JP5516432B2 - Variable valve operating apparatus for internal combustion engine and internal combustion engine provided with the same - Google Patents

Description

  The present invention relates to a variable valve operating apparatus for an internal combustion engine and an internal combustion engine including the variable valve operating apparatus, and more particularly, to a variable valve operating apparatus for an internal combustion engine capable of changing a valve operating angle and an internal combustion engine including the variable valve operating apparatus.

  Conventionally, for example, Patent Document 1 discloses a variable valve timing mechanism including a cam working angle changing unit that can continuously change the working angle of an intake valve. In this conventional cam working angle changing section, the relative rotation angle between the intermediate cam that receives the rotational force of the drive cam and the swing cam that pushes the intake valve is adjusted by adjusting the axial position of the control rod by the actuator. Is changed. With this configuration, the conventional variable valve timing mechanism can change the operating angle of the intake valve according to the position of the control rod (control member) adjusted by the actuator.

JP 2008-274962 A JP 2005-180238 A

  In the conventional variable valve timing mechanism described above, when the operating angle of the intake valve is reciprocally changed between the small operating angle side and the large operating angle side by reciprocating the control rod (control member), the actuator It is necessary to switch the driving direction of the control rod by forward and backward. As a result, when the operating angle of the intake valve is shifted from the large operating angle side to the small operating angle side by the actuator, a larger operating angle than the current operating angle is requested (or conversely, the actuator When the operating angle of the intake valve is moving from the small operating angle side to the large operating angle side during the period when the operating angle smaller than the current operating angle is requested), the drive direction of the control rod by the actuator When the actuator is switched in the reverse direction, the inertial force of the actuator generated by the operation of the actuator so far is added, so that a large load may act on the actuator when switching the driving direction of the actuator. For this reason, when the actuator uses, for example, an electric motor, there is a concern about an increase in power consumption and heat generation due to an increase in current. In addition, there is a concern about the acceleration of gear wear due to an increase in the load acting on the gear inside the actuator.

  The present invention has been made to solve the above-described problems. When the valve operating angle is reciprocally changed between the small operating angle side and the large operating angle side, a large load acts on the actuator. It is an object of the present invention to provide a variable valve operating apparatus for an internal combustion engine and an internal combustion engine provided with the same that can prevent the occurrence of problems associated with such a large load acting on an actuator.

A first invention is a variable valve operating apparatus for an internal combustion engine,
A control member whose position is adjusted to change the working angle of the valve;
An actuator for adjusting the position of the control member;
A variable valve operating apparatus for an internal combustion engine configured to be able to return the position of the control member to the original position again in the process in which the actuator operates in one direction,
In the first case where a larger working angle than the current working angle is requested during the period when the working angle of the valve is changed from the large working angle side to the small working angle side by the actuator, or The operation of the actuator is performed in the second case in which a working angle smaller than the current working angle is requested during a period in which the working angle of the valve is changed from the small working angle side to the large working angle side by the actuator. Actuator control means for performing one-way control for controlling the actuator in one direction so that the control member moves to a position where the required operating angle of the valve can be obtained without changing the direction;
It is characterized by providing.

The second invention is the first invention, wherein
The variable valve operating device is:
As the control member, a guide member having a raceway surface formed so as to cover a drive cam shaft that rotationally drives a driven cam lobe that drives the valve;
By changing the relative rotation angle of the driven cam lobe with respect to the drive cam shaft in accordance with the control position of the guide member, the driven cam lobe with respect to the drive cam shaft is rotated during one rotation of the drive cam shaft. A variable cam speed mechanism to increase or decrease the relative rotational speed;
Including
By moving the guide member in a plane direction perpendicular to the axis of the drive cam shaft by the actuator, the rotational speed of the driven cam lobe is changed during one rotation of the drive cam shaft, and the working angle of the valve is increased. It can be changed.

The third invention is the first or second invention, wherein
The actuator control means includes
Switching request degree determination means for determining whether switching of the valve operating angle in the first case or the second case is a high load switching request with a high load on the actuator;
When it is determined by the switching request degree determination means that the high load switching request is selected, the one-way control is selected, and when the switching request degree determination means determines that the request is not the high load switching request Is a control mode switching for selecting swing control for controlling the actuator so that the control member moves to a position where the required operating angle of the valve is obtained after switching the operating direction of the actuator to the reverse direction. Means,
It is characterized by including.

According to a fourth invention, in any one of the first to third inventions,
The actuator includes a variable working angle cam having a cam surface in contact with the control member, and a drive unit that rotationally drives the variable working angle cam.
The variable valve operating device is:
Biasing means for biasing the control member toward the cam surface;
From the first contact point on the cam surface, which is far from the rotation center of the variable working angle cam, to the second contact point on the cam surface, the distance from the rotation center being shorter than the first contact point. When the rotational position of the variable operating angle cam is controlled by the actuator so that the contact point between the control member and the variable operating angle cam changes, the cam having the shortest distance from the rotation center A second actuator that controls the actuator so that the operating angle variable cam is rotationally driven with the second contact point existing ahead of the shortest contact point as a target position after passing through the shortest contact point on the surface Control means;
Is further provided.

The fifth invention is an internal combustion engine comprising the variable valve operating apparatus for an internal combustion engine according to any one of the first to fourth inventions,
The valve is an intake valve,
The actuator includes a variable working angle cam having a cam surface in contact with the control member, and a drive unit that rotationally drives the variable working angle cam.
The working angle variable cam has a profile that is line symmetric with respect to a straight line orthogonal to the rotational axis as seen from the rotational axis direction of the working angle variable cam.
An intake flow rate detecting means for detecting an intake air flow rate of the internal combustion engine;
First suction when the working angle variable cam is rotated forward with the longest contact point having the longest distance from the rotation center of the working angle variable cam or the shortest contact point having the shortest distance as a reference working angle position. A working angle for detecting a working angle of the valve based on a comparison result between an air flow rate value and a second intake air flow rate value when the working angle variable cam is reversely rotated by the same amount of swing as in the forward rotation. An abnormality determining means for determining whether there is an abnormality in the shape of the sensor or the variable working angle cam;
Is further provided.

The sixth invention is the fifth invention, wherein
The abnormality determining means compares the first intake air flow rate value with the second intake air flow rate value while changing the swing amount a plurality of times, but compares the first intake air flow rate value with the second intake air flow rate value. When the intake air flow rate value does not show the same air flow rate characteristic, it is determined that an abnormality has occurred in the working angle sensor.

  According to the first invention, by using the one-way control in the first case or the second case, the inertial force of the actuator generated by the operation of the actuator so far is added. Thus, it is possible to prevent a large load from acting on the actuator when the driving direction of the actuator is switched. As a result, it is possible to prevent the occurrence of problems associated with such a large load acting on the actuator.

  According to the second aspect of the invention, the rotational speed of the driven cam lobe during one rotation of the drive camshaft is changed by moving the guide member as a control member in the plane direction orthogonal to the axis of the drive camshaft by the actuator. Thus, the effects of the first aspect of the invention can be achieved with respect to the variable valve operating apparatus having a configuration that allows the operating angle of the valve to be changed.

  According to the third aspect of the present invention, an increase in the driving load of the actuator is prevented in a situation where a high load switching request with a high load on the actuator is issued, and the adjustment of the operating angle is smooth in other situations. You can do it.

  The control member from the first contact point on the cam surface that is far from the rotation center of the variable working angle cam to the second contact point on the cam surface that is shorter than the rotation center than the first contact point. When the rotational position of the operating angle variable cam is controlled by the actuator so that the contact point between the operating angle variable cam and the operating angle variable cam changes, the urging force generated by the urging means drives the operating angle variable cam by the actuator. Acts as an assisting force. Under such circumstances where the assist force is applied, after the variable operating angle cam rotates to a position exceeding the shortest contact point on the cam surface where the distance from the rotation center is the shortest, an operating angle based on the biasing force is applied. The moment around the rotation center of the variable cam acts as a reaction force for the rotation of the actuator. According to the fourth invention, in the case where the operating angle variable cam is rotated under such a situation where the assist force is applied, the second existing at the tip of the shortest contact point after passing through the shortest contact point. By controlling the actuator so that the operating angle variable cam is rotationally driven with the contact point as a target position, the moment based on the biasing force can be applied as a braking force with respect to the inertial force (moment) of the actuator. As a result, the braking force generated by the actuator to stop the operating angle variable cam at the target position can be as much as the moment of inertia of the actuator cannot be offset by the moment based on the biasing force. For this reason, in such a case, the force (torque) required for the actuator can be reduced.

