JP2000282900A - Oscillation prevention device for electromagnetic actuator for control shaft drive - Google Patents

Abstract

(57) [Problem] To prevent unnecessary swing control of an electromagnetic actuator caused by swinging of a control shaft due to torque fluctuation due to rotation of a camshaft, thereby improving durability of the electromagnetic actuator. To provide an anti-swing device for an electromagnetic actuator for driving a control shaft. A control axis detected by an operation angle sensor is provided.
The signal obtained by arithmetically processing the operating angle signal of No. 6 by the digital filters 1 and 2 is input to the control unit CPU.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable valve operating device for an internal combustion engine which can vary the lift amount (operating angle of a control shaft) of an intake / exhaust valve of the internal combustion engine according to the operating state of the engine.
The present invention relates to an anti-swing device for an electromagnetic actuator for driving a control shaft, which prevents oscillation of an electromagnetic actuator that drives a control shaft.

[0002]

2. Description of the Related Art As is well known, in order to improve fuel efficiency at low engine low speed and low load, to ensure stable driving performance, and to secure sufficient output by improving intake air filling efficiency at high speed and high load, intake air intake and air intake are controlled. Various variable valve devices for variably controlling the opening / closing timing of an exhaust valve and the valve lift amount according to the engine operating state have been conventionally provided.
Japanese Patent No. 137305 is known.

[0005] Referring to FIG. 18, the outline thereof will be described. A cam shaft 2 is provided at a position substantially above the center of the upper deck of the cylinder head 1, and a cam 2 a is integrally provided on the outer periphery of the cam shaft 2. ing. A control shaft 3 is arranged in parallel on the side of the cam shaft 2.
A rocker arm 5 is pivotally supported via an eccentric cam 4.

On the other hand, at the upper end of an intake valve 6 slidably provided on the cylinder head 1, a swing cam 8 is arranged via a valve lifter 7. The swing cam 8 is swingably supported by a support shaft 9 disposed above the valve lifter 7 in parallel with the cam shaft 2, and a lower cam surface 8 a is in contact with the upper surface of the valve lifter 7. . The rocker arm 5 has one end 5a abutting on the outer peripheral surface of the cam 2a and the other end 5b abutting on the upper end surface 8b of the swing cam 8, thereby lifting the lift of the cam 2a. And, it transmits to the intake valve 6 via the valve lifter 7.

Further, as shown in FIG. 19, the control shaft 3 is controlled by an electromagnetic actuator such as a DC servomotor.
The eccentric cam 4 is rotated and driven within a predetermined angle range via a reduction gear, thereby controlling the rotation position of the eccentric cam 4, thereby changing the swing fulcrum of the rocker arm 5.

In FIG. 18, when the eccentric cam 4 is controlled to a predetermined forward / reverse rotation position, the swing fulcrum of the rocker arm 5 changes, and the upper end face 8b of the swing cam 8 at the other end 5b.
Is changed in the vertical direction in the figure, whereby the swing locus of the swing cam 8 changes with the change of the contact position of the cam surface 8a of the swing cam 8 with the upper surface of the valve lifter 7. The opening / closing timing of the intake valve 6 and the valve lift amount are variably controlled with a change in the operating angle of the control shaft 3. Reference numeral “10” in the drawing indicates a spring that constantly biases the upper end surface 8b of the swing cam 8 against the other end 5b of the rocker arm 5.

FIG. 19 shows a variable valve operating apparatus in which the opening / closing timing and valve lift of the intake valve 6 are variably controlled by changing the swing fulcrum of the rocker arm 5 as described above. As described above, the operating angle (rotational position) of the control shaft 3 for changing the swing fulcrum is detected by an operating angle sensor (for control) such as a potentiometer, and based on the detected operating angle signal, the control unit CPU In, comparing the detection result and the target,
The drive control signal is feedback-controlled so that the operation angle (rotational position) of the control shaft 3 is accurately controlled to a target operation angle (rotational position) corresponding to a target valve characteristic.

[0008]

However, the camshaft rotates in synchronization with the rotation of the engine (1 of the engine speed).
/ 2), the same cycle (frequency) as the number of revolutions of the camshaft
Is applied to the control shaft, and the control shaft is rocked by the torque fluctuation, and the rocking is detected as a fluctuation of the working angle by the working angle detecting means. In the angle feedback control, the drive control signal for driving the electromagnetic actuator is fluctuated. As a result, the motor shaft of the electromagnetic actuator constantly swings finely, so that the brushes of the armatures are worn and the durability is reduced. There was a problem to make it.

The present invention has been made in view of the above-mentioned conventional problems, and prevents unnecessary swing control of an electromagnetic actuator due to swing of a control shaft due to torque fluctuation due to rotation of a cam shaft. Accordingly, it is an object of the present invention to provide a control shaft drive electromagnetic actuator rocking prevention device capable of improving the durability of the electromagnetic actuator.

