JP2008291747A - Diagnostic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a diagnostic device capable of inhibiting wrong determination that a drive mechanism is normal when it is determined whether the drive mechanism is normal or not. <P>SOLUTION: It is determined that a variable vale gear is normal (S106) under a condition where target operation angle Rt is changing from a previous condition (S104: Yes), in other words, where actual operation angle Rr is to be changed, when it is determined that no fixing abnormality exists in a variable valve gear (S102: Yes). determination whether the variable valve gear is normal or not is suspended when the target operation angle Rt is not changing (S104: No). Consequently, it is inhibited to determine that the variable valve gear is normal based on determination that no fixing abnormality exists in the variable valve mechanism under a condition that the actual operation angle Rr is not to be changed. Consequently, wrong determination that the variable valve gear is normal is inhibited based on the determination. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a diagnostic apparatus.

  Conventionally, when driving various drive mechanisms, the target drive state of the drive mechanism is variably set as the target drive state, and the drive mechanism is motorized so that the actual drive state of the drive mechanism matches the target drive state. It is performed by such as. As a drive mechanism that is driven in this way, for example, a variable valve mechanism that changes the valve characteristics of an engine valve in an internal combustion engine is known.

  In addition, there is a possibility that the drive mechanism may have a sticking abnormality. As a diagnostic device for detecting the sticking abnormality, the sticking abnormality is based on the actual driving state of the driving mechanism that is driven so that the actual driving state matches the target driving state. It is conceivable to adopt one that determines the presence or absence of the. The determination of the presence or absence of sticking abnormality in the judgment of the presence or absence of sticking abnormality can be performed as shown in the following [1] and [2], for example. [1] Based on the fact that the difference between the actual drive state and the target drive state is large, it is determined that there is a sticking abnormality in the drive mechanism (see Patent Document 1). [2] When the drive mechanism is driven by a motor, an abnormal value is obtained when the drive command value or drive current of the motor, which is a parameter indicating the actual drive state of the drive mechanism, attempts to match the actual drive state with the target drive state. Based on this, it is determined that there is a sticking abnormality in the drive mechanism.

In the diagnostic device, it is also determined whether or not the drive mechanism is normal. Such determination of normality may be performed based on the determination of the absence of the fixing abnormality in the determination of the presence or absence of the fixing abnormality in the drive mechanism.
JP 2006-70789 A (FIG. 5, paragraphs [0048] to [0050])

By the way, if the determination that the drive mechanism is normal is performed as described above, the determination that the drive mechanism is normal is incorrect under the following circumstances.
That is, when the determination of [1] above is adopted, the deviation of the actual driving state from the target driving state is not large under the situation where the fixing abnormality occurs when the actual driving state matches the target driving state. From this, it is determined that there is no sticking abnormality, and based on this, an erroneous determination is made that it is normal.

  In addition, when the determination of [2] is adopted, the parameter represents the actual driving state of the driving mechanism under a situation where a sticking abnormality occurs when the actual driving state of the driving mechanism is not changed. Since the drive command value and drive current of the motor do not show abnormal values, it is determined that there is no abnormality in fixing, and based on that, an erroneous determination is made that it is normal.

  Note that such a problem of erroneous determination of normality is not limited to the variable valve mechanism that makes the valve characteristics of the engine valve variable, but is generally common to other drive mechanisms.

  The present invention has been made in view of such circumstances, and the object thereof is to suppress erroneous determination that the drive mechanism is normal when determining whether or not the drive mechanism is normal. It is to provide a diagnostic device.

In the following, means for achieving the above object and its effects are described.
In order to achieve the above object, the invention described in claim 1 is applied to a drive mechanism that is driven such that the actual drive state matches the target drive state that is variably set, and the actual drive state of the drive mechanism In the diagnostic device for determining the presence or absence of the sticking abnormality of the drive mechanism based on the above, when it is judged that the sticking abnormality is not present, it is normal on the condition that a change from the previous state of the target drive state has occurred. And determining means for deferring whether or not it is normal when the change has not occurred.

  According to the above configuration, when it is determined that there is no sticking abnormality in the drive mechanism, it is determined that the target drive state is normal on the condition that a change from the previous state has occurred, and otherwise it is normal. Judgment whether or not there is pending. Here, the fact that the target drive state of the drive mechanism changes from the previous state means that the actual drive state of the drive mechanism is going to be changed. Therefore, it is possible to suppress the determination that the drive mechanism is normal based on the determination that there is no sticking abnormality in the drive mechanism under a situation where the actual drive state of the drive mechanism is not being changed. Then, it is possible to suppress the occurrence of a false determination that it is normal based on the determination being made.