  The working angle variable cam has a profile set so as to be line symmetric as described above. Therefore, if the output value of the working angle sensor and the actual working angle are matched, the intake angle can be reduced when the working angle variable cam is swung evenly with respect to the reference working angle position. The same working angle of the valve should be obtained and the same air flow characteristics should be obtained. However, if the same air flow rate characteristics cannot be obtained, the working angle sensor value may not match the actual working angle due to the malfunction of the working angle sensor, or the shape of the variable working angle cam It can be determined that an abnormality has occurred. Therefore, according to the fifth aspect of the invention, the comparison is performed based on the first and second intake air flow rates when the variable working angle cam is controlled in both directions with a uniform swing amount with respect to the reference working angle position. With a simple method, during operation of the internal combustion engine, it is possible to determine whether there is an abnormality in the shape of the working angle sensor that detects the working angle of the valve or the working angle variable cam.

  According to the sixth invention, it is possible to determine the presence or absence of abnormality of the working angle sensor using the comparison result of the first and second intake air flow values when the swing amount is changed a plurality of times.

It is a figure for demonstrating the system configuration | structure of the internal combustion engine in Embodiment 1 of this invention. It is a perspective view which shows roughly the whole structure of the intake variable valve operating apparatus shown in FIG. FIG. 2 is a view for explaining a configuration around a drive cam shaft provided in the intake variable valve operating apparatus shown in FIG. 1. It is sectional drawing which cut | disconnected the intake variable valve operating apparatus by the AA line shown in FIG. It is the perspective view which looked at the intake variable valve operating apparatus from the arrow B direction in FIG. It is a figure for demonstrating the specific structure of the actuator shown in FIG. It is a figure showing the relationship between the working angle variable cam rotated by the actuator and the guide member. It is a schematic diagram for demonstrating operation | movement of the intake variable valve operating apparatus accompanying the displacement of a guide member. A diagram showing the change in the operating angle of the intake valve accompanying the displacement of the guide member and the difference (change) in the rotation angle θ between the drive cam shaft and the driven cam lobe (relative to the value in the reference state) accompanying the displacement of the guide member It is. It is a figure for demonstrating rocking | fluctuation control of the working angle variable cam for changing the working angle of an intake valve reciprocally. It is a figure for demonstrating the one-way control of the working angle variable cam for changing the working angle of an intake valve reciprocally. It is a figure for demonstrating the driving | running condition in which the one-way control of a working angle variable cam is performed. It is a flowchart of the routine performed in Embodiment 1 of the present invention. It is a figure for demonstrating the adjustment method of the working angle referred for contrast with the adjustment method of the characteristic working angle in Embodiment 2 of this invention. It is a figure for demonstrating the adjustment method of the characteristic working angle in Embodiment 2 of this invention. It is a figure for demonstrating the matching confirmation method with the characteristic working angle sensor value and actual working angle in Embodiment 3 of this invention. It is a figure for demonstrating the matching confirmation method with the characteristic working angle sensor value and actual working angle in Embodiment 3 of this invention. It is a flowchart of the routine performed in Embodiment 3 of the present invention.

Embodiment 1 FIG.
[System configuration of internal combustion engine]
FIG. 1 is a diagram for explaining a system configuration of an internal combustion engine 10 according to Embodiment 1 of the present invention. The internal combustion engine 10 is, for example, an in-line four-cylinder engine having four cylinders (# 1 to # 4). A combustion chamber 12 is formed in the cylinder of the internal combustion engine 10. An intake passage 14 and an exhaust passage 16 communicate with the combustion chamber 12.

  An air flow meter 18 that outputs a signal corresponding to the flow rate of air sucked into the intake passage 14 is provided in the vicinity of the inlet of the intake passage 14. An electronically controlled throttle valve 20 is provided downstream of the air flow meter 18. A fuel injection valve 22 for injecting fuel into the intake port of the internal combustion engine 10 is disposed downstream of the throttle valve 20. A spark plug 24 is attached to the cylinder head provided in the internal combustion engine 10 so as to protrude from the top of the combustion chamber 12 to the combustion chamber 12.

  An intake port 26 and an exhaust valve for bringing the combustion chamber 12 and the intake passage 14 or the combustion chamber 12 and the exhaust passage 16 into a conductive state or a cut-off state are respectively provided in the intake port of the intake passage 14 and the exhaust port of the exhaust passage 16. 28 is provided. The intake valve 26 and the exhaust valve 28 are driven by an intake variable valve operating device 30 and an exhaust variable valve operating device 32, respectively. The specific configuration of these variable valve gears 30 and 32 will be described later with reference to FIGS.

  A crank angle sensor 36 for detecting the crank angle and the engine speed is disposed in the vicinity of the crankshaft 34. Further, the system shown in FIG. 1 includes an ECU (Electronic Control Unit) 38. In addition to the air flow meter 18 and the crank angle sensor 36 described above, an accelerator opening sensor 40 for detecting the amount of depression of the accelerator pedal (accelerator opening) of the vehicle on which the internal combustion engine 10 is mounted, etc. Various sensors for detecting the operating state of the internal combustion engine 10 are connected. Various actuators for controlling the operating state of the internal combustion engine 10 such as the throttle valve 20, the fuel injection valve 22, the spark plug 24, and the variable valve gears 30 and 32 are connected to the output portion of the ECU 38. ing. The ECU 38 controls the operating state of the internal combustion engine 10 by operating various actuators according to a predetermined program based on the sensor outputs.

  Next, the basic configuration and the basic operation of the variable valve gears 30 and 32 will be described with reference to FIGS. Here, the intake variable valve operating device 30 will be described as an example, but the exhaust variable valve operating device 32 is also configured in the same manner as the intake variable valve operating device 30.

[Basic configuration of variable valve gear]
FIG. 2 is a perspective view schematically showing the overall configuration of the intake variable valve operating apparatus 30 shown in FIG. FIG. 3 is a view for explaining the configuration around the drive cam shaft 42 provided in the intake variable valve operating apparatus 30 shown in FIG.
As shown in FIGS. 2 and 3, the intake variable valve operating apparatus 30 (hereinafter sometimes simply referred to as “variable valve operating apparatus 30”) includes a drive cam shaft 42. The drive camshaft 42 is connected to the crankshaft 34 via a timing pulley 44 and a timing chain (not shown), and is configured to rotate at a half speed of the crankshaft 34. As shown in FIG. 3, a variable valve timing (VVT) mechanism 46 that allows the rotation phase of the drive cam shaft 42 to change with respect to the rotation of the crankshaft 34 is interposed between the drive cam shaft 42 and the timing pulley 44. ing.

  As shown in FIG. 3, a cam piece 48 is attached to the drive camshaft 42 for each cylinder. The cam piece 48 is concentric with the drive cam shaft 42 and is rotatably supported by the drive cam shaft 42. The cam piece 48 is formed with two driven cam lobes 48 a for driving the intake valve 26.

  In addition, a drive arm 50 having a drive arm portion 50a protruding outward in the radial direction of the drive cam shaft 42 is integrally fixed to the drive cam shaft 42 for each cylinder. Further, the cam piece 48 is integrally formed with a driven arm portion 48b protruding outward in the radial direction of the drive cam shaft 42 in the vicinity of the driven cam lobe 48a closer to the drive arm 50 for the same cylinder.

The description will be continued with the addition of FIG. 4 and FIG.
4 is a cross-sectional view of the intake variable valve operating apparatus 30 taken along line AA shown in FIG. FIG. 5 is a perspective view of the intake variable valve operating apparatus 30 as seen from the direction of arrow B in FIG. In FIG. 4, illustration of a part of the link plate 64 is omitted, and illustration of the guide member 66 is omitted in FIG.

