JP2002267038A - Control device of solenoid valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control device of a solenoid valve capable of ensuring normal opening/closing operation of a valve element, and appropriately suppressing degradation of its driving responsiveness. SOLUTION: An exhaust valve 10 for the solenoid valve comprises a valve element 19, electric magnets 61 and 62 for applying the electromagnetic force to an armature 28 provided on the valve element 19, and permanent magnets 40 and 46 for applying the magnetic force between the electric magnets 61 and 62 and the armature 28 when the armature 28 is located in the vicinity of the electric magnets 61 and 62. An electronic control device 50 supplies the release current to the electric magnets 61 and 62 so that the magnetic flux opposite to the magnetic flux of the permanent magnets 40 and 46 is generated by the electric magnets 61 and 62 when the armature 28 is released from the condition that the armature is attracted to and held at the part in the vicinity of the electric magnets 61 and 62 by the magnetic force of the permanent magnets 40 and 46. The electronic control device 50 monitors the displacement of the valve element 19, and stops the supply of the release current on the condition that the displacement is not less than the predetermined value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for an electromagnetically driven valve that opens and closes a valve body based on the electromagnetic force of an electromagnet.

[0002]

2. Description of the Related Art Conventionally, there has been known a control device of an electromagnetically driven valve which opens and closes a valve body based on an electromagnetic force of an electromagnet. In this type of device, the armature provided on the valve body is attracted by the electromagnetic force of an electromagnet,
The valve is driven toward its fully open position or fully closed position. Further, a permanent magnet is provided in the core of the electromagnet, and when the armature is located near the electromagnet, the armature is attracted to the electromagnet (accurately, the core) by the magnetic force of the permanent magnet. Therefore, even if the electromagnetic force is not generated in the electromagnet or the electromagnetic force is made sufficiently small, the valve body can be attracted and held at its displacement end (fully open position or fully closed position) by the magnetic force of the permanent magnet. When the body is driven to open and close, power consumption can be reduced.

By the way, the armature is attracted to the electromagnet by the magnetic force of the permanent magnet, and the armature is released from the electromagnet while the valve body is held at one of the displacement ends, and the valve body is moved to the other displacement end. , The magnetic force of the permanent magnet acts between the armature and the electromagnet, and the magnetic force hinders the displacement of the armature.

Therefore, conventionally, Japanese Patent Application Laid-Open No. 2000-1709 describes
As described in Japanese Patent No. 52, when opening the armature from the electromagnet and driving the valve body, an opening current is supplied to the electromagnet so that a magnetic flux in the opposite direction to the magnetic flux of the permanent magnet is generated,
The electromagnetic force generated thereby cancels out the magnetic force of the permanent magnet.

[0005]

By supplying an opening current to the electromagnet to cancel the magnetic force of the permanent magnet, the armature is quickly released from the electromagnet, and the displacement of the armature is hindered. As a result, it is possible to suppress a decrease in the drive response of the valve element.

However, in this conventional apparatus, since the time for supplying the open current to the electromagnet is set to a fixed value, the following inconveniences are caused.
For example, if lubricating oil adheres to the attraction surface between the armature and the electromagnet, an external force (so-called reverse squeezing force) that prevents displacement of the armature when the armature is separated from the electromagnet is generated. Further, for example, when such an electromagnetically driven valve is applied to an intake valve or an exhaust valve of an internal combustion engine, a similar external force is generated by an in-cylinder pressure or the like, and the displacement of the valve body is prevented by the external force. . Then, the armature is released from the electromagnet under such a state that the armature displacement, in other words, the external force which hinders the displacement of the valve body, acts on these armatures and the valve body, and the valve body is moved from one displacement end to the other. When the armature is driven toward the displacement end, supply of the opening current may be stopped before the armature is sufficiently separated from the electromagnet. In such a case,
The armature is pulled back to the electromagnet side again by the magnetic force of the permanent magnet, so that not only the drive response is lowered but also the normal opening and closing operation of the valve element cannot be ensured.

[0007] The present invention has been made in view of such circumstances, and an object thereof is to provide an armature or a valve body for driving a valve body of an electromagnetically driven valve from one displacement end to the other displacement end. An object of the present invention is to provide a control device for an electromagnetically driven valve that can ensure a normal opening and closing operation of a valve body even when an external force acts on the valve and can appropriately suppress a decrease in drive response.

[0008]

The means for solving the above problems and the operation and effects thereof will be described below. According to the first aspect of the present invention, a valve element, an electromagnet for applying an electromagnetic force to an armature provided on the valve element, and a position between the electromagnet and the armature when the armature is located near the electromagnet. A permanent magnet that applies a magnetic force to the armature, and when the armature is released from a state of being attracted and held near the electromagnet by the magnetic force of the permanent magnet, a magnetic flux opposite to the magnetic flux of the permanent magnet is generated by the electromagnet. In an electromagnetically driven valve control device for supplying an opening current to the electromagnet, a detecting means for detecting an amount of displacement of the armature from the electromagnet is provided on condition that the detected amount of displacement is equal to or more than a predetermined amount. Stopping means for stopping the supply of the open current.

