JP4609279B2 - Control device for internal combustion engine - Google Patents

Description

  The present invention relates to a control device for an internal combustion engine. More specifically, the present invention relates to a control device for an internal combustion engine that controls an internal combustion engine including a variable valve mechanism that can change the valve opening characteristic of an exhaust valve.

  Japanese Patent Laid-Open No. 2000-204981 discloses a control device for an internal combustion engine. In this technique, an internal combustion engine includes a throttle valve that opens and closes an intake passage, an intake and exhaust valve, and a valve mechanism that controls the opening and closing characteristics of the intake and exhaust valves. During the operation of such an internal combustion engine, when the intake valve is opened and the piston is lowered at the TDC (Top Dead Center; hereinafter referred to as “intake TDC”) near the intake start point, the intake port is lowered. The air-fuel mixture is sucked into the cylinder from the side. Here, when the throttle of the throttle valve is large and the pressure on the intake port side is small, a force for pulling the piston back to the TDC side acts inside the cylinder. Since this force becomes an intake resistance, a pump loss (intake loss) occurs. In order to reduce this pump loss, for example, there is a case where control is performed to reduce the intake resistance in the intake stroke by reducing the throttle valve throttle and setting the intake port close to atmospheric pressure. However, if the pump loss is reduced uniformly, the engine brake during deceleration is also reduced. That is, when deceleration is requested, it may not be possible to secure the required engine brake.

  For this reason, in the above-described prior art, at the time of deceleration, the throttle valve is throttled so that the pressure in the intake port is reduced. As a result, the pump loss increases and the engine brake necessary for deceleration is ensured. At this time, if the in-cylinder pressure becomes excessively small due to the negative pressure of the intake port, the amount of the lubricating oil sucked into the combustion chamber may increase. Therefore, in the above prior art, when the internal combustion engine is in a decelerating state, a lower limit value of the required intake air amount is set within a range in which the amount of sucked lubricating oil is within the allowable range, and the set intake air amount The valve closing timing of the intake valve is controlled so as to be equal to or greater than the lower limit value. As a result, the closing timing of the intake valve is prevented from being advanced too early, and the in-cylinder pressure at the BDC of the piston is prevented from becoming excessively small. That is, according to the control device of the above prior art, at the time of deceleration, the throttle valve is throttled to reduce the pressure in the intake port, thereby ensuring the necessary engine brake and the intake air amount to ensure the intake air amount. By controlling the closing timing of the valve, the amount of sucking up the lubricating oil can be suppressed within an allowable range.

JP 2000-204981 A Japanese Patent Publication No.7-116981 JP 2002-256863 A JP 2001-342878 A

  In the above prior art, the throttle valve is throttled so that the pressure in the intake port becomes low during deceleration, thereby increasing the pump loss and securing the engine brake. However, a certain amount of time is required from when the throttle valve is throttled until the intake passage downstream of the throttle valve actually reaches the target negative pressure. Therefore, in response to the deceleration request, a time lag occurs until the pumping loss is actually generated and the deceleration feeling is obtained.

  The present invention has been made to solve the above-described problems, and has an object to provide an improved control device for an internal combustion engine that can immediately generate a pump loss in response to a deceleration request. To do.

In order to achieve the above object, a first invention is a control device for controlling an internal combustion engine including a variable valve mechanism that changes a valve opening characteristic of an exhaust valve,
An exhaust valve control means for increasing a pump loss by controlling a valve opening characteristic of the exhaust valve when the internal combustion engine is decelerated is provided.

In a second aspect based on the first aspect, the internal combustion engine includes an intake throttle valve that opens and closes an intake passage.
Opening degree changing means for changing the opening degree of the intake throttle valve;
Fuel supply stop determination means for determining whether or not the internal combustion engine is operating in a state where fuel supply is stopped;
An opening degree control means for increasing the opening degree of the intake throttle valve when it is determined that the internal combustion engine is operating in a state where fuel supply is stopped;
It is characterized by providing.

According to a third invention, in the second invention, there is provided deceleration request detecting means for detecting a deceleration request of the internal combustion engine,
The opening control means reduces the opening of the intake throttle valve when the deceleration request is detected,
The exhaust valve control means advances the valve opening timing of the exhaust valve when the deceleration request is detected.

According to a fourth invention, in the third invention, when the opening timing of the exhaust valve is advanced and the opening of the intake throttle valve is reduced when the deceleration request is detected, Pump loss detecting means for detecting the total pump loss of the internal combustion engine;
A pump loss determination means for determining whether or not the total pump loss has reached a determination value;
A deceleration end detecting means for detecting the end of deceleration with respect to the deceleration request of the internal combustion engine,
The exhaust valve control means returns the valve opening timing of the exhaust valve to the original valve opening timing when it is determined that the total pump loss has reached the determination value.
The opening degree control means returns the opening degree of the intake throttle valve to the original opening degree when the end of deceleration is detected.

According to a fifth invention, in the first or second invention, comprising a deceleration request detecting means for detecting a deceleration request of the internal combustion engine,
The exhaust valve control means advances the valve opening timing of the exhaust valve when the deceleration request is detected.

According to a sixth invention, in the fifth invention, provided is a deceleration end detecting means for detecting the end of deceleration in response to the deceleration request of the internal combustion engine,
When the end of deceleration of the internal combustion engine is detected, the exhaust valve control means delays the opening timing of the exhaust valve by a predetermined angle, and opens the original valve before the deceleration request is detected. It is characterized by returning to timing.

According to a seventh invention, in the first or second invention, comprising a deceleration request predicting means for predicting a deceleration request of the internal combustion engine,
The exhaust valve control means advances the valve opening timing of the exhaust valve when the deceleration request is predicted.

According to an eighth invention, in the seventh invention, there is provided deceleration execution detecting means for detecting deceleration execution of the internal combustion engine,
The exhaust valve control means delays the opening timing of the exhaust valve by a predetermined angle when the deceleration of the internal combustion engine is detected, and the original valve opening before the deceleration request is detected. It is characterized by returning to timing.

According to a ninth invention, in the first or second invention, a torque calculating means for calculating a required torque of the internal combustion engine;
Based on the calculated torque, valve opening timing calculating means for calculating an advance amount of the valve opening timing of the exhaust valve;
With
The exhaust valve control means advances the valve opening timing of the exhaust valve based on the calculated advance amount.

A tenth aspect of the invention is the ninth aspect of the invention, comprising deceleration execution detecting means for detecting the deceleration of the internal combustion engine,
The exhaust valve control means delays the valve opening timing of the exhaust valve by a predetermined angle when the deceleration of the internal combustion engine is detected, and returns to the original valve opening timing before being advanced. It is characterized by that.

An eleventh invention is the ninth or tenth invention, wherein torque detecting means for detecting torque generated by the internal combustion engine;
Correction value calculation means for obtaining a correction value for the advance amount of the valve opening timing based on the detected generated torque and the required torque, and
The valve opening timing determining means determines the valve opening timing in consideration of the correction value.

  According to the first invention, the opening characteristic of the exhaust valve is controlled when the internal combustion engine is decelerated. Therefore, the required pump loss can be generated immediately upon deceleration.

  According to the second invention, the opening of the intake throttle valve is increased when the fuel supply is stopped. Thereby, pump loss can be reduced and fuel consumption can be improved. In addition, even when the pump loss reduction operation is executed in this way, the demand for an increase in pump loss can be quickly coped with by controlling the valve opening characteristics of the exhaust valve.