  As shown in FIGS. 4 and 5, one end of a drive link 54 is rotatably connected to the drive arm portion 50 a via a cam shaft side rotation shaft 52. In addition, one end of a driven link 58 is rotatably connected to the driven arm portion 48 b via a cam lobe side rotation shaft 56. The other end of the drive link 54 and the other end of the driven link 58 are connected via a control roller side rotating shaft 60. A control roller 62 and a link plate 64 are interposed between the drive link 54 and the driven link 58 on the control roller side rotating shaft 60.

  As described above, the variable valve operating apparatus 30 of the present embodiment includes the drive arm portion 50a and the driven arm portion 48b having the shaft center of the drive cam shaft 42 as a common rotation center, the drive link 54, and the driven link 58. As shown in FIG. 4, a link mechanism 65 that is a four-bar link connected in a pantograph shape (diamond shape) is provided.

  As shown in FIG. 5, the link plate 64 is formed by bending two annular plate portions so as to be concentric. The link plate 64 is disposed on the control roller-side rotation shaft 60 in a state where the drive cam shaft 42 passes through the link plate 64 and the control roller 62 is sandwiched from the outside.

  As shown in FIG. 4, a raceway surface 66 a 1 of the guide member 66 is disposed on the outer peripheral side of the link plate 64 so as to further cover the link plate 64 through which the drive cam shaft 42 penetrates. More specifically, the track surface 66a1 of the present embodiment is configured by a circumferential surface. The control roller 62 is rotatably supported by the control roller side rotation shaft 60 at a position in contact with the track surface 66a1 so that the control roller 62 can roll on the track surface 66a1 in conjunction with the rotation of the drive cam shaft 42. .

  Further, as shown in FIG. 4, in addition to the control roller 62, two holding rollers 68 are rotatably attached to the link plate 64 via a holding rotary shaft 70 at a position in contact with the track surface 66a1. Yes. More specifically, the three rollers 62 and 68 including the two holding rollers 68 in addition to the control roller 62 are arranged at equiangular intervals around the drive cam shaft 42. 62 and 68 are attached to the link plate 64. With such a configuration, the position of the control roller 62 attached to the link plate 64 with respect to the track surface 66a1 is defined. For this reason, the control roller 62 rolls on the raceway surface 66a1 while always in contact with the raceway surface 66a1 as the drive cam shaft 42 rotates. As a result of defining the position of the control roller 62, the relative rotation angle θ (see FIG. 4) of the driven cam lobe 48a with respect to the rotation angle of the drive cam shaft 42 is also specified via the drive link 54 and the driven link 58. Will be.

  As shown in FIGS. 2 and 4, the guide member 66 includes an annular portion 66a having the raceway surface 66a1 for each cylinder. As shown in FIG. 2, the annular portion 66a of each cylinder is integrally connected by being bridged via a bridging portion 66b. The guide member 66 is movable in the vertical direction in FIG. 4 (that is, in the vertical direction of the cylinder), and the movement in the horizontal direction in FIG. 4 and the axial direction of the drive cam shaft 42 is restricted. These are supported by a cylinder head or a cam carrier via a predetermined support member (not shown). Further, as shown in FIG. 4, the guide member 66 is biased by the spring 71 in the downward direction (downward of the cylinder) in FIG. 4 (more specifically, toward the working angle variable cam 82 described later). Has been. The other end of the spring 71 is attached to a head cover (not shown).

  FIG. 6 is a diagram for explaining a specific configuration of the actuator 72 shown in FIG. More specifically, FIG. 6A is a view of the actuator 72 viewed from the direction of the arrow C in FIG. 2, and FIG. 6B is a view of the actuator 72 in the direction of the arrow C in FIG. It is the figure seen from the direction of the view D. 2 and 6B, the motor 74 and the worm gear 76 are not shown.

  The variable valve operating apparatus 30 according to the present embodiment moves the guide member 66 in a predetermined direction in the movement direction shown in FIG. 4 (in this embodiment, it coincides with the axial direction of the cylinder of the internal combustion engine). An actuator 72 for driving within the range is provided. More specifically, the actuator 72 has, as a reference state, a state in which the center point of the raceway surface 66a1 that is a circumferential surface coincides with the center point of the drive cam shaft 42 as viewed from the axial direction of the drive cam shaft 42. The guide member 66 is moved so that the center point of the track surface 66a1 moves along the normal direction of the axis of the drive cam shaft 42 and the axial direction of the cylinder (that is, in the vertical direction in FIG. 4).

  As shown in FIG. 6A, the actuator 72 includes an electric motor (hereinafter simply “motor”) 74, a worm gear 76 fixed to the output shaft of the motor 74, and a worm wheel meshed with the worm gear 76. 78. The motor 74 is driven based on a command from the ECU 38. As shown in FIG. 6B, a control shaft 80 concentric with the worm wheel 78 is fixed to the worm wheel 78. Two variable operating angle cams 82 are fixed to the control shaft 80 corresponding to the two bridging portions 66b of the guide member 66 in parallel. Further, a working angle sensor 84 for obtaining the working angle of the intake valve 26 by detecting the rotation angle of the control shaft 80 is disposed in the vicinity of the control shaft 80. The working angle sensor 84 is connected to the ECU 38. The working angle sensor for acquiring the working angle of the intake valve 26 is not limited to the one having the above-described configuration, and for example, a stroke sensor that detects the stroke of the guide member 66 may be used.

  FIG. 7 is a view showing the relationship between the variable operating angle cam 82 driven by the actuator 72 and the guide member 66. More specifically, FIG. 7A shows the longest distance from the rotation center of the variable working angle cam 82 (hereinafter abbreviated as “cam rotation center”) when viewed from the axial direction of the control shaft 80. The state in which the operating angle variable cam 82 is in contact with the guide member 66 at the longest contact point is shown. In this state, the guide member 66 is most displaced in the upward direction in FIG. 7 (that is, the upward direction of the cylinder of the internal combustion engine) within the above movement range. On the other hand, FIG. 7B shows a state in which the variable operating angle cam 82 is in contact with the guide member 66 at the shortest contact point where the distance from the cam rotation center is the shortest when viewed from the axial direction of the control shaft 80. ing. In this state, the guide member 66 is most displaced in the downward direction in FIG. 7 (that is, the downward direction of the cylinder of the internal combustion engine) within the moving range.

  According to the actuator 72 having the above-described configuration, the rotation angle of the operating angle variable cam 82 is controlled by the motor 74, so that the position of the guide member 66 is set to an arbitrary position within the movement range (stroke shown in FIG. 7). Can be adjusted. Further, as shown in FIG. 7, the working angle variable cam 82 of the present embodiment is axisymmetric with respect to a straight line connecting the longest contact point and the shortest contact point when viewed from the axial direction of the control shaft 80. You have a profile set up as follows.

[Basic operation of variable valve system]
Next, the basic operation of the variable valve operating apparatus 30 of the present embodiment will be described with reference to FIGS.
FIG. 8 is a schematic diagram for explaining the operation of the intake variable valve operating apparatus 30 accompanying the displacement of the guide member 66. In addition, each figure of FIG. 8 is the figure which represented typically the main structures of the variable valve apparatus 30 seeing from the reverse direction to the said FIG. Further, FIG. 9 shows a change in the operating angle of the intake valve 26 accompanying the displacement of the guide member 66, and the drive cam shaft 42 and the driven cam lobe 48a (relative to the values in the reference state) accompanying the displacement of the guide member 66. It is a figure showing the difference (change) of rotation angle (theta).

  When the drive cam shaft 42 rotates in the rotation direction of the drive cam shaft 42 shown in FIG. 8, the rotational force of the drive cam shaft 42 is driven via the drive arm portion 50 a fixed integrally to the drive cam shaft 42. It is transmitted to the link 54. The rotational force of the drive cam shaft 42 transmitted to the drive link 54 is transmitted to the driven cam lob 48a formed integrally with the driven arm portion 48b via the control roller side rotary shaft 60 and the driven link 58. As described above, the rotational force of the drive cam shaft 42 is transmitted to the driven cam lobe 48 a via the link mechanism 65.

  As a result, in synchronization with the rotation of the drive cam shaft 42, each element of the link mechanism 65 and the driven cam lobe 48a rotate in the same direction as the drive cam shaft 42. At this time, as described above, the control roller 62 rolls on the raceway surface 66a1 in a state where it is always in contact with the raceway surface 66a1.

