JP2012041877A - Variable valve device for internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a variable valve device for an internal combustion engine that can shorten the period for filling up at least either an advance chamber or a retard chamber with working oil.SOLUTION: The variable valve device for an internal combustion engine includes: a hydraulic valve timing variable mechanism having a function to change valve timing VT and a function to fix the valve timing VT at an intermediate angle VTmdl; and an oil pump driven by a crankshaft and supplying working oil to the advance chamber and the retard chamber. Then, the variable valve device is configured to adjust and increase the idling speed NI based on the fact that the period TC after the start of an engine is shorter than the adjusting and increasing period, and to perform a working oil filling control to complete the adjusting and increasing based on the fact that the period TC after the start of the engine is longer than the adjusting and increasing period TX.

Description

  The present invention provides a hydraulic variable valve mechanism having a function of changing a valve timing by a change in volume of an advance chamber and a retard chamber and a function of fixing a valve timing to a specific angle by a fixing mechanism, and a crankshaft. The present invention relates to a variable valve operating apparatus for an internal combustion engine including a pump that is driven to supply hydraulic oil to an advance chamber and a retard chamber.

  As a variable valve operating apparatus for the internal combustion engine, one described in Patent Document 1 is known. The variable valve mechanism of the variable valve apparatus is provided with a fixing mechanism for fixing the valve timing at a specific angle.

  The valve timing is fixed at a specific angle by maintaining the operation state of the fixing mechanism in the fixed operation state from when the engine start is started until the hydraulic oil is filled in the advance chamber. Further, when the advance chamber is filled with hydraulic oil, the operation state of the fixing mechanism is changed to the release operation state, so that the valve timing is fixed to a specific angle.

JP-A-9-324613

By the way, when the fixing mechanism is changed from the fixed operation state to the release operation state at an early time after the engine is started, the valve timing can be changed early.
However, according to the variable valve device, since the fixed operation state is maintained until the advance oil is filled in the advance chamber, it is difficult to change the valve timing early after the engine is started.

  Therefore, a structure that can change the fixing mechanism to the release operation state before the advance chamber is filled with hydraulic oil is adopted, and the fixing mechanism is fixed before the advance chamber is filled with hydraulic oil. It is conceivable to change the valve timing from the state to the release operation state. However, when the advance chamber is not filled with hydraulic oil, the valve timing cannot be appropriately changed or maintained.

  Therefore, in order to change the valve timing appropriately and early after the start of the engine start, it is required to fill the advance chamber with the hydraulic oil early. Here, an example is given in which the fixing mechanism is changed to the release operation state when the advance chamber is filled with hydraulic oil. However, for any variable valve operating apparatus that includes the fixing mechanism, The same can be said for the above.

  The present invention has been made in view of such a situation, and an object of the present invention is to shorten a period until hydraulic oil is filled in at least one of the advance chamber and the retard chamber after the start of the engine. Another object of the present invention is to provide a variable valve operating apparatus for an internal combustion engine.

In the following, means for achieving the above object and its effects are described.
(1) The invention according to claim 1 is a hydraulic type having a function of changing the valve timing by changing the volume of the advance chamber and the retard chamber and a function of fixing the valve timing to a specific angle by a fixing mechanism. In a variable valve operating apparatus for an internal combustion engine including a variable valve mechanism and a pump that is driven by a crankshaft and supplies hydraulic oil to the advance chamber and the retard chamber, an elapsed period after the start of engine start is a predetermined period The gist of the present invention is to perform the hydraulic oil filling control so that the idle rotation speed when the time is smaller than the idle rotation speed when the elapsed period is larger than the predetermined period.

  In the present invention, since the idle rotation speed is increased as described above, the discharge amount of the pump increases when the elapsed period after the start of engine start is smaller than the predetermined period. As a result, the amount of hydraulic oil supplied to at least one of the advance chamber and the retard chamber increases, so that the period until the hydraulic oil is filled into at least one of the advance chamber and the retard chamber after the start of the engine is started. Can be shortened.

  (2) The invention according to claim 2 is the variable valve operating apparatus for the internal combustion engine according to claim 1, wherein, in the hydraulic oil filling control, the elapsed period is smaller than the control period as the predetermined period. The gist is to perform control to increase the idle rotation speed, and to end the control to increase the idle rotation speed when the elapsed period is longer than the control period.

  In the present invention, since the idle rotation speed is increased as described above, the pump discharge amount when the elapsed period is smaller than the control period is increased. As a result, the amount of hydraulic oil supplied to at least one of the advance chamber and the retard chamber increases, so that the period until the hydraulic oil is filled into at least one of the advance chamber and the retard chamber after the start of the engine is started. Can be shortened.

(3) The third aspect of the invention is characterized in that, in the variable valve operating apparatus for an internal combustion engine according to the first or second aspect, the control period is set based on the temperature of the hydraulic oil.
The filling speed of the hydraulic oil into the advance chamber and the retard chamber changes according to the temperature of the hydraulic oil having a correlation with the viscosity of the hydraulic oil. According to this invention, since the control period is set based on the temperature of the hydraulic oil, it is possible to set an appropriate control period according to the viscosity of the hydraulic oil.

  (4) The invention according to claim 4 is the variable valve operating apparatus for the internal combustion engine according to any one of claims 1 to 4, wherein the engine cooling water temperature, the intake air temperature, and the current engine from the previous engine stop. The gist is to estimate the temperature of the hydraulic oil based on at least one of the elapsed time until the start and the outside air temperature.

  In this invention, the temperature of the hydraulic oil is detected because the temperature of the hydraulic oil is estimated based on at least one of the engine cooling water temperature and the intake air temperature, the elapsed time from the previous engine stop to the current engine start and the outside air temperature. There is no need to provide an oil temperature sensor.

  (5) The invention according to claim 5 is the variable valve operating apparatus for an internal combustion engine according to any one of claims 1 to 4, wherein the variable valve operating apparatus includes the advance chamber and the retard chamber. And a hydraulic control valve having a plurality of operation modes for controlling a supply mode of hydraulic fluid of the fixing mechanism, and the fixing mechanism sets the valve timing to the specific angle according to the operation mode of the hydraulic control valve. Is changed to a fixed operation state that is an operation state to be fixed to, or a release operation state that is an operation state to release the valve timing from being fixed to the specific angle, and the hydraulic control valve is configured as the plurality of operation modes, A first mode in which the operating state of the fixing mechanism is maintained in the fixed operating state and hydraulic oil is supplied to at least one of the advance chamber and the retard chamber; and the operating state of the fixing mechanism is set to the fixed operation state. And a second mode in which a smaller amount of hydraulic oil than in the first mode is supplied to at least one of the advance chamber and the retard chamber, and when the hydraulic oil filling control is performed, The gist is that the mode is set.

  In the present invention, when the hydraulic oil filling control is performed, the operation mode of the hydraulic control valve is set to the first mode in which the amount of hydraulic oil supplied to at least one of the advance chamber and the retard chamber is larger than the second mode. Therefore, the hydraulic oil filling period can be further shortened. The fixing operation state of the fixing mechanism includes a state where the valve timing is fixed and a state where the valve timing is about to be fixed.

  (6) The invention according to claim 6 is the variable valve operating apparatus for an internal combustion engine according to any one of claims 1 to 5, wherein the intermediate angle between the most advanced angle and the most retarded angle is the specified value. The gist is that it is set as a corner.

  According to the present invention, in an internal combustion engine having a variable valve mechanism that fixes a valve timing to an intermediate angle between the most advanced angle and the most retarded angle, the filling period of hydraulic oil after the start of the engine is shortened. Can do.

The schematic diagram which shows typically the structure of an internal combustion engine provided with this about the variable valve operating apparatus of the internal combustion engine of one Embodiment of this invention. Sectional drawing which shows the cross-sectional structure along the radial direction about the valve timing variable mechanism of the embodiment. Sectional drawing which shows what expanded the cross-sectional structure which follows the DA-DA line | wire of FIG. 2 about the valve timing variable mechanism of the embodiment. Sectional drawing which shows what expanded the cross-sectional structure which follows the DA-DA line | wire of FIG. 2 about the valve timing variable mechanism of the embodiment. Sectional drawing which shows the 1st limiting mechanism and the cross-sectional structure of the periphery of the valve timing variable mechanism of the embodiment. The schematic diagram which shows typically the hydraulic system of the valve timing variable mechanism of the embodiment. The table which shows the relationship between the operation mode of the embodiment, and the supply-and-discharge state of the lubricating oil with respect to a valve timing variable mechanism. The map which shows the relationship between the cooling water temperature used for "idle rotational speed control" performed by the electronic controller of the embodiment, and a basic idle rotational speed. The map which shows the relationship between the cooling water temperature used for the "hydraulic oil filling control" performed by the electronic control apparatus of the embodiment, and a raise correction period. The map which shows the relationship between the cooling water temperature used for the "hydraulic oil filling control" performed by the electronic controller of the embodiment, and the correction amount for filling. The map which shows the relationship between cooling water temperature and idle rotation speed about "idle rotation speed control" performed by the electronic control apparatus of the embodiment. The flowchart which shows the procedure of "hydraulic oil filling control" performed by the electronic control apparatus of the embodiment. The timing chart which shows an example of the execution aspect about "idle rotational speed control" of the embodiment. The timing chart which shows an example of the execution aspect about "idle rotational speed control" of the embodiment.

