WO2014199690A1 - Control device and control method for internal combustion engine - Google Patents

Abstract

The present invention pertains to a control device and a control method for internal combustion engine provided with a variable valve actuation mechanism for varying the closing timing of the inlet valve, and a variable compression ratio mechanism for varying the top dead point position of the piston. According to this control device and control method, when the direction of change of the compression ratio produced by both mechanisms differs, the response of the compression ratio change produced by the variable valve actuation mechanism is delayed. Thus, in the event that the response of the compression ratio change produced by the variable valve actuation mechanism is faster as compared with that of the variable compression ratio mechanism, the change in compression ratio produced by the variable valve actuation mechanism is attuned to the change in compression ratio produced by the a variable compression ratio mechanism, minimizing transient states in which the effective compression ratio is momentarily too great or too small.

Description

Control device and control method for internal combustion engine

The present invention relates to a control apparatus and control method for an internal combustion engine, comprising: a variable valve mechanism that changes the closing timing of the intake valve; and a variable compression ratio mechanism that changes the compression ratio by changing the top dead center position of the piston. About.

Patent Document 1 discloses an internal combustion engine that includes a variable valve mechanism that changes the closing timing of an intake valve and a compression ratio variable mechanism that changes a compression ratio by changing the top dead center position of a piston. At the start of the engine, the variable valve ratio mechanism maintains the compression ratio at a high compression ratio equivalent to idling, and the variable valve mechanism sets the closing timing of the intake valve at a time away from the bottom dead center at the initial stage of cranking. A control device is disclosed that closes the closing timing of the intake valve to the bottom dead center after cranking is started.

JP 2002-276446 A

In an internal combustion engine having a variable valve mechanism that changes the closing timing of the intake valve and a compression ratio variable mechanism that changes the compression ratio by changing the top dead center position of the piston, the closing timing IVC by the variable valve mechanism For example, when the variable valve mechanism and the variable compression ratio mechanism are operated in parallel, the closing timing is changed depending on the difference between the change speed of the compression ratio and the change speed of the mechanical compression ratio by the variable compression ratio mechanism. In some cases, the effective compression ratio determined by the IVC and the mechanical compression ratio becomes temporarily too large or too small, which has been a cause of deterioration in flammability and knocking.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a control device and a control method for an internal combustion engine that can prevent the effective compression ratio from temporarily becoming excessively high or low in a transient state.

Therefore, the control device according to the present invention includes a control unit that changes the operation of the other in accordance with one operation state of the variable valve mechanism and the compression ratio variable mechanism.
The control method according to the present invention includes the following steps.
Detecting one operating state of the variable valve mechanism and the compression ratio variable mechanism;
The other operation is changed according to the operation state.

According to the above invention, it is possible to prevent the effective compression ratio from temporarily becoming too large or too small in the transient state, and thus it is possible to suppress the deterioration of combustibility and the occurrence of knocking in the transient state.

1 is a system diagram of an internal combustion engine in an embodiment of the present invention. It is a figure which shows the pattern of the cooperative control in embodiment of this invention. In the embodiment of the present invention, it is a diagram illustrating an operating state in which the change direction of the compression ratio in the variable valve mechanism and the change direction of the compression ratio by the variable compression ratio mechanism are different from each other, and FIG. (B) is a figure which shows the operation | movement in a fuel consumption priority state. It is a figure which illustrates the driving | running state in which the change direction of the compression ratio in a variable valve mechanism and the change direction of the compression ratio by a compression ratio variable mechanism become the same mutually in embodiment of this invention, (A) is a start state. The operation is shown, and (B) is a diagram showing the operation in the fast idle state. It is a figure which illustrates the driving | running state in which the change direction of the compression ratio in a variable valve mechanism and the change direction of the compression ratio by a compression ratio variable mechanism become the same mutually in embodiment of this invention, (A) is a weak supercharging state (B) is a figure which shows the operation | movement in the generation | occurrence | production state of pre-ignition or knocking. It is a figure which illustrates the driving | running state which operates only a compression ratio variable mechanism in embodiment of this invention, (A) shows the action | operation in a weak supercharging state, (B) shows the action | operation in a high supercharging state. FIG. It is a figure which illustrates the driving | running state which operates only a variable valve mechanism in embodiment of this invention, (A) shows the operation | movement in a low load and a fuel-saving state, (B) is in a medium load and a fuel-saving state. FIG. It is a time chart which shows the mode of the compression ratio change when not implementing cooperative control in embodiment of this invention. It is a time chart which shows the mode of the compression ratio change at the time of implementing the cooperative control in embodiment of this invention. It is a block diagram which shows the function which correct | amends the target value of a compression ratio variable mechanism in embodiment of this invention. It is a block diagram which shows the calculation process of the overcorrection gain in embodiment of this invention. It is a block diagram which shows the calculation function of the gain for a restriction | limiting process in embodiment of this invention. It is a block diagram which shows the function which correct | amends the target value of a variable valve mechanism in embodiment of this invention.

Embodiments of the present invention will be described below.
FIG. 1 is a diagram showing an example of an internal combustion engine to which a control device and a control method according to the present invention can be applied.
The internal combustion engine 10 shown in FIG. 1 has a variable compression ratio mechanism (VCR) 50 that changes the compression ratio by changing the top dead center position of the piston 33, and a variable valve mechanism that changes the closing timing IVC of the intake valve 81. VTC) 82.

The variable compression ratio mechanism 50 connects the crankshaft 32 and the piston 33 with the lower link 11 and the upper link 12 and restricts the movement of the lower link 11 with the control link 13 to change the top dead center position of the piston 33. This is a mechanism for changing the compression ratio of the internal combustion engine 10.
The lower link 11 is configured to be split into two left and right members, and is attached to the crankpin 32b of the crankshaft 32 through a substantially central connecting hole. And the lower link 11 rotates centering on the crankpin 32b.

The crankshaft 32 includes a plurality of journals 32a and a crankpin 32b. The journal 32 a is rotatably supported by the cylinder block 31 and the ladder frame 34. The crank pin 32b is eccentric by a predetermined amount from the journal 32a, and the lower link 11 is rotatably connected thereto.
One end of the lower link 11 is connected to the upper link 12 via a connecting pin 21, and the other end of the lower link 11 is connected to the control link 13 via a connecting pin 22.

The lower end of the upper link 12 is connected to one end of the lower link 11 via the connecting pin 21, and the upper end of the upper link 12 is connected to the piston 33 via the piston pin 23.
The piston 33 receives the combustion pressure and reciprocates in the cylinder 31 a of the cylinder block 31.

The control link 13 is rotatably connected to the lower link 11 via a connecting pin 22 provided at the tip, and the other end of the control link 13 is eccentrically connected to the control shaft 25 via a connecting pin 24. The control link 13 swings around the connecting pin 24.
A gear is formed on the control shaft 25, and the gear meshes with a pinion 53 provided on the rotation shaft 52 of the actuator 51. And the control shaft 25 is rotated by the actuator 51, and the connection pin 24 moves.

The control device 70 controls the actuator 51 to rotate the control shaft 25, thereby changing the top dead center position of the piston 33 and changing the compression ratio of the internal combustion engine 10.
The variable compression ratio mechanism 50 is a known mechanism that changes the mechanical compression ratio of the internal combustion engine 10 by changing the top dead center position of the piston 33, and its detailed structure is limited to that shown in FIG. Not.

As an example, the variable valve mechanism 82 is a known variable valve that changes the relative rotation phase angle of the intake camshaft 83 with respect to the crankshaft 32 to change the open period of the intake valve 81 in the advance direction and the retard direction. Timing mechanism.
Here, when the opening period of the intake valve 81 is advanced by the variable valve mechanism 82, the opening timing IVO and the closing timing IVC of the intake valve 81 change in the advance direction, and when the opening period is retarded, the intake valve 81 Since the opening timing IVO and the closing timing IVC of 81 change in the retarding direction, the variable valve mechanism 82 is a mechanism that changes the closing timing IVC of the intake valve 81.

Then, the compression ratio is changed by changing the closing timing IVC of the intake valve 81 by the variable valve mechanism 82. For example, if the closing timing IVC is retarded in the angular region after the bottom dead center BDC of the piston 33, the compression ratio is changed. Conversely, if the closing timing IVC is advanced in the angular region after the bottom dead center BDC of the piston 33, the compression ratio increases.
The variable valve mechanism 82 is not limited to a mechanism that changes the relative rotational phase angle of the intake camshaft 83 with respect to the crankshaft 32, and a known mechanism that makes the closing timing IVC of the intake valve 81 variable can be appropriately employed.

For example, when the variable valve mechanism 82 that makes the opening period of the intake valve 81 variable is provided, the closing timing IVC of the intake valve 81 changes in the retard direction and the advance direction as the opening period of the intake valve 81 increases or decreases. It will be.
That is, if the opening period is increased while the central phase of the opening period of the intake valve 81 is constant, the closing timing IVC will be retarded, and conversely if the opening period is decreased, the closing timing IVC will be The lead angle will change.

The variable valve mechanism 82 is a combination of a first mechanism that changes the relative rotational phase angle of the intake camshaft 83 with respect to the crankshaft 32 and a second mechanism that makes the opening period of the intake valve 81 variable. be able to.
Further, when an electromagnetic valve drive device that opens and closes the intake valve 81 by an actuator such as an electromagnet is provided, the closing timing IVC of the intake valve 81 can be arbitrarily changed by controlling the opening and closing timing. The electromagnetic valve driving device corresponds to a variable valve mechanism that changes the closing timing IVC of the intake valve 81.
Further, an exhaust-side variable valve timing mechanism that makes the valve timing of the exhaust valve 91 variable can be provided.

The internal combustion engine 10 includes a fuel injection device 41. The fuel injection device 41 is disposed, for example, so as to incline toward the piston 33 side toward the combustion chamber side so that the spray direction obliquely intersects the axis of the cylinder bore, and directly injects fuel into the cylinder. To do. That is, the internal combustion engine 10 shown in FIG. 1 is a direct injection type internal combustion engine.
However, the fuel injection device 41 is not limited to a device that directly injects fuel into the cylinder, but can be a device that injects fuel into the intake port on the upstream side of the intake valve 81. Both a device for directly injecting fuel into the cylinder and a device for injecting fuel into the intake port can be provided.

The control device 70 changes the top dead center position of the piston 33 by controlling the compression ratio variable mechanism 50, changes the closing timing IVC of the intake valve 81 by controlling the variable valve mechanism 82, The fuel injection by the injection device 41 and the ignition timing by the spark plug 42 are controlled.
The control device 70 includes a microcomputer having a CPU, a ROM, a RAM, an input / output interface, etc., and inputs detection signals from various sensors, and a compression ratio variable mechanism 50, a variable valve mechanism 82, a fuel injection. The operation signal of the ignition coil etc. of the apparatus 41 and the spark plug 42 is output.

