JP6380256B2 - Variable valve operating device for internal combustion engine - Google Patents

Description

  The present invention relates to a variable valve operating apparatus for an internal combustion engine.

  Various lift variable mechanisms that change the operating characteristics of an intake valve or an exhaust valve of an internal combustion engine have been proposed. For example, the variable valve device of Patent Document 1 includes a cam lobe member that protrudes and retreats from a cam base member that is integrally disposed on a camshaft, and the cam lobe member is protruded or retracted (stored) in two steps by hydraulic pressure. The lift amount of the intake valve or exhaust valve is varied. Specifically, by controlling the oil control valve disposed in the oil passage, the cam lobe member is selectively switched between a supply state in which a hydraulic pressure higher than a predetermined pressure is supplied and a stop state in which the hydraulic supply is stopped. The state is selectively switched.

  Further, in Patent Document 2, in order to switch from the driving state of the intake valve by the low-speed cam in the intake camshaft to the driving state by the high-speed cam according to the change in the operating state, Disclosed is a valve timing control device that shifts to a supply state. In this device, when shifting from the hydraulic supply stop state to the hydraulic pressure supply state, the rotational speed of the electric oil pump is increased in the operation region immediately before the shift compared to other times. By increasing the pressure just upstream of the oil control valve as the number of rotations of the electric oil pump increases, a mechanism that switches the drive state of the intake valve immediately when the oil control valve is opened to supply hydraulic pressure It is made to operate.

International Publication No. 2014/030226 JP 2000-345872 A

  By the way, in the apparatus of Patent Document 2, when the transition from the hydraulic pressure supply stop state to the hydraulic pressure supply state is made, the rotation speed of the electric oil pump is constantly increased. However, depending on the operation state immediately before the transition, the supply hydraulic pressure of the oil pump may already be sufficiently higher than the hydraulic pressure required for switching the variable mechanism. In such a case, uniform control of such an oil pump will only result in energy consumption and will not contribute to improving the responsiveness of the mechanism.

  Accordingly, an object of the present invention is to more suitably improve the responsiveness of hydraulic control in a variable valve apparatus.

According to one aspect of the invention,
A variable mechanism that is provided in a valve mechanism of an internal combustion engine and changes the operating characteristics of an intake valve or an exhaust valve of the internal combustion engine by hydraulic pressure;
An oil control valve for controlling the amount of hydraulic oil supplied to the variable mechanism;
A variable oil pump provided upstream of the oil control valve;
A control unit for controlling the opening of the oil control valve in accordance with the operating state of the internal combustion engine, and for controlling the oil pump so as to vary the discharge capacity of hydraulic oil in accordance with the operating state of the internal combustion engine; A variable valve operating apparatus for an internal combustion engine comprising:
When the operating state of the internal combustion engine is in the operating region, the control unit supplies the variable mechanism with an amount of operating oil that operates the variable mechanism, and the operating state of the internal combustion engine is outside the operating region. Controlling the oil control valve so that the variable mechanism is not supplied to the variable mechanism when the variable mechanism is in the region,
The non-operation area has a switching preparation area adjacent to the operation area,
The switching preparation area is an operation area determined along a boundary between the non-operation area and the operation area,
The controller is
When the operating state of the internal combustion engine is in the switching preparation region and the discharge capacity set by the oil pump is in an operating region below a predetermined level,
When the rotational speed of the internal combustion engine is less than a predetermined value, the oil pump is controlled to increase the discharge capacity of the oil pump to the predetermined level or more,
When the rotational speed of the internal combustion engine is equal to or higher than the predetermined value, the hydraulic pump supplies less hydraulic fluid to the variable mechanism without increasing the discharge capacity of the oil pump to the predetermined level or higher. The oil control valve is controlled so that the opening of the oil control valve becomes the predetermined opening.
A variable valve operating apparatus for an internal combustion engine is provided.

  In the variable valve operating apparatus for an internal combustion engine according to the above aspect of the present invention, when the operating state of the internal combustion engine is in the switching preparation region and the discharge capacity set by the oil pump is in the operating region below a predetermined level, the internal combustion engine When the rotational speed of the engine is less than a predetermined value, the oil pump is controlled to increase the discharge capacity of the oil pump to a predetermined level or higher. When the rotational speed of the internal combustion engine is higher than the predetermined value, the discharge of the oil pump is controlled. Without increasing the capacity above the predetermined level, the opening of the oil control valve is such that the opening of the oil control valve is at a predetermined opening that supplies less than the amount by which the variable mechanism operates to the variable mechanism. The oil control valve is controlled. Thus, even when the operating state of the internal combustion engine is in the switching preparation region, when the oil pump is additionally operated and controlled when the discharge capacity set by the oil pump is in the operating region below a predetermined level, There are times when it is not. Therefore, according to the one aspect of the present invention, by limiting the additional operation of the oil pump, it is possible to improve the operation responsiveness by the hydraulic pressure of the variable mechanism while suppressing energy consumption. The effect is demonstrated.