  An embodiment of the present invention will be described with reference to FIGS. In the present embodiment, an example in which the present invention is embodied as a variable valve operating apparatus for an internal combustion engine including a valve timing variable mechanism that changes the valve timing of the intake valve is shown.

  As shown in FIG. 1, the internal combustion engine 1 includes an engine main body 10 that rotates a crankshaft 15 through combustion of an air-fuel mixture, a valve operating device 20 that includes each element of a valve operating system, hydraulic oil in the engine main body 10, and the like. And a control device 100 that comprehensively controls various devices including these devices.

  The engine body 10 includes a cylinder block 11 in which the air-fuel mixture is combusted, a cylinder head 12 provided with a valve gear 20, and an oil pan 13 that stores hydraulic oil supplied to each part of the engine body 10.

  The 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 respectively push down these valves, and the rotation of the intake camshaft 22 with respect to the rotational phase of the crankshaft 15. And a valve timing variable mechanism 30 that changes the phase (hereinafter, “valve timing VT”).

  The hydraulic mechanism 80 includes an oil pump 81 that discharges hydraulic oil from the oil pan 13, a hydraulic oil passage 90 that supplies hydraulic oil discharged from the oil pump 81 to each part of the internal combustion engine 1, and a variable valve timing mechanism 30. And an oil control valve 82 for controlling the supply mode and the discharge mode of the hydraulic oil.

  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. .

  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 “cam angle DA”) to the electronic control unit 101. The cooling water temperature sensor 104 outputs a signal corresponding to the temperature of the cooling water (hereinafter, “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 of 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 cam angle DA is calculated based on the output signal of the cam position sensor 103. Further, a calculation value corresponding to the valve timing VT is calculated based on the crank angle CA and the cam angle DA. Further, an operation value corresponding to the cooling water temperature TW is calculated based on the output signal of the cooling water temperature sensor 104.

  The control performed by the electronic control unit 101 includes idle rotation speed control for maintaining the engine rotation speed NE in an idle operation state constant, and operation valve timing control for changing the valve timing VT during engine operation, And phase locking control for fixing the valve timing VT based on an engine stop request or the like.

  Hereinafter, the period from when the start request of the internal combustion engine 1 is set to when the internal combustion engine 1 shifts to the idle operation state is referred to as “engine start”. The period from when the request for stopping the internal combustion engine 1 is set to when the rotation of the internal combustion engine 1 stops is referred to as “when the engine is stopped”. Further, a period during which the rotation of the internal combustion engine 1 is stopped is referred to as “engine stopped”.

  In the valve timing control during operation, the valve timing VT is changed from the most advanced valve timing (hereinafter, “most advanced angle VTmax”) to the most retarded valve timing (hereinafter, “most delayed angle VTmin” based on the engine operating state. )). Here, the engine speed NE, the engine load, and the like are used as parameters that define the engine operating state.

  In the phase lock control, a “phase lock request” that is a request to lock the valve timing VT to a specific valve timing (hereinafter, “intermediate angle VTmdl”) between the most retarded angle VTmin and the most advanced angle VTmax is set. Control of the oil control valve 82 for fixing the valve timing VT to the intermediate angle VTmdl. The phase lock request is set based on an engine stop request or an idle operation request.

  As the intermediate angle VTmdl, a valve timing VT suitable for engine start is set. When comparing the case where the valve timing VT is maintained at the intermediate angle VTmdl at the time of engine start with the case where the valve timing VT is maintained at the retard angle side valve timing VT, the engine startability is higher than the former. Is higher.

The structure of the variable valve timing mechanism 30 will be described with reference to FIG.
The variable valve timing mechanism 30 includes a housing rotor 31 that rotates in synchronization with the crankshaft 15, a vane rotor 35 that rotates in synchronization with the intake camshaft 22, and a fixing mechanism 40 that fixes the valve timing VT to the intermediate angle VTmdl. Including. Furthermore, an opening mechanism 70 (see FIG. 3) and a vane discharge oil passage 96 for promoting the discharge of hydraulic oil from the advance chamber 37 and the retard chamber 38 when the engine is stopped and during the engine stop are included.

  Then, the valve timing VT is changed by changing the rotation phase of the vane rotor 35 with respect to the rotation phase of the housing rotor 31 (hereinafter, “relative rotation phase P”). An arrow RA in the drawing indicates the rotation direction of the sprocket 33 (crankshaft 15) and the intake camshaft 22.

  The housing rotor 31 includes a housing main body 32 serving as a main body thereof, a sprocket 33 attached to one end side in the axial direction of the housing main body 32, and a cover 34 attached to the other end side in the axial direction of the housing main body 32 (see FIG. 3). Including. The sprocket 33 is connected to the crankshaft 15 via a timing chain (not shown).

  The housing body 32 is provided with three partition walls 32 </ b> A that protrude in the radial direction of the rotation shaft of the housing rotor 31. The housing body 32, the sprocket 33, and the cover 34 are fixed to each other by three bolts B inserted in the axial direction.

  The vane rotor 35 is fixed to an end portion of the intake camshaft 22 and is disposed in a space in the housing body 32. The vane rotor 35 is provided with three vanes 35 </ b> A projecting between adjacent partition walls 32 </ b> A of the housing body 32.

  Three accommodating chambers 36 are formed between the adjacent partition walls 32A. The storage chamber 36 is formed by being surrounded by the inner peripheral surface of the housing body 32, the outer peripheral surface of the vane rotor 35, the sprocket 33, and the cover 34. Moreover, it is divided into the advance chamber 37 and the retard chamber 38 by the corresponding vane 35A (see FIG. 3).

  The advance chamber 37 is formed behind the vane 35A in the accommodation chamber 36 in the rotational direction RA of the intake camshaft. The retard chamber 38 is formed in the accommodation chamber 36 in front of the vane 35 </ b> A in the rotational direction RA of the intake camshaft 22. The volumes of the advance chamber 37 and the retard chamber 38 change according to the supply / discharge state of the hydraulic oil with respect to the variable valve timing mechanism 30.

  The fixing mechanism 40 includes a first limiting mechanism 50 and a second limiting mechanism 60 that limit the change of the valve timing VT. The first limiting mechanism 50 and the second limiting mechanism 60 are arranged in different vanes 35A.

The operation of the variable valve timing mechanism 30 will be described.
When the vane rotor 35 rotates with respect to the housing rotor 31 in the advance side, that is, in the rotation direction RA by supplying the hydraulic oil to the advance chamber 37 and discharging the hydraulic oil from the retard chamber 38, the valve timing VT is advanced. To do. When the vane rotor 35 rotates most forward with respect to the housing rotor 31, that is, when the relative rotational phase P is at the most forward phase in the rotational direction RA (hereinafter referred to as "most advanced phase PH"), the valve timing VT is set to the most advanced angle VTmax.

  When the vane rotor 35 rotates with respect to the housing rotor 31 on the retard side, that is, on the side opposite to the rotation direction RA by discharging the hydraulic oil from the advance chamber 37 and supplying the hydraulic oil to the retard chamber 38, the valve timing. VT is retarded. When the vane rotor 35 rotates to the most retarded angle with respect to the housing rotor 31, that is, when the relative rotation phase P is at the most rearward phase in the rotation direction RA (hereinafter, “most retarded angle PL”), the valve timing VT is set to the most retarded angle VTmin.

  With reference to FIG. 3 and FIG. 4, the structures of the first limiting mechanism 50 and the second limiting mechanism 60 will be described. 3 and 4 show a cross-sectional structure of the variable valve timing mechanism 30 along the DA-DA line in FIG. 2 developed on a plane. Hereinafter, the direction in which the first restriction pin 51 of the first restriction mechanism 50 protrudes from the vane 35A is referred to as “projection direction ZA”, and the direction in which the restriction pin 51 is accommodated in the vane 35A is referred to as “accommodation direction ZB”. .

  The first limiting mechanism 50 includes a first limiting pin 51 that moves relative to the vane 35A, a first engagement groove 56 that is formed corresponding to a trajectory in the circumferential direction of the first limiting pin 51, and a first limiting pin. And a first limiting spring 52 for pushing 51 in the protruding direction ZA. Furthermore, a first restriction chamber 53 including a first release chamber 54 for accommodating the first restriction pin 51 and a spring chamber 55 for accommodating the first restriction spring 52 is included. The first restriction pin 51, the first restriction spring 52, and the first restriction chamber 53 are provided in the vane 35A. The first engagement groove 56 is provided in the housing rotor 31. The first release chamber 54 is connected to the oil control valve 82 by a release oil passage 95 (see FIG. 6).

  The first restriction pin 51 moves in the protruding direction ZA and the receiving direction ZB with respect to the vane 35A and protrudes to the outside of the vane 35A, and the protruding direction ZA and the receiving direction with respect to the vane 35A in the vane 35A. It is comprised by the outer side pin 51A which moves to ZB.

As the first limiting spring 52, an outer spring 52A for pushing the outer pin 51A in the protruding direction ZA and an inner spring 52B for pushing the inner pin 51B in the protruding direction ZA are provided.
The first restriction chamber 53 is partitioned into a first release chamber 54 and a first spring chamber 55 by an outer pin 51A and an inner pin 51B. For this reason, when there is no circulation of the lubricating oil through the clearance, the lubricating oil does not flow between the first release chamber 54 and the first spring chamber 55.

