JP5229245B2 - Start control device for internal combustion engine - Google Patents

Description

  The present invention relates to an internal combustion engine start control device that controls a start mode of an internal combustion engine including a hydraulic variable valve mechanism that changes a valve timing of an intake valve.

As a variable valve mechanism, for example, one described in Patent Document 1 is known.
The variable valve mechanism of Patent Document 1 includes a first rotating body that rotates in synchronization with a crankshaft, a second rotating body that rotates in synchronization with a camshaft, and these rotating bodies that are engaged with each other to And a fixing mechanism that fixes the valve timing to a specific angle that is on the more advanced side than the most retarded angle.

  In this variable valve mechanism, the valve timing is adjusted by engaging the first rotating body and the second rotating body with each other by a fixing mechanism at the time of starting the engine, utilizing the fact that the valve timing is advanced with cranking. It is fixed at a specific angle that is more advanced than the most retarded angle.

JP 09-324613 A

  Here, when the oil temperature is relatively high when the engine is started, the high oil temperature is started, and when the oil temperature is relatively low when the engine is started, the low oil temperature is started. And the rotation resistance of the crankshaft are different from each other at the start of the low oil temperature. For this reason, when comparing the increase speed of the engine rotation speed at the start of the high oil temperature and the increase speed of the engine rotation speed at the start of the low oil temperature, the former is larger than the latter. Further, the advance speed of the valve timing is larger at the high oil temperature start than at the low oil temperature start.

On the other hand, at the time of low rotational speed at the time of engine start, torque shock accompanying combustion tends to occur as the actual compression ratio increases.
Therefore, the actual compression ratio tends to become excessively large at the low engine speed when starting the engine at a high oil temperature when the engine speed increases and the valve timing advance speed is large compared to the low oil temperature start. Due to this, the frequency of occurrence of torque shock is high.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an internal combustion engine start control device capable of suppressing the occurrence of torque shock at the time of engine start with a high lubricating oil temperature. is there.

In the following, means for achieving the above object and its effects are described.
In this column (means for solving the problems), “high oil temperature start” indicates when the engine is started and the lubricating oil temperature is higher than a predetermined temperature, and “low oil temperature start” indicates that the engine is started. And when the lubricating oil temperature is lower than a predetermined temperature.

  The “lubricating temperature” and “temperature serving as an index of lubricating oil temperature” described in each claim include the following. That is, the “lubricating oil temperature” includes both a temperature obtained based on the output of a sensor that senses the temperature of the lubricating oil and a temperature estimated based on a parameter correlated with the temperature of the lubricating oil. The parameters include the integrated value of the fuel injection amount from the start of the previous engine start operation to the engine stop, the integrated value of the intake air amount from the start of the previous engine start operation to the engine stop, and the current engine start At least one of the temperatures of the cooling water of the internal combustion engine at the time can be employed. The “temperature serving as an index of the temperature of the lubricating oil” includes the temperature of a substance having a high correlation with the temperature of the lubricating oil. As the temperature having the high correlation, at least one of the temperature of the cooling water of the internal combustion engine and the temperature of the main body of the internal combustion engine can be employed.

  (1) According to the first aspect of the present invention, there is provided an internal combustion engine start control device for controlling a start mode of an internal combustion engine including a hydraulic variable valve mechanism that changes a valve timing of an intake valve. Lubricating oil temperature or its index temperature is the lubricating oil temperature, the engine speed is increased when the engine is started and the lubricating oil temperature is higher than the predetermined temperature, and the rising speed A is the engine oil speed. The gist is to perform start-up rotation speed control in which the increase speed of the engine rotation speed when the engine speed is lower than the predetermined temperature is the increase speed B and the increase speed A is smaller than the increase speed B.

  In the present invention, since the starting rotational speed control is performed so that the rising speed A is smaller than the rising speed B, the increase speed of the actual compression ratio accompanying the increase in the engine rotational speed at the start of the high oil temperature is It is smaller than the case where is not performed. As a result, a situation in which the actual compression ratio becomes excessively large at the low rotational speed at the start of the high oil temperature is less likely to occur, so that a torque shock can be prevented from occurring at the start of the engine having a high lubricating oil temperature.

  (2) The invention according to claim 2 is an internal combustion engine start control device for controlling a start mode of an internal combustion engine including a hydraulic variable valve mechanism that changes a valve timing of an intake valve. Lubricating oil temperature or its index temperature is the lubricating oil temperature, and the control that adjusts the engine speed increase at engine start is the start speed control. When the engine speed is increased and the engine speed is increased when the engine speed is increased, the engine speed when the engine oil speed is higher than a predetermined temperature. The gist is to perform the rotational speed control at start-up so that the ascending speed A is smaller than the ascending speed B.

  In the present invention, since the engine speed is controlled when the engine is started and the lubricating oil temperature is higher than a predetermined temperature, the increase speed of the actual compression ratio accompanying the increase in the engine speed at the start of the high oil temperature is It becomes smaller than the case where the rotational speed control is not performed. As a result, a situation in which the actual compression ratio becomes excessively large at the low rotational speed at the start of the high oil temperature is less likely to occur, so that a torque shock can be prevented from occurring at the start of the engine having a high lubricating oil temperature.

  (3) According to a third aspect of the present invention, there is provided a start control device for an internal combustion engine that controls a start mode of an internal combustion engine including a hydraulic variable valve mechanism that changes a valve timing of an intake valve. When the temperature of the engine or its index is the lubricating oil temperature and the engine is started and the lubricating oil temperature is higher than the predetermined temperature, the engine rotational speed is set so that the engine rotational speed does not exceed a preset judgment speed. The gist is that the rotational speed control at the start for adjusting the rising speed is performed, and the rotational speed control at the start is not performed when the engine is started and the lubricating oil temperature is lower than the predetermined temperature.

  In the present invention, since the engine speed is controlled when the engine is started and the lubricating oil temperature is higher than a predetermined temperature, the increase speed of the actual compression ratio accompanying the increase in the engine speed at the start of the high oil temperature is It becomes smaller than the case where the rotational speed control is not performed. As a result, a situation in which the actual compression ratio becomes excessively large at the low rotational speed at the start of the high oil temperature is less likely to occur, so that a torque shock can be prevented from occurring at the start of the engine having a high lubricating oil temperature.

  (4) According to a fourth aspect of the present invention, there is provided an internal combustion engine start control device for controlling a start mode of an internal combustion engine including a hydraulic variable valve mechanism that changes a valve timing of an intake valve. If the temperature of the engine or its index is the lubricating oil temperature and the engine is started, the lubricating oil temperature is higher than a predetermined temperature, and the rising speed of the engine rotational speed is greater than a preset judgment speed, the engine rotational speed The gist of the present invention is to perform start-up rotation speed control for reducing the rising speed of the engine, and not to perform the start-up rotation speed control when starting the engine and when the lubricating oil temperature is lower than the predetermined temperature.

  In the present invention, when the increase speed of the engine rotational speed at the time of starting the engine is larger than the determination speed and when the lubricating oil temperature is higher than the predetermined temperature, the rotational speed control at the time of starting is performed. The increase speed of the actual compression ratio as the speed increases is smaller than that in the case where the rotation speed control at the start is not performed. As a result, a situation in which the actual compression ratio becomes excessively large at the low rotational speed at the start of the high oil temperature is less likely to occur, so that a torque shock can be prevented from occurring at the start of the engine having a high lubricating oil temperature.

  (5) The invention according to claim 5 is the internal combustion engine start control device according to any one of claims 1 to 4, wherein in the start time rotational speed control, a motor for applying torque to the crankshaft is provided. The gist is to adjust the increasing speed of the engine rotational speed by controlling.

  In the present invention, since the increase speed of the engine rotation speed is adjusted by controlling the motor that applies torque to the crankshaft, it is more preferable that the actual compression ratio becomes excessively large at the low rotation speed at the start of the high oil temperature. Can be suppressed.

  (6) The invention according to claim 6 is an internal combustion engine start control device for controlling a start mode of an internal combustion engine including a hydraulic variable valve mechanism that changes a valve timing of an intake valve. Lubricating oil temperature or its index temperature is defined as lubricating oil temperature, and when the engine starts and when the lubricating oil temperature is higher than a predetermined temperature, the advance speed of the variable valve mechanism is defined as advance speed A, and when the engine is started and lubricated. The gist of the present invention is to perform start-up advance speed control in which the advance speed of the variable valve mechanism when the oil temperature is lower than the predetermined temperature is set to the advance speed B, and the advance speed A is made smaller than the advance speed B. .