According to a second aspect of the present invention, in the first aspect of the present invention, the drive mechanism is configured to change a valve characteristic of an engine valve in an internal combustion engine.
In a drive mechanism that varies the valve characteristics of an engine valve in an internal combustion engine, the target drive state is fixed to a state suitable for the engine operation, such as during warm-up operation or steady operation of the internal combustion engine, and the actual drive state is Since there are many situations where the target drive state is fixed and the state is not changed from that state, there is a high possibility that an erroneous determination of normality will occur. However, even if there is such a tendency, it is determined that the drive mechanism is normal based on the determination that there is no abnormality in fixing in the drive mechanism under a situation where the actual drive state of the drive mechanism is not changed. This can be suppressed. Then, it is possible to suppress the occurrence of a false determination that it is normal based on the determination being made.

  According to a third aspect of the present invention, in the second aspect of the invention, the determination that the change from the previous state of the target drive state has occurred is based on a predetermined amount of change from the previous state of the target drive state. The predetermined value is set to a size that can be determined to be normal based on the determination that there is no abnormality in fixing. did.

  The fact that the target drive state has been judged to be free of sticking abnormality in the drive mechanism while showing a change of a predetermined value or more from the previous state means that the actual drive state is changed by changing the target drive state. It means that it is judged that there is no sticking abnormality. According to the above configuration, the size of the predetermined value is set to a size that can be determined to be normal based on the determination that there is no sticking abnormality at this time. Therefore, when it is determined that the normal state is determined based on the determination that there is no sticking abnormality and that the target drive state has changed from the previous state, the determination is more accurate. Can be.

  According to a fourth aspect of the present invention, in the second or third aspect of the present invention, when the determination means determines that there is no sticking abnormality, the target drive state has changed from a previous state. In addition, the gist is to determine that the actual driving state is normal on the condition that a change from the previous state has occurred.

  According to the above configuration, when it is determined that there is no sticking abnormality in the drive mechanism, in addition to the change in the target drive state from the previous state, the change in the actual drive state from the previous state occurs. It is judged that it is normal on the condition. Here, the fact that the target drive state of the drive mechanism changes from the previous state means that the actual drive state of the drive mechanism is going to be changed. Further, the fact that the actual drive state of the drive mechanism changes from the previous state means that the actual drive state has actually changed in accordance with the change in the target drive state. Therefore, it is determined that there is no sticking abnormality in the drive mechanism under a situation where the actual drive state of the drive mechanism is not being changed, and further, under a situation where the actual drive state is not actually changing. Based on the above, it is no longer determined that it is normal. For this reason, it can suppress that the erroneous determination of being normal based on the determination being performed, and the determination of being normal can be made more accurately.

  According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the determination that the change from the previous state of the actual drive state has occurred is that the amount of change from the previous state of the actual drive state is a predetermined value. Based on the above, the gist is that the predetermined value is set to a size that can be determined to be normal based on the determination that there is no abnormality in fixing. .

  The fact that the actual drive state shows a change of a predetermined value or more from the previous state and it is determined that there is no sticking abnormality in the drive mechanism means that the sticking while the actual drive state changes according to the change of the target drive state It means that it was judged that there was no abnormality. According to the above configuration, the size of the predetermined value is set to a size that can be determined to be normal based on the determination that there is no sticking abnormality at this time. Therefore, it is determined that there is no sticking abnormality, it is determined that a change from the previous state of the target drive state has occurred, and a change from the previous state of the actual drive state has occurred. Therefore, when it is determined that it is normal, the determination can be made more accurate.

Hereinafter, an embodiment in which the present invention is applied to a variable valve mechanism for an automobile engine will be described with reference to FIGS.
FIG. 1 is an enlarged sectional view showing a structure around a cylinder head 2 of a predetermined cylinder in the engine 1. In the engine 1, a combustion chamber 6 is defined by a cylinder head 2, a cylinder block 3, and a piston 5, and an intake passage 7 and an exhaust passage 8 are connected to the combustion chamber 6. The intake passage 7 and the combustion chamber 6 are communicated and blocked by the opening / closing operation of the intake valve 9, and the exhaust passage 8 and the combustion chamber 6 are communicated and blocked by the opening / closing operation of the exhaust valve 10. Become.