[0010]

According to a first aspect of the present invention, there is provided a control shaft driving electromagnetic actuator oscillating preventing apparatus according to the first aspect of the present invention, wherein a control shaft disposed substantially parallel to a cam shaft. A control cam eccentrically fixed to the outer periphery of the control shaft; a rocker arm pivotally supported by the control cam; and one end of the rocker arm swingably driven according to rotation of the camshaft. Swing drive means, a swing cam that swings in association with the other end of the rocker arm to open the engine valve, control operating angle detecting means for detecting an operating angle of the control shaft, and the control An electromagnetic actuator that rotationally drives the shaft to a target operating angle, and rotates the control shaft to a target operating angle position according to the operating state of the engine based on the operating angle signal of the control shaft detected by the control operating angle detecting means. Control means for driving; In the variable valve device for an internal combustion engine,
A rotation speed detection unit that detects the rotation speed of the internal combustion engine, and a band elimination filter that reduces an output gain in a frequency band corresponding to the frequency of the rotation speed of the internal combustion engine detected by the rotation speed detection unit, The control means is configured to input a signal obtained by subjecting the operating angle signal of the control axis detected by the control operating angle detecting means to arithmetic processing by the band elimination filter to the control means.

According to a second aspect of the present invention, there is provided an anti-swing device for a control shaft driving electromagnetic actuator, wherein the two band elimination filters are provided so as to be within a predetermined rotational speed range of the internal combustion engine. , Only the first band elimination filter is operated, and an output value calculated by a constant corresponding to the rotation speed region of the internal combustion engine at that time is output to the control means. When the operation shifts to the region, the second band elimination filter is operated to start the calculation of the output value with a constant corresponding to the rotation speed region of the shifted internal combustion engine. When the calculation is completed, the output value is calculated. A means configured to stop the operation of the first band elimination filter at the same time as outputting to the control means.

According to a third aspect of the present invention, there is provided an anti-swing device for a control shaft driving electromagnetic actuator, wherein the one or more band elimination filters are provided in a range of a predetermined number of rotations of an internal combustion engine. The output value calculated based on the constant corresponding to the engine speed region at that time is output to the control means, and when the rotation speed region of the internal combustion engine shifts to another region, the operating angle detection means While the operating angle value detected in the above is output to the control means as it is, the output value is calculated based on a constant corresponding to the shifted engine speed region, and the output value is calculated at the time when the calculation is completed. The means is configured to output to the control means.

[0013]

According to the first aspect of the present invention, as described above, the operating angle signal of the control shaft detected by the control operating angle detecting means is filtered by the band elimination filter. A signal subjected to the arithmetic processing is input to the control means, and control for rotating the control shaft to a target operating angle position according to the operating state of the engine is performed based on the input signal. Unnecessary swing control of the electromagnetic actuator caused by swinging of the control shaft due to the torque fluctuation caused by the electromagnetic actuator is prevented, so that the durability of the electromagnetic actuator is enhanced.

According to a second aspect of the present invention, in the first aspect of the present invention, the first band elimination is performed when the rotational speed of the internal combustion engine is within a predetermined rotational speed range. Only the filter is operated, and an output value calculated by a constant corresponding to the rotation speed range of the internal combustion engine at that time is output to the control means. When the rotation speed range of the internal combustion engine shifts to another range, the second value is output. The band elimination filter is operated to start calculating an output value with a constant corresponding to the shifted rotation speed region of the internal combustion engine. When the calculation is completed, the output value is output to the control means, The operation of the first band elimination filter is stopped. In this way, by switching between the two band elimination filters, the engine at that time is always used. Optimum processing corresponding to the rotation speed region is performed.

According to a third aspect of the present invention, in the first aspect of the invention, when the rotational speed of the internal combustion engine is within a predetermined rotational speed range, the engine rotational speed range at that time is within a predetermined range. An output value calculated based on a constant corresponding to the above is output to the control means, and when the rotation speed region of the internal combustion engine shifts to another region, the operation angle value detected by the operation angle detection means is used as it is. While outputting to the control means, the output value is calculated based on the constant corresponding to the shifted engine speed region, and the output value is output to the control means when the calculation is completed. Only one band elimination filter is required, and the cost is reduced.

[0016]

Embodiments of the present invention will be described below. (First Embodiment of the Invention) FIGS. 1 to 3 show a variable valve operating device of an engine (internal combustion engine) according to a first embodiment of the present invention, in which two intake valves are provided for each cylinder. The valve mechanism VEL will be described below. However, it is clear that the engine valve is not limited to the intake valve and the number of intake valves is not limited.

