JP5525403B2 - 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 including a solenoid that exhibits a driving force for switching an opening / closing operation characteristic of an engine valve.

  A variable valve operating apparatus for an internal combustion engine in which the operating characteristic of an engine valve is changed by the operation of a solenoid attached to the engine body is known from Patent Document 1.

JP 2007-162579 A

  In such a variable valve operating apparatus, it is necessary to detect whether or not the solenoid is normally operated and switching of the opening / closing operation characteristics of the engine valve is completed. A sensor for detecting the lift amount of the engine valve is provided, or the detection value of the PB sensor for detecting the intake negative pressure is used, but a dedicated sensor for detecting the lift amount of the engine valve is required, Since complicated control such as initial diagnosis logic for ensuring reliability is required, the cost increases.

  The present invention has been made in view of such circumstances, and provides a variable valve operating apparatus for an internal combustion engine that can quickly and reliably detect the operating state of a solenoid while avoiding an increase in cost. For the purpose.

To achieve the above object, the present invention provides a solenoid which exerts a driving force for switching the opening and closing characteristic of the engine valve, comprising a switching control means for controlling the energization of the solenoid, is該切control means, in the solenoid A normal detection state in which the movement amount of the movable core reaches a predetermined movement amount, and a movement amount of the movable core A variable valve operating apparatus for an internal combustion engine that performs an operation state determination as to whether the solenoid is present in an abnormal operation state in which is less than a predetermined movement amount based on a current value detected by the current detection unit. The switching control means is configured such that when the solenoid is in a normal operation state, the current value once increased after the start of energization is On the basis that rises to a predetermined current value from the maximum value after it has been reduced 20% or more, to perform the operation state determined by the energization start time course after the solenoid current value detected by the current detection unit First feature.

According to the present invention, in addition to the configuration of the first feature, when the solenoid is in a normal operating state, the switching control means determines the operating state based on a change over time after the start of energization of the solenoid. The set time set as the time during the process of increasing the current value once increased after the start of energization from the maximum value at the time of increase by 20% or more to the predetermined current value has elapsed after the start of energization to the solenoid. A second feature is that the operation state determination is sometimes executed.

The present invention also includes a solenoid that exhibits a driving force for switching the opening / closing operation characteristics of the engine valve, and switching control means for controlling energization of the solenoid, and the switching control means is associated with the movement of the movable core by the solenoid. A current detection unit that detects a change in a current value caused by a change in impedance, a normal operation state in which the moving amount of the movable core reaches a predetermined moving amount, and the moving amount of the movable core is less than the predetermined moving amount; A variable valve operating apparatus for an internal combustion engine that performs an operation state determination as to whether the solenoid is in an abnormal operation state based on a current value detected by the current detection unit, wherein the switching control means When it is determined that the solenoid is in an abnormal operating state, the energization of the solenoid and the operation state determination in the energized state are repeated. That row and third features.

Further, according to the present invention, in addition to the configuration of the second or third feature, the switching control means may be configured so that the solenoid is not activated even when the energization of the solenoid and the operation state determination in the energized state are repeatedly executed a predetermined number of times. It is a fourth feature that when it is determined that the normal operation state is maintained, it is determined that the failure state exists.

The present invention also includes a solenoid that exhibits a driving force for switching the opening / closing operation characteristics of the engine valve, and switching control means for controlling energization of the solenoid, and the switching control means is associated with the movement of the movable core by the solenoid. A current detection unit that detects a change in a current value caused by a change in impedance, a normal operation state in which the moving amount of the movable core reaches a predetermined moving amount, and the moving amount of the movable core is less than the predetermined moving amount; A variable valve operating apparatus for an internal combustion engine that performs an operation state determination as to whether the solenoid is in an abnormal operation state based on a current value detected by the current detection unit, wherein the switching control means Is a duty cycle that repeats an energization on / off cycle to maintain the solenoid operating state after a lapse of a predetermined time from the start of energization of the solenoid. And executes the control, and to perform the solenoid operating state determined by the current value detected by the current detection unit at the time of the duty control executed fifth feature.

In addition to any of the configurations of the first to fifth features, the present invention includes a rocker arm that is linked and connected to the engine valve and is arranged adjacent to each other and has different cam profiles. A plurality of rocker arms respectively driven by a plurality of cams, a connecting position for connecting adjacent rocker arms, and a connecting release position for releasing the connection can be moved in the axial direction, and can be slid on the rocker arms while abutting each other. A plurality of connecting pins spring-biased toward one of the axial directions fitted to the solenoid, and the solenoid that moves the movable core in a direction parallel to the sliding direction of the connecting pins is in conjunction with the connection pin as possible to presses the connection pin in the axial direction the other, shall be the sixth aspect to be connected.