As the above various sensors, the internal combustion engine 10 includes a load sensor 61 that detects the engine load TP, a rotation sensor 62 that detects the engine rotational speed NE, a water temperature sensor 63 that detects the temperature TW of the cooling water of the internal combustion engine 10, and the like. It is provided.
The control device 70 detects the operating state of the internal combustion engine 10 based on the outputs of the various sensors, and the compression ratio variable mechanism 50, the variable valve mechanism 82, and the fuel injection device 41 according to the operating state of the internal combustion engine 10. The operation amount of the ignition coil of the spark plug 42 is determined.

In the control of the compression ratio variable mechanism 50 and the variable valve mechanism 82, the control device 70 refers to a map that stores the target value of the control amount of each mechanism according to the operating conditions such as the engine load TP and the engine speed NE, for example. Then, the target value is set, and the manipulated variable is calculated and output according to the deviation between the control value detected value and the target value.
Here, the compression ratio of the internal combustion engine 10 is changed by the compression ratio variable mechanism 50, and the compression ratio is changed by changing the closing timing IVC of the intake valve 81 by the variable valve mechanism 82. The compression ratio CRe is determined by the top dead center position of the piston 33 and the closing timing IVC of the intake valve 81.

For this reason, when the variable compression ratio mechanism 50 and / or the variable valve mechanism 82 are controlled, the effective compression ratio CRe becomes transiently excessive or excessive due to a difference in the compression ratio response between the mechanisms, and the combustibility deteriorates. And may cause knocking.
For example, in parallel with the control for increasing the compression ratio by the compression ratio variable mechanism 50, when the variable valve mechanism 82 is used to perform the control for decreasing the compression ratio by changing the closing timing IVC, the closing timing by the variable valve mechanism 82 is used. When the decrease in the compression ratio CRivc due to the change in IVC proceeds prior to the increase in the compression ratio CRm by the compression ratio variable mechanism 50, the phenomenon that the effective compression ratio CRe temporarily falls below the final target effective compression ratio CRetg. appear.

On the contrary, in the case where the variable valve mechanism 82 performs the control to increase the compression ratio by changing the closing timing IVC in parallel with the control to decrease the compression ratio by the compression ratio variable mechanism 50, the compression by the variable valve mechanism 82 is performed. When the increase in the ratio CRivc proceeds prior to the decrease in the compression ratio CRm by the compression ratio variable mechanism 50, a phenomenon occurs in which the effective compression ratio CRe temporarily exceeds the final target effective compression ratio CRetg.

Further, when the effective compression ratio CRe is changed by either the compression ratio variable mechanism 50 or the variable valve mechanism 82, convergence to the target effective compression ratio CRetg may be delayed.
Therefore, the control device 70 performs a process of changing the other operation in accordance with one operation state of the variable valve mechanism 82 and the compression ratio variable mechanism 50, thereby transiently depending on the difference in responsiveness between the mechanisms. The effective compression ratio CRe is prevented from becoming excessively large or small, and the convergence response to the target effective compression ratio CRetg is improved.
In the following, the process of changing the other operation according to one operation state of the variable valve mechanism 82 and the compression ratio variable mechanism 50 is also referred to as cooperative control.

FIG. 2 is a diagram showing the characteristics of the cooperative control by the control device 70, and shows the processing contents of the cooperative control for each combination pattern of the operating state of the variable valve mechanism 82 and the operating state of the compression ratio variable mechanism 50.
The 1st column in Drawing 2 shows the number of the combination pattern of an operation state.

The second column in FIG. 2 shows the correlation between the actual effective compression ratio CRe and the target effective compression ratio CRetg.
Specifically, the target effective compression ratio CRetg and the actual effective compression ratio CRe substantially coincide with each other, the target effective compression ratio CRetg is higher than the actual effective compression ratio CRe, and the target effective compression ratio CRetg is higher than the actual effective compression ratio CRe. Are also divided into three patterns with a low state.
The state in which the target effective compression ratio CRetg is higher than the actual effective compression ratio CRe is an operation state in which the actual effective compression ratio CRe is increased, and the target effective compression ratio CRetg is lower than the actual effective compression ratio CRe. Is an operation state in which the actual effective compression ratio CRe is decreased.
The state in which the compression ratio substantially matches the target value is, for example, a state in which the actual compression ratio is included in a predetermined range including the target value in the compression ratio control, and an operation for bringing the actual compression ratio closer to the target compression ratio. Is in a state to be stopped.

Further, the actual effective compression ratio CRe is obtained from the detected value of the control amount of the variable valve mechanism 82 and the detected value of the control amount of the variable compression ratio mechanism 50, and the target effective compression ratio CRetg is the variable valve mechanism 82. And the target value of the control amount of the compression ratio variable mechanism 50 can be obtained.
The actual compression ratio CRivc that is variable by the variable valve mechanism 82 is obtained from the detected value of the control amount of the variable valve mechanism 82, and the target value CRivctg of the actual compression ratio CRivc is the control value of the variable valve mechanism 82. It can be obtained from the target value of quantity. Similarly, the actual compression ratio CRm that is variable by the compression ratio variable mechanism 50 is obtained from the detected value of the control amount of the compression ratio variable mechanism 50, and the target value CRmtg of the actual compression ratio CRm is the value of the compression ratio variable mechanism 50. It can be obtained from the target value of the controlled variable.

The third example in FIG. 2 shows the correlation between the target compression ratio CRivctg and the actual compression ratio CRivc in the variable valve mechanism 82. The target compression ratio CRivctg is substantially equal to the target compression ratio CRivctg. The pattern is divided into three patterns: a state where the actual compression ratio CRivc is higher and a state where the target compression ratio CRivctg is lower than the actual compression ratio CRivc.
The state in which the target compression ratio CRivctg is higher than the actual compression ratio CRivc is an operation state in which the actual compression ratio CRivc is increased and an operation state in which the closing timing IVC is brought close to the bottom dead center BDC. The state lower than the ratio CRivc is an operation state in which the actual compression ratio CRivc is decreased and an operation state in which the closing timing IVC is moved away from the bottom dead center BDC.
Then, the state in which the target effective compression ratio CRetg in the second example is higher than the actual effective compression ratio CRe and the state in which the target effective compression ratio CRetg is lower than the actual effective compression ratio CRe are determined depending on the compression ratio state of the variable valve mechanism 82, respectively. Cases are divided into 3 patterns.

Further, the fourth column in FIG. 2 shows the correlation between the target compression ratio CRmtg and the actual compression ratio CRm in the variable compression ratio mechanism 50.
Specifically, the target compression ratio CRmtg and the actual compression ratio CRm substantially coincide with each other, the target compression ratio CRmtg is higher than the actual compression ratio CRm, and the target compression ratio CRmtg is lower than the actual compression ratio CRm. It is divided into patterns.
The state in which the target compression ratio CRmtg is higher than the actual compression ratio CRm is an operating state in which the actual compression ratio CRm is increased, and the state in which the target compression ratio CRmtg is lower than the actual compression ratio CRm is the actual compression ratio CRm. This is an operation state that reduces

Then, a state in which the target compression ratio CRivctg and the actual compression ratio CRivc of the third example substantially match, a state in which the target compression ratio CRivctg is higher than the actual compression ratio CRivc, and a state in which the target compression ratio CRivctg is lower than the actual compression ratio CRivc. The three patterns are divided according to the compression ratio state of the compression ratio variable mechanism 50.
The control state of the compression ratio is divided into 19 patterns as described in the first example by the above-mentioned second column to fourth column, and the compression ratio variable mechanism 50 and the variable valve mechanism 82 are controlled for each of these patterns. The fifth example-ninth column shows how the change is made by cooperative control.

Hereinafter, the control contents in each of the 19 patterns shown in FIG. 2 will be described in detail.
First, the first pattern in which the actual effective compression ratio CRe and the target effective compression ratio CRetg substantially coincide is a steady state in which the control amounts of the compression ratio variable mechanism 50 and the variable valve mechanism 82 both converge to the target value. Therefore, control of the compression ratio variable mechanism 50 and the variable valve mechanism 82 is not necessary.

The second pattern to the tenth pattern are states in which the actual effective compression ratio CRe is lower than the target effective compression ratio CRetg, and the second pattern to the fourth pattern are the actual compression ratio CRivctg and the actual compression ratio in the variable valve mechanism 82. The steady state in which the compression ratio CRivc substantially matches is divided into three patterns according to the compression ratio state of the compression ratio variable mechanism 50.

In the second pattern, the target compression ratio CRivctg and the actual compression ratio CRivc substantially match in the variable valve mechanism 82, and the target compression ratio CRmtg and the actual compression ratio CRm substantially match in the variable compression ratio mechanism 50. However, the actual effective compression ratio CRe is lower than the target effective compression ratio CRetg.
However, in reality, there is no possibility that the actual effective compression ratio CRe and the target value CRetg are different from each other even though the control amounts of the variable valve mechanism 82 and the compression ratio variable mechanism 50 converge to the target value. The control setting corresponding to the second pattern is not necessary.

In other words, FIG. 2 shows all combination patterns of operating states that are classified based on the magnitude relationship between the actual compression ratio and the target compression ratio, but includes patterns that are not possible in practice. This corresponds to a pattern that is impossible.
In the third pattern, the target compression ratio CRivctg and the actual compression ratio CRivc substantially coincide with each other in the variable valve mechanism 82, while the target compression ratio CRmtg in the variable compression ratio mechanism 50 is higher than the actual compression ratio CRm. This is an operation state in which the compression ratio is increased by the ratio variable mechanism 50 and the actual effective compression ratio CRe is increased toward the target effective compression ratio CRetg.

Here, the actual effective compression ratio CRe is the target value CRetg when the variable valve mechanism 82 is operated in the direction of increasing the compression ratio in parallel rather than operating only the variable compression ratio mechanism 50 in the direction of increasing the compression ratio. The convergence response is improved.
Accordingly, the control device 70 performs cooperative control in which the variable valve mechanism 82 changes the closing timing IVC of the intake valve 81 in the increasing direction of the compression ratio in parallel with the normal control in which the compression ratio variable mechanism 50 increases the compression ratio CRm. , The actual effective compression ratio CRe is accelerated toward the target effective compression ratio CRetg, and after sufficiently approaching the target effective compression ratio CRetg, the compression ratio CRm is increased by the variable compression ratio mechanism 50. Then, the process of gradually returning the closing timing IVC to the target value is performed.

That is, in the variable valve mechanism 82, the target compression ratio CRivctg corresponding to the engine operating state and the actual compression ratio CRivc substantially coincide with each other, so there is no need to move the closing timing IVC by the variable valve mechanism 82. In order to increase the actual effective compression ratio CRe with good response, the closing timing IVC is changed in the direction of increasing the compression ratio in parallel with the operation of increasing the compression ratio CRm by the compression ratio variable mechanism 50, and the target of the actual effective compression ratio CRe is increased. Achieving an effective compression ratio CRetg is accelerated.
As a result, the actual effective compression ratio CRe can be followed and changed with good response to an increase in the target effective compression ratio CRetg corresponding to a change in the operating state of the internal combustion engine 10, thereby ensuring a compression temperature.

