JP2003269644A - Electromagnetic force control device for electromagnetically driven valve - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To highly precisely control a solenoid driven valve by taking account of an individual difference and a time course of a spring of a solenoid valve. <P>SOLUTION: Until it is determined ('YES' in S212) that a valve closure retaining state of the solenoid driven valve is nearly broken, a value of a valve closure state retaining current ihup is lowered for every time the valve is turned into a valve closure retaining state (S208). A spring constant K is renewed based on the valve closure state retaining current ihup after the lowering (S218). This constitution allows a more appropriate spring constant to be newly set so as to improve the accuracy of an attraction current and a retaining current to be found based on the spring constant K, and highly precise control of the solenoid valve, taking account of the individual difference and the time course of the spring is made. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic force control device for an electromagnetically driven valve.

[0002]

2. Description of the Related Art A control device has been proposed in which an electromagnetically driven valve is used for an intake valve and an exhaust valve of an internal combustion engine (Japanese Patent Laid-Open Nos. 2000-234534 and 2001-2).
21022, JP 2001-221360). In these control devices, the speed of the mover or the valve is adjusted by adjusting the target current amount, target position, and motion characteristic target value for the electromagnet in order to reduce collision noise and response. Further, in these disclosed technologies, the electromagnetically driven valve is modeled as a spring-mass vibration system, and the current value output to the electromagnet is calculated based on a physical model in which the mass, viscosity coefficient, and spring constant of the moving part are used as model parameters. It is also proposed to set.

[0003]

The spring constant is taken into consideration in the control of the electromagnetically driven valve not only in the case of modeling as described above, but conventionally, the spring constant at the time of designing or manufacturing the electromagnetically driven valve is considered. It is assumed that does not change.

However, since springs incorporated in electromagnetically driven valves have individual differences, the spring constants are not always the same in all electromagnetically driven valves. Further, even if there is no individual difference in manufacturing and the spring constant is the same, the spring constant may change over time.

Therefore, as in the prior art, if the electromagnetic force is controlled such that all electromagnetically driven valves have the same spring constant or the spring constant does not change over time, the target current amount and target position with respect to the electromagnet are controlled. , It becomes impossible to accurately obtain parameters such as target values of motion characteristics. For this reason, control accuracy may be deteriorated, and collision noise reduction and responsiveness may not be sufficiently achieved. This may cause not only the spring constant but also an individual difference in the offset amount and a change over time when an offset is applied to the spring.

An object of the present invention is to enable highly accurate electromagnetically driven valve control in consideration of individual differences of springs and changes over time.

[0007]

[Means for Solving the Problems] Means for achieving the above-mentioned objects and their effects will be described below. The electromagnetic force control device for an electromagnetically driven valve according to claim 1 is an electromagnetic force control device for controlling the electromagnetic force of an electromagnetically driven valve driven by the cooperation of a spring force and an electromagnetic force, and is based on an output of a drive current. Opening / closing drive means for adjusting the electromagnetic force to drive the electromagnetically driven valve to be opened or closed, and opening / closing for adjusting the electromagnetic force by the output of the holding current to hold the electromagnetically driven valve in the open or closed state. It is characterized by comprising state holding means and correction means for correcting the drive current value of the opening / closing drive means based on the holding state maintenance information of the electromagnetically driven valve corresponding to the change of the holding current value.

When the holding current value output from the opening / closing state holding means is changed to the holding state of the electromagnetically driven valve, that is, when the holding state begins to become impossible, the electromagnetic force generated by the holding current is held. Turns out to be unsuitable for. That is, it is found that the balance between the electromagnetic force for holding the electromagnetically driven valve in the open or closed state against the spring force and the spring force has begun to collapse.
If the holding state is maintained even if the holding current value is changed, it indicates that the electromagnetic force generated by the changed holding current is not out of balance with the spring force. ing. Therefore, the degree of spring constant is reflected in the holding state maintenance information of the electromagnetically driven valve with respect to the change of the holding current value.

Therefore, if the correction means corrects the drive current value output by the opening / closing drive means on the basis of the holding state maintaining information, the drive current for driving the electromagnetically driven valve will be subject to individual differences in springs and changes over time. Adjustments that take into consideration can be added. In this way, it is possible to perform highly accurate electromagnetically driven valve control in consideration of individual differences of springs and changes over time.

An electromagnetic force control device for an electromagnetically driven valve according to a second aspect of the present invention is an electromagnetic force control device for controlling an electromagnetic force of an electromagnetically driven valve driven by cooperation of a spring force and an electromagnetic force. The opening / closing drive means for adjusting the electromagnetic force to output the electromagnetically driven valve so that the electromagnetically driven valve is opened or closed, and the output of the holding current to adjust the electromagnetic force to open or close the electromagnetically driven valve. Modification for holding the opening / closing state holding means and the driving current value of the opening / closing driving means and the holding current value of the opening / closing state holding means based on holding state maintenance information of the electromagnetically driven valve corresponding to the change of the holding current value And means.

In this case, the correction means corrects both the drive current value output by the open / close drive means and the hold current value output by the open / close state holding means based on the hold state maintenance information. For this reason, it is possible to control the electromagnetically driven valve with higher accuracy in consideration of individual differences of springs and changes over time.

According to a third aspect of the present invention, there is provided an electromagnetic force control device for an electromagnetically driven valve, wherein the holding current value is changed and the holding state of the electromagnetically driven valve corresponding to the change cannot be maintained. The holding state maintenance information detecting means for detecting the holding current value up to the above as the holding state maintenance information is provided.

The holding state maintaining information can be detected by the holding state maintaining information detecting means as a holding current value until the holding state of the electromagnetically driven valve changes. The correction means corrects the current value based on the holding current value up to the change in the holding state, thereby making it possible to perform highly accurate electromagnetically driven valve control in consideration of individual differences of springs and changes over time.

Here, the "holding current value until the holding state of the electromagnetically driven valve cannot be maintained" is the holding current value changed until the holding state of the electromagnetically driven valve cannot be maintained as described above. If so, any holding current value is applicable. Therefore, one, a plurality, or all of these holding current values can be grasped as holding state maintenance information.

According to a fourth aspect of the present invention, in the electromagnetic force control device for an electromagnetically driven valve according to the third aspect, the holding state maintaining information detecting means detects the holding state maintaining information when the electromagnetically driven valve is used, and the correcting means. Is characterized in that the current value is corrected according to the holding state maintenance information obtained by the holding state maintenance information detecting means when the electromagnetically driven valve is used.

As described above, when the electromagnetically driven valve is used, the holding state maintaining information detecting means and the correcting means function to control the spring even when the spring changes with time or when the spring is replaced. The appropriate current value of can be output immediately. For this reason, it becomes possible to perform highly accurate electromagnetically driven valve control that can consider individual differences of springs and changes over time in real time.

According to a fifth aspect of the present invention, in the electromagnetic force control device for an electromagnetically driven valve according to the third or fourth aspect, in the holding state maintaining information detecting means, the open / close state holding means holds the electromagnetically driven valve in an open or closed state. The holding current value is changed by decreasing the holding current value at the time of carrying out, and the holding current value until the holding state of the electromagnetically driven valve cannot be maintained is obtained as the holding state maintaining information.

More specifically, the holding state maintaining information detecting means changes the holding current value for obtaining the holding state maintaining information by reducing the holding current value. As a result, the holding current value up to the lower limit can be obtained as the holding state maintenance information, and this holding state maintenance information can be used to correct the current value.

According to a sixth aspect of the present invention, in the electromagnetic force control device for an electromagnetically driven valve according to the fifth aspect, the holding state maintaining information detecting means changes the holding state of the electromagnetically driven valve as the holding current value decreases. When it occurs, the holding current value is immediately increased to maintain the holding state of the electromagnetically driven valve.

As described above, if the holding state maintaining information detecting means decreases the holding current value and the holding state of the electromagnetically driven valve changes, the holding current value immediately before reflects the degree of the spring constant most accurately. The held state maintenance information can be detected. However, if it is left as it is, the holding state may be completely destroyed. Therefore, the holding state maintaining information detecting means immediately increases the holding current value to maintain the holding state of the electromagnetically driven valve when the holding state of the electromagnetically driven valve changes. As a result, even if the holding state maintenance information detecting means detects the holding state maintenance information when the electromagnetically driven valve is used, there is no problem in the operation of the electromagnetically driven valve.

According to a seventh aspect of the present invention, in the electromagnetic force control device for an electromagnetically driven valve according to the sixth aspect, the holding state maintaining information detecting means is configured to maintain the holding state of the electromagnetically driven valve by increasing the holding current value. The holding current value is returned to the value before the previous holding current value was decreased.

When the balance between the electromagnetic force and the spring force is lost due to the reduction of the holding current value by the holding state maintenance information detecting means, the holding current value set to be reduced at this time is not an appropriate current value and The holding current value of is a more appropriate current value. Therefore, the holding state maintaining information detecting means returns the holding current value to the value before the immediately preceding holding current value decrease after the holding state of the electromagnetically driven valve is maintained by the increase of the holding current value. This allows the holding current value to be immediately set to an appropriate level. Therefore, the open / closed state holding means does not supply useless electric energy,
The holding state can be reliably maintained.

According to an eighth aspect of the present invention, there is provided an electromagnetic force control device for an electromagnetically driven valve according to any one of the third to seventh aspects, wherein the holding state maintaining information detecting means opens or closes the electromagnetically driven valve by the opening / closing state holding means. When it comes to holding in the state,
It is characterized in that the holding current value changed last time is further changed.

If the holding state maintaining information detecting means does not change the holding state once even if the holding current value is changed, the holding current value changed last time is further changed. By repeating this, the holding state change can be finally caused. As described above, the holding state maintenance information detection means can obtain more appropriate holding state maintenance information by changing the holding current value stepwise, and also detects the holding state maintenance information when the electromagnetically driven valve is used. However, it does not destabilize the operation of the electromagnetically driven valve.

Even after the holding state has changed,
When the holding state maintenance information detecting means changes the holding current value, appropriate holding state maintenance information can be obtained even if the spring changes with time or the spring is replaced thereafter.

According to a ninth aspect of the present invention, there is provided an electromagnetic force control device for an electromagnetically driven valve according to any one of the first to eighth aspects, wherein the correcting means applies the spring force when the electromagnetically driven valve is held open or closed. Obtaining the spring constant equivalent value of the electromagnetically driven valve based on the displacement amount of the spring being generated and the holding state maintenance information,
The current value is corrected according to the spring constant equivalent value.

When the holding state of the electromagnetically driven valve changes due to the change of the holding current value, that is, when the holding state starts to become impossible due to the change of the holding electromagnetic force, the balance with the spring force begins to be lost. . Further, when the holding state is maintained even if the holding electromagnetic force is changed, it indicates that the holding electromagnetic force after the change is not out of balance with the spring force. The degree of spring constant is reflected in the holding state maintenance information of the electromagnetically driven valve for such a change in the holding current value. Therefore, it is possible to obtain the spring constant equivalent value of the spring that is generating the spring force, based on the holding state maintenance information and the spring displacement amount.

As described above, the correction means can easily obtain the spring constant equivalent value of the spring which is still incorporated in the electromagnetically driven valve. In this way, even if there are individual differences or changes over time in the springs incorporated in the electromagnetically driven valve, the actual spring constant can be easily reflected in the correction of the current value. Highly accurate electromagnetically driven valve control that takes into account changes is possible.