The variable valve operating device shown in FIGS. 1 to 3 includes a pair of intake valves 12 and 12 provided on a cylinder head 11 via a valve guide (not shown) so as to be slidable, and an upper portion of the cylinder head 11. A hollow camshaft 13 rotatably supported by a cam bearing 14 and two eccentric cams 15, 15 which are rotating cams fixed to the camshaft 13 by press fitting or the like.
A control shaft 16 rotatably supported by the same cam bearing 14 above the cam shaft 13, and a pair of rocker arms 18, 18 rotatably supported by the control shaft 16 via a control cam 17. And a pair of independent swing cams 20, 20 disposed at the upper ends of the intake valves 12, 12 via valve lifters 19, 19, respectively.

The eccentric cams 15, 15 and the rocker arms 18, 18 are linked by link arms 25, 25, while the rocker arms 18, 18 and the swing cam 2 are linked.
0 and 20 are linked by link members 26 and 26. The camshaft 13 is disposed along the engine front-rear direction (cylinder row direction), and also via a driven sprocket (not shown) provided at one end or a timing chain wound around the driven sprocket. Torque is transmitted from the crankshaft of the engine.

The cam bearing 14 is provided on the cylinder head 11.
A main bracket 14a provided at an upper end portion of the main bracket 14 and supporting an upper portion of the camshaft 13, and a sub-bracket 14b provided at an upper end portion of the main bracket 14a and rotatably supporting the control shaft 16; 14a, 14
b is fixed together from above by a pair of bolts 14c, 14c.

As shown in FIG. 4, the two eccentric cams 15 have a substantially ring shape, a small-diameter cam body 15a, and a flange 1 provided integrally on the outer end face of the cam body 15a.
5b, the cam shaft insertion hole 15c is formed in the inner axial direction, and the axis X of the cam body 15a is eccentric by a predetermined amount in the radial direction from the axis Y of the cam shaft 13.

Each of the eccentric cams 15 has a camshaft 13
, Are press-fitted and fixed via cam shaft insertion holes 15c on both outer sides not interfering with the valve lifters 19, 19, and the outer peripheral surfaces 15 of both cam bodies 15a, 15a.
d and 15d are formed in the same cam profile.

As shown in FIG. 3, each of the rocker arms 18 is formed in a substantially crank shape when viewed from a plane, and a base 18a provided at the center is supported by the control cam 17 so as to rotate independently. A pin hole 18d into which the pin 21 connected to the distal end of the link arm 25 is press-fitted is formed through one end 18b protruding from each outer end of each base 18a, while each cylindrical shape is formed. A pin hole 18e into which a pin 28 connected to one end 26a of each link member 26 described later is press-fitted is inserted into the other end 18c protruding from each inner end of the base 18a.
Are formed.

Each of the control cams 17 has a cylindrical shape and is fixed to the outer periphery of the control shaft 16, and the position of the axis P1 is eccentric from the axis P2 of the control shaft 16 by α as shown in FIG. I have.

The swing cam 20 is shown in FIGS.
As shown in the figure, the base end portion 2 has a substantially horizontal U-shape and has a substantially annular shape.
2 has a support hole 22a through which the camshaft 13 is inserted and rotatably supported.
8 is provided with a pin hole 23a at the end 23 located on the other end 18c side.
Are formed through.

The lower end of the oscillating cam 20 has a base end 2.
A base circular surface 24a on the two sides and a cam surface 24b extending in an arc shape from the base circular surface 24a toward the end edge of the end portion 23 are formed.
The base circular surface 24a and the cam surface 24b abut on a predetermined position on the upper surface of each valve lifter 19 according to the swing position of the swing cam 20.

That is, in view of the valve lift characteristics shown in FIG. 5, the predetermined angle range θ1 of the base circular surface 24a is a base circle section as shown in FIG. 1, and the predetermined angle range θ1 from the base circle section θ1 of the cam surface 24b. The range θ2 is set to be a so-called ramp section, and the predetermined angle range θ3 from the ramp section θ2 of the cam surface 24b is set to be a lift section.

The link arm 25 has a relatively large annular base 25a and a protruding end 25b projecting from a predetermined position on the outer peripheral surface of the base 25a. The eccentric cam 15 has a cam hole 15c rotatably fitted on the outer peripheral surface of the cam main body 15a, while a protruding end 25b has a pin hole 25d through which the pin 21 is rotatably inserted. Is formed. Note that the link arm 25 and the eccentric cam 15 constitute a swing drive unit.

Further, as shown in FIG. 1, the link member 26 is formed in a linear shape having a predetermined length, and circular end portions 26a and 26b have the other end portion 1 of the rocker arm 18.
8c and each pin hole 18d, 23 of the end 23 of the swing cam 20.
Pin insertion holes 26c and 26d through which the ends of the pins 28 and 29 press-fitted into a are rotatably inserted are formed.
At one end of each of the pins 21, 28, 29, snap rings 30, 31, 32 for regulating the axial movement of the link arm 25 and the link member 26 are provided.