In the fourth pattern, while the target compression ratio CRivctg and the actual compression ratio CRivc substantially coincide with each other in the variable valve mechanism 82, the target compression ratio CRmtg in the variable compression ratio mechanism 50 is lower than the actual value CRm. The target effective compression ratio CRetg is higher than the actual effective compression ratio CRe.
However, in the steady state where the variable valve mechanism 82 converges to the target, there is no possibility that the operation direction of the compression ratio variable mechanism 50 differs from the operation direction of the actual effective compression ratio CRe, and the fourth pattern is the second pattern. Similarly to the above, the pattern is impossible in practice, and the control setting corresponding to the fourth pattern is unnecessary.

The fifth pattern to the seventh pattern divide the state where the target compression ratio CRivctg is higher than the actual compression ratio CRivc in the variable valve mechanism 82 into three patterns depending on the compression ratio state of the compression ratio variable mechanism 50.
In the fifth pattern, the compression ratio CRivc is increased by the variable valve mechanism 82 in a state where the actual compression ratio CRm converges to the target compression ratio CRmtg in the variable compression ratio mechanism 50, and the actual effective compression ratio CRe is set to the target effective compression. This is a state of increasing toward the ratio CRetg.

In this case, the actual effective compression ratio CRe is equal to the target effective compression ratio when the variable compression ratio mechanism 50 is operated in parallel to increase the compression ratio, rather than only the variable valve mechanism 82 is operated in the increasing direction of the compression ratio. The ratio CRetg will be reached early.
Therefore, the control device 70 performs cooperative control for increasing the compression ratio by the compression ratio variable mechanism 50 in parallel with the normal control for increasing the compression ratio by the variable valve mechanism 82, thereby achieving the target of the actual effective compression ratio CRe. The increase toward the effective compression ratio CRetg is accelerated.

Then, after sufficiently approaching the target effective compression ratio CRetg, the top dead center position of the piston 33 is gradually changed in the direction in which the compression ratio decreases as the compression ratio increases by the variable valve mechanism 82, and the actual compression is performed. Processing for returning the ratio CRm to the target compression ratio CRmtg is performed.
As a result, the actual effective compression ratio CRe can be tracked and changed with good response to an increase in the target effective compression ratio CRetg in accordance with a change in the operating state of the internal combustion engine 10, thereby ensuring the compression temperature.

The sixth pattern is a state in which the compression ratio is increased by the compression ratio variable mechanism 50 and the variable valve mechanism 82 to increase the actual effective compression ratio CRe toward the target effective compression ratio CRetg.
In this case, the response of the cooperative control for changing the operation of the variable valve mechanism 82 so that the actual compression ratio CRivc exceeds the target value CRivctg is generated, that is, the control for increasing the compression ratio CRivc by the variable valve mechanism 82. By implementing the early control, an increase in the actual effective compression ratio CRe toward the target effective compression ratio CRetg is promoted.

As a result, the actual effective compression ratio CRe can be tracked and changed with good response to an increase in the target effective compression ratio CRetg in accordance with a change in the operating state of the internal combustion engine 10, thereby ensuring the compression temperature.
Here, the responsiveness to change the effective compression ratio CRe is faster in the variable valve mechanism 82 than in the compression ratio variable mechanism 50, so that the variable valve mechanism is more apt to generate than an overshoot in the compression ratio variable mechanism 50. The effect of improving the responsiveness of the increase change in the effective compression ratio CRe is greater when the mechanism 82 generates the overshoot.
Further, overshoot can be generated in both the compression ratio variable mechanism 50 and the variable valve mechanism 82, but in this case, the control stability is impaired, and the effective compression ratio CRe may be temporarily excessively increased. Therefore, in this embodiment, the variable valve mechanism 82 generates an overshoot.

In the seventh pattern, the actual effective compression ratio CRe is increased and changed. However, the variable valve mechanism 82 is operated in the increasing direction of the compression ratio, and the variable compression ratio mechanism 50 is operated in the decreasing direction of the compression ratio. The reduction ratio of the compression ratio by the compression ratio variable mechanism 50 is smaller than the increase ratio of the compression ratio by the variable valve mechanism 82, and as a result, the actual effective compression ratio CRe is increased and changed by the difference in the compression ratio change between the two. It is.

In the seventh pattern, since the response of the change in the compression ratio by the variable valve mechanism 82 is faster than that in the compression ratio variable mechanism 50, the compression ratio CRm by the compression ratio variable mechanism 50 is earlier than when the compression ratio CRm decreases to the target compression ratio CRmtg. The compression ratio CRivc by the variable valve mechanism 82 increases to the target compression ratio CRivctg, and the actual effective compression ratio CRe may transiently exceed the target effective compression ratio CRetg and become excessive.

Therefore, the control device 70 reduces the increase response of the compression ratio CRivc by the variable valve mechanism 82, and determines the time for the actual compression ratio CRivc by the variable valve mechanism 82 to reach the target compression ratio CRivctg by the compression ratio by the compression ratio variable mechanism 50. A process of limiting the increase in the compression ratio CRivc, which approaches the time when CRm reaches the target compression ratio CRmtg, is performed.
Thereby, it is possible to suppress the increase change of the compression ratio CRivc by the variable valve mechanism 82 from preceding the decrease change of the compression ratio CRm by the compression ratio variable mechanism 50, and the actual effective compression ratio CRe is transiently changed to the target effective compression ratio. Exceeding CRetg can be prevented from becoming excessive.

The eighth pattern to the tenth pattern are states in which the effective compression ratio CRe is increased and changed, and in the variable valve mechanism 82, the target compression ratio CRivctg is lower than the actual compression ratio CRivc. The pattern is divided into three patterns according to the compression ratio state.
The eighth pattern is an operation state in which the effective compression ratio CRe is increased, and the variable valve mechanism 82 is in a decrease operation state of the compression ratio CRivc, but the compression ratio variable mechanism 50 is in a steady state that converges to the target. This is the case.
In such a state, since the operation direction of the effective compression ratio CRe and the operation direction of the compression ratio CRivc are opposite and the compression ratio variable mechanism 50 is stationary, it is impossible in practice. Like the four patterns, it is a pattern that is not actually possible, and control setting corresponding to the eighth pattern is unnecessary.

Although the ninth pattern is a state in which the effective compression ratio CRe is increased and changed, the variable valve mechanism 82 is operated in the decreasing direction of the compression ratio CRivc, the compression ratio variable mechanism 50 is operated in the increasing direction of the compression ratio CRm, Since the increase margin of the compression ratio CRm by the compression ratio variable mechanism 50 is larger than the decrease margin of the compression ratio CRivc by the variable valve mechanism 82, as a result, the effective compression ratio CRe is increased by the difference in the compression ratio change between the two. It is a state to change.
In the ninth pattern, since the response of the compression ratio change by the variable valve mechanism 82 is faster than the variable compression ratio mechanism 50, the actual compression ratio CRm in the variable compression ratio mechanism 50 is larger than the target compression ratio CRmtg. There is a possibility that the actual compression ratio CRivc is quickly reduced to the target compression ratio CRivctg in the variable valve mechanism 82 and the effective compression ratio CRe transiently exceeds the target effective compression ratio CRetg and becomes too small.

Therefore, the control device 70 reduces the decrease response of the compression ratio CRivc by the variable valve mechanism 82, and the time that the actual compression ratio CRivc reaches the target compression ratio CRivctg in the variable valve mechanism 82 is actually compressed in the variable compression ratio mechanism 50. A process of limiting the decrease in the compression ratio CRivc is performed so as to approach the time when the ratio CRm reaches the target compression ratio CRmtg.
Thereby, it is possible to suppress the decrease change of the compression ratio CRivc caused by the variable valve mechanism 82 from preceding the increase change of the compression ratio CRm caused by the variable compression ratio mechanism 50, and the actual effective compression ratio CRe is transiently changed to the target effective compression ratio. It is possible to suppress the excess from CRetg.

The tenth pattern is a state in which the effective compression ratio CRe is increased and changed, but the target compression ratio in both the variable valve mechanism 82 and the compression ratio variable mechanism 50 is lower than the actual compression ratio, and the actual compression ratio is reduced. Pattern.
However, although both the variable valve mechanism 82 and the compression ratio variable mechanism 50 are in the process of decreasing the compression ratio, the effective compression ratio CRe does not increase and change as a result, and the tenth pattern is not actually possible. The control setting corresponding to the tenth pattern is not necessary.

The eleventh pattern to the nineteenth pattern are patterns in which the target effective compression ratio CRetg is lower than the actual effective compression ratio CRe and decreases the actual effective compression ratio CRe, and the eleventh pattern to the thirteenth pattern are variable valve actuations. The steady state in which the actual compression ratio CRivc substantially matches the target compression ratio CRivctg in the mechanism 82 is divided into patterns according to the operating state of the compression ratio variable mechanism 50.

In the eleventh pattern, the variable valve mechanism 82 is in a steady state where the actual compression ratio CRivc substantially matches the target compression ratio CRivctg, and in the compression ratio variable mechanism 50, the actual compression ratio CRm becomes the target compression ratio CRmtg. It is a steady state that is approximately the same.
However, although both the variable valve mechanism 82 and the compression ratio variable mechanism 50 are in a steady state, it is actually impossible to reduce the effective compression ratio CRe, and the control setting corresponding to the eleventh pattern is unnecessary. It is.

The twelfth pattern is a steady state in which the actual compression ratio CRivc substantially matches the target compression ratio CRivctg in the variable valve mechanism 82, and the actual compression ratio CRm in the variable compression ratio mechanism 50 is greater than the target compression ratio CRmtg. Is also in the process of increasing the compression ratio.
However, in this case, the effective compression ratio CRe cannot be decreased and decreased by increasing the actual compression ratio CRm, and the twelfth pattern is a pattern that is not actually possible. The control setting corresponding to the twelfth pattern is It is unnecessary.

The thirteenth pattern is a steady state in which the actual compression ratio CRivc substantially matches the target compression ratio CRivctg in the variable valve mechanism 82, and the actual compression ratio CRm in the variable compression ratio mechanism 50 is greater than the target compression ratio CRmtg. Is also in the process of reducing the high compression ratio. That is, the effective compression ratio CRe is decreased by operating the compression ratio variable mechanism 50.
In the thirteenth pattern, the variable valve mechanism 82 is in a steady state where the actual compression ratio CRivc converges to the target compression ratio CRivctg, but only the compression ratio variable mechanism 50 is operated to decrease the effective compression ratio CRe. Then, the convergence of the effective compression ratio CRe is delayed.

