JPWO2014027488A1 - Control device and control method for variable compression ratio internal combustion engine - Google Patents

Abstract

An actuator (motor) for driving the control shaft 14 of the variable compression ratio mechanism is disposed outside the engine body (1), and an actuator case (22) is attached to the side wall (7) of the engine body (1). Based on the vehicle inclination angle and vehicle acceleration, the lubricating oil flows into the actuator case (22) from the inside of the engine body (1) through the communication hole (29) formed through the side wall (7). , The responsiveness of the compression ratio change deteriorates as the oil agitation resistance increases, and there is a risk that knocking may occur transiently when the compression ratio is changed to the low compression ratio side. The target compression ratio set accordingly is corrected to the low compression ratio side.

Description

  The present invention relates to a variable compression ratio internal combustion engine including a variable compression ratio mechanism capable of changing an engine compression ratio, and more particularly to correction of a target compression ratio according to the oil level of lubricating oil stored in an actuator case.

  Conventionally, the present applicant has proposed a variable compression ratio mechanism that can change the engine compression ratio using a multi-link type piston-crank mechanism (see, for example, Patent Document 1). Such a variable compression ratio mechanism is configured to control the engine compression ratio according to the engine operating state by changing the rotational position of the control shaft by an actuator such as a motor. The target compression ratio, which is the target value of the engine compression ratio, is set according to the engine operating state.Generally, the target compression ratio is increased on the low rotation and low load side for the purpose of improving fuel efficiency, and on the high rotation and high load side. The target compression ratio is lowered in order to suppress the occurrence of knocking.

JP 2004-257254 A

  In the case of a structure in which the actuator of the variable compression ratio mechanism is arranged outside the engine body for the purpose of reducing the size of the engine body or protecting the actuator, for example, the actuator case that houses the output shaft of the actuator and the speed reducer Attached to the side wall. Lubricating oil is supplied into the actuator case, and the lubricating oil lubricates the output shaft of the actuator accommodated in the actuator case, the bearing portion of the speed reducer, and the like. Further, a communication hole through which a lever for connecting the control shaft of the variable compression ratio mechanism and the actuator side is inserted is formed in the side wall of the engine body, and the lubricating oil supplied to the inside of the actuator case through the communication hole is supplied to the engine. It is configured to be returned to the inside of the main body.

  In such a structure, when the vehicle tilts on a slope or when the oil level in the oil pan of the engine body changes as the vehicle accelerates or decelerates, the actuator from the inside of the engine body passes through the communication hole. Lubricant flows into the case (backflow). In this way, when the lubricating oil flows into the actuator case (reverse flow), the oil level in the actuator case becomes higher than necessary, such as a reduction gear housed in the actuator case. Oil agitation resistance increases and the responsiveness at the time of changing the compression ratio deteriorates. For this reason, for example, when transitioning from a high compression ratio setting state to a low compression ratio setting state during engine acceleration, there is a possibility that knocking may occur transiently due to a decrease in response speed.

  The present invention has been made in view of such circumstances, and is in an inflow state in which lubricating oil flows (backflow) from the inside of the engine body into the actuator case through the communication hole, thereby responsiveness of changing the compression ratio. The purpose is to prevent or avoid the occurrence of knocking caused by this even if the deterioration occurs.

  A variable compression ratio mechanism that changes the engine compression ratio according to the rotational position of the control shaft, an actuator that is disposed outside the engine body, changes and holds the rotational position of the control shaft, and is attached to a side wall of the engine body. And an actuator case in which at least a part of the actuator is accommodated and disposed therein, and through the communication hole formed through the side wall of the engine body, the lubricating oil is supplied from the inside of the engine body to the inside of the actuator case. Is configured to allow inflow. The target compression ratio is set according to the engine operating state. The oil level height of the lubricating oil stored in the actuator case is detected or estimated, and the target compression ratio is corrected according to the oil level height.