  In the present invention, since the advance angle speed control is performed so that the advance angle speed A is smaller than the advance angle speed B, the increase speed of the actual compression ratio accompanying the increase in the engine speed at the start of the high oil temperature is the start advance angle speed. It becomes smaller than the case where control is not performed. As a result, a situation in which the actual compression ratio becomes excessively large at the low rotational speed at the start of the high oil temperature is less likely to occur, so that a torque shock can be prevented from occurring at the start of the engine having a high lubricating oil temperature.

  (7) The invention according to claim 7 is an internal combustion engine start control device for controlling a start mode of an internal combustion engine including a hydraulic variable valve mechanism that changes a valve timing of an intake valve. The control of adjusting the advance speed of the variable valve mechanism at the start of the engine was set as the start advance speed control, and the start speed advance control was performed. The advance speed of the variable valve mechanism at the time is the advance speed A, and the advance speed of the variable valve mechanism when the start speed control is not performed is the advance speed B. The gist of the present invention is that the starting advance speed control is performed so that the advance speed A is smaller than the advance speed B when the temperature is higher than a predetermined temperature.

  In this invention, since the advance angle speed control is performed at the time of engine start and when the lubricating oil temperature is higher than a predetermined temperature, the increase rate of the actual compression ratio accompanying the increase in the engine rotation speed at the time of high oil temperature start is It becomes smaller than the case where the time advance angular velocity control is not performed. As a result, a situation in which the actual compression ratio becomes excessively large at the low rotational speed at the start of the high oil temperature is less likely to occur, so that a torque shock can be prevented from occurring at the start of the engine having a high lubricating oil temperature.

  (8) According to an eighth aspect of the present invention, there is provided an internal combustion engine start control device that controls a start mode of an internal combustion engine including a hydraulic variable valve mechanism that changes a valve timing of an intake valve. When the engine is started and the lubricating oil temperature is higher than a predetermined temperature, the advance angle speed of the variable valve mechanism is controlled so as not to exceed a predetermined determination speed. The gist of the invention is that the starting advance speed control for adjusting the advance speed of the variable valve mechanism is performed, and the start advance speed control is not performed when the engine is started and the lubricating oil temperature is lower than the predetermined temperature.

  In this invention, since the advance angle speed control is performed at the time of engine start and when the lubricating oil temperature is higher than a predetermined temperature, the increase rate of the actual compression ratio accompanying the increase in the engine rotation speed at the time of high oil temperature start is It becomes smaller than the case where the rotational speed control is not performed. As a result, a situation in which the actual compression ratio becomes excessively large at the low rotational speed at the start of the high oil temperature is less likely to occur, so that a torque shock can be prevented from occurring at the start of the engine having a high lubricating oil temperature.

  (9) According to the ninth aspect of the present invention, there is provided an internal combustion engine start control device that controls a start mode of an internal combustion engine including a hydraulic variable valve mechanism that changes a valve timing of an intake valve. When the temperature of the variable valve mechanism is higher than a predetermined determination speed when the engine is started and the lubricating oil temperature is higher than a predetermined temperature, the temperature or the temperature serving as an index thereof is the lubricating oil temperature. The gist is that the starting advance speed control is performed to reduce the advance speed of the variable valve mechanism, and the start advance speed control is not performed when the engine is started and the lubricating oil temperature is lower than the predetermined temperature.

  In the present invention, when the advance angle speed of the variable valve mechanism at the time of starting the engine is larger than a preset determination speed and when the lubricating oil temperature is higher than a predetermined temperature, the advance angle speed control is performed at the time of high oil temperature. The increase speed of the actual compression ratio accompanying the increase in the engine rotational speed at the time of starting becomes smaller than that when the starting advance speed control is not performed. As a result, a situation in which the actual compression ratio becomes excessively large at the low rotational speed at the start of the high oil temperature is less likely to occur, so that a torque shock can be prevented from occurring at the start of the engine having a high lubricating oil temperature.

  (10) The invention according to claim 10 is the start control device for an internal combustion engine according to any one of claims 6 to 9, wherein the fluctuation range of the torque of the camshaft is adjusted in the starting advance speed control. Thus, the gist is to adjust the advance speed of the variable valve mechanism.

  The advance speed at the start of the high oil temperature varies depending on the torque fluctuation of the camshaft. In the above invention, since the advance speed of the variable valve mechanism is adjusted by controlling the fluctuation range of the torque of the camshaft, it is more preferable that the actual compression ratio becomes excessively large at the low rotational speed at the start of the high oil temperature. Can be suppressed.

  (11) According to an eleventh aspect of the present invention, in the start control device for an internal combustion engine according to the tenth aspect, in the starting advance speed control, the motor for applying torque to the crankshaft is controlled to control the camshaft. The gist is to adjust the fluctuation range of the torque.

  In this invention, since the fluctuation range of the torque of the camshaft is adjusted by controlling the motor that applies torque to the crankshaft, the actual compression ratio becomes excessively large at the low rotational speed at the start of the high oil temperature. It can suppress suitably.

  (12) The invention according to claim 12 is an internal combustion engine start control device for controlling a start mode of an internal combustion engine including a hydraulic variable valve mechanism that changes a valve timing of an intake valve. Alternatively, the temperature serving as the index is defined as the lubricating oil temperature, the increase rate of the actual compression ratio when the engine is started and the lubricating oil temperature is higher than the predetermined temperature is defined as the increasing speed A, and the lubricating oil temperature is determined when the engine is started and the lubricating oil temperature is the predetermined temperature. The increase speed of the actual compression ratio at a lower speed is set as the increase speed B, and the increase speed control at the time of starting is performed to make the increase speed A smaller than the increase speed B by controlling the motor that applies torque to the crankshaft. It is a summary.

  In this invention, since the increase speed control at the time of starting is made to make the increase speed A smaller than the increase speed B by the control of the motor that applies torque to the crankshaft, the actual compression accompanying the increase in the engine speed at the start of the high oil temperature The rate of increase in the ratio is smaller than when the increase rate control at the start is not performed. As a result, a situation in which the actual compression ratio becomes excessively large at the low rotational speed at the start of the high oil temperature is less likely to occur, so that a torque shock can be prevented from occurring at the start of the engine having a high lubricating oil temperature.

  (13) The invention according to claim 13 is an internal combustion engine start control device that controls a start mode of an internal combustion engine including a hydraulic variable valve mechanism that changes a valve timing of an intake valve. The temperature or its index temperature is the lubricating oil temperature, and the control that adjusts the increase speed of the actual compression ratio by controlling the motor that applies torque to the crankshaft is the start speed increase control. The increase speed of the actual compression ratio when the engine is broken is defined as an increase speed A, and the increase speed of the actual compression ratio when the start speed increase control is not performed is defined as the increase speed B. The gist is that the increase speed control at the start is performed so that the increase speed A is smaller than the increase speed B when the temperature is higher than the temperature.

  In this invention, since the increase speed control at the start is performed so that the increase speed A becomes smaller than the increase speed B, the increase speed of the actual compression ratio accompanying the increase in the engine speed at the start of the high oil temperature is increased at the start. It becomes smaller than the case where speed control is not performed. As a result, a situation in which the actual compression ratio becomes excessively large at the low rotational speed at the start of the high oil temperature is less likely to occur, so that a torque shock can be prevented from occurring at the start of the engine having a high lubricating oil temperature.

  (14) According to the fourteenth aspect of the present invention, there is provided an internal combustion engine start control device that controls a start mode of an internal combustion engine including a hydraulic variable valve mechanism that changes a valve timing of an intake valve. The temperature that is the temperature or its index is the lubricating oil temperature, and the control that adjusts the speed of increase in the actual compression ratio by controlling the motor that applies torque to the crankshaft is the speed increasing control at the start. When the temperature is higher than the predetermined temperature, the increase speed control at the start is performed so that the increase speed of the actual compression ratio does not exceed a preset determination speed, and when the engine is started and the lubricating oil temperature is lower than the predetermined temperature, The gist is that the speed increase control at the start is not performed.

  In this invention, since the increase speed control at the start is performed when the engine is started and the lubricating oil temperature is higher than the predetermined temperature, the increase speed of the actual compression ratio at the start of the high oil temperature is not controlled at the start. Smaller than the case. As a result, a situation in which the actual compression ratio becomes excessively large at the low rotational speed at the start of the high oil temperature is less likely to occur, so that a torque shock can be prevented from occurring at the start of the engine having a high lubricating oil temperature.