According to the above configuration, the supply of the open current is stopped when the armature is sufficiently separated from the electromagnet, so that the armature is reliably displaced in a direction away from the electromagnet. As a result, even when an external force acts on the armature or the valve body, a normal opening / closing operation of the valve body can be ensured, and a decrease in the drive response can be suitably suppressed.

According to a second aspect of the present invention, in the control apparatus for an electromagnetically driven valve according to the first aspect, a setting means for variably setting the magnitude of the opening current so as to decrease as the displacement increases. I am preparing for it.

When the armature is displaced in a direction away from the electromagnet and the distance between the two is increased, the proportion of the magnetic flux generated by the permanent magnet that leaks from between the armature and the electromagnet increases, and the armature and the electromagnet are displaced. And the magnetic force of the permanent magnet acting between them also decreases. Therefore, in such a case, even if the magnitude of the open current is reduced,
The armature is not pulled back to the electromagnet side by the magnetic force of the permanent magnet.

[0012] In this regard, in the invention according to claim 2,
Since the magnitude of the open current is reduced as the displacement of the armature from the electromagnet increases,
It is possible to reduce power consumption while suppressing a decrease in drive response and the like.

According to the third aspect of the present invention, the valve body, the electromagnet for applying an electromagnetic force to the armature provided on the valve body, and the electromagnet and the armature when the armature is located near the electromagnet. And a permanent magnet that applies a magnetic force between the electromagnet and the armature when the armature is released from a state in which the armature is attracted and held near the electromagnet by the magnetic force of the permanent magnet. A controller for detecting a displacement speed of the armature when the solenoid is released from the electromagnet and displaced, and wherein the detected displacement speed is a predetermined value. And stopping means for stopping the supply of the open current on condition that the speed becomes equal to or higher than the speed.

According to the above configuration, the supply of the open current is stopped when the speed at which the armature separates from the electromagnet becomes sufficiently large, so that the armature can be reliably displaced in the direction away from the electromagnet. I will be. As a result, even when an external force acts on the armature or the valve body, a normal opening / closing operation of the valve body can be ensured, and a decrease in the drive response can be suitably suppressed.

According to a fourth aspect of the present invention, in the control apparatus for an electromagnetically driven valve according to the third aspect, the detecting means additionally detects a displacement amount of the armature from the electromagnet, and the detected displacement There is further provided setting means for variably setting the magnitude of the open current so as to decrease as the amount increases.

According to the above configuration, since the magnitude of the open current is reduced as the displacement of the armature from the electromagnet increases, the power consumption can be reduced while suppressing a decrease in drive response and the like. Can be achieved.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a control device for opening and closing an intake valve and an exhaust valve of an internal combustion engine, respectively, will be described below.

In this embodiment, both the intake valve and the exhaust valve are configured as electromagnetically driven valves that are opened and closed based on the electromagnetic force of an electromagnet. Since these intake valves and exhaust valves have the same configuration, peripheral configuration, and drive control mode, an exhaust valve will be described below as an example.

As shown in FIG. 1, this exhaust valve 10
A valve shaft 20 supported reciprocally in the cylinder head 18, an armature shaft 26 disposed coaxially with the valve shaft 20 and reciprocating with the valve shaft 20, and provided at one end of the valve shaft 20. The valve body 19 includes an umbrella section 16 and an electromagnetic drive section 21 for reciprocatingly driving the valve body 19.

An exhaust port 14 communicating with the combustion chamber 12 is formed in the cylinder head 18, and a valve seat 15 is formed around the opening of the exhaust port 14. Valve shaft 2
The exhaust port 14 is opened and closed by the umbrella portion 16 being separated from and seated on the valve seat 15 with the reciprocation of zero.

A lower retainer 22 is fixed to an end of the valve shaft 20 opposite to the end where the umbrella portion 16 is provided. A lower spring 24 is arranged between the lower retainer 22 and the cylinder head 18 in a compressed state. Due to the elastic force of the lower spring 24, the valve element 1
9 is urged in the valve closing direction (upward in FIG. 1).

A disk-shaped armature 28 made of a material having high magnetic permeability is fixed to a substantially central portion of the armature shaft 26 in the axial direction. An armature retainer 30 is fixed to one end of the armature shaft 26. An end of the armature shaft 26 opposite to the end to which the retainer 30 is fixed abuts on an end of the valve shaft 20 on the lower retainer 22 side.

