JP3367225B2 - Valve timing adjustment device for internal combustion engine - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an operating condition of an internal combustion engine.
The opening and closing timing of the intake and exhaust valves (valve timing
Valve timing adjustment device for adjusting
Is what you do. 2. Description of the Related Art Conventionally, for example, Japanese Patent Laid-Open No. 6-159105
In the valve timing adjustment device disclosed in the official gazette,
Hydraulic control valve having a solenoid as a driving means
The operating state of this hydraulic control valve is
The drive signal is learned at the time of
Control of the hydraulic control valve according to the drive signal calculated by the control device.
Apply current to the solenoid. And such Soleno
In response to the current flowing through the actuator (hereinafter referred to as the solenoid current).
Change the opening of the hydraulic control valve or switch the oil passage
Perform hydraulic control to determine the relative rotation angle between the crankshaft and camshaft.
Adjust the valve timing to match the target rotation angle.
Swelling. [0003] By the way, such a problem
Abnormal solenoid current in valve timing adjustment device
If it is too large, the solenoid will burn out due to abnormal heating.
And other adverse effects. Therefore, the solenoid current
Guards are on. In this case, the width of this guard
(Hereinafter referred to as guard width)
It does not have to flow. Also, the oil against the solenoid current
The opening degree characteristics of the pressure control valve have product variations. Therefore,
Considering these things, the guard width is quite wide
You. [0004] At this time, whether the valve timing is constant or not.
Control to make a large change to the advance or retard side from
Is a guard that opens the control valve fully.
The response speed can be maximized and there is no problem of response delay.
However, if the guard width is wide, the valve timing will be retarded
From control to advance control or from advance control to retard
If the control is suddenly reversed, the corresponding solenoid
It takes time for the current to change, which causes the hydraulic control valve to open.
Response and delay in response to oil level changes and
The problem of delay in response to
You. [0005] This is because the solenoid current is
Response delay to the voltage applied to the
When the hydraulic control valve closes from full open or
The control valve opens the oil path on the opposite side
When open, the change width of the solenoid current increases,
This is because it takes time to change the solenoid current. That
As a result, response delay due to change in hydraulic control valve opening or switching of oil passage
And delays in valve timing adjustment response
It becomes a problem that it slips. In order to deal with such a problem, the guard width is simply reduced.
Simply narrowing the product will cause the hydraulic control valve to move to full open depending on the product.
Response occurs due to slow response
There will be a delay. Therefore, the present invention
In order to deal with such unavoidable events, the valve timing of the internal combustion engine must be adjusted.
Consider the variation in control valve products
To control the control signal to the solenoid of the control valve.
Value is set to a value that maximizes the control valve opening.
Response time for valve timing adjustment, and
Minimize the current change width of the solenoid to minimize current change delay
Response delay of the valve timing adjustment device
is there. Means for Solving the Problems To solve the above problems,
Therefore, in the invention described in claim 1, the internal combustion engine (1)
Difference between crankshaft (2) and camshaft (4, 5)
A phase difference adjusting device (40) for adjusting the pressure in accordance with the oil pressure;
A solenoid (64) for responding to the current supplied to the solenoid.
The hydraulic pressure to the phase difference adjusting device (40) is controlled by the opening
Control valve (30) and the current to the solenoid (64)
Current adjusting means (49) for adjusting, the crankshaft (2)
The intake valve and the exhaust valve are set based on the relative rotation angles with the camshafts (4, 5).
Detect the actual valve timing of at least one of the air valves
Actual valve timing detection means (42, 44, 48, 10
1) and an intake valve and an intake valve according to the operating state of the internal combustion engine (1).
Set the target valve timing for at least one of the exhaust valves
Target valve timing setting means (48, 100)
And the actual valve timing is set to the valve target timing.
System for feedback control to match
Control signal output for outputting a control signal to the current adjusting means (49)
Means (48, 102) and the actual valve timing.
The phase difference adjusting device (40) to a predetermined phase difference adjusting state.
Control signal or solenoid to current adjusting means (49)
(64) and learns the control signal based on the learned value.
Control signal output from the signal output means (48, 102)
Learning means ((48, 103) for applying correction, and learning
The opening of the control valve (30) is minimized based on the learning value of the means.
A guard having a large width is set, and the control signal output means (4
8, 102) is placed in the guard.
And guard means (48, 104) for limiting
Provided with a characteristic valve timing adjustment device for internal combustion engines
Is done. [0008] In addition, the parentheses of each means and each component described above.
Reference numerals in the parentheses denote specific means and configurations described in embodiments described later.
It shows the correspondence with the element. [0009] As described above, the first aspect of the present invention.