According to a tenth aspect of the present invention, in the electromagnetic force control device for an electromagnetically driven valve, the electromagnetically driven valve according to the ninth aspect is the first
Either the movable element driven by the cooperation of the spring force of the spring and the electromagnetic force and the first spring are closed or opened by the spring force of the second spring on the assumption that the spring constant is the same. A valve element that is urged in the direction, and the opening and closing operation is performed by moving the valve element that is in contact with the movable element by driving the movable element, and either full closing or full opening of the valve element is performed. Is an electromagnetically driven valve in which the mover and the valve body are in a non-contact state, and the correction means is a closed side or an open side of the valve body in which the mover and the valve body are not in a non-contact state. On the other hand, based on the displacement amount of the combined spring of the first spring and the second spring and the holding state maintaining information, the spring constant equivalent value of the combined spring of the first spring and the second spring is obtained. , The synthetic spring constant equivalent value and the mover and the valve body are not Offset in the first spring based on the displacement amount of the combined spring of the first spring and the second spring and the holding state maintenance information on the other of the closed side and the open side of the valve body that is in a touch state An amount is obtained, and the current value is corrected according to the offset amount.

In controlling an electromagnetically driven valve in which two springs are provided with an offset as described above, it may be necessary to consider individual differences in the offset amount and changes over time. In particular, when the mover and the valve body are in non-contact with each other when fully closed or fully opened, the driving of the mover is controlled by the relationship between the spring constant of one spring and the offset amount for high accuracy. Various controls can be realized.

Therefore, in the invention described in claim 10,
The first spring based on the displacement amount of the combined spring of the first spring and the second spring and the holding state maintenance information on one of the closed side and the open side of the valve body in which the mover and the valve body are not in a non-contact state. And a spring constant equivalent value of the composite of the second spring is obtained. First spring and second
Since it is assumed that the spring has the same spring constant, the spring constant equivalent value of the first spring can be obtained as a value of 1/2 of the combined spring constant equivalent value.

Then, on the other of the closed side and the open side of the valve body in which the mover and the valve body are in a non-contact state, the holding state maintenance information can be obtained only for the first spring, and the mover for only the first spring is obtained. The holding electromagnetic force until the holding state of is changed is known.

The spring force of the first spring in the holding state where the mover and the valve body are not in contact with each other is the spring constant equivalent value of the first spring and the combined spring of the first spring and the second spring. It is calculated from the displacement amount and the offset amount of the first spring. Then, by making the spring force of the first spring equal to the holding electromagnetic force appearing in the holding state maintenance information at this time, the correction means can obtain the offset amount of the first spring from this relationship.

In this way, the offset amount of the spring that is still incorporated in the electromagnetically driven valve can be easily obtained.
Even if the offset amount of the spring incorporated in the electromagnetically driven valve varies from individual to individual or changes over time, it can be reflected in the correction of the current value. Therefore, it is possible to perform highly accurate electromagnetically driven valve control in consideration of individual differences of springs and changes over time.

[0035]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] FIG. 1 is a schematic configuration diagram of an electromagnetically driven valve 2 to which the above-described invention is applied. Here, the electromagnetically driven valve 2 is used as an intake valve and an exhaust valve of an internal combustion engine mounted on a vehicle. Since the intake valve and the exhaust valve have the same basic configuration, the electromagnetically driven valve 2 in FIG. 1 will be described as an intake valve.

The electromagnetically driven valve 2 includes a valve section 4 and an electromagnetically driven section 6.
And a displacement sensor unit 7 (corresponding to displacement amount detecting means). The valve section 4 has a poppet type valve body 8 and is supported by a cylinder head 10 by a valve shaft 8a so as to be capable of reciprocating. An intake port 14 communicating with the combustion chamber 12 is formed in the cylinder head 10.
A valve seat 16 on which the valve body 8 is seated is formed at the opening of the combustion chamber 12 on the side of the combustion chamber 12.

A lower retainer 18 is provided on one end side of the valve shaft 8a. Lower retainer 18 and cylinder head 1
A lower spring 20 is arranged between 0 and 0 in a compressed state. The lower spring 20 urges the entire valve body 8 in the valve closing direction (upward direction in FIG. 1).

The electromagnetic drive unit 6 includes an armature 22 (corresponding to a mover), a lower core 24 and an upper core 26. The armature 22, the lower core 24, and the upper core 26 are made of a high magnetic permeability material. Disk-shaped armature 2
An armature shaft 22a is provided at the center of 2 to slidably pass through the center holes of the lower core 24 and the upper core 26. An upper retainer 28 is fixed to the armature shaft 22a penetrating the upper core 26, and an upper spring 30 is arranged in a compressed state between the upper retainer 28 and the casing 6a of the electromagnetic drive unit 6. This upper spring 30 causes the armature shaft 22a to move toward the valve body 8 (downward in FIG. 1).
Is urged by.

Therefore, when the lower end 22b of the armature shaft 22a and the upper end 8b of the valve shaft 8a are in contact with each other and the lower core 24 and the upper core 26 are not excited, the spring force of the lower spring 20 and the upper spring 30 is The armature shaft 22a and the valve shaft 8a stop at the equilibrium position. The lower spring 20 and the upper spring 30 use the same spring. The armature 22 is set to be located at the center between the lower core 24 and the upper core 26 at the equilibrium position of the spring force.
FIG. 1 shows this equilibrium state. This equilibrium position is set as the displacement amount x = 0 (mm) of the armature 22, and the lower core 24
The side is minus and the upper core 26 side is plus.

The displacement sensor unit 7 is attached to the casing 6a of the electromagnetic drive unit 6, and detects the displacement amount x of the armature 22 by detecting the insertion amount of the armature shaft 22a inserted through the casing 6a. A displacement signal representing the displacement amount x is sent to the electronic control unit (ECU) 32.
Is output to.

Inside the lower core 24, the lower coil 24a
However, the upper coil 26a is arranged inside the upper core 26, and an electromagnetic force for attracting the armature 22 can be generated in the lower core 24 and the upper core 26 by the exciting current output from the ECU 32, respectively. When an exciting current is supplied to the lower coil 24a and the lower core 24 attracts the armature 22, the armature 22 applies the spring force of the upper spring 30 and the electromagnetic force of the lower core 24 to the valve body 8 side. As a result, the valve body 8 moves in the direction of further separating from the valve seat 16 against the spring force of the lower spring 20, and the opening degree as an intake valve is increased. The intake valve has the maximum opening when the armature 22 is in contact with the lower core 24.

When an exciting current is supplied to the upper coil 26a and the upper core 26 attracts the armature 22, the armature 22 moves toward the upper core 26 side against the spring force of the upper spring 30. As a result, the valve body 8 is moved in the direction of approaching the valve seat 16 by the spring force of the lower spring 20, and the opening degree of the intake valve is reduced. When the armature 22 is in contact with the upper core 26, the valve body 8 is already in contact with the valve seat 16 and the intake valve is fully closed.

Therefore, the ECU 32 controls the exciting current to the lower coil 24a and the upper coil 26a in synchronization with the rotation of the internal combustion engine, so that the opening and closing of the intake valve and the opening of the intake valve can be controlled to desired states. The same applies to the exhaust valve.

As shown in FIG. 2A, when the valve is fully opened, the lower end portion 22b of the armature shaft 22a has the valve shaft 8
It remains in contact with the upper end 8b of a. However, FIG.
As shown in (B), when the valve is fully closed, the valve body 8 is seated on the valve seat 16 before the armature 22 contacts the upper core 26, so that the lower end portion 22b of the armature shaft 22a.
Is away from the upper end 8b of the valve shaft 8a. Therefore,
In the final stage of valve closing (movement of distance xg in the figure), the lower spring 20 does not act, and the armature 22 moves upward in the figure against the spring force of the upper spring 30 only by the electromagnetic force.

The ECU 32 is an electronic circuit mainly composed of a microcomputer, and data of the displacement sensor section 7 and sensors 34 including various sensors arranged in the internal combustion engine or other ECU 36 including the internal combustion engine control ECU. Based on the information obtained by communication, the electromagnetically driven valve 2
Drive control.

The valve opening / closing drive control processing executed by the ECU 32 is shown in FIGS. This process is a process executed after the internal combustion engine is started, and is repeatedly executed at an extremely short fixed time period. Although this process is also described for the intake valve, the valve opening / closing drive control process for the exhaust valve is similarly performed on the exhaust valve side.

When this process is started, it is first determined whether or not there is a request to drive the intake valve to close the valve (S100). This determination is made based on whether the intake valve closing drive request is output from the internal combustion engine control ECU 36 side. Here, let us consider a case in which the valve opening request state has occurred until the immediately preceding control cycle, and a valve closing request has occurred in the current control cycle. That is, it is assumed that the electromagnetically driven valve 2 is in the valve open state shown in FIG. Since it is a valve closing request ("YES" in S100), next, the supply of the valve opening state holding current ihlow to the lower coil 24a holding the armature 22 to the lower core 24 by suction is stopped (S102). For example, the lower coil current Ilow is stopped as shown in the timing chart of FIG. 5 (time t0).

It should be noted that the electromagnetic force Femlow for maintaining the valve-opening state generated by the valve-opening state holding current ihlow flowing to the lower coil 24a immediately before the supply is stopped, and the spring force Fslp of the composite spring by the lower spring 20 and the upper spring 30. Has a relationship as shown in the following Expression 1. Incidentally, FIG.
At 2, the upward force is positive.

[0049]

[Formula 1] | Femlow | ≧ Fslp [Equation 1] When the spring constant of the combined spring of the lower spring 20 and the upper spring 30 is Kc in the valve open state of FIG. 2 (A), the spring force is an upward force. Fslp is expressed by the following equation 2.

[0050]

[Formula 2] Fslp = −Kc · x [Equation 2] Here, the lower spring 20 and the upper spring 30 are used.
Since the same spring is used for and, each spring constant is K, and the combined spring constant Kc = 2K.

Further, the valve opening state holding electromagnetic force Femlow (<0), which is a downward force, is expressed as shown in the following expression 3.

[0052]

Femlow = fl (gaplow, ihlow) [Equation 3] Here, the gap gaplow represents the gap between the lower core 24 and the armature 22. fl (gapl
ow, ihlow) is the electromagnetic force Feml for holding the valve open state from the gap gaplow and the valve open state holding current ihlow.
It is a function or map that finds ow. fl (gap
low, ihlow) depends on the design of the magnetic path and coil in the electromagnetically driven valve 2, but the larger the gap gaplow, the smaller the absolute value of the valve opening state holding electromagnetic force Femlow, and the larger the valve opening state holding current ihlow opens the valve. The absolute value of the state holding electromagnetic force Femlow tends to increase.

Accordingly, the valve-opening state holding current ihlow to the lower coil 24a is stopped by the process of step S102, so that the valve-opening state holding electromagnetic force Femlow.
Disappears, and only the spring force Fslp causes the armature 22
And the valve body 8 starts moving upward.

Next, it is judged whether or not the armature 22 has passed the center between the lower core 24 and the upper core 26 (S).
104). Based on the detection by the displacement sensor unit 7, for example, it is determined whether or not the armature 22 has reached the central position (displacement amount x = 0) or the positions before and after this position.

During a period in which the armature 22 does not pass through the center between the lower core 24 and the upper core 26 ("NO" in S104), this process is temporarily terminated. When the armature 22 and the valve body 8 reach the position shown in FIG. 1 or the position before and after this (“YE” in S104).
S ", FIG. 5: time t1), and then it is determined whether or not the armature 22 has contacted the upper core 26 (S106).
Since the armature 22 has just reached the center between the lower core 24 and the upper core 26 or has just reached the center, it is determined to be "NO" in step S106, and the suction current iaup (corresponding to the drive current) is supplied as the upper coil current Iup ( (S108), this process is once terminated. As a result, the armature 22 is attracted by the upper core 26 and approaches the upper core 26 without stopping midway.

As the attracting current iaup, the armature 22 is moved to the upper core based on the valve closing state holding current ihup obtained in step S216 described later or based on the spring constant K obtained in step S218. This value is used because an appropriate value has been calculated for adsorption to the 26. Also, in the latter half of the suction period, as the armature 22 approaches the upper core 26, the suction current iaup is reduced based on the valve closing state holding current ihup and the spring constant K so that the value of the suction current iaup becomes smaller to reduce collision noise. Controlled.