  According to the present invention, when the lubricating oil flows into the actuator case from the inside of the engine body through the communication hole (reverse flow), the oil surface height in the actuator case increases, and the responsiveness of changing the compression ratio deteriorates. Even so, by correcting the target compression ratio according to the oil level height, the occurrence of knocking due to the deterioration of the responsiveness can be suppressed and avoided in advance.

The block diagram which shows simply the variable compression ratio mechanism of the variable compression ratio internal combustion engine which concerns on one Example of this invention. The perspective view which shows typically the connection structure of the control shaft and motor of the said variable compression ratio mechanism. The block diagram which shows simply the control apparatus of the said variable compression ratio internal combustion engine. The flowchart which shows the flow of the compression ratio control of the said Example. Sectional drawing which shows the said variable compression ratio internal combustion engine. Sectional drawing which shows typically the change of the oil level height by vehicle acceleration. Sectional drawing which shows typically the change of the oil level height by vehicle inclination. Explanatory drawing which shows some installation examples of the actuator case of the said Example.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. First, an example of a variable compression ratio mechanism using a multi-link piston-crank mechanism will be described with reference to FIG. Since this mechanism is known as described in Japanese Patent Application Laid-Open No. 2004-257254, etc., only a simple description will be given.

  A cylinder block 1A constituting a part of an engine body 1 of an internal combustion engine has a piston 3 of each cylinder slidably fitted in the cylinder 2 and a crankshaft 4 supported rotatably. . The variable compression ratio mechanism 10 is rotatably supported on a lower link 11 rotatably attached to the crankpin 5 of the crankshaft 4, an upper link 12 connecting the lower link 11 and the piston 3, and the engine body 1 side. A control shaft 14, an eccentric shaft portion 15 provided eccentric to the control shaft 14, and a control link 13 connecting the eccentric shaft portion 15 and the lower link 11. The piston 3 and the upper end of the upper link 12 are connected via a piston pin 16 so as to be relatively rotatable, and the lower end of the upper link 12 and the lower link 11 are connected via an upper link side connecting pin 17 so as to be relatively rotatable, The upper end of the control link 13 and the lower link 11 are connected to each other via a control link side connecting pin 18 so as to be relatively rotatable, and the lower end of the control link 13 is rotatably attached to the eccentric shaft portion 15.

  Referring to FIGS. 1 and 2, a motor 19 as an actuator of the variable compression ratio mechanism 10 is connected to the control shaft 14 via a connection mechanism 20 having a speed reducer 21. By changing the rotation angle position of the control shaft 14 by the motor 19, the piston stroke characteristics including the piston top dead center position and the piston bottom dead center position change with the change in the posture of the lower link 11, and the engine The compression ratio changes. Therefore, by controlling the drive of the motor 19 by the engine control unit 30 (see FIG. 3), the engine compression ratio can be controlled according to the engine operating state. The actuator is not limited to the electric motor 19 and may be a hydraulic drive actuator.

  The control shaft 14 is rotatably supported inside the engine body 1 including the cylinder block 1A and an oil pan upper 1B fixed to the cylinder block 1A. On the other hand, the motor 19 is disposed outside the engine body 1, and more specifically, on the rear side of the engine case 22 attached to the side wall 7 on the intake side of the oil pan upper 1 </ b> B constituting a part of the engine body 1. It is attached.

  The speed reducer 21 decelerates the rotation of the output shaft of the motor 19 and transmits it to the control shaft 14. Here, a wave gear mechanism is used. The wave gear mechanism is the same as that described in Japanese Patent Application No. 2011-259752 previously filed by the present applicant, and the description thereof is omitted here. The speed reducer is not limited to such a wave gear mechanism, and other types of rotational speed reducers can also be used.