The guard means (48, 104)
However, the width of the guard is determined by the learning means (48, 103).
The maximum opening of the control valve (30) is determined based on the learning control signal.
Set the width to Thereby, the product of the control valve (30)
The solenoid valve of the control valve (30)
Guard width for control signal to
However, the opening of the control valve (30) can be maximized. Furthermore, the current
Valves with a minimum change width and current change delay
The response delay of the timing adjustment device can be prevented. Subordinate
Therefore, when changing the valve timing greatly,
By driving the valve (30) to full open, responsiveness is improved.
Valve timing can be adjusted. An embodiment of the present invention will be described below with reference to the drawings.
I do. FIG. 1 shows a double overhead cam type internal combustion for a vehicle.
1 shows an embodiment of the present invention applied to an engine 1. Internal combustion engine 1
In this case, the power from the crankshaft 2 is
By the chain 3, through each sprocket 13a, 13b
To be transmitted to the exhaust side camshaft 4 and the intake side camshaft 5
Has become. A phase difference adjusting device 40 is provided on the intake side camshaft 5.
(See the hatched area in FIG. 1). Ma
A camshaft position sensor 44 is attached to the camshaft 5.
The crankshaft 2 has a crank position sensor
42 are attached. Here, the crank position
The sensor 42 generates N detection pulses with one rotation of the crankshaft 2.
When the signal is generated, the camshaft position sensor 44
One rotation generates 2N detection pulse signals.
ing. Also, the maximum value of the timing conversion angle of the cam shaft 5 is
When θmax crank angle is set, N <360 degrees / θmax
The number N of detection pulse signals is set so as to be x. Thus, the crank position sensor 42
These detection pulse signals and the detection pulse signal
Between the detected pulse signal from the camshaft position sensor 44
The actual valve timing of the intake valve is calculated from the relative rotation angle θ of
Will be issued. Specifically, the crank position sensor 42 and the
Each detection pulse signal from the system shaft position sensor 44 is
Input to the microcomputer 48 of the
Based on this, the actual valve timing is calculated. Ma
In addition, whether the intake air amount sensor, water temperature sensor, throttle sensor, etc.
The various detection signals generated from this are also input to the microcomputer 48.
The target valve timing of the intake valve
Is calculated. In the microcomputer 48,
Means that the actual valve timing of the intake valve is the target valve timing
Feedback control calculation is performed to match
You. As a result, the linear solenoid 64 (spool valve 3
Target current to be supplied to the driving electromagnetic actuator (0)
Control signal of the internal combustion engine control device 46
49. The current control circuit 49 is a linear solenoid
A circuit (not shown) for detecting the current flowing through the
Have. Then, the current control circuit 49
Based on the control signal from the computer 48, the detected current is
Feedback control is performed to match the flow. In addition,
The current feedback control part is
It may be incorporated in the microcomputer 48. Under the above feedback control,
The spool valve 30 is controlled. And control like this
From the oil pan 28 through the spool valve 30
Hydraulic oil is pumped by the oil pump 29, and the phase difference is adjusted.
The amount of hydraulic oil to the regulating device 40 is controlled. Below,
The configuration of the phase difference adjusting device 40 will be further described with reference to FIG.
This will be described in detail. The phase difference adjusting device 40 is provided as shown in FIG.
Attached to the cylinder head 25 of the internal combustion engine 1
I have. The phase difference adjusting device 40 has a substantially cylindrical camshaft sleeve.
The camshaft sleeve 11 includes a sleeve 11.
The large-diameter cylindrical portion and the left end of the camshaft 5 shown in FIG.
They are fitted coaxially. And this camshaft slide
The hollow partition 11c of the valve 11 is used for press-fitting and bolting of the pin 12.
The cam shaft 5 is connected to the end of the camshaft 5 by tightening the cam 10.
Thereby, the camshaft sleeve 11 is integrated with the camshaft 5.
Rotate. The large-diameter cylindrical portion of the cam shaft sleeve 11
External teeth helical spline 11a is formed on the outer peripheral surface.
ing. Further, the cam shaft sleeve 11 is a small-diameter cylinder.
Portion 11b, and the small-diameter cylindrical portion 11b
Coaxially extending into the substantially cylindrical hollow portion of the jing 23.
You. Note that the housing 23 is attached to its flange portion 23a.
To the cylinder head 25 by tightening the bolt 24
Have been killed. The sprocket 13a is an annular camshaft 5
Open end of rib 5a and large-diameter cylindrical portion of camshaft sleeve 11
Between the camshaft and the
5 is coaxially supported so as to be relatively rotatable. Sproquet
On the left side of the unit 13a shown in FIG.