Therefore, the control device 70 performs coordinated control in which the variable valve mechanism 82 changes the closing timing IVC of the intake valve 81 in the direction of decreasing the compression ratio in parallel with the normal control in which the compression ratio variable mechanism 50 decreases the compression ratio CRm. To accelerate the decrease of the actual effective compression ratio CRe toward the target effective compression ratio CRetg, and after the actual effective compression ratio CRe has sufficiently approached the target effective compression ratio CRetg, the compression ratio CRm by the compression ratio variable mechanism 50 The process of gradually returning the closing timing IVC to the target value is performed as the decrease in the value proceeds.

That is, in the variable valve mechanism 82, the target compression ratio CRivctg and the actual compression ratio CRivc substantially coincide with each other, so there is no need to move the closing timing IVC by the variable valve mechanism 82, but the effective compression ratio CRe is quickly increased. In order to reduce the target compression ratio, the target effective compression ratio of the actual effective compression ratio CRe is changed by temporarily changing the closing timing IVC in the direction of decreasing the compression ratio in parallel with the operation of decreasing the compression ratio CRm by the variable compression ratio mechanism 50. Accelerate reaching CRetg.
As a result, the effective effective compression ratio CRe is followed and changed with good response to the decreasing change in the target effective compression ratio CRetg in accordance with the change in the operating state of the internal combustion engine 10, thereby promptly reducing the compression temperature.

The fourteenth pattern to the sixteenth pattern are patterns in which the target effective compression ratio CRetg is lower than the actual effective compression ratio CRe, and the actual effective compression ratio CRe is decreased. In the variable valve mechanism 82, the actual compression ratio CRivc is The state in which the actual compression ratio CRivc is being increased is lower than the target compression ratio CRivctg and is divided into patterns according to the operating state of the compression ratio variable mechanism 50.

The 14th pattern is a state in which the variable valve mechanism 82 is operating to increase the actual compression ratio CRivc and the compression ratio CRm by the variable compression ratio mechanism 50 substantially matches the target compression ratio CRmtg. However, even if the variable valve mechanism 82 is operated in the increasing direction of the compression ratio CRivc in the steady state of the compression ratio variable mechanism 50, the actual effective compression ratio CRe will not be decreased. This is an impossible state, and control setting corresponding to the 14th pattern is unnecessary.

The fifteenth pattern is a state in which the variable valve mechanism 82 is in the process of increasing the actual compression ratio CRivc and the variable compression ratio mechanism 50 is in the process of increasing the compression ratio CRm. However, since the actual effective compression ratio CRe is not decreased when the variable valve mechanism 82 and the compression ratio variable mechanism 50 are in the increasing operation, the fifteenth pattern is actually impossible. Control settings corresponding to 15 patterns are not required.

In the sixteenth pattern, when the variable valve mechanism 82 is in the process of increasing the actual compression ratio CRivc, the actual effective compression ratio CRe is finally obtained by operating the compression ratio variable mechanism 50 in the decreasing direction of the compression ratio CRm. Is a state in which
In the sixteenth pattern, since the response of the compression ratio change by the variable valve mechanism 82 is faster than the compression ratio variable mechanism 50, the actual compression ratio CRm in the compression ratio variable mechanism 50 is less than the target compression ratio CRmtg. There is a possibility that the actual compression ratio CRivc will increase to the target compression ratio CRivctg early in the variable valve mechanism 82 and the effective compression ratio CRe will transiently exceed the target value CRetg and become excessive.

Therefore, the control device 70 reduces the increase response of the compression ratio CRivc by the variable valve mechanism 82, and the time for the actual compression ratio CRivc to reach the target compression ratio CRivctg in the variable valve mechanism 82 is actually compressed in the compression ratio variable mechanism 50. A process of limiting the increase in the compression ratio CRivc is performed so that the ratio CRm approaches the time for reaching the target compression ratio CRmtg.
Thereby, it is possible to suppress the increase change of the compression ratio CRivc by the variable valve mechanism 82 from preceding the decrease change of the compression ratio CRm by the compression ratio variable mechanism 50, and the actual effective compression ratio CRe is transiently changed to the target effective compression ratio. Exceeding CRetg can be prevented from becoming excessive.

The seventeenth pattern to the nineteenth pattern are patterns in which the target effective compression ratio CRetg is lower than the actual effective compression ratio CRe, and the actual effective compression ratio CRe is decreased, and the actual compression ratio CRivc in the variable valve mechanism 82 is The state in which the actual compression ratio CRivc is being decreased is higher than the target compression ratio CRivctg, and is divided into patterns according to the operating state of the compression ratio variable mechanism 50.

In the seventeenth pattern, the variable valve mechanism 82 is in a decreasing operation state of the actual compression ratio CRivc, while the variable compression ratio mechanism 50 is a steady state in which the actual compression ratio CRm and the target compression ratio CRmtg substantially coincide.
That is, the actual effective compression ratio CRe is decreased by operating the variable valve mechanism 82 to decrease the actual compression ratio CRivc, but only the variable valve mechanism 82 is operated in the decreasing direction of the compression ratio CRivc. Rather, the actual effective compression ratio CRe quickly decreases to the target value CRetg when the compression ratio variable mechanism 50 is operated in the direction of decreasing the compression ratio CRm in parallel.

Therefore, the control device 70 performs the cooperative control in which the compression ratio variable mechanism 50 decreases the compression ratio CRm in parallel with the normal control in which the variable valve mechanism 82 decreases the compression ratio CRivc, so that the actual effective compression ratio CRe The reduction toward the target effective compression ratio CRetg is accelerated.
Then, after the actual effective compression ratio CRe becomes sufficiently close to the target effective compression ratio CRetg, the top dead center position of the piston 33 is increased in the direction in which the compression ratio CRm increases as the compression ratio CRivc decreases by the variable valve mechanism 82. A process of gradually changing to the target compression ratio CRmtg is performed.
As a result, the actual effective compression ratio CRe is tracked and changed with good response to the decrease in the target effective compression ratio CRetg corresponding to the change in the operating state of the internal combustion engine 10, thereby promptly reducing the compression temperature. Can do.

In the eighteenth pattern, the variable valve mechanism 82 is in the decreasing operation state of the actual compression ratio CRivc, while in the compression ratio variable mechanism 50, the actual compression ratio CRm is lower than the target compression ratio CRmtg and the increasing operation state of the actual compression ratio CRm. It is. In other words, in the 18th pattern, the actual compression ratio CRm is increased in parallel with the actual compression ratio CRivc decreasing operation, and the actual compression ratio CRivc is more effective than the increasing amount of the actual compression ratio CRm. This is a situation where the compression ratio CRe is decreased.

In the 18th pattern, since the response of the compression ratio change by the variable valve mechanism 82 is faster than the compression ratio variable mechanism 50, the actual compression ratio CRm in the compression ratio variable mechanism 50 is larger than the target compression ratio CRmtg. There is a possibility that the actual compression ratio CRivc is quickly reduced to the target compression ratio CRivctg in the variable valve mechanism 82 and the effective compression ratio CRe transiently exceeds the target effective compression ratio CRetg and becomes too small.

Therefore, the control device 70 reduces the decrease response of the compression ratio CRivc by the variable valve mechanism 82, and the time that the actual compression ratio CRivc reaches the target compression ratio CRivctg in the variable valve mechanism 82 is actually compressed in the variable compression ratio mechanism 50. A process of limiting the decrease in the compression ratio CRivc is performed so as to approach the time when the ratio CRm reaches the target compression ratio CRmtg.
As a result, it is possible to suppress the decrease change of the compression ratio CRivc caused by the variable valve mechanism 82 from preceding the increase change of the compression ratio CRm caused by the compression ratio variable mechanism 50, so that the effective effective compression ratio CRe is transiently changed to the target effective compression ratio CRetg. It is possible to suppress the excess from exceeding.

In the nineteenth pattern, the variable valve mechanism 82 is in the decreasing operation state of the actual compression ratio CRivc, while the actual compression ratio CRm is also higher in the compression ratio variable mechanism 50 than the target compression ratio CRmtg. It is. That is, the nineteenth pattern is a situation in which the reduction operation of the actual compression ratio CRm is performed in parallel with the operation of reducing the actual compression ratio CRivc, and the effective compression ratio CRe is reduced by both mechanisms.

In this case, cooperative control for changing the operation of the variable valve mechanism 82 so that an overshoot occurs in which the compression ratio CRivc by the variable valve mechanism 82 exceeds the target compression ratio CRivctg, that is, the compression ratio CRivc by the variable valve mechanism 82. By implementing the control that speeds up the response of the decrease control, the reduction of the actual effective compression ratio CRe toward the target effective compression ratio CRetg is promoted.
As a result, the actual effective compression ratio CRe can be tracked and changed with good response to a decrease in the target effective compression ratio CRetg corresponding to a change in the operating state of the internal combustion engine 10, thereby promptly reducing the compression temperature. it can.

As described above, among the first pattern to the nineteenth pattern shown in FIG. 2, the situations that are not actually possible are the second pattern, the fourth pattern, the eighth pattern, the tenth pattern, the eleventh pattern, the twelfth pattern. It is a pattern, 14th pattern, and 15th pattern, and the control apparatus 70 implements the cooperative control according to each state in states other than this.

Here, the cooperative control of the control device 70 uses the target compression ratio according to the engine operating state as it is, thereby correcting the cooperative control substantially for both mechanisms 50 and 82 and the target compression ratio. Limiting processing for the variable valve mechanism 82 for suppressing the compression ratio from excessively increasing or decreasing excessively by reducing the response speed toward the standard, and the compression ratio variable mechanism 50 and the variable valve One of the mechanisms 82 is roughly divided into overcorrection processing that speeds up the convergence of the effective compression ratio CRe to the target effective compression ratio CRetg by intentionally increasing the transient response and increasing the overshoot.
The correction is not performed on the first pattern, the limiting process is performed on the seventh pattern, the ninth pattern, the sixteenth pattern, and the eighteenth pattern, and the overcorrection process is performed on the third pattern, the fifth pattern, and the sixth pattern. The pattern, the 13th pattern, the 17th pattern, and the 19th pattern are used.

Below, the operating state change of the internal combustion engine 10 which the control apparatus 70 will implement cooperative control is illustrated.
FIG. 3 is an example of a change in the engine operating state in which the change direction of the compression ratio CRm by the variable compression ratio mechanism 50 and the change direction of the compression ratio CRivc by the variable valve mechanism 82 are different.

In the operation state of FIG. 3 (A), a variable valve mechanism is provided in order to increase the amount of charged air and improve the action of sucking exhaust gas into the exhaust passage and promoting the inflow of air into the combustion chamber. As the operation of 82, the closing timing IVC of the intake valve 81 is brought close to the bottom dead center BDC, and the valve overlap period is expanded.
Further, in the operation state of FIG. 3A, as the operation of the compression ratio variable mechanism 50, the compression ratio CRm is lowered to further increase the upper limit of the supercharging pressure.