The control shaft 16 has a D shaft provided at one end.
The electromagnetic actuator 101 is rotationally driven within a predetermined rotation angle range by an electromagnetic actuator 101 such as a C servo motor. As shown in FIG.
Are controlled by a control signal from a control unit CPU as control means. The control unit CPU includes a crank angle sensor 10
3. A current engine operating state is detected based on detection signals from various sensors such as an air flow meter 104, a water temperature sensor 105, and an engine speed sensor 106, and a target engine operation state is determined in accordance with the detected engine operating state. The valve characteristics are determined, and the control shaft 1 is moved to an angular position corresponding to the target valve characteristics.
6 to output a control signal to the electromagnetic actuator 101.

In the following, the operation of the variable valve apparatus will be described. First, when the engine is running at low speed and low load, the electromagnetic actuator 101 is driven to rotate to one side by a control signal from the control unit CPU. Therefore, the control cam 1
6A and 7B, the axis P1 is held at the upper left rotation position from the axis P2 of the control shaft 16 as shown in FIGS.
a moves upward away from the camshaft 13. For this reason,
The entire rocker arm 18 moves upward with respect to the camshaft 13, whereby each swing cam 20 is slightly lifted at its end 23 via the link member 26, and the entire rocker arm 20 moves leftward. Rotate.

6A and 6B, when the eccentric cam 15 rotates and pushes up one end 18b of the rocker arm 18 via the link arm 25, the lift amount of the rocker arm 20 is increased via the link member 26. The lift amount L1 is relatively small as shown in FIG. 6B.

Therefore, in such a low speed and low load range, the valve lift becomes small as shown by the broken line in FIG.
The opening timing of each intake valve 12 is delayed (operating angle is reduced), and the valve overlap with the exhaust valve is reduced. For this reason, improvement in fuel consumption and stable rotation of the engine can be obtained.

On the other hand, when the engine shifts at the time of high speed and high load of the engine, the electromagnetic actuator 101 is rotationally driven in the opposite direction by a control signal from the control unit CPU. Therefore, as shown in FIGS. 7A and 7B, the control shaft 16 rotates the control cam 17 clockwise from the position shown in FIG.
The axis P1 (thick portion 17a) is moved downward. For this reason, the rocker arm 18 is now moved in its entirety in the direction of the camshaft 13 (downward), and the other end 18 c is
The upper end 23 of the swing cam 20 is pressed downward via the link member 26 to rotate the entire swing cam 20 clockwise by a predetermined amount.

Accordingly, the valve lifter 1 of the swing cam 20
The contact position of the lower surface with respect to the upper surface 9 moves to the left position as shown in FIGS. 7A and 7B. For this reason, the eccentric cam 15 rotates as shown in FIG.
When b is pushed up via the link arm 25, the lift amount L2 with respect to the valve lifter 19 increases as shown in FIG. 7B.

Therefore, in such a high-speed, high-load region, the cam lift characteristic becomes larger than that in the low-speed, low-load region, and the valve lift (operating angle) increases as shown by the solid line in FIG. The opening timing is earlier and the closing timing is later. As a result, the intake charging efficiency is improved, and a sufficient output can be secured.

As described above, in the above-described variable valve apparatus, not only the opening / closing timing and the valve lift (operating angle) of each intake valve 12 can be varied, but also each eccentric cam 15 and each swing Since the moving cam 20 and the moving cam 20 are provided coaxially, the arrangement space in the engine width direction can be sufficiently reduced.
Further, since each rocker arm 18 does not need to be installed in the width direction of the engine, it can be formed in a small "H" shape just above the camshaft, so that the entire apparatus can be made compact. As a result, the mountability of the device on the engine is improved. Further, since the apparatus can be mounted according to the current arrangement of the camshafts 13 without changing the arrangement of the camshafts 13, the mountability to the engine is also improved in this respect.

Further, by providing the eccentric cam 15 and the oscillating cam 20 coaxially on the cam shaft 13, the oscillating cam 20
A dedicated support shaft for supporting the shaft is not required, and the number of parts can be reduced, and the cam shaft 13 and the oscillating cam 20 are not displaced from each other. Can be prevented.

Further, since each eccentric cam 15 is arranged offset from each valve lifter 19 and arranged at a position where they do not interfere with each other, the outer shape of each cam 15 can be made large.
The degree of freedom in designing the outer peripheral surface 15a of the eccentric cam 15 can be improved, whereby a sufficient lift amount for securing the swing amount of the swing cam 20 can be secured.
A sufficient cam width for reducing the driving surface pressure of the eccentric cam 15 can be secured.