Proket sleeve 15 passes through each of its flanges
Coaxially by pressing the pin 14 and tightening the bolt 16
Installed. This allows the sprocket sleeve
Numeral 15 is to rotate integrally with the sprocket 13a.
ing. This sprocket sleeve 15 is
5b, and the cylindrical portion 15b is provided with a camshaft three
In the hollow portion of the housing 23 so as to surround the
It extends coaxially. In the middle portion of the inner peripheral surface of the cylindrical portion 15b,
An internal tooth helical spline 15a is formed.
The internal tooth helical spline 15a is
Twist in the direction opposite to the external tooth helical spline 11a
It is formed to have. In addition, external tooth helical sp
Any of line 11a and internal helical spline 15a
One of them is a straight tooth parallel to the axial direction with a torsion angle of zero.
May be constituted by a spline having A small-diameter cylindrical portion of the camshaft sleeve 11 described above.
11b and the cylindrical portion 15b of the sprocket sleeve 15
Between them, an annular space 90 having a substantially uniform cross section in the axial direction is formed.
The annular space 90 has a substantially circular shape.
Cylindrical hydraulic piston 17 slides axially and liquid-tight
If possible, it is coaxially supported by the camshaft sleeve 11.
You. On the right side of the inner peripheral surface of the hydraulic piston 17,
Is the external helical spline 11 of the camshaft sleeve 11
helical spline 17a meshing with a.
On the other hand, on the right side of the outer peripheral surface of the hydraulic piston 17,
Is the internal helical splice of the sprocket sleeve 15
External tooth helical spline 17b meshing with pin 15a
Has been established. As a result, each of these splines
The timing chain 3 (see FIG. 1)
Of the crankshaft 2 transmitted to the sprocket 13a through the
Rolling sprocket sleeve 15, hydraulic piston 17 and
And transmitted to the camshaft 5 via the camshaft sleeve 11. A hydraulic piston 17 is formed at the left end.
An oil seal 70 is provided on the outer peripheral edge of the annular flange.
In the space 90, the cylindrical portion 1 of the sprocket sleeve 15
5b so as to be in liquid-tight contact with the inner peripheral surface
You. Note that a cross section L
The annular leg portion 17c extending in the shape of a letter
Engage with the central step (hereinafter referred to as right stopper) to
The right movement of the piston 17 is stopped. As described above, the hydraulic pressure is
By providing the piston 17, the annular space 90 is provided.
Is divided into two chambers. Thereby, the advance side hydraulic chamber 2
2 is formed on the left side of the hydraulic piston 17 while the retard side
A hydraulic chamber 32 is formed on the right side of the flange of the hydraulic piston 17.
It is. In addition, the sealing property between the hydraulic chambers 22 and 32
Is secured by the oil seal 70 described above. At the left end opening of the sprocket sleeve 15
Has an end plate 50 mounted coaxially.
You. This end plate 50 has a cylindrical portion and an annular flange portion.
It is formed in an inverted L-shaped cross section.
The annular flange of the sprocket 50 is on the left of the sprocket sleeve 15.
It is coaxially fixed to the end opening. End plate 5
An annular groove is formed on the outer peripheral surface of the cylindrical portion 0.
An oil seal 71 is mounted in the annular groove. What
The annular flange of the end plate 50 is a hydraulic piston
17 by engagement with the annular flange of the hydraulic piston 17
Stopper for stopping left movement (hereinafter referred to as left stopper
)). End plate 50 and camshaft sleeve 1
On the left side of 1, a ring formed in a U-shaped cross-section
The pressing plate 51 is pressed into the
A cam shaft sleeve 11 is provided on the inner surface of the annular left wall of the housing 23.
The ring plate 51 is mounted coaxially.
The cylindrical portion of the end plate 50 and the
The small-diameter cylindrical portion 11b of the shaft sleeve 11 is rotatably supported.
Have been. Also, the small diameter side cylindrical portion of the ring plate 51
In the annular groove formed on the outer peripheral surface of the
The oil seal 72 is mounted on a ring
To secure the seal between the shaft 51 and the camshaft sleeve 11.
You. On the other hand, the oil seal 71 described above is
To secure the seal between the ring 50 and the ring plate 51.
You. As a result, the sealing performance in the advance side hydraulic chamber 22 is ensured.
Is preserved. The small-diameter cylindrical portion of the ring plate 51 and the how
A bolt 52 is provided in the hollow portion of the annular left side wall of the jing 23.
The bolt 52 is fitted axially, and its right end face is
, The inner peripheral surface of the small-diameter cylindrical portion of the camshaft sleeve 11 and the hollow
A cylindrical space 91 is formed between the partition and the partition 11c. Ma
A hydraulic passage 61b is provided inside the bolt 52 as shown in FIG.