It is a conceptual diagram which shows the outline of the variable valve operating apparatus of the internal combustion engine which concerns on this embodiment. It is a whole perspective view of a variable mechanism. It is a vertical front view of a variable mechanism, and shows a state when the cam lobe member is in the retracted position. It is a vertical front view of a variable mechanism, and shows a state when a cam lobe member is in a protruding position. It is the sectional view on the AA line in FIG. 3 for demonstrating the action | operation of a variable mechanism. It is the sectional view on the AA line in FIG. 4 for demonstrating the action | operation of a variable mechanism. It is sectional drawing for demonstrating the action | operation of a variable mechanism. It is sectional drawing for demonstrating the action | operation of a variable mechanism. The map for control of an oil control valve and an oil pump is shown. It is an enlarged view of FIG.9 (c). It is a flowchart of the basic control of an oil control valve. 6 is a flowchart for controlling the oil control valve and the oil pump when the operating state of the internal combustion engine is in a non-operating region.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  In FIG. 1, a variable valve operating apparatus according to an embodiment of the present invention includes a variable mechanism 40 that is provided in a valve operating mechanism of an engine (internal combustion engine) 1 and changes an operating characteristic (that is, valve opening characteristic) of an intake valve 25. It consists of

  Here, the variable mechanism 40 is a lift variable mechanism, and is configured to be able to change the lift amount of the intake valve in accordance with the engine rotation speed and the engine load, that is, the operating state. The engine 1 is an in-line four-cylinder diesel engine for vehicles. However, the type of engine to which the present invention is applied is arbitrary, and the use or purpose of use of the present invention is not limited to changing the valve lift amount according to the engine rotational speed and load. That is, in the present embodiment, the variable mechanism 40 mainly changes the lift amount of the intake valve 25. However, the present invention provides at least one of valve timing, operating angle, and lift amount by hydraulic pressure. The present invention can be applied to various engines including a variable mechanism that is variable. Two intake valves 25 are provided for each cylinder. In FIG. 1, only the intake valve 25 and the variable mechanism 40 related to one cylinder are illustrated, and other cylinders and peripheral mechanisms related to these other cylinders are not shown. The present invention may be applied not only to the intake valve but also to the exhaust valve.

  The engine 1 is provided with a variable oil pump 4 for pumping hydraulic oil in an oil pan 2 through an oil strainer 3 and pumping it. Here, the oil pump 4 is of a mechanical type driven by a crankshaft. The oil pump 4 is configured to vary the discharge capacity of hydraulic oil (specifically, the discharge amount at the same engine speed). The oil pump 4 is a two-stage variable discharge pump, more specifically, a two-stage variable displacement pump. The oil pump 4 is controlled such that when the engine operating state is in the low hydraulic operation region, the discharge capacity is on the low level side, thereby having an oil discharge amount with a relatively small volume. On the other hand, the oil pump 4 is controlled such that when the engine operating state is in the high hydraulic operating region (outside the low hydraulic operating region), the discharge capacity is on the high level side. Compared to when in the operating region, the oil discharge amount is relatively large. However, the discharge amount per rotation of the oil pump 4 may be made variable by the number of stages greater than two stages or continuously. The oil pump may be an electric type that is operated by a motor.

  An oil filter 6 is provided in the hydraulic oil supply passage 5 connected to the discharge port of the oil pump 4, and an oil control valve (OCV) is provided in a supply route (supply oil passage) to the variable lift mechanism 40 on the downstream side. ) 7 is provided. The oil control valve 7 is an electromagnetically driven flow control valve having a single spool valve that protrudes and retracts in the axial direction by, for example, a solenoid, and the opening area of the output port is controlled by controlling the amount of operation in the axial direction. Thus, the hydraulic fluid pumped from the oil pump 4 can be supplied to the variable mechanism 40. The oil control valve 7 can also drain (discharge) the hydraulic oil in the variable mechanism 40 in a state where the supply amount to the variable mechanism 40 is zero. The variable mechanism 40 operates by changing the amount of hydraulic oil supplied from the oil control valve 7.

  Next, the variable mechanism 40 will be described with reference to FIGS. The variable mechanism 40 can change the lift amount of the intake valve 25 between the low lift state and the high lift state by the hydraulic pressure of the hydraulic oil. Here, the “low lift state” refers to a state in which the intake valve 25 is lifted over a relatively low lift amount of the two selective lift amounts, and the “high lift state” refers to the state in which the intake valve 25 is It means a state where the lift is carried out over a relatively high lift amount among the two lift amounts. A rocker arm 24, a valve spring 26 and a hydraulic lash adjuster 27 are provided for each intake valve 25. The rocker arm 24 is provided with a roller, and is swung by the variable mechanism 40 with the hydraulic lash adjuster 27 as a fulcrum, whereby the intake valve 25 is lifted or opened.

  As shown in FIG. 2, the variable mechanism 40 includes a drive shaft 41 and a cam unit 42 that is coaxially connected and fixed to the drive shaft 41. The cam unit 42 is provided for each cylinder, but may be provided across a plurality of cylinders. However, the attachment method of the cam unit 42 with respect to the drive shaft 41 is arbitrary. Thus, the variable mechanism 40 as a whole extends in the cylinder row direction, that is, in the crankshaft axis direction so as to cover all cylinders.

  The drive shaft 41 and the cam unit 42 have a common center axis X. Here, for convenience, the direction of the central axis X is simply referred to as the axial direction.

  The drive shaft 41 is rotatably supported on the cylinder head by a bearing (not shown). The drive shaft 41 is connected at one end thereof to the crankshaft via a power transmission mechanism such as a belt / pulley mechanism. Therefore, both the drive shaft 41 and the cam unit 42 are rotationally driven by the drive force from the crankshaft. The rotation direction of the drive shaft 41 and the cam unit 42 is indicated by R in the figure. A known variable valve timing mechanism may be provided between the drive shaft 41 and the power transmission mechanism.

  The cam unit 42 includes a cam base member 43 that forms a main body thereof, and two cam lobe members 44 that are arranged independently or connected to the front side and the rear side of the single cam base member 43 and that can swing or pivot. One cam lobe member 44 corresponds to one intake valve 25.

  The cam base member 43 is formed to have a larger diameter than the drive shaft 41, and an outer peripheral surface thereof is a low lift cam portion 45 for realizing a low lift state. The low lift cam portion 45 has a positive lift amount with respect to the base circle 45a (see FIGS. 2 and 3). The low lift cam portion 45 is provided at a position corresponding to the two intake valves 25. Each low lift cam portion 45 is provided with a slit 46, and a cam lobe member 44 is inserted into each slit 46. The cam lobe member 44 has a substantially U-shape as shown in FIGS. However, the lift amount of the low lift cam portion may be zero. Further, the lift amount by the low lift cam portion for the two intake valves may be different, and in this case, one lift amount may be zero.