In particular, the eccentric cam 15 is formed in a ring shape, and the entire outer peripheral surface is formed in the fitting hole 25 of the link arm base 25a.
Since the entire inner peripheral surface of c is in sliding contact, the surface pressure on the outer peripheral surface is dispersed, and the surface pressure can be sufficiently reduced. Therefore, the fitting hole 25
The occurrence of abrasion between the inner peripheral surfaces of c can be suppressed and lubrication can be easily performed. Further, the degree of freedom in selecting the material of the eccentric cam 15 is improved with a decrease in the surface pressure, and a material that is easy to process and can be selected at a low cost can be selected. The swing cams 20 and 20 corresponding to the respective intake valves 12 are integrated. , So that the eccentric cam 15 and the rocker arm 18 are united, and each intake valve 1
It may be configured to be shared between the two.

By the way, in the above-mentioned variable valve actuation, the control shaft 16 is driven to an angular position corresponding to the target valve characteristic, and the actual valve characteristic is controlled to the target valve characteristic. If the accuracy or the relationship between the angular position of the control shaft 16 and the valve characteristics varies, it becomes impossible to accurately control the actual valve characteristics to the target valve characteristics.

Therefore, in the first embodiment of the present invention, as shown in the block diagram of FIG. 10, the operating angle (rotational position) of the control shaft 16 for changing the swing fulcrum is determined by an operating angle sensor such as a potentiometer. (Control operating angle detecting means) 1
02, based on the detected operating angle signal, the control unit CPU compares the detected operating angle with the target operating angle, and determines the operating angle (rotational position) of the control shaft 16 as the target valve characteristic. The drive control signal for the electromagnetic actuator 101 such as a DC servomotor is feedback-controlled so that the target operation angle (rotational position) corresponding to the above is obtained. A reduction gear 1 is provided between the electromagnetic actuator 101 and the control shaft 16.
07 is interposed.

However, as described above, the cam shaft 13 rotates in synchronization with the rotation of the engine (1/3 of the engine speed).
2) When the control shaft 16 is subjected to the torque fluctuation of the same cycle (frequency) as the rotation speed of the cam shaft 13 via the swing cam 20, the link arm 25, the link member 26, and the rocker arm 18, the torque fluctuation causes The control shaft 16 is finely swung, and the swing is detected as an operating angle fluctuation by the operating angle sensor 102. Therefore, in the feedback control of the control shaft operating angle based on the detected operating angle signal, the electromagnetic actuator 101 is operated. Since the drive control signal to be driven is varied, the motor shaft of the electromagnetic actuator 101 always swings finely, so that the brushes of the armatures wear out, resulting in a problem that durability is reduced.

Therefore, as a solution to the above problem, in the first embodiment of the present invention, the control shaft 1 detected by the operating angle sensor 102 is provided in the control unit CPU.
6, two band elimination filters BEF for removing an operation angle fluctuation signal component of the control shaft 16 due to a torque fluctuation due to the rotation of the cam shaft 13 from the operation angle signal of FIG.
1, BEF2 (hereinafter referred to as digital filters 1 and 2)
It has.

That is, the torque fluctuation transmitted to the control shaft 16 is:
Since the signal is synchronized (１ ／) with the engine speed, digital filters 1 and 2 for reducing the gain of only the signal of the frequency band component are attached to the output of the operating angle sensor 102. FIG. 11 is a characteristic diagram of the digital filters 1 and 2, (a) is an output gain characteristic with respect to an input frequency,
(B) shows the output phase characteristic with respect to the input frequency. FIG. 12 shows that a digital filter for 2000 rpm and a 5000
FIG. 6 is an input / output characteristic diagram when a digital filter for rpm is applied. As shown in this figure, it is necessary to switch the digital filter characteristic for each predetermined region of the engine speed.

The digital (discrete time) filters 1 and 2 (band elimination filters BEF1 and BEF1)
BEF2) requires a recursive calculation, so that two digital filter operation functions are previously provided in the control unit CP.
U, and when the engine speed is within a certain range, only one digital filter is activated,
The output value is used for operating angle control of the control shaft 16, and the second digital filter is operated only when the engine speed shifts to another region. The filter constant at that time is a constant corresponding to the shifted engine speed region, and this constant is stored in advance in the memory of the control unit CPU, and a constant corresponding to the engine speed at that time is stored in the memory of the control unit CPU. Called and used. When the time required for the recursive calculation of the digital filter has elapsed, the output value is set to the second digital filter output value, and the first digital filter stops the calculation. Thereafter, the above processing is performed alternately each time the engine speed range changes.

Next, the contents of the signal processing circuit for processing the operating angle detection signal by the two digital filters 1 and 2 are shown in FIG.
3 will be described. First, in step S1, the engine speed N signal is read, and in step S2, the operating angle (rotation angle) of the control shaft 16 is read.

In step S3, it is determined whether or not the engine speed N is within the previously read engine speed region. If the engine speed N is within the previously read engine speed region, the digital filter 2 is calculating in step S4. It is determined whether or not the calculation is being performed. If the calculation is being performed, the calculation of the digital filter 2 is continued in step S5. Then, in step S6, it is determined whether or not the calculation of the digital filter 2 is completed. At the time, after replacing the digital filter 2 with the digital filter 1 in step S7 and replacing the constant of the digital filter 2 with the constant of the digital filter 1 in step S8,
In step S13, the output value of the digital filter 1 is output, and one flow ends.

