JPH11210916A - Control device for solenoid driven valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To maintain good responsiveness and to effectively prevent occurring of hunting by providing a gain exchanging means which sets as control gain of feedback control to a low gain when a valve element is kept at a displacement end and sets it to a high gain when the valve element removes between displacement ends. SOLUTION: A control gain is amplified largely when a valve element 22 moves from a vale closing end to a valve opening end, and is amplitude slightly when the valve member 22 reaches the valve opening end. When the control gain is large, forward switching element 86 and a backward switching element 88 are driven at a large duty ratio. Good responsiveness of exciting current In to a commanding current Ic is secured. When the control gain is small, the forward switching element 86 and the backward switching element 88 are driven at a small duty ratio. Accurate controlling of the exciting current supplied to a lower coil 54 prevents the generation of hunting. In addition, a control device of a solenoid driven valve 20 prevents responsiveness from being damaged.

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, and more particularly to a control of an electromagnetically driven valve suitable for controlling an electromagnetically driven valve functioning as an intake valve or an exhaust valve of an internal combustion engine for a vehicle. Related to the device.

[0002]

2. Description of the Related Art Conventionally, for example, Japanese Patent Application Laid-Open No. 8-2846.
As disclosed in Japanese Patent No. 26, an electromagnetically driven valve that functions as an intake valve or an exhaust valve of an internal combustion engine is known. The conventional electromagnetically driven valve includes a valve body, an armature displaced integrally with the valve body, an elastic body for urging the armature to a neutral position, electromagnetic coils disposed above and below the armature, and a core holding the electromagnetic coil. Have. In the above-described conventional electromagnetically driven valve, when an exciting current is supplied to the electromagnetic coil, a magnetic flux that flows back and forth inside and outside the electromagnetic coil through the core and the armature is generated. At this time, an electromagnetic force acts between the core and the armature to attract them. Therefore, according to the above-mentioned conventional electromagnetically driven valve, the valve element can be opened and closed by alternately supplying the exciting current to the electromagnetic coils disposed above and below the armature.

In the above-mentioned conventional electromagnetically driven valve, the exciting current supplied to the electromagnetic coil is controlled by feedback control (hereinafter referred to as F / B control). F / B
The control command current is set to be large when the valve is away from the seating position, and to be small when the valve is close to the seating position. When the exciting current changes in the same manner as the command current, the valve element can be reliably attracted to the vicinity of the seating position, and the valve element can arrive at the seating position gently. Therefore, according to the conventional control device for an electromagnetically driven valve, stable operability can be ensured while excellent silence is ensured.

[0004]

In the above-described electromagnetically driven valve, it is effective to increase the control gain of the F / B control in order to ensure the response of the exciting current. However, when the control gain is large, the phenomenon that the exciting current fluctuates sharply with respect to the command current, that is, hunting is likely to occur.

By the way, high responsiveness is not always required for the exciting current used for controlling the electromagnetically driven valve. Specifically, when the valve element is displaced between the valve opening end and the valve closing end, high responsiveness to the exciting current is required. On the other hand, when the valve body arrives at the seating position and maintains that state, high responsiveness to the exciting current is not required. Therefore, when the state is maintained after the valve body reaches the seating position, it is not necessary to increase the control gain of the F / B control. Therefore, after the valve body reaches the seating position, the F / B
By lowering the control gain of the control, it is possible to effectively prevent hunting from occurring without impairing the responsiveness of the electromagnetically driven valve.

In the above-mentioned conventional control device for an electromagnetically driven valve, the control gain of the F / B control is always kept constant.
In this regard, the above-described conventional electromagnetically driven valve control device still has room for improvement in improving control accuracy. The present invention has been made in view of the above points, and an object of the present invention is to provide a control device for an electromagnetically driven valve that can effectively prevent hunting while ensuring excellent responsiveness.

[0007]

The above object is achieved by the present invention.
As described in the above, an armature displaced together with the valve body, an electromagnet for applying an electromagnetic force to the armature, excitation current detection means for detecting an excitation current actually flowing through the electromagnet, and the excitation current is a predetermined command current Current control means for performing feedback control of the exciting current so as to approach
Wherein the current control means applies first voltage to the electromagnet in a positive direction and second current application means applies a voltage to the electromagnet in a reverse direction. Gain switching means for setting the control gain of the feedback control to a low gain when the valve body is held at the displacement end and a high gain when the valve body is displaced between the displacement ends. This is achieved by a control device for an electromagnetically driven valve, comprising:

In the present invention, the control gain of the F / B control is set to a low gain when the valve body is held at the valve opening end or the valve closing end, and the valve body is displaced between the valve opening end and the valve closing end. Switch to high gain. When the control gain is small, a voltage is applied to the electromagnet with a small duty ratio. When a voltage is applied with a small duty ratio, no large electromagnetic force is generated between the electromagnet and the armature. In this case, hunting of the exciting current can be prevented. On the other hand, when the control gain is large, a voltage is applied to the electromagnet at a large duty ratio. In this case, the response of the exciting current can be kept high. Therefore, according to the present invention, excellent responsiveness can be ensured and hunting can be prevented.

[0009] The object of the present invention is as described in claim 2.
An armature that displaces with the valve body, an electromagnet that applies an electromagnetic force to the armature, an excitation current detection unit that detects an excitation current that actually flows through the electromagnet, and the excitation current approaches a predetermined command current. A control device for an electromagnetically driven valve, comprising: a current control unit that performs feedback control of an exciting current; wherein the current control unit applies a voltage to the electromagnet in a positive direction; And a second voltage applying means for applying a voltage in the opposite direction to the second voltage applying means when the deviation between the command current and the exciting current exceeds a first predetermined value. The first voltage applying means to an operating state, and when the deviation falls below a second predetermined value which is smaller than the first predetermined value, the second voltage is used instead of the first voltage applying means. Voltage It is achieved by the control apparatus for an electromagnetically driven valve, characterized in that it comprises a voltage switching means to the pressurizing means actuated state.