Until the armature 22 contacts the upper core 26 (“NO” in S106), the suction current iaup is continuously output to the upper coil 26a (S108, times t1 to t2).

If the armature 22 contacts the upper core 26 as shown in FIG.
ES ", FIG. 5: time t2), a valve closing state holding current ihup output process (S110) for setting the upper coil current Iup to the valve closing state holding current ihup is executed.
Immediately before the contact between the armature 22 and the upper core 26, the valve body 8 contacts the valve seat 16 and the intake valve is fully closed. Then, thereafter, the lower end portion 22b of the armature shaft 22a moves away from the upper end portion 8b of the valve shaft 8a, the armature 22 moves, and the armature 22 and the upper core 26 come into contact with each other.

FIG. 4 shows the details of the valve closed state holding current ihup output processing. When this process is started, first, it is determined whether or not a condition for reducing the valve closed state holding current ihup is satisfied (S200). The condition for reducing the valve-closing state holding current ihup is that the waiting time has elapsed after the armature 22 abuts the upper core 26, and a change determination of the holding state of the armature 22 due to the reduction of the valve-closing state holding current ihup described later. It is a condition that holds when it is not implemented.

Therefore, the armature 22 is the upper core 2
Immediately after the contact with No. 6, since the waiting time has not elapsed, the condition for reducing the valve closing state holding current ihup is not satisfied (“NO” in S200), and the value of the valve closing state holding current ihup set before is set. As a result, a holding current is output to the upper coil 26a (S210). After that, until the waiting time elapses (“NO” in S200), the constant valve closed state holding current ihup is continuously output to the upper coil 26a (time t2 to t3).

The valve-closing state holding electromagnetic force Femup generated by the valve-closing state holding current ihup flowing to the upper coil 26a and the spring force Fsup of the upper spring 30 have a relationship as shown in the following equation (4).

[0062]

[Formula 4] Femup ≧ | Fsup | | [Equation 4] Since the spring constant of the upper spring 30 is K, the downward spring force Fsup (<0) is given by the following Equation 5:
It is expressed like.

[0063]

Fsup = −K · x−K · xofs [Equation 5] Here, xofs represents the offset amount of the upper spring 30.

Electromagnetic force Fe for holding the valve closed, which is an upward force
Mup is expressed as shown in the following Expression 6.

[0065]

## EQU00006 ## Femup = fu (gapup, ihup) [Equation 6] Here, the gap gapup represents the gap between the upper core 26 and the armature 22. fu (gapu
p, ihup) is a function or a map for obtaining the valve closed state holding electromagnetic force Femup from the gap gapup and the valve closed state holding current ihup. fu (gappup, ih
up) depends on the design of the magnetic path and coil in the electromagnetically driven valve 2, but the absolute value of the electromagnetic force Femup for holding the valve closed state decreases as the gap gapup increases, and the valve closed state holding current increases as the valve holding state holding current ihup increases. The absolute value of the electromagnetic force Femup tends to increase.

When the waiting time has elapsed ("YE" in S200)
S ”), and then it is determined whether the temporary suction execution flag XIp is“ OFF ”(S202). As will be described later, the temporary suction execution flag XIp is used to temporarily maintain the contact state between the armature 22 and the upper core 26 when the holding state of the armature 22 changes due to the reduction of the valve closing state holding current ihup. 26a is a flag that indicates that the amount of current flowing to 26a is increasing. In the initial setting when the internal combustion engine is started, XIp = “OFF” is set.

Initially, XIp = "OFF", so (S
If the answer is "YES" in 202, then it is determined whether or not it is the first process after the armature 22 has contacted the upper core 26 (S204). If it is the first ("YE" in S204
S ”), the current value of the valve closing state holding current ihup is saved as the save current value ihupold (S206). Then, the value of the valve closed state holding current ihup is reduced as in the following Expression 7 (S208).

[0068]

## EQU00007 ## ihup ← ihup-.DELTA.ihup [Equation 7] where .DELTA.ihup is a gradually decreasing value, and the valve closing state holding current i
It is a value for gradually reducing hup step by step.
The gradual decrease value Δihup may be a constant value, and, for example, depending on the value of the valve closing state holding current ihup, the valve closing state holding current ihup
You may set to a fixed ratio of up.

Then, with respect to the upper coil 26a, the valve closing state holding current ihup reduced in step S208.
The holding current is output according to the value of (S210, time t
3) Then, this process is once terminated. That is, after time t3,
As described in the equation 6, the valve closed state maintaining electromagnetic force Femup generated in the upper core 26 becomes small.

In the next control cycle, steps S200 and S
Although “YES” in 202, but it is not the first, it is determined to be “NO” in step S204, and it is determined whether or not the holding state has changed (S212). Here, the change in the holding state indicates a state in which the equation 4 is no longer satisfied due to the decrease in the valve-closing state holding electromagnetic force Femup in step S208, and the armature 22 begins to separate from the upper core 26. This change in the holding state is identified by the detection of the displacement sensor unit 7.

If the holding state has not changed (S2
12 is "NO"), and then it is determined whether or not the waiting time for detecting the change in the holding state has elapsed (S214). If the waiting time has not elapsed (“NO” in S214),
The holding current output (S210) according to the value of the valve closing state holding current ihup reduced this time is continued (time t3 and after).

As illustrated in FIG. 5, when the waiting time elapses (“YES” in S214, time t4) without the change in the holding state being detected (“NO” in S212), as shown in the following equation 8, A process of slightly increasing the valve state holding current ihup is executed (S216).

[0073]

[Equation 8] ihup ← ihup + isup (Equation 8) where isup is an increase correction amount, and isup <Δih
There is an up relationship. The reason why the valve closing state holding current ihup is slightly increased by the increased correction amount isup is that the valve closing state may become unstable if the valve closing state holding current ihup is reduced. That is, when the valve-closing state holding current ihup has fallen close to the lower limit, the holding state may not have changed accidentally during the waiting time (time t3 to t4). The armature 22 may be separated from the upper core 26 during the valve closing period due to some shock thereafter. In order to avoid this unstable state, the valve closing state holding current ihup is slightly increased.

Then, the spring constant K is calculated (S218). Here, the spring constant K is determined in step S216.
The valve-closed state holding electromagnetic force Femup generated by the valve-closed state holding current ihup set by the above is balanced with the spring force Fsup by the upper spring 30 (Fem.
It is calculated as follows assuming that (up = −Fsup).

That is, if "Femup = -Fsup", the relation of the following equation 9 is established from the above equations 5 and 6.

[0076]

## EQU00009 ## fu (gapup, ihup) = K.x + K.xofs [Equation 9] Here, on the left side of Equation 9, the gap gapup = 0,
The valve-closed state holding current ihup is the value set by the above equation 8. Further, the displacement amount x as a composite spring when the armature 22 is in contact with the upper core 26 on the right side x
Is detected by the displacement sensor unit 7. Therefore, assuming that the offset amount xofs is constant, the spring constant K is calculated because the unknown number is only the spring constant K, as shown in the following Expression 10.

[0077]

[Equation 10] K ← fu (gapup, ihup) / (x + xofs) [Equation 10] This value of K is used as a new spring constant of the lower spring 20 and the upper spring 30 in the control of the electromagnetically driven valve 2. . As a result, the suction current iaup when the valve is closed
Also, in the control of the suction current ialow at the time of valve opening and the valve opening state holding current ihlow, which will be described later, the lower spring 2
0 and upper spring 30 are combined spring constant Kc
(= 2K), or depending on the case, upper spring 30
The spring constant (K) can be updated to an appropriate value. Thus
It becomes possible to set more appropriate suction currents iaup, ialow and valve opening state holding current ihlow than before.

It should be noted that instead of the valve closing state holding current ihup set in step S216, the valve closing state holding current ihup reduced in step S208 at the time of this valve closing.
The spring constant K may be calculated from Equation 10 using

Then, the holding current is output to the upper coil 26a in accordance with the value of the valve closing state holding current ihup obtained in step S216 (S210, time t).
4) Then, this process is once terminated.

In the next control cycle, the valve closed state holding current ih
Since the change in the holding state of the armature 22 due to the decrease in up is determined (“NO” in S200), after that (time t4 to t5), step S2 is performed in the current holding period.
With the valve closed state holding current ihup set in FIG.
The closed valve holding state of (B) is maintained.

Returning to the description of FIG. 3, when the intake valve closing period ends and the intake valve opening drive request is output from the internal combustion engine control ECU 36 side (“NO” in S100, time t).
5) Next, the supply of the valve-closed state holding current ihup, which has been supplied to the upper coil 26a, is stopped (S11).
2). As a result, the electromagnetic force Femup for maintaining the valve closed state disappears, and the spring force Fsup of only the upper spring 30 causes the armature 22 to start moving downward.
Then, when the lower end portion 22b of the armature shaft 22a comes into contact with the upper end portion 8b of the valve shaft 8a, the armature 22 and the valve body 8 are both moved downward by the spring force Fslp, which is a parallel combination of the lower spring 20 and the upper spring 30. To move towards.

Next, it is judged whether or not the armature 22 has passed the center between the lower core 24 and the upper core 26 (S).
114). In this determination, similarly to the process of step S104, it is determined whether or not the armature 22 has reached the center position (displacement amount x = 0) or a position before or after this position by the detection by the displacement sensor unit 7.

During a period in which the armature 22 does not pass through the center between the lower core 24 and the upper core 26 ("NO" in S114), this process is temporarily terminated. When the armature 22 and the valve body 8 reach the position shown in FIG. 1 or the position before and after this (“YE” in S114).
S ”, time t6), and then armature 22 is lower core 24.
It is determined whether or not the contact has been made (S116). Since the armature 22 has just arrived at or near the center between the lower core 24 and the upper core 26, step S116.
Then, it is determined to be "NO", the suction current iallow is supplied as the lower coil current Ilow (S118), and the present process is once ended. As a result, the armature 22 is sucked by the lower core 24 and approaches the lower core 24 without stopping midway.

Here, as the attracting current iallow,
An appropriate value for adsorbing the armature 22 to the lower core 24 is calculated based on the valve closing state holding current ihup obtained in step S216 or based on the spring constant K obtained in step S218. Therefore, this value is used. Further, in the latter half of the suction period, as the armature 22 approaches the lower core 24, the value of the suction current ialow becomes smaller to reduce the collision noise, so that the value of the valve closing state holding current ihup and the spring constant K are reduced. Controlled.

While the armature 22 is not in contact with the lower core 24 ("NO" in S116), the lower coil 24
The output of the attracting current ialow to a is continued (S
118).

Then, as shown in FIG. 2A, if the armature 22 contacts the lower core 24 ("YE" in S116).
S ”, time t7), the value of the valve open state holding current ihlow is set as the lower coil current Ilow (S120).
The value of the valve opening state holding current ihlow is the valve closing state holding current ihup obtained in step S216 described above.
Or the spring constant K obtained in step S218.

For example, the spring force F calculated by the above equation 2
The absolute value of slp and the valve-opening state holding electromagnetic force Femlow obtained by the above equation 3 are set to be equal.
That is, the valve open state holding current ihlow is calculated so that the following expression 11 is established.

[0088]

[Formula 11] Kc · x = fl (gaplow, ihlow) [Equation 11] Here, the composite spring constant Kc is a value twice the spring constant K updated in step S218, and the displacement amount x is the displacement. Since the gap gaplow = 0 is obtained from the sensor unit 7, the valve open state holding current ihlow can be obtained from the above equation 11.

In this way, the appropriate valve open state holding current i
It becomes possible to hold the electromagnetically driven valve 2 in the open state at hlow. Next, when the intake valve opening period ends and the intake valve closing drive request is output from the internal combustion engine control ECU 36 side (“YES” in S100, time t8), the above-described steps S102 to S110 are performed. To be executed. In this process, in step S108, the suction current iaup is reduced corresponding to the update of the spring constant K (time t).
9). In addition, the valve closed state holding current ihup output processing (S11
0, FIG. 4), the valve closing state holding current ihup output at the initial stage (time t10 to t11) is also set in the previous step S216.
This is the value set in.