  (15) According to the fifteenth aspect of the present invention, there is provided an internal combustion engine start control apparatus for controlling a start mode of an internal combustion engine including a hydraulic variable valve mechanism that changes a valve timing of an intake valve. The temperature that is the temperature or its index is the lubricating oil temperature, and the control that adjusts the speed of increase in the actual compression ratio by controlling the motor that applies torque to the crankshaft is the speed increasing control at the start. When the engine speed is higher than the predetermined temperature and when the increase speed of the actual compression ratio is higher than a predetermined determination speed, the increase speed control at the start is performed so that the increase speed of the actual compression ratio decreases, The gist is that when the lubricating oil temperature is lower than the predetermined temperature, the starting speed increase control is not performed.

  In the present invention, when the increase speed of the actual compression ratio of the variable valve mechanism at the time of starting the engine is greater than a preset determination speed and when the lubricating oil temperature is higher than a predetermined temperature, the increase speed control at the time of starting is performed. The increase speed of the actual compression ratio at the start of the high oil temperature is smaller than that when the increase speed control at the start is not performed. As a result, a situation in which the actual compression ratio becomes excessively large at the low rotational speed at the start of the high oil temperature is less likely to occur, so that a torque shock can be prevented from occurring at the start of the engine having a high lubricating oil temperature.

  (16) The invention according to claim 16 is the start control device for an internal combustion engine according to any one of claims 5 or 11 to 15, wherein a plurality of control patterns preset as the motor control patterns are provided. The gist is to control the motor by selecting a control pattern to be used based on the engine operation state.

  The speed of increase of the actual compression ratio accompanying the camshaft torque fluctuation at the start of the high oil temperature varies depending on the engine operating state. In the above invention, since the motor control pattern is selected based on the engine operating state, it is possible to more suitably suppress the actual compression ratio from becoming excessively large at the low rotational speed at the start of the high oil temperature.

  (17) The invention according to claim 17 is the start control device for the internal combustion engine according to any one of claims 1 to 16, wherein the variable valve mechanism rotates in synchronization with a crankshaft. A rotating body, a second rotating body that rotates in synchronization with the camshaft, and a fixing mechanism that engages these rotating bodies and fixes the valve timing of the intake valve at a specific angle that is more advanced than the most retarded angle. The gist is to include.

  In an internal combustion engine including a fixing mechanism, when the valve timing is fixed at a specific angle by the fixing mechanism, the increase in the actual compression ratio due to the advance of the valve timing is not reduced. For this reason, compared with an internal combustion engine that does not include a fixing mechanism, the frequency of occurrence of torque shock due to the excessively large actual compression ratio is higher. According to the above invention, since the internal combustion engine including the fixing mechanism has the configuration of the invention according to any one of claims 1 to 16, the valve timing is fixed to a specific angle by the fixing mechanism to improve the startability. It is possible to achieve both reduction and suppression of occurrence of torque shock caused by an excessively large actual compression ratio.

1 is a cross-sectional view showing a cross-sectional structure of an internal combustion engine including a start control device according to a first embodiment of the present invention. (A) is a top view which shows the planar structure, (b) is sectional drawing which shows the cross-sectional structure which followed the DA-DA line of (a) about the valve timing variable mechanism of the embodiment. The operation | movement figure which shows operation | movement when a vane rotor rotates with respect to a housing rotor about the valve timing variable mechanism of the embodiment. The timing chart which shows the change aspect of the engine speed at the time of start-up of an internal combustion engine, and an actual compression ratio. The flowchart which shows the process sequence about the "starting time torque control process" performed by the electronic controller of the embodiment. The flowchart which shows the process sequence of the "starting torque control process" performed by the electronic controller about 2nd Embodiment of this invention.

(First embodiment)
A first embodiment of the present invention will be described with reference to FIGS. In this embodiment, an example in which the present invention is embodied as a start control device for an internal combustion engine mounted on a hybrid vehicle is shown.

  As shown in FIG. 1, the hybrid vehicle includes an internal combustion engine 1 that drives wheels by power generated by combustion of an air-fuel mixture, a battery 62 that stores electric power, and a direct current of the battery 62 that is converted into an alternating current. An inverter 63 to be supplied to various electric devices, a motor generator 61 for driving the wheels by electric power supplied from a battery 62, and a control device 100 for comprehensively controlling these devices are provided.

  The internal combustion engine 1 includes an engine main body 10 including a cylinder block 11, a cylinder head 12, and an oil pan 13, a variable valve operating device 20 including each element of a valve operating system provided on the cylinder head 12, an engine main body 10, and the like. And a lubricating device 50 for supplying lubricating oil to the oil.

  The variable valve gear 20 includes an intake valve 21 and an exhaust valve 23 that open and close the combustion chamber 14, an intake camshaft 22 and an exhaust camshaft 24 that push down these valves, and the rotation of the intake camshaft 22 relative to the rotational phase of the crankshaft 15. The valve timing variable mechanism 30 is configured to change the phase (hereinafter referred to as “intake valve timing VT”).

  The lubricating device 50 includes an oil pump 52 that discharges the lubricating oil from the oil pan 13, an oil passage 51 that supplies the lubricating oil discharged from the oil pump 52 to each part of the internal combustion engine 1, and a variable valve timing mechanism 30. An oil control valve 53 for controlling the supply mode of the lubricating oil is included.

  The control device 100 includes an electronic control device 101 that performs various arithmetic processes for controlling the internal combustion engine 1, and various sensors including a crank position sensor 102, a cam position sensor 103, and a cooling water temperature sensor 104. It is configured to include.

  The crank position sensor 102 outputs a signal corresponding to the rotation angle of the crankshaft 15 (hereinafter “crank angle CA”) to the electronic control unit 101. The cam position sensor 103 outputs a signal corresponding to the rotation angle of the intake camshaft 22 (hereinafter referred to as “intake cam angle DA”) to the electronic control unit 101. The cooling water temperature sensor 104 is provided in the vicinity of the cooling water outlet of the cylinder head 12 and outputs a signal corresponding to the cooling water temperature (hereinafter referred to as “cooling water temperature TW”) to the electronic control unit 101.

  The electronic control device 101 calculates the following parameters for use in various controls. That is, a calculation value corresponding to the crank angle CA is calculated based on the output signal from the crank position sensor 102. Further, a calculated value corresponding to the rotational speed of the crankshaft 15 (hereinafter referred to as “engine rotational speed NE”) is calculated based on the calculated value of the crank angle CA. Further, a calculation value corresponding to the intake cam angle DA is calculated based on an output signal from the cam position sensor 103. Further, an operation value corresponding to the cooling water temperature TW is calculated based on an output signal from the cooling water temperature sensor 104. Further, a calculated value corresponding to the temperature of the lubricating oil (hereinafter referred to as “lubricating oil temperature TL”) is calculated based on the calculated value of the cooling water temperature TW. Further, a calculation value corresponding to the intake valve timing VT is calculated based on the crank angle CA and the intake cam angle DA.

  The control performed by the electronic control device 101 includes vehicle start control for controlling the operation mode of the internal combustion engine 1 and the motor generator 61 when starting the vehicle, and start / stop control for controlling stop and start of the internal combustion engine 1 after the vehicle start, And valve timing control for changing the intake valve timing VT.

  In the vehicle start control, a hybrid system including the internal combustion engine 1 and the motor generator 61 is started based on an operation of switching the ignition switch of the vehicle from OFF to ON. Further, the hybrid system is stopped based on the operation of switching the ignition switch from on to off. When the hybrid system is activated, cranking by the motor generator 61 is started in order to start the warm-up operation of the internal combustion engine 1. When there is a request to stop the hybrid system, the hybrid system is stopped after completion of predetermined control performed when the internal combustion engine 1 is stopped, including valve timing control.

  In the start / stop control, cranking of the internal combustion engine 1 by the motor generator 61 is started when a condition for starting the operation of the internal combustion engine 1 is satisfied after the hybrid system is started and the internal combustion engine 1 is stopped. . In addition, when a condition for stopping the operation of the internal combustion engine 1 is established after the hybrid system is started and the internal combustion engine 1 is operating, predetermined control that is performed when the internal combustion engine 1 is stopped, including valve timing control. Is completed, the operation of the internal combustion engine 1 is stopped.

  In the valve timing control, during operation of the internal combustion engine 1, the intake valve timing VT is changed between the most advanced angle VTmax and the most retarded angle VTmin based on the engine operating state and the vehicle running state. Further, when the internal combustion engine 1 is stopped, the intake valve timing VT is changed to the most retarded angle VTmin.

  The configuration of the variable valve timing mechanism 30 will be described with reference to FIG. 2A shows a planar structure of the variable mechanism 30 with the cover 34 shown in FIG. 2B removed from the housing body 32. FIG. In the same figure, an arrow RA indicates the rotation direction of the intake camshaft 22 and the sprocket 33 (hereinafter referred to as “rotation direction RA”).