In addition to the configuration of the fifth feature of the present invention, the switching control means detects the current value detected by the current detection unit immediately after the start of execution of the duty control or the current detection unit in the immediately preceding cycle. The seventh characteristic is that the operation state of the solenoid at the time of execution of the duty control is determined by using the current value as a reference value.

  The intake valve 23 of the embodiment corresponds to the engine valve of the present invention, the first and second intake-side rocker arms 32 and 33 of the embodiment correspond to the rocker arm of the present invention, and the pause cam 43 of the embodiment. The intake side cam 44 corresponds to the cam of the present invention, the first and second connecting pins 55 and 56 of the embodiment correspond to the connecting pin of the present invention, and the ECU 80 of the embodiment controls the switching control means of the present invention. Corresponding to

According to the onset bright, the switching control means determines whether the solenoid is in any state of the normal operating conditions and abnormal operating conditions based on the current value detected by the current detecting unit having the該切control means Therefore, it is possible to detect the operating state of the solenoid promptly and with high reliability while reducing the cost without providing a special sensor.

In particular , according to the first feature of the present invention, since the solenoid operating state is determined by the current value change with the passage of time from the start of energization when the solenoid is in the normal operating state, the short time immediately after the energization is started. The operating state of the solenoid can be determined by time.

Further, in particular , according to the second feature of the present invention, when the solenoid is in a normal operating state, the current value once increased after the start of energization falls to a predetermined current value after decreasing by 20% or more from the maximum value at the time of the increase. When the set time set as the time during the ascending process elapses, the operating state can be determined in a shorter time by performing the operating state determination.

Further, particularly according to the third feature of the present invention, when it is determined that the solenoid is in an abnormal operating state, the energization of the solenoid and the operation state determination in the energized state are repeated. This can be done more reliably.

In particular , according to the fourth aspect of the present invention, when the solenoid remains in an abnormally operating state even when the energization of the solenoid and the operation state determination in the energized state are repeatedly performed a predetermined number of times, a failure is caused. Since it is in the state, the failure state of the variable valve operating apparatus can be detected with a simple configuration.

In particular, according to the fifth feature of the present invention, it is possible to reduce current consumption by executing duty control that repeats an energization on / off cycle after a predetermined time has elapsed from the start of energization of the solenoid. Since the solenoid operating state is determined based on the current value when the control is executed, it is possible to improve the reliability of the variable valve operating apparatus by determining whether or not the energized state of the solenoid is maintained.

In particular , according to the sixth aspect of the present invention, the plurality of connecting pins are slidably fitted to the plurality of rocker arms so that the connection and release of the connection can be switched, and the plurality of connection pins are spring-biased in one axial direction. Since the solenoid is linked and connected by pressing the connecting pins toward the other in the axial direction when the solenoid is energized, the structure that returns the connecting pins and the movable core of the solenoid to the initial position when the solenoid is not energized is simple. it is Ru can be.

In particular , according to the seventh feature of the present invention, when the operation state of the solenoid at the time of executing the duty control is determined, the current value immediately after the start of the duty control execution or the current value in the immediately preceding cycle is used as the reference value. In addition, when duty control is executed with a small difference in current value between the normal operation state and the non-normal operation state, it can be determined with higher accuracy whether the energization state of the solenoid is maintained.

Longitudinal sectional view of main part of internal combustion engine 2-2 line top view of FIG. 1 is a cross-sectional view taken along line 3-3 in FIG. 1 when the intake side rocker arm is in a disconnected state. 4 is an enlarged view of the part indicated by an arrow Diagram showing schematic configuration of control system Diagram showing changes in voltage and current after starting energization to solenoid Flowchart showing part of solenoid energization control and operating state determination processing procedure Flowchart showing remainder of energization control and operation state determination processing procedure of solenoid The figure which expands and shows the principal part of FIG.

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

  A first embodiment of the present invention will be described with reference to FIGS. 1 to 9. First, in FIG. 1, the internal combustion engine is a small-sized one mounted on a motorcycle, for example, and its engine body 10. Is formed between a cylinder block 11 having a cylinder bore 12 in which a piston 13 is slidably fitted and a combustion chamber 14 in which the top of the piston 13 faces to the cylinder block 11, and is coupled to the cylinder block 11. And a head cover 16 coupled to the cylinder head 15 so as to form a valve operating chamber 17 between the cylinder head 15 and the cylinder head 15.