  In the first limiting mechanism 50, when the hydraulic pressure in the first release chamber 54 is smaller than the resultant force of the inner spring 52B and the outer spring 52A, the first limiting pin 51 is held in a state of attempting to operate in the protruding direction ZA. On the other hand, when the hydraulic pressure in the first release chamber 54 is larger than the resultant force of the inner spring 52B and the outer spring 52A, the first limit pin 51 is held in a state of attempting to operate in the accommodation direction ZB.

  The first engagement groove 56 includes two grooves having different depths, that is, a first lower groove 57 having a relatively large depth and a first upper groove 58 having a relatively small depth. The first upper groove 58 is provided on the retard side with respect to the first lower groove 57.

  A first advance angle end portion 56A, which is an end portion of the first lower groove 57 on the advance angle side, is provided at a position corresponding to a phase corresponding to the intermediate angle VTmdl (hereinafter referred to as “intermediate phase PM”). The first retarded angle end 56B, which is the retarded end of the first upper groove 58, is provided at a position corresponding to the first retarded phase PX1 located on the retarded side with respect to the intermediate phase PM. The second retarded angle end 56C, which is the retarded end of the first lower groove 57, is provided at a position corresponding to the second retarded phase PX2 between the intermediate phase PM and the first retarded phase PX. ing.

  The second restriction mechanism 60 includes a second restriction pin 61 that moves relative to the vane 35A, a second engagement groove 66 that is formed corresponding to a trajectory in the circumferential direction of the second restriction pin 61, and a second restriction pin. And a second limiting spring 62 for pushing 61 in the protruding direction ZA. Furthermore, a second restriction chamber 63 including a second release chamber 64 for accommodating the second restriction pin 61 and a spring chamber 65 for accommodating the second restriction spring 62 is included. The second restriction pin 61, the second restriction spring 62, and the second restriction chamber 63 are provided in the vane 35A. The second engagement groove 66 is provided in the housing rotor 31. The second release chamber 64 is connected to the oil control valve 82 by a release oil passage 95 (see FIG. 6).

  The second limit pin 61 moves in the protruding direction ZA and the receiving direction ZB with respect to the vane 35A and protrudes to the outside of the vane 35A, and the protruding direction ZA and the receiving direction with respect to the vane 35A in the vane 35A. It is comprised by the outer side pin 61A which moves to ZB.

As the second limiting spring 62, an outer spring 62A for pushing the outer pin 61A in the projecting direction ZA and an inner spring 62B for pushing the inner pin 61B in the projecting direction ZA are provided.
The second restriction chamber 63 is divided into a second release chamber 64 and a second spring chamber 65 by an outer pin 61A and an inner pin 61B. For this reason, when it is assumed that there is no circulation of the lubricating oil through the clearance, the lubricating oil does not flow between the second release chamber 64 and the second spring chamber 65.

  In the second restriction mechanism 60, when the hydraulic pressure in the second release chamber 64 is smaller than the resultant force of the inner spring 62B and the outer spring 62A, the second restriction pin 61 is held in a state of attempting to operate in the protruding direction ZA. On the other hand, when the hydraulic pressure in the second release chamber 64 is larger than the resultant force of the inner spring 62B and the outer spring 62A, the second limit pin 61 is held in a state of attempting to operate in the accommodation direction ZB.

  The second engagement groove 66 includes two grooves having different depths, that is, a second lower groove 67 having a relatively large depth and a second upper groove 68 having a relatively small depth. The second upper groove 68 is provided on the retard side with respect to the second lower groove 67.

  The second advance end 66A, which is the end on the advance side of the second lower groove 67, is provided at a position corresponding to the advance phase PY on the advance side with respect to the intermediate phase PM. The third retard angle end portion 66B, which is the retard angle side end portion of the second upper groove 68, is provided at a position corresponding to the third retard angle phase PX3 on the retard angle side with respect to the first retard angle phase PX1. . A fourth retard angle end portion 66C, which is an end portion on the retard angle side of the second lower groove 67 of the second engagement groove 66, is provided at a position corresponding to the intermediate phase PM.

  As shown in FIG. 4, when the inner pin 51B and the inner pin 61B protrude into the first lower groove 57 and the second lower groove 67, respectively, the first limiting mechanism 50 causes the relative rotational phase P to advance toward the advance side. Since the change is restricted and the change to the retard side of the relative rotation phase P is restricted by the second limiting mechanism 60, the relative rotation phase P is fixed to the intermediate phase PM. That is, the fixing mechanism 40 fixes the valve timing VT to the intermediate angle VTmdl by fixing the relative rotational phase P to the intermediate phase PM in cooperation with the first limiting mechanism 50 and the second limiting mechanism 60.

The structure of the opening mechanism 70 will be described.
The opening mechanism 70 includes, for the vane 35A provided with the first limiting mechanism 50, a first opening mechanism 71 that communicates the advance chamber 37 and the retard chamber 38 with an external space via the first spring chamber 55; The vane 35 </ b> A provided with the second restriction mechanism 60 is configured by a second opening mechanism 72 that communicates the advance chamber 37 and the retard chamber 38 with an external space via the second spring chamber 65.

  The first opening mechanism 71 includes a restriction chamber opening passage 71A that allows the first spring chamber 55 and the external space to communicate with each other, and an advance chamber opening passage 71B that allows the first spring chamber 55 and the advance chamber 37 to communicate with each other. The retard chamber opening passage 71 </ b> C that allows the first spring chamber 55 and the retard chamber 38 to communicate with each other, and the outer pin 51 </ b> A of the first limiting mechanism 50.

  The second opening mechanism 72 includes a restriction chamber opening passage 72A that allows the second spring chamber 65 and the external space to communicate with each other, and an advance chamber opening passage 72B that allows the second restriction chamber 63 and the advance chamber 37 to communicate with each other. The retarding chamber opening passage 72 </ b> C that allows the second restricting chamber 63 and the retarding chamber 38 to communicate with each other, and the outer pin 61 </ b> A of the second restricting mechanism 60 are configured.

  With reference to FIG. 5, operations of the first limiting mechanism 50 and the first opening mechanism 71 will be described. Note that the same applies to the second restriction mechanism 60 and the second opening mechanism 72, and the description of the operations of the second restriction mechanism 60 and the second opening mechanism 72 is omitted.

  As shown in FIG. 5A, when the outer pin 51A is held at the position closest to the receiving direction ZB by the hydraulic pressure of the first release chamber 54, the entire inner pin 51B is stored in the vane 35A. Yes. Hereinafter, the state of the fixing mechanism 40 is referred to as a “release operation state”.

  At this time, the outer pin 51A comes into contact with the inner pin 51B, and the inner pin 51B is accommodated in the vane 35A by pushing the inner pin 51B in the accommodating direction ZB. Further, the restriction chamber opening passage 71A and the first spring chamber 55 are closed by the outer pin 51A. Further, the advance chamber opening passage 71B and the first spring chamber 55 are closed by the outer pin 51A. Further, the retard chamber opening passage 71C and the first spring chamber 55 are closed by the outer pin 51A. Hereinafter, this state is referred to as a “closed state” of the opening mechanism 70. At this time, the flow of air between the external space and the first spring chamber 55 is blocked, so that an air flow occurs between the first spring chamber 55 and the advance chamber 37 and the retard chamber 38. There is no.

  As shown in FIGS. 5B and 5C, when the first release chamber 54 is filled with hydraulic oil, the outer pin 51A is held at the position closest to the protruding direction ZA. Hereinafter, the state of the fixing mechanism 40 is referred to as a “fixing operation state”.

  As shown in FIG. 5B, when the fixing mechanism 40 is in the fixing operation state and the relative rotation phase P is in a phase not corresponding to the first engagement groove 56, the tip of the inner pin 51 </ b> B is positioned on the cover 34. It contacts with the wall surface and is accommodated in the vane 35A.

  At this time, the restriction chamber opening passage 71A and the first spring chamber 55 communicate with each other. Further, the advance chamber opening passage 71B and the first spring chamber 55 communicate with each other. Further, the retard chamber opening passage 71C and the first spring chamber 55 communicate with each other. Hereinafter, this state is referred to as an “open state” of the opening mechanism 70. At this time, since air flow between the external space and the first spring chamber 55 is allowed, air flow between the first spring chamber 55 and the advance chamber 37 and the retard chamber 38 is allowed. Is done.

  As shown in FIG. 5C, when the fixing mechanism 40 is in the fixing operation state and the relative rotation phase P is in a phase corresponding to the first engagement groove 56, the inner pin 51 </ b> B is in the first engagement groove 56. It is held in a state protruding from the vane 35A toward the inside.

  At this time, the opening mechanism 70 is in an open state. In addition, since air flow between the external space and the first spring chamber 55 is allowed, air flow between the first spring chamber 55 and the advance chamber 37 and the retard chamber 38 is allowed. .