  According to the third and fourth inventions, when the deceleration request of the internal combustion engine is detected, the opening degree of the intake throttle valve is reduced and the opening timing of the exhaust valve is advanced. As a result, it is possible to immediately generate the pump loss necessary for the deceleration request and to stably maintain the generated pump loss.

  According to the fifth invention, when the deceleration request of the internal combustion engine is detected, the valve opening timing of the exhaust valve is advanced. As a result, the necessary pump loss can be generated quickly in response to the deceleration request.

  According to the sixth invention, when the end of deceleration is detected, the valve opening timing of the exhaust valve is retarded by a predetermined angle and returned to the original valve opening timing. Thereby, it can suppress that a big shock generate | occur | produces when returning valve opening timing.

  According to the seventh aspect of the invention, when the deceleration request of the internal combustion engine is predicted, the valve opening timing of the exhaust valve is advanced. Thus, the necessary pump loss can be generated more quickly in response to the deceleration request.

  According to the eighth invention, when deceleration execution is detected, the valve opening timing of the exhaust valve is retarded by a predetermined angle and returned to the original valve opening timing. Thereby, it is possible to suppress the generation of a large torque when returning the valve opening timing.

  According to the ninth and tenth aspects, the required torque is calculated, and the valve opening timing of the exhaust valve is advanced based on the advance amount determined based on the required torque. Therefore, necessary pump loss can be generated and fuel consumption can be improved.

  According to the eleventh aspect, the advance amount of the valve opening timing can be corrected based on the generated torque and the required torque. Therefore, necessary pump loss can be generated more reliably.

  Embodiments of the present invention will be described below with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and the description thereof is simplified or omitted.

Embodiment 1 FIG.
[System configuration of the first embodiment]
FIG. 1 is a schematic diagram for illustrating a control system for an internal combustion engine according to Embodiment 1 of the present invention. As shown in FIG. 1, the system according to the first embodiment includes an internal combustion engine 2. The internal combustion engine 2 includes a cylinder 4. Although only a cross section of one cylinder 4 is shown in FIG. 1, the internal combustion engine 2 includes a plurality of cylinders 4. A piston 6 is disposed inside the cylinder 4. The piston 6 is connected to the crankshaft 10 via a connecting rod 8. In the vicinity of the crankshaft 10, a rotational speed sensor 12 for detecting the rotational speed is disposed. A combustion chamber 14 is provided above the piston 6 in the cylinder 4. A spark plug 16 is assembled in the combustion chamber 14 so that the tip is exposed.

  An intake port 18 and an exhaust port 20 communicate with the combustion chamber 14. The intake port 18 is provided with an intake valve 22 that opens and closes the intake port 18. The exhaust port 20 is provided with an exhaust valve 24 that opens and closes the exhaust port 20. The internal combustion engine 2 includes an intake cam 26 that drives the intake valve 22 and an exhaust cam 28 that drives the exhaust valve 24. The intake cam 26 and the exhaust cam 28 are connected to the crankshaft 10 via cam pulleys, timing belts, and the like. The intake cam 26 and the exhaust cam 28 rotate in conjunction with the rotation of the crankshaft 10 to operate the intake valve 22 and the exhaust valve 24. As a result, the intake port 18 and the exhaust port 20 are opened and closed.

  The intake cam 26 is connected to a VVT mechanism (Variable Valve Timing Mechanism) 30 via a camshaft or the like. The VVT mechanism 30 can change the operating angle and lift amount of the intake valve 22 via the intake cam 26 for each cylinder 4. The exhaust cam 28 is connected to the VVT mechanism 32 via a cam shaft or the like. The VVT mechanism 32 can change the operating angle and lift amount of the exhaust valve 24 via the exhaust cam 28 for each cylinder 4. Note that the structures of the VVT mechanism 30 and the VVT mechanism 32 are not particularly novel, and detailed description thereof is omitted here. A cam position sensor 34 that detects the rotational position of the cam is disposed in the vicinity of the intake cam 26, and a cam position sensor 36 is disposed in the vicinity of the exhaust cam 28.

  As described above, the internal combustion engine 2 has a plurality of cylinders 4. The intake port 18 of each cylinder 4 is connected to a common intake manifold 38. Specifically, the intake manifold 38 is composed of a plurality of branch pipes and a single main pipe connecting these branch pipes together. The intake manifold 38 communicates with the intake port 18 of each cylinder 4 at the end of each branch pipe. On the other hand, the exhaust port 20 of each cylinder 4 is connected to a common exhaust manifold 40. Specifically, the exhaust manifold 40 is composed of a plurality of branch pipes and a single main pipe connecting these branch pipes together. The exhaust manifold 40 communicates with the exhaust port 20 of each cylinder 4 at the end of each branch pipe.

  An injector 42 is assembled to each branch pipe of the intake manifold 38 communicating with each cylinder 4. An electronically controlled throttle valve 44 is disposed in the main pipe of the intake manifold 38 upstream of the injector 42. The throttle valve 44 adjusts the amount of air flowing into the intake manifold 38 by changing its opening. The opening degree of the throttle valve 44 is electrically controlled based on an acceleration / deceleration request by an accelerator operation or the like via an actuator. That is, the throttle opening can be controlled without being based on the accelerator opening. An air flow meter 46 is disposed in the main pipe of the intake manifold 38 upstream of the throttle valve 44. The air flow meter 46 emits an output corresponding to the flow rate of air flowing through the main pipe. On the other hand, an air-fuel ratio sensor 48 is attached to the main pipe of the exhaust manifold 40. The air-fuel ratio sensor 48 emits an output corresponding to the exhaust air-fuel ratio.

  The internal combustion engine 2 includes an ECU (Electronic Control Unit) 50. The ECU 50 acquires information necessary for controlling the internal combustion engine 2 from various sensors such as the rotational speed sensor 12, the cam position sensors 34 and 36, the air flow meter 46, and the air-fuel ratio sensor 48. Further, the crankshaft 10, the spark plug 16, the VVT mechanisms 30, 32, the injector 42, and the throttle valve 44 are controlled based on the acquired information.

[Control during normal driving during fuel cut]
FIG. 2 is a timing diagram for illustrating valve timings during normal travel during fuel cut according to Embodiment 1 of the present invention. FIG. 2A shows the valve timing of the exhaust valve 24, and FIG. 2B shows the valve timing of the intake valve 22. In the first embodiment, the fuel supply is stopped (fuel cut; hereinafter referred to as “F / C”) in order to improve fuel efficiency in the case of coasting in which the internal combustion engine 2 is maintained in autonomous rotation by the inertial force of the vehicle. In addition, the pump loss is reduced by executing the valve control as shown in FIG. 2 (hereinafter referred to as “pump loss reduction operation mode”).