  As shown in FIG. 2A, the variable valve timing mechanism 30 is synchronized with the shaft 15 by being fixed to the housing rotor 31 that rotates in synchronization with the crankshaft 15 and the end of the intake camshaft 22. And the rotating vane rotor 35.

  The housing rotor 31 is connected to the crankshaft 15 via a timing chain (not shown), and rotates in synchronization with the shaft 15. The housing rotor 31 is assembled inside the sprocket 33 to be integrated therewith. The housing body 32 is rotated in a manner, and the cover 34 is attached to the body 32.

  A vane rotor 35 is accommodated in the housing body 32. Further, three partition walls 31A that protrude toward the vane rotor 35 in the radial direction are provided. The vane rotor 35 is provided with three vanes 36 that project toward the housing body 32 and divide the three vane storage chambers 37 between the partition walls 31A into an advance chamber 38 and a retard chamber 39, respectively.

  The advance chamber 38 is located behind the vane 36 in the rotation direction RA of the intake camshaft 22 in one vane storage chamber 37, and the variable valve timing mechanism 30 by the oil control valve 53 of the lubricating device 50. The volume changes according to the supply / discharge state of the lubricating oil. The retarding chamber 39 is located in the vane 36 in front of the vane 36 in the rotational direction RA of the intake camshaft 22, and the valve timing variable mechanism by the lubricating device 50 is the same as the advance chamber 38. The volume changes according to the lubricating oil supply / discharge state of 30.

  The variable valve timing mechanism 30 changes the intake valve timing VT by changing the relative rotation phase of the vane rotor 35 with respect to the housing rotor 31 (hereinafter referred to as “rotation phase P”) based on the above configuration. Specifically, the change of the intake valve timing VT by the variable mechanism 30 is performed as follows.

  When the vane rotor 35 rotates with respect to the housing rotor 31 in the advance side, that is, in the rotation direction RA of the intake camshaft 22 due to the supply of the lubricant oil to the advance chamber 38 and the discharge of the lubricant oil from the retard chamber 39, The valve timing VT changes to the advance side. When the vane rotor 35 rotates to the advance side with respect to the housing rotor 31, that is, when the rotation phase P of the vane rotor 35 is at the most forward phase in the rotation direction RA (hereinafter, “most advanced angle phase PMAX”). The intake valve timing VT is set to the most advanced angle VTmax. As the most advanced angle phase PMAX, a position where the vane 36 abuts against the partition wall 31A on the retard chamber 39 side or a position where the vane 36 is near the partition wall 31A on the retard chamber 39 side is set.

  By discharging the lubricating oil from the advance chamber 38 and supplying the lubricating oil to the retard chamber 39, the vane rotor 35 rotates with respect to the housing rotor 31 on the retard side, that is, on the rear side in the rotational direction RA of the intake camshaft 22. The intake valve timing VT changes to the retard side. When the vane rotor 35 rotates to the retard side with respect to the control limit with respect to the housing rotor 31, that is, the rotational phase P of the vane rotor 35 is the most rearward phase in the rotational direction RA (hereinafter referred to as "most retarded phase PMIN"). ), The intake valve timing VT is set to the most retarded angle VTmin. As the most retarded phase PMIN, a position where the vane 36 abuts against the partition wall 31A on the advance chamber 38 side or a position where the vane 36 is near the partition wall 31A on the advance chamber 38 side is set.

  The flow of the lubricating oil between each of the advance chamber 38 and the retard chamber 39 and the lubricating device 50 is blocked, that is, the lubricant oil is held in each of the advance chamber 38 and the retard chamber 39. Thus, when the relative rotation between the housing rotor 31 and the vane rotor 35 is disabled, the intake valve timing VT is maintained at that time.

  The variable valve timing mechanism 30 is provided with an intermediate lock mechanism 40 that fixes the intake valve timing VT to a specific timing (hereinafter, “intermediate angle VTmdl”) between the most advanced angle VTmax and the most retarded angle VTmin. Yes. As the intermediate angle VTmdl, an intake valve timing VT suitable for engine start is set. When the engine is started, when the intake valve timing VT is set to the intermediate angle VTmdl and when the intake valve timing VT is set to the retarded angle side, a higher startability is secured in the former. Become so.

  The intermediate lock mechanism 40 operates based on the supply of lubricating oil from the lubricating device 50 and regulates the rotation of the vane rotor 35 relative to the housing rotor 31 regardless of the hydraulic pressure in the advance chamber 38 and the retard chamber 39. When the rotational phase P is at a rotational phase corresponding to the intermediate angle VTmdl (hereinafter referred to as “intermediate angle phase PMDL”), the housing rotor 31 and the vane rotor 35 are fixed to each other, and the intake valve timing VT is set to the intermediate angle VTmdl. Hold.

  Specifically, as shown in FIG. 2B, the lock pin 42 provided on the vane 36 and moving with respect to the vane 36 and the lubricating oil 50 supplied from the lubricating device 50 are also provided on the vane 36. A lock chamber 44 to be discharged, a lock spring 43 which is also provided in the vane 36 and pushes the lock pin 42 in one direction, and a lock hole 41 provided in the housing rotor 31 are configured. The housing rotor 31 is formed with a lock groove 41 </ b> A along the track in the circumferential direction of the lock pin 42 from the lock hole 41 to a predetermined position on the retard side. The depth of the lock groove 41 </ b> A is set smaller than the depth of the lock hole 41.

  Based on the relationship between the force of the lubricating oil in the lock chamber 44 and the force of the lock spring 43, the lock pin 42 protrudes from the vane 36 (hereinafter referred to as “protrusion direction Z <b> 2”) and the direction retracted into the vane 36 (hereinafter referred to as “removal direction”) "Accommodating direction Z1"). The hydraulic pressure in the lock chamber 44 acts on the lock pin 42 in the accommodating direction Z1. The force of the lock spring 43 acts on the lock pin 42 in the protruding direction Z2.

The intermediate lock mechanism 40 operates as follows.
When the lubricating oil is discharged from the lock chamber 44 by the lubricating device 50 and the lock chamber 44 is not filled with the lubricating oil, the force in the protruding direction Z2 by the lock spring 43 exceeds the force in the accommodating direction Z1 by the lubricating oil in the lock chamber 44. become. As a result, a force in the protruding direction Z2 acts on the lock pin 42. The force in the projecting direction Z2 with respect to the lock pin 42 in a state where the rotational phase P is at the intermediate angle phase PMDL, that is, in a state where the circumferential positions of the lock pin 42 and the lock hole 41 coincide with each other. , The lock pin 42 protrudes from the vane 36 and is fitted into the lock hole 41. As a result, the housing rotor 31 and the vane rotor 35 are fixed to each other through the engagement between the lock pin 42 and the lock hole 41, so that the rotational phase P is held at the intermediate angle phase PMDL.

  On the other hand, when the lubricating oil is supplied to the lock chamber 44 by the lubricating device 50 and the lock chamber 44 is filled with the lubricating oil, the force in the accommodation direction Z <b> 1 by the lubricant in the lock chamber 44 is the protruding direction by the lock spring 43. It exceeds the power of Z2. As a result, a force in the accommodation direction Z <b> 1 is applied to the lock pin 42. When the force in the accommodation direction Z1 acts on the lock pin 42 with the lock pin 42 fitted in the lock hole 41, the lock pin 42 is detached from the lock hole 41 and accommodated in the vane 36. Is done. Thereby, the fixing of the housing rotor 31 and the vane rotor 35 is released, and relative rotation thereof is allowed.

  With reference to FIG. 3, the operation mode of the variable valve timing mechanism 30 when the engine is stopped and when the engine is started will be described. FIG. 3 shows a part of the cross-sectional structure taken along the line DA-DA in FIG.

  When an operation stop request for the internal combustion engine 1 is detected, the intake valve timing VT is changed toward the most retarded angle VTmin by the valve timing control. As shown in FIG. 3A, after the rotational phase P of the vane rotor 35 relative to the housing rotor 31 is changed to the most retarded angle phase PMIN and the intake valve timing VT is set to the most retarded angle VTmin, the internal combustion engine 1 Operation is stopped.

  As shown in FIG. 3A, the rotational phase P of the vane rotor 35 with respect to the housing rotor 31 is at the most retarded phase PMIN immediately before the start operation of the internal combustion engine 1 is started. Further, since the hydraulic pressure in the lock chamber 44 is released, the lock pin 42 is in a state of attempting to move in the protruding direction Z2 with respect to the vane 36.