  Then, the lubricating oil is supplied to the first release chamber 54 via the release oil passage 95 (see FIG. 6) that connects the first release chamber 54 and the oil control valve 82 to each other, so that the first release chamber 54 When the hydraulic pressure exceeds the force of the first limiting spring 52, the outer pin 51A moves in the accommodation direction ZB. In addition, the inner pin 51B in contact with the outer pin 51A moves in the accommodation direction ZB together with the outer pin 51A. Then, when the outer pin 51A and the inner pin 51B move to the position closest to the accommodation direction ZB, the state of the fixing mechanism 40 is changed to the release operation state.

  With reference to FIG. 6, a flow mode of hydraulic oil between the hydraulic mechanism 80 and the variable valve timing mechanism 30 will be described. The figure schematically shows the configuration of the oil passage between the hydraulic mechanism 80 and the variable valve timing mechanism 30.

  The oil control valve 82 and the advance chamber 37 are connected to each other via an advance oil passage 93. The oil control valve 82 and the retard chamber 38 are connected to each other via a retard oil passage 94. The oil control valve 82 and the release chambers 54 and 64 are connected to each other via a release oil passage 95. The oil control valve 82 and the oil pump 81 are connected to each other via a supply oil passage 91. The oil control valve 82 and the oil pan 13 are connected to each other via a discharge oil path 92. The advance chamber 37 and retard chamber 38 and the oil pan 13 are connected to each other via a vane discharge oil passage 96.

  The vane discharge oil passage 96 includes an advance chamber discharge oil passage 97 and a retard chamber discharge oil passage 98. The advance chamber discharge oil passage 97 connects the advance chamber 37 and the discharge oil passage 92 to each other. The retard chamber exhaust oil passage 98 connects the retard chamber 38 and the exhaust oil passage 92 to each other.

  When the engine is stopped and when the engine is stopped, the hydraulic oil is discharged from the release chambers 54 and 64, so that the opening mechanism 70 shifts from the closed state to the open state. Thereby, the air in the external space is supplied to the advance chamber 37 and the retard chamber 38 via the opening mechanism 70. Then, hydraulic oil is discharged from the advance chamber 37 and the retard chamber 38 via the vane discharge oil passage 96 according to the amount of air supplied to the advance chamber 37 and the retard chamber 38.

  FIG. 7A shows the relationship between each operation mode of the oil control valve 82 and the supply / discharge state of the hydraulic oil in the advance chamber 37, the retard chamber 38, and the release chambers 54 and 64. FIG. 7B shows the relationship between the operation modes and the operation modes of the variable mechanism 30 and the limit pins 51 and 61. In the following description, the flow rate of the hydraulic oil and the operation speed of the variable mechanism 30 are compared between the operation modes under the condition that the discharge amount of the oil pump 81 is the same.

  Each item of FIG.7 (b) shows the following respectively. That is, the “advance angle” indicates a state in which a force to rotate relative to the advance side is applied to the vane rotor 35 and a state where the vane rotor 35 rotates relative to the advance side. The “retard angle” indicates a state in which a force to rotate relative to the retard side is applied to the vane rotor 35 and a state in which the vane rotor 35 rotates relative to the retard side. “Hold” indicates a state in which the relative rotation phase P is held at a constant phase by hydraulic pressure. The “protrusion” indicates a state in which each of the limit pins 51 and 61 is about to protrude toward the outside of the vane 35A, and a state in which each of the limit pins 51 and 61 protrudes to the outside of the vane 35A. Further, “accommodation” indicates a state in which the respective limit pins 51 and 61 are about to move into the vane 35A and a state in which the respective limit pins 51 and 61 are accommodated in the vane 35A.

  When the operation mode of the oil control valve 82 is mode A1, the operation state of the valve 82 is that the hydraulic oil is supplied to the advance chamber 37, the hydraulic oil is discharged from the retard chamber 38, and the first release chamber 54 is discharged. In addition, the operating oil is discharged from the second release chamber 64. As a result, the vane rotor 35 rotates relative to the advance side, and a force in the protruding direction ZA is applied to each of the limit pins 51 and 61.

  When the operation mode of the oil control valve 82 is mode A2, the operation state of the valve 82 is such that a smaller amount of hydraulic oil is supplied to the advance chamber 37 than the mode A1 and mode A3, and hydraulic oil is supplied from the retard chamber 38. The hydraulic fluid is discharged and the hydraulic fluid is discharged from the first release chamber 54 and the second release chamber 64. As a result, the vane rotor 35 relatively rotates toward the advance side at a lower speed than that in the mode A1, and a force in the protruding direction ZA is applied to each of the limit pins 51 and 61.

  When the operation mode of the oil control valve 82 is mode A3, the operation state of the valve 82 is to supply hydraulic oil to the advance chamber 37, discharge hydraulic oil from the retard chamber 38, and to release the first release chamber 54. And it is in the operation state which supplies hydraulic fluid to the 2nd cancellation | release chamber 64. FIG. As a result, the vane rotor 35 relatively rotates toward the advance side, and a force in the accommodation direction ZB is applied to each of the limit pins 51 and 61.

  When the operation mode of the oil control valve 82 is mode A4, the operation state of the valve 82 is that the advance chamber 37 and the retard chamber 38 are closed, and hydraulic oil is supplied to the first release chamber 54 and the second release chamber 64. It is in the operating state to supply. As a result, the relative rotational phase P is maintained, and a force in the accommodation direction ZB is applied to each of the limit pins 51 and 61.

  When the operation mode of the oil control valve 82 is mode A5, the operation state of the valve 82 is that the hydraulic oil is discharged from the advance chamber 37, the hydraulic oil is supplied to the retard chamber 38, and the first release chamber 54 is operated. And it is in the operation state which supplies hydraulic fluid to the 2nd cancellation | release chamber 64. FIG. As a result, the vane rotor 35 relatively rotates toward the retard side, and a force in the accommodation direction ZB is applied to each of the limit pins 51 and 61.

The operation mode is switched as follows based on the engine operating state.
During normal engine operation, one of modes A3 to A5 is selected according to the engine operation state. When the engine stop request is detected and the valve timing VT is on the retard side with respect to the intermediate angle VTmdl, the mode A1 is selected. When the engine is shifted from the normal operation to the idle operation state, the mode A2 is selected.

  When the engine is started, mode A1 is selected. As a result, the hydraulic oil is supplied to the advance chamber 37 via the advance oil passage 93. At this time, since the open state of the opening mechanism 70 is maintained, the advance chamber 37 and the retard chamber 38 corresponding to the vane 35A provided with the release mechanisms 71 and 72 advance through the advance oil passage 93. The hydraulic oil supplied to the corner chamber 37 is also supplied to the advance chamber 37 and the retard chamber 38 via the opening mechanism 70. Further, in the advance angle chamber 37 corresponding to the vane 35 </ b> A in which the release mechanisms 71 and 72 are not provided, hydraulic oil is supplied via the advance angle oil passage 93.

  When the electronic control unit 101 determines that there is a phase lock request for fixing the valve timing VT to the intermediate angle VTmdl, the operation mode is set to mode A1 in a state where the valve timing VT is on the retard side with respect to the intermediate angle VTmdl. The command signal to transmit is transmitted to the oil control valve 82.

  As a result, the hydraulic oil is supplied to the advance chamber 37 and the hydraulic oil in the retard chamber 38 is discharged, so that the vane rotor 35 rotates relative to the advance side. Further, since the hydraulic oil is discharged from the first release chamber 54 and the second release chamber 64, each of the limit pins 51 and 61 is maintained in a state of trying to protrude from the vane 35A. When the relative rotational phase P reaches the intermediate phase PM, the limit pins 51 and 61 are abutted against the ends of the first lower groove 57 and the second lower groove 67, so that the valve timing VT is changed to the intermediate angle VTmdl. Fixed to.

  However, when the engine is stopped, the valve timing VT may be stopped without being fixed to the intermediate angle VTmdl. In this case, as the hydraulic oil is discharged from the advance chamber 37 and the retard chamber 38 while the engine is stopped, the vane rotor 35 rotates relative to the retard side. Thereby, the relative rotational phase P is maintained at the most retarded phase PL. Then, after the start of cranking at the next engine start, the vane rotor 35 rotates in the advance direction with respect to the housing rotor 31 due to cam torque fluctuation.

  At this time, if the hydraulic oil is discharged from the first release chamber 54 and the second release chamber 64 while the engine is stopped, the first limit pin 51 and the second limit pin 61 are protruded by the limit springs 52 and 62 in the protruding direction. It is maintained in a state of trying to move to ZA. For this reason, each time the relative rotational phase P reaches the second retarded phase PX2, the third retarded phase PX3, and the first retarded phase PX1, the retard angle of the valve timing VT is limited by the limit pins 51 and 61. When the relative rotational phase P reaches the intermediate phase PM, the valve timing VT is fixed at the intermediate angle VTmdl.

  In addition, since the variable valve timing mechanism 30 of the internal combustion engine 1 is provided with the opening mechanism 70, external air is supplied to the advance chamber 37 and the retard chamber 38 when the engine is stopped and when the engine is stopped. This facilitates the discharge of hydraulic oil from the advance chamber 37 and the retard chamber 38 when the engine is stopped and during the engine stop. For this reason, it is suppressed that the change of the valve timing VT based on the cam torque variation is hindered by the hydraulic oil due to the hydraulic oil remaining in the advance chamber 37 and the retard chamber 38 during cranking. .