On the other hand, in the operating state of FIG. 3B, the variable valve mechanism 82 is operated by delaying the closing timing IVC of the intake valve 81 from the bottom dead center BDC as compared with the operating state of FIG. The expansion ratio is higher than that in the case of FIG. Further, in the operation state of FIG. 3B, as the operation of the compression ratio variable mechanism 50, the compression ratio CRm is set higher than that in the operation state of FIG.
Therefore, in the transient state that changes from the operation state of FIG. 3A to the operation state of FIG. 3B, the compression ratio CRivc is decreased while the compression ratio CRm is increased. In a transient state that changes from the operation state of B) to the operation state of FIG. 3A, the compression ratio CRm is decreased while the compression ratio CRivc is increased.

As described above, as a transient state in which the change direction of the compression ratio CRm by the compression ratio variable mechanism 50 and the change direction of the compression ratio CRivc by the variable valve mechanism 82 are different, the seventh pattern of the first pattern to the nineteenth pattern is used. The ninth pattern, the sixteenth pattern, and the eighteenth pattern correspond to each other, and in any case, the limiting process for reducing the operation response of the variable valve mechanism 82 is performed.
That is, when the compression ratio CRivc is changed in the direction opposite to the change direction of the compression ratio CRm, if the change of the compression ratio CRivc precedes the change of the compression ratio CRm, the effective compression ratio CRe is changed in the change direction of the compression ratio CRivc. Since it changes excessively, the excessive change of the effective compression ratio CRe is suppressed by delaying the change of the compression ratio CRivc.

FIG. 4 is an example of a change in the engine operating state in which the change direction of the compression ratio CRm by the compression ratio variable mechanism 50 and the change direction of the compression ratio CRivc by the variable valve mechanism 82 are the same.
FIG. 4 shows the transition from the starting state of (A) to the fast idle state of (B). In order to improve the operational stability of the internal combustion engine 10 with the transition from the starting to the fast idle, the compression ratio CRm And the compression ratio CRivc is increased.

As described above, in the transient state in which the compression ratio CRm is increased by the compression ratio variable mechanism 50 and the compression ratio CRivc is increased by the variable valve mechanism 82, the sixth pattern among the first pattern to the nineteenth pattern is Correspondingly, in this case, by performing an overcorrection process that speeds up the operation response of the variable valve mechanism 82, the effective compression ratio CRe that can improve the operational stability of the internal combustion engine 10 is changed with good response.

FIG. 5 is also an example of a change in the engine operating state in which the change direction of the compression ratio CRm by the compression ratio variable mechanism 50 and the change direction of the compression ratio CRivc by the variable valve mechanism 82 are the same. In the case of abnormal combustion such as pre-ignition or knocking in the weak boost pressure state of ()), an example of setting the compression ratio state of (B) to eliminate such abnormal combustion will be shown.
In this case, in order to eliminate abnormal combustion, the variable valve mechanism 82 moves the closing timing IVC away from the bottom dead center BDC to lower the compression ratio CRivc, and the compression ratio variable mechanism 50 lowers the compression ratio CRm. Reduce the compression temperature.

That is, this is a transient state in which the compression ratio CRm is lowered by the compression ratio variable mechanism 50 and the compression ratio CRivc is lowered by the variable valve mechanism 82, and the operating state includes the first pattern to the nineteenth pattern. The 19th pattern is applicable.
In the nineteenth pattern, by performing an overcorrection process that speeds up the operation response of the variable valve mechanism 82, the effective compression ratio CRe that can suppress abnormal combustion is changed with good response so that abnormal combustion can be suppressed quickly. To.

FIG. 6 shows an example of a pattern in which only the compression ratio variable mechanism 50 is operated in response to a change in the operating state of the internal combustion engine 10 without an operation request for the variable valve mechanism 82 based on a change in the operating state of the internal combustion engine 10. Indicates.
In FIG. 6, (B) is an operation state where the boost pressure is higher than (A), and the compression ratio CRm is higher in the weak boost pressure state of (A) than in the high boost pressure state of (B). While the thermal efficiency is secured by increasing the value, the upper limit of the supercharging pressure is increased by lowering the compression ratio CRm in the high supercharging pressure state of (B) than in the case of the weak supercharging pressure of (A). Like that.

Accordingly, the compression ratio CRm by the compression ratio variable mechanism 50 is lowered with the transition from the weak supercharging pressure state of (A) to the high supercharging pressure state of (B), and conversely, the high supercharging of (B). The compression ratio CRm by the compression ratio variable mechanism 50 is increased with the transition from the pressure state to the weak supercharging pressure state of (A).
The operation state corresponds to the third pattern and the thirteenth pattern of the first pattern to the nineteenth pattern, and the third pattern corresponds to the low supercharging pressure state of (A) from the high supercharging pressure state of (B). The thirteenth pattern corresponds to the transition from the weak supercharging pressure state of (A) to the high supercharging pressure state of (B).

In the third pattern and the thirteenth pattern, an operation request for the variable valve mechanism 82 based on a change in the operating state of the internal combustion engine 10 does not occur, but in order to improve the convergence response of the effective compression ratio CRe, the compression ratio The variable valve mechanism 82 is transiently operated so that the compression ratio CRivc changes in the same direction as the change direction of CRm. As a result, in the transition state from the weak supercharging pressure state of (A) to the high supercharging pressure state of (B), the upper limit of the supercharging pressure is quickly increased, and from the high supercharging pressure state of (B) (A ) In the state of transition to the weak supercharging pressure state, it is possible to quickly obtain thermal efficiency.

FIG. 7 shows an example of a pattern in which only the variable valve mechanism 82 is operated in response to a change in the operating state of the internal combustion engine 10 without an operation request of the variable compression ratio mechanism 50 based on a change in the operating state of the internal combustion engine 10. Indicates.
In FIG. 7, (A) and (B) are both fuel-saving driving states, but (A) is a low-load state, and (B) is a medium-load state with a higher engine load. In either case, the compression ratio CRm is set higher to ensure the compression temperature in order to perform the fuel consumption operation. However, in the low load state of (A), the closing timing IVC is set to the bottom dead center BDC as compared to (B). By reducing the compression ratio CRivc further away from the fuel, the fuel efficiency is improved with a higher expansion ratio than in (B).

Accordingly, the variable valve mechanism 82 increases the compression ratio CRivc in accordance with the transition from the low load and fuel saving state of (A) to the medium load and fuel saving state of (B). The variable valve mechanism 82 lowers the compression ratio CRivc in accordance with the transition from the load and fuel saving state to the low load and fuel saving state (A).
The operating state corresponds to the fifth pattern and the seventeenth pattern of the first pattern to the nineteenth pattern. The fifth pattern corresponds to the low load and fuel saving state of (A) and the medium load and saving of (B). The 17th pattern corresponds to the transition state from the medium load and fuel saving state to the low fuel consumption state of FIG.

In the fifth pattern and the 17th pattern, an operation request for the compression ratio variable mechanism 50 based on a change in the operating state of the internal combustion engine 10 is not generated, but in order to improve the convergence response of the effective compression ratio CRe, the compression ratio The compression ratio variable mechanism 50 is transiently operated so that the compression ratio CRm changes in the same direction as the change direction of CRivc, thereby improving the convergence response of the effective compression ratio CRe.
2 is not limited to performing all of the cooperative control shown in FIG. 2, either the overcorrection process or the restriction process is omitted, or the compression ratio variable mechanism 50 in the overcorrection process is omitted. Or the process for the variable valve mechanism 82 is omitted, or one of the process for suppressing the compression ratio from being excessive and the process for suppressing the compression ratio from being limited is omitted. be able to.

FIG. 8 shows an example of the operating state of the variable compression ratio mechanism 50 and the variable valve mechanism 82 when the accelerator is fully opened to fully closed.
In the example shown in FIG. 8, the target effective compression ratio CRetg is changed to be lower than when the accelerator is fully opened by operating the accelerator to be fully closed. The mechanism 82 is achieved by retarding the closing timing IVC of the intake valve 81 in the region after the bottom dead center to decrease the compression ratio CRivc while increasing the compression ratio CRm by the compression ratio variable mechanism 50.

That is, the reduction ratio of the compression ratio CRivc in the variable valve mechanism 82 is made larger than the reduction margin of the target effective compression ratio CRetg, and the compression ratio CRm is increased by the compression ratio variable mechanism 50 by the amount that the compression ratio CRivc decreases excessively. Thus, the actual effective compression ratio CRe is made to approach the target effective compression ratio CRetg.
When the change in the compression ratio is caused, if the response of the change in the compression ratio by the variable valve mechanism 82 is faster than the response in the change in the compression ratio by the compression ratio variable mechanism 50, as illustrated in FIG. As a result of the decrease in the compression ratio CRivc preceding the increase in the engine, an overshoot occurs in which the actual effective compression ratio CRe decreases beyond the target effective compression ratio CRetg, and the actual effective compression ratio CRe is a lower limit value corresponding to the operating state. Transiently below CRmin, the compression temperature may temporarily drop excessively.

That is, in FIG. 8, the accelerator is switched from fully open to fully closed at time t1, and accordingly, the target compression ratio CRmtg in the variable compression ratio mechanism 50 increases, while the target compression ratio CRivctg in the variable valve mechanism 82 is descend.
Here, since the response of the compression ratio change by the variable valve mechanism 82 is faster than the variable compression ratio mechanism 50, the variable valve mechanism 82 reaches the target compression ratio CRivctg at the time t2 while the actual compression ratio CRivc reaches the target compression ratio CRivctg. In the variable compression ratio mechanism 50, the actual compression ratio CRm may reach the target compression ratio CRmtg at a time t3 later than the time t2.

Due to the difference in the response time to the target compression ratio, the actual compression ratio CRm hardly changes between time t1 and time t2, whereas the actual effective compression ratio CRivc is decreased. CRe may fall below the target effective compression ratio CRetg.
Therefore, as illustrated in FIG. 9, the control device 70 performs the restriction process that suppresses the change in the compression ratio CRivc as compared to the case where the restriction process is not performed, so that the compression ratio CRivc is greater than the increase in the compression ratio CRm. The compression ratio CRivc and the compression ratio CRm reach the target values at substantially the same time.

In FIG. 9, at time t1, the accelerator switches from fully open to fully closed, and accordingly, the target compression ratio CRmtg in the variable compression ratio mechanism 50 increases and the target compression ratio CRivctg in the variable valve mechanism 82 decreases.
Here, in the control of the variable valve mechanism 82, the control device 70 sets a target value FCRivctg for limiting processing that follows the target compression ratio CRivctg instead of the target compression ratio CRivctg corresponding to the operation state, The variable valve mechanism 82 is controlled in accordance with the target value FCRivctg for the limiting process so that the compression ratio CRivc converges to the target compression ratio CRivctg near time t3 when the actual compression ratio CRm reaches the target compression ratio CRmtg.
Even if the response of the compression ratio change by the variable valve mechanism 82 is faster than the response of the compression ratio change by the compression ratio variable mechanism 50, the effective effective compression ratio CRe is equal to the target effective compression ratio CRetg. It can suppress that it falls exceeding, and can suppress that compression temperature falls too much.