  Specifically, in the pump loss reduction operation mode during F / C, the throttle valve 44 is opened (hereinafter referred to as “non-throttling”) in order to suppress the negative pressure on the intake port 18 side to a pressure close to atmospheric pressure. And). In this state, as shown in FIG. 2A, the opening timing of the exhaust valve 24 (hereinafter referred to as “EVO”) is controlled so that it opens slightly earlier than the BDC (Bottom Dead Center) near the exhaust start point. Is done. Further, the closing timing of the exhaust valve 24 (hereinafter referred to as “EVC”) is controlled to be in the vicinity of the TDC (Top Dead Center) near the intake start point. On the other hand, as shown in FIG. 2B, the valve opening timing (hereinafter “IVO”) of the intake valve 22 is controlled to be in the vicinity of the TDC near the intake start point. Further, the valve closing timing of the intake valve 22 (hereinafter referred to as “IVC”) is advanced so as to be a timing of early closing slightly after the middle of the intake stroke. In the following description of the present embodiment, the “expansion stroke”, “exhaust stroke”, “intake stroke”, and “compression stroke” are respectively performed between the TDC and the BDC regardless of the valve timing. It is assumed that the travel is divided every 90 degrees. The TDC or BDC at the start of each stroke is referred to as “expansion TDC”, “exhaust BDC”, “intake TDC”, or “compression BDC”, respectively.

  FIG. 3 is a graph for explaining the relationship between the cylinder pressure and the combustion chamber volume in the pump loss reduction operation mode during F / C cut. In FIG. 3, the horizontal axis represents the combustion chamber volume, and the vertical axis represents the in-cylinder pressure. In FIG. 3, “expansion”, “exhaust”, “intake”, and “compression” represent the cases where the piston 6 is in expansion TDC, exhaust BDC, intake TDC, and compression BDC, respectively. As shown in FIG. 3, during F / C cut, no torque is generated due to explosion / expansion, so the positive torque generated in the expansion stroke and the negative torque in the compression stroke are the same.

  On the other hand, when the exhaust valve 24 is opened near the compression BDC, the in-cylinder pressure rises to the pressure in the exhaust port 20 (about atmospheric pressure). Thereafter, the exhaust proceeds with the pressure kept substantially constant. Further, since the throttle valve 44 is opened, the intake port 18 side is maintained at a pressure close to the atmospheric pressure, and the negative pressure is low. Therefore, even if the intake valve 22 is opened near the intake BDC and the exhaust valve 24 is closed, the in-cylinder pressure is lowered from the atmospheric pressure without changing substantially. In the middle of the intake stroke, the intake valve 22 is closed at IVC near the middle of the intake stroke. Here, both the intake valve 22 and the exhaust valve 24 are closed, and then the in-cylinder pressure decreases as the piston 6 descends. At this time, a force to pull back to the TDC side acts on the piston 6. That is, as indicated by the hatched portion that rises to the left in FIG. 3, the difference between the reduced in-cylinder pressure after IVC and the exhaust pipe pressure (atmospheric pressure) in the exhaust stroke occurs as a pump loss.

  As shown in FIG. 3, the generated pump loss is sufficiently small because the intake port 18 side is at atmospheric pressure by non-throttling control. During operation of the internal combustion engine 2 in the F / C state, the rotation of the internal combustion engine 2 is maintained by the inertial force. Here, the operation in the F / C state is performed within the range of the revolving speed at which the internal combustion engine 2 can immediately autonomously rotate when the fuel supply is resumed. That is, F / C is performed until the rotational speed of the internal combustion engine 2 is reduced to the return rotational speed. In the first embodiment, as shown in FIG. 3, in normal running during F / C, the pump loss reduction operation mode is adopted and the pump loss is reduced. The period until it can be extended. Therefore, the operation in the F / C state can be maintained for a long time, and the fuel consumption can be improved.

[Control during deceleration during fuel cut]
As described above, since the pump loss is reduced in the F / C pump loss reduction operation mode, there is a case where the pump loss corresponding to the deceleration request cannot be secured when the deceleration request is made. For this reason, for example, it can be considered that the throttle valve is throttled from the non-throttling state to return to the throttling state and the intake port 18 side is controlled to have a negative pressure. According to this method, during the intake stroke until the piston 6 reaches the compression BDC from the intake TDC, a force to pull back to the piston 6 is generated, so that the pump loss can be increased. However, in the case of this method, it takes some time until the intake port 18 becomes negative pressure after the throttle valve 44 is brought into the throttling state after the deceleration request. For this reason, it is difficult to generate a necessary pump loss immediately in response to a deceleration request, and a time lag occurs until a necessary feeling of deceleration is generated.

  On the other hand, in the first embodiment, the following control is performed in order to immediately generate a pump loss in response to the deceleration request. FIG. 4 is a timing diagram for explaining the valve timing when a deceleration request is made. 4A shows the valve timing of the exhaust valve 24, and FIG. 4B shows the valve timing of the intake valve 22. Even during the F / C, when there is a further deceleration request in the pump loss reduction operation mode (hereinafter referred to as “deceleration mode”), in the first embodiment, the non-throttling state is continuously controlled and the intake port 18 side Is maintained at a pressure as high as atmospheric pressure. In this state, as shown in FIG. 4A, the exhaust valve 24 is opened at a timing slightly before reaching the middle of the expansion stroke (EVO (1)). In other words, the advance of the EVO is greatly controlled. Thereafter, when the piston 6 passes through the exhaust BDC and reaches the intake TDC, the exhaust valve 24 is closed (EVC). The intake valve 22 is controlled at the same timing as the pump loss reduction operation mode of FIG. Specifically, the intake valve 22 is opened in the vicinity of the intake TDC (IVO), and then closed when the vicinity of the middle of the intake stroke is passed (IVC).

  FIG. 5 is a graph for explaining the relationship between the combustion chamber volume and the in-cylinder pressure in the control of the deceleration mode during F / C according to the first embodiment. In FIG. 5, the horizontal axis represents the combustion chamber volume, and the vertical axis represents the in-cylinder pressure. In FIG. 5, “expansion”, “exhaust”, “intake”, and “compression” represent the time when the piston 6 is in expansion TDC, exhaust BDC, intake TDC, and compression BDC, respectively. As shown in FIG. 5, the in-cylinder pressure decreases as the piston 6 descends from the expansion TDC. The exhaust valve 24 opens at EVO (1) in the vicinity where the piston 6 has passed the midpoint of the expansion TDC. When the exhaust valve 24 is opened, the in-cylinder pressure is reduced to the exhaust pipe pressure (atmospheric pressure) at once. Thereafter, with the in-cylinder pressure maintained at atmospheric pressure, the piston 6 descends to the exhaust BDC. In this way, by reducing the in-cylinder pressure of the piston 6 to atmospheric pressure in the middle of the expansion stroke, the positive torque generated in the expansion stroke is greatly reduced. The positive torque in the intake stroke, the negative torque in the exhaust stroke, and the compression stroke are generated in the same manner as shown in FIG. Therefore, the pump loss is increased by the amount of torque reduced in the expansion stroke, and a large pump loss is generated as shown by the hatched portion rising to the left in FIG. Therefore, it is possible to secure a necessary pump loss for the deceleration request.

  Further, according to the control as described above, by opening the exhaust valve 24 at an early stage of the expansion stroke, the positive torque generated in the expansion stroke can be greatly reduced and the pump loss can be increased. . Therefore, when there is a deceleration request during F / C, it does not cause a time lag as in the case of control to change the throttle valve opening to make negative pressure in the intake port, and matches the driver's feeling of deceleration. Immediate pump loss can be generated.

[Control during normal driving during firing]
FIG. 6 is a timing diagram for explaining the valve timing during the fuel supply operation of the first embodiment. FIG. 6A shows the valve timing of the exhaust valve 24, and FIG. 6B shows the valve timing of the intake valve 22. FIG. 6 shows valve timings in the normal traveling mode in a state where fuel is supplied and torque is generated by explosion / expansion (hereinafter referred to as “firing”). As shown in FIG. 6A, the valve timing of the exhaust valve 24 is the same as that in the pump loss reduction operation mode in F / C of FIG. 2, and EVO is EVO (0 slightly before the compression BDC). The EVC is controlled near the intake TDC. On the other hand, as shown in FIG. 6B, the intake valve 22 opens near the intake TDC (IVO) and closes slightly after the compression TDC. As a result, the fresh air necessary for ignition is sufficiently sucked into the cylinder 4.