  The cylinder head 2 is provided with an intake camshaft 11 and an exhaust camshaft 12 for driving the intake valve 9 and the exhaust valve 10. The intake camshaft 11 and the exhaust camshaft 12 are rotated by transmission of rotation from the crankshaft (output shaft) of the engine 1. The intake camshaft 11 and the exhaust camshaft 12 are provided with an intake cam 11a and an exhaust cam 12a, respectively. The intake valve 9 and the exhaust valve 10 are opened and closed through integral rotation of the intake cam shaft 11 and the exhaust cam shaft 12 of the intake cam 11a and the exhaust cam 12a.

  Further, the engine 1 includes a variable valve mechanism 14 that varies the maximum lift amount and operating angle of the intake valve 9 as a variable valve mechanism that varies the valve characteristics of the engine valves such as the intake valve 9 and the exhaust valve 10. It is provided between the intake cam 11a and the intake valve 9. Through the operation of the variable valve mechanism 14, for example, the maximum lift amount and the operating angle are controlled to increase as the engine operation state that requires a larger amount of intake air is achieved. This is because the larger the maximum lift amount and the operating angle, the more efficiently the air is sucked into the combustion chamber 6 from the intake passage 7 and the above-described requirements regarding the intake air amount can be satisfied.

Next, the detailed structure of the variable valve mechanism 14 will be described.
The variable valve mechanism 14 includes an input arm 17 that is pushed by a rotating intake cam 11 a and swings about the axes of a rocker shaft 15 and a control shaft 16 that extend parallel to the intake cam shaft 11, and the input arm 17 And an output arm 18 that swings about the axis based on the swing. The input arm 17 is rotatably attached to a roller 19 and is biased toward the intake cam 11a by a coil spring 20 so that the roller 19 is pressed against the intake cam 11a. Further, the output arm 18 is pressed against the rocker arm 21 when swinging, and lifts the intake valve 9 via the rocker arm 21.

  The base end portion of the rocker arm 21 is supported by a lash adjuster 22, and the distal end portion of the rocker arm 21 is in contact with the intake valve 9. The rocker arm 21 is urged toward the output arm 18 by the valve spring 24 of the intake valve 9, whereby a roller 23 rotatably supported between the base end portion and the distal end portion of the rocker arm 21 is applied to the output arm 18. It is pressed. Therefore, when the input arm 17 and the output arm 18 swing based on the rotation of the intake cam 11a, the output arm 18 lifts the intake valve 9 via the rocker arm 21, and the intake valve 9 is opened and closed.

  In the variable valve mechanism 14, the relative position of the input arm 17 and the output arm 18 in the swing direction is changed by displacing the control shaft 16 disposed in the pipe-shaped rocker shaft 15 in the axial direction. Is possible. As described above, when the relative position of the input arm 17 and the output arm 18 in the swing direction is changed, the maximum lift amount and the operating angle of the intake valve 9 are made variable. That is, the closer the input arm 17 and the output arm 18 are to each other in the swing direction, the smaller the maximum lift amount and the operating angle of the intake valve 9 become in a synchronized state. On the contrary, as the input arm 17 and the output arm 18 are separated from each other in the swinging direction, the maximum lift amount and the operating angle of the intake valve 9 become larger in a synchronized state.

Next, the internal structure of the variable valve mechanism 14 will be described with reference to FIGS.
FIG. 2 is a cutaway perspective view showing the inner structure of the input arm 17 and the output arm 18 in the variable valve mechanism 14.

  The variable valve mechanism 14 includes a cylindrical slider 26 disposed inside the input arm 17 and the output arm 18. The rocker shaft 15 is inserted into the slider 26, and the control shaft 16 is inserted into the rocker shaft 15. When the control shaft 16 moves in the axial direction, the movement is transmitted to the slider 26 by an engaging member (not shown) attached to the control shaft 16, and the slider 26 is also displaced in the axial direction. On the outer wall of the slider 26, an input gear 27a having a helical spline 27 is fixed at the center in the longitudinal direction, and an output gear 29a having a helical spline 29 is fixed at both ends in the longitudinal direction.