  In the cam base member 43, a recess 47 is formed between the two low lift cam portions 45. A support shaft 48 is provided so as to penetrate the cam base member 43 in the axial direction. The support shaft 48 is inserted into the shaft hole 49 of the base end portion 44 </ b> B of the cam lobe member 44. Thereby, the cam lobe member 44 can turn or swing around the support shaft 48.

  The cam lobe member 44 can swing between a retracted position (shown in FIG. 3) that does not protrude from the cam base member 43 and a protruded position (shown in FIG. 4) that protrudes radially outward from the cam base member 43 to the maximum extent. . The protruding position corresponds to the high lift state, and the retracted position corresponds to the low lift state. The two cam lobe members 44 are respectively provided with stopper pins 50 protruding in the axial direction, and these stopper pins 50 are slidably inserted into the long holes 51 provided in the cam base member 43. The movement of the stopper pin 50 is restricted by the long hole 51, and as a result, the swing range of the cam lobe member 44, in particular, the protruding position is defined. Although described later in detail, the cam lobe member 44 is locked at the protruding position. The cam lobe member 44 is not locked in the retracted position, and the cam lobe member 44 is lost (retracted into the slit 46) by the valve spring reaction force via the rocker arm 24 each time it rotates. In addition, you may further employ | adopt the mechanism in which the cam lobe member 44 is locked in a retracted position.

  In FIG. 2, for convenience, the cam lobe member 44 located in the axially forward Fr is in the retracted position and the cam lobe member 44 located in the axially rearward Rr is in the protruding position. Located in the same position.

  The recess 47 is provided with two springs 52 and 52 for urging the two cam lobe members 44 toward the protruding positions. The spring 52 is a torsion spring biased in the expanding direction and is wound around the support shaft 48. A base end portion of the spring 52 is fixed to the cam base member 43 via a fixed shaft 53. The tip end of the spring 52 is engaged with the stopper pin 50, and the stopper pin 50 and thus the cam lobe member 44 are urged toward the protruding position.

  Thus, when the cam lobe member 44 is in the protruding position, the cam unit 42 can bring the intake valve 25 into a high lift state. On the other hand, when the cam lobe member 44 is in the retracted position, the cam unit 42 places the intake valve 25 in a low lift state.

  In addition, the variable mechanism 40 includes a lock mechanism 60 (see FIG. 5) for switching the lock state of the cam lobe member 44 at the projecting position, specifically, a lock mechanism 60 for locking the cam lobe member 44 at the projecting position. Prepare. Hereinafter, the configuration of the lock mechanism 60 and the operation of the variable mechanism 40 will be described with reference to FIGS. 5-8 schematically represent the AA cross section of FIG. 3 in each state. 5-8, the rocker arm 24 and the intake valve 25 are added for easy understanding.

  FIG. 5 shows a state when the cam lobe member 44 is in the retracted position as shown in FIG. Here, as can be understood from the above description and related drawings, the cam unit 42 is configured to be symmetrical in the longitudinal direction in the axial direction. Accordingly, only the configuration on the front side will be described here. It will be understood that this description applies to the rear configuration as well.

  A supply path 61 extending coaxially with the central axis X is provided inside the drive shaft 41 and the cam base member 43. A path 62 extending radially outward from the supply path 61 is formed in the cam base member 43. The path 62 extends outward in the radial direction, and then extends forward and backward in the axial direction toward the slit 46.

  Inside the cam base member 43, a pin hole 64H communicating with the path 62 and a pin hole 65H coaxial with the pin hole 64H and having the same diameter are provided. The pin holes 65H are located at positions facing each other across the slit 46 from the pin hole 64H. Pins 64P and 65P having the same diameter are slidably inserted into the pin holes 64H and 65H, respectively. The pin hole 65H is provided with a spring 65S for urging the pin 65P toward the slit 46 side.

  By changing the engagement state of these pins 64P, 65P, 66P and the pin holes 64H, 65H, 66H, the cam lobe member 44 can be locked at the protruding position.

  Hydraulic oil or hydraulic pressure is supplied from the oil pump 4 to the supply path 61 via the oil control valve 7.

  FIG. 5 shows a state when the cam lobe member 44 is in the retracted position as shown in FIG. At this time, the supply path 61 is not supplied with an operable amount and pressure of hydraulic oil (hydraulic off state), and as shown in FIG. 5, the pin 66P inserted into the pin hole 66H of the cam lobe member 44. Is prevented from moving in the axial direction on the wall surface of the slit 46. Although the cam lobe member 44 is always urged in the protruding direction by the spring 52, as described above, it is not locked in the retracted position. Therefore, the cam lobe member 44 is lost by the reaction force of the valve spring via the rocker arm 24 (slit 46). Evacuation operation). Therefore, only the low lift cam portion 45 acts on the rocker arm 24, and the cam lobe member 44 does not substantially contribute to the lift amount.

  In this state, when the cam base member 43 rotates and the cam lobe member 44 comes to a position where it does not ride on the rocker arm 24, the cam lobe member 44 is biased by the spring 52 (FIG. 2) that applies force in the protruding direction, and the drive shaft 41. It gradually moves to the protruding position due to centrifugal force due to rotation. During this movement, the cam lobe member 44 carries the pin 66P while holding the pin 66P in its own pin hole 66H. In the process of lost operation for each rotation (outward path and return path), the axis of the pin 66P coincides with the axis of the pin holes 64H and 65H. Does not engage with the pin hole 65H.