  FIG. 7 is a graph for explaining the relationship between the combustion chamber volume and the in-cylinder pressure under the control of the normal travel mode during the firing in the first embodiment. In FIG. 7, the horizontal axis represents the combustion chamber volume, and the vertical axis represents the in-cylinder pressure. In FIG. 7, “expansion”, “exhaust”, “intake”, and “compression” represent the cases where the piston 6 is in the expansion TDC, exhaust BDC, intake TDC, and compression BDC, respectively. As shown in FIG. 7, in the expansion stroke, when the ignition is performed in the vicinity of the expansion TDC, the air-fuel mixture in the cylinder 4 expands and the in-cylinder pressure increases. Therefore, while the piston 6 descends to the exhaust BDC, the internal combustion engine 2 generates a large torque and performs positive work. In the intake stroke, the internal combustion engine 2 performs a slight but positive work until the piston 6 reaches the compression BDC from the intake TDC. On the other hand, during the compression stroke, the internal combustion engine 2 performs a negative work during the compression stroke in which the piston 6 descends from the compression BDC to the expansion TDC and during the exhaust stroke, the piston 6 descends from the exhaust BDC to the intake TDC.

  Here, since the firing is in progress, the positive work in the expansion stroke is larger than the negative work amount in the compression stroke, and a large indicated torque is generated as indicated by the upward slanting line in FIG. On the other hand, as indicated by the slanting line on the left, and in the intake stroke, the intake port 18 has a negative pressure rather than the exhaust pipe pressure (atmospheric pressure) until the piston 6 reaches the compression BDC from the intake TDC. Therefore, intake loss occurs due to the force of pulling back to the TDC side until the piston 6 reaches the compression BDC. However, the indicated torque is sufficiently larger than the generated pump loss, and the internal combustion engine 2 can generate a sufficient driving force.

[Control during deceleration during deceleration]
FIG. 8 is a timing diagram for illustrating the valve timing in the deceleration mode during firing in the first embodiment of the present invention. FIG. 8A shows the valve timing of the exhaust valve 24, and FIG. 8B shows the valve timing of the intake valve 22. As shown in FIG. 8A, the exhaust valve 24 is controlled in the same manner as in the deceleration mode during F / C in order to immediately respond to the deceleration request. Specifically, at the time of deceleration, EVO is controlled to EVO (1) that opens greatly early, and is opened slightly before the middle of the expansion stroke. Further, the EVC of the exhaust valve 24 is set near the intake TDC. On the other hand, as shown in FIG. 8B, the timing of the intake valve 22 during the firing and the deceleration mode is the same as the timing of the intake valve 22 during the normal running during the firing shown in FIG. 6B. This ensures a fresh air volume necessary for firing.

  FIG. 9 is a graph for explaining the relationship between the combustion chamber volume and the in-cylinder pressure under the control of the deceleration mode during the above firing. In FIG. 9, the horizontal axis represents the combustion chamber volume, and the vertical axis represents the in-cylinder pressure. In FIG. 9, “expansion”, “exhaust”, “intake”, and “compression” represent the cases where the piston 6 is in the expansion TDC, exhaust BDC, intake TDC, and compression BDC, respectively. As shown in FIG. 9, while the piston 6 extends from the expansion TDC to the exhaust BDC, positive work is performed and torque is generated. However, as described above, the EVO is greatly advanced, and the exhaust valve 24 is opened by EVO (1) slightly before the middle of the expansion stroke. For this reason, in EVO (1), the in-cylinder pressure is rapidly reduced to near atmospheric pressure and maintained as it is. As a result, the positive torque generated in the expansion stroke is also greatly reduced as compared with the normal travel mode. Further, during the intake stroke, the piston 6 is slightly plus work and torque is generated in the same manner as in the normal travel mode during the period from the intake TDC to the compression BDC. On the other hand, a negative torque is generated during the period from the compression BDC to the expansion TDC and from the exhaust BDC to the intake TDC. The positive torque and the negative torque in the intake stroke are the same as those in the normal travel mode during firing.

  Therefore, the positive torque in the expansion stroke, which decreases when the exhaust valve 24 is quickly opened in EVO (1), is the difference in torque from the normal travel mode. As shown in FIG. 9, the indicated torque (upward sloping line) decreases, and the pump loss (upward sloping line part) increases. Thereby, the required engine braking force can be ensured in response to the deceleration request.

[Regarding the control routine of the first embodiment]
FIG. 10 is a flowchart for illustrating a control routine executed by the control device in the first embodiment of the present invention. The routine of FIG. 10 is a routine that is repeatedly executed during operation of the internal combustion engine. In the routine of FIG. 10, it is first determined whether or not F / C is currently being performed (step S102). That is, it is determined whether the fuel supply is stopped or not. If it is determined in step S102 that F / C is being performed, it is determined whether or not the current pump loss reduction operation mode is set (step S104). Specifically, it is determined whether or not the valve timing shown in FIG. If it is determined that the operation mode is not the pump loss reduction operation mode, the control according to the first embodiment is not necessary, so this process is temporarily terminated.

  In step S102, if it is not recognized that the operation is in F / C, and if it is determined in step S104 that the operation is performed under the operation condition that reduces the pump loss, the pump loss is required. It is determined whether or not a deceleration request has been issued (step S106). The deceleration request is determined based on, for example, the rotational speed, speed, accelerator operation amount, etc. of the internal combustion engine 2. If the deceleration request is not accepted, the process is temporarily terminated.

  On the other hand, if it is recognized in step S106 that a deceleration request has been issued, EVO advancement is performed (step S108). Specifically, a control signal is generated from the ECU 50 to the VVT mechanism 32, and the valve opening timing of the exhaust valve 24 is controlled by the VVT mechanism 32. As a result, the EVO is advanced based on the advance amount stored in the ECU 50 in advance, and is set to the timing of EVO (1) (see FIGS. 4 and 8) that opens slightly earlier than the middle of the expansion stroke. Thus, the pump loss can be immediately increased and the negative torque can be increased in response to a deceleration request from the state of the pump loss reduction operation mode during F / C or the normal travel mode during firing.

  Next, it is determined whether or not deceleration has ended (step S110). If it is determined in step S110 that deceleration has ended, EVO is returned to the original valve timing. Specifically, as shown in FIGS. 2 and 6, EVO is retarded to EVO (0) slightly before exhaust BDC. Thereafter, this process is terminated. On the other hand, if the end of deceleration is not recognized, the traveling in the state where EVO is advanced to EVO (1) is continued until the end of deceleration is recognized in step S110.

  As described above, in the first embodiment, when a deceleration request is issued even in the pump loss reduction operation mode during F / C or in the normal travel mode during firing. As the EVO is advanced, the pump loss can be immediately increased. Therefore, it is possible to generate the necessary pump loss earlier for the required deceleration than in the case of the control in which the opening degree of the throttle valve 44 is changed and the pump loss is increased by the intake negative pressure. Therefore, the time lag with respect to the deceleration request can be reduced, and for example, the uncomfortable feeling of the deceleration that the driver has can be eliminated.