  The state shown in FIG. 8B is a state where the center point of the drive camshaft 42 and the center point of the raceway surface 66a1 coincide (the reference state), and the raceway surface 66a1 of the present embodiment is It is a circumferential surface. For this reason, there is no change in the distance between the rotation center of the drive cam shaft 42 and the rotation center of the control roller 62 while the control roller 62 makes one rotation on the track surface 66a1 with the rotation of the drive cam shaft 42. There is no change in the relative rotation angle θ of the driven cam lobe 48a with respect to the cam shaft 42. Accordingly, in the reference state shown in FIG. 8B, the driven cam lobe 48a makes one rotation with the drive cam shaft 42 at a constant speed.

  Next, in the state shown in FIG. 8A, compared with the reference state shown in FIG. 8B, the track surface 66a1 moves most in the above movement range in the upward direction (upward direction of the cylinder) in FIG. Shows the state. In this state, when the control roller 62 is positioned on the lower half side of the raceway surface 66a1, the distance between the rotation center of the drive cam shaft 42 and the rotation center of the control roller 62 is narrower than in the reference state. become. When the distance is narrowed in the lower half section, the relative rotation angle θ of the driven cam lobe 48a with respect to the drive camshaft 42 is increased as compared with the reference state. The rotation direction of the drive cam shaft 42 is clockwise in FIG. Therefore, when the rotation angle θ is increased in the lower half section, the rotational position of the driven cam lob 48a is advanced to the front side in the rotational direction of the drive cam shaft 42 with respect to the drive cam shaft 42 as compared to the reference state. become. Hereinafter, a section in which such an action occurs when the rotation angle θ is larger than that in the reference state may be referred to as an “acceleration section”.

  On the other hand, in the state shown in FIG. 8C, compared with the reference state shown in FIG. 8B, the track surface 66a1 has moved most in the moving range in the downward direction (downward direction of the cylinder) in FIG. Indicates the state. In this state, when the control roller 62 is positioned on the lower half side of the raceway surface 66a1, the distance between the rotation center of the drive cam shaft 42 and the rotation center of the control roller 62 is wider than that in the reference state. become. When the distance is increased in the lower half section, the relative rotation angle θ of the driven cam lobe 48a with respect to the drive cam shaft 42 is reduced as compared with the reference state. As a result, the rotational position of the driven cam lobe 48a is delayed to the rear side in the rotational direction of the drive camshaft 42 with respect to the drive camshaft 42 as compared with the reference state. Hereinafter, a section in which such an action occurs due to the rotation angle θ being reduced compared to the reference state may be referred to as a “deceleration section”.

(Intake valve operating angle)
In the variable valve operating apparatus 30 of the present embodiment, as shown in FIG. 8A, the speed increasing section when the raceway surface 66a1 moves upward is set so as to overlap the lift section of the driven cam lobe 48a. . Here, in the control state of the guide member 66 shown in FIGS. 8A and 8C, the control roller is located near the point where the horizontal line passing through the center point of the drive cam shaft 42 and the raceway surface 66a1 in FIG. When 62 passes, the distance between the center point of the drive cam shaft 42 and the center point of the control roller 62 becomes equal to the value in the reference state, so that the rotation angle θ becomes the value in the reference state. There is an equal timing (hereinafter, such timing is referred to as “equal rotation angle timing”). In the present embodiment, as shown in FIG. 8, when the guide member 66 is moved upward within the moving range by the actuator 72, the one that switches from the deceleration zone to the acceleration zone (that is, the right side in FIG. 8). The position of the control roller 62 with respect to the raceway surface 66a1 is set so that the equal rotation angle timing of the intake valve 26 and the opening timing IVO of the intake valve 26 coincide (almost).

  According to the variable valve operating apparatus 30 of the present embodiment having the above settings, when the raceway surface 66a1 moves upward as shown in FIG. 8A, in the lift section on the opening side of the intake valve 26, The driven cam lobe 48a rotates while proceeding forward with respect to the drive cam shaft 42. For this reason, the rotational speed of the driven cam lobe 48a relative to the drive camshaft 42 increases as compared with the reference state (at the constant speed) shown in FIG. 8B. Therefore, in this case, as shown in FIG. 9A with “lift at high speed (small working angle)”, the intake air is compared with the “lift at constant speed” in the reference state. The lift amount of the valve 26 reaches the maximum lift amount early. Further, in this case, after the control roller 62 passes the position just below the raceway surface 66a1 (after the intake valve 26 has been opened, the cam angle is 90 ° and the crank angle is 180 ° CA), the drive cam The relative rotational speed of the driven cam lobe 48a with respect to the shaft 42 begins to decrease. Therefore, in the case of an intake valve having a general setting in which the operating angle exceeds 180 ° CA, the acceleration (negative value) of the intake valve 26 near the closing timing of the intake valve 26 as compared with “lift at constant speed”. ) Becomes smaller. However, since the rotational speed of the driven cam lobe 48a is greatly increased in the interval from when the intake valve 26 is opened until the control roller 62 reaches a position directly below the raceway surface 66a1, the closing timing of the intake valve 26 is also large. Compared to “lift at constant speed”. Thereby, the operating angle of the intake valve 26 can be made smaller than the constant speed lift.

  Further, according to the variable valve operating apparatus 30 in the present embodiment, when the raceway surface 66a1 moves downward as shown in FIG. 8C, in the lift section on the opening side of the intake valve 26, the drive cam The driven cam lobe 48a rotates while being delayed rearward with respect to the shaft 42. For this reason, the rotational speed of the driven cam lobe 48a relative to the drive camshaft 42 is reduced as compared with the reference state (at the constant speed) shown in FIG. 8B. For this reason, in this case, as indicated by “lift during deceleration (large working angle)” in FIG. 9A, the intake valve is compared with the “lift during constant speed” in the reference state. The timing at which the lift amount 26 reaches the maximum lift amount is delayed. Further, the closing timing of the intake valve 26 is also delayed compared to the “lift at constant speed” for the reason opposite to that described above with respect to the “lift at acceleration”. As a result, the operating angle of the intake valve 26 can be increased compared to the constant speed lift.

  Further, in the variable valve operating apparatus 30 according to the present embodiment, as described above, the control roller 62 for the raceway surface 66a1 so that the equal rotation angle timing on the right side in FIG. 8 coincides with the opening timing IVO of the intake valve 26. The position of is set. According to such setting, the rotation angle θ of the driven cam lobe 48a at the opening timing of the intake valve 26 can be made (almost) constant regardless of the position of the track surface 66a1 controlled by the actuator 72. As a result, as shown in FIG. 9A, it is possible to change the operating angle (ie, phase coupling) while keeping the opening timing of the intake valve 26 constant (or substantially constant).

  As described above, according to the variable valve operating apparatus 30 of the present embodiment, the operating angle variable cam 82 is rotationally driven by the actuator 72 to move the track surface 66a1 up and down along the axial direction of the cylinder. The distance between the rotation center of the drive cam shaft 42 and the rotation center of the control roller 62 changes, and the rotation angle θ between the drive cam shaft 42 and the driven cam lobe 48a changes. Further, the greater the amount of movement of the track surface 66a1, the greater the amount of change in the rotation angle θ. As a result, the rotational speed of the driven cam lobe 48a is continuously changed during one rotation of the drive cam shaft 42 according to the rotational position of the variable operating angle cam 82 by the actuator 72 (control position of the track surface 66a1 of the guide member 66). It can be increased or decreased. As a result, the operating angle of the intake valve 26 can be continuously varied according to the rotational position of the operating angle variable cam 82 (the control position of the track surface 66a1).

[Characteristic Control in Embodiment 1]
(Adjustment method of working angle of intake valve according to operating conditions in Embodiment 1)
In the internal combustion engine 10 of the present embodiment, the guide member 66 is moved by the actuator 72 so that the control state of the intake variable valve operating apparatus 30 becomes the control state shown in FIG. I try to drive it. As a result, in this case, the working angle of the intake valve 26 is controlled to a value on the large working angle side within a predetermined working angle setting range (for example, about 320 ° CA). In such a large working angle control, the intake valve 26 opens slowly, so that the closing timing of the intake valve 26 is delayed, and a so-called Atkinson cycle in which operation is performed with a small amount of air by returning the air once sucked. Become. Thereby, reduction of pumping loss can be aimed at.