In the present invention, when the deviation between the exciting current actually flowing through the electromagnet and the ideal command current exceeds a first predetermined value, the voltage switching means replaces the first voltage applying means with the first voltage applying means. The operation state is switched to the voltage application means. Further, when the deviation is smaller than a second predetermined value, the voltage switching means switches the operation state to the second voltage applying means instead of the first voltage applying means. If the deviation fluctuates between the first predetermined value and the second predetermined value after the exciting current approaches the value of the command current, the operation state of the voltage applying means does not switch. If the operation state of the voltage applying means is not switched, only the voltage by the original voltage applying means is applied to the electromagnet, and only the electromagnetic force associated with the applied voltage is generated between the electromagnet and the armature. Thus, according to the present invention,
If the deviation fluctuates between a first predetermined value and a second predetermined value, hunting can be prevented by not frequently changing the electromagnetic force generated between the electromagnet and the armature. .

Further, the above object is achieved by an armature displaced together with a valve body, an electromagnet for applying an electromagnetic force to the armature, and an excitation for detecting an excitation current actually flowing through the electromagnet. Current control means for performing feedback control of the exciting current so that the exciting current approaches a predetermined command current, a control device for an electromagnetically driven valve comprising: A first voltage applying means for applying a voltage in the positive direction, and a second voltage applying means for applying a voltage in the reverse direction to the electromagnet, and a deviation between the command current and the exciting current. Wherein both of the first voltage applying means and the second voltage applying means are deactivated when the power supply belongs to a predetermined dead zone. It is achieved.

In the present invention, when the deviation between the exciting current actually flowing through the electromagnet and the ideal command current exceeds the dead zone, a duty ratio is calculated, and a voltage based on the duty ratio is applied to the electromagnet. . If the deviation is within the dead zone, no voltage is applied to the electromagnet. If no voltage is applied to the electromagnet, no electromagnetic force is generated between the electromagnet and the armature to attract the two. Therefore, according to the present invention, it is possible to prevent hunting from occurring by not generating an electromagnetic force between the electromagnet and the armature unnecessarily when the deviation fluctuates in the dead zone region.

[0013]

FIG. 1 shows an overall configuration diagram of a control device of an electromagnetically driven valve 20 according to an embodiment of the present invention. The electromagnetically driven valve 20 has a valve body 22. The valve body 22 is disposed inside the cylinder head 24 with its lower end in the figure exposed to the combustion chamber of the internal combustion engine. The valve body 22 constitutes an exhaust valve or an intake valve of the internal combustion engine. A port 26 is provided in the cylinder head 24. Port 26
Is provided with a valve seat 28. When the valve body 22 separates from or is seated on the valve seat 28, the port 2
6 is controlled.

A valve shaft 30 is fixed to the valve body 22. The valve shaft 30 is slidably held in the axial direction by a valve guide 32. The valve guide 32 is supported by a lower cap 34. An armature holder 36 is fixed to the valve shaft 30. Armature holder 3
Numeral 6 is made of a non-magnetic material having high hardness or a material having low magnetic properties.

A lower retainer 38 is fixed to a lower end of the armature holder 36. A lower spring 40 is provided between the lower retainer 38 and the lower cap 34. The lower spring 40 includes a lower retainer 38.
That is, the armature holder 36 is urged upward. On the other hand, an upper retainer 42 is fixed to the upper end of the armature holder 36. The lower end of an upper spring 44 is in contact with the upper part of the upper retainer 42. An upper cap 46 is provided on the outer periphery of the upper spring 44. An adjuster bolt 48 is screwed to the upper cap 46. The lower end of the adjuster bolt 48 is in contact with the upper end of the upper spring 44. The upper spring 44 urges the upper retainer 42, that is, the armature holder 36 downward.

An armature 50 is joined to the armature holder 36. The armature 50 is an annular member made of a soft magnetic material. An upper coil 52 is provided above the armature 50, and a lower coil 54 is provided below the armature 50. The upper coil 52 is held by the upper core 56, while the lower coil 54 is held by the lower core 58. The upper core 56 and the lower core 58 are both members made of a magnetic material.

An outer cylinder 60 is provided around the outer periphery of the upper core 56 and the lower core 58. The outer cylinder 60 holds the upper core 56 and the lower core 58 such that a predetermined space is secured between the upper core 56 and the lower core 58. Further, the armature 50 described above is maintained at a neutral position between the urging force of the upper spring 44 and the urging force of the lower spring 40. The adjuster bolt 48 described above is adjusted so that the neutral position of the armature 50 is located at an intermediate position between the upper core 56 and the lower core 58.

The system of this embodiment is an electronic control unit for an engine (hereinafter referred to as E) as a control device for the electromagnetically driven valve 20.
CU) 62. The ECU 62 is connected to a crank angle sensor 64. The crank angle sensor 64 generates a pulse signal according to the rotation angle of the crankshaft of the internal combustion engine. The ECU 62 detects the crank angle based on the pulse signal. The ECU 62 includes the upper coil 52 and the lower coil 54 described above.
Is connected. The ECU 62 controls a command current to be supplied to the upper coil 52 or the lower coil 54 based on the detected crank angle.

Hereinafter, the operation of the electromagnetically driven valve 20 will be described with reference to FIG. 2A shows the displacement of the valve element 22, FIG. 2B shows the command current to be supplied to the upper coil 52, and FIG. 2C shows the command current to be supplied to the lower coil 54. Show. The control device of the electromagnetically driven valve 20 includes:
The F / B control of the exciting current is performed so that the exciting current matches the command current shown in FIGS.