  In the first embodiment, during the F / C and during the firing, the valve timing of the exhaust valve 24 is the same in the normal travel mode, and the advance amount of EVO when a deceleration request is made In the above description, the same control is performed. However, the present invention is not limited to this, and appropriate timing and advance amount may be determined during F / C and during firing, and control may be performed based on the timing and advance amount.

  For example, the exhaust valve 24 and the throttle valve 44 in FIG. 1 correspond to the “exhaust valve” and “intake throttle valve” of the present invention, respectively. In the first embodiment, the “exhaust valve control means” of the present invention is realized by executing step S108.

Embodiment 2. FIG.
The system according to the second embodiment has the same configuration as the system according to the first embodiment. The second embodiment performs the same control as the first embodiment except that the method of returning the EVO of the exhaust valve 24 after the EVO advance angle control is performed in response to the deceleration request. is there. FIG. 11 is a diagram for explaining how to return the valve timing of the exhaust valve in the second embodiment from the advance angle control. FIG. 11A shows the valve timing of the exhaust valve 24, and FIG. 11B shows the valve timing of the intake valve 22. In the second embodiment, similarly to the first embodiment, when there is a deceleration request that requires an increase in pump loss, the exhaust valve 24 is controlled so as to be in the timing of early opening. Specifically, as shown in FIG. 11B, the exhaust valve 24 is advanced to the timing of EVO (1) slightly before the middle of the expansion stroke. When the deceleration is completed, the valve timing of the exhaust valve 24 is retarded by a predetermined retardation amount ω at a slow position and returned to the original valve timing EVO (0). That is, as shown in FIG. 11 (b), the EVO (1) of the exhaust valve 24 is gradually retarded to EVO (2) and EVO (3) every cycle, and finally EVO (0). Returned to

  FIG. 12 is a graph for explaining a change in the relationship between the combustion chamber volume and the in-cylinder pressure when the EVO is gradually changed and returned to the original timing from the deceleration mode during the firing operation. In FIG. 12, the horizontal axis represents the combustion chamber volume, and the vertical axis represents the in-cylinder pressure. In FIG. 12, “expansion”, “exhaust”, “intake”, and “compression” represent the cases where the piston 6 is in the expansion TDC, exhaust BDC, intake TDC, and compression BDC, respectively. As shown in FIG. 12, as the valve timing of the exhaust valve 24 gradually changes, the timing at which the in-cylinder pressure suddenly decreases in the expansion stroke is delayed as EVO is gradually retarded from EVO (1). As a result, the positive work in the expansion stroke is gradually increased, and the generated positive torque is increased. Accordingly, the indicated torque gradually increases as indicated by the dotted line portion. Along with this, the pump loss (upward left slanting line) gradually decreases. When the valve timing becomes EVO (0), the illustrated torque returns to a large state, as in the original valve timing, and a large torque can be secured as in the normal firing operation.

  As shown in FIG. 12, the valve timing of the exhaust valve 24 gradually changes by a predetermined angle ω from EVO (1) to EVO (0). For this reason, it is possible to return to the normal traveling mode during firing while gradually changing the generated torque from the deceleration state. Therefore, it is possible to suppress a large impact due to torque fluctuation when shifting from the deceleration mode to the normal travel mode. Similarly, when the exhaust valve 24 returns from the deceleration mode during F / C to the valve timing of the normal travel mode during F / C, the exhaust valve 24 is gradually changed by the retard amount ω. Therefore, the torque can be gradually changed from a state in which the pump loss during deceleration is large to a state in which the pump loss in the pump loss reduction operation mode is small, and generation of a large impact due to torque fluctuation can be suppressed.

  FIG. 13 is a flowchart for illustrating a control routine executed in the second embodiment. The routine of FIG. 13 is the same as the routine of the first embodiment except that steps S202 to 206 are executed instead of step S112 of the routine of FIG. Specifically, as in FIG. 10, when steps S102 to S110 are executed and the end of deceleration is recognized, in step S202, when the current EVO is retarded by a predetermined retardation amount ω, the original EVO (0) It is determined whether or not the angle is more retarded. Here, since it is now the timing of EVO (1), it is determined in step S202 that it is not retarded from the original EVO (0), and the current EVO is retarded by a predetermined retardation amount ω. (Step S204). More specifically, EVO (1) in a state in which the advance angle is controlled is delayed by an amount of retardation ω, and is set to EVO (2). It is assumed that the retard amount ω is stored in the ECU 50 in advance.

  The determination in step S202 and the retardation in step S204 are repeated, and EVO is gradually retarded from EVO (1) to EVO (2) and EVO (3). If it is determined in step S202 that EVO is retarded from EVO (0) when the retard amount is further retarded by ω, it is retarded to the original EVO (0) (step S206). This process ends.

  As described above, in the second embodiment, after the EVO is advanced and the pump loss is generated, when the deceleration is completed and the EVO is returned to the original timing, the gradual change is made by the predetermined retardation amount ω. It is controlled to let it return. Therefore, when the valve timing of the exhaust valve 24 is returned, it can be returned in stages without generating a large torque fluctuation, and thus it is possible to suppress the occurrence of a large shock.

  In the second embodiment, the case where the control is performed so as to retard the ω when returning the valve timing has been described. However, in the present invention, the control for returning the valve timing to the original value is not limited to using the amount of retardation (deg / ° CA) with respect to the crank angle as a parameter, and other parameters may be used. Examples of such control parameters include an angle per unit time (deg / ms) and an angle per cycle (deg / cycle).

  In the second embodiment, the “deceleration request detecting means” of the present invention is realized by executing step S106, and the “deceleration end detecting means” of the present invention is realized by executing step S110. By executing step S118 and steps 204 to S206, the “exhaust valve control means” of the present invention is realized.

Embodiment 3 FIG.
The system of the third embodiment has the same configuration as the system of the first embodiment. The system of the third embodiment is the same as the system of the second embodiment, except that the timing for performing the advance control of the EVO in response to the deceleration request and the timing for returning the valve timing thereafter are different. Control.

  Specifically, the systems of the first and second embodiments perform EVO advance control when a deceleration request is accepted, whereas the system of the third embodiment is predicted to have a deceleration request. In this case, the EVO is advanced. The advance amount is the same as in the first and second embodiments, and EVO is advanced to EVO (1). Thereby, the pump loss of the internal combustion engine 2 can be increased at an early stage in preparation for a deceleration request. Therefore, as in the first and second embodiments, when the deceleration request is confirmed, the time lag from the deceleration request to the actual deceleration is suppressed compared to the case where the advance angle of the EVO is controlled. You can decelerate to match the feeling of deceleration you have.

  Further, in the system of the third embodiment, deceleration is executed and EVO retardation is started. At the time of retarding, as in the second embodiment, the retarded amount is retarded by the retard amount ω from EVO (1) to return to the original valve timing EVO (0). Thereby, after deceleration is performed, the torque step when returning the valve timing can be eliminated, and the original operation mode can be smoothly connected. Further, since the valve timing is retarded simultaneously with the deceleration, it is possible to return to the normal traveling mode at an early stage.