  On the other hand, as shown in FIG. 3, an annular inner gear 28 a having a helical spline 28 is formed on the inner wall of the input arm 17, and an annular inner tooth having a helical spline 30 is formed on the inner wall of the output arm 18. A gear 30a is formed. The internal gear 28a of the input arm 17 is meshed with the input gear 27a (FIG. 2) of the slider 26, and the internal gear 30a of the output arm 18 is meshed with the output gear 29a (FIG. 2) of the slider 26. The helical splines 27 and 28 and the helical splines 29 and 30 have different inclination angles, for example, the inclination directions of the tooth traces are opposite to each other.

  Then, when the slider 26 is displaced in the coaxial line direction based on the movement of the control shaft 16 in the axial direction, the input arm 17 and the output arm 18 swing due to the meshing of the helical splines 27 and 29 and the helical splines 28 and 30. The relative position with respect to the direction is changed. Specifically, as the slider 26 is displaced in the direction of arrow L in FIG. 2, the relative positions of the input arm 17 and the output arm 18 with respect to the swinging direction are changed closer to each other, and the slider 26 is moved in the direction of arrow H. The relative positions are changed so as to be separated from each other as they are displaced. By changing the relative positions of the input arm 17 and the output arm 18 in the swinging direction, the maximum lift amount and operating angle of the intake valve 9 when the output arm 18 swings due to the rotation of the intake cam 11a can be made variable. .

  Next, an actuator for displacing the control shaft 16 in the axial direction to operate the variable valve mechanism 14 and a control device for driving and controlling the actuator will be described with reference to FIG.

  The actuator includes a motor 47 connected to a base end portion (right end portion in the drawing) of the control shaft 16 shown in FIG. The conversion mechanism 48 is for converting the rotational motion of the motor 47 into linear motion in the axial direction of the control shaft 16. Then, the control shaft 16 is displaced in the axial direction through the rotational drive of the motor 47 within a predetermined rotational angle range, for example, the rotational drive of the motor 47 within the rotational angle range (0 to 3600 °) for 10 rotations. Therefore, the variable valve mechanism 14 is driven.

  By the way, when the motor 47 is rotated in the reverse direction, the control shaft 16 is displaced toward the tip (left end in the figure), and the relative positions of the input arm 17 and the output arm 18 in the swinging direction are changed so as to approach each other. . When the motor 47 is rotated forward, the control shaft 16 is displaced toward the base end (right end in the figure), and the relative positions of the input arm 17 and the output arm 18 in the swing direction are changed so as to be separated from each other. The The maximum lift amount and operation of the intake valve 9 when the output arm 18 swings due to the rotation of the intake cam 11a through the change of the relative position in the swing direction of the input arm 17 and the output arm 18 by the rotation drive of the motor 47. The corner is variable.

  The control device for driving and controlling the actuator (motor 47) includes an electronic control device 50 that performs various controls of the engine 1 such as control of valve characteristics of the intake valve 9 such as the maximum lift amount and operating angle of the intake valve 9. Yes. The electronic control unit 50 includes a CPU that executes arithmetic processing related to the above various controls, a ROM that stores programs and data necessary for the control, a RAM that temporarily stores arithmetic results of the CPU, and an external interface. The input / output port for inputting / outputting the signal is provided.

Various sensors including the sensors shown below are connected to the input port of the electronic control unit 50.
An accelerator position sensor 51 that detects the amount of depression of the accelerator pedal (accelerator depression amount) that is depressed by the driver of the automobile.

A throttle position sensor 52 that detects the opening (throttle opening) of a throttle valve provided in the intake passage 7 of the engine 1.
An air flow meter 53 for detecting the amount of air taken into the combustion chamber 6 through the intake passage 7;

A crank position sensor 54 that outputs a signal corresponding to the rotation of the output shaft of the engine 1 and is used for detecting the engine rotation speed and the like.
A water temperature sensor 55 that detects the cooling water temperature of the engine 1.

  Position sensors 56 and 57 that, when the rotor of the motor 47 rotates, output pulsed signals with their phases shifted according to the magnetism of the multipolar magnet that rotates integrally with the rotor.

A current sensor 58 that detects the drive current of the motor 47.
A drive circuit for the motor 47 is connected to the output port of the electronic control unit 50. The electronic control unit 50 grasps the engine operating state based on the detection signals input from the various sensors. Then, based on the grasped engine operating state, the motor 47 is driven to displace the control shaft 16 in the axial direction, whereby the variable valve mechanism 14 is operated and the valve characteristics of the intake valve 9 are controlled. The valve characteristics of the intake valve 9, that is, the maximum lift amount and operating angle of the intake valve 9 correspond to the axial position of the control shaft 16, in other words, the rotation angle of the motor 47 within the predetermined rotation angle range.