  Further, in the internal combustion engine 10 of the present embodiment, at the time of acceleration, the guide member 66 is controlled by the actuator 72 so that the control state of the intake variable valve apparatus 30 becomes the control state shown in FIG. ing. As a result, in this case, the operating angle of the intake valve 26 is controlled to a value on the small operating angle side in the operating angle setting range (for example, about 220 ° CA). In such a small operating angle control, since the intake air is not blown back, the charging efficiency of the intake air can be increased and the acceleration performance can be improved.

  By the way, during the driving of the vehicle, the driver frequently turns on / off the accelerator pedal according to the driving situation. For example, in the case where the accelerator pedal is turned on when the internal combustion engine 10 is in an idle state, and the accelerator pedal is turned off again during the accompanying acceleration, the internal combustion engine 10 having the above operating angle setting is used. The operating angle of the intake valve 26 is changed from the large operating angle side toward the small operating angle side, and a command to change to the large operating angle side is issued again during the change. That is, the operating angle of the intake valve 26 is reciprocally changed between the large operating angle side and the small operating angle side. Hereinafter, the characteristic one-way control of the variable working angle cam 82 performed in this embodiment when the working angle of the intake valve 26 is reciprocally changed in this way is referred to for comparison with this control. A description will be given together with the swing control of the variable angle cam 82.

FIG. 10 is a view for explaining swing control of the variable operating angle cam 82 for reciprocally changing the operating angle of the intake valve 26.
When the accelerator pedal is turned on in the idling state, in this swing control, the operating angle variable cam 82 is rotationally driven in a predetermined rotation direction (here, the right rotation direction in FIG. 10), From the large operating angle control state shown in FIG. 10 (A) to the small operating angle control state shown in FIG. 10 (C) via the intermediate operating angle control state shown in FIG. 10 (B). The working angle is controlled. When the accelerator pedal is turned off during the transition to the target small operating angle control state, the operating angle variable cam 82 is rotated clockwise by the motor 74 of the actuator 72 as shown in FIG. Then, the rotation direction of the operating angle variable cam 82 is reversed in the reverse direction (the left rotation direction in FIG. 10). Then, through the intermediate working angle control state shown in FIG. 10D, the original large working angle control state is controlled as shown in FIG.

  However, in such swing control, when a reciprocating operation at a steep operating angle is required, the driving direction of the guide member 66 is reversed by reversing the operating angle variable cam 82 by the motor 74. When the direction is switched, the inertial force of the actuator 72 generated by the operation of the motor 74 so far is added as a moment, so that a large load acts on the actuator 72 when the driving direction of the actuator 72 is switched. For this reason, there are concerns about an increase in power consumption and heat generation due to an increase in current. Moreover, there is a concern that the wear of the gear is promoted due to an increase in the load acting on the gear (worm gear 76 and worm wheel 78) inside the actuator 72.

FIG. 11 is a diagram for explaining one-way control of the variable operating angle cam 82 for reciprocally changing the operating angle of the intake valve 26.
Also in this one-way control, by rotating the working angle variable cam 82 in a predetermined rotational direction (here, the right rotational direction in FIG. 10), the large working angle control state shown in FIG. With respect to the point of controlling the operating angle of the intake valve 26 toward the small operating angle control state shown in FIG. 11C via the intermediate operating angle control state shown in FIG. It is the same. In addition, in this one-way control, when the accelerator pedal is turned off during the transition to the target small working angle control state, as shown in FIGS. 11 (C) and 11 (D), the working angle is set. The profile on the opposite side of the working angle variable cam 82 is used over the longest contact point without changing the rotational direction of the variable cam 82. Then, the original large working angle control state is controlled as shown in FIG.

  Furthermore, this one-way control is not limited to the case of returning to the original large working angle control state as in the example shown in FIG. 11, but the working angle is overcome by moving over the longest contact point without reversing the working angle variable cam 82. Also included are those that control to any working angle value on the opposite profile of the variable cam 82. Also, this one-way control is performed when the small working angle side is changed from the small working angle side to the large working angle side and a command to change to the small working angle side is issued again during the change. The same applies to the same.

  According to the one-way control of the present embodiment described above, it is not necessary to reverse the driving direction of the motor 74 while the inertia force of the actuator 72 generated by the rotation of the motor 74 is acting. When the operating angle is reciprocally changed between the small operating angle side and the large operating angle side, it is possible to prevent a large load from acting on the actuator 72 (motor 74, worm gear 76, worm wheel 78). Therefore, the power consumption of the motor 74 can be reduced, and wear can be reduced by reducing the load on the gears (worm gear 76 and worm wheel 78) inside the actuator 72.

(Switching between unidirectional control and swing control according to the operating conditions of the internal combustion engine)
As described above, according to the one-way control of the working angle variable cam 82, the actuator 72 does not cause an increase in the driving load in a situation where the driving load of the actuator 72 becomes large in the swing control. Can be operated. However, the operating angle of the intake valve 26 is continuously and reciprocally changed between the small operating angle side and the large operating angle side (hereinafter simply referred to as “reciprocating operation of the operating angle”). If not, or even if the operating angle is reciprocated, a large driving load will not act on the actuator 72 if the operating angle control direction is switched slowly. As described above, when the large driving load is not applied to the actuator 72, it is preferable to use the swing control in which the variable width between the current operating angle and the target operating angle is smaller than that in the one-way control. The working angle can be adjusted smoothly.

  Therefore, in this embodiment, the one-way control and the swing control of the variable working angle cam 82 are used separately according to the operating conditions of the internal combustion engine 10. More specifically, one-way control is used when a reciprocating operation with a steep operating angle is required (when a high load switching request with a high load on the actuator 72 is issued).

FIG. 12 is a diagram for explaining operating conditions in which the one-way control of the working angle variable cam 82 is performed. According to the setting of the operating angle of the intake valve 26 of the present embodiment described above, when the accelerator pedal is ON when the internal combustion engine 10 is in the idle state, as shown in FIG. Is controlled to have a large operating angle. In this state, when the accelerator pedal is turned on at timing t1 in FIG. 12, the operating angle of the intake valve 26 is controlled toward the target small operating angle. A timing t2 in FIG. 12 indicates a timing at which the accelerator pedal is turned off and the vehicle brake is depressed during the change of the operating angle. In this embodiment, when the rate of change of the accelerator opening (the absolute value thereof) when the accelerator pedal is returned to the OFF state is higher than a predetermined value, a reciprocating operation with a steep operating angle is required. One-way control is selected. As a result, when the operating angle variable cam 82 is continuously rotated in the same direction as before, the operating angle of the intake valve 26 passes through the minimum operating angle as shown in FIG. The profile on the opposite side of the variable cam 82 is used to control the target large working angle.
Furthermore, in the example shown in FIG. 12, the accelerator pedal is turned on at timing t3 in the middle of changing the operating angle toward such a large operating angle. In the present embodiment, in the same way as when the accelerator pedal is OFF, when the change rate (the absolute value thereof) of the accelerator opening when the accelerator pedal is depressed in the ON state is higher than a predetermined value, a sudden action is caused. It is determined that corner reciprocation is required, and one-way control is selected. As a result, the operating angle variable cam 82 is continuously rotated in the same direction as before, so that the operating angle of the intake valve 26 passes through the maximum operating angle as shown in FIG. The profile on the opposite side of the variable cam 82 is used to control the target small working angle.

  Further, in this embodiment, when the reciprocating operation of the working angle is not performed and when the reciprocating operation of the working angle is performed slowly (that is, the variable operating angle is low), the swinging is not performed in one direction. Dynamic control was used.