In the electromagnetically driven valve 20, when no exciting current flows through the upper coil 52 and the lower coil 54, the armature 50 is maintained at the neutral position.
In this state, when the supply of the exciting current to the lower coil 54 is started, the lower coil 5
4. A magnetic flux is generated that flows through the armature 50 and the air gap formed therebetween. When the above-described magnetic flux is generated, an electromagnetic force for attracting both is generated between the lower coil 54 and the armature 50.

When the above-described electromagnetic force acts on the armature 50, the armature 50, that is, the valve body 22, is displaced downward in FIG. 1 against the urging force of the lower spring 40. After that, the displacement is
The process is continued until 0 contacts the lower core 58. 2, the time t ₀ before showing a state where the armature 50 is held in the closed end. As shown in FIG. 2 (B), when the holding of the armature 50, the command current to the upper coil 52 is controlled to a predetermined holding current I _H. The holding current I _H is
This is the minimum current required to hold the armature 50 at the valve-close end.

When a valve opening request is issued to the valve element 22, the command current changes from I _H to “0” (time t ₀ in FIG. 2). When the supply of the command current to the upper coil 52 is stopped, the exciting current eventually disappears, and the electromagnetic force required to attract and hold the armature 50 at the valve closing end disappears.
When the electromagnetic force disappears, the valve body 22 is displaced downward in FIG. 1 by the urging force of the upper spring 44.

As shown in FIG. 2C, the upper coil 5
After the supply of the command current to 2 is stopped, if the time t ₁ has elapsed the predetermined time, the command current to the lower coil 54 is controlled to a predetermined attraction current I _A. Attraction current I _A is supplied continuously for a predetermined time T _A. When the command current is maintained in the suction current I _A as described above, eventually the lower coil 54 is excited current is supplied, the lower core 58 and the armature 50
Electromagnetic force is generated to attract to the side. When the above electromagnetic force acts on the armature 50, the valve body 22 is displaced downward in FIG. 1 against the urging force of the lower spring 40.

The armature 50 and the lower core 58
Between the armature 50 and the lower core 58 rapidly increases to a large value. On the other hand, the upper spring 44 and the lower spring 40
Of the armature 50 increases proportionally as the armature 50 approaches the lower core 58. Therefore, in order to reliably and quietly adsorb and hold the valve body 22 at the valve opening end, a large current is applied when the valve body 22 is away from the valve opening end, and the valve body 22 is A small current when approaching the lower coil 54.
Preferably.

In the present embodiment, the command current to the lower coil 54, as shown in FIG. 2 (C), the valve body 22 by a predetermined time T _A has passed is the time t ₂ in proximity to the open end, the transition It is controlled to a current I _M. The transition current I _M is a current that decreases as the armature 50 approaches the valve-open end.
The transition current I _M is continuously supplied for a predetermined time T _M. When the predetermined time T _M has elapsed the valve body 22 is time t ₃ and the lower core 58 abuts, the command current to the lower coil 54 is controlled to the holding current I _H. The holding current I _H is a minimum necessary current for holding the armature 50 by suction at the valve closing end.

Therefore, after the supply of the holding current I _H to the upper coil 52 is stopped, a predetermined command current is supplied to the lower coil 54 at a predetermined timing, so that the valve element held at the valve closing end is maintained. 22 can be displaced to the valve opening end. Thereafter, after the supply of the holding current I _H to the lower coil 54 is stopped, a predetermined command current is supplied to the upper coil 52 at a predetermined timing, so that the valve body 22 is displaced from the valve opening end to the valve closing end. Can be done.

As described above, according to the electromagnetically driven valve 20 of the present embodiment, the predetermined exciting current is alternately supplied to the upper coil 52 and the lower coil 54 at a predetermined timing, so that the valve element 22 can be reliably and reliably. The opening and closing operation can be performed quietly. As described above, the ECU 62 performs F / B control on the exciting current supplied to the lower coil 54. That is, the exciting current supplied to the lower coil 54 is controlled so that the deviation between the command current that changes in a predetermined order set in advance and the exciting current that actually flows through the lower coil 54 becomes “0”. In this F / B control, it is effective to increase the control gain in order to increase the response of the exciting current. However, as the control gain is larger, hunting is more likely to occur in the exciting current.

In the electromagnetically driven valve 20, when the valve body 22 is displaced between the valve opening end and the valve closing end, it is preferable that the exciting current exhibits a high response. On the other hand, when the state is maintained after the valve element 22 arrives at the valve-opening end, the excitation current does not need to exhibit high responsiveness. For this reason, the electromagnetically driven valve 20
In the above, after the valve body 22 is held at the valve-open end, F /
The control gain of the B control is to be reduced. According to the above process, unnecessary hunting can be prevented from occurring without impairing the responsiveness of the electromagnetically driven valve 20.

FIG. 3 is a circuit diagram of a control circuit formed inside the ECU 62. FIG. 3 shows a control circuit for the lower coil 54. The ECU 62 includes a similar circuit for the upper coil 52. Since these circuits do not differ in configuration, the configuration and operation of only the control circuit of the lower coil 54 will be described below.

As shown in FIG. 3, the ECU 62 has a command circuit 66 built therein. The command circuit 66 is a circuit that calculates a command signal to be supplied to the lower coil 54 based on the output of the crank angle sensor 64. In the command circuit 66,
A subtraction circuit 68 is connected. The command circuit 66 outputs the above command current (I _c ) to the subtraction circuit 68. A current detection circuit 91 to be described later is connected to the subtraction circuit 68. The excitation current (I _m ) output from the current detection circuit 91 is input to the subtraction circuit 68. Subtraction circuit 68, the deviation between the command current I _c and the excitation current I _m I _c -
Computing the I _m. The main switching element control circuit 70 and the sub switching element control circuit 72
Is connected. The subtraction circuit 68 supplies the calculated result to the main switching element control circuit 70 and the sub switching element control circuit 72.