  The rotation angle of the motor 47 can be grasped based on pulse signals output from the two position sensors 56 and 57 when the rotor rotates. That is, the edges of the pulse signals output from the position sensors 56 and 57 during the rotation of the rotor are counted, and the actual rotation angle within the rotation angle range of the motor 47 is grasped based on the counted value. Based on the actual rotation angle of the motor 47 thus grasped, the maximum lift amount and the operating angle of the intake valve 9 at that time can be grasped.

  By the way, in order to operate the variable valve mechanism 14 by driving the motor 47 and precisely control the maximum lift amount and operating angle of the intake valve 9, the actual maximum lift and operating angle are set based on the rotation angle of the motor 47. It is important to detect and control the drive of the motor 47 so that the maximum lift amount and operating angle become the target maximum lift amount and operating angle. Since the maximum lift amount and the operating angle of the intake valve 9 are changed in a synchronized state, a target maximum value is used below using a parameter called the actual operating angle Rr as a value corresponding to the actual maximum lift amount and operating angle. A parameter called a target operating angle Rt is used as a value corresponding to the lift amount and the operating angle.

  The actual operating angle Rr is a value representing the actual driving state of the variable valve mechanism 14 and is detected based on the rotation angle of the motor 47 ascertained from the count value of the edge of the pulse signal described above. The target operating angle Rt is a value representing the target driving state of the variable valve mechanism 14 and is variably set according to the operating state of the engine 1 grasped based on the detection signals input from the various sensors. When the target operating angle Rt changes according to the operating state of the engine 1, the motor 47 is driven so that the actual operating angle Rr matches the target operating angle Rt.

  In the motor 47, the driving speed of the motor 47 when the actual operating angle Rr is brought close to the target operating angle Rt is set to a drive command value determined according to the difference between the actual operating angle Rr and the target operating angle Rt. It is driven to be variable in response. In other words, the greater the difference between the actual operating angle Rr and the target operating angle Rt, the larger the drive command value becomes in order to increase the driving speed of the motor 47 when the actual operating angle Rr approaches the target operating angle Rt. To be done. Conversely, the smaller the difference between the actual operating angle Rr and the target operating angle Rt, the smaller the drive command value becomes in order to slow down the driving speed of the motor 47 when the actual operating angle Rr approaches the target operating angle Rt. To be. The drive command value is gradually increased when the actual operating angle Rr cannot be matched with the target operating angle Rt even if the motor 47 is driven so as to bring the actual operating angle Rr closer to the target operating angle Rt. It is made to become.

  From the above, the drive command value of the motor 47 is a parameter that represents the actual drive state of the variable valve mechanism 14 that operates by driving the motor 47. As the drive command value is increased to increase the drive speed of the motor 47, the drive current of the motor 47 shows a larger value. Therefore, the drive current of the motor 47 is also a parameter that represents the actual drive state of the variable valve mechanism 14 that operates by driving the motor 47.

Next, an outline of a procedure for diagnosing the variable valve mechanism 14, in other words, determining whether there is a sticking abnormality in the mechanism 14 and determining that it is normal will be described.
In the determination of the presence or absence of the sticking abnormality in the variable valve mechanism 14, the judgment that the sticking abnormality is present in the mechanism 14 uses at least one of the methods shown in the following [1] and [2]. Done. [1] Based on the fact that the deviation of the actual operating angle Rr from the target operating angle Rt is greater than a predetermined determination value, it is determined that a sticking abnormality has occurred in the variable valve mechanism 14. [2] Based on the fact that the drive command value and drive current of the motor 47 show an abnormal value when trying to make the actual operating angle Rr coincide with the target operating angle Rt, there is an abnormality in the fixing of the variable valve mechanism 14. to decide.

  Further, regarding the determination that the variable valve mechanism 14 is normal, for example, when the above-described determination that there is a sticking abnormality in the variable valve mechanism 14 is not made, in other words, there is no sticking abnormality in the mechanism 14. This can be done when it is determined. However, when it is determined that the normal operation angle is normal, the actual operation angle Rr is tried to change, for example, the target operation angle Rt is constant in a state where the actual operation angle Rr matches the target operation angle Rt. In such a situation, there is a possibility that the determination of normality based on the determination that there is no sticking abnormality in the variable valve mechanism 14 will be incorrect.