An upper core 32 is positioned and fixed between the upper retainer 30 and the armature 28 in a casing (not shown) of the electromagnetic drive section 21. Similarly, in this casing, a lower core 34 is located and fixed between the armature 28 and the lower retainer 22. Each of the upper core 32 and the lower core 34 is formed in an annular shape from a material having a high magnetic permeability, and the armature shaft 26 is inserted through the center thereof so as to be able to reciprocate.

An upper spring 38 is disposed in a compressed state between the upper cap 36 and the upper retainer 30 provided on the casing. The valve body 19 is urged in the valve opening direction (downward in FIG. 1) by the elastic force of the upper spring 38.

A displacement sensor 52 is attached to the upper cap 36. This displacement amount sensor 52
Outputs a voltage signal that changes according to the distance between the sensor 52 and the retainer 30. Therefore, the displacement of the valve element 19 (= the displacement of the armature 28) can be detected based on this voltage signal.

On the surface of the upper core 32 facing the armature 28, there is formed an annular groove 43 centered on the axis of the armature shaft 26. In the groove 43, an annular upper coil 42 is also provided. I have. The upper coil 42 and the upper core 32 constitute an electromagnet (closing drive electromagnet) 61 for driving the valve element 19 in the valve closing direction.

On the surface of the upper core 32 located on the side opposite to the armature 28, an annular groove 41 is formed centered on the axis of the armature shaft 26. 40 are provided. When the armature 28 is located in the vicinity of the closing drive electromagnet 61, the magnetic force of the permanent magnet 40 acts as an attraction between the armature 28 and the closing drive electromagnet 61 (upper core 32). The closing drive electromagnet 61 is attracted against the elastic force of the upper spring 38. As a result, even when the drive current to the closing drive electromagnet 61 is sufficiently small, the armature 28 is maintained in a state of being attracted to the electromagnet 61. When the armature 28 is attracted to the closing drive electromagnet 61 in this way, the umbrella portion 16 is seated on the valve seat 15 and the exhaust valve 1
0 indicates a fully closed state. The position of the valve element 19 at this time is hereinafter referred to as a “fully closed position”.

On the other hand, in the lower core 34, the armature 2
An annular groove 45 is formed on the surface facing the armature 8 around the axis of the armature shaft 26, and a lower coil 44 also having an annular shape is disposed in the groove 45. An electromagnet (opening electromagnet) 62 for driving the valve element 19 in the valve opening direction is constituted by the lower coil 44 and the lower core 34.

Further, in the lower core 34, the armature 2
An annular groove 47 centering on the axis of the armature shaft 26 is formed on a surface opposite to the surface 8, and a ring-shaped permanent magnet 46 is also disposed in the groove 47. When the armature 28 is located near the opening drive electromagnet 62,
The magnetic force of the permanent magnet 46 acts as an attractive force between the armature 28 and the opening drive electromagnet 62 (lower core 34), and the armature 28 is opposed to the elastic force of the lower spring 24 by this attraction force. 62. As a result, even if the drive current to the open drive electromagnet 62 is sufficiently small, the armature 28 is
2 is held as it is. When the armature 28 is attracted to the opening drive electromagnet 62 in this manner, the umbrella portion 16 is in the state most distant from the valve seat 15 and the exhaust valve 10 is in the fully open state. The position of the valve element 19 at this time is hereinafter referred to as a “fully open position”.

The above-mentioned electromagnets 61 and 62 (more precisely, their respective coils 42 and 44) are energized by an electronic control unit 50 which controls various controls of the internal combustion engine. The electronic control unit 50 includes a CPU, a memory,
A drive circuit for outputting a drive current (exciting current) to the first and the second 62, an input circuit for capturing a detection signal of the displacement sensor 52,
An A / D converter (all not shown) for A / D converting the detection signal is provided.

FIG. 1 shows that no electromagnetic force is generated in each of the electromagnets 61 and 62, and the armature 28 is separated from both of the electromagnets 61 and 62, so that the influence of the magnetic force of each of the permanent magnets 40 and 46 is extremely large. The state of the valve element 19 when it has become smaller is shown. In this state, the armature 28 applies the elastic force of each spring 24, 38 and each permanent magnet 40, 46.
At a substantially intermediate position between the cores 32 and 34 in which the magnetic forces of the two are balanced. In this state, the umbrella portion 16 is connected to the valve seat 15.
, And the exhaust valve 10 is in a half-open state. The position of the valve element 19 in this state is hereinafter referred to as a “neutral position”.