The output terminals of the sub-switching element control circuit 72 include a forward output terminal 72f and a reverse output terminal 72r.
And are arranged. The base terminal of the forward switching element 74 is connected to the forward output terminal 72f. On the other hand, the base terminal of the reverse switching element 76 is connected to the reverse output terminal 72r. Both the forward switching element 74 and the reverse switching element 76 are configured by NPN transistors.

The sub-switching element control circuit 72, when the deviation I _c -I _m ≧ 0, the forward switching device 74 is turned on, and if the deviation I _c -I _m <0, reverse switching device 76 Is turned on. The forward switching element 74 and the reverse switching element 76 are not simultaneously turned on.

The main switching element control circuit 70
Switching circuit 78, gain switching command circuit 80, triangular wave oscillation
A circuit 82 and a comparison circuit 84 are provided. Gain off
The result calculated by the subtraction circuit 68 is supplied to the conversion circuit 78.
Is done. The two gain switching circuits 78 are arranged in parallel.
Analog switches 92 and 94 are provided. analog
Both the switches 92 and 94 have the difference I
_c-I_m, And resistors 98, 98 respectively.
100 are connected in series. The resistance value of the resistor 98 (R
₁) Is the resistance value (R_TwoTo a smaller value than
Is set. Both resistors 98 and 100 are operational amplifiers
102 is connected to the inverting input terminal. Operational amplifier 1
The non-inverting input terminal 02 is grounded. Also, Opea
A resistor is connected between the inverting input terminal and the output terminal of the amplifier 102.
(Resistance R _Three) 104 is connected.

In the above configuration, the resistor 98, the operational amplifier 102, and the resistor 104 form an inverting amplifier circuit. Similarly, the resistor 100, the operational amplifier 102, and the resistor 104 also constitute an inverting amplifier circuit. Therefore, when the analog switch 92 is turned on, the operational amplifier 1
A voltage (V = − (R ₃ / R ₁ ) ·) obtained by amplifying the deviation I _c −I _m by a predetermined control gain R ₃ / R ₁ is provided to an output terminal of the second circuit.
(I _c -I _m)) appear. When the analog switch 94 is turned on, the voltage (V = − (R ₃ / R ₂ ) ·) obtained by amplifying the deviation I _c −I _m with a predetermined control gain R ₃ / R ₂ is output to the output terminal of the operational amplifier 102. (I _c -I _m))
Appears.

As described above, the resistance R ₁ is smaller than the resistance R ₂ . Therefore, according to the above configuration, a large control gain can be realized by turning on the analog switch 92, and a small control gain can be realized by turning on the analog switch 94. The gain switch command circuit 80 is connected to the analog switch 92. In addition, the analog switch 9
4 has a gain switching command circuit 8 via an inverter 96.
0 is connected. The gain switching command circuit 80 is a circuit that outputs an ON signal while the valve body 22 is displaced from the valve-closing end to the valve-opening end, and outputs an OFF signal when the valve body 22 is held at the valve-opening end. is there. Accordingly, the analog switch 92 is turned on while the valve body 22 is displaced from the valve-closed end to the valve-opened end. The analog switch 94 is turned on when the valve body 22 is held at the valve opening end.
Note that the analog switches 92 and 94 are not simultaneously turned on.

For this reason, according to the control device for the electromagnetically driven valve 20 of the present embodiment, the deviation I _c -I _m is increased by the large control gain R _{3 in} the process in which the valve body 22 is displaced from the closed end to the open end. / R
_After amplifying at ₁ , and after the valve body 22 reaches the valve opening end,
The deviation I _c -I _m may be amplified by a small control gain R ₃ / R _2. The output signal of the operational amplifier 102 is input to the comparison circuit 84. Further, a triangular wave oscillation circuit 82 is connected to the comparison circuit 84. Triangular wave oscillation circuit 82
Is a circuit that generates a triangular wave that repeatedly increases and decreases within a predetermined range at a predetermined frequency. The comparison circuit 84 includes the operational amplifier 10
2 (hereinafter, this value is referred to as _Vref ) and the triangular wave generated by the triangular wave oscillation circuit 82 (hereinafter, this value is V _tri)
And outputs a high signal or a low signal according to the magnitude relationship between the two.

The output terminal of the comparison circuit 84 is provided with a forward output terminal 70f and a reverse output terminal 70r. At the forward output terminal 70f, a high signal appears when V _ref <V _tri and a low signal appears when V _ref > V _tri . Also, V _ref > V is applied to the reverse output terminal 70r.
_A high signal appears when _tri , and a low signal appears when _Vref <Vtri. The high signal and the low signal form a duty signal that repeatedly outputs a pulse signal at a predetermined cycle. Comparison circuit 84, the deviation | I _c -I _m | larger the is configured to increase the duty ratio of these duty signals.

The above-mentioned duty signal has a deviation I _c -I
_In the region where _m ≧ 0, the voltage is supplied to the base terminal of the forward switching element 86. In the region where the deviation I _c −I _m <0,
It is supplied to the base terminal of the reverse switching element 88. Both the forward switching element 86 and the reverse switching element 88 are formed by NPN transistors.

Therefore, when the deviation I _c −I _m ≧ 0,
It turned on at a duty ratio corresponding to the magnitude | forward switching device 86 is deviation | I _c -I _m. Also,
If the deviation I _c -I _m <0, the reverse switching device 88 is the deviation | turned on at a duty ratio corresponding to the magnitude | I _c -I _m. The forward switching element 86 and the reverse switching element 88 are not simultaneously turned on.