Below, an example of the specific processing content of the cooperative control by the control apparatus 70 is demonstrated.
As shown in FIG. 2 described above, the compression ratio variable mechanism 50 is classified into either a pattern that does not operate as cooperative control or a pattern that performs overcorrection processing as cooperative control. The patterns for performing the overcorrection processing are the fifth pattern and the seventeenth pattern.

Therefore, the control device 70 does not perform cooperative control for the compression ratio variable mechanism 50 based on the operation directions of the effective compression ratio CRe, the compression ratio CRivc, and the compression ratio CRm, and performs excessive control as cooperative control for the compression ratio variable mechanism 50. When the correction process is performed, the state number STVCR is set based on the determination result.
Here, as shown in the ninth column of FIG. 2, for example, when cooperative control is not performed for the compression ratio variable mechanism 50, the state number STVCR = 0 is set, and overcorrection processing is performed for the compression ratio variable mechanism 50. Sets the state number STVCR = 2. That is, the state number STVCR = 2 is set when it corresponds to the fifth pattern and the 17th pattern, and the state number STVCR = 0 is set otherwise.

On the other hand, the variable valve mechanism 82 is classified into one of a pattern that does not operate as cooperative control, a pattern that performs overcorrection processing as cooperative control, and a pattern that performs restriction processing as cooperative control. The patterns for performing overcorrection processing as cooperative control are the third pattern, the sixth pattern, the thirteenth pattern, and the nineteenth pattern, and the patterns for performing restriction processing as cooperative control are the seventh pattern, Nine patterns, sixteenth pattern, and eighteenth pattern.

Therefore, the control device 70 does not perform cooperative control for the variable valve mechanism 82 based on the operating directions of the effective compression ratio CRe, the compression ratio CRivc, and the compression ratio CRm, and controls the variable valve mechanism 82 as excessive control as cooperative control. A determination is made between when the correction process is performed and when a limit process as cooperative control is performed for the variable valve mechanism 82, and the state number STVTC is set based on the determination result.

Here, as shown in the eighth column of FIG. 2, for example, when cooperative control is not performed for the variable valve mechanism 82, the state number STVTC = 0 is set, and overcorrection processing is performed for the variable valve mechanism 82. Is set to state number STVTC = 2, and is set to state number STVTC = 1 when the variable valve mechanism 82 is subjected to restriction processing.
That is, the state number STVTC = 2 when corresponding to the third pattern, the sixth pattern, the thirteenth pattern, and the nineteenth pattern, and the state corresponding to the seventh pattern, the ninth pattern, the sixteenth pattern, and the eighteenth pattern. The number STVTC = 1, otherwise the state number STVTC = 0.

Here, the control device 70 determines whether or not to perform cooperative control on the compression ratio variable mechanism 50 and the variable valve mechanism 82 based on the state numbers STVCR and STVTC. The target compression ratio MCRmtg and the target compression ratio MCRivctg set based on the operating state are set as final target values FCRmtg and FCRivctg as they are.
On the other hand, when performing cooperative control, the controller 70 corrects the target compression ratio MCRmtg and the target compression ratio MCRivctg as final target values FCRmtg and FCRivctg.

Then, the control device 70 performs cooperative control by a target compression ratio correction process for controlling the compression ratio variable mechanism 50 and the variable valve mechanism 82 based on the final target values FCRmtg and FCRivctg.
The engine operating state used for setting the target compression ratio MCRmtg and the target compression ratio MCRivctg includes engine load, engine speed, engine temperature, supercharging pressure, presence / absence of abnormal combustion, and whether or not the engine is in a starting state. included.

FIG. 10 is a block diagram showing a calculation process of the target value FCRmtg of the compression ratio variable mechanism 50 by the control device 70.
The first comparison calculation unit 101 receives the state number STVCR and “0”, which is the value of the state number STVCR when the cooperative control is not performed.
When the state number STVCR is 0, the first comparison operation unit 101 outputs a High signal, and when the state number STVCR is other than 0, the first comparison operation unit 101 outputs a Low signal.

The output of the first comparison calculation unit 101 is input to the first output switching unit 102 as a switching control signal, and the first output switching unit 102 outputs one of the two values input as the correction value of the target compression ratio MCRmtg. Select and output according to the output of the first comparison operation unit 101.
As the correction value of the target compression ratio MCRmtg, a value that is not substantially corrected and a value corresponding to the error amount in the variable valve mechanism 82 are input to the first output switching unit 102.

The first output switching unit 102 outputs a correction value that does not substantially perform correction when the output of the first comparison calculation unit 101 is a high signal, that is, when cooperative control is not performed, and the first comparison When the output of the calculation unit 101 is a Low signal, that is, when cooperative control is performed, a correction value corresponding to the error amount in the variable valve mechanism 82 is output.
The output of the first output switching unit 102 is input to one input terminal of the correction unit 103, and the target compression ratio MCRmtg is input to the other input terminal of the correction unit 103.

Then, the correcting unit 103 outputs the result of correcting the target compression ratio MCRmtg with the correction value as the target value FCRmtg after the correction process.
The correction unit 103 outputs the target value FCRmtg to the conversion unit 104, and the conversion unit 104 converts the corrected target compression ratio FCRmtg into a control amount of the compression ratio variable mechanism 50.

Further, the target angle TGVCR of the control shaft 25 output from the conversion unit 104 is output to the limiting unit 105.
The limiting unit 105 outputs the upper limit value as the final target angle TGVCR if the input target angle TGVCR exceeds the upper limit value, and finally sets the lower limit value if the input target angle TGVCR is lower than the lower limit value. If the target angle TGVCR is output within the range between the upper limit value and the lower limit value, the input target angle TGVCR is output as it is as the final target angle TGVCR.

Then, the control device 70 calculates and outputs an operation amount of the actuator 51 based on proportional integral control based on a deviation between the final target angle TGVCR and the actual angle of the control shaft 25, and thereby outputs the target angle TGVCR. Feedback control is performed to bring the actual angle of the control shaft 25 closer.

Here, the correction value calculation of the target compression ratio MCRmtg corresponding to the error amount in the variable valve mechanism 82 will be described in detail.
The multiplication unit 106 includes an error amount in the variable valve mechanism 82, a deviation data between the target compression ratio CRivctg and the actual compression ratio CRivc, and a gain for converting the error amount into a correction value of the target compression ratio MCRmtg. And the result of multiplying the error amount by the gain is output as a correction value for the target compression ratio MCRmtg.

The second output switching unit 107 outputs a gain to the multiplication unit 106.
The second output switching unit 107 receives a gain set in conformity with the limiting process and a gain set in conformity with the overcorrection process, and outputs two values according to the output of the second comparison operation unit 108. Either one is output.
The limiting process gain and the overcorrection gain input to the second output switching unit 107 can be given as fixed values, and can be variably set according to the operating conditions of the internal combustion engine 10.

The operating conditions used for variably setting the limiting processing gain and the overcorrection gain include transients of the effective compression ratio such as the actual effective compression ratio CRe, the cylinder intake fresh air amount, the residual gas amount in the combustion chamber, the compression temperature, and the knocking sensitivity. Various conditions related to the request level of response can be used.
The knocking sensitivity is an index value that represents the ease with which knocking occurs.
That is, if the correction level of the target compression ratio is not increased, the gain is increased and the correction level is decreased under conditions that cause a decrease in acceleration performance, occurrence of abnormal combustion, deterioration of exhaust properties, deterioration of combustibility, starting failure, etc. If the above event can be sufficiently suppressed even if it is suppressed, the gain is reduced.

FIG. 11 is a block diagram showing an overcorrection gain calculation function in the control device 70, for each condition of the actual effective compression ratio CRe, the cylinder intake fresh air amount, the residual gas amount in the combustion chamber, the compression temperature, and the knocking sensitivity. In addition, an overcorrection gain is set in an overcorrection gain setting unit 301-305.
The overcorrection gain set in each of the overcorrection gain setting units 301-305 is output to the comparison calculation unit 306, and the comparison calculation unit 306 sets the overcorrection gain set in each of the overcorrection gain setting units 301-305. The largest gain is output as the final overcorrection gain.

Here, in the overcorrection gain setting unit 301 that sets the overcorrection gain based on the actual effective compression ratio CRe, the overcorrection gain is reduced in the vicinity of the median value of the variable range according to the engine operating conditions. The overcorrection gain is increased as the upper and lower limit values are approached.
This is because if the actual effective compression ratio CRe is near the median value of the variable range, there is a large margin for reaching the upper and lower limits, and even if there is a slight delay in the transient change of the actual effective compression ratio CRe, Therefore, the overcorrection gain is reduced. On the other hand, in the state where the actual effective compression ratio CRe is close to the upper and lower limit values, it is easy to go out of the variable range due to a delay in the transient change of the actual effective compression ratio CRe, so the overcorrection gain is increased to prevent the upper and lower limit values from being exceeded. To do.

Further, the overcorrection gain setting unit 302 that sets the overcorrection gain based on the cylinder intake fresh air amount sets the overcorrection gain to a larger value as the fresh air amount increases. This is because the amount of fresh air increases and the compression temperature rises and knocking is likely to occur, and knocking is likely to occur due to a response delay of the actual effective compression ratio CRe.
Further, the overcorrection gain setting unit 303 that sets the overcorrection gain based on the residual gas amount sets the overcorrection gain to a smaller value as the residual gas amount increases. This is because when the amount of residual gas is large, the combustion temperature decreases and NOx can be reduced. However, when the amount of residual gas is small, the combustion temperature rises, and this results in an increase in NOx due to the overlap of the response delay of the effective compression ratio. It is for suppressing.

The overcorrection gain setting unit 304 that sets the overcorrection gain based on the compression temperature decreases the overcorrection gain as the compression temperature increases. This is because abnormal combustion such as knocking is more likely to occur when the increase response of the effective compression ratio is increased with a high compression temperature, and when the decrease response of the effective compression ratio is increased with a high compression temperature, This is because there is a possibility of causing a deterioration in combustibility.
In addition, the overcorrection gain setting unit 305 that sets the overcorrection gain based on the knocking sensitivity decreases the overcorrection gain as the knocking sensitivity increases. This is because knocking may occur if the transient response of the effective compression ratio is increased under conditions where knocking is likely to occur.
The state where the knocking sensitivity is high is, for example, a case where the anti-knock property of the fuel used is low.

On the other hand, FIG. 12 is a block diagram illustrating a function for calculating a limiting process gain in the control device 70.
As for the limiting processing gain, the limiting processing gain is set in the limiting processing gain setting unit 401-405 for each of the actual effective compression ratio CRe, the cylinder intake fresh air amount, the residual gas amount in the combustion chamber, the compression temperature, and the knocking sensitivity. The comparison calculation unit 406 outputs the largest gain among the limit processing gains set by the limit processing gain setting units 401 to 405 as the final limit processing gain.