Next, a description will be given of the operation of the exhaust valve 10 which is driven to open and close through energization control of the electromagnets 61 and 62. FIG. 2 shows that after the exhaust valve 10 is held in a fully closed state, the exhaust valve 10 is driven to open to shift to a fully open state, and then further driven to close to shift from the fully open state to a fully closed state again. In this case, the drive current supplied to the closing drive electromagnet 61 (FIG. 13A), the drive current supplied to the open drive electromagnet 62 (FIG. 14B), and the displacement x of the valve body 19 6 is a timing chart showing the time transition of the respective items. When the valve element 19 is driven to open, the distance from the fully closed position to the actual position of the valve element 19 (the valve element 19
And the closing drive electromagnet 61), and the valve body 19
Is driven, the distance from the fully open position to the actual position of the valve element 19 (the distance between the valve element 19 and the opening drive electromagnet 62) is defined as the displacement x of the valve element 19, respectively. .

In the period from timing t0 to t1 in FIG. 2, the holding current Ia is supplied to the closing drive electromagnet 61. The magnitude of the holding current Ia is set so that the armature 28 can be attracted to the closing drive electromagnet 61 and held in that state. Further, the holding current Ia
Is set so that the magnetic flux in the same direction as the magnetic flux generated by the permanent magnet 40 is generated by the closing drive electromagnet 61. Thus, the closing drive electromagnet 6
When the holding current Ia is supplied to the armature 1, a combined force of the electromagnetic force of the closing drive electromagnet 61 and the magnetic force of the permanent magnet 40 acts on the armature 28, and the armature 28 causes the elasticity of the upper spring 38 to be increased. The state is attracted to the closing drive electromagnet 61 against the force. As a result, the valve element 19 is held at the fully closed position.

Next, when the valve body 19 is driven to open from this state, first, the holding current Ia for the closing drive electromagnet 61 is held.
At the same time as the supply of the opening current Ib to the electromagnet 61 is started (timing t1). The direction and magnitude of the opening current Ib are such that a magnetic flux in a direction opposite to the direction of the magnetic flux generated by the permanent magnet 40 is generated by the closing drive electromagnet 61, whereby the magnetic force of the permanent magnet 40 can be canceled. Each is set. Therefore, as shown in FIG. 2A, the direction of the opening current Ib is set to be opposite to the direction of the holding current Ia. When the opening current Ib is supplied to the closing drive electromagnet 61 in this manner, the armature 28 is opened from the closing drive electromagnet 61, and the valve body 19 is moved from the fully closed position by the elastic force of the upper spring 38. It is displaced in the valve opening direction (timing t1 to t4).

When the valve body 19 is further displaced and the displacement x reaches the predetermined amount xo (timing t2), the supply of the opening current Ib to the closing drive electromagnet 61 is stopped. After that, the valve element 19 is moved to its own inertia force and the upper spring 38.
With the elastic force of (1), the valve is further displaced in the valve opening direction.

Thereafter, when the valve element 19 reaches a position on the valve opening side by a predetermined amount from the neutral position (timing t3), the attracting current Ic is supplied to the opening drive electromagnet 62. The magnitude of the attracting current Ic is, for example, of the valve body 19 so that the armature 28 can be attracted to the valve opening side at a predetermined speed and the armature 28 can be surely attracted to the opening drive electromagnet 62. It is set based on the displacement x. Further, the direction of the attracting current Ic is set such that a magnetic flux having the same direction as the magnetic flux generated by the permanent magnet 40 is generated by the open drive electromagnet 62. By supplying the attracting current Ic to the electromagnet 62 for opening drive in this way, a combined force of the electromagnetic force of the electromagnet 62 for opening drive and the magnetic force of the permanent magnet 46 acts on the armature 28. Then, the armature 28 is sucked in the valve opening direction against the elastic force of the lower spring 24 by this resultant force, and accordingly, the valve body 19 reaches its fully open position (timing t4).

When the valve element 19 reaches the fully open position in this way, the holding current Ia is supplied to the opening drive electromagnet 62 thereafter until a predetermined period (timing t4 to t5) elapses. Similar to the current supplied to the closing drive electromagnet 61, the holding current Ia is set so that the armature 28 can be attracted to the open driving electromagnet 62 and held in that state. The direction is set so that the magnetic flux in the same direction as the magnetic flux generated by the opening drive electromagnet 62 is generated by the open drive electromagnet 62. By supplying the holding current Ia to the electromagnet 62 for opening drive in this way, the electromagnet 62
And the magnetic force of the permanent magnet 46 acts. This resultant force causes the armature 28 to oppose the elastic force of the lower spring 24 and open drive electromagnets 62.
, And the valve element 19 is held at the fully open position.

When the valve body 19 is driven to close from this state and is again displaced to the fully closed position (timing t5 to t8).
In the same manner as in the case where the valve element 19 is driven to open from the fully closed position and displaced to the fully open position, the electromagnet 6
1 and the open drive electromagnet 62 are selectively energized.

In this embodiment, the open current Ib to the electromagnet 61 for closing drive and the electromagnet 62 for
Is controlled based on the displacement x of the valve body 19. Hereinafter, a specific procedure of control for supplying and stopping the opening current Ib will be described with reference to FIG.
This will be described with reference to the flowchart of FIG. Note that a series of processes shown in this flowchart is repeatedly executed by the electronic control device 50 at a predetermined control cycle.