The collector terminal of the forward switching element 74 and the collector terminal of the reverse switching element 76 are both connected to the power supply terminal 90. On the other hand, the emitter terminal of the forward switching element 86 and the emitter terminal of the reverse switching element 88 are both grounded. The inflow terminal 54 a of the lower coil 54 is connected to the emitter terminal of the forward switching element 74 and the collector terminal of the reverse switching element 88 via a current detection circuit 91. Current detection circuit 91 is a circuit for outputting an electric signal corresponding to the excitation current I _m that actually flows through the lower coil 54. The output signal of the current detection circuit 91 is supplied to the subtraction circuit 68 described above. On the other hand, the outflow terminal 54b of the lower coil 54 is connected to the collector terminal of the forward switching element 86 and the emitter terminal of the reverse switching element 76.

[0041] In the control apparatus for an electromagnetically driven valve 20 of the present embodiment, in the case of deviation I _c -I _m ≧ 0, together with the forward switching device 74 is always turned on, the forward switching device 86 deviation | It is turned on at a duty ratio according to the magnitude of I _c −I _m | and the control gain (R ₃ / R ₁ or R ₃ / R ₂ ). Also, the deviation I _c -I _m <
In the case of 0, together with the reverse switching device 76 is always turned on, reverse switching device 88 is deviation | I _c -I _m | size and the control gain (R ₃ / R ₁ or R ₃ / R ₂ ) Turns on with a duty ratio according to ₂ ).

As described above, the control gain is greatly amplified when the valve body 22 is displaced from the valve-closing end to the valve-opening end, and is small when the valve body 22 reaches the valve-opening end. When the control gain is large, the forward switching element 86 and the reverse switching element 88 can be driven with a large duty ratio. In this case, it is possible to ensure the excellent response of the excitation current I _m with respect to the command current I _c. On the other hand, when the control gain is small, the forward switching element 86 and the backward switching element 88 can be driven with a small duty ratio. In this case, the exciting current supplied to the lower coil 54 can be controlled with high precision to prevent hunting. Therefore, according to the control device for the electromagnetically driven valve 20, unnecessary hunting can be prevented from occurring without impairing the responsiveness.

In the above embodiment, the upper core 56 and the upper coil 52, and the lower core 58 and the lower coil 54 correspond to the above-mentioned "electromagnet", and the upper spring 44 and the lower spring 40 correspond to the above-mentioned "elastic body". , Respectively. The current detection circuit 9
2. The "exciting current detecting means" according to claim 1, wherein the first detecting means detects an exciting current actually flowing through the lower coil.
But by the main switching element control circuit 70 and the sub-switching element control circuit 72 controls the exciting current supplied to the lower coil 54 based on the deviation between the command current I _c and the exciting current I _m of claim 1, wherein " 2. The "first voltage applying means" according to claim 1, wherein the "current control means" is such that the main switching element control circuit 70 and the sub switching element control circuit 72 turn on the forward switching element control circuits 74 and 86. Are the main switching element control circuit 70 and the sub switching element control circuit 7
2 turns on the reverse switching element control circuits 76 and 88, so that the "second voltage applying means" according to claim 1 allows the gain switching circuit 78 to control the control gain in accordance with a command from the gain switching command circuit 80. The "gain switching means" according to claim 1 is realized by switching.

FIG. 4 shows a flowchart of an example of a main routine executed by the control device for the electromagnetically driven valve 20 according to the second embodiment of the present invention. The present embodiment is a system for realizing the subtraction circuit 68 and the main switching element control circuit 70 shown in FIG. 3 by using a computer. The routine shown in FIG. 4 is repeatedly started each time the processing is completed. When the routine shown in FIG. 4 is started, first, the process of step 110 is executed.

In step 110, the electromagnetically driven valve 20 detects the displacement position of the valve body 22 that is displaced between the valve opening end and the valve closing end. In the present embodiment, the displacement position of the valve body 22 is determined, for example, by the elapsed time after the valve opening or closing request of the valve body 22 is issued, or by the output of a displacement sensor that detects the displacement of the valve body 22. It is calculated based on. In step 112, the lower coil 5 is determined based on the position of the valve body 22.
Command current I _c used in the fourth F / B control is calculated.

In step 114, the lower coil 5 is actually
4 the excitation current I _m flowing is detected to. Step 11
In 6, it is determined whether or not the valve element 22 is in the suction period,
It is determined whether or not 2 is displaced between the valve opening end and the valve closing end. As a result, if it is determined that the suction period is for the valve element 22, the process of step 118 is executed next.
On the other hand, if it is determined that the period is not the suction period of the valve element 22,
Next, the process of step 120 is performed.

In step 118, a process for setting the control gain used for the F / B control of the exciting current to a high gain is executed. In step 120, a process of setting the control gain used for the F / B control of the exciting current to a low gain is executed.
The low gain is a predetermined value smaller than the high gain described above.

[0048] At step 122, the deviation between the command current I _c and the exciting current I _m is calculated, the duty ratio is calculated based on the control gain set by the deviation and the step 118 or 120. Step 124
Then, the duty signal having the duty ratio calculated in step 122 is supplied to the forward switching element 86 or the backward switching element 88.
When the process of step 124 ends, the current routine ends.

According to the above processing, when the valve body 22 is displaced from the valve closing end to the valve opening end, a large control gain is applied to the valve body 2.
2 can output a small control gain when it reaches the valve opening end. Therefore, according to the control device for the electromagnetically driven valve 20 of the present embodiment, unnecessary hunting can be prevented from occurring without impairing the responsiveness. In the above embodiment, the "gain switching means" according to the first embodiment is realized by the ECU 62 executing the processing of steps 118 and 120.