  By the way, when the change of the valve timing VT is started during the period until the hydraulic oil is filled in the advance chamber 37 and the retard chamber 38 after the engine is started and after the engine is started, the hydraulic oil is not filled. Thus, the valve timing VT cannot be appropriately changed or maintained.

  Therefore, in the internal combustion engine 1, the change mechanism of the valve timing VT is started during the period until the advance chamber 37 and the retard chamber 38 are filled with the hydraulic oil, that is, the operation mode of the oil control valve 82 is switched and the fixing mechanism is changed. It is prohibited to change 40 from the fixed operation state to the release operation state.

On the other hand, when the advance chamber 37 and the retard chamber 38 are filled with the hydraulic oil at an early stage after the start of the engine start, the change of the valve timing VT can also be started at an early stage accordingly.
Therefore, the electronic control unit 101 shortens the filling period of the hydraulic oil in the advance chamber 37 and the retard chamber 38 and starts the change of the valve timing VT at an early stage. The “hydraulic oil filling control” is performed to correct the engine rotational speed NE in the idle operation state.

Hereinafter, details of the idle rotation speed control and the hydraulic oil filling speed control will be described.
In the idle rotation speed control, a target value (hereinafter referred to as “idle rotation speed NI”) of the engine rotation speed NE in the idle operation state is set, and the intake air amount and fuel are set so that the engine rotation speed NE converges to the idle rotation speed NI. Control the injection amount. The idle rotation speed control includes “idle rotation speed control after warm-up” performed after completion of warm-up, “cold idle rotation speed control” performed before completion of warm-up, and idle rotation speed NI. The “hydraulic oil filling control” for calculating the correction amount is included. The idle rotation speed NI is set as follows based on the engine operating state.

  In other words, the basic idle speed NI set based on the warm-up state (hereinafter referred to as “the basic idle speed NIX”) and the correction amount of the idle speed NI corresponding to the engine operating state and the like at that time are obtained. Calculated and the correction amount reflected in the basic idle rotation speed NX is calculated as the idle rotation speed NI. As the correction amount of the idle rotation speed NI, a correction amount corresponding to the coolant temperature TW (hereinafter, “charging correction amount ΔX”) is calculated by “hydraulic oil filling control” in FIG.

  In the “idle rotation speed control after warm-up” and “cold idle rotation speed control”, the basic idle rotation speed NIX is calculated based on the coolant temperature TW. Here, the basic idle speed NIX is calculated by applying the cooling water temperature TW at that time to the map shown in FIG.

FIG. 8 shows the relationship between the coolant temperature TW and the basic idle speed NIX.
In the idle rotation speed control after warm-up, a “post-warm target speed NIA” that is constant with respect to the coolant temperature TW is calculated as the basic idle rotation speed NIX in the region where the coolant temperature TW is equal to or higher than the warm-up completion temperature TWA.

  In the cold idle rotation speed control, a variable “cold target speed NIB” that is variable with respect to the cooling water temperature TW is calculated as the basic idle rotation speed NIX in the region where the cooling water temperature TW is lower than the warm-up completion temperature TWA. The cold target speed NIB is set to gradually decrease as the cooling water temperature TW decreases. The warm-up completion temperature TWA is set in advance as a value for determining whether or not the warm-up of the internal combustion engine 1 has been completed based on a comparison with the cooling water temperature TW.

  Hereinafter, an engine operation state in which the coolant temperature TW is lower than the warm-up completion temperature TWA is referred to as “cold state”, and an engine operation state in which the coolant temperature TW is equal to or higher than the warm-up completion temperature TWA is referred to as “warm-up completion state”. Further, an engine start state in which the engine is started in the cold state is referred to as “cold start”, and an engine start state in which the engine is started in the warm-up completed state is referred to as “warm-up start”.

  In “hydraulic oil filling control”, the hydraulic oil filling period is shortened based on the fact that the elapsed period from the start of engine starting (hereinafter, “post-starting period TC”) is less than the increase correction period TX as the control period. The increase correction of the idle rotation speed NI is performed. Then, based on the fact that the post-start period TC is equal to or longer than the increase correction period TX, the increase correction of the idle rotation speed NI for shortening the hydraulic oil filling period is terminated.

  The increase correction period TX is set based on the coolant temperature TW at the start of engine start. Further, when the post-start period TC is less than the increase correction period TX, the charging correction amount ΔX is set based on the cooling water temperature TW. When the post-start period TC is equal to or greater than the increase correction period TX, the setting of the charging correction amount ΔX based on the coolant temperature TW is ended.

FIG. 9 shows the relationship between the coolant temperature TW and the increase correction period TX.
In the region where the cooling water temperature TW at the time of starting the engine is relatively low, the increase correction period TX gradually increases as the cooling water temperature TW decreases. Further, in the region where the coolant temperature TW is relatively high, the increase correction period TX is always constant with respect to the coolant temperature TW.

  When the coolant temperature TW is low, the period of time until the hydraulic oil is filled in the advance chamber 37 and the retard chamber 38 due to the high viscosity of the hydraulic oil is long. Further, when the cooling water temperature TW is high, the period of time until the hydraulic oil is filled in the advance chamber 37 and the retard chamber 38 due to the low viscosity of the hydraulic oil is short. In the map of FIG. 9, in consideration of this, a period obtained by experiments or the like in advance as a sufficient period until the advance chamber 37 and the retard chamber 38 are filled with hydraulic oil is set as the increase correction period TX. Has been.

FIG. 10 shows the relationship between the cooling water temperature TW and the filling correction amount ΔX.
The filling correction amount ΔX is obtained by increasing the idle rotation speed NI and increasing the discharge amount of the oil pump 81 until the advance chamber 37 and the retard chamber 38 are filled with the lubricating oil after the engine start is started. Is set as a correction amount for shortening the period.

  In a region where the coolant temperature TW is lower than a predetermined temperature (hereinafter, “correction reference temperature TWB”) lower than the warm-up completion temperature TWA, the filling correction amount ΔX is set to “0”. In the region where the coolant temperature TW is equal to or higher than the correction reference temperature TWB and lower than the warm-up completion temperature TWA, the charging correction amount ΔX is set to gradually increase as the coolant temperature TW increases. In the region where the coolant temperature TW is equal to or higher than the warm-up completion temperature TWA, the charging correction amount ΔX is set to a constant magnitude with respect to the coolant temperature TW.

  As shown in FIG. 8, when the cooling water temperature TW is lower than the corrected reference temperature TWB, the basic idle rotation speed NIX (cold target speed NIB) is set larger than when the cooling water temperature TW is higher than the corrected reference temperature TWB. Is done. Further, the amount of change in the basic idle rotation speed NIX (cold target speed NIB) with respect to the coolant temperature TW is also set large.

For this reason, even if the increase correction of the idle rotation speed NI by the correction amount ΔX for filling is not applied, there is a low possibility that the filling period of the lubricating oil in the advance chamber 37 and the retard chamber 38 becomes excessively long.
Therefore, in the map of FIG. 10, the filling correction amount ΔX is set to “0” in the region where the coolant temperature TW is lower than the correction reference temperature TWB. When it is required to further shorten the period for filling the advance oil in the advance chamber 37 and the retard chamber 38, the charging correction amount ΔX is set to “0” in the region where the coolant temperature TW is lower than the correction reference temperature TWB. Can be set to a larger value.

  FIG. 11 shows the relationship between the idle rotation speed NI and the cooling water temperature TW. The solid line in the figure shows the change in the idle rotation speed NI with respect to the cooling water temperature TW when the post-start period TC is less than the increase correction period TX, and the two-dot chain line in the figure shows the post-start period TC in the increase correction period The change of the idle rotation speed NI with respect to the cooling water temperature TW at the time of TX or more is shown.

  When the post-start period TC is less than the increase correction period TX and is in the cold state, a value obtained by correcting the increase in the cold target speed NIB based on the charging correction amount ΔX is set as the idle rotation speed NI.

  When the after-start period TC is less than the increase correction period TX and is in a cold state, the value after the warm-up target speed NIA is corrected for increase based on the charging correction amount ΔX is set as the idle rotation speed NI.

  That is, as indicated by the solid line in the figure, when the post-start period TC is less than the increase correction period TX and the cooling water temperature TW is less than the correction reference temperature TWB, the idle rotation speed NI decreases as the cooling water temperature TW increases. Further, when the post-start period TC is less than the increase correction period TX and the cooling water temperature TW is equal to or higher than the correction reference temperature TWB, the idle rotation speed NI is constant with respect to the cooling water temperature TW.

  Further, as indicated by a two-dot chain line in the figure, when the post-start period TC is equal to or greater than the increase correction period TX, the cold target speed NIB is set as the idle rotational speed NI. Therefore, until the cooling water temperature TW reaches the warm-up completion temperature TWA, the idle rotation speed NI decreases as the cooling water temperature TW increases. Further, when the cooling water temperature TW is equal to or higher than the warm-up completion temperature TWA, the idle rotation speed NI is constant with respect to the cooling water temperature TW.

  With reference to FIG. 12, a specific processing procedure of “hydraulic oil filling control” will be described. Note that this processing is executed by the electronic control apparatus 101, and once reaching the end step, the same processing is repeated again from step S11.