  The coupling mechanism 20 is provided with an auxiliary control shaft 23 that rotates integrally with the output shaft of the speed reducer 21. The auxiliary control shaft 23 is rotatably accommodated in an actuator case 22 placed on the side of the oil pan side wall 7 and is arranged in the longitudinal direction of the engine along the oil pan side wall 7 (that is, a direction parallel to the control shaft 14). It extends to. The control shaft 14 disposed inside the engine body 1 where the lubricating oil scatters and the auxiliary control shaft 23 disposed outside the engine body 1 are mechanically connected by a lever 24 inserted through the oil pan side wall 7. Both 14 and 23 rotate in conjunction with each other. The oil pan side wall 7 has a through hole 29 (see FIGS. 5 and 6) through which the lever 24 is inserted, and the actuator case 22 is attached to the oil pan side wall 7 so as to close the communication hole 29. Has been.

  As shown in FIGS. 2 and 5, one end of the lever 24 and the tip of the first arm portion 25 extending radially outward from the center of the control shaft 14 are relatively rotated via a first connecting pin 26. Connected as possible. The other end of the lever 24 and the tip end of the second arm portion 27 extending radially outward from the center of the auxiliary control shaft 23 are connected via a second connecting pin 28 so as to be relatively rotatable.

  Referring to FIG. 3, the tilt angle sensor 31 detects a vehicle tilt angle A, the acceleration sensor 32 detects a vehicle acceleration G, and the accelerator opening sensor 33 is an accelerator pedal operated by a driver. The accelerator opening APO is detected, and the rotational speed sensor 34 detects the engine rotational speed Ne. Detection signals from these sensors 31 to 34 are output to the engine control unit 30. The engine control unit 30 is a digital computer system having a function of storing and executing various engine control processes, and a control signal corresponding to a target compression ratio Tε described later based on signals input from the sensors 31 to 34. Is output to the motor 19, and the motor 19 is driven and controlled.

  FIG. 4 is a flowchart showing the flow of compression ratio control according to the present embodiment. In step S1, the accelerator opening APO and the engine speed Ne are read. In step S2, the basic target compression ratio Mε is calculated based on the accelerator opening APO (or engine load or intake air amount) and the engine rotational speed Ne. In step S3, the vehicle inclination angle A and the vehicle acceleration G are read. In step S4, it is determined whether the vehicle inclination angle A is greater than or equal to a predetermined value thA. If the vehicle inclination angle A is equal to or greater than the predetermined value thA, the process proceeds to step S5, and a correction value Hε of the target compression ratio Tε with respect to the basic target compression ratio Mε is calculated based on the magnitude of the vehicle inclination angle A. Specifically, the correction value Hε to the low compression ratio side of the target compression ratio Tε increases as the inclination angle A increases.

  If the vehicle inclination angle A is less than the predetermined value thA, the process proceeds from step S4 to step S6, and it is determined whether the vehicle acceleration G is equal to or greater than a predetermined value thG. If the vehicle acceleration G is equal to or greater than the predetermined value thG, the process proceeds to step S7, and a correction value Hε of the target compression ratio Tε with respect to the basic target compression ratio Mε is calculated based on the magnitude of the vehicle acceleration G. Specifically, the correction value Hε to the low compression ratio side of the target compression ratio Tε increases as the vehicle acceleration G increases.

  In step S8, based on the correction value Hε calculated in step S5 or step S7, the basic target compression ratio Mε is corrected to calculate the final target compression ratio Tε. Specifically, the target compression ratio Tε is obtained by subtracting the correction value Hε from the basic target compression ratio Mε.

  If the vehicle inclination angle A is less than the predetermined value thA and the vehicle acceleration G is less than the predetermined value thG, the determination in both steps S4 and S6 is denied and the process proceeds to step S9 to correct the target compression ratio. Instead, the basic target compression ratio Mε is set as the final target compression ratio Tε.

  In step S10, based on the final target compression ratio Tε set in step S8 or step S9, a control signal is output to the motor 19 to drive and control the motor 19 toward the target compression ratio Tε.

  Next, characteristic configurations and operational effects of the present invention will be listed below with reference to the illustrated embodiments.