As shown in FIG.
The passage 61b has a cylindrical space 91 at its axial passage.
Communicates within. The hydraulic passage 61b has a radius
At both ends of the directional passage, formed on the outer peripheral surface of the bolt 52
It communicates with the inside of the annular groove. In the left wall of the housing 23, oil
The pressure passage 61a is formed as shown in FIG.
The hydraulic passage 61a is formed by the annular groove of the bolt 52 and the hydraulic passage.
61b and communicate with the inside of the cylindrical space 91 via
The camshaft sleeve 11 is opened so as to open into the cylindrical space 91.
Through the hydraulic passage 61c formed into the retard-side hydraulic chamber 32.
Communicating. In the left wall portion of the housing 23, the advance side
A hydraulic passage 60 communicating with the hydraulic chamber 22 is further formed.
I have. These hydraulic passages 61a and 60
3 which is formed in the left wall portion and accommodates a spool valve 30 described later.
It is open in a cylindrical hollow part 95 formed therein. Also,
A hydraulic supply passage 65 is provided in the cylindrical hollow portion 95.
The hydraulic supply passage 65 is open at the end.
Pressure from the oil pan 28 of the Seki 1 by the oil pump 29
The supplied working oil is supplied into the cylindrical hollow portion 95. What
The hydraulic release passage 66 is opened in the oil pan 28.
Then, the operating oil is returned to the oil pan 28. Next, referring to FIG.
The configuration will be described. The spool valve 30 has a cylindrical hollow portion.
And a cylinder 30a constituted by an inner wall of the cylinder 95.
Left fitted slidably in the axial direction in the cylinder 30a
And a spool 31 having a pair of right lands.
ing. The cylinder 30a communicates with the hydraulic passage 61a.
Hydraulic port 30b and the hydraulic pressure communicating with the hydraulic port 60
A port 30c is formed. For cylinder 30a
The suction port 30 communicating with the hydraulic supply path 65
d, the two discharge ports 30e communicating with the hydraulic release passage 66,
30f are formed. And each of these hydraulic ports
30b, 30c, suction port 30d and both discharge ports
Switching of communication between 30e and 30f and the degree of communication (spool
The control of the opening degree of the valve 30 is performed by controlling the cylinder 30 of the spool 31.
This is done by sliding within a. The right end of the cylinder 30a shown in FIG.
A coil spring 31a is provided in the
The coil spring 31 is installed at the right end side.
“a” always urges the spool 31 to the left in the figure.
On the other hand, a linear solenoid
A solenoid 64 is provided on the left end side of the spool 31 in the drawing.
You. Depending on the value of the current flowing through the linear solenoid 64,
When an electromagnetic force is induced in the linear solenoid 64,
The spool 31 is moved by the coil spring 31 by this electromagnetic force.
It slides rightward against the biasing force of a. Hereinafter, the spool valve 30 constructed as described above will be described.
Of communication of each hydraulic passage by sliding of the spool 31
Control and opening control will be described. As shown in FIG.
As described above, the spool 31 is
Receiving magnetic force, against the urging force of coil spring 31a
When sliding to the right, the suction port 30d and the hydraulic port 3
0c are connected to each other by the right movement of the right land of the spool 31.
The hydraulic supply passage 65 and the hydraulic passage 60 communicate with each other.
Therefore, the hydraulic pressure from the oil pump 29 is supplied to the advance hydraulic chamber.
22. At the same time, discharge port 30e and oil
The pressure port 30b moves to the right of the left land of the spool 31
The hydraulic passage 61a and the hydraulic release passage 66
Communicate. For this reason, the hydraulic pressure in the retard hydraulic chamber 32 is released.
Is done. As a result, the hydraulic piston 17 is
90 (see FIG. 2), the camshaft is pushed to the right.
5 rotates, and the sprocket 13a
And advance relatively. As shown in FIG. 3B, the spool 31
When in the center, the discharge port 30 of the hydraulic port 30b
e and the suction port 30d of the hydraulic port 30c.
Communication is provided by the lands on the left and right sides of the spool 31
Is cut off. For this reason, each hydraulic chamber on the advance side and retard side
If there is no leakage of hydraulic oil from 22, 32,
The position of the button 17 is kept as it is. Therefore,
Rotation phase difference between the unit 13a and the cam shaft 5,
Imming does not change. As shown in FIG. 3C, the spool 31
Under the stop of generation of electromagnetic force from the linear solenoid 64
It is urged by the coil spring 31a and slides to the left.