In this series of processing, first, it is determined whether or not the current control timing is the opening / closing drive start timing of the exhaust valve 10 (timings t1 and t5 in FIG. 2) (step 100). If it is not the opening / closing drive start timing (step 100: NO), this series of processing is temporarily ended.

On the other hand, if the current control timing is the opening / closing drive start timing (step 100: YES),
Next, the displacement x of the valve body 19 is taken in based on the detection signal of the displacement sensor 52 (step 110). And
It is determined whether or not the displacement amount x is equal to or greater than a predetermined amount xo (step 120).

The predetermined amount xo is such that the armature 28 is sufficiently separated from the electromagnets 61 and 62 and the permanent magnets 40 and 4
This is a determination value for determining that the magnetic force of No. 6 has reached a state where it can be quickly displaced in the valve opening direction or the valve closing direction without being pulled back to the electromagnets 61 and 62 side.
Therefore, when the displacement amount x of the valve body 19 becomes equal to or more than the predetermined amount xo during the opening drive, the valve body 19 is surely secured even if the supply of the opening current Ib to the closing drive electromagnet 61 is subsequently stopped. Then, it is moved away from the electromagnet 61 in the valve opening direction. Similarly, when the displacement x of the valve element 19 is equal to or more than the predetermined amount xo during the closing drive, the opening current Ib to the opening driving electromagnet 62 is thereafter changed.
Is stopped, the valve element 19 is reliably separated from the electromagnet 62 and displaced in the valve closing direction.

If it is determined that the displacement x of the valve body 19 has not reached the predetermined amount xo (step 120:
NO), the open current Ib is calculated based on the displacement x (step 140).

FIG. 4 is a calculation map referred to when calculating the open current Ib. As shown by the solid line in the figure, the open current Ib is a value when the displacement x is “0”,
That is, the initial value Ib0 is set to a size that can reliably cancel the magnetic flux generated by the permanent magnets 40 and 46 by the magnetic flux generated by the electromagnets 61 and 62. Further, the magnitude of the opening current Ib is variably set so as to decrease in proportion to the increase in the displacement x.
The reason why the magnitude of the opening current Ib is variably set based on the displacement amount x in this manner is as follows.

For example, when the displacement x of the valve element 19 increases during the opening drive, the armature 28 and the electromagnet 61 for closing drive increase.
Of the magnetic flux generated by the permanent magnet 40, the proportion of the magnetic flux leaking from between the armature 28 and the closing drive electromagnet 61 also increases, and the armature 28 and the closing drive The magnetic force of the permanent magnet 40 acting between it and the electromagnet 61 is also reduced. In such a case, even if the magnitude of the opening current Ib is reduced, the armature 28 does not return to the closing drive electromagnet 61 due to the magnetic force of the permanent magnet 40. Similarly, when the displacement x of the valve body 19 is increased during the closing drive, the armature 28 is controlled by the magnetic force of the permanent magnet 46 even if the magnitude of the opening current Ib is reduced.
You won't be pulled back to your side.

Therefore, when the displacement x of the valve body 19 increases in this way, it is desirable to reduce the magnitude of the open current Ib accordingly to minimize the power consumption. In the present embodiment, in view of this point, the magnitude of the open current Ib is set to be smaller as the displacement x increases,
The power consumption is reduced while suppressing a decrease in drive response caused by the armature 28 being pulled back by the magnetic force of the permanent magnets 40 and 46.

When the open current Ib is calculated in this manner, the open current Ib is supplied to the electromagnet 61 for closing drive during the open drive and to the electromagnet 62 for open drive during the close drive through the drive circuit of the electronic control unit 50. Each is output (step 150). Thereafter, until the displacement amount x of the valve body 19 becomes equal to or more than the predetermined amount xo, the previous steps 110 to 1 are performed.
The processes up to 50 are repeatedly executed.

On the other hand, when the valve body 19 is further displaced and the displacement x becomes equal to or larger than the predetermined amount xo (step 120: YE
S), since the armature 28 is sufficiently separated from the electromagnets 61 and 62 and is not pulled back to the electromagnets 61 and 62 by the magnetic force of the permanent magnets 40 and 46, the output of the opening current Ib is stopped ( Step 130). Then, this series of processing is temporarily ended.

FIG. 5 shows the displacement x of the valve body 19 (see FIG. 5) when the valve body 19 at the fully closed position is driven to open.
6A is a timing chart showing a temporal transition of (a)) and a drive current (FIG. 5B) supplied to the closing drive electromagnet 61.