  From this state, the operation when the cam lobe member 44 is moved to the protruding position and locked to the protruding position is as follows. First, the oil control valve 7 connects the oil passage to the variable mechanism 40 and supplies the supply passage 61 with an operable amount (that is, a predetermined pressure or more). When the cam lobe member 44 moves from the retracted position to the protruding position, the axis of the pin 66P coincides with the axes of the pin holes 64H and 65H, as shown in FIG. FIG. 6 shows a state when the cam lobe member 44 reaches the protruding position. At this time, the pin hole 66H of the tip end portion 44C of the cam lobe member 44 is aligned with the pin holes 64H and 65H of the cam base member 43.

  Since the supply of the operable oil is still continued, when the cam lobe member 44 is in the protruding position, as shown in FIG. 7, the pins 64P, 65P, 66P are spring 65S by the hydraulic pressure from the path 62. The pin 64P is inserted in common in a state straddling the pin holes 64H and 66H. Accordingly, as shown in FIG. 4, the cam lobe member 44 is locked to the cam base member 43 at the protruding position. In order to keep the cam lobe member 44 locked in the protruding position, it is necessary to maintain the supply of hydraulic oil in an amount that the lock mechanism 60 can operate.

  Next, the operation when the cam lobe member 44 is moved from the protruding position to the retracted position will be described.

  First, from the state shown in FIG. 7, the supply of the operable amount of hydraulic oil is stopped. That is, the oil control valve 7 is set to the drain position, the supply of hydraulic oil to the supply path 61 is stopped, and the oil is discharged from the supply path 61. Then, as shown in FIG. 8, the pins 64P, 65P, 66P are pushed toward the path 62 by the spring 65S, and the pins 64P, 66P are disengaged from the pin holes 65H, 66H. That is, the three pins 64P, 65P, 66P are arranged only in the corresponding pin holes 64H, 65H, 66H, respectively. As a result, the cam lobe member 44 is unlocked from the protruding position, and the cam lobe member 44 can move toward the retracted position.

  When the cam base member 43 rotates in this state and the cam lobe member 44 rides on the rocker arm 24, the cam lobe member 44 gradually moves to the retracted position by the reaction force of the valve spring. During this movement, the cam lobe member 44 carries the pin 66P while holding the pin 66P in its own pin hole 66H. In this way, the cam lobe member 44 returns to the retracted state of FIG.

  In summary, the cam lobe member 44 is locked at the protruding position when an amount of hydraulic oil that can be operated by the lock mechanism 60 is supplied, and is not locked when the amount of hydraulic oil is not supplied. Can be done. Here, the supply state of the operable amount of hydraulic oil is realized when the engine operating state is in a predetermined operating range (hereinafter referred to as the operating range), and the non-operating amount of hydraulic fluid is not supplied. The supply state is realized when the operating state of the engine is in a predetermined non-operation region (hereinafter referred to as a non-operation region) outside the operation region.

  The oil control valve 7 and the oil pump 4 are respectively connected to an electronic control unit (hereinafter referred to as “ECU”) 100 (see FIG. 1) as a control unit. The ECU 100 includes an arithmetic device (for example, a CPU), a storage device (for example, a ROM, a RAM), an input / output port, etc., all not shown. In the ECU 100, various sensors include, for example, an engine rotation speed sensor 101 for detecting the engine rotation speed, an engine load sensor 102 for detecting the engine load, and a water temperature sensor 103 for detecting the cooling water temperature of the engine. Are electrically connected via an A / D converter or the like (not shown). As the engine rotation speed sensor 101, a crank angle sensor for detecting a crank angle may be used. As the engine load sensor 102, for example, at least one of an accelerator opening sensor for detecting the accelerator opening, an intake pressure sensor for detecting the intake pressure, and an air flow meter for detecting the intake air amount is used. Use it. The ECU 100 controls the oil control valve 7, the oil pump 4, and the like in addition to the fuel injection valve in accordance with the operating state of the engine 1 based on the detection values of various sensors. The ECU 100 stores a control program for controlling the oil control valve 7 in accordance with the operating state of the engine 1 and various maps referred to when the control program is executed. Similarly, the ECU 100 stores a control program for controlling the oil pump 4 according to the operating state of the engine 1 and various maps referred to when the control program is executed.

Specifically, the ECU 100 stores (stores) the mapped data shown in FIGS. 9A to 9C. FIG. 10 is an enlarged view of FIG. Although details will be described later, FIGS. 9 and 10 are based on the above two controls. The preconditioning control is simply shown in the following (A) and (B).
(A) The oil control valve 7 supplies an amount of hydraulic oil that can actuate the lock mechanism 60 of the variable mechanism 40 (that is, an amount that can lock the cam lobe member 44 in the protruding position) when the engine is in the operating range. In order to supply, it is controlled to a predetermined opening, here fully open. On the other hand, when the engine operating state is in the non-operating region, the oil control valve 7 is controlled to the closed side so as not to supply such amount of hydraulic oil.
(B) The oil pump 4 having a variable two-stage discharge amount is controlled such that when the engine operating state is in a predetermined low hydraulic pressure operation region (hereinafter referred to as a low hydraulic pressure region), the discharge capacity is on the low level side. On the other hand, the oil pump 4 is controlled such that when the engine operating state is in a predetermined high hydraulic pressure operation region (hereinafter referred to as a high hydraulic pressure region), the discharge capacity is on the high level side.

  Now, when there was not enough hydraulic oil between the oil control valve 7 and the lock mechanism 60 (for example, the supply path 61), the engine was closed when the operating state shifted from the non-operating region to the operating region. Even when the oil control valve 7 is fully opened, it may be difficult to cause the operation of the lock mechanism 60 within a predetermined cycle. Such a response delay may be improved from the viewpoints of drivability and engine fuel consumption improvement.