The electronic control device 101 performs the following processes as “hydraulic oil filling control”.
When it is determined in step S11 that the ignition switch has not been switched from OFF to ON, the determination process 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, an increase correction period TX is calculated in step S12 based on the coolant temperature TW at the start of engine start (see FIG. 9). In the next step S13, the operation mode of the oil control valve 82 is set to mode A1.

  In step S14, a charging correction amount ΔX is set based on the cooling water temperature TW at that time (see FIG. 10). Then, the idle rotational speed NI is corrected to increase based on the filling correction amount ΔX. As a result, the period until the hydraulic oil is filled in the advance chamber 37 and the retard chamber 38 by the increase correction of the idle rotation speed NI by the correction amount ΔX for filling is shortened.

In step S15, when it is determined that the post-start period TC is smaller than the increase correction period TX, the processes in steps S14 and S15 are repeated for each predetermined calculation cycle.
When it is determined in step S15 that the post-start period TC is equal to or greater than the increase correction period TX, the increase correction of the idle rotation speed NI based on the charging correction amount ΔX is ended. Further, the operation mode of the oil control valve 82 is set to mode A2.

  With reference to FIG. 13 and FIG. 14, an execution mode of “idle rotation speed control” will be described. FIG. 13 shows an example of the execution mode at the warm-up start, and FIG. 14 shows an example of the execution mode at the cold start.

  Here, the internal combustion engine 1 of the present embodiment is that the hydraulic oil filling control is not executed and that the operation mode of the oil control valve 82 is changed from the mode A1 to the mode A2 at the timing when the engine is started to the idle operation state. In other respects, an internal combustion engine having the same configuration as the internal combustion engine 1 is referred to as a “virtual internal combustion engine”.

  With reference to FIG. 13, the idle rotation speed control at the time of warm-up start will be described. In the figure, the execution mode of idle rotation speed control by the internal combustion engine 1 of the present embodiment is indicated by a solid line in the figure, and the execution mode of idle rotation speed control by a virtual internal combustion engine is indicated by a two-dot chain line. Yes.

In the internal combustion engine 1 of the present embodiment, idle rotation speed control is performed as follows.
When the engine start request is set at time t10, the warm-up target speed NIA is set as the basic idle rotation speed NIX. Further, an increase correction period TX is set based on the coolant temperature TW, and an increase correction of the charging correction amount ΔX is executed.

  At time t12, that is, when the post-start period TC reaches the ascending correction period TX, the hydraulic oil filling state of the advance chamber 37 and the retard chamber 38 is changed from the incomplete filling state to the filling completion state, and the filling correction amount ΔX Ascending correction is terminated. Further, the operation mode of the oil control valve 82 is changed from mode A1 to mode A2. After this, the operation mode of the oil control valve 82 is set to any of modes A1 to A5 based on the engine operating state.

In a virtual internal combustion engine, idle rotation speed control is performed as follows.
When the engine start request is set at time t10, the warm-up target speed NIA is set as the basic idle rotation speed NIX.

At time t11, that is, when the engine operating state shifts to the idle operating state, the operation mode of the oil control valve 82 is changed from mode A1 to mode A2.
At time t13, that is, when the post-start period TC reaches a period longer than the increase correction period TX by a predetermined period TA, the hydraulic oil filling state of the advance chamber 37 and the retard chamber 38 is changed from the unfilled state to the filled state. become.

  As described above, according to the internal combustion engine 1 of the present embodiment, the idle rotation speed NI is corrected to be increased by the hydraulic oil charging control, and the oil control valve 82 is operated until the post-start period TC becomes equal to or higher than the increase correction period TX. Since the operation mode is set to mode A1, the hydraulic oil filling period after the engine start at the time of warm-up start is shorter than that of the virtual internal combustion engine.

  With reference to FIG. 14, the idle rotation speed control at the cold start will be described. In the figure, the execution mode of idle rotation speed control by the internal combustion engine 1 of the present embodiment is indicated by a solid line in the figure, and the execution mode of idle rotation speed control by a virtual internal combustion engine is indicated by a two-dot chain line. Yes.

In the internal combustion engine 1 of the present embodiment, idle rotation speed control is performed as follows.
When the engine start request is set at time t20, the cold target speed NIB is set as the basic idle rotation speed NIX. Further, an increase correction period TX is set based on the coolant temperature TW, and an increase correction of the charging correction amount ΔX is executed.

  At time t22, that is, when the post-start period TC reaches the ascending correction period TX, the hydraulic oil filling state of the advance chamber 37 and the retard chamber 38 is changed from the unfilled state to the filled state, and the filling correction amount ΔX Ascending correction is terminated. Further, the operation mode of the oil control valve 82 is changed from mode A1 to mode A2. After this, the operation mode of the oil control valve 82 is set to any of modes A1 to A5 based on the engine operating state.

  At the time t24, that is, when the coolant temperature TW reaches the warm-up completion temperature TWA, the target speed NIA after warm-up is accompanied by the transition of the idle speed control from the cold idling speed control to the post-warm idle speed control. Is set as the basic idle speed NIX.

In a virtual internal combustion engine, idle rotation speed control is performed as follows.
When the engine start request is set at time t20, the cold target speed NIB is set as the basic idle rotation speed NIX.

At time t21, that is, when the engine operating state shifts to the idle operating state, the operation mode of the oil control valve 82 is changed from mode A1 to mode A2.
At time t23, that is, when the post-start period TC reaches a period longer than the ascent correction period TX by a predetermined period TB, the hydraulic oil filling state of the advance chamber 37 and the retard chamber 38 is changed from the unfilled state to the filled state. become.

  At the time t24, that is, when the coolant temperature TW reaches the warm-up completion temperature TWA, the target speed NIA after warm-up is accompanied by the transition of the idle speed control from the cold idling speed control to the post-warm idle speed control. Is set as the basic idle speed NIX.

  As described above, according to the internal combustion engine 1 of the present embodiment, the idle rotation speed NI is corrected to be increased by the hydraulic oil charging control, and the oil control valve 82 is operated until the post-start period TC becomes equal to or higher than the increase correction period TX. Since the operation mode is set to mode A1, the hydraulic oil filling period after the engine start at the time of cold start is shorter than that of the virtual internal combustion engine.

According to this embodiment, the following effects can be obtained.
(1) In the present embodiment, the idle rotation speed NI is corrected to be increased based on the post-start period TC being smaller than the increase correction period TX, and is increased based on the post-start period TC being greater than the increase correction period TX. Perform hydraulic oil filling control to end the correction. As a result, the supply amount of hydraulic oil to the advance chamber 37 and the retard chamber 38 increases as the discharge amount of the oil pump 81 increases, so that the advance chamber 37 and the retard chamber 38 operate after the engine is started. The period until the oil is filled can be shortened.

  (2) In the present embodiment, when the post-start period TC is equal to or greater than the increase correction period TX, the increase correction of the idle rotation speed NI using the charging correction amount ΔX is completed. For this reason, the deterioration of fuel consumption is suppressed as compared with the configuration in which the increase correction of the idle rotation speed NI using the charging correction amount ΔX is continued until the shift from the idle operation state to the normal operation state.

(3) In this embodiment, the rising correction period TX is set based on the temperature of the hydraulic oil. For this reason, it is possible to set an appropriate increase correction period TX according to the viscosity of the hydraulic oil.
(4) In the present embodiment, the charging correction amount ΔX is set to “0” when the coolant temperature TW is equal to or lower than the correction reference temperature TWB. Since the cold target speed NIB when the cooling water temperature TW is equal to or lower than the corrected reference temperature TWB is large, when the cooling water temperature TW is lower than the corrected reference temperature TWB, the advance chamber 37 and the retard chamber 38 are filled with hydraulic oil. There is little possibility that the period until will be long. For this reason, when the coolant temperature TW is equal to or lower than the correction reference temperature TWB, deterioration of fuel consumption is suppressed as compared with the case where the charging correction amount ΔX is set to a speed greater than “0”.

(5) In the present embodiment, the temperature of the hydraulic oil is estimated based on the coolant temperature TW. For this reason, it is not necessary to provide an oil temperature sensor for detecting the temperature of the hydraulic oil.
(6) The oil control valve 82 of the present embodiment has modes A1 to A5 for controlling the hydraulic oil supply mode of the advance chamber 37, the retard chamber 38, and the fixing mechanism 40. The fixing mechanism 40 is held in the fixed operation state or the release operation state based on the hydraulic oil supplied via the oil control valve 82. In the mode A <b> 1, the operation state of the fixing mechanism 40 is maintained in the fixed operation state and the hydraulic oil is supplied to the advance chamber 37. In the mode A2, the operation state of the fixing mechanism 40 is maintained in the fixed operation state, and a smaller amount of hydraulic oil is supplied to the advance chamber 37 than in the mode A1. When the hydraulic oil filling control is performed, the operation mode of the oil control valve 82 is set to the mode A1 in which the amount of hydraulic oil supplied to the advance chamber 37 is larger than the mode A2. For this reason, the filling period of the hydraulic oil can be further shortened.

  (7) In the present embodiment, an intermediate angle VTmdl between the most advanced angle VTmax and the most retarded angle VTmin is set as the specific angle. For this reason, in the internal combustion engine 1 including the variable valve timing mechanism 30 that fixes the valve timing VT to the intermediate angle VTmdl between the most advanced angle VTmax and the most retarded angle VTmin, the hydraulic oil filling period after the start of the engine is started. It can be shortened.