  The cylinder head 15 is provided with an intake port 18 and an exhaust port 19 that can communicate with the combustion chamber 14. An intake device 21 having a fuel injection valve 20 is connected to the intake port 18, and the exhaust port 19 is not shown. An exhaust device is connected.

Referring also to FIG. 2, the cylinder head 15 includes a pair of intake valves 23 and 23 serving as engine valves for switching communication / blocking of the intake port 18 to the combustion chamber 14, and an exhaust port 19. A single exhaust valve 24 that switches between communication and shut-off to the combustion chamber 14 is disposed so as to be openable and closable. The intake valves 23 are energized in the valve closing direction by valve springs 25, and the exhaust valve 24 is a valve. The spring 26 is biased in the valve closing direction. A pair of spark plugs 28 and 29 are attached to the cylinder head 15 so that the tip of the cylinder head 15 faces the combustion chamber 14, and a valve formed between the cylinder head 15 and the head cover 16 with reference to FIG. The chamber 17 houses a valve operating device 30 that opens and closes the intake valves 23 and the exhaust valve 24.

  The valve gear 30 includes a single camshaft 31 disposed between the intake valves 23... And the exhaust valves 24 in common with the intake valves 23... And the exhaust valves 24, a pair of intake valves 23. The first and second intake side rocker arms 32 and 33 interposed between the exhaust valve 24 and the exhaust side rocker arm 34 interposed between the exhaust valve 24 and the camshaft 31 are provided.

  An intermediate portion of the exhaust side rocker arm 34 is supported by an exhaust side rocker shaft 35 having an axis parallel to the camshaft 31 so as to be swingable, and one end portion of the exhaust side rocker arm 34 is provided on the camshaft 31. A roller 37 that is in rolling contact with the exhaust side cam 36 is pivotally supported, and a tappet screw 38 that abuts on the stem end 24a of the exhaust valve 24 is screwed to the other end of the exhaust side rocker arm 34 so that the advance / retreat position can be adjusted. Is done.

  The first and second intake side rocker arms 32 and 33 are arranged adjacent to each other in the direction along the axis of the camshaft 31, and are rocked by an intake side rocker shaft 39 having an axis parallel to the exhaust side rocker shaft 35. It is supported movably. Tappet screws 40, 40 that are in contact with the stem ends 23a of the intake valves 23 are screwed into one end portions of the first and second intake side rocker arms 32, 33 so that the forward / backward positions can be adjusted. A roller 41 that is in rolling contact with a resting cam 43 provided on the camshaft 31 is pivotally supported at the other end of the first intake side rocker arm 32, and the other end of the second intake side rocker arm 33 is A roller 42 that is in rolling contact with an intake side cam 44 provided on the camshaft 31 is pivotally supported.

  The camshaft 31 is disposed at positions spaced apart in the direction along the axis of the camshaft 31 and is provided with ball bearings 47 on the first and second holder portions 45, 46 that protrude integrally with the cylinder head 15. , 48, and is supported rotatably through the camshaft 31, and the end of the camshaft 31 protruding from the second holder portion 46 has a crankshaft (not shown) connected to the piston 13. A driven sprocket 50 that constitutes a part of the timing transmission mechanism 49 that reduces the rotational power to 1/2 and transmits it to the camshaft 31 is fixed, and a cam chain that constitutes a part of the timing transmission mechanism 49. 51 is wound around the driven sprocket 50.

  The intake side rocker shaft 39 and the exhaust side rocker shaft 35 are disposed on both sides of the camshaft 31, and both end portions of the intake side rocker shaft 39 and the exhaust side rocker shaft 35 are first and second holder portions. 45 and 46 are fitted and supported.

  By the way, the intake cam 44 has an arcuate base circle 44a along a virtual circle centered on the central axis of the camshaft 31, and the base circle 44a so as to protrude outward from the virtual circle. The cam crest portions 44b are connected to both ends in the circumferential direction. On the other hand, the pause cam 43 is capable of closing and pausing the intake valve 23 linked to and connected to the first intake rocker arm 32 of the intake valves 23... And the cam profile different from the intake cam 44. The intake valve 23 is basically a circle substantially along the imaginary circle, but in order to prevent a fuel pool from occurring when the intake valve 23 is completely closed. Is formed so as to have an outer peripheral surface that opens the valve slightly.