  [1] As shown in FIG. 5, an oil pan lower 1C is fixed below the oil pan upper 1B so as to close the opening on the lower surface, and an oil composed of the oil pan upper 1B and the oil pan lower 1C. Lubricating oil is stored inside the pan. On the side wall 7 of the engine body 1 (oil pan upper 1B) to which the actuator case 22 is attached, the control shaft 14 disposed inside the engine body 1 and the deceleration disposed inside the actuator case 22 as described above. A communication hole 29 through which a lever 24 for connecting the auxiliary control shaft 23 of the machine 21 is inserted is formed. Although not shown, the engine body 1 is formed with an oil supply passage (not shown) for forcibly supplying lubricating oil from the engine body side to the inside of the actuator case 22. The lubricating oil supplied into the actuator case 22 appropriately lubricates the reduction gear 21 and the bearing portion and link connecting portion of the motor output shaft, and then returns to the inside of the oil pan of the engine body 1 through the communication hole 29. It is. Therefore, a certain amount of lubricating oil is stored inside the actuator case 22, and the oil level height is approximately in the vicinity of the lower end position 41 of the communication hole 29. An oil discharge passage for returning the lubricating oil in the actuator case 22 to the oil pan may be provided separately from the communication hole 29. In this case, the oil level height position in the actuator case 22 is the same as that of the communication hole 29. It becomes near the lower end position (41) of the lower one in the oil discharge passage.

  The lower end position 41 of the communication hole 29 (or oil discharge passage) in the in-vehicle state is set to a position higher than the oil level height position 42 of the lubricating oil stored in the oil pan of the engine body 1 by a certain distance ΔD. Yes. Therefore, as shown in FIG. 5, in a normal state where the vehicle is substantially stopped on a horizontal plane, the lubricating oil is returned from the inside of the actuator case 22 to the inside of the engine body 1 through the communication hole 29, while the communication hole 29. Thus, the lubricating oil does not inadvertently flow (backflow) from the inside of the engine body 1 into the actuator case 22 through the engine body 1.

  However, for example, as shown in FIG. 6, when the vehicle acceleration (including vehicle acceleration in the deceleration direction) G increases and the oil level 43 is greatly inclined in a predetermined direction with respect to the horizontal plane 44, or as shown in FIG. When the oil level 45 is greatly inclined with respect to the engine body 1 due to the vehicle being largely inclined with respect to the horizontal plane, the lubricating oil flows from the inside of the engine body 1 into the actuator case 22 through the communication hole 29. There is a risk of backflow. In this case, the oil level in the actuator case 22 becomes higher than necessary, and the oil agitation resistance when the speed reducer 21 rotates is increased, and the responsiveness at the time of changing the compression ratio is deteriorated / decreased. If the responsiveness decreases in this way, for example, during the transitional transition from the setting of the high compression ratio to the setting of the low compression ratio, such as during engine acceleration, the change to the low compression ratio side is delayed, and knocking is made transiently. May occur.

  Therefore, in this embodiment, the oil level of the lubricating oil stored in the actuator case 22 that fluctuates when the lubricating oil flows (reversely flows) from the inside of the engine body 1 to the inside of the actuator case 22 through the communication hole 29 as described above. The height is detected or estimated (oil level height acquisition means), and the target compression ratio (Tε) is corrected according to the oil level height (compression ratio correction means). In the routine of FIG. 4, steps S4 and S6 correspond to oil level height acquisition means for estimating the fluctuation of oil level due to inflow (reverse flow) of lubricating oil, and steps S5, S7 and S8 are compression ratio correction means. It corresponds to.

  In this way, by correcting the target compression ratio according to the oil level height, for example, the oil agitation resistance increases due to the inflow (back flow) of the lubricating oil into the actuator case 22, and the responsiveness when changing the compression ratio is increased. Even in such a situation, the target compression ratio is corrected to the low compression ratio side in advance, so that the occurrence of knocking due to the deterioration in responsiveness can be suppressed / prevented in advance.

  [2] More specifically, it is determined whether or not the lubricating oil is flowing into the actuator case 22 from the inside of the engine body 1 through the communication hole 29 (inflow state determining means). The target compression ratio is corrected according to the inflow state. In the routine of FIG. 4, steps S4 and S6 correspond to the inflow state determination means, and steps S5, S7 and S8 correspond to the compression ratio correction means.