  FIG. 14 is a schematic diagram for illustrating a control routine executed in the third embodiment of the present invention. The routine shown in FIG. 14 is the same as the routine of FIG. 13 except that S302 is executed instead of step S106 of FIG. 13 and S304 is executed instead of S110. Specifically, when steps S102 to S104 are executed as in the second embodiment and it is determined in step S102 that the F / C operation is not being performed, and in step S104, it is determined that the pump loss reduction operation mode is in effect. Then, it is determined whether or not a deceleration request is expected to be issued (step S302). Prediction of whether or not a deceleration request is issued is obtained by, for example, obtaining a change in the rotational speed of the internal combustion engine 2, a change in speed, a change in accelerator opening, etc., and whether or not the change is greater than a predetermined value. It is determined based on. Further, for example, it can be predicted whether or not a deceleration request is issued from navigation information or the like.

  In step S302, when the deceleration request is not predicted, the process is temporarily terminated. On the other hand, when the deceleration request is predicted in step S302, the EVO is advanced in step S108 as in the second embodiment. The advance amount is stored in the ECU 50 in advance, and is advanced to EVO (1) shown in FIG. 4 here. Thereafter, it is determined whether or not deceleration has been performed based on the deceleration request (step S304). The determination as to whether or not deceleration has been performed is comprehensively determined from the rotational speed, speed, accelerator opening, valve timing, and the like of the internal combustion engine 2. If the deceleration execution is not permitted, the traveling in the state in which the advance angle control is performed in step S108 is continued until the deceleration execution is permitted in step S304. On the other hand, when the deceleration is recognized in step S304, thereafter, gradually, until the EVO changes from EVO (1) to EVO (0), similarly to the processing in the case where the end of deceleration is recognized in the second embodiment. (Steps S202 to S206).

  As described above, in the third embodiment, the EVO is advanced in advance when the deceleration request is predicted, and when the deceleration is actually performed, the EVO is gradually returned to the original timing. Do. Therefore, the pump loss can be generated more quickly with respect to the deceleration request, and a feeling of deceleration according to the deceleration request can be generated at a more appropriate timing. When deceleration is performed, control for returning EVO to EVO (0) is started. Thereby, after deceleration is cancelled | released, it can be made to return to normal driving mode at an earlier stage.

  In the third embodiment, a case has been described in which, after the EVO advance angle, when the original timing is restored, the delay amount ω is gradually changed. However, the present invention is not necessarily limited to this, and as described in the first embodiment, after the deceleration is performed, EVO (1) may be immediately returned to EVO (0).

  In the third embodiment, by executing step S302, the “deceleration request predicting means” of the present invention is realized, and by executing step S304, the “deceleration execution detecting means” of the present invention is realized, By executing step S108 and steps S202 to S206, an “exhaust valve control means” is realized.

Embodiment 4 FIG.
The fourth embodiment has the same configuration as the system described in the first embodiment. This system calculates the required torque, changes the EVO timing according to the result, and calculates the actual torque after the change and uses it for feedback control (hereinafter F / B control). The same control as that of the first embodiment is performed.

Specifically, the following control is performed particularly in the system of the fourth embodiment.
(1) Calculate the required torque. Specifically, the required torque is calculated based on detection results from various sensors relating to operating conditions such as the rotational speed, speed, and accelerator opening of the internal combustion engine 2. In the fourth embodiment, when the calculated required torque is a deceleration request, that is, when a negative torque is requested, EVO advance angle control is performed.

  (2) The advance amount of EVO is determined and controlled based on the required torque. In the control of the first to third embodiments, the advance amount of EVO uses a preset value (EVO (1)). On the other hand, in the fourth embodiment, the advance amount of EVO is determined from the relationship with the pump loss necessary for generating the torque based on the calculated required torque. Specifically, as described in FIGS. 3 to 6, even during F / C or during the firing operation, if the advance amount is large, the pump loss is large, and the advance amount is When it is small, the pump loss tends to be small. Therefore, when the required negative torque is large, a large advance amount is set so that the pump loss is large, and when the negative required torque is small, a small advance amount is set so that the pump loss is small. Is done. In addition, other engine control values such as the opening of the throttle valve 44 influence the advance amount of EVO. The ECU 50 stores in advance a relationship between the amount of advance of the EVO and other engine control values with respect to the required torque as a map. The calculation of the EVO advance amount is executed based on this map.

  (3) After the EVO is advanced based on the required torque, the actually generated torque is calculated based on the amount of advance of the EVO and the control value of the internal combustion engine 2 or various sensor outputs, etc. Used for control. Specifically, the generated torque is calculated based on pump loss and friction due to throttle valve opening control during EVO and F / C, or EVO at the time of firing and engine generated torque. The ECU 50 stores in advance a map of the relationship between pump loss and friction due to throttle valve opening control during EVO and F / C, or the relationship between EVO and engine-generated torque during firing. Thereafter, a correction value for correcting the EVO advance amount for generating the required torque is obtained from the difference between the calculated torque and the required torque. F / B control is performed by correcting the advance amount of EVO in accordance with the correction value.

  As described above, in the fourth embodiment, the required EVO advance amount is obtained based on the required torque, and the EVO is advanced based on the required EVO advance amount, so that necessary pump loss can be generated and fuel efficiency can be improved. Can be achieved. Further, the actually generated torque is obtained, and F / B control is performed based on the obtained torque. Therefore, the required torque can be generated more reliably and efficient control can be performed.

  FIG. 15 is a flowchart for illustrating a control routine executed in the fourth embodiment of the present invention. In the routine of FIG. 15, first, in step S402, changes in the engine speed, speed, accelerator opening, etc. of the internal combustion engine 2 are detected. Based on the change, the required torque is calculated (step S404). Next, it is determined whether or not a deceleration request has been issued (step S406). Specifically, it is determined that a deceleration request has been issued when the required torque calculated in step S404 is a negative torque equal to or less than a predetermined value. In step S406, if it is not recognized that a deceleration request has been issued, this routine is temporarily terminated.

  On the other hand, if it is determined in step S406 that a deceleration request has been issued, an EVO advance amount corresponding to the required torque is calculated (step S408). The EVO advance amount is calculated based on a map corresponding to the required torque stored in the ECU 50 in advance.

  Next, according to the calculated EVO advance amount, the advance of EVO is performed (step S410). The EVO is changed by changing the rotation angle of the exhaust cam 28 via the cam shaft by the VVT mechanism 32. Next, the generated torque is calculated (step S412). As described above, the generated torque is calculated based on the map of the relationship between EVO and pump loss and friction due to throttle valve opening control during F / C, or the relationship between EVO and engine generated torque during firing. The This map is stored in the ECU 50 in advance.

  Next, based on the calculated torque, it is determined whether or not deceleration has ended (step S414). In step S414, when the end of deceleration is not recognized, the F / B control of the EVO advance amount is executed from the generated torque and the required torque (step S416). That is, a correction value for the EVO advance amount is obtained from the generated torque and the required torque. Thereafter, when the EVO advance amount is obtained again in step S408, the value obtained from the relationship between the required torque and the advance amount is corrected by this correction value, and the EVO advance amount is calculated. Thereafter, EVO advance is performed based on the reset EVO advance amount (step S410), and the control after step S412 is similarly executed. Such control is repeated until the end of deceleration is recognized in step S418, and when the end of deceleration is recognized in step S418, this process is once ended.

  As described above, according to the fourth embodiment, the required torque required during the control of the internal combustion engine 2 is calculated, the EVO advance amount is set based on this, and the EVO is advanced. Therefore, necessary pump loss can be generated appropriately, and fuel consumption can be improved. Further, in the fourth embodiment, a correction value is obtained from the calculated request torque and the generated torque, and feedback control is performed. Therefore, the required torque can be generated more reliably, and the operation efficiency of the internal combustion engine 2 can be improved.