  The first and second intake-side rocker arms 32 and 33 are provided with a rest cam 43 independent of the second intake-side rocker arm 33 that swings the roller 41 of the first intake-side rocker arm 32 following the intake-side cam 44. When the internal combustion engine is kept in low-speed operation, one intake valve 23 is closed and stopped, and the other intake valve 23 is opened and closed in an operation mode corresponding to the cam profile of the intake side cam 44. And the first and second intake side rocker arms 32 and 33 are connected to switch the state in which the intake valves 23 are opened and closed in an operation mode corresponding to the cam profile of the intake side cam 44 during high speed operation of the internal combustion engine. Valve operating characteristic changing means 54 is provided.

  Referring also to FIG. 4, the valve operating characteristic changing means 54 is provided above the first and second intake side rocker arms 32 and 33 between the intake side rocker shaft 39 and the camshaft 31. The first and second intake-side rocker arms 32, 33 are connected to each other so that they can move in the axial direction between the connection position for connecting the first and second intake-side rocker arms 32, 33 and the connection release position for releasing the connection. First and second connecting pins 55 and 56 are slidably fitted to 33.

  In the first intake side rocker arm 32, a first guide hole 57 having an end wall 57 a on the opposite side to the second intake side rocker arm 33 and formed in a bottomed shape is parallel to the intake side rocker shaft 39. The second intake side rocker arm 33 is provided with an axis, and has a bottom having an axis parallel to the intake side rocker shaft 39 and closed on the opposite side to the first intake side rocker arm 32 by an end wall 58a. A second guide hole 58 formed in a shape is provided. Moreover, the first and second guide holes 57 and 58 are formed to have the same diameter so as to be coaxially connected at the timing when the intake valves 23 are in the closed state.

  The first connecting pin 55 formed in a short cylindrical shape is slidably fitted into the first guide hole 57 so that a part thereof can be fitted into the second guide hole 58, and the end A shaft portion 55a that slidably fits a through hole 59 provided in the center portion of the wall 57a is integrally and coaxially connected to the first connecting pin 55.

  The second connecting pin 56 is formed in a bottomed cylindrical shape with the end wall 58a side of the second guide hole 58 open, and is slidably fitted in the second guide hole 58. A spring 60 is provided between the pin 56 and the end wall 58a to bias the first and second connecting pins 55 and 56 that are in contact with each other toward one side in the axial direction (the right side in FIGS. 3 and 4). An open hole 61 is provided in the end wall 58a.

  Thus, the valve operating characteristic changing means 54 is engaged with the first and second intake side rocker arms by fitting a part of the first connecting pin 55 into the second guide hole 58 against the spring force of the spring 60. 32 and 33 are connected, and the first and second contact surfaces of the first and second connection pins 55 and 56 are arranged between the first and second intake side rocker arms 32 and 33 by the spring force of the spring 60. By moving the connecting pins 55 and 56 in the axial direction, the connection between the first and second intake side rocker arms 32 and 33 is released.

  A solenoid 62 as an actuator having a housing 63 attached to the engine body 10 is interlocked with one end of the shaft portion 55a of the first connection pin 55 on one end side in the axial direction of the first and second connection pins 55, 56. The shaft portion 55a applies the pressing force from the solenoid 62 in the direction of moving the first and second connection pins 55, 56 to the side connecting the first and second intake side rocker arms 32, 33. Can be affected.

  A housing 63 of the solenoid 62 is attached to the cylinder head 15 and the head cover 16 of the engine body 10 via a mounting plate 67, and the housing 63 and the mounting plate 67 include a plurality of bolts 68. Are attached to the cylinder head 15 and the head cover 16 by fastening together.

  The solenoid 62 has a movable core 64 supported by the housing 63 so as to move in the axial direction when energized. The movable core 64 is connected to one end of the shaft portion 55 a of the first connecting pin 55. The transmission rod 66 is connected via a transmission rod 66, and the transmission rod 66 is slidably supported by a rod support portion 45 a formed integrally with the first holder portion 45 of the cylinder head 15.

  Such a pressing force from the movable core 64 of the solenoid 62 is transmitted to one end of the shaft portion 55a of the first connecting pin 55 through the transmission rod 66, and the transmission rod 66 is transmitted to the cylinder head 15 of the engine body 10. Since it is slidably supported, the force in the bending direction caused by sliding contact with one end of the first connecting pin 55 that swings together with the first intake side rocker arm 32 supports the movable core 64 in the housing 63 of the solenoid 62. The structure for supporting the movable core 64 in the housing 63 can be simplified without reaching the structure.