Then, the suction port 30b and the hydraulic port 30d
Supply by the left movement of the left land of the
The passage 65 and the hydraulic passage 61a are communicated. For this reason,
The hydraulic pressure from the oil pump 29 is sent to the retard hydraulic chamber 32 by pressure.
It is. On the other hand, the discharge port 30f and the hydraulic port 30c
Is communicated by the left movement of the right land of the spool 31 and the oil
The pressure passage 60 communicates with the hydraulic pressure release passage 66. others
Accordingly, the hydraulic pressure in the advance hydraulic pressure chamber 22 is released. By this
Then, the hydraulic piston 17 is pushed to the left in the annular space 90.
The cam shaft 5 rotates in the opposite direction to the above,
The rocket 13a, that is, the retard angle relative to the crankshaft 2
I do. FIGS. 3 (a), 3 (b) and 3 (c)
Port 30b and port 30e (or port 30
d) and the port 30c and port 30d
(Or port 30f), the spool 31
Each port of each land on the left and right sides due to the right (or left) movement of the
Is controlled by the degree of opening with respect to the gates 30b and 30c. Figure
4 is the inside of the spool valve 30 under certain operating conditions of the internal combustion engine 1.
Of the spool 31 (hereinafter referred to as the spool position).
) And the actual valve timing change speed
FIG. In this characteristic diagram, the actual valve timing
The area where the change speed is positive corresponds to the advance side area, while the actual
The region where the change timing of the lube timing is negative corresponds to the retard side region.
You. The spool position on the horizontal axis in this characteristic diagram is
It is proportional to the solenoid current. In this characteristic diagram, each symbol (a),
(B) and (c) are the spurs of FIGS. 3 (a), (b) and (c).
Spool position corresponding to each position of
You. Actual valve timing as shown by the symbol (b)
The spool position that does not change depends on the hydraulic chamber, hydraulic piping,
Hydraulic oil leaking from each part of the oil valve 31 and the oil pump 29
There is only one point that is balanced with the amount of hydraulic oil pumped from the factory. Sa
In addition, this point is due to the hydraulic oil discharge depending on the internal combustion engine speed and temperature.
Due to fluctuations in the output pressure, the characteristics change as shown in FIG.
It always fluctuates. Also, the winding of the linear solenoid 64
Resistance and product variations such as the dimensions of the spool 31
Thus, this point and the manner of changing the characteristics are different for each product. This
The solenoid current at the point where the actual advance angle of
Called holding current. The valve timing is set based on the holding current.
To advance the angle, increase the solenoid current.
If you want to make the angle, reduce the solenoid current,
The phase difference adjusting device 40 can be controlled. Such a place
If the actual valve timing does not change as described above,
The valve position changes, so the valve timing is precisely
Learning the holding current sequentially for stable and stable control
It turns out that it is necessary. In all products, valve timing
To guarantee use up to the maximum speed of
Id current can flow from Imin to Imax in FIG.
Need to be done. Where Imin and Imax
Indicates that the valve timing change speed is saturated as shown in FIG.
It corresponds to the value when summing, respectively. FIG.
Microcomputer 48, current control circuit 49, phase
The function corresponding to the difference adjustment device 40 and other various elements is functional.
FIG. The target valve timing calculation section 100 calculates
Air volume sensor, water temperature sensor, throttle opening sensor, etc.
Target target based on the internal combustion engine operating conditions detected from the seed signal.
Calculate the lube timing. Actual valve timing calculator
101 is a crank position sensor 42 and a cam shaft position sensor.
The actual valve timing is calculated based on the signal from the sensor 44.
You. The current calculator 102 calculates the target valve timing
, Actual valve timing, and holding from the learning unit 103
Energizes the linear solenoid 64 based on the current learning value
Target current value is calculated. The learning unit 103
Learning the holding current based on the
You. The guard setting section 104 includes a current calculating section 102
Whether the target current value calculated in step is within a predetermined range
If the current is not within the range, set the target current
To the upper and lower limits. The predetermined range is determined by the learning unit 103.
It is set based on these holding currents. Feedback control
The unit 105 controls the linear solenoid 64 based on the target current value.
Feedback control of the current to the
Activate FIG. 7 is a graph showing the target current calculated by the current calculator 102.
It is a flowchart for value calculation. Step S11
0, the target valve timing r and the actual valve timing
The control deviation e = r−y is calculated from the length y. Next step
In step S111, the PD control calculation is performed based on the control deviation e.
By doing so, the feedback current If becomes
Required. ## EQU1 ## If = Kp.times.e + Kd.times.de / dt In the equation (1), codes Kp and Kd are respectively
Represents a constant. In step S112, the target current Id is
Calculated from the feedback current If and the holding current Ih by the following equation.
Will be issued. Id = If + Ih Next, the holding current learning in the learning section 103 will be described.