  (8) In the present embodiment, the valve timing variable mechanism 30 is provided with the opening mechanism 70 and the vane discharge oil passage 96. For this reason, when the discharge of the hydraulic oil is promoted by the opening mechanism 70 and the vane discharge oil passage 96, compared to a valve timing variable mechanism that does not include the opening mechanism 70 and the vane discharge oil passage 96, the next starting time The remaining amount of hydraulic oil in the advance chamber 37 and the retard chamber 38 is small. In this case, as compared with a variable valve timing mechanism that does not include the opening mechanism 70, the time required to fill the advance chamber 37 and the retard chamber 38 with hydraulic oil becomes longer. That is, according to the configuration including the opening mechanism 70 and the vane discharge oil passage 96, the frequency with which the filling period becomes longer tends to increase.

  In the present embodiment, by performing hydraulic oil filling control in idle rotation speed control, the idle rotation speed NI after engine startup is corrected to increase. For this reason, said frequency can be reduced.

(Other embodiments)
In addition, the embodiment of the present invention is not limited to the above-described embodiment. For example, the embodiment can be modified as follows and can be implemented. The following modifications are not applied only to the above-described embodiment, and different modifications can be combined with each other.

In the above embodiment, the amount of hydraulic oil remaining in the advance chamber 37 when the engine is started (estimated remaining amount QA) and the amount of hydraulic oil remaining in the retard chamber 38 when the engine is started (estimated remaining amount) It is also possible to estimate at least one of QB) and perform at least one of the following (A) to (E) based on at least one of these estimated remaining amounts.
(A) When at least one of the estimated remaining amount QA and the estimated remaining amount QB is equal to or greater than a predetermined amount, the increase correction of the idle rotation speed NI based on the charging correction amount ΔX is not performed.
(B) The charging correction amount ΔX is decreased as at least one of the estimated remaining amount QA and the estimated remaining amount QB is larger.
(C) Instead of the process of setting the charging correction amount ΔX based on the cooling water temperature TW, the charging correction amount ΔX is set so as to decrease as at least one of the estimated remaining amount QA and the estimated remaining amount QB increases. Process.
(D) The rising correction period TX is set based on at least one of the estimated remaining amount QA and the estimated remaining amount QB.
(E) Instead of the process of setting the increase correction period TX based on the coolant temperature TW, the process of setting the increase correction period TX is performed based on at least one of the estimated remaining amount QA and the estimated remaining amount QB.

  The estimated remaining amount QA and the estimated remaining amount QB can be calculated based on the elapsed time from the previous engine stop to the start of the current engine start. Further, other parameters having a correlation with the discharge amount of the hydraulic oil from at least one of the advance chamber 37 and the retard chamber 38 when the engine is stopped, for example, the temperature of the hydraulic oil when the engine is stopped and the hydraulic oil when the engine is stopped The estimated remaining amount can be calculated in consideration of at least one of the pressures.

In the above embodiment, the increase correction period TX is set to be smaller as the cooling water temperature TW becomes higher. However, a constant increase correction period TX can be set for the cooling water temperature TW.
In the above embodiment, the increase correction period TX is set to be smaller as the cooling water temperature TW is higher. However, this can be changed as follows. That is, the first rising correction period TXL and the second rising correction period TXH longer than the first rising correction period TXL are prepared in advance. The first increase correction period TXL can be set when the temperature is equal to or higher than the reference cooling water temperature TW, and the second increase correction period TXH can be set when the temperature is lower than the reference cooling water temperature TW.

  In the above embodiment, the increase correction period TX is set to be smaller as the coolant temperature TW becomes higher. However, when the coolant temperature TW at the time of starting the engine is equal to or higher than the determination temperature, the increase correction period TX is set to a predetermined period and the engine is started. When the coolant temperature TW at that time is lower than the determination temperature, the increase correction period TX can be set to “0”. As the determination temperature, for example, the warm-up completion temperature TWA or the correction reference temperature TWB can be used.

  In the above embodiment, when it is determined in step S15 of the “hydraulic oil filling control” that the post-start period TC is equal to or greater than the increase correction period TX, the increase correction of the idle rotation speed NI is completed, but the post-start period TC is When it is determined that the period is longer than the increase correction period TX, the increase correction of the idle rotation speed NI can be ended.

  In the “hydraulic oil filling control” of the above embodiment, the basic idle rotation speed NIX calculated by the “idle rotation speed control after warm-up” or the “cold idle rotation speed control” in step S14 is used as the correction amount ΔX for filling. The idle rotation speed NI is calculated by correcting the increase based on the above, but the calculation method of the idle rotation speed NI is not limited to this. That is, instead of the calculation method of correcting the basic idle speed NIX to be increased based on the filling correction amount ΔX, the relationship between the idle rotation speed NI including the amount corresponding to the filling correction amount ΔX and the cooling water temperature TW is previously determined. It is also possible to use a method of setting and calculating the idle rotation speed NI based on this relationship and the cooling water temperature TW at that time.

  In this case, when the post-start period TC is less than the determination period corresponding to the increase correction period TX, the idle rotation speed NI including the amount corresponding to the filling correction amount ΔX is set as the idle rotation speed NI at that time. The When the post-start period TC is equal to or greater than the determination period corresponding to the increase correction period TX, the idle speed NI smaller than the idle speed NI including the amount corresponding to the charging correction amount ΔX is “idle speed after warm-up”. It is set by “speed control” or “cold idle speed control”.

  In the above embodiment, the start time of the post-start period TC and the increase correction period TX is set as the start time of the engine start. However, the post-start period TC and the start of the increase correction period TX are set arbitrarily after the start of the engine start. It is also possible to set the time. For example, the start time of the post-start period TC and the upward correction period TX is set as the time when the engine is shifted to the idle operation state.

The setting mode of the filling correction amount ΔX in the above embodiment can be changed as shown in the following (A) to (D).
(A) The charging correction amount ΔX is set to a constant value larger than “0” with respect to the cooling water temperature TW.
(B) The correction amount ΔX for filling is decreased as the cooling water temperature TW increases.
(C) When the coolant temperature TW is lower than the warm-up completion temperature TWA, the charging correction amount ΔX is set to “0”, and when the cooling water temperature TW is equal to or higher than the warm-up completion temperature TWA, the charging correction amount ΔX is greater than “0”. To.
(D) When the cooling water temperature TW is equal to or lower than the correction reference temperature TWB, the charging correction amount ΔX is set to a value larger than “0”.

  In the above embodiment, the filling correction amount ΔX is set based on the cooling water temperature TW, but the filling correction amount ΔX can also be set based on the post-start period TC instead of the cooling water temperature TW. In this case, a map that defines the relationship between the post-start period TC and the filling correction amount ΔX is prepared. As a specific setting mode of this map, in the region where the post-start period TC is less than the control period, the charging correction amount ΔX gradually decreases as the post-start period TC increases, and the post-start period TC is equal to or greater than the control period. In this area, a filling correction amount ΔX of “0” can be employed. According to this configuration, the filling correction amount ΔX calculated when the post-start period TC is less than the predetermined period is larger than the filling correction amount ΔX calculated when the post-start period TC is equal to or greater than the predetermined period. Become.

  In the above embodiment, the charging correction amount ΔX is set based on the cooling water temperature TW. However, when the correction amount ΔY of the idle rotation speed NI different from the charging correction amount ΔX is set, the correction amount ΔY is set to this correction amount ΔY. Based on this, the filling correction amount ΔX can be changed. Specifically, when the hydraulic oil filling period is expected to be shortened by the correction amount ΔY, correction for reducing the filling correction amount ΔX is performed.

  In the above embodiment, the rising correction period TX and the charging correction amount ΔX are set based on the coolant temperature TW, but the rising correction period TX and the charging correction amount ΔX are set based on the detection value of the oil temperature sensor. You can also. Further, the oil temperature is estimated based on at least one of the intake air temperature, the elapsed time from the previous engine stop to the current engine start, and the outside air temperature, and the rising correction period TX and the filling correction based on the estimated oil temperature. The amount ΔX can also be set.

  In the above embodiment, the operation mode of the oil control valve 82 is set to mode A1 until the post-start period TC reaches the increase correction period TX, but the period set to mode A1 is shorter than the increase correction period TX. You can also In addition to the increase correction period TX, the set period of the mode A1 can be set according to the temperature of the hydraulic oil. As an example of the setting mode in this case, there is an example in which the setting time of mode A1 is increased as the temperature of the hydraulic oil is lower.

In the above embodiment, the operation mode of the oil control valve 82 is set to the mode A1 during the ascent correction period TX, but it can be set to the mode A2.
In the above embodiment, when the post-start period TC is equal to or greater than the increase correction period TX, the operation mode of the oil control valve 82 is set to mode A2, but is set to any of modes A3 to A5 without passing through mode A2. You can also.

  In the above embodiment, when the operation mode of the oil control valve 82 is set to mode A1, the hydraulic oil is supplied to the advance chamber 37 and the hydraulic oil of the retard chamber 38 is discharged. This can be changed as follows. That is, when the operation mode of the oil control valve 82 is set to mode A1, the hydraulic oil in the advance chamber 37 is discharged and the hydraulic oil is supplied to the retard chamber 38. Further, the hydraulic oil can be supplied to the advance chamber 37 and the hydraulic oil can be supplied to the retard chamber 38.