  Further, since the transmission rod 66 is slidably supported by the rod support portion 45a formed integrally with the first holder portion 45 of the cylinder head 15, no special parts for supporting the transmission rod 66 are required. The number of parts can be reduced, and the processing accuracy of the rod support portion 45a for supporting the transmission rod 66 can be increased.

  Further, the shaft portion 55 a is in contact with the other end portion of the transmission rod 66, one end of which is in contact with the movable core 64, offset from the axis of the transmission rod 66. That is, the other end of the transmission rod 66 is provided with a disc-like contact plate 66a projecting radially outward from the other end in an integrated and coaxial manner, from the center of the contact plate 66a. The shaft portion 55a of the first connecting pin 55 is brought into contact with the shifted position. In this way, the shaft portion 55a of the first connecting pin 55 is in contact with the position deviated from the center of the contact plate portion 66a, so that the transmission rod is in response to the swing of the first intake side rocker arm 32. The force that rotates the transmission rod 66 about its axis acts on 66, and the contact portion between the shaft portion 55a of the first connecting pin 55 and the abutting plate portion 66a can be changed, and the lifetime is reduced due to wear. Can be suppressed.

  Further, as clearly shown in FIG. 3, the oil is applied to the inner surface of the head cover 16 toward the contact surfaces of the first and second intake side rocker arms 32 and 33 and the first connecting pin 55 and the transmission rod 66. A pair of ribs 71 and 72 for dripping water is integrally projected. Therefore, it is not necessary to configure a complicated oil passage structure, and oil can be guided between the adjacent first and second intake side rocker arms 32 and 33, and the contact surfaces of the first connecting pin 55 and the transmission rod 66 can be contacted. Oil can be guided and the weight of the cylinder head 15 and the head cover 16 can be reduced.

  By the way, the movable core 64 is disposed through the housing 63 of the solenoid 62, and at one end thereof, the first and second connecting pins 55 and 56 are pushed toward the other side in the axial direction. A flange 73 that restricts the stroke of the movable core 64 by contacting the housing 63 is provided. A cover 74 that covers the housing 63 is attached to the engine body 10 via the attachment plate 67, and this cover 74 is attached to the attachment plate 67 via bolts 75. Moreover, on the surface of the cover 74 facing the flange 73, rubber, resin elastomer, and control material that contact the flange 73 when the movable core 64 moves to the side away from the housing 63. A damping material 76 made of a vibration metal or the like is fixed. Thereby, the movable core 64 pushed from the first connecting pin 55 side is brought into contact with the vibration damping material 76 and the movable core 64 is prevented from being flipped in the reverse direction, and the movable core 64 is moved. It is possible to suppress the generation of operating noise associated with.

  In FIG. 5, an ECU 80, which is a switching control means for controlling energization of the solenoid 62, includes a resistor 81 provided between the solenoid 62 and the ground, an FET 82 provided between the solenoid 62 and a power source (not shown), And a diode 84 connected in parallel to a series circuit composed of a solenoid 62 and the resistor 81, and a current detector for detecting a change in current value generated by a change in impedance accompanying the movement of the movable core 64 in the solenoid 62. The current detector 84 is connected between the resistor 81 and the solenoid 62.

By the way, as shown in FIG. 6, the ECU 80 keeps applying a voltage of, for example, 10 V for a predetermined time T, for example, 320 msec from the start of energization at time t _0. After the elapse of a predetermined time T from the start, duty control is performed to repeat the energization on / off cycle so as to maintain the operating state of the solenoid 62. In the duty control, for example, 1.7 msec. For example, it is repeatedly turned off for 2.5 milliseconds. By performing such duty control, the current flowing through the solenoid 62 is, for example, 6.7 A during the predetermined time T, whereas when the duty control is performed, the maximum value of the current is, for example, 3.8 A, The average value of the current is 2.4A.

  In addition, the ECU 80 causes the solenoid 62 to be in either a normal operation state in which the movement amount of the movable core 64 reaches a predetermined movement amount or an abnormal operation state in which the movement amount of the movable core 64 is less than the predetermined movement amount. Whether or not there is an operating state is determined based on the current value detected by the current detector 84.

  Thus, the energization control and operation state determination of the solenoid 62 are executed according to the processing procedure shown in FIGS. 7 and 8. First, in step S1 of FIG. Step S2 determines whether the engine speed has increased beyond the speed at which the second intake side rocker arms 32, 33 are connected to open and close the intake valves 23 with operating characteristics corresponding to the cam profile of the intake side cam 44. Judge with.