If there is no change in the holding state of the armature 22 due to the valve closing state holding current ihup reduction processing (time t11 to t12) in step S208 of the holding current output processing (FIG. 4) (“NO” in S212 and S214). "Y
ES ”), and a new valve closing state holding current ihup is set (S216, time t12). Then, the spring constant K is updated (S218). After that, the above-described current control is repeated according to the new spring constant K.

Next, a case will be described in which the holding state is changed (“YES” in S212) by the valve closing state holding current ihup reduction processing (S208) in the holding current output processing (FIG. 4). The timing chart in this case is shown in FIG.

The change in the holding state at this time indicates that the armature 22 is starting to separate from the upper core 26 due to the reduction of the valve closing state holding electromagnetic force Femup (FIG. 6: time t20 to t21), and the relationship of the following expression 12 is generated. It turns out.

[0093]

[Equation 12] Femup <| Fsup | ... [Equation 12] Therefore, the armature 22 is first surely connected to the upper core 26.
In order to hold the value, the value of the valve closing state holding current ihup is increased by the calculation of the following expression 13 (S220).

[0094]

[Equation 13] ihup ← ihup + ipup [Equation 13] Here, ipup is an increase correction value, and, for example, a fixed value is set, but the valve closing state holding current iup is increased to a value close to the suction current iup. The value is set. Further, instead of the equation 13, the valve closed state holding current ih
The value of the suction current iaup may be set to the value of up.

Then, the temporary suction execution flag XIp is set to "ON" (S222), and the holding current is output to the upper coil 26a by the value of the valve closing state holding current ihup obtained in step S220 (S21).
0, time t21), this processing is once terminated.

In the next control cycle, since XIp = “ON” is determined after “YES” is determined in step S200 (“NO” in S202), it is determined whether or not the waiting time has elapsed next. (S224). In this case, the waiting time is the closed valve holding current ihu in step S220.
By increasing p, the armature 22 is surely moved to the upper core 26
It is provided to hold it.

Until the waiting time elapses (“NO” in S224), the suction hold (S210) by the valve closing state hold current ihup set in step S220 is continued (time t21 to t22). When the waiting time has elapsed (“YES” in S224, time t22), the withdrawal current value ihupold is set to the valve closed state holding current ihup (S226). This withdrawal current value ihupold is the valve closing state holding current ihup at the time of this valve closing (S20
This is a value obtained by saving the initial valve closed state holding current ihup in step S206 immediately before step 8). This withdrawal current value ih
upold represents the valve closing state holding current ihup used to obtain the spring constant K at the time of the previous valve closing.

Then, the temporary suction execution flag XIp is set to "OF
"F" is set, and the holding current is output to the upper coil 26a according to the value of the valve closing state holding current ihup set in step S226 (S210, time t2.
2) Then, this process is once terminated.

In the next control cycle, the valve closed state holding current ih
Since the holding state change determination of the armature 22 due to the reduction of up is completed (“NO” in S200), the valve closing state holding current ihup set in step S226 is subsequently performed.
The state in which the holding current is output according to the value of (S210) continues (time t22 to t23). In this way, the process for reducing the valve closed state holding current ihup is canceled, so the spring constant K is not updated.

When a valve opening drive request is made (“NO” in S100 of FIG. 3), steps S112 to S described above are performed.
The processing of 120 is executed (time t23 to t26). At this time, the suction current ial output in step S118
ow and the valve opening state holding current ihlow output in step S120 are both adjusted based on the valve closing state holding current ihup or the spring constant K. However, in the immediately preceding valve closing period, since the valve closed state holding current ihup and the spring constant K are not updated, the suction current ialow is set based on the same valve closed state holding current ihup or the spring constant K as in the previous valve opening. The valve open state holding current ihlow is adjusted (time t24 to t26).

When a valve closing drive request is made (“YES” in S100 of FIG. 3, time t26), the processes of steps S102 to S110 described above are executed (time t26).
~ T29). However, in step S200 of the valve closed state holding current ihup output process (S110, FIG. 4), the armature 22 is separated from the upper core 26 by further reduction of the valve closed state holding current ihup, so the valve closed state holding current ihup is increased. The reduction condition is not satisfied. Therefore, the valve closed state holding current ihup is reduced (S
208, S216) and the spring constant K is not updated (S218) (time t27 to t29).

However, the valve-closed state is maintained every time the internal combustion engine is started, or every time the operating time of the internal combustion engine, the cumulative number of revolutions of the internal combustion engine, or the mileage of the vehicle equipped with the internal combustion engine exceeds a reference value. The history that the armature 22 is separated from the upper core 26 is canceled by the reduction of the holding current ihup. As a result, the valve closed state holding current ihup
The reduction condition can be satisfied. In this way, the valve-closing state holding current ihup can be reduced again when the valve is closed as described above, and the valve-closing state holding current i due to the change over time of the spring i
It is possible to update the level of hup and the spring constant K.

In the first embodiment described above, steps S108 and S118 correspond to the processing as the opening / closing driving means in the electromagnetic force control device for the electromagnetically driven valve. In addition, steps S120 and S210 are the same as the open / close state holding means, and steps S204 to S208 and S212 to S21 are the same.
6, S220 to S228 correspond to the processing as the holding state maintenance information detecting means. Furthermore, in step S218, the valve closing state holding current iup or the suction currents iaup and ialow and the valve opening state holding current i performed based on the spring constant K.
The process of obtaining hlow corresponds to the process as the correction means.

According to the first embodiment described above, the following effects can be obtained. (I). In the holding current output process (FIG. 4), step S21
The value of the valve closing state holding current ihup is reduced each time the valve closing holding state is reached until it is determined in 2 that the valve closing holding state of the electromagnetically driven valve 2 is about to collapse (S208). Then, based on the valve closing state holding current ihup obtained by increasing and correcting the valve closing state holding current ihup after the reduction in step S216, the spring constant K in step S218 is determined.
The spring constant K is updated by calculation.

The situation where the contact state between the upper core 26 and the armature 22 is maintained even if the valve closed state holding current ihup is reduced to weaken the valve closed state holding electromagnetic force Femup is as follows.
It indicates that the spring constant K of the upper spring 30 is smaller than the designed value or the value at the beginning of use.

Therefore, in the calculation of step S218,
By obtaining the spring constant K corresponding to the valve-closing state holding electromagnetic force Femup generated by the valve-closing state holding current ihup, a more appropriate spring constant K can be newly set. Therefore, the suction currents iaup, ialow and the valve opening state holding current ih obtained based on the spring constant K are obtained.
The accuracy of low can be increased. In this way, it is possible to perform highly accurate electromagnetically driven valve control in consideration of individual differences and changes over time in the lower spring 20 and the upper spring 30.

Moreover, when the internal combustion engine is actually operating, the value of the closed valve holding current ihup of the electromagnetically driven valve 2 is reduced so that the calculated spring constant K approaches the actual spring constant value. is doing. Therefore, even if the lower spring 20 and the upper spring 30 change with time during operation of the internal combustion engine, or if these springs 20,
Even when 30 is replaced, an appropriate current value for controlling the electromagnetically driven valve 2 can be immediately output. For this reason, it becomes possible to perform highly accurate electromagnetically driven valve control that can take into consideration individual differences and changes over time in the lower spring 20 and the upper spring 30 in real time.

Since such an electromagnetically driven valve 2 is used as an intake valve and an exhaust valve of an internal combustion engine, a highly accurate intake valve and exhaust valve in consideration of individual differences of the lower spring 20 and the upper spring 30 and changes over time. The drive control of the valve becomes possible, and highly accurate internal combustion engine control can be continuously executed.

(B). In step S218, the spring constant K
Is updated until the holding state changes in step S212, that is, until the closed state of the electromagnetically driven valve 2 cannot be maintained. So in the end,
The spring constant K set based on the value of the valve closed state holding current ihup before the reduction process that causes the valve closed state to not be maintained can be obtained. This finally obtained spring constant K is the most accurate value that has been repeatedly obtained. Therefore, it is possible to finally reach the most accurate electromagnetically driven valve control.

(C). When it is determined that the holding state has changed (“YES” in S212), the valve closing state holding current ihup is immediately increased (S220). As a result, even if the valve closed state holding current ihup is reduced (S208) in order to obtain an accurate spring constant K when the electromagnetically driven valve 2 is used, the valve closed state is not destroyed, so There is no problem in the operation of 2.

(D). After the valve closing state holding current ihup is increased (S220), the valve closing state holding current ihup is increased.
Of the valve closing state holding current ihup before the previous reduction process
Has been returned to the value of (S226). Therefore, the valve-closed state holding current ihup can be immediately set to an appropriate level, so that wasteful electric energy is not supplied.
The closed state of the electromagnetically driven valve 2 can be reliably maintained.

(E). As described above, as long as the closed valve holding state is maintained, the gradually decreasing value Δi
The reduction of the hup amount is executed for the valve closed state holding current ihup (S208). By repeating such stepwise reduction processing, it is possible to gradually approach the value of the valve closing state holding current ihup that can finally obtain the spring constant K most accurately. Therefore, when the electromagnetically driven valve 2 is used, the operation of the electromagnetically driven valve 2 is not destabilized even if the valve closing state holding current ihup is reduced.

(F). When obtaining the suction currents iaup, ialow and the valve opening state holding current ihlow based on the valve closing state holding current ihup, the same effects as (a) to (e) are obtained.

[Embodiment 2] In the present embodiment, the point that the valve opening / closing drive processing and the valve-opening state holding current ihlow output processing shown in FIGS. 7 and 8 are executed instead of FIGS. Form 1 is different. Further, timing charts showing an example of the control of the present embodiment are as shown in FIGS.

In the valve opening / closing drive process (FIG. 7), steps S300 to S308 and S312 to S318 are performed as shown in FIG.
Steps S100 to S10 in the valve opening / closing drive process
8, the same as S112 to S118. The difference from FIG. 3 is the processing in steps S310 and S320.

Of these steps, step S310 is executed when the armature 22 contacts the upper core 26 ("YES" in step S306, time t37), and is a process for setting the value of the valve closing state holding current ihup as the upper coil current Iup. Is. As for the value of the valve closed state holding current ihup, the valve closed state holding current ihup is obtained so that the equation 9 described in the first embodiment is satisfied. Where spring constant K
Is a value updated in step S419 to be described later, the displacement amount x is obtained from the displacement sensor unit 7, the gap gapup = 0, and the offset amount xofs is constant. The state holding current ihup can be obtained. In this manner, the electromagnetically driven valve 2 can be held in the closed state with the appropriate closed state holding current ihup.

The valve open state holding current ihlow output processing in step S320 is as shown in FIG. Here, steps S400 to S416, S420 to S428
Is different only in that the valve open state holding current ihlow of the lower coil 24a is set as a control target in order to detect the change in the holding state of the armature 22 by the lower core 24. That is, steps S200 to S21 of FIG.
6, S220 to S228, the valve closed state holding current ihup and the withdrawal current value ihupo for the upper coil 26a.
ld, the gradually decreasing value Δihup, the increasing correction amount isup, and the increasing correction value ipup are used. On the other hand, in steps S400 to S416 and S420 to S428 in FIG. 8, the valve open state holding current ihlow for the lower coil 24a,
The withdrawal current value ihlowold, the gradual decrease value Δihlow, the increase correction amount islow, and the increase correction value iplow are used.

Then, in FIG. 8, the following processing is performed in steps S418 and S419 executed after step S416. First, in step S418, the combined spring constant Kc is calculated. The combined spring constant Kc is the valve opening state holding current ihl set in step S416.
electromagnetic force Femlow for holding the valve open state caused by ow
And the spring force Fslp of the composite spring formed by the lower spring 20 and the upper spring 30 are balanced (Fsl
p = −Femlow) is calculated as follows.