FIG. 13 is a flowchart showing a control routine executed by the ECU 38 in order to realize the control in the first embodiment of the present invention.
In the routine shown in FIG. 13, first, it is determined whether or not there is a request for a reciprocating operation of the working angle of the intake valve 26 (step 100). Specifically, in step 100, the accelerator pedal 26 is operated while the operating angle of the intake valve 26 is changed from the small operating angle side to the large operating angle side or from the large operating angle side to the small operating angle side. The accelerator opening sensor 40 is used to determine whether or not a stepping operation (stepping operation from an OFF state or a small opening) or an accelerator pedal return operation (OFF state or returning to a small opening) has been performed. . According to such a determination, when the accelerator pedal is depressed while the operating angle of the intake valve 26 is being changed from the small operating angle side to the large operating angle side, the operation during the change is performed. It can be determined that there is a request for the reciprocating operation of the working angle to return the angle to the small working angle side. Similarly, the working angle of the intake valve 26 is changed from the large working angle side to the small working angle side. In the middle, when the accelerator pedal is returned, it can be determined that there is a request for a reciprocating operation of the operating angle that returns the operating angle being changed to the large operating angle side.

  If it is determined in step 100 that a request for a reciprocating operation of the operating angle has not been issued, the swing control is selected as a method for adjusting the operating angle of the intake valve 26 in this case (step 102). . On the other hand, if it is determined in step 100 that there is a request for a reciprocating operation at the working angle, it is determined whether or not the request is a request for a reciprocating operation at an abrupt working angle (step 104).

  Specifically, in step 104, it is determined whether or not the absolute value of the rate of change of the accelerator opening when the determination in step 100 is satisfied is greater than a predetermined value. When the accelerator pedal is gently operated, the variable valve device 30 is accompanied by a decrease in the variable speed of the operating angle of the intake valve 26. On the other hand, when the accelerator pedal is operated quickly, The variable speed of the operating angle of the intake valve 26 is set to be high. For this reason, by determining whether or not the absolute value of the rate of change of the accelerator opening is greater than a predetermined value, it is possible to determine whether or not there is a request for a reciprocating operation at a steep operating angle.

  If it is determined in step 104 that a request for a sudden reciprocation of the working angle has been issued, the one-way control is selected as a method for adjusting the working angle of the intake valve 26 in this case (step 106). On the other hand, if it is determined in step 104 that a request for a reciprocating operation with a steep operating angle has not been made and a request for a reciprocating operation with a gentle operating angle has been issued, the intake valve 26 in this case is determined. The swing control is selected as a method for adjusting the working angle of (step 102).

  According to the routine shown in FIG. 13 described above, depending on the operating conditions of the internal combustion engine 10 (here, whether or not the accelerator opening is changed and the magnitude of the change rate), the one-way control and the swing control are performed. From this, the adjustment method of the operating angle of the intake valve 26 is selected. This makes it possible to smoothly adjust the operating angle in other situations while preventing an increase in the driving load of the actuator 72 in a situation where a reciprocating operation with a steep operating angle is required.

  Incidentally, in the first embodiment described above, a method for adjusting the operating angle of the intake valve 26 by the actuator 72 (one-way control of the operating angle variable cam 82) for the variable intake valve operating device 30 that rotationally drives the intake valve 26. And the separation of the one-way control and the swing control according to the operating conditions). However, the object of the adjustment method is not limited to the intake variable valve operating apparatus 30, but may be the exhaust variable valve operating apparatus 32 that rotationally drives the exhaust valve 28.

In the first embodiment described above, the guide member 66 having the raceway surface 66a1 corresponds to the “control member” in the first invention. Further, the “actuator control means” according to the first aspect of the present invention is realized by the ECU 38 executing the series of processes of steps 100 to 106.
In the first embodiment described above, the link mechanism 65, the link plate 64, and the holding roller 68 correspond to the “variable cam speed mechanism” in the second aspect of the invention.
In the first embodiment described above, the ECU 38 executes the process of step 104, so that the “switching request degree determination means” in the third aspect of the present invention performs the above step according to the determination result of step 104. By executing the process 102 or 106, the “control mode switching means” in the third aspect of the present invention is realized.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described with reference to FIGS.
[Characteristic adjustment method of working angle in the second embodiment]
Also in this embodiment, it is assumed that the intake variable valve operating apparatus 30 and the exhaust variable valve operating apparatus 32 having the configuration described with reference to FIGS. 1 to 9 are provided. Here, the intake variable valve operating device 30 will be described as an example, but this adjustment method is an exhaust variable operating system that rotationally drives the intake variable valve operating device 30 that rotates the intake valve 26 and the exhaust valve 28. The present invention can be applied to both the valve device 32.

  As shown in FIG. 7, the variable valve apparatus 30 is configured such that the guide member 66 and the variable working angle cam from the cam rotation center (the rotation center of the variable working angle cam 82) are controlled under the minimum operating angle. The distance from the cam rotation center to the contact point between the guide member 66 and the variable working angle cam 82 is the shortest under the condition where the distance to the contact point 82 is the longest and the maximum working angle is controlled. It is configured. The guide member 66 is urged toward the variable operating angle cam 82 by a spring 71. Accordingly, when the working angle variable cam 82 rotates to change the working angle of the intake valve 26 from the small working angle side to the large working angle side, a moment around the control axis based on the spring load of the spring 71 acts. It acts to assist the rotation of the variable angle cam 82. When the operating angle variable cam 82 rotates in the opposite direction, the moment acts as a reaction force for the rotation of the operating angle variable cam 82.

  The working angle adjustment method of the present embodiment is intended for a situation in which the working angle is adjusted from a small working angle side to an arbitrary working angle on the large working angle side (excluding the maximum working angle). . FIG. 14 is a diagram for describing a working angle adjustment technique referred to for comparison with a characteristic working angle adjustment technique according to the second embodiment of the present invention. In the contrast adjustment method shown in FIG. 14, the target operating angle is obtained by rotating the operating angle variable cam 82 clockwise from the small operating angle position shown in FIG. The operating angle variable cam 82 is rotated up to. Then, as shown in FIG. 14B, the braking force by the motor 74 is generated immediately before the operating angle variable cam 82 rotates to the position where the target operating angle can be obtained.

  According to the adjustment method shown in FIG. 14, the braking by the motor 74 that resists the moment based on the spring load and the inertia force (moment) of the actuator 72 acting in the same direction as the moment in this case. Power is required. Further, as described above, the variable operating angle cam 82 is set so as to be symmetrical with respect to a straight line connecting the longest contact point and the shortest contact point when viewed from the axial direction of the control shaft 80. Have a profile. For this reason, the contact points (hereinafter referred to as “target contact points”) at which the target operating angle is obtained are present on both sides of the cam surface of the variable operating angle cam 82 across the straight line. Become. The adjustment method shown in FIG. 14 can be said to be a method of varying the working angle variable cam 82 toward the target contact point closer to the small working angle position.

FIG. 15 is a diagram for explaining a characteristic working angle adjustment method according to the second embodiment of the present invention.
The adjustment method of the present embodiment shown in FIG. 15 is the same as the adjustment method shown in FIG. 14 described above with respect to the point that the action angle variable cam 82 is rotated clockwise from the small action angle position shown in FIG. It is the same. In addition, in this adjustment method, as shown in FIG. 15B, the same working angle is obtained at a contact point that exists beyond the target position in the adjustment method shown in FIG. 14 and further passes through the shortest contact point. The operating angle variable cam 82 is rotated rightward in FIG. 15 toward the intended position.

  After the contact point between the operating angle variable cam 82 and the guide member 66 exceeds the shortest contact point by the adjustment method of this embodiment shown in FIG. 15, the moment based on the spring load is as shown in FIG. In addition, it will switch from the previous clockwise rotation to the left rotation. As a result, when the operating angle variable cam 82 is stopped at the target position, this moment can be applied as a braking force against the inertial force (moment) of the actuator 72. As a result, the braking force by the motor 74 only needs to be such that the moment of inertia of the actuator 72 cannot be offset by the moment based on the spring load (note that the direction of the braking force by the motor 74 is the moment based on the spring load. Since it changes in accordance with the magnitude relationship with the moment of inertia, it is expressed by arrows in both directions in FIG. Therefore, according to the method of adjusting the working angle of the present embodiment, the working angle is adjusted by rotating the working angle variable cam 82 in the direction in which the moment based on the spring load acts as an assist force for the rotation of the working angle variable cam 82. In the adjustment, the force (torque) necessary for the motor 74 to control the rotational position of the operating angle variable cam 82 can be reduced.