As described above, in this embodiment, for example, when the valve body 19 is driven to open from the fully closed position, the electromagnet for closing drive is provided on condition that the displacement x of the valve body 19 is equal to or greater than the predetermined amount xo. The supply of the open current Ib to 61 is stopped. For this reason, when the external force (the external force acting in the valve closing direction) that hinders the displacement of the valve element 19 and the armature 28 is relatively small (see each solid line in FIG. 5), the closing drive electromagnet 6
The open current Ib supplied to the switch 1 rapidly decreases, and the supply time (timing t1 to t2 in FIG. 5) also decreases. As a result, the power consumption of the valve element 19 can be kept small while a normal opening operation is ensured.

On the other hand, when the external force is relatively large and the displacement of the valve element 19 is hindered, the decreasing speed of the opening current Ib decreases, and the supply time (timing t1 to t2 'in FIG. 5).
(See each dashed line in FIG. 5). As a result, the armature 28 is reliably prevented from being pulled back to the closing drive electromagnet 61 side, and the normal opening operation of the valve element 19 is ensured.

Similarly, when the valve body 19 is driven to close from the fully open position, when the external force (external force acting in the valve opening direction) is relatively small, the normal closing operation of the valve body 19 is ensured. While the power consumption is kept small,
When the external force is relatively large, the armature 28 is reliably prevented from being pulled back to the opening drive electromagnet 62 side,
The normal closing operation of the valve element 19 is ensured.

The procedure for controlling the supply and stop of the opening current Ib has been described above by taking the case of opening and closing the exhaust valve 10 as an example. The supply of the opening current Ib and its stop are controlled.

According to the control device of the present embodiment, which controls the supply and stop of the open current Ib in the manner described above, the following operational effects can be obtained.

The displacement x of the valve body 19 (displacement of the armature 28) is monitored, and the supply of the opening current Ib is stopped on condition that the displacement x becomes equal to or more than a predetermined amount xo. Therefore, for example, the armature 28 and each core 32, 3
Armature 28 such as a reverse squeeze force generated by the lubricating oil and a force based on the in-cylinder pressure (internal pressure of combustion chamber 12).
When the armature 28 is sufficiently separated from each of the electromagnets 61 and 62, the supply of the opening current Ib is stopped even when an external force that hinders the displacement is applied to the valve body 19 and the valve body 19. Therefore, the armature 28 is connected to each of the electromagnets 61 and 62.
Is reliably displaced in the direction away from the object.
As a result, a normal opening and closing operation of the valve element 19 can be ensured, and a decrease in the drive response can be suitably suppressed.

Since the magnitude of the opening current Ib is reduced as the displacement x of the valve body 19 increases, it is possible to reduce the power consumption while suppressing a decrease in drive response and the like. Become like

Further, for example, when the timing for stopping the supply of the opening current Ib is determined based on the elapsed time from the start of the supply of the opening current Ib, the normal opening / closing operation of the valve element 19 is performed. In order to secure this, it is necessary to set the supply time of the opening current Ib to be long beforehand in anticipation of a case where a large external force acts on the valve element 19 and the armature 28, and an increase in power consumption cannot be avoided. Become. On the other hand, according to the present embodiment, the time at which the supply of the opening current Ib is stopped is determined based on the displacement x of the valve body 19, and therefore, the supply time of the opening current Ib is determined by the valve body. Each time it is changed in accordance with the actual behavior of the nineteen. As a result, the supply time of the open current Ib is not set to be excessively long, and the power consumption can be more suitably reduced.

As described above, one embodiment of the present invention has been described. However, the embodiment can be modified as follows. In the above embodiment, the opening current Ib is variably set based on the displacement x of the valve element 19, but the opening current Ib can be set to a constant value. In this case, it is desirable to set the magnitude of the open current Ib so that the magnetic force of each of the permanent magnets 40 and 46 can be canceled to “0”.

In the above embodiment, each of the permanent magnets 40, 4
Armature 28 by means of the magnetic force of
Although the predetermined amount xo for determining that the state has not been pulled back to the side is set to a constant value, the predetermined amount xo is variably set so as to increase as the in-cylinder pressure increases. You may. When the external force based on the in-cylinder pressure increases, the supply of the opening current Ib is stopped, and even if the magnetic force of the permanent magnets 40 and 46 acting on the armature 28 is sufficiently small, each of the electromagnets 6
It may be pulled back to the 1,62 side. Therefore, as in the above configuration, the larger the in-cylinder pressure, in other words, the larger the external force acting to pull back the armature 28 toward the electromagnets 61 and 62, the larger the predetermined amount xo. By setting, the normal opening / closing operation of the valve element 19 can be more reliably ensured, and a decrease in the drive responsiveness can be more suitably suppressed.
The in-cylinder pressure may be directly detected by a sensor provided in the combustion chamber 12, or may be based on an engine operating state such as an engine speed or an engine load (for example, a fuel injection amount or an intake air amount). It may be estimated.