  [3] If it is determined that the inflow state is present, the target compression ratio is corrected to the low compression ratio side. As a result, as described above, even in a situation where the oil agitation resistance increases due to the inflow (reverse flow) of the lubricating oil into the actuator case 22 and the responsiveness deteriorates, the target compression ratio is set to the low compression ratio in advance. By correcting to the side, occurrence of knocking due to deterioration of responsiveness can be suppressed and avoided in advance.

  [4] When the acceleration G of the vehicle is detected by the acceleration sensor 32 and the acceleration G of the vehicle is greater than or equal to a predetermined value thG in a predetermined direction as shown in step S6 of FIG. 4, it is determined that the inflow state is present. (Step S6). As a result, as shown in FIG. 6, the oil level 43 is inclined by the acceleration G of the vehicle, so that it is possible to accurately determine the inflow state in which the lubricating oil flows into the actuator case 22 through the communication hole 29. In addition, you may make it estimate the vehicle acceleration G from the change of a vehicle speed, etc., without providing the acceleration sensor 32. FIG.

  [5] If it is determined that the vehicle is in the inflow state, the target compression ratio is corrected according to the magnitude of the acceleration G of the vehicle, as shown in step S7 of FIG. That is, as the acceleration G increases, the amount of lubricating oil flowing into the actuator case 22 increases, so the correction value Hε toward the low compression ratio side increases. As a result, the target compression ratio Tε can be corrected with high accuracy in a form corresponding to the magnitude of the acceleration G.

  [6] Further, in the same manner as the vehicle acceleration G described above, the angular acceleration at the time of turning the vehicle is detected or estimated, and when the angular acceleration is equal to or greater than a predetermined value, it is determined that the inflow state is present, and the target compression ratio is set. Correction to the low compression ratio side. Therefore, even when the lubricating oil stored in the oil pan is unevenly distributed due to the angular acceleration due to turning of the vehicle and the amount of lubricating oil flowing into the actuator case 22 increases, the target compression ratio is set to a low compression ratio in advance. By correcting to the side, occurrence of knocking due to the deterioration of responsiveness as described above can be suppressed and prevented in advance.

  [7] FIG. 8 shows some installation examples L1 to L4 of the actuator case 22 with respect to the engine body 1. The engine main body 1 is mounted on the vehicle in a so-called horizontal orientation in which the vehicle longitudinal direction is the vehicle width direction, and an automatic transmission or a continuously variable transmission is disposed on the engine rear side (left side in the vehicle width direction) of the engine main body 1. Etc., a transmission 8 is connected in series.

  In the installation examples L <b> 1 to L <b> 4 of FIG. 8, the actuator case 22 is arranged closer to the center of the engine body 1 in the vehicle width direction. That is, in the installation examples L1 and L3, the actuator case 22 is arranged on the left side in the vehicle width direction with respect to the center of the engine body 1, and in the installation examples L2 and L4, the actuator case 22 is in the vehicle width direction with respect to the center of the engine body 1. It is arranged on the right side of. Accordingly, when an angular acceleration of a predetermined value or more is generated on one side in the vehicle width direction where the actuator case 22 is disposed by turning the vehicle, the amount of lubricating oil flowing into the actuator case 22 through the communication hole 29 increases. From the above, it is determined that the inflow state is present and the target compression ratio is corrected to the low compression ratio side so as to suppress and avoid the occurrence of knocking.

  For example, when the actuator case 22 is arranged to the left in the vehicle width direction (close to the transmission 8) with respect to the center of the engine body 1 as in the installation examples L1 and L3, the left side in the vehicle width direction by turning the vehicle When an angular acceleration of a predetermined value or more occurs, the flow of lubricating oil into the actuator case 22 through the communication hole 29 increases, so that the target compression ratio is set so as to prevent and avoid the occurrence of knocking. Correct to the low compression ratio. On the other hand, as shown in the installation examples L2 and L4, when the actuator case 22 is arranged on the right side of the engine body 1 in the vehicle width direction (on the side opposite to the transmission 8), When angular acceleration of a predetermined value or more to the right in the width direction occurs, the lubricating oil flowing into the actuator case 22 through the communication hole 29 increases, so the target compression ratio is corrected to the low compression ratio side.