If the engine speed has changed from the previously read engine speed range in step S3, the flow advances to step S9 to read a constant for the digital filter 2, and in step S10 the digital filter 2 is calculated. After the calculation of the digital filter 1 is performed in step S11, the output value of the digital filter 1 is output in step S13, thereby completing one flow.

In the determination in step S4,
If the digital filter 2 is not being calculated, and if the digital filter 2 has not been calculated in step S6, the process proceeds to step S12, where the digital filter 1 is calculated. An output value of 1 is output, and this ends one flow.

That is, when the engine speed changes, the constant used for the digital filter is called from the memory of the control unit CPU according to the changed speed, and the calculation of the second digital filter is started. In addition,
The first digital filter continues to perform calculations.

Since the digital filter performs recursive calculation and cannot be used unless it is calculated several times, the first digital filter (corresponding to the engine speed before the change) is used for several sampling times after the engine speed changes. Is used for controlling the operating angle of the control shaft 16.

When the second digital filter (corresponding to the changed engine speed) becomes usable, the calculation of the first digital filter is stopped, and the output of the second digital filter is changed. Used for controlling the operation angle of the control shaft 16. After that, the second digital filter is treated as the first digital filter. The above operation is repeated every time the engine speed changes.

As described above, the digital filters 1 and 2 are switched each time the engine speed range changes. However, since the engine speed changes every moment, in practice, FIG.
As shown in the figure, the engine rotation speed is divided into several rotation speed regions 1 to 7, and while in a certain region, the calculation of the digital filter is performed with a constant corresponding to the center frequency of the region. I have. N1 to N6 indicate the frequencies corresponding to the branch points between the engine speed ranges (1 to 7), and n1 to n7 indicate the center of the digital filter corresponding to each engine speed range (1 to 7). Indicates the frequency. Also,
FIG. 15 shows filter constants (1 to 7) (filter frequencies) for the respective engine speed ranges (1 to 7).

The digital filter is defined by the following transfer function. G (Z) = (a1 + a2 · Z ⁻¹ + a3 · Z ⁻² ) / (1 + b1 · Z ⁻¹ + b2 · Z
^-2 ) Here, a1, a2, a3, b1, and b2 are filter constants.

The transfer function of the digital filter is calculated by the following equation. Current filter output Yn = a1, Un + a2, Un-1 + a3, Un-2 + b1, Yn-
1 + b2 · Yn-2 Note that the subscript n indicates the sampling timing.

As described above, in the first embodiment of the present invention, a signal obtained by subjecting the operating angle signal of the control axis detected by the operating angle sensor to arithmetic processing by the digital filters 1 and 2 is input to the control unit CPU. By doing so, it is possible to prevent unnecessary swing control of the electromagnetic actuator 102 due to the swing of the control shaft 16 due to torque fluctuation due to the rotation of the cam shaft 13, whereby the durability of the electromagnetic actuator 102 can be prevented. The effect that the property can be improved is acquired.

Also, two digital filters 1 and 2 are provided. When the digital filter 1 is within a predetermined rotation speed range of the internal combustion engine, only one of the digital filters 1 is operated to calculate a constant corresponding to the engine rotation speed range at that time. The output value obtained is output to the control unit CPU, and when the engine speed region shifts to another region, the other digital filter 2 is operated to calculate the output value with a constant corresponding to the shifted engine speed region. Is started and the output value is output to the control unit CPU when the calculation is completed, and at the same time, the operation of the one digital filter is stopped, so that the optimum value corresponding to the engine speed region at that time is always obtained. This makes it possible to perform an effective process.

(Second Embodiment of the Invention) Next, a description will be given of an anti-swing device of a control shaft driving electromagnetic actuator according to a second embodiment of the present invention. In the second embodiment of the present invention, as shown in the block diagram of FIG. 16, one digital filter 10 provided in the control unit CPU is used.
The signal processing is performed only by the (band elimination filter BEF10), and the other configuration is the same as that of the first embodiment of the present invention. Therefore, description thereof will be omitted, and only different points will be described.

That is, the torque fluctuation transmitted to the control shaft 16 is:
Since it is synchronized (１ ／) with the engine speed, a digital filter 10 for reducing the gain of only the signal of the frequency band component is attached to the output of the working angle sensor 102.

As described above, the digital filter 10 needs to switch the filter characteristic for each predetermined region of the engine speed, and the digital (discrete time) filter (band elimination filter B
Since EF10) requires a recursive calculation, the control unit CPU is provided with a digital filter operation function in advance, and when the engine speed is within a certain range, a constant corresponding to the engine speed region at that time is used. Is used for operating angle control of the control shaft 16, and when the engine speed shifts to another region, the operating angle value detected by the operating angle sensor 102 is output as it is. The output value is calculated based on a constant corresponding to the shifted engine speed region, and the output value is output when the time required for the recursive calculation has elapsed. The above processing is performed each time is changed.