I do. FIG. 8 is a diagram illustrating the holding current learning in the learning unit 103.
It is a flowchart for the following. In step S121
Thus, it is determined whether the actual valve timing is constant. Real
If the valve timing is not constant, step S1
21 is NO, and learning is performed in step S124.
The counter is reset to T = 0, and the arithmetic processing ends.
You. If the actual valve timing is constant,
YES is determined in Step S121, and Step S12 is performed.
In 2, the learning counter value T has passed Xsec or more.
Is determined. The value T of the learning counter is Xsec
If not, N is determined in step S122.
It is determined to be O, and the arithmetic processing is terminated as it is. Learning power
If the counter value T has exceeded Xsec,
YES is determined in Step S122, and Step S12 is determined.
In 3, the learning of the holding current is performed with Ih = Id.
After that, in step S124, the learning counter is set to T = 0.
Is reset, and the arithmetic processing ends. FIG. 9 shows that the holding current has not been correctly learned.
Control in the right state, and learn the holding current correctly at point A in the figure.
The experimental results when learning are shown. Hold current is learned correctly
During the period during which the current is not coming, the learning holding current Ihg and the true holding current
This is a period in which Ihrs do not match. At this time,
Actual valve timing y is steady with respect to lube timing r
State has a control deviation e. The feedback at this time
The current is de / dt = 0 because of the steady state.
f = Kp × e. The target current is Id = If + Ihg
= Kp × e + Ihg, but the actual valve timing varies.
From the fact that Id = Ihr.
Call Id is calculated in the microcomputer 48.
It can be detected because it is a value that has been set. Because of this,
In this state, by setting the holding current Ihg = Id,
The holding current can be learned. In the figure, hold at point A
By learning the current correctly, the subsequent control deviation e becomes zero.
Has converged to. Next, the guard in the guard setting unit 104
The setting method of will be described. FIG. 10 shows the holding current Ih
And the upper and lower limit values Imax1 and Imi of the guard width to be set.
It is a characteristic view showing the relationship with n1. Spout of holding current Ih
To open the spool valve 30 fully from the
The range of change in the solenoid current is determined by the spool valve 30 as a product.
In consideration of variation, ΔImax is required on the advanced side
Also, ΔImin is required on the retard side. Therefore, the upper limit value of the guard width is set to Imax1 =
Ih + ΔImax, and the lower limit of the guard width is Im.
If in1 = Ih-ΔImin, the spool valve 30 is
Can be driven to full open on the advance side and retard side
You. However, each ΔImax and ΔImin are as described above.
It is determined based on the holding current Ih. Because of this, holding
It does not use the current Ih as a reference, and takes into account the variation of all products.
ΔImax and ΔImin are both narrower than
You. FIG. 11 shows the processing in the guard setting unit 104.
FIG. In step S130, the eye
Target current Id is larger than guard upper limit value Ih + ΔImax
Is determined. The target current Id is equal to the guard upper limit value Ih.
If it is larger than + ΔImax, the process proceeds to step S130.
Is determined to be YES, and in the next step S133,
The target current Id = Ih + ΔImax is set, and the
Processing is terminated. The target current Id is equal to the guard upper limit value Ih + ΔIm
If not larger than ax, N is determined in step S130.
O, and in the next step S131, the target current Id
Is smaller than guard lower limit value Ih-ΔImin.
Is determined. The target current Id is equal to the guard lower limit value Ih-ΔImi.
If it is smaller than n, it is determined YES in step S131.
In the next step S132, the target current Id = I
h−ΔImin is set, and the calculation process is terminated. Eye
The target current Id is smaller than the guard lower limit value Ih-ΔImin
If not, it is determined NO in step S131, and the
The process ends. As described above, the spur of the holding current Ih
The spool valve 30 from the position of the
The range of change in the solenoid current is
In consideration of the fluctuation, the holding current Ih
Requires ΔImax while ΔImin on the retard side
I need. Based on this, the upper limit of the guard width is set to Ima
x1 = Ih + ΔImax, and the lower limit of the guard width
Is set to Imin1 = Ih-ΔImin. As a result, the product variation of the spool valve 30
Control of the spool valve solenoid regardless of the key
Spool valve with guard width for signal not too short or too short
Can be maximized. Therefore, large valve timing
When the spool valve 30 is to be changed sharply, the spool valve 30 is advanced and retarded.
Drive to full open on the
Regardless of the response delay to the applied voltage of the current,
Valve timing can be adjusted with good responsiveness. In other words, the characteristics of the spool valve for each product
The combined solenoid current, that is, the control signal to the solenoid 64
The guard width of the signal value has upper and lower limits as described above
By doing so, the width can be reduced, and as a result, the sp
Minimizes the effect of solenoid valve response delay
Can be obtained. Also, the guard width of the solenoid current
Upper and lower limits may cause the spool valve to be fully open, as described above.