That is, if “Fslp = −Femlow”, the following equation 14 is established from the above equations 2 and 3.

[0120]

Kc · x = fl (gaplow, ihlow) [Equation 14] Here, on the left side of Equation 14, the armature 22 is lower core 24
The displacement amount x when it is in contact with is detected by the displacement sensor unit 7. Gap gap = 0 on the right side
And the valve open state holding current ihlow is calculated in step S41.
6 is a value set as in the following Expression 15.

[0121]

[Equation 15] ihlow ← ihlow + islow (Equation 15) Here, the increase correction amount islow is determined by the above step S216.
This corresponds to the increased correction amount isup described in (FIG. 4).

Therefore, since the unknown number is only the composite spring constant Kc, the composite spring constant Kc is calculated as shown in the following expression 16.

[0123]

[Expression 16] Kc ← fl (gaplow, ihlow) / x [Equation 16] Next, in step S419, the combined spring constant Kc is set to 1
By multiplying by / 2, the spring constant K common to the lower spring 20 and the upper spring 30 is obtained.

The value of this spring constant K is set to the lower spring 2
0 and a new spring constant of the upper spring 30. By using this new spring constant K (Kc in some cases), the above-mentioned attraction currents iaup, ialow
Also, it becomes possible to set the valve closed state holding current ihup to an appropriate value. In the timing chart of FIG. 9, time t3
At 4, t42, the value of the spring constant K is updated based on the value of the valve opening state holding current ihlow, and the suction currents iaup, ialow and the valve closing state holding current ihup are set based on the value of the spring constant K. ing.

Further, in the timing chart of FIG. 10, the valve open state holding current ihlow decreases (time t50 to t5).
As a result of 1), since the armature 22 starts to separate from the lower core 24 (time t51), the valve-opening state holding current ih immediately.
It shows a state in which the valve opening state is maintained by increasing low. After that, the valve open state holding current ihlow is not reduced (S408), and the update of the spring constant K is stopped.

In the above-described second embodiment, steps S308 and S318 are the same as the opening / closing driving means in the electromagnetic force control device for the electromagnetically driven valve.
S410 corresponds to the process as the opened / closed state holding unit.
In addition, steps S404 to S408, S412 to S41
6, S420 to S428 correspond to the processing as the holding state maintenance information detecting means. Further, steps S418, S
419, valve open state holding current ihlow or spring constant K,
The process of obtaining the suction currents iaup, ialow and the valve closing state holding current ihup performed based on Kc corresponds to the process as the correction unit.

According to the second embodiment described above, the following effects can be obtained. (I). Even in the valve open state, the valve open state holding current ih
By detecting the change in the valve open state with the reduction of low, (a) to (e) of the first embodiment
The effect equivalent to can be produced.

(B). The above effect (a) is also obtained when the suction currents iaup and ialow and the valve closed state holding current ihup are obtained based on the valve opened state holding current ihlow. [Third Embodiment] This embodiment differs from the second embodiment in that the valve opening / closing drive processing shown in FIG. 11 is executed instead of the above-mentioned FIG. This valve opening / closing drive processing (Fig. 1
In 1), steps S500 to S508 and S51.
2 to S520 are the same as steps S300 to S308 and S312 to S320 in the valve opening / closing drive process of FIG. The difference from FIG. 7 is that the valve closed state holding current ihup output process shown in FIG. 12 is executed as step S510 instead of step S310.

Output process for holding current ihup of valve closed state (see FIG.
2) will be described. Incidentally, here, step S600-
S616, S620 to S628 are the same processes as steps S200 to S216 and S220 to S228 of the valve closed state holding current ihup output process (FIG. 4) shown in the first embodiment, and only step S618 is the spring constant. This is different from step S218 in which K is calculated.

At step S618, step S5 has already been performed.
The spring constant K updated at 20 (the same processing as in FIG. 8)
Is used to calculate the offset amount xofs in the upper spring 30. The calculation of the offset amount xofs is performed as follows.

That is, the valve-closing state holding electromagnetic force Femup generated by the valve-closing state holding current ihup newly set in step S616 and the spring force Fsup of the upper spring 30 are balanced (Femup = -Fsu).
p), the relationship of Expression 9 shown in the first embodiment is satisfied.

Here, the gap gapup = 0, the valve-closing state holding current ihup is set in step S616, the displacement amount x is detected by the displacement sensor unit 7, and the spring constant K is obtained in step S520. ing. Therefore, the offset amount xofs can be calculated as shown in the following Expression 17.

[0133]

Xofs ← {fu (gapup, ihup) / K} -x [Expression 17] In this way, the offset amount xofs can be updated.

Then, the updated offset amount xof
s and the spring constant K obtained in steps 418 and S419, the suction current iaup and the valve closing state holding current ihup at the time of valve closing are set based on the above equations 5 and 10.

In the above-described third embodiment, steps S508 and S518 are the same as the opening / closing driving means in the electromagnetic force control device for the electromagnetically driven valve.
S610 corresponds to the process as the opened / closed state holding unit.
In addition, steps S404 to S408, S412 to S41
6, S420 to S428 correspond to the processing as the holding state maintenance information detecting means. Further, steps S418, S
419, S604 to S608, S612 to S628, the valve opening state holding current ihlow or the spring constants K and Kc, or the suction current ia performed based on the offset amount xofs.
The process of obtaining up, ialow and the valve closed state holding current ihup corresponds to the process as the correction means.

According to the third embodiment described above, the following effects can be obtained. (I). It is possible to produce the same effects as those of (a) and (b) of the second embodiment.

(B). By executing the valve closed state holding current ihup output process (FIG. 12), the offset amount xofs can be updated. Therefore, the more accurate suction current ia
It is possible to adjust up and the valve closing state holding current ihup. Therefore, even if the offset amount xofs of the upper spring 30 incorporated in the electromagnetically driven valve 2 varies from individual to individual or changes over time, it can be reflected in the control current value and electromagnetic force for the electromagnetically driven valve 2. Therefore, it is possible to perform more highly accurate electromagnetically driven valve control in consideration of individual differences of the upper springs 30 and changes over time.

Then, such an offset amount xofs
Also in the update of (b) to (e) of the first embodiment
Produces the same effect as. [Fourth Embodiment] In the first to third embodiments,
Even before the armature 22 starts to separate from the lower core 24 or the upper core 26, the valve open state holding current ihlo
The spring constant K and the offset amount xofs are adjusted so as to obtain more accurate values in accordance with the reduction of w and the valve closed state holding current ihup.
Are being updated in stages.

In this embodiment, the spring constant K is updated by
The armature 22 is triggered by the fact that the armature 22 starts to separate from the lower core 24 or the upper core 26.
The present embodiment is different from the first embodiment in that the valve closed state holding current ihup output processing of FIG. 13 is executed instead of the processing of FIG.

If "YES" is determined in step S106 of the valve opening / closing drive process (FIG. 3) shown in the first embodiment, the valve closed state holding current ihup output process (FIG. 13).
Is started.

In FIG. 13, first, the valve closed state holding current ih
It is determined whether or not the up reduction condition is satisfied (S70).
0). The conditions for reducing the valve closing state holding current ihup are as described in step S200 of the first embodiment. Immediately after the armature 22 contacts the upper core 26, the condition for reducing the valve closed state holding current ihup is not satisfied (“NO” in S700), and the upper coil 26a is supplied with the value of the valve closed state holding current ihup set in advance. On the other hand, the holding current is output (S710). After that, until the waiting time elapses (“NO” in S700), the constant valve closed state holding current ihup is applied to the upper coil 26a.
The output is continued (S710). This state corresponds to times t62 to t63 in the timing chart shown in FIG.

When the waiting time elapses (“YE
S ”), and then it is determined whether the temporary suction execution flag XIp is“ OFF ”(S702). Since XIp = “OFF” is set in the initial setting when the internal combustion engine is started (S
Then, it is determined whether or not it is the first process after the armature 22 contacts the upper core 26 (S704). If it is the first time ("YE" in S704)
S ”), the current value of the gradually decreasing cumulative value ΣΔihup is saved as the saving gradually decreasing cumulative value ΣΔihupold (S70).
6). Then, as shown in the following equation 18, the gradually decreasing cumulative value ΣΔihup
Then, the gradually decreasing value Δihup is accumulated (S707).

[0143]

[Formula 18] ΣΔihup ← ΣΔihup + Δihup [Equation 18] Incidentally, regarding the gradual decrease value Δihup, step S in FIG.
208, and the gradual decrease cumulative value ΣΔi
The initial setting value of hup is "0".

Next, as shown in the following equation 19, the valve closed state holding current i
The value of hup is calculated (S708).

[0145]

[Formula 19] ihup ← ihupb-ΣΔihup [Equation 19] Here, the valve closing state holding current reference value ihupb is a reference value of the valve closing state holding current ihup, and is a value updated in step S725 described later. .

Then, the holding current is output to the upper coil 26a according to the value of the valve closing state holding current ihup obtained by the above equation 19 (S710, time t6).
3) Then, this process is once terminated. That is, from time t63, the valve-closing state holding current ihup is reduced as shown in the equation 19 and the valve-closing state holding electromagnetic force Femup generated in the upper core 26 becomes smaller.

In the next control cycle, steps S700 and S
Although "YES" in 702, it is determined "NO" in step S704, and it is determined whether or not the holding state has changed (S712). Here, the change in the holding state is as described in step S212 in FIG. 4, and is found by the detection of the displacement sensor unit 7.

If the holding state has not changed (S7)
12 is "NO"), and then it is determined whether or not the waiting time for detecting the change in the holding state has elapsed (S714). If the waiting time has not elapsed (“NO” in S714),
Valve closed state holding current ih set in step S708
The holding current output (S710) depending on the value of up is continued (time t63 and thereafter).

As illustrated in FIG. 14, when the waiting time elapses (“YES” in S714, time t64) without a change in the holding state being detected (“NO” in S712),
Next, the calculation of the temporary spring constant Kv is executed (S716).
Here, the provisional spring constant Kv is a balance between the valve closing state holding electromagnetic force Femup generated by the valve closing state holding current ihup set in step S708 and the spring force Fsup of the upper spring 30 (Femup = -F).
Sup) is obtained by the calculation of the equation 10 in the first embodiment.

Then, the valve closed state holding current ihup is returned to the valve closed state holding current reference value ihupb (S718). Here, the valve-closing state holding current ihup is returned to the valve-closing state holding current reference value ihupb because some shock occurs in the electromagnetically driven valve 2 after the observation of the holding state due to the reduction of the valve-closing state holding current ihup is completed. This is also to prevent the armature 22 from being easily separated from the upper core 26 during the valve closing period.

Then, the holding current is output to the upper coil 26a in accordance with the value of the valve closing state holding current ihup set in step S718 (S710, time t6).
4) Then, this process is once terminated.

In the next control cycle, the valve closed state holding current ih
Since the change determination of the holding state of the armature 22 due to the reduction of the up is performed (“NO” in S700), the constant valve closing state holding current ihup is thereafter set in the current valve closing period.
Then, the closed valve holding state is maintained (time t64 to t65).

In the valve opening / closing drive process (FIG. 3), when the intake valve closing period ends and the intake valve open drive request is output from the internal combustion engine control ECU 36 side (“N” in S100).
"O", time t65), then, the supply of the valve-closing state holding current ihup, which has been supplied to the upper coil 26a, is stopped (S112). After that, if the armature 22 passes through the center between the lower core 24 and the upper core 26 according to the process described in the first embodiment (“YES” in S114, S
At 116, "NO"), the suction current ialow is supplied as the lower coil current Ilow (S118, time t66).
~ T67). As a result, the armature 22 is sucked by the lower core 24 and approaches the lower core 24 without stopping midway. Here, the suction current iallow is set based on the spring constant K updated and set in step S728 described later, like the suction current iaup and the valve-opening state holding current ihlow. Note that in the example of FIG. 14, the spring constant K during the immediately preceding valve closing period (particularly at time t64).
Is not updated, the suction current ialow has the same value as the previous valve opening period.