  In the fourth embodiment, the case where the map is used when calculating the torque actually generated after the EVO advance has been described. However, the present invention is not limited to this, and torque may be calculated by other methods. For example, instead of the map, the ECU 50 can calculate the relationship between the EVO and the relationship between the pump loss and the friction caused by the throttle valve opening control during the F / C, and the relationship between the EVO during firing and the engine generated torque. The calculation module may be stored in advance, and the torque may be calculated based on the calculation module. Further, a method of installing a sensor for measuring the in-cylinder pressure, measuring the in-cylinder pressure, and calculating the generated torque by calculating the combustion pressure from the in-cylinder pressure in the ECU 50 can be considered. A method of directly obtaining the torque by installing a torque sensor is also conceivable.

  In addition, the case where the valve timing is immediately returned to the original valve timing as in the first embodiment has been described after the end of deceleration. However, the present invention is not limited to this, and the valve timing may be gradually changed as in the second embodiment. Further, the valve timing may be determined by another method based on the required torque obtained in step S404.

  In the fourth embodiment, by executing step S404, the “torque amount calculating means” of the present invention is realized, and by executing step S408, “valve opening timing determining means” is realized, and step S410 is executed. The “exhaust valve control means” is realized by executing, the “torque detecting means” is realized by executing step S412, and the “correction value calculating means” is realized by executing step S416.

Embodiment 5 FIG.
The system configuration of the fifth embodiment is the same as that described in the first embodiment. In the control of the fifth embodiment, after the deceleration request is determined, the throttle valve opening is controlled in addition to the advance control of the EVO. More specifically, when a deceleration request is accepted, EVO advance angle control is performed as in the first embodiment, and the throttle valve is throttled to change the throttle valve 44 from the non-throttling state to the throttling state. FIG. 16 is a graph for explaining the relationship between the combustion chamber volume and the in-cylinder pressure when throttling is performed during F / C. In FIG. 16, the horizontal axis represents the combustion chamber volume, and the vertical axis represents the in-cylinder pressure. Further, in FIG. 16, “expansion”, “exhaust”, “intake”, and “compression” represent the cases where the piston 6 is in the expansion TDC, exhaust BDC, intake TDC, and compression BDC, respectively.

  As shown in FIG. 16, when the throttle loss state is set during F / C and during the pump loss reduction operation, the intake port 18 side is under negative pressure from the atmospheric pressure, and receives a force for pulling back the piston 6 in the intake stroke. Accordingly, as indicated by the diagonally upward slanting line in the figure, a pump loss (intake loss) due to a pressure difference between the exhaust stroke and the intake stroke occurs. This pump loss is larger than that in the case of the non-throttling shown in FIG.

  FIG. 17 is a graph illustrating the relationship between pump loss and time. FIG. 17A shows the case where EVO is advanced, FIG. 17B shows the case where throttling is performed, and FIG. 17C shows that the EVO is advanced and throttle valve is simultaneously controlled. It is a graph for explaining the case. As shown in FIG. 17A, when the advance angle control of the EVO is performed, the pump loss is increased in a short time from the advance angle control, and the necessary pump loss can be generated. Further, as shown in FIG. 17B, the pumping loss also occurs when throttling is performed and the intake port 18 is set to a negative pressure. However, after enlarging the throttle valve 44, it takes some time for the intake port 18 to actually become negative pressure. Therefore, the time until the pump loss occurs is slower than the EVO advance angle control, and a large time lag as shown in FIG. 17B occurs.

  In the fifth embodiment, the pump loss by the EVO advance angle control of FIG. 17A and the pump loss by the throttle valve control of FIG. 17B are used together. Specifically, when a deceleration request is made, the throttle valve 44 is controlled together with the EVO advance angle control. When the sum of the pump loss increased by the advance control of the EVO and the pump loss by the throttling control of the throttle valve 44 reaches the target value of the required pump loss, the EVO is gradually retarded to Control to return to valve timing. At this time, the pump loss due to the EVO control decreases, but the pump loss due to the throttle valve 44 control gradually increases. Therefore, as shown in FIG. 17C, the pump loss can be maintained at the target value even after the EVO retardation is started.

  FIG. 18 is a flowchart for illustrating a control routine in the fifth embodiment of the present invention. In the routine of FIG. 18, it is first determined in step S502 whether or not F / C is being performed. If it is determined that F / C is being performed, it is determined in step S504 whether or not the pump loss reduction operation mode is set. Since the control in FIG. 18 is executed during the pump loss reduction operation mode during F / C, it is determined that the F / C is not being performed in step S502 and the pump loss reduction operation is not being performed in step S504. If so, the process is temporarily terminated.

  On the other hand, if it is determined in steps S502 and S504 that the engine is in F / C and the pump loss reduction operation mode, it is determined in step S506 whether a deceleration request has been issued as in step S106 of FIG. Is done. If the deceleration request is not accepted, the process is temporarily terminated. On the other hand, if a deceleration request is accepted in step S506, EVO advance angle control is executed (step S508). EVO is advanced to EVO (1) as in the first embodiment. As a result, as shown in FIG. 17A, a pump loss due to the EVO advance angle occurs. Subsequently, the non-throttle pump loss operation mode is stopped, and the throttle valve 44 is enlarged (step S510). As a result, a negative pressure is generated in the intake port 18 and the pump loss gradually increases as shown in FIG.

  Next, it is determined whether or not the total pump loss of the pump loss due to the EVO advance angle and the pump loss due to the throttling has reached the target value required for the deceleration request (step S512). The target value is stored in the ECU 50 in advance. If the total pump loss ≧ target value is not satisfied, the EVO advance angle and throttling control are continued in step S512 until this condition is satisfied.

  On the other hand, if the establishment of the total pump loss ≧ target value is recognized, the EVO is retarded and the original valve timing EVO (0) is returned (step S514). Thereafter, it is determined whether or not the end of deceleration is permitted (step S516). When the end of deceleration is not recognized, the operation of the internal combustion engine 2 is continued under an operating condition in which the pump loss due to throttling is large. On the other hand, when the end of deceleration is recognized, this process is once ended. The throttle valve is appropriately determined according to the subsequent operating conditions.

  As described above, in the fifth embodiment, in addition to the EVO advance angle control, the non-throttling is stopped to secure the intake negative pressure to generate the pump loss. Therefore, it is possible to respond to the deceleration request at an earlier stage and to generate the intake negative pressure by throttling to keep the pump loss at the target value, so that the necessary pump loss can be more reliably maintained.

  In the fifth embodiment, the case where the EVO is retarded when the total pump loss reaches a predetermined target value has been described. However, the present invention is not limited to this. For example, as described in the fourth embodiment, a required torque is obtained, a target value corresponding to the required torque is set each time, and this is used as a determination value. It is also possible.

  In the fifth embodiment, the case where the EVO is immediately returned to the original valve timing after reaching the target value has been described. However, in the present invention, the retarding control of the EVO can be gradually changed by executing steps S202 to S206 of the second embodiment.

  In the fifth embodiment, the case where the EVO is retarded immediately after the total pump loss reaches the target value has been described. However, the present invention is not limited to this, and control for returning the EVO to the original state may be performed after the end of deceleration is determined.