  As shown in FIG. 3B, after the start operation of the internal combustion engine 1 is started, the rotational phase P of the vane rotor 35 with respect to the housing rotor 31 is changed to the advance side in accordance with the torque fluctuation of the intake camshaft 22. At this time, the lock pin 42 protrudes from the vane 36 and is abutted against the lock groove 41A.

  As shown in FIG. 3C, when the rotation phase P of the vane rotor 35 further changes from the state in which the lock pin 42 is abutted against the lock groove 41A and reaches the intermediate angle phase PMDL, The pin 42 is fitted into the lock hole 41. As a result, relative rotation between the housing rotor 31 and the vane rotor 35 is disabled, and the intake valve timing VT is fixed to the intermediate angle VTmdl.

  As described above, since the intake valve timing VT is at the most retarded angle VTmin immediately after the start operation of the internal combustion engine 1 is started, an excessive increase in the actual compression ratio E immediately after the start operation is started is suppressed. Is done. In addition, since the intake valve timing VT is fixed to the intermediate angle VTmdl after the start operation is started, good startability of the internal combustion engine 1 is ensured even in a situation where the environmental temperature is extremely low.

  Referring to FIG. 4, at the time of engine start in which the lubricating oil temperature TL is higher than the reference temperature TLX (hereinafter referred to as “high oil temperature start-up”) and at the time of engine start in which the lubricating oil temperature TL is equal to or lower than the reference temperature TLX (hereinafter referred to as Changes in the engine speed NE and the actual compression ratio E during “low oil temperature start”) will be described.

FIG. 4A shows how the engine speed NE changes when the internal combustion engine 1 is started.
When the internal combustion engine 1 is started at a high oil temperature, the engine speed NE changes as indicated by the curve NH. Further, at the start of the low oil temperature, the engine speed NE changes as indicated by the curve NL. That is, since the rotational resistance of the crankshaft 15 at the start of the high oil temperature is smaller than the rotational resistance of the crankshaft 15 at the start of the low oil temperature, the cranking torque of the motor generator 61 is high under the same conditions. The rising speed of the engine rotation speed NE at the time of starting becomes larger than the rising speed of the engine rotation speed NE at the time of starting the low oil temperature.

  4B, the internal combustion engine having the same structure as the internal combustion engine 1 except that the variable valve timing mechanism 30 and the mechanism for driving the variable valve timing mechanism 30 are not provided. The change aspect of the actual compression ratio E at the time of high oil temperature start and low oil temperature start in each virtual engine is shown. Hereinafter, the smallest one of the actual compression ratios E that enables the air-fuel mixture to be combusted by ignition of the spark plug is indicated as “combustion limit compression ratio EX”.

  When the virtual engine is started at a low oil temperature, the actual compression ratio E changes as indicated by the curve LA in the figure. That is, the actual compression ratio E gradually increases as the engine rotational speed NE rises after the engine start operation is started at time t11, and the combustion limit compression ratio E1 when the predetermined period SA has elapsed from time t11. To reach.

  When the internal combustion engine 1 is started at a low oil temperature, the actual compression ratio E changes as indicated by a curve LB in the figure. That is, the actual compression ratio E gradually increases as the engine speed NE increases after the engine start operation is started at time t11, and at time t14 when a predetermined period SB shorter than the predetermined period SA has elapsed from time t11. The combustion limit compression ratio E1 is reached. In the period from time t11 to time t14, the actual compression ratio E is greater than the actual compression ratio E at the time of starting the low oil temperature of the virtual engine by an amount corresponding to the advance amount of the intake valve timing VT by the variable valve timing mechanism 30. Also grows.

  When the virtual engine starts at a high oil temperature, the actual compression ratio E changes as indicated by the curve HA in the figure. That is, the actual compression ratio E gradually increases as the engine rotational speed NE increases after the engine starting operation is started at time t11, and the increasing speed of the engine rotational speed NE is larger than when the virtual engine is started at a low oil temperature. Thus, the combustion limit compression ratio E1 is reached at time t13 when a predetermined period SC shorter than the predetermined period SA has elapsed from time t11.

  When the internal combustion engine 1 is started at a high oil temperature, the actual compression ratio E changes as indicated by a curve HB in the figure. That is, the actual compression ratio E gradually increases as the engine rotational speed NE rises after the engine starting operation is started at time t11, and the increasing speed of the engine rotational speed NE is greater than when the internal combustion engine 1 is started at a low oil temperature. By being large, the combustion limit compression ratio E1 is reached at time t12 when a predetermined period SD shorter than the predetermined period SB has elapsed from time t11. In the period from time t11 to time t12, the actual compression ratio E is greater than the actual compression ratio E at the time of starting the low oil temperature of the virtual engine by an amount corresponding to the advance amount of the intake valve timing VT by the variable valve timing mechanism 30. Also grows.

  As described above, when the internal combustion engine 1 is started at a high oil temperature, the increase speed of the actual compression ratio E is increased due to the increasing speed of the engine speed NE higher than when the internal combustion engine 1 is started at a low oil temperature. Further, when the internal combustion engine 1 is started at a high oil temperature, the rate of increase of the actual compression ratio E is increased due to the larger advance amount of the intake valve timing VT than when the virtual engine is started at a high oil temperature.

  On the other hand, when the internal combustion engine 1 is started, when the actual compression ratio E is excessively large at the low rotational speed, that is, when the actual compression ratio E exceeds the combustion limit compression ratio E1 when the engine rotational speed NE is less than the reference rotational speed NEX. The torque shock associated with combustion is likely to occur due to the large actual compression ratio E.

  For this reason, at the time of high oil temperature start of the internal combustion engine 1 at which the increase rate of the actual compression ratio E is large, compared to at the time of low oil temperature start of the internal combustion engine 1, high oil temperature start of the virtual engine, and low oil temperature start of the virtual engine. Thus, a torque shock due to an excessively large actual compression ratio E is likely to occur.

  Therefore, the electronic control unit 101 performs the starting advance speed control for reducing the advance speed of the variable valve timing mechanism 30 and reducing the increase speed of the actual compression ratio E when the internal combustion engine 1 is started at a high oil temperature. The generation of torque shock at the start of high oil temperature is suppressed. In the starting advance angular velocity control, the cranking torque of the motor generator 61 is controlled so that the fluctuation range of the torque of the intake camshaft 22 is smaller than when the control is not executed. By performing the torque control of the motor generator 61, the torque fluctuation range of the intake camshaft 22 is smaller when the internal combustion engine 1 is started at a high oil temperature than when the torque control is not performed.

  Since the advance speed of the intake valve timing VT at the time of engine startup basically changes due to the influence of the torque fluctuation range of the intake camshaft 22, the intake valve timing is reduced by reducing the torque fluctuation range as described above. The advance speed of the VT is also reduced.

  As a result, of the actual compression ratio E that increases with the increase in the engine speed NE and the advance angle of the intake valve timing VT when the internal combustion engine 1 is started at a high oil temperature, an increase with the advance angle of the intake valve timing VT is obtained. Therefore, the occurrence of torque shock is suppressed as compared with the high oil temperature start time in which the advance angle speed control is not performed. The advance speed indicates the relative rotational phase change speed in the advance direction of the housing rotor 31 and the vane rotor 35, that is, the advance amount of the intake valve timing VT per unit time.

  With reference to FIG. 5, the content of the “starting torque control process” that defines a specific processing procedure of the starting angular velocity control will be described. This process is repeatedly performed at predetermined calculation intervals by the electronic control device 101 while the hybrid system is activated.

The electronic control apparatus 101 performs the following processes as “starting torque control process”.
When it is determined in step S11 that the ignition switch is not switched from OFF to ON, the determination in step S11 is performed again after a predetermined calculation period has elapsed.

  When it is determined in step S11 that the ignition switch has been switched from OFF to ON, the calculated value of the coolant temperature TW is acquired in the next step S12.

  In step S13, the period from the last stop of the operation of the internal combustion engine 1 to the start of the current hybrid system (hereinafter referred to as “intermittent period SX”), and the calculation of the coolant temperature TW acquired in step S12. Based on the value, a calculated value of the lubricating oil temperature TL is calculated. That is, the lubricating oil temperature TL when the start operation of the internal combustion engine 1 is started is estimated based on the intermittent period SX and the coolant temperature TW.

  In step S14, the torque control pattern of the motor generator 61 is selected based on the calculated value of the lubricating oil temperature TL. The torque control pattern includes a high oil temperature pattern corresponding to when the lubricating oil temperature TL is higher than the reference temperature TLX (during high oil temperature start), and a lubricating oil temperature TL equal to or lower than the reference temperature TLX (low oil temperature). A low oil temperature pattern corresponding to (at start-up) is set in advance. The high oil temperature pattern further includes a plurality of control patterns according to the lubricating oil temperature TL and the engine operating state.