Then, as shown in FIG. 2A, if the armature 22 contacts the lower core 24 ("YE" in S116).
S ", time t67), the value of the valve opening state holding current ihlow is set and output as the lower coil current Ilow (S1).
20). The value of the valve open state holding current ihlow is obtained so that the equation 11 described in the first embodiment is satisfied. As the combined spring constant Kc of the equation 11, a value twice the spring constant K updated in step S728 described later is used. Also in this case, since the spring constant K is not updated in the immediately preceding valve closing period, the valve opening state holding current ihlow has the same value as the previous valve opening period. In this way, the electromagnetically driven valve 2 is kept open.

Next, when the intake valve opening period is over and the intake valve closing drive request is output from the internal combustion engine control ECU 36 side (“YES” in S100), the explanation is given in the first embodiment. The steps S102 to S108 and the process of FIG. 13 are executed. In this process, in step S108, the spring constant K has not been updated in the previous valve closing period, so the value of the suction current iaup is the same as the previous valve closing period (time t69 to t70).

When the armature 22 contacts the upper core 26 ("YES" in S106 in FIG. 3), the same value as the previous valve closing period is maintained until the waiting time elapses ("NO" in S700 in FIG. 13). The valve-closed state holding current ihup is output (S710, time t70 to t71). When the waiting time has elapsed (“YES” in S700, time t
71), since the temporary suction execution flag XIp is "OFF", it is determined to be "YES" in step S702. Since this is the first process after the armature 22 has contacted the upper core 26, it is determined to be "YES" in step S704. Then, the current value of the gradual decrease cumulative value ΣΔihup is saved as the saved gradual decrease cumulative value ΣΔihupold (S706), and the gradual decrease cumulative value ΣΔih is calculated as in the equation (18).
The gradually decreasing value Δihup is accumulated in up (S707). As a result, the gradually decreasing cumulative value ΣΔihup is gradually decreased.
An increase of p minutes is made.

Then, the value of the valve-closed state holding current ihup is obtained as in the equation (19) (S708). Step S7
Due to 07, the cumulative value ΣΔihu gradually decreases from the previous valve closing period.
Since p is increasing, the previous valve closing state holding current ihu
The valve-closing state holding current ihup is set to be lower when the valve-closing state holding current ihup is reduced this time (time t71 to t72) than when p is reduced (time t63 to t64). Therefore, the valve-closing state holding electromagnetic force Femup generated in the upper core 26 is reduced as compared to the previous time when the valve-closing state holding current ihup was reduced.

In the next control cycle, steps S700 and S
Although "YES" in 702, it is determined "NO" in step S704, and it is determined whether or not the holding state has changed (S712). If the holding state has not changed (“NO” in S712), it is next determined whether or not the waiting time for detecting the holding state has elapsed (S714). If the waiting time has not elapsed (S71
4 is “NO”), the holding current output according to the value of the valve closing state holding current ihup set in step S708 (S71
0) is continued (time t71 to t72).

Then, as illustrated in FIG. 14, the change in the holding state is not detected again (“N” in S712).
O ”), and when the waiting time has elapsed (“ YES ”in S714).
S ”, time t72), and then the temporary spring constant Kv is calculated again (S716). As described above, the temporary spring constant Kv is the valve-closing state holding electromagnetic force Fe generated by the valve-closing state holding current ihup set in step S708.
It is obtained by the calculation of the above-mentioned equation 10 assuming that the mup and the spring force Fsup of the upper spring 30 are in balance (Femup = −Fsup). For this reason, the temporary spring constant Kv is calculated as a value smaller than that in the previous valve closing period because the valve closing state holding current ihup is reduced in step S708.

Then, the valve closed state holding current ihup is returned to the valve closed state holding current reference value ihupb (S718). Then, the holding current output according to the value of the valve closing state holding current ihup set in step S718 is output to the upper coil 26a (S710, time t72), and the present process is once ended.

As described above, even if the valve closing state holding current ihup is temporarily reduced for each valve closing period in step S708 and the degree of reduction is gradually increased, the holding state of the armature 22 with respect to the upper core 26 is changed. If not, only the temporary spring constant Kv is updated (S71).
6). Therefore, the level of the valve closed state holding current ihup is maintained and the spring constant K is also maintained without being updated. Therefore, the levels of the suction currents iaup and ialow and the valve open state holding current ihlow are also maintained.

Next, in the valve closing state holding current ihup output processing (FIG. 13), when the holding state change occurs due to the valve closing state holding current ihup reduction processing (S708) (S71).
"YES" in 2) will be described. A timing chart in this case is shown in FIG.

The change in the holding state at this time shows that the armature 22 is starting to separate from the upper core 26 due to the reduction of the valve closing state holding electromagnetic force Femup (time t80 to t81), and the equation described in the first embodiment is used. It is found that 12 relationships (Femup <| Fsup |) have occurred.

Therefore, in order to reliably hold the armature 22 in the upper core 26, the value of the valve closed state holding current ihup is increased by the following equation 20 (S720).

[0165]

[Equation 20] ihup ← ihubb + ipup [Equation 20] Here, ipup is an increase correction value, and may be a constant value, for example, but it may be a constant value, but the valve closing state holding current reference value iupb may be summed to hold the valve closing state. Current iup is attracted current iau
A value is set to increase the value close to p. Further, instead of the expression 20, the value of the suction current iaup may be set to the value of the valve closed state holding current ihup.

Then, the temporary suction execution flag XIp is set to "ON" (S722), and the holding current is output to the upper coil 26a according to the value of the valve closing state holding current ihup obtained in step S720 (S71).
0, time t81), this process is once terminated.

In the next control cycle, since XIp = “ON” is determined after “YES” is determined in step S700 (“NO” in S702), it is determined whether or not the waiting time has elapsed next. (S724). In this case, the waiting time is equal to the valve closing state holding current ihu in step S720.
By increasing p, the armature 22 is surely moved to the upper core 26
It is provided to hold it.

Until the waiting time elapses (“NO” in S724), the suction hold (S710) by the valve closed state holding current ihup set in step S720 is continued (time t81 to t82). When the waiting time has elapsed (“YES” in S724, time t82), the valve closed state holding current reference value ihupb is updated as in the following Expression 21 (S725).

[0169]

[Equation 21] ihupb ← ihupb-ΣΔihupold + isup [Equation 21] Since it is determined to be "YES" in step S712, the valve closing state holding current iup set in equation S19 in step S708 is: It can be determined that the electromagnetic force Femup for maintaining the valve closed state is slightly lower than the | spring force Fsup |. Therefore, in the equation 21, the valve closing state holding current ihup obtained by the equation 19 is increased by the increase correction amount isup to make the valve closing state holding electromagnetic force Femup equal to or slightly larger than the | spring force Fsup |. A value that can be increased is obtained, and the valve closed state holding current reference value ihupb is updated with this value.

Next, the updated valve closing state holding current reference value ihupb is set to the valve closing state holding current ihup (S
726), the gradually decreasing cumulative value ΣΔihup is returned to “0” (S
727).

Then, the spring constant K is set to the above-mentioned step S71.
The latest provisional spring constant Kv obtained in step 6, that is, the provisional spring constant Kv in the state where the valve-closing state holding electromagnetic force Femup is actually equal to | spring force Fsup | is set (S
728). Next, the temporary suction execution flag XIp is set to “OFF”
Is set (S729). Then, the valve closing state holding current ihup output to the upper coil 26a is output in step S726.
Change to the value set in (S710, time t8
2). In this way, this processing is once terminated.

In the next control cycle, the valve closed state holding current ih
Since the determination of the change in the holding state of the armature 22 due to the reduction of up has been completed (“NO” in S700), the valve closing state holding current ihu set in step S726 will be subsequently performed.
State in which holding current is output according to the value of p (S710)
Continues (time t82 to t83).

When a valve opening drive request is made (“NO” in S100 of FIG. 3), the steps S112 to S described above are performed.
The processing of 120 is executed. At this time, step S118
And the suction current ialow output at step S12
Both the valve opening state holding current ihlow output at 0 are adjusted based on the spring constant K updated in the immediately preceding valve closing period (time t84 to t86).

When a valve closing drive request is made (“YES” in S100 of FIG. 3), the above-mentioned steps S102-
The processing of S108 and S110 (FIG. 13) is executed.
However, step S700 of the holding current output process (FIG. 13)
In the above, since the armature 22 is separated from the upper core 26 in the further reduction of the valve closing state holding current ihup, the valve closing state holding current ihup reducing condition is not satisfied. Therefore, the valve closed state holding current i
Hup reduction (S708) and update of spring constant K (S71
6, S728) is not performed (time t87 to t).
89).

However, as described above, each time the internal combustion engine is started, or every time the operating time of the internal combustion engine, the cumulative number of revolutions of the internal combustion engine, or the mileage of the vehicle in which the internal combustion engine is mounted exceeds the reference value, The history of the armature 22 being separated from the upper core 26 is canceled by reducing the valve-closed state holding current ihup. As a result, the valve closed state holding current ihup reduction condition can be satisfied again. Thus
Again, as described above, when the valve is closed, the closed state holding current ihu
The p reduction processing becomes possible, and it becomes possible to update the level of the valve closed state holding current ihup and the spring constant K with the change of the spring with time.

The suction currents iaup, ialow and the valve-opening state holding current ihlow were obtained based on the spring constant K. However, in addition to this, the valve-closing state holding current reference value ihupb
You may ask based on.

In the above-described fourth embodiment, steps S108 and S118 are performed as the opening / closing driving means in the electromagnetic force control device for the electromagnetically driven valve.
S710 corresponds to the processing as the opened / closed state holding unit.
In addition, steps S704 to S708, S712, S71
4, S718 to S727 and S729 correspond to the processing as the holding state maintenance information detecting means. Furthermore, step S
716, S728, valve closing state holding current reference value ihupb
Alternatively, the suction current iaup, ia performed based on the spring constant K
The process of obtaining low and the valve-opening state holding current ihlow corresponds to the process as the correction unit.

According to the fourth embodiment described above, the following effects can be obtained. (I). In the holding current output process (FIG. 13), step S
Until it is determined in 712 that the electromagnetically closed valve 2 cannot be maintained in the closed state, the degree of reduction of the closed state holding current ihup is gradually increased each time the closed state is maintained (S707). , S708). When the closed valve holding state of the electromagnetically driven valve 2 cannot be maintained ("YES" in S712), the temporary spring constant Kv obtained in the immediately previous valve closed holding state is set to the spring constant K ( S72
8) and the spring constant K is updated accordingly.

Therefore, the spring constant K is set to an appropriate spring constant K.
The suction currents iaup and ialow and the valve opening state holding current ih can be set based on the spring constant K.
The accuracy of the processing for obtaining low can be increased. In this way, it is possible to perform highly accurate electromagnetically driven valve control in consideration of individual differences and changes over time in the lower spring 20 and the upper spring 30.

Moreover, when the internal combustion engine is actually operating, the spring constant K is updated by reducing the value of the closed valve holding current ihup of the electromagnetically driven valve 2. Therefore, even when the lower spring 20 and the upper spring 30 change over time during operation of the internal combustion engine, or when the springs are replaced and installed in the internal combustion engine, an appropriate current for controlling the electromagnetically driven valve 2 is obtained. The value can be output immediately. For this reason, it becomes possible to perform highly accurate electromagnetically driven valve control that can take into consideration individual differences and changes over time in the lower spring 20 and the upper spring 30 in real time.

Since such an electromagnetically driven valve 2 is used as an intake valve and an exhaust valve of an internal combustion engine, a highly accurate intake valve and exhaust valve in consideration of individual differences of the lower spring 20 and the upper spring 30 and changes over time. The drive control of the valve becomes possible, and highly accurate internal combustion engine control can be continuously executed.