  When it is confirmed in step S2 that the engine speed has reached or exceeded a predetermined value, the power is turned on so that the solenoid 62 is energized in the next step S3, and the current value is detected by the current detector 84 in step S4. .

By the way, when the solenoid 62 is in a normal operation state in which the moving amount of the movable core 64 reaches a predetermined moving amount, as shown in FIG. 9, the current value temporarily increases after the start of energization at time t ₀ , and the time t current value ₁ is decreased after reaching a _1, from the highest value a ₁ is inverted at time t ₂ which is reduced by ΔA to a ₂ rises again during rising, a predetermined current value a ₃ at time t ₄ ΔA is a value of 20% or more of the maximum value A ₁ at the time of the first rise at time t ₁ , for example, a value of 20% to 55%. On the other hand, when the solenoid 62 is in an abnormal operation state in which the moving amount of the movable core 64 is less than a predetermined moving amount, the maximum value A at the time of the first rise at time t ₁ as shown by the chain line in FIG. _The amount of decrease from ₁ is less than 20%, for example 3 to 10%.

Thus, the ECU 80 is based on the fact that when the solenoid 62 is in a normal operating state, the current value once increased after the start of energization decreases to 20% or more from the maximum value at the time of the increase and then increases to a predetermined current value. The operation state is determined based on the change over time of the current value detected by the current detector 84 after the start of energization of the solenoid 62. In step S5 after the current value is detected in step S4, It is determined whether or not the current value when the set time Xm seconds elapses is less than the predetermined current value A _{0. When} the current value <A ₀ , the process proceeds from step S5 to step S6 to determine the normal operation state.

Here, as shown in FIG. 9, the set time Xm seconds is the current value once increased after the start of energization when the solenoid 62 is in the normal operating state, from the maximum value A ₁ to A ₂ at the time of the increase. % Is set as an elapsed time from the energization start time t ₀ until time t ₃ in the process of increasing to the predetermined current value A ₃ after being reduced by at least%, and the predetermined current value A ₀ The current value is set to be smaller than the current value at time t ₃ assumed when 62 is in the abnormal operation state and larger than the current value at time t ₃ when solenoid 62 is in the normal operation state. In other words, the current value at time t ₃ in the region indicated by the oblique lines in FIG. 9 is set as the predetermined current value A ₀ .

If it is determined in step S5 that the current value ≧ A _0, it is determined in step S7 that it is in an abnormal operation state, and in step S8 the power is turned off, and then it is determined that the operation state is in an abnormal state N times. It is determined in step S9 whether or not it has reached the (for example, the third) time. If it has not reached the Nth time, the process returns to step S3, and if it has reached the Nth time, a fail display is made in step S10.

  That is, when the ECU 80 determines that the solenoid 62 is in an abnormal operating state at the start of energization of the solenoid 62, the ECU 80 repeatedly executes the energization of the solenoid 62 and the operation state determination in the energized state. When it is determined that the solenoid 62 remains in an abnormal operation state even when the solenoid 62 is energized and the operation state determination in the energized state is repeatedly performed a predetermined number of times (N times), the failure state is indicated. Judgment will be made.

  When it is determined in step S6 that the operation is normal, the process proceeds to step S11 in FIG. 8 to execute duty control. By the way, even when the duty control is executed, there is a possibility that the movable core 64 may return due to being bounced by the shaft portion 55a of the first connecting pin 55. In order to detect such an abnormal operation state, the ECU 80 The operation state determination of the solenoid 62 based on the current value detected by the current detection unit 84 is also executed when the duty control is executed. Here, the current value when the solenoid 62 is in the normal operating state during duty control changes as shown by the solid line in FIG. 9, whereas the current value when the solenoid 62 is in the abnormal operating state is shown in FIG. The operating state of the solenoid 62 during execution of duty control can be detected by detecting the difference between the current values.

  However, the difference between the current values is very small, and in order to make a more accurate determination, a reference value is set in step S12, and then the reference value and the current value are compared in step S12. At this time, the reference value is a current value detected by the current detection unit 84 immediately after the start of execution of the duty control or a current value detected by the current detection unit 84 in the immediately preceding on / off cycle as a reference value. When it is confirmed that the difference between the reference value and the current value is within a predetermined range in step S14, it is determined in step S15 that the solenoid 62 is in a normal operating state.

  If it is confirmed in step S14 that the difference between the reference value and the current value is outside the predetermined range, it is determined in step S16 that the solenoid 62 is in an abnormal operation state, and the power is turned off in step S17. In step S18, it is determined whether or not it is determined that the abnormal operation state has reached the set number of times M (for example, the third time). If not, the process returns to step S3. When it reaches, a fail display is made in step S19.