  On the other hand, like the engine 1, for example, a variable oil pump (for example, an oil pump in which the volume of the hydraulic oil chamber of the oil pump is variable according to the operation state of the engine) is provided so as to suppress energy loss. Depending on the operating condition of the engine, when it shifts from the non-operating area to the operating area, the set discharge capacity of the oil pump has already increased to a level sufficient for suitable operation of the locking mechanism There can be. In such a case, measures for improving the response delay of the lock mechanism 60 (for example, measures described in Patent Document 2) will not be required.

  Therefore, in the engine 1, at least one of the oil control valve 7 and the oil pump 4 is controlled as necessary before the operation state of the engine shifts from the non-operation region to the operation region. As shown in FIG. 10, a switching preparation area AP adjacent to the operating area AA is defined in the non-operating area AN as an operating area in the previous stage where the engine operating state shifts from the non-operating area to the operating area. The switching preparation area AP is an operation area determined along the boundary between the non-operation area AN and the operation area AA. Here, when the operating state of the engine is in the non-operating area AN, when shifting to the switching preparation area AP, the lock mechanism 60 is operated with good responsiveness when the operating state subsequently reaches the operating area AA. The control described later is performed so that Briefly, when the engine operating state is in the non-operating area AN and the transition is made to the switching preparation area AP, the locking mechanism 60 is not operated between the oil control valve 7 and the locking mechanism 60 as necessary. In addition to or instead of this, the discharge capacity of the oil pump 4 is made higher than the discharge capacity corresponding to the engine operating state. The data shown in FIGS. 9 and 10 are used to control the oil control valve 7 and the oil pump 4 when the engine operating state shifts to the switching preparation region in the non-operating region.

  First, FIG. 9 and FIG. 10 will be described in detail. As described above, FIG. 10 is an enlarged view of FIG. First, FIG. 10 will be described.

  In FIG. 10 (and FIG. 9C), the horizontal axis indicates the engine rotation speed, the vertical axis indicates the engine load, the non-operation area AN and the operation area AA, the high hydraulic pressure area BH, and the low hydraulic pressure area BL. Are shown superimposed. In FIG. 10, a line L1 indicates a boundary between the non-operation area AN and the operation area AA, and a line L2 indicates a boundary between the high hydraulic pressure area BH and the low hydraulic pressure area BL. The line L1 is a substantially straight line extending from the high load low rotation speed side toward the low load high rotation speed side, the non-operation area AN is an area on the low load low rotation side, and the operation area AA is a high load high rotation speed. This is the speed side area. Note that the line L1 may be, for example, a curved boundary depending on the control. In FIG. 10, an arrow a1 conceptually indicates the expansion of the operation area AA with reference to the line L1, and the arrow a2 conceptually indicates the expansion of the non-operation area AN with reference to the line L1. The line L2 is bent at a right angle in the middle, and defines the boundary between the low hydraulic pressure region BL on the low load low rotational speed side and the high hydraulic pressure region BH on the high load or high rotational speed side. Note that the line L2 may be bent at a certain angle (for example, an angle larger than 90 °) depending on the control. In FIG. 10, an arrow b1 conceptually indicates the expansion of the high hydraulic pressure region BH with reference to the line L2, and the arrow b2 conceptually indicates the expansion of the low hydraulic pressure region BL with reference to the line L2.

  As is clear from FIG. 10, the line L1 and the line L2 intersect, more precisely, at two places. As shown in FIG. 10, a switching preparation area AP adjacent to the operation area AA is defined in a band shape in the non-operation area AN. The width or width of the switching preparation area AP may be set according to the required responsiveness of the lock mechanism 60.

  On the other hand, FIG. 9A shows the pressure in the oil passage upstream of the oil control valve 7 (more specifically, the pressure in the oil passage between the oil control valve 7 and the oil pump 4) and the engine operating state. The relationship with the opening degree of the oil control valve 7 when it exists in the switching preparation area | region AP is shown. In FIG. 9A, the vertical axis represents the pressure in the oil passage upstream of the oil control valve 7 (hereinafter referred to as OCV pre-hydraulic pressure), and the horizontal axis represents the opening of the oil control valve 7 in the switching preparation region. I am taking a degree. The oil pressure before OCV in FIG. 9A is set in accordance with the engine operating state because the oil control valve 7 is closed and no oil is supplied to the lock mechanism 60 on the downstream side. It is determined based on the discharge capacity (specifically, the volume per rotation) and the engine speed at that time. The first predetermined pressure PA is an oil control valve that has been closed until the operating state of the engine is shifted from the non-operation area AN to the operation area AA when the pre-OCV oil pressure is equal to or higher than the first predetermined pressure PA. It is determined that the lock mechanism 60 can be operated within a predetermined cycle by opening 7 to a predetermined opening, here fully open. Accordingly, a preparation unnecessary area (corresponding unnecessary area) is defined when the pre-OCV hydraulic pressure is equal to or higher than the first predetermined pressure PA. However, when the pre-OCV hydraulic pressure is lower than the first predetermined pressure PA, the oil control valve 7 that has been closed until then is fully opened when the engine operating state shifts from the non-operating region AN to the operating region AA. Therefore, the lock mechanism 60 cannot be operated within a predetermined cycle. In particular, when the pre-OCV hydraulic pressure is lower than the third predetermined pressure PC (lower than the first predetermined pressure PA), even if the oil control valve 7 is controlled to open, the engine 1 can obtain a desired response. I can't. That is, when the pre-OCV hydraulic pressure is a pressure between the first predetermined pressure PA and the third predetermined pressure PC (for example, the second predetermined pressure PB), desired response can be obtained by controlling the oil control valve 7. Can do.