  [8] As shown in the installation examples L1 and L2 in FIG. 8, when the actuator case 22 is disposed near the front of the vehicle of the engine body 1, the deceleration (acceleration in the deceleration direction) G during vehicle deceleration is When it is equal to or greater than the predetermined value thG, the lubricating oil in the oil pan is unevenly distributed in the vehicle front direction, and the lubricating oil flowing into the actuator case 22 through the communication hole 29 increases. Then, the target compression ratio is corrected to the low compression ratio side. Further, as shown in installation examples L3 and L4 in FIG. 8, when the actuator case 22 is arranged near the vehicle rear side of the engine body 1, when the acceleration G during vehicle acceleration is equal to or greater than a predetermined value thG, Since the lubricating oil in the oil pan is unevenly distributed toward the vehicle rear side and the lubricating oil flowing into the actuator case 22 through the communication hole 29 increases, it is determined that the inflow state is present, and the target compression ratio is reduced. Correct the compression ratio.

  [9] The inclination angle A of the vehicle is detected by the inclination angle sensor 31, and the inclination angle A is predetermined in a predetermined inclination direction in which the actuator case 22 is installed with respect to the horizontal plane, as shown in step S4 of FIG. When it is inclined at an inclination angle thA or more, it is determined that the inflow state is present. As a result, as shown in FIG. 7, it is possible to accurately determine the inflow state in which the lubricating oil flows into the actuator case 22 through the communication hole 29 due to the inclination of the vehicle.

  [10] If it is determined that the inflow state is present, the target compression ratio is corrected according to the magnitude of the vehicle inclination angle A, as shown in step S5 of FIG. Specifically, as the inclination angle A increases, the inflow amount of the lubricating oil increases, so the correction amount Hε to the low compression ratio side of the target compression ratio is increased. As a result, the target compression ratio Tε can be accurately corrected in a form corresponding to the magnitude of the inclination angle A.

  [11] As shown in installation examples L1 and L2 in FIG. 8, when the actuator case 22 is disposed closer to the vehicle front side of the engine body 1, the vehicle front side is inclined downward, and the inclination angle A 7 is equal to or greater than the predetermined value thA, as shown in FIG. 7, the lubricating oil in the oil pan is unevenly distributed on the front side of the vehicle, and the amount of lubricating oil flowing into the actuator case 22 increases. It determines with it being in an inflow state, and correct | amends a target compression ratio to the low compression ratio side.

  [12] As shown in installation examples L3 and L4 in FIG. 8, when the actuator case 22 is disposed closer to the vehicle rear side of the engine body 1, the vehicle rear side is inclined downward, and the inclination angle A Is greater than or equal to a predetermined value thA, the lubricating oil in the oil pan is unevenly distributed toward the rear of the vehicle, and the amount of lubricating oil flowing into the actuator case 22 through the communication hole 29 increases. The target compression ratio is corrected to the low compression ratio side.

  [13] When the actuator case 22 is arranged closer to one side of the engine body 1 in the vehicle width direction, one side in the vehicle width direction is inclined downward, and the inclination angle A is equal to or greater than a predetermined value thA. In this case, it is determined that the inflow state is present, and the target compression ratio is corrected to the low compression ratio side. For example, as shown in installation examples L1 and L3 in FIG. 8, when the actuator case 22 is installed on the left side of the engine body 1 in the vehicle width direction (closer to the transmission 8), the left side in the vehicle width direction. Is inclined downward, the amount of lubricating oil flowing into the actuator case 22 increases. Therefore, it is determined that the inflow state is present, and correction to the low compression ratio side is performed. On the other hand, when the actuator case 22 is installed on the right side in the vehicle width direction (on the opposite side to the transmission 8) from the center of the engine body 1 as in the installation examples L2 and L4 in FIG. When the right side of the direction inclines downward, the amount of lubricating oil flowing into the actuator case 22 increases. Therefore, it is determined that the inflow state is present, and correction to the low compression ratio side is performed.