FIG. 5 is a circuit diagram of a control circuit formed inside an ECU 130 functioning as a control device of the electromagnetically driven valve 20 according to a third embodiment of the present invention. FIG. 5 shows a control circuit for the lower coil 54. ECU130
Has a similar circuit for the upper coil 52. Since these circuits do not differ in configuration, the configuration and operation of only the control circuit of the lower coil 54 will be described below. In FIG. 5, the same components as those of the control circuit shown in FIG. 3 are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIG. 5, the ECU 130 has a built-in hysteresis circuit 131. The hysteresis circuit 131 is connected to the subtraction circuit. The hysteresis circuit 131 includes resistors 132 (resistance value R ₄ ) and 134 (resistance value R ₅ ) and an operational amplifier 136. The deviation I _c -I _m is supplied from the subtraction circuit 68 to the resistor 132. The resistor 132 is connected to a non-inverting input terminal of the operational amplifier 136. The inverting input terminal of the operational amplifier 136 is grounded. Further, a resistor 134 is connected between the non-inverting input terminal and the output terminal of the operational amplifier 136.

In the above configuration, the resistor 132, the resistor 1
34 and the operational amplifier 136 constitute a Schmidt circuit
I do. According to the above configuration, the output terminal of the operational amplifier 136
If a high voltage (+ V) appears on the child, a subtraction circuit
Deviation I supplied from 68_c-I_mIs the predetermined value V_L(= −
(R_Four/ R_Five) .V), the operational amplifier 1
36 output terminals switch to low voltage (-V). Ma
Also, a low voltage (-V) is applied to the output terminal of the operational amplifier 136.
If so, the deviation I_c-I_mIs the predetermined value V _H(=
(R_Four/ R_Five) .V) or more, the operational amplifier 1
36 output terminals are switched to a high voltage (+ V).

FIG. 6 shows the relationship between the above-mentioned deviation and the output voltage. As shown in FIG. 6, according to the hysteresis circuit 131, a hysteresis can be formed between the deviation as the input voltage and the output voltage. The output terminal of the operational amplifier 136 is connected to the switching element control circuit 138. The output terminals of the switching element control circuit 138 are provided with forward switching terminals 138f ₁ and 138f ₂ and reverse switching terminals 138r ₁ and 138r ₂ . Forward switching terminal 138f ₁ , 1
38f ₂ are forward switching elements 74 and 8 respectively.
6 base terminal. On the other hand, reverse switching terminals 138r ₁ and 138r ₂ are connected to base terminals of reverse switching elements 76 and 88, respectively.

[0054] The switching element control circuit 138, when the input signal from the hysteresis circuit 131 is high voltage, i.e., when the excitation current I _m is insufficient for the command current I _c, the forward switching devices 74 Is turned on, and the forward switching element 86 is deviated |
The on-state at a duty ratio corresponding to the magnitude | I _c -I _m. Further, the switching element control circuit 138 includes:
If the input signal from the hysteresis circuit 131 is low voltage, i.e., when the excitation current I _m against the command current I _c is excessive, and the reverse switching device 76 to the ON state, and reverse switching device 88 deviation |
The on-state at a duty ratio corresponding to the magnitude | I _c -I _m.

[0055] In the above configuration, the forward switching devices 74, 86 is the case of the on state, the excitation current I _m in the forward direction to the lower coil 54 increases. In this case, the deviation I
_c -I _m is reduced. Also, if the reverse switching device 76 and 88 is on, the excitation current I _m in the forward direction to the lower coil 54 decreases. In this case, the deviation I _c −
I _m increases.

In the control device for the electromagnetically driven valve 20 of the present embodiment, after the forward switching elements 74 and 86 are turned on, the forward switching elements 74 and 86 are continuously turned on until the deviation falls to a value satisfying I _c −I _m <V _L. The direction switching elements 74 and 86 are kept on, and the reverse switching elements 76 and 88 are kept off. Also, the reverse switching element 7
After 6,88 shifts to the ON state, the deviation I _c -I _m
The forward switching elements 74 and 86 are kept off, and the reverse switching elements 76 and 88 are kept on until the voltage rises to a value satisfying> V _H.

[0057] Therefore, according to the control apparatus for an electromagnetically driven valve 20 of the present embodiment, the excitation current I _m after reaches the vicinity of the command current I _c, the forward switching devices 74, 86 and reverse switching device 76, It is possible to reliably prevent the occurrence of hunting due to the repeated ON / OFF state of the switch 88 unnecessarily. In the above embodiment, the switching element control circuit 138 turns on the forward switching elements 74 and 86 to turn on the first switching element.
The voltage application means of the switching element control circuit 138
By turning on the reverse switching elements 76 and 88, the "second voltage applying means" is realized, and the "voltage switching means" is realized by executing the hysteresis circuit 131.

FIG. 7 shows a flowchart of an example of a main routine executed by the control device of the electromagnetically driven valve 20 according to the fourth embodiment of the present invention. This embodiment is a system that realizes the hysteresis circuit 131 shown in FIG. 5 using a computer. The routine shown in FIG. 7 is repeatedly started each time the processing is completed. When the routine shown in FIG. 7 is started, first, the process of step 140 is executed.

[0059] At step 140, the command current I _c used in the F / B control of the lower coil 54 based on the position of the valve body 22 is calculated. In step 142, the excitation current I _m that actually flows through the lower coil 54 is detected. In step 144, the deviation between the command current I _c and the exciting current I _m is calculated.

In step 146, it is determined whether the direction of the voltage applied to the lower coil 54 is the forward direction. As a result, in the case of the forward direction, the process of step 148 is executed next. On the other hand, in the case of the opposite direction, the next step 152
Is performed. In step 148, the command current I
_c and deviation I _c -I _m of the excitation current I _m is equal to or less than V _L is determined. As a result, the deviation I _c −I _m is V _L
If it is less than the above, the process of step 150 is executed next. On the other hand, if the deviation I _c -I _m is not less than _VL ,
That is, the deviation I _c -I _m is in the case of more than V _L, the present routine is ended.