The external force applied to the valve element 19 is as follows:
In addition to those based on such in-cylinder pressure, there are those based on intake pressure for intake valves and those based on exhaust pressure for exhaust valves. Therefore, the external force acting on the intake valve based on the differential pressure between the intake pressure and the in-cylinder pressure is estimated, and the external force acting on the exhaust valve based on the differential pressure between the exhaust pressure and the in-cylinder pressure is estimated. The predetermined amount xo may be variably set based on the above.

Further, the displacement of the valve element 19 is hindered by the resistance of the sliding portion thereof (for example, the sliding portion between the cores 32 and 34 and the cylinder head 18). Further, the magnitude of this resistance has a correlation with the temperature of the lubricating oil at the sliding portion, and increases as the temperature decreases and the viscosity of the lubricating oil increases. Therefore, the magnitude of this resistance is estimated based on the engine operating state (for example, the engine cooling water temperature, the integrated value of the fuel injection amount, and the like). Based on the magnitude of this resistance, the larger the resistance, the more the predetermined amount xo This may be variably set so as to increase.

In the above embodiment, the displacement x of the valve body 19
Focusing on the fact that the magnetic force of the permanent magnets 40 and 46 acting between the armature 28 and each of the electromagnets 61 and 62 decreases when the displacement increases, the magnitude of the opening current Ib decreases so that the displacement x decreases as the displacement x increases. Is variably set. Here, when the displacement x of the valve element 19 increases, the magnetic force of the permanent magnets 40 and 46 acting between the armature 28 and each of the electromagnets 61 and 62 certainly decreases. Various external forces (in-cylinder pressure,
External force based on exhaust pressure and resistance at sliding part of valve element 19)
, The armature 28 is pulled back to the electromagnets 61 and 62 by this external force. In view of this point, for example, as shown by a one-dot chain line and a two-dot chain line in FIG. 4, the opening current Ib
May be set to decrease as the external force increases.

When the valve body 19 is driven from the fully closed position or the fully open position, the greater the displacement speed of the valve body 19 (= the displacement speed of the armature 28), even if the displacement amount x is the same, The possibility that the armature 28 is pulled back toward the electromagnets 61 and 62 is reduced. Therefore, the displacement speed may be calculated from the displacement amount x of the valve element 19, and may be sequentially corrected so that the predetermined amount xo decreases as the displacement speed increases.

Regarding the above displacement speed, it is possible to adopt a configuration in which the supply of the opening current Ib is stopped when the displacement speed of the valve element 19 becomes equal to or higher than a predetermined speed. Also in this case, the supply of the opening current Ib and the stop thereof can be controlled according to the same procedure as the procedure shown in the flowchart of FIG. That is, in the series of processes shown in this flowchart, step 11
At 0, the displacement amount x is taken in and the displacement speed is calculated. At step 120, it is determined whether or not the displacement speed is equal to or higher than a predetermined speed. If the speed is less than the predetermined speed (step 120: NO), step 1
If the speed is equal to or higher than the predetermined speed (step 120: YES), the supply of the opening current Ib is stopped (step 130).

Further, when the supply of the opening current Ib is stopped when the displacement speed of the valve element 19 becomes equal to or higher than the predetermined speed, the same manner as in the case where the predetermined amount xo is variably set. The predetermined speed can be variably set based on various external forces (external force based on in-cylinder pressure, suction / exhaust pressure, and resistance at the sliding portion of the valve element 19).

In the above embodiment, the control device according to the present invention is applied to the control device of the electromagnetically driven valve functioning as an intake valve or an exhaust valve of an internal combustion engine. However, the present invention is not limited to this. The technical idea that can be grasped from the above embodiment and its modified example will be described below.

(A) In the control device for an electromagnetically driven valve according to any one of claims 1 to 4, the valve body functions as an intake valve or an exhaust valve of an internal combustion engine, and the stopping means is provided at the position. An electromagnetically driven valve control device for variably setting a fixed amount based on the in-cylinder pressure of the internal combustion engine.

(B) In the control apparatus for an electromagnetically driven valve according to the above (a), the stopping means estimates the in-cylinder pressure based on an engine operating state.

(C) In the control device for an electromagnetically driven valve according to any one of claims 1 to 4, the valve body functions as an intake valve or an exhaust valve of an internal combustion engine, and the stopping means is provided with the valve. An electromagnetically driven valve control device for estimating a sliding resistance of a body based on an engine operating state, and variably setting the predetermined amount so as to increase as the estimated sliding resistance decreases.

(D) The control device for an electromagnetically driven valve according to the above (c), wherein the stopping means estimates the sliding resistance based on the engine cooling water temperature.

(E) In the control device for an electromagnetically driven valve according to claim 1 or 2, the detecting means also detects the displacement speed of the armature, and the stopping means increases the detected displacement speed. A control device for an electromagnetically driven valve that variably sets the predetermined amount so as to decrease as the value decreases.