(B). If it is determined that the holding state has changed (“YES” in S712), the valve closing state holding current ihup is immediately increased (S720). This prevents the electromagnetically driven valve 2 from operating because the closed valve holding state is not destroyed even if the valve closed state holding current ihup is reduced in order to obtain an accurate spring constant K when the electromagnetically driven valve 2 is used. No problems will occur. Further, after the valve closing state holding current ihup is increased (S720), the value of the valve closing state holding current ihup is balanced with the spring force Fsup and the holding electromagnetic force Femup so that the upper core 26 can hold the armature 22. The value of the state holding current ihup is set (S725, S726). Therefore, the valve closed state holding current ihup can be set to an appropriate level, so that the valve closed state of the electromagnetically driven valve 2 can be reliably maintained without supplying unnecessary electric energy.

(C). As long as the holding state is maintained,
Each time the valve-holding state is established, the degree of reduction processing of the valve-closing state holding current ihup is increased stepwise by the gradual decrease value Δiup (S707, S708). By repeating this, the valve closing state holding current ihu in which the holding state is not maintained
The degree of p can be obtained. Moreover, when the process for reducing the valve-closed state holding current ihup is completed (S714: "YE
S ”), the valve closed state holding current reference value ihupb is returned to the original value. Therefore, the operation of the electromagnetically driven valve 2 can be maintained in a stable state as much as possible, and the value of the valve closing state holding current ihup that can most accurately obtain the spring constant K can be obtained as the holding state maintenance information.

(D). Valve closed state holding current reference value ihup
Also when obtaining the suction currents iaup, ialow and the valve-opening state holding current ihlow performed based on b, the above (A) to
The same effect as (C) is produced.

[Fifth Embodiment] In this embodiment, instead of steps S725 to S729 of the valve closed state holding current ihup output processing (FIG. 13) of the fourth embodiment, FIG.
Other processes for executing the process shown in are as described in the fourth embodiment.

A series of processes shown in FIG. 16 (S730 to S7)
48) is a process for reducing the valve closing state holding current ihup (S7).
If it becomes impossible to maintain the holding state due to (07, S708) (“YES” in S712), the holding state is ensured by increasing the valve closing state holding current ihup (S720) (“YES” in S724). To be executed. still,
An example of control in the fifth embodiment is shown in the timing chart of FIG.

First, the temporary spring constant cumulative value ΣKv is added to the temporary spring constant K calculated in the immediately preceding step S716.
The value of v is accumulated (S730). The temporary spring constant cumulative value ΣKv is initially set to “0”.

Next, the Kv counter is incremented (S732). This Kv counter is a temporary spring constant cumulative value Σ
It represents the cumulative number of temporary spring constants Kv in Kv, and is initially set to "0".

Then, it is judged whether or not the Kv counter has reached the reference number N (for example, 4 times) (S734).
If the Kv counter is less than the reference number N (S73).
4 is “NO”), and then the valve closing state holding current ihup is set to the valve closing state holding current reference value ihupb (S74).
4). Unlike the fourth embodiment, the valve closing state holding current reference value ihupb is not the value updated by the reduction, but the original valve closing state holding current reference value ihupb is used. That is, even if the value of the valve closed state holding current ihup that cannot maintain the valve closed state is maintained, the valve closed state holding current ihup is returned to the original value. And the gradually decreasing cumulative value ΣΔi
hup is returned to "0" (S746), the temporary suction execution flag XIp is set to "OFF" (S748), and step S
At 710 (FIG. 13), the valve closed state holding current ihup is output.

That is, as shown in FIG. 17, the valve-closed state holding current ih is executed by increasing the degree of reduction for each valve closed state.
By the up reduction processing (time t100 to t101),
Even if the closed valve holding state cannot be maintained, the spring constant K is not immediately updated at this point, and the output current amount is not adapted to the updated spring constant K. Until the number of times that the closed valve holding state cannot be maintained due to the reduction process of the closed valve holding current ihup reaches N times, the valve closed state holding current reference value ihupb and the original spring constant K are maintained and the closed valve state is maintained. The holding current ihup reduction process is repeated from the beginning (time t109 to t110).

When the number of times the closed valve holding state cannot be maintained due to the reduction processing of the closed valve holding current ihup reaches N times (Kv counter = N, “YE” in S734).
S ”), the spring constant K is calculated as the average value of N provisional spring constants Kv obtained immediately before the closed valve holding state cannot be maintained, as in the following Expression 22 (S736).

[0192]

[Equation 22] K ← ΣKv / N [Equation 22] Next, using the spring constant K updated as in Equation 22, it is appropriate to maintain the valve closed state when the valve closed state holding current ihup is set. Valve closed state holding current reference value ihu
pb is calculated (S738). That is, using the updated spring constant K, the spring force Fsup of the upper spring 30 is calculated by the equation 5 of the first embodiment. Then, the valve closing state holding current reference value ihupb that obtains the valve closing state holding electromagnetic force Femup that can stably maintain the valve closing state with the minimum current amount with respect to this spring force Fsup is calculated from the relationship of the above equation 9. To do.

Then, the Kv counter is cleared and returned to "0" (S740), and the temporary spring constant cumulative value ΣKv is returned to "0" (S742). Further, the valve closing state holding current reference value ihupb updated in step S738 is set to the valve closing state holding current ihup (S744).

Then, the gradually decreasing cumulative value ΣΔihup is returned to "0" (S746), and the temporary suction execution flag XIp is set to "OF".
F "(S748) and step S710 (FIG. 13)
At, the valve closed state holding current ihup is output. As a result, the valve closed state holding current ihup corresponding to the actual spring constant K is output.

In the fifth embodiment described above, steps S108 and S118 are performed as the opening / closing driving means in the electromagnetic force control device for the electromagnetically driven valve, and steps S120 and S118 are performed.
S710 corresponds to the processing as the opened / closed state holding unit.
In addition, steps S704 to S708, S712, S71
4, S718 to S724, S744 to S748 correspond to the processing as the holding state maintenance information detecting means. further,
The process of obtaining the suction currents iaup, ialow and the valve-opening state holding current ihlow performed based on steps S716, S730 to S742, and the spring constant K corresponds to the process as the correction unit.

According to the fifth embodiment described above, the following effects can be obtained. (I). The effects (a) to (c) of the fourth embodiment are produced. (B). Since the spring constant K is calculated as an average value of N provisional spring constants Kv obtained by the process of reducing the valve closing state holding current ihup repeated N times, the provisional spring constant Kv of Even if the measured value varies, an accurate value can be obtained by averaging N times. Therefore, highly accurate electromagnetically driven valve control is possible.

[Embodiment 6] In the present embodiment, when the condition for reducing the valve closed state holding current ihup is not satisfied in the valve closed state holding current ihup output processing (FIG. 4) of the first embodiment ( The difference from the first embodiment is that the processing shown in FIG. 18 is executed in S200).

That is, "NO" in step S200.
When it is determined that it is determined whether or not the armature disengagement process flag Xdn is “OFF” (S232). The armature disengagement processing flag Xdn increases the valve closed state holding current ihup to maintain the valve closed state as described later when the armature 22 in the held state starts to be detached from the upper core 26 by the detection of the displacement sensor unit 7. It is a flag that is set to "ON" during the operation. The armature disengagement process flag Xdn is set to "OFF" by default.

If Xdn = "OFF" (S232)
Then, "YES"), and then it is determined whether or not the holding state has changed (S234). Here, the change in holding state is
Unlike step S212, the valve closed state holding current i
It does not depend on the hup reduction processing (S208). Here, the electromagnetic force Fe for maintaining the valve closed state is caused by some other cause.
The state in which the mup cannot counter the spring force Fsup and the armature 22 starts to separate from the upper core 26 is shown. This change in the holding state is identified by the detection of the displacement sensor unit 7.

If the holding state has not changed ("NO" in S234), the current value of the valve closing state holding current ihup is maintained and output (S210). Therefore Xdn =
If it is "OFF"("YES" in S232) and there is no change in the holding state ("NO" in S234), the same processing as in the first embodiment is performed.

Time t12 in the timing chart of FIG.
As shown in 0, when the holding state of the armature 22 by the upper core 26 changes due to some cause (“YES” in S234), the valve closing state holding current ihup
Is increased by the increase correction value dup (S236). Then, the armature disengagement process flag Xdn is set to "ON" (S238), and the valve closing state holding current ihup is output at the value set in step S236 (S210).

Since Xdn = "ON" is set in this way, in the next control cycle, "N" is obtained in step S200.
After it is determined to be "O", it is determined to be "NO" in step S232, and then it is determined whether or not the standby time has elapsed (S240). In this case, the waiting time is S23.
It is provided to surely hold the armature 22 in the upper core 26 by increasing the valve closed state holding current ihup by 6.

Until the waiting time elapses (“NO” in S240, times t120 to t121), step S23.
The output of the valve closing state holding current ihup at the value increased by 6 continues (S210).

When the waiting time has elapsed ("YE" in S240)
S ”, time t121), processing flag X at armature departure
"OFF" is set to dn (S242), and the valve closed state holding current ihup reduction condition is satisfied (S244). As a result, in the next control cycle, it is determined to be "YES" in step S200, and the processing as described in the first embodiment is executed. That is, step S
From the valve closing state holding current ihup increased at 236,
Processing for reducing the valve closed state holding current ihup (S208)
Is started (time t121). If the holding state does not change (“NO” in S212, “YE” in S214).
S ”), and the spring constant K is updated (S218, time t12).
2). In this case, the spring constant K becomes larger than the value before the time t122. After that, the process of reducing the valve closing state holding current ihup (S208) is executed for each valve closing holding period until the holding state changes (time t129 to t13).
0). If the holding state has not changed (“NO” in S212, “YES” in S214), the spring constant K is updated (S218, time t130). That is, as described in the first embodiment, the spring constant K is gradually reduced for each valve closing period.

After that, as shown in the timing chart of FIG. 20, when the holding state changes (“Y” in S212).
ES ”, time t141), the spring constant K is not updated. After that (time t142-), the valve closed state holding current ihu
Since the p reduction condition is no longer satisfied, the valve closed state holding current ihu
p determines.

According to the sixth embodiment described above, the following effects can be obtained. (I). The effects of the first embodiment are produced. (B). When the actual spring constant K becomes large for some reason, or when the spring constant K obtained by the valve closed state holding current ihup reduction processing is smaller than the actual value, the valve closed state holding current ihup is reduced ( S
208), the armature 22 may start to separate from the upper core 26. In this case, it is assumed that the spring constant K is larger than the currently set value, and the valve closing state holding current ihup reduction processing (S
Since 208) is executed to obtain the spring constant K again, the inaccurate spring constant K is canceled and the accurate spring constant K is determined. Therefore, it is possible to control the electromagnetically driven valve 2 with higher accuracy.

[Other Embodiments] (a). In each of the above-described embodiments, the current value for generating the attracting electromagnetic force (corresponding to the driving electromagnetic force) and the holding electromagnetic force is updated by the spring constant K or the offset amount xo.
It was set to correspond to fs. In the present invention, the adjustment of the current value itself is not limited to such control. For example, as in the disclosed technique shown in the above-mentioned related art, the electromagnetically driven valve 2 is modeled as a spring-mass vibration system, and model parameters including the spring constant K and the offset amount updated in the processing of each of the above-described embodiments. May be used to control the electromagnetically driven valve 2. That is, based on the model parameters including the updated spring constant K and the offset amount xofs and the positions of the armature 22 and the valve body 8, the current value is set so that the operation of the armature 22 and the valve body 8 has the target operating characteristics. The electromagnetically driven valve 2 may be controlled by adjusting.

(B). In each of the above-described embodiments, the updated spring constant K is set to the suction currents iaup and ialow,
Valve closed state holding current ihup or valve opened state holding current ihl
ow and ow, but the attracting currents iaup, ial
It may be reflected only in ow. Even in this case, since the appropriate suction currents iaup and ialow can be output, the electromagnetically driven valve can be reliably driven without supplying unnecessary current.