  In the low oil temperature pattern, the cranking torque of the motor generator 61 is kept constant and the internal combustion engine 1 is cranked. In the high oil temperature pattern, the cranking torque of the motor generator 61 is set to be different from the low oil temperature pattern so that the fluctuation range of the torque of the intake camshaft 22 is smaller than the predetermined fluctuation range. Cranking 1 is performed. Here, the predetermined fluctuation range indicates a fluctuation range in a range where the advance angle speed of the intake valve timing VT does not reach a magnitude causing a torque shock.

  The magnitude of the cranking torque required to make the torque fluctuation range smaller than the predetermined fluctuation range varies depending on the lubricating oil temperature TL and the like. For this reason, the cranking torque set by each of the plurality of high oil temperature patterns includes both larger and smaller cranking torques than the low oil temperature pattern.

  In the “starting torque control process”, the magnitude of the cranking torque necessary to make the torque fluctuation range smaller than the predetermined fluctuation range is grasped in advance by performing a test or the like, and a plurality of the torque fluctuation ranges are based on this. High oil temperature pattern is set.

As described above in detail, according to the present embodiment, the following effects can be obtained.
(1) In this embodiment, since the starting advance speed control is performed at the start of the high oil temperature, the increase speed of the actual compression ratio E accompanying the increase in the engine speed NE at the start of the high oil temperature is the start advance speed control. It is smaller than the case where is not performed. As a result, a situation in which the actual compression ratio E becomes excessively large at a low rotational speed at the start of a high oil temperature is less likely to occur, so that a torque shock can be prevented from occurring at the start of a high oil temperature.

  (2) In this embodiment, the advance speed of the variable valve timing mechanism 30 is adjusted by adjusting the fluctuation range of the torque of the intake camshaft 22. Thereby, it can suppress more appropriately that the actual compression ratio E becomes large too much at the time of the low rotation speed at the time of high oil temperature start-up.

  (3) In the starting advance angular velocity control of this embodiment, the fluctuation range of the torque of the intake camshaft 22 is adjusted by controlling the motor generator 61 that applies torque to the crankshaft 15. Thereby, it can suppress more appropriately that the actual compression ratio E becomes large too much at the time of the low rotation speed at the time of high oil temperature start.

  (4) In this embodiment, the control pattern of the motor generator 61 is selected from a plurality of preset control patterns based on the engine operating state. Thereby, it can suppress more appropriately that the actual compression ratio E becomes large too much at the time of the low rotation speed at the time of high oil temperature start-up.

  (5) In the internal combustion engine 1 including the intermediate lock mechanism 40, when the intake valve timing VT is fixed to the intermediate angle VTmdl by the intermediate lock mechanism 40, the actual compression ratio E increases with the advance angle of the intake valve timing VT. Minutes never decrease. For this reason, compared with an internal combustion engine that does not include the intermediate lock mechanism 40, the frequency of occurrence of torque shock due to the excessively large actual compression ratio E becomes higher.

  In the present embodiment, in order to perform the starting advance angular velocity control in such an internal combustion engine 1, the intermediate lock mechanism 40 fixes the intake valve timing VT to the intermediate angle VTmdl to improve the startability, and the actual compression ratio. It is possible to achieve both suppression of the occurrence of torque shock caused by E being excessively large.

  (6) The cranking torque of the motor generator 61 is larger than the cranking torque of a general starter motor. For this reason, the rising speed of the engine rotational speed NE at the start of the internal combustion engine 1 is higher than the increasing speed of the engine rotational speed NE at the start of the internal combustion engine including the starter motor. That is, the internal combustion engine 1 of the hybrid vehicle tends to have a larger actual compression ratio E when the engine starts at a low speed. In the present embodiment, since the starting angular velocity control is performed, it is possible to suppress the occurrence of a torque shock when the hybrid vehicle engine is started.

  (7) In the present embodiment, the starting advance speed control is performed only when the lubricant temperature TL is higher than the reference temperature TLX. As a result, the advance speed is not reduced by the same control at the time of engine start when the engine temperature is in an extremely cold environment where the lubricating oil temperature TL is extremely low. A decrease in startability can be suppressed.

(Second Embodiment)
A second embodiment of the present invention will be described with reference to FIG.
The internal combustion engine 1 of the present embodiment is configured by changing a part of the content of the start control of the first embodiment. The details of this changed part are shown below. In addition, since the structure similar to 1st Embodiment is employ | adopted about the other point, about the common structure, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  In the first embodiment, in order to suppress the torque shock at the time of starting the high oil temperature, the advance speed at the time of starting which reduces the increase speed of the actual compression ratio E at the time of starting the high oil temperature by reducing the advance speed of the variable valve timing mechanism 30. Angular velocity control is performed.

  On the other hand, in the present embodiment, as a control for suppressing the torque shock at the start of the high oil temperature, the increase speed of the engine speed NE at the start of the high oil temperature is changed to the increase of the engine speed NE at the start of the low oil temperature. The rotational speed control at the time of starting is performed to reduce the speed of increase of the actual compression ratio E at the time of starting the high oil temperature by making it smaller than the speed.

Details of the rotational speed control at the start will be described.
The electronic control device 101 performs the following processes as “starting torque control processing” that defines a specific processing procedure for starting rotational speed control. The “starting torque control process” corresponds to the “starting torque control process” of the first embodiment, in which the contents after step S14 are changed to the following steps S24 to S26. As processes other than these steps S24 to S26, the same processes as those in the “starting torque control process” of the first embodiment are performed.

  When it is determined in step S24 that the lubricating oil temperature TL is higher than the reference temperature TLX, the cranking torque of the motor generator 61 is set to a torque larger than the cranking torque at the time of starting the low oil temperature in the next step S25. That is, the cranking by the motor generator 61 is performed in a state where the command value of the cranking torque at the start of the high oil temperature is set larger than the command value of the cranking torque at the start of the low oil temperature.

  When it is determined in step S24 that the lubricating oil temperature TL is lower than the reference temperature TLX, the cranking torque of the motor generator 61 is set to the cranking torque at the time of starting the low oil temperature in the next step S26. That is, the cranking by the motor generator 61 is performed in a state where the command value of the cranking torque at the start of the low oil temperature is set to be smaller than the command value of the cranking torque at the start of the high oil temperature.

  According to this embodiment, the effect of (1) of the first embodiment, that is, the effect that it is possible to suppress the occurrence of a torque shock at the start of high oil temperature, and (2), ( The effects of 3) and (5) to (7) can be achieved.

(Other embodiments)
In addition, the embodiment of the present invention is not limited to the above-described embodiments, and can be carried out, for example, in the following manner. The following modifications are not applied only to the above embodiments, and different modifications can be combined with each other.

The content of the starting advance angular velocity control of the first embodiment can be changed to any of the following (A1) to (A3).
(A1) Torque control of the motor generator 61 is performed so that the advance speed of the variable valve timing mechanism 30 at the start of the high oil temperature is smaller than the advance speed of the variable valve timing mechanism 30 at the start of the low oil temperature.
(A2) At the time of starting the high oil temperature, torque control of the motor generator 61 is performed so that the advance speed of the variable valve timing mechanism 30 does not exceed a preset determination speed. On the other hand, the starting advance speed control is not performed at the time of starting the low oil temperature.
(A3) Torque control of the motor generator 61 is performed so that the advance speed of the variable valve timing mechanism 30 is reduced when the high oil temperature is started and the advance speed of the variable valve timing mechanism 30 is higher than a preset determination speed. . On the other hand, the starting advance speed control is not performed at the time of starting the low oil temperature.

In place of the starting advance angle speed control of the first embodiment, for example, the following starting speed increasing control (B1) to (B4) can be performed. In this control, torque control of motor generator 61 is performed based on the measured value or estimated value of actual compression ratio E.
(B1) The increasing speed of the actual compression ratio E when the starting increase speed control is performed is the increasing speed A, and the increasing speed of the actual compression ratio E when the starting increasing speed control is not performed is the increasing speed B. As described above, torque control of the motor generator 61 is performed so that the increase speed A is smaller than the increase speed B at the start of the high oil temperature.
(B2) Torque control of the motor generator 61 is performed so that the increase speed of the actual compression ratio E at the start of the high oil temperature is smaller than the increase speed of the actual compression ratio E at the start of the low oil temperature.
(B3) At the time of starting the high oil temperature, torque control of the motor generator 61 is performed so that the increasing speed of the actual compression ratio E does not exceed a preset determination speed. On the other hand, the starting speed increase control is not performed at the time of starting the low oil temperature.
(B4) Torque control of the motor generator 61 is performed so that the increase speed of the actual compression ratio E is reduced at the start of the high oil temperature and when the increase speed of the actual compression ratio E is higher than a preset determination speed. On the other hand, the starting speed increase control is not performed at the time of starting the low oil temperature.