  [14] The change (inclination) of the oil level due to the inertial action based on the vehicle acceleration G occurs later in time than the direct change (inclination) of the oil level according to the vehicle inclination angle A. FIG. As shown in FIG. 4, in a situation where the vehicle inclination angle A is equal to or greater than a predetermined value thA in a predetermined direction with respect to a horizontal plane, and the vehicle acceleration G is equal to or greater than the predetermined value thG in a predetermined direction, first, the change in the vehicle inclination angle A In step S5, the compression ratio correction by the vehicle inclination angle A (first compression ratio correction means) and the compression ratio correction by the vehicle acceleration G in step S7 (second compression ratio correction) are performed. Among the means), the compression ratio correction (first compression ratio correction means) based on the vehicle inclination angle A in step S5 is preferentially performed. Specifically, in the routine of FIG. 4, if the vehicle tilt angle A is equal to or greater than the predetermined value thA in step S4, the process proceeds to step S5 without determining the vehicle tilt angle A in step S6, and the correction value Hε Is calculated.

  [15] When the inflow amount of the lubricating oil from the inside of the engine body 1 to the inside of the actuator case 22 increases, foreign matter (so-called contamination) flows into the actuator case 22 together with the lubricating oil in the oil pan. There is a possibility that foreign matter may enter the gears and bearings, leading to malfunctions and degradation of the operation response. In this embodiment, therefore, foreign matter may be mixed into the actuator case 22 under operating conditions in which the amount of lubricating oil flowing from the inside of the engine body 1 into the actuator case 22 exceeds a predetermined value. In order to suppress or avoid the malfunction due to the mixing of the engine, the change of the engine compression ratio, that is, the operation of the motor 19 is limited.

As described above, the present invention has been described based on the specific embodiments. However, the present invention is not limited to the above-described embodiments, and includes various modifications and changes. For example, in the case of engine operating conditions that are unlikely to cause knocking due to poor responsiveness, such as when the amount of change in the accelerator pedal opening APO is equal to or less than a predetermined value, the fuel consumption associated with the correction of the compression ratio You may make it prohibit the correction | amendment of the compression ratio mentioned above so that a fall etc. may be suppressed.

Claims (16)