(C). Although the spring constant K is reflected in the current control of the electromagnetically driven valve 2 in each of the above-described embodiments, it is reflected in the current control by simply detecting the spring constant K or simply detecting the offset amount xofs. You don't have to. That is, it may only function as the spring constant K detecting device / method or the offset amount xofs detecting device / method. In the case of this configuration, the detected spring constant K
Alternatively, when the offset amount xofs deviates from an appropriate range, the performance of the electromagnetically driven valve may be affected, and a manager of the internal combustion engine, for example, a driver in the case of an automobile may be warned.

Further, the spring constant K or the offset amount xofs is reflected in the current control of the electromagnetically driven valve 2 as in each of the above-mentioned embodiments, and when the spring constant K or the offset amount xofs is out of the proper range, the electromagnetic constant is changed. Since the performance of the drive valve 2 is affected, the manager of the internal combustion engine may be warned.

(D). In each of the above-described embodiments, the amount of current is adjusted to reflect the spring constant K in the electromagnetic force, but the electromagnetic force may be adjusted by voltage control or the like.

(E). In the fourth embodiment, the process of updating the spring constant K for the first time when the balance between the holding electromagnetic force and the spring force starts to be lost is applied as a modification of the first embodiment. It can also be applied to the second embodiment or the third embodiment.

That is, the update of the composite spring constant Kc and the offset amount xofs may be executed with the start of the armature 22 moving away from the lower core 24 or the upper core 26 as a trigger.

(F). In the fifth embodiment, the process of detecting and averaging the temporary spring constant Kv is applied a plurality of times as a modified example of the first embodiment, but this process is applied to the second embodiment or the third embodiment. Can also be applied.

(G). In the first to third embodiments, the valve closed state holding current ihup or the valve opened state holding current i immediately before the balance between the electromagnetic holding force and the spring force begins to be lost.
Spring constant K or offset x based on hlow
ofs was set. However, the valve closing state holding current ihu before and after the moment when the balance between the holding electromagnetic force and the spring force begins to be lost.
p or the valve open state holding current ihlow is the spring constant K
And offset amount xofs are reflected. Therefore, the valve closed state holding current ihup or the valve open state holding current ihl immediately after the balance between the electromagnetic holding force and the spring force begins to be lost.
spring constant K or offset amount xof based on ow
You may set s.

(H). In each of the above embodiments, the displacement amount x detected by the displacement sensor unit 7 indicating that the armature 22 has begun to separate from the lower core 24 or the upper core 26.
However, it may be judged by the displacement speed. That is, by providing a displacement speed sensor,
It may be determined that the armature 22 has begun to separate from the lower core 24 or the upper core 26 when the displacement speed is generated from the stopped state of the armature 22.

(I). As in the case of the sixth embodiment, the process of FIG. 21 is executed after it is determined as “NO” in step S400 of the valve opening state holding current ihlow output process (FIG. 8) of the second embodiment. Is also good. The content is the same as the processing of FIG. 18 of the sixth embodiment, except that the valve-opening state holding current ihlow is controlled instead of the valve-closing state holding current ihup. By executing the processing of FIG. 21, in addition to the effect of the second embodiment, in the control at the time of opening the valve, (B) of the sixth embodiment
The same effect as can be obtained.

Further, by combining the processing of FIGS. 8 and 21 together with the processing of FIGS. 4 and 18 described in the sixth embodiment, the above-described operation is performed both when the valve is closed and when it is opened. It is possible to produce the same effect as in (6) of the sixth aspect.

(J). In the fourth embodiment, the temporary spring constant Kv is stored while the holding state can be maintained,
The latest temporary spring constant Kv is set as the spring constant K when the held state cannot be maintained. Instead, the temporary spring constant Kv is not stored and the valve closing state holding current reference value ihup updated when the holding state cannot be maintained.
The spring constant K may be calculated based on b (S725).

Also in the fifth embodiment, the temporary spring constant Kv is stored and accumulated, the spring constant K is obtained from the average value of the temporary spring constant Kv, and the valve closing state holding current reference value ihupb is calculated from this spring constant K. Was calculated. Instead of this
The temporary spring constant Kv is not stored and accumulated, but the gradually decreasing cumulative value ΣΔ
ihup is accumulated N times each time the holding state cannot be maintained, and step S72 is performed based on the value of 1 / N of this accumulated value.
The valve closed state holding current reference value ihupb may be obtained as shown in FIG. The spring constant K is the valve closing state holding current reference value i
It should be calculated from hupb.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of an electromagnetically driven valve used as an intake / exhaust valve of an internal combustion engine for a vehicle as a first embodiment.

FIG. 2 is an operation explanatory view of the electromagnetically driven valve.

FIG. 3 is a flowchart of a valve opening / closing drive process executed by the ECU in the first embodiment.

FIG. 4 is a flow chart of a valve closed state holding current ihup output process.

FIG. 5 is a timing chart showing an example of control according to the first embodiment.

FIG. 6 is a timing chart showing an example of control according to the first embodiment.

FIG. 7 is a flowchart of valve opening / closing drive processing according to the second embodiment.

FIG. 8 is a flowchart of a valve open state holding current ihlow output process.

FIG. 9 is a timing chart showing an example of control according to the second embodiment.

FIG. 10 is a timing chart showing an example of control according to the second embodiment.

FIG. 11 is a flowchart of valve opening / closing drive processing according to the third embodiment.

FIG. 12 is a flowchart of a valve closed state holding current ihup output process.

FIG. 13 is a flowchart of a valve closed state holding current ihup output process according to the fourth embodiment.

FIG. 14 is a timing chart showing an example of control according to the fourth embodiment.

FIG. 15 is a timing chart showing an example of control according to the fourth embodiment.

FIG. 16 is a flowchart of a part of a valve closed state holding current ihup output process according to the fifth embodiment.

FIG. 17 is a timing chart showing an example of control according to the fifth embodiment.

FIG. 18 is a flowchart of a part of a valve closed state holding current ihup output process according to the sixth embodiment.

FIG. 19 is a timing chart showing an example of control according to the sixth embodiment.

FIG. 20 is a timing chart showing an example of control according to the sixth embodiment.

FIG. 21 is a valve-opening state holding current ihlo according to another embodiment.
w Part of the flowchart of the output process.

[Explanation of symbols]

2 ... Electromagnetic drive valve, 4 ... Valve part, 6 ... Electromagnetic drive part, 6a
... Casing, 7 ... Displacement sensor part, 8 ... Valve body, 8a ... Valve shaft, 8b ... Upper end part, 10 ... Cylinder head, 12 ... Combustion chamber, 14 ... Intake port, 16 ... Valve seat, 18 ... Lower retainer, 20 ... Lower spring, 22 ... Armature, 22a
... Armature shaft, 22b ... Lower end, 24 ... Lower core, 24a ... Lower coil, 26 ... Upper core, 26a ...
Upper coil, 28 ... Upper retainer, 30 ... Upper spring, 32 ... ECU, 34 ... Sensors, 36 ... ECU for internal combustion engine control.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 3G018 AB09 BA38 DA24 DA36 DA39                       DA41 DA66 GA04 GA27                 3G092 AA11 DA01 DA02 DA07 DF05                       DG09 EA02 EA13 FA36 FA48                       HA13X HA13Z                 3H106 DA07 DA25 DB03 DB12 DB26                       DB32 DC02 DC17 DD04 EE04                       EE20 FA02 FA07 FB01 FB07                       KK17

Claims (10)

[Claims] 1. An electromagnetic force control device for controlling an electromagnetic force of an electromagnetically driven valve driven by the cooperation of a spring force and an electromagnetic force, wherein the electromagnetic force is adjusted by the output of a drive current. Open / close drive means for driving the open / closed state, open / close state holding means for adjusting the electromagnetic force by the output of the holding current to hold the electromagnetically driven valve in the open / closed state, and the holding current value An electromagnetic force control device for an electromagnetically driven valve, comprising: a correction unit that corrects a drive current value of the opening / closing driving unit based on holding state maintenance information of the electromagnetically driven valve corresponding to the change. 2. An electromagnetic force control device for controlling the electromagnetic force of an electromagnetically driven valve driven by the cooperation of a spring force and an electromagnetic force, wherein the electromagnetic force is adjusted by the output of a drive current. Open / close drive means for driving the open / closed state, open / close state holding means for adjusting the electromagnetic force by the output of the holding current to hold the electromagnetically driven valve in the open / closed state, and the holding current value An electromagnetic drive, comprising: a correction unit that corrects the drive current value of the opening / closing drive unit and the holding current value of the open / close state holding unit based on the holding state maintenance information of the electromagnetically driven valve corresponding to the change. Valve electromagnetic force control device. 3. The holding current value according to claim 1 or 2 until the holding current value is changed and the holding state of the electromagnetically driven valve corresponding to the change cannot be maintained, as the holding state maintaining information. An electromagnetic force control device for an electromagnetically driven valve, comprising a holding state maintaining information detecting means for detecting. 4. The holding state maintenance information detection means according to claim 3, wherein the holding state maintenance information is detected when the electromagnetically driven valve is used, and the correction means is provided when the electromagnetically driven valve is used. An electromagnetic force control device for an electromagnetically driven valve, wherein the current value is corrected in accordance with the holding state maintenance information obtained by the detection means. 5. The holding state maintaining information detecting means according to claim 3, wherein the holding current value is reduced by reducing the holding current value when the opening / closing state holding means holds the electromagnetically driven valve in an open or closed state. An electromagnetic force control device for an electromagnetically driven valve, wherein the current value is changed and the holding current value until the holding state of the electromagnetically driven valve cannot be maintained is obtained as the holding state maintenance information. 6. The holding state maintaining information detecting means according to claim 5, wherein when the holding state of the electromagnetically driven valve changes with the decrease of the holding current value, the holding current value is immediately increased. An electromagnetic force control device for an electromagnetically driven valve, characterized in that the holding state of the electromagnetically driven valve is maintained. 7. The holding state maintaining information detecting means according to claim 6, wherein after the holding state of the electromagnetically driven valve is maintained by increasing the holding current value, the holding current value is decreased by the immediately preceding holding current value. An electromagnetic force control device for an electromagnetically driven valve characterized by returning to a previous value. 8. The holding state maintaining information detecting means according to claim 3, wherein the holding state maintaining information detecting means is changed last time when the opening / closing state holding means holds the electromagnetically driven valve in an open or closed state. An electromagnetic force control device for an electromagnetically driven valve, wherein the holding current value is further changed. 9. The displacement amount of a spring that generates the spring force when holding an electromagnetically driven valve in an open or closed state, and the holding state maintenance according to any one of claims 1 to 8. An electromagnetic force control device for an electromagnetically driven valve, wherein a spring constant equivalent value of an electromagnetically driven valve is obtained based on information, and the current value is corrected according to the spring constant equivalent value. 10. The electromagnetically driven valve according to claim 9,
Either the movable element, which is driven by the cooperation of the spring force of the first spring and the electromagnetic force, or the second spring, which is assumed to have the same spring constant, closes or opens the spring. And a valve element that is urged in one direction. When the movable element is driven, the valve element that is in contact with the movable element is moved to perform an opening / closing operation, and the valve element is fully closed or fully opened. It is an electromagnetically driven valve in which the mover and the valve body are in non-contact with each other, and the correction means is a closed side of the valve body in which the mover and the valve body are not in non-contact state or Based on the displacement amount of the combined spring of the first spring and the second spring on the one side of the open side and the holding state maintenance information, a combined spring constant equivalent value of the first spring and the second spring is calculated. In addition to obtaining, the synthetic spring constant equivalent value, the mover and the valve body In the first spring based on the displacement amount of the combined spring of the first spring and the second spring and the holding state maintenance information on the other of the closed side and the open side of the valve body in the non-contact state. An electromagnetic force control device for an electromagnetically driven valve, wherein an offset amount is obtained, and the current value is corrected according to the offset amount.