Next, the contents of the signal processing circuit for processing the operating angle detection signal by one digital filter 10 are shown in FIG.
A description will be given based on the flowchart of FIG. First, in step S21, an engine speed N signal is read, and in step S22, an operation angle (rotation angle) signal of the control shaft 16 is read.

In step S23, it is determined whether or not the engine speed N is within the previously read engine speed region. If the engine speed N is within the previously read engine speed region, the digital filter 10 newly calculates in step S24. It is determined whether or not the calculation is being performed. If the calculation is being performed, the calculation of the new digital filter 10 is continued in step S25, and then it is determined whether or not the calculation of the new digital filter 10 is completed in step S26. If it has been completed, step S3
In step 3, the output value of the new digital filter 10 is set as a filter output, and one flow is completed.

If the engine speed has changed from the previously read engine speed range in step S23, the process proceeds to step S27, where a new constant for the digital filter 10 corresponding to the shifted engine speed range is obtained. Is read, the calculation of the new digital filter 10 is started in step S28, the calculation of the new digital filter 10 is continued in step S29, and the process proceeds to step S30, where the read operating angle is directly used as the filter output. This is output in step S33, and one flow is completed.

If it is determined in step S24 that a new digital filter 10 is not being calculated,
Proceeding to step S31, the digital filter 10 is calculated based on the filter constant read at the beginning of the control, and the filter output is output in step S33, thus ending one flow.

If the calculation of the new digital filter 10 has not been completed in step S26, the process proceeds to step 32, where the read operating angle is used as it is as a filter output, and the filter output is output in step S33. This completes one flow.

As described above, in the second embodiment of the present invention, signal processing is performed by only one digital filter 10, so that the effect of reducing costs can be obtained. Can be

Although the embodiments of the present invention have been described above, the specific configuration is not limited to the embodiments of the present invention, and design changes and the like may be made without departing from the gist of the present invention. This is also included in the present invention.

For example, in the embodiment of the present invention, an intake valve is taken as an example of an engine valve, but the invention can also be applied to an exhaust valve. Further, the variable valve mechanism to which the present invention is applied is not limited to the structure illustrated in the embodiment of the present invention, but may be the structure illustrated in the conventional example or other variable valve mechanisms. The present invention can be applied to all mechanisms.

[0069]

As described above in detail, in the swing prevention device for the control shaft drive motor according to the first aspect of the present invention, the rotational speed of the internal combustion engine is detected in the variable valve operating device of the internal combustion engine. Rotation speed detection means, and a band elimination filter for lowering the output gain in a frequency band corresponding to the frequency of the rotation speed of the internal combustion engine detected by the rotation speed detection means, the control operating angle detection means By adopting means configured to input a signal obtained by arithmetically processing the detected operating angle signal of the control axis by the band elimination filter to the control means, the control axis is caused by torque fluctuation due to rotation of the camshaft. Unnecessary swing control of the electromagnetic actuator caused by swinging is prevented,
The effect is obtained that the durability of the electromagnetic actuator can be increased.

According to a second aspect of the present invention, there is provided an oscillation preventing device for an electromagnetic actuator for driving a control shaft, wherein the two band elimination filters are provided so as to be within a predetermined rotational speed range of the internal combustion engine. , Only the first band elimination filter is operated, and an output value calculated by a constant corresponding to the rotation speed region of the internal combustion engine at that time is output to the control means. When the operation shifts to the region, the second band elimination filter is operated to start the calculation of the output value with a constant corresponding to the rotation speed region of the shifted internal combustion engine. When the calculation is completed, the output value is calculated. A means configured to stop the operation of the first band elimination filter at the same time as outputting to the control means, so that the air at that time is always output. Jin optimum processing corresponding to the rotational speed region is to be performed.

According to a third aspect of the present invention, there is provided an anti-swing device for a control shaft driving electromagnetic actuator, wherein the one or more band elimination filters are provided so as to be within a predetermined rotational speed range of the internal combustion engine. The output value calculated based on the constant corresponding to the engine speed region at that time is output to the control means, and when the rotation speed region of the internal combustion engine shifts to another region, the operating angle detection means While the operating angle value detected in the above is output to the control means as it is, the output value is calculated based on a constant corresponding to the shifted engine speed region, and the output value is calculated at the time when the calculation is completed. By providing the output to the control means, only one band elimination filter needs to be provided, and the cost can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view (a cross-sectional view taken along line AA in FIG. 2) showing a variable valve operating device according to Embodiment 1 of the present invention.

FIG. 2 is a side view of the variable valve operating device.