  9A is associated with the data in FIG. 9C by the data in FIG. 9B. The data of FIG. 9 (b) shows the engine rotation speed according to the discharge capacity of the oil pump 4 set according to the engine operating state, with the engine rotation speed on the horizontal axis and the pre-OCV hydraulic pressure on the vertical axis. The change in the pre-OCV hydraulic pressure due to is shown. A line L3 indicates a change in the pre-OCV hydraulic pressure according to the engine rotation speed when the discharge capacity of the oil pump is set to the high level side. A line L4 indicates a change in the pre-OCV hydraulic pressure according to the engine speed when the discharge capacity of the oil pump is set to the low level side.

  Control of the oil control valve 7 and the oil pump 4 using the data of FIG. 9 (and FIG. 10) will be further described based on the flowcharts of FIGS.

  In step S1101 of FIG. 11, it is determined whether the engine operating state is in a non-operating region. Here, the engine rotation speed is detected from the output of the engine rotation speed sensor 101, and the engine load is detected from the output of the engine load sensor 102. Then, by searching for data as shown in FIG. 10 and FIG. 9C based on the detected engine speed and engine load, that is, the engine operating state, whether or not the engine operating state is in the non-operating area AN. (That is, whether or not it is in the operation area AA).

  When the engine operating state is in the non-operation area AN, an affirmative determination is made in step S1101, and the non-operation flag is turned ON in step S1103. On the other hand, when the engine operating state is not in the non-operation area AN, that is, in the operation area AA, a negative determination is made in step S1101, and the non-operation flag is turned off in step S1105. Here, in the initial state, the non-operation flag is set to ON, but may be set to OFF.

  When the non-operation flag is set to OFF, the ECU 100 outputs an operation signal so that the oil control valve 7 is fully opened. Thereby, as described above, the hydraulic pressure is supplied to the lock mechanism 60 and the cam lobe member is locked at the protruding position.

  On the other hand, when the non-operation flag is set to ON, the reference control mode is set in the initial state. When the reference control mode is set, the ECU 100 outputs an operation signal so that the oil control valve 7 is closed, that is, the hydraulic oil is not supplied from the oil control valve 7 to the lock mechanism 60 side.

  Here, the case where the non-operation flag is set to ON will be further described with reference to FIG. FIG. 12 is a control flowchart executed when the non-operation flag is set to ON. Therefore, even when the control is performed based on the flowchart of FIG. 12, when the non-operation flag is turned OFF in step S1105, as described above, the oil control valve 7 is fully opened. .

  In step S1201, it is determined whether or not the engine operating state is in the switching preparation area AP (see FIGS. 10 and 9C). This determination is performed by searching the data of FIG. 10 based on the detected engine operating state, as in the determination in step S1101.

  Since the engine operating state is not in the switching preparation area AP, if a negative determination is made in step S1201, the reference control mode is set in step S1203 as in the initial state.

  On the other hand, since the engine operating state is in the switching preparation area AP, if an affirmative determination is made in step S1201, mapped data corresponding to the engine coolant temperature at that time is selected. The engine coolant temperature is detected based on the output signal of the water temperature sensor 103. Based on the detected engine coolant temperature, ECU 100 selects data mapped in accordance with the water temperature from predetermined data. The lower the engine cooling water temperature, the lower the temperature of the engine oil, and the lower the temperature of the oil, the higher the viscosity of the oil. The higher the viscosity of the hydraulic oil, the smaller the relief amount from the oil control valve 7, and the tendency for the oil to decrease in the supply oil passage on the downstream side of the oil control valve 7 becomes milder. That is, the higher the viscosity of the hydraulic oil, the lower the amount of oil leakage from the supply oil passage. Since the amount of oil between the oil control valve 7 and the lock mechanism 60 changes according to the amount of oil leakage, the responsiveness of the lock mechanism 60 is also affected. Thus, here, a plurality of maps set in accordance with the engine coolant temperature are stored, and one map (FIG. 9, particularly FIG. 9A) is selected from them. Note that it will be easily understood by those skilled in the art that the area for subdividing the switching preparation area AP, which will be described later, changes as FIG. 9A changes.

  In the next step S1207, it is determined whether or not the operating state of the engine is in the low hydraulic pressure region BL (see FIG. 10 and FIG. 9C). Since the engine operating state is in the low hydraulic pressure region, when an affirmative determination is made in step S1207, it is determined in step S1209 whether or not the engine operating state is in the incompatible region. The inoperable region is a lock mechanism when the pre-OCV hydraulic pressure is low and the engine operating state is in the switching preparation region AP with the discharge capacity of the oil pump set when the engine operating state is in the low hydraulic region. Even if the oil control valve 7 is opened at a predetermined opening degree less than full open so as to supply hydraulic oil to the extent that 60 does not operate, the oil control valve is fully opened when the engine operating state shifts to the operating range. By doing so, it indicates an operating region in which the lock mechanism 60 cannot be operated within a predetermined cycle. The non-corresponding region corresponds to the region III in FIGS. 10 and 9C, and corresponds to the region below the third predetermined pressure PC in FIG. 9A.

  If an affirmative determination is made in step S1209 because the engine operating state is in the unacceptable region, the pump control mode is set in step S1211. As a result, the ECU 100 outputs an operation signal to the oil pump 4 so that the discharge capacity of the oil pump set according to the operating state of the engine is changed to the high level side.

  On the other hand, if a negative determination is made in step S1209 because the engine operating state is not in the unacceptable region, an oil control valve control mode (hereinafter, OCV control mode) is set in step S1213. Thereby, the ECU 100 opens the opening of the oil control valve 7 so that the discharge capacity of the oil pump set in accordance with the operating state of the engine is not changed and the amount of hydraulic oil that does not operate the lock mechanism 60 is supplied. An operation signal is output to the oil control valve 7 so that the valve opens at a predetermined opening less than fully open and greater than fully closed. The predetermined opening at this time is variable according to the operating state of the engine based on the data (line L5) in FIG. In step S1209, since the engine operating state is not in the unacceptable region, a negative determination is made when the engine operating state is located in region IV of FIGS. 10 and 9C.

