference value ΔPim1th (the reference value ΔPimth according to the first embodiment). It may be determined whether it is less than (which may be the same value) (step S601).

  When the intake manifold pressure difference ΔPim1 is less than the reference value ΔPim1th (step S601: YES), the ECU 100 sets a fail flag Fg_fail1 that specifies whether or not the first surge tank valve 302 is closed, and the first surge tank valve 302 is closed. (Step S602), and the failure detection process is similarly executed for the second surge tank valve 305. When the intake manifold pressure deviation ΔPim1 is greater than or equal to the reference value ΔPim1th (step S601: NO), the failure detection process for the second surge tank valve 305 is performed while the fail opening / closing flag Fg_sg1 is maintained in the off state. The

  When the failure detection process is executed for the second surge tank valve 305, the intake manifold pressure deviation ΔPim2 representing the intake manifold pressure deviation calculated for the second surge tank valve 305 is set to the reference value ΔPim2th (the above-described ΔPim1th or the first implementation). It is determined whether or not it is less than ΔPimth according to the form (step S603).

  When the intake manifold pressure difference ΔPim2 is less than the reference value ΔPim2th (step S603: YES), the ECU 100 sets a fail flag Fg_fail2 that defines whether or not the second surge tank valve 305 is closed, and the second surge tank valve 305 is closed. Is set to an on state indicating that the error has occurred (step S604), and an alternative process is executed (step S700). If the intake manifold pressure deviation ΔPim2 is greater than or equal to the reference value ΔPim2th (step S603: NO), the substitute process is executed while the fail opening / closing flag Fg_sg2 is maintained in the OFF state. Note that when the alternative process is executed, the failure handling control is terminated.

  Here, the details of the substitution process will be described with reference to FIG. FIG. 12 is a flowchart of the alternative process. In the figure, the same reference numerals are given to the same portions as those in FIG. 4, and the description thereof will be omitted as appropriate.

  In FIG. 12, the ECU 100 refers to the setting states of the fail opening / closing flag Fg_sg1 and the fail opening / closing flag Fg_sg2, and determines whether or not both surge tank valves have a closed failure (step S701). If both surge tank valves have a closed failure (step S701: YES), the ECU 100 sets the prohibition flag Fg_stp to the on state (step S203), and stores information on these flags in a predetermined storage unit (for example, RAM or The data is written in the flash memory or the like (step S204), and the substitution process is terminated.

  On the other hand, at least one of the surge tank valves operates normally (in view of the nature of the fail flag, “normally operates” in this case means that the valve is opened at least in response to a valve opening instruction. ) (Step S701: NO), the ECU 100 determines whether or not the first surge tank valve 302 has a closed failure (step S702). When only the first surge tank valve 302 has a closed failure (step S702: YES), the ECU 100 determines whether or not to substitute the first surge tank valve 302 for the second surge tank valve 305. The substitution flag Fg_sg12 Is set to an on state indicating that the second surge tank valve 305 is replaced with the first surge tank valve 302 (step S703), and the process proceeds to step S204.

  When the first surge tank valve 302 is normal (step S702: NO), the ECU 100 determines whether or not the second surge tank valve 305 has a closed failure (step S704). When only the second surge tank valve 305 has a closed failure (step S704: YES), the ECU 100 determines whether or not to substitute the first surge tank valve 302 for the second surge tank valve 305. Is set to an on state indicating that the first surge tank valve 302 is replaced with the second surge tank valve 305 (step S705), and the process proceeds to step S204. If both surge tank valves operate normally (step S704: NO), the ECU 100 maintains all the substitution flags in the off state (that is, the substitution flag is off by default), and the process proceeds to step S204. To migrate.