A variable compression ratio mechanism that changes the engine compression ratio according to the rotational position of the control shaft;
An actuator disposed outside the engine body for changing and holding the rotational position of the control shaft;
An actuator case attached to a side wall of the engine body, wherein at least a part of the actuator is housed and disposed therein,
In a control device for a variable compression ratio internal combustion engine configured to allow lubricating oil to flow from the inside of the engine body into the actuator case through a communication hole formed through the side wall of the engine body.
Target compression ratio setting means for setting a target compression ratio according to the engine operating state;
Oil level height acquisition means for detecting or estimating the oil level height of the lubricating oil stored in the actuator case;
A control apparatus for a variable compression ratio internal combustion engine, comprising compression ratio correction means for correcting the target compression ratio in accordance with the oil level height. Inflow state determination means for determining whether or not the lubricating oil flows into the actuator case from the inside of the engine body through the communication hole,
The control apparatus for a variable compression ratio internal combustion engine according to claim 1, wherein the compression ratio correction means corrects the target compression ratio in accordance with the inflow state.   The control apparatus for a variable compression ratio internal combustion engine according to claim 2, wherein the compression ratio correction means corrects the target compression ratio to the low compression ratio side when the inflow state determination means determines that the inflow state is present. . Having an acceleration acquisition means for detecting or estimating the acceleration of the vehicle;
The control apparatus for a variable compression ratio internal combustion engine according to claim 2 or 3, wherein the inflow state determination means determines that the inflow state is in the inflow state when the acceleration of the vehicle is not less than a predetermined value in a predetermined direction.   The control apparatus for a variable compression ratio internal combustion engine according to claim 4, wherein the compression ratio correction means corrects the target compression ratio in accordance with a magnitude of acceleration of the vehicle.   The control of the variable compression ratio internal combustion engine according to any one of claims 2 to 5, wherein the inflow state determination means determines that the inflow state is present when an angular acceleration at the time of turning of the vehicle is a predetermined value or more in a predetermined direction. apparatus. The actuator case is arranged on one side of the engine body in the vehicle width direction,
The said inflow state determination means determines that it is the said inflow state, when the angular acceleration more than a predetermined value generate | occur | produces in the vehicle width direction one side where the said actuator case is arrange | positioned at the time of vehicle turning. A control device for a variable compression ratio internal combustion engine. The actuator case is arranged near the front of the engine body vehicle,
The control apparatus for a variable compression ratio internal combustion engine according to any one of claims 2 to 6, wherein the inflow state determination means determines that the inflow state is in the case where the vehicle acceleration in the deceleration direction is equal to or greater than a predetermined value. Inclination angle acquisition means for detecting or estimating the inclination angle of the vehicle,
The control device for a variable compression ratio internal combustion engine according to any one of claims 2 to 6, wherein the inflow state determining means determines that the inflow state is in the inflow state when the inclination angle is equal to or greater than a predetermined value in a predetermined direction.   10. The control apparatus for a variable compression ratio internal combustion engine according to claim 9, wherein the compression ratio correction means corrects the target compression ratio based on a magnitude of an inclination angle of the vehicle. The actuator case is arranged near the front of the engine body vehicle,
The variable compression ratio internal combustion engine according to claim 9 or 10, wherein the inflow state determining means determines that the inflow state is in the inflow state when the front side of the vehicle is inclined downward and the inclination angle is equal to or greater than a predetermined value. Control device. The actuator case is disposed near the vehicle rear of the engine body,
11. The variable compression ratio internal combustion engine according to claim 9, wherein the inflow state determination unit determines that the inflow state is in the inflow state when the rear side of the vehicle is inclined downward and the inclination angle is equal to or greater than a predetermined value. Control device. The actuator case is arranged on one side of the engine body in the vehicle width direction,
The variable compression according to claim 9 or 10, wherein the inflow state determining means determines that the inflow state is present when one side in the vehicle width direction is inclined downward and an inclination angle is equal to or greater than a predetermined value. A control device for a specific internal combustion engine. The compression ratio correcting means is
First compression ratio correction means for correcting the target compression ratio when the inclination angle of the vehicle is greater than or equal to a predetermined value in a predetermined direction;
A second compression ratio correcting means for correcting the target compression ratio when the acceleration of the vehicle is equal to or greater than a predetermined value in a predetermined direction;
In addition, when the vehicle inclination angle is a predetermined value or more in a predetermined direction with respect to the horizontal plane and the vehicle acceleration is a predetermined value or more in the predetermined direction, the first compression ratio correction means and the second compression The control apparatus for a variable compression ratio internal combustion engine according to claim 9 or 10, wherein the correction of the target compression ratio by the first compression ratio correction means is preferentially performed among the ratio correction means.   The change in the engine compression ratio is limited under an operating condition in which an inflow amount of lubricating oil flowing from the inside of the engine body into the actuator case through the communication hole is a predetermined value or more. A control device for a variable compression ratio internal combustion engine. A variable compression ratio mechanism that changes the engine compression ratio according to the rotational position of the control shaft;
An actuator disposed outside the engine body for changing and holding the rotational position of the control shaft;
An actuator case attached to a side wall of the engine body, wherein at least a part of the actuator is housed and disposed therein,
In a control method of a variable compression ratio internal combustion engine configured to allow lubricating oil to flow from the inside of the engine body to the inside of the actuator case through a communication hole formed through the side wall of the engine body.
Set the target compression ratio according to the engine operating condition,
Detecting or estimating the oil level of the lubricating oil stored in the actuator case,
The target compression ratio is corrected according to the oil level height.
A control method for a variable compression ratio internal combustion engine.

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