Here, the setting characteristic of the limiting process gain according to the actual effective compression ratio CRe in the limiting process gain setting unit 401 is the same as the characteristic in the overcorrection gain setting unit 301, but the limiting process gain setting unit The characteristic of the limiting processing gain in 402-405 is opposite to the characteristic of the overcorrection gain in the overcorrection gain setting unit 302-305.
The limit processing gain setting unit 402 sets the limit processing gain to a smaller value as the amount of fresh air increases. This is to prevent the operation stability of the internal combustion engine 10 from being deteriorated due to a transiently excessive decrease in the actual effective compression ratio CRe in a state where the amount of fresh air is small.

Further, the limit processing gain setting unit 403 sets the limit processing gain to a larger value as the residual gas amount increases. This is to prevent the combustion stability of the internal combustion engine 10 from being lowered by the actual effective compression ratio CRe becoming transiently too low when the amount of residual gas is large and the combustion temperature is lowered.
Further, the restriction processing gain setting unit 404 increases the restriction processing gain as the compression temperature increases. This is to prevent abnormal combustion from occurring due to a transient excessive increase in the actual effective compression ratio CRe when the compression temperature is high.

Further, the limit processing gain setting unit 405 increases the limit processing gain as the knocking sensitivity is higher. This is because knocking may occur due to a transient excessive increase in the actual effective compression ratio CRe under conditions where knocking is likely to occur.
As operating conditions used for variable setting of the overcorrection gain and the limit processing gain, the gain can be set by combining one or more of the five conditions such as the effective compression ratio described above. In addition to the above five conditions, other conditions such as the engine speed NE, the cooling water temperature TW, the ignition timing, the air-fuel ratio, and the intake air temperature can be used.

Further, the gain for each operating condition can be weighted, or the basic gain based on the effective compression ratio can be corrected according to other operating conditions.
Further, the overcorrection gain and the limit processing gain used in the calculation processing of a target value FCRivctg described later can also be set variably as described above.

In the block diagram of FIG. 10, the state number STVCR and “1” which is the value of the state number STVCR when the restriction process is performed are input to the second comparison operation unit 108, and the state number STVCR is 1. If the state number STVCR is other than 1, the Low signal is output.

Then, when the output of the second comparison operation unit 108 is a High signal, in other words, when the state number STVCR = 1, the second output switching unit 107 outputs a gain suitable for the limiting process, When the output of the comparison operation unit 108 is a low signal, in other words, when the state number STVCR = 0 or the state number STVCR = 2, a gain suitable for overcorrection processing is output.
Here, since the state number STVCR is set to either 0 or 2, the output of the second comparison operation unit 108 holds the Low signal, and the output of the second output switching unit 107 is subjected to overcorrection processing. It will be held at a suitable gain.

However, if the state number STVCR = 0 and the pattern does not perform overcorrection processing, the first output switching unit 102 outputs a value that does not change the target compression ratio MCRmtg as a correction value.
Therefore, the target compression ratio MCRmtg is changed with the correction value corresponding to the error amount in the variable valve mechanism 82 only when the overcorrection process with the state number STVCR = 2 is performed, and the overcorrection process is executed. The

For example, in the fifth pattern in which the overcorrection processing is set in the variable compression ratio mechanism 50, the target compression ratio CRivctg is higher than the actual compression ratio CRivc in the variable valve mechanism 82, and the actual compression ratio CRivc is increased. When the target compression ratio MCRmtg is corrected by the function shown in FIG. 10, the target compression ratio MCRmtg is corrected to the higher compression ratio side as the error amount in the variable valve mechanism 82 is larger.
If the compression ratio variable mechanism 50 is in a steady state in which the target compression ratio MCRmtg and the actual compression ratio CRm substantially coincide with each other, and the target compression ratio CRmtg is corrected to a higher compression ratio, the actual compression ratio CRm is changed. The variable compression ratio mechanism 50 is operated to increase the target compression ratio CRmtg after correction.

As a result, when the variable valve mechanism 82 is operated to the side where the compression ratio CRivc increases, in other words, when the initial error amount when the target compression ratio CRivctg increases and changes is large, actual compression by the variable valve mechanism 82 is performed. In parallel with the increase in the ratio CRivc, the actual compression ratio CRm is increased by the compression ratio variable mechanism 50, and the effective compression ratio CRe determined by the actual compression ratio CRivc and the actual compression ratio CRm is determined only by the variable valve mechanism 82. Compared with the case where it operates, it increases and changes with good response.

When the actual compression ratio CRivc approaches the target compression ratio CRivctg in the variable valve mechanism 82 and the error amount in the variable valve mechanism 82 decreases, the target compression ratio MCRmtg in the compression ratio variable mechanism 50 corresponds to the decrease in the error amount. The increase correction amount of the engine is decreased, the control returns to the state controlled to the target compression ratio MCRmtg, the overcorrection process is terminated, and finally, the increase request amount of the effective compression ratio CRe is the actual compression ratio by the variable valve mechanism 82. It converges to a state that is satisfied by the increment of CRivc.

Further, in the seventeenth pattern in which the overcorrection processing is set in the variable compression ratio mechanism 50, the target compression ratio CRivctg is lower than the actual compression ratio CRivc in the variable valve mechanism 82. On the other hand, in the seventeenth pattern, the error amount becomes a negative value, so that the target compression ratio MCRmtg is corrected to the compression ratio decreasing side.
As a result, in response to a request for reducing the effective compression ratio CRe, the variable valve mechanism 82 operates to reduce the compression ratio CRivc, and the compression ratio variable mechanism 50 operates to decrease the compression ratio CRm in parallel. As a result, the effective compression ratio CRe decreases with good response.

FIG. 13 is a block diagram showing a calculation process of the target value FCRivctg of the variable valve mechanism 82 by the control device 70.
The first comparison calculation unit 201 receives the state number STVTC and “0” which is the value of the state number STVTC when the cooperative control is not performed. When the state number STVTC is 0, the first comparison calculation unit 201 201 outputs a High signal. When the state number STVTC is other than 0, the first comparison operation unit 201 outputs a Low signal.

The output of the first comparison calculation unit 201 is input to the first output switching unit 202 as a switching control signal, and the first output switching unit 202 outputs one of the two values input as the correction value of the target compression ratio MCRivctg. Select and output according to the output of the first comparison operation unit 201.
As the correction value of the target compression ratio MCRivctg, a value that is not substantially corrected and a value corresponding to the error amount in the compression ratio variable mechanism 50 are input to the first output switching unit 202.

Then, the first output switching unit 202 outputs a correction value that does not substantially perform correction when the output of the first comparison calculation unit 201 is a high signal, that is, when the cooperative control is not performed, and the first comparison When the output of the calculation unit 201 is a low signal, that is, when cooperative control is performed, a correction value corresponding to the error amount in the compression ratio variable mechanism 50 is output.
The output of the first output switching unit 202 is input to one input terminal of the correction unit 203, and the target compression ratio MCRivctg is input to the other input terminal of the correction unit 203.

Then, the correcting unit 203 outputs the result of correcting the target compression ratio MCRivctg with the correction value as the corrected target compression ratio FCRivctg.
The correction unit 203 outputs the corrected target compression ratio FCRivctg to the conversion unit 204, and the conversion unit 204 changes the corrected target compression ratio FCRivctg based on the state of the compression ratio by the compression ratio variable mechanism 50 at that time. It converts into the data of the conversion angle in the valve mechanism 82, and outputs it as the final control target value TGVTC of the variable valve mechanism 82.

Then, the control device 70 calculates and outputs the operation amount of the actuator of the variable valve mechanism 82 based on proportional integral control based on the deviation between the final target conversion angle TGVTC and the actual conversion angle. Feedback control is performed to bring the actual conversion angle closer to the target conversion angle.

Subsequently, the correction value calculation of the target compression ratio MCRivctg corresponding to the error amount in the compression ratio variable mechanism 50 will be described in detail.
The multiplying unit 206 includes an error amount in the compression ratio variable mechanism 50, a deviation data between the target compression ratio CRmtg and the actual compression ratio CRm, and a gain for converting the error amount into a correction value of the target compression ratio MCRivctg. And the result of multiplying the error amount by the gain is output as a correction value for the target compression ratio MCRivctg.

The second output switching unit 207 outputs a gain to the multiplication unit 206.
The second output switching unit 207 receives a gain set in conformity with the limiting process and a gain set in conformity with the overcorrection process, and two gains are set according to the output of the second comparison operation unit 208. Either one is output.
Note that the gain input to the second output switching unit 207 can be a variable that can be changed in accordance with the engine operating conditions, similarly to the second output switching unit 107 shown in FIG.

The second comparison operation unit 208 is input with the state number STVTC and “1” which is the value of the state number STVTC when the restriction process is performed. If the state number STVTC is 1, a high signal is output. If the state number STVTC is other than 1, a Low signal is output.
The second output switching unit 207 outputs a gain suitable for the limiting process when the output of the second comparison operation unit 208 is a high signal, in other words, when the state number STVTC = 1, When the output of the comparison operation unit 208 is a low signal, in other words, when the state number STVTC = 0 or the state number STVTC = 2, a gain suitable for overcorrection processing is output.

Here, even when the state number STVTC is 0 and cooperative control is not performed in the variable valve mechanism 82, the second output switching unit 207 outputs a gain suitable for the overcorrection processing.
However, when the state number STVTC = 0 and the pattern does not perform the overcorrection process and the restriction process, the first output switching unit 202 outputs a value that does not change the target compression ratio MCRivctg as a correction value. Therefore, in the case of the pattern in which the overcorrection process and the restriction process are not performed with the state number STVTC = 0, even if the gain for the overcorrection process is output from the second output switching unit 207, the overcorrection process is performed on the target compression ratio MCRivctg. Will not be applied.

For example, in the third pattern in which execution of overcorrection processing in the variable valve mechanism 82 is set, the target compression ratio CRmg is higher than the actual compression ratio CRmc in the compression ratio variable mechanism 50, but the actual compression ratio CRm is increased. When the target compression ratio MCRivctg is corrected by the function shown in FIG. 13, the target compression ratio MCRivctg is corrected to the higher compression ratio as the error amount in the compression ratio variable mechanism 50 increases.
In the variable valve mechanism 82, if the target compression ratio MCRivctg is corrected to a higher compression ratio in a steady state where the target compression ratio MCRivctg and the actual compression ratio CRivc substantially coincide with each other, the actual compression ratio CRivc is The variable valve mechanism 82 is operated to increase the target compression ratio CRivctg after correction.

As a result, when the variable compression ratio mechanism 50 is operated to the side where the compression ratio CRm increases, in other words, when the initial error amount when the target compression ratio CRmtg increases and changes is large, the actual compression by the compression ratio variable mechanism 50 is performed. In parallel with the increase in the ratio CRm, the actual compression ratio CRivc is increased by the variable valve mechanism 82, and the effective compression ratio CRe determined by the actual compression ratio CRivc and the actual compression ratio CRm is determined only by the compression ratio variable mechanism 50. Compared with the case where it operates, it increases and changes with good response.