  In the first embodiment, one torque control pattern is selected from a plurality of preset high oil temperature patterns at the time of high oil temperature start, but one torque control pattern at the time of high oil temperature start is combined. You can also

  In the first embodiment, the contents of the plurality of high oil temperature patterns are set so that the torque fluctuation width of the intake camshaft 22 at the start of the high oil temperature is smaller than the predetermined fluctuation width. The contents of the high oil temperature pattern can be changed as follows. That is, the contents of the plurality of high oil temperature patterns are set so that the torque fluctuation width of the intake camshaft 22 at the start of the high oil temperature is smaller than the torque fluctuation width of the intake camshaft 22 at the low oil temperature start. You can also.

  In the first embodiment, when it is determined that the high oil temperature is started based on the lubricating oil temperature TL, the high oil temperature pattern is selected as the torque control pattern of the motor generator 61 and the variable valve timing mechanism 30 Although the advance speed is lowered, it can be changed as follows. That is, the determination of whether the high oil temperature is started or the low oil temperature is started together with the determination of whether or not the cooling water temperature sensor 104 is abnormal. When it is determined that there is an abnormality in the cooling water temperature sensor 104, it is prohibited to select the high oil temperature pattern as the torque control pattern of the motor generator 61. Then, the low oil temperature pattern is selected as the torque control pattern, and cranking by the motor generator 61 is performed.

  According to the starting advance angle speed control exemplified here, the torque control for reducing the advance angle speed of the variable valve timing mechanism 30 at the start of the high oil temperature is performed, and the advancement of the variable valve timing mechanism 30 at the start of the high oil temperature. The case where the torque control for reducing the angular velocity is not performed is included. When the torque control is performed, the advance speed is smaller than the advance speed when the torque control is not performed. Therefore, the increase speed of the actual compression ratio E is also not controlled when the torque control is performed. Smaller than.

-The content of the rotational speed control at the time of start of the said 2nd Embodiment can also be changed into either of the following (C1)-(C3).
(C1) The rising speed of the engine rotational speed NE when the starting rotational speed control is performed is the rising speed A, and the rising speed of the engine rotational speed NE when the starting rotational speed control is not performed is the rising speed B. As described above, torque control of the motor generator 61 is performed so that the rising speed A is smaller than the rising speed B at the start of the high oil temperature.
(C2) At the start of the high oil temperature, torque control of the motor generator 61 is performed so that the rising speed of the engine rotation speed NE does not exceed a preset determination speed. On the other hand, the starting rotational speed control is not performed at the time of starting the low oil temperature.
(C3) Torque control of the motor generator 61 is performed so that the rising speed of the engine rotation speed NE decreases when the high oil temperature is started and when the rising speed of the engine rotation speed NE is higher than a predetermined determination speed. On the other hand, the starting rotational speed control is not performed at the time of starting the low oil temperature.

  In the second embodiment, when it is determined that the high oil temperature start is based on the lubricating oil temperature TL, the cranking torque of the motor generator 61 is set to a torque larger than the cranking torque at the low oil temperature start. Thus, the increase speed of the engine rotational speed NE is reduced, but this can be changed as follows. That is, the determination as to whether the high oil temperature is started or the low oil temperature is started and the determination as to whether or not an abnormality has occurred in the cooling water temperature sensor 104 are performed. When it is determined that the high oil temperature is starting and it is determined that the cooling water temperature sensor 104 is abnormal, the cranking torque of the motor generator 61 is set to be larger than the cranking torque when starting the low oil temperature. Is prohibited. Then, a low oil temperature torque is set as the cranking torque, and the cranking by the motor generator 61 is performed.

  According to the starting rotational speed control exemplified here, the torque control for reducing the increasing speed of the engine rotational speed NE at the time of starting the high oil temperature and the increasing speed of the engine rotational speed NE at the time of starting the high oil temperature are performed. The case where the torque control for reducing is not performed is included. Since the increase speed of the engine rotation speed NE when torque control is performed is smaller than the increase speed of the engine rotation speed NE when torque control is not performed, this increases the increase speed of the actual compression ratio E. The case where the torque control is performed is smaller than the case where the torque control is not performed.

In each of the above embodiments, the lubricating oil temperature TL is estimated based on the cooling water temperature TW and the intermittent period SX, but the lubricating oil temperature TL can also be measured by a sensor.
In each of the above embodiments, the lubricating oil temperature TL is estimated based on the cooling water temperature TW and the intermittent period SX, but the parameters used for estimating the lubricating oil temperature TL are not limited thereto. For example, instead of or in addition to the cooling water temperature TW and the intermittent period SX, an integrated value of the fuel injection amount from the start of the previous start operation of the internal combustion engine 1 until the operation is stopped is adopted. You can also. Further, instead of or in addition to the cooling water temperature TW and the intermittent period SX, an integrated value of the intake air amount from the start of the previous start operation of the internal combustion engine 1 until the operation is stopped is adopted. You can also.

  In each of the above embodiments, it is determined whether or not the high oil temperature is started based on the estimated value of the lubricating oil temperature TL. However, instead of the estimated value of the lubricating oil temperature TL, the lubricating oil temperature TL An index temperature can also be employed. As the temperature serving as the index, a temperature of a substance having a high correlation with the lubricating oil temperature TL can be employed. Specifically, at least one of the coolant temperature TW and the temperature of the engine body 10 can be employed.

  In the “starting torque control process” of each of the above embodiments, the torque control of the motor generator 61 is performed on the condition that the ignition switch is switched from OFF to ON. The conditions are not limited to the conditions exemplified in each embodiment. For example, separately from the above conditions, the torque control of the motor generator 61 is performed based on the fact that the condition for starting the operation of the internal combustion engine 1 is established after the hybrid system is started and the internal combustion engine 1 is stopped. It can also be done. According to this configuration, it is possible to suppress the occurrence of a torque shock not only when the internal combustion engine 1 is started based on the operation of the ignition switch but also when the internal combustion engine 1 is started at a high oil temperature by the start / stop control.

  In each of the above embodiments, the present invention is applied to the internal combustion engine 1 that includes the variable valve timing mechanism 30 including the intermediate lock mechanism 40. However, the variable valve timing mechanism 30 that does not include the intermediate lock mechanism 40 is used. The present invention can also be applied to the internal combustion engine 1 provided. That is, the present invention can be applied to any internal combustion engine provided with a hydraulic valve timing variable mechanism.

  In each of the above embodiments, the present invention is applied to a hybrid vehicle in which the battery 62 and the internal combustion engine 1 are mounted as driving power sources. However, the present invention is also applied to a vehicle in which only the internal combustion engine is mounted as a driving power source. Can do.

  DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 10 ... Engine main body, 11 ... Cylinder block, 12 ... Cylinder head, 13 ... Oil pan, 14 ... Combustion chamber, 15 ... Crankshaft, 20 ... Variable valve apparatus, 21 ... Intake valve, 22 ... Intake Camshaft, 23 ... exhaust valve, 24 ... exhaust camshaft, 30 ... variable valve timing mechanism (variable valve mechanism), 31 ... housing rotor (first rotating body), 31A ... partition wall, 32 ... housing body, 33 ... Sprocket, 34 ... cover, 35 ... vane rotor (second rotating body), 36 ... vane, 37 ... vane storage chamber, 38 ... advance chamber, 39 ... retard chamber, 40 ... intermediate lock mechanism (fixing mechanism), 41 ... Lock hole, 41A ... Lock groove, 42 ... Lock pin, 43 ... Lock spring, 44 ... Lock chamber, 50 ... Lubrication device, 51 ... Oil passage, 52 ... Oil pump, 53 ... O Control valve, 61 ... motor generator, 62 ... battery, 63 ... inverter, 100 ... control device (starting control device), 101 ... electronic control device, 102 ... crank position sensor, 103 ... cam position sensor, 104 ... cooling water temperature Sensor.