  As a result of the execution of the substitute process, in the valve drive control illustrated in FIG. 9, when the open / close flag Fg_sg1 is set to the on state and the substitute flag Fg_sg12 is set to the on state, the process according to step S511 is performed. The first surge tank valve 302 is maintained in a closed state, and the second surge tank valve 305 is controlled to be opened instead of the first surge tank valve 302 in the process according to step S512. When the open / close flag Fg_sg2 is set to the on state and the substitute flag Fg_sg21 is set to the on state, the second surge tank valve 305 is maintained in the closed state in the process according to step S512, and the process proceeds to step S511. In such processing, the first surge tank valve 302 is controlled to be in an open state instead of the second surge tank valve 305. That is, impulse charge using the second branch tube 304 is executed in the fourth region, and impulse charge using the first branch tube 301 is executed in the fifth region.

  At this time, as already described, the first branch pipe 301 is for a relatively low rotation area and the second branch pipe 304 is for a relatively high rotation area. Compared to the case where the valve is opened and impulse charge is performed, the effect of increasing the intake charge amount is likely to be reduced. Therefore, the ECU 100 corrects the valve opening timing of the impulse valve 226 when performing this type of substitution.

  As a more specific example, for example, when impulse charge in the fifth region, which is a relatively high rotation region, is performed using the first branch pipe 301 for the relatively low rotation region, the impulse valve 226 described above is used. The opening timing of the impulse valve 226 is advanced within the limits of the opening / closing control, and the peak of the positive pressure wave is synchronized with the closing timing of the intake valve 207 as much as possible. Alternatively, for example, when the impulse charge in the fourth region, which is a relatively low rotation region, is performed using the second branch pipe 304 for the relatively high rotation region, the range of the restriction on the opening / closing control for the impulse valve 226 already described. The valve opening timing of the impulse valve 226 is retarded, and the peak of the positive pressure wave is similarly synchronized with the valve closing timing of the intake valve 207 as much as possible. That is, in this case, the ECU 100 also functions as an example of the “correction unit” according to the present invention. The correction mode is not limited in any way as long as the correction can be expected to improve the intake charge amount.

  Thus, according to the present embodiment, when either one of the surge tank valves operates normally, the execution of the impulse charge is prohibited in the region where the engine speed Ne is less than the first reference value Ne1. However, it is possible to enjoy as much as possible the practical benefits related to the increase in the intake charge amount while preventing deterioration of fuel consumption and emissions.

  In each embodiment of the present invention, the surge tank 223 is arranged in parallel with the intake pipe 204 and is configured to communicate with each other via a communication hole and various branch pipes. Therefore, when the intake air travels through the intake passage 204 and passes through the entrance portion of each branch pipe, the intake air resonates at a predetermined resonance frequency.

  This resonance frequency is variable according to the cross-sectional area of the branch pipe, the length, and the volume of the surge tank 223. It is possible to function as a so-called resonator by setting so as to resonate with respect to a frequency at which the sound pressure level becomes relatively large, and to reduce intake sound having a specific frequency.

  In addition, according to the intake control device of the present invention, the restriction on the installation position of the tank is obviously less than that in the case where the tank is arranged in series in the intake passage, and the installation position of the tank is more It is possible to set the position where the effect can be drawn out, and a higher profit related to the increase in the intake charge amount (or the increase in the intake charge efficiency) due to the inertia supercharging is provided.

  The present invention is not limited to the above-described embodiments, and can be changed as appropriate without departing from the spirit or concept of the invention that can be read from the claims and the entire specification. The control device is also included in the technical scope of the present invention.