  That is, when the ECU 80 determines that the solenoid 62 is in an abnormal operating state during duty control of the solenoid 62, the ECU 80 repeatedly executes energization of the solenoid 62 and the operation state determination in the energized state. When it is determined that the solenoid 62 remains in an abnormal operating state even if the solenoid 62 is energized and the operation state determination in the energized state is repeatedly performed a predetermined number of times (M times), the failure state is indicated. Judgment will be made.

  Next, the operation of this embodiment will be described. An ECU 80 that controls energization of the solenoid 62 detects a change in current value generated by a change in impedance accompanying the movement of the movable core 64 by the solenoid 62. 84, and the solenoid 62 is in any of a normal operation state in which the movement amount of the movable core 64 reaches a predetermined movement amount and an abnormal operation state in which the movement amount of the movable core 64 is less than the predetermined movement amount. Since the determination of the operation state is performed based on the current value detected by the current detection unit 84, the operation state of the solenoid 62 can be changed promptly while reducing the cost by eliminating the need for a special sensor. It can be detected with high reliability.

  Further, the ECU 80 determines that the current value once increased after the start of energization when the solenoid 62 is in a normal operating state is increased to a predetermined current value after being decreased by 20% or more from the maximum value at the time of the increase. Since the operating state is determined based on the change over time of the current value detected by the detector 84 after the start of energization of the solenoid 62, the operating state of the solenoid 62 can be determined in a short time immediately after the start of energization.

  Moreover, when the ECU 80 determines the operation state based on the change over time after the energization of the solenoid 62 is started, the current value once increased after the start of energization when the solenoid 62 is in the normal operation state is determined from the highest value at the time of the increase. Since the operation state determination is executed when the set time Xm seconds set as a time in the middle of the process of increasing to a predetermined current value after decreasing by 20% or more has elapsed after the energization of the solenoid 62 has started, the operation state determination is made shorter. The operating state can be determined by time.

  When the ECU 62 determines that the solenoid 62 is in an abnormal operation state, the ECU 62 repeatedly executes energization of the solenoid 62 and operation state determination in the energization state, so that the operation characteristics of the intake valves 23. It can be done reliably.

  Further, the ECU 80 is in a fail state when it is determined that the solenoid 62 remains in an abnormal operating state even when the energization of the solenoid 62 and the operation state determination in the energized state are repeatedly performed a predetermined number of times. Therefore, the fail state of the variable valve operating apparatus can be detected with a simple configuration.

  The solenoid 62 is slidably fitted to the first and second intake-side rocker arms 32 and 33 so as to be able to switch between connection and disconnection, and is urged by a spring biased in the axial direction. Since the two connecting pins 55 and 56 are linked and connected so as to press the connecting pins 55 and 56 toward the other in the axial direction when energized, the connecting pins 55 and 56 and the solenoid 62 are energized when the solenoid 62 is not energized. A structure for returning the movable core 64 to the initial position can be easily configured.

  In addition, the ECU 80 executes duty control that repeats an energization on / off cycle so as to maintain the operating state of the solenoid 62 after a predetermined time has elapsed from the start of energization of the solenoid 62, so that current consumption can be reduced. Since the operation state of the solenoid 62 is determined based on the current value when the duty control is executed, it is possible to improve the reliability of the variable valve apparatus by determining whether or not the energized state of the solenoid 62 is maintained.

  Further, the ECU 80 uses the current value detected by the current detection unit 84 immediately after the start of execution of the duty control or the current value detected by the current detection unit 84 in the immediately preceding cycle as a reference value when the duty control is executed. Therefore, it is more accurately determined whether or not the energized state of the solenoid 62 is maintained when duty control is executed with a small difference in current value between the normal operating state and the abnormal operating state. can do.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various design changes can be made without departing from the present invention described in the claims. Is possible.

  For example, the present invention can also be applied to a valve operating device for an exhaust valve.