When the actual compression ratio CRm approaches the target compression ratio CRmtg in the compression ratio variable mechanism 50 and the error amount in the compression ratio variable mechanism 50 decreases, the target compression ratio MCRivctg in the variable valve mechanism 82 according to the decrease in the error amount. The increase correction amount decreases, the control returns to the state controlled to the target compression ratio MCRivctg, and the overcorrection processing is terminated. Finally, the increase request amount of the effective compression ratio CRe is the actual compression ratio by the compression ratio variable mechanism 50. It converges to a state that is satisfied by the increment of CRm.

Further, in the thirteenth pattern in which execution of overcorrection processing in the variable valve mechanism 82 is set, since the target compression ratio CRmtg is lower than the actual compression ratio CRm in the compression ratio variable mechanism 50, the error amount is plus in the third pattern. On the other hand, in the thirteenth pattern, the error amount becomes a negative value, so that the target compression ratio MCRivctg is corrected to the decreasing side.
As a result, in response to a request to reduce the effective compression ratio CRe, the compression ratio variable mechanism 50 operates to reduce the compression ratio CRm, and in parallel, the variable valve mechanism 82 operates to decrease the compression ratio CRivc. As a result, the effective compression ratio CRe decreases with good response.

Further, in the sixth pattern in which the over-correction process is set in the variable valve mechanism 82, the error amount is a positive value because the target compression ratio CRmtg is higher than the actual compression ratio CRm in the compression ratio variable mechanism 50. The target compression ratio MCRivctg is corrected to the increasing side.
On the other hand, in the variable valve mechanism 82, the target compression ratio CRivctg is higher than the actual compression ratio CRivc, and the actual compression ratio CRivc is increased, and the target compression ratio MCRivctg is based on the error amount on the compression ratio variable mechanism 50 side. Is corrected to increase, an overshoot occurs in which the actual compression ratio CRivc in the variable valve mechanism 82 becomes larger than the target compression ratio MCRivctg in a state where the compression ratio variable mechanism 50 has not reached the target compression ratio CRmtg. To do.

That is, since the actual compression ratio CRm does not reach the target compression ratio CRmtg, the actual compression ratio CRivc by the variable valve mechanism 82 is increased to a value higher than the target compression ratio MCRivctg by the amount that the effective compression ratio CRe is lower than the target. The effective compression ratio CRe is quickly converged to the target.
The final target FCRivctg in the variable valve mechanism 82 returns to the original target compression ratio MCRivctg in accordance with the decrease in the error amount in the compression ratio variable mechanism 50, and the overcorrection processing of the variable valve mechanism 82 ends.

In contrast to the above-described sixth pattern, the nineteenth pattern is a case where both the compression ratio variable mechanism 50 and the variable valve mechanism 82 operate in the decreasing direction of the compression ratio. In the nineteenth pattern, the compression ratio variable mechanism Since the error amount at 50 is negative, the target compression ratio MCRivctg in the variable valve mechanism 82 is corrected to the decreasing side, and the effective compression ratio CRe is reduced with good response to the target.

Further, in the seventh pattern in which the restriction processing in the variable valve mechanism 82 is set, since the target compression ratio CRmtg is lower than the actual compression ratio CRm in the compression ratio variable mechanism 50, the error amount in the compression ratio variable mechanism 50 is reduced. Is a negative value.
On the other hand, the variable valve mechanism 82 is in an operating state in which the target compression ratio CRivctg is higher than the actual compression ratio CRivc and the actual compression ratio CRivc is increased, but the error amount in the compression ratio variable mechanism 50 is a negative value. As a result, the target compression ratio CRivctg in the variable valve mechanism 82 is corrected to decrease as the error amount in the compression ratio variable mechanism 50 increases.

Therefore, in the variable valve mechanism 82, the response to the increase change of the actual compression ratio CRivc toward the target compression ratio MCRivctg is delayed, and the error amount in the compression ratio variable mechanism 50 becomes close to zero, that is, the compression After the actual compression ratio CRm in the variable ratio mechanism 50 converges near the target compression ratio CRmtg, the final target value FCRivctg in the variable valve mechanism 82 returns to the original target compression ratio MCRivctg.

Therefore, by performing the limiting process, the change in the actual compression ratio CRivc by the variable valve mechanism 82 is synchronized with the change in the actual compression ratio CRm by the variable compression ratio mechanism 50, and the actual compression ratio CRm of the variable compression ratio mechanism 50 is The actual compression ratio CRivc of the variable valve mechanism 82 converges to the vicinity of the target compression ratio MCRivctg substantially in synchronization with the convergence to the vicinity of the target compression ratio CRmtg. As a result, the effective compression ratio CRe is suppressed from becoming excessively transient because the operation of increasing the compression ratio MCRivc by the variable valve mechanism 82 precedes the operation of decreasing the compression ratio CRm by the variable compression ratio mechanism 50. The

Similarly, in the ninth pattern in which the restriction process of the variable valve mechanism 82 is performed, the error amount in the compression ratio variable mechanism 50 is positive, so that the target compression ratio MCRivctg in the variable valve mechanism 82 is increased. And the reduction in the compression ratio CRivc in the variable valve mechanism 82 is delayed, thereby suppressing the effective compression ratio CRe from becoming transiently excessive.

Although the contents of the present invention have been specifically described with reference to the preferred embodiments, it is obvious that those skilled in the art can take various modifications based on the basic technical idea and teachings of the present invention. It is.
10 and 13, the target values of the variable valve mechanism 82 and the compression ratio variable mechanism 50 are corrected. However, the overcorrection process and the limit process are limited to the target value correction process. Instead, various arithmetic processes that can cause a change in the actual compression ratio similar to the overcorrection process and the limit process shown in FIGS. 10 and 13 can be appropriately employed.

For example, in the correction of the detection value of the actual compression ratio used for the calculation of the operation amount of the variable valve mechanism 82 and the compression ratio variable mechanism 50, or in the calculation of the operation amount based on the error amount, as a process instead of the target value correction process There are gain correction, operation amount correction, limitation, holding, and the like, and these can be used in combination.

Further, the limiting process of the variable valve mechanism 82 is not limited to the process of synchronizing the convergence of the variable valve mechanism 82 with the convergence of the compression ratio variable mechanism 50, and the response of the compression ratio change by the variable valve mechanism 82 is It is possible to suppress the effective compression ratio CRe from changing excessively by delaying the restriction process from the case where the restriction process is not performed.

In the above embodiment, the target compression ratio is set based on the engine operating state and the target compression ratio is corrected in the cooperative control. However, the control shaft angle and the conversion angle of the closing timing IVC are based on the engine operating state. The target compression ratio can be read as the target angle or the target conversion angle.

10 ... Engine, 33 ... Piston, 50 ... Compression ratio variable mechanism, 70 ... Control device, 81 ... Intake valve, 82 ... Variable valve mechanism

Claims (15)

1. A control device applied to an internal combustion engine comprising: a variable valve mechanism that changes a closing timing of an intake valve; and a compression ratio variable mechanism that changes a compression ratio by changing a top dead center position of a piston,
   A control device for an internal combustion engine, comprising: a control unit that changes the operation of one of the variable valve mechanism and the compression ratio variable mechanism according to one operation state.
2. 2. The control device for an internal combustion engine according to claim 1, wherein the control unit changes the operation of the variable valve mechanism when the variable valve mechanism and the compression ratio variable mechanism are operated in parallel.
3. When the control unit operates the variable valve mechanism and the compression ratio variable mechanism in parallel, the effective compression ratio change direction by the variable valve mechanism and the compression ratio change direction by the compression ratio variable mechanism. The control device for an internal combustion engine according to claim 2, wherein the response speed of the variable valve mechanism is changed according to
4. When the change direction of the effective compression ratio by the variable valve mechanism and the change direction of the compression ratio by the compression ratio variable mechanism are different, the control unit determines the response speed of the variable valve mechanism as compared to the same case. The control device for an internal combustion engine according to claim 3, wherein the control device is lowered.
5. The control unit has the same direction as the change direction of the effective compression ratio due to the change of the intake valve closing timing when the variable valve mechanism changes the closing timing of the intake valve in the convergence state of the compression ratio variable mechanism. The control apparatus for an internal combustion engine according to claim 1, wherein the compression ratio variable mechanism is operated so as to change the compression ratio.
6. The control device for an internal combustion engine according to claim 1, wherein the control unit changes the other target value in accordance with an error amount of one of the variable valve mechanism and the compression ratio variable mechanism.
7. The control unit delays a response of a change in the compression ratio by the variable valve mechanism when a change direction of the compression ratio by the variable valve mechanism is different from a change direction of the compression ratio by the variable compression ratio mechanism. The control apparatus for an internal combustion engine according to claim 1.
8. The control unit accelerates a response of a change in the compression ratio by the variable valve mechanism when a change direction of the compression ratio by the variable valve mechanism and a change direction of the compression ratio by the variable compression ratio mechanism are the same. The control apparatus for an internal combustion engine according to claim 1.
9. The controller, when operating the variable valve mechanism in a steady state of the compression ratio variable mechanism, operates the compression ratio variable mechanism in the same direction as the change direction of the compression ratio by the variable valve mechanism, The control device for an internal combustion engine according to claim 1.
10. The control device for an internal combustion engine according to claim 1, wherein the control unit variably sets the change degree of the operation of the other mechanism in accordance with an engine operating condition.
11. The control unit variably sets a change degree of operation of the other mechanism in accordance with at least one of an actual effective compression ratio, a fresh air amount, a residual gas amount, a compression temperature, and a knocking sensitivity. The control apparatus for an internal combustion engine according to claim 10.
12. A control method for an internal combustion engine, comprising: a variable valve mechanism that changes a closing timing of an intake valve; and a compression ratio variable mechanism that changes a compression ratio by changing a top dead center position of a piston. Including,
    Detecting one operating state of the variable valve mechanism and the compression ratio variable mechanism;
    The other operation is changed according to the operation state.
13. The control method of the internal combustion engine according to claim 12,
    The step of changing the operation includes the following steps:
    When the variable valve mechanism and the compression ratio variable mechanism are operated in parallel, the operation of the variable valve mechanism is changed.
14. The method of controlling an internal combustion engine according to claim 13,
    The step of changing the operation of the variable valve mechanism includes the following steps:
    When operating the variable valve mechanism and the compression ratio variable mechanism in parallel, the variable valve mechanism according to the change direction of the effective compression ratio by the variable valve mechanism and the change direction of the compression ratio by the compression ratio variable mechanism Change the response speed of the variable valve mechanism.
15. The control method of the internal combustion engine according to claim 12,
    The step of changing the operation includes the following steps:
    When the closing timing of the intake valve is changed by the variable valve mechanism in the convergence state of the variable compression ratio mechanism, the compression ratio is changed in the same direction as the change direction of the effective compression ratio due to the change of the closing timing of the intake valve. Then, the compression ratio variable mechanism is operated.

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