  That is, in making the determination of [1] above, in a situation where the abnormal valve mechanism 14 is stuck abnormally in a state where the actual operating angle Rr and the target operating angle Rt coincide with each other, the target operating angle of the actual operating angle Rr. Since the deviation from Rt does not exceed the determination value, it is determined that there is no sticking abnormality, and based on that, a false determination is made that it is normal. Further, in making the determination of [2] above, in the situation where the variable valve mechanism 14 is stuck abnormally in a state where the actual operating angle Rr is not being changed, such as when the target operating angle Rt is changed, Since the drive command value and drive current of the motor 47 do not show an abnormal value, it is determined that there is no sticking abnormality, and based on that, an erroneous determination is made that it is normal.

  In particular, in the engine 1, during warm-up operation or steady operation, the target operating angle Rt is fixed to the engine operating state, and the actual operating angle Rr is fixed to the target operating angle Rt and changed from that state. Since many situations that do not attempt to occur occur, there is a tendency that the possibility of erroneous determination that the variable valve mechanism 14 described above is normal occurs.

  Therefore, in this embodiment, when it is determined that there is no sticking abnormality in the variable valve mechanism 14, the target operating angle Rt is changed from the previous state, and the actual operating angle Rr is the previous state. It is determined that the mechanism 14 is normal on the condition that a change has occurred. Furthermore, when the target operating angle Rt and the actual operating angle Rr have not changed, the determination as to whether or not the variable valve mechanism 14 is normal is suspended. As a result, the variable valve mechanism 14 can be used under a situation where the actual operating angle Rr is not changed, for example, the target operating angle Rt is constant while the actual operating angle Rr matches the target operating angle Rt. It is possible to suppress the determination of being normal based on the determination that there is no sticking abnormality. Then, it is possible to suppress the occurrence of a false determination that it is normal based on the determination being made.

  Next, details of a procedure for determining whether there is a sticking abnormality in the variable valve mechanism 14 and determining that it is normal will be described with reference to a flowchart of FIG. 5 showing a diagnostic routine. This diagnosis routine is periodically executed through the electronic control unit 50, for example, with a time interruption at predetermined time intervals.

  In this routine, as the processing in step S101, the target operating angle Rt that is variably set and the actual operating angle Rr that is detected are stored in the RAM of the electronic control unit 50 every predetermined time. As the predetermined time, a time (for example, 1 second) longer than the execution cycle of the diagnostic routine is used. In step S102, it is determined whether or not there is a sticking abnormality in the variable valve mechanism 14 by using at least one of the above [1] and [2]. If a negative determination is made in step S102, it is determined that there is a sticking abnormality in the variable valve mechanism 14 (S107). If an affirmative determination is made in step S102, the process from step S103 is executed as a process for determining whether or not the variable valve mechanism 14 is normal.

  In this series of processes, first, as the process of step S103, it is determined whether or not the execution condition for executing the determination of whether or not it is normal is satisfied. The execution condition here is that the voltage of the battery that is a power supply source for driving the motor 47 is an appropriate value (for example, 8 V) or more and that the rotation angle of the motor 47 is deviated from the appropriate value. Various conditions such as not being in the learning process for learning the learning value so as to be the obtained value, and the like. Then, when all of these various conditions are satisfied, it is determined in step S103 that the execution condition is satisfied. Thereafter, a process of determining whether or not the target operating angle Rt has changed from the previous state (S104), and a process of determining whether or not the actual operating angle Rr has changed from the previous state. (S105) is executed.

  In the process of step S104, whether or not the difference between the current target operating angle Rt and the target operating angle Rt stored in the RAM (the absolute value of the difference between them) is equal to or greater than a predetermined value α (a> 0). To be judged. Here, if the difference is equal to or greater than the predetermined value α, which is a value larger than “0”, the variable valve mechanism in step S102 while changing the actual operating angle Rr by changing the target operating angle Rt. 14 means that no sticking abnormality is determined. Note that the magnitude of the predetermined value α is set to a magnitude at which it can be determined that the variable valve mechanism 14 is normal based on the determination that there is no abnormal sticking at this time.