  In the fifth embodiment, the “deceleration request detecting means” of the present invention is realized by executing step S506, and the “pump loss detecting means” and the “pump loss determining means” are executed by executing step S512. By implementing step S516, the “deceleration end means” is realized, by executing steps S508 and S514, the “exhaust valve control means” is realized, and by executing step S510, the “opening degree control means” is realized. Is realized.

  In the above embodiment, when referring to the number of each element, quantity, quantity, range, etc., unless otherwise specified or clearly specified in principle, the number referred to It is not limited. Further, the structures described in the embodiments, steps in the method, and the like are not necessarily essential to the present invention unless otherwise specified or clearly specified in principle.

It is a schematic diagram for demonstrating the control system of the internal combustion engine in Embodiment 1 of this invention. It is a figure for demonstrating the valve timing of F / C in Embodiment 1 of this invention and normal driving | running | working mode. 6 is a graph for illustrating the relationship between the combustion chamber volume and the in-cylinder pressure during F / C and under the control of the normal travel mode according to Embodiment 1 of the present invention. It is a figure for demonstrating the valve timing in F / C and deceleration mode in Embodiment 1 of this invention. It is a graph for demonstrating the relationship between the combustion chamber volume and cylinder pressure in F / C of Embodiment 1 of this invention, and under control of the deceleration mode. It is a figure for demonstrating the valve timing in the firing mode in normal driving mode in Embodiment 1 of this invention. It is a graph for demonstrating the relationship between the combustion chamber volume and cylinder pressure in the firing of Embodiment 1 of this invention and under control of normal driving mode. 5 is a timing diagram for illustrating valve timing in a deceleration mode during firing in the first embodiment of the present invention. It is a graph for demonstrating the relationship between the combustion chamber volume and in-cylinder pressure under control of the deceleration mode during firing of Embodiment 1 of this invention. It is a flowchart for demonstrating the routine of control performed in Embodiment 1 of this invention. It is a figure for demonstrating the valve timing in the case of returning the exhaust valve in Embodiment 2 of this invention from advance angle control to the original control. It is a graph for demonstrating the change of the relationship between a combustion chamber volume and in-cylinder pressure in the case of gradually changing from the valve timing of the deceleration mode during the firing of Embodiment 2 of this invention, and returning to the original valve timing. . It is a flowchart for demonstrating the routine of control performed in Embodiment 2 of this invention. It is a flowchart for demonstrating the routine of control performed in Embodiment 3 of this invention. It is a flowchart for demonstrating the routine of control performed in Embodiment 4 of this invention. It is a graph for demonstrating the relationship between the combustion chamber volume and cylinder pressure in F / C of Embodiment 5 of this invention, and during a pump loss reduction operation stop. It is a graph showing the relationship between time and pump loss in Embodiment 5 of this invention. It is a flowchart for demonstrating the routine of control performed in Embodiment 5 of this invention.

Explanation of symbols

2 Internal combustion engine 4 Cylinder 6 Piston 8 Connecting rod 10 Crankshaft 12 Rotational speed sensor 14 Combustion chamber 16 Spark plug 18 Intake port 20 Exhaust port 22 Intake valve 24 Exhaust valve 26 Intake cam 28 Exhaust cam 30 VVT mechanism 32 VVT mechanism 34 Cam position sensor 36 Cam position sensor 38 Intake manifold 40 Exhaust manifold 42 Injector 44 Throttle valve 46 Air flow meter 48 Air-fuel ratio sensor 50 ECU

Claims (5)

A control device that controls an internal combustion engine that includes a variable valve mechanism that changes a valve opening characteristic of an exhaust valve and an intake throttle valve that opens and closes an intake passage ,
Opening degree changing means for changing the opening degree of the intake throttle valve;
Deceleration request detecting means for detecting a deceleration request of the internal combustion engine;
Fuel supply stop determination means for determining whether or not the internal combustion engine is operating in a state where fuel supply is stopped;
A deceleration end detecting means for detecting the end of deceleration in response to the deceleration request of the internal combustion engine;
When it is determined that the internal combustion engine is operating with fuel supply stopped, the opening of the intake throttle valve is increased, and when the deceleration request is detected, the intake throttle valve is opened. An opening degree control means for returning the opening degree of the intake throttle valve to the original opening degree when the end of deceleration is detected,
Pump loss for detecting the total pump loss of the internal combustion engine when the opening timing of the exhaust valve is advanced and the opening of the intake throttle valve is reduced when the deceleration request is detected Detection means;
A pump loss determination means for determining whether or not the total pump loss has reached a determination value;
When the deceleration request is detected, the opening timing of the exhaust valve is advanced to increase the pump loss, and when it is determined that the total pump loss has reached the determination value, the exhaust valve Exhaust valve control means for controlling the valve opening timing to return to the original valve opening timing ;
A control device for an internal combustion engine, comprising: A control device for controlling an internal combustion engine including a variable valve mechanism that changes a valve opening characteristic of an exhaust valve,
Deceleration request detecting means for detecting a deceleration request of the internal combustion engine ;
A deceleration end detecting means for detecting the end of deceleration in response to the deceleration request of the internal combustion engine;
When the deceleration request is detected, the opening timing of the exhaust valve is advanced to increase the pump loss, and when the end of deceleration of the internal combustion engine is detected, the opening timing of the exhaust valve is Exhaust valve control means for delaying by a predetermined angle and controlling to return to the original valve opening timing before the deceleration request is detected;
Control device for the internal combustion engine you comprising: a. A control device for controlling an internal combustion engine including a variable valve mechanism that changes a valve opening characteristic of an exhaust valve,
Deceleration request prediction means for predicting a deceleration request of the internal combustion engine ;
A deceleration execution detecting means for detecting execution of deceleration of the internal combustion engine;
If the previous SL deceleration demand is predicted to increase the pumping loss by advancing the opening timing of the exhaust valve, if the deceleration embodiment of the internal combustion engine is detected, the valve opening timing of the exhaust valve An exhaust valve control means that delays by a predetermined angle and returns to the original valve opening timing before the deceleration request is predicted;
Control device for the internal combustion engine you comprising: a. A control device for controlling an internal combustion engine including a variable valve mechanism that changes a valve opening characteristic of an exhaust valve,
A deceleration execution detecting means for detecting execution of deceleration of the internal combustion engine;
Torque calculating means for calculating a required torque of the internal combustion engine;
Based on the calculated torque, valve opening timing calculating means for calculating an advance amount of the valve opening timing of the exhaust valve;
Torque detecting means for detecting torque generated by the internal combustion engine;
A corrected advance amount output means for correcting the advance amount of the valve opening timing by a correction value corresponding to the detected generated torque and the required torque, and obtaining a corrected advance amount;
Based on the previous SL correction advance amount, by advancing the opening timing of the exhaust valve to increase the pumping loss, when the deceleration embodiment of the internal combustion engine is detected, the valve opening timing of the exhaust valve, An exhaust valve control means that delays by a predetermined angle and returns to the original valve opening timing before being advanced;
Control device for the internal combustion engine you comprising: a. The internal combustion engine includes an intake throttle valve that opens and closes an intake passage,
Opening degree changing means for changing the opening degree of the intake throttle valve;
Fuel supply stop determination means for determining whether or not the internal combustion engine is operating in a state where fuel supply is stopped;
An opening degree control means for increasing the opening degree of the intake throttle valve when it is determined that the internal combustion engine is operating in a state where fuel supply is stopped;
5. The control device for an internal combustion engine according to claim 2, further comprising:

Images