  Returning to step S1207, if a negative determination is made in step S1207 because the engine operating state is not in the low hydraulic pressure region BL (that is, the engine operating state is in the high hydraulic pressure region BH), in step S1215, the engine operating state is the corresponding required region. It is determined whether or not there is. Here, the required action area means that the engine operating state is a non-operating area when the discharge capacity of the oil pump is set according to the engine operating condition and the oil control valve 7 is fully closed. The operation region in which the lock mechanism 60 cannot be operated within a predetermined cycle by fully opening the oil control valve 7 when shifting from the operation region to the operation region is indicated. In other words, the handling required area refers to an area that needs to be handled in order to improve the responsiveness of the locking mechanism. The required area corresponds to the area I in FIGS. 10 and 9C.

  If an affirmative determination is made in step S1215 because the engine operating state is in the required response region, in step S1217, the OCV control mode is set in the same manner as in step S1213. On the other hand, when a negative determination is made in step S1215 because the engine operating state is not in the required area, the process reaches step S1203 and the reference control mode is set. In step S1215, since the engine operating state is not in the required area, a negative determination is made because the engine operating state is region II in FIGS. 10 and 9C (2 in FIGS. 9C and 10). When it is located in two separate areas.

  Further, control of the oil control valve 7 and the oil pump 4 will be described. When the operating state of the engine is in the switching preparation region AP and in the high hydraulic pressure region, it corresponds to the regions I and II in FIG. 9C and FIG. 10 (No determination in step S1207). At this time, since the discharge performance of the oil pump is set on the high level side, the relationship of line L3 is established in FIG. 9B. Looking at the region I via the line L3, the region I corresponds to a region between the first predetermined pressure PA and the third predetermined pressure PC in FIG. In this region I, the engine rotational speed is on the low rotational speed side as compared with the region II, so the pre-OCV hydraulic pressure is not high to the extent that preparation control is unnecessary. Therefore, in order to increase the responsiveness of the lock mechanism 60 to a desired level, the oil control valve 7 is controlled so as to have a predetermined opening along the line L5 shown in FIG. 9A (step S1217). The predetermined opening is obtained by obtaining the pre-OCV oil pressure along the line L3 in FIG. 9B at the detected engine speed, and the opening obtained along the line L5 in FIG. 9A by the pre-OCV oil pressure. It is. Note that the line L5 extends between the second predetermined pressure PB and the third predetermined pressure PC so as to be inclined at an angle close to a right angle with respect to the horizontal axis. This opening along the line L5 between the second predetermined pressure PB and the third predetermined pressure PC does not operate the lock mechanism, but the hydraulic oil in the oil path between the oil control valve 7 and the lock mechanism 60. The filling amount is determined to be almost full. For example, the constant opening is an opening of about 70% when the full opening is 100%.

  Region II corresponds to a preparation-unnecessary region equal to or higher than the first predetermined pressure PA in FIG. 9A (negative determination in step S1215). That is, since the discharge performance of the oil pump is set to the high level side and the engine rotation speed is on the high rotation speed side, the pre-OCV hydraulic pressure is increased to a level that does not require preparation control. Therefore, at this time, the oil control valve 7 is controlled to be fully closed (that is, the hydraulic oil is not supplied to the lock mechanism side) because the engine operating state is in the non-operating region and the reference control mode is set. The

  On the other hand, when the operating state of the engine is in the switching preparation area AP and in the low hydraulic pressure area, it corresponds to the areas III and IV of FIG. 9C (positive determination in step S1207). At this time, since the discharge performance of the oil pump is set on the low level side, the relationship of line L4 is established in FIG. 9B. Looking at the region IV via the line L4, the region IV is a region between the first predetermined pressure PA and the third predetermined pressure PC in FIG. 9A, particularly here, the second predetermined pressure PB and the third predetermined pressure. It corresponds to the area between the PC. In this region IV, the engine speed is higher than that in the region III, and therefore, the pre-OCV hydraulic pressure is not low in the region IV. Therefore, in order to increase the responsiveness of the lock mechanism 60 to a desired level, the oil control valve 7 is controlled to have a predetermined opening along the line L5 shown in FIG. 9A (step S1213). The predetermined opening is obtained by obtaining the pre-OCV oil pressure along the line L4 in FIG. 9B at the detected engine speed, and the opening obtained along the line L5 in FIG. 9A by the pre-OCV oil pressure. It is.

  Region III is a region (region where the engine rotational speed is lower than the predetermined value Na) lower than the region IV (the engine rotational speed is equal to or higher than the predetermined value Na). This corresponds to a non-corresponding region below a predetermined pressure (Yes in step S1209). In this state, since the pre-OCV hydraulic pressure is considerably low (because the set discharge capacity of the oil pump 4 is less than a predetermined level and the engine rotational speed is low), hydraulic oil is supplied to such an extent that the lock mechanism 60 does not operate. Even if the oil control valve 7 is opened, it is difficult to operate the lock mechanism 60 within a predetermined cycle even if the oil control valve 7 is fully opened when the operating state of the engine is shifted to the operation region. . Therefore, at this time, the oil pump 4 is controlled to the high level side so that the set discharge capacity of the oil pump 4 becomes a predetermined level or more.

  By setting the oil pump 4 to the high level side instead of setting according to the operating state of the engine, the relationship of the line L3 is established in FIG. 9B. Here, referring to FIG. 10 in which FIG. 9C is enlarged, among the regions III, the region IIIa on the high rotational speed side corresponds to the preparation unnecessary region in FIG. 9A, but the remaining regions. IIIb corresponds to a region between the first predetermined pressure PA and the third predetermined pressure PC in FIG. 9A, particularly here, a region between the first predetermined pressure PA and the second predetermined pressure PB. . Therefore, in the region IIIa, in the region IIIa, the oil control valve 7 is controlled to be fully closed as in the region II, but in the region IIIb, as in the region I, the oil control valve 7 is further controlled. It opens at a predetermined opening.