  In the processing of step S105, it is determined whether or not the difference between the current actual operating angle Rr and the actual operating angle Rr stored in the RAM (the absolute value of the difference between them) is equal to or greater than a predetermined value β (β> 0). To be judged. Here, when the difference is equal to or greater than the predetermined value β, which is a value larger than “0”, the actual operating angle Rr actually changes according to the change in the target operating angle Rt, and the variable motion is performed in step S102. This means that it has been determined that there is no abnormality in sticking in the valve mechanism 14. The magnitude of the predetermined value β is set to a magnitude that allows the variable valve mechanism 14 to be determined to be normal based on the determination that there is no sticking abnormality.

  Then, on the condition that affirmative determination is made in both step S104 and step S105, in other words, when it is determined that there is no sticking abnormality in the variable valve mechanism 14, a change in the target operating angle Rt has occurred. And that the actual operating angle Rr has changed with the change in the target operating angle Rt, it is determined that the mechanism 14 is normal (S106). On the other hand, when a negative determination is made at step S104, or when an affirmative determination is made at step S104, a negative determination is made at step S105, the determination as to whether or not the variable valve mechanism 14 is normal is put on hold.

According to the embodiment described in detail above, the following effects can be obtained.
(1) When it is determined that there is no sticking abnormality in the variable valve mechanism 14, the target operating angle Rt has changed from the previous state, in other words, the actual operating angle Rr is to be changed. Is determined that the mechanism 14 is normal. When the target operating angle Rt has not changed, the determination as to whether or not the variable valve mechanism 14 is normal is suspended. For this reason, it is determined that the mechanism 14 is normal based on the determination that the variable valve mechanism 14 is not stuck abnormally under the situation where the actual operating angle Rr is not changed. Can be suppressed. Then, based on the determination being made, it is possible to suppress an erroneous determination that the operation is normal.

  In the engine 1, the target operating angle Rt is fixed to the engine operating state during warm-up operation or steady operation, and the actual operating angle Rr is fixed to the target operating angle Rt and changed from that state. Since many situations that do not attempt to occur occur, there is a tendency that the possibility of erroneous determination that the variable valve mechanism 14 described above is normal occurs. However, even if there is such a tendency, it is determined that the normal state is determined based on the determination that there is no abnormality in the fixed valve mechanism 14 under the situation where the actual operating angle Rr is not changed. It is possible to suppress the occurrence of an erroneous determination that it is normal based on the determination being made.

  (2) In the determination that the target operating angle Rt has changed from the previous state (YES in S104 in FIG. 5), the amount of change at the time of the change is greater than or equal to a predetermined value α, that is, the current This is based on the fact that the difference between the target operating angle Rt and the target operating angle Rt stored in the RAM is equal to or greater than a predetermined value α. The magnitude of the predetermined value α is such that it can be determined that the mechanism 14 is normal based on the determination that there is no sticking abnormality in the variable valve mechanism 14 (YES in step S102 in FIG. 5). Set to Therefore, it is determined that the variable valve mechanism 14 is normal based on the determination that the fixing abnormality is not present and the determination that the target operating angle Rt has changed from the previous state. Sometimes the decision can be made more accurate.

  (3) Regarding the determination as to whether or not the variable valve mechanism 14 is normal, more specifically, when it is determined that there is no sticking abnormality in the mechanism 14, the target operating angle Rt changes from the previous state. In addition to the occurrence, the determination that the normal operation angle Rr is normal is made on the condition that a change from the previous state has occurred. When the actual operating angle Rr has not changed, the determination as to whether or not the variable valve mechanism 14 is normal is suspended. Here, the fact that the actual operating angle Rr changes from the previous state means that the actual operating angle Rr has actually changed in accordance with the change in the target operating angle Rt. Therefore, under the situation where the actual operating angle Rr is not changed by the change of the target operating angle Rt, and further under the situation where the actual operating angle Rr is not actually changed, the variable valve mechanism 14 The determination that the mechanism 14 is normal can be suppressed based on the determination that there is no fixing abnormality. For this reason, it is possible to suppress an erroneous determination of being normal based on the determination being made, and it is possible to more accurately determine that it is normal.