In step 150, the direction of the voltage applied to the lower coil 54 in the forward direction is switched to the reverse direction. When the process of step 150 ends, the current process ends. In step 152, the deviation I _c -I _m between the command current I _c and the exciting current I _m is whether greater than V _H is determined. As a result, the deviation I _c -I _m is greater than V _H is, the process of step 154 is performed.
On the other hand, when the deviation I _c -I _m is not greater than V _H, that is, the deviation I _c -I _m is if: V _H is, the present routine is terminated.

In step 154, the direction of the voltage applied to the lower coil 54 in the reverse direction is switched to the forward direction. When the process of step 154 ends, the current process ends. According to the above processing, the deviation I _c -I _m is V
_When it is less than _L , the voltage applied to the lower coil 54 in the forward direction can be switched in the reverse direction. Further, it is possible to switch when the deviation I _c -I _m is greater than V _H, the voltage applied in the reverse direction to the lower coil 54 in the forward direction. Therefore, the electromagnetically driven valve 20 of the present embodiment
According to the control device of the above, it is possible to prevent unnecessary voltage switching,
Hunting can be prevented from occurring.

In the above embodiment, the ECU 13
0 executes steps 150 and 154, thereby realizing the "voltage switching means" according to claim 2. FIG. 8 is a circuit diagram of a control circuit formed inside an ECU 156 functioning as a control device of the electromagnetically driven valve 20 according to a fifth embodiment of the present invention. FIG. 8 shows a control circuit for the lower coil 54. The ECU 156
A similar circuit is provided for the upper coil 52. Since these circuits have no difference in configuration, the configuration and operation of only the control circuit of the lower coil 54 will be described below. FIG.
In FIG. 6, the same components as those of the control circuit shown in FIG.

As shown in FIG. 8, the main switching element control circuit 157 is built in the ECU 156. The main switching element control circuit 157 includes a comparison circuit 84 and a triangular wave oscillation circuit 158. Triangular wave oscillation circuit 15
8 is a circuit which emits a triangular wave that repeats periodically increased and reduced between the maximum value -V ₂ and the minimum value -V _1. The output signal of the triangular wave oscillation circuit 158 is supplied to the comparison circuit 84. Comparator circuit 84 compares the deviation I _c -I _m supplied from the subtraction circuit 68 (= V _ref), and a triangular wave values triangular wave oscillation circuit 158 emitted (= V _tri) (FIG. 9
(A)), a high signal or a low signal is output according to the magnitude relation between the two. The high signal and the low signal form a duty signal that outputs a pulse signal at a predetermined cycle (FIG. 9B).

The output terminal of the main switching element control circuit 157 is provided with a forward switching terminal 157f and a reverse switching terminal 157r. The forward switching terminal 157f is connected to the forward switching element 8
6 base terminal. On the other hand, the reverse switching terminal 157r is connected to the base terminal of the reverse switching element 88.

The main switching element control circuit 157 is
Difference I_c-I_mIf ≧ 0, the forward switching element 8
6 supplies a duty signal to the base terminal of
Difference I _c-I_m<0, the reverse switching element 8
8 to supply a duty signal to the base terminal.
Has been established. Therefore, the deviation I_c-I_mIf ≧ 0,
The forward switching element 86 has a deviation | I_c-I_m| Large
It is turned on at a duty ratio according to the size,
Deviation I _c-I_m<0, reverse switching element
88 is the deviation | I_c-I_mDuty according to the size of |
It is turned on at the same ratio.

[0067] Figure 9 shows the waveforms for comparing the deviation I _c -I _m and a triangular wave. As described above, the triangular wave oscillation circuit 1
The maximum value of the triangular wave 57 is set to -V _2. In the control circuit of the electromagnetically driven valve 20 of this embodiment, the deviation I _c −
When _Im has a value between “0” and −V ₂ (the hatched portion in FIG. 9), the forward switching element 86 is supplied with a duty signal having a duty ratio of 0%. That is, no forward voltage is applied to the lower coil 54. In such situations, between -V ₂ and "0", the dead zone of the deviation I _c -I _m is formed. Therefore, according to the control apparatus for an electromagnetically driven valve 20 of the present embodiment, the lower core when the deviation between the command current I _c and the exciting current I _m resides in the dead zone 58
The generation of electromagnetic force between the armature 50 and the armature 50 can be suppressed, and the occurrence of hunting can be prevented.

[0068] In the above embodiment, the main switching element control circuit 157 is the command current I _c and the exciting current I _m
By controlling the exciting current supplied to the lower coil 54 based on the deviation from the above, the "current control means" according to the third aspect is realized. FIG. 10 shows a flowchart of an example of a main routine executed in the sixth embodiment of the present invention. This embodiment is a system for realizing the main switching element control circuit 157 shown in FIG. 8 using a computer. The routine shown in FIG. 10 is repeatedly started each time the processing is completed. When the routine shown in FIG. 10 is started, first, the process of step 160 is executed.

In step 160, the electromagnetically driven valve 20 detects a displacement position where the valve body 22 is displaced between the valve opening end and the valve closing end. In step 162, the command current I _c used in the F / B control of the lower coil 54 based on the position of the valve body 22 is calculated. In step 164, the excitation current I _m that actually flows through the lower coil 54 is detected.

[0070] At step 166, the deviation I _c -I _m between the command current I _c and the exciting current I _m is calculated, the deviation I _c -I _m whether exceeds the dead band region is determined. As a result, the deviation I _c -I _m is if exceeding the dead zone, the process of step 168 is performed. on the other hand,
If the deviation I _c -I _m does not exceed the dead zone, the routine is terminated.