Claims (17)

In an internal combustion engine start control device that controls a start mode of an internal combustion engine including a hydraulic variable valve mechanism that changes a valve timing of an intake valve,
The temperature of the lubricating oil of the internal combustion engine or a temperature indicative thereof is defined as the lubricating oil temperature, the increasing speed of the engine rotation speed when the engine is started and when the lubricating oil temperature is higher than a predetermined temperature is defined as the increasing speed A, and Ascending speed B, the rising speed of the engine rotation speed when the lubricating oil temperature is lower than the predetermined temperature,
An internal-combustion-engine start control device that performs start-up rotational speed control that makes the ascent speed A smaller than the ascent speed B. In an internal combustion engine start control device that controls a start mode of an internal combustion engine including a hydraulic variable valve mechanism that changes a valve timing of an intake valve,
The temperature of the lubricating oil of the internal combustion engine or its index temperature is set as the lubricating oil temperature, and the control for adjusting the increase speed of the engine speed at the start of the engine is the start speed control, and the start speed control is performed. Ascending speed A is the rising speed of the engine speed when the engine speed is increased, and ascending speed B is the increasing speed of the engine speed when the starting speed control is not performed.
An internal combustion engine start control apparatus characterized in that the start speed control is performed so that the ascent speed A is smaller than the ascent speed B when the engine is started and the lubricating oil temperature is higher than a predetermined temperature. In an internal combustion engine start control device that controls a start mode of an internal combustion engine including a hydraulic variable valve mechanism that changes a valve timing of an intake valve,
Lubricating oil temperature or its index temperature as lubricating oil temperature,
When starting the engine and when the lubricating oil temperature is higher than a predetermined temperature, start speed control is performed to adjust the increase speed of the engine rotation speed so that the increase speed of the engine rotation speed does not exceed a preset determination speed,
The start control device for an internal combustion engine, wherein the engine speed control is not performed when the engine is started and the lubricating oil temperature is lower than the predetermined temperature. In an internal combustion engine start control device that controls a start mode of an internal combustion engine including a hydraulic variable valve mechanism that changes a valve timing of an intake valve,
Lubricating oil temperature or its index temperature as lubricating oil temperature,
When the engine is started and the lubricating oil temperature is higher than a predetermined temperature, and when the increase speed of the engine rotation speed is larger than a preset determination speed, the engine rotation speed control is performed to reduce the increase speed of the engine rotation speed. ,
The start control device for an internal combustion engine, wherein the engine speed control is not performed when the engine is started and the lubricating oil temperature is lower than the predetermined temperature. The start control device for an internal combustion engine according to any one of claims 1 to 4,
In the starting rotational speed control, the engine speed increasing speed is adjusted by controlling a motor that applies torque to the crankshaft. In an internal combustion engine start control device that controls a start mode of an internal combustion engine including a hydraulic variable valve mechanism that changes a valve timing of an intake valve,
The temperature of the lubricating oil of the internal combustion engine or a temperature as an index thereof is defined as the lubricating oil temperature, and the advance speed of the variable valve mechanism when the engine is started and the lubricating oil temperature is higher than a predetermined temperature is defined as the advanced speed A, and the engine is started. And an advance speed B of the variable valve mechanism when the lubricating oil temperature is lower than the predetermined temperature,
A start control device for an internal combustion engine characterized by performing start time advance speed control for making the advance speed A smaller than the advance speed B. In an internal combustion engine start control device that controls a start mode of an internal combustion engine including a hydraulic variable valve mechanism that changes a valve timing of an intake valve,
The temperature of the lubricating oil of the internal combustion engine or its index temperature is the lubricating oil temperature, and the control for adjusting the advance speed of the variable valve mechanism at the start of the engine is the start advance speed control. The advance speed of the variable valve mechanism when it is performed is the advance speed A, and the advance speed of the variable valve mechanism when the start speed control is not performed is the advance speed B.
An internal combustion engine start control apparatus, wherein the start advance speed control is performed so that the advance speed A is smaller than the advance speed B when the engine is started and the lubricating oil temperature is higher than a predetermined temperature. In an internal combustion engine start control device that controls a start mode of an internal combustion engine including a hydraulic variable valve mechanism that changes a valve timing of an intake valve,
Lubricating oil temperature or its index temperature as lubricating oil temperature,
When starting the engine and when the lubricating oil temperature is higher than a predetermined temperature, the advance angle speed at start time is adjusted so that the advance angle speed of the variable valve mechanism does not exceed a preset determination speed Control
The start control device for an internal combustion engine, wherein the starting advance angular velocity control is not performed when the engine is started and the lubricating oil temperature is lower than the predetermined temperature. In an internal combustion engine start control device that controls a start mode of an internal combustion engine including a hydraulic variable valve mechanism that changes a valve timing of an intake valve,
Lubricating oil temperature or its index temperature as lubricating oil temperature,
When starting the engine and when the lubricating oil temperature is higher than a predetermined temperature, and when the advance speed of the variable valve mechanism is higher than a preset determination speed, the advance at start-up is performed to reduce the advance speed of the variable valve mechanism. Perform angular velocity control,
The start control device for an internal combustion engine, wherein the starting advance angular velocity control is not performed when the engine is started and the lubricating oil temperature is lower than the predetermined temperature. The internal combustion engine start control device according to any one of claims 6 to 9,
In the starting advance speed control, an advance speed of the variable valve mechanism is adjusted by adjusting a fluctuation range of a torque of a camshaft. The start control device for an internal combustion engine according to claim 10,
In the starting advance speed control, the fluctuation range of the camshaft torque is adjusted by controlling a motor that applies torque to the crankshaft. In an internal combustion engine start control device for controlling a start mode of an internal combustion engine including a hydraulic variable valve mechanism that changes a valve timing of an intake valve,
Lubricating oil temperature or its index temperature is the lubricating oil temperature, the actual compression ratio increase rate when the engine is started and when the lubricating oil temperature is higher than the predetermined temperature is the increasing speed A, and the lubricating oil temperature when the engine is started. Is an increase rate B of the actual compression ratio when the temperature is lower than the predetermined temperature,
An internal combustion engine start control device, characterized in that start speed increase control is performed to make the increase speed A smaller than the increase speed B by controlling a motor that applies torque to a crankshaft. In an internal combustion engine start control device that controls a start mode of an internal combustion engine including a hydraulic variable valve mechanism that changes a valve timing of an intake valve,
Lubricating oil temperature or its index temperature is the lubricating oil temperature, and the control that adjusts the increase speed of the actual compression ratio by controlling the motor that gives torque to the crankshaft is the increasing speed control at the start, and the increasing speed at the start The increase speed of the actual compression ratio when the control is performed is the increase speed A, and the increase speed of the actual compression ratio when the increase speed control at the start is not performed is the increase speed B.
The start control device for an internal combustion engine, wherein the start speed increase control is performed so that the increase speed A is smaller than the increase speed B when the engine is started and the lubricating oil temperature is higher than the predetermined temperature. . In an internal combustion engine start control device that controls a start mode of an internal combustion engine including a hydraulic variable valve mechanism that changes a valve timing of an intake valve,
Lubricating oil temperature or its index temperature is the lubricating oil temperature, and the control that adjusts the speed of increase in the actual compression ratio by controlling the motor that applies torque to the crankshaft is referred to as starting speed increasing control.
When the engine is started and the lubricating oil temperature is higher than a predetermined temperature, the increase speed control at the start is performed so that the increase speed of the actual compression ratio does not exceed a preset determination speed,
The start control device for an internal combustion engine, wherein the start speed increasing speed control is not performed when the engine is started and the lubricating oil temperature is lower than the predetermined temperature. In an internal combustion engine start control device that controls a start mode of an internal combustion engine including a hydraulic variable valve mechanism that changes a valve timing of an intake valve,
Lubricating oil temperature or its index temperature is the lubricating oil temperature, and the control that adjusts the speed of increase in the actual compression ratio by controlling the motor that applies torque to the crankshaft is referred to as starting speed increasing control.
When the engine is started and when the lubricating oil temperature is higher than a predetermined temperature, and when the increase speed of the actual compression ratio is larger than a predetermined determination speed, the increase speed at the start is reduced so that the increase speed of the actual compression ratio decreases. Control
The start control device for an internal combustion engine, wherein the start speed increasing speed control is not performed when the engine is started and the lubricating oil temperature is lower than the predetermined temperature. The internal combustion engine start control device according to any one of claims 5 and 11 to 15,
An internal combustion engine start control apparatus, wherein a control pattern to be used is selected from a plurality of control patterns set in advance as a control pattern of the motor based on an engine operating state to control the motor. The start control device for an internal combustion engine according to any one of claims 1 to 16,
The variable valve mechanism includes a first rotating body that rotates in synchronization with the crankshaft, a second rotating body that rotates in synchronization with the camshaft, and the rotating bodies that engage with each other to adjust the valve timing of the intake valve. An internal combustion engine start control device, comprising: a fixing mechanism that fixes at a specific angle that is more advanced than the most retarded angle.

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