23 ... Intake valve 32 as an engine valve ... First intake side rocker arm as a rocker arm 333 ... Second intake side rocker arm 43 as a rocker arm ... Stop cam 44 as a cam ... As a cam Intake side cam 55... First connection pin 56 as a connection pin... Second connection pin 62 as a connection pin... Solenoid 64... Movable core 80.
84 ... Current detection unit

Claims (7)

Includes a solenoid (62) for exerting a driving force for switching the opening and closing characteristic of the engine valve (23), and its solenoid switching control means for controlling the energization of (62) (80),該切control means (80) And a current detector (84) for detecting a change in current value caused by a change in impedance accompanying the movement of the movable core (64) in the solenoid (62), and the amount of movement of the movable core (64) is Whether the solenoid (62) is in the normal operation state in which the predetermined movement amount is reached or the abnormal operation state in which the movement amount of the movable core (64) is less than the predetermined movement amount is determined by the current. A variable valve operating apparatus for an internal combustion engine, which is executed based on a current value detected by a detection unit (84) ,
When the solenoid (62) is in a normal operating state, the switching control means (80) increases to a predetermined current value after the current value once increased after the start of energization has decreased by 20% or more from the maximum value at the time of the increase. On the basis of this, the operating state determination is performed based on the change over time of the current value detected by the current detector (84) after the start of energization of the solenoid (62). Place. When the solenoid (62) is in a normal operating state, the switching control means (80) temporarily rises after the energization is started in determining the operating state based on a change over time after the energization of the solenoid (62) is started. When a set time set as a time in the process of increasing to a predetermined current value after the current value has decreased by 20% or more from the maximum value at the time of increase has elapsed after the energization of the solenoid (62) has started. variable valve device for an internal combustion engine according to claim 1, wherein the executing the operation state determination. A solenoid (62) that exhibits a driving force for switching the opening / closing operation characteristics of the engine valve (23); and a switching control means (80) for controlling energization of the solenoid (62). And a current detector (84) for detecting a change in current value caused by a change in impedance accompanying the movement of the movable core (64) in the solenoid (62), and the amount of movement of the movable core (64) is Whether the solenoid (62) is in the normal operation state in which the predetermined movement amount is reached or the abnormal operation state in which the movement amount of the movable core (64) is less than the predetermined movement amount is determined by the current. A variable valve operating apparatus for an internal combustion engine, which is executed based on a current value detected by a detection unit (84),
When the switching control means (80) determines that the solenoid (62) is in an abnormal operation state, the switching control means (80) repeatedly executes energization of the solenoid (62) and the operation state determination in the energization state. variable valve system of the internal combustion engine shall be the feature. The switching control means (80) determines that the solenoid (62) remains in an abnormal operating state even when the energization of the solenoid (62) and the operation state determination in the energized state are repeatedly performed a predetermined number of times. The variable valve operating apparatus for an internal combustion engine according to claim 2 or 3 , wherein it is determined that the engine is in a failed state. A solenoid (62) that exhibits a driving force for switching the opening / closing operation characteristics of the engine valve (23); and a switching control means (80) for controlling energization of the solenoid (62). And a current detector (84) for detecting a change in current value caused by a change in impedance accompanying the movement of the movable core (64) in the solenoid (62), and the amount of movement of the movable core (64) is Whether the solenoid (62) is in the normal operation state in which the predetermined movement amount is reached or the abnormal operation state in which the movement amount of the movable core (64) is less than the predetermined movement amount is determined by the current. A variable valve operating apparatus for an internal combustion engine, which is executed based on a current value detected by a detection unit (84),
The switching control means (80) executes duty control for repeating energization on / off cycles so as to maintain the operating state of the solenoid (62) after a predetermined time has elapsed from the start of energization of the solenoid (62). , the current detection unit (84) to perform an operation state determination of the solenoid (62) by a current value detected by the variable valve apparatus of the internal combustion engine you wherein when the duty control executed. A plurality of cams (43, 44) each including a rocker arm (32, 33) linked and connected to the engine valve (23) and arranged adjacent to each other and having different cam profiles (43, 44). The rocker arms (32, 33) and the adjacent rocker arms (32, 33) are connected to each other and the rocker arms (32, 33) are in contact with each other while allowing axial movement between the connection position and the connection release position for releasing the connection. 33) each having a plurality of connecting pins (55, 56) spring-biased toward one axial direction that are slidably fitted to each other, and the sliding direction of these connecting pins (55, 56); The solenoid (62) that moves the movable core (64) in a parallel direction can press the connecting pins (55, 56) toward the other axial direction when energized. Serial connecting linkage to the pin (55, 56), the variable BenSo location of an internal combustion engine according to claim 1, characterized in that it is connected. The switching control means (80) is based on the current value detected by the current detection unit (84) immediately after the start of execution of the duty control or the current value detected by the current detection unit (84) in the immediately preceding cycle. 6. The variable valve operating apparatus for an internal combustion engine according to claim 5 , wherein the operation state of the solenoid (62) when the duty control is executed is determined as a value.

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