1 is a schematic configuration diagram conceptually showing a configuration of an engine system according to a first embodiment of the present invention. It is a flowchart of the valve drive control performed by ECU in the engine system of FIG. It is a schematic diagram of each control mode matched with the operating condition of the engine. 2 is a flowchart of failure response control executed by an ECU in the engine system of FIG. 1. It is a flowchart of the failure detection process performed in the failure handling control of FIG. It is a flowchart of the average intake manifold pressure calculation process performed in the failure detection process of FIG. It is a schematic diagram showing the one hour characteristic of intake manifold pressure. It is a schematic block diagram which represents notionally the structure of the engine system which concerns on 2nd Embodiment of this invention. It is a flowchart of valve drive control concerning a 2nd embodiment. It is a schematic diagram of each control mode matched with the operating condition of the engine. It is a flowchart of the failure response control which concerns on 2nd Embodiment of this invention. It is a flowchart of the alternative process performed in the failure handling control of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... Engine system, 100 ... ECU, 200 ... Engine, 202 ... Cylinder, 204 ... Intake pipe, 205 ... Diesel throttle valve, 206 ... Communication pipe, 207 ... Intake valve, 216 ... Turbine, 218 ... Compressor, 221 ... Intercooler , 222 ... branch pipe, 223 ... surge tank, 224 ... surge tank valve, 225 ... actuator, 226 ... impulse valve, 227 ... actuator, 230 ... intake manifold pressure sensor, 300 ... engine, 301 ... first branch pipe, 302 ... first DESCRIPTION OF SYMBOLS 1 surge tank valve, 303 ... 1st actuator, 304 ... 2nd branch pipe, 305 ... 2nd surge tank valve, 306 ... 2nd actuator.

Claims (9)

An intake passage that is mounted in a vehicle and communicates with the inside of the cylinder, and an intake control valve that is installed in the intake passage and that can achieve inertia supercharging using intake pulsation by controlling the open / close state according to predetermined open / close control And an intake control device for an internal combustion engine comprising at least one opening and a tank arranged in parallel so as to communicate with the intake passage through the opening on the upstream side of the intake control valve. ,
An on-off valve that connects the tank and the intake passage when the valve is opened and shuts off the communication between the tank and the intake passage when the valve is closed;
An intake control device for an internal combustion engine, comprising: control means for controlling an open / close state of the on-off valve based on an operating condition of the vehicle. When the vehicle accelerates from a state where the internal combustion engine is in a predetermined low rotation region, the control means (i) opens the on-off valve and permits execution of the on-off control. (Ii) a second control mode in which the on-off valve is opened and the execution of the on-off control is prohibited; and (iii) a third control mode in which the on-off valve is closed and the execution of the on-off control is prohibited. The intake control device for an internal combustion engine according to claim 1, wherein one control mode is selectively executed in order. The control means includes a first rotation region in which the engine speed is less than a first reference value, a second rotation region in which the engine rotation speed is less than a second reference value defined as a value greater than or equal to the first reference value, and the second 3. The intake control device for an internal combustion engine according to claim 2, wherein the first control mode, the second control mode, and the third control mode are selected when belonging to a third rotation region that is equal to or greater than a reference value. . The intake control apparatus for an internal combustion engine according to claim 2 or 3, wherein the control means continuously executes the second control mode for a predetermined time when the second control mode is selected. The tank has a plurality of the openings in a direction along the intake passage,
The on-off valve is provided corresponding to each of the plurality of openings,
When the opening / closing valve is opened, the control means sequentially opens from the opening / closing valve located upstream of the plurality of opening / closing valves as the engine speed of the internal combustion engine increases. The intake control device for an internal combustion engine according to any one of claims 1 to 4, wherein: Based on the intake pressure related to the intake air when the opening / closing control is performed during the period in which the opening / closing valve is controlled to open, the presence / absence of a closing failure of the opening / closing valve controlled to open is determined. The intake control device for an internal combustion engine according to any one of claims 1 to 5, further comprising discrimination means for discriminating. The tank has a plurality of the openings in a direction along the intake passage,
The on-off valve is provided corresponding to each of the plurality of openings,
When it is determined that the open / close valve that has been controlled to open has a closed failure, the control means replaces the open / close valve that has been determined to have the closed failure with the closed failure. The intake control apparatus for an internal combustion engine according to claim 6, wherein the open / close state of the other open / close valves excluding the open / close valve determined to be present is controlled. 8. The internal combustion engine according to claim 7, further comprising a correcting unit that corrects an opening / closing timing of the intake control valve related to the opening / closing control when an opening / closing state of the other opening / closing valve is controlled. Intake control device. 9. The apparatus according to claim 6, further comprising a restricting unit that restricts execution of the opening / closing control when it is determined that the opening / closing valve is controlled to open. The intake control device for an internal combustion engine according to any one of the preceding claims.

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