FIG. 3 is a plan view of the variable valve device.

FIG. 4 is a perspective view showing an eccentric cam used in the variable valve device.

FIG. 5 is a valve lift characteristic diagram corresponding to a base end surface and a cam surface of an oscillating cam in the variable valve operating device.

FIG. 6 is a cross-sectional view (cross-sectional view taken along the line BB in FIG. 2) showing the operation of the variable valve device at low speed and low load.

FIG. 7 is a cross-sectional view (a cross-sectional view taken along the line BB of FIG. 2) illustrating an operation of the variable valve device at a high speed and a high load.

FIG. 8 is a characteristic diagram of valve timing and valve lift of the variable valve operating device.

FIG. 9 is a block diagram mainly showing an operating angle control system of the variable valve operating device.

FIG. 10 is a block diagram showing a switching control system of mainly two digital filters of the variable valve apparatus.

11A and 11B are characteristic diagrams of the digital filter, wherein FIG. 11A is an output gain characteristic diagram for an input frequency, and FIG. 11B is an output phase characteristic diagram for an input frequency.

FIG. 12 is an input / output characteristic diagram of the digital filter.

FIG. 13 is a flowchart showing the contents of an operation angle detection signal processing circuit of the variable valve operating device.

FIG. 14 is a view showing a method of selecting the digital filter according to an engine speed region.

FIG. 15 is a diagram showing a call filter constant of the digital filter with respect to each engine speed region.

FIG. 16 is a block diagram showing a switching control system mainly for a digital filter of the variable valve operating apparatus according to Embodiment 2 of the present invention.

FIG. 17 is a block diagram showing a switching control system of mainly two digital filters of the variable valve apparatus according to Embodiment 2 of the present invention.

FIG. 18 is a sectional view showing a conventional variable valve operating device.

FIG. 19 is a block diagram mainly showing an operation angle control system of a conventional variable valve apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 12 Intake valve 13 Cam shaft 15 Eccentric cam (oscillation drive means) 16 Control shaft 17 Control cam 18 Rocker arm 20 Oscillation cam 25 Link arm (oscillation drive means) CPU control unit (control means) 101 Electromagnetic actuator 102 Operating angle sensor (Control angle detection means) 106 Revolution sensor (revolution detection means) BEF1 Band elimination filter BEF2 Band elimination filter BEF10 Band elimination filter

Continued on front page F-term (reference) 3G016 AA06 AA19 BA03 BA23 BA36 BB04 CA10 CA12 CA21 CA22 CA25 CA27 CA44 CA46 CA47 CA48 CA52 DA23 GA01 3G092 AA11 DA01 DA02 DA05 DA14 DG03 DG08 DG09 EA11 EB07 EC01 FA09 FA13 FA50 HA13Z01 HA13Z

Claims (3)

[Claims] A control shaft disposed substantially parallel to the cam shaft; a control cam eccentrically fixed to an outer periphery of the control shaft; a rocker arm pivotally supported by the control cam; Swing drive means for swinging and driving one end of the rocker arm in response to rotation of a camshaft; a swing cam for swinging and opening an engine valve in association with the other end of the rocker arm; Control operating angle detecting means for detecting the operating angle of the shaft; an electromagnetic actuator for driving the control shaft to rotate to the target operating angle; and an operating angle signal of the control axis detected by the control operating angle detecting means. Control means for rotating the control shaft to a target operating angle position in accordance with the operating state of the engine; anda variable valve operating device for the internal combustion engine, comprising: a rotational speed detecting means for detecting a rotational speed of the internal combustion engine; Detected by the rotation speed detecting means. A band elimination filter for lowering an output gain in a frequency band corresponding to a frequency of a rotation speed of the fuel engine, wherein the band elimination filter outputs an operation angle signal of a control shaft detected by the control operation angle detection unit. And a control unit for inputting the signal processed by the control unit to the control unit. 2. The band elimination filter according to claim 2,
When the engine speed is within a predetermined internal combustion engine speed range,
When only the band elimination filter is operated, an output value calculated by a constant corresponding to the rotation speed region of the internal combustion engine at that time is output to the control means, and when the rotation speed region of the internal combustion engine shifts to another region. Activates the second band elimination filter, starts the calculation of the output value with a constant corresponding to the speed range of the shifted internal combustion engine, and outputs the output value to the control means when the calculation is completed. 2. The device according to claim 1, wherein the operation of the first band elimination filter is stopped at the same time. 3. The band elimination filter according to claim 1,
Output a value calculated based on a constant corresponding to the engine speed region at that time when the engine speed is within a predetermined engine speed region to the control means, When shifting to the region, while the operating angle value detected by the operating angle detecting means is output to the control means as it is, the output value is calculated based on a constant corresponding to the shifted engine speed region, 2. The apparatus according to claim 1, wherein the output value is output to the control means when the calculation is completed.