Value, the response speed of valve timing adjustment is impaired.
There is no problem. Next, the guard setting unit 104 of this embodiment is used.
Valve timing adjustment device and guard setting
Valve timing adjustment device when not using the part 104
By comparing each test result with
Will be described. In both tests, the spool valve 30 and
Then, the upper limit product of FIG. 5 was adopted. Each test result is
Valve timing r is suddenly retarded at point A and point B
And the actual valve timing at this time
Observing the change due to feedback control of y
You. FIG. 12 does not use the guard setting unit 104.
The test results are shown below. The target current value
The upper and lower limits of the gate width are set for all products in FIG.
This guarantees the full opening of the spool valve.
And the lower limit value Imin. At the time of sharp retard at point A, target
The current Id reaches the lower limit guard value Imin. Such a place
The solenoid current to the solenoid 64 (hereinafter, the solenoid current
The current Id is referred to as the target current Id.
Is controlled. At this time, the spool valve
It becomes fully open in the passage. Therefore, the valve timing adjustment device
The position is retarded at the highest speed. When the vehicle has turned to a sharp advance at point B, the target current Id
Is the upper limit guard value Imax, and the solenoid current Is
Is controlled to aim at the target current Id. But,
Held at point C because the change width of solenoid current Is is large
It takes a considerable time to reach the current Ih.
Therefore, during that time, the actual valve timing y continues to retard.
I will. As a result, the actual valve timing y
It will be delayed to reach the timing r. Note that the change width of the target current Id becomes smaller.
The constants Kp and Kd in the current calculator 102 are reduced to small values.
There is a setting method, but when the control deviation becomes small,
The feedback current If becomes too small and the valve tie
The timing of the change in timing suddenly drops and the actual valve timing
This slows down the convergence of the
Method should be avoided. FIG. 13 shows that the guard setting unit 104 is used.
These are the test results. Guard width of target current value at this time
The upper and lower limits are based on the holding current as shown in FIG.
The upper limit value Imax1 and the lower limit value Imi
n1. At the time of a sharp retard at point A, the target current Id is
Limit value Imin1 only, so
The change in the gate current Is is slightly slower than that in FIG. I
However, when the vehicle turns to a sharp advance at the point B, the solenoid current Is
The time until the point C1 reaches the holding current Ih is as shown in FIG.
Is shortened compared to Therefore, the actual valve timing y
The amount of retard can prevent the control deviation from expanding, and
The target valve timing r can be reached quickly. Note that the holding current Ih is replaced with Imin.
Is large and the holding current I
Both Imin and Imax are far apart from h
In this case, substantially the same operation and effect as above can be secured.
You. Further, in the above embodiment, the intake valve of the internal combustion engine 1
Timing adjustment device for adjusting the opening / closing timing of the valve
Although an example in which the present invention is applied has been described,
The exhaust valve or both the intake valve and the exhaust valve of the internal combustion engine 1
Timing adjustment device for adjusting the opening / closing timing of the valve
The present invention may be applied to the present invention. In implementing the present invention, the above-described embodiment
In FIG. 8, as shown in FIG.
Becomes constant and the value T of the learning counter becomes Xsec or more.
When the holding current is learned as Ih = Id when
Instead of this, the following learning method was used instead.
May be employed. That is, the hydraulic piston 17
Linear solenoid corresponding to the operating state in which
Control signal corresponding to the target current to
Linear motion corresponding to the operating state in which the
A control signal corresponding to the target current to the solenoid 64, or
Means that the hydraulic piston 17 is held in its actual position
The control signal corresponding to the state may be learned. In the embodiment described above, the phase difference
The adjusting device has an advance hydraulic chamber and a retard hydraulic chamber.
The valve timing is adjusted by adjusting the hydraulic pressure supply to both chambers.
Control valve using a structure that advances or retards
Supply, hold and discharge hydraulic pressure to the advance hydraulic chamber
The mode can be switched to
At the same time to discharge, hold, and supply hydraulic pressure to the retard side hydraulic chamber.
3 mode, and the holding mode is almost
That the spool valve 30 having a configuration given by the flow value is used.
From the control signal that keeps the valve timing at a constant value
Learn the value and set the guard around the learned value
Guard width and maximum retard opening on the advance side from the width
And set the control signal value to this value.
It is restricted within the guard width. However, in the above configuration
Instead, a configuration in which the holding mode is obtained in a predetermined current value range is used.