  Note that when the engine operating state is in the region III, the oil pump 4 is set to the high level side instead of the setting according to the engine operating state. However, this setting causes the engine operating state to be in the operating region AA. It may be canceled when transitioned, or may continue for a predetermined time after transition. The setting release timing of the oil pump 4 may be set according to the desired responsiveness to the lock mechanism 60.

  As described above, in the engine 1, the switching preparation area AP partially overlaps the operation area (the low hydraulic pressure area in the above embodiment) where the discharge capacity of the oil pump is set to be lower than a predetermined level. When the operating state of the engine is shifted directly from the operating region to the operating region, sufficient responsiveness of the lock mechanism 60 cannot be obtained simply by opening the oil control valve 7. Therefore, when the engine operating state is in such an operating region, the oil pump 4 is configured to increase the discharge capacity of the oil pump 4 to a predetermined level or more depending on the setting according to the engine operating state of the oil pump 4 and the engine speed. 4 and / or the opening degree of the oil control valve 7 is set to a predetermined opening degree so as to supply hydraulic oil less than the amount by which the lock mechanism 60 of the variable lift mechanism 40 is operated. Control the oil control valve. In particular, when the engine operating state is in the switching preparation region AP and the low hydraulic pressure region, and the engine rotation speed is equal to or higher than a predetermined value (predetermined speed), the discharge capacity of the oil pump is not increased to a predetermined level or higher. The oil control valve is controlled so that the opening of the oil control valve becomes a predetermined opening that supplies less than the amount that the variable mechanism operates to the variable mechanism. Further, when the engine operating state is in the operation region (high hydraulic pressure region in the above embodiment) in which the discharge capacity of the oil pump is set to a predetermined level or more in the switching preparation region AP, the lift is performed only when necessary. The oil control valve is controlled so that the opening degree of the oil control valve 7 becomes a predetermined opening degree that supplies less than the amount of hydraulic oil to which the lock mechanism 60 of the variable mechanism 40 is operated. Therefore, in the variable valve operating apparatus of the present embodiment applied to the engine 1, the additional operation to the high level side (that is, the high discharge amount side) of the oil pump 4 is limited, and according to the operating state of the engine. While suppressing energy consumption based on the discharge capacity of the oil pump 4, it is possible to more appropriately increase the operation response by the hydraulic pressure of the lock mechanism of the variable lift mechanism.

  Although one embodiment according to the present invention has been described above, the present invention allows various modifications. For example, as described above, the discharge capacity of the oil pump 4 is not limited to being changed to two stages, and may be variable in multiple stages or continuously. In order to increase the responsiveness of the mechanism 60 to a desired level, the discharge capacity of the oil pump may be increased to a predetermined level or higher. That is, in this case, it is desired to obtain a desired level of responsiveness of the lock mechanism 60, but since the oil pump discharge capacity is below a predetermined level, the responsiveness cannot be obtained. The oil pump should be controlled so that Further, in the region IIIb, both the additional control of the oil pump and the additional control of the oil control valve are performed. However, when the discharge capacity of the oil pump 4 is continuously variable, for example, compared to the region IIIa. In the region IIIb, the oil pump may be further controlled to set a higher discharge power capability level.

The embodiment of the present invention is not limited to the above-described embodiment, and includes all modifications, applications, and equivalents included in the concept of the present invention defined by the claims. Therefore, the present invention should not be construed as being limited, and can be applied to any other technique belonging to the scope of the idea of the present invention.

DESCRIPTION OF SYMBOLS 1 Engine 4 Oil pump 7 Oil control valve 24 Rocker arm 25 Intake valve 40 Variable mechanism 43 Cam base member 44 Cam lobe member 60 Lock mechanism 100 Electronic control unit (ECU)

Claims (1)

A variable mechanism that is provided in a valve mechanism of an internal combustion engine and changes the operating characteristics of an intake valve or an exhaust valve of the internal combustion engine by hydraulic pressure;
An oil control valve for controlling the amount of hydraulic oil supplied to the variable mechanism;
A variable oil pump provided upstream of the oil control valve;
A control unit for controlling the opening of the oil control valve in accordance with the operating state of the internal combustion engine, and for controlling the oil pump so as to vary the discharge capacity of hydraulic oil in accordance with the operating state of the internal combustion engine; A variable valve operating apparatus for an internal combustion engine comprising:
When the operating state of the internal combustion engine is in the operating region, the control unit supplies the variable mechanism with an amount of operating oil that operates the variable mechanism, and the operating state of the internal combustion engine is outside the operating region. Controlling the oil control valve so that the variable mechanism is not supplied to the variable mechanism when the variable mechanism is in the region,
The non-operation area has a switching preparation area adjacent to the operation area,
The switching preparation area is an operation area determined along a boundary between the non-operation area and the operation area,
The controller is
When the operating state of the internal combustion engine is in the switching preparation region and the discharge capacity set by the oil pump is in an operating region below a predetermined level,
When the rotational speed of the internal combustion engine is less than a predetermined value, the oil pump is controlled to increase the discharge capacity of the oil pump to the predetermined level or more,
When the rotational speed of the internal combustion engine is equal to or higher than the predetermined value, hydraulic oil that is less than the amount by which the variable mechanism operates is supplied to the variable mechanism without increasing the discharge capacity of the oil pump to the predetermined level or higher. The oil control valve is controlled so that the opening of the oil control valve becomes the predetermined opening.
A variable valve operating device for an internal combustion engine.