  (4) In the determination that the actual operating angle Rr has changed from the previous state (YES in S105 in FIG. 5), the amount of change at the time of the change is equal to or greater than a predetermined value β, that is, the current This is based on the fact that the difference between the actual operating angle Rr and the actual operating angle Rr stored in the RAM is equal to or greater than a predetermined value β. The predetermined value β is large enough to determine that the mechanism 14 is normal based on the determination that there is no sticking abnormality in the variable valve mechanism 14 (YES in step S102 in FIG. 5). Set to Accordingly, it is determined that there is no abnormality in fixing, it is determined that the target operating angle Rt has changed from the previous state, and the actual operating angle Rr has changed from the previous state. When it is determined that the variable valve mechanism 14 is normal based on the determination that the variable valve mechanism 14 is present, the determination can be made more accurate.

In addition, the said embodiment can also be changed as follows, for example.
In determining that the variable valve mechanism 14 is normal, the condition that the actual operating angle Rr is changed from the previous state (step 105 in FIG. 5) may be eliminated.

In determining that there is a sticking abnormality in the variable valve mechanism 14, only one of the determination in [1] and the determination in [2] may be used.
The present invention may be applied to a variable valve mechanism that varies the opening / closing timing of the valve 9 as the valve characteristic of the intake valve 9 by making the relative rotational phase of the intake camshaft 11 relative to the crankshaft variable.

-When the variable valve mechanism which makes the valve characteristic of the exhaust valve 10 variable is provided, you may apply this invention to the variable valve mechanism.
The present invention may be applied to drive mechanisms other than the variable valve mechanism 14.

The expanded sectional view which shows the structure around the cylinder head of the engine to which the variable valve mechanism of this embodiment is applied. The fracture | rupture perspective view which shows the internal structure of the said variable valve mechanism. The fracture | rupture perspective view which shows the internal structure of an input arm and an output arm. 4 is a schematic diagram showing an actuator that drives the variable valve mechanism and a control device that drives and controls the actuator. The flowchart which shows the procedure which performs the diagnosis of a variable valve mechanism.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Engine, 2 ... Cylinder head, 3 ... Cylinder block, 5 ... Piston, 6 ... Combustion chamber, 7 ... Intake passage, 8 ... Exhaust passage, 9 ... Intake valve, 10 ... Exhaust valve, 11 ... Intake camshaft, 12 DESCRIPTION OF SYMBOLS ... Exhaust cam shaft, 11a ... Intake cam, 12a ... Exhaust cam, 14 ... Variable valve mechanism, 15 ... Rocker shaft, 16 ... Control shaft, 17 ... Input arm, 18 ... Output arm, 19 ... Roller, 20 ... Coil spring , 21 ... Rocker arm, 22 ... Rush adjuster, 24 ... Valve spring, 23 ... Roller, 26 ... Slider, 27 ... Helical spline, 27a ... Input gear, 28 ... Helical spline, 28a ... Internal gear, 29 ... Helical spline, 29a ... output gear, 30 ... helical spline, 30a ... internal gear, 48 ... conversion mechanism, 4 ... motor, 50 ... electronic control unit, 51 ... accelerator position sensor, 52 ... throttle position sensor, 53 ... air flow meter, 54 ... crank position sensor, 55 ... water temperature sensor, 56, 57 ... position sensor, 58 ... current sensor.

Claims (5)

In a diagnosis device that is applied to a drive mechanism that is driven so that an actual drive state matches a target drive state that is variably set, and that determines whether there is a sticking abnormality of the drive mechanism based on the actual drive state of the drive mechanism ,
When it is determined that there is no sticking abnormality, it is determined that the target drive state is normal on the condition that a change from the previous state has occurred, and whether or not the target drive state is normal when the change has not occurred A diagnostic device comprising: a determination unit that puts the determination on hold. The diagnostic device according to claim 1, wherein the drive mechanism is for changing a valve characteristic of an engine valve in an internal combustion engine. The determination that a change from the previous state of the target drive state has occurred is made based on the amount of change from the previous state of the target drive state being a predetermined value or more,
The diagnostic apparatus according to claim 2, wherein the predetermined value is set to a size that can be determined to be normal based on the determination that the sticking abnormality is not present. When the determination means determines that there is no sticking abnormality, in addition to a change from the previous state of the target drive state, a change from the previous state of the actual drive state has occurred. The diagnosis device according to claim 2, wherein the diagnosis device determines that the device is normal. The determination that a change from the previous state of the actual driving state has occurred is made based on the amount of change from the previous state of the actual driving state being a predetermined value or more,
The diagnostic apparatus according to claim 4, wherein the predetermined value is set to a size that can be determined to be normal based on the determination that the fixing abnormality is not present.

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