  In the above embodiment, the modes A1 to A5 are provided as the operation modes of the oil control valve 82, but other operation modes can be added to the modes A1 to A5. Also, one of mode A1 and mode A2 can be omitted.

  In the above embodiment, the hydraulic oil supply / discharge mode for the advance chamber 37, the retard chamber 38, and the release chambers 54 and 64 is controlled by the single oil control valve 82. The hydraulic oil supply / discharge mode of the corner chamber 38 and the hydraulic oil supply / discharge mode of the release chambers 54 and 64 can be controlled by separate oil control valves.

  In the above embodiment, the first opening mechanism 71 and the second opening mechanism 72 are provided in the variable valve timing mechanism 30, but at least one of the first opening mechanism 71 and the second opening mechanism 72 can be omitted.

  In the above embodiment, the advance angle chamber discharge oil passage 97 and the retard angle chamber discharge oil passage 98 are provided in the variable valve timing mechanism 30, but at least one of the advance angle chamber discharge oil passage 97 and the retard angle chamber discharge oil passage 98 is provided. Can be omitted.

  In the above embodiment, the hydraulic oil supply / discharge mode for the release chambers 54 and 64 is controlled by the release oil passage 95 to control the operation of the limit pins 51 and 61. However, the advance oil passage 93 and the retard angle are controlled. The operation of the limit pin can be controlled by the hydraulic oil supplied to at least one of the oil passages 94.

  In the above-described embodiment, the restricting pins 51 and 61 are provided on the vane rotor 35 and the engaging grooves 56 and 66 are provided on the housing rotor 31. However, this can be changed as follows. That is, at least one of the restricting pins 51 and 61 can be provided on the housing rotor 31, and at least one of the engaging grooves 56 and 66 can be provided on the vane rotor 35.

In the above embodiment, the first restriction groove 56 including the first lower groove 57 and the first upper groove 58 is formed in the first restriction mechanism 50. It is also possible to add at least one of (A) and (B).
(A) Instead of the first lower groove 57, a hole into which the first limit pin 51 is fitted is formed in the intermediate phase PM. In this case, the first upper groove 58 is extended to the hole of the intermediate phase PM.
(B) The first upper groove 58 is omitted.

In the above embodiment, the second restriction groove 60 including the second lower groove 67 and the second upper groove 68 is formed in the second restriction mechanism 60. It is also possible to add at least one of (A) and (B).
(A) Instead of the second lower groove 67, a hole into which the second limit pin 61 is fitted is formed in the intermediate phase PM.
(B) The second upper groove 68 is omitted.

  In the above embodiment, as the structure of the variable valve timing mechanism 30, the structure in which the respective limit pins 51 and 61 move in the axial direction of the vane rotor 35 is adopted. However, the following modifications can be made. In other words, the limit pins 51, 61 are provided on the vane 35A so that the limit pins 51, 61 move in the radial direction with respect to the vane rotor 35, and the respective portions of the housing rotor 31 corresponding to the limit pins 51, 61 are associated with each other. Joint grooves 56 and 66 can also be provided.

  In the above embodiment, the variable valve timing mechanism 30 for changing the valve timing VT of the intake valve 21 is adopted. However, instead of or in addition to this, the variable valve timing mechanism for changing the valve timing VT of the exhaust valve 23. Can also be adopted.

  In the above embodiment, the fixing mechanism 40 for fixing the valve timing VT to the intermediate angle VTmdl is provided. However, instead of or in addition to this, the most advanced angle for fixing the valve timing VT to the most advanced angle VTmax. A fixing mechanism may be provided in the valve timing variable mechanism 30.

  In the above embodiment, the fixing mechanism 40 for fixing the valve timing VT to the intermediate angle VTmdl is provided. However, instead of or in addition to this, the most retarded angle for fixing the valve timing VT to the most retarded angle VTmin. A fixing mechanism may be provided in the valve timing variable mechanism 30.

  -The structure of the variable valve apparatus used as the application object of this invention is not restricted to the structure illustrated by the said embodiment. That is, the present invention is applicable to any variable valve operating device as long as the device includes a hydraulic variable valve operating mechanism having a function of changing the valve timing and a function of fixing the valve timing to a specific angle by the fixing mechanism. Can be applied, and even in that case, an effect similar to the effect of the above embodiment can be obtained.

  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 ... Valve operating device, 21 ... Intake valve, 22 ... Intake cam Shaft, 23 ... exhaust valve, 24 ... exhaust camshaft, 30 ... variable valve timing mechanism (variable valve mechanism), 31 ... housing rotor, 32 ... housing body, 32A ... partition wall, 33 ... sprocket, 34 ... cover, 35 ... Vane rotor, 35A ... Vane, 36 ... accommodating chamber, 37 ... advanced chamber, 38 ... retarded chamber, 40 ... fixing mechanism, 50 ... first limiting mechanism, 51 ... first limiting pin, 51A ... outer pin, 51B ... Inner pin, 52 ... first restriction spring, 52A ... outer spring, 52B ... inner spring, 53 ... first restriction chamber, 54 ... first release chamber, 55 ... first spring chamber, 56 ... first Fitting groove, 56A ... first advance end, 56B ... first retard end, 56C ... second retard end, 57 ... first lower groove, 58 ... first upper groove, 60 ... second limiting mechanism 61 ... second limit pin, 61A ... outer pin, 61B ... inner pin, 62 ... second limit spring, 62A ... outer spring, 62B ... inner spring, 63 ... second limit chamber, 64 ... second release chamber, 65 2nd spring chamber, 66 ... 2nd engagement groove, 66A ... 2nd advance end, 66B ... 3rd retard end, 66C ... 4th retard end, 67 ... 2nd lower step groove, 68 ... Second upper groove, 70 ... Opening mechanism, 71 ... First opening mechanism, 71A ... Air opening passage, 71B ... Advance chamber opening passage, 71C ... Delay chamber opening passage, 72 ... Second opening mechanism, 72A ... Air opening Passage, 72B ... advance chamber release passage, 72C ... retard chamber release passage, 80 ... hydraulic mechanism, 81 ... oil pump, 82 ... oil control Control valve, 90 ... hydraulic oil passage, 91 ... supply oil passage, 92 ... discharge oil passage, 93 ... advance oil passage, 94 ... retard oil passage, 95 ... release oil passage, 96 ... vane discharge oil passage, 97 ... advance Corner chamber exhaust oil passage, 98 ... retard chamber exhaust oil passage, 100 ... control device, 101 ... electronic control device, 102 ... crank position sensor, 103 ... cam position sensor, 104 ... cooling water temperature sensor.

Claims (6)

A hydraulic variable valve mechanism having a function of changing the valve timing by changing the volume of the advance chamber and the retard chamber and a function of fixing the valve timing to a specific angle by a fixing mechanism; In a variable valve operating apparatus for an internal combustion engine comprising an advance chamber and a pump for supplying hydraulic oil to the retard chamber,
Hydraulic oil filling control is performed to make the idle rotation speed when the elapsed period after the start of the engine is smaller than the predetermined period larger than the idle rotation speed when the elapsed period is larger than the predetermined period. A variable valve operating device for an internal combustion engine. The variable valve operating apparatus for an internal combustion engine according to claim 1,
In the hydraulic oil filling control, control is performed to increase the idle rotation speed when the elapsed period is smaller than the control period as the predetermined period, and when the elapsed period is greater than the control period, the idle rotation speed is controlled. The variable valve operating apparatus for an internal combustion engine is characterized in that the control for increasing the pressure is terminated. The variable valve operating apparatus for an internal combustion engine according to claim 2,
The variable valve operating apparatus for an internal combustion engine, wherein the control period is set based on a temperature of hydraulic oil. The variable valve operating apparatus for an internal combustion engine according to any one of claims 1 to 3,
A variable valve operating apparatus for an internal combustion engine, wherein the temperature of hydraulic oil is estimated based on at least one of an engine cooling water temperature, an intake air temperature, an elapsed time from the previous engine stop to the current engine start, and an outside air temperature . The variable valve operating apparatus for an internal combustion engine according to any one of claims 1 to 4,
The variable valve operating apparatus includes a hydraulic control valve having a plurality of operation modes for controlling a supply mode of hydraulic oil in the advance chamber, the retard chamber, and the fixing mechanism,
The fixing mechanism is a fixed operation state in which the valve timing is fixed to the specific angle according to an operation mode of the hydraulic control valve, or an operation state in which the valve timing is released from being fixed to the specific angle. Is changed to the release operation state,
The hydraulic control valve has, as the plurality of operation modes, a first mode that maintains an operation state of the fixing mechanism in the fixed operation state and supplies hydraulic oil to at least one of the advance chamber and the retard chamber. And a second mode for maintaining the operation state of the fixing mechanism in the fixed operation state and supplying a smaller amount of hydraulic oil than the first mode to at least one of the advance chamber and the retard chamber, The variable valve operating apparatus for an internal combustion engine, wherein the first mode is set when the hydraulic oil filling control is performed. The variable valve operating apparatus for an internal combustion engine according to any one of claims 1 to 5,
An intermediate angle between a most advanced angle and a most retarded angle is set as the specific angle. A variable valve operating apparatus for an internal combustion engine, characterized in that:

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