If a control valve is used, for example, the valve timing
Control signal value that begins to change to the advance side or the retard side.
Learning, and using the learning value as a reference, either advanced or retarded
In consideration of the current value range in which the above holding mode can be obtained,
Guard value to be the maximum opening on the advance side and maximum opening on the retard side
A guard value may be set. In addition, the advance side hydraulic chamber
Advance side to switch to three modes of supply, hold and discharge of hydraulic pressure
Control valve and discharge, hold and supply hydraulic pressure to the retard hydraulic chamber
Configuration using two retard control valves that switch to three modes
In this case, the advance control valve and the retard control valve
The learning value is obtained independently for each of
May be set. Further, in the above embodiment, in the arithmetic processing unit,
Learn control signal values that can be easily known and
Although the signal value was limited based on the guard, the current of the solenoid
Value and feedback control the solenoid current value.
Current control circuit 49 to microcomputer 48
The current value is input, and this current value is learned and learned.
Set a guard based on the learning current value to limit the control signal,
A configuration that substantially limits the current value may be adopted. further,
In the above embodiment, the valve timing is controlled by feedback.
Control the valve timing feedback loop with a microphone
The current value is feedback controlled by a computer.
The current value feedback group
Is configured by an analog circuit using
Back loop is also digital processing by microcomputer.
It may be reasonable. The present invention is not limited to an internal combustion engine for an automobile.
It can also be applied to motorcycle or marine internal combustion engines.
Phase difference adjusting device in the rotation transmission path between the rank shaft and cam shaft
The overhead cam type internal combustion engine
Not limited to this, it can be applied to overhead valve type internal combustion engines, etc.
Wear. In addition, each of the flowcharts in the above-described embodiment
Each step is a hardware logic as a function execution means.
It may be realized by a hardware configuration.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic overall configuration diagram showing one embodiment of the present invention applied to a double overhead cam type internal combustion engine. FIG. 2 is an enlarged sectional view of the phase difference adjusting device shown in FIG. FIG. 3 is an operation explanatory view of the spool valve shown in FIG. 2; FIG. 4 is a characteristic diagram showing a relationship between a spool position and a valve timing change speed. FIG. 5 shows a relationship between a solenoid current and a valve timing change speed (dy / d) in a relation between an upper limit product and a lower limit product variation.
FIG. 6 is a characteristic diagram showing a relationship with t). 6 is a functional block diagram showing the configuration of the embodiment shown in FIG. 1; FIG. 7 is a flowchart showing the content of a calculation in a current calculation unit shown in FIG. 6; FIG. 8 is a flow chart showing a holding current learning content in a learning unit shown in FIG. 6; FIG. 9 is a characteristic diagram showing an experimental result regarding the holding current learning process. FIG. 10 is a characteristic diagram showing a current guard value corresponding to a maximum opening of a spool valve in a relationship between a solenoid current and a valve timing change speed. FIG. 11 is a flowchart for setting a guard. FIG. 12 is a time chart of a test result representing a change in valve timing when there is no guard of a solenoid current. FIG. 13 is a time chart of a test result showing a change in valve timing when there is a guard of a solenoid current. [Description of Signs] 1 ... internal combustion engine, 2 ... crankshaft, 3 ... timing chain, 4 ... exhaust camshaft, 5 ... intake camshaft, 13a, 13b ... Sprocket, 29 ・
..Hydraulic pump, 30 ... Spool valve, 40 ... Phase difference adjusting device, 48 ... Microcomputer, 49
... current control circuit, 64 ... solenoid.

Claims (1)

(57) Claims: 1. A phase difference adjusting device for adjusting a phase difference between a crankshaft and a camshaft of an internal combustion engine according to oil pressure, and a solenoid. A control valve for controlling a hydraulic pressure to the phase difference adjusting device by an opening degree according to a current; a current adjusting means for adjusting a current to the solenoid; and an intake based on a relative rotation angle between the crankshaft and the camshaft. Actual valve timing detection means for detecting actual valve timing of at least one of a valve and an exhaust valve; target valve timing setting means for setting at least one target valve timing of an intake valve and an exhaust valve in accordance with an operation state of the internal combustion engine Outputting a control signal to the current adjusting means for performing feedback control so that the actual valve timing coincides with the valve target timing. A signal output unit, learning a control signal to the current adjustment unit or a current to the solenoid based on the actual valve timing to set the phase difference adjustment device to a predetermined phase difference adjustment state, and performing the control based on the learned value. Learning means for correcting the control signal output from the signal output means, and a guard having a width that maximizes the opening of the control valve is set based on the learning value of the learning means, and the control signal output means A valve means for limiting the output control signal to the inside of the guard.