[0071] At step 168, the duty ratio is calculated by the calculation result of the difference I _c -I _m between the command current I _c and the exciting current I _m. In step 170, the duty signal having the duty ratio calculated in step 168 is supplied to the forward switching element 86 or the backward switching element 88. When the process of step 170 ends, the current routine ends.

According to the above processing, when the deviation I _c -I _m does not exceed the dead zone, no voltage is applied to the lower coil 54. On the other hand, when the deviation I _c -I _m exceeds the dead zone, calculating a duty ratio based on the deviation I _c -I _m and the triangular wave, it is possible to apply a voltage corresponding to the duty ratio to the lower coil 54. Therefore, according to the control device for the electromagnetically driven valve 20 of the present embodiment, it is possible to suppress the unnecessary application of the voltage to the lower coil 54 and prevent the occurrence of hunting.

In the above embodiment, the ECU 15
6 executes the processing of step 170, thereby realizing the "current control means" according to claim 3.

[0074]

As described above, according to the first aspect of the present invention, it is possible to prevent hunting while ensuring excellent responsiveness of the electromagnetically driven valve. As described above, according to the second aspect of the invention, hunting can be prevented from occurring by not frequently switching the voltage applied to the electromagnet.

According to the third aspect of the present invention, hunting can be prevented by not frequently switching the voltage applied to the electromagnet.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of an electromagnetically driven valve control device according to an embodiment of the present invention.

FIG. 2A is a time chart showing a displacement of a valve body. FIG. 2B is a time chart of the command current supplied to the upper coil. FIG. 2C is a time chart of the current supplied to the lower coil.

FIG. 3 is a circuit diagram of a control circuit formed inside the engine electronic control device according to the first embodiment of the present invention.

FIG. 4 is a flowchart of an example of a main routine executed in a second embodiment of the present invention.

FIG. 5 is a circuit diagram of a control circuit formed inside an engine electronic control device according to a third embodiment of the present invention.

FIG. 6 is a diagram showing a relationship between a deviation between a command current and an exciting current and an output voltage in a third embodiment of the present invention.

FIG. 7 is a flowchart of an example of a main routine executed in a fourth embodiment of the present invention.

FIG. 8 is a circuit diagram of a control circuit formed inside an engine electronic control device according to a fifth embodiment of the present invention.

FIG. 9 (A) shows a fifth embodiment of the present invention.
FIG. 9 is a diagram for comparing a triangular wave having a predetermined cycle with a deviation between an ideal command current and an exciting current. FIG. 9B shows a pulse signal adjusted to a duty ratio according to a deviation between an ideal command current and an exciting current.

FIG. 10 is a flowchart of an example of a main routine executed in a sixth embodiment of the present invention.

[Explanation of symbols]

Reference Signs List 20 electromagnetically driven valve 22 valve element 50 armature 52 upper coil 54 lower coil 62, 130, 156 engine electronic control unit (E
CU) 66 Command circuit 68 Subtraction circuit 70, 157 Main switching element control circuit 70f, 72f Forward output terminal 70r, 72r Reverse output terminal 72 Secondary switching element control circuit 74 _, 86 Forward switching element 76, 88 Reverse switching element 78 gain switching circuit 80 gain switching command circuit 82,158 triangular wave oscillation circuit 84 comparison circuit 90 power supply terminal 91 current detection circuit 92,94 analog switch 98,100,104,132,134 resistor 102,136 operational amplifier 131 hysteresis circuit 138 switching element Control circuit

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takashi Deo 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Masahiko Asano 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation (72) Inventor Tatsuo Iida 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Hiroyuki Hattori 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation

Claims (3)

[Claims] An armature displaced together with a valve element; an electromagnet for applying an electromagnetic force to the armature; an exciting current detecting means for detecting an exciting current actually flowing through the electromagnet; Current control means for performing feedback control of the exciting current so as to approach
A control device for an electromagnetically driven valve comprising: a first voltage application unit that applies a voltage in a positive direction to the electromagnet; and a second voltage application unit that applies a voltage in a reverse direction to the electromagnet. Gain switching means for setting the control gain of the feedback control to a low gain when the valve body is held at the displacement end and a high gain when the valve body is displaced between the displacement ends. A control device for an electromagnetically driven valve, comprising: 2. An armature displaced together with a valve body, an electromagnet for applying an electromagnetic force to the armature, exciting current detecting means for detecting an exciting current actually flowing through the electromagnet, and a command current which is a predetermined command current. Current control means for performing feedback control of the exciting current so as to approach
A control device for an electromagnetically driven valve comprising: a first voltage application unit that applies a voltage in a positive direction to the electromagnet; and a second voltage application unit that applies a voltage in a reverse direction to the electromagnet. And when the deviation between the command current and the exciting current exceeds a first predetermined value, the first voltage applying means is set to an operating state instead of the second voltage applying means. When the deviation falls below a second predetermined value that is smaller than the first predetermined value,
And a voltage switching means for activating the second voltage applying means in place of the voltage applying means. 3. An armature displaced together with a valve body, an electromagnet for applying an electromagnetic force to the armature, exciting current detecting means for detecting an exciting current actually flowing through the electromagnet, and a command current which is a predetermined command current. Current control means for performing feedback control of the exciting current so as to approach
A control device for an electromagnetically driven valve comprising: a first voltage application unit that applies a voltage in a positive direction to the electromagnet; and a second voltage application unit that applies a voltage in a reverse direction to the electromagnet. And when the deviation between the command current and the exciting current belongs to a predetermined dead zone region, both the first voltage applying unit and the second voltage applying unit are deactivated. A control device for an electromagnetically driven valve, wherein the control device is in a state.