  In the second embodiment described above, the control shaft 80, the electric motor 74, the worm gear 76 and the worm wheel 78 are the “driving part” in the fourth invention, and the spring 71 is the “biasing” in the fourth invention. It corresponds to “means”. Further, the “second actuator control means” according to the fourth aspect of the present invention is realized by the ECU 38 executing the control described with reference to FIG.

Embodiment 3 FIG.
Next, a third embodiment of the present invention will be described with reference to FIGS.
[Method for Confirming Matching between Characteristic Working Angle Sensor Value and Actual Working Angle in Embodiment 3]
Also in this embodiment, it is assumed that the intake variable valve operating apparatus 30 having the configuration described with reference to FIGS. 1 to 9 is provided.

  In the variable valve operating apparatus 30, in order to control the actual operating angle of the intake valve 26 to the target operating angle, the actual operating angle of the intake valve 26 is acquired based on the output value of the operating angle sensor 84. However, the output value of the working angle sensor 84 may deviate from the normal value due to misassembly of the working angle sensor 84 or loosening due to irregular operation during operation. As a method for determining such a deviation (abnormality) in the output value of the working angle sensor, for example, a stopper that restricts the rotation of the control shaft is provided, and the rotation of the control shaft when it is abutted against the stopper A method of matching the working angle sensor value with the actual working angle using the position as the reference position for the working angle control is conceivable. However, with such a technique, the reference position itself changes due to deformation of the stopper position or the like, and it may be difficult to accurately determine whether or not the above alignment is achieved.

  Therefore, in the present embodiment, in the variable valve operating apparatus 30, it is determined using the control described below whether or not the output value of the working angle sensor 84 is matched with the actual working angle. . FIGS. 16 and 17 are diagrams for explaining a matching check method between the characteristic working angle sensor value and the actual working angle in the third embodiment of the present invention. As shown in FIG. 16A, first, when the internal combustion engine 10 is in a steady state (for example, in an idle state), the operating angle of the intake valve 26 becomes the maximum operating angle, that is, operates at the shortest contact point. The rotational position of the variable working angle cam 82 is controlled so that the variable angle cam 82 and the guide member 66 are in contact with each other. In this method, the rotational position of the variable working angle cam 82 in this case is set as the reference working angle position.

  Next, as shown in FIGS. 16 (B) and 16 (C), the operating angle variable cam 82 is rotated evenly in both directions by a predetermined oscillation amount with respect to the reference operating angle position (oscillation). The intake air flow rates in A and rocking B) were compared. If these intake air flow rates do not become the same value, the working angle sensor value and the actual working angle are not matched due to the displacement of the working angle sensor 84, or the working angle variable cam 82 It is conceivable that the cam surface is deformed. Therefore, in such a case, the intake air flow rate is compared in a state where the operating angle variable cam 82 is rotated evenly in both directions with a plurality of (for example, 2 to 3) patterns of swinging amounts different from the above. . If the same intake air flow rate is not obtained in the swing A and the swing B even though such an additional comparison is performed, it is assumed that the position error abnormality of the working angle sensor 84 has occurred. Judgment was made.

FIG. 18 is a flowchart showing a control routine executed by the ECU 38 in order to realize a matching confirmation method between the characteristic working angle sensor value and the actual working angle in the third embodiment of the present invention.
In the routine shown in FIG. 18, first, the rotational position of the variable operating angle cam 82 is controlled so as to be the reference operating angle position (in this embodiment, the maximum operating angle position) (step 200). The working angle variable cam 82 has a profile set so as to be line-symmetric (left-right symmetric) as described above. For this reason, the reference operating angle position is not limited to the maximum operating angle position, and may be the minimum operating angle position.

  Next, the operating angle variable cam 82 is swung the same with respect to the reference operating angle position and the intake air flow rate when the operating angle variable cam is rotated clockwise (swing A). The intake air flow rate in the state of being rotated counterclockwise by the amount of movement (swing B) is acquired using the air flow meter 18 (step 202).

  Next, it is determined whether or not the difference between the intake air flow rate during swing A and the intake air flow rate during swing B is equal to or less than a predetermined value (step 204). The predetermined value in this step 204 is a value set in advance as a threshold value for determining whether or not these intake air flow rates are substantially the same values under the situation where the intake air flow rate is controlled to the same operating angle. It is.

  If the determination in step 204 is established, a normal determination is made (step 206). That is, it is determined that there is no positional deviation abnormality of the working angle sensor 84 and that the output value of the working angle sensor 84 matches the actual working angle.

  On the other hand, if the determination in step 204 is not established, the amount of swing of the operating angle variable cam 82 with respect to the reference operating angle position is changed, and the intake air flow rate and the swing B during swing A (right rotation) are changed. The intake air flow rate at the time of (left rotation) is acquired again (step 208). Next, as in step 204, it is determined whether or not the difference between the intake air flow rate during swing A and the intake air flow rate during swing B is equal to or less than the predetermined value (step 210).

  If the determination in step 210 is satisfied, it is determined that the cam surface of the variable working angle cam 82 is deformed (step 212). On the other hand, if the determination in step 210 is not established, it is then determined whether or not the number of changes in the swing amount has reached a predetermined number (for example, 2 times) (step 214). As a result, when the number of changes in the swing amount has not yet reached the predetermined number, the processes of steps 208 and 210 are repeatedly executed. On the other hand, when the number of changes in the swing amount reaches the predetermined number, it is determined that an abnormality (positional deviation abnormality) of the operating angle sensor 84 has occurred (step 216).

  The working angle variable cam 82 has a profile set so as to be line-symmetric (left-right symmetric) as described above. Therefore, if the output value of the working angle sensor 84 and the actual working angle are matched, when the working angle variable cam 82 is evenly rotated in the left and right directions with respect to the reference working angle position. The same operating angle of the intake valve 26 should be obtained, and the same air flow characteristic should be obtained. However, if the same intake air flow rate cannot be obtained, the operating angle sensor value matches the actual operating angle due to the displacement of the operating angle sensor 84 as in the routine shown in FIG. It can be determined that the cam surface of the variable working angle cam 82 is not deformed.

  Then, according to the above routine, if the intake air flow rate during the swing A and the swing B becomes the same value while the swing amount is changed in a plurality of patterns, the displacement of the working angle sensor 84 is shifted. However, it is determined that the cam surface of the variable operating angle cam 82 is deformed. On the other hand, if the intake air flow rate at the time of swing A and swing B does not become the same value even though the swing amount is changed in a plurality of patterns and the intake air flow rate is acquired, the variable operating angle cam 82 is obtained. It is determined that the working angle sensor 84 is not deformed, and the working angle sensor 84 is misaligned, and the working angle sensor value and the actual working angle are not matched.

  As described above, according to the confirmation method of the present embodiment, it is only necessary to compare the intake air flow rate when the variable working angle cam 82 is rotated with the same swing amount in both directions with respect to the reference working angle position. Since abnormality determination is possible, highly reliable determination can be performed by changing and confirming the amount of rocking in a plurality of patterns. Then, according to the confirmation method of the present embodiment, during the operation of the internal combustion engine 10, it is determined whether or not there is a positional deviation abnormality of the working angle sensor 84, that is, whether or not the working angle sensor value matches the actual working angle. Can do.

  In the third embodiment described above, the air flow meter 18 corresponds to the “intake flow rate detecting means” in the fifth aspect of the invention. Further, the “abnormality determination means” according to the fifth aspect of the present invention is realized by the ECU 38 executing the series of processes of steps 200 to 216 described above.

  By the way, in the first to third embodiments described above, the control position of the guide member 66 is changed by adjusting the rotation position of the variable operating angle cam 82 by the actuator 72, whereby the drive cam shaft 42 is rotated once. The rotation speed of the driven cam lobe 48a is increased or decreased during this time, and the variable valve operating devices 30 and 32 having a configuration in which the operating angle of the intake valve 26 and the exhaust valve 28 can be changed are described as an example. . However, the variable valve operating apparatus for an internal combustion engine that is the subject of the present invention is not limited to the one having the above-described configuration, and a control member whose position is adjusted to change the operating angle of the valve, and an actuator that adjusts the position of the control member The control member may be configured so that the position of the control member can return to the original position again in the process in which the actuator operates in one direction.