According to the configurations described in the above (a) to (e), the predetermined amount can be set to a value commensurate with the external force based on the in-cylinder pressure, the resistance of the sliding portion, or the displacement speed of the valve element. Therefore, a normal opening and closing operation of the valve body can be reliably ensured, and a decrease in drive response can be suitably suppressed.

(F) In the control device for an electromagnetically driven valve according to claim 2 or 4, the valve body functions as an intake valve or an exhaust valve of an internal combustion engine, and the setting means increases the displacement. A control device for an electromagnetically driven valve that variably sets a reduction rate when the magnitude of the open current is reduced in accordance with the following equation so as to decrease as the in-cylinder pressure of the internal combustion engine increases.

(G) In the control device for an electromagnetically driven valve according to the above (f), the setting means estimates the in-cylinder pressure based on an engine operating state.

(H) In the control device for an electromagnetically driven valve according to claim 2 or 4, the valve body functions as an intake valve or an exhaust valve of an internal combustion engine, and the setting means slides the valve body. The dynamic resistance is estimated based on the engine operating state, and the decreasing rate when the magnitude of the opening current is reduced according to the increase in the displacement amount is changed so as to decrease as the estimated sliding resistance decreases. Control device of electromagnetic drive valve to be set.

(I) The electromagnetically driven valve control device according to (h), wherein the setting means estimates the sliding resistance based on the engine cooling water temperature.

According to the configurations described in the above (f) to (i), the rate of decrease when the open current is reduced in accordance with the increase in the displacement of the armature is reduced by the external force based on the in-cylinder pressure and the resistance of the sliding portion. Therefore, a normal opening and closing operation of the valve body can be reliably ensured, and a decrease in the drive response can be suitably suppressed.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an exhaust valve and a control device thereof.

FIG. 2 is a timing chart showing an example of a temporal transition of a drive current supplied to an electromagnet and a displacement amount of a valve body.

FIG. 3 is a flowchart showing a procedure for controlling supply and stop of the open current.

FIG. 4 is a calculation map showing a relationship between an opening current and a displacement amount of a valve body.

FIG. 5 is a timing chart showing an example of a temporal change of a displacement amount of a valve body and a drive current supplied to an electromagnet.

[Description of Signs] 10 ... exhaust valve, 12 ... combustion chamber, 14 ... exhaust port, 15
... valve seat, 16 ... umbrella part, 18 ... cylinder head, 19 ... valve body, 20 ... valve shaft, 21 ... electromagnetic drive unit, 22 ... lower retainer, 24 ... lower spring, 26 ... armature shaft, 28
… Armature, 30… Applitainer, 32… Upper core, 34… Lower core, 36… Upper cap, 38… Upper spring, 40… Permanent magnet, 41… Groove, 42… Upper coil, 43… Groove, 44… Lower coil, 45… Groove ,
46: permanent magnet, 47: groove, 50: electronic control unit, 52
... Displacement sensor 61, electromagnet for closing drive, 62 electromagnet for driving open.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01F 7/18 H01F 7/18 G

Claims (4)

[Claims] A valve body, an electromagnet for applying an electromagnetic force to an armature provided on the valve body, and a magnetic force acting between the electromagnet and the armature when the armature is located near the electromagnet. A permanent magnet that causes the permanent magnet to be released from a state in which the armature is attracted and held near the electromagnet by the magnetic force of the permanent magnet. In the control device for an electromagnetically driven valve that supplies an opening current, a detection unit that detects an amount of displacement of the armature from the electromagnet, and a condition that the detected amount of displacement is equal to or more than a predetermined amount. A control device for an electromagnetically driven valve, comprising: a stop means for stopping supply. 2. The electromagnetically driven valve control device according to claim 1, further comprising setting means for variably setting the magnitude of the open current so as to decrease as the displacement amount increases. 3. A valve, an electromagnet for applying an electromagnetic force to an armature provided on the valve, and a magnetic force acting between the electromagnet and the armature when the armature is located near the electromagnet. A permanent magnet that causes the permanent magnet to be released from a state in which the armature is attracted and held near the electromagnet by the magnetic force of the permanent magnet. In the electromagnetically driven valve control device that supplies an opening current, a detecting unit that detects a displacement speed of the armature when the armature is displaced by being released from the electromagnet; and that the detected displacement speed is equal to or higher than a predetermined speed. A control device for an electromagnetically driven valve, comprising: a stop means for stopping supply of the open current in a condition. 4. The control device for an electromagnetically driven valve according to claim 3, wherein said detecting means additionally detects a displacement amount of said armature from said electromagnet, and decreases as said detected displacement amount increases. The electromagnetically driven valve control device further includes setting means for variably setting the magnitude of the open current.