  In the above-described first to third embodiments, the profile set to be symmetrical with respect to the straight line connecting the longest contact point and the shortest contact point as seen from the axial direction of the control shaft 80 is used. The operating angle variable cam 82 is provided. However, in performing the control of the first and second embodiments described above, the operating angle variable cam does not necessarily have to be set to be line-symmetric with respect to the straight line. That is, if there are a plurality of contact points that are used as control target values and have the same operating angle on both sides of the cam angle in the operating angle variable cam, It does not necessarily have to be line symmetrical as described above.

  In the first to third embodiments described above, the electric motor 74 is used as a drive source of the actuator 72 that rotationally drives the operating angle variable cam 82. However, the drive source of the actuator 72 is not limited to the electric motor 74, and may be a hydraulic drive source, for example.

  Further, in the first to third embodiments described above, the driven link 58 is disposed in front of the drive link 54 in the rotational direction of the drive cam shaft 42 with the control roller 62 interposed between the driven link 58 and the drive link 54. In addition, as shown in FIG. 8A, the speed increasing section when the track surface 66a1 moves upward is set to overlap the lift section of the driven cam lobe 48a. As a result, when the raceway surface 66a1 moves upward, the valve operating angle can be made smaller than that at the constant speed, and conversely, when the raceway surface 66a1 moves downward, the valve action. The angle can be made larger than that at constant speed. However, the variable valve operating apparatus in the present invention is not limited to such a configuration. That is, for example, as shown in FIG. 8A, in the case where the speed increasing section when the track surface 66a1 moves upward is set to overlap the lift section of the driven cam lobe 48a, the driven link 58 is Alternatively, the control roller 62 may be interposed between the drive link 54 and the drive link 54, and the drive cam shaft 42 may be disposed behind the drive link 54 in the rotational direction. According to such a configuration, when the raceway surface 66a1 moves upward as shown in FIG. 8A, the driven cam lobe 48a rotates while being delayed with respect to the drive cam shaft 42. The operating angle of the valve can be made larger than that at the constant speed, and conversely, when the raceway surface 66a1 moves downward, the working angle of the valve can be made smaller than that at the constant speed.

  In the first to third embodiments described above, a state in which the center point of the raceway surface 66a1 that is the circumferential surface and the center point of the drive cam shaft 42 coincide with each other when viewed from the axial direction of the drive cam shaft 42 is a reference. As a position, an actuator 72 that moves the guide member 66 so that the center point of the raceway surface 66a1 moves along the normal direction of the axis of the drive cam shaft 42 and the axial direction of the cylinder (vertical direction in FIG. 8 and the like). I have to prepare. However, in the present invention, the direction of movement of the guide member for changing the rotation angle of the driven cam lobe relative to the drive cam shaft is not limited to the above, and may be a plane direction orthogonal to the axis of the drive cam shaft.

DESCRIPTION OF SYMBOLS 10 Internal combustion engine 12 Combustion chamber 14 Intake passage 18 Air flow meter 20 Throttle valve 26 Intake valve 28 Exhaust valve 30 Intake variable valve operating device 32 Exhaust variable valve operating device 34 Crankshaft 36 Crank angle sensor 38 ECU (Electronic Control Unit)
40 accelerator opening sensor 42 drive cam shaft 48 cam piece 48a driven cam lobe 48b driven arm portion 50 drive arm 50a drive arm portion 52 cam shaft side rotating shaft 54 drive link 56 cam lobe side rotating shaft 58 driven link 60 control roller side rotating shaft 62 control Roller 64 Link plate 65 Link mechanism 66 Guide member 66a Guide member annular portion 66a1 Guide member raceway surface 66b Guide member bridging portion 68 Holding roller 70 Holding rotary shaft 71 Spring 72 Actuator 74 Electric motor 76 Warm gear 78 Warm wheel 80 Control Shaft 82 Variable working angle cam 84 Working angle sensor

Claims (6)

A control member whose position is adjusted to change the working angle of the valve;
An actuator for adjusting the position of the control member;
A variable valve operating apparatus for an internal combustion engine configured to be able to return the position of the control member to the original position again in the process in which the actuator operates in one direction,
In the first case where a larger working angle than the current working angle is requested during the period when the working angle of the valve is changed from the large working angle side to the small working angle side by the actuator, or The operation of the actuator is performed in the second case in which a working angle smaller than the current working angle is requested during a period in which the working angle of the valve is changed from the small working angle side to the large working angle side by the actuator. Actuator control means for performing one-way control for controlling the actuator in one direction so that the control member moves to a position where the required operating angle of the valve can be obtained without changing the direction;
A variable valve operating apparatus for an internal combustion engine, comprising: The variable valve operating device is:
As the control member, a guide member having a raceway surface formed so as to cover a drive cam shaft that rotationally drives a driven cam lobe that drives the valve;
By changing the relative rotation angle of the driven cam lobe with respect to the drive cam shaft in accordance with the control position of the guide member, the driven cam lobe with respect to the drive cam shaft is rotated during one rotation of the drive cam shaft. A variable cam speed mechanism to increase or decrease the relative rotational speed;
Including
By moving the guide member in a plane direction perpendicular to the axis of the drive cam shaft by the actuator, the rotational speed of the driven cam lobe is changed during one rotation of the drive cam shaft, and the working angle of the valve is increased. 2. The variable valve operating apparatus for an internal combustion engine according to claim 1, wherein the variable valve operating apparatus is changeable. The actuator control means includes
Switching request degree determination means for determining whether switching of the valve operating angle in the first case or the second case is a high load switching request with a high load on the actuator;
When it is determined by the switching request degree determination means that the high load switching request is selected, the one-way control is selected, and when the switching request degree determination means determines that the request is not the high load switching request Is a control mode switching for selecting swing control for controlling the actuator so that the control member moves to a position where the required operating angle of the valve is obtained after switching the operating direction of the actuator to the reverse direction. Means,
The variable valve operating apparatus for an internal combustion engine according to claim 1 or 2, characterized by comprising: The actuator includes a variable working angle cam having a cam surface in contact with the control member, and a drive unit that rotationally drives the variable working angle cam.
The variable valve operating device is:
Biasing means for biasing the control member toward the cam surface;
From the first contact point on the cam surface, which is far from the rotation center of the variable working angle cam, to the second contact point on the cam surface, the distance from the rotation center being shorter than the first contact point. When the rotational position of the variable operating angle cam is controlled by the actuator so that the contact point between the control member and the variable operating angle cam changes, the cam having the shortest distance from the rotation center A second actuator that controls the actuator so that the operating angle variable cam is rotationally driven with the second contact point existing ahead of the shortest contact point as a target position after passing through the shortest contact point on the surface Control means;
The variable valve operating apparatus for an internal combustion engine according to any one of claims 1 to 3, further comprising: The valve is an intake valve,
The actuator includes a variable working angle cam having a cam surface in contact with the control member, and a drive unit that rotationally drives the variable working angle cam.
The working angle variable cam has a profile that is line symmetric with respect to a straight line orthogonal to the rotational axis as seen from the rotational axis direction of the working angle variable cam.
An intake flow rate detecting means for detecting an intake air flow rate of the internal combustion engine;
First suction when the working angle variable cam is rotated forward with the longest contact point having the longest distance from the rotation center of the working angle variable cam or the shortest contact point having the shortest distance as a reference working angle position. A working angle for detecting a working angle of the valve based on a comparison result between an air flow rate value and a second intake air flow rate value when the working angle variable cam is reversely rotated by the same amount of swing as in the forward rotation. An abnormality determining means for determining whether there is an abnormality in the shape of the sensor or the variable working angle cam;
An internal combustion engine comprising the variable valve operating apparatus for an internal combustion engine according to any one of claims 1 to 4, further comprising:   The abnormality determining means compares the first intake air flow rate value with the second intake air flow rate value while changing the swing amount a plurality of times, but compares the first intake air flow rate value with the second intake air flow rate value. 6. An internal combustion engine having a variable valve operating system for an internal combustion engine according to claim 5, wherein when the intake air flow rate value does not show the same air flow rate characteristic, it is determined that an abnormality has occurred